人脐带间充质干细胞移植治疗初发1型糖尿病鼠*★

摘要

BACKGROUND:Mesenchymal stem cel s have self-replicating, immune tolerance and tissue repair characteristics. Type 1 diabetes mel itus is an autoimmune disease mainly resulting from islet beta-cel damage. In view of this, mesenchymal stem cel s can be considered to prevent and treat type 1 diabetes mel itus. OBJECTIVE:To observe the effect of umbilical cord mesenchymal stem cel transplantation on the newly-onset type 1 diabetic mice (NOD mice). METHODS:Type 1 diabetes model mice (NOD mice) were selected and divided into control group (Group A, mice without onset were injected with normal saline 1 mL into the tail vein), interventional group (Group B, onset mice were injected with 1 mL stem cel s into the tail vein, 1 × 106 cel s per mouse), and group without injection of umbilical cord mesenchymal stem cel s after onset (Group C, onset mice were injected with normal saline 1 mL into the tail vein). Three months later, blood glucose and daily insulin dose were detected;the number and proportion of CD4+, CD8+T cel s and CD4+CD25+regulatory T cel s were determined using a flow cytometry;levels of interleukin-2, interleukin-10 and tumor necrosis factor alpha were detected using enzyme linked immunosorbent assay;and fasting and 2-hour postprandial C-peptide levels were detected using enzyme-linked immunosorbent double antibody sandwich method. Islet morphology and lymphocyte infiltration were observed based on pathological sections. The number and size of the isletαandβcel s were determined by using immunohistochemical method. RESULTS AND CONCLUSION:(1) Compared with the group C, the immunohistochemical results confirmed that infiltration of lymphocytes in the group B was significantly reduced, the structure of isletαandβcel s was more complete and the number ofαandβcel s was significantly increased and consistent. (2) Compared with the group C, the CD4+T cel number and the rate of CD4+/CD8+T cel s in the group B were lower (P<0.05), while the number of CD4+CD25+regulatory T cel s in the group B was higher (P<0.01). (3) Compared with the group C, the tumor necrosis factor-αlevel was significantly lower in the group B, but interleukin-10 level was increased in the group B (P<0.01). (4) Compared with the group C, the group B had lower blood glucose level and insulin dose, but a higher C-peptide level (P<0.05). It is indicated that umbilical cord-derived mesenchymal stem cel s have a positive effect on the treatment of onset type 1 diabetes mel itus, which can reduce blood glucose level and insulin dose.%　　背景：间充质干细胞具有自我复制、诱导免疫耐受和组织修复的特性，而1型糖尿病是以胰岛β细胞受损为主的自身免疫性疾病。鉴于此，考虑间充质干细胞可预防治疗1型糖尿病。目的：观察脐带间充质干细胞对初发1型糖尿病鼠(NOD鼠)的治疗作用。方法：选用1型糖尿病模型鼠(NOD 小鼠)，分为3组，正常对照组为未发病鼠，尾静脉注射生理盐水1 mL；发病后脐带间充质干细胞干预组尾静脉注射脐带间充质干细胞1 mL，1.0×106/只；发病后未用干细胞干预组尾静脉注射生理盐水1 mL。观察3个月，检测NOD鼠血糖、每天胰岛素使用剂量；流式细胞仪检测反应性CD4+、CD8+T细胞、CD4+CD25+调节性T细胞的数量及比例；ELISA法检测白细胞介素2、白细胞介素10、肿瘤坏死因子α水平；酶联免疫双抗体夹心法测定空腹和餐后2 h C肽水平；病理切片观察胰岛的形态，淋巴细胞浸润情况；免疫组化观察胰岛α和β细胞的数量和体积。结果与结论：①与未用干细胞干预组比较，脐带间充质干细胞干预组免疫组化证实淋巴细胞浸润明显减少，胰岛α、β细胞结构更完整，α和β细胞数量明显上升且一致。②脐带间充质干细胞干预组CD4+T细胞数量、CD4+/CD8+T 细胞比值均低于未用干细胞干预组(P <0.05)，而脐带间充质干细胞干预组CD4+CD25+调节性T细胞数量明显高于未用干细胞干预组(P<0.01)。③脐带间充质干细胞干预组肿瘤坏死因子α水平明显低于未用干细胞干预组，而白细胞介素10水平较未用干细胞干预组明显上升(P <0.01)。④脐带间充质干细胞干预组血糖水平及胰岛素用量明显小于未用干细胞干预组，C肽水平较未用干细胞干预组升高(P <0.05)。结果可见脐带间充质干细胞可降低初发1型糖尿病的血糖及胰岛素的用量，治疗1型糖尿病效果比较明显。