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Bibliography on: Alzheimer Disease — Current Literature

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Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 22 Apr 2024 at 01:35 Created: 

Alzheimer Disease — Current Literature

Alzheimer's disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, and eventually the ability to carry out the simplest tasks. In most people with Alzheimer's, symptoms first appear in their mid-60s. Alzheimer's is the most common cause of dementia among older adults. Dementia is the loss of cognitive functioning — thinking, remembering, and reasoning — and behavioral abilities to such an extent that it interferes with a person's daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person's functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living. Scientists don't yet fully understand what causes Alzheimer's disease in most people. There is a genetic component to some cases of early-onset Alzheimer's disease. Late-onset Alzheimer's arises from a complex series of brain changes that occur over decades. The causes probably include a combination of genetic, environmental, and lifestyle factors. The importance of any one of these factors in increasing or decreasing the risk of developing Alzheimer's may differ from person to person. This bibliography runs a generic query on "Alzheimer" and then restricts the results to papers published in or after 2017.

Created with PubMed® Query: 2022:2024[dp] AND ( alzheimer*[TIAB] ) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2024-04-20

Lai JZ, Lin CY, Chen SJ, et al (2024)

Temporal-Focusing Multiphoton Excitation Single-Molecule Localization Microscopy Using Spontaneously Blinking Fluorophores.

Angewandte Chemie (International ed. in English) [Epub ahead of print].

Single-molecule localization microscopy (SMLM) based on temporal-focusing multiphoton excitation (TFMPE) and single-wavelength excitation is used to visualize the three-dimensional (3D) distribution of spontaneously blinking fluorophore-labeled subcellular structures in a thick specimen with a nanoscale-level spatial resolution. To eliminate the photobleaching effect of unlocalized molecules in out-of-focus regions for improving the utilization rate of the photon budget in 3D SMLM imaging, SMLM with single-wavelength TFMPE achieves wide-field and axially confined two-photon excitation (TPE) of spontaneously blinking fluorophores. TPE spectral measurement of blinking fluorophores is then conducted through TFMPE imaging at a tunable excitation wavelength, yielding the optimal TPE wavelength for increasing the number of detected photons from a single blinking event during SMLM. Subsequently, the TPE fluorescence of blinking fluorophores is recorded to obtain a two-dimensional TFMPE-SMLM image of the microtubules in cancer cells with a localization precision of 18 ± 6 nm and an overall imaging resolution of approximately 51 nm, which is estimated based on the contribution of Nyquist resolution and localization precision. Combined with astigmatic imaging, the system is capable of 3D TFMPE-SMLM imaging of brain tissue section of a 5XFAD transgenic mouse with the pathological features of Alzheimer's disease, revealing the distribution of neurotoxic amyloid-beta peptide deposits.

RevDate: 2024-04-19

Selkoe DJ (2024)

The advent of Alzheimer treatments will change the trajectory of human aging.

Nature aging, 4(4):453-463.

Slowing neurodegenerative disorders of late life has lagged behind progress on other chronic diseases. But advances in two areas, biochemical pathology and human genetics, have now identified early pathogenic events, enabling molecular hypotheses and disease-modifying treatments. A salient example is the discovery that antibodies to amyloid ß-protein, long debated as a causative factor in Alzheimer's disease (AD), clear amyloid plaques, decrease levels of abnormal tau proteins and slow cognitive decline. Approval of amyloid antibodies as the first disease-modifying treatments means a gradually rising fraction of the world's estimated 60 million people with symptomatic disease may decline less or even stabilize. Society is entering an era in which the unchecked devastation of AD is no longer inevitable. This Perspective considers the impact of slowing AD and other neurodegenerative disorders on the trajectory of aging, allowing people to survive into late life with less functional decline. The implications of this moment for medicine and society are profound.

RevDate: 2024-04-21

Ackmann J, Brüge A, Gotina L, et al (2024)

Structural determinants for activation of the Tau kinase CDK5 by the serotonin receptor 5-HT7R.

Cell communication and signaling : CCS, 22(1):233.

BACKGROUND: Multiple neurodegenerative diseases are induced by the formation and deposition of protein aggregates. In particular, the microtubule-associated protein Tau leads to the development of so-called tauopathies characterized by the aggregation of hyperphosphorylated Tau within neurons. We recently showed that the constitutive activity of the serotonin receptor 7 (5-HT7R) is required for Tau hyperphosphorylation and aggregation through activation of the cyclin-dependent kinase 5 (CDK5). We also demonstrated physical interaction between 5-HT7R and CDK5 at the plasma membrane suggesting that the 5-HT7R/CDK5 complex is an integral part of the signaling network involved in Tau-mediated pathology.

METHODS: Using biochemical, microscopic, molecular biological, computational and AI-based approaches, we investigated structural requirements for the formation of 5-HT7R/CDK5 complex.

RESULTS: We demonstrated that 5-HT7R domains responsible for coupling to Gs proteins are not involved in receptor interaction with CDK5. We also created a structural model of the 5-HT7R/CDK5 complex and refined the interaction interface. The model predicted two conserved phenylalanine residues, F278 and F281, within the third intracellular loop of 5-HT7R to be potentially important for complex formation. While site-directed mutagenesis of these residues did not influence Gs protein-mediated receptor signaling, replacement of both phenylalanines by alanine residues significantly reduced 5-HT7R/CDK5 interaction and receptor-mediated CDK5 activation, leading to reduced Tau hyperphosphorylation and aggregation. Molecular dynamics simulations of 5-HT7R/CDK5 complex for wild-type and receptor mutants confirmed binding interface stability of the initial model.

CONCLUSIONS: Our results provide a structural basis for the development of novel drugs targeting the 5-HT7R/CDK5 interaction interface for the selective treatment of Tau-related disorders, including frontotemporal dementia and Alzheimer's disease.

RevDate: 2024-04-19

Hao X, Abeysinghe R, Zheng F, et al (2024)

Mapping of Alzheimer's disease related data elements and the NIH Common Data Elements.

BMC medical informatics and decision making, 24(Suppl 3):103.

BACKGROUND: Alzheimer's Disease (AD) is a devastating disease that destroys memory and other cognitive functions. There has been an increasing research effort to prevent and treat AD. In the US, two major data sharing resources for AD research are the National Alzheimer's Coordinating Center (NACC) and the Alzheimer's Disease Neuroimaging Initiative (ADNI); Additionally, the National Institutes of Health (NIH) Common Data Elements (CDE) Repository has been developed to facilitate data sharing and improve the interoperability among data sets in various disease research areas.

METHOD: To better understand how AD-related data elements in these resources are interoperable with each other, we leverage different representation models to map data elements from different resources: NACC to ADNI, NACC to NIH CDE, and ADNI to NIH CDE. We explore bag-of-words based and word embeddings based models (Word2Vec and BioWordVec) to perform the data element mappings in these resources.

RESULTS: The data dictionaries downloaded on November 23, 2021 contain 1,195 data elements in NACC, 13,918 in ADNI, and 27,213 in NIH CDE Repository. Data element preprocessing reduced the numbers of NACC and ADNI data elements for mapping to 1,099 and 7,584 respectively. Manual evaluation of the mapping results showed that the bag-of-words based approach achieved the best precision, while the BioWordVec based approach attained the best recall. In total, the three approaches mapped 175 out of 1,099 (15.92%) NACC data elements to ADNI; 107 out of 1,099 (9.74%) NACC data elements to NIH CDE; and 171 out of 7,584 (2.25%) ADNI data elements to NIH CDE.

CONCLUSIONS: The bag-of-words based and word embeddings based approaches showed promise in mapping AD-related data elements between different resources. Although the mapping approaches need further improvement, our result indicates that there is a critical need to standardize CDEs across these valuable AD research resources in order to maximize the discoveries regarding AD pathophysiology, diagnosis, and treatment that can be gleaned from them.

RevDate: 2024-04-19

Mo R, Jiang M, Xu H, et al (2024)

Effect of probiotics on cognitive function in adults with mild cognitive impairment or Alzheimer's disease: A meta-analysis of randomized controlled trials.

Medicina clinica pii:S0025-7753(24)00130-1 [Epub ahead of print].

BACKGROUND: Recent clinical studies have yielded controversial results regarding the effect of probiotics on cognitive function in Alzheimer's disease (AD) or mild cognitive impairment (MCI) subjects. To clarify the efficacy of probiotics on cognition, we conducted a meta-analysis of randomized controlled trials (RCTs).

METHODS: Instructions of the PRISMA 2020 statement were followed. Literature from the PubMed, Embase and Cochrane databases were systematically searched and manually screened for relevant published RCTs. We performed statistical analysis using RevMan, and assessed the risk of bias using the R software.

RESULTS: A total of 12 studies comprising 852 patients with MCI or AD were identified. The results of meta-analysis showed that probiotics improved global cognitive function (SMD=0.67; 95% CI, 0.32, 1.02), recall/delayed memory (SMD=0.67; 95% CI: 0.32, 1.02), attention (SMD=0.31; 95% CI: 0.04, 0.58) and visuospatial/constructional (SMD=0.24; 95% CI: 0.06, 0.42) cognitive domain.

CONCLUSION: This meta-analysis found that probiotic supplementation is associated with an improvement in cognitive performance among patients with AD and MCI. However, current evidence is limited, and more reliable large-scale RCTs with higher methodological quality are needed.

RevDate: 2024-04-21

Jain N (2024)

The molecular interplay between human and bacterial amyloids: Implications in neurodegenerative diseases.

Biochimica et biophysica acta. Proteins and proteomics, 1872(4):141018 pii:S1570-9639(24)00025-6 [Epub ahead of print].

Neurodegenerative disorders such as Parkinson's (PD) and Alzheimer's diseases (AD) are linked with the assembly and accumulation of proteins into structured scaffold called amyloids. These diseases pose significant challenges due to their complex and multifaceted nature. While the primary focus has been on endogenous amyloids, recent evidence suggests that bacterial amyloids may contribute to the development and exacerbation of such disorders. The gut-brain axis is emerging as a communication pathway between bacterial and human amyloids. This review delves into the novel role and potential mechanism of bacterial amyloids in modulating human amyloid formation and the progression of AD and PD.

RevDate: 2024-04-19

Sutovsky P, Hamilton LE, Zigo M, et al (2024)

Biomarker-based human and animal sperm phenotyping: the good, the bad and the ugly.

Biology of reproduction pii:7653800 [Epub ahead of print].

Conventional, brightfield-microscopic semen analysis provides important baseline information about sperm quality of an individual; however, it falls short of identifying subtle subcellular and molecular defects in cohorts of "bad", defective human and animal spermatozoa with seemingly normal phenotypes. To bridge this gap, it is desirable to increase the precision of andrological evaluation in humans and livestock animals by pursuing advanced biomarker-based imaging methods. This review, spiced up with occasional classic movie references but seriously scholastic at the same time, focuses mainly on the biomarkers of altered male germ cell proteostasis resulting in post-testicular carryovers of proteins associated with ubiquitin-proteasome system. Also addressed are sperm redox homeostasis, epididymal sperm maturation, sperm-seminal plasma interactions and sperm surface glycosylation. Zinc ion homeostasis-associated biomarkers and sperm-borne components, including the elements of neurodegenerative pathways such as Huntington's and Alzheimer's disease, are discussed. Such spectrum of biomarkers, imaged by highly specific vital fluorescent molecular probes, lectins, and antibodies, reveals both obvious and subtle defects of sperm chromatin, DNA and accessory structures of the sperm head and tail. Introduction of next generation image-based flow cytometry into research and clinical andrology will soon enable the incorporation of machine and deep learning algorithms with the end point of developing simple, label-free methods for clinical diagnostics and high throughput phenotyping of spermatozoa in humans and economically important livestock animals.

RevDate: 2024-04-19

Fruhwürth S, Zetterberg H, SR Paludan (2024)

Microglia and amyloid plaque formation in Alzheimer's disease - Evidence, possible mechanisms, and future challenges.

Journal of neuroimmunology, 390:578342 pii:S0165-5728(24)00060-2 [Epub ahead of print].

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive decline that severely affects patients and their families. Genetic and environmental risk factors, such as viral infections, synergize to accelerate the aging-associated neurodegeneration. Genetic risk factors for late-onset AD (LOAD), which accounts for most AD cases, are predominantly implicated in microglial and immune cell functions. As such, microglia play a major role in formation of amyloid beta (Aβ) plaques, the major pathological hallmark of AD. This review aims to provide an overview of the current knowledge regarding the role of microglia in Aβ plaque formation, as well as their impact on morphological and functional diversity of Aβ plaques. Based on this discussion, we seek to identify challenges and opportunities in this field with potential therapeutic implications.

RevDate: 2024-04-19

Korinek K, Zimmer Z, Teerawichitchainan B, et al (2024)

Cognitive function following early life war-time stress exposure in a cohort of Vietnamese older adults.

Social science & medicine (1982), 349:116800 pii:S0277-9536(24)00244-2 [Epub ahead of print].

Although Alzheimer's Disease is a leading cause of death in Vietnam and other post-conflict, low- and middle-income countries, aside from studies of veterans in western populations, research on war-related violence and deprivation as risk factors for cognitive disorders remains sparse. Using data from the Vietnam Health and Aging Study, which relied upon a multistage probability sample of 2447 older adults residing in districts of northern Vietnam differentially exposed to wartime bombing and numerous war-related stressors, this paper investigates associations between early-life war-related stressors and later-life cognitive function in a cohort whose transition to adulthood took place during the American-Vietnam War. Relationships among experiences of severe childhood hunger, war-related violence and environmental hardships, military service, and cognitive function in an analytical sample of 2162 Vietnamese older adults are estimated using quantile regression. Cognitive function is assessed by a modified Mini-Mental State Examination (MMSE) score. Analyses also address posttraumatic stress disorder (PTSD), cardiovascular health, and health behaviors as potential mediators between early life war-related stressors and current cognitive function. Results indicate that experiences of severe hunger in childhood and environmental hardships are associated with poorer cognitive function in older adulthood. PTSD, cardiovascular risk (i.e., hypertension) and disease (i.e., stroke), each of which is heightened by exposure to wartime stressors, are associated with lower cognitive scores. Results suggest that certain war exposures, like involvement in combat duties, are associated with higher cognitive function scores, suggesting that military service either positively selects for cognitive function, or certain forms of service may impart cognitive resilience. Following recent calls to incorporate population-specific stressors to advance explanatory models of cognitive function, these findings suggest that it is critical to assess the enduring scars and resilience of armed conflict in global efforts to understand, prevent, and treat cognitive impairment, Alzheimer's Disease, and related dementias.

RevDate: 2024-04-19

Ropert B, Gallrein C, B Schumacher (2024)

DNA repair deficiencies and neurodegeneration.

DNA repair, 138:103679 pii:S1568-7864(24)00055-7 [Epub ahead of print].

Neurodegenerative diseases are the second most prevalent cause of death in industrialized countries. Alzheimer's Disease is the most widespread and also most acknowledged form of dementia today. Together with Parkinson's Disease they account for over 90 % cases of neurodegenerative disorders caused by proteopathies. Far less known are the neurodegenerative pathologies in DNA repair deficiency syndromes. Such diseases like Cockayne - or Werner Syndrome are described as progeroid syndromes - diseases that cause the premature ageing of the affected persons, and there are clear implications of such diseases in neurologic dysfunction and degeneration. In this review, we aim to draw the attention on commonalities between proteopathy-associated neurodegeneration and neurodegeneration caused by DNA repair defects and discuss how mitochondria are implicated in the development of both disorder classes. Furthermore, we highlight how nematodes are a valuable and indispensable model organism to study conserved neurodegenerative processes in a fast-forward manner.

RevDate: 2024-04-19

Chen Y, Lai M, M Tao (2024)

Evaluating the efficacy and safety of Alzheimer's disease drugs: A meta-analysis and systematic review.

Medicine, 103(16):e37799.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Dementia severity was assessed mainly through cognitive function, psychobehavioral symptoms, and daily living ability. Currently, there are not many drugs that can be selected to treat mild to moderate AD, and the value of drugs remains controversial.

OBJECTIVE: The aim of this study is to quantitatively evaluate the efficacy and safety of cholinesterase inhibitors (ChEIs), memantine, and sodium oligomannate (GV-971) in the treatment of patients with AD. Additionally, molecular docking analysis will be used to investigate the binding affinities of donepezil, galantamine, rivastigmine, and memantine with key receptor proteins associated with AD, including beta-amyloid (Abeta), microtubule-associated protein (MAP), apolipoprotein E4 (APOE4), and Mitofusin-2 (MFN2), to further validate the results of the meta-analysis.

METHODS: We obtained clinical trials characterized by randomization, placebo control, and double-blinded methodologies concerning ChEIs, memantine, and GV-971. Statistical analysis was performed using Review Manager Version 5.4 software. Molecular docking was also conducted to evaluate the results.

RESULTS: All drugs improved the cognitive function, with the effect value ranging from -1.23 (95% CI -2.17 to -0.30) for 20 mg memantine to -3.29 (95% CI -4.14 to -2.45) for 32 mg galantamine. Although 32 mg galanthamine and GV-971 did not improve the clinicians' Global Impression of Change scale, other drugs showed significant results compared with placebo. On NPI, only 10 mg of donepezil and 24 mg of galantamine had improvement effects. On ADCS/ADL, only 20 mg memantine and 900 mg GV-971 had no significant difference from the placebo. Donepezil 5 mg and GV-971 900 mg did not increase the drug withdrawal rates due to various reasons or adverse reactions when compared to the placebo. Donepezil demonstrated superior binding to the protein and exhibited greater efficacy compared to other drugs.

CONCLUSION: ChEIs, memantine, and GV-971 all can slow the progression of AD but have different effects on respective assessments. Donepezil and GV-971 were relatively well tolerated.

RevDate: 2024-04-19

Anonymous (2024)

Erratum to: Ubiquitin Specific Protease 13 Regulates Tau Accumulation and Clearance in Models of Alzheimer's Disease.

Journal of Alzheimer's disease : JAD, 98(4):1543-1546.

RevDate: 2024-04-19

Borghammer P, Okkels N, D Weintraub (2024)

Parkinson's Disease and Dementia with Lewy Bodies: One and the Same.

Journal of Parkinson's disease pii:JPD240002 [Epub ahead of print].

The question whether Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) are expressions of the same underlying disease has been vigorously debated for decades. The recently proposed biological definitions of Lewy body disease, which do not assign any particular importance to the dopamine system over other degenerating neurotransmitter systems, has once more brought the discussion about different types of Lewy body disease to the forefront. Here, we briefly compare PDD and DLB in terms of their symptoms, imaging findings, and neuropathology, ultimately finding them to be indistinguishable. We then present a conceptual framework to demonstrate how one can view different clinical syndromes as manifestations of a shared underlying Lewy body disease. Early Parkinson's disease, isolated RBD, pure autonomic failure and other autonomic symptoms, and perhaps even psychiatric symptoms, represent diverse manifestations of the initial clinical stages of Lewy body disease. They are characterized by heterogeneous and comparatively limited neuronal dysfunction and damage. In contrast, Lewy body dementia, an encompassing term for both PDD and DLB, represents a more uniform and advanced stage of the disease. Patients in this category display extensive and severe Lewy pathology, frequently accompanied by co-existing pathologies, as well as multi-system neuronal dysfunction and degeneration. Thus, we propose that Lewy body disease should be viewed as a single encompassing disease entity. Phenotypic variance is caused by the presence of individual risk factors, disease mechanisms, and co-pathologies. Distinct subtypes of Lewy body disease can therefore be defined by subtype-specific disease mechanisms or biomarkers.

