Oxidative stress-mediated up-regulation of myocardial ischemic preconditioning up-regulated protein 1 gene expression in H9c2 cardiomyocytes is regulated by cyclic AMP-response element binding protein.
The cyclic AMP (cAMP)/protein kinase A (PKA) cascade plays a central role in cardiomyocyte proliferation and apoptosis. Here, we show that H(2)O(2) stimulates expression of the antiapoptotic myocardial ischemic preconditioning up-regulated protein 1 (Mipu1) gene in H9c2 cardiomyocytes through a pathway involving the cAMP-response element binding protein (CREB). Stimulation of H9c2 cardiomyocytes with H(2)O(2) resulted in increased Mipu1 promoter activity. Analysis of the rat Mipu1 promoter revealed two potential cAMP-response elements, one of which (CRE-II, TGTGGATGTTGACGAGCTTGT) was shown, using mutagenesis and deletion analysis, to be functional. Subsequent studies established that H(2)O(2) increased phosphorylation of CREB serine 133 through a pathway involving PKA activation. Phospho-CREB was demonstrated to bind to CRE-II of the Mipu1 promoter, and H(2)O(2) treatment resulted in increases in their interaction as assessed by ChIP. Furthermore, H(2)O(2)-mediated up-regulation of Mipu1 protein expression was abrogated by the suppression of CREB expression with small interfering RNA of CREB. It was demonstrated that the H(2)O(2)-induced up-regulation of Mipu1 in H9c2 cardiomyocytes was mediated by cAMP/PKA-dependent CREB activation.
Qu
Shunlin
S
Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410078, People's Republic of China.
Zhu
Honglin
H
Wei
Xing
X
Zhang
Chi
C
Jiang
Lei
L
Liu
Yin
Y
Luo
Qi
Q
Xiao
Xianzhong
X
D000818:Animals; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D020869:Gene Expression Profiling; D006861:Hydrogen Peroxide / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics*; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D051381:Rats; D012097:Repressor Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D017362:Cyclic AMP Response Element-Binding Protein; C520710:Mipu1 protein, rat; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D006861:Hydrogen Peroxide