Development of allosteric modulators of the MC4 receptor

MC4受体变构调节剂的开发

• 批准号: 8253011
• 负责人: Julien Albert Sebag
• 金额: $ 5.13万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8253011
• 关键词: Adrenergic Receptor; Adverse effects; Agonist; Allosteric Site; Animals; Behavioral; Biochemical; Biological Assay; Biology; Body Weight; Cell Line; Cells; Chemicals; Clinical Trials; Code; Collaborations; Complement; Cyclic AMP; Development; Drug Delivery Systems; Eating; Energy Metabolism; Exhibits; Fatty acid glycerol esters; Food; Food Energy; Funding Agency; Goals; Grant; Homeostasis; Human; Hyperphagia; In Vitro; Institutes; Isoproterenol; Knock-out; Knockout Mice; Knowledge; Laboratories; Lead; Libraries; Ligands; Link; Measures; Melanocortin 4 Receptor; Mentors; Metabolic; Methods; Modeling; Molecular; Monitor; Morbid Obesity; Mus; Mutation; Nature; Obesity; Oxygen Consumption; Pattern; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacology; Phenotype; Physiological; Process; Promega; Receptor Signaling; Role; Running; Screening procedure; Signal Transduction; Specificity; Syndrome; System; Technology; Testing; Therapeutic; Time; Training; Transgenic Animals; United States National Institutes of Health; Validation; analog; base; chemical property; chemical synthesis; common treatment; counterscreen; drug development; drug discovery; early onset; efficacy testing; high throughput screening; in vivo; melanocortin receptor; mouse model; obesity in children; pre-clinical; programs; receptor; receptor coupling; response; severe early onset obesity; skills; small molecule; success

DESCRIPTION (provided by applicant): The Melanocortin-4 receptor (MC4R) is a critical regulator of energy homeostasis and controls food intake and energy expenditure. In humans, mutations in the MC4R are responsible for up to 5% of early onset obesity. Consequently, MC4R has been a target of the major pharmaceutical companies for the development of MC4R agonists to treat obesity. However, clinical trials of potent MC4R agonists, all of which have been orthosteric in nature, failed due to unwanted side-effects. Our goal is to develop allosteric modulators of the MC4R that will efficiently treat obesity without causing dangerous side effects. Based on the current knowledge on allosteric modulators, we hypothesize that a molecule that would potentiate MC4R signaling in an allosteric fashion would not only be more specific and more potent, but also safer than a direct orthosteric agonist. Indeed, allosteric modulators are less likely to cause side effects since they do not directly activate the target receptor but potentiate its response to endogenous agonist, in this case 1-MSH, in a more physiological temporo-spatial pattern. In addition, due to the lower conservation of allosteric sites, allosteric modulators are usually more specific than direct agonists. In order to identify such modulators of the MC4R, we have run a high-throughput screen (HTS) using the Vanderbilt compound library (160,000 compounds) and a system, based on the promega pGLO technology, that allows real time recording of cAMP responses in cells and the definitive identification of allosteric modulators. Hits identified by the screen were counterscreened for their activity at a similar Gs-coupled receptor (22-adrenergic receptor) in order to eliminate compounds that are not specific to the MC4R. 0.1% of the compounds from the library (166) were identified via this process as MC4R specific positive allosteric modulators. The first aim of this application will consist in characterizing these lead compounds using cell based pharmacological and biochemical methods. The most promising compounds will then be advanced to chemical optimization using technology-enabled synthesis to make and test large numbers of analogues of selected hits. The second aim will consist in testing in-vivo the best existing compounds as well as the most promising compounds that will arise from chemical optimization using the MC4R knockout mouse model of obesity. Indeed, WT, MC4R and MC4R-/- mice will be treated with vehicle or with the selected compounds while food intake, oxygen consumption and body weight will be monitored. Thus, the scientific goals of this training grant will be to develop small molecule drug-like compounds and use them to test in vivo the hypothesis that positive allosteric MC4R modulators may be useful for the treatment of syndromic, and possibly dietary obesity. The training goal will be to complement the candidate's existing skills in molecular pharmacology with extensive training in drug discovery technology, medicinal and chemical biology, small animal and transgenic/knockout husbandry, and small animal physiological and behavioral analysis. The candidate will have access to a leading laboratory in melanocortin receptors and obesity (mentor's laboratory), an academic drug discovery program with a proven record of success (Vanderbilt Institute for Chemical Biology), and leading NIH-funded source for mouse phenotyping (Vanderbilt Mouse Metabolic Phenotyping Center) to provide the training necessary to accomplish the program goals. PUBLIC HEALTH RELEVANCE: Haploin sufficiency of the melanocortin-4 receptor (MC4R) is responsible for up to 5% of severe early onset obesity. The development of potent allosteric modulators of the MC4R, proposed in this application, would provide a therapeutic approach to the treatment of this common Mendelian syndrome. The potential application of these compounds to common dietary obesity will also be examined.

