Stem Cell-Derived Motoneurons in the Adult mammalian CNS

成年哺乳动物中枢神经系统中干细胞衍生的运动神经元

• 批准号: 7013966
• 负责人: DOUGLAS A KERR
• 金额: $ 36.87万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7013966
• 关键词: cell cell interaction; cell differentiation; cell growth regulation; embryonic stem cell; growth factor receptors; insulinlike growth factor; laboratory rat; mature animal; motor neurons; nerve stem cell; nervous system regeneration; nervous system transplantation; neurogenesis; neurotrophic factors; nonhuman therapy evaluation; spinal cord injury; stem cell transplantation

DESCRIPTION (provided by applicant): We have found that motoneuron-differentiated ES cells survive when transplanted into adult rats with a motoneuron injury and that many of the cells exhibit immunohistochemical features of mature motoneurons. In this project, we will determine strategies that facilitate the generation of functional ES cell-derived motoneurons in the injured adult, mammalian CNS. In specific aim 1, we will define host-applied and ex vivo strategies that optimize motoneuron differentiation and survival in the acutely damaged spinal cord. We will determine the ability of these cells to survive and engraft within the rat spinal cord at each of several differentiation stages (i.e. pluripotent stem cell, committed neural precursor, committed motoneuron precursor or postmitotic motoneuron). Additionally, we will explore whether the environment into which the cells are transplanted modulates survival and differentiation. In specific aim 2, we will test approaches that enhance the ability of ES cell-derived axons to overcome CNS white matter-mediated axonal repulsion. We will modulate the activity of NOGO-R, P75-NTR and RhoA in order to transiently render the transplanted ES cells less susceptible to host repulsive cues as they navigate surrounding white matter. In specific aim 3, we will test approaches that enhance the ability of ES cell-derived motoneurons to extend axons distally and allow the formation of functional neuromuscular junctions in vivo. Based on expression of neurotrophin receptors on ES-derived motoneurons, we propose to peripherally express cognate ligands (including IGF-1 and GDNF) that will attract ES-cell derived motor axons to grow distally and to innervate muscle. Retrograde labeling, electrophysiologic testing and behavioral studies will determine the effectiveness of these strategies in generating functional motoneurons and restoring motor units in paralyzed animals. These studies will define an important transplantation approach for motoneuron disease such as ALS and SMA and for spinal cord injury and other spinal disorders.

描述（由申请人提供）： 我们已经发现，运动神经元分化的ES细胞存活移植到成年大鼠运动神经元损伤，许多细胞表现出成熟的运动神经元的免疫组化特征。在这个项目中，我们将确定的战略，促进功能ES细胞衍生的运动神经元在受伤的成年哺乳动物中枢神经系统的产生。在具体目标1中，我们将定义宿主应用和离体策略，优化急性损伤脊髓中运动神经元的分化和存活。我们将确定这些细胞在几个分化阶段（即多能干细胞、定向神经前体、定向运动神经元前体或有丝分裂后运动神经元）的每一个分化阶段在大鼠脊髓内存活和移植的能力。此外，我们将探讨细胞移植的环境是否调节存活和分化。在具体目标2中，我们将测试增强ES细胞衍生的轴突克服CNS白色物质介导的轴突排斥的能力的方法。我们将调节NOGO-R、P75-NTR和RhoA的活性，以便使移植的ES细胞在它们导航周围的白色物质时对宿主排斥性线索不那么敏感。在具体目标3中，我们将测试增强ES细胞衍生的运动神经元向远端延伸轴突并允许在体内形成功能性神经肌肉接头的能力的方法。基于神经营养因子受体在ES细胞源性运动神经元上的表达，我们建议外周表达同源配体（包括IGF-1和GDNF），其将吸引ES细胞源性运动轴突向远端生长并支配肌肉。逆行标记，电生理测试和行为研究将确定这些策略在产生功能运动神经元和恢复瘫痪动物的运动单位的有效性。这些研究将为运动神经元疾病（如ALS和SMA）以及脊髓损伤和其他脊髓疾病确定一种重要的移植方法。