scholarly journals Link between Aluminum and the Pathogenesis of Alzheimer's Disease: The Integration of the Aluminum and Amyloid Cascade Hypotheses

2011 ◽  
Vol 2011 ◽  
pp. 1-17 ◽  
Author(s):  
Masahiro Kawahara ◽  
Midori Kato-Negishi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Kii Peninsula ◽  
Aluminum Exposure ◽  
Scientific Debate ◽  
Aluminum Neurotoxicity ◽  
The Subject ◽  
The Relationship ◽  
Amyloid Cascade ◽  
Lateral Sclerosis

Whilst being environmentally abundant, aluminum is not essential for life. On the contrary, aluminum is a widely recognized neurotoxin that inhibits more than 200 biologically important functions and causes various adverse effects in plants, animals, and humans. The relationship between aluminum exposure and neurodegenerative diseases, including dialysis encephalopathy, amyotrophic lateral sclerosis and Parkinsonism dementia in the Kii Peninsula and Guam, and Alzheimer's disease (AD) has been suggested. In particular, the link between aluminum and Alzheimer's disease has been the subject of scientific debate for several decades. However, the complex characteristics of aluminum bioavailability make it difficult to evaluate its toxicity and therefore, the relationship remains to be established. Mounting evidence has suggested that significance of oligomerization ofβ-amyloid protein and neurotoxicity in the molecular mechanism of AD pathogenesis. Aluminum may play crucial roles as a cross-linker inβ-amyloid oligomerization. Here, we review the detailed characteristics of aluminum neurotoxicity based on our own studies and the recent literatures. Our aim is to revisit the link between aluminum and AD and to integrate aluminum and amyloid cascade hypotheses in the context ofβ-amyloid oligomerization and the interactions with other metals.

Scopolamine, a Toxin-Induced Experimental Model, Used for Research in Alzheimer’s Disease

2020 ◽  
Vol 19 (2) ◽  
pp. 85-93
Author(s):  
Win Ning Chen ◽  
Keng Yoon Yeong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Cognitive Disorders ◽  
Experimental Models ◽  
Disease Research ◽  
Cholinergic Dysfunction ◽  
The Relationship ◽  
Amyloid Cascade ◽  
Derivatives Of

Scopolamine as a drug is often used to treat motion sickness. Derivatives of scopolamine have also found applications as antispasmodic drugs among others. In neuroscience-related research, it is often used to induce cognitive disorders in experimental models as it readily permeates the bloodbrain barrier. In the context of Alzheimer’s disease, its effects include causing cholinergic dysfunction and increasing amyloid-β deposition, both of which are hallmarks of the disease. Hence, the application of scopolamine in Alzheimer’s disease research is proven pivotal but seldom discussed. In this review, the relationship between scopolamine and Alzheimer’s disease will be delineated through an overall effect of scopolamine administration and its specific mechanisms of action, discussing mainly its influences on cholinergic function and amyloid cascade. The validity of scopolamine as a model of cognitive impairment or neurotoxin model will also be discussed in terms of advantages and limitations with future insights.

scholarly journals The Association betweenC9orf72Repeats and Risk of Alzheimer’s Disease and Amyotrophic Lateral Sclerosis: A Meta-Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Li Shu ◽  
Qiying Sun ◽  
Yuan Zhang ◽  
Qian Xu ◽  
Jifeng Guo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyotrophic Lateral Sclerosis ◽  
Frontotemporal Dementia ◽  
Meta Analysis ◽  
Sporadic Als ◽  
Repeat Expansions ◽  
Positive Correlations ◽  
The Relationship ◽  
Lateral Sclerosis

C9orf72is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in Caucasian populations. However, the relationship betweenC9orf72repeats and Alzheimer’s disease (AD) was not clear. Additionally, there were few articles assessingC9orf72in other ethnicities with ALS. In this meta-analysis, we aimed to investigate the relationship betweenC9orf72repeat expansions (≥30 repeats) and intermediate repeat copies (20–29 repeats) and AD or ALS. The results suggested positive correlations betweenC9orf72repeat expansions and the risk of Alzheimer’s disease (OR = 6.36, 95% CI = 3.13–12.92, andp<0.00001), while intermediate repeat copies ofC9orf72gene were not associated with the risk of the disease.C9orf72repeat expansions were positively correlated with the risk of familial and sporadic ALS (OR = 293.25, 95% CI = 148.17–580.38, andp<0.00001; OR = 35.57, 95% CI = 19.61–64.51, andp<0.00001). There was a positive correlation between the gene variations and ALS risk among Caucasians and Asians (OR = 57.56, 95% CI = 36.73–90.22, andp<0.00001; OR = 6.35, 95% CI = 1.39–29.02, andp=0.02).

scholarly journals The Pathogenesis of Alzheimer's Disease: A Reevaluation of the “Amyloid Cascade Hypothesis”

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
R. A. Armstrong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Senile Plaques ◽  
Amyloid Cascade Hypothesis ◽  
Amyloid A ◽  
Molecular Determinants ◽  
Relationship Of ◽  
The Relationship ◽  
Amyloid Cascade

The most influential theory to explain the pathogenesis of Alzheimer's disease (AD) has been the “Amyloid Cascade Hypothesis” (ACH) first formulated in 1992. The ACH proposes that the deposition ofβ-amyloid (Aβ) is the initial pathological event in AD leading to the formation of senile plaques (SPs) and then to neurofibrillary tangles (NFTs) death of neurons, and ultimately dementia. This paper examines two questions regarding the ACH: (1) is there a relationship between the pathogenesis of SPs and NFTs, and (2) what is the relationship of these lesions to disease pathogenesis? These questions are examined in relation to studies of the morphology and molecular determinants of SPs and NFTs, the effects of gene mutation, degeneration induced by head injury, the effects of experimentally induced brain lesions, transgenic studies, and the degeneration of anatomical pathways. It was concluded that SPs and NFTs develop independently and may be the products rather than the causes of neurodegeneration in AD. A modification to the ACH is proposed which may better explain the pathogenesis of AD, especially of late-onset cases of the disease.

