scholarly journals ORAI2 Down-Regulation Potentiates SOCE and Decreases Aβ42 Accumulation in Human Neuroglioma Cells

2020 ◽  
Vol 21 (15) ◽  
pp. 5288
Author(s):  
Elena Scremin ◽  
Mario Agostini ◽  
Alessandro Leparulo ◽  
Tullio Pozzan ◽  
Elisa Greotti ◽  
...  
Keyword(s):  
Amyloid Precursor Protein ◽  
Glial Cells ◽  
Amyloid Beta ◽  
Senile Plaques ◽  
Large Body ◽  
Plaque Formation ◽  
Aβ Production ◽  
Proteolytic Product ◽  
Potential Tool

Senile plaques, the hallmarks of Alzheimer’s Disease (AD), are generated by the deposition of amyloid-beta (Aβ), the proteolytic product of amyloid precursor protein (APP), by β and γ-secretase. A large body of evidence points towards a role for Ca2+ imbalances in the pathophysiology of both sporadic and familial forms of AD (FAD). A reduction in store-operated Ca2+ entry (SOCE) is shared by numerous FAD-linked mutations, and SOCE is involved in Aβ accumulation in different model cells. In neurons, both the role and components of SOCE remain quite obscure, whereas in astrocytes, SOCE controls their Ca2+-based excitability and communication to neurons. Glial cells are also directly involved in Aβ production and clearance. Here, we focus on the role of ORAI2, a key SOCE component, in modulating SOCE in the human neuroglioma cell line H4. We show that ORAI2 overexpression reduces both SOCE level and stores Ca2+ content, while ORAI2 downregulation significantly increases SOCE amplitude without affecting store Ca2+ handling. In Aβ-secreting H4-APPswe cells, SOCE inhibition by BTP2 and SOCE augmentation by ORAI2 downregulation respectively increases and decreases Aβ42 accumulation. Based on these findings, we suggest ORAI2 downregulation as a potential tool to rescue defective SOCE in AD, while preventing plaque formation.

scholarly journals Natural Compounds with Anti-BACE1 Activity as Promising Therapeutic Drugs for Treating Alzheimerʼs Disease

Planta Medica ◽  
2019 ◽  
Vol 85 (17) ◽  
pp. 1316-1325 ◽  
Author(s):  
Mehjabeen Naushad ◽  
Siva Sundara Kumar Durairajan ◽  
Amal Kanti Bera ◽  
Sanjib Senapati ◽  
Min Li
Keyword(s):  
Amyloid Precursor Protein ◽  
Amyloid Beta ◽  
Neuronal Damage ◽  
Senile Plaques ◽  
Natural Compounds ◽  
Precursor Protein ◽  
Amyloid Beta Peptide ◽  
Primary Concern ◽  
Increased Risk ◽  
Beta Peptide

AbstractAlzheimerʼs disease is a neurodegenerative disease that leads to irreversible neuronal damage. Senile plaques, composed of amyloid beta peptide, is the principal abnormal characteristic of the disease. Among the factors involved, the secretase enzymes, namely, α secretase, beta-site amyloid precursor protein-cleaving enzyme, β secretase, and γ secretase, hold consequential importance. Beta-site amyloid precursor protein-cleaving enzyme 1 is considered to be the rate-limiting factor in the production of amyloid beta peptide. Research supporting the concept of inhibition of beta-site amyloid precursor protein-cleaving enzyme activity as one of the effective therapeutic targets in the mitigation of Alzheimerʼs disease is well accepted. The identification of natural compounds, such as β-amyloid precursor protein-selective beta-site amyloid precursor protein-cleaving enzyme inhibitors, and the idea of compartmentalisation of the beta-site amyloid precursor protein-cleaving enzyme 1 action have caused a dire need to closely examine the natural compounds and their effectiveness in the disease mitigation. Many natural compounds have been reported to effectively modulate beta-site amyloid precursor protein-cleaving enzyme 1. At lower doses, compounds like 2,2′,4′-trihydroxychalcone acid, quercetin, and myricetin have been shown to effectively reduce beta-site amyloid precursor protein-cleaving enzyme 1 activity. The currently used five drugs that are marketed and used for the management of Alzheimerʼs disease have an increased risk of toxicity and restricted therapeutic efficiency, hence, the search for new anti-Alzheimerʼs disease drugs is of primary concern. A variety of natural compounds having pure pharmacological moieties showing multitargeting activity and others exhibiting specific beta-site amyloid precursor protein-cleaving enzyme 1 inhibition as discussed below have superior biosafety. Many of these compounds, which are isolated from medicinal herbs and marine flora, have been long used for the treatment of various ailments since ancient times in the Chinese and Ayurvedic medical systems. The aim of this article is to review the available data on the selected natural compounds, giving emphasis to the inhibition of beta-site amyloid precursor protein-cleaving enzyme 1 activity as a mode of Alzheimerʼs disease treatment.