RevDate: 2024-04-19

Janbek J, Laursen TM, Frimodt-Møller N, et al (2024)

Risk of Major Types of Dementias Following Hospital-Diagnosed Infections and Autoimmune Diseases.

Journal of Alzheimer's disease : JAD, 98(4):1503-1514.

BACKGROUND: Population-based studies have shown an increased risk of dementia after infections, but weaker links were reported for autoimmune diseases. Evidence is scarce for whether the links may be modified by the dementia or exposure subtype.

OBJECTIVE: We aimed to investigate the association between infections and/or autoimmune diseases and rates of major types of dementias in the short- and long terms.

METHODS: Nationwide nested case-control study of dementia cases (65+ years) diagnosed in Denmark 2016-2020 and dementia-free controls. Exposures were hospital-diagnosed infections and autoimmune diseases in the preceding 35 years. Two groups of dementia cases were those diagnosed in memory clinics (MC) and those diagnosed outside memory clinics (non-memory clinic cases, NMC).

RESULTS: In total, 26,738 individuals were MC and 12,534 were NMC cases. Following any infection, the incidence rate ratio (IRR) for MC cases was 1.23 (95% CI 1.20-1.27) and 1.70 for NMC cases (1.62-1.76). Long-term increased rates were seen for vascular dementia and NMC cases. IRRs for autoimmune diseases were overall statistically insignificant.

CONCLUSIONS: Cases with vascular dementia and not Alzheimer's disease, and a subgroup of cases identified with poorer health have increased long-term risk following infections. Autoimmune diseases were not associated with any type of dementia. Notably increased risks (attributed to the short term) and for NMC cases may indicate that immunosenescence rather than de novo infection explains the links. Future focus on such groups and on the role of vascular pathology will explain the infection-dementia links, especially in the long term.

RevDate: 2024-04-19

Das S (2024)

Omics Approaches in Alzheimer's Disease Research.

Journal of Alzheimer's disease : JAD pii:JAD240272 [Epub ahead of print].

RevDate: 2024-04-19

Zhang Z, MJR Lim (2024)

Incident Dementia After Spontaneous Intracerebral Hemorrhage.

Journal of Alzheimer's disease : JAD pii:JAD240111 [Epub ahead of print].

Post-stroke cognitive impairment and dementia (PSCID) is a complication that affects long-term functional outcomes after stroke. Studies on dementia after long-term follow-up in stroke have focused predominantly on ischemic stroke, which may be different from the development of dementia after spontaneous intracerebral hemorrhage (ICH). In this review, we summarize the existing data and hypotheses on the development of dementia after spontaneous ICH, review the management of post-ICH dementia, and suggest areas for future research. Dementia after spontaneous ICH has a cumulative incidence of up to 32.0-37.4% at 5 years post-ICH. Although the pathophysiology of post-ICH dementia has not been fully understood, two main theoretical frameworks can be considered: 1) the triggering role of ICH (both primary and secondary brain injury) in precipitating cognitive decline and dementia; and 2) the contributory role of pre-existing brain pathology (including small vessel disease and neurodegenerative pathology), reduced cognitive reserve, and genetic factors predisposing to cognitive dysfunction. These pathophysiological pathways may have synergistic effects that converge on dysfunction of the neurovascular unit and disruptions in functional connectivity leading to dementia post-ICH. Management of post-ICH dementia may include screening and monitoring, cognitive therapy, and pharmacotherapy. Non-invasive brain stimulation is an emerging therapeutic modality under investigation for safety and efficacy. Our review highlights that there remains a paucity of data and standardized reporting on incident dementia after spontaneous ICH. Further research is imperative for determining the incidence, risk factors, and pathophysiology of post-ICH dementia, in order to identify new therapies for the treatment of this debilitating condition.

RevDate: 2024-04-19

Nakanishi M, Yamasaki S, Nakashima T, et al (2024)

Association Between Dementia, Change in Home-Care Use, and Depressive Symptoms During the COVID-19 Pandemic: A Longitudinal Study Using Data from Three Cohort Studies.

Journal of Alzheimer's disease : JAD pii:JAD240097 [Epub ahead of print].

BACKGROUND: The emotional impact of the coronavirus disease 2019 (COVID-19) pandemic on people with dementia has been quantified. However, little is known about the impact of change in home-care use owing to the pandemic.

OBJECTIVE: To determine the longitudinal association between dementia, change in home-care use, and depressive symptoms during the pandemic.

METHODS: We included data of 43,782 home-dwelling older adults from the English Longitudinal Study of Ageing (ELSA), Study of health, Ageing and Retirement in Europe (SHARE), and National Health and Aging Trends Study (NHATS). This study considered the latest main wave survey prior to the pandemic as the baseline, and the COVID-19 survey as follow-up. In a series of coordinated analyses, multilevel binomial logistic regression model was used to examine the association between baseline dementia, change in home-care use at follow-up, and presence of depressive symptoms.

RESULTS: Dementia, using the ELSA, SHARE, and NHATS datasets, was identified in 2.9%, 2.3%, and 6.5% of older adults, and home-care use reduced in 1.7%, 2.8%, and 1.1% of individuals with dementia, respectively. Dementia was significantly associated with the increased risk of depressive symptoms in all three cohorts. However, the interaction between dementia and period (follow-up) was non-significant in SHARE and NHATS. Across all three cohorts, home-care use during the pandemic, regardless of change in amount, was significantly associated with increased depressive symptoms, compared to the non-use of home care.

CONCLUSIONS: These results highlight the need for tailoring dementia care at home to promote independence and provide sustainable emotional support.

RevDate: 2024-04-19

Chong TWH, H Macpherson (2024)

Pounding the Pavement: Is the Path to Brain Health Steeper for People Experiencing Greater Socioeconomic Deprivation?.

Journal of Alzheimer's disease : JAD pii:JAD240095 [Epub ahead of print].

Dementia is a global public health priority. Physical activity has myriad health benefits, including for reducing dementia risk. To increase physical activity, detailed understanding of influencing factors is needed. Socioeconomic deprivation affects many aspects of health and wellbeing. Qualitative research with older people experiencing socioeconomic deprivation is needed to explore barriers and enablers to engaging in physical activity, with the view to co-designing interventions for implementation trials. A whole of society approach is pivotal to improving effectiveness of physical activity interventions for older adults with cognitive impairment, and target support for people experiencing socioeconomic deprivation, to improve their health outcomes.

RevDate: 2024-04-19

Boujelbane MA, Trabelsi K, Salem A, et al (2024)

Eye Tracking During Visual Paired-Comparison Tasks: A Systematic Review and Meta-Analysis of the Diagnostic Test Accuracy for Detecting Cognitive Decline.

Journal of Alzheimer's disease : JAD pii:JAD240028 [Epub ahead of print].

BACKGROUND: Alzheimer's disease and mild cognitive impairment (MCI) progress silently, making early diagnosis challenging, especially in less educated populations. The visual paired comparison (VPC) task, utilizing eye-tracking movement (ETM) technology, offers a promising alternative for early detection of memory decline.

OBJECTIVE: This systematic review and meta-analysis evaluated the efficacy of the VPC task, utilizing ETM as a tool for assessing age-related cognitive changes.

METHODS: A comprehensive search across five databases and grey literature focused on healthy and impaired memory participants assessed through the ETM-based VPC task. The primary outcomes were novelty preference scores and eye movement metrics. The risk of bias of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Random-effects meta-analyses calculated Hedges' g effect size. Sensitivity and specificity of the VPC were meta-analytically pooled.

RESULTS: The systematic review included 12 articles, involving 1,022 participants (aged 18 to 90 years, with education ranging from 6.5 to 20.0 years), with a low risk of bias and minimal applicability concerns across all items. Five studies contributed to the meta-analysis, revealing a significant effect favoring the VPC task for recognition memory detection (k = 9, g = -1.03). Pooled sensitivity and specificity analyses demonstrated VPC effectiveness as a recognition memory assessment tool (0.84 and 0.75, respectively).

CONCLUSIONS: The VPC task, utilizing ETM, may serve as a biomarker for early memory decline detection. Its use as a digital eye-tracking tool presents a possible alternative to traditional tests, warranting further research for application in neurodegenerative disease diagnosis.

RevDate: 2024-04-19

Khaled M, Al-Jamal H, Tajer L, et al (2024)

Alzheimer's Disease in Lebanon: Exploring Genetic and Environmental Risk Factors-A Comprehensive Review.

Journal of Alzheimer's disease : JAD pii:JAD231432 [Epub ahead of print].

Alzheimer's disease (AD) is a neurodegenerative condition that displays a high prevalence in Lebanon causing a local burden in healthcare and socio-economic sectors. Unfortunately, the lack of prevalence studies and clinical trials in Lebanon minimizes the improvement of AD patient health status. In this review, we include over 155 articles to cover the different aspects of AD ranging from mechanisms to possible treatment and management tools. We highlight some important modifiable and non-modifiable risk factors of the disease including genetics, age, cardiovascular diseases, smoking, etc. Finally, we propose a hypothetical genetic synergy model between APOE4 and TREM2 genes which constitutes a potential early diagnostic tool that helps in reducing the risk of AD based on preventative measures decades before cognitive decline. The studies on AD in Lebanon and the Middle East are scarce. This review points out the importance of genetic mapping in the understanding of disease pathology which is crucial for the emergence of novel diagnostic tools. Hence, we establish a rigid basis for further research to identify the most influential genetic and environmental risk factors for the purpose of using more specific diagnostic tools and possibly adopting a local management protocol.

RevDate: 2024-04-19

Tahami Monfared AA, Khachatryan A, Hummel N, et al (2024)

Assessing Quality of Life, Economic Burden, and Independence Across the Alzheimer's Disease Continuum Using Patient-Caregiver Dyad Surveys.

Journal of Alzheimer's disease : JAD pii:JAD231259 [Epub ahead of print].

BACKGROUND: Alzheimer's disease (AD) and mild cognitive impairment (MCI) have negative quality of life (QoL) and economic impacts on patients and their caregivers and may increase along the disease continuum from MCI to mild, moderate, and severe AD.

OBJECTIVE: To assess how patient and caregiver QoL, indirect and intangible costs are associated with MCI and AD severity.

METHODS: An on-line survey of physician-identified patient-caregiver dyads living in the United States was conducted from June-October 2022 and included questions to both patients and their caregivers. Dementia Quality of Life Proxy, the Care-related Quality of Life, Work Productivity and Activity Impairment, and Dependence scale were incorporated into the survey. Regression analyses investigated the association between disease severity and QoL and cost outcomes with adjustment for baseline characteristics.

RESULTS: One-hundred patient-caregiver dyads were assessed with the survey (MCI, n = 27; mild AD, n = 27; moderate AD, n = 25; severe AD, n = 21). Decreased QoL was found with worsening severity in patients (p < 0.01) and in unpaid (informal) caregivers (n = 79; p = 0.02). Dependence increased with disease severity (p < 0.01). Advanced disease severity was associated with higher costs to employers (p = 0.04), but not with indirect costs to caregivers. Patient and unpaid caregiver intangible costs increased with disease severity (p < 0.01). A significant trend of higher summed costs (indirect costs to caregivers, costs to employers, intangible costs to patients and caregivers) in more severe AD was observed (p < 0.01).

CONCLUSIONS: Patient QoL and functional independence and unpaid caregiver QoL decrease as AD severity increases. Intangible costs to patients and summed costs increase with disease severity and are highest in severe AD.

RevDate: 2024-04-19

Cai J, Xie D, Kong F, et al (2024)

Effect and Mechanism of Rapamycin on Cognitive Deficits in Animal Models of Alzheimer's Disease: A Systematic Review and Meta-analysis of Preclinical Studies.

BACKGROUND: Alzheimer's disease (AD), the most common form of dementia, remains long-term and challenging to diagnose. Furthermore, there is currently no medication to completely cure AD patients. Rapamycin has been clinically demonstrated to postpone the aging process in mice and improve learning and memory abilities in animal models of AD. Therefore, rapamycin has the potential to be significant in the discovery and development of drugs for AD patients.

OBJECTIVE: The main objective of this systematic review and meta-analysis was to investigate the effects and mechanisms of rapamycin on animal models of AD by examining behavioral indicators and pathological features.

METHODS: Six databases were searched and 4,277 articles were retrieved. In conclusion, 13 studies were included according to predefined criteria. Three authors independently judged the selected literature and methodological quality. Use of subgroup analyses to explore potential mechanistic effects of rapamycin interventions: animal models of AD, specific types of transgenic animal models, dosage, and periodicity of administration.

RESULTS: The results of Morris Water Maze (MWM) behavioral test showed that escape latency was shortened by 15.60 seconds with rapamycin therapy, indicating that learning ability was enhanced in AD mice; and the number of traversed platforms was increased by 1.53 times, indicating that the improved memory ability significantly corrected the memory deficits.

CONCLUSIONS: Rapamycin therapy reduced age-related plaque deposition by decreasing AβPP production and down-regulating β-secretase and γ-secretase activities, furthermore increased amyloid-β clearance by promoting autophagy, as well as reduced tau hyperphosphorylation by up-regulating insulin-degrading enzyme levels.

RevDate: 2024-04-19

Sighinolfi G, Mitolo M, Pizzagalli F, et al (2024)

Sulcal Morphometry Predicts Mild Cognitive Impairment Conversion to Alzheimer's Disease.

Journal of Alzheimer's disease : JAD pii:JAD231192 [Epub ahead of print].

BACKGROUND: Being able to differentiate mild cognitive impairment (MCI) patients who would eventually convert (MCIc) to Alzheimer's disease (AD) from those who would not (MCInc) is a key challenge for prognosis.

OBJECTIVE: This study aimed to investigate the ability of sulcal morphometry to predict MCI progression to AD, dedicating special attention to an accurate identification of sulci.

METHODS: Twenty-five AD patients, thirty-seven MCI and twenty-five healthy controls (HC) underwent a brain-MR protocol (1.5T scanner) including a high-resolution T1-weighted sequence. MCI patients underwent a neuropsychological assessment at baseline and were clinically re-evaluated after a mean of 2.3 years. At follow-up, 12 MCI were classified as MCInc and 25 as MCIc. Sulcal morphometry was investigated using the BrainVISA framework. Consistency of sulci across subjects was ensured by visual inspection and manual correction of the automatic labelling in each subject. Sulcal surface, depth, length, and width were retrieved from 106 sulci. Features were compared across groups and their classification accuracy in predicting MCI conversion was tested. Potential relationships between sulcal features and cognitive scores were explored using Spearman's correlation.

RESULTS: The width of sulci in the temporo-occipital region strongly differentiated between each pair of groups. Comparing MCIc and MCInc, the width of several sulci in the bilateral temporo-occipital and left frontal areas was significantly altered. Higher width of frontal sulci was associated with worse performances in short-term verbal memory and phonemic fluency.

CONCLUSIONS: Sulcal morphometry emerged as a strong tool for differentiating HC, MCI, and AD, demonstrating its potential prognostic value for the MCI population.

RevDate: 2024-04-19

Choi YY, Lee JJ, Te Nijenhuis J, et al (2024)

Multi-Ethnic Norms for Volumes of Subcortical and Lobar Brain Structures Measured by Neuro I: Ethnicity May Improve the Diagnosis of Alzheimer's Disease1.

Journal of Alzheimer's disease : JAD pii:JAD231182 [Epub ahead of print].

BACKGROUND: We previously demonstrated the validity of a regression model that included ethnicity as a novel predictor for predicting normative brain volumes in old age. The model was optimized using brain volumes measured with a standard tool FreeSurfer.

OBJECTIVE: Here we further verified the prediction model using newly estimated brain volumes from Neuro I, a quantitative brain analysis system developed for Korean populations.

METHODS: Lobar and subcortical volumes were estimated from MRI images of 1,629 normal Korean and 786 Caucasian subjects (age range 59-89) and were predicted in linear regression from ethnicity, age, sex, intracranial volume, magnetic field strength, and scanner manufacturers.

RESULTS: In the regression model predicting the new volumes, ethnicity was again a substantial predictor in most regions. Additionally, the model-based z-scores of regions were calculated for 428 AD patients and the matched controls, and then employed for diagnostic classification. When the AD classifier adopted the z-scores adjusted for ethnicity, the diagnostic accuracy has noticeably improved (AUC = 0.85, ΔAUC = + 0.04, D = 4.10, p <  0.001).

CONCLUSIONS: Our results suggest that the prediction model remains robust across different measurement tool, and ethnicity significantly contributes to the establishment of norms for brain volumes and the development of a diagnostic system for neurodegenerative diseases.

RevDate: 2024-04-19

Etekochay MO, Amaravadhi AR, González GV, et al (2024)

Unveiling New Strategies Facilitating the Implementation of Artificial Intelligence in Neuroimaging for the Early Detection of Alzheimer's Disease.

Journal of Alzheimer's disease : JAD pii:JAD231135 [Epub ahead of print].

Alzheimer's disease (AD) is a chronic neurodegenerative disorder with a global impact. The past few decades have witnessed significant strides in comprehending the underlying pathophysiological mechanisms and developing diagnostic methodologies for AD, such as neuroimaging approaches. Neuroimaging techniques, including positron emission tomography and magnetic resonance imaging, have revolutionized the field by providing valuable insights into the structural and functional alterations in the brains of individuals with AD. These imaging modalities enable the detection of early biomarkers such as amyloid-β plaques and tau protein tangles, facilitating early and precise diagnosis. Furthermore, the emerging technologies encompassing blood-based biomarkers and neurochemical profiling exhibit promising results in the identification of specific molecular signatures for AD. The integration of machine learning algorithms and artificial intelligence has enhanced the predictive capacity of these diagnostic tools when analyzing complex datasets. In this review article, we will highlight not only some of the most used diagnostic imaging approaches in neurodegeneration research but focus much more on new tools like artificial intelligence, emphasizing their application in the realm of AD. These advancements hold immense potential for early detection and intervention, thereby paving the way for personalized therapeutic strategies and ultimately augmenting the quality of life for individuals affected by AD.

RevDate: 2024-04-19

Chandrasekaran G, Xie SX, Alzheimer’s Disease Neuroimaging Initiative (2024)

Improving Regression Analysis with Imputation in a Longitudinal Study of Alzheimer's Disease.

Journal of Alzheimer's disease : JAD pii:JAD231047 [Epub ahead of print].

BACKGROUND: Missing data is prevalent in the Alzheimer's Disease Neuroimaging Initiative (ADNI). It is common to deal with missingness by removing subjects with missing entries prior to statistical analysis; however, this can lead to significant efficiency loss and sometimes bias. It has yet to be demonstrated that the imputation approach to handling this issue can be valuable in some longitudinal regression settings.

OBJECTIVE: The purpose of this study is to demonstrate the importance of imputation and how imputation is correctly done in ADNI by analyzing longitudinal Alzheimer's Disease Assessment Scale -Cognitive Subscale 13 (ADAS-Cog 13) scores and their association with baseline patient characteristics.

METHODS: We studied 1,063 subjects in ADNI with mild cognitive impairment. Longitudinal ADAS-Cog 13 scores were modeled with a linear mixed-effects model with baseline clinical and demographic characteristics as predictors. The model estimates obtained without imputation were compared with those obtained after imputation with Multiple Imputation by Chained Equations (MICE). We justify application of MICE by investigating the missing data mechanism and model assumptions. We also assess robustness of the results to the choice of imputation method.

