老龄大鼠心脏缺血预处理后热休克蛋白27的变化研究  

Expression of Heat Shock Protein27 in Rat Myocardium Damaged by Ischemia-Reperfusion

作　　者：路艳[1] 陈莹[2] 李宗斌[1] 赵玉生[1] 

机构地区：[1]中国人民解放军总医院老年心血管病研究所,北京市100853 [2]北京清华大学玉泉医院

出　　处：《中国全科医学》2011年第12期1308-1310,1320,共4页Chinese General Practice

基　　金：国家自然科学基金资助项目(30440071)

摘　　要：目的观察热休克蛋白(HSP)27在青年大鼠及老年大鼠心肌缺血预处理时的mRNA和蛋白表达量及变化规律。方法大鼠在体心脏经缺血5 m in、再灌注5 m in(反复3次)预处理后,于0、5、15、45、60 m in取左心室缺血的前壁与非缺血的后壁肌组织分别匀浆,采用RT-PCR方法观察缺血预处理对青年及老龄大鼠HSP27 mRNA在不同时间点表达的改变情况,离心取上清液及沉淀蛋白分别用W estern B lot检测HSP27在预处理不同时刻可溶性蛋白及不溶性蛋白含量的改变。新鲜冷冻心肌组织采用免疫荧光方法标记HSP27,在激光共聚焦显微镜下观察青年大鼠及老年大鼠在缺血预处理后HSP27在不同时间点的分布情况。结果 (1)经缺血预处理后约15 m in,老年大鼠及青年大鼠HSP27 mRNA的表达即有所增加。(2)青年大鼠心脏缺血预处理后即刻前壁缺血组织HSP27从胞质(上清液)移至不溶性成分细胞骨架(沉淀),至15 m in时大部分移到沉淀中,在45 m in时HSP27则几乎全部复位到上清液中。(3)免疫组织学检查显示青年大鼠HSP27在IPC后15 m in向Z线及润盘部位聚集;老年大鼠中HSP27移位程度与青年大鼠相比明显减弱。结论老年大鼠心肌组织中小分子HSP丧失移位能力,可能是老年大鼠缺血预处理保护作用减弱的重要原因之一。Objective Previous studies have shown that the small heat shock proteins（sHSPs） protect the myocardium from ischemia-preconditioning（I/P）-induced damage.The present study is designed to investigate whether the expression of HSP27 in the I/R-induced damaged myocardium is different in aging and young rats.Methods Sixty-four SD rats were prepared to establish I/P models and randomly divided into groups I（n=4,young control）,II（n=20,young model）,III（n=4,aging control）,IV（n=20,aging model）.Heart tissues were collected at different time after I/P-induced damage for further use.RT-PCR and Western blot analysis were performed to determine the expression of HSP27 mRNA and protein.Double immunofluorescence labeling-confocal microscopy was used to observe the translocation of HSP27 after I/P.Results（1） RT-PCR showed that the expression of HSP27 mRNA and protein did not change in aging or adult rats,but the expression of HSP27 mRNA increased after about 15 min ischemia treatment.（2） Western blot demonstrated HSP27 protein in anterior wall of left ventricle transferred from the cytosol to sites of the myofibrillar system immediately after I/P in adult rats as compared with aged rats,HSP27 was found in the myofibrillar syste after about 15 min ischemia treatment,and nearly all HSP27 transferred to cytosol after 45 min ischemia treatment.（3） Immunohistology indicated that after 15 min ischemia pretreatment,HSP27 protein shifted more to Z line and I band in adult rats than in aged rats.Conclusion The present results demonstrate that translocation ability of HSP27 in aging rat reduces,which may explain the reasons for reduced protectve effect on I/P.

关 键 词：老年 大鼠 缺血预处理 心肌 热休克蛋白质类 

分 类 号：R364.12[医药卫生—病理学]