title: [Effect of gene silencing of integrin β1 on the proliferation and secretory function of airway smooth muscle in asthmatic mice].
abstract: OBJECTIVE
  to investigate the effect of gene silencing of integrin β1 on the proliferation and secretory function of airway smooth muscle cells (ASMC) in asthmatic mice.
  
  
  METHODS
  integrin β1 gene was silenced by using RNAi technology in the fifth generation ASMC of normal and asthmatic mice. The integrin β1 mRNA expression and integrin β1 protein were analyzed by RT-PCR and Western blot respectively before and after the integrin β1 gene silencing in ASMC. The cell proliferation changes of ASMC were measured by MTT assay before and after gene silencing of integrin β1. The cell cycle distribution and apoptosis rate were analyzed by flow cytometry. The expression of interleukin (IL)-6 and RANTES were analyzed by ELISA assay.
  
  
  RESULTS
  (1) integrin β1 mRNA expression by RT-PCR (0.907 ± 0.041) was significantly higher in asthma control group compared with normal control group (0.527 ± 0.027) (t = 24.632, P < 0.05), and was significantly decreased in asthma siRNA intervention group (0.503 ± 0.034) compared with asthma control group (t = 24.079, P < 0.05). There was no significant difference in the normal group compared with the intervention group (t = 1.077, P > 0.05). (2) Integrin β1 protein expression (0.733 ± 0.067) was significantly higher (t = 13.622, P < 0.05) in the asthma control group compared with normal control group (0.386 ± 0.044), and was significantly reduced in the asthma siRNA intervention group (0.453 ± 0.074) compared with the control group (t = 8.880, P < 0.05). There was no significant change in the normal control group after the intervention (t = 1.908, P > 0.05). (3) The absorbance value was significantly enhanced in the asthma control group compared with the same period of normal control group (t = 9.528, 5.799, 3.372, all P < 0.05), and was significantly reduced in asthma siRNA intervention group compared with the same period of asthma control group (t = 2.684, 2.546, 2.897, all P < 0.05), and no significant changes in normal group after the intervention (t = 0.067, 1.198, 0.589, all P > 0.05). (4) The S + G(2)/M phase ratio of ASMC was significantly higher in asthma control group [(49 ± 4)%] compared with normal control group (34 ± 4)% (t = 8.035, P < 0.05), and was significantly lower in the asthma siRNA intervention group [(42 ± 7)%] compared with asthma control group (t = 2.212, P < 0.05), and no significant changes in normal control group after the intervention (t = 0.699, P > 0.05). (5) The apoptosis rate was significantly lower in asthma control group [(3.9 ± 1.4)%] compared with normal control group [(7.4 ± 0.5)%] (t = 7.465, P < 0.05), and was significantly higher in asthma siRNA intervention group [(12.6 ± 2.4)%] compared with asthma control group (t = 9.839, P < 0.05), but no significant changes in normal control group after the intervention (t = 2.094, P > 0.05). (6) The secreted IL-6 [(545 ± 28) ng/L] and RANTES [(345 ± 28) ng/L] were higher in asthma control group compared with the normal control group [(219 ± 26) ng/L, (138 ± 16) ng/L, respectively, t = 26.789, 20.451, all P < 0.05], and was significantly decreased in the asthma siRNA intervention group [(347 ± 26) ng/L, (250 ± 24) ng/L] compared with asthma control group (t = 6.192, 4.590, all P < 0.05), while there was no significant difference in the normal control group after the intervention.
  
  
  CONCLUSIONS
  gene silencing targeting integrin β1 inhibited proliferation and secretion, but promoted apoptosis of ASMC from asthmatic mice.
authors.affiliation: Department of Respiratory Medicine, Second Clinical Medical College, Jinan University, Shenzhen 518020, China. szchester@163.com
authors.forename: Chen
authors.initials: C
authors.lastname: Qiu
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Diao
authors.forename: Hui
authors.initials: H
authors.lastname: Qi
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Ren
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis; D001249:Asthma / Q000235:genetics / Q000473:pathology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D020868:Gene Silencing; D019012:Integrin beta1 / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000378:metabolism; D012137:Respiratory System
chemical_list: D019012:Integrin beta1