TY - JOUR
T1 - Glutaredoxin 2 prevents H2O2-induced cell apoptosis by protecting complex I activity in the mitochondria
AU - Wu, Hongli
AU - Xing, Kuiyi
AU - Lou, Marjorie F.
N1 - Funding Information:
The authors appreciate Vadim Gladyshev of the University of Nebraska-Lincoln (UNL) for providing mouse Grx2 plasmid, and Joel Lechner (also UNL) for reading this manuscript. This work has been supported by the National Institute of Health .
PY - 2010/10
Y1 - 2010/10
N2 - Glutaredoxin 2 (Grx2) belongs to the oxidoreductase family and is an isozyme of glutaredoxin 1 (Grx1) present in the mitochondria, however its function is not well understood. The purpose of this study is to evaluate the potential anti-apoptotic function of Grx2 by examining its ability to protect complex I in the mitochondrial electron transport system using human lens epithelial cells as a model. We found that cells treated with 200μM hydrogen peroxide (H2O2) for 24h exhibited decreased viability and became apoptotic with corresponding Bax up-regulation, Bcl-2 down-regulation, caspase 3 activation and mitochondrial cytochrome c leakage. Grx2 over-expression (OE) could protect cells against H2O2-induced damage while Grx2 knockdown (KD) showed the opposite effect. Under the same conditions, H2O2 treatment caused 50% inactivation of complex I activity in control cells (vector only), 75% in Grx2 KD cells but only 20% in Grx2 OE cells. Furthermore, the inactivated complex I in the H2O2-treated cells could be protected mostly by importing the purified nascent Grx2 protein, but not the Grx2 protein mutated at the active site with C70S, or C73S, or with C70S plus C73S. Immunoprecipitation study also revealed that Grx2 co-precipitated with complex I, but not complex II, in the mitochondrial lysate. Thus, the mechanism of Grx2 protection against H2O2-induced apoptosis is likely associated with its ability to preserve complex I.
AB - Glutaredoxin 2 (Grx2) belongs to the oxidoreductase family and is an isozyme of glutaredoxin 1 (Grx1) present in the mitochondria, however its function is not well understood. The purpose of this study is to evaluate the potential anti-apoptotic function of Grx2 by examining its ability to protect complex I in the mitochondrial electron transport system using human lens epithelial cells as a model. We found that cells treated with 200μM hydrogen peroxide (H2O2) for 24h exhibited decreased viability and became apoptotic with corresponding Bax up-regulation, Bcl-2 down-regulation, caspase 3 activation and mitochondrial cytochrome c leakage. Grx2 over-expression (OE) could protect cells against H2O2-induced damage while Grx2 knockdown (KD) showed the opposite effect. Under the same conditions, H2O2 treatment caused 50% inactivation of complex I activity in control cells (vector only), 75% in Grx2 KD cells but only 20% in Grx2 OE cells. Furthermore, the inactivated complex I in the H2O2-treated cells could be protected mostly by importing the purified nascent Grx2 protein, but not the Grx2 protein mutated at the active site with C70S, or C73S, or with C70S plus C73S. Immunoprecipitation study also revealed that Grx2 co-precipitated with complex I, but not complex II, in the mitochondrial lysate. Thus, the mechanism of Grx2 protection against H2O2-induced apoptosis is likely associated with its ability to preserve complex I.
KW - Apoptosis
KW - Complex I
KW - Free radical
KW - Glutaredoxin2
KW - Hydrogen peroxide
KW - Mitochondria
KW - Reactive oxygen species (ROS)
UR - http://www.scopus.com/inward/record.url?scp=77955556206&partnerID=8YFLogxK
U2 - 10.1016/j.bbabio.2010.06.003
DO - 10.1016/j.bbabio.2010.06.003
M3 - Article
C2 - 20547138
AN - SCOPUS:77955556206
SN - 0005-2728
VL - 1797
SP - 1705
EP - 1715
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 10
ER -