In vitro differentiation of rat mesenchymal stem cells to hepatocyte lineage

OBJECTIVES Mesenchyme is a type of undifferentiated loose connective tissue that is derived mostly from mesoderm. Recently, mesenchymal stem cells (MSCs), as adult stem cells (ASCs) able to divide into a variety of different cells, are of utmost importance for stem cell research. In this research, ability of the liver extract to induce differentiation of rat derived omentum tissue mesenchymal stem cells (rOT-MSCs) into hepatocyte cells (HCs) was investigated. MATERIALS AND METHODS After isolation and confirmation of rOT-MSCs they were co-cultured with liver extract and hepatogenic differentiation was monitored. Expressions of mesenchymal stem cell markers were also analyzed via flow cytometry. Moreover, expressions of octamer-binding transcription factor-4 (Oct-4), Wilm's tumor suppressor gene-1 (WT-1), albumin (ALB), alpha fetoprotein (AFP), cytokeratin-18 (CK-18), and mRNAs were analyzed using RT-PCR on days 16, 18 and 21. ALB production was analyzed by immunocytochemistry and western blot. Furthermore, glycogen and urea production were determined via periodic acid-Schiff (PAS) staining and colorimetric assays respectively. RESULTS The phenotypic characterization revealed the positive expressions of CD90, CD44 and negative expression of CD45 in rOT-MSCs. These cells also expressed mRNA of Oct-4 and WT-1 as markers of omentum tissue. Differentiated rOT-MSCs in presence of 6 µg/ml liver extract expressed ALB, AFP, CK-18, glycogen and urea as specific markers of HCs. CONCLUSION These observations suggest that liver extract is potentially able to induce differentiation of MSCs into hepatocyte lineage and can be considered an available source for imposing tissue healing on the damaged liver.