【摘要】 目的研究micro RNA-133(mi R-133)在心肌梗死中心肌的表达,并探讨mi R-133是否通过调节Tgfb1(Transforming growth factor,beta 1)改善心肌梗死后心肌重构的分子机制。方法实验选用成年的C57BL/6J雄性小鼠40只,按要求分为:假手术组(Sham,20只)与心肌梗死组(MI,20只),行左冠状动脉前降支结扎术,建立实验动物模型。采用荧光定量PCR技术(Quantitative RT-PCR)检测20例心肌梗死组和20例假手术组心肌中mi R-133的表达。分离并培养乳鼠心脏成纤维细胞(NMVFs),转染mi R-133 mimics和Tgf b1si RNA至NMVFs细胞,采用Quantitative RT-PCR及Western blot技术检测Ⅰ型胶原(Col1a1)、Ⅲ型胶原纤维(Col3a1)的m RNA及蛋白表达。通过数据库及生物信息学软件预测mi R-133的靶基因,并利用双荧光素酶报告基因系统进行验证。转染靶基因干扰RNA并观察其对NMVFs细胞中Col1a1与Col3a1表达的影响。结果 mi R-133在心肌梗死组心肌中的表达比假手术组明显降低(p=0.002)。体外转染mi R-133可明显降低NMVFs细胞中Col1a1与Col3a1的表达。经生物信息学预测及体外双荧光素酶报告基因系统验证,证实Tgfb1是mi R-133的靶基因。干扰Tgf b1的表达同样能降低NMVFs细胞中Col1a1与Col3a1的表达。结论 mi R-133在心肌梗死中心肌的表达下调,其具有改善心肌梗死后心肌重构的功能。mi R-133可能通过介导Tgfb1调控成纤维细胞的纤维化进而改善心肌梗死后心肌重构的发生。更多还原

【Abstract】 Objective To study the expression of micro RNA-133(mi R-133) in myocardium of myocardial infarction and explore whether mi R-133 can participates in improving myocardial remodeling via Tgfb1(Transforming growth factor, beta 1) after myocardial infarction. Methods 40 adult C57BL/6J male mice were randomly divided into two group: control group(Sham, n=20) and myocardial infarction group(MI, n=20), and the MI group subjected to left anterior descending coronary artery(LAD) occlusion. Quantitative RT-PCR(q RT-PCR) was used to detect the expression of mi R-133 in 20 cases myocardium of myocardial infarction group and control group. The neonatal mouse ventricle fibroblasts(NMVFs) were isolated and cultured. After being transfected with the mi R-133 mimics and Tgfb1 si RNA, the expression of collagen I and collagen III in NMVFs cell was detected using Quantitative RTPCR and Western blot. The targeted gene of mi R-133 in NMVFs cell was predicted by bioinformatics and verified by dual luciferase reporter assay. At the same time, interfering the expression of target gene observed its effect on the expression of collagen I and collagen III in NMVFs cell. Results mi R-133 was down-regulated in the MI group comparing with the Sham group(p=0.002). mi R-133 can decrease the expression of collagen I and collagen III in NMVFs cell. The target genes of mi R-133 was Tgfb1 in NMVFs cell, which was testified by dual luciferase reporter assay. Interfering Tgfb1 gene can also decrease the expression of collagen I and collagen III in NMVFs cell. Conclusions The expression of mi R-133 is down-regulated in myocardium of myocardial infarction. Mi R-133 can regulate the expression of Tgfb1 and participate in the process of improving myocardial remodeling after myocardial infarction.更多还原