Objective: To observe the effects of transforming growth factor-beta 3 gene transfer on type I collagen synthesis of cells of HSC-T6.
Methods: Transforming growth factor-beta 1 expression plasmid and transforming growth factor-beta 3 expression plasmid were constructed. The recombinant expression plasmids pcDNA3.1(+)-TGF beta 1 and pcDNA3.1(+)-TGF beta 3 were respectively transfected and cotransfected into cultured HSC-T6 cells; expression of TGF betav1, TGF beta 3, type I collagen mRNA were detected by real-time quantitative PCR, expression of TGF beta 1 and type I collagen protein were detected by Western blot. The recombinant expression plasmid pcDNA3.1(+)-TGF beta 1 was transfected into cultured HSC-T6 cells; positive clones were selected by G418. The positive clones were transfected by the recombinant expression plasmid pcDNA3.1(+)-TGF beta 3; expression of TGF beta 1, TGF beta 3 and type I collagen mRNA were detected by real-time quantitative PCR; expression of TGF beta 1 and type I collagen protein were detected by Western blot.
Results: HSC-T6 was transfected by recombinant expression plasmid pcDNA3.1(+)-TGF beta 1 and pcDNA3.1(+)-TGF beta 3 and the transfection efficiency was 28.2%. After the cells were transfected with pcDNA3.1-TGF beta 3, type I collagen mRNA and the protein expression in the cells were higher than those in the untransfected cells (control group) (P < 0.05). The increase reached to the maximal at 72 h after the transfection. Expressions of type I collagen mRNA and the protein in the cells transfected by pcDNA3.1(+)-TGF beta 1 were higher than in those cotransfected by pcDNA3.1(+)-TGF beta 1 and pcDNA3.1(+)-TGF beta 3 (P < 0.05). TGF beta 1 protein, type I collagen mRNA and type I collagen protein expression significantly decreased in the clones transfected by recombinant expression plasmid pcDNA3.1(+)-TGF beta 3 (P < 0.05), but the changes of TGF beta 1 mRNA were not significant (P > 0.05).
Conclusions: Expression of type I collagen increased after the cultured HSC-T6 cells were transfected by TGF beta 3 gene. The significant decrease of the expression of type I collagen of the TGF beta 3 gene transfected positive clones suggests that TGF beta 3 could inhibit the occurrence of liver fibrosis.