Faculty Opinions recommendation of Amyloid beta 42 peptide (Abeta42)-lowering compounds directly bind to Abeta and interfere with amyloid precursor protein (APP) transmembrane dimerization.

The Alzheimer disease is a age related neurodegenerative disease. The factors causing alzheimer disease are numerous. Research on humans and rodent models predicted various causative factors involved in Alzheimer disease progression. Among them, neuroinflammation, oxidative stress and apoptosis play a major role because of accumulation of extracellular amyloid beta peptides. Here, the clearance of amyloid beta peptide plays a major role because of the imbalance in the production and clearance of the amyloid beta peptide. Additionally, neuroinflammation by microglia, astrocytes, cytokines, chemokines and the complement system also have a major role in Alzheimer disease. The physiological clearance pathways involved in amyloid beta peptide are glymphatic, vascular and immune pathways. Amyloid precursor protein, low density lipoprotein receptor-related protein 1, receptor for advanced glycation end product, apolipoprotein E, clusterin, aquaporin 4, auto-antibodies, complement system, cytokines and microglia are involved in amyloid beta peptide clearance pathways across the blood brain barrier. The plaque formation in the brain by alternative splicing of amyloid precursor protein and production of misfolded protein results in amyloid beta agglomeration. This insoluble amyloid beta leads to neurodegenerative cascade and neuronal cell death occurs. Studies had shown disturbed sleep may be a risk factor for dementia and cognitive decline. In this review, the therapeutic targets for alzheimer disease via focussing on pathways for amyloid beta clearance are discussed.

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Remodeling Alzheimer-amyloidosis models by seeding

Molecular Neurodegeneration ◽

10.1186/s13024-021-00429-4 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Brittany S. Ulm ◽

David R. Borchelt ◽

Brenda D. Moore

Keyword(s):

Amyloid Precursor Protein ◽

Neurodegenerative Diseases ◽

Amyloid Beta ◽

Precursor Protein ◽

Time Interval ◽

Murine Models ◽

Brain Pathology ◽

Amyloid Deposits ◽

Transgenic Murine Models ◽

Mutant Genes

AbstractAlzheimer’s disease (AD) is among the most prevalent neurodegenerative diseases, with brain pathology defined by extracellular amyloid beta deposits and intracellular tau aggregates. To aid in research efforts to improve understanding of this disease, transgenic murine models have been developed that replicate aspects of AD pathology. Familial AD is associated with mutations in the amyloid precursor protein and in the presenilins (associated with amyloidosis); transgenic amyloid models feature one or more of these mutant genes. Recent advances in seeding methods provide a means to alter the morphology of resultant amyloid deposits and the age that pathology develops. In this review, we discuss the variety of factors that influence the seeding of amyloid beta pathology, including the source of seed, the time interval after seeding, the nature of the transgenic host, and the preparation of the seeding inoculum.

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Presenilin complexes with the C-terminal fragments of amyloid precursor protein at the sites of amyloid beta -protein generation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.97.16.9299 ◽

2000 ◽

Vol 97 (16) ◽

pp. 9299-9304 ◽

Cited By ~ 99

Author(s):

W. Xia ◽

W. J. Ray ◽

B. L. Ostaszewski ◽

T. Rahmati ◽

W. T. Kimberly ◽

...

Keyword(s):

Amyloid Precursor Protein ◽

Amyloid Beta ◽

Precursor Protein ◽

Amyloid Beta Protein

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The orphan drug dichloroacetate reduces amyloid beta-peptide production whilst promoting non-amyloidogenic proteolysis of the amyloid precursor protein

PLoS ONE ◽

10.1371/journal.pone.0255715 ◽

2022 ◽

Vol 17 (1) ◽

pp. e0255715

Author(s):

Edward T. Parkin ◽

Jessica E. Hammond ◽

Lauren Owens ◽

Matthew D. Hodges

Keyword(s):

