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（UCHL 1）以高水平表达， 在神经元中的浓度，并可能发挥重要作用的轴突运输和突触 功能UCHL 1的活性在通过泛素降解异常神经元蛋白中是重要的 蛋白酶体途径因此，UCHL 1可能通过以下途径在损伤后的恢复中发挥重要作用： 几种机制。在初步研究中，构建了TAT-UCHL 1蛋白， 用TAT-UCHL 1治疗减少了通过以下检测到的轴突损伤： APP免疫细胞化学和减少海马细胞死亡后，控制皮质 影响（CCI）。在UCHL 1的152个半胱氨酸处发现了一个反应性脂质结合位点 它负责展开和灭活酶。一只带有 构建了C152 A突变，发现其显著减少了轴突损伤， 改善CCI后的运动行为。携带具有UCHL 1活性的C90 A突变的小鼠， 也构建了缺乏水解酶活性的。 本研究的目的是：1）确定UCHL 1 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。（二） 确定UCHL 1水解酶活性在轴突损伤、神经元死亡和神经元死亡中的作用。 CCI后小鼠的运动和认知行为。3)测试是否使用 TAT-UCHL 1融合蛋白将减少体外牵张模型中的轴突损伤， 体内TBI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TBI后轴突保存和功能恢复。完成这些研究将 提高关于UCHL 1在神经元修复和功能中作用的科学知识 TBI后的恢复和测试新的TAT-UCHL 1蛋白作为解决轴突损伤的新策略 损伤

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.