Abstract
A recent study documented a role of adenosine A3-Akt-cAMP response element-binding protein (CREB) survival signaling in resveratrol preconditioning of the heart. In this study, we demonstrate that resveratrol-mediated CREB activation can also occur through an Akt-independent pathway. Isolated rat hearts were perfused for 15 min with Krebs-Henseleit bicarbonate (KHB) buffer containing resveratrol in the absence or presence of adenosine A3 receptor blocker MRS-1191 [3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicar-boxylate], phosphatidylinositol 3 (PI3)-kinase inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride], mitogen-activated extracellular signal-regulated protein kinase inhibitor PD098059 [2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one], or a combination of LY294002 and PD098059. All hearts were subsequently subjected to 30-min ischemia followed by 2-h reperfusion. Cardioprotection was examined by determining infarct size, cardiomyocyte apoptosis, and ventricular recovery. Resveratrol phosphorylated both Akt and CREB that was blocked by MRS-1191, which also abolished cardioprotective abilities of resveratrol. LY294002 completely inhibited Akt phosphorylation but partially blocked the phosphorylation of CREB. Inhibition of PI3-kinase also partially blocked resveratrol's ability to precondition the heart. PD098059 partially blocked the phosphorylation of CREB and resveratrol-mediated cardioprotection. Preperfusing the hearts with LY294002 and PD098059 together completely abolished the phosphorylation of CREB, simultaneously inhibiting resveratrol-mediated cardioprotection. The results indicate that resveratrol preconditions the hearts through adenosine A3 receptor signaling that triggers the phosphorylation of CREB through both Akt-dependent and -independent pathways, leading to cardioprotection.
Footnotes
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This study was supported in part by National Institutes of Health Grants HL 22559, HL 33889, HL 34360, HL 56803, and HL75665.
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.105.084285.
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ABBREVIATIONS: CREB, cAMP response-element binding protein; PI3, phosphatidylinositol 3; MAPK, mitogen-activated protein kinase; MEK, mitogen-activated extracellular signal-regulated protein kinase; MRS-1191 (MRS), 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicar-boxylate; PD098,059 (PD), 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; LY294002 (LY), 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride; DMSO, dimethyl sulfoxide; KHB, Krebs-Henseleit bicarbonate; LVDP, left ventricular developed pressure; LVdp/dt, maximum first derivatives of developed pressure; TUNEL, terminal deoxynucleotidyl transferase dUTP nick-end labeling; p-CREB, phosphorylated cAMP response-element binding protein; Res, resveratrol; R, reperfusion; PC, preconditioning; iNOS, inducible nitric-oxide synthase.
- Received January 29, 2005.
- Accepted May 3, 2005.
- The American Society for Pharmacology and Experimental Therapeutics
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