Targeting the PMP22 Protein to Develop Leads Against Charcot-Marie-Tooth Disease

项目摘要 Charcot-Marie-Tooth病(CMTD)是一种遗传性周围神经病，发病率为1：2500 人类。CTMD的病理特征是PNS髓鞘严重缺陷。目前没有 对这种疾病的药物治疗或治疗。超过75%的CMTD病例是由 三体致雪旺细胞野生型(WT)外周髓鞘蛋白(PMP22)过表达 PMP22表达不足(WT/空)，或遗传显性杂合性(WT/突变) 改变PMP22蛋白序列的突变。已知WT PMP22可以正确折叠和传输 在健康条件下只有20%的效率。我们的基本原理是，这些小分子 PMP22的表达水平或体内折叠效率有可能成为有效的治疗手段 探员们。减少蛋白质表达的药物很可能被证明对最常见的 基于三体的过度表达导致的CMTD(1A型)形式。另一方面，起作用的药物 折叠校正子或表达增强剂可能被证明对由以下原因引起的各种CMTD有效 PMP22表达不足和/或错误折叠。该项目的具体目标旨在建立 药物发现计划的基础是为最常见的疾病开发治疗化合物 Charcot-Marie-Tooth病(CMTD)的各种形式，由影响 编码外周髓鞘蛋白22(PMP22)的PMP22基因，PMP22是一种四胺基膜蛋白。 这些目标是： 目的1.建立一种可用于高通量筛选(HTS)的初步检测方法 识别改变野生型(WT)和疾病突变体总表达的小分子模式 PMP22的形式，或增强细胞表面膜的蛋白质运输。 目标2.进行初步筛选，以发现和表征调节总胆固醇的先导化合物 PMP22和/或提高PMP22细胞表面转运效率的表达水平。确定命中 浓度-反应(效价)曲线。 目的3.使用Schwann细胞进行HIT的二次筛查，并在 髓鞘形成试验。进行生物物理研究，以测试先导化合物是否以一种 包括直接与PMP22蛋白结合，并测试它们对PMP22蛋白稳定性的影响。 该项目的成功完成将提供一系列准备就绪的先导化合物 为了未来对先导化合物结构的药物化学优化，在 可用的CMTD小鼠和大鼠模型，以及临床前测试。

Project Summary Charcot-Marie-Tooth Disease (CMTD) is a debilitating hereditary peripheral neuropathy that afflicts 1:2500 humans. The hallmark of CTMD pathology is severely defective PNS myelin. There is currently no pharmacological treatment or cure for this disease. Over 75% of all cases of CMTD are caused by Schwann cell overexpression of wild type (WT) peripheral myelin protein (PMP22) due to trisomy, underexpression of PMP22 (for the WT/null case), or genetically dominant heterozygous (WT/mutant) mutations that alter the PMP22 protein sequence. WT PMP22 is known to properly fold and traffic with only 20% efficiency under healthy conditions. Our driving rationale is that small molecules that tune either the expression levels or in vivo folding efficiency of PMP22 have the potential to be effective therapeutic agents. Drugs that reduce expression of the protein are likely to prove effective against the most common form of CMTD (Type 1A) caused by trisomy-based overexpression. On the other hand, drugs that act as folding correctors or expression enhancers are likely to prove effective for forms of CMTD caused by underexpression and/or misfolding of PMP22. The Specific Aims of this project are designed to establish the foundations for a drug discovery program to develop therapeutic compounds for the most common forms of Charcot-Marie-Tooth Disease (CMTD), which are caused by genetic variations that impact the PMP22 gene that encodes peripheral myelin protein 22 (PMP22), a tetraspan membrane protein. These Aims are: Aim 1. Develop a primary assay that can be implemented in high throughput screening (HTS) mode to identify small molecules that alter the total expression of wild type (WT) and disease mutant forms of PMP22, or that enhance the cell surface membrane trafficking of the protein. Aim 2. Conduct primary screens to discover and characterize lead compounds that modulate total expression levels of PMP22 and/or that enhance PMP22 cell surface trafficking efficiency. Determine hit concentration-response (potency) curves. Aim 3. Conduct a secondary screen of hits using Schwann cells and test for hit efficacy in a myelination assay. Conduct biophysical studies to test whether lead compounds act in a way what involves direct binding to the PMP22 protein and also test for their impact on PMP22 protein stability. Successful completion of this project will provide a series of lead compounds that will be ready for future medicinal chemistry optimization of lead compound structures, efficacy testing in available mouse and rat models of CMTD, and pre-clinical testing.