Hepatogenic differentiation of human mesenchymal stem cells from adipose tissue in comparison with bone marrow mesenchymal stem cells

AIM: To investigate and compare the hepatogenic transdifferentiation of adipose tissue-derived stem cells (ADSC) and bone marrow-derived mesenchymal stem cells (BMSC) in vitro. Transdifferentiation of BMSC into hepatic cells in vivo has been described. Adipose tissue represents an accessible source of ADSC, with similar characteristics to BMSC.METHODS: BMSCs were obtained from patients under-going total hip arthroplasty and ADSC from human adi-pose tissue obtained from lipectomy. Cells were grown in medium containing 15% human serum. Cultures were serum deprived for 2 d before cultivating under similar pro-hepatogenic conditions to those of liver develop-ment using a 2-step protocol with sequential addition of growth factors, cytokines and hormones. Hepatic differ-entiation was RT-PCR-assessed and liver-marker genes were immunohistochemically analysed. RESULTS: BMSC and ADSC exhibited a fibroblastic mor-phology that changed to a polygonal shape when cells differentiated. Expression of stem cell marker Thy1 de-creased in differentiated ADSC and BMSC. However, the expression of the hepatic markers, albumin and CYPs increased to a similar extent in differentiated BMSC and ADSC. Hepatic gene activation could be attributed to in-creased liver-enriched transcription factors (C/EBPβ and HNF4α), as demonstrated by adenoviral expression vec-tors.CONCLUSION: Mesenchymal stem cells can be induced to hepatogenic transdifferentiation in vitro. ADSCs have a similar hepatogenic differentiation potential to BMSC, but a longer culture period and higher proliferation ca-pacity. Therefore, adipose tissue may be an ideal source of large amounts of autologous stem cells, and may become an alternative for hepatocyte regeneration, liver cell transplantation or preclinical drug testing.