Endogenous hydrogen peroxide regulates glutathione redox via nuclear factor erythroid 2-related factor 2 downstream of phosphatidylinositol 3-kinase during muscle differentiation.
We reported previously that endogenous reactive oxygen species (ROS) function as myogenic signaling molecules. It has also been determined that excess ROS induce electrophile-response element (EpRE)-driven gene expression via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Nonetheless, the relationship between the metabolism of ROS (eg, H(2)O(2)) through glutathione (GSH) up-regulation, GSH-dependent reduction of H(2)O(2), and Nrf2-dependent gene regulation is not well established. Therefore, we attempted to determine whether H(2)O(2) controls the intracellular GSH redox state via the Nrf2-glutamate-cysteine ligase (GCL)/glutathione reductase (GR)-GSH signaling pathway. In our experiments, enhanced H(2)O(2) generation was accompanied by an increase in both total GSH levels and the GSH/GSSG ratio during muscle differentiation. Both GCL and GR transcriptional expression levels were markedly increased during muscle differentiation but reduced by catalase treatment. Nrf2 protein expression and nuclear translocation increased during myogenesis. The inhibition of GCL, GR, and Nrf2 both by inhibitors and by RNA interference blocked muscle differentiation. Phosphatidylinositol 3-kinase regulated the expression of the GCL C (a catalytic subunit) and GR genes via the induction of Nrf2 nuclear translocation and expression. In conclusion, endogenous H(2)O(2) generated during muscle differentiation not only functions as a signaling molecule, but also regulates the GSH redox state via activation of the Nrf2-GCL/GR-GSH signaling pathway downstream of phosphatidylinositol 3-kinase.
Ding
Yan
Y
Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Korea.
Choi
Kyu Jin
KJ
Kim
Jin Hwan
JH
Han
Xuezhe
X
Piao
Yuji
Y
Jeong
Jin-Hyun
JH
Choe
Wonchae
W
Kang
Insug
I
Ha
Joohun
J
Forman
Henry Jay
HJ
Lee
Jinhwa
J
Yoon
Kyung-Sik
KS
Kim
Sung Soo
SS
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D005978:Glutathione / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D051379:Mice; D018482:Muscle, Skeletal / Q000166:cytology* / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology / Q000502:physiology; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D010084:Oxidation-Reduction; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction
D051267:NF-E2-Related Factor 2; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D005980:Glutathione Reductase; D019869:Phosphatidylinositol 3-Kinases; D005978:Glutathione