RESUMEN

Objective:To investigate the mechanism of Smad7 gene modified bone marrow mesenchymal stem cells ( Smad7-BMSCs) to prevent hepatic fibrosis in vitro. Methods:Smad7-EGFP-BMSCs were established by isolating and purifying BMSCs of rats, and transfecting Ad-Smad7-EGFP. HSC-T6 were divided into Group A, Group B, Group C and Group D, which were respectively incubated with Smad7-EGFP-BMSCs, BMSCs, Smad7 plasmid and PBS for 72 hours. The level of Smad7and TGF-β1protein in the culture solution was determined by ELISA. The expression of mRNA and protein of Smad7,TGF-β1,Col Ⅰ and α-SMA in the hepatic stellate cells were respectively determined by Western blot and RT-PCR. Cellular apoptosis was determined by flow cytometry. Results:(1)The results of ELISA showed that the level of TGF-β1 protein decreased(P<0. 01) but the level of Smad7 protein increased (P<0. 01) in Group B,Group C and Group D compared with Group A;the level of TGF-β1 protein decreased(P<0. 01) but the level of Smad7 protein increased (P<0. 01) in Group D compared with Group B and Group C. (2)The results of Western blot and RT-PCR showed that the level of mRNA and protein of Smad7,TGF-β1,Col Ⅰ and α-SMA decreased(P<0. 01) but the level of mRNA and protein of Smad7 protein increased (P<0. 01) in Group B,Group C and Group D compared with Group A;the level of mRNA and protein of Smad7,TGF-β1,ColⅠandα-SMA decreased(P<0. 01) but the level of mRNA and protein of Smad7 protein increased (P<0. 01) in Group D compared with Group B and Group C. (3)The results of flow cytometry showed that the rate of cellular apoptosis de-creased(P<0. 01),but the level of Smad7 protein increased (P<0. 01) in Group B,Group C and Group D compared with Group A;the rate of cellular apoptosis decreased(P<0. 01)in Group D compared with Group B and Group C. Conclusion:Smad7-BMSCs can have the effect of anti-hepatic fibrosis by affecting TGF-β1 signal pathway and promoting cellular apoptosis in hepatic stellate cells.