Deciphering Alzheimer’s Disease Pathogenic Pathway: Role of Chronic Brain Hypoperfusion on p-Tau and mTOR

2021 ◽  
Vol 79 (4) ◽  
pp. 1381-1396
Author(s):  
Jack C. de la Torre
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Aging ◽  
Memory Function ◽  
Mammalian Target Of Rapamycin ◽  
Tau Phosphorylation ◽  
Clinical Feature ◽  
Fast Axonal Transport ◽  
Current Topic

This review examines new biomolecular findings that lend support to the hemodynamic role played by chronic brain hypoperfusion (CBH) in driving a pathway to Alzheimer’s disease (AD). CBH is a common clinical feature of AD and the current topic of intense investigation in AD models. CBH is also the basis for the vascular hypothesis of AD which we originally proposed in 1993. New biomolecular findings reveal the interplay of CBH in increasing tau phosphorylation (p-Tau) in the hippocampus and cortex of AD mice, damaging fast axonal transport, increasing signaling of mammalian target of rapamycin (mTOR), impairing learning-memory function, and promoting the formation of neurofibrillary tangles, a neuropathologic hallmark of AD. These pathologic elements have been singularly linked with neurodegeneration and AD but their abnormal, collective participation during brain aging have not been fully examined. The format for this review will provide a consolidated analysis of each pathologic phase contributing to cognitive decline and AD onset, summarized in nine chronological steps. These steps galvanize each factor’s active participation and contribution in constructing a biomolecular pathway to AD onset generated by CBH.

Decoding the Inter-relationship between Sleep Disorders and Alzheimer’s disease Pathogenesis

2020 ◽  
Vol 19 ◽  
Author(s):  
Zeba Mueed ◽  
Pankaj Kumar Rai ◽  
Mohammad A. Kamal ◽  
Nitesh Kumar Poddar
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Sleep Disorders ◽  
Sleep Disturbances ◽  
Mammalian Target Of Rapamycin ◽  
Light Therapy ◽  
Paired Helical Filaments ◽  
Bidirectional Relationship ◽  
Causative Agents

Alzheimer’s disease (AD), characterized by abnormally phosphorylated tau, paired helical filaments (PHFs), neurofibrillary tangles (NFTs), deregulated mammalian target of rapamycin (mTOR), Aβ deposits, is a multifactorial disease with sleep disorders being one of the causative agents. Therefore, we have reviewed the literature and have tried to decode the existence of positive feedback, reciprocal and a bidirectional relationship allying between sleep disturbances and AD. Much light has been thrown on the role of tau pathology and amyloid pathology in sleep pathology and its association with AD pathology. We have also discussed the role of melatonin in regulating sleep disorders and AD. The neuroprotective action of melatonin via inhibiting tau hyperphosphorylation and Aβ deposition has also been pondered upon. Moreover, astrocytes involvement in aggravating AD has also been highlighted in this review. Several therapeutic approaches aimed at improving both sleep disorders and AD have been duly discussed such as administration of antidepressants and antihistamines, immunotherapy, metal chelators, melatonin supplementation, light therapy and physical activity. Despite consistent efforts, the complete etiology concerning sleep disorder and AD is still unclear. Therefore, further research is needed to unravel the mechanism involved and also to develop strategies that may help in obstructing AD in its preclinical stage.

scholarly journals Discovery of a dual-action small molecule that improves neuropathological features of Alzheimer’s disease mice

2022 ◽  
Vol 119 (3) ◽  
pp. e2115082119
Author(s):  
Min Hee Park ◽  
Kang Ho Park ◽  
Byung Jo Choi ◽  
Wan Hui Han ◽  
Hee Ji Yoon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Therapeutic Potential ◽  
Memory Function ◽  
Selective Inhibition ◽  
Acid Sphingomyelinase ◽  
Hippocampal Neurogenesis ◽  
Ghrelin Receptor ◽  
Dual Action

Alzheimer’s disease (AD) is characterized by complex, multifactorial neuropathology, suggesting that small molecules targeting multiple neuropathological factors are likely required to successfully impact clinical progression. Acid sphingomyelinase (ASM) activation has been recognized as an important contributor to these neuropathological features in AD, leading to the concept of using ASM inhibitors for the treatment of this disorder. Here we report the identification of KARI 201, a direct ASM inhibitor evaluated for AD treatment. KARI 201 exhibits highly selective inhibition effects on ASM, with excellent pharmacokinetic properties, especially with regard to brain distribution. Unexpectedly, we found another role of KARI 201 as a ghrelin receptor agonist, which also has therapeutic potential for AD treatment. This dual role of KARI 201 in neurons efficiently rescued neuropathological features in AD mice, including amyloid beta deposition, autophagy dysfunction, neuroinflammation, synaptic loss, and decreased hippocampal neurogenesis and synaptic plasticity, leading to an improvement in memory function. Our data highlight the possibility of potential clinical application of KARI 201 as an innovative and multifaceted drug for AD treatment.

