【摘要】 目的 ：探讨miR-320b激动剂对心肌梗死大鼠心室重塑的影响。方法 ：建立心肌梗死大鼠模型，将大鼠随机分为假手术组、模型组、阴性对照组、miR-320b过表达组。RT-PCR检测miR-320b、MHC-α、MHC-β mRNA水平；TTC染色检测心肌梗死面积；超声心动图检测左心室收缩压峰值（LVSP）、左心室舒张末期压（LVEDP）、左心室短轴缩短率（LVFS）和左心室射血分数（LVEF）;H-E染色检测心肌组织形态学；TUNEL染色检测心肌细胞凋亡；免疫印迹检测凋亡相关蛋白表达水平；ELISA检测肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)水平。结果 ：与假手术组比较，模型组大鼠miR-320b、MHC-α mRNA水平降低，MHC-βmRNA水平和心肌梗死面积升高，LVEF、LVFS、LVSP降低，LVEDP升高，心肌组织细胞凋亡率升高，Bax/Bcl-2、cleaved caspase-3/caspase-3、cleaved caspase-9/caspase-9比值升高，TNF-α、IL-1β、IL-6水平升高，差异均有统计学意义。与模型组比较，miR-320b过表达组大鼠miR-320b、MHC-α mRNA水平升高，MHC-β mRNA水平和心肌梗死面积降低，LVEF、LVFS、LVSP升高，LVEDP降低，心肌组织病理损伤程度明显改善，心肌组织细胞凋亡率降低，Bax/Bcl-2、cleaved caspase-3/caspase-3、cleaved caspase-9/caspase-9比值降低，TNF-α、IL-1β、IL-6水平降低，差异均有统计学意义。结论 ：miR-320b过表达可改善心肌梗死大鼠模型心室重塑。更多还原

【Abstract】 Objective : To investigate the effect of miR-320b agonist on ventricular remodeling in rats with myocardial infarction. Methods : Rat models of myocardial infarction were established and randomly divided into four groups: the sham operation group(sham), the model group(model), the negative control group(agomir-NC), and the miR-320b over-expression group(miR-320b agomir). The mRNA levels of miR-320b, MHC-α and MHC-βwere detected by RT-PCR. TTC staining was used to detect myocardial infarction area. Peak left ventricular systolic peak pressure(LVSP), left ventricular end-diastolic pressure(LVEDP), left ventricular fractional shortening rate(LVFS) and left ventricular ejection fraction(LVEF) were measured by echocardiography. H-E staining was used to detect myocardial histomorphology. Cardiomyocyte apoptosis was detected by TUNEL staining and expression of apoptosis-related proteins was detected by Western blotting. The levels of TNF-α, IL-1β and IL-6 were detected by ELISA. Results : Compared with the sham group, the mRNA levels of miR-320b and MHC-α in model group were decreased, while the mRNA levels of MHC-β and myocardial infarction area were increased, while LVEF, LVFS and LVSP were decreased, LVEDP was increased, and the apoptosis rate of myocardial tissue cells was increased. Ratio of Bax/Bcl-2, cleaved caspase-3/caspase-3, cleaved caspase-9/caspase-9, and TNF-α, IL-1β and IL-6 levels were increased with statistical significance. Compared with the model group, mRNA levels of miR-320b and MHC-α in miR-320b agomir group were increased, mRNA levels of MHC-β and myocardial infarction area were decreased, LVEF, LVFS, LVSP were increased, and LVEDAP was decreased. The degree of pathological injury of myocardial tissue was significantly improved. There were decreased apoptosis rate, decreased Bax/Bcl-2, cleaved caspase-3/caspase-3, cleaved caspase-9/caspase-9, decreased TNF-α, IL-1β, and IL-6 levels.The differences were statistically significant. Conclusion : Overexpression of miR-320b can improve ventricular remodeling in rats with myocardial infarction.更多还原