ERK phosphorylation mediates sildenafil-induced myocardial protection against ischemia-reperfusion injury in mice
ERK phosphorylation mediates sildenafil-induced myocardial protection against ischemia-reperfusion injury in mice
复制标题
DOI：
10.1152/ajpheart.00100.2009
复制
发表时间：
2009-05-01
影响因子：
4.8
通讯作者：
Kukreja, Rakesh C.
中科院分区：
文献类型：
--
作者：
Das, Anindita;Salloum, Fadi N.;Kukreja, Rakesh C.
Das A、Salloum FN、Xi L、Rao YJ、Kukreja RC。 ERK 磷酸化介导西地那非诱导的小鼠心肌针对缺血再灌注损伤的保护作用。 Am J Physiol Heart Circ Physiol 296：H1236-H1243，2009。首次发表于 2009 年 3 月 13 日； doi:10.1152/ajpheart.00100.2009.-西地那非是 5 型磷酸二酯酶的选择性抑制剂，通过激活 cGMP 依赖性蛋白激酶 (PKG) 诱导针对心肌缺血再灌注损伤的强大保护。我们进一步假设生存激酶 ERK 的 PKG 依赖性激活可能通过诱导内皮一氧化氮合酶 (eNOS)/诱导型一氧化氮合酶 (iNOS) 和 Bcl-2 在西地那非诱导的心脏保护中发挥致病作用。我们的结果表明，在整体缺血再灌注之前，在 Langendorff 离体小鼠心脏中急性冠状动脉内输注西地那非可显着减少心肌梗死面积（从 29.4 +/- 2.4% 至 15.9 +/- 3.0%；P < 0.05）。与 ERK 抑制剂 PD98059 联合治疗消除了西地那非诱导的保护作用 (31.8 +/- 4.4%)。为了进一步评估 ERK 在延迟心脏保护中的作用，在全身缺血再灌注前 24 小时用西地那非 (ip) 治疗小鼠。在西地那非治疗前 30 分钟施用 (ip) PD98059。梗死面积从对照组的 27.6 +/- 3.3% 减少到西地那非治疗小鼠的 7.1 +/- 1.5%（P < 0.05）。 PD98059 也消除了西地那非的延迟保护作用 (22.5 +/- 2.3%)。蛋白质印迹显示，治疗 24 小时后，西地那非显着增加 ERK1/2 和 GSK-3 β 的磷酸化，并诱导心脏中 iNOS、eNOS、Bcl-2 和 PKG 活性。 PD98059 抑制 iNOS、eNOS 和 Bcl-2 的增强表达以及 GSK-3 beta 的磷酸化。 PD98059 对西地那非诱导的 PKG 激活没有影响。我们的结论是，这些研究提供了第一个直接证据，表明 PKG 依赖性 ERK 磷酸化对于诱导 eNOS/iNOS 和 Bcl-2 以及由此产生的西地那非心脏保护作用是不可或缺的。
Das A, Salloum FN, Xi L, Rao YJ, Kukreja RC. ERK phosphorylation mediates sildenafil-induced myocardial protection against ischemia-reperfusion injury in mice. Am J Physiol Heart Circ Physiol 296: H1236-H1243, 2009. First published March 13, 2009; doi:10.1152/ajpheart.00100.2009.-Sildenafil, a selective inhibitor of phosphodiesterase type 5, induces powerful protection against myocardial ischemia-reperfusion injury through activation of cGMP-dependent protein kinase (PKG). We further hypothesized that PKG-dependent activation of survival kinase ERK may play a causative role in sildenafil-induced cardioprotection via induction of endothelial nitric oxide synthase (eNOS)/inducible nitric oxide synthase (iNOS) and Bcl-2. Our results show that acute intracoronary infusion of sildenafil in Langendorff isolated mouse hearts before global ischemia-reperfusion significantly reduced myocardial infarct size (from 29.4 +/- 2.4% to 15.9 +/- 3.0%; P < 0.05). Cotreatment with ERK inhibitor PD98059 abrogated sildenafil-induced protection (31.8 +/- 4.4%). To further evaluate the role of ERK in delayed cardioprotection, mice were treated with sildenafil (ip) 24 h before global ischemia-reperfusion. PD98059 was administered (ip) 30 min before sildenafil treatment. Infarct size was reduced from 27.6 +/- 3.3% in controls to 7.1 +/- 1.5% in sildenafil-treated mice (P < 0.05). The delayed protective effect of sildenafil was also abolished by PD98059 (22.5 +/- 2.3%). Western blots revealed that sildenafil significantly increased phosphorylation of ERK1/2 and GSK-3 beta and induced iNOS, eNOS, Bcl-2, and PKG activity in the heart 24 h after treatment. PD98059 inhibited the enhanced expression of iNOS, eNOS, and Bcl-2 and the phosphorylation of GSK-3 beta. PD98059 had no effect on the sildenafil-induced activation of PKG. We conclude that these studies provide first direct evidence that PKG-dependent ERK phosphorylation is indispensable for the induction of eNOS/iNOS and Bcl-2 and the resulting cardioprotection by sildenafil.