高血压对大鼠血管平滑肌细胞结缔组织生长因子表达水平的影响及其意义

Effect and significance of hypertension on connective tissue growth factor expression in vascular smooth muscle cells in rats

目的:探讨大鼠血管平滑肌细胞(VSMCs)结缔组织生长因子(CTGF)表达水平在高血压血管重构中的变化及其意义。方法:以4周龄及16周龄的自发性高血压大鼠(SHR)为模型,以相同周龄的Wistar-Kyoto(WKY)大鼠为正常对照,采用tail cuff法测量SHR及WKY大鼠尾动脉收缩压。开胸后分离胸主动脉,分别测量胸主动脉中层厚度(M)和管腔内径(L),并计算二者的比值(M/L)。应用免疫荧光技术结合激光共聚焦显微镜观察,对CTGF的表达进行定位及定量检测。采用Western blot分析和实时定量RT-PCR,检测不同周龄的SHR主动脉组织内CT-GF、III型胶原(Col III)蛋白及其mRNA的表达。结果:4周龄SHR主动脉M、L、M/L以及ColⅢ蛋白与mRNA表达水平较同龄的WKY相比,均无显著性差异;但CTGF蛋白及mRNA表达水平均明显增高(P<0.05)。16周龄的SHR与同龄的WKY大鼠相比,胸主动脉的M无明显变化;而L显著增高,M/L显著降低(P<0.01);CTGF和ColⅢ的表达亦显著升高(P<0.01)。结论:实验结果提示,异常的血流动力学因素可调节VSMCs中CTGF的表达,从而引起细胞外基质释放增加,导致血管重构的发生。

AIM：To explore the varied expression level of connective tissue growth factor（CTGF） in rat vascular smooth muscle cells（VSMCs） and its significance.METHODS：Using age-matched Wistar-Kyoto（WKY） rats as control,the lumen diameter（L）,media thickness（M）,and media/lumen ratio（M/L） from 4-week-old and 16-week-old SHR were detected,respectively.Protein expression in vascular cells of WKY rats and SHR was then detected by immunohistochemical techniques and Western blot,and mRNA level was analyzed by real-time reverse transcription-polymerase chain reaction with SYBR（RT-qPCR）.RESULTS：The ratio of L,M and M/L in 4-week-old SHR were similar to that in 4-week-old WKY rats（P0.05）,and the protein and mRNA level of Col III in vascular cells of 4-week-old SHR were also similar to that of age-matched rats WKY rats.CTGF expression was upregulated significantly（P0.05）.In 16-week-old SHR,the ratio of M/L were lower compared with age-matched WKY rats（P0.01）.Protein and mRNA levels of Col III and CTGF in 16-week-old SHR were significantly higher than that of 16-week-old WKY（P0.01）.CONCLUSION：Abnormal hemodynamic changes may regulate CTGF expression in VSMCs.Increased expression of CTGF may contribute to vascular remodeling in hypertension.