[Effects of silicon dioxide on expression of alpha-smooth muscle actin in human lung fibroblasts].
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.
Hu
Yong-bin
YB
Department of Pathology, Xiangya School of Medicine, Centre South University, Changsha 410078, China.
Zeng
Qing-fu
QF
Peng
Jin-wu
JW
Chu
Ling
L
Li
Xiang
X
Wang
Jin-sheng
JS
Jiang
Hai-ying
HY
Wen
Ji-fang
JF
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
D000199:Actins; D053773:Transforming Growth Factor beta1; D012822:Silicon Dioxide