描述（由申请人提供）：黑素皮质素-4受体（Melanocortin-4 receptor, MC4R）是能量稳态的关键调节因子，控制食物摄入和能量消耗。在人类中，高达5%的早发性肥胖是由MC4R突变引起的。因此，MC4R一直是主要制药公司开发治疗肥胖的MC4R激动剂的目标。然而，强效MC4R激动剂的临床试验，所有这些在本质上都是矫形的，由于不必要的副作用而失败。我们的目标是开发MC4R的变构调节剂，它将有效地治疗肥胖，而不会产生危险的副作用。基于目前对变构调节剂的了解，我们假设一种能够以变构方式增强MC4R信号的分子不仅比直接的正构激动剂更特异、更有效，而且更安全。事实上，变构调节剂不太可能引起副作用，因为它们不直接激活靶受体，而是以更生理的时空模式增强其对内源性激动剂（在本例中为1-MSH）的反应。此外，由于变构位点的保守性较低，变构调节剂通常比直接激动剂更具特异性。为了鉴定MC4R的此类调制剂，我们使用Vanderbilt化合物库（160,000种化合物）和基于promega pGLO技术的系统运行了高通量筛选（HTS），该系统可以实时记录细胞中的cAMP反应并确定变弹性调制剂。通过筛选确定的靶点对类似的gs偶联受体（22-肾上腺素能受体）的活性进行反筛选，以消除非MC4R特异性的化合物。通过该方法，从文库中鉴定出0.1%的化合物（166个）为MC4R特异性正变构调节剂。本应用的第一个目的是利用基于细胞的药理学和生化方法来表征这些先导化合物。然后，最有希望的化合物将被推进到化学优化，使用技术支持的合成来制造和测试大量选定命中的类似物。第二个目标将包括在体内测试现有的最佳化合物，以及使用MC4R敲除肥胖小鼠模型进行化学优化后产生的最有希望的化合物。事实上，WT、MC4R和MC4R-/-小鼠将被用载药或选定的化合物治疗，同时监测食物摄入量、耗氧量和体重。因此，这项培训拨款的科学目标将是开发小分子类药物化合物，并使用它们在体内测试阳性变弹性MC4R调节剂可能对治疗综合征和可能的饮食性肥胖有用的假设。培训目标将是通过在药物发现技术、药物和化学生物学、小动物和转基因/基因敲除畜牧业以及小动物生理和行为分析方面的广泛培训来补充候选人在分子药理学方面的现有技能。候选人将有机会进入黑素皮质素受体和肥胖的领先实验室（导师的实验室），一个具有成功记录的学术药物发现项目（范德比尔特化学生物学研究所），以及美国国立卫生研究院资助的小鼠表型研究的主要来源（范德比尔特小鼠代谢表型中心），为完成项目目标提供必要的培训。