Effects Of Recombinant Transforming Growth Factor-β₃ Gene On Hepatic Fibrosis-related Protein Expressions Intracullular And Extracellular Of Hepatic Stellate Cell

Objective:Liver fibrosis is caused by over deposition of extracellular matrix (ECM) in liver. Transforming growth factor (TGF)-β₁ plays a pivotal role in the process of liver fibrosis, it can inhibit the regeneration of hepatic cells, promote the activation of hepatic stellate cell (HSC) as well as enhance the deposition and reduce the degradation of ECM. There have been some researches showing that TGF-β₃ performs an anti-fibrosis function under certain conditions, but no study has thus far specifically demonstrated the relation between TGF-β₃ and the liver fibrosis. This study aims at exploring the influence of recom-binant TGF-β₃ on protein synthesis and secretion intracellular and extracellular of HSC, so as to investigate the effect of TGF-β₃ on anti-liver fibrosis.Methods: Plasmid pcDNA3.1 (+)-TGF-β₃ and pcDNA3.1 (+)-TGF-β₁ were well con-structed. A positive cell clone stably and highly expressing TGF-β₁ was established after being screened by G418 medium, and the positive cloneswere transfected by recombinant TGF-β₃. HSC-T6 cells were cultured and divided into four groups: blank control group; pcDNA3. 1 (+)-enhanced green fluorescent protein (EGFP)-transfected group ( negative control group ) ; pcDNA3. 1 (+)-TGF-β₁ transfected group (TGF-β₁ positive clone group ) ; pcDNA3. 1 (+)-TGF-β₃ transfected positive clones group (TGF-β₃ interfered group). West-ern blot and ELISA were respectively used to detect the protein synthesis and secretion of TGF-β₁, typeⅠcollagen, matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1.Results: The protein expressions of TGF-β₁, typeⅠcollagen, MMP-2 and TIMP-1 in the TGF-β₁ positive clone group were obviously higher than those in the blank control group and negative control group (P < 0. 05), while the protein expression of MMP-9 was significantly lower. Compared with the TGF-β₁ positive clone group, the protein expres-sions of TGF-β₁, typeⅠcollagen and TIMP-1 in TGF-β₃ interfered group were much low-er (P < 0. 05), and MMP-2 was lower, but the difference had no statistical significance. The protein expression of MMP-9 was obviously higher (P < 0. 05).Conclusions: Recombinant TGF-β₃ reduces the synthesis and secretion of typeⅠcollagen, and inhibits the collagen deposition by adjusting the expression of matrix metal-loproteinases and their inhibitors.