血管紧张素Ⅱ对血管外膜成纤维细胞亚群转化的影响

Effect of angiotensin Ⅱ on phenotypic transformation in vascular adventitial fibroblast subpopulations

目的：探讨血管紧张素Ⅱ（Ang Ⅱ）对大鼠胸主动脉血管外膜成纤维细胞亚群转化的影响。方法：采用克隆环法进行血管外膜成纤维细胞的单克隆培养,逆转录聚合酶链反应（RT-PCR）和免疫荧光染色方法鉴定细胞纯度;随机分为对照组和Ang Ⅱ（10-1 000 nmol/L）组,采用荧光定量聚合酶链式反应（FQ-PCR）、免疫荧光染色和Western blot法检测α-平滑肌肌动蛋白（α-SMA）的表达情况。结果：克隆环法获得血管外膜成纤维细胞2个亚群：圆形细胞亚群和纺锤形细胞亚群。自分型后,从第3代至第8代,纺锤形细胞亚群的α-SMA表达量有减少趋势,而圆形细胞亚群的α-SMA表达量显著增多。在Ang Ⅱ诱导下,纺锤形细胞亚群和圆形细胞亚群的α-SMA表达量均增多,且圆形细胞亚群随Ang Ⅱ浓度（10-1 000 nmol/L）的增加,α-SMA的表达量显著增多（P〈0.01）。Western blot实验结果显示,Ang Ⅱ能刺激圆形细胞亚群更多地转化为肌成纤维细胞。结论：Ang Ⅱ能不同程度地影响外膜成纤维细胞亚群的分化能力,进一步揭示出2个细胞亚群在血管重构过程中扮演不同角色。

AIM：To explore the effect of angiotensin Ⅱ（ Ang Ⅱ） on phenotypic transformation in adventitial fibroblast subpopulations isolated from rat thoracic aorta.METHODS：Vascular adventitial fibroblasts were individually expanded by the method of cloning rings.The isolated cells were identified by reverse transcription-polymerase chain reaction（ RT-PCR） and immunofluorescence staining.The rat vascular adventitial fibroblasts were cultured in vitro and incubated with or without Ang Ⅱ.Using the methods of fluorescence quantitative polymerase chain reaction（ FQ-PCR）,immunofluorescence staining and Western blot,the expression of α-smooth muscle actin（ α-SMA） was detected.RESULTS：The spindle cells and round cells were isolated by the method of cloning rings.From passage 3 to passage 8,α-SMA expression was decreased in the spindle cells,and increased significantly in the round cells.Induced by Ang Ⅱ,the expression of α-SMA was increased in the 2 cell subpopulations,and that in the round cells was significantly increased（ P〈0.01）.The results of Western blot indicated that Ang Ⅱ stimulated the subpopulation of the round cells to transfer to myofibroblasts.CONCLUSION：Ang Ⅱ promotes the phenotypic transformation of adventitial fibroblast subpopulations,and the 2 subpopulations may play an important role in vascular remodeling and reparative process.