Roxithromycin can induce apoptosis of airway smooth muscle cells from asthmatic rats by up-regulating the expression of P27~(kip-1) protein in vitro

Objective:To observe the effects of Roxithromycin(RXM) on P27 expression and its apoptosisinducing effect in airway smooth muscle cells(AMSCs) in vitro. Methods:ASMCs from asthmatic rats cultured in vitro were exposed to RXM with different final concentrations(10,25,50 and 100μg/mL,that was group R10,group R25,group R50,group R100). Cells without RXM exposure served as the control(group R0). Cell proliferation and apoptosis were examined after the treatment of RXM for 48 h. P27 mRNA and protein expressions were measured by RT-PCR and Western Blot. Activated Caspase-3 and Caspase-9 expressions were determined by Western Blot. Results:Apoptosis rate increased in a dose-dependent manner after the treatment of RXM,while survival rate decreased. Compared with the control group(3.3±1.2)%,apoptosis rate in experimental groups [(5.8±2.2)%,(6.3±1.1)%,(14.8±8.0)%,(39.4±7.9)% respectively for group R10,group R25,group R50,group R100] were higher. P27 mRNA expression(0.31±0.05,0.35±0.07,0.38±0.06,0.47±0.05) and P27 protein expression(0.82±0.29,0.97±0.33,1.02±0.37,1.44±0.18) increased after stimulation,while the measurements in the control group were 0.27±0.05 and 0.37±0.42. Furthermore,activated Caspase-3 and Caspase-9 expressions in experimental groups were much higher than that in the control group. P27 mRNA and protein expressions had a negative correlation with survival rate(rs=0.864,P0.01; rs=0.639,P0.05),but a positive correlation with apoptosis rate(rs=0.684,P0.01; rs=0.622,P0.05). Conclusion:RXM plays a role in anti-proliferation and pro-apoptosis,by up-regulating P27 expression of ASMCs in vitro.