目的:研究氟伐他汀抑制血管紧张素Ⅱ(AngⅡ)与血小板源性生长因子-BB(PDGF-BB)诱导的大鼠血管平滑肌细胞(VSMCs)迁移的可能机制。方法:采用体外培养大鼠胸主动脉平滑肌细胞;用特异性单克隆磷酸化热休克蛋白27(phospho-HSP27)抗体的Western blotting检测HSP27的活性;用FITC-鬼笔环肽标记F-actin并在激光共聚焦显微镜下观察细胞骨架的形态变化;采用改良的Boyden微孔膜双槽法进行细胞迁移实验。结果:AngⅡ和PDGF-BB呈浓度依赖性诱导VSMCs的HSP27磷酸化,使VSMCs内F-actin数量明显增加,纵向平行排列,形成应力纤维丝,并促进细胞迁移。100μmol/L HSP27阻断剂槲皮素可阻抑AngⅡ、PDGF-BB刺激VSMCs后产生的应力纤维丝形成,对AngⅡ、PDGF-BB诱导的VSMCs迁移的抑制率分别为55.3%和53.6%,P〈0.01。氟伐他汀抑制AngⅡ和PDGF-BB诱导的HSP27磷酸化,并有量效关系,抑制作用在10-5mol/L时最显著,最大抑制率分别为42.1%和58.5%,P〈0.01。结论:氟伐他汀可能通过抑制HSP27磷酸化影响VSMCs的迁移。
AIM: To investigate the inhibitory effects of fluvastatin on the migration of rat vascular smooth muscle cells(VSMCs) induced by angiotensin II(AngⅡ) and platelet derived growth factor-BB(PDGF-BB).METHODS: Cultured VSMCs derived from rat thoracic aorta were used.The activity of heat shock protein 27(HSP27) was evaluated by Western blotting with specific phospho-HSP27 antibody.The effect of F-actin polymerization was detected by FITC-phalloidine staining and examined by confocal microscopy.Modified Boyden chamber technique was employed for VSMCs migration assessment.RESULTS: The phosphorylation of HSP27 in VSMCs was increased by the stimulation of AngⅡ and PDGF-BB in a concentration-dependent manner.Treatment with AngⅡ and PDGF-BB resulted in a substantial increase in the number of stress fibers and rearrangement of these structures into ordered parallel arrays.The migration of VSMCs was promoted by AngⅡ and PDGF-BB.Reorganization of actin cytoskeleton stimulated with AngⅡ and PDGF-BB was inhibited by a specific HSP27 inhibitor quercetin(100 μmol/L) pretreatment.The inhibitory rates of 100 μmol/L quercetin on the migration of VSMCs induced by AngⅡ and PDGF-BB were 55.3% and 53.6%,respectively(P0.01).The phosphorylation of HSP27 in response to AngⅡ and PDGF-BB was suppressed by fluvastatin in a dose-dependent manner,and maximal inhibitory rates were between 42.1% and 58.5% with 10-5 mol/L fluvastatin,respectively(P0.01).CONCLUSION: Fluvastatin influences the migration of VSMCs in part by inhibiting HSP27 phosphorylation.