Effects of Hepatocyte Growth Factor on TGF-β1 Triggered Tubular Epithelial-Myofibroblast Transdifferentiation by CTGF in vitro

Objective To observe the effects of hepatocyte growth factor (HGF) on TGF-β1 triggered tubular epithelial-myofibroblast transdifferentiation(TEMT) and on the expression of connective tissue growth factor (CTGF). Methods The morphology of transdifferentiate tubular cells was observed using phase-contrast microscopy and scanning electron microscopy. α-SMA was assessed by immunohistochemistry and semiquantified by mean intergrated opitical density (IOD). The level of fibronectin (FN) in the culture supernatant was measured by ELISA. CTGF mRNA expression was examined by RT-PCR. Results The TGF-β1-induced TEMT characterized by expression of α-SMA was shown by immunohistochemistry. TGF-β1 was also shown to stimulate the secretion of FN in cultured supernatant and the CTGF mRNA expression of NRK52E cells. There was no statistically significant difference between HGF-treated groups and control group in the result of α-SMA immunostaining and the level of FN, except that CTGF mRNA expression was slightly increased in the HGF-treated groups. The addition of HGF inhibited the TGF-β1-induced TEMT, the secretion of FN, and the CTGF expression of NRK52E cells, there was a significant correlation between the expression of CTGF and the expression of α-SMA. Conclusion HGF could block TEMT and FN secretion triggered by TGF-β1, which implies that HGF could participate in renal interstitial fibrosis as a negative regulator. The negative regulation of transdifferentiation of HGF may be partially achieved by attenuation of CTGF expression.