Amyloid Precursor Protein ◽

Orphan Drug ◽

Amyloid Beta ◽

Precursor Protein ◽

Amyloid Beta Peptide ◽

Amyloid Beta Peptides ◽

Over Expression ◽

Beta Peptides ◽

Amyloidogenic Processing ◽

Beta Peptide

The amyloid cascade hypothesis proposes that excessive accumulation of amyloid beta-peptides is the initiating event in Alzheimer’s disease. These neurotoxic peptides are generated from the amyloid precursor protein via sequential cleavage by β- and γ-secretases in the ’amyloidogenic’ proteolytic pathway. Alternatively, the amyloid precursor protein can be processed via the ’non-amyloidogenic’ pathway which, through the action of the α-secretase a disintegrin and metalloproteinase (ADAM) 10, both precludes amyloid beta-peptide formation and has the additional benefit of generating a neuroprotective soluble amyloid precursor protein fragment, sAPPα. In the current study, we investigated whether the orphan drug, dichloroacetate, could alter amyloid precursor protein proteolysis. In SH-SY5Y neuroblastoma cells, dichloroacetate enhanced sAPPα generation whilst inhibiting β–secretase processing of endogenous amyloid precursor protein and the subsequent generation of amyloid beta-peptides. Over-expression of the amyloid precursor protein partly ablated the effect of dichloroacetate on amyloidogenic and non-amyloidogenic processing whilst over-expression of the β-secretase only ablated the effect on amyloidogenic processing. Similar enhancement of ADAM-mediated amyloid precursor protein processing by dichloroacetate was observed in unrelated cell lines and the effect was not exclusive to the amyloid precursor protein as an ADAM substrate, as indicated by dichloroacetate-enhanced proteolysis of the Notch ligand, Jagged1. Despite altering proteolysis of the amyloid precursor protein, dichloroacetate did not significantly affect the expression/activity of α-, β- or γ-secretases. In conclusion, dichloroacetate can inhibit amyloidogenic and promote non-amyloidogenic proteolysis of the amyloid precursor protein. Given the small size and blood-brain-barrier permeability of the drug, further research into its mechanism of action with respect to APP proteolysis may lead to the development of therapies for slowing the progression of Alzheimer’s disease.

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SPON1 Can Reduce Amyloid Beta and Reverse Cognitive Impairment and Memory Dysfunction in Alzheimer’s Disease Mouse Model

Cells ◽

10.3390/cells9051275 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1275

Author(s):

Soo Yong Park ◽

Joo Yeong Kang ◽

Taehee Lee ◽

Donggyu Nam ◽

Chang-Jin Jeon ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Mouse Model ◽

Amyloid Precursor Protein ◽

Amyloid Beta ◽

Physiological Activity ◽

Precursor Protein ◽

Age Related

Alzheimer’s disease (AD) is a complex, age-related neurodegenerative disease that is the most common form of dementia. However, the cure for AD has not yet been founded. The accumulation of amyloid beta (Aβ) is considered to be a hallmark of AD. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), also known as beta secretase is the initiating enzyme in the amyloidogenic pathway. Blocking BACE1 could reduce the amount of Aβ, but this would also prohibit the other functions of BACE1 in brain physiological activity. SPONDIN1 (SPON1) is known to bind to the BACE1 binding site of the amyloid precursor protein (APP) and blocks the initiating amyloidogenesis. Here, we show the effect of SPON1 in Aβ reduction in vitro in neural cells and in an in vivo AD mouse model. We engineered mouse induced neural stem cells (iNSCs) to express Spon1. iNSCs harboring mouse Spon1 secreted SPON1 protein and reduced the quantity of Aβ when co-cultured with Aβ-secreting Neuro 2a cells. The human SPON1 gene itself also reduced Aβ in HEK 293T cells expressing the human APP transgene with AD-linked mutations through lentiviral-mediated delivery. We also demonstrated that injecting SPON1 reduced the amount of Aβ and ameliorated cognitive dysfunction and memory impairment in 5xFAD mice expressing human APP and PSEN1 transgenes with five AD-linked mutations.

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