title: [Effects of silicon dioxide on expression of alpha-smooth muscle actin in human lung fibroblasts].
abstract: OBJECTIVE
  To investigate the effects of SiO(2) on the expression of alpha-smooth muscle actin (alpha-SMA) in human lung fibroblasts in vitro and vivo.
  
  
  METHODS
  The experimental group comprised 32 rats while 32 rats were included in the control. In vivo, the expression of alpha-SMA in lung tissues of rats exposed to SiO(2), the supernate of RAW264.7 cells, SiO(2) and the growth factor beta(1) (TGF-beta(1)) were investigated, respectively.
  
  
  RESULTS
  (1) alpha-SMA positive myofibroblasts appeared in the lung tissues of the 28th day groups exposed to SiO(2). (2) The expression of alpha-SMA in HLF-02 cells was unregulated by TGF-beta(1) and supernate of RAW264.7 cells exposed to SiO(2). (3) The expression of alpha-SMA in HLF-02 cells was not induced by SiO(2).
  
  
  CONCLUSIONS
  Myofibroblasts related to silicosis, and the appearance of myofibroblasts (in vitro) are independent on direct stimulation by SiO(2), but related to the mediator (TGF-beta(1)) secreted by SiO(2) stimulated macrophages.
authors.affiliation: Department of Pathology, Xiangya School of Medicine, Centre South University, Changsha 410078, China.
authors.forename: Yong-bin
authors.initials: YB
authors.lastname: Hu
authors.forename: Qing-fu
authors.initials: QF
authors.lastname: Zeng
authors.forename: Jin-wu
authors.initials: JW
authors.lastname: Peng
authors.forename: Ling
authors.initials: L
authors.lastname: Chu
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Jin-sheng
authors.initials: JS
authors.lastname: Wang
authors.forename: Hai-ying
authors.initials: HY
authors.lastname: Jiang
authors.forename: Ji-fang
authors.initials: JF
authors.lastname: Wen
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012822:Silicon Dioxide / Q000494:pharmacology*; D012829:Silicosis / Q000378:metabolism* / Q000473:pathology; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D000199:Actins; D053773:Transforming Growth Factor beta1; D012822:Silicon Dioxide