Inhibitory effects of HGF on TGF-[$1 induced a-SMA and extracellular matrix synthesis in cultured fibro-blasts derived from urethral scar

Objective To examine the inhibitory effects of HGF on TGF-β1 induced a-SMA andextracellular matrix synthesis in cultured fibroblasts derived from urethral scar. Methods Fibroblasts isolated from urethral scar were cultured ex vivo. After the fibroblasts reached confluence, cells were detached using trypsin/ethylenediamine tetra-acetic acid. All experiments were performed using the cells at the fourth passage. At 80~ confluence, TGF-~I （5 ng/ml） and HGF （10-40 ng/ml） were added to the culture medium. After 72 hours co-incubation, the mRNA of a-SMA was studied by RTPC1K The productions of collagen I, Ⅲ and fibronectin in supernatants were also examined using ELISA. Results TGF-β1 markedly induced a-SMA mRNA expression in cultured fibroblasts. Howev- er, HGF could abrogated TGF-β1-induced a-SMA mRNA expression in a dose-dependent manner （P〈 0. 05）. The levels of collagen type I were 0. 51 ± 0. 04,0. 78 ± 0. 05,0. 71 ± 0. 02,0. 63 ± 0. 03, and 0. 57 ± 0. 02 in control, TGF-β1, TGF-β1 ＋ 10 ng/ml HGF, TGF-β1 ＋ 20 ng/ml HGF, and TGF-β1 ＋ 10 ng/ml HGF group, respectively. The levels of collagen type III were 0. 12 ±0. 0l, 0. 29± 0. 02, 0. 21 ±0. 02,0. 14 ±0. 01, and 0. 08 ±0. 01 in control, TGF-131, TGF-β1 ＋ 10 ng/ml HGF, TGF-β1 ＋ 20 ng/ml HGF, and TGF-β1 ＋ 10 ng/ml HGF group, respectively. And the levels of fibronectin were 0.24±0.03,0.51 ± 0.02,0.49 ± 0.01,0.38 ± 0.02,0.28 ± 0.01 in control, TGF-β1, TGF-β1 ＋ 10 ng/ml HGF, TGF-β1 ＋ 20 ng/ml HGF, and TGF-β1 ＋ 10 ng/ml HGF group, respectively. TGF-β1 significantly stimulated collagen I,Ⅲ and fibroneetin production in fibroblasts （P〈0. 01）. However, HGF could reduced abrogated the up-regulation of collagen I, III and fibronectin induced by TGF-β1 in a dose-dependent manner （P〈0. 05）. Conclusions HGF can effectively inhibit TGF-131 induced a- SMA and extracellular matrix synthesis in cultured fibroblasts derived from urethral scar. Key words: Hepatocyte growth factor;  Transforming growth factor beta; Urethral scars;  Fibroblasts; α-smooth muscle actins