NADPH oxidase promotes Parkinsonian phenotypes by impairing autophagic flux in an mTORC1-independent fashion in a cellular model of Parkinson's disease

Sci Rep. 2016 Mar 10:6:22866. doi: 10.1038/srep22866.

Abstract

Oxidative stress and aberrant accumulation of misfolded proteins in the cytosol are key pathological features associated with Parkinson's disease (PD). NADPH oxidase (Nox2) is upregulated in the pathogenesis of PD; however, the underlying mechanism(s) of Nox2-mediated oxidative stress in PD pathogenesis are still unknown. Using a rotenone-inducible cellular model of PD, we observed that a short exposure to rotenone (0.5 μM) resulted in impaired autophagic flux through activation of a Nox2 dependent Src/PI3K/Akt axis, with a consequent disruption of a Beclin1-VPS34 interaction that was independent of mTORC1 activity. Sustained exposure to rotenone at a higher dose (10 μM) decreased mTORC1 activity; however, autophagic flux was still impaired due to dysregulation of lysosomal activity with subsequent induction of the apoptotic machinery. Cumulatively, our results highlight a complex pathogenic mechanism for PD where short- and long-term oxidative stress alters different signaling pathways, ultimately resulting in anomalous autophagic activity and disease phenotype. Inhibition of Nox2-dependent oxidative stress attenuated the impaired autophagy and cell death, highlighting the importance and therapeutic potential of these pathways for treating patients with PD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Autophagy
  • Cell Line, Tumor
  • Humans
  • Mechanistic Target of Rapamycin Complex 1
  • Membrane Glycoproteins / metabolism*
  • Multiprotein Complexes / metabolism*
  • NADPH Oxidase 2
  • NADPH Oxidases / metabolism*
  • Oxidative Stress
  • Parkinson Disease / metabolism*
  • Parkinson Disease / pathology
  • Rotenone / pharmacology
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Membrane Glycoproteins
  • Multiprotein Complexes
  • Rotenone
  • CYBB protein, human
  • NADPH Oxidase 2
  • NADPH Oxidases
  • Mechanistic Target of Rapamycin Complex 1
  • TOR Serine-Threonine Kinases