Effect of interferon-gamma on hepatic stellate cells stimulated by acetaldehyde

Liver fibrosis in alcoholics has been linked to the oxidation of ethanol to the highly reactive compound acetaldehyde and accumulating evidence has indicated a close link between alcohol and TGF-beta1. Although, it is considered that IFN-gamma inhibits the transcription of matrix, it has not been well defined whether IFN-gamma could inhibit the expression of matrix induced by acetaldehyde in

HSC were divided into 5 groups, 4 groups were treated with different doses (0, 1000, 1500, 2000 IU/mL) of IFN-gamma and acetaldehyde (200pM) for 24 and 48 h. For the control group, HSC were treated only with medium. The collagen, alpha-SMA, TGF-beta1, Smad4, Smad7 and TGFbetaRI protein expression in HSC were examined by western blot analysis. 5-Bromo-2'-deoxy-uridine (BrdU) labeling assay was used to determine the effect of IFN-gamma on the proliferation of HSC.

IFN-gamma exhibited a dose-dependent inhibitory effect on a-SMA, collagen type I, collagen type III protein expression in HSC (p<0.01); also IFN-gamma implemented a dose-dependent inhibitory effect on TGF-beta1, Smad4 and especially TGFBRI protein expression in HSC (p<0.01). There was no influence of IFN-gamma on HSC proliferation by BrdU labeling assay.

The present data indicated that IFN-gamma could inhibit the collagen expression in HSC stimulated by acetaldehyde. IFN-gamma could down-regulate the TGF-beta1, Smad4 and especially TGFbetaRI in HSC after acetaldehyde stimulation. This experiment showed 1000, 1500, 2000 IU/mL IFN-gamma were effective and safe to down-regulate the extracellular matrix induced by acetaldehyde in vitro.