Develop a combinatorial therapy for spinal cord injury

项目摘要 切断的中枢神经系统轴突不能再生，主要是因为成年神经元固有的生长能力降低， 神经元和轴突延伸的不良环境。Co-I的实验室发现，Wnt家族分子及其 受体在脊髓损伤（SCI）后上调并介导再生 之间 成人 受损纤维束的失效。 几种Wnt受体，Ryk是至关重要的介导排斥轴突生长在发展过程中， 神经胶质瘢痕产生的硫酸软骨素蛋白聚糖（CSPGs）强烈抑制了CNS损伤后的细胞凋亡。 轴突延伸，是治疗CNS损伤的主要外源性分子靶点。PI的团队设计了 通过靶向CSPG受体LAR和PTPσ的关键活性结构域阻断其功能的小肽 并证明了它们促进轴突生长的高效性。分别用3 组合肽促进受损CNS轴突的稳健再生。我们假设抑制这两者 Wnt和CSPG信号代表了增强神经元生长能力和降低神经元生长能力的双重途径。 在病变部位的环境抑制影响。我们建议刺激成年人的轴突再生 通过遗传和药理学方法抑制Ryk和LAR/PTPσ， 在我们的实验室里。在目的1中，我们将研究转基因删除Ryk+的协同作用， LAR/PTPσ受体对脊髓损伤小鼠轴突再生和恢复的促进作用。我们将 确定删除Ryk + LAR或Ryk + PTPσ受体是否协同作用以刺激轴突 生长和增强SCI后双基因敲除小鼠的神经元可塑性。在目标2中，我们将确定 用抗体或选择性拮抗剂阻断Ryk、LAR和PTPσ受体 促进脊髓损伤成年大鼠的轴突再生和恢复。我们将比较 靶向单个受体的治疗，促进多个下行道的再生和 SCI后的运动功能。在目标3中，我们将研究阻断两种或三种药物的联合治疗是否 受体在横断或挫伤SCI大鼠中产生更好的轴突再生和功能恢复，旨在 确定哺乳动物SCI的最佳治疗方法。基于我们的试点研究的可喜成果，我们 预测我们的联合策略将促进受损轴突束的戏剧性再生， 体内运动功能。我们的新策略是在损伤后给予可递送的化合物， 促进开发用于CNS病变的实用组合疗法。

Project Summary Severed CNS axons fail to regenerate largely because of the reduced intrinsic growth capacity of adult neurons and poor environment for axon extension. The Co-I's Lab finds that the Wnt family molecules and their receptors are upregulated after spinal cord injury (SCI) and mediates regrowth Among adult failure of injured fiber tracts. several Wnt receptors, Ryk is crucial for mediating repulsive axon growth during development and in CNS after injury.Chondroitin sulfate proteoglycans (CSPGs) generated by glial scars strongly suppress axon extension and are major extrinsic molecular targets for treating CNS injury. The PI's group designed small peptides to block functions of CSPG receptors LAR and PTPσ by targeting their critical activity domains and demonstrated their high efficiency for promoting axon growth. Blocking each of the two receptors with 3 combined peptides promotes robust regeneration of injured CNS axons. We hypothesize that inhibiting both Wnt and CSPG signals represents a dual approach of enhancing neuronal growth capacity and reducing environmental inhibitory influence at the lesion site. We propose to stimulate robust axon regrowth in adult rodents with transection or contusion SCI by inhibiting Ryk and LAR/PTPσ with genetic and pharmacological approaches available in our labs. In Aim 1, we will study synergistic actions of transgenically deleting Ryk plus each of LAR/PTPσ receptors on promoting axon regeneration and recovery in mice with SCI. We will determine whether deleting Ryk plus LAR or Ryk plus PTPσ receptors acts synergistically to stimulate axon growth and enhance neuronal plasticity in double knockout mice after SCI. In Aim 2, we will determine whether blocking each of Ryk, LAR and PTPσ receptors with antibody or selective antagonists pharmacologically promotes axon regeneration and recovery in adult rats with SCI. We will compare effectiveness of the treatments that target individual receptors in promoting regrowth of multiple descending tracts and recovery of locomotor functions after SCI. In Aim 3, we will study whether combination therapies that block two or three receptors yield better axon regrowth and functional recovery in rats with transection or contusion SCI, aiming to identify the optimal therapy for mammals with SCI. Based on the promising results from our pilot studies, we predict that our combined strategies will promote dramatic regeneration of injured axon tracts and recovery of locomotion function in vivo. Our novel strategy of administering deliverable compounds post-injury may facilitate development of a practical combinatorial therapy for CNS lesions.