摘要
目的血管外膜成纤维细胞(AF)的表型转化在血管重塑过程中起了重要作用。通过观察血管紧张素Ⅱ(AngⅡ)对血管AF中RhoA/ROCK通路活性的影响,探讨该通路在AF/肌成纤维细胞(MF)表型转化中的作用。方法AngⅡ刺激体外培养的SD大鼠血管AF,测定刺激后10、30min RhoA的活性变化,并分别测定2、6、12、24hROCK底物肌球蛋白磷酸酶目标亚单位1(MYPT1)的磷酸化水平,Western blot检测AF/MF表型转化标记蛋白α平滑肌肌动蛋白(α-SM-actin)的表达,并观察腺病毒dominant negative N19RhoA(dnN19RhoA,MOI=200)和ROCK抑制剂Y27632(10μmol/L)对α-SM-actin表达的影响。结果AngⅡ刺激使AFRhoA活性的明显增强及ROCK底物MYPT1的磷酸化水平明显增加。刺激30min RhoA活性约为未刺激的3倍,刺激12hMYPT1的磷酸化约为未刺激的3.5倍。dnN19RhoA和Y27632均可明显抑制AngⅡ诱导的血管AFα-SM-actin表达,抑制α-SM-actin表达程度均约为75%。结论AngⅡ可激活血管AF中的RhoA/ROCK通路,该通路参与了AngⅡ诱导的血管AF/MF表型转化。
Objective Phenotypic differentiation of vascular adventitial fibroblasts （AF） plays a vital role in vascular remodeling. This study examined the effect of angiotensin Ⅱ （Ang Ⅱ ） on RhoA/ROCK activity in AF, aiming to explore the role of RhoA/ROCK signaling pathway in Ang Ⅱ induced adventitial fibroblasts differentiation to myofibroblasts（MF）. Methods AF were cultured with Ang Ⅱ stimulation （10^-7 mol/L）. Rho pulldown assay was recruited for RhoA activity determination after Ang II stimulation 10 min and 30 min. Phosphorylated MYPT1 （Myosin phosphatase target subunit 1, MYPT1） expression was used to evaluate ROCK activity. Inhibition of RhoA and ROCK was achieved by infection with adenovirus coding dominant negative N19RhoA （dnN19RhoA, MOI=200） or treatment with Y27632 （ 10 μmol/L）, respectively. Results RhoA in AF was activated by Ang Ⅱ , and the expression of phosphorylated MYPT1 was significantly increased, α-SM-actin expression induced by Ang Ⅱ was markedly inhibited by dnN19RhoA and Y27632. Conclusion RhoA/ROCK pathway in adventitial fibroblasts could be activated by Ang Ⅱ , and this pathway is involved in AF/MF differentiation induced by Ang Ⅱ.
出处
《中华高血压杂志》
CAS
CSCD
北大核心
2007年第6期493-496,共4页
Chinese Journal of Hypertension
基金
国家重点基础研究发展计划973计划课题任务书(2004CB518603
2006CB503804)
上海市科委基础重点项目(05JC14038)项目资助
