Role of UCHL1 in Axonal Injury and Recovery after TBI

弥漫性轴索损伤是运动和认知后遗症的主要组成部分 创伤性脑损伤(TBI)。泛素C末端水解酶L1(UCHL1)高表达 神经元中的浓度，并可能在轴突运输和突触中发挥重要作用 功能。UCHL1的S活性在通过泛素降解异常神经元蛋白中起重要作用 蛋白酶体途径。因此，UCHL1可能通过以下途径在损伤后的恢复中发挥重要作用 有几种机制。在初步研究中，构建了一种TAT-UCHL1蛋白，该蛋白很容易 当被给予ip时进入大脑。TAT-UCHL1治疗减少轴突损伤 APP免疫细胞化学和减少皮质控制后的海马细胞死亡 对小鼠的影响(CCI)。在UCHL1的152位半胱氨酸上发现了一个活性脂结合位点 负责酶的解离和失活。一只敲进去的老鼠，带着一只 构建了C152A突变，并发现显著减少了轴突损伤和 改善了CCI后的运动行为。携带具有UCHL1活性的C90A突变的小鼠 也构建了不具水解酶活性的菌株。 本研究的目标是：1)确定UCHL1 C152位点在 CCI后小鼠的轴突损伤、神经元死亡以及运动和认知行为。2) 确定UCHL1水解酶活性在轴突损伤、神经元死亡和 CCI后小鼠的运动和认知行为。3)测试系统治疗是否有 TAT-UCHL1融合蛋白将减轻体外牵张模型和大鼠的轴突损伤 活体脑损伤模型，并改善CCI后小鼠的长期运动和认知功能。 这些研究的广泛的长期目标是开发新的方法， 促进脑外伤后轴突的保护和功能恢复。完成这些研究后， 提高关于UCHL1在神经元修复和功能中的作用的科学知识 脑外伤后的恢复和检测新的TAT-UCHL1蛋白作为处理轴突的新策略 受伤。

Diffuse axonal injury is a major component of the motor and cognitive sequela of traumatic brain injury (TBI). Ubiquitin C-terminal hydrolase L1 (UCHL1) is expressed at high concentrations in neurons and may play an important role axonal transport and synaptic function. UCHL1's activity is important in degrading abnormal neuronal protein via the ubiquitin proteasome pathway. Thus, UCHL1 may play an important role in recovery after injury via several mechanisms. In preliminary studies, a TAT-UCHL1 protein was constructed that readily enters the brain when given i.p. Treatment with TAT-UCHL1 reduced axonal injury detected by APP immunocytochemistry and decreased hippocampal cell death after controlled cortical impact (CCI) in mice. A reactive lipid binding site at the 152 cysteine of UCHL1 was identified that is responsible for unfolding and inactivating the enzyme. A knock-in mouse bearing a C152A mutation was constructed and found to have significantly reduced axonal injury and improved motor behavior after CCI. A mouse bearing a C90A mutation with UCHL1 activity that is devoid of hydrolase activity was also constructed. The goals of the current study are: 1) Determine the role of the UCHL1 C152 site in axonal injury, neuronal death, and motor and cognitive behavior after CCI in mice. 2) Determine the role of UCHL1 hydrolase activity in axonal injury, neuronal death, and motor and cognitive behavior after CCI in mice. 3) Test whether systemic treatment with TAT-UCHL1 fusion proteins will reduce axonal injury in the in vitro stretch model and in vivo TBI model, and improve long term motor and cognitive function after CCI in mice. The broad long term objective of these studies is to develop novel approaches that promote axonal preservation and functional recovery after TBI. Completion of these studies will improve scientific knowledge regarding the role of UCHL1 in neuronal repair and functional recovery after TBI and test novel TAT-UCHL1 proteins as a novel strategy to address axonal injury.