RESULTS: The fixed-effects estimates of the linear mixed-effects model after imputation with MICE yield valid, tighter confidence intervals, thus improving the efficiency of the analysis when compared to the analysis done without imputation.

CONCLUSIONS: Our study demonstrates the importance of accounting for missing data in ADNI. When deciding to perform imputation, care should be taken in choosing the approach, as an invalid one can compromise the statistical analyses.

RevDate: 2024-04-19

Yoo HS, Kim HK, Lee JH, et al (2024)

Association of Basal Forebrain Volume with Amyloid, Tau, and Cognition in Alzheimer's Disease.

Journal of Alzheimer's disease : JAD pii:JAD230975 [Epub ahead of print].

BACKGROUND: Degeneration of cholinergic basal forebrain (BF) neurons characterizes Alzheimer's disease (AD). However, what role the BF plays in the dynamics of AD pathophysiology has not been investigated precisely.

OBJECTIVE: To investigate the baseline and longitudinal roles of BF along with core neuropathologies in AD.

METHODS: In this retrospective cohort study, we enrolled 113 subjects (38 amyloid [Aβ]-negative cognitively unimpaired, 6 Aβ-positive cognitively unimpaired, 39 with prodromal AD, and 30 with AD dementia) who performed brain MRI for BF volume and cortical thickness, 18F-florbetaben PET for Aβ, 18F-flortaucipir PET for tau, and detailed cognitive testing longitudinally. We investigated the baseline and longitudinal association of BF volume with Aβ and tau standardized uptake value ratio and cognition.

RESULTS: Cross-sectionally, lower BF volume was not independently associated with higher cortical Aβ, but it was associated with tau burden. Tau burden in the orbitofrontal, insular, lateral temporal, inferior temporo-occipital, and anterior cingulate cortices were associated with progressive BF atrophy. Lower BF volume was associated with faster Aβ accumulation, mainly in the prefrontal, anterior temporal, cingulate, and medial occipital cortices. BF volume was associated with progressive decline in language and memory functions regardless of baseline Aβ and tau burden.

CONCLUSIONS: Tau deposition affected progressive BF atrophy, which in turn accelerated amyloid deposition, leading to a vicious cycle. Also, lower baseline BF volume independently predicted deterioration in cognitive function.

RevDate: 2024-04-19

Dorado-Martínez C, Montiel-Flores E, Ordoñez-Librado JL, et al (2024)

Histological and Memory Alterations in an Innovative Alzheimer's Disease Animal Model by Vanadium Pentoxide Inhalation.

Journal of Alzheimer's disease : JAD pii:JAD230818 [Epub ahead of print].

BACKGROUND: Previous work from our group has shown that chronic exposure to Vanadium pentoxide (V2O5) causes cytoskeletal alterations suggesting that V2O5 can interact with cytoskeletal proteins through polymerization and tyrosine phosphatases inhibition, causing Alzheimer's disease (AD)-like hippocampal cell death.

OBJECTIVE: This work aims to characterize an innovative AD experimental model through chronic V2O5 inhalation, analyzing the spatial memory alterations and the presence of neurofibrillary tangles (NFTs), amyloid-β (Aβ) senile plaques, cerebral amyloid angiopathy, and dendritic spine loss in AD-related brain structures.

METHODS: 20 male Wistar rats were divided into control (deionized water) and experimental (0.02 M V2O5 1 h, 3/week for 6 months) groups (n = 10). The T-maze test was used to assess spatial memory once a month. After 6 months, histological alterations of the frontal and entorhinal cortices, CA1, subiculum, and amygdala were analyzed by performing Congo red, Bielschowsky, and Golgi impregnation.

RESULTS: Cognitive results in the T-maze showed memory impairment from the third month of V2O5 inhalation. We also noted NFTs, Aβ plaque accumulation in the vascular endothelium and pyramidal neurons, dendritic spine, and neuronal loss in all the analyzed structures, CA1 being the most affected.

CONCLUSIONS: This model characterizes neurodegenerative changes specific to AD. Our model is compatible with Braak AD stage IV, which represents a moment where it is feasible to propose therapies that have a positive impact on stopping neuronal damage.

RevDate: 2024-04-19

Orrú CD, Groveman BR, Hughson AG, et al (2024)

Sensitive detection of pathological seeds of α-synuclein, tau and prion protein on solid surfaces.

PLoS pathogens, 20(4):e1012175 pii:PPATHOGENS-D-24-00348 [Epub ahead of print].

Prions or prion-like aggregates such as those composed of PrP, α-synuclein, and tau are key features of proteinopathies such as prion, Parkinson's and Alzheimer's diseases, respectively. Their presence on solid surfaces may be biohazardous under some circumstances. PrP prions bound to solids are detectable by ultrasensitive real-time quaking-induced conversion (RT-QuIC) assays if the solids can be immersed in assay wells or transferred to pads. Here we show that PrP prions can remain detectable on steel wires for at least a year, or even after enzymatic cleaning and sterilization. We also show that contamination of larger objects with pathological seeds of α-synuclein, tau, and PrP can be detected by simply assaying a sampling medium that has been transiently applied to the surface. Human α-synuclein seeds in dementia with Lewy bodies brain tissue was detected by α-synuclein RT-QuIC after drying of tissue dilutions with concentrations as low as 10-6 onto stainless steel. Tau RT-QuIC detected tau seeding activity on steel exposed to Alzheimer's disease brain tissue diluted as much as a billion fold. Prion RT-QuIC assays detected seeding activity on plates exposed to brain dilutions as extreme as 10-5-10-8 from prion-affected humans, sheep, cattle and cervids. Sampling medium collected from surgical instruments used in necropsies of sporadic Creutzfeldt-Jakob disease-infected transgenic mice was positive down to 10-6 dilution. Sensitivity for prion detection was not sacrificed by omitting the recombinant PrP substrate from the sampling medium during its application to a surface and subsequent storage as long as the substrate was added prior to performing the assay reaction. Our findings demonstrate practical prototypic surface RT-QuIC protocols for the highly sensitive detection of pathologic seeds of α-synuclein, tau, and PrP on solid objects.

RevDate: 2024-04-19

Awarayi NS, Twum F, Hayfron-Acquah JB, et al (2024)

A bilateral filtering-based image enhancement for Alzheimer disease classification using CNN.

PloS one, 19(4):e0302358 pii:PONE-D-23-12558.

This study aims to develop an optimally performing convolutional neural network to classify Alzheimer's disease into mild cognitive impairment, normal controls, or Alzheimer's disease classes using a magnetic resonance imaging dataset. To achieve this, we focused the study on addressing the challenge of image noise, which impacts the performance of deep learning models. The study introduced a scheme for enhancing images to improve the quality of the datasets. Specifically, an image enhancement algorithm based on histogram equalization and bilateral filtering techniques was deployed to reduce noise and enhance the quality of the images. Subsequently, a convolutional neural network model comprising four convolutional layers and two hidden layers was devised for classifying Alzheimer's disease into three (3) distinct categories, namely mild cognitive impairment, Alzheimer's disease, and normal controls. The model was trained and evaluated using a 10-fold cross-validation sampling approach with a learning rate of 0.001 and 200 training epochs at each instance. The proposed model yielded notable results, such as an accuracy of 93.45% and an area under the curve value of 0.99 when trained on the three classes. The model further showed superior results on binary classification compared with existing methods. The model recorded 94.39%, 94.92%, and 95.62% accuracies for Alzheimer's disease versus normal controls, Alzheimer's disease versus mild cognitive impairment, and mild cognitive impairment versus normal controls classes, respectively.

RevDate: 2024-04-19

Rubin R (2024)

Could GLP-1 Receptor Agonists like Semaglutide Treat Addiction, Alzheimer Disease, and Other Conditions?.

JAMA pii:2817996 [Epub ahead of print].

RevDate: 2024-04-19

Rahimi A, Sameei P, Mousavi S, et al (2024)

Application of CRISPR/Cas9 System in the Treatment of Alzheimer's Disease and Neurodegenerative Diseases.

Molecular neurobiology [Epub ahead of print].

Alzheimer's, Parkinson's, and Huntington's are some of the most common neurological disorders, which affect millions of people worldwide. Although there have been many treatments for these diseases, there are still no effective treatments to treat or completely stop these disorders. Perhaps the lack of proper treatment for these diseases can be related to various reasons, but the poor results related to recent clinical research also prompted doctors to look for new treatment approaches. In this regard, various researchers from all over the world have provided many new treatments, one of which is CRISPR/Cas9. Today, the CRISPR/Cas9 system is mostly used for genetic modifications in various species. In addition, by using the abilities available in the CRISPR/Cas9 system, researchers can either remove or modify DNA sequences, which in this way can establish a suitable and useful treatment method for the treatment of genetic diseases that have undergone mutations. We conducted a non-systematic review of articles and study results from various databases, including PubMed, Medline, Web of Science, and Scopus, in recent years. and have investigated new treatment methods in neurodegenerative diseases with a focus on Alzheimer's disease. Then, in the following sections, the treatment methods were classified into three groups: anti-tau, anti-amyloid, and anti-APOE regimens. Finally, we discussed various applications of the CRISPR/Cas-9 system in Alzheimer's disease. Today, using CRISPR/Cas-9 technology, scientists create Alzheimer's disease models that have a more realistic phenotype and reveal the processes of pathogenesis; following the screening of defective genes, they establish treatments for this disease.

RevDate: 2024-04-19

Csiszar A, Ungvari A, Patai R, et al (2024)

Atherosclerotic burden and cerebral small vessel disease: exploring the link through microvascular aging and cerebral microhemorrhages.

GeroScience [Epub ahead of print].

Cerebral microhemorrhages (CMHs, also known as cerebral microbleeds) are a critical but frequently underestimated aspect of cerebral small vessel disease (CSVD), bearing substantial clinical consequences. Detectable through sensitive neuroimaging techniques, CMHs reveal an extensive pathological landscape. They are prevalent in the aging population, with multiple CMHs often being observed in a given individual. CMHs are closely associated with accelerated cognitive decline and are increasingly recognized as key contributors to the pathogenesis of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). This review paper delves into the hypothesis that atherosclerosis, a prevalent age-related large vessel disease, extends its pathological influence into the cerebral microcirculation, thereby contributing to the development and progression of CSVD, with a specific focus on CMHs. We explore the concept of vascular aging as a continuum, bridging macrovascular pathologies like atherosclerosis with microvascular abnormalities characteristic of CSVD. We posit that the same risk factors precipitating accelerated aging in large vessels (i.e., atherogenesis), primarily through oxidative stress and inflammatory pathways, similarly instigate accelerated microvascular aging. Accelerated microvascular aging leads to increased microvascular fragility, which in turn predisposes to the formation of CMHs. The presence of hypertension and amyloid pathology further intensifies this process. We comprehensively overview the current body of evidence supporting this interconnected vascular hypothesis. Our review includes an examination of epidemiological data, which provides insights into the prevalence and impact of CMHs in the context of atherosclerosis and CSVD. Furthermore, we explore the shared mechanisms between large vessel aging, atherogenesis, microvascular aging, and CSVD, particularly focusing on how these intertwined processes contribute to the genesis of CMHs. By highlighting the role of vascular aging in the pathophysiology of CMHs, this review seeks to enhance the understanding of CSVD and its links to systemic vascular disorders. Our aim is to provide insights that could inform future therapeutic approaches and research directions in the realm of neurovascular health.

RevDate: 2024-04-19

White ZB, Nair S, M Bredel (2024)

The role of annexins in central nervous system development and disease.

Journal of molecular medicine (Berlin, Germany) [Epub ahead of print].

Annexins, a group of Ca[2+]-dependent phospholipid-binding proteins, exert diverse roles in neuronal development, normal central nervous system (CNS) functioning, neurological disorders, and CNS tumors. This paper reviews the roles of individual annexins (A1-A13) in these contexts. Annexins possess unique structural and functional features, such as Ca[2+]-dependent binding to phospholipids, participating in membrane organization, and modulating cell signaling. They are implicated in various CNS processes, including endocytosis, exocytosis, and stabilization of plasma membranes. Annexins exhibit dynamic roles in neuronal development, influencing differentiation, proliferation, and synaptic formation in CNS tissues. Notably, annexins such as ANXA1 and ANXA2 play roles in apoptosis and blood-brain barrier (BBB) integrity. Neurological disorders, including Alzheimer's disease, multiple sclerosis, and depression, involve annexin dysregulation, influencing neuroinflammation, blood-brain barrier integrity, and stress responses. Moreover, annexins contribute to the pathogenesis of CNS tumors, either promoting or suppressing tumor growth, angiogenesis, and invasion. Annexin expression patterns vary across different CNS tumor types, providing potential prognostic markers and therapeutic targets. This review underscores the multifaceted roles of annexins in the CNS, highlighting their importance in normal functioning, disease progression, and potential therapeutic interventions.

RevDate: 2024-04-19

Austin ME, Ingram LA, McCollum Q, et al (2024)

A dual approach to addressing gaps in scholar diversity in aging research.

Gerontology & geriatrics education [Epub ahead of print].

The number of people with Alzheimer's disease and related dementias (ADRD) in the United States is steadily increasing, with minoritized populations having a disproportionate burden of disease. One strategy to address the racial and ethnic disparities in aging is to diversify scholars in the field of aging, to increase dynamic solution development and create cultural congruence among researchers and participants. The National Institute on Aging has a committed effort to increase and diversify the number of scientists who conduct aging and ADRD research, placing a call for Centers to focus on this effort. In response to the National Institute on Aging call, the Carolina Center for Alzheimer's Disease and Minority Research, housed at the University of South Carolina, proposed a dual approach to addressing these gaps through a joint national conference and mentorship program for underrepresented minoritized faculty. After one year of the program, the participating scholars were surveyed, and successes and growth points of the program were identified to help guide the improvement of this dual approach to addressing gaps in scholar diversity in aging research.

RevDate: 2024-04-19

Liampas I, Siokas V, Zoupa E, et al (2024)

Neuropsychiatric Symptoms and White Matter Hyperintensities in Older Adults without Dementia.

International psychogeriatrics pii:S1041610224000607 [Epub ahead of print].

OBJECTIVE: We aimed to examine associations between neuropsychiatric symptoms (NPS) and white matter hyperintensities (WMH) status in older adults without dementia under the hypothesis that WMH increased the odds of having NPS.

DESIGN: Longitudinal analysis of data acquired from the National Alzheimer's Coordinating Center Uniform Data Set.

SETTINGS: Data were derived from 46 National Institute on Aging - funded Alzheimer's Disease Research Centers.

PARTICIPANTS: NACC participants aged ≥50 years with available data on WMH severity with a diagnosis of mild cognitive impairment (MCI) or who were cognitively unimpaired (CU) were studied. Among 4617 CU participants, 376 had moderate and 54 extensive WMH. Among 3170 participants with MCI, 471 had moderate and 88 had extensive WMH.Measurements: Using Cardiovascular Health Study (CHS) scores, WMH were coded as no to mild (CHS score: 0-4), moderate (score: 5-6) or extensive (score: 7-8). NPS were quantified on the Neuropsychiatric Inventory Questionnaire. Binary logistic regression models estimated the odds of reporting each of 12 NPS by WMH status separately for individuals with MCI or who were CU.

RESULTS: Compared to CU individuals with no to mild WMH, the odds of having elation [9.87,(2.63-37.10)], disinhibition [4.42,(1.28-15.32)], agitation [3.51,(1.29-9.54)] or anxiety [2.74,(1.28-5.88)] were higher for the extensive WMH group, whereas the odds of having disinhibition were higher for the moderate WMH group [1.94,(1.05-3.61)]. In the MCI group, he odds of NPS did not vary by WMH status.

CONCLUSIONS: Extensive WMH were associated with higher odds of NPS in CU older adults but not in those with MCI.

RevDate: 2024-04-19

Nabizadeh F, Pirahesh K, Aarabi MH, et al (2024)

Behavioral and dysexecutive variant of Alzheimer's disease: Insights from structural and molecular imaging studies.

Heliyon, 10(8):e29420.

Frontal variant Alzheimer's disease (AD) manifests with either behavioral or dysexecutive syndromes. Recent efforts to gain a deeper understanding of this phenotype have led to a re-conceptualization of frontal AD. Behavioral (bAD) and dysexecutive (dAD) phenotypes could be considered subtypes, as suggested by both clinical and neuroimaging studies. In this review, we focused on imaging studies to highlight specific brain patterns in these two uncommon clinical AD phenotypes. Although studies did not compare directly these two variants, a common epicenter located in the frontal cortex could be inferred. On the contrary, 18[F]-FDG-PET findings suggested differing metabolic patterns, with bAD showing specific involvement of frontal regions and dAD exhibiting widespread alterations. Structural MRI findings confirmed this pattern, suggesting that degeneration might involve neural circuits associated with behavioral control in bAD and attentional networks in dAD. Furthermore, molecular imaging has identified different neocortical tau distribution in bAD and dAD patients compared to typical AD patients, although the distribution is remarkably heterogeneous. In contrast, Aβ deposition patterns are less differentiated between these atypical variants and typical AD. Although preliminary, these findings underscore the complexity of AD frontal phenotypes and suggest that they represent distinct entities. Further research is essential to refine our understanding of the pathophysiological mechanisms in frontal AD.

RevDate: 2024-04-19

Wu J, Chen J, Ge Y, et al (2024)

Neuroprotective effect of tanshinone IIA-modified mesenchymal stem cells in a lipopolysaccharide-induced neuroinflammation model.

Heliyon, 10(8):e29424.

In this study, the neuroprotective potential of tanshinone IIA (TIIA)-modified mesenchymal stem cells (MSC) were investigated using a murine model of lipopolysaccharide (LPS)-induced neuroinflammation. The cognitive performance of the mice was assessed using the Y-maze and Morris water maze tests, while immunofluorescence and Western blot analyses were employed to evaluate the hippocampal expression of pertinent markers and inflammatory factors, respectively. The results from the behavioral experiments demonstrated discernible differences in learning and memory abilities between the model group and the control group (P < 0.05), confirming the successful induction of neuroinflammation. Both the MSC and TIIA-MSC groups exhibited enhancements in the cognitive abilities of neuroinflammatory mice, with the TIIA-MSC group demonstrating a more pronounced improvement (P < 0.01). Immunofluorescence analysis revealed significant activation of microglia in the model group, while the MSC and TIIA-MSC groups exhibited a reduction in hippocampal microglial activation, with the TIIA-MSC group displaying a more substantial decrease. A statistically significant difference in the expression levels of IL-1, IL-6, and TNF-α was observed between the model and control groups (P < 0.05), indicating that IL-1, IL-6, and TNF-α were downregulated in both the MSC and TIIA-MSC groups. Notably, the downregulatory effect was more prominent in the TIIA-MSC group (P < 0.01). Compared to MSC treatment alone, the administration of TIIA-modified MSC demonstrated a superior protective effect against lipopolysaccharide-induced neuroinflammation. These findings underscore the potential therapeutic efficacy of TIIA-modified MSC in mitigating neuroinflammatory responses.

RevDate: 2024-04-19

Yan F, Yang M, Sun Y, et al (2024)

Case report: Methicillin-resistant Staphylococcus aureus with penicillin susceptible (PS-MRSA): first clinical report from a psychiatric hospital in China.

Frontiers in medicine, 11:1380369.

