血管紧张素Ⅱ与分泌型卷曲相关蛋白5在心肌细胞肥大中相关性研究

Relationship Between Angiotensin Ⅱ,Secreted Frizzled-related Protein 5 and Rat's Cardiomyocyte Hypertrophy in Vitro

目的:探讨分泌型卷曲相关蛋白5(s FRP5)在心肌细胞肥大中的表达情况及其发挥的作用。方法:体外培养SD乳鼠心肌细胞,应用血管紧张素Ⅱ(AngⅡ)诱导心肌细胞肥大。替米沙坦、PD123319分别阻滞血管紧张素1型受体(AT1R)、血管紧张素2型受体(AT2R)的表达,逆转录聚合酶链反应(RT-PCR)及蛋白免疫印迹法(Western bolt)检测sFRP5、脑利钠肽(BNP)及肿瘤坏死因子-a(TNF-a)的表达。结果:s FRP5能够在心肌细胞中表达。sFRP5 mRNA及蛋白水平、BNP蛋白水平的表达随AngⅡ干预时间的延长而增加,48 h达到最高值(P<0.05)。与AngⅡ(10^(-6) mol/L)组相比,AngⅡ+替米沙坦(10μmol/L)组sFRP5 mRNA和蛋白水平显著降低(P<0.05),AngⅡ+PD123319(10μmol/L)组sFRP5 mRNA和蛋白水平差异无统计学意义(P>0.05);与AngⅡ(10^(-6) mo1/L)+sFRP5(0 ng/ml)组比较,AngⅡ(10^(-6) mo1/L)+sFRP5(10 ng/ml)组及AngⅡ(10^(-6) mo1/L)+sFRP5(100 ng/ml)组BNP蛋白及TNF-a的蛋白表达水平明显下降(P<0.05)。结论:在AngⅡ诱导的心肌细胞肥大过程中,主要通过血管紧张素Ⅱ型受体上调sFRP5的表达,且sFRP5在抑制心肌细胞肥大中发挥作用。

Objective： To investigate the expression and effect of secreted frizzled-related protein 5 （sFRP5） in rat＇s cardiomyocyte hypertrophy in vitro. Methods： Neonatal rat＇s ventricular myocytes were cultured in vitro, cardiomyocyte hypertrophy was induced by Ang Ⅱ. Telmisartan and PD123319 were used to block angiotensin type 1 receptor （AT1R） and angiotensin type 2 receptor （AT2R） respectively. RT-PCR and Western-blot analysis were conducted to examine the expressions of sFRP5, BNP and TNF-α. Results： sFRP5 was expressed in cardiomyocytes. The mRNA and protein expressions of sFRP5, protein expression of BNP were increased by prolonged time of AngⅡ treatment, the maximum expression was observed at 48 h, P〈0.05. Compared with Ang Ⅱ （10^-6mol/L） group, the mRNA and protein expressions of sFRP5 in Ang Ⅱ ＋Telmisartan （10 μmol/L） group were decreased, P〈0.05, those expressions were similar in Ang Ⅱ ＋PD123319 （10 μmol/L） group, P〉0.05. Compared with AngⅡ （10^-6 mo1/L）＋sFRP5 （0 ng/ml） group, protein expressions of BNP and TNF-α were decreased inAng Ⅱ （10^-6 mo1/L）＋sFRP5 （10 ng/ml） group and in Ang Ⅱ （10^-6 mo1/L）＋sFRP5 （100 ng/ml） group respectively, P〈0.05. Conclusion： For in vitro process of Ang Ⅱ induced neonatal rat＇s cardiomyocyte hypertrophy, using Ang Ⅱ receptor could up-regulate sFRP5 expression and sFRP5 plays an important role in cardiomyocyte hypertrophy.