Kinase Inhibitors against Neurodegeneration

描述（由申请人提供）：尼曼-皮克C型（Niemann-Pick type C， NPC）是一种罕见且致命的神经内脏储存疾病，目前无法治疗，在大多数情况下（95%），NPC是由NPC1基因突变引起的，该基因编码一种在胆固醇转运中起重要作用的糖蛋白。NPC的大脑也以轴突异常、神经原纤维缠结（nft）和进行性神经变性为特征。导致鼻咽癌病理的机制尚不清楚，尽管鼻咽癌突变细胞中胆固醇代谢的改变导致轴突和神经元变性以及tau蛋白的过度磷酸化，这是nft的主要成分。有趣的是，在鼻咽癌和阿尔茨海默病（AD）中观察到的nft在化学和形态学上难以区分，在AD中，它们与痴呆的严重程度相关。在NPC1-/-小鼠的大脑中，几种蛋白激酶的活性发生改变，这些改变可能导致tau修饰和神经元死亡。特别是，细胞周期蛋白依赖性激酶5 （cdk5）和丝裂原活化蛋白激酶（MAPK）的活性在npcl缺陷细胞中升高。这表明特定蛋白激酶活性的增加在鼻咽癌发病中起关键作用。提出的实验针对以下问题：(1)cdk5， gsk3 - β和MAP激酶对tau过磷酸化和NFT形成的贡献是什么？(2)这些激酶在NPC1-/-小鼠病理发展中的作用是什么？因此，我们的具体目标是：(i)利用ApoE-/-小鼠培养的海马切片确定各种蛋白激酶抑制剂对建立良好的tau过度磷酸化和NFT形成的体外模型的影响，（ii）测试Aim 1中获得的每种蛋白激酶最有效的抑制剂对类似模型的影响，该模型使用培养的NPC1-/-小鼠海马和小脑切片。（iii）在NPC1-/-小鼠体内验证选定的蛋白激酶抑制剂可以防止tau过度磷酸化、神经元变性、小胶质细胞和星形胶质细胞反应以及运动缺陷的假设。拟议的研究有可能(i)确定负责tau过度磷酸化和缠结形成的途径，（ii）提供有关特定蛋白激酶在鼻咽癌疾病其他病理表现中的作用的关键信息，以及（iii）为针对鼻咽癌和AD的基本方面的广泛药物发现计划开辟道路。

DESCRIPTION (provided by applicant): Niemann-Pick type C (NPC) is a rare and fatal neurovisceral storage disorder that is currently untreatable, in most cases (95%), NPC is caused by mutations of the NPC1 gene, which encodes a glycoprotein playing an important role in cholesterol transport. NPC brains are also characterized by axonal abnormalities, neurofibrillary tangles (NFTs), and progressive neurodegeneration. The mechanisms leading to pathology in NPC are not well understood, although altered cholesterol metabolism in NPC mutant cells leads to axonal and neuronal degeneration as well as to hyperphosphorylation of the tau protein, which is the major component of NFTs. Interestingly, the NFTs observed in NPC and in Alzheimer's disease (AD) are chemically and morphologically indistinguishable and, in AD, they correlate with the severity of dementia. In brains from NPC1-/- mice, the activity of several protein kinases is altered and these alterations may result in tau modifications and neuronal death. In particular, the activities of cyclin-dependent kinase 5 (cdk5) and mitogen-activated protein kinase (MAPK) are elevated in NPCl-defective cells. This suggests that increased activity of selected protein kinases plays a critical role in NPC pathogenesis. The proposed experiments are directed at the following questions: (1) What are the contributions of cdk5, GSK3-beta, and MAP kinases to tau hyperphosphorylation and NFT formation? (2) What are the contributions of these kinases in the development of pathology taking place in NPC1-/- mice? Therefore, our specific aims are to (i) determine the effects of a variety of protein kinase inhibitors on a well established in vitro model of tau hyperphosphorylation and NFT formation using cultured hippocampal slices from ApoE-/- mice, (ii) test the effects of the most potent inhibitors of each class of protein kinases obtained in Aim 1 on a similar model that uses cultured hippocampal and cerebellar slices from NPC1-/- mice, and (iii) test the hypothesis that selected protein kinase inhibitors will prevent tau hyperphosphorylation, neuronal degeneration, microglial and astroglial reaction, and motor deficits in NPC1-/- mice in vivo. The proposed studies have the potential to (i) identify the pathway responsible for tau hyperphosphorylation and tangle formation, (ii) provide critical information concerning the role of specific protein kinases in other pathological manifestations of NPC disease, and (iii) open the way to broad-based drug discovery programs directed at essential aspects of NPC and AD.