OBJECTIVETo elucidate the effects of sodium butyrate on rat hepatic oval cell differentiation in vitro.

METHODSHepatic oval cells were isolated from rats fed with a choline-deficient diet supplemented with 0.1% (w/w) ethonine for 4 to 6 weeks. The cultured hepatic oval cells were identified by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). After hepatic oval cells were treated with sodium butyrate, the morphological changes were studied through Giemsa staining and the albumin expression level was tested by Western blot.

RESULTSImmunohistochemical results showed the isolated cells were positive for both mature hepatocyte marker albumin and bile duct cell marker cytokeratin-19. Furthermore, RT-PCR results showed that the cells expressed stem cell marker c-kit, but not hematopoietic stem cell marker CD34. In short, the isolated cells were rat hepatic oval cells. 0.75 mmol/L sodium butyrate induced obvious phenotype changes of hepatic oval cells, including enlargement of the oval cells, a decrease in nucleus to cytoplasm ratio, and a 50% increase in the number of binucleated cells. Western blot results showed that 0.75 mmol/L sodium butyrate markedly raised the expression of albumin.

CONCLUSIONSodium butyrate, a differentiation promoting agent, can induce rat hepatic oval cells (liver progenitor cells) to differentiate into mature hepatocytes in vitro.