Analytical methods to explore Amyloid-β-Peptide variants beyond Aβ1-40 and Aβ1-42

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.

Download Full-text

Insights into amyloid disease from fly models

Essays in Biochemistry ◽

10.1042/bse0560069 ◽

2014 ◽

Vol 56 ◽

pp. 69-83 ◽

Cited By ~ 1

Author(s):

Ko-Fan Chen ◽

Damian C. Crowther

Keyword(s):

Drosophila Melanogaster ◽

Neurodegenerative Disorders ◽

Amyloid Β ◽

Amyloid Β Peptide ◽

Disease Pathogenesis ◽

Amyloid Aggregates ◽

Aβ Amyloid ◽

Polypeptide Chains ◽

Amyloid Diseases

The formation of amyloid aggregates is a feature of most, if not all, polypeptide chains. In vivo modelling of this process has been undertaken in the fruitfly Drosophila melanogaster with remarkable success. Models of both neurological and systemic amyloid diseases have been generated and have informed our understanding of disease pathogenesis in two main ways. First, the toxic amyloid species have been at least partially characterized, for example in the case of the Aβ (amyloid β-peptide) associated with Alzheimer's disease. Secondly, the genetic underpinning of model disease-linked phenotypes has been characterized for a number of neurodegenerative disorders. The current challenge is to integrate our understanding of disease-linked processes in the fly with our growing knowledge of human disease, for the benefit of patients.

Download Full-text

Identification of the major amyloid β-peptide-degrading enzyme in brain

Neuroscience Research ◽

10.1016/s0168-0102(00)81590-4 ◽

2000 ◽

Vol 38 ◽

pp. S124

Author(s):

N Iwata

Keyword(s):

Amyloid Β ◽

Amyloid Β Peptide ◽

Degrading Enzyme

Download Full-text

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

Current Alzheimer Research ◽

10.2174/1567205014666171128102557 ◽

2018 ◽

Vol 15 (6) ◽

pp. 531-543 ◽

Cited By ~ 4

Author(s):

Dominik Szwajgier ◽

Ewa Baranowska-Wojcik ◽

Kamila Borowiec

Keyword(s):

Phenolic Acids ◽

Ex Vivo ◽

Amyloid Β ◽

Inhibitory Effect ◽

In Vivo Studies ◽

Amyloid Β Peptide ◽

Beneficial Effects ◽

Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

Download Full-text

Is it All Said for NSAIDs in Alzheimer’s Disease? Role of Mitochondrial Calcium Uptake

Current Alzheimer Research ◽

10.2174/1567205015666171227154016 ◽

2018 ◽

Vol 15 (6) ◽

pp. 504-510 ◽

Cited By ~ 9

Author(s):

Sara Sanz-Blasco ◽

Maria Calvo-Rodríguez ◽

Erica Caballero ◽

Monica Garcia-Durillo ◽

Lucia Nunez ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cell Death ◽

Amyloid Β ◽

Epidemiological Data ◽

Amyloid Β Peptide ◽

Aβ Oligomers ◽

Mitochondrial Potential ◽

Disease Modifying Drugs ◽

Definitive Evidence

Objectives: Epidemiological data suggest that non-steroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer's disease (AD). Unfortunately, recent trials have failed in providing compelling evidence of neuroprotection. Discussion as to why NSAIDs effectivity is uncertain is ongoing. Possible explanations include the view that NSAIDs and other possible disease-modifying drugs should be provided before the patients develop symptoms of AD or cognitive decline. In addition, NSAID targets for neuroprotection are unclear. Both COX-dependent and independent mechanisms have been proposed, including γ-secretase that cleaves the amyloid precursor protein (APP) and yields amyloid β peptide (Aβ). Methods: We have proposed a neuroprotection mechanism for NSAIDs based on inhibition of mitochondrial Ca2+ overload. Aβ oligomers promote Ca2+ influx and mitochondrial Ca2+ overload leading to neuron cell death. Several non-specific NSAIDs including ibuprofen, sulindac, indomethacin and Rflurbiprofen depolarize mitochondria in the low µM range and prevent mitochondrial Ca2+ overload induced by Aβ oligomers and/or N-methyl-D-aspartate (NMDA). However, at larger concentrations, NSAIDs may collapse mitochondrial potential (ΔΨ) leading to cell death. Results: Accordingly, this mechanism may explain neuroprotection at low concentrations and damage at larger doses, thus providing clues on the failure of promising trials. Perhaps lower NSAID concentrations and/or alternative compounds with larger dynamic ranges should be considered for future trials to provide definitive evidence of neuroprotection against AD.

Download Full-text