[Effects of silica on the expression of plasminogen activator inhibitor-1 and activator protein-1 in human alveolar epithelial cells type II].
OBJECTIVE
To investigate the mechanism of silicosis by observing the effects of silica on the expression of plasminogen activator inhibitor-1 (PAI-1) and activator protein-1 (AP-1) in human alveolar epithelial cells type II (A549).


METHODS
A549 cell and SiO(2) (200 microg /ml) were co-cultured for 0, 4, 8, 16 and 24 h respectively. The reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and SP immunocytochemistry were used for detections of the PAI-1 mRNA and protein expression. The nucleoprotein and total protein expression of AP-1 were investigated by Western blotting.


RESULTS
The expression levels of PAI-1 mRNA and protein were increased in a time-dependent manner(r(mRNA) = 0.911, r(protein) = 0.902, P < 0.05). The expressions of PAI-1 mRNA and protein in experimental groups were higher than that in control group (P < 0.05) and was the highest in 24 h group [(0.73 +/- 0.01) vs (0.36 +/- .03)]. The nucleoprotein expressions of c-jun/c-fos in experimental groups were also higher than in control group (P < 0.05), and the nucleoprotein expression level of c-jun was the highest in 4 h group [(1.54 +/- 0.02) vs (0.56 +/- 0.03)]; the nucleoprotein expression level of c-fos was the highest in 8 h group [(0.36 +/- 0.01) vs (0.15 +/- 0.01)]. Both c-jun and c-fos expression were decreased after 16 h, but the total protein expression of c-jun/c-fos had no difference in all experimental groups. The positive signal of PAI-1 was located in cytoplasm and nucleus.


CONCLUSIONS
SiO(2) could induce PAI-1 expression of A549 in a time-dependent manner, and AP-1 activation can be observed in early time.
Lin
Zhi
Z
Department of Pathology, Monitoring Center for Appraising National Drug Safety, Chinese Institute for Supervision of Drugs and Biological Products in Medicine, Beijing 100050, China. linzhi95013@163.com
Hu
Yong-bin
YB
Feng
De-Yun
DY
Chu
Ling
L
Wang
Jin-sheng
JS
Zeng
Qing-fu
QF
D056809:Alveolar Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D012822:Silicon Dioxide / Q000633:toxicity*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D017395:Plasminogen Activator Inhibitor 1; D018808:Transcription Factor AP-1; D012822:Silicon Dioxide