成人胰腺干细胞分离及转分化为胰岛的研究

目的 通过对成人胰腺干细胞分离和转分化为胰岛过程的研究以便更进一步了解及改进胰腺干细胞分离、培养、鉴定方法。方法 成人胰腺组织以胶原酶消化，密度梯度离心法获得纯化的胰腺外分泌细胞、导管上皮细胞和胰岛。导管上皮细胞在体外共培养27d，观察细胞形态学变化及干细胞特异性转录基因PDX—1，CK—19蛋白等的表达。结果 上述方法可获得大量胰腺导管上皮细胞。体外培养第1天即可见PDX—1，CK—19阳性细胞，胰腺导管上皮细胞迅速分裂增殖并转变为有分化能力的干细胞继而转分化为三维结构的胰岛细胞。培养27d后，平均每克胰腺组织可生成760个胰岛。结论 用改进的方法可获得大量成人胰腺导管上皮细胞，并可在体外转分化为大量具有内分泌功能的胰岛，可能为克服胰岛移植的供体短缺提供一条新途径。

Adult human pancreatic stem cells' isolation and transdifferentiation to islet cells

Objective To study the transdifferentiation of pancreatic stem cells to islet cells through isolation,cultivation and transdifferentiation of adult human pancreatic duct cells.Methods Adult human pancreas was digested with collagenase followed by density gradient to purify islets from acinar and ductal tissue.Duct epithelial cells were cultivated for up to 27 days.Samples were taken to observe the morphological changes and the expressions of transdifferentiation gene PDX-1 and protein CK-19 by immunocytochemistry.Results A large number of duct epithelial cells were harvested after the isolation of islets.Some duct epithelial cells were positive for PDX-1 and CK-19 at first day and the duct epithelial cells proliferated and expanded rapidly and then transdifferentiated to stem cells and finally 3D islets.760 islets/g pancreatic tissue were harvested on day 27.Conclusion A large number of adult pancreatic duct cells could be isolated and transdifferentiated to islet cells in vitro under the improved conditions,which might provide a novel way to overcome the donor shortage of islet transplantation.