Das Samarjit, Tosaki Arpad, Bagchi Debasis, Maulik Nilanjana, Das Dipak K
Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, CT 06030-1110, USA.
J Pharmacol Exp Ther. 2005 Aug;314(2):762-9. doi: 10.1124/jpet.105.084285. Epub 2005 May 5.
A recent study documented a role of adenosine A(3)-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 A(3) 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 A(3) receptor signaling that triggers the phosphorylation of CREB through both Akt-dependent and -independent pathways, leading to cardioprotection.
最近的一项研究记录了腺苷A(3)-蛋白激酶B（Akt）-环磷酸腺苷反应元件结合蛋白（CREB）生存信号通路在白藜芦醇对心脏预处理中的作用。在本研究中，我们证明白藜芦醇介导的CREB激活也可通过不依赖Akt的途径发生。将离体大鼠心脏用含有白藜芦醇的克雷布斯-亨塞尔特碳酸氢盐（KHB）缓冲液灌注15分钟，灌注时分别加入或不加入腺苷A(3)受体阻滞剂MRS-1191[3-乙基-5-苄基-2-甲基-4-苯基乙炔基-6-苯基-1,4-(±)-二氢吡啶-3,5-二羧酸酯]、磷脂酰肌醇3（PI3）-激酶抑制剂LY294002[2-(4-吗啉基)-8-苯基-1(4H)-苯并吡喃-4-酮盐酸盐]、丝裂原活化的细胞外信号调节蛋白激酶抑制剂PD098059[2-(2-氨基-3-甲氧基苯基)-4H-1-苯并吡喃-4-酮]，或LY294002与PD098059的组合。随后所有心脏均经历30分钟的缺血，接着是2小时的再灌注。通过测定梗死面积、心肌细胞凋亡和心室恢复情况来检测心脏保护作用。白藜芦醇使Akt和CREB磷酸化，这一作用被MRS-1191阻断，MRS-1191也消除了白藜芦醇的心脏保护能力。LY294002完全抑制Akt磷酸化，但部分阻断CREB的磷酸化。抑制PI3-激酶也部分阻断了白藜芦醇对心脏的预处理能力。PD098059部分阻断CREB的磷酸化以及白藜芦醇介导的心脏保护作用。用LY294002和PD098059共同预灌注心脏完全消除了CREB的磷酸化，同时抑制了白藜芦醇介导的心脏保护作用。结果表明，白藜芦醇通过腺苷A(3)受体信号通路对心脏进行预处理，该信号通路通过依赖Akt和不依赖Akt的途径触发CREB的磷酸化，从而产生心脏保护作用。
