Effect of combined treatment with transplantation of BMSCs and an neuroprotective agent,FK506 on enhancement of amelieration of ischemic brain damege.

目的：骨髓基质细胞(BMSCs)移植可改善动物缺血性脑损伤。本研究探讨骨髓间充质干细胞移植联合免疫抑制剂FK506对实验性卒中大鼠的神经保护作用。方法：雄性SD大鼠建立大脑中动脉闭塞模型。缺血后2~6h，随机分为BMSCs+FK506组、BMSCs组、FK506组和赋形剂组。结果：脑缺血后2小时组，脑梗塞体积和神经功能评分均较单用组有显著改善，并持续7天。联合用药组较单纯用药组明显减少TUNEL阳性细胞数，增加Bcl2表达，降低Bax表达，抑制中性粒细胞浸润和小胶质/巨噬细胞活化。在缺血后6h治疗组中，只有联合治疗组的脑梗塞体积、水肿指数和神经功能评分显著减少。结论：FK506联合治疗增强了BMSCs的抗凋亡和抗炎作用，提高了移植细胞的存活率，延长了BMSCs的治疗时间窗。

Aims : Transplantation of bone marrow stromal cells(BMSCs)has been shown to ameliorate ischemic brain injury in animals. In the present study, we investigated whether the transplantation of BMSCs combined with FK506, a clinically used immunosuppressant, enhanced neuroprotective effects in rat experimental stroke.Methods : Male Sprague-Dawley rats underwent transient 90 min middle cerebral artery occlusion(MCAO). Two or 6 hours after ischemia onset, the rats were randomly assigned to receive intravenous administration of BMSCs plus FK506, BMSCs alone, FK506 alone, or vehicle. Infarct volume, and neurological and immunohistological assessments were performed to examine the effects of these therapies.Results : In 2-hour post-ischemia treatment groups, siginificant improvement of infarct volume and neurological scores were observed 1 day after combination therapy compared with monotherapy, and this neuroprotection continued for 7 days. Combination therapy significantly reduced the number of TUNEL-positive apoptotic cells, increased Bcl-2 expression, decreased Bax expression, and suppressed neutrophil infiltration and microglia/macrophage activation compared to monotherapy. In 6-hour post-ischemia treatment groups, a significant reduction of infarct volume, edema index, and neurological score was observed only in combination therapy group. Moreover, the number of engrafted BMSCs on day 7 with combination therapy was significantly higher than with BMSCs alone.Conclusion : Combination therapy using FK506 enhanced the anti-apoptotic and anti-inflammatory effects of BMSCs and increased the survival of transplanted cells, leading to expansion of the therapeutic time window for BMSCs.