Effect Of Human UPA Gene-Modified Bone Marrow-Derived Mesenchymal Stem Cells On The PI3K/AKT Signaling Pathway In Rats With CCL4-Induced Hepatic Fibrosis

Objective To explore the therapeutic effect of human urokinase-type plasminogen activator (uPA) gene-modified bone marrow derived mesenchymal stem cells (BMSCs) transplantation on liver fibrosis rats included by carbon tetrachloride (CC14), and to further investigate the effect of uPA gene-modified BMSCs on PI3K/AKT signaling pathway.Methods BMSCs, isolated and cultured in vitro, were transfected with adenoviral vector expressing human uPA(AduPA), and then the AduPA-BMSCs were transplanted into rats with liver fibrosis. Sprague-Dawley (SD) rats with 6-8 weeks old (n=40) were randomly divided into four groups. To induce liver fibrosis, the three groups (n=30) were injected subcutaneously with 40% CC14 every three days for eight weeks. At the end of the fourth week, the four groups were respectively divided into uPA-BMSCs group (injected via the tail vein with 2×106 AduPA-transfected BMSCs, n=10), BMSCs group (injected via the tail vein with 2×106 untransfected BMSCs, n=10), model group (injected via the tail vein with an equal volume of normal saline, n=10) and normal control group (injected via the tail vein with an equal volume of normal saline, n=10). All rats were sacrificed after 8 weeks, Immunohistochemistry was used to detect hepatic stellate stem cell apoptosis and activation. Western blot and quantitative reverse transcription-polymerase chain reaction were used to determine protein and mRNA expression levels.Results The expression ofa-SMA in liver tissues was significantly reduced in in the uPA-BMSCs group compared with BMSCs group and model group, which refers to the reduction of hepatic stellate cell activation; Consistent with this result, a-SMA and TUNEL double immunofluorescence staining showed that the number of apoptosis of activated hepatic stellate cells in liver tissues was obviously reduced in the uPA-BMSCs group compared with the BMSCs group and model group. Contrasted with other groups, the MMP-2 mRNA expression in liver tissues was up-regulated distinctly in the uPA-BMSCs group, whereas the TIMP-1 mNRA and COL-1 mRNA as well as the protein expression of p-pi3k、p-AKT and p-GSK-3p in liver tissues was down-regulated in the uPA-BMSCs group (P< 0.05 for all).Conclusion Transplantation of uPA gene-modified BMSCs can effectively attenuate the carbon tetrachloride-(CC14-) induced liver fibrosis. Furthermore, treatment with uPA gene modified BMSCs also resulted in a decrease in expression of molecules of the PI3K/AKT signaling pathway an.