Chemical genomic profiling for hereditary dystonia

描述（由申请人提供）：早发性（DYT 1）肌张力障碍是一种遗传性运动障碍，涉及严重的运动障碍，被认为反映了基底神经节内的功能障碍。受影响的个人发展持续的，不自主的肌肉收缩和扭曲的姿势，几乎没有治疗方案存在。大多数病例与杂合密码子缺失有关，该密码子缺失从编码蛋白质torsinA的羧基末端去除了谷氨酸。扭转蛋白A被认为在内质网（ER）内作为分泌途径内的分子伴侣起作用。多项研究表明，DYT 1的发病机制反映了torsinA功能的丧失，可能是由于突变蛋白的显性负效应。我们最近进行了一项基于靶点的筛选，确定了一组torsinA的小分子配体，其中一种可以挽救DYT 1细胞中的功能缺陷。这种化合物是一种由学术实验室合成的新型醛，尚未获得FDA批准。在这个项目中，我们建议使用这种化合物作为探针，以寻找其他已知的FDA批准的药物，模仿其效果。如果这种药物存在，它们可能会更快地进入肌张力障碍的人体试验，因为它们已经被批准用于临床。我们将首先在存在或不存在我们的先导化合物的情况下对来自DYT 1患者和对照的原代成纤维细胞进行全基因组表达分析。这些基因签名将用于查询新的数据库，连接图（CMap）。通过从用大量已知药物单独处理的培养细胞中获得基因表达特征来创建CMap。数据库软件将允许我们寻找预测在未处理的DYT 1细胞中表型复制我们的测试化合物和/或逆转基因表达谱的药物。我们将使用基因集富集分析（GSEA）进一步分析基因表达结果，以确定DYT 1细胞相对于对照可能差异调节的功能途径。我们将获得通过CMap鉴定的任何药物以及已知作用于GSEA分析所涉及的靶点和/或途径的药物，并在DYT 1细胞测定中将新候选药物与我们的测试化合物进行比较。据我们所知，这项分析将是人类DYT 1细胞的第一个转录谱，并将利用我们团队收集的大量原发性肌张力障碍患者细胞。这些结果可能通过揭示突变蛋白干扰的细胞通路，同时寻求治疗肌张力障碍的新候选药物，为DYT 1的发病机制提供新的见解。 公共卫生相关性：早发性（DYT 1）肌张力障碍是一种致残性运动障碍，通常始于青春期。虽然目前的治疗选择有限，但在受影响的个体中观察到的正常脑结构和细胞死亡的缺乏表明该疾病可以通过药物治疗。在这个项目中，我们提出了一种新的策略来寻找肌张力障碍的新候选药物，该策略结合了（1）原发性DYT 1患者与对照细胞的全基因组表达谱;和（2）一种强大的新发现工具，连接图，将基因表达特征与特定的已知药物联系起来。

DESCRIPTION (provided by applicant): Early onset (DYT1) dystonia is a hereditary movement disorder involving severe motor impairment believed to reflect a dysfunction within the basal ganglia. Affected individuals develop sustained, involuntary muscle contractions and twisted postures for which few treatment options exist. Most cases are linked to a heterozygous codon deletion which removes a glutamic acid from the carboxy terminus of the encoded protein, torsinA. TorsinA is thought to function within the endoplasmic reticulum (ER) as a molecular chaperone within the secretory pathway. Multiple studies suggest that DYT1 pathogenesis reflects a loss of torsinA function, possibly due to dominant negative effects of the mutant protein. We recently performed a target-based screen that identified a set of small molecule ligands for torsinA, one of which rescues a functional defect in DYT1 cells. This compound is a novel aldehyde synthesized by an academic laboratory and not yet FDA-approved. In this project we propose to use this compound as a probe to find other, known FDA-approved drugs which mimic its effects. If such drugs exist, they could potentially be moved into human trials for dystonia more quickly as they are already approved for clinical use. We will first perform a genomewide expression analysis on primary fibroblasts from DYT1 patients and control in the presence or absence of our lead compound. These gene signatures will be used to query a new database, the Connectivity Map (CMap). CMap was created by obtaining gene expression signatures from cultured cells treated individually with a large collection of known drugs. The database software will allow us to seek drugs predicted to phenocopy our test compound and/or reverse the gene expression profile in untreated DYT1 cells. We will further analyze the gene expression results using Gene Set Enrichment Analysis (GSEA) to identify functional pathways that may be differentially regulated in DYT1 cells relative to controls. We will obtain any drugs identified by CMap as well as ones known to act on targets and/or pathways implicated by the GSEA analysis and compare the new candidates to our test compound in a DYT1 cellular assay. To our knowledge, this analysis would be the first transcriptional profile of human DYT1 cells ever performed and would take advantage of the large inventory of primary dystonia patient cells collected by our team. The results may offer new insight into DYT1 pathogenesis by revealing cellular pathways perturbed by the mutant protein while also seeking new candidates to treat dystonia. PUBLIC HEALTH RELEVANCE: Early onset (DYT1) dystonia is a crippling movement disorder that typically begins during adolescence. Although current therapeutic options are limited, the normal brain structure and absence of cell death observed in affected individuals suggest that the disease could be drug treatable. In this project we propose a novel strategy to find new drug candidates for dystonia that combines (1) genomewide expression profiling of primary DYT1 patient vs. control cells; and (2) a powerful new discovery tool, the Connectivity Map, that links gene expression signatures to specific known drugs.