A Novel PSEN1 K311R Mutation Discovered in Chinese Families with Late-Onset Alzheimer’s Disease Affects Amyloid-β Production and Tau Phosphorylation

Background: While the angiotensin-converting enzyme degrades amyloid-β, angiotensinconverting enzyme inhibitors (ACEis) may slow cognitive decline by way of cholinergic effects, by increasing brain substance P and boosting the activity of neprilysin, and by modulating glucose homeostasis and augmenting the secretion of adipokines to enhance insulin sensitivity in patients with Alzheimer’s disease dementia (AD). We aimed to investigate whether ACE gene polymorphisms rs1800764 and rs4291 are associated with cognitive and functional change in patients with AD, while also taking APOE haplotypes and anti-hypertensive treatment with ACEis into account for stratification. Methods: Consecutive late-onset AD patients were screened with cognitive tests, while their caregivers were queried for functional and caregiver burden scores. Prospective pharmacogenetic correlations were estimated for one year, considering APOE and ACE genotypes and haplotypes, and treatment with ACEis. Results: For 193 patients, minor allele frequencies were 0.497 for rs1800764 – C (44.6% heterozygotes) and 0.345 for rs4291 – T (38.9% heterozygotes), both in Hardy-Weinberg equilibrium. Almost 94% of all patients used cholinesterase inhibitors, while 155 (80.3%) had arterial hypertension, and 124 used ACEis. No functional impacts were found regarding any genotypes or pharmacological treatment. Either for carriers of ACE haplotypes that included rs1800764 – T and rs4291 – A, or for APOE4- carriers of rs1800764 – T or rs4291 – T, ACEis slowed cognitive decline independently of blood pressure variations. APOE4+ carriers were not responsive to treatment with ACEis. Conclusion: ACEis may slow cognitive decline for patients with AD, more remarkably for APOE4- carriers of specific ACE genotypes.

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Tau and TDP-43 synergy: a novel therapeutic target for sporadic late-onset Alzheimer’s disease

GeroScience ◽

10.1007/s11357-021-00407-0 ◽

2021 ◽

Author(s):

Caitlin S. Latimer ◽

Nicole F. Liachko

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Late Onset ◽

Hippocampal Sclerosis ◽

Model Organism ◽

Amyloid Β ◽

Underlying Disease ◽

Therapeutic Interventions ◽

Disease Biology ◽

Rapid Cognitive Decline

AbstractAlzheimer’s disease (AD) is traditionally defined by the presence of two types of protein aggregates in the brain: amyloid plaques comprised of the protein amyloid-β (Aβ) and neurofibrillary tangles containing the protein tau. However, a large proportion (up to 57%) of AD patients also have TDP-43 aggregates present as an additional comorbid pathology. The presence of TDP-43 aggregates in AD correlates with hippocampal sclerosis, worse brain atrophy, more severe cognitive impairment, and more rapid cognitive decline. In patients with mixed Aβ, tau, and TDP-43 pathology, TDP-43 may interact with neurodegenerative processes in AD, worsening outcomes. While considerable progress has been made to characterize TDP-43 pathology in AD and late-onset dementia, there remains a critical need for mechanistic studies to understand underlying disease biology and develop therapeutic interventions. This perspectives article reviews the current understanding of these processes from autopsy cohort studies and model organism-based research, and proposes targeting neurotoxic synergies between tau and TDP-43 as a new therapeutic strategy for AD with comorbid TDP-43 pathology.

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A Novel AβPP M722K Mutation Affects Amyloid-β Secretion and Tau Phosphorylation and May Cause Early-Onset Familial Alzheimer’s Disease in Chinese Individuals

Journal of Alzheimer s Disease ◽

10.3233/jad-143231 ◽

2015 ◽

Vol 47 (1) ◽

pp. 157-165 ◽

Cited By ~ 7

Author(s):

Qianqian Wang ◽

Jianping Jia ◽

Wei Qin ◽

Liyong Wu ◽

Dan Li ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Early Onset ◽

Amyloid Β ◽

Tau Phosphorylation ◽

Familial Alzheimer’S Disease ◽

Familial Alzheimer's Disease

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Cerebrospinal Fluid Biomarkers of Alzheimer’s Disease: Current Evidence and Future Perspectives

Brain Sciences ◽

10.3390/brainsci11020215 ◽

2021 ◽

Vol 11 (2) ◽

pp. 215

Author(s):

Donovan A. McGrowder ◽

Fabian Miller ◽

Kurt Vaz ◽

Chukwuemeka Nwokocha ◽

Cameil Wilson-Clarke ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Late Onset ◽

Amyloid Β ◽

Current Evidence ◽

Csf Biomarkers ◽

Diagnostic Efficacy ◽

Neurofilament Light ◽

New Biomarkers

Alzheimer’s disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer’s disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer’s disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer’s disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer’s disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.

