目的：探讨罗红霉素（RXM）经caveolin-1- p- ERK1/2对离体哮喘大鼠气道平滑肌细胞（ASMCs）cyclinD1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，以卵白蛋白致敏和激发复制哮喘气道重塑模型；采用Im-age- Pro Plus Version 6.0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RXM[A组（只含0.1%DMSO）、R10组（含RXM10μg/ml+0.1%DMSO）、R25组（含RXM 25μg/ml+0.1%DM-SO）、R50组（含RXM50μg/ml+0.1%DMSO）、R100组（含RXM 100μg/ml+0.1%DMSO）]干预哮喘ASMCs后细胞的增殖情况， Western blot测定caveolin-1、p- ERK、cyclinD1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ASMCs A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，cyclinD1表达明显低于A组及R10组，差异均有统计学意义（P＜0.05或0.01）；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0.01）。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cyclinD1蛋白表达呈正相关（P＜0.05或0.01）；caveolin-1与p- ERK蛋白表达呈负相关（P＜0.01），与cyclinD1蛋白表达呈正相关（P＜0.01）；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。%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- Dawley 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 wal thickness(Wat/Pbm) and the bronchial smooth muscle thickness(Wam/Pbm) were measured with im-age- pro plus 6.0;the changes of caveolae 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:RXM10μg/mL+0.1%DM-SO, groupR25:RXM 25μg/ml+0.1%DMSO, group R50:RXM50μg/ml+0.1%DMSO, group R100:RXM 100μg/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, Wam/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 al intervention groups was lower than that in group A, particularly in group R100 (P<0.05). The expression of caveolin- 1 in group R100 was significantly higher and the expression of cyclinD1 was significantly lower than those in group A and group R10 (P<0.05 or P<0.01);the expression of P- ERK in group R25, R50, R100 were signifi-cantly lower than those in group A (P<0.05 or P<0.01). There were significantly negative correlation of cellactivity 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 cyclinD1 (P<0.01). Conclusion Roxithromycin inhibits cy-clinD1 expression and cellproliferation in ASMCs from asthmatic rats, which is associated with up- regulation of caveolin- 1 ex-pressions and down- regulation of p- ERK expressions.
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