OBJECTIVETo explore whether the mesenchymal stem cells (MSCs) of rats can be induced into hepatocytes and the condition of differentiation in vitro.

METHODSMesenchymal stem cells were collected from the femora of SD rats by density gradient centrifugation and identified by flow cytometric analysis and alkaline phosphatase (AKP) staining. MSCs were divided into 4 groups to induce differentiation with the different concentration of hepatocyte growth factor (HGF) in culture medium. The concentration of each group was group A 0 ng/ml, group B 10 ng/ml, group C 20 ng/ml and group D 40 ng/ml, respectively. The morphological changes of MSCs were observed by phase-contrast microscope. On day 1, 3, 7, 14, 21 and 28, mRNA of albumin, AFP and CK18 of MSCs of each group were examined by reverse transcription polymerase chain reaction (RT-PCR), and the expressions of them were also detected with immunohistochemistry technique.

RESULTSMesenchymal stem cells collected from the femora of SD rats expressed antigens of CD29, CD44 and CD90, but not CD34 and CD45. AKP staining was negative for all of MSCs. On day 7, AFP mRNA of MSCs in group C and D could be detected by RT-PCR, and increased on day 14, and then directed on day 21. Albumin and CK18 mRNA of MSCs in group C and D could also be detected from day 14 to day 28 by RT-PCR. On the contrary, mRNA of AFP, CK18 and albumin was not detected in group A and B of culture. Immunocytochemical analysis for CK18, albumin and AFP showed positive staining reaction for AFP on day 7, for CK18 and albumin on day 14 in group C and D, and negative staining reaction both in group A and B of culture.

CONCLUSIONMSCs of adult rats cultured in high concentration of HGF can differentiate into hepatocytes.