Chemical genomic profiling for hereditary dystonia

描述(由申请人提供)：早发性(DYT1)肌张力障碍是一种遗传性运动障碍，涉及严重的运动障碍，据信反映了基底节内的功能障碍。受影响的人会出现持续性的、非自愿的肌肉收缩和扭曲的姿势，几乎没有治疗选择。大多数病例与杂合性密码子缺失有关，该杂合性密码子缺失会从编码蛋白质TorsinA的羧基末端移除谷氨酸。TorsinA被认为在内质网(ER)内作为分泌途径中的分子伴侣发挥作用。多项研究表明，DYT1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TorsinA的一组小分子配体，其中一种可以挽救DYT1细胞的功能缺陷。该化合物是由一家学术实验室合成的一种新型醛，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，寻找其他已知的FDA批准的药物来模拟其效果。如果存在这样的药物，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。我们将首先对DYT1患者和对照的原代成纤维细胞进行全基因组表达分析，无论是否存在我们的先导化合物。这些基因签名将被用来查询一个新的数据库--连接图谱(Cmap)。Cmap是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签名而创建的。数据库软件将允许我们寻找药物，预计将复制我们的测试化合物和/或逆转未经处理的DYT1细胞的基因表达谱。我们将使用基因集浓缩分析(GSEA)进一步分析基因表达结果，以确定在DYT1细胞中可能与对照组相比差异调控的功能通路。我们将获得CMAP确定的任何药物以及那些已知作用于GSEA分析所涉及的靶点和/或途径的药物，并在DYT1细胞测试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，这项分析将是有史以来第一次对人类DYT1细胞进行转录图谱分析，并将利用我们团队收集的原代肌张力障碍患者细胞的大量库存。这一结果可能为DYT1的发病机制提供新的见解，揭示被突变蛋白干扰的细胞通路，同时也寻找治疗肌张力障碍的新候选药物。 公共卫生相关性：早发性(DYT1)肌张力障碍是一种严重的运动障碍，通常始于青春期。尽管目前的治疗选择有限，但在受影响的个体中观察到的正常大脑结构和没有细胞死亡表明，这种疾病可能是药物可以治疗的。在这个项目中，我们提出了一种新的策略来寻找治疗肌张力障碍的新药候选药物，该策略结合了(1)DYT1患者与对照细胞的全基因组表达谱；(2)一个强大的新发现工具，连接图，它将基因表达签名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.