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Summary: Adipose-derived adult stem (ADAS) cells can be easily obtained in large quantities. Previous studies have suggested that all-trans-retinoic acid (ATRA) plays an important role in the differentiation of mesenchymal stem cells toward an epithelial lineage. In order to verify that ADAS-cells can differentiate into an epithelial lineage retaining most of the characteristics of stem cells, ADAS-cells were isolated and cultured. They were induced to differentiate toward an epithelial lineage in vitro. Differentiated epithelial cells were assayed as to whether they retain characteristics of stem cells by RT-PCR and cell cycle stage analysis, and were further induced to differentiate toward an osteogenic lineage. RT-PCR analysis revealed that no CK5, CK10 or CK19 mRNA was detected in ADAS-cells, CK19 but not CK5 or CK10 mRNA was detected in differentiated cells at passage 1, CK10 and CK19 expression but not CK5 mRNA was detected in differentiated cells at passage 10. After induction, the expression of CK19 was observed by immunofluorescent staining. Positive staining with alkaline phosphatase (ALP) and Von Kossa staining verified that differentiated epithelial cells still had potential to further differentiate toward an osteogenic lineage. These experiments provide proof that ADAS-cells can differentiate into an epithelial lineage retaining most of the characteristics of stem cells. [Copyright &y& Elsevier]

Human embryonic stem cells (hES cells) are pluripotent and provide a unique, unlimited resource for human hepatocytes, which can serve as a novel cell source for cell transplantation and bioartificial liver (BAL). Here, we have developed a procedure by which hES cells can differentiate into hepatocyte-like cells. After being cultured in suspension in bacteriological petri dishes for 7 d, hES cells developed into cystic embryoid bodies (EBs). The EBs were then cultured in conditional medium containing dexamethasone and insulin in collagen type I-coated tissue culture dishes for two weeks. The hES cell-derived hepatocyte-like cells (HLCs) displayed some morphologic characteristics of hepatocytes. Reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence cell staining proved that the induced HLCs expressed several hepatocyte specific genes including AFP, ALB, CYP1B1 and cytokeratins CK18 and CK19. Furthermore, the induced cells executed a range of hepatocyte functions, such as ICG uptake/excretion, glycogen deposits, albumin production and ammonium metabolism. Taken together, our results show that HLCs exhibit similar morphologic, phenotypic, and functional characteristics to hepatocytes. [ABSTRACT FROM AUTHOR]

Studies of transplantation in vivo indicted that bone marrow derived stem cells had a potential to differentiate into mature hepatocytes. However, there are lots of doubts and uncertainties in the influencing factors and control agents of effectively inducing stem cell differentiation in vitro, the efficiency of stem cells' differentiation into hepatocytes and differentiated cells' life-span and functional state, etc. In this study, rat bone marrow derived Thy-l+β2M- cells (BDTCs) were induced to differentiate into hepatocytes by co-culturing with CFSC/HGF feeder layers which expressed hHGF efficiently and stably. RT-PCR and immunofluorescent texts proved induced BDTCs expressed infant and adult hepatocyte specific genes. Further more, these cells displayed functions of indocyanine green (ICG) uptake, ammonium metabolism and albumin production. It was shown that growth factors together with hepatic nonparenchyma cells provided a feasible microenvironment for differentiation of bone marrow stem cells into hepatocytes. The studies not only provided a significant biological model for going deep into the mechanism of stem cell plasticity, but also offered a theoretical and technical foundation of gene and stem cell engineering-based regenerative medicine for end-stage liver diseases. [ABSTRACT FROM AUTHOR]