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Genetic variability at the amyloid-β precursor protein locus may contribute to the risk of late-onset Alzheimer's disease

Neuroscience Letters ◽

10.1016/s0304-3940(99)00417-6 ◽

1999 ◽

Vol 269 (2) ◽

pp. 67-70 ◽

Cited By ~ 25

Author(s):

Fabienne Wavrant-De Vrièze ◽

Richard Crook ◽

Peter Holmans ◽

Patrick Kehoe ◽

Michael J. Owen ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Genetic Variability ◽

Late Onset ◽

Amyloid Β ◽

Precursor Protein ◽

Protein Locus

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Poor Diet, Stress, and Inactivity Converge to Form a “Perfect Storm” That Drives Alzheimer’s Disease Pathogenesis

Neurodegenerative Diseases ◽

10.1159/000503451 ◽

2019 ◽

Vol 19 (2) ◽

pp. 60-77 ◽

Cited By ~ 2

Author(s):

Anthony G. Pacholko ◽

Caitlin A. Wotton ◽

Lane K. Bekar

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Environmental Factors ◽

Late Onset ◽

Caloric Intake ◽

Amyloid Β ◽

Tau Proteins ◽

Loss Of Function ◽

Brain Insulin Resistance ◽

Perfect Storm

North American incidence of Alzheimer’s disease (AD) is expected to more than double over the coming generation. Although genetic factors surrounding the production and clearance of amyloid-β and phosphorylated tau proteins are known to be responsible for a subset of early-onset AD cases, they do not explain the pathogenesis of the far more prevalent sporadic late-onset variant of the disease. It is thus likely that lifestyle and environmental factors contribute to neurodegenerative processes implicated in the pathogenesis of AD. Herein, we review evidence that (1) excess sucrose consumption induces AD-associated liver pathologies and brain insulin resistance, (2) chronic stress overdrives activity of locus coeruleus neurons, leading to loss of function (a common event in neurodegeneration), (3) high-sugar diets and stress promote the loss of neuroprotective sex hormones in men and women, and (4) Western dietary trends set the stage for a lithium-deficient state. We propose that these factors may intersect as part of a “perfect storm” to contribute to the widespread prevalence of neurodegeneration and AD. In addition, we put forth the argument that exercise and supplementation with trace lithium can counteract many of the deleterious consequences associated with excessive caloric intake and perpetual stress. We conclude that lifestyle and environmental factors likely contribute to AD pathogenesis and that simple lifestyle and dietary changes can help counteract their effects.

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Neuronal heparan sulfates promote amyloid pathology by modulating brain amyloid-β clearance and aggregation in Alzheimer’s disease

Science Translational Medicine ◽

10.1126/scitranslmed.aad3650 ◽

2016 ◽

Vol 8 (332) ◽

pp. 332ra44-332ra44 ◽

Cited By ~ 49

Author(s):

Chia-Chen Liu ◽

Na Zhao ◽

Yu Yamaguchi ◽

John R. Cirrito ◽

Takahisa Kanekiyo ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Late Onset ◽

Amyloid Β ◽

Amyloid Plaques ◽

Therapeutic Interventions ◽

Postmortem Human Brain ◽

Aβ Clearance ◽

Heparan Sulfates ◽

The Brain

Accumulation of amyloid-β (Aβ) peptide in the brain is the first critical step in the pathogenesis of Alzheimer’s disease (AD). Studies in humans suggest that Aβ clearance from the brain is frequently impaired in late-onset AD. Aβ accumulation leads to the formation of Aβ aggregates, which injure synapses and contribute to eventual neurodegeneration. Cell surface heparan sulfates (HSs), expressed on all cell types including neurons, have been implicated in several features in the pathogenesis of AD including its colocalization with amyloid plaques and modulatory role in Aβ aggregation. We show that removal of neuronal HS by conditional deletion of the Ext1 gene, which encodes an essential glycosyltransferase for HS biosynthesis, in postnatal neurons of amyloid model APP/PS1 mice led to a reduction in both Aβ oligomerization and the deposition of amyloid plaques. In vivo microdialysis experiments also detected an accelerated rate of Aβ clearance in the brain interstitial fluid, suggesting that neuronal HS either inhibited or represented an inefficient pathway for Aβ clearance. We found that the amounts of various HS proteoglycans (HSPGs) were increased in postmortem human brain tissues from AD patients, suggesting that this pathway may contribute directly to amyloid pathogenesis. Our findings have implications for AD pathogenesis and provide insight into therapeutic interventions targeting Aβ-HSPG interactions.

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Fibrillogenesis in Alzheimer's disease of amyloid β peptides and apolipoprotein E

Biochemical Journal ◽

10.1042/bj3060599 ◽

1995 ◽

Vol 306 (2) ◽

pp. 599-604 ◽

Cited By ~ 152

Author(s):

E M Castano ◽

F Prelli ◽

T Wisniewski ◽

A Golabek ◽

R A Kumar ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Apolipoprotein E ◽

Late Onset ◽

Senile Plaques ◽

Amyloid Β ◽

Fibril Formation ◽

Tau Proteins ◽

Amyloid Formation

A central event in Alzheimer's disease is the conformational change from normally circulating soluble amyloid beta peptides (A beta) and tau proteins into amyloid fibrils, in the form of senile plaques and neurofibrillary tangles respectively. The apolipoprotein E (apoE) gene locus has recently been associated with late-onset Alzheimer's disease. It is not know whether apoE plays a direct role in the pathogenesis of the disease. In the present work we have investigated whether apoE can affect the known spontaneous in vitro formation of amyloid-like fibrils by synthetic A beta analogues using a thioflavine-T assay for fibril formation, electron microscopy and Congo Red staining. Our results show that, under the conditions used, apoE directly promotes amyloid fibril formation, increasing both the rate of fibrillogenesis and the total amount of amyloid formed. ApoE accelerated fibril formation of both wild-type A beta-(1-40) and A beta-(1-40A), an analogue created by the replacement of valine with alanine at residue 18, which alone produces few amyloid-like fibrils. However, apoE produced only a minimal effect on A beta-(1-40Q), found in the Dutch variant of Alzheimer's disease. When recombinant apoE isoforms were used, apoE4 was more efficient than apoE3 at enhancing amyloid formation. These in vitro observations support the hypothesis that apoE acts as a pathological chaperone, promoting the beta-pleated-sheet conformation of soluble A beta into amyloid fibres, and provide a possible explanation for the association of the apoE4 genetic isoform with Alzheimer's disease.

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