不同途径移植人脐带间充质干细胞治疗糖尿病大鼠

目的观察不同途径移植人脐带间充质干细胞(hUCMSCs)对糖尿病大鼠的治疗效果。方法 60只SD大鼠单次腹腔注射链脲佐菌素(70 mg.kg-1)建立糖尿病模型,成模后随机分为糖尿病模型组、胰腺被膜下移植组、肾被膜下移植组及肝实质内移植组,每组14只;另取10只大鼠为正常对照组。分别于各干细胞移植组大鼠胰腺被膜下、左肾被膜下、肝实质内注射0.5 mL hUCMSCs悬液(1×106个);糖尿病模型组及正常对照组于胰腺被膜下注射生理盐水0.5 mL。移植后动态观察空腹血糖(FBG)、空腹胰岛素(FINS)、体质量变化,6周后处死大鼠,取相关组织行病理学检查及胰岛素、胰十二指肠同源异型盒基因(PDX-1)、巢蛋白mRNA表达测定。结果移植前各组大鼠体质量比较差异无统计学意义(P>0.05);各干细胞移植组及糖尿病模型组大鼠FBG值高于正常对照组(P<0.05),FINS水平低于正常对照组(P<0.05);各干细胞移植组及糖尿病模型组大鼠FBG和FINS水平组间比较差异无统计学意义(P>0.05)。移植5周末,与正常对照组比较,各干细胞移植组及糖尿病模型组大鼠体质量及FINS降低,FBG增高,差异均有统计学意义(P<0.05);与糖尿病模型组比较,各干细胞移植组大鼠体质量及FINS升高,FBG降低,差异均有统计学意义(P<0.05);与胰腺被膜下移植组比较,肾被膜下及肝实质内移植组大鼠体质量降低,FBG升高,FINS水平降低,差异均有统计学意义(P<0.05)。与正常对照组相比,各实验组大鼠平均阳性染色面积均降低(P<0.05);胰腺被膜下移植组阳性染色面积大于糖尿病模型组(P<0.05);所有组织切片均未检测到人胰岛素的表达。与正常对照组比较,胰腺被膜下移植组、糖尿病模型组大鼠胰岛素mRNA表达量均降低(P<0.05),大鼠PDX-1及巢蛋白mRNA表达量均增高(P<0.05)。与糖尿病模型组比较,胰腺被膜下移植组大鼠胰岛素、PDX-1及巢蛋白mRNA表达量均增高(P<0.05)。各实验组均未检测到人胰岛素、PDX-1及巢蛋白mRNA表达。结论不同移植途径对hUCM-SCs治疗糖尿病的效果有影响,胰腺被膜下移植效果优于其他途径。hUCMSCs并未分化为β细胞,但其能够促进内源性胰腺干细胞增殖、分化。

Transplantation of human umbilical cord mesenchymal stem cells in different transplanted sites for treatment of diabetic rats

Objective To observe the therapeutic efficacy of human umbilical cord mesenchymal stem cells(hUCMSCs) transplantation in different sites for treatment of diabetic rats.Methods Sixty Sprague-Dawley rats were intraperitoneal injected with streptozotocin to establish diabetes mellitus model.Then the model rats were divided randomly into diabetic model group,pancreatic subcapsular place transplantation group,renal subcapsular place transplantation group and liver parenchyma transplantation group,with 14 rats in each group.Ten rats were selected as normal control group.The 0.5 mL hUCMSCs(1×106) were injected into the rats′ pancreatic subcapsular place,renal subcapsular place and liver parenchyma of each transplantation group respectively.The normal control group and diabetic model group were injected with normal saline solution into pancreatic subcapsular place.Body weight,fasting blood glucose(FBG) and fasting insulin(FINS) levels were measured weekly after transplantation.Six weeks post-transplantation,the rats were executed and the related tissues were taken to observe the histological changes and the expression of insulin,pancreatic duodenal homeobox-1(PDX-1) and nidogen mRNA was determined.Results The body weights of rats among all groups before transplantation were no significant difference(P>0.05);the FBG levels of each stem cells transplantation group and diabetic model group were higher than those of the normal control group(P<0.05) and the FINS levels were lower than those of the normal control group(P<0.05);the levels of FBG and FINS levels among the stem cells transplantation group,diabetic model group had no significant difference(P>0.05).Five weeks after transplantation,compared with normal control group,the FBG increased,FINS and body weight reduced in each stem cells transplantation group and diabetic model group(P<0.05).Compared with the diabetic model group,the FBG reduced,the body weights and FINS increased in each stem cells transplantation group(P<0.05).Compared with the pancreatic subcapsular place transplantation group,the body weights and the levels of FINS reduced,but FBG increased in the renal subcapsular place transplantation group and liver parenchyma place transplantation group(P<0.05).Compared with the normal control group,the average positive stained area reduced in all experiment groups(P<0.05);the positive stained area of the pancreatic subcapsular place transplantation group was larger than that of the diabetic model group(P<0.05);the expression of human insulin was not detected in all tissue sections.Compared with the normal control group,the mRNA expressions of rat insuline reduced(P<0.05) and the rat PDX-1 and nidogen mRNA expression increased in the pancreatic subcapsular place transplantation group and the diabetic model group(P<0.05).Compared with the diabetic model group,the rat insulin,PDX-1 and nidogen mRNA expression of pancreatic subcapsular place transplantation group increased(P<0.05).Human insulin,PDX-1,and nidogen mRNA expression were not detected in all experiment groups.Conclusion Pathway of hUCMSCs transplantation has direct relationship with therapeutic efficacy of diabetes.Pancreatic subcapsular place transplantation has better effects than the others transplantation pathway.hUCMSCs don′t differentiate into β cells,but can initiate pancreatic stem cells proliferation and differentiation.