Endosomal Dysfunction Induced by Directly Over-Activating Rab5 Recapitulates Prodromal and Neurodegenerative Features of Alzheimer's Disease

Autor: Balapal S. Basavarajappa, Philip Stavrides, Chris N. Goulbourne, Monika Pawlik, Ju-Hyun Lee, Anna Pensalfini, Cynthia Bleiwas, Seonil Kim, Sandipkumar Darji, Martin J. Berg, Ying Jiang, John F. Smiley, Ralph A. Nixon, Shivakumar Subbanna, Chunfeng Huo
Rok vydání: 2019
Předmět:
Zdroj: SSRN Electronic Journal.
ISSN: 1556-5068
Popis: Neuronal endosomal dysfunction, the earliest known pathobiology specific to Alzheimer’s disease (AD), is mediated by aberrant activation of Rab5 triggered by APP-βeta secretase cleaved C-terminal fragment (APP-βCTF). To distinguish pathophysiological consequences specific to over-activated Rab5 itself, we activated Rab5 independently from APP-βCTF in a novel mouse model (PA-Rab5). We report that Rab5 over-activation alone recapitulates diverse prodromal and degenerative features of AD. Modest neuron-specific transgenic Rab5 expression inducing hyper-activation of Rab5 comparable to that in AD brain reproduced AD-related Rab5-endosomal enlargement and mistrafficking; hippocampal synaptic plasticity deficits via accelerated AMPAR endocytosis and dendritic spine loss; and tau hyperphosphorylation via activated glycogen synthase kinase-3β. Importantly, Rab5-mediated endosomal dysfunction induced progressive cholinergic neurodegeneration and impaired hippocampal dependent memory. Aberrant neuronal Rab5-endosome signaling, therefore, drives a novel pathogenic cascade distinct from β-amyloid-related neurotoxicity, which includes prodromal and neurodegenerative features of AD, and suggests Rab5 over-activation as a new therapeutic target.
Databáze: OpenAIRE