scholarly journals Nutraceutical and Probiotic Approaches to Examine Molecular Interactions of the Amyloid Precursor Protein APP in Drosophila Models of Alzheimer’s Disease

2021 ◽  
Vol 22 (13) ◽  
pp. 7022
Author(s):  
David Jalali ◽  
Justine Anne Guevarra ◽  
Luz Martinez ◽  
Lily Hung ◽  
Fernando J Vonhoff
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Models ◽  
Amyloid Precursor Protein ◽  
Senile Plaques ◽  
Precursor Protein ◽  
Mammalian Brain ◽  
Shed Light ◽  
Drosophila Models

Studies using animal models have shed light into the molecular and cellular basis for the neuropathology observed in patients with Alzheimer’s disease (AD). In particular, the role of the amyloid precursor protein (APP) plays a crucial role in the formation of senile plaques and aging-dependent degeneration. Here, we focus our review on recent findings using the Drosophila AD model to expand our understanding of APP molecular function and interactions, including insights gained from the fly homolog APP-like (APPL). Finally, as there is still no cure for AD, we review some approaches that have shown promising results in ameliorating AD-associated phenotypes, with special attention on the use of nutraceuticals and their molecular effects, as well as interactions with the gut microbiome. Overall, the phenomena described here are of fundamental significance for understanding network development and degeneration. Given the highly conserved nature of fundamental signaling pathways, the insight gained from animal models such as Drosophila melanogaster will likely advance the understanding of the mammalian brain, and thus be relevant to human health.

Trafficking of cell-surface amyloid beta-protein precursor. I. Secretion, endocytosis and recycling as detected by labeled monoclonal antibody

1996 ◽  
Vol 109 (5) ◽  
pp. 991-998 ◽  
Author(s):  
E.H. Koo ◽  
S.L. Squazzo ◽  
D.J. Selkoe ◽  
C.H. Koo
Keyword(s):  
Monoclonal Antibody ◽  
Cell Surface ◽  
Amyloid Precursor Protein ◽  
Amyloid Beta ◽  
Senile Plaques ◽  
Beta Amyloid ◽  
Precursor Protein ◽  
Secretory Product ◽  
Amyloid Beta Protein ◽  
Lysosomal Compartment