scholarly journals Identification of retinoblastoma binding protein 7 (Rbbp7) as a mediator against tau acetylation and subsequent neuronal loss in Alzheimer’s disease and related tauopathies

2021 ◽  
Author(s):  
Nikhil Dave ◽  
Austin S. Vural ◽  
Ignazio S. Piras ◽  
Wendy Winslow ◽  
Likith Surendra ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Death ◽  
Binding Protein ◽  
Tau Phosphorylation ◽  
Neuritic Plaque ◽  
Post Mortem ◽  
Post Mortem Brain ◽  
Tau Acetylation

AbstractEvidence indicates that tau hyper-phosphorylation and subsequent neurofibrillary tangle formation contribute to the extensive neuronal death in Alzheimer’s disease (AD) and related tauopathies. Recent work has identified that increased tau acetylation can promote tau phosphorylation. Tau acetylation occurs at lysine 280 resulting from increased expression of the lysine acetyltransferase p300. The exact upstream mechanisms mediating p300 expression remain elusive. Additional work highlights the role of the epigenome in tau pathogenesis, suggesting that dysregulation of epigenetic proteins may contribute to acetylation and hyper-phosphorylation of tau. Here, we identify and focus on the histone-binding subunit of the Nucleosome Remodeling and Deacetylase (NuRD) complex: Retinoblastoma-Binding Protein 7 (Rbbp7). Rbbp7 chaperones chromatin remodeling proteins to their nuclear histone substrates, including histone acetylases and deacetylases. Notably, Rbbp7 binds to p300, suggesting that it may play a role in modulating tau acetylation. We interrogated Rbbp7 in post-mortem brain tissue, cell lines and mouse models of AD. We found reduced Rbbp7 mRNA expression in AD cases, a significant negative correlation with CERAD (neuritic plaque density) and Braak Staging (pathogenic tau inclusions) and a significant positive correlation with post-mortem brain weight. We also found a neuron-specific downregulation of Rbbp7 mRNA in AD patients. Rbbp7 protein levels were significantly decreased in 3xTg-AD and PS19 mice compared to NonTg, but no decreases were found in APP/PS1 mice that lack tau pathology. In vitro, Rbbp7 overexpression rescued TauP301L-induced cytotoxicity in immortalized hippocampal cells and primary cortical neurons. In vivo, hippocampal Rbbp7 overexpression rescued neuronal death in the CA1 of PS19 mice. Mechanistically, we found that increased Rbbp7 reduced p300 levels, tau acetylation at lysine 280 and tau phosphorylation at AT8 and AT100 sites. Collectively, these data identify a novel role of Rbbp7, protecting against tau-related pathologies, and highlight its potential as a therapeutic target in AD and related tauopathies.

Glycogen Synthase Kinase 3 (GSK3): Its Role and Inhibitors

2020 ◽  
Vol 20 (17) ◽  
pp. 1522-1534 ◽  
Author(s):  
Pankaj Wadhwa ◽  
Priti Jain ◽  
Hemant R. Jadhav
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Glycogen Synthase ◽  
High Specificity ◽  
Tau Phosphorylation ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Important Target ◽  
The Brain

: Glycogen Synthase Kinase 3 (GSK3) is one of the Serine/Threonine protein kinases, which has gained a lot of attention for its role in a variety of pathways. It has two isoforms, GSK3α and GSK3β. However, GSK3β is highly expressed in different areas of the brain and has been implicated in Alzheimer’s disease as it is involved in tau phosphorylation. Due to its high specificity concerning substrate recognition, GSK3 has been considered as an important target. In the last decade, several GSK3 inhibitors have been reported and two molecules are in clinical trials. This review collates the information published in the last decade about the role of GSK3 in Alzheimer’s disease and progress in the development of its inhibitors. Using this collated information, medicinal chemists can strategize and design novel GSK3 inhibitors that could be useful in the treatment of Alzheimer’s disease.

Role of microtubule-associated protein tau phosphorylation in Alzheimer’s disease

2017 ◽  
Vol 37 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Rong-hong Ma ◽  
Yao Zhang ◽  
Xiao-yue Hong ◽  
Jun-fei Zhang ◽  
Jian-Zhi Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Phosphorylation ◽  
Protein Tau ◽  
Microtubule Associated Protein Tau

Role of ASK1/p38 Cascade in a Mouse Model of Alzheimer’s Disease and Brain Aging

2017 ◽  
Vol 61 (1) ◽  
pp. 259-263 ◽  
Author(s):  
Yu Hasegawa ◽  
Kensuke Toyama ◽  
Ken Uekawa ◽  
Hidenori Ichijo ◽  
Shokei Kim-Mitsuyama
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Brain Aging ◽  
Model Of Alzheimer’S Disease
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