成人胰腺干细胞转分化为胰岛细胞过程中的形态学观察

Morphological Changes of Adult Human Pancreatic Stem Cells Transdifferentiating into Islet Cells.

目的 :观察成人胰腺干细胞转分化为胰岛过程中的形态学变化 ,以便更深入了解有关机制。方法 :人胰腺组织经胶原酶消化后 ,用梯度离心法将胰腺外分泌细胞和胰岛分离 ,混于外分泌组织中的导管上皮细胞即具有转分化潜能的干细胞。在体外经CMRL10 6 6及不含血清的DMEM /F12加多种营养因子的培养液中培养 2 7d ,在培养的不同时间点取细胞作PDX 1、CK 19等单抗的免疫组化染色。光镜和电镜观察不同时间点的细胞形态学变化。结果 :上述方法可获得大量以往在胰岛分离时丢弃的胰腺导管上皮细胞。经体外一定条件的培养后 ,其形态学变化过程为 :导管上皮细胞迅速分裂增殖转变为有分化能力的干细胞继而转分化为胰岛细胞。结论 :成人胰腺的导管上皮具有干细胞潜能 ,并可在体外转分化为大量具有内分泌功能的胰岛。

Objective: To observe the morphological changes of undertaken by the adult human pancreatic stem cells transdifferentiating into islet cells, in order to elucidate the mechanism of the process. Methods: Adult human pancreatic tissue was submitted to digestion by collegenase; the islets were then separated from the exocrine tissue by density gradient centrifugation. Duct epithelial cells were cultivated up to 27 days in CMRL1066 and then in serum-free DMEM/F12 medium with the addition of nutrition factors. Samples were taken at different time points for light and electron microscopy and for immunocytochemistry with antibodies against PDX-1 and CK-19. Results: A large number of duct epithelialial cells were harvested after the isolation of islets. Duct epithelial cells proliferated and expanded and then transdifferentiated into stem cells, and finally into islet cells. Conclusions: Adult pancreatic duct cells are potential stem cells and can be transdifferentiate into islet cells in vitro under certain conditions.