Amyloid beta-protein, the principal constituent of amyloid fibrils found in senile plaques and blood vessels in Alzheimer's disease, is constitutively produced and released into medium of cultured cells. Amyloid beta-protein is derived by proteolysis of the beta-amyloid precursor protein by unclear mechanisms. Beta-amyloid precursor protein is a transmembrane protein which can be processed to release a large secretory product or processed in the endosomal/lysosomal pathway without secretion. Previous studies have shown that from the cell surface, beta-amyloid precursor protein may be released after cleavage or internalized without cleavage, the latter in a pathway that both produces amyloid beta-protein and also targets some molecules to the lysosomal compartment. Analysis of beta-amyloid precursor protein trafficking is confounded by the concomitant secretion and internalization of molecules from the cell surface. To address this issue, we developed an assay, based on the binding of radioiodinated monoclonal antibody, to measure the release and internalization of cell surface beta-amyloid precursor protein in transfected cells. With this approach, we showed that surface beta-amyloid precursor protein is either rapidly released or internalized, such that the duration at the cell surface is very short. Approximately 30% of cell surface beta-amyloid precursor protein molecules are released. Following internalization, a fraction of molecules are recycled while the majority of molecules are rapidly sorted to the lysosomal compartment for degradation When the C terminus of beta-amyloid precursor protein is deleted, secretion is increased by approximately 2.5-fold as compared to wild-type molecules. There is concomitant decrease in internalization in these mutant molecules as well as prolongation of the resident time on the cell surface. This observation is consistent with recent evidence that signals within the cytoplasmic domain mediate beta-amyloid precursor protein internalization.

P4-204: Potential role of the formyl-peptide-receptors and scavenger receptor MARCO in the signal transduction of amyloid beta 1-42 (Aβ42) in glial cells

2009 ◽  
Vol 5 (4S_Part_16) ◽  
pp. P490-P490
Author(s):  
Lars-Ove Brandenburg ◽  
Maximilian Konrad ◽  
Christoph J. Wruck ◽  
Thomas Koch ◽  
Ralph Lucius ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Glial Cells ◽  
Amyloid Beta ◽  
Potential Role ◽  
Scavenger Receptor ◽  
Peptide Receptors ◽  
Formyl Peptide Receptors ◽  
Formyl Peptide

G-lymphatic, vascular and immune pathways for Aβ clearance cascade and therapeutic targets for Alzheimer’s disease

2020 ◽  
Vol 23 ◽  
Author(s):  
Saurav Chakraborty ◽  
Jyothsna ThimmaReddygari ◽  
Divakar Selvaraj
Keyword(s):  
Alzheimer Disease ◽  
Amyloid Precursor Protein ◽  
Amyloid Beta ◽  
Complement System ◽  
Therapeutic Targets ◽  
Neuronal Cell ◽  
Precursor Protein ◽  
Amyloid Beta Peptide ◽  
Beta Peptide ◽  
Immune Pathways

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.

Exploring the Role of Aggregated Proteomes in the Pathogenesis of Alzheimer’s Disease

2020 ◽  
Vol 21 (12) ◽  
pp. 1164-1173
Author(s):  
Siju Ellickal Narayanan ◽  
Nikhila Sekhar ◽  
Rajalakshmi Ganesan Rajamma ◽  
Akash Marathakam ◽  
Abdullah Al Mamun ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Early Onset ◽  
Late Onset ◽  
Precursor Protein ◽  
Brain Disorder ◽  
Amyloid Aβ ◽  
T Tau

: Alzheimer’s disease (AD) is a progressive brain disorder and one of the most common causes of dementia and death. AD can be of two types; early-onset and late-onset, where late-onset AD occurs sporadically while early-onset AD results from a mutation in any of the three genes that include amyloid precursor protein (APP), presenilin 1 (PSEN 1) and presenilin 2 (PSEN 2). Biologically, AD is defined by the presence of the distinct neuropathological profile that consists of the extracellular β-amyloid (Aβ) deposition in the form of diffuse neuritic plaques, intraneuronal neurofibrillary tangles (NFTs) and neuropil threads; in dystrophic neuritis, consisting of aggregated hyperphosphorylated tau protein. Elevated levels of (Aβ), total tau (t-tau) and phosphorylated tau (ptau) in cerebrospinal fluid (CSF) have become an important biomarker for the identification of this neurodegenerative disease. The aggregation of Aβ peptide derived from amyloid precursor protein initiates a series of events that involve inflammation, tau hyperphosphorylation and its deposition, in addition to synaptic dysfunction and neurodegeneration, ultimately resulting in dementia. The current review focuses on the role of proteomes in the pathogenesis of AD.

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