A chemical approach to elucidating the structure-function relationships of chondronitin sulfate glycosaminoglycans

阐明硫酸软骨素糖胺聚糖结构与功能关系的化学方法

• 批准号: 8965476
• 负责人: Linda C Hsieh-Wilson
• 金额: $ 53.63万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8965476
• 关键词: Aging; Antibodies; Axon; Biological Process; Biology; Brain; Cell Surface Receptors; Chemicals; Chondroitin Sulfate A; Chondroitin Sulfates; Cicatrix; Complex; Development; Disease; Eph Family Receptors; Ephrins; Event; Family; Genes; Genetic; Global Change; Glycosaminoglycans; Goals; Grant; Health; Immunoglobulin Fragments; Injury; Inorganic Sulfates; Knockout Mice; Lead; Ligands; Malignant Neoplasms; Mediating; Methods; Molecular; Monoclonal Antibodies; Natural regeneration; Nerve Regeneration; Nervous system structure; Neuronal Plasticity; Neurons; Neurophysiology - biologic function; Neuropilin-1; Organic Chemistry; Pathway interactions; Pattern; Play; Polymers; Polysaccharides; Process; Proteins; Receptor Activation; Regulation; Research; Role; Semaphorin-3A; Signal Pathway; Signal Transduction; Signaling Protein; Spinal Cord; Spinal cord injury; Structure; Structure-Activity Relationship; Synaptic plasticity; System; Unspecified or Sulfate Ion Sulfates; Viral; Visual Cortex; Work; axon regeneration; central nervous system injury; chondroitin sulfate glycosaminoglycan; in vivo; inhibitor/antagonist; insight; mimetics; neural circuit; neurodevelopment; novel; novel strategies; novel therapeutic intervention; novel therapeutics; optic nerve regeneration; plexin; polysulfated glycosaminoglycan; programs; receptor; repaired; response; small molecule; sulfation; sulfotransferase; tool

 DESCRIPTION (provided by applicant): This project will focus on chondroitin sulfate glycosaminoglycans (CS GAGs), a class of polysaccharides that play important roles in development, viral invasion, cancer, and spinal cord injury. CS GAGs display diverse sulfation patterns that are spatiotemporally regulated in vivo. However, efforts to identify functions for specific sulfation motifs have been hampered by the structural complexity of CS and a lack of tools. In this grant, we will combine the power of both organic chemistry and biology to overcome these challenges and identify novel functions for specific motifs in the nervous system. The broad objectives of this program are to: (1) advance a fundamental understanding of the structure-function relationships of CS GAGs, (2) understand the roles of CS GAGs in neuroplasticity and regeneration, and (3) develop new approaches to study and manipulate GAG-mediated biological processes, with the long-term goal of stimulating synaptic plasticity and neuronal repair. In the last granting period, we developed a set of chemical tools to study specific sulfation motifs and discovered that a particular motif, CS-E, inhibits axon regeneration after spinal cord injury. Blocking the CS-E motif using an anti-CS-E antibody stimulated axon regeneration in vivo. Moreover, we found that this same motif repels axons and plays a critical role in neural circuit formation during brain development. An important observation from this work was that the activity of CS-E required its interaction with cell-surface receptors and activation of specific inhibitory signaling pathways in neurons. In the present grant, we will develop new approaches to modulate the interactions of CS-E with neuronal receptors, including the viral-mediated delivery of single-chain anti-CS-E antibodies, small- molecule sulfotransferase inhibitors, and glycopolymer mimetics (Aim 1). We will study how CS-E regulates protein signaling complexes, with a particular focus on semaphorin-3A/neuropilin-1/plexin A (Sema3A/Nrp1/PlxnA) and ephrin/Eph receptor (Efn/Eph) complexes (Aims 2a and 3a). Finally, we will investigate the ability of the agents developed in Aim 1 to promote neuroplasticity in the visual cortex (Aims 2b,c) and axon regeneration after spinal cord injury (Aim 3b). These studies are expected to provide new chemical tools to advance an understanding of GAGs and fundamentally change how CS GAGs are viewed - from being static, passive molecules to ligands that actively regulate important signaling pathways. Finally, if successful, the agents developed in Aim 1 could lead to novel therapeutic strategies for stimulating neuronal plasticity and repair in the case of aging, injury, and disease.

 描述（由申请人提供）：该项目将重点关注硫酸软骨素糖胺聚糖（CS GAG），这是一类在发育、病毒入侵、癌症和脊髓损伤中发挥重要作用的多糖。 CS GAG 显示出体内时空调节的多种硫酸化模式。然而，由于 CS 的结构复杂性和工具的缺乏，鉴定特定硫酸化基序功能的努力受到了阻碍。在这笔资助中，我们将结合有机化学和生物学的力量来克服这些挑战，并确定神经系统中特定基序的新功能。该计划的主要目标是：(1) 增进对 CS GAG 结构功能关系的基本了解，(2) 了解 CS GAG 在神经可塑性和再生中的作用，以及 (3) 开发新方法来研究和操纵 GAG 介导的生物过程，长期目标是刺激突触可塑性和神经元修复。 在最后的资助期间，我们开发了一套化学工具来研究特定的硫酸化基序，并发现特定的基序CS-E可以抑制脊髓损伤后的轴突再生。使用抗 CS-E 抗体阻断 CS-E 基序可刺激体内轴突再生。此外，我们发现同样的基序排斥轴突，并在大脑发育过程中的神经回路形成中发挥关键作用。这项工作的一个重要观察结果是，CS-E 的活性需要其与细胞表面受体的相互作用以及神经元中特定抑制信号通路的激活。 在本次资助中，我们将开发新方法来调节 CS-E 与神经元受体的相互作用，包括病毒介导的单链抗 CS-E 抗体、小分子磺基转移酶抑制剂和糖聚合物模拟物的递送（目标 1）。我们将研究 CS-E 如何调节蛋白质信号传导复合物，特别关注 semaphorin-3A/neuropilin-1/plexin A (Sema3A/Nrp1/PlxnA) 和 ephrin/Eph 受体 (Efn/Eph) 复合物（目标 2a 和 3a）。最后，我们将研究目标 1 中开发的药物促进视觉皮层神经可塑性（目标 2b、c）和脊髓损伤后轴突再生（目标 3b）的能力。这些研究预计将提供新的化学工具，以增进对 GAG 的理解，并从根本上改变人们对 CS GAG 的看法——从静态、被动分子到主动调节重要信号通路的配体。最后，如果成功，目标 1 中开发的药物可能会带来新的治疗策略，在衰老、损伤和疾病的情况下刺激神经元可塑性和修复。