DJ-1 protects dopaminergic neurons against rotenone-induced apoptosis by enhancing ERK-dependent mitophagy.
Loss-of-function mutations in the gene encoding the multifunctional protein, DJ-1, have been implicated in the pathogenesis of early-onset familial Parkinson's disease (PD), suggesting that DJ-1 may act as a neuroprotectant for dopaminergic (DA) neurons. Enhanced autophagy may benefit PD by clearing damaged organelles and protein aggregates; thus, we determined if DJ-1 protects DA neurons against mitochondrial dysfunction and oxidative stress through an autophagic pathway. Cultured DA cells (MN9D) overexpressing DJ-1 were treated with the mitochondrial complex I inhibitor, rotenone. In addition, rotenone was injected into the left substantia nigra of rats 4weeks after injection with a DJ-1 expression vector. Overexpression of DJ-1 protected MN9D cells against apoptosis, significantly enhanced the survival of nigral DA neurons after rotenone treatment in vivo, and rescued rat behavioral abnormalities. Overexpression of DJ-1 enhanced rotenone-evoked expression of the autophagic markers, beclin-1 and LC3II, while transmission electron microscopy and confocal imaging revealed that the ultrastructural signs of autophagy were increased by DJ-1. The neuroprotective effects of DJ-1 were blocked by phosphoinositol 3-kinase and the autophagy inhibitor, 3-methyladenine, and by the ERK pathway inhibitor, U0126. Confocal imaging revealed that the size of p62-positive puncta decreased significantly in DJ-1 overexpression of MN9D cells 12h after rotenone treatment, suggesting that DJ-1 reveals the ability to clear aggregated p62 associated with PD. Factors that control autophagy, including DJ-1, may inhibit rotenone-induced apoptosis and present novel targets for therapeutic intervention in PD.
Beijing Institute for Neuroscience, Capital Medical University, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Center of Neural Regeneration and Repair, Beijing Key Laboratory of Brain Major Disorders-State Key Lab Incubation Base, Beijing Neuroscience Disciplines, Beijing 100069, China.
H
H
Gao
W
W
Yang
Z
Z
Qi
L
L
Lu
C
C
Duan
C
C
Zhao
H
H
Yang
D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism*; D042967:Electron Transport Complex I / Q000037:antagonists & inhibitors*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008297:Male; D046529:Microscopy, Electron, Transmission; D063306:Mitophagy; D015513:Oncogene Proteins / Q000378:metabolism*; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology; D000071617:Protein Deglycase DJ-1; D051381:Rats; D012402:Rotenone / Q000494:pharmacology*; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D012402:Rotenone; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1; D042967:Electron Transport Complex I