Effect of Rho signaling pathway on SiO₂ induced α-SMA expression in human bronchial epithelial cells.
OBJECTIVE
To investigate the role of Rho in SiO₂ induced α-SMA expression in human bronchial epithelial cells (HBECs).


METHODS
HBECs were cultured and stimulated with SiO₂. Immunocytochemistry and Western blot were used to detect the expression of α-SMA. The activity of Rho was determined by GST pull down assay. In the prevention experiment, SiO₂-stimulated HBECs were incubated with Rho inhibitor Y27632, and the expression of α-SMA was examined by Western blot.


RESULTS
With SiO₂ (0-300 μg/mL) treatment, the expression of α-SMA increased gradually, and 200 μg/mL of SiO₂ led to the highest expression of α-SMA which was (5.09±1.98) times of the expression of α-SMA in the control group(P<0.01). HBECs treated with SiO₂ (200 μg/mL) for indicated time (1, 2, 6, 12, and 24 h) showed an obvious increase of Rho activity(P<0.01). Y27632 inhibited SiO₂-induced α-SMA expression significantly, and the inhibition rate of 20 and 30 μmol/L Y27632 was 68% and 75%, respectively (P<0.01).


CONCLUSIONS
Rho signaling pathway may mediate SiO₂ induced α-SMA expression in HBECs.
Department of Pathology, Xiangya School of Medicine, Central South University, Changsha 410013, China.
Xin
X
Jiang
Yongbin
Y
Hu
Guannan
G
Liang
Haiying
H
Jiang
Jianhua
J
Zhou
D000199:Actins / Q000378:metabolism*; D000577:Amides / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D012822:Silicon Dioxide / Q000494:pharmacology*; D054460:rho-Associated Kinases / Q000378:metabolism / Q000502:physiology*
C541116:ACTA2 protein, human; D000199:Actins; D000577:Amides; D004791:Enzyme Inhibitors; D011725:Pyridines; C108830:Y 27632; D012822:Silicon Dioxide; D054460:rho-Associated Kinases