Amyloid β-peptide and Alzheimer's disease

2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Senile Plaques ◽  
Strong Support ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Amyloid Cascade Hypothesis ◽  
Sequence Of Events ◽  
Aβ Amyloid ◽  
Amyloid Cascade

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.

MiR-335-5p Inhibits β-Amyloid (Aβ) Accumulation to Attenuate Cognitive Deficits Through Targeting c-jun-N-terminal Kinase 3 in Alzheimer’s Disease

2020 ◽  
Vol 17 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Dan Wang ◽  
Zhifu Fei ◽  
Song Luo ◽  
Hai Wang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transgenic Mice ◽  
Western Blot ◽  
Mrna Expression ◽  
Cognitive Deficits ◽  
Protein Levels ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
The Relationship

Objectives: Alzheimer's disease (AD), also known as senile dementia, is a common neurodegenerative disease characterized by progressive cognitive impairment and personality changes. Numerous evidences have suggested that microRNAs (miRNAs) are involved in the pathogenesis and development of AD. However, the exact role of miR-335-5p in the progression of AD is still not clearly clarified. Methods: The protein and mRNA levels were measured by western blot and RNA extraction and quantitative real-time PCR (qRT-PCR), respectively. The relationship between miR-335-5p and c-jun-N-terminal kinase 3 (JNK3) was confirmed by dual-luciferase reporter assay. SH-SY5Y cells were transfected with APP mutant gene to establish the in vitro AD cell model. Flow cytometry and western blot were performed to evaluate cell apoptosis. The APP/PS1 transgenic mice were used as an in vivo AD model. Morris water maze test was performed to assess the effect of miR- 335-5p on the cognitive deficits in APP/PS1 transgenic mice. Results: The JNK3 mRNA expression and protein levels of JNK3 and β-Amyloid (Aβ) were significantly up-regulated, and the mRNA expression of miR-335-5p was down-regulated in the brain tissues of AD patients. The expression levels of miR-335-5p and JNK3 were significantly inversely correlated. Further, the dual Luciferase assay verified the relationship between miR-335- 5p and JNK3. Overexpression of miR-335-5p significantly decreased the protein levels of JNK3 and Aβ and inhibited apoptosis in SH-SY5Y/APPswe cells, whereas the inhibition of miR-335-5p obtained the opposite results. Moreover, the overexpression of miR-335-5p remarkably improved the cognitive abilities of APP/PS1 mice. Conclusion: The results revealed that the increased JNK3 expression, negatively regulated by miR-335-5p, may be a potential mechanism that contributes to Aβ accumulation and AD progression, indicating a novel approach for AD treatment.

A Biomarker Combining Imaging and Neuropsychological Assessment for Tracking Early Alzheimer's Disease in Clinical Trials

2018 ◽  
Vol 15 (5) ◽  
pp. 429-442 ◽  
Author(s):  
Nishant Verma ◽  
S. Natasha Beretvas ◽  
Belen Pascual ◽  
Joseph C. Masdeu ◽  
Mia K. Markey ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Cognitive Impairment ◽  
Latent Variable ◽  
Brain Regions ◽  
Disease Assessment ◽  
Latent Variable Analysis ◽  
The Relationship ◽  
Selection Of

Background: Combining optimized cognitive (Alzheimer's Disease Assessment Scale- Cognitive subscale, ADAS-Cog) and atrophy markers of Alzheimer's disease for tracking progression in clinical trials may provide greater sensitivity than currently used methods, which have yielded negative results in multiple recent trials. Furthermore, it is critical to clarify the relationship among the subcomponents yielded by cognitive and imaging testing, to address the symptomatic and anatomical variability of Alzheimer's disease. Method: Using latent variable analysis, we thoroughly investigated the relationship between cognitive impairment, as assessed on the ADAS-Cog, and cerebral atrophy. A biomarker was developed for Alzheimer's clinical trials that combines cognitive and atrophy markers. Results: Atrophy within specific brain regions was found to be closely related with impairment in cognitive domains of memory, language, and praxis. The proposed biomarker showed significantly better sensitivity in tracking progression of cognitive impairment than the ADAS-Cog in simulated trials and a real world problem. The biomarker also improved the selection of MCI patients (78.8±4.9% specificity at 80% sensitivity) that will evolve to Alzheimer's disease for clinical trials. Conclusion: The proposed biomarker provides a boost to the efficacy of clinical trials focused in the mild cognitive impairment (MCI) stage by significantly improving the sensitivity to detect treatment effects and improving the selection of MCI patients that will evolve to Alzheimer’s disease.

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