骨髓间充质干细胞移植对糖尿病大鼠的治疗作用

目的 观察同种大鼠骨髓间充质干细胞(BMSC)移植对糖尿病的治疗作用及其可能机制.方法 分离、培养和扩增供者(3～4周龄的SD大鼠)的BMSC,将成年SD大鼠分为正常对照组(12只)和糖尿病组(44只,制作糖尿病模型);糖尿病组大鼠又分为不移植对照组(12只)和移植组(32只).将分离纯化的同种大鼠BMSC经移植组大鼠尾静脉植入体内,每只大鼠移植BMSC约3×10~6个.移植后动态观察各组的血糖和胰岛素水平;移植后28 d制备胰腺组织切片,通过激光共聚焦显微镜观察移植的BMSC对内源性胰岛细胞再生的影响.结果 正常对照组血糖在4.0 mmol/L左右波动;不移植对照组血糖显著升高,维持在23～27 mmol/L;移植组血糖明显降低,术后72 h平均血糖值为(11.7±2.4)mmol/L,并维持稳定至35 d[血糖值(15.4±6.3)mmol/L].移植组血清胰岛素水平较不移植对照组明显增高,术后12 d时分别为(0.90±0.14)μg/ml和(0.35±0.06)μg/ml(P<0.01),但仍明显低于正常对照组的(1.32±0.14)μg/ml,差异有统计学意义(P<0.05).正常对照组大鼠胰腺组织切片内胰岛素阳性细胞聚集,但增殖的细胞极少,约为(11±6)个/mm~2,内源性增生的胰岛素阳性细胞约(7±4)个/mm~2.不移植对照组大鼠胰腺组织中胰岛素阳性细胞较正常对照组少,但存在明显的增生.增殖细胞约(25±4)个/mm~2.其中内源性增生的胰岛素阳性细胞约(13±5)个/mm~2,与正常对照组比较,差异有统计学意义(P<0.05).移植组胰岛体积较不移植对照组增大,增殖细胞和内源性增生的胰岛素阳性细胞均明显增多,分别为(45±9)个/mm~2和(23±11)个/mm~2,与正常对照组、不移植对照组之间比较,差异均有统计学意义(P<0.01).结论 糖尿病大鼠经同种BMSC移植后,可能通过促进内源性胰岛细胞新生发挥治疗作用,这可能为糖尿病的治疗提供一条新的途径.

Bone marrow mesenhymal stem cells promote endogenous islet-regeneration in diabetic rats

Objective To observe the curative effectiveness of bone marrow mesenhymal stem cells (BMSCs) transplantation in diabetic rat model and the possible mechanism. Methods After BMSCs were transplanted into heterogeneic diabetic rats through vena caudalis (3 × l0~6),the blood glucose level,and blood insulin level were determined. Confocal microscopy was used to observe the effects of BMSCs on endogenous islet regeneratioa Results At the 72nd h after transplantation (experimental groups),the glucose level was (11. 7 ± 2. 4) mmol/L,and sustained for more than 2 months, which was significantly lower than that in model group [(25. 43 ± 5. 27) mmol/L]. Simultaneously, although the level of insulin in experimental group was still lower than that in normal control group [(0. 9 + 0. 14) μg/mL vs. (1. 32 ± 0. 14) μg/mL respectively, P<0. 01], it was significantly higher than that in model group [(0. 35 ± 0. 06) μg/mL). In order to investigate the effects of BMSCs transplantation on islet-injury, BrdU was used. It was shown that the number of BrdU~+ cells was more in experimental group than that in model group [(45 ± 9)/mm~2 vs. (25 ± 4)/ mm~2,P<0. 05], suggesting BMSCs could promote regeneration of pancreas. In model group, the number of endogenous regeneration of islet (BrdU~+ insluin~+ cells) was (13 ± 5)/mm~2, and that in experimental group was (23 ±11)/mm~2, indicating that BMSCs could improve endogenous islet regeneratioa Conclusion BMSCs transplantation could promote endogenous regeneration of islet in diabetic rats, which might lead to widespread cell replacement therapy for diabetes.