2型血管紧张素受体阻断对离体工作大鼠心脏缺血再灌注后丝裂原活化蛋白激酶激活的影响。

Effect of angiotensin II type 2 receptor blockade on activation of mitogen-activated protein kinases after ischemia-reperfusion in isolated working rat hearts.

作者信息

Kumar Dinender, Menon Vijayan, Ford William R, Clanachan Alexander S, Jugdutt Bodh I

机构信息

Cardiovascular Research Center, Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA.

出版信息

J Cardiovasc Pharmacol Ther. 2003 Dec;8(4):285-96. doi: 10.1177/107424840300800406.

DOI:10.1177/107424840300800406

PMID:14740078

Abstract

BACKGROUND

The stress-responsive mitogen-activated protein kinases (MAPKs) (p38-MAPK, c-Jun NH2-terminal kinase [JNK-1 and JNK-2], and extracellular signal regulated kinases [ERK-1 and ERK-2]) might be involved in angiotensin II (AII)-induced ischemia-reperfusion injury. Cardioprotection induced by AII type 1 (AT1) and type 2 (AT2) receptor blockade during ischemia-reperfusion is associated with protein kinase Cepsilon (PKCepsilon), nitric oxide, and cyclic guanosine monophosphate (cGMP) signaling. Our aim was to assess the effect of selective AT1 and AT2 receptor blockade with losartan and PD123,319, respectively, on MAPK expression after ischemia-reperfusion in isolated working rat hearts.

METHODS

Groups of six hearts were subjected to global ischemia (30 minutes) followed by reperfusion (30 minutes) and exposed to no drug/no ischemia-reperfusion (control), ischemia-reperfusion/no drug, and ischemia-reperfusion with losartan (1 microM), or PD123,319 (0.3 microM) and additional groups. AT1/AT2 receptor expression, MAPKs, PKCepsilon, and cGMP, and changes in mechanical function were measured. Western blotting was done on left ventricular tissue for AT1/AT2, p38/phosphorylated-p38 (p-p38), phosphorylated (p)-JNK-1/-2, phosphorylated (p)-ERK-1/-2, and PKCepsilon proteins; Northern blots for AT1/AT2 mRNA; and enzyme immunoassay for cGMP.

RESULTS

Compared with controls, ischemia-reperfusion induced significant left ventricular dysfunction, decreased AT2 protein and mRNA, increased p-p38 and p-JNK-1/-2, did not change p-ERK-1/-2 or PKCepsilon, and decreased cGMP. PD123,319 improved left ventricular recovery after ischemia-reperfusion, increased AT2 protein and mRNA, mildly increased p-p38, normalized p-JNK-1, did not change p-ERK-1/-2, and increased PKCepsilon and cGMP. Losartan did not change p-p38, increased p-JNK-1, and did not change pERK-1/-2, PKCepsilon, or cGMP.

CONCLUSIONS

The overall results suggest that the activation of p38-MAPK and JNK might be linked to AII signaling and play a significant role in acute ischemia-reperfusion injury as well as in the cardioprotective effect of AT2 receptor blockade.

摘要

背景

应激反应性丝裂原活化蛋白激酶（MAPKs）（p38-MAPK、c-Jun氨基末端激酶[JNK-1和JNK-2]以及细胞外信号调节激酶[ERK-1和ERK-2]）可能参与血管紧张素II（AII）诱导的缺血再灌注损伤。在缺血再灌注期间，1型（AT1）和2型（AT2）血管紧张素受体阻断诱导的心脏保护作用与蛋白激酶Cε（PKCε）、一氧化氮和环磷酸鸟苷（cGMP）信号传导有关。我们的目的是分别评估用氯沙坦和PD123,319选择性阻断AT1和AT2受体对离体工作大鼠心脏缺血再灌注后MAPK表达的影响。

方法

将六组心脏进行全心缺血（30分钟），随后再灌注（30分钟），并分别给予无药物/无缺血再灌注（对照）、缺血再灌注/无药物，以及缺血再灌注加氯沙坦（1μM）或PD123,319（0.3μM）等处理。检测AT1/AT2受体表达、MAPKs、PKCε、cGMP以及机械功能的变化。对左心室组织进行蛋白质免疫印迹检测AT1/AT2、p38/磷酸化-p38（p-p38）、磷酸化（p）-JNK-1/-2、磷酸化（p）-ERK-1/-2和PKCε蛋白；对AT1/AT2 mRNA进行Northern印迹检测；对cGMP进行酶免疫测定。

结果

与对照组相比，缺血再灌注导致左心室功能显著障碍，AT2蛋白和mRNA减少，p-p38和p-JNK-1/-2增加，p-ERK-1/-2或PKCε无变化，cGMP减少。PD123,319改善了缺血再灌注后的左心室恢复，增加了AT2蛋白和mRNA，轻度增加了p-p38，使p-JNK-1恢复正常，p-ERK-1/-2无变化，并增加了PKCε和cGMP。氯沙坦对p-p38无影响，增加了p-JNK-1，对pERK-1/-2、PKCε或cGMP无影响。