ESCRT-0 dysfunction compromises autophagic degradation of protein aggregates and facilitates ER stress-mediated neurodegeneration via apoptotic and necroptotic pathways

作者：Oshima Ryuji; Hasegawa Takafumi; Tamai Keiichi; Sugeno Naoto; Yoshida Shun; Kobayashi Junpei; Kikuchi Akio; Baba Toru; Futatsugi Akira; Sato Ikuro; Satoh Kennichi; Takeda Atsushi; Aoki Masashi; Tanaka Nobuyuki

来源：Scientific Reports, 2016, 6(1): 24997.

DOI：10.1038/srep24997

Endosomal sorting required for transport (ESCRT) complexes orchestrate endo-lysosomal sorting of ubiquitinated proteins, multivesicular body formation and autophagic degradation. Defects in the ESCRT pathway have been implicated in many neurodegenerative diseases, but the underlying molecular mechanisms that link them to neurodegeneration remain unknown. In this study, we showed that forebrain-specific ablation of ESCRT-0/Hrs induced marked hippocampal neuronal cell loss accompanied by the accumulation of ubiquitinated proteins, including alpha-synuclein, TDP-43 and huntingtin as well as the autophagic substrate SQSTM1/p62. Consistent with this, silencing of Hrs in cultured cells not only led to alpha-synuclein and TDP-43 accumulation in addition to impaired autophagic flux but also suppressed cell viability through the induction of ER stress followed by the activation of JNK and RIPK1, a key regulator of necroptosis. Moreover, necrostatin-1, a specific inhibitor of RIPK1, and pan-caspase inhibitors partially reduced the neurotoxicity in the Hrs-silenced cells. Altogether, these findings suggest that the disruption of ESCRT-0/Hrs in the nervous system compromises autophagic/lysosomal degradation of neurodegenerative disease-related proteins, which thereby triggers ER stress-mediated apoptotic and necroptotic cell death.

• 出版日期2016-4-26