Neurotransplantation and Training to Promote Recovery of Chronic SCI Cats

神经移植和训练促进慢性脊髓损伤猫的康复

• 批准号: 8323867
• 负责人: John D. Houle
• 金额: $ 35.44万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8323867
• 关键词: Acute; Address; Adult; Affect; Animal Model; Animals; Axon; Back; Behavioral; Biomechanics; Brain; Chemicals; Chest; Chondroitin Sulfate Proteoglycan; Chondroitinases; Chronic; Cicatrix; Combined Modality Therapy; Communication; Data; Detection; Distal; Electric Stimulation; Environment; FOS gene; Felis catus; Financial compensation; Forelimb; Fostering; Future; Gait; Growth; Hindlimb; Human; Hyaluronidase; Implant; Individual; Injury; Interneurons; Investigation; Joints; Label; Learning; Lesion; Limb structure; Link; Locomotion; Locomotor Recovery; Measures; Modeling; Muscle; Natural regeneration; Nerve; Neurons; Neurorehabilitation; Operative Surgical Procedures; Organ Transplantation; Pain; Pathway interactions; Patients; Perception; Peripheral Nerves; Peripheral nerve injury; Physical therapy; Physiological; Procedures; Process; Rattus; Recovery; Recovery of Function; Rehabilitation therapy; Research; Risk; Role; Sensory Ganglia; Site; Source; Spinal; Spinal Cord; Spinal Injuries; Spinal cord injury; Synapses; Techniques; Testing; Thromboplastin; Time; Tissues; Training; Translations; Transplantation; Work; axon growth; axon regeneration; base; clinical application; clinically relevant; design; immunocytochemistry; immunoreactivity; improved; injured; kinematics; locomotor tasks; neurotrophic factor; novel; pre-clinical; reconstruction; regenerative; repaired; research study; response; scale up; success; synaptogenesis; treatment strategy

DESCRIPTION (provided by applicant): Peripheral nerve grafts (PNGs) provide an excellent substratum for axonal regrowth; they can direct regenerating axons towards a specific target and they facilitate electrophysiological experimentation to detect synaptic connectivity between regenerating axons and distal spinal cord neurons. A major impediment to this and all other transplantation approaches after spinal cord injury is the poor growth of axons out of the graft back into the host spinal cord. We have combined Chondroitinase (ChABC, to digest inhibitory chondroitin sulfate proteoglycan molecules) with PN grafting in rats and have anatomical and electrophysiological evidence for functional synapse formation by injured, regenerating axons in both acute and delayed (chronic injury) treatment paradigms. Recently we replicated this rat acute PNG approach in cats where we observed thousands of axons regenerating into the graft, a small percentage of which extended from the graft into the spinal cord distal to the injury, and spinal neurons synaptically activated (determined by c-Fos immunoreactivity) after electrical stimulation of the nerve graft. While we will continue to use rat models for expanding our treatment repertoire, the objective of this study is to focus on application of our treatment strategies to chronically injured cats as a necessary preclinical step before translation into human research. The cat model permits us to investigate issues related to the scaling up of a transplantation model, cats are easily trained to perform locomotor tasks, and recovery of function can be assessed by kinematic and electrophysiological measures. The biomechanics of locomotion are better defined in cats and cats have a hindlimb gait that is close to human than is the rat. The proposed work also will provide information about the ability to effectively treat glial scarring in a large animal, the ability to promote structural and functional regeneration in a large animal with a chronic injury and the potential for rehabilitation training to foster regeneration and functional recovery. There are 2 Specific Aims for this project. 1) We will identify the source and extent of axonal regeneration into a PNG after chronic injury and test whether these axons form functional connections across the lesion. 2) We will test whether the start time of physical rehabilitation affects outgrowth, integration and/or synaptic activity of regenerating axons. A combination of treatment strategies will be used, including transplantation, ChABC treatments and treadmill training to promote activity dependent plasticity. Structural repair will be assessed by anatomical tract tracing and immunocytochemical labeling; forelimb-hindlimb coordination will be assessed by kinematic and electromyogram (EMG) analysis; functional reconnection will be measured during electrophysiological stimulation of the graft and by c-fos expression in synaptically activated neurons. Surgical intervention after SCI usually is not an option until the patient is stabilized, thus the majority of individuals with SCI likely will be chronically injured before a treatment strategy for repair is initiated. Our work with chronically injured rats demonstrates the ability to promote long distance regeneration with formation of functionally active synapses distal to an injury. The proposed study will take advantage of the treatment approaches that have been (and are being) developed with chronically injured rats, but will apply them to a large animal model of SCI. This preclinical advancement is a crucial step towards translation to a clinical application. We propose a unique approach to address a very important aspect of SCI, i.e. chronic injury in a large animal model. Locomotor training of injured cats has been carried out by numerous labs, but not in a situation where axon regeneration is facilitated. This will be a novel application of neuroregeneration and neurorehabilitation techniques to increase our understanding of the potential for repair after SCI.

