Regulatory effects of 3 kinds of antifibrotic cytokines an activity of transforming growth factor-β1 gene promoter / 第二军医大学学报

ABSTRACT

Objective: To study the regulatory effects of antifibrotic cytokines, interleukin 10 (IL-10), hepatocyte growth factor (HGF), and interferon-gamma (IFN-γ) on activity of TGF-β1 gene promoter, so as to assess the antifibrotic mechanism of cytokines. Methods: Sequence - 1328-+812 of TGF-β1 gene, which contains the - 509 C>T polymorphism, was selected as putative promoter. The recombinant constructions containing - 1328-+ 812 of TGF-β1 gene and CAT reporter gene (phTGF2. 14T, phTGF2. 14C) were constructed and transfected into HepG2 cells with liposomal transfection method, then the transfected HepG2 cells were treated with IL-10(4 ng/ml), HGF(10 ng/ml) or IFN-γ(20 ng/ml). Reporter gene activity was analyzed by ELISA. Results: Reporter gene activity in cells transfected with phTGF2. 14C was significantly higher than those transfected with phTGF2. 14T (P<0.01). IFN-γ significantly inhibited the reporter gene activity in HepG2 cells transfected with phTGF2. 14C or phTGF2. 14T(P<0.05); HGF significantly increased the reporter gene activity in cells transfected with phTGF2. 14C (P<0.05). IL-10 had no effects on the activities of cells transfected with phTGF2. 14C or phTGF2.14T. Conclusion: C allele at - 509 can increase the promoter activity of TGF-β1 gene in HepG2 cells. The antifibrotic effect of IFN-γ might be related to its inhibitory effect on the putative promoter activity of TGF-β 1 gene; the antifibrotic effects of HGF and IL-10 may not be through regulation of TGF-beta1 gene transcription.