Publication
ErbB2 regulates autophagic flux to modulate the proteostasis of APP-CTFs in Alzheimer's disease.
Wang Bo-Jeng, Her Guor Mour, Hu Ming-Kuan, Chen Yun-Wen, Tung Ying-Tsen, Wu Pei-Yi, Hsu Wen-Ming, Lee Hsinyu, Jin Lee-Way, Hwang Sheng-Ping L, Chen Rita P-Y, Huang Chang-Jen, Liao Yung-Feng
Abstract
Proteolytic processing of amyloid precursor protein (APP) C-terminal fragments (CTFs) by γ-secretase underlies the pathogenesis of Alzheimer's disease (AD). An RNA interference screen using APP-CTF [99-residue CTF (C99)]- and Notch-specific γ-secretase interaction assays identified a unique ErbB2-centered signaling network that was predicted to preferentially govern the proteostasis of APP-C99. Consistently, significantly elevated levels of ErbB2 were confirmed in the hippocampus of human AD brains. We then found that ErbB2 effectively suppressed autophagic flux by physically dissociating Beclin-1 from the Vps34-Vps15 complex independent of its kinase activity. Down-regulation of ErbB2 by CL-387,785 decreased the levels of C99 and secreted amyloid-β in cellular, zebrafish, and mouse models of AD, through the activation of autophagy. Oral administration of an ErbB2-targeted CL-387,785 for 3 wk significantly improves the cognitive functions of APP/presenilin-1 (PS1) transgenic mice. This work unveils a noncanonical function of ErbB2 in modulating autophagy and establishes ErbB2 as a therapeutic target for AD.