RESUMO
【Objective】 To use hairy enhancer of split 1 (Hes1) to regulate the differentiation of liver epithelial progenitor cells (LEPCs) into cholangiocytes. 【Methods】 The vectors, pTet-on and pTRE2hyg-Hes1, were transfected into LEPCs. The expression of Hes1 was induced by doxycycline (DOX) with different concentrations (0, 0.1, 1, 5, 10, 50, 100 and 500 μg/mL). The expressions of Hes1, molecular markers of hepatocyte and cholangiocyte, glutathione synthetase (Gss), keratin 19 (Krt19) and hepatic nuclear factor 1β (HNF1β) in LEPCs were verified by Western blotting, RT-PCR, Real-time PCR, immunocytochemistry and immunofluorescence. 【Results】 The expression of Hes1 in LEPCs transfected by pTet-on/pTRE2hyg-Hes1 was increased by 11.21 fold when induced by DOX at 10 ug/mL, which drove the LEPCs to differentiate into biliary epithelial cells. With increasing expression of Hes1, cholangiocyte markers, Krt19 and HNF1β, were significantly upregulated, while the hepatocyte marker, Gss, was obviously downregulated. 【Conclusion】 DOX at 10 μg/mL may induce a suitably up-regulated expression of Hes1 in LEPCs double-transfected by pTet-on and pTRE2hyg-Hes1, and the suitable high-expression rather than over-expression of Hes1 can regulate LEPCs to differentiate into cholangiocytes.
RESUMO
Objective To reconstruct the deformity of appearance and function of patients with bone defect, co-cultured system with two stem cells were combined with partial deproteinized biological bone to reconstruct the defect of tibia which is one of the main weight-bearing bone. Methods The bone marrow and peripheral blood were harvested form 18 New Zealand rabbits to isolated bone marrow stem cells and epithelial progenitor cells, and engineering bone was constructed with co-cultured system with these two stem cells and partial deproteinized biological bones; about 1 CM of bone defect of each rabbit was made with bone rongeur, then engineering bones were transplanted into the defect area, the osteogenesis and bone defect recovery were observed on day 14, 28 and month 2.Results The difference of absorbance values of BMSCs group, co-cultured cell group and blank group at each time point and between groups were all statistically significant (P＜0.001), and the collagen content of bone tissue increased gradually after implantation of tissue engineered bone, and the difference between each group was statistically significant (P ＜0.001). The repairment of bone defect with the PDPBB combined with BMSCs and EPCs system has the strongest ability to repair the structure andfunction of the tibial defect area. Conclusion The engineering bone constructed with two stem cells and partial deproteinized bone is a good material for bone defect reconstruction.