Li Peiying, Tessler Alan, Han Steve S W, Fischer Itzhak, Rao Mahendra S, Selzer Michael E
Department of Neurology and the David Mahoney Institute of Neurological Sciences, University of Pennsylvania Medical Center, Philadelphia 19104-4283, USA.
Arch Neurol. 2005 Feb;62(2):223-9. doi: 10.1001/archneur.62.2.223.
Replacement of neurons and glia by transplantation has been proposed as a therapy for neurodegenerative diseases, including amyotrophic lateral sclerosis. This strategy requires using human motor neuronal progenitor cells or xenografts of animal cells, but there is little evidence that xenografted neuronal cells can survive in spinal cord despite immunosuppression.
To clarify the mechanisms responsible for the death of xenografted neurons in spinal cord.
Cells from an immortalized, neuronally committed, human embryonic spinal cord-derived cell line (HSP1) that expresses motor neuronal properties in vitro were transplanted into adult rat spinal cord. The rats were killed at intervals up to 8 weeks and serial sections through the graft sites were processed for immunofluorescence using primary antibodies against human nuclear and mitochondrial antigens, microtubule-associated protein 2, TUJ1, CD5, natural killer cells, and activated microglia-macrophages, caspase-3 and caspase-9.
Grafted cells did not migrate and underwent partial differentiation along a neuronal pathway. They were rejected after 4 weeks despite cyclosporine immunosuppression. Cells died by apoptosis via the cytochrome c/caspase-9/caspase-3 pathway. The host response included natural killer cells and activated microglia-macrophages but few T cells.
Intraspinal neuronal xenotransplantation failed because of apoptotic cell death. Neither T cells nor the spinal cord environment, which favors gliogenesis, are likely to have been responsible, but natural killer cells may have been involved.
通过移植来替代神经元和神经胶质细胞已被提议作为治疗包括肌萎缩侧索硬化症在内的神经退行性疾病的一种疗法。该策略需要使用人类运动神经元祖细胞或动物细胞异种移植物，但几乎没有证据表明异种移植的神经元细胞在免疫抑制的情况下能在脊髓中存活。
阐明脊髓中异种移植神经元死亡的机制。
将来自永生化、具有神经元定向性、源自人类胚胎脊髓的细胞系（HSP1）的细胞（该细胞系在体外表现出运动神经元特性）移植到成年大鼠脊髓中。在长达8周的时间内定期处死大鼠，并对通过移植部位的连续切片进行免疫荧光处理，使用针对人类核抗原和线粒体抗原、微管相关蛋白2、TUJ1、CD5、自然杀伤细胞、活化的小胶质细胞 - 巨噬细胞、半胱天冬酶 - 3和半胱天冬酶 - 9的一抗。
移植的细胞没有迁移，而是沿着神经元途径进行了部分分化。尽管使用了环孢素免疫抑制，它们在4周后仍被排斥。细胞通过细胞色素c/半胱天冬酶 - 9/半胱天冬酶 - 3途径凋亡死亡。宿主反应包括自然杀伤细胞和活化的小胶质细胞 - 巨噬细胞，但T细胞很少。
脊髓内神经元异种移植因凋亡性细胞死亡而失败。T细胞和有利于胶质细胞生成的脊髓环境都不太可能是原因，但自然杀伤细胞可能参与其中。
