小鼠胚胎干细胞不同分化阶段UGT1a1、UGT1a6和mGST1的表达特征

Characterization of UGT1a1, UGT1a6 and mGST1 at different stages of differentiation of mouse embryonic stem cells

背景:目前对于小鼠胚胎干细胞不同分化阶段的尿普二磷酸葡萄糖醛酞转移酶1a1、尿普二磷酸葡萄糖醛酞转移酶1a6和微粒体谷肤甘肤S-转移酶1表达特征缺乏研究,报道较少。目的:观察小鼠胚胎干细胞不同分化阶段普二磷酸葡萄糖醛酞转移酶1a1、尿普二磷酸葡萄糖醛酞转移酶1a6和微粒体谷肤甘肤S-转移酶1的表达特征。方法:分离培养Wistar大鼠胚胎成纤维细胞,制备饲养层细胞。将胚胎干细胞接种于饲养层细胞上,诱导胚胎干细胞分化为肝细胞,采用Western blot检测尿普二磷酸葡萄糖醛酞转移酶1a1、尿普二磷酸葡萄糖醛酞转移酶1a6和微粒体谷肤甘肤S-转移酶1表达特征,色谱法测定计算微粒体谷肤甘肤S-转移酶1催化活性。结果与结论:在胚胎干细胞在分化为肝细胞过程中,尿普二磷酸葡萄糖醛酞转移酶1a1呈现上升趋势;尿普二磷酸葡萄糖醛酞转移酶1a6在分化起初并未发现其表达,而在分化第18天后表达相对较高;微粒体谷肤甘肤S-转移酶1在胚胎干细胞分化为干细胞整个过程中均具有较高的表达,但表达丰度均低于成年小鼠干细胞。干细胞分化第18天,肝组织微粒存在微粒体谷肤甘肤S-转移酶1催化活性为7.65μmol/(min·g)。结果表明,胚胎干细胞分化为肝细胞过程中,尿普二磷酸葡萄糖醛酞转移酶1a1相对比较稳定,尿普二磷酸葡萄糖醛酞转移酶1a6在分化不同过程中呈现出上升趋势,而微粒体谷肤甘肤S-转移酶1在胚胎干细胞分化为肝细胞过程中表达甚微。

BACKGROUND：Until now, limited information has been neported on the characterization of udines 5-diphosphateglucuronosyl transferase （UGT） 1a1, UGT1a6, and microsomal glutathione S-transferase 1 （mGST1） during the differentiation of mouse embryonic stem cel s. OBJECTIVE：To observe the expression characteristics of UGT1a1, UGT1a6 and mGST1 at different stages of differentiation of mouse embryonic stem cel s. METHODS：Embryonic fibroblasts from Wistar rats were isolated and cultured as feeder cel s. Mouse embryonic stem cel s seeded onto these feeder cel s were induced to differentiate into hepatocytes. Subsequently, expression of UGT1a1, UGT1a6 and mGST1 was detected using western blot assay, and catalytic activity of mGST1 was determined by high performance liquid chromatography. RESULTS AND CONCLUSION：Increasing UGT1a1 expression was visible during the whole cel differentiation, while UGT1a6 exhibited no expression initial y but a higher level at 18 days of differentiation. mGST1 expression was visible at high level throughout the differentiation, but its expressive abundance was stil lower than that in the adult mouse stem cel s. At 18 days after the beginning of differentiation, the catalytic activity of mGST1 in microsomal liver tissue was 7.65μmol/（min·g）. Taken together, stabilized UGT1a1, increased UGT1a6 and little mGST1 expression are confirmed in the differentiation of embryonic stem cel s into hepatocytes.