枯草溶菌素转换酶9在大鼠心肌缺血再灌注损伤中的表达变化

Expression of proproteinconvertase subtilisin/kexin type 9 in myocardial ischemia-reperfusion injury in rats

目的:研究枯草溶菌素转换酶9(proproteinconvertase subtilisin/kexin type 9,PCSK9)在大鼠心肌缺血再灌注损伤中的表达变化。方法:采用大鼠心肌缺血再灌注损伤模型,大鼠分4组:对照组(n=5)、实验组分别为缺血45 min再灌注6 h、12 h及24 h组(各组n=5)。实验终点时,收集血液及缺血区心肌组织,全自动生化分析仪测定心肌酶谱(CK、CK-MB和LDH),HE染色观察心肌组织病理学改变,分别采用实时定量PCR及Western blot方法检测心肌PCSK9 mRNA及蛋白水平表达的改变。结果:与对照组相比,实验组CK、CK-MB和LDH在6 h和12 h组均明显升高有统计学意义,24 h组恢复正常;HE染色发现心肌组织病理损伤随着再灌注时间延长而加重;实验各组心肌PCSK9 mRNA及蛋白水平表达均显著高于对照组,并且随着再灌注时间的延长表达水平逐渐增高。结论:PCSK9可能参与心肌缺血再灌注损伤的病理生理过程。

Objective：To investigate the expression of proproteinconvertase subtilisin/kexin type 9（PCSK9） in the rats myocardium impaired by ischemia-reperfusion.Methods：The left descending coronary artery（LAD） of rats was occluded for 45 min,followed by reperfusion of 6,12,or 24 h,respectively.The levels of creatine kinase（CK）,creatine kinase MB（CK-MB） and lactate dehydrogenase（LDH） in serum were measured by automatic biochemical analyzer.The pathological changes in myocardium of rat were examined by HE staining.The expression of PCSK9 in myocardium was detected by RT-PCR and Western blot.Results：The levels of CK,CK-MB and LDH were significantly increased after 6 h and 12 h of reperfusion,and restored to normal level after 24 h of reperfusion.The reperfusion-induced myocardial damage increased in a time-dependent manner.The expression of PCSK9 mRNA and protein were significantly and time-depentently increased by ischemia-reperfusion injury.Conclusion：PCSK9 may be invovled in the myocardial ischemia-reperfusion injury.