Objective To study the effect of pravastatin on the survival of islet xenografts.MethodsPigtomouse islet transplantation was performed. The models were divided into 4 groups: group A (control); group B, treated with CsA; group C, treated with pravastatin; group D, treatment with combined CsA with pravastatin. The survival time (ST) of the grafts in each group were recorded. Histological examination was used to detect the inflammation and islet cells in the graft. The infiltrated cells were detected by immunohistochemistry with CD4+, CD8+ and CD68 monoclonal antibody. The serum NO was measured. RTPCR was used in the test of IFNγ mRNA.ResultsThe ST of group A,B,C,D was (6.2±0.82) d, (9.2±1.92) d, (7.2±1.30) d, (11.2±1.76) d respectively, the ST of group D was much longer than that of the other groups (P＜0.05).Compared to that in other groups, less infiltrated cell in group D was found. On the 4th postoperative day, the serum NO in group A was (105.0±19.3) mmol/L,significantly higher than that in group B 〔(88.20±21.04) mmol/L〕, in group C 〔(70.7±17.8) mmol/L)〕 and in group D 〔(56.30±16.4) mmol/L〕. When rejection occurred, the serum NO in group C and D was (83.7±10.6) mmol/L and (71.3±13.8) mmol/L, also lower than that in group A (P＜0.05), the serum NO in group B was (104.7±16.3) mmol/L, compared that in group A, no significance was present (Pgt;0.05）. On the 4th postoperative day, the serum expression of IFNγ mRNA in group D was 23.5±4.6, lower than that in group A (28.8±4.8), and no significance was present compared with that in group B and C. ConclusionPravastatin can abate the role of macrophages, especially combined with Cyclosporine, and can prolong the survival of islet xenograft.
【摘要】 目的 探讨同种异基因骨髓间充质干细胞（bone mesenchamal stem cells，BMSC）静脉输注对大鼠到小鼠胰岛移植物的功能保护和小鼠糖尿病状态改善。 方法 全骨髓培养法获得C57BL/6小鼠BMSC。不连续梯度离心法分离纯化Sprague-Dawley（SD）大鼠胰岛，将300胰岛当量的胰岛单独或与BMSC联合移植入链脲菌素诱导的糖尿病BALB/c小鼠肾包膜下，并通过尾静脉在移植后0、3和5 d注射CM-DiI标记的BMSC 5×105/只，对照组给于磷酸盐缓冲溶液。移植后监测血糖，第9天处死小鼠，取肝、脾、胸腺、淋巴结和移植胰岛的肾脏，冰冻切片，荧光显微镜观察CM-DiI标记细胞的组织分布；免疫荧光法观察移植物中胰岛素和胰高血糖素表达，评价胰岛的功能。 结果 BMSC静脉输注后主要分布于胸腺，其次是脾脏和淋巴结，肾和肝组织中未观察到BMSC；BMSC联合胰岛移植组血糖控制水平优于其他组，且在第7天的口服糖耐量实验优于单纯胰岛移植组。 结论 与胰岛联合移植的BMSC对受者免疫器官和组织有明显的趋向性，且对胰岛细胞的体内存活有一定保护作用。【Abstract】 Objective To research on the protection function by the allogeneic rat bone mesenchymal stem cells (BMSC) on rat to mouse islet transplantation and the improvement of diabetic state in mouse. Methods BMSC were prepared from C57BL/6 mouse bone marrow cells and identified by flow cytometry (FCM). Islets were isolated from Sprague-Dawley (SD) rats with Ficoll discontinuous centrifugation. CM-DiI labeled BMSC at 5×105 for one mouse were intravenously infused into STZ induced diabetic BALB/c mice after rat to mouse islet transplantation at day 0, 3 and 5. Mice with PBS intravenously infused after islet transplantation were set as the negative controls. Blood glucose was monitored every day at the first 3 days after transplantation, and then monitored every two days. At day 9 after transplantation, spleen, thymus, lymph nods, liver and islets recipient kidney were harvested. Ice slices were prepared and CM-DiI labeled cells were investigated with fluorescence microscope. Results CM-DiI-labeled BMSC were mainly distributed in thymus followed by spleen and lymph nodes. In liver and kidney, there was no red fluorescence observed. The blood sugar control for combined BMSC infusion group was superior to other groups, and the control level of islet combined BMSC infusion group were better than single islet transplantation group in OGTT at day 7. Conclusion Allogeneic BMSC can sustain the insulin secretion of islets in vivo and tend to distribute in immune organs or adenoid tissues after infusion.
Objective To study the effect of anti-CD40L monoclonal antibody on the rejection of rat pancreatic islet xenografts and its mechanism. Methods The animal models of human-rat pancreatic islet xenografts were established and were treated with anti-CD40L monoclonal antibody. The levels of blood glucose of transplantation rats were measured and the survival of grafts and transplantation rats were observed after transplantation. The morphological changes of grafts were observed and the levels of cytokines (IL-2 and TNF-α) were quantified by ELISA. Results ①Level of blood glucose in all the rats with diabetes decreased to normal on day (2.3±0.2) after transplantation. The average level blood glucose of control group began to increase on day (8.1±0.6), while the treatment group began to increase on day (18.5±1.2) after transplantation, which was significantly postponed compared with control respectively (P＜0.01). ②Grafts of treatment group and control group survived for (22±8.2) and (10±2.1) days respectively. Survival of grafts in treatment group was significant longer than that in control group (P＜0.01). ③Survival of transplantation rats were (35±6.5) and (21±5.7) days in treatment group and control group respectively. The survival of transplantation rats in treatment group was significant longer than that in control group (P＜0.05). ④Levels of serum IL-2 and TNF-α in control group increased dramatically within (3.2±0.3) days and reached peak within (7.3±0.5) days after transplantation, which were significantly higher than those measured before transplantation (P＜0.01); While in treatment group, the levels of serum IL-2 and TNF-α began to increase on day (22.6±1.7) after transplantation, and reached peak on day (28.5±2.2), which was significantly postponed than those in control group (P＜0.01). Conclusion Anti-CD40L monoclonal antibody can inhibit the rejection of rat pancreatic islet xenografts and prolong the survival time of transplantation rats and grafts.
ObjectiveTo explore the effect of transplanting neonatal porcine islet cells of pig via hepatic portal vein in type Ⅰ diabetic monkeys.MethodIn this study, three pig-monkey islet xenotransplantation experiments were carried out by using α-1, 3-galactosyltransferase (GGTA1) gene knockout neonatal pig islet cells.ResultsThree macaques were successfully transplanted with islet cells. After the operation, their vital signs were stable and no symptoms of venous embolism occurred. After transplantation, the blood glucose and the dosage of exogenous insulin were significantly reduced, and the specific porcine C-peptide could be detected. Three macaques developed symptoms of ketoacidosis, and one macaque developed wound infection. After symptomatic treatment, all of them survived for 16 weeks.ConclusionGGTA1 knockout neonatal porcine islet cells transplanted through hepatic portal vein is effective for the treatment of type Ⅰ diabetes.