Abstract: BACKGROUND AND AIM: To study the differentiation of mouse liver epithelial progenitor cells(LEPCs) to cholangiocytes induced by hairy and enhancer of split 1(Hes1)gene in vitro. MATERIALS AND METHODS: The Hes1 gene was amplified by PCR from mouse tail genomic DNA and subcloned into pEGFP-C1 and pcDNA3.1 vector．LEPCs were transfected and performed in vitro. Cholangiocyte markers, CK19, GGT, HNF6 and HNF1β; hepatocyte markers, GS and BGP; hepatic oval cell marker, Thy-1 were assayed with RT-PCR and Real-time PCR. The fluorescence of the LEPCs tagged with EGFP was observed in vitro. RESULTS: Cholangiocyte markers, CK19, GGT, HNF6 and HNF1β, were up-regulated. Hepatocyte markers GS and BGP, and hepatic oval cell marker Thy-1, were down- regulated. CONCLUSION: It indicated that LEPCs differentiated to cholangiocytes initially in vitro. and Hes1 might play important roles in the differentiation of LEPCs and influence cholangiocyte versus hepatocyte fate determination.

Key words: Hes1, liver epithelial progenitor cell, differentiation, cholangiocyte