This case report documents the first instance of Penicillin-Susceptible Methicillin-Resistant Staphylococcus aureus (PS-MRSA) in a Chinese psychiatric hospital. The strain was isolated from a patient with Alzheimer's disease who had a lower respiratory tract infection. Clinical and laboratory analyses, including mass spectrometry, antibiotic susceptibility testing, and whole-genome sequencing, confirmed the PS-MRSA strain. In this case, we systematically introduce the clinical symptoms, laboratory findings, and treatment responses associated with this PS-MRSA strain. This discovery offers a new perspective on our understanding of resistance mechanisms and expands our considerations for existing antibiotic treatments. It may fill a gap in the classification of MRSA strains, enhance the spectrum of MRSA resistance, and complete the therapeutic strategies for MRSA.

RevDate: 2024-04-19

Clifford JO, Anand S, Tarpin-Bernard F, et al (2024)

Episodic memory assessment: effects of sex and age on performance and response time during a continuous recognition task.

Frontiers in human neuroscience, 18:1304221.

INTRODUCTION: Continuous recognition tasks (CRTs) assess episodic memory (EM), the central functional disturbance in Alzheimer's disease and several related disorders. The online MemTrax computerized CRT provides a platform for screening and assessment that is engaging and can be repeated frequently. MemTrax presents complex visual stimuli, which require complex involvement of the lateral and medial temporal lobes and can be completed in less than 2 min. Results include number of correct recognitions (HITs), recognition failures (MISSes = 1-HITs), correct rejections (CRs), false alarms (FAs = 1-CRs), total correct (TC = HITs + CRs), and response times (RTs) for each HIT and FA. Prior analyses of MemTrax CRT data show no effects of sex but an effect of age on performance. The number of HITs corresponds to faster RT-HITs more closely than TC, and CRs do not relate to RT-HITs. RT-HITs show a typical skewed distribution, and cumulative RT-HITs fit a negative survival curve (RevEx). Thus, this study aimed to define precisely the effects of sex and age on HITS, CRs, RT-HITs, and the dynamics of RTs in an engaged population.

METHODS: MemTrax CRT online data on 18,255 individuals was analyzed for sex, age, and distributions of HITs, CRs, MISSes, FAs, TC, and relationships to both RT-HITs and RT-FAs.

RESULTS: HITs corresponded more closely to RT-HITs than did TC because CRs did not relate to RT-HITs. RT-FAs had a broader distribution than RT-HITs and were faster than RT-HITs in about half of the sample, slower in the other half. Performance metrics for men and women were the same. HITs declined with age as RT-HITs increased. CRs also decreased with age and RT-FAs increased, but with no correlation. The group over aged 50 years had RT-HITs distributions slower than under 50 years. For both age ranges, the RevEx model explained more than 99% of the variance in RT-HITs.

DISCUSSION: The dichotomy of HITs and CRs suggests opposing cognitive strategies: (1) less certainty about recognitions, in association with slower RT-HITs and lower HIT percentages suggests recognition difficulty, leading to more MISSes, and (2) decreased CRs (more FAs) but faster RTs to HITs and FAs, suggesting overly quick decisions leading to errors. MemTrax CRT performance provides an indication of EM (HITs and RT-HITs may relate to function of the temporal lobe), executive function (FAs may relate to function of the frontal lobe), processing speed (RTs), cognitive ability, and age-related changes. This CRT provides potential clinical screening utility for early Alzheimer's disease and other conditions affecting EM, other cognitive functions, and more accurate impairment assessment to track changes over time.

RevDate: 2024-04-19

Cao L, Han K, Lin L, et al (2024)

Reversal of the concreteness effect can be detected in the natural speech of older adults with amnestic, but not non-amnestic, mild cognitive impairment.

Alzheimer's & dementia (Amsterdam, Netherlands), 16(2):e12588.

INTRODUCTION: Patients with Alzheimer's disease present with difficulty in lexical retrieval and reversal of the concreteness effect in nouns. Little is known about the phenomena before the onset of symptoms. We anticipate early linguistic signs in the speech of people who suffer from amnestic mild cognitive impairment (MCI). Here, we report the results of a corpus-linguistic approach to the early detection of cognitive impairment.

METHODS: One hundred forty-eight English-speaking Singaporeans provided natural speech data, on topics of their choice; 74 were diagnosed with single-domain MCI (38 amnestic, 36 non-amnestic), 74 cognitively healthy. The recordings yield 267,310 words, which are tagged for parts of speech. We calculate the per-minute word counts and concreteness scores of all tagged words, nouns, and verbs in the dataset.

RESULTS: Compared to controls, subjects with amnestic MCI produce fewer but more abstract nouns. Verbs are not affected.

DISCUSSION: Slower retrieval of nouns and the reversal of the concreteness effect in nouns are manifested in natural speech and can be detected early through corpus-based analysis.

HIGHLIGHTS: Reversal of the concreteness effect is manifested in patients with Alzheimer's disease (AD) and semantic dementia.The paper reports a corpus-based analysis of natural speech by people with amnestic and non-amnestic mild cognitive impairment (MCI) and cognitively healthy controls.People with amnestic MCI produce fewer and more abstract nouns than people with non-amnestic MCI and healthy controls. Verbs appear to be unaffected.The imageability problem can be detected in natural everyday speech by people with amnestic MCI, which carries a higher risk of conversion to AD.

RevDate: 2024-04-19

Cai M, Zheng Q, Chen Y, et al (2024)

Insights from the neural guidance factor Netrin-1 into neurodegeneration and other diseases.

Frontiers in molecular neuroscience, 17:1379726.

Netrin-1 was initially discovered as a neuronal growth cue for axonal guidance, and its functions have later been identified in inflammation, tumorigenesis, neurodegeneration, and other disorders. We have recently found its alterations in the brains with Alzheimer's disease, which might provide important clues to the mechanisms of some unique pathologies. To provide better understanding of this promising molecule, we here summarize research progresses in genetics, pathology, biochemistry, cell biology and other studies of Netrin-1 about its mechanistic roles and biomarker potentials with an emphasis on clinical neurodegenerative disorders in order to expand understanding of this promising molecular player in human diseases.

RevDate: 2024-04-19

Katsuki F, Spratt TJ, Brown RE, et al (2024)

Sleep-Deep-Learner is taught sleep-wake scoring by the end-user to complete each record in their style.

Sleep advances : a journal of the Sleep Research Society, 5(1):zpae022.

Sleep-wake scoring is a time-consuming, tedious but essential component of clinical and preclinical sleep research. Sleep scoring is even more laborious and challenging in rodents due to the smaller EEG amplitude differences between states and the rapid state transitions which necessitate scoring in shorter epochs. Although many automated rodent sleep scoring methods exist, they do not perform as well when scoring new datasets, especially those which involve changes in the EEG/EMG profile. Thus, manual scoring by expert scorers remains the gold standard. Here we take a different approach to this problem by using a neural network to accelerate the scoring of expert scorers. Sleep-Deep-Learner creates a bespoke deep convolution neural network model for individual electroencephalographic or local-field-potential (LFP) records via transfer learning of GoogLeNet, by learning from a small subset of manual scores of each EEG/LFP record as provided by the end-user. Sleep-Deep-Learner then automates scoring of the remainder of the EEG/LFP record. A novel REM sleep scoring correction procedure further enhanced accuracy. Sleep-Deep-Learner reliably scores EEG and LFP data and retains sleep-wake architecture in wild-type mice, in sleep induced by the hypnotic zolpidem, in a mouse model of Alzheimer's disease and in a genetic knock-down study, when compared to manual scoring. Sleep-Deep-Learner reduced manual scoring time to 1/12. Since Sleep-Deep-Learner uses transfer learning on each independent recording, it is not biased by previously scored existing datasets. Thus, we find Sleep-Deep-Learner performs well when used on signals altered by a drug, disease model, or genetic modification.

RevDate: 2024-04-19

Li H, Li XD, Yan CH, et al (2024)

Rational design of a near-infrared fluorescent probe for monitoring butyrylcholinesterase activity and its application in development of inhibitors.

Frontiers in bioengineering and biotechnology, 12:1387146.

Butyrylcholinesterase (BChE) is widely expressed in multiple tissues and has a vital role in several key human disorders, such as Alzheimer's disease and tumorigenesis. However, the role of BChE in human disorders has not been investigated. Thus, to quantitatively detect and visualize dynamical variations in BChE activity is essential for exploring the biological roles of BChE in the progression of a number of human disorders. Herein, based on the substrate characteristics of BChE, we customized and synthesized three near-infrared (NIR) fluorescent probe substrates with cyanine-skeleton, and finally selected a NIR fluorescence probe substrate named CYBA. The CYBA demonstrated a significant increase in fluorescence when interacting with BChE, but mainly avoided AChE. Upon the addition of BChE, CYBA could be specifically hydrolyzed to TBO, resulting in a significant NIR fluorescence signal enhancement at 710 nm. Systematic evaluation revealed that CYBA exhibited exceptional chemical stability in complex biosamples and possessed remarkable selectivity and sensitivity towards BChE. Moreover, CYBA was successfully applied for real-time imaging of endogenous BChE activity in two types of nerve-related living cells. Additionally, CYBA demonstrated exceptional stability in the detection of complex biological samples in plasma recovery studies (97.51%-104.01%). Furthermore, CYBA was used to construct a high-throughput screening (HTS) method for BChE inhibitors using human plasma as the enzyme source. We evaluated inhibitory effects of a series of natural products and four flavonoids were identified as potent inhibitors of BChE. Collectively, CYBA can serve as a practical tool to track the changes of BChE activity in complicated biological environments due to its excellent capabilities.

RevDate: 2024-04-19

Jiang S, Sydney EJ, Runyan AM, et al (2024)

5-HT4 receptor agonists treatment reduces tau pathology and behavioral deficit in the PS19 mouse model of tauopathy.

Frontiers in cellular neuroscience, 18:1338502.

BACKGROUND: Accumulation of tau in synapses in the early stages of Alzheimer's disease (AD) has been shown to cause synaptic damage, synaptic loss, and the spread of tau pathology through trans-synaptically connected neurons. Moreover, synaptic loss correlates with a decline in cognitive function, providing an opportunity to investigate therapeutic strategies to target synapses and synaptic tau to rescue or prevent cognitive decline in AD. One of the promising synaptic targets is the 5-HT4 serotonergic receptor present postsynaptically in the brain structures involved in the memory processes. 5-HT4R stimulation exerts synaptogenic and pro-cognitive effects involving synapse-to-nucleus signaling essential for synaptic plasticity. However, it is not known whether 5-HT4R activation has a therapeutic effect on tau pathology.

METHODS: The goal of this study was to investigate the impact of chronic stimulation of 5-HT4R by two agonists, prucalopride and RS-67333, in PS19 mice, a model of tauopathy. We utilized gradient assays to isolate pre- and post-synaptic compartments, followed by biochemical analyses for tau species and ubiquitinated proteins in the synaptic compartments and total brain tissue. Next, we performed kinetic assays to test the proteasome's hydrolysis capacity in treatment conditions. Moreover, behavioral tests such as the open field and non-maternal nest-building tests were used to evaluate anxiety-like behaviors and hippocampal-related cognitive functioning in the treatment paradigm.

RESULTS: Our results show that 5-HT4R agonism reduced tauopathy, reduced synaptic tau, increased proteasome activity, and improved cognitive functioning in PS19 mice. Our data suggest that enhanced proteasome activity by synaptic mediated signaling leads to the enhanced turnover of tau initially within synapses where the receptors are localized, and over time, the treatment attenuated the accumulation of tau aggregation and improved cognitive functioning of the PS19 mice.

CONCLUSION: Therefore, stimulation of 5-HT4R offers a promising therapy to rescue synapses from the accumulation of toxic synaptic tau, evident in the early stages of AD.

RevDate: 2024-04-19

Tsai HH, Liu CJ, Lee BC, et al (2024)

Cerebral tau pathology in cerebral amyloid angiopathy.

Brain communications, 6(2):fcae086.

Tau, a hallmark of Alzheimer's disease, is poorly characterized in cerebral amyloid angiopathy. We aimed to assess the clinico-radiological correlations between tau positron emission tomography scans and cerebral amyloid angiopathy. We assessed cerebral amyloid and hyperphosphorylated tau in patients with probable cerebral amyloid angiopathy (n = 31) and hypertensive small vessel disease (n = 27) using [11]C-Pittsburgh compound B and [18]F-T807 positron emission tomography. Multivariable regression models were employed to assess radio-clinical features related to cerebral tau pathology in cerebral amyloid angiopathy. Cerebral amyloid angiopathy exhibited a higher cerebral tau burden in the inferior temporal lobe [1.25 (1.17-1.42) versus 1.08 (1.05-1.22), P < 0.001] and all Braak stage regions of interest (P < 0.05) than hypertensive small vessel disease, although the differences were attenuated after age adjustment. Cerebral tau pathology was significantly associated with cerebral amyloid angiopathy-related vascular markers, including cortical superficial siderosis (β = 0.12, 95% confidence interval 0.04-0.21) and cerebral amyloid angiopathy score (β = 0.12, 95% confidence interval 0.03-0.21) after adjustment for age, ApoE4 status and whole cortex amyloid load. Tau pathology correlated significantly with cognitive score (Spearman's ρ=-0.56, P = 0.001) and hippocampal volume (-0.49, P = 0.007), even after adjustment. In conclusion, tau pathology is more frequent in sporadic cerebral amyloid angiopathy than in hypertensive small vessel disease. Cerebral amyloid angiopathy-related vascular pathologies, especially cortical superficial siderosis, are potential markers of cerebral tau pathology suggestive of concomitant Alzheimer's disease.

RevDate: 2024-04-19

Miles G, Smith M, Zook N, et al (2024)

EM-COGLOAD: An investigation into age and cognitive load detection using eye tracking and deep learning.

Computational and structural biotechnology journal, 24:264-280.

Alzheimer's Disease is the most prevalent neurodegenerative disease, and is a leading cause of disability among the elderly. Eye movement behaviour demonstrates potential as a non-invasive biomarker for Alzheimer's Disease, with changes detectable at an early stage after initial onset. This paper introduces a new publicly available dataset: EM-COGLOAD (available at https://osf.io/zjtdq/, DOI: 10.17605/OSF.IO/ZJTDQ). A dual-task paradigm was used to create effects of declined cognitive performance in 75 healthy adults as they carried out visual tracking tasks. Their eye movement was recorded, and time series classification of the extracted eye movement traces was explored using a range of deep learning techniques. The results of this showed that convolutional neural networks were able to achieve an accuracy of 87.5% when distinguishing between eye movement under low and high cognitive load, and 76% when distinguishing between the oldest and youngest age groups.

RevDate: 2024-04-19

Rana V, Ghosh S, Bhatt A, et al (2024)

N-Methyl-D-Aspartate (NMDA) Receptor Antagonists and Their Pharmacological Implication: A Medicinal Chemistry-Oriented Perspective Outline.

Current medicinal chemistry pii:CMC-EPUB-139809 [Epub ahead of print].

N-methyl-D-aspartate (NMDA) receptors, i.e., inotropic glutamate receptors, are important in synaptic plasticity, brain growth, memory, and learning. The activation of NMDA is done by neurotransmitter glutamate and co-agonist (glycine or D-serine) binding. However, the over-activation of NMDA elevates the intracellular calcium influx, which causes various neurological diseases and disorders. Therefore, to prevent excitotoxicity and neuronal death, inhibition of NMDA must be done using its antagonist. This review delineates the structure of subunits of NMDA and the conformational changes induced after the binding of agonists (glycine and D-serine) and antagonists (ifenprodil, etc.). Additionally, reported NMDA antagonists from different sources, such as synthetic, semisynthetic, and natural resources, are explained by their mechanism of action and pharmacological role. The comprehensive report also addresses the chemical spacing of NMDA inhibitors and in-vivo and in-vitro models to test NMDA antagonists. Since the Blood-Brain Barrier (BBB) is the primary membrane that prevents the penetration of a wide variety of drug molecules, we also elaborate on the medicinal chemistry approach to improve the effectiveness of their antagonists.

RevDate: 2024-04-18

Li T, Hu Z, Qiao L, et al (2024)

Chronic kidney disease and cognitive performance: NHANES 2011-2014.

BMC geriatrics, 24(1):351.

PURPOSE: Previous studies suggest an association between chronic kidney disease (CKD) and cognitive impairment. The purpose of this study was to explore the association between the diverse stages of CKD and the cognitive performance of elderly American adults.

METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 were used. Multivariate adjusted logistic regression, subgroup analysis, and the restricted cubic spline model were used to assess the associations of CKD stage and estimated glomerular filtration rate (eGFR) with cognitive performance. The measures used to evaluate cognitive function included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, the Animal Fluency test, and the Digit Symbol Substitution test (DSST).

RESULTS: This study included 2234 participants aged ≥ 60 years. According to the fully adjusted model, stages 3-5 CKD were significantly associated with the CERAD test score (OR = 0.70, 95% CI [0.51, 0.97], p = 0.033), the Animal Fluency test score (OR = 0.64, 95% CI [0.48, 0.85], p = 0.005), and the DSST score (OR = 0.60, 95% CI [0.41, 0.88], p = 0.013). In addition, the incidence of poor cognitive function increased with decreasing eGFR, especially for individuals with low and moderate eGFRs. Both the DSST score (p nonlinearity < 0.0001) and the Animal Fluency test score (p nonlinearity = 0.0001) had nonlinear dose-response relationships with the eGFR. However, a linear relationship was shown between the eGFR and CERAD test score (p nonlinearity = 0.073).

CONCLUSIONS: CKD, especially stages3-5 CKD, was significantly associated with poor cognitive performance in terms of executive function, learning, processing speed, concentration, and working memory ability. All adults with CKD should be screened for cognitive impairment.

RevDate: 2024-04-18

Alp S, Akan T, Bhuiyan MS, et al (2024)

Joint transformer architecture in brain 3D MRI classification: its application in Alzheimer's disease classification.

Scientific reports, 14(1):8996.

Alzheimer's disease (AD), a neurodegenerative disease that mostly affects the elderly, slowly impairs memory, cognition, and daily tasks. AD has long been one of the most debilitating chronic neurological disorders, affecting mostly people over 65. In this study, we investigated the use of Vision Transformer (ViT) for Magnetic Resonance Image processing in the context of AD diagnosis. ViT was utilized to extract features from MRIs, map them to a feature sequence, perform sequence modeling to maintain interdependencies, and classify features using a time series transformer. The proposed model was evaluated using ADNI T1-weighted MRIs for binary and multiclass classification. Two data collections, Complete 1Yr 1.5T and Complete 3Yr 3T, from the ADNI database were used for training and testing. A random split approach was used, allocating 60% for training and 20% for testing and validation, resulting in sample sizes of (211, 70, 70) and (1378, 458, 458), respectively. The performance of our proposed model was compared to various deep learning models, including CNN with BiL-STM and ViT with Bi-LSTM. The suggested technique diagnoses AD with high accuracy (99.048% for binary and 99.014% for multiclass classification), precision, recall, and F-score. Our proposed method offers researchers an approach to more efficient early clinical diagnosis and interventions.

RevDate: 2024-04-18

Rachmian N, Medina S, Cherqui U, et al (2024)

Identification of senescent, TREM2-expressing microglia in aging and Alzheimer's disease model mouse brain.

Nature neuroscience [Epub ahead of print].

