小鼠肝多能干细胞分化的调控

The regulating factors during the differentiation of mouse hepatic pluripotent stem cells.Abstract.In type Ι, insulin-dependent diabetes, the insulin-producing pancreatic β cells were selectively destroyed as a result of progressive autoimmune response. We don't know what triggers the autoimmune diabetes, have little understanding of the genetic and environmental factors regulating its progression, and have a confused view of the final effector mechanism. Since β cells are perceived as end-stage differentiated cells having limited capacity for regeneration in situ, individuals with IDD resulting from β cells loss or dysfunction require life-long insulin therapy. The β cell replacement therapy could be a cure for type 1 diabetes, however this procedure is limited by the scarcity of material. Some patients with islet transplantation failure, the graft had induced panel reactive antibodies. Pancreatic stem cells may be useful as a source of cells for transplantation in insulin-dependent diabetes. In vitro cultivation would permit genetic modification of these cells to overcome immune reaction. .It was reported that the adult hepatic stem cells could trans-differentiated into pancreatic endocrine hormone-producing cells in vitro and pancreatic ductal tissue could differentiate to form islet cells. We isolated the fetal hepatic stem cells from ED11.5-ED13.5 mice by FACS sorting according to the methods reported by Suzuki A. The isolated cells were cultured with different stimulators, the insulin-producing cells were selected by dithizone staining. The marker gene expression of islet cells were detected by RT-PCR. It was shown that high-glucose and nicotinamide could stimulate insulin expression. The in vivo experiment should be further explored..This study might be a potential approach in cell therapy-based treatment of insulin-dependent diabetes by generating insulin-producing cells from stem cells and nonpancreatic tissue..

I型糖尿病是胰岛β细胞数量减少，胰岛素分泌量绝对缺乏造成糖代谢紊乱，属多基因遗传病，对糖尿病的基因治疗带来很大困难。干细胞治疗无需了解其发病的确切机制， 能克服基因治疗的困难。长期以来，胰岛细胞被认为是分化终末细胞，糖尿病的细胞治疗存在着供体细胞缺乏和免疫排斥等难题。开发胰岛干细胞资源有广泛的应用前景，近年来有报道，体外诱导胰腺管细胞向胰岛细胞分化及肝脏卵圆细胞向胰岛细胞横向分化。在胚胎发育过程中，肝脏和胰腺都来自于内胚层干细胞，日本学者铃木氏报告了小鼠胎肝中有内胚层干细胞存在。我们用流式细胞仪分离小鼠胎肝多能干细胞，在体外培养条件下，诱导肝多能干细胞向胰岛细胞分化，探讨影响肝多能干细胞定向分化的因素。用双硫腙染色法筛选胰岛β细胞， 用RT-PCR 检测标志基因的表达。高浓度的葡萄糖, 烟碱等有刺激胰岛素表达的作用，体内实验有待进一步研究，以建立胰岛β细胞系，开发糖尿病细胞治疗的新资源。