自发性高血压大鼠心肌组织microRNA-97a与TGF-β1蛋白表达的改变及意义

Expression of microRNA-97a and TGF-β1 protein in myocardium of spontaneously hypertensive rats and its significance

目的观察Micro RNA-97a(miRNA-97a)与TGF-β1蛋白在自发性高血压大鼠(SHR)心肌组织中的表达改变和关系。方法取8只8周龄雄性自发性高血压大鼠为SHR组,8只8周龄雄性Wistar大鼠为对照组,通过无创血压测量分析系统测大鼠尾动脉血压,8周后股动脉放血处死大鼠,HE染色观察大鼠心脏形态学改变,PCR法检测大鼠心脏中miRNA-97a的表达,Western blot检测TGF-β1、血管紧张素Ⅱ(AngⅡ)蛋白和I型胶原(Col-Ⅰ)和Ⅲ型胶原(Col-Ⅲ)蛋白的表达水平。结果 SHR组的收缩压和舒张压明显升高,心肌CVF和PVCA明显升高,TGF-β1蛋白,Col-Ⅰ和Col-Ⅲ蛋白的表达水平明显升高,miRNA-97a表达水平明显降低,与对照组比较,差异均有统计学意义(P<0.01)。PCR结果显示,SHR组心肌miRNA-97a表达水平为对照组的(24.6±4.7)%,SHR组心肌组织miRNA-97a与TGF-β1蛋白表达水平呈负相关(r=-0.785,P<0.01)。结论 SHR心肌组织miRNA-97a表达下调,伴随TGF-β1蛋白表达升高和胶原合成增加。miRNA-97a与TGF-β1可能参与SHR大鼠的心肌纤维化。

Objective To observe the changes of microRNA-97 a and transforming growth factor β 1（ TGF-β1）protein in the myocardium of spontaneously hypertensive rats（ SHR）. Methods 8 male spontaneously hypertensive（ SHR） rats as SHR group,8 male Wistar rats for control group,Arterial blood pressure was detected by a noninvasive blood pressure measurement and analysis system. 8 weeks after femoral artery,HE staining was used to observe the changes of morphology of the rat heart,the expression of miRNA-97 a was checked by Real-time PCR method for detection of rat heart. Western blot was used to detect the TGF-β 1,angiotensin II（ Ang II） protein and type I collagen（ Col I） and type III collagen（ Col III） protein expression level. Results In SHR group,systolic blood pressure and diastolic blood pressure increased significantly,TGF-β1 protein and Col I and Col III protein expression levels increased significantly,miRNA-97 a expression levels were significantly lower than that of control group（ P 0. 01）. Real-time PCR results showed that the level of miRNA-97 a expression in SHR group was（ 24. 6 ＋ 4. 7） % in control group,the expression level of miRNA-97 a in SHR group was negatively correlated with the expression of TGF-β1（ r = 0. 785,P 0. 01） in group.Conclusion The level of miRNA-97 a is down-regulated along with the up-regulation of TGF-β 1 protein expression and collagen synthesis in the myocardial tissues of SHR. miRNA-97 a and TGF-β 1 may be involved in myocardial fibrosis in SHR.