Mechanisms of secondary injury after SCI

描述（由申请人提供）：先天免疫反应显然是中枢神经系统创伤中继发性损伤级联的一个组成部分，但胶质细胞和单核细胞来源的促炎细胞因子的作用被多种浓度依赖性受体介导的多种下游效应和快速变化和进化的微环境所复杂化。我们的新发现有力地支持了TNF和AMPAR变化在中枢神经系统损伤后继发性损伤和恢复中至关重要的假设。使用可溶性TNF受体蛋白（sTNFR1）隔离TNF可减少颈椎脊髓损伤，并以高度剂量依赖的方式改善神经预后。我们建议扩展TNF和AMPAR转运作为SCI治疗靶点的研究，使用多变量方法来测试临床前疗效。依那西普（ETAN）是一种用于类风湿性关节炎的tnf隔离蛋白生物制剂；托吡酯（TPM）是一种具有AMPAR拮抗作用的神经保护、抗癫痫药物。我们将单独或联合使用这些药物来打击AMPAR贩运和AMPAR活动。我们将系统地评估这些药物的生物学反应，使用早期损伤后的生物标志物，预测我们之前的工作中的神经预后。我们将使用生物标志物数据来规划临床前剂量和时间方案，以评估颈椎和胸椎大鼠脊髓损伤的有效性，并评估其对自主神经、感觉和运动结果的影响。这些努力旨在推动抗肿瘤坏死因子治疗脊髓损伤的临床应用，也可能适用于其他中枢神经系统退行性疾病。我们提出了三个具体目标：目标1：我们将评估ETAN和TPM对脊髓损伤后AMPAR表面生物标志物表达、细胞死亡和促炎细胞因子产生的时间过程和程度的影响。我们预测这些治疗将减少细胞死亡的前馈级联。目标2。在这些数据的指导下，我们将通过各种前肢功能测试（梳理、脚爪放置、t台行走和IBB），优化单次和联合治疗的剂量和时间，以最大限度地提高单侧颈椎脊髓损伤后6周的恢复。目的3：我们将测试优化药物方案对胸部挫伤损伤恢复的影响，使用一系列测试，包括自主神经、感觉和运动结果。这将确定疗效是否适用于多种脊髓损伤模型。TNF和ampar也参与神经损伤后慢性超敏反应的产生（Choi et al, 2010），我们将测试这种情况是否也发生在脊髓损伤后。TPM已被用于治疗慢性脊髓损伤疼痛。我们预测，使用ETAN和TPM的急性治疗可以改善运动结果，也会减少长期的异常性疼痛和强直性、厌恶性中枢性疼痛（King等人，2009年），后者通过位置偏好测试来衡量。

DESCRIPTION (provided by applicant): The innate immune response is clearly an integral part of the secondary injury cascade in CNS trauma, but the role of glial and monocyte derived pro-inflammatory cytokines is complicated by multiple downstream effects mediated by multiple concentration-dependent receptors, and a rapidly changing and evolving microenvironment. We have new findings that strongly support the hypothesis that TNF and AMPAR changes are critical in both secondary injury and recovery after CNS injury. Sequestering TNF using soluble TNF receptor protein (sTNFR1) reduces damage after cervical SCI, and, in a highly dose-dependent manner, improves neurological outcomes. We propose to extend our studies of TNF and AMPAR trafficking as a therapeutic target for SCI using a multivariate approach to test preclinical efficacy. Etanercept (ETAN) is a TNF-sequestering protein biologic used clinically in rheumatoid arthritis; topiramate (TPM) is a neuroprotective, anti-epileptic drug that has AMPAR antagonism. We will use these drugs to target AMPAR-trafficking and AMPAR activity, separately and in combination. We will systematically evaluate the biological responses to these drugs using early post-injury biomarkers that have predicted neurological outcomes in our prior work. We will use the biomarker data to plan preclinical dose and timing regimens to evaluate effectiveness in both cervical and thoracic rat SCI, and evaluate their effects on autonomic, sensory and motor outcomes. These efforts are aimed at moving towards clinical application of anti-TNF therapies for SCI, and may be applicable to other CNS degenerative disorders as well. We propose three specific aims: Aim 1: We will evaluate the effects of ETAN and TPM on the time course and extent of biomarkers of AMPAR surface expression, cell death and the production of pro-inflammatory cytokines after cervical SCI. We predict that these treatments will reduce the feed-forward cascade of cell death. Aim 2. Guided by these data, we will optimize dose and timing of single and combination therapies to maximize six week recovery after unilateral cervical SCI using a variety of forelimb functional tests (grooming, paw placement, Catwalk and IBB). Aim 3: We will test the effects of optimized drug regimens on recovery from thoracic contusion lesions using a battery of tests that includes autonomic, sensory, and motor outcomes. This will establish whether efficacy extends to multiple models of SCI. TNF and AMPARs are also involved in the production of chronic hypersensitivity after nerve injury (Choi et al, 2010), and we will test whether this occurs after SCI as well. TPM is already used to treat chronic SCI pain. We predict that acute treatments with ETAN and TPM that result in better motor outcomes will also result in reductions in long term allodynia and in tonic, aversive central pain (King et al, 2009), the latter measured by place preference tests. PUBLIC HEALTH RELEVANCE: This project is aimed at the preclinical development of therapies for spinal cord injury (SCI). The drugs we will use target a unique aspect of the 'secondary injury' process: namely the role of tumor necrosis factor in altering the effects of a neurotransmitter, glutamate, on neurons and glial cells. Some of these drugs are already approved for other indications (e.g. etanercept and topiramate), so progress to clinical applications could be rapid, leading to better recovery after SCI and savings of health care costs.