Alteration of Dynein Function Affects α-Synuclein Degradation via the Autophagosome-Lysosome Pathway

作者:Li, Da; Shi, Ji-Jun; Mao, Cheng-Jie; Liu, Sha; Wang, Jian-Da; Chen, Jing; Wang, Fen; Yang, Ya-Ping; Hu, Wei-Dong; Hu, Li-Fang*; Liu, Chun-Feng
来源:International Journal of Molecular Sciences, 2013, 14(12): 24242-24254.
DOI:10.3390/ijms141224242

摘要

Growing evidence suggests that dynein dysfunction may be implicated in the pathogenesis of neurodegeneration. It plays a central role in aggresome formation, the delivery of autophagosome to lysosome for fusion and degradation, which is a pro-survival mechanism essential for the bulk degradation of misfolded proteins and damaged organells. Previous studies reported that dynein dysfuntion was associated with aberrant aggregation of -synuclein, which is a major component of inclusion bodies in Parkinson's disease (PD). However, it remains unclear what roles dynein plays in -synuclein degradation. Our study demonstrated a decrease of dynein expression in neurotoxin-induced PD models in vitro and in vivo, accompanied by an increase of -synuclein protein level. Dynein down-regulation induced by siRNA resulted in a prolonged half-life of -synuclein and its over-accumulation in A53T overexpressing PC12 cells. Dynein knockdown also prompted the increase of microtubule-associated protein 1 light chain 3 (LC3-II) and sequestosome 1 (SQSTM1, p62) expression, and the accumulation of autophagic vacuoles. Moreover, dynein suppression impaired the autophagosome fusion with lysosome. In summary, our findings indicate that dynein is critical for the clearance of aberrant -synuclein via autophagosome-lysosome pathway.