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

摘要

Objective To observe the changes of microRNA-97a and transforming growth factor β1 ( 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-97a was checked by Real-time PCR method for detection of rat heart.Western blot was used to detect the TGF-β1, 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-97a expression levels were significantly lower than that of control group (P <0.01).Real-time PCR results showed that the level of miRNA-97a expression in SHR group was (24.6 +4.7)%in control group, the expression level of miRNA-97a 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-97a is down-regulated along with the up-regulation of TGF-β1 protein expression and collagen synthesis in the myocardial tissues of SHR .miRNA-97a and TGF-β1 may be involved in myocardial fibrosis in SHR.%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。