肝细胞分化过程中肝细胞极化分子的表达与调节

Expression and modulation of hepatocyte polarity molecules during hepatocyte differentiation

目的研究肝细胞极化标志分子在体外成人骨髓间充质干细胞向肝细胞分化过程中的表达和分布。方法从成人骨髓中分离间充质干细胞,在体外诱导分化为成熟肝细胞。应用溴甲酚绿法和免疫荧光法检测白蛋白的表达。应用实时定量PCR方法观察肝细胞极化标志蛋白多药耐药相关蛋白2(MRP2)、清道夫受体B1(SR-B1)和钠-牛磺胆酸共同转运多肽(NTCP)在诱导分化过程中mRNA水平表达。应用免疫荧光方法在共聚焦显微镜下观察MRP2和SR-B1在细胞膜上的分布情况。结果成人骨髓间充质干细胞经诱导后分化表达白蛋白;MRP2、SR-B1和NTCP mRNA随着肝细胞分化成熟呈时间依赖性升高;熊去氧胆酸(UDCA)上调上述mRNA的表达。MRP2和SR-B1在肝细胞膜上呈特征性分区分布。结论成人骨髓间充质干细胞具有向极化肝细胞分化的潜能。肝细胞体外分化可以作为研究肝细胞极化形成和调节机制的良好模型。

Objective To explore the expression and distribution pattern of cell polarization molecules during the hepatocyte differentiation from human bone marrow mesenchymal stem cells in vitro. Methods Adult bone marrow cells were isolated and induced into mature hepatocytes in vitro.The albumin expression in hepatocytes was detected by bromocresol green method and immunofluorescence.The mRNA expression of polarized hepatocyte marker molecules,multidrug-resistance-associated protein-2（MRP2）,scavenger receptor-B1（SR-B1）and Na＋/taurocholate cotransporting polypeptide（NTCP）,was analyzed using realtimce-associated PCR during the culture period.The distribution patterns of MRP2 and SR-B1 were observed by immunofluorescence and confocal microscopy. Results Albumin was found to express in cells after induced by human bone marrow mesenchymal stem cells.The mRNA expression levels of MRP2,SR-B1 and NTCP time-dependently increased during the hepatocyte differentiation.UDCA up-regulated the expression of MRP2,SR-B1 and NTCP mRNA.The location of MRP2 and SR-B1 on the cell membrane was characteristically distributed. Conclusion Human bone marrow mesenchymal stem cells exist a potential to differentiate into mature hepatocytes with polarization capacity.The potential hepatocyte differentiation in vitro provides a useful model for studying the formation and modulation of hepatocyte polarization.