ABSTRACT
BACKGROUND: Studies of biological characteristics of mesenchymal stem cells (MSCs) and regulatory factors that influenced the differentiation of MSCs have shown that the proportion of the natural differentiation from in vitro primarily cultured MSCs into hepatocytes was low, and to select a suitable inductor is important to enhance the differentiation of MSCs into hepatocytes.OBJECTIVE: To verify the feasibility of induced differentiation of rat bone marrow MSCs (BMSCs) into hepatocytes using the combination of hepatocyte growth factor (HGF), epidermal growth factor (EGF) and fibroblast growth factor (FGF-4).DESIGN, TIME AND SETTING: The cytological in vitro study was performed at the Experimental Center, Weifang Medical College in August 2007.MATERIALS: Totally 40 Sprague-Dawley rats were supplied by the Experimental Animal Center, Weifang Medical College.METHODS: Rat BMSCs were incubated by adherent method. BMSCs at passage 3 were assigned to 2 groups. BMSCs in the blank control group were treated with L-DMEM containing 10% fetal bovine serum. BMSCs in the combination group were treated with 10 μg/L FGF, 8 μg/L HGF and 8 μg/L EGF following above-mentioned procedures.MAIN OUTCOME MEASURES: Inverted microscope was used to observe the morphological changes in cells.Immunofluorescence method was used to observe the expression of alpha-fetoprotein (AFP) and albumin (ALB). PAS was employed to detect the expression of glycogen. Fox green intake experiment was conducted. Enzymology was utilized to test the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP).RESULTS: BMSCs in the combination group presented polygonal, orbicular or round shape. BMSCs in the blank control group remained spindle. BMSCs in the combination group were positive for AFP and ALB at day 14 following culture, and a few PAS-positive and fox green-positive cells were found at day 7. Positive cells became more over time. Synthesis of ALT, AST and ALP was detected at day 14, reached a peak at 21 days, and then decreased. Above-described indexes were negative in the blank control group.CONCLUSION: After induced by the FGF, HGF and EGF, BMSCs have the ability to differentiate into hepatocytes in vitro.