Alzheimer's disease (AD) and dementia in general are age-related diseases with multiple contributing factors, including brain inflammation. Microglia, and specifically those expressing the AD risk gene TREM2, are considered important players in AD, but their exact contribution to pathology remains unclear. In this study, using high-throughput mass cytometry in the 5×FAD mouse model of amyloidosis, we identified senescent microglia that express high levels of TREM2 but also exhibit a distinct signature from TREM2-dependent disease-associated microglia (DAM). This senescent microglial protein signature was found in various mouse models that show cognitive decline, including aging, amyloidosis and tauopathy. TREM2-null mice had fewer microglia with a senescent signature. Treating 5×FAD mice with the senolytic BCL2 family inhibitor ABT-737 reduced senescent microglia, but not the DAM population, and this was accompanied by improved cognition and reduced brain inflammation. Our results suggest a dual and opposite involvement of TREM2 in microglial states, which must be considered when contemplating TREM2 as a therapeutic target in AD.

RevDate: 2024-04-18

Petit P, Gondard E, Gandon G, et al (2024)

Correction: Agricultural activities and risk of Alzheimer's disease: the TRACTOR project, a nationwide retrospective cohort study.

RevDate: 2024-04-18

Crespo L, Sede Lucena B, Martínez FG, et al (2024)

Selenium bioactive compounds produced by beneficial microbes.

Advances in applied microbiology, 126:63-92.

Selenium (Se) is an essential trace element present as selenocysteine (SeCys) in selenoproteins, which have an important role in thyroid metabolism and the redox system in humans. Se deficiency affects between 500 and 1000 million people worldwide. Increasing Se intake can prevent from bacterial and viral infections. Se deficiency has been associated with cancer, Alzheimer, Parkinson, decreased thyroid function, and male infertility. Se intake depends on the food consumed which is directly related to the amount of Se in the soil as well as on its availability. Se is unevenly distributed on the earth's crust, being scarce in some regions and in excess in others. The easiest way to counteract the symptoms of Se deficiency is to enhance the Se status of the human diet. Se salts are the most toxic form of Se, while Se amino acids and Se-nanoparticles (SeNPs) are the least toxic and most bio-available forms. Some bacteria transform Se salts into these Se species. Generally accepted as safe selenized microorganisms can be directly used in the manufacture of selenized fermented and/or probiotic foods. On the other hand, plant growth-promoting bacteria and/or the SeNPs produced by them can be used to promote plant growth and produce crops enriched with Se. In this chapter we discuss bacterial Se metabolism, the effect of Se on human health, the applications of SeNPs and Se-enriched bacteria, as well as their effect on food fortification. Different strategies to counteract Se deficiency by enriching foods using sustainable strategies and their possible implications for improving human health are discussed.

RevDate: 2024-04-18

Frye BM, Negrey JD, Johnson CSC, et al (2024)

Mediterranean diet protects against a neuroinflammatory cortical transcriptome: Associations with brain volumetrics, peripheral inflammation, social isolation, and anxiety in nonhuman primates (Macaca fascicularis).

Brain, behavior, and immunity pii:S0889-1591(24)00361-1 [Epub ahead of print].

Mediterranean diets may be neuroprotective and prevent cognitive decline relative to Western diets, however the underlying biology is poorly understood. We assessed the effects of Western versus Mediterranean-like diets on RNAseq-generated transcriptional profiles in lateral temporal cortex and their relationships with longitudinal changes in neuroanatomy, circulating monocyte gene expression, and observations of social isolation and anxiety in 38 socially-housed, middle-aged female cynomolgus macaques (Macaca fascicularis). Diet resulted in differential expression of seven transcripts (FDR < 0.05). Cyclin dependent kinase 14 (CDK14), a proinflammatory regulator, was lower in the Mediterranean group. The remaining six transcripts [i.e., "lunatic fringe" (LFNG), mannose receptor C type 2 (MRC2), solute carrier family 3 member 2 (SLCA32), butyrophilin subfamily 2 member A1 (BTN2A1), katanin regulatory subunit B1 (KATNB1), and transmembrane protein 268 (TMEM268)] were higher in cortex of the Mediterranean group and generally associated with anti-inflammatory/neuroprotective pathways. KATNB1 encodes a subcomponent of katanin, important in maintaining microtubule homeostasis. BTN2A1 is involved in immunomodulation of γδ T-cells which have anti-neuroinflammatory and neuroprotective effects. CDK14, LFNG, MRC2, and SLCA32 are associated with inflammatory pathways. The latter four differentially expressed cortex transcripts were associated with peripheral monocyte transcript levels, neuroanatomical changes determined by MRI, and with social isolation and anxiety. These results provide important insights into the potential mechanistic processes linking diet, peripheral and central inflammation, and behavior. Collectively, our results provide evidence that, relative to Western diets, Mediterranean diets confer protection against peripheral and central inflammation which is reflected in preserved brain structure and socioemotional behavior. Ultimately, such protective effects may confer resilience to the development of neuropathology and associated disease.

RevDate: 2024-04-18

Park JE, Chaudhary CL, Bhattarai D, et al (2024)

Brain-Permeable Immunoproteasome-Targeting Macrocyclic Peptide Epoxyketones for Alzheimer's Disease.

Journal of medicinal chemistry [Epub ahead of print].

Previously, we demonstrated that linear peptide epoxyketones targeting the immunoproteasome (iP) could ameliorate cognitive deficits in mouse models of Alzheimer's disease (AD) independently of amyloid deposition. We also reported the first iP-targeting macrocyclic peptide epoxyketones, which exhibit improved metabolic stability compared with their linear counterparts. Here, we prepared additional macrocyclic peptide epoxyketones and compared them with existing macrocyclic iP inhibitors by assessing Caco2 cell-based permeability and microsomal stability, providing the four best macrocyclic iP inhibitors. We then evaluated the four compounds using the Ames test and the potency assays in BV2 cells, selecting compound 5 as our AD drug lead. When 5 was administered intravenously (40 mg/kg) or orally (150 mg/kg) into healthy BALB/c mice, we observed considerable iP inhibition in the mouse brain, indicating good blood-brain barrier permeability and target engagement. Combined results suggest that 5 is a promising AD drug lead that may need further investigation.

RevDate: 2024-04-18

Mei N, Liang J, McRae DM, et al (2024)

Localized surface plasmon resonance and atomic force microscopy study of model lipid membranes and their interactions with amyloid and melatonin.

Nanotechnology [Epub ahead of print].

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid plaques in the brain. The toxicity of amyloid to neuronal cell surfaces arises from interactions between small intermediate aggregates, namely amyloid oligomers, and the cell membrane. The nature of these interactions changes with age and disease progression. In our previous work, we demonstrated that both membrane composition and nanoscale structure play crucial roles in amyloid-membrane interactions. In our previous work, we demonstrated that both membrane composition and nanoscale structure play crucial roles in amyloid toxicity, and that membrane models mimicking healthy neuron were less affected by amyloid than model membranes mimicking AD neuronal membranes. This understanding introduces the possibility of modifying membrane properties with membrane-active molecules, such as melatonin, to protect them from amyloid-induced damage. In the present study, we employed atomic force microscopy (AFM) and localized surface plasmon resonance (LSPR) to investigate the protective effects of melatonin. We utilized synthetic lipid membranes that mimic the neuronal cellular membrane at various stages of AD and explored their interactions with amyloid-β (1-42) in the presence of melatonin. Our findings reveal that the early diseased membrane model is particularly vulnerable to amyloid binding and subsequent damage. However, melatonin exerts its most potent protective effect on this early-stage membrane. These results suggest that melatonin could act at the membrane level to alleviate amyloid toxicity, offering the most protection during the initial stages of AD.

RevDate: 2024-04-18

Durham PG, Butnariu A, Alghorazi R, et al (2024)

Current clinical investigations of focused ultrasound blood-brain barrier disruption: A review.

Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 21(3):e00352 pii:S1878-7479(24)00038-2 [Epub ahead of print].

The blood-brain barrier (BBB) presents a formidable challenge in delivering therapeutic agents to the central nervous system. Ultrasound-mediated BBB disruption has emerged as a promising non-invasive technique to enhance drug delivery to the brain. This manuscript reviews fundamental principles of ultrasound-based techniques and their mechanisms of action in temporarily permeabilizing the BBB. Clinical trials employing ultrasound for BBB disruption are discussed, summarizing diverse applications ranging from the treatment of neurodegenerative diseases to targeted drug delivery for brain tumors. The review also addresses safety considerations, outlining the current understanding of potential risks and mitigation strategies associated with ultrasound exposure, including real-time monitoring and assessment of treatment efficacy. Among the large number of studies, significant successes are highlighted thus providing perspective on the future direction of the field.

RevDate: 2024-04-18

Morales K, Adewuyi M, Johnson C, et al (2024)

The effect of combining an e-learning module with s Virtual Dementia Tour® on knowledge and attitudes toward person-centered dementia care in prelicensure nursing education.

Nurse education in practice, 77:103951 pii:S1471-5953(24)00080-5 [Epub ahead of print].

BACKGROUND: Due to the global prevalence of dementia the U. S. Department of Health and Human Services' National Plan to Address Alzheimer's Disease recommended that healthcare professionals prepare to address the complex needs of people with dementia. To address this gap, nursing programs adopted experiential learning methods. While such methodologies are increasingly used, limited evidence exists to inform best teaching practices.

PURPOSE: This study evaluated the combined effect of an e-learning module with a virtual simulation on nursing students' knowledge and attitudes of dementia.

METHODS: The study followed quasi-experimental design with a cross-over and pretest/posttest design. A convenience sample of nursing students was recruited from three public universities in the Southeast United States.

RESULTS: Significant improvements in attitudes toward people with dementia were found in students with previous dementia care experience or those employed to provide services to people with dementia. Experience was a stronger predictor of attitudes than education. However, the reliability of the Dementia Knowledge Assessment Scale was not sufficient in this study.

SIGNIFICANCE: The findings may inform best practices in nursing education to prepare graduates to provide quality care for people with dementia.

RevDate: 2024-04-18

Romano JD, Truong V, Kumar R, et al (2024)

The Alzheimer's Knowledge Base: A Knowledge Graph for Alzheimer Disease Research.

Journal of medical Internet research, 26:e46777 pii:v26i1e46777.

BACKGROUND: As global populations age and become susceptible to neurodegenerative illnesses, new therapies for Alzheimer disease (AD) are urgently needed. Existing data resources for drug discovery and repurposing fail to capture relationships central to the disease's etiology and response to drugs.

OBJECTIVE: We designed the Alzheimer's Knowledge Base (AlzKB) to alleviate this need by providing a comprehensive knowledge representation of AD etiology and candidate therapeutics.

METHODS: We designed the AlzKB as a large, heterogeneous graph knowledge base assembled using 22 diverse external data sources describing biological and pharmaceutical entities at different levels of organization (eg, chemicals, genes, anatomy, and diseases). AlzKB uses a Web Ontology Language 2 ontology to enforce semantic consistency and allow for ontological inference. We provide a public version of AlzKB and allow users to run and modify local versions of the knowledge base.

RESULTS: AlzKB is freely available on the web and currently contains 118,902 entities with 1,309,527 relationships between those entities. To demonstrate its value, we used graph data science and machine learning to (1) propose new therapeutic targets based on similarities of AD to Parkinson disease and (2) repurpose existing drugs that may treat AD. For each use case, AlzKB recovers known therapeutic associations while proposing biologically plausible new ones.

CONCLUSIONS: AlzKB is a new, publicly available knowledge resource that enables researchers to discover complex translational associations for AD drug discovery. Through 2 use cases, we show that it is a valuable tool for proposing novel therapeutic hypotheses based on public biomedical knowledge.

RevDate: 2024-04-18

Rodríguez-Vidal L, Alcauter S, FA Barrios (2024)

The functional connectivity of the human claustrum, according to the Human Connectome Project database.

PloS one, 19(4):e0298349.

The claustrum is an irregular and fine sheet of grey matter in the basolateral telencephalon present in almost all mammals. The claustrum has been the object of several studies using animal models and, more recently, in human beings using neuroimaging. One of the most extended cognitive processes attributed to the claustrum is the salience process, which is also related to the insular cortex. In the same way, studies with human subjects and functional magnetic resonance imaging have reported the coactivation of the claustrum/insular cortex in the integration of sensory signals. This coactivation has been reported in the left claustrum/insular cortex or in the right claustrum/insular cortex. The asymmetry has been reported in task studies and literature related to neurological disorders such as Alzheimer's disease and schizophrenia, relating the severity of delusions with the reduction in left claustral volume. We present a functional connectivity study of the claustrum. Resting-state functional and anatomical MRI data from 100 healthy subjects were analyzed; taken from the Human Connectome Project (HCP, NIH Blueprint: The Human Connectome Project), with 2x2x2 mm3 voxel resolution. We hypothesize that 1) the claustrum is a node involved in different brain networks, 2) the functional connectivity pattern of the claustrum is different from the insular cortex's pattern, and 3) the asymmetry is present in the claustrum's functional connectivity. Our findings include at least three brain networks related to the claustrum. We found functional connectivity between the claustrum, frontoparietal network, and the default mode network as a distinctive attribute. The functional connectivity between the right claustrum with the frontoparietal network and the dorsal attention network supports the hypothesis of claustral asymmetry. These findings provide functional evidence, suggesting that the claustrum is coupled with the frontoparietal network serving together to instantiate new task states by flexibly modulating and interacting with other control and processing networks.

RevDate: 2024-04-18

Lacey C, Paterson T, Gawryluk JR, et al (2024)

Impact of APOE-ε alleles on brain structure and cognitive function in healthy older adults: A VBM and DTI replication study.

PloS one, 19(4):e0292576.

BACKGROUND: The Apolipoprotein E (APOE) gene has been established in the Alzheimer's disease (AD) literature to impact brain structure and function and may also show congruent effects in healthy older adults, although findings in this population are much less consistent. The current study aimed to replicate and expand the multimodal approach employed by Honea et al. Structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and neuropsychological measures were used to investigate the impact of APOE-ε status on grey matter structure, white matter integrity, and cognitive functioning.

METHODS: Data were obtained from the Alzheimer's Disease Initiative Phase 3 (ADNI3) database. Baseline MRI, DTI and cognitive composite scores for memory (ADNI-Mem) and executive function (ADNI-EF) were acquired from 116 healthy controls. Participants were grouped according to APOE allele presence (APOE-ε2+ N = 17, APOE-ε3ε3 N = 64, APOE-ε4+ N = 35). Voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) were used to compare grey matter volume (GMV) and white matter integrity, respectively, between APOE-ε2+ and APOE-ε3ε3 controls, and again between APOE-ε4+ and APOE-ε3ε3 controls. Multivariate analysis of covariance (MANCOVA) was used to examine the effects of APOE polymorphism on memory and EF across all APOE groups with age, sex and education as regressors of no interest. Cognitive scores were correlated (Pearson r) with imaging metrics within groups.

RESULTS: No significant differences were seen across groups, within groups in MRI metrics, or cognitive performance (p>0.05, corrected for multiple comparisons).

CONCLUSIONS: The current study partially replicated and extended previous findings from an earlier multimodal study (Honea 2009). Future studies should clarify APOE mechanisms in healthy ageing by adding other imaging, cognitive, and lifestyle metrics and longitudinal design in larger sample sizes.

RevDate: 2024-04-18

Sánchez-Juan P, Valeriano-Lorenzo E, Ruiz-González A, et al (2024)

Serum GFAP levels correlate with astrocyte reactivity, post-mortem brain atrophy and neurofibrillary tangles.

Brain : a journal of neurology pii:7649220 [Epub ahead of print].

Glial fibrillary acidic protein (GFAP), a proxy of astrocyte reactivity, has been proposed as biomarker of Alzheimer's disease. However, there is limited information about the correlation between blood biomarkers and post-mortem neuropathology. In a single-centre prospective clinicopathological cohort of 139 dementia patients, for which the time-frame between GFAP level determination and neuropathological assessment was exceptionally short (on average 139 days), we analysed this biomarker, measured at three time points, in relation to proxies of disease progression such as cognitive decline and brain weight. Most importantly, we investigated the use of blood GFAP to detect the neuropathological hallmarks of Alzheimer's disease, while accounting for potential influences of the most frequent brain co-pathologies. The main findings demonstrated an association between serum GFAP level and post-mortem tau pathology (β = 12.85; P < 0.001) that was independent of amyloid deposits (β = 13.23; P = 0.02). A mediation analysis provided additional support for the role of astrocytic activation as a link between amyloid and tau pathology in Alzheimer's disease. Furthermore, a negative correlation was observed between pre-mortem serum GFAP and brain weight at post-mortem (r = -0.35; P < 0.001). This finding, together with evidence of a negative correlation with cognitive assessments (r = -0.27; P = 0.005), supports the role of GFAP as a biomarker for disease monitoring, even in the late phases of Alzheimer's disease. Moreover, the diagnostic performance of GFAP in advanced dementia patients was explored, and its discriminative power (area under the receiver operator characteristic curve at baseline = 0.91) in differentiating neuropathologically-confirmed Alzheimer's disease dementias from non-Alzheimer's disease dementias was determined, despite the challenging scenario of advanced age and frequent co-pathologies in these patients. Independently of Alzheimer's disease, serum GFAP levels were shown to be associated with two other pathologies targeting the temporal lobes-hippocampal sclerosis (β = 3.64; P = 0.03) and argyrophilic grain disease (β = -6.11; P = 0.02). Finally, serum GFAP levels were revealed to be correlated with astrocyte reactivity, using the brain GFAP-immunostained area as a proxy (ρ = 0.21; P = 0.02). Our results contribute to increasing evidence suggesting a role for blood GFAP as an Alzheimer's disease biomarker, and the findings offer mechanistic insights into the relationship between blood GFAP and Alzheimer's disease neuropathology, highlighting its ties with tau burden. Moreover, the data highlighting an independent association between serum GFAP levels and other neuropathological lesions provide information for clinicians to consider when interpreting test results. The longitudinal design and correlation with post-mortem data reinforce the robustness of our findings. However, studies correlating blood biomarkers and neuropathological assessments are still scant, and further research is needed to replicate and validate these results in diverse populations.

RevDate: 2024-04-18

Limberger C, ER Zimmer (2024)

Blood GFAP reflects astrocyte reactivity to Alzheimer's pathology in post-mortem brain tissue.

Brain : a journal of neurology pii:7649226 [Epub ahead of print].

RevDate: 2024-04-18

André C, Martineau-Dussault MÈ, Baril AA, et al (2024)

REM sleep is reduced in late middle-aged and older APOE4 allele carriers.

Sleep pii:7650434 [Epub ahead of print].

STUDY OBJECTIVES: Apolipoprotein E ɛ4 (APOE4) is the strongest genetic risk factor for Alzheimer's disease (AD). In addition, APOE4 carriers may exhibit sleep disturbances, but conflicting results have been reported, such that there is no clear consensus regarding which aspects of sleep are impacted. Our objective was to compare objective sleep architecture between APOE4 carriers and non-carriers, and to investigate the modulating impact of age, sex, cognitive status and obstructive sleep apnea.

METHODS: 198 dementia-free participants aged >55 years old (mean age: 68.7 ± 8.08 years old, 40.91% women, 41 APOE4 carriers) were recruited in this cross-sectional study. They underwent polysomnography, APOE4 genotyping and a neuropsychological evaluation. ANCOVAs assessed the effect of APOE4 status on sleep architecture, controlling for age, sex, cognitive status and the apnea-hypopnea index. Interaction terms were added between APOE4 status and covariates.

RESULTS: REM sleep percentage (F=9.95, p=0.002, ηp2=0.049) and duration (F=9.23, p=0.003, ηp2=0.047) were lower in APOE4 carriers. The results were replicated in a subsample of 112 participants without moderate-to-severe obstructive sleep apnea. There were no significant interactions between APOE4 status and age, sex, cognitive status and obstructive sleep apnea in the whole sample.

