微囊蛋白-1蛋白参与哮喘气道平滑肌细胞增殖中ERK1/2调控以及罗红霉素的干预

Prevention by caveolin-1 of the proliferation of the asthmatic airway smooth muscle cells is most likely mediated by ERK1/2 signal pathway and regulation of roxithromycin

目的:在细胞水平研究微囊蛋白-1(caveolin-1)对气道平滑肌细胞(ASMCs)的增殖作用以及对ERK1/2的通路调控,探讨caveolin-1抑制ASMCs增殖的可能机制。方法:复制哮喘大鼠模型,光镜观察肺组织病理变化,透射电镜观察ASMCs上微囊(caveolae)的结构及变化,用组织贴壁法体外培养气道平滑肌细胞,实验设正常对照组(A组)、哮喘组(B组)、ERK1/2信号通路阻断剂PD98059(C组)、罗红霉素组(D组)、caveolae结构破坏药物β-甲基环糊精组(E组);用CCK-8法检测各组细胞的增殖情况,逆转录-聚合酶链测定(RT-PCR)和蛋白质印迹法(Western Blot)检测ERK mRNA和p-ERK1/2蛋白的表达;Western Blot法检测各组caveolin-1蛋白细胞表达。结果:CCK-8检测结果显示D组及C组ASMCs增殖反应低于B组,D组(0.59±0.15)vs B组(0.96±0.14),P<0.05,C组(0.63±0.11)vs(0.96±0.14),P<0.05;E组ASMCs增殖反应较B组进一步活跃(1.26±0.21)vs(0.96±0.14),P<0.05。D组及C组ASMCs上caveolin-1的表达较B组明显升高,P<0.01,pERK1/2蛋白以及ERK mRNA表达较B组降低,E组相反。D组ASMCs的ERK mRNA和p-ERK1/2蛋白表达水平均显著低于B组及E组(P<0.01)。结论:caveolin-1可能是ASMCs内信号转导的负调控蛋白,这一作用可能是通过抑制ERK信号通路实现。罗红霉素可能上调caveolin-1蛋白的表达量,抑制ERK mRNA表达和翻译,从而抑制哮喘大鼠ASMCs的增殖。

AIM： To explore the effect of caveolin-1 on ERK signal pathway in ariway smooth muscle cells （ASMCs） of asthmatic rats and observe regulation of roxithromycin to expression of caveolin-1. METHODS： Asthmatic rats were copied. Morphological of the eaveolae in airway smooth muscle cells （ASMCs） were observed by electron microscopy [EM]. The histopathology change of pulmonary tissues wereobserved by light microscope. The smooth mus- cle cells were isolated by adherent from the bronchial tree in vitro, which were divided into five groups, control group （group A）, asthmatic airway smooth muscle cells group （group E）, MAPKs signal pathway＇ s blocking agent （PD98059） group （group C）, roxithroymcin group （ group D ）, methyl-β-cyclodextrin （MI3CD） to disrupt caveolae group （group E）.ASMCs proliferation of each group were exam- ined by CCK-8. The protein expressions of cave- olin-land pERK were detected by western blot and the mRNA expressions of ERK were detec- ted by RT-PCR. RESULTS：Compared with the control group B, the ASMCs was pretreated with PD98059 and roxithroymcin for an hour, the proliferation on ASMC were weakened, P% 0.05~ in group E, after the ASMCs was pretrea- ted with MβCD, the proliferation on ASMCs were increased, P〈0.05. The expressions of protein of caveolin-1 was significantly increased in group C and group D （P〈0.01）, while theexpressions of protein or mRNA of ERK were significantly decreased in group C and group D （P〈0.01）, but decreased in group E. CONCLU- SION. Caveolin-1 maybe prevent the prolifera- tion of the asthmatic ASMCs, which is most like- ly mediated by ERK1/2 signal pathway. ROX may increase the expression of caveolin-1 and in- hibit the proliferation in cultured ASMCs from chronic asthmatic rats.