摘要
目的探讨Janus激酶2/信号转导和转录激活子3(JAK2/STAT3)信号通路在心肌细胞缺氧损伤中的作用。方法体外培养的新生大鼠心肌细胞,构建缺氧模型,按随机数字表法分为正常对照组、缺氧组、JAK2抑制剂AG490处理组和STAT3抑制剂Statti c处理组。采用细胞计数试剂盒CCK-8检测心肌细胞活力,采用比色法检测细胞上清液中的乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)含量,并采用缺口末端标记法(TUNEL)检测各组细胞的凋亡率。采用蛋白质印迹(Western blot)检测JAK2及STAT3蛋白表达及磷酸化情况。结果与正常对照组相比,缺氧组心肌细胞成活率明显降低,为对照组的30.14%±6.23%(P<0.01),细胞上清液中LDH、MDA含量升高明显,分别为(50.11±2.58)U/L和(19.55±1.81)mol/L(均为P<0.01),SOD活力则显著降低,为(10.21±0.57)U/ml(P<0.01),缺氧组凋亡率明显升高,为24.24%±4.37%(P<0.01),JAK2、STAT3磷酸化水平上调。AG490及Stattic预处理后,JAK2及STAT3磷酸化水平降低,心肌细胞成活率明显升高(P<0.01),LDH、MDA含量显著低于缺氧组(均为P<0.01),SOD活力则高于缺氧组(P<0.01)。结论 JAK2/STAT3信号通路参与了缺氧所致心肌细胞损伤,抑制JAK/STAT通路有助于减轻缺氧所致心肌损伤。
Objective To explore the role of Janus kinase 2/the signal transducers and activators of transcription 3 （JAK2/STAT3） signaling pathway in hypoxic injury of myocardial cells. Methods In vitro cultured neonatal rat myocardial cells were exposed to hypoxia and then divided into four groups： control group, hypoxia group, JAK2 inhibitor ACA90 treatment group and STAT3 inhibitor Stattic treatment group. The vitality of myocardial cells was measured by CCK- 8 Kit. Lactate dehydrogenase （LDH）, malonaldehyde （MDA） and superoxide dismutase （SOD） in supernatant of cells were measured by colorimetry. The ratio of cell apoptosis was determined by TUNEL and the levels of STAT3 protein expression and phosphorylation were detected by Western blot. Results Compared with control group, survival rate of myocardial cells was significantly decreased in hypoxia group. LDH and MDA in supernatant were significantly increased and SOD was significantly decreased in hypoxia group. The ratio of cell apoptosis was significantly increased and the levels of phosphorylation of JAK2 and STAT3 were up-regulated in hypoxia group. After AG490 and Stattic pre-treated, however, the levels of phosphorylation of JAK2 and STAT3 were down-regnlated and the survival rate of myocardial cell was significantly increased （ P 〈 0. 01 ） . Conclusions JAK2/STAT3 signaling pathway is involved in hypoxic injury of myocardial cells. JAK/STAT pathway inhibition conduces to reduce myocardial injury by hypoxia.
出处
《中国心血管杂志》
2011年第5期374-377,共4页
Chinese Journal of Cardiovascular Medicine
