Abstract
Reactive oxygen species (ROS) exert pleiotropic effects on a wide array of signaling proteins that regulate cellular growth and apoptosis. This study shows that long-term treatment with a low concentration of H2O2 leads to the activation of signaling pathways involving extracellular signal-regulated kinase, ribosomal protein S6 kinase, and protein kinase D (PKD) that increase cAMP binding response element protein (CREB) phosphorylation at Ser133 in cardiomyocytes. Although CREB-Ser133 phosphorylation typically mediates cAMP-dependent increases in CREB target gene expression, the H2O2-dependent increase in CREB-Ser133 phosphorylation is accompanied by a decrease in CREB protein abundance and no change in Cre-luciferase reporter activity. Mutagenesis studies indicate that H2O2 decreases CREB protein abundance via a mechanism that does not require CREB-Ser133 phosphorylation. Rather, the H2O2-dependent decrease in CREB protein is prevented by the proteasome inhibitor lactacystin, by inhibitors of mitogen-activated protein kinase kinase or protein kinase C activity, or by adenoviral-mediated delivery of a small interfering RNA that decreases PKD1 expression. A PKD1-dependent mechanism that links oxidative stress to decreased CREB protein abundance is predicted to contribute to the pathogenesis of heart failure by influencing cardiac growth and apoptosis responses.
- CREB, cAMP binding response element protein
- β-gal, β-galactosidase
- CRE, cAMP response element
- GF109203X, 3-[1-[3-(dimethylaminopropyl]-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione monohydrochloride
- ERK, extracellular signal-regulated kinase
- MEK, mitogen-activated protein kinase kinase
- PKA, protein kinase A
- PKC, protein kinase C
- PKD, protein kinase D
- PSSA, phospho-site-specific antibodies
- ROS, reactive oxygen species
- RSK, p90 kDa ribosomal S6 kinase
- WT, wild type
- CBP, cAMP binding response element protein binding protein
- ATF-1, activating transcription factor 1
- U0126, 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene.
Footnotes
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These studies were supported by United States Public Health Service and National Institutes of Health National Heart, Lung, and Blood Institute [Grants HL67101, HL77860, and T32-HL076116].
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Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org.
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ABBREVIATIONS:
- Received March 25, 2009.
- Accepted July 17, 2009.
- © 2009 The American Society for Pharmacology and Experimental Therapeutics
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