Effect Of Gene Silencing Of Integrin β1 On The Proliferation And Secretory Function Of Airway Smooth Muscle

Objective:In vitro experiments,studying the effect of gene silencing of integrinβ1 on the proliferation and secretory function of airway smooth muscle cells(ASMC) in asthmatic mice,in order to further clarify the pathogenesis of asthma,look for more targeted therapies and provide a theoretical basis.Methods:Mice sensitized with ovalbumin conjuncted with Al(OH)₃,were challenged with repeated exposure to aerosolized ovalbumin,normal and asthmatic ASMC were separaed,purified and cultured from mice and identified as smooth muscle cells by immunocytochemistry;we silenced the integrinβ1 gene of the fifth generation ASMC,compared the content of integrinβ1 by RT-PCR and Western blot,detected the cell proliferation by MTT,estimated the cell cycle and the cell apoptosis by flow cytometry,measured the content of IL-6 and RANTES by ELISA.Results:(1)Airway epithelial cell get hyperplasia,extensive infiltration of inflammatory cells in mice of asthma group,which bronchial wall become thickness,bronchial smooth muscle wall is increased significantly thicker than the normal group(2) asthma PBS control group showed the content of integrinβ1 mRNA(0.9073±0.0406) was significantly higher than normal control group (0.5274±0.0271)by RT-PCR(P＜0.05),and asthma siRNA intervention group(0.5034±0.0342) was significantly reduced than asthma PBS control group(P＜0.05),the normal group was no significant change after the intervention(P＞0.05);(3) asthma PBS control group showed the content of integrinβ1 protein expression(0.7330±0.0670) than normal PBS control group(0.3858±0.0443) was significantly higher by Western blot(P＜0.05),asthma siRNA intervention group (0.4534±0.0735) was significantly reduced than the PBS control group(P＜0.05),the normal group was no significant change after the intervention(P＞0.05);(4) the absorbance value of the asthma PBS control group was significantly enhanced than in the same period in normal PBS control group by MTT(P＜0.05),and the absorbance value of asthma siRNA intervention group was significantly reduced than the same period of asthma PBS control group(P＜0.05),the absorbance value of normal group had no significant changes after the intervention(P＞0.05).(5) asthma PBS control group ASMC in the S+ G2 / M phase ratio(48.7±3.50)%was significantly higher than normal PBS control group(34.59±3.71)%(P＜0.05),and asthma siRNA intervention group ASMC in the S + G2 /M phase ratio(42.4±6.95)%was significantly lower than asthma PBS control group(P＜0.05),the normal group had no significant change after the intervention(P＞0.05);(6) asthma PBS control group apoptosis rate(3.88±1.41)%was significantly lower than normal PBS control group(7.41±0.49)%(P＜0.05),the apoptosis rate of asthma siRNA intervention group was significantly higher (12.56±2.40)%than asthma PBS control group(P＜0.05),normal group had no significant change after the intervention(P＞0.05);(7) Asthma PBS control group secreted IL-6(545.39±27.87pg/ml), RANTES(345.39±27.88pg/ml) higher than the normal PBS control group(219.10±26.57pg/ml, 137.80±15.92pg/ml,P＜0.05),asthma siRNA intervention group(respectively,347.54±25.55pg/ml, 250.04±24.58pg/ml) was significantly lower than asthma PBS control group(P＜0.05),while the normal group was no significant difference after the intervention.Conclusion:The expression of integrinβ1 increased in asthma group,gene silencing targeting integrinβ1 can inhibit ASMC proliferation,reduce asthma ASMC secretory function,promote ASMC apoptosis,has positive significance in asthma therapy.