目的：探索大鼠骨髓间质干细胞体外诱导分化为胰岛素分泌细胞的方法。为解决胰岛移植物来源匮乏这一问题提供新的思路。方法：采用横向分化技术,将成年大鼠骨髓间质干细胞诱导成为胰岛素分泌细胞。间接免疫荧光法鉴定诱导前后细胞nestin、胰岛素、胰高血糖素、生长抑素及Pdx-1的表达,RT-PCR法检测诱导前后细胞nestin,胰岛素-1,葡萄糖转运子-2,葡萄糖激酶及其转录因子Isl-1,Pdx-1,Pax-4和Pax-6 mRNA的表达;测定24 h胰岛素分泌量和胰岛素刺激实验评价诱导前后细胞的功能。结果：诱导5 h,nestin阳性细胞为(44.6±7.3)％;诱导24 h,nestin阳性细胞增至(61.8±8.4)％;此后,nestin阳性细胞数目开始下降,诱导第14天后,nestin表达基本消失。诱导后的胰岛素分泌细胞可以表达胰岛素、胰高血糖素、生长抑素和Pdx-1等蛋白;表达胰岛素-1、葡萄糖转运子-2、葡萄糖激酶及其多种转录因子mRNA;胰岛素分泌量增加;胰岛素刺激实验反应敏感等。而诱导前MSCc不县备上述特点。结论：大鼠骨髓间质干细胞体外可以诱导成为胰岛素分泌细胞,为胰岛移植开辟新的研究思路。

OBJECTIVE: To explore the protocol that induced marrow mesenchymal stem cells (MSCs) differentiating into islel-secreting cells in vitro and to provide new clues for the sources of islet transplantation. METHODS: Using a defined culture medium and technique for transdifferentiation, MSCs from adult SI) rats were guided into specific insulin-secreting cells. The expressions of nestin and islet-specific hormones and proteins, such as insulin, glucagon, somatoslatin and pancreatic duodenal homeohox 1 (Pdx-1) were analyzed by indirect immunofluorescence cytochemistry staining before and after induction. The expressions of pancreatic islet cell differentiation-related transcripts, such as neslin, insulin 1, glucose transporter 2 (GLUT 2), Isl-f, Pdx-1, Pax-4 mid Pax-6 were detected by reverse transcription-PCR (RT-PCR). In addition, the quantity of insulin secretion was examined using radioinimuna-issay. RESULTS: Five hours after induction, (44.6 ± 7. 3)% of differentiated MSCs expressed nestin and it increased to (61. 8 ± 8. 4)% 24 hs after induction, but the expression of nestin almust disappeared at day 14. In the meantime, islet-like cellular clusters appeared after day 14 and became more apparent by day 28. Differentiated cells were found to be immunoreactive to insulin, glucagon, somalostatin and Pdx-1, and expressed insulin 1, GLUT 2, GK, Isl-1, PDX-1, Pax-4, Pax-6 mRNA. In addition, the results of cumulative quantities of insulin of 24 hs and the stimulation index showed that differentiated cells were able to produce insulin at higher levels, and displayed glucose-dependent insulin release in vitro. CONCLUSIONS: Adult rat MSCs can be differentiated into insulin-secreting cells in vitro. This approach might lead to widespread cell replacement therapy for Type 1 diabetes.