描述（由申请人提供）：周围神经移植（PNG）为轴突再生提供了极好的底层；他们可以将轴突引导到特定靶标，并促进电生理实验，以检测再生轴突和脊髓远端神经元之间的突触连通性。脊髓损伤后这种和所有其他移植方法的主要障碍是，轴突从移植物中的生长较差，回到宿主脊髓中。我们将软骨素酶（CHABC，硫酸硫酸软骨蛋白蛋白聚糖分子）与大鼠的PN接枝结合在一起，并在急性和延迟（慢性损伤）治疗的轴突中具有解剖学和电生理证据，可通过受伤的轴突进行损伤，再生轴突的功能突触形成。最近，我们在猫中复制了这种大鼠急性PNG方法，在该猫中，我们观察到成千上万的轴突重生为移植物，其中一小部分从移植物延伸至损伤远端的脊髓，脊柱神经元突触激活（通过C-FOS免疫反应性确定），在电刺激植物后，C-FOS免疫反应性）。尽管我们将继续使用大鼠模型来扩展我们的治疗库，但本研究的目的是将我们的治疗策略专注于长期受伤的猫，作为在转化为人类研究之前的必要临床前一步。 CAT模型允许我们调查与扩展移植模型相关的问题，很容易训练CAT来执行运动任务，并且可以通过运动学和电生理学指标评估功能的恢复。运动的生物力学在猫中可以更好地定义，而猫的后肢步态与人类相比接近人类。拟议的工作还将提供有关有效治疗大动物中神经胶质疤痕的能力，促进具有慢性损伤的大动物的结构和功能再生的能力，以及进行康复训练的潜力以促进再生和功能恢复。该项目有2个具体目标。 1）我们将在慢性损伤后确定轴突再生的来源和程度，并测试这些轴突是否在整个病变中形成功能连接。 2）我们将测试身体康复的开始时间是否会影响再生轴突的生长，整合和/或突触活动。将使用治疗策略的组合，包括移植，CHABC治疗和跑步机训练，以促进依赖活动的可塑性。结构修复将通过解剖学追踪和免疫细胞化学标记来评估；前肢协调将通过运动学和肌电图（EMG）分析评估；功能重新连接将在对移植物的电生理刺激和突触激活神经元中的C-FOS表达时进行测量。在患者稳定之前，SCI之后的手术干预通常是选择，因此，大多数SCI患者可能会在启动修复治疗策略之前长期受伤。我们与长期损伤大鼠的工作证明了促进长距离再生的能力，并形成了损伤远端的功能性突触。拟议的研究将利用慢性损伤大鼠开发的治疗方法，但将其应用于大型SCI动物模型。这种临床前的进步是转化为临床应用的关键步骤。我们提出了一种独特的方法来解决SCI非常重要的方面，即大型动物模型中的慢性损伤。许多实验室已经对受伤的猫进行了运动训练，但在轴突再生的情况下没有进行。这将是神经创造和神经康复技术的新应用，以增加我们对SCI后修复潜力的理解。