Objective: To investigate the differentiation of bone marrow derived Thy-1(+)beta(2)M(-) cells (BDTC) into mature and functional liver cells and its mechanism.
Methods: BDTC were cocultured with allyl alcohol (AA)-injured hepatocytes and cultured alone in conditional medium containing HGF and bFGF, respectively. BDTC morphologic transformation was observed with phase-contrast and electron-microscopy. Hepatocyte-specific gene expression in cultured BDTC was identified by immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Indocyanine green (ICG) ingestion/excretion and urea, albumin production were carried out to evaluate hepatocyte-related function.
Results: Some BDTC derived hepatocyte-like cells with high nuclear to cytoplasmic ratio containing mono- or multi-nuclei and abundant mitochondria, endoplasmic reticulum and glycogenic granules appeared after 7-day culture in both the two culture systems. These cells expressed hepatocyte-specific genes (AFP, OV-6, CK18, etc.), and possessed functions of ICG uptake, albumin production and ammonium metabolism.
Conclusion: Rat BDTCs could differentiate into mature and functional liver cells in special stimulation systems. Moreover, these differentiations were realized by "transdifferentiation", and might dispense with "cell fusion".