转录因子NKx2-5表达在大鼠右心室心肌重塑模型的变化

Expression of homeobox transcription factor NKx2-5 in experimental rat of right ventricular myocardial remodeling

目的:观察增加大鼠右心室压力负荷后,右心室心肌重塑与同源盒转录因子NKx2-5表达的变化。方法:注射野百合碱(MCT)制作大鼠肺动脉高压模型,测量大鼠不同时间点肺动脉压和右心室肥厚指数;采用RT-PCR法和Westernblot分析,分别测定右心室心肌NKx2-5及其下游基因心房利钠因子(ANF)的mRNA及蛋白表达。结果:注射MCT后第14天,右室心肌明显肥厚,NKx2-5与ANF的mRNA及蛋白表达亦明显增加,与其呈明显正相关。结论:右心室壁压力负荷增加可作为原发性刺激,使在心脏胚胎发育早期表达的心脏同源盒基因NKx2-5表达增加,NKx2-5在成熟心肌重塑中可能起作用。

Objective:To investigate the expression of the cardiac-specific homeobox transcription factor Nkx2-5 in right heart ventricular remodeling associated with pulmonary hypertension induced by monocrotaline(MCT). Methods:MCT was delivered as a single subcutaneous injection(60 mg/kg) into male Sprague-Dawley rats. The mean pulmonary arterial pressure(mPAP) was measured by right-heart catheterization. The weight ratio of the right heart ventricle(RV) to that of left ventricle and septum weight(LV+S)[RV/(LV + S)] was measured and calculated. RT-PCR and Western blot were used to detecte expression of NKx2-5 and ANF. Results:After 14 days of MCT injection, the right ventricular hypertrophy was found. RV/(LV+SP) of the model group was larger than that of the control group. The expression of NKx2-5 and ANF in right heart ventricular tissue began to increase significantly 14 days after the injection of MCT. Conclusion:The right ventricular pressure overload can evoke increasing of NKx2-5 expression, which will be expressed during cardiac development. This suggests NKx2-5 may play a role in the induction of adult myocardial remodeling.