ES CELL TRANSPLANTATION AFTER SPINAL CORD INJURY

要求拨款以支持一个新的研究计划项目，该项目旨在探索胚胎干细胞移植恢复脊髓损伤后丧失的功能的潜力。拟议项目团队的成员已经积累了在小鼠胚胎干细胞向下分化的神经系、减少神经系统细胞死亡的方法以及创伤性脊髓损伤的啮齿动物模型方面的工作经验。在构成本提议的具体背景的实验中，项目组成员获得了证据，表明小鼠胚胎干细胞来源的神经谱系细胞(ESNLCs)可以成功地移植到大鼠脊髓撞击损伤后9天形成的脊髓空洞/囊肿中。这些移植的ESNLC存活至少数周，部分填充空洞并迁移到宿主组织中，并表达分化的少突胶质细胞、星形胶质细胞和神经元的标志。申请的项目项目资金将使项目团队成员能够以系统和假设驱动的方式在这些早期实验的基础上发展。根据直接观察，大多数移植的ESNLC在移植后的48小时内死亡，特别是神经元在随后的几天内继续死亡，这里提出的实验的重点将是通过旨在阻断细胞凋亡和兴奋毒性的药理学和基因工程方法来提高移植的ESNLC的存活率。预计未来几年开展的工作可能会以其他方式优化ESNLC移植程序。

Grant funds are requested to support a new research Program Project aimed at initiating an exploration of the potential of embryonic stem (ES) cell transplantation for restoring lost functions after spinal cord injury. Members of the proposed Project team have already developed experience working with mouse ES cells differentiated down neural lineages, methods for reducing cell death in the nervous system, and rodent models of traumatic spinal cord injury. In the experiments that form the specific background for the present proposal, Project team members have obtained evidence that mouse ES-cell derived neural lineage cells (ESNLCs) can be successfully transplanted into the syrinx/cyst that forms nine days after impact injury to the rat spinal cord . These transplanted ESNLCs survived for at least many weeks, partially filling the syrinx and migrating into host tissue, and expressed markers for differentiated oligodendrocytes, astrocytes, and neurons. The requested Program Project funding would enable Project team members to build on these early experiments in a systematic and hypothesis-driven fashion. Based on direct observations that a majority of transplanted ESNLCs die over the first 48 hours following transplantation and that neurons in particular continue to die over subsequent days, the emphasis of the experiments proposed here will be on improving the survival of transplanted ESNLCs through pharmacological and genetic engineering approaches aimed at blocking apoptosis and excitotoxicity. It is anticipated that work performed in subsequent years may be directed at optimizing the ESNLC transplantation procedure in other ways.