Objective   To investigate the effect of hypoxic condition on the expressions of RhoA

ROCK1and connective tissue growth factor (CTGF) in human fetal fibroblasts

and the beneficial effects of fasudil in the hypoxia-induced pulmonary fibrosis. 

    Methods   Human fetal fibroblasts (MRC-5 cells) were cultured under hypoxic condition (37 ℃

5 %CO

2

2%O

2

93%N

2

) for 0

6

12

and 24 h respectively. The cells cultured in a condition of 21%O

2

74%N

2

and 5% CO

2

were used as control. The effect of fasudil was investigated in normal group

hypoxia group and intervention groups (6

12 or 25 μmol/L fasudil) under the corresponding oxygen condition for 24 h. The protein levels of HIF-1α

RhoA

ROCK1

and CTGF were assayed by Western blotting. RT-PCR was performed to detect CTGF mRNA levels. Cell viability was measured by thiazolyl blue (MTT) assay. The concentration of collagen type Ⅰ (Col Ⅰ) in fibroblast cells’ supernatant were determined by ELISA.    Results   The protein levels of RhoA

ROCK1 and CTGF were up-regulated by hypoxia in a time-dependent manner. Different concentrations of fasudil all inhibited the expressions of protein and mRNA of CTGF after 24 h of hypoxia (P0.01

0.05). Compared with the hypoxia for 24 h

fasudil all inhibited cell proliferation activity and the secretion of Col Ⅰ in fibroblast cells’s supernatant for hypoxia 24 h (P0.01).    Conclusion   Hypoxia exerts a potential brotic stimulus probabily through activating Rho/Rock signal pathway

thus up-regulates the expression of CTGF

and finally triggers a series of  brotic responses. These changes could be markedly inhibited by fasudil. Fasudil attenuates hypoxia-induced pulmonary fibrosis

which may be due to suppressing the Rho/Rock signal pathway.