Loss of PINK1 impairs stress-induced autophagy and cell survival

PLoS One. 2014 Apr 21;9(4):e95288. doi: 10.1371/journal.pone.0095288. eCollection 2014.

Abstract

The mitochondrial kinase PINK1 and the ubiquitin ligase Parkin are participating in quality control after CCCP- or ROS-induced mitochondrial damage, and their dysfunction is associated with the development and progression of Parkinson's disease. Furthermore, PINK1 expression is also induced by starvation indicating an additional role for PINK1 in stress response. Therefore, the effects of PINK1 deficiency on the autophago-lysosomal pathway during stress were investigated. Under trophic deprivation SH-SY5Y cells with stable PINK1 knockdown showed downregulation of key autophagic genes, including Beclin, LC3 and LAMP-2. In good agreement, protein levels of LC3-II and LAMP-2 but not of LAMP-1 were reduced in different cell model systems with PINK1 knockdown or knockout after addition of different stressors. This downregulation of autophagic factors caused increased apoptosis, which could be rescued by overexpression of LC3 or PINK1. Taken together, the PINK1-mediated reduction of autophagic key factors during stress resulted in increased cell death, thus defining an additional pathway that could contribute to the progression of Parkinson's disease in patients with PINK1 mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Autophagy* / genetics
  • Cell Line
  • Cell Proliferation
  • Cell Survival / genetics
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • Humans
  • Lysosomal-Associated Membrane Protein 2 / metabolism
  • Microtubule-Associated Proteins / metabolism
  • Models, Biological
  • Protein Kinases / deficiency*
  • Protein Kinases / metabolism
  • Stress, Physiological* / genetics

Substances

  • LAMP2 protein, human
  • Lysosomal-Associated Membrane Protein 2
  • MAP1LC3A protein, human
  • Microtubule-Associated Proteins
  • Protein Kinases
  • PTEN-induced putative kinase

Grants and funding

German Federal Ministry of Education (BMBF 01GS08138), National Genome Research Network (NGFNplus), GerontoMitoSys network (BMBF PTJ 0315584A). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.