CSPG receptors and PTEN in CNS regeneration

CSPG 受体和 PTEN 在 CNS 再生中的作用

• 批准号: 8696112
• 负责人: SHUXIN LI
• 金额: $ 34.07万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8696112
• 关键词: Address; Adult; Area; Axon; Behavioral; Chondroitin Sulfate Proteoglycan; Cicatrix; Development; Dose; Environment; Failure; Fiber; Growth; In Vitro; Injury; Intrinsic factor; Knock-out; Knockout Mice; Lesion; Locomotor Recovery; Mediating; Modeling; Molecular; Molecular Target; Mus; Natural regeneration; Neurites; Neurons; Optic Nerve; PTEN gene; Pathway interactions; Patients; Peptides; Phosphoric Monoester Hydrolases; Recovery; Recovery of Function; Rodent; Signal Pathway; Signal Transduction; Site; Spinal Cord transection injury; Spinal cord injury; Testing; Therapeutic; Transgenic Mice; Transgenic Organisms; Tumor Suppressor Genes; axon growth; axon regeneration; base; central nervous system injury; combinatorial; design; extracellular; improved; in vivo; inhibitor/antagonist; inhibitory neuron; injured; mimetics; novel; novel strategies; public health relevance; receptor; regenerative; research study

DESCRIPTION (provided by applicant): By using novel, systemically deliverable, small inhibitory peptides developed in the PI's lab, we aim to determine whether targeting both extracellular inhibitory and neuron-intrinsic factors can markedly improve axon regeneration and functional recovery after spinal cord injury (SCI). Severed CNS axons fail to regenerate due to the extrinsic inhibitory environment and the reduced intrinsic growth capacity of mature neurons. Chondroitin sulfate proteoglycans (CSPGs) generated by glial scars strongly suppress axon extension into and beyond the lesion area and are the major molecular targets for treating SCI. Recently, we and other labs identified the LAR and PTP¿ phosphatases as receptors that mediate CSPG inhibition. Deleting either of them stimulated axon growth after SCI. Recent studies using conditional knockout mice suggested that PTEN critically restricts the intrinsic regenerative capacity of injured CNS axons. Thus, suppressing CSPG receptors and PTEN is promising for promoting axon regeneration after CNS injury. We have designed small peptides to block functions of these inhibitory molecules by targeting their specific domains and demonstrated the high efficacy of our peptides for promoting axon growth in vitro and in vivo. Since CSPGs and PTEN appear to limit growth by different signaling pathways, inhibition of both may act synergistically to promote axon regeneration by reducing environmental inhibitory influence at the lesion site and enhancing intrinsic growth capacity of mature neurons. We hypothesize that CSPGs and PTEN are critical contributors to regenerative failure of CNS neurons and that combined inhibition of both promotes axon regeneration better than inhibition of either one alone. We propose to address the following 3 Specific Aims: 1) determine whether transgenic deletion or peptide blockade of two CSPG receptors yields better axon growth in vitro and in vivo and functional recovery in adult mice with SCI than suppressing either receptor alone; 2) determine whether PTEN blockade with peptides stimulates similar degrees of axon growth and functional recovery as transgenic PTEN deletion in vitro and in vivo; 3) determine whether blocking both CSPG signaling and PTEN with peptides promotes greater axon regeneration and behavioral recovery after SCI than blocking either one alone. The results of peptide treatments will be compared with those of transgenic mouse experiments. Our novel strategy to administer small compounds systemically alone or in combination may facilitate development of a practical therapy for CNS injury.

描述（由申请人提供）：通过使用 PI 实验室开发的新型、可全身递送的小抑制肽，我们的目的是确定针对细胞外抑制因子和神经元内在因子是否可以显着改善脊髓损伤 (SCI) 后的轴突再生和功能恢复。由于外部抑制环境和成熟神经元内在生长能力的降低，切断的中枢神经系统轴突无法再生。神经胶质疤痕产生的硫酸软骨素蛋白多糖 (CSPG) 强烈抑制轴突延伸至病变区域或超出病变区域，是治疗 SCI 的主要分子靶点。最近，我们和其他实验室确定了 LAR 和 PTP¿ 磷酸酶作为介导 CSPG 抑制的受体。删除其中任何一个都会刺激 SCI 后轴突的生长。最近使用条件敲除小鼠的研究表明，PTEN 严重限制了受损中枢神经系统轴突的内在再生能力。因此，抑制CSPG受体和PTEN有望促进中枢神经系统损伤后的轴突再生。我们设计了小肽，通过靶向这些抑制分子的特定结构域来阻断其功能，并证明了我们的肽在体外和体内促进轴突生长的高效性。由于 CSPG 和 PTEN 似乎通过不同的信号通路来限制生长，因此抑制两者可能会协同作用，通过减少病变部位的环境抑制影响并增强成熟神经元的内在生长能力来促进轴突再生。我们假设 CSPG 和 PTEN 是 CNS 神经元再生失败的关键因素，并且联合抑制两者比单独抑制任一者更能促进轴突再生。我们建议解决以下 3 个具体目标：1) 确定两个 CSPG 受体的转基因缺失或肽阻断是否比单独抑制任一受体在体外和体内产生更好的轴突生长，以及成年 SCI 小鼠的功能恢复； 2) 确定用肽阻断 PTEN 是否在体外和体内刺激与转基因 PTEN 缺失相似程度的轴突生长和功能恢复； 3) 确定用肽同时阻断 CSPG 信号传导和 PTEN 是否比单独阻断其中之一更能促进 SCI 后的轴突再生和行为恢复。肽治疗的结果将与转基因小鼠实验的结果进行比较。我们单独或联合全身施用小化合物的新策略可能有助于开发中枢神经系统损伤的实用疗法。