大鼠胰腺干细胞转分化成胰岛细胞的研究

Study of rat pancreatic sten cells diffentiated into pancreatic islet cells

目的 本研究将大鼠胰腺干细胞诱导分化成胰岛细胞,为胰岛移植的临床应用提供可替代资源。方法 大鼠胰腺干细胞经体外培养,免疫组化鉴定CK-19,无血清培养基培养,使其转分化成胰岛,双硫棕染色鉴定。对诱导后胰岛细胞行葡萄糖刺激试验,用RIA法测其胰岛素、C肽的分泌功能并与天然胰岛相比较。结果 胰腺干细胞在体外大量增生,免疫组化显示CK-19阳性,诱导4周后得到胰岛样细胞团,双硫棕染色阳性。检测上清,诱导的胰岛在高糖刺激下胰岛素的分泌量为低糖的5倍;在葡萄糖低浓度（3.8mM）和高浓度（16.5mM）时,诱导的胰岛胰岛素分泌量分别约为天然胰岛的1/28和1/35,C肽分泌量分别为天然胰岛的1/29和1/22。结论 大鼠胰腺干细胞在体外可有效扩增,可转分化为胰岛团,该胰岛团随葡萄糖浓度的高低调节胰岛素。

Objective To diffenrentiate rat pancreatic stem cells into pancreatic islet cells which substitute cell resource for the clinical application of islet transplantation. Methods Rat pancreatic stem cells were cultured in vitro and were identified with CK-19 by immunocytochemical stain. Then, pancreatic stem cells were cultivated in serum-free medium to give rise to islet-like cluster and were identified by DTZ. The islet population＇s function such as insulin and C-peptide secretion was researched by radioimmunoassay （ RIA）and compared with the normal islet cells. Results The rat pancreatic stem ceils could be proliferated efficiently and the immunohistochemistry results showed positive expression of CK-19. After four weeks,there was induction of the stem cells into neoislets that DTZ staining was positive. The neoislets could release insulin and C-peptide in response to glucose as the normal islet could do, in detail, neoislets released insulin in high glucose concentration five times more than in the low. The neols- lets secreted insulin which was 1/28 of the normal in low glucose and 1/35 in the high. They also secreted C-peptide under the same stimulation which was 1/29 of the normal in low glucose and 1/22 in the high. Conclusion Rat pancreatic stem cells can be expanded efficiently and differentiated into endocrinal cells which could release insulin and C-peptide in vitro under glucose stimulation.