Chemical chaperones for Niemann-Pick C disease

描述(申请人提供)：NPC1病是一种严重的溶酶体脂肪沉积症，胆固醇和其他脂质从内酶体/溶酶体(E/L)系统中流出有缺陷，导致神经变性和过早死亡。导致鼻咽癌疾病主要形式的蛋白质NPC1是已知的。初步鉴定表明，NPC1可能是晚期内吞体膜上的一种脂质渗透酶。然而，NPC1的确切功能(S)及其在鼻咽癌疾病发病机制中的作用仍然是未知的，目前还没有治疗这种衰弱疾病的形式。我们假设许多NPC1突变是疾病引起的，因为突变的蛋白质不能从内质网成熟，因此不能靶向晚期的内体。最近，药理上相关的化学伴侣在促进突变蛋白成熟从而部分挽救蛋白活性方面显示出巨大的前景。我们将首先建立一种检测突变的NPC1蛋白成熟和内质网退出的方法。其次，我们将使用我们内部的高通量设施来鉴定可以拯救突变的NPC1蛋白的化学伴侣。这些分子随后将在基于细胞的分析中进行评估，以确定鼻咽癌表型纠正的水平，并评估它们在未来的动物和NPC1患者研究中的有效性。小分子伴侣的成功鉴定将为这种方法提供“原则证明”，并为研究NPC1和其他由膜蛋白错误折叠引起的破坏性神经疾病提供一条新的途径。

DESCRIPTION (provided by applicant): NPC1 disease is a severe lysosomal lipidosis in which the egress of cholesterol and other lipids from the endosomal/ lysosomal (E/L) system is defective, leading to neurodegeneration and premature demise. The protein responsible for the major form of NPC disease, NPC1 is known. Preliminary characterization suggests that NPC1 may act as a lipid permease on the membranes of late endosomes. However, the exact function(s) of NPC1 and its role in NPC disease pathogenesis remain elusive and no form of treatment for this debilitating disorder is currently available. We hypothesize that many NPC1 mutations are disease causing due to the fact that the mutant proteins are unable to mature from the endoplasmic reticulum and are thus unable to be targeted to the late endosome. Pharmacologically relevant chemical chaperones have shown great promise recently in enhancing mutant protein maturation and thus partial rescue of protein activity. We will first establish an assay for detecting the maturation and ER exit of mutant NPC1 proteins. Second, we will use our in-house high throughput facility to identify chemical chaperones that can rescue mutant NPC1 proteins. These molecules will then be evaluated in cell-based assays to determine the level of NPC phenotype correction and assess their utility in future animal and NPC1 patient studies. Successful identification of small molecule chaperones will provide "Proof-of-principle" for this type of approach, and a new avenue of research for NPC1 and other devastating neurological disorders caused by membrane protein misfolding.