Runt相关转录因子3在小鼠心肌纤维化中的作用  

Role of runt-related transcription factor 3 in myocardial fibrosis in mice

作　　者：赵谦 邹勇[1] 刘波[1] 余信强[1] 张苏川[1] ZHAO Qian;ZOU Yong;LIU Bo;YU Xinqiang;ZHANG Suchuan(Department of Cardiovascular Diseases,Affiliated Hospital of Jianghan University,Wuhan,Hubei Province,430015,China)

机构地区：[1]江汉大学附属医院心血管内科,武汉430015

出　　处：《第三军医大学学报》2021年第24期2640-2647,共8页Journal of Third Military Medical University

基　　金：湖北省卫生健康委员会课题(WJ2019Q057)。

摘　　要：目的探讨Runt相关转录因子3(runt related transcription factor 3,Runx3)在心肌梗死(myocardial infarction,MI)后心脏成纤维细胞分化、Ⅰ型胶原(collagenⅠ,ColⅠ)合成和增殖中的作用。方法选择C57BL/6J雄性小鼠为研究对象。分为模型组(MI)和假手术组(Sham),MI组采用结扎左冠状动脉建立MI模型,分别在建模后7、14、28 d处死小鼠;Sham组不结扎左冠状动脉。另将Sham组和MI组小鼠建模前尾静脉分别注射Runx3小干扰RNA(si-Runx3)或阴性对照siRNA(si-NC),建模后28 d处死,分为Sham+si-NC组、Sham+si-Runx3组、MI 28 d+si-NC组和MI 28 d+si-Runx3组,每组8只。应用免疫荧光染色和Western blot检测小鼠心脏中Runx3、α-SMA和ColⅠ的水平,采用超声心动图评价心功能,免疫组化方法检测Ki67阳性细胞。体外实验中,从1~3 d龄的C57BL/6小鼠中分离心脏成纤维细胞,观察TGF-β1以不同浓度和刺激时间对细胞中Runx3蛋白影响,并分析Runx3基因敲除对心脏成纤维细胞的ColⅠ合成和增殖的响。结果免疫荧光染色和Western blot结果,随着MI时间的延长,小鼠纤维化区域Runx3、α-SMA和ColⅠ表达上调。MI后28 d,与注射si-NC小鼠相比,注射si-Runx3小鼠左心室射血分数(ejection fraction,EF)、缩短分数(shortened fraction,FS)、心输出量(cardiac output,CO)。上调(P<0.05),而舒张末期左心室内径(decreased left ventricular end-diastolic diameter,LVIDd)和收缩期左心室内径(decreased left ventricular,LVIDs)下调(P<0.05)。MI后28 d,MI诱导的Runx3和α-SMA表达和对Ki67阳性细胞增殖作用被si-Runx3阻断。TGF-β1以浓度和时间依赖性方式上调Runx3蛋白表达;Runx3基因敲除不仅抑制TGF-β1诱导的心脏成纤维细胞分化,减少ColⅠ合成,而且减弱了心脏成纤维细胞增殖。结论 Runx3参与了心脏成纤维细胞分化和增殖。Objective To investigate the role of runt related transcription factor 3(Runx3) in cardiac fibroblasts differentiation,proliferation as well as synthesis of type I collagen after myocardial infarction(MI) in mice.Methods Male C57 BL/6 J mice were selected and randomly divided into model group(MI group,treated with ligation of left coronary artery) and Sham group,and were sacrificed at the 7 th,14 th and 28 th days after modeling(n=6 for each group),respectively.In addition,Runx3 small interfering RNA(si-Runx3) was injected via the tail vein of mice before modeling to achieve Runx3 knockdown,negative siRNA(si-NC) as the matched control.According to the treatment they received,the mice were subsequently allocated into Sham+si-NC group,Sham+si-Runx3 group,MI 28 d+si-NC group and MI 28 d+si-Runx3 group(n=8),and were sacrificed in 28 d after modeling.The levels of Runx3,alpha-smooth muscle actin(α-SMA) and type I collagen in the heart were determined by immunofluorescence staining and Western blotting.The cardiac function was evaluated by echocardiography,and Ki67 positive cells were observed using immunohistochemical assay.After cardiac fibroblasts were isolated from C57 BL/6 mice and cultured for 1~3 d,and the effects of TGF-β1 at different concentrations and for different stimulation times on Runx3 protein were observed in the cells.The effects of Runx3 gene knockout on type I collagen synthesis and proliferation of cardiac fibroblasts were also analyzed.Results Immunofluorescence staining and Western blotting showed that the expression levels of Runx3,α-SMA and type I collagen in the fibrosis regions were up-regulated with the extended duration of MI.As compared with the MI 28 d+si-NC group,the MI 28 d+si-Runx3 group had increased left ventricular ejection fraction(LVEF),fractional shortening(FS) and cardiac output(P<0.05),and decreased left ventricular end-diastolic diameter(LVIDd) and decreased left ventricular(LVIDs)(P<0.05) in 28 d after MI;the expression levels of Runx3 and α-SMA and the proliferation of

关 键 词：RUNT相关转录因子3 心肌纤维化 心肌梗死 小鼠 心脏成纤维细胞 

分 类 号：R341[医药卫生—基础医学] R363.21