Role of UCH-L1 in Ischemic Injury and Recovery

在体外防止神经细胞死亡和预防神经细胞死亡的高效神经保护药物 体内灰质损伤还没有成功地转化为人类中风的治疗方法。原因何在 解释这种翻译失败的假设包括许多神经保护治疗缺乏效果 关于脑白质损伤和侧重于大多数不实用的治疗靶点的超急性机制 中风患者。 泛素C末端水解酶L1(UCHL1)是一种多功能蛋白，选择性表达于 遍布大脑的神经元和轴突。UCHL1在轴突运输和维持中起重要作用 轴突完整性以及通过泛素蛋白酶体途径去除异常蛋白。UCHL1 调节突触功能，可能参与记忆功能。携带基因突变的人类和小鼠 UCHL1有广泛的运动系统异常。我们假设UCLH1可能在 保护轴突的完整性和突触功能，促进中风后的运动恢复。 在前一个资金周期中，我们发现UCHL1的152个半胱氨酸结合了活性脂质和 使酶失活。我们构建了一只携带阻止该位点结合的突变的小鼠(C152a) 研究发现，这种突变保留了轴突的完整性和突触功能，并促进了运动的恢复 脑缺血后的体外和体内实验。我们现在已经构建了一种携带突变(C90A)的小鼠 取消UCHL1水解酶活性。此外，我们还构建了TAT-UCHL1蛋白，很容易 全身给药后对神经元进行转导。 我们提出了以下具体目标： 目的1：测试C90A突变是否会加剧灰质和白质的完整性 加重缺血后的运动障碍 目的2：测试TAT-UCHL1蛋白治疗是否会减少灰质和白质损伤 改善缺血后轴突传导、突触功能和运动行为。 目的3：测试C152A突变是否能预防脑白质病变和认知改变 小鼠和老年小鼠血管性痴呆模型的建立。 这些研究的广泛的长期目标是开发既促进灰白和灰白的治疗 卒中后脑白质保护与功能恢复。这些研究将提高科学知识 关于UCHL1和在卒中和血管性痴呆中的作用并测试新的TAT-UCHL1蛋白 临床前中风模型。

Neuroprotective drugs that are highly effective in preventing neuronal cell death in vitro and preventing gray matter injury in vivo have not been successfully translated into therapies for human stroke. The reasons hypothesized to explain this failure of translation include the lack of effect of many neuroprotective treatments on white matter injury and a focus on hyperacute mechanisms that are not practical treatment targets in most patients with stroke. Ubiquitin C-terminal hydrolase L1 (UCHL1) is a multifunctional protein that is selectively expressed in neurons and axons throughout brain. UCHL1 plays an important role in axonal transport and maintaining axonal integrity as well as removing abnormal proteins via the ubiquitin proteasome pathway. UCHL1 regulates synaptic function and may be involved in memory function. Humans and mice with mutations in UCHL1 have extensive motor system abnormalities. We hypothesize that UCLH1 may play an important role in preserving axonal integrity and synaptic function promoting motor recovery after stroke. In the previous cycle of funding, we found that the 152 cysteine of UCHL1 binds reactive lipids and inactivates the enzyme. We constructed a mouse bearing a mutation that prevents binding at the site (C152A) and found that this mutation preserves axonal integrity and synaptic function and promotes motor recovery after cerebral ischemia in vitro and in vivo. We now have constructed a mouse bearing a mutation (C90A) that abolishes the UCHL1 hydrolase activity. In addition, we have constructed TAT-UCHL1 proteins that readily transduces neurons after systemic administration. We propose the following specific aims: Aim 1: Test whether the C90A mutation exacerbates gray and white matter integrity and exacerbates motor impairment after ischemia Aim 2: Test whether treatment with TAT-UCHL1 proteins will reduce gray and white matter injury and improve axonal conduction, synaptic function and motor behavior after ischemia. Aim 3 : Test whether the C152A mutation prevents white matter pathology and cognitive change in a model of vascular dementia in young and old mice. The broad long term objectives of these studies are to develop treatments that promote both gray and white matter preservation and functional recovery after stroke. These studies will improve scientific knowledge regarding the role of UCHL1 and in stroke and vascular dementia and test novel TAT-UCHL1 proteins in preclinical stroke models.