CONCLUSIONS: Our results show that APOE4 carriers exhibit lower REM sleep duration, including in cognitively unimpaired individuals, possibly resulting from early neurodegenerative processes in regions involved in REM sleep generation and maintenance.

RevDate: 2024-04-19
CmpDate: 2024-04-19

Huang Z, He G, Sun S, et al (2024)

Causal relationship of genetically predicted particulate matter 2.5 level with Alzheimer's disease and the mediating effect of dehydroepiandrosterone sulphate.

Annals of human biology, 51(1):2337731.

BACKGROUND: The causal association between particulate matter 2.5 (PM2.5) and Alzheimer's disease (AD) remains inconclusive, and the mediators of the association have yet to be explored.

AIMS: We aimed to assess the potential causal relationship between PM2.5 and AD, and to investigate the mediating role of dehydroepiandrosterone sulphate (DHEAS).

SUBJECTS AND METHODS: We implemented a two-sample Mendelian randomisation (MR) study to examine the genetic predisposition to PM2.5 exposure and its association with AD. The inverse-variance weighted (IVW) method served as the primary analytical tool to estimate the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS: There were 6 and 4 genetic variants associated with DHEAS and PM2.5, respectively. Based on the multivariable MR analysis, we found that after adjusting for DHEAS, each standard deviation increase in PM2.5 was associated with the risk of AD (OR: 2.96, 95% CI: 1.33, 6.58, p = 0.00769). The MR Egger intercept test did not detect horizontal pleiotropy for PM2.5 (P-pleiotropy = 0.879) and DHEAS(P-pleiotropy = 0.941). According to the results of the mediation analysis, DHEAS accounted for 18.3% of the association between PM2.5 and AD.

CONCLUSION: Our findings affirm a significant causal association between PM2.5 exposure and AD, with DHEAS playing a mediating role in this relationship.

RevDate: 2024-04-18

Chai B, Wu Y, Yang H, et al (2024)

Tau Aggregation-Dependent Lipid Peroxide Accumulation Driven by the hsa_circ_0001546/14-3-3/CAMK2D/Tau Complex Inhibits Epithelial Ovarian Cancer Peritoneal Metastasis.

Advanced science (Weinheim, Baden-Wurttemberg, Germany) [Epub ahead of print].

Intraperitoneal dissemination is the main method of epithelial ovarian cancer (EOC) metastasis, which is related to poor prognosis and a high recurrence rate. Circular RNAs (circRNAs) are a novel class of endogenous RNAs with covalently closed loop structures that are implicated in the regulation of tumor development. In this study, hsa_circ_0001546 is downregulated in EOC primary and metastatic tissues vs. control tissues and this phenotype has a favorable effect on EOC OS and DFS. hsa_circ_0001546 can directly bind with 14-3-3 proteins to act as a chaperone molecule and has a limited positive effect on 14-3-3 protein stability. This complex recruits CAMK2D to induce the Ser324 phosphorylation of Tau proteins, changing the phosphorylation status of Tau bound to 14-3-3 and ultimately forming the hsa_circ_0001546/14-3-3/CAMK2D/Tau complex. The existence of this complex stimulates the production of Tau aggregation, which then induces the accumulation of lipid peroxides (LPOs) and causes LPO-dependent ferroptosis. In vivo, treatment with ferrostatin-1 and TRx0237 rescued the inhibitory effect of hsa_circ_0001546 on EOC cell spreading. Therefore, based on this results, ferroptosis caused by Tau aggregation occurs in EOC cells, which is not only in Alzheimer's disease- or Parkinson's disease-related cells and this kind of ferroptosis driven by the hsa_circ_0001546/14-3-3/CAMK2D/Tau complex is LPO-dependent rather than GPX4-dependent is hypothesized.

RevDate: 2024-04-18

Tesi N, van der Lee S, Hulsman M, et al (2024)

Cognitively healthy centenarians are genetically protected against Alzheimer's disease.

Alzheimer's & dementia : the journal of the Alzheimer's Association [Epub ahead of print].

BACKGROUND: Alzheimer's disease (AD) prevalence increases with age, yet a small fraction of the population reaches ages > 100 years without cognitive decline. We studied the genetic factors associated with such resilience against AD.

METHODS: Genome-wide association studies identified 86 single nucleotide polymorphisms (SNPs) associated with AD risk. We estimated SNP frequency in 2281 AD cases, 3165 age-matched controls, and 346 cognitively healthy centenarians. We calculated a polygenic risk score (PRS) for each individual and investigated the functional properties of SNPs enriched/depleted in centenarians.

RESULTS: Cognitively healthy centenarians were enriched with the protective alleles of the SNPs associated with AD risk. The protective effect concentrated on the alleles in/near ANKH, GRN, TMEM106B, SORT1, PLCG2, RIN3, and APOE genes. This translated to >5-fold lower PRS in centenarians compared to AD cases (P = 7.69 × 10[-71]), and 2-fold lower compared to age-matched controls (P = 5.83 × 10[-17]).

DISCUSSION: Maintaining cognitive health until extreme ages requires complex genetic protection against AD, which concentrates on the genes associated with the endolysosomal and immune systems.

HIGHLIGHTS: Cognitively healthy cent enarians are enriched with the protective alleles of genetic variants associated with Alzheimer's disease (AD). The protective effect is concentrated on variants involved in the immune and endolysosomal systems. Combining variants into a polygenic risk score (PRS) translated to > 5-fold lower PRS in centenarians compared to AD cases, and ≈ 2-fold lower compared to middle-aged healthy controls.

RevDate: 2024-04-19
CmpDate: 2024-04-19

Schlein E, Andersson KG, Dallas T, et al (2024)

Reducing neonatal Fc receptor binding enhances clearance and brain-to-blood ratio of TfR-delivered bispecific amyloid-β antibody.

mAbs, 16(1):2339337.

Recent development of amyloid-β (Aβ)-targeted immunotherapies for Alzheimer's disease (AD) have highlighted the need for accurate diagnostic methods. Antibody-based positron emission tomography (PET) ligands are well suited for this purpose as they can be directed toward the same target as the therapeutic antibody. Bispecific, brain-penetrating antibodies can achieve sufficient brain concentrations, but their slow blood clearance remains a challenge, since it prolongs the time required to achieve a target-specific PET signal. Here, two antibodies were designed based on the Aβ antibody bapineuzumab (Bapi) - one monospecific IgG (Bapi) and one bispecific antibody with an antigen binding fragment (Fab) of the transferrin receptor (TfR) antibody 8D3 fused to one of the heavy chains (Bapi-Fab8D3) for active, TfR-mediated transport into the brain. A variant of each antibody was designed to harbor a mutation to the neonatal Fc receptor (FcRn) binding domain, to increase clearance. Blood and brain pharmacokinetics of radiolabeled antibodies were studied in wildtype (WT) and AD mice (App[NL-G-F]). The FcRn mutation substantially reduced blood half-life of both Bapi and Bapi-Fab8D3. Bapi-Fab8D3 showed high brain uptake and the brain-to-blood ratio of its FcRn mutated form was significantly higher in App[NL-G-F] mice than in WT mice 12 h after injection and increased further up to 168 h. Ex vivo autoradiography showed specific antibody retention in areas with abundant Aβ pathology. Taken together, these results suggest that reducing FcRn binding of a full-sized bispecific antibody increases the systemic elimination and could thereby drastically reduce the time from injection to in vivo imaging.

RevDate: 2024-04-18

Andrade SM, de Oliveira Marques CC, de Lucena LC, et al (2024)

Effect of transcranial direct current stimulation and transcranial magnetic stimulation on the cognitive function of individuals with Alzheimer's disease: a systematic review with meta-analysis and meta-regression.

Neurological research [Epub ahead of print].

OBJECTIVE: To analyze the effects of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) on the cognitive function of individuals with Alzheimer's disease (AD).

METHODS: This systematic review with meta-analysis and meta-regression included randomized clinical trials published until 05/2022. We included studies conducted with individuals with AD of both sexes, aged between 55 and 85 years, treated with tDCS, TMS, or both.

RESULTS: Twenty-one studies were included in the systematic review and sixteen in the meta-analysis. Meta-regression suggested a significant influence of anodic tDCS with current intensity of 1.5 mA on cognitive function. Significant results were found with treatment frequencies of three and five days a week for two weeks. Subgroup analysis found that anodic tDCS influences cognitive function, regardless of AD stage. Similar was observed for TMS using a frequency of 20 Hz and current intensity of 90% of the resting motor threshold.

DISCUSSION: Anodal tDCS and 20 Hz TMS have demonstrated the ability to improve cognitive function in AD by modulating neural activity. These therapies are safe and well-tolerated, offering promise as adjuncts to available pharmacological treatments. Studies with greater methodological rigor and parameter standardization are warranted. Comprehensive investigations involving neuroimaging techniques may provide a better understanding of the interaction between induced electrical fields and the complex neural networks affected in AD, paving the way for more personalized and effective neurostimulation approaches.

RevDate: 2024-04-18

Wang J, Huang Q, He K, et al (2024)

Presynaptic density determined by SV2A PET is closely associated with postsynaptic metabotropic glutamate receptor 5 availability and independent of amyloid pathology in early cognitive impairment.

Alzheimer's & dementia : the journal of the Alzheimer's Association [Epub ahead of print].

INTRODUCTION: Metabotropic glutamate receptor 5 (mGluR5) is involved in regulating integrative brain function and synaptic transmission. Aberrant mGluR5 signaling and relevant synaptic failure play a key role in the pathophysiological mechanism of Alzheimer's disease (AD).

METHODS: Ten cognitively impaired (CI) individuals and 10 healthy controls (HCs) underwent [[18]F]SynVesT-1 and [[18]F]PSS232 positron emission tomography (PET)/magnetic resonance to assess synaptic density and mGluR5 availability. The associations between mGluR5 availability and synaptic density were examined. A mediation analysis was performed to investigate the possible mediating effects of mGluR5 availability and synaptic loss on the relationship between amyloid deposition and cognition.

RESULTS: CI patients exhibited lower mGluR5 availability and synaptic density in the medial temporal lobe than HCs. Regional synaptic density was closely associated with regional mGluR5 availability. mGluR5 availability and synaptic loss partially mediated the relationship between amyloid deposition and cognition.

CONCLUSIONS: Reductions in mGluR5 availability and synaptic density exhibit similar spatial patterns in AD and are closely linked.

HIGHLIGHTS: Cognitively impaired patients exhibited lower mGluR5 availability and synaptic density in the medial temporal lobe than HCs. Reductions in mGluR5 availability and synaptic density exhibit similar spatial patterns in AD. Regional synaptic density was closely associated with regional mGluR5 availability. mGluR5 availability and synaptic loss partially mediated the relationship between amyloid deposition and global cognition. With further research, modulating mGluR5 availability might be a potential therapeutic strategy for improving synaptic function in AD.

RevDate: 2024-04-19
CmpDate: 2024-04-19

Akkaya D, Seyhan G, Sari S, et al (2024)

In vitro and in silico investigation of FDA-approved drugs to be repurposed against Alzheimer's disease.

Drug development research, 85(3):e22184.

Alzheimer's disease (AD), one of the main causes of dementia, is a neurodegenerative disorder. Cholinesterase inhibitors are used in the treatment of AD, but prolonged use of these drugs can lead to serious side effects. Drug repurposing is an approach that aims to reveal the effectiveness of drugs in different diseases beyond their clinical uses. In this work, we investigated in vitro and in silico inhibitory effects of 11 different drugs on cholinesterases. The results showed that trimebutine, theophylline, and levamisole had the highest acetylcholinesterase inhibitory actions among the tested drugs, and these drugs inhibited by 68.70 ± 0.46, 53.25 ± 3.40, and 44.03 ± 1.20%, respectively at 1000 µM. In addition, these drugs are bound to acetylcholinesterase via competitive manner. Molecular modeling predicted good fitness in acetylcholinesterase active site for these drugs and possible central nervous system action for trimebutine. All of these results demonstrated that trimebutine was determined to be the drug with the highest potential for use in AD.

RevDate: 2024-04-18

Yoshida K, Forrest SL, Ichimata S, et al (2024)

Revisiting the relevance of Hirano bodies in neurodegenerative diseases.

Neuropathology and applied neurobiology, 50(2):e12978.

AIMS: Hirano bodies (HBs) are eosinophilic pathological structures with two morphological phenotypes commonly found in the hippocampal CA1 region in Alzheimer's disease (AD). This study evaluated the prevalence and distribution of HBs in AD and other neurodegenerative diseases.

METHODS: This cross-sectional study systematically evaluated HBs in a cohort of 193 cases with major neurodegenerative diseases, including AD (n = 91), Lewy body disease (LBD, n = 87), progressive supranuclear palsy (PSP, n = 36), multiple system atrophy (MSA, n = 14) and controls (n = 26). The prevalence, number and morphology of HBs in the stratum lacunosum (HBL) and CA1 pyramidal cell layer were examined. In addition, we investigated the presence of HBs in five additional hippocampal subregions.

RESULTS: The morphological types of HBs in CA1 were divided into three, including a newly discovered type, and were evaluated separately, with their morphology confirmed in three dimensions: (1) classic rod-shaped HB (CHB), (2) balloon-shaped HB (BHB) and the newly described (3) string-shaped HB (SHB). The prevalence of each HB type differed between disease groups: Compared with controls, for CHB in AD, AD + LBD, PSP and corticobasal degeneration, for BHB in AD + LBD and PSP, and SHB in AD + LBD and PSP were significantly increased. Regression analysis showed that CHBs were independently associated with higher Braak NFT stage, BHBs with LBD and TDP-43 pathology, SHBs with higher Braak NFT stage, PSP and argyrophilic grain disease and HBLs with MSA.

CONCLUSIONS: This study demonstrates that HBs are associated with diverse neurodegenerative diseases and shows that morphological types appear distinctively in various conditions.

RevDate: 2024-04-18

Rinaldi M, Pezone A, Quadrini GI, et al (2024)

Targeting shared pathways in tauopathies and age-related macular degeneration: implications for novel therapies.

Frontiers in aging neuroscience, 16:1371745.

The intricate parallels in structure and function between the human retina and the central nervous system designate the retina as a prospective avenue for understanding brain-related processes. This review extensively explores the shared physiopathological mechanisms connecting age-related macular degeneration (AMD) and proteinopathies, with a specific focus on tauopathies. The pivotal involvement of oxidative stress and cellular senescence emerges as key drivers of pathogenesis in both conditions. Uncovering these shared elements not only has the potential to enhance our understanding of intricate neurodegenerative diseases but also sets the stage for pioneering therapeutic approaches in AMD.

RevDate: 2024-04-18

Imtiaz A, Shimonaka S, Uddin MN, et al (2024)

Selection of lansoprazole from an FDA-approved drug library to inhibit the Alzheimer's disease seed-dependent formation of tau aggregates.

Frontiers in aging neuroscience, 16:1368291.

The efficacy of current treatments is still insufficient for Alzheimer's disease (AD), the most common cause of Dementia. Out of the two pathological hallmarks of AD amyloid-β plaques and neurofibrillary tangles, comprising of tau protein, tau pathology strongly correlates with the symptoms of AD. Previously, screening for inhibitors of tau aggregation that target recombinant tau aggregates have been attempted. Since a recent cryo-EM analysis revealed distinct differences in the folding patterns of heparin-induced recombinant tau filaments and AD tau filaments, this study focused on AD seed-dependent tau aggregation in drug repositioning for AD. We screened 763 compounds from an FDA-approved drug library using an AD seed-induced tau aggregation in SH-SY5Y cell-based assay. In the first screening, 180 compounds were selected, 72 of which were excluded based on the results of lactate dehydrogenase assay. In the third screening with evaluations of soluble and insoluble tau, 38 compounds were selected. In the fourth screening with 3 different AD seeds, 4 compounds, lansoprazole, calcipotriene, desogestrel, and pentamidine isethionate, were selected. After AD seed-induced real-time quaking-induced conversion, lansoprazole was selected as the most suitable drug for repositioning. The intranasal administration of lansoprazole for 4 months to AD seed-injected mice improved locomotor activity and reduced both the amount of insoluble tau and the extent of phosphorylated tau-positive areas. Alanine replacement of the predicted binding site to an AD filament indicated the involvement of Q351, H362, and K369 in lansoprazole and C-shaped tau filaments. These results suggest the potential of lansoprazole as a candidate for drug repositioning to an inhibitor of tau aggregate formation in AD.

RevDate: 2024-04-18

Kong J, Lin X, Wang B, et al (2024)

Physical activity may a probably protective factor for postoperative delirium: the PNDABLE study.

Frontiers in aging neuroscience, 16:1353449.

OBJECTIVE: This study aims to explore the relationship between physical activity (PA) and postoperative delirium (POD).

METHODS: We selected 400 patients from the Perioperative Neurocognitive Disorder and Biomarkers Lifestyle (PNDABLE) database, and the patients in the PNDABLE database were sampled and tested Alzheimer's biomarkers. The diagnosis of POD was made using the Confusion Assessment Scale (CAM) and the severity was assessed using Memorial Delirium Assessment Scale (MDAS). Mini-Mental State Examination (MMSE) scale was used to detect the mental state of the patients. Enzyme-linked immunosorbent assay (ELISA) was used to detect the level of preoperative cerebrospinal fluid (CSF) biomarkers, such as amyloid β plaque 42 (Aβ42), total tau protein (T-tau), and phosphorylated tau protein (P-tau). Logistic regression, sensitivity analysis, and post hoc analysis were used to explore the relationship between risk and protective factors on POD. We used the mediating effect to explore whether PA mediates the occurrence of POD through CSF biomarkers.

RESULTS: The incidence of POD was 17.5%. According to our research, the consequence prompted that PA might be the protective factor for POD [odds ratio (OR): 0.336, 95% confidence interval (95 CI) 0.206-0.548, P < 0.001]. The result of logistic regression revealed that CSF biomarker Aβ42 (OR: 0.997, 95 CI 0.996-0.999, P < 0.001) might be a protective factor against POD, and the T-tau (OR: 1.006, 95 CI 1.003-1.009, P = 0.001) and P-tau (OR: 1.039, 95 CI 1.018-1.059, P < 0.001) might risk factors for POD. Sensitivity analysis confirmed the correlation between PA and CSF biomarkers in the patients with POD. Mediation effect analysis showed that PA may reduce the occurrence of POD partly through CSF biomarkers, such as Aβ42 (proportion: 11%, P < 0.05), T-tau (proportion: 13%, P < 0.05), and P-tau (proportion: 12%, P < 0.05).

CONCLUSION: Physical activity is probably a protective factor for POD and may exert a mediating effect through CSF biomarkers.

RevDate: 2024-04-18

Singh SP, Gupta S, JC Rajapakse (2024)

Sparse Deep Neural Network for Encoding and Decoding the Structural Connectome.

IEEE journal of translational engineering in health and medicine, 12:371-381.

