Hepatocyte Growth Factor-induced Differentiation of BMSCs toward Hepatocyte-like Cells via the NF-κB and P38MAPK Signaling Pathway

Abstract

Bone marrow mesenchymal stem cells(BMSCs) have great potential ability of multi-directional differentiation and reproductive activity. Recent studys have demonstrated that BMSCs can be induced into hepatocyte-like cells. However, the molecular mechanism of hepatocellular differentiation remains unknown. In this study, we investigated the nexus between p38 MAPK and NF-κB signaling pathway in the process of the hepatocellular differentiation. We isolated BMSCs from femurs and tibias of rats. The third generation were divided into three main groups: induction group, inhibition group and negative control group. Hepatic differentiation was induced by 10% fetal bovine serum with hepatocyte growth factor(HGF). The inhibitors of p38 (SB203580) and NF-κB(BAY 11-7082) were added to the differentiation medium for inhibition of signaling molecular activities. Morphological characteristics and transferring function of the differentiated cells were examined by indocyanine green (ICG) uptake assay. Immunohistochemical staining was used to evaluate the protein expression position of NF-кB. And western blot analysis was used to detect the protein expression of several markers, including the specifc markers of hepatocytes(AAT), phosphorylated-p38(p-p38) and NF-кB. NF-кB were observed transferred into nuclear in the induction group. The respective inhibitors inhibited the expressions of NF-кB and p-p38 effectively. Compared to the induction group, expressions of specifc marker, AAT, were decreased visibly in the p38 and NF-κB inhibitor-treated groups. Notably, expression of NF-κB were significantly lowered in the p38 inhibitor-treated group. These data suggest both NF-κB pathway and p38MAPK pathway participate in the hepatocellular differentiation of BMSCs, p38MAPK can affect the regulation of NF-κB to this process of differentiation.