人骨髓间质干细胞经心脏移植治疗超氧化物歧化酶1-G93A转基因鼠的疗效

Effect of human mesenchymal stem cells intracardiac transplantation on superoxide dismutase 1- G93A mice

目的研究经心脏移植人骨髓间质干细胞（hMSCs）对肌萎缩侧索硬化（ALs）模型鼠发病时间、生存期和病理的影响。方法体外培养扩增hMSCs，流式细胞仪鉴定其性质及纯度。将3×10。个第5代hMSCs经心脏移植入预放疗的8周龄超氧化物歧化酶1（SOD1）-G93A转基因鼠，用Weyd4分法评定移植鼠和未治疗鼠的生存期、发病时间，采取尼氏染色计数脊髓前角运动神经元，通过免疫荧光检测人特异性核抗原验证hMSCs在受体鼠中枢神经系统中的植入。结果生存分析显示，经心脏移植hMSCs的ALS模型鼠平均发病时间为（172．85±5．82）d，比未治疗组[（156．56±3．60）d]延迟16d，差异有统计学意义（χ2=10．888，P=0．001）；hMSCs经心脏移植组平均生存期为（202．19±d．09）d，比未治疗组[（188．32±3．51）d]延长14d，差异有统计学意义（χ2=3．917，P=0．04）。尼氏染色显示在20周时移植鼠脊髓前角大运动神经元计数多于未治疗鼠；终末期hMSCs移植鼠中，在脑和脊髓前角病变区可检测到人特异性核抗原。结论hMSCs可经心脏移植，在ALS模型鼠中可长期植入，延长生存期，延缓脊髓前角运动神经元的丢失。

Objective To study the changes of life span and pathology in superoxide dismutase 1 （SOD1）-G93A mice after intraeardiac transplantation of human mesenchymal stem cells （hMSCs）. Methods hMSCs were isolated from bone marrow cells obtained from healthy donors and cultured. The purity and morphology were assessed by flow eytometry （FCM）. hMSCs （3 ×106 ） resuspended in 0. 2 ml DMEM was injected into the heart of 8 week-old SOD1-G93A mice. In non-transplantion control SOD1-G93A mice, only DMEM was injected. The mice were evaluated for signs of motor deficit with 4-point scoring system previously described by Weydt et al. The age of onset and life span in mice were assessed. The pathological change including number of motor neurons was investigated by Nissl staining. Immunofluoreseence staining with specific human nuclear antibody was used to confirm the transplant of hMSCs in mice. Results The onset symptoms in untreated SOD1-G93A mice appeared at （ 156. 56 ± 3.60） days of age and the average life span was （188.32 ± 3.51 ） days. hMSCs transplantation delayed the onset of ALS type symptoms about 16 days（χ2= 10. 888, P =0.001） and prolonged the life span about 14 days compared to the untreated SOD1-G93A littermates（ （202. 19 ±4. 09） days vs （ 188.32 ± 3.51 ） days, X2 = 3. 917, P =0.04）. The loss of motor neurons in untreated mice was earlier and more severe than in hMSCs transplanted mice. At 20 weeks, the number of motor neurons in transplanted mice was significantly higher than those in untreated mice. Human specific nuclear antigen in brain and spinal cord was detected in transplanted SOD1-G93A mice. Conclusion hMSCs can be implanted for a long-term into central nervous system by intracardiac transplantation and the transplantation can prolong life span, and delay the onset of the disease and motor neuron loss in SOD1-G93A mice.