Brain state classification by applying deep learning techniques on neuroimaging data has become a recent topic of research. However, unlike domains where the data is low dimensional or there are large number of available training samples, neuroimaging data is high dimensional and has few training samples. To tackle these issues, we present a sparse feedforward deep neural architecture for encoding and decoding the structural connectome of the human brain. We use a sparsely connected element-wise multiplication as the first hidden layer and a fixed transform layer as the output layer. The number of trainable parameters and the training time is significantly reduced compared to feedforward networks. We demonstrate superior performance of this architecture in encoding the structural connectome implicated in Alzheimer's disease (AD) and Parkinson's disease (PD) from DTI brain scans. For decoding, we propose recursive feature elimination (RFE) algorithm based on DeepLIFT, layer-wise relevance propagation (LRP), and Integrated Gradients (IG) algorithms to remove irrelevant features and thereby identify key biomarkers associated with AD and PD. We show that the proposed architecture reduces 45.1% and 47.1% of the trainable parameters compared to a feedforward DNN with an increase in accuracy by 2.6 % and 3.1% for cognitively normal (CN) vs AD and CN vs PD classification, respectively. We also show that the proposed RFE method leads to a further increase in accuracy by 2.1% and 4% for CN vs AD and CN vs PD classification, while removing approximately 90% to 95% irrelevant features. Furthermore, we argue that the biomarkers (i.e., key brain regions and connections) identified are consistent with previous literature. We show that relevancy score-based methods can yield high discriminative power and are suitable for brain decoding. We also show that the proposed approach led to a reduction in the number of trainable network parameters, an increase in classification accuracy, and a detection of brain connections and regions that were consistent with earlier studies.

RevDate: 2024-04-18

Salmon E, Lekeu F, Quittre A, et al (2024)

Awareness and cognitive rehabilitation in Alzheimer's disease and frontotemporal dementia.

Alzheimer's & dementia (New York, N. Y.), 10(2):e12469.

INTRODUCTION: Awareness influences the evolution of neurodegenerative dementias. We gathered participants' and caregivers assessments of dependence in daily activities and we studied how each score would be related to next year participant autonomy, independently of other explicative variables.

METHOD: We retrospectively analyzed data from mildly demented participants with a clinical diagnosis of Alzheimer's disease (AD, n = 186) and frontotemporal dementia (FTD, n = 29) and their relatives. A research tool was used to assess participant dependence in 98 daily activities and associated caregiver burden. A discrepancy score between the patient's and relative's judgment was calculated to evaluate awareness of dependence in activities at baseline. This dependence scores, as well as sex, age, education, and 1 year difference in Mini-Mental State Examination were taken as possible explicative variables for dependence in activities adapted by therapists during a 1-year cognitive rehabilitation program.

RESULTS: Patients with FTD showed less awareness for daily dependence (discrepancy 20.9% vs. 11.8% in AD). Both groups benefited from cognitive rehabilitation (25% decrease in dependence) and subjective burden of relatives was decreased in both groups. In the AD group, there was a significant positive relationship between both caregiver (P < 0.001) and participant's (P < 0.02) evaluation of dependence in daily activities at inclusion and dependence of participants in adapted activities after 1 year.

DISCUSSION: Awareness of impairment in daily activities is a clinical symptom that is more important at inclusion in FTD than in AD. However, in participants with AD who, as a group, significantly benefit from a cognitive rehabilitation program, not only caregiver's but also participant's assessment of dependence at baseline is correlated to subsequent, next year greater dependence in daily activities adapted by the therapists. Although discrepant, both caregiver and participant evaluations appear to be important variables to understand the evolution and the benefit of care in participants at early stages of dementia.

RevDate: 2024-04-17

Liu J, Wu H, Robertson DH, et al (2024)

Text mining and portal development for gene-specific publications on Alzheimer's disease and other neurodegenerative diseases.

BMC medical informatics and decision making, 24(Suppl 3):98.

BACKGROUND: Tremendous research efforts have been made in the Alzheimer's disease (AD) field to understand the disease etiology, progression and discover treatments for AD. Many mechanistic hypotheses, therapeutic targets and treatment strategies have been proposed in the last few decades. Reviewing previous work and staying current on this ever-growing body of AD publications is an essential yet difficult task for AD researchers.

METHODS: In this study, we designed and implemented a natural language processing (NLP) pipeline to extract gene-specific neurodegenerative disease (ND) -focused information from the PubMed database. The collected publication information was filtered and cleaned to construct AD-related gene-specific publication profiles. Six categories of AD-related information are extracted from the processed publication data: publication trend by year, dementia type occurrence, brain region occurrence, mouse model information, keywords occurrence, and co-occurring genes. A user-friendly web portal is then developed using Django framework to provide gene query functions and data visualizations for the generalized and summarized publication information.

RESULTS: By implementing the NLP pipeline, we extracted gene-specific ND-related publication information from the abstracts of the publications in the PubMed database. The results are summarized and visualized through an interactive web query portal. Multiple visualization windows display the ND publication trends, mouse models used, dementia types, involved brain regions, keywords to major AD-related biological processes, and co-occurring genes. Direct links to PubMed sites are provided for all recorded publications on the query result page of the web portal.

CONCLUSION: The resulting portal is a valuable tool and data source for quick querying and displaying AD publications tailored to users' interested research areas and gene targets, which is especially convenient for users without informatic mining skills. Our study will not only keep AD field researchers updated with the progress of AD research, assist them in conducting preliminary examinations efficiently, but also offers additional support for hypothesis generation and validation which will contribute significantly to the communication, dissemination, and progress of AD research.

RevDate: 2024-04-17

Dai T, Lou J, Kong D, et al (2024)

Choroid plexus enlargement in amyotrophic lateral sclerosis patients and its correlation with clinical disability and blood-CSF barrier permeability.

Fluids and barriers of the CNS, 21(1):36.

BACKGROUND: Using in vivo neuroimaging techniques, growing evidence has demonstrated that the choroid plexus (CP) volume is enlarged in patients with several neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. However, although animal and postmortem findings suggest that CP abnormalities are likely important pathological mechanisms underlying amyotrophic lateral sclerosis (ALS), the third most common neurodegenerative disease, no available study has been conducted to thoroughly assess CP abnormalities and their clinical relevance in vivo in ALS patients to date. Thus, we aimed to determine whether in vivo CP enlargement may occur in ALS patients. We also aimed to identify the relationships of CP volume with clinical disabilities and blood-CSF barrier (BCSFB) permeability in ALS patients.

METHODS: In this retrospective study, based on structural MRI data, CP volume was assessed using a Gaussian mixture model and underwent further manual correction in 155 ALS patients and 105 age- and sex-matched HCs from October 2021 to April 2023. The ALS Functional Rating Scale-Revised (ALSFRS-R) was used to assess clinical disability. The CSF/serum albumin quotient (Qalb) was used to assess BCSFB permeability. Moreover, all the ALS patients completed genetic testing, and according to genetic testing, the ALS patients were further divided into genetic ALS subgroup and sporadic ALS subgroup.

RESULTS: We found that compared with HCs, ALS patients had a significantly higher CP volume (p < 0.001). Moreover, compared with HCs, CP volume was significantly increased in both ALS patients with and without known genetic mutations after family-wise error correction (p = 0.006 and p < 0.001, respectively), while there were no significant differences between the two ALS groups. Furthermore, the CP volume was significantly correlated with the ALSFRS-r score (r = -0.226; p = 0.005) and the Qalb (r = 0.479; p < 0.001) in ALS patients.

CONCLUSION: Our study first demonstrates CP enlargement in vivo in ALS patients, and continues to suggest an important pathogenetic role for CP abnormalities in ALS. Moreover, assessing CP volume is likely a noninvasive and easy-to-implement approach for screening BCSFB dysfunction in ALS patients.

RevDate: 2024-04-17

Zhang Y, Jia Z, Wang J, et al (2024)

Research Hotspots and Frontiers of Alzheimer's Disease and Gut Microbiota: A Knowledge Mapping and Text Mining Analysis.

Molecular neurobiology [Epub ahead of print].

Gut microbiota has been confirmed to be closely related to Alzheimer's disease (AD). Research on gut microbiota and AD has also increased significantly. This study aimed to conduct a bibliometric and visual analysis of published studies related to gut microbiota and AD. Based on the Web of Science Core Collection SCI-Expanded database, we utilize Excel 2019 and visualization analysis tools VOSviewer, Co-Occurrence13.2 (COOC13.2), Citespace, HistCite, and Bibliometrix (R-Tool of R-Studio) for analysis. A total of 1093 related kinds of literature were included, and the number of papers presented an overall increasing trend. The country/region with the most publications is China, the institution is Zhejiang University, the author is Walter J Lukiw from the USA, and the journal is the Journal of Alzheimer's Disease. Hotspot research areas include the relationship between gut microbiota metabolism and AD, AD treatments related to the gut microbiota, and diseases related to AD and gut microbiota. The future research direction may be T cells, NLRP3 inflammasome, and Porphyromonas gingivalis. Studies on AD and gut microbiota have grown rapidly in recent years. Our research results may provide valuable references for readers and help researchers better find new research directions in the future.

RevDate: 2024-04-17

Da Mesquita S, R Rua (2024)

Brain border-associated macrophages: common denominators in infection, aging, and Alzheimer's disease?.

Trends in immunology pii:S1471-4906(24)00065-6 [Epub ahead of print].

Mammalian brain border-associated macrophages (BAMs) are strategically positioned to support vital properties and processes: for example, the composition of the brain's perivascular extracellular matrix and cerebrospinal fluid flow via the glymphatic pathway. BAMs also effectively restrict the spread of infectious microbes into the brain. However, while fighting infections, BAMs sustain long-term transcriptomic changes and can be replaced by inflammatory monocytes, potentially leading to a gradual loss of their beneficial homeostatic functions. We hypothesize that by expediting the deterioration of BAMs, multiple infection episodes might be associated with accelerated brain aging and the putative development of neurodegenerative diseases. Our viewpoint is supported by recent studies suggesting that rejuvenating aged BAMs, and counterbalancing their detrimental inflammatory signatures during infections, might hold promise in treating aging-related neurological disorders, including Alzheimer's disease (AD).

RevDate: 2024-04-17

Hu X, Ma YN, Y Xia (2024)

Association between abnormal lipid metabolism and Alzheimer's disease: New research has revealed significant findings on the APOE4 genotype in microglia.

Bioscience trends [Epub ahead of print].

APOE4 is widely recognized as a genetic risk factor for Alzheimer's disease (AD), implicated in 60-80% of all AD cases. Recent research suggests that microglia carrying the APOE4 genotype display abnormal lipid metabolism and accumulate lipid droplets, which may exacerbate the pathology of AD. Microglia play a critical role in immune surveillance within the central nervous system and are responsible for removing harmful particles and preserving neuronal function. The APOE4 genotype causes abnormal lipid metabolism in microglia, resulting in excessive accumulation of lipid droplets. This accumulation not only impairs the phagocytic and clearance capabilities of microglia but also disrupts their interactions with neurons, resulting in disorganization and neurodegenerative alterations at the neuronal network level. In addition, the presence of APOE4 modifies the metabolic landscape of microglia, particularly affecting purinergic signaling and lipid metabolism, thereby exacerbating the pathological processes of AD. In conclusion, the accumulation of lipid droplets and abnormal lipid metabolism may be critical mechanisms in the progression of AD in microglia carrying the APOE4 genotype.

RevDate: 2024-04-17

Wisch JK, McKay NS, Boerwinkle AH, et al (2024)

Comparison of tau spread in people with Down syndrome versus autosomal-dominant Alzheimer's disease: a cross-sectional study.

The Lancet. Neurology, 23(5):500-510.

BACKGROUND: In people with genetic forms of Alzheimer's disease, such as in Down syndrome and autosomal-dominant Alzheimer's disease, pathological changes specific to Alzheimer's disease (ie, accumulation of amyloid and tau) occur in the brain at a young age, when comorbidities related to ageing are not present. Studies including these cohorts could, therefore, improve our understanding of the early pathogenesis of Alzheimer's disease and be useful when designing preventive interventions targeted at disease pathology or when planning clinical trials. We compared the magnitude, spatial extent, and temporal ordering of tau spread in people with Down syndrome and autosomal-dominant Alzheimer's disease.

METHODS: In this cross-sectional observational study, we included participants (aged ≥25 years) from two cohort studies. First, we collected data from the Dominantly Inherited Alzheimer's Network studies (DIAN-OBS and DIAN-TU), which include carriers of autosomal-dominant Alzheimer's disease genetic mutations and non-carrier familial controls recruited in Australia, Europe, and the USA between 2008 and 2022. Second, we collected data from the Alzheimer Biomarkers Consortium-Down Syndrome study, which includes people with Down syndrome and sibling controls recruited from the UK and USA between 2015 and 2021. Controls from the two studies were combined into a single group of familial controls. All participants had completed structural MRI and tau PET ([18]F-flortaucipir) imaging. We applied Gaussian mixture modelling to identify regions of high tau PET burden and regions with the earliest changes in tau binding for each cohort separately. We estimated regional tau PET burden as a function of cortical amyloid burden for both cohorts. Finally, we compared the temporal pattern of tau PET burden relative to that of amyloid.

FINDINGS: We included 137 people with Down syndrome (mean age 38·5 years [SD 8·2], 74 [54%] male, and 63 [46%] female), 49 individuals with autosomal-dominant Alzheimer's disease (mean age 43·9 years [11·2], 22 [45%] male, and 27 [55%] female), and 85 familial controls, pooled from across both studies (mean age 41·5 years [12·1], 28 [33%] male, and 57 [67%] female), who satisfied the PET quality-control procedure for tau-PET imaging processing. 134 (98%) people with Down syndrome, 44 (90%) with autosomal-dominant Alzheimer's disease, and 77 (91%) controls also completed an amyloid PET scan within 3 years of tau PET imaging. Spatially, tau PET burden was observed most frequently in subcortical and medial temporal regions in people with Down syndrome, and within the medial temporal lobe in people with autosomal-dominant Alzheimer's disease. Across the brain, people with Down syndrome had greater concentrations of tau for a given level of amyloid compared with people with autosomal-dominant Alzheimer's disease. Temporally, increases in tau were more strongly associated with increases in amyloid for people with Down syndrome compared with autosomal-dominant Alzheimer's disease.

INTERPRETATION: Although the general progression of amyloid followed by tau is similar for people Down syndrome and people with autosomal-dominant Alzheimer's disease, we found subtle differences in the spatial distribution, timing, and magnitude of the tau burden between these two cohorts. These differences might have important implications; differences in the temporal pattern of tau accumulation might influence the timing of drug administration in clinical trials, whereas differences in the spatial pattern and magnitude of tau burden might affect disease progression.

FUNDING: None.

RevDate: 2024-04-17

Nordberg A (2024)

Insights into the progression of genetic Alzheimer's disease from tau PET.

The Lancet. Neurology, 23(5):453-454.

RevDate: 2024-04-17

Yang J, Liao Y, Cao C, et al (2024)

Structural identification and anti-neuroinflammatory effects of a pectin-arabinoglucuronogalactan complex, AOPB-1-1, isolated from Asparagus officinalis.

International journal of biological macromolecules pii:S0141-8130(24)02398-5 [Epub ahead of print].

Asparagus officinalis L. is a horticultural crop that contains a variety of bioactive compounds with anti-inflammatory effects. Aqueous extracts of A. officinalis can noticeably improve the learning and memory function of model mice. Herein, a pectin-arabinoglucuronogalactan complex (AOPB-1-1) with a relative molecular weight of 90.8 kDa was isolated from A. officinalis. The repeating structural unit of AOPB-1-1 was identified through monosaccharide composition, methylation analysis, uronic acid reduction, partial acid hydrolysis, and nuclear magnetic resonance spectroscopy. AOPB-1-1 contains the rhamnogalacturonan-I (RG-I) domain of pectin polysaccharides (PPs) and arabinoglucuronogalactan (AGG) regions. The backbone of the AGG region is composed of →3,6)-β-D-Galp-(1 → and →4)-β-D-Glcp-(1 → residues substituted at the 4-position to the →4)-α-D-GalAp-(1 → residues of the RG-I main chain. The anti-neuroinflammatory activity of AOPB-1-1 suggests that it can significantly reduce the content of inflammatory cytokines, including nitric oxide, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) and inhibit the expression of inflammatory genes including cyclooxygenase-2, nitric oxide synthase, TNF-α, IL-6, and interleukin-1β in LPS-stimulated BV2 cells. Furthermore, its inhibitory effects on TNF-α and IL-6 levels were even better than those of minocycline. The significant anti-neuroinflammatory activity of AOPB-1-1 suggests its applicability as a therapeutic option for the treatment of Alzheimer's disease.

RevDate: 2024-04-17

Zhang Q, Li F, Wei M, et al (2024)

Prediction of Cognitive Progression Due to Alzheimer's Disease in Normal Subjects Based on Individual Default Mode Network Metabolic Connectivity Strength.

Biological psychiatry. Cognitive neuroscience and neuroimaging pii:S2451-9022(24)00104-6 [Epub ahead of print].

BACKGROUND: Predicting cognitive decline in those already Aβ positive or Tau positive among the aging population poses clinical challenges. In Alzheimer's disease (AD) research, intra-default mode network (DMN) connections play a pivotal role in diagnosis. This paper proposes metabolic connectivity within the DMN as a supplementary biomarker to the AT(N) framework.

METHODS: Extracting data from 1292 subjects in the Alzheimer's Disease Neuroimaging Initiative, we collected paired T1-weighted structural MRI and [18]F-labeled-fluorodeoxyglucose positron emission computed tomography (PET) scans. Individual metabolic DMN networks were constructed, and metabolic connectivity (MC) strength in DMN was assessed. In the cognitively unimpaired (CU) group, the Cox model identified CU(MC+), high-risk subjects, with Kaplan-Meier survival analyses and hazard ratio (HR) revealing MC strength's predictive performance. Spearman correlation analyses explored relationships between MC strength, AT(N) biomarkers, and clinical scales. DMN standard uptake value ratio (SUVR) provided comparative insights in the analyses.

RESULTS: Both MC strength and SUVR exhibit gradual declines with cognitive deterioration, displaying significant intergroup differences. Survival analyses indicate enhanced Aβ and Tau prediction with both metrics, with MC strength outperforming SUVR. Combined MC strength and Aβ yield optimal predictive performance (HR = 9.29), followed by MC strength and Tau (HR = 8.92). In CU(MC+), MC strength correlates significantly with CSF Aβ42 and AV45 PET SUVR (r = 0.22, -0.19). Generally, MC strength's correlation with AT(N) biomarkers exceeded SUVR.

CONCLUSIONS: Individuals with normal cognition and disrupted DMN metabolic connectivity face an elevated cognitive decline risk linked to Aβ, preceding metabolic issues.

RevDate: 2024-04-17

Raghav D, Shukla S, P Jadiya (2024)

Mitochondrial calcium signaling in non-neuronal cells: Implications for Alzheimer's disease pathogenesis.

Biochimica et biophysica acta. Molecular basis of disease pii:S0925-4439(24)00158-3 [Epub ahead of print].

Mitochondrial dysregulation is pivotal in Alzheimer's disease (AD) pathogenesis. Calcium governs vital mitochondrial processes impacting energy conversion, oxidative stress, and cell death signaling. Disruptions in mitochondrial calcium (mCa[2+]) handling induce calcium overload and trigger the opening of mitochondrial permeability transition pore, ensuing energy deprivation and resulting in AD-related neuronal cell death. However, the role of mCa[2+] in non-neuronal cells (microglia, astrocytes, oligodendrocytes, endothelial cells, and pericytes) remains elusive. This review provides a comprehensive exploration of mitochondrial heterogeneity and calcium signaling, offering insights into specific differences among various brain cell types in AD.

RevDate: 2024-04-17

Pérez-Morales M, Bello-Medina PC, González-Franco DA, et al (2024)

STEERING THE MICROBIOTA-GUT-BRAIN AXIS BY ANTIBIOTICS TO MODEL NEURO-IMMUNE-ENDOCRINE DISORDERS.

