摘要
目的 研究miR-21-3p在心肌梗死后心肌纤维化重塑中的作用与机制。方法 选取40只C57雄性小鼠,随机分为正常组、假手术组、心肌梗死+病毒对照组、心肌梗死+miR-21-3p抑制组各10只。利用miR-21-3p mimics转染心肌成纤维细胞,转染48 h以后,利用实时定量PCR及免疫荧光的方法检测mi R-21-3p对心肌成纤维细胞分化以及胶原合成的影响;手术完成4周后行小动物心脏超声、Masson染色以及定量PCR检测各组实验小鼠心功能状态及心肌纤维化程度。利用双荧光素酶实验以及蛋白电泳实验,明确miR-21-3p与磷酸酶和张力蛋白同源物(PTEN)的调控关系。结果 miR-21-3p在心梗组织中显著上调,miR-21-3p表达上调可以显著促进心肌成纤维细胞的增殖、迁移以及分化功能;相较于心肌梗死+病毒对照组,心肌梗死+miR-21-3p抑制组小鼠的左心室射血分数显著改善[(36.12±6.54)%比(18.72±4.23)%,P<0.05],左心室舒张末容积内径显著减少[(3.54±2.13)mm比(5.67±1.42)mm,P<0.05],同时伴有心肌纤维化面积的显著减轻[(23.42±2.69)mm^(2)比(42.12±7.15)mm^(2),P<0.05]。MiR-21-3p可以靶向结合PTEN的3’非编码区(3’UTR),并抑制PTEN的蛋白表达。结论 MiR-21-3P通过抑制PTEN的表达,介导心肌梗死后心肌纤维化的发生以及心功能的恶化。
Objective To explore the role and mechanism of miR-21-3p in myocardiac fibrosis after myocardial infarction(MI).Methods Forty male mice were randomly divided into 4 groups as the control group(n=10),sham group(n=10),MI-NC group(n=10)and MI-miR-21-3p inhibitors group(n=10).The myoardiac fibroblasts were transfected with miR-21-3p mimics for 48 hours,and then qPCR and immunofluorescence were used to assess the influence of miR-21-3p on the myocardiac fibroblasts differentiation and collagen production.Four weeks post-MI,cardiac function and the severity of pathological myocardiac fibrosis were assessed by echocardiography and Masson staining respectively in each group of the experimental mice.Dual luciferase activity assay and western blotting were used to verify the relationship between miR-21-3p and phosphatase and tension homologue(PTEN).Results MiR-21-3p was significantly upregulated in the tissue of MI.Echocardiograph showed that MiR-21-3p inhibitors remarkably improved cardiac function post-MI compared with the MI-NC group,as indicated by the higher ejection fraction[(36.12±6.54)%vs.(18.72±4.23)%,P<0.05]and the smaller left ventricular end diastolic diameter[(3.54±2.13)mm vs.(5.67±1.42)mm,P<0.05].Consistently,a less severity of myocardiac fibrosis was detected in the MI-miR-21-3p inhibitors group than in the MI-NC group as assessed by Masson staining[(23.42±2.69)mm2 vs.(42.12±7.15)mm2,P<0.05].Furthermore,dual luciferase activity assay and western blot verified that miR-21-3p targeted 3’UTR of PTEN and inhibited the expression of PTEN in protein level respectively.Conclusion MiR-21-3p promoted myocardiac fibrosis and aggravated cardiac function following MI by targeting PTEN.
作者
姜威芳
潘丽婷
李为真
JIANG Wei-fang;PAN Li-ting;LI Wei-zhen(Department of Cardiology,Jiading Branch of Shanghai General Hospital(Jiangqiao Hospital,Jiading District),Shanghai 201800,China)
出处
《中国心血管病研究》
CAS
2023年第1期56-60,共5页
Chinese Journal of Cardiovascular Research
基金
上海市第一人民医院嘉定分院“科技创新项目”(202116A)
上海市嘉定区第五批医学重点学科资助项目(2020-jdyxzdxk-16)。
