大鼠肌源性干细胞植入糖尿病鼠胰腺后的存活能力及血糖调节

背景：肌源性干细胞易于提取、分离及扩增，在特定条件下可分化为骨软骨、肌肉等中胚层组织细胞，还可以跨胚层分化为神经细胞等。 目的：观察糖尿病鼠胰腺内植入的肌源性干细胞存活情况，及其调节血糖的效果。 设计、时间及地点：细胞学体外观察，于2007-04/09在辽宁医学院科学实验中心完成。 材料：SPF/VAF级新生5 d龄SD大鼠31只，由辽宁医学院实验动物中心提供。造模使用的链脲佐菌素为星隆达公司产品。 方法：取5只大鼠的前肢肱三头肌与后肢腓肠肌，采用差速贴壁法纯化扩增大鼠肌源性干细胞，传至第3代用于移植，临用前以携带绿色荧光蛋白的腺病毒悬液进行转染。取20只大鼠，通过尾静脉注射链脲佐菌素建立糖尿病模型，15只成功造模，取12只随机均分为2组：细胞移植组胰腺被膜下移植肌源性干细胞约2×106个，模型对照组同法给予等量不含细胞的培养液。余6只大鼠作为正常对照组。 主要观察指标：肌源性干细胞移植至胰腺后的存活情况，移植后大鼠血糖浓度的变化。 结果：移植后1周，胰腺组织呈网架样结构，表达较强的黄绿色荧光；4周后仍有荧光表达，但强度减弱。与模型对照组比较，移植前2 d细胞移植组大鼠血糖浓度无明显差异（P > 0.05）；移植后4，8 d，大鼠血糖浓度一直处于较高水平；至移植后第4，8周大鼠血糖浓度明显下降（t=-2.416~8.372，P < 0.01）。 结论：肌源性干细胞移植后能在糖尿病模型鼠的胰腺部位存活，且一定程度上可下调大鼠血糖浓度。

Survival and regulatory effects of rat muscle derived stem cells on blood glucose level in the pancreatic gland of diabetic rats following transplantation

BACKGROUND: Muscle derived stem cells (MDSCs) have a pluripotent ability to differentiate into a variety of cells under certain conditions such as myocytes, cartilage cells and neural cells. OBJECTIVE: To observe the survival of MDSCs in pancreatic gland of diabetic rats and the regulatory effects on blood glucose. DESIGN, TIME AND SETTING: The in vitro cytology study was performed at the Science Experimental Center of Liaoning Medical College from April to September 2007. MATERIALS: A total of 31 SPF/VAF Sprague Dawley rats aged 5 days were obtained from Animal Experimental Center of Liaoning Medical College. Streptozotocin was purchased from Xinglongda. METHODS: Triceps brachii of the forelimbs and gastrocnemius of the postlimbs of 5 rats were obtained. MDSCs were purified and amplified using the differential adherence method. At the third passage, MDSCs were transfected using adenovirus suspension carrying green fluorescent protein. Twenty rat models of diabetes were established by infusing streptozotocin via the tail vein. Fifteen successful rat models were obtain, and twelve of them were randomly divided into two groups. Rat models in the cell transplantation group were intraperitoneally injected with 2×106 MDSCs. Rat models in the model control group were injected with the same volume of cell medium. Remaining six rats served as the normal control group. MAIN OUTCOME MEASURES: The survival of MDSCs in pancreatic gland of diabetic rats and blood glucose concentrations following transplantation were measured. RESULTS: The pancreatic tissues were rack-like structure at 1 week after transplantation, expressed yellow-green fluorescence strongly, while expressed weakly at 4 weeks after transplantation. Compared with the model control group, no significant difference was found in blood glucose concentrations in rats of the cell transplantation group at 2 days prior to transplantation (P > 0.05). At 4 and 8 days following transplantation, rat blood glucose concentration was in a high level, but significantly decreased at 4 and 8 weeks following transplantation (t=-2.416-8.372, P < 0.01). CONCLUSION: MDSCs can survive in the pancreatic gland of model rats after transplantation, and can downregulate rat blood glucose concentration.