Alteration of dynein function affects α-synuclein degradation via the autophagosome-lysosome pathway

Int J Mol Sci. 2013 Dec 13;14(12):24242-54. doi: 10.3390/ijms141224242.

Abstract

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 α-synuclein, which is a major component of inclusion bodies in Parkinson's disease (PD). However, it remains unclear what roles dynein plays in α-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 α-synuclein protein level. Dynein down-regulation induced by siRNA resulted in a prolonged half-life of α-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 α-synuclein via autophagosome-lysosome pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Autophagy*
  • Dyneins / antagonists & inhibitors
  • Dyneins / genetics
  • Dyneins / metabolism*
  • Heat-Shock Proteins / metabolism
  • Lysosomes / metabolism*
  • Male
  • Microtubule-Associated Proteins / metabolism
  • PC12 Cells
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Sequestosome-1 Protein
  • Up-Regulation
  • alpha-Synuclein / genetics
  • alpha-Synuclein / metabolism*

Substances

  • Heat-Shock Proteins
  • LC3 protein, rat
  • Microtubule-Associated Proteins
  • RNA, Small Interfering
  • Sequestosome-1 Protein
  • Sqstm1 protein, rat
  • alpha-Synuclein
  • Dyneins