罗红霉熬caveolin-1-p—ERK1／2对离体哮喘大鼠气道平滑肌细胞cyclinD1表达的影响

目的探讨罗红霉素（RXM）经caveolin-1-P-ERKl／2对离体哮喘大鼠气道平滑肌细胞（ASMCs）cyclinDl表达的影响。方法将30只SPF级雄性SD大鼠随机均分为对照组和哮喘组，以卵自蛋白致敏和激发复制哮喘气道重塑模型；采用Im—age—ProPlusVersion60图像分析软件测定支气管壁和支气管平滑肌层厚度；透射电镜观察两组大鼠ASMCs微囊表达情况；CCK-8检测不同浓度RXMA组（只含0．1％DMSO）、R10组（含RXMl0．g／ml＋0．1％DMSO）、R25组（含RXM25ug／ml＋01％DM—S0）、R50组（含RXM50ug／ml＋0．1％DMSO）、R100组（含RXM100tJg／ml＋0.1％DMSO）1干预哮喘ASMCs后细胞的增殖情况，Westernblot测定caveolin-1、P—ERK、cyclinDl的蛋白表达。结果哮喘组支气管壁和支气管平滑肌层明显增厚，而微囊表达匮乏。哮喘组大鼠支气管壁与平滑肌层厚度均高于对照组（均P〈0．01）。各RXM干预组ASMCsA值均低于A组，其中R100组明显低于A组（P〈0．05）。R100组caveolin-1表达明显高于A组及R10组，cyclinDl表达明显低于A组及Rt0组，差异均有统计学意义（P〈0，05或O．01）；R25、R50、R100组P—ERK表达均明显低于A组，差异均有统计学意义（P〈0．05或001）。哮喘ASMCs增殖活性与caveolin-1蛋白表达呈负相关（P〈0．05），与P—ERK及cyclinDl蛋白表达呈正相关（P〈005或0．01）；caveolin-1与P—ERK蛋白表达呈负相关（P〈0．01），与cyclinDl蛋白表达呈正相关（P〈001）；P—ERK与cyclinD1蛋白表达呈正相关（P〈0．01）。结论RXM可能通过上调caveolin-1表达、抑制ERK1／2活化，进而影响cyclinD1的表达，从而抑制哮喘大鼠ASMCs增殖。

Effect of roxithromycin on cyclin D1 expression in airway smooth muscle cells of asthmatic rats and its mechanism CHEN Huijun,WANG Rui/i,DA/ Yuanrong. Department of Respiratory Medicine,Jinhua Municipa/ Central Hospita/, Jinhua 321000, China

Objective To investigate the effect of roxithromycin （RXM） on cyclinD1 expression in cultured airway smooth muscle cells （ASMCs）of asthmatic rats and its mechanism. Methods Thirty male Sprague-Dawtey rats were randomly divided into control group and asthmatic group. The chronic asthma was induced by the sensitization and provocation of ovalbumin in rats. The total bronchial wall thickness（Wat/Pbm） and the bronchial smooth muscle thickness（Wam/Pbm） were measured with im- age-pro plus 6.0;the changes of caveotae in AMSCs were observed by transmission electron microscope. The proliferation of cultured ASMCs induced by different concentrations of roxithromycin（group A： 0.1% DMSO, group R10： RXM lOiJg/mL＋0.1%DM- SO, groupR25： RXM 25ug/ml＋0.1% DMSO, group R50： RXM501Jg/mI＋0.1%DMSO, group R 100： RXM 1001Jg/ml＋0.1% DMSO was tested by CCK-8. The protein expressions of caveolin-1, P-ERK, cyclinD1 of ASMCs were measured by Western blot. Results The Wat/Pbm, Warn/Pbm of asthmatic group were significantly higher than those of control group （P〈0.01）. There were a few of caveolae in ASMCs of asthmatic rats. A value in all intervention groups was lower than that in group A, particularly in group RIO0 （P〈0.05）. The expression of caveolin-1 in group RIO0 was significantly higher and the expression of cyclinD1 was significantly lower than those in group A and group R10 （P〈O.05 or P〈O.01）; the expression of P-ERK in group R25, R50, RIO0 were signifi- cantly lower than those in group A （P〈0.05 or P〈0.01）. There were significantly negative correlation of cell activity rate of asth- matic rats with the expressions of caveolin-1 protein （P〈0.05） and positive correlation with the expressions of P-ERK or cyclinD1 protein （P〈0.05 or P〈0.01）. The expression of caveolin-1 protein was negatively correlated with P-ERK and cyclinD1 （P〈0.01）, and the expression of P-ERK protein was positively correlated with eyclinD1 （P〈0.01）. Conclusion Roxithromycin inhibits cy-clinD1 expression and cell proliferation in ASMCs from asthmatic rats, which is associated with up-regulation of caveolin-1 ex- pressions and down-regulation of p-ERK expressions.