The Primate Corticospinal Connectome and Transcriptome

灵长类动物皮质脊髓连接组和转录组

• 批准号: 10211059
• 负责人: MARK H. TUSZYNSKI
• 金额: $ 66.34万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10211059
• 关键词: Adult; Affinity Chromatography; Axon; Brain; Cells; Cervical spinal cord structure; Corticospinal Tracts; Data; Distal; Embryo; Genes; Genetic Transcription; Grant; Growth; Hand; Human; Injury; Interneurons; Intervention; Knowledge; Label; Lesion; Macaca mulatta; Monkeys; Motor; Motor Cortex; Motor Neurons; Mus; Natural regeneration; Nature; Neurons; Pathway interactions; Primates; Property; Rattus; Recovery; Recovery of Function; Reporting; RiboTag; Ribosomes; Rodent; Series; Site; Spinal Cord; Spinal cord injury; Synapses; System; Therapeutic Intervention; Time; Translations; Up-Regulation; Viral; Viral Vector; Work; axon injury; base; cell type; connectome; critical period; functional improvement; improved; injured; motor control; nerve stem cell; neural graft; novel; programs; regenerative; relating to nervous system; severe injury; stem cells; time use; transcriptome; transcriptome sequencing

Project Summary Efforts to promote recovery of function after human spinal cord injury (SCI) will likely require interventions targeting the corticospinal motor system, the most important pathway for voluntary motor control in humans. In a series of studies over the past 4 years we have found that corticospinal tract (CST) axons regenerate into spinal cord neural stem cell (NSC) grafts placed into sites of SCI in mice, rats and monkeys. These regenerating CST axons form synapses with the graft, and the graft in turn extends very large numbers of new axons from the injury site over long distances into the distal spinal cord. Neural relays across the injury are thereby formed, supporting functional improvement. This work is on a human translational path and IND-enabling work is in progress. This grant proposes two new directions that will be critically important in supporting human translation. First, we recently reported that injured adult mouse CST neurons revert to an embryonic transcriptional state that lasts for two weeks after SCI, a time during which CST axons can regenerate. This finding establishes a critical period for intervention after mouse SCI to support recovery. Does the same transcriptional reversion to a pro-growth embryonic state occur in the primate brain? If so, how long does it last? Work in Aim 1 will definitively answer this question, identifying for the first time what may be an optimal time window for therapeutic intervention of any type to support functional recovery in primates, including humans. We will perform RNA sequencing (RNAseq) specifically of CST neurons after SCI in rhesus monkeys using intersectional viral approaches, based on supportive preliminary data in monkeys. In Aim 2 we propose for the first time using novel viral vectors to anterogradely, trans-synaptically trace primate corticospinal projections to the spinal cord. Our preliminary studies demonstrate that rodent CST axons project nearly entirely to spinal cord interneurons, whereas in primates the vast preponderance of CST axons terminate directly on alpha motor neurons. Knowing the precise targets of CST projections to the spinal cord will both markedly extend our basic knowledge of motor system organization in primates, and will allow optimization of stem cell graft properties to enhance neural relay formation across sites of SCI. Unlike other neural stem cell programs for SCI, our work aims to directly re-form critical neural relays across a severe injury, rather than target spared axons through grafts of OPCs; knowledge gained from this aim could markedly improve relay formation across injury sites in the primate system.

项目概要 人类脊髓损伤 (SCI) 后促进功能恢复的努力可能需要干预措施 针对皮质脊髓运动系统，这是自主运动控制的最重要途径 人类。在过去 4 年的一系列研究中，我们发现皮质脊髓束 (CST) 轴突 再生为脊髓神经干细胞（NSC）移植物，植入小鼠、大鼠和脊髓损伤部位 猴子。这些再生的 CST 轴突与移植物形成突触，而移植物又延伸得非常长。 大量新轴突从损伤部位长距离进入远端脊髓。神经 由此形成跨损伤的中继，支持功能改善。这项工作是针对人类的 转化路径和 IND 支持工作正在进行中。 这笔赠款提出了两个新方向，这对于支持人工翻译至关重要。 首先，我们最近报道受损的成年小鼠 CST 神经元恢复到胚胎转录状态 SCI 后持续两周的状态，在此期间 CST 轴突可以再生。这一发现 建立了小鼠 SCI 后干预的关键期以支持康复。也一样吗 灵长类动物大脑中是否发生转录逆转至促生长胚胎状态？如果是这样，需要多长时间 最后吗？目标 1 中的工作将明确回答这个问题，首次确定什么可能是 支持灵长类动物功能恢复的任何类型治疗干预的最佳时间窗口， 包括人类。我们将在 SCI 后专门对 CST 神经元进行 RNA 测序 (RNAseq) 基于猴子的支持性初步数据，使用交叉病毒方法对恒河猴进行研究。 在目标 2 中，我们首次提出使用新型病毒载体进行顺行、跨突触追踪 灵长类动物的皮质脊髓投射到脊髓。我们的初步研究表明，啮齿动物 CST 轴突几乎完全投射到脊髓中间神经元，而在灵长类动物中，绝大多数 CST 轴突直接终止于 α 运动神经元。了解 CST 预测的精确目标 脊髓将显着扩展我们对灵长类动物运动系统组织的基础知识， 并将允许优化干细胞移植特性，以增强跨位点的神经中继形成 SCI。与其他 SCI 神经干细胞项目不同，我们的工作旨在直接重塑关键神经细胞 跨越严重损伤进行中继，而不是通过 OPC 移植物瞄准幸存的轴突；获得的知识 这一目标可以显着改善灵长类动物系统中损伤部位的中继形成。