title: Roles of Rho/Rock signaling pathway in silica-induced epithelial-mesenchymal transition in human bronchial epithelial cells.
abstract: OBJECTIVE
  To investigate the roles of Rho/Rock signaling pathway in silica-induced Epithelial-mesenchymal transition (EMT) in human bronchial epithelial cells (BEC) in vitro.
  
  
  METHODS
  Human BEC were incubated with silica with various concentrations for indicated times. Cell viability was assayed by MTT test. Morphologic Changes were observed by microscope. Mesenchymal marker α-smooth muscle actin (α-SMA), vimentin (Vim), and epithelial marker E-cadherin (E-cad) were analyzed by Western Blot. The pull-down assay was used to measure Rho activity. In the prevention experiments, the specific inhibitor for Rho effector ROCK (Y27632) was used to inhibit the activity of Rho.
  
  
  RESULTS
  Human BEC stimulated with silica were converted from a "cobblestone" epithelial structure into an elongated fibroblast-like shape structure. Incubation of human BEC with silica induced de novo expression of α-SMA and Vim, and loss of E-cad. Also, silica treatment resulted in Rho activation in human BEC. Y27632 up-regulated the E-cad expression but attenuated α-SMA and Vim expression in silica-stimulated cells.
  
  
  CONCLUSIONS
  The activation of Rho/ROCK signaling pathways is most likely involved in Silica-induced EMT in human bronchial epithelial cells.
authors.affiliation: Department of Pathology, Xiangya Basic Medical School, Central South University, Changsha 410013, Hunan, China.
authors.forename: Yong Bin
authors.initials: YB
authors.lastname: Hu
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Guan Nan
authors.initials: GN
authors.lastname: Liang
authors.forename: Zheng Hao
authors.initials: ZH
authors.lastname: Deng
authors.forename: Hai Ying
authors.initials: HY
authors.lastname: Jiang
authors.forename: Jian Hua
authors.initials: JH
authors.lastname: Zhou
mesh_terms: D000199:Actins / Q000378:metabolism; D001980:Bronchi / Q000166:cytology; D015820:Cadherins / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D011791:Quartz / Q000633:toxicity*; D015398:Signal Transduction; D014746:Vimentin / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D015820:Cadherins; D014746:Vimentin; D011791:Quartz; D054460:rho-Associated Kinases
keywords: Bronchial epithelial cell; Epithelial-to-mesenchymal transition; Rho; Silica