脂联素通过分泌型卷曲相关蛋白2及相关通路缓解AngⅡ诱导的心肌肥厚

目的 探讨脂联素(APN)通过调控分泌型卷曲相关蛋白2(SFRP2)及相关通路对血管紧张素Ⅱ(AngⅡ)诱导的心肌肥厚的作用及机制。 方法 出生3d Wistar大鼠中分离出原代心室肌细胞(NRVMs)。采用免疫荧光法检测NRVMs的骨架蛋白α-SMA的表达。将提取的NRVMs分为空白组、1 nmol/L组、10 nmol/L组、100 nmol/L组、500 nmol/L组,检测不同浓度AngⅡ对NRVMs的作用。将NRVMs分为空白组、AngⅡ组、APN+AngⅡ组、AngⅡ+APN+si-sFRP2组、AngⅡ+APN+LiCl组、APN组、SP600125+AngⅡ组以及SB203580+AngⅡ组检测APN对AngⅡ作用的影响。采用Western blotting法检测各组细胞sFRP2的表达量以及Wnt/β-catenin、p38/JNK通路的激活。采用qPCR法检测各组细胞心肌肥厚相关指标以及sFRP2的表达水平。 结果 在NRVMs中加入AngⅡ24 h后,与空白组相比,1 nmol/L组、10 nmol/L组、100 nmol/L组、500 nmol/L组ANP、BNP的表达升高(F_ANP=27.30, P=0.002;F_BNP=38.18, P=0.002),p-JNK和p-p38表达均升高(F_p-JNK=57.65,P<0.001; F_p-p38 =8.880,P=0.018),sFRP2的表达下调(F_AngⅡ=47.53,P<0.001)。加入APN预处理1 h后,与单加AngⅡ组相比,APN+AngⅡ组NRVMs心功能损伤标志物ANP、BNP的表达降低(F_ANP=101.8,P<0.001;F_BNP=51.14,P<0.001),sFRP2的含量上调(F=88.93,P<0.001),同时Wnt/β-catenin(F=41.33,P=0.006)及p38/JNK(F_p38=73.42,P<0.001;F_JNK=39.28,P=0.002)通路的激活被抑制。加入p38/JNK通路抑制剂后,能够达到APN预处理的效果(F_ANP=122.9, P<0.001; F_BNP= 202.3, P<0.001)。 结论 APN可能通过上调sFRP2,抑制Wnt/β-catenin、p38/JNK通路的激活,从而抑制AngⅡ诱导的心肌肥厚。

Adiponectin alleviated angiotensin II induced myocardial hypertrophy through sFRP2 and the related pathways

Objective To explore whether adiponectin(APN)involves in the regulation of angiotensin Ⅱ(Ang Ⅱ)-induced myocardial hypertrophy through secreted frizzled-related protein 2(sFRP2)and to determine the related pathways. Methods Neonatal rat ventricular myocytes(NRVMs)were isolated from 3-day-old Wistar rats to detect the expression of α-SMA, a NRVMs cytoskeleton protein with immunofluorescence. NRVMs were divided into control group, 1 nmol/L group, 10 nmol/L group, 100 nmol/L group and 500 nmol/L group to detect the effects of different concentrations of Ang Ⅱ on NRVMs. NRVMs were then divided into control group, Ang Ⅱ group, APN+Ang Ⅱ group, Ang Ⅱ+APN+si-sFRP2 group, Ang Ⅱ+APN+LiCl group, APN group, SP600125+Ang Ⅱ group and SB203580+Ang Ⅱ group to explore the effects of APN on Ang Ⅱ. The expression of sFRP2 and activation of Wnt/β-catenin and p38/JNK pathways in each group were determined with Western blotting. The indexes related to myocardial hypertrophy and sFRP2 mRNA in each group were determined with qPCR. Results ANP and BNP were increased(F_ANP=27.30, P=0.002; F_BNP=38.18, P=0.002), expressions of p-p38 and p-JNK were increased(F_p-JNK=57.65, P<0.001; F_p-p38=8.880, P=0.018)and expression of sFRP2 was down-regulated(F_AngⅡ=47.53, P<0.001)with Ang Ⅱ treatment for 24 hours compared with control group. APN pretreatment decreased the expressions of ANP and BNP(F_ANP=101.8, P<0.001; F_BNP=51.14, P<0.001), up-regulated the expression of sFRP2(F=88.93, P<0.001), and inhibited the activation of Wnt/β-catenin(F=41.33, P=0.006)and p38/JNK pathways(F_p38=73.42, P<0.001; F_JNK=39.28, P=0.002)compared with the Ang Ⅱ group. The treatment of p38/JNK pathway inhibitors achieved the effects of APN pretreatment(F_ANP=122.9, P<0.001; F_BNP=202.3, P<0.001). Conclusion APN may inhibit Ang Ⅱ induced myocardial hypertrophy by up-regulating sFRP2 and inhibiting the activation of Wnt/β-catenin and p38/JNK pathways.