Abstract: 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 caveolae in airway smooth muscle cells (ASMCs) were observed by electron microscopy [EM]. The histopathology change of pulmonary tissues were observed by light microscope. The smooth muscle 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 (MβCD) to disrupt caveolae group (group E).SMCs proliferation of each group were examined by CCK-8. The protein expressions of caveolin-1and pERK were detected by western blot and the mRNA expressions of ERK were detected 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 pretreated 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 the expressions of protein or mRNA of ERK were significantly decreased in group C and group D (P<0.01), but decreased in group E. CONCLUSION: Caveolin-1 maybe prevent the proliferation of the asthmatic ASMCs, which is most likely mediated by ERK1/2 signal pathway. ROX may increase the expression of caveolin-1 and inhibit the proliferation in cultured ASMCs from chronic asthmatic rats.

Key words: asthma, caveolin-1, ERK1/2, proliferation, roxithromycin