血管紧张素-(1-7)及丝裂原活化蛋白激酶激酶抑制剂U0126对血管紧张素Ⅱ诱导的大鼠右心室心肌成纤维细胞增殖的影响

Effects of angiotensin-(1-7)and mitogen activated protein kinase kinase inhibitor U0126 on angiotensinⅡinduced proliferation of rat right ventricular cardiac fibroblasts

目的通过大鼠右心室心肌成纤维细胞(RVCFs)体外培养,探讨血管紧张素(Ang)-(1-7)及丝裂原活化蛋白激酶激酶抑制剂U0126对AngⅡ诱导的RVCFs的影响。方法提取乳大鼠RVCFs,经过抗波形蛋白免疫荧光法鉴定,传代培养至第3代,随机分为对照组、AngⅡ组、Ang-(1-7)组(分为低、中、高剂量组)、U0126组(分为低、中、高剂量组)。采用噻唑蓝比色法测定各组细胞增殖情况;蛋白质印迹法检测各组Ⅰ型胶原蛋白α1(COL1A1)表达水平;免疫组织化学法测定转化生长因子β1(TGF-β1)表达水平。结果AngⅡ组RVCFs的细胞增殖率明显高于对照组[(141.7±9.6)%比(100.0±0.0)%],Ang-(1-7)低、中、高剂量组,U0126低、中、高剂量组RVCFs的细胞增殖率[(118.2±4.9)%、(52.1±5.9)%、(43.6±2.5)%,(43.0±2.3)%、(43.3±3.7)%、(49.4±4.6)%]均显著低于AngⅡ组(均P<0.05),且Ang-(1-7)对RVCFs增殖的抑制作用呈剂量反应关系。AngⅡ能促进RVCFs COL1A1表达,Ang-(1-7)及U0126对AngⅡ诱导的COL1A1表达均有抑制作用。TGF-β1免疫组化阳性反应分级示对照组(+)、AngⅡ组(+++)、Ang-(1-7)组(++)、U0126组(+)。结论Ang-(1-7)、U0126可部分抵消AngⅡ刺激导致的RVCFs增殖,抑制TGF-β1和COL1A1的蛋白表达。

Objective To investigate the effects of angiotensin(Ang)-(1-7)and mitogen activated protein kinase kinase inhibitor U0126 on angiotensinⅡinduced rat right ventricular cardiac fibroblasts(RVCFs)cultured in vitro.Methods RVCFs of suckling rats were extracted and identified by anti-vimentin immunofluorescence method.The RVCFs were subcultured to the third generation and randomly divided into control group,AngⅡgroup,Ang-(1-7)group(including low,medium,high dose groups)and U0126 group(including low,medium,high dose groups).Methyl thiazolyl trazolium(MTT)was used to detect RVCFs multiplication colorimetric assay.Western blotting was used to measure the expression levels of collagen type 1 alpha 1(COL1 A1).Immunohistochemistry was used to measure the expression levels of transforming growth factor-β1(TGF-β1).Results The cell proliferation rate of RVCFs in AngⅡgroup was significantly higher than that of the control group[(141.7±9.6)%vs(100.0±0.0)%].The cell proliferation rate of RVCFs in Ang-(1-7)low,medium,high dose groups and U0126 low,middle,high dose groups[(118.2±4.9)%,(52.1±5.9)%,(43.6±2.5)%,(43.0±2.3)%,(43.3±3.7)%,(49.4±4.6)%]were significantly higher than those in AngⅡgroup(all P<0.05).The inhibitory effect of Ang-(1-7)on the proliferation of RVCFs showed a dose response relationship.AngⅡcould promote the expression of COL1 A1 in RVCFs,and Ang-(1-7)and U0126 inhibited the expression of COL1 A1 in RVCFs induced by AngⅡ.Immunohistochemical grading of TGF-β1 showed the control group(+),AngⅡgroup(+++),Ang-(1-7)group(++),U0126 group(+).Conclusion Ang-(1-7)and U0126 can partially counteract the proliferation of RVCFs induced by AngⅡand inhibit the protein expression of TGF-β1 and COL1 A1.