Neuroimmunomodulation pii:000538927 [Epub ahead of print].

BACKGROUND: Over the last century, animal models have been employed to study the gut-brain axis and its relationship with physiological processes, including those necessary for survival, such as food intake regulation and thermoregulation; those involved in diseases, ranging from inflammation to obesity; and those concerned to the development of neurodegenerative diseases and neuropsychiatric disorders, such as Alzheimer's disease and autism spectrum disorder, respectively.

SUMMARY: The gut microbiota has been recognized in the last decade as an essential functional component of this axis. Many reports demonstrate that the gut microbiota influences the development of a vast array of physiological processes. Experiments that use animal models to assess the effect of the gut microbiota on the brain and behavior may involve the acute or chronic administration of wide-spectrum antibiotics.

KEY MESSAGES: This narrative review summarizes the beneficial or detrimental effects of antibiotics administered prenatally or postnatally to rodents during acute or chronic periods in a wide range of protocols. These include animal models of disease and behavioral paradigms of learning and memory, anxiety, obsessive-compulsive disorder, and autism spectrum disorder. Biomarkers and behavioral assays associated with antibiotic exposure are also included in this review.

RevDate: 2024-04-17

Luo Z, Zhang X, Fleig A, et al (2024)

TRPM7 in neurodevelopment and therapeutic prospects for neurodegenerative disease.

Cell calcium, 120:102886 pii:S0143-4160(24)00044-7 [Epub ahead of print].

Neurodevelopment, a complex and highly regulated process, plays a foundational role in shaping the structure and function of the nervous system. The transient receptor potential melastatin 7 (TRPM7), a divalent cation channel with an α-kinase domain, mediates a wide range of cellular functions, including proliferation, migration, cell adhesion, and survival, all of which are essential processes in neurodevelopment. The global knockout of either TRPM7 or TRPM7-kinase is embryonically lethal, highlighting the crucial role of TRPM7 in development in vivo. Subsequent research further revealed that TRPM7 is indeed involved in various key processes throughout neurodevelopment, from maintaining pluripotency during embryogenesis to regulating gastrulation, neural tube closure, axonal outgrowth, synaptic density, and learning and memory. Moreover, a discrepancy in TRPM7 expression and/or function has been associated with neuropathological conditions, including ischemic stroke, Alzheimer's disease, and Parkinson's disease. Understanding the mechanisms of proper neurodevelopment may provide us with the knowledge required to develop therapeutic interventions that can overcome the challenges of regeneration in CNS injuries and neurodegenerative diseases. Considering that ion channels are the third-largest class targeted for drug development, TRPM7's dual roles in development and degeneration emphasize its therapeutic potential. This review provides a comprehensive overview of the current literature on TRPM7 in various aspects of neurodevelopment. It also discusses the links between neurodevelopment and neurodegeneration, and highlights TRPM7 as a potential therapeutic target for neurodegenerative disorders, with a focus on repair and regeneration.

RevDate: 2024-04-17

Park B, Kim Y, Park J, et al (2024)

Integrating Biomarkers From Virtual Reality and Magnetic Resonance Imaging for the Early Detection of Mild Cognitive Impairment Using a Multimodal Learning Approach: Validation Study.

Journal of medical Internet research, 26:e54538 pii:v26i1e54538.

BACKGROUND: Early detection of mild cognitive impairment (MCI), a transitional stage between normal aging and Alzheimer disease, is crucial for preventing the progression of dementia. Virtual reality (VR) biomarkers have proven to be effective in capturing behaviors associated with subtle deficits in instrumental activities of daily living, such as challenges in using a food-ordering kiosk, for early detection of MCI. On the other hand, magnetic resonance imaging (MRI) biomarkers have demonstrated their efficacy in quantifying observable structural brain changes that can aid in early MCI detection. Nevertheless, the relationship between VR-derived and MRI biomarkers remains an open question. In this context, we explored the integration of VR-derived and MRI biomarkers to enhance early MCI detection through a multimodal learning approach.

OBJECTIVE: We aimed to evaluate and compare the efficacy of VR-derived and MRI biomarkers in the classification of MCI while also examining the strengths and weaknesses of each approach. Furthermore, we focused on improving early MCI detection by leveraging multimodal learning to integrate VR-derived and MRI biomarkers.

METHODS: The study encompassed a total of 54 participants, comprising 22 (41%) healthy controls and 32 (59%) patients with MCI. Participants completed a virtual kiosk test to collect 4 VR-derived biomarkers (hand movement speed, scanpath length, time to completion, and the number of errors), and T1-weighted MRI scans were performed to collect 22 MRI biomarkers from both hemispheres. Analyses of covariance were used to compare these biomarkers between healthy controls and patients with MCI, with age considered as a covariate. Subsequently, the biomarkers that exhibited significant differences between the 2 groups were used to train and validate a multimodal learning model aimed at early screening for patients with MCI among healthy controls.

RESULTS: The support vector machine (SVM) using only VR-derived biomarkers achieved a sensitivity of 87.5% and specificity of 90%, whereas the MRI biomarkers showed a sensitivity of 90.9% and specificity of 71.4%. Moreover, a correlation analysis revealed a significant association between MRI-observed brain atrophy and impaired performance in instrumental activities of daily living in the VR environment. Notably, the integration of both VR-derived and MRI biomarkers into a multimodal SVM model yielded superior results compared to unimodal SVM models, achieving higher accuracy (94.4%), sensitivity (100%), specificity (90.9%), precision (87.5%), and F1-score (93.3%).

CONCLUSIONS: The results indicate that VR-derived biomarkers, characterized by their high specificity, can be valuable as a robust, early screening tool for MCI in a broader older adult population. On the other hand, MRI biomarkers, known for their high sensitivity, excel at confirming the presence of MCI. Moreover, the multimodal learning approach introduced in our study provides valuable insights into the improvement of early MCI detection by integrating a diverse set of biomarkers.

RevDate: 2024-04-17

Cortese GP, Bartosch AMW, Xiao H, et al (2024)

ZCCHC17 knockdown phenocopies Alzheimer's disease-related loss of synaptic proteins and hyperexcitability.

Journal of neuropathology and experimental neurology pii:7648666 [Epub ahead of print].

ZCCHC17 is a master regulator of synaptic gene expression and has recently been shown to play a role in splicing of neuronal mRNA. We previously showed that ZCCHC17 protein declines in Alzheimer's disease (AD) brain tissue before there is significant gliosis and neuronal loss, that ZCCHC17 loss partially replicates observed splicing abnormalities in AD brain tissue, and that maintenance of ZCCHC17 levels is predicted to support cognitive resilience in AD. Here, we assessed the functional consequences of reduced ZCCHC17 expression in primary cortical neuronal cultures using siRNA knockdown. Consistent with its previously identified role in synaptic gene expression, loss of ZCCHC17 led to loss of synaptic protein expression. Patch recording of neurons shows that ZCCHC17 loss significantly disrupted the excitation/inhibition balance of neurotransmission, and favored excitatory-dominant synaptic activity as measured by an increase in spontaneous excitatory post synaptic currents and action potential firing rate, and a decrease in spontaneous inhibitory post synaptic currents. These findings are consistent with the hyperexcitable phenotype seen in AD animal models and in patients. We are the first to assess the functional consequences of ZCCHC17 knockdown in neurons and conclude that ZCCHC17 loss partially phenocopies AD-related loss of synaptic proteins and hyperexcitability.

RevDate: 2024-04-18
CmpDate: 2024-04-18

Fan Q, Hoang MN, DuBose L, et al (2024)

The Olera.care Digital Caregiving Assistance Platform for Dementia Caregivers: Preliminary Evaluation Study.

JMIR aging, 7:e55132 pii:v7i1e55132.

BACKGROUND: The increasing prevalence of Alzheimer disease and Alzheimer disease-related dementia in the United States has amplified the health care burden and caregiving challenges, especially for caregivers of people living with dementia. A web-based care planning tool, Olera.care, was developed to aid caregivers in managing common challenges associated with dementia care.

OBJECTIVE: This study aims to preliminarily evaluate the quality and usability of the Olera.care platform and assess the preferences of using the technology and interests in learning about different older adult care services among caregivers.

METHODS: For interview 1, we aim to understand caregiving needs and let the participants start engaging with the platform. After they engage with the platform, we schedule the second interview and let the participants complete the Mobile Application Rating Scale. The survey also included sociodemographic characteristics, caregiving experiences, communication preferences in technology adoption, and older adult care service use and interests. Descriptive statistics were used to describe the quality and usability of the platform and characteristics of the participants. We conducted 2-sample 2-tailed t tests to examine the differences in the Mobile Application Rating Scale evaluation scores by caregiver characteristics.

RESULTS: Overall, 30 adult caregivers in Texas completed the evaluation. The majority were aged ≥50 years (25/30, 83%), women (23/30, 77%), White (25/30, 83%), and financially stable (20/30, 67%). The Olera.care platform evaluation showed high satisfaction, with an overall mean rating of 4.57 (SD 0.57) of 5, and scored well in engagement (mean 4.10, SD 0.61), functionality (mean 4.46, SD 0.44), aesthetics (mean 4.58, SD 0.53), and information quality (mean 4.76, SD 0.44) consistently across all participants. A statistically significant difference (P=.02) was observed in functionality evaluation scores by duration of caregiving, with caregivers dedicating more hours to care rating it higher than those providing less care (mean 4.6, SD 0.4 vs mean 4.2, SD 0.5). In addition, caregivers with less caregiving experience reported significantly higher evaluation scores for aesthetics (P=.04) and information quality (P=.03) compared to those with longer years of caregiving. All participants expressed a willingness to recommend the app to others, and 90% (27/30) rated the app overall positively. Most of the participants (21/30, 70%) favored anonymous interactions before receiving personalized feedback and preferred computer browsers over mobile apps. Medical home health services were the most used, with a diverse range of services being used. Caregiver support groups, medical providers, memory care, meal services, and adult day care were among the most desired services for future exploration.

CONCLUSIONS: The Olera.care web-based platform is a practical, engaging, easy-to-use, visually appealing, and informative tool for dementia caregivers. Future development and research are essential to enhance the platform and comprehensively evaluate it among a broader population.

RevDate: 2024-04-17

Strnad Š, Vrkoslav V, Mengr A, et al (2024)

Thermal evaporation as sample preparation for silver-assisted laser desorption/ionization mass spectrometry imaging of cholesterol in amyloid tissues.

The Analyst [Epub ahead of print].

Cholesterol plays an important biological role in the body, and its disruption in homeostasis and synthesis has been implicated in several diseases. Mapping the locations of cholesterol is crucial for gaining a better understanding of these conditions. Silver deposition has proven to be an effective method for analyzing cholesterol using mass spectrometry imaging (MSI). We optimized and evaluated thermal evaporation as an alternative deposition technique to sputtering for silver deposition in MSI of cholesterol. A silver layer with a thickness of 6 nm provided an optimal combination of cholesterol signal intensity and mass resolution. The deposition of an ultrathin nanofilm of silver enabled high-resolution MSI with a pixel size of 10 μm. We used this optimized method to visualize the distribution of cholesterol in the senile plaques in the brains of APP/PS1 mice, a model that resembles Alzheimer's disease pathology. We found that cholesterol was evenly distributed across the frontal cortex tissue, with no evidence of plaque-like accumulation. Additionally, we investigated the presence and distribution of cholesterol in myocardial sections of a human heart affected by wild-type ATTR amyloidosis. We identified the presence of cholesterol in areas with amyloid deposition, but complete colocalization was not observed.

RevDate: 2024-04-18
CmpDate: 2024-04-18

Furneri G, Varrasi S, Guerrera CS, et al (2024)

Combining Mini-Mental State Examination and Montreal Cognitive Assessment for assessing the clinical efficacy of cholinesterase inhibitors in mild Alzheimer's disease: a pilot study.

Aging clinical and experimental research, 36(1):95.

Current drugs for Alzheimer's Disease (AD), such as cholinesterase inhibitors (ChEIs), exert only symptomatic activity. Different psychometric tools are needed to assess cognitive and non-cognitive dimensions during pharmacological treatment. In this pilot study, we monitored 33 mild-AD patients treated with ChEIs. Specifically, we evaluated the effects of 6 months (Group 1 = 17 patients) and 9 months (Group 2 = 16 patients) of ChEIs administration on cognition with the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Frontal Assessment Battery (FAB), while depressive symptoms were measured with the Hamilton Depression Rating Scale (HDRS). After 6 months (Group 1), a significant decrease in MoCA performance was detected. After 9 months (Group 2), a significant decrease in MMSE, MoCA, and FAB performance was observed. ChEIs did not modify depressive symptoms. Overall, our data suggest MoCA is a potentially useful tool for evaluating the effectiveness of ChEIs.

RevDate: 2024-04-17

Seyedmirzaei H, Salmannezhad A, Ashayeri H, et al (2024)

Growth-Associated Protein 43 and Tensor-Based Morphometry Indices in Mild Cognitive Impairment.

Neuroinformatics [Epub ahead of print].

Growth-associated protein 43 (GAP-43) is found in the axonal terminal of neurons in the limbic system, which is affected in people with Alzheimer's disease (AD). We assumed GAP-43 may contribute to AD progression and serve as a biomarker. So, in a two-year follow-up study, we assessed GAP-43 changes and whether they are correlated with tensor-based morphometry (TBM) findings in patients with mild cognitive impairment (MCI). We included MCI and cognitively normal (CN) people with available baseline and follow-up cerebrospinal fluid (CSF) GAP-43 and TBM findings from the ADNI database. We assessed the difference between the two groups and correlations in each group at each time point. CSF GAP-43 and TBM measures were similar in the two study groups in all time points, except for the accelerated anatomical region of interest (ROI) of CN subjects that were significantly greater than those of MCI. The only significant correlations with GAP-43 observed were those inverse correlations with accelerated and non-accelerated anatomical ROI in MCI subjects at baseline. Plus, all TBM metrics decreased significantly in all study groups during the follow-up in contrast to CSF GAP-43 levels. Our study revealed significant associations between CSF GAP-43 levels and TBM indices among people of the AD spectrum.

RevDate: 2024-04-17

Alexander CM, Martyr A, L Clare (2024)

Healthcare Awareness Profile Interview: Development of a new evidence-based brief clinical tool to assess awareness in people with dementia.

Neuropsychological rehabilitation [Epub ahead of print].

People with dementia vary in awareness of difficulties. Evaluating awareness could facilitate personalized care. However, current research measures are unsuitable for practical clinical application. We aimed to develop a brief multidimensional awareness interview for clinical use. Informed by available evidence about awareness of dementia, items suitable for both in-person and remote administration were modified from validated measures or developed for clinical application. The interview was administered via telephone or videoconference to 31 community-dwelling people with mild-to-moderate dementia. An informant completed a corresponding questionnaire. A multidimensional profile of awareness was created using self-report of symptoms, and discrepancies between self-rating and either informant rating or objective memory task performance. Feedback from participants and informants and discussions with clinical advisory and patient and public involvement groups helped finalize the interview. Remote administration was straightforward taking on average under 11 min. Awareness profiles showed a spectrum of awareness across domains. Feedback indicated that the items were acceptable and understandable. Certain aspects could be mildly upsetting where current difficulties were highlighted. Subject to further validation, the Healthcare Awareness Profile Interview (HAPI) shows potential as an evidence-based brief clinical tool for assessing awareness in people with mild-to-moderate dementia.

RevDate: 2024-04-18
CmpDate: 2024-04-18

Chen X, Y Shi (2024)

Generating Homogeneous Brain Organoids from Human iPSCs.

Methods in molecular biology (Clifton, N.J.), 2794:157-167.

There is a high demand for the development of in vitro models for human brain development and diseases due to the inaccessibility of human brain tissues. The human iPSC-derived brain organoids provide a promising in vitro model for studying human brain development and disorders. However, it is challenging to generate a large number of brain organoids with high consistency for modeling human neurological diseases. Here, we describe a method for generating high-yield brain organoids with high consistency by combining large-scale embryoid body (EB) generation and incorporating a quality control screening step during differentiation. The method described in this chapter provides a robust way to generate brain organoids for studying human brain development and modeling neurological diseases.

RevDate: 2024-04-18
CmpDate: 2024-04-18

Wang C, Cerneckis J, Y Shi (2024)

Directed Differentiation of Neurons from Human iPSCs for Modeling Neurological Disorders.

Methods in molecular biology (Clifton, N.J.), 2794:141-155.

Human-induced pluripotent stem cell (hiPSC) technology has enabled comprehensive human cell-based disease modeling in vitro. Due to limited accessibility of primary human neurons as well as species-specific divergence between human and rodent brain tissues, hiPSC-derived neurons have become a popular tool for studying neuronal biology in a dish. Here, we provide methods for transcription factor-driven directed differentiation of neurons from hiPSCs via a neural progenitor cell (NPC) intermediate. Doxycycline-inducible expression of neuron fate-determining transcription factors neurogenin 2 (NGN2) and achaete-scute homolog 1 (ASCL1) enables rapid and controllable differentiation of human neurons for disease modeling applications. The provided method is also designed to improve the reproducibility of human neuron differentiation by reducing the batch-to-batch variation of NPC differentiation and lentiviral transduction.

RevDate: 2024-04-18
CmpDate: 2024-04-18

Dai M, Guo Z, Xia H, et al (2024)

Predicting the efficacy of donepezil intervention in Alzheimer's disease patients using regional homogeneity in the inferior orbitofrontal cortex.

Aging clinical and experimental research, 36(1):94.

BACKGROUND: Although donepezil is a commonly used drug for treating Alzheimer's disease (AD), the mechanisms by which it affects patients' functional brain activity, and thus modulates clinical symptoms, remain unclear.

METHODS: In the present study, we used resting-state functional magnetic resonance imaging (MRI) and regional homogeneity (ReHo) to investigate the effects of donepezil on local brain activity in AD patients. Resting-state functional MRI data were collected from 32 subjects: 16 healthy controls and 16 AD patients. All 16 AD patients underwent 6 months of donepezil treatment and received two MRI scans (pre- and post-intervention). Analysis of covariance and post hoc analyses were used to compare ReHo differences among the healthy controls, pre-intervention AD patients, and post-intervention AD patients. Pearson correlation analysis was used to examine relationships between ReHo values in differential brain regions and clinical symptoms.

RESULTS: Compared with healthy controls, post-intervention AD patients had reduced ReHo in the orbital part of the inferior frontal gyrus, and pre-intervention AD patients had reduced ReHo in the orbital part of the right inferior frontal gyrus. Pattern recognition models revealed that pre-intervention ReHo values in abnormal brain regions of AD patients were 76% accurate for predicting the efficacy of donepezil on cognitive function and 65% accurate for predicting its efficacy on depressive symptoms.

CONCLUSIONS: These findings deepen our understanding of the brain mechanisms underlying the clinical efficacy of donepezil in AD patients, and provide a novel way to predict its clinical efficacy in such patients.

RevDate: 2024-04-17

Perneczky R, Arbeitsgruppe Neue Therapieformen des Deutschen Netzwerks Gedächtnisambulanzen (DNG), S Nitschmann (2024)

[The monoclonal antibody gantenerumab in the treatment of early Alzheimer's disease].

Innere Medizin (Heidelberg, Germany) [Epub ahead of print].

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RJR Experience and Expertise

Researcher

Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.

Educator

Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.

Administrator

Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.

Technologist

Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.

Publisher

While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.

Speaker

Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.

Facilitator

Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.

Designer

Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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