[Effects of gene-transfected bone marrow-derived liver stem cell transplantation on accumulation of extracellular matrix in rats with liver fibrosis].

Objective: To explore the effects of urokinase-type plasminogen activator (uPA) gene-modified bone marrow-derived stem cell (BDLSC) transplantation on accumulation of extracellular matrix (ECM) in hepatic tissue in liver fibrosis.

Methods: BDLSCs obtained from 10 male Fisher344 rats were transfected by adenovirus-mediated human uPA (AduPA) in vitro. Twenty-seven female rats were randomly divided into 3 equal groups to undergo subcutaneous injection of carbon tetrachloride to establish liver fibrosis models and then randomly divided into 3 equal groups: model group injected with normal saline via caudal vein, BDLSC group injected with 2 x 10(6) BDLSCs via caudal vein, and BDLSC-uPA group injected with 2 x 10(6) AduPA-transfected BDLSCs. Eight weeks later the serum levels of alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), albumin (ALB), and ECM levels, i.e., hyaluronic acid, laminin (LN), and procollagen III (PC III), were detected. Then the rats were killed with their livers taken out. The hydroxyproline (Hyp) content of the liver was detected by alkaline hydrolysis. RT-PCR was used to examine the expression of collagen I and III (COLI and COLIII), matrix metalloproteinases-2, 3, and 9 (MMP-2, 3, and 9), and tissue inhibitor of metalloproteinase-1 and 2 (TIMP-1 and 2).

Results: Compared with those of the model group the levels of ALT, AST, and TBIL of the BDLSC-uPA group were all significantly lower, and the ALB level was higher (all P < 0.05). The ECM levels of BDLSC-uPA group were all significantly lower than those of the model group or BDLSC group too (all P < 0.05). Hyp content of the liver decreased dramatically. The mRNA expression levels of COLI and COLIII of the liver of the BDLSC-uPA group were significantly lower (38.9 +/- 2.7, 8.5 +/- 1.6), and the mRNA expression levels of MMP-2, -3, and MMP-9 mRNA (157.5 +/- 32.6, 105.5 +/- 14.6, 187.5 +/- 22.8) were significantly higher than those of the model group or BDLSC group (all P < 0.05), but no significant differences were observed in the mRNA expression of TIMP-1 and 2 mRNA between the 3 groups (all P > 0.05).

Conclusion: uPA gene-modified BDLSC transplantation improves the liver function and suppresses the hepatic fibrosis in liver cirrhosis through up-regulating the expression of MMPs and promoting the degradation of ECM.