A variant of the autophagic receptor NDP52 counteracts phospho-TAU accumulation and emerges as a protective factor for Alzheimer Disease.

Abstract

Selective elimination of early pathological TAU species may be a promising therapeutic strategy to reduce TAU accumulation that contributes to neurodegeneration and hallmarks Alzheimer disease (AD). By performing a genetic analysis of a cohort of 435 patients with (AD), we defined the NDP52GE variant (rs550510) of the autophagic receptor NDP52 (also known as CALCOCO2) as a protective factor for AD. We provide evidence that in in vitro systems and in a Drosophila melanogaster model of TAU-induced AD, NDP52 reduces the accumulation of pathological forms of TAU through the autophagic process and rescues typical neurodegenerative phenotypes induced by hTAU-toxicity. More importantly, we showed that the NDP52GE variant is much more effective in this respect than NDP52WT. Mechanistically, we showed that NDP52 directly binds pathological phospho-TAU, and that NDP52WT and NDP52GE bind them with comparable efficiency. On the contrary, we showed that NDP52GE binds the autophagic machinery (LC3C and LC3B) more efficiently than NDP52WT. We also showed for the first time that NDP52 is a direct target of protein phosphatase 2A (PP2A) in vitro, opening the way to the possibility that this phosphatase may fine-tune the autophagic function of NDP52 in AD. Finally, we found a positive correlation between the worldwide distribution of the allele encoding NDP52GE and the incidence or prevalence of AD. Overall, our work highlights the variant NDP52GE as a resilience factor in AD that shows a robust effectiveness to drive pathological TAU degradation.