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Oxidative Medicine and Cellular Longevity
Volume 2 (2009), Issue 1, Pages 36-42
http://dx.doi.org/10.4161/oxim.2.1.7985

Oxidative Stress Induction of DJ-1 Protein in Reactive Astrocytes Scavenges Free Radicals and Reduces Cell Injury

1Department of Neurobiology, Kyoto Pharmaceutical University, Kyoto, Japan
2Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
3Department of Molecular Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
4Biomedical MR Science Center, Shiga University of Medical Science, Otsu, Japan
5Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Japan
6Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
7Department of Neurobiology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
8Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan

Received 15 January 2009; Revised 26 January 2009; Accepted 29 January 2009

Copyright © 2009 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Under cerebral ischemia/reperfusion-induced oxidative conditions, astrocytes accumulate and activate in the ischemic region. DJ-1 has recently been shown to be a sensor of oxidative stress in living cells. However, the function of astrocytic DJ-1 is still unknown. In the present study, to clarify the effect of astrocytic DJ-1 protein under massive oxidative insult, we used a focal ischemic rat model that had been subjected to middle cerebral artery occlusion (MCAO) and reperfusion. We then investigated changes in the distribution of DJ-1 in astrocytes, DJ-1 release from cultured astrocytes, and the effects of recombinant DJ-1 protein on hydrogen peroxide (H2O2)-induced death in normal and DJ-1-knockdown SH-SY5Y cells and on in vitro scavenging of hydroxyl radicals (OH) by electron spin resonance spectrometry. At 24 h after 2-h MCAO and reperfusion, an infarct lesion was markedly observed using magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining. In addition, reactive astrocytes enhanced DJ-1 expression in the penumbral zone of the ischemic core and that DJ-1 protein was extracellularly released from astrocytes by H2O2 in in vitro primary cultures. Although DJ-1-knockdown SH-SY5Y cells were markedly vulnerable to oxidative stress, treatment with glutathione S-transferase-tagged recombinant human DJ-1 protein (GST-DJ-1) significantly inhibited H2O2-induced cell death. In addition, GST-DJ-1 protein directly scavenged OH. These results suggest that oxidative stress induces the release of astrocytic DJ-1 protein, which may contribute to astrocyte-mediated neuroprotection.