miRNA-21与JAK2-STAT3通路在心肌缺血后处理保护心肌中的相互影响  

Crosstalk between miRNA-21 and JAK2-STAT3 Pathway in Protective Effect of Myocardial Ischemic Postconditioning

作　　者：薛才广[1] 梁德刚[1] 魏民新[1] 田轶魁[1] 

机构地区：[1]天津医科大学总医院心血管外科,300052

出　　处：《天津医药》2013年第5期451-454,共4页Tianjin Medical Journal

基　　金：国家自然科学基金资助项目(项目编号:81041042);天津市应用基础及前沿技术研究计划项目(项目编号:10JCZDJC19200)

摘　　要：目的观察miRNA-21在缺血后处理心肌保护机制中的作用,并探讨其与JAK2-STAT3通路在心肌缺血后处理保护心肌机制中的相互影响。方法将健康雄性成年Wistar大鼠随机分为假手术组(Sham组)、缺血再灌注损伤组(I/R组)、缺血后处理组(PostC组)、缺血后处理+miRNA-21抑制物处理组(PostC+antagomiR-21组)和缺血后处理+AG490组(PostC+AG490组)。原位末端脱氧核苷酸转移酶标记(TUNEL)法检测心肌细胞凋亡指数;Westernblot法检测总STAT3(t-STAT3)及磷酸化STAT3(p-STAT3)蛋白水平;荧光实时定量(qRT)-PCR检测心肌组织miRNA-21表达水平。结果与I/R组相比,PostC组再灌注后心肌细胞凋亡指数显著减少,miRNA-21表达水平及STAT3磷酸化水平显著上调。使用antagomiR-21可显著削弱PostC心肌保护作用。PostC+antagomiR-21组与PostC组相比,STAT3的磷酸化水平显著降低。PostC+AG490组与PostC组比较,STAT3的磷酸化水平及miRNA-21表达均显著降低。结论 miRNA-21在PostC心肌保护机制中发挥调控作用。在后处理适应性机制中STAT3与miRNA-21可能存在某种回路调控机制。Objective To investigate the protective effect of miRNA-21 on myocardial ischemic postconditioning, and to explore the interaction effects in the mechanism of myocardial protection with JAK2-STAT3 pathway in ischemic post- conditioning. Methods The healthy adult male Wistar rats were randomly divided into five groups： sham group, ischemia-re- peffusion injury group （I/R）, ischemic postconditioning group （PostC）, ischemic posteonditioning ＋ antagomiR-21 treatment group （PostC ＋ antagomiR-21）, and ischemic postconditioning ＋ AG490 group （PostC ＋ AG490）. In situ terminal deoxynucle- otidyl transferase labeling （TUNEL） staining was used to analyze myocardial apoptotic index. Western blot was used to detect total STAT3 （t-STAT3） and phospho-STAT3 （p-STAT3） protein levels. The miRNA-21 levels were detected by quantitative reverse transcriptase-polymerase chain reaction （qRT-PCR）. Results Compared with I/R group, the myocardial apoptotic index was significantly reduced in PostC group after reperfusion, and the expression levels of miRNA-21 and STAT3 phos- phorylation were significantly up-regulated. The protective effect of isehemic postconditioning was significantly weakened by antagomiR-21. The phosphorylation level of STAT3 was significantly decreased in PostC ＋ antagomiR-21 group than that of PostC group. Compared with PostC group, levels of STAT3 phosphorylation and miRNA-21 were significantly lower in PostC＋ AG490 group. Conclusion miRNA-21 plays a regulatory role in myocardial ischemic postconditioning. JAK2-STAT3 path- way and miRNA-21 may be some kind of loop regulatory mechanism in post-processing adaptive mechanism.

关 键 词：心肌再灌注损伤 微RNAs 原位缺口末端标记 细胞凋亡 STAT3转录因子 大鼠 WISTAR 缺血后处理 

分 类 号：R542.22[医药卫生—心血管疾病]