骨髓间充质干细胞对同种异体胰岛的保护作用

目的 研究小鼠骨髓间充质干细胞(mesenehymal stem cells,MSCs)对同种异体胰岛的保护作用.方法 将C57BL/6小鼠骨髓间充质干细胞按照3×104/孔的密度预先接种至24孔培养板,次日分离纯化BALB/c小鼠胰岛,将其分为链脲菌素(streptozotocin,STZ)处理(诱导化学损伤)、混合淋巴细胞反应(mixed lymphocyte reaction,MLR)处理(诱导免疫损伤)、空白处理三组,与预先接种的MSCs进行共培养.作为实验对照,另设三组胰岛在不加MSCs的条件下进行体外培养.5 d后,用吖啶橙(acridine orange,AO)/碘化丙啶(propidium iodide,PI)荧光染色评估胰岛活力,葡萄糖刺激的胰岛素分泌实验检测其功能,比较MSCs共培养组与对照组胰岛在低糖、高糖刺激下的胰岛素分泌量及刺激指数(即高糖刺激胰岛素分泌量/低糖刺激胰岛素分泌量比值).结果 AO/PI染色显示,STZ或MLR处理的胰岛中有大量红色荧光的死细胞,而与MSCs共培养的胰岛中死细胞明显减少,绿色荧光的活细胞明显增加;STZ或MLR处理组胰岛在低糖、高糖刺激下的胰岛素分泌水平及刺激指数均显著下降,而与MSCs共培养者较相应对照组胰岛功能明显改善(P＜0.05).结论 小鼠骨髓间充质干细胞可减轻同种异体胰岛的化学及免疫损伤,保护游离胰岛的活力与功能.

Abstract：

Objective To study the protection of mouse bone marrow-derived mesenchymal stem cells ( MSCs) for allogenic islets. Method MSCs from C57BL/6 mice were preceded to a 24-well culture plate with the density of 3 × 104/well. On the second day, islets were isolated, purified and divided to undergo streptozotocin (STZ) induced chemical injury and mixed lymphocyte reaction ( MLR) respectively. Then, treated and control islets were respectively divided into the following groups: islets + MSCs, STZ-islets + MSCs, and MLR-islets + MSCs. As control groups for their counterparts, treated or non-treated islets were also cultured without MSCs. On the 5th day incubation, glucose-stimulated insulin secretion test was performed to assess the function of islets in different groups, comparing their insulin-secretion amount stimulated by low or high glucose and the stimulation index determined by the ratio of (insulin amount secreted under high-glucose stimulation)/(insulin amount secreted under low-glucose stimulation ). Islet viability was evaluated by acridine orange (AO)/propidium iodide (PI) fluorescence staining. Result As shown by AO/PI staining, large numbers of dead cell with red fluorescence could be observed in STZ- or MLR- treated islets without MSCs, while the number of dead cells obviously reduced in MSC-cocultured islets with increased viable cells of green fluorescence. STZ- or MLR- treated islets exhibited apparently decreased insulin-secretion amount either under low- or high-glucose stimulation, as well as the stimulation index. The insulin-secretion function was significantly improved in islets cocultured with allogenic MSCs (P ＜ 0. 05 ). Conclusions Bone marrow-derived MSCs can protect isolated allogenic islets against chemical and immunological injury.

Bone marrow-derived mesenchymal stem cells protect allogenic islets

Objective To study the protection of mouse bone marrow-derived mesenchymal stem cells ( MSCs) for allogenic islets. Method MSCs from C57BL/6 mice were preceded to a 24-well culture plate with the density of 3 × 104/well. On the second day, islets were isolated, purified and divided to undergo streptozotocin (STZ) induced chemical injury and mixed lymphocyte reaction ( MLR) respectively. Then, treated and control islets were respectively divided into the following groups: islets + MSCs, STZ-islets + MSCs, and MLR-islets + MSCs. As control groups for their counterparts, treated or non-treated islets were also cultured without MSCs. On the 5th day incubation, glucose-stimulated insulin secretion test was performed to assess the function of islets in different groups, comparing their insulin-secretion amount stimulated by low or high glucose and the stimulation index determined by the ratio of (insulin amount secreted under high-glucose stimulation)/(insulin amount secreted under low-glucose stimulation ). Islet viability was evaluated by acridine orange (AO)/propidium iodide (PI) fluorescence staining. Result As shown by AO/PI staining, large numbers of dead cell with red fluorescence could be observed in STZ- or MLR- treated islets without MSCs, while the number of dead cells obviously reduced in MSC-cocultured islets with increased viable cells of green fluorescence. STZ- or MLR- treated islets exhibited apparently decreased insulin-secretion amount either under low- or high-glucose stimulation, as well as the stimulation index. The insulin-secretion function was significantly improved in islets cocultured with allogenic MSCs (P ＜ 0. 05 ). Conclusions Bone marrow-derived MSCs can protect isolated allogenic islets against chemical and immunological injury.