Objective    To study the inhibitory effect of mycophenolate mofetil (MMF) on expression of TGF-β in pulmonary fibroblasts (WI26 cells) and its application value.     Methods    Pulmonary fibroblasts were divided into control group

MMF group

TGF-β group

and MMF+TGF-β group

after routine culture. Expression of TGF-β-induced COL1A1 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Expression of COL1 proteins was detected by Western blot analysis and chloramphenicol acetyl transferase assay

respectively. Difference in contractility of collagen fibers and migration of cells was observed in collagen matrix contraction test and cell scratch test.     Results    The expression level of COL1A1 mRNA was higher in MMF group than in control group 24 and 48 h after treatment with MMF (77.0%±2.9% vs 38.0%±3.7%)

and was lower in MMF group than in control group 24 and 48 h after treatment with TGF-β and MMF+ TGF-β (134.0%±3.1% vs 189.0%±2.4%

and 95.0%±2.7% vs 71.0%±3.3%

P0.05)

indicating that MMF can inhibit the expression of COL1A1 mRNA 48 h after treatment with TGF-β.  The expression level of COL1A1 protein was 44.0%±1.9%

145.0%±1.5%

and 79.0%±2.5% lower in MMF

TGF-β

and MMF+ TGF-β groups

respectively

than in control group

48 h after treatment with TGF-β

indicating that MMF can suppress the expression of COL1A1 protein. Collagen matrix contraction test and cell scratch test showed that MMF can inhibit the growth of fibroblasts.     Conclusion    MMF can protect cells against TGF-β-induced fibrosis.