Development of an HTS assay to identify FXR antagonists

性状（由申请人提供）：人核激素受体（NR）超家族成员作为类固醇、甲状腺激素、类维生素A、氧化固醇、脂肪酸和胆汁酸的受体。几乎所有具有已鉴定配体的NR都是治疗多种疾病（包括糖尿病、血脂异常、炎症和癌症）的药物的成功靶点。FXR是作为胆汁酸的生理受体起作用的NR。FXR在胆汁酸稳态以及葡萄糖和脂质代谢中起关键作用。FXR已被认为是治疗血脂异常（动脉粥样硬化）、糖尿病和胆结石的药物靶标。虽然已经鉴定了几种FXR的合成激动剂，但尚未鉴定出选择性拮抗剂。因此，可用于表征这种受体的化学工具是有限的。拟议的研究重点是开发鉴定FXR拮抗剂的测定方法，这些拮抗剂可用作化学工具，以充分表征FXR的生物学功能，并验证该受体作为潜在的药物靶点。为了开发鉴定FXR拮抗剂所需的测定法，将提出以下具体目标：（1）开发和验证以高通量筛选形式检测FXR拮抗剂的生化测定法。(2)开发和验证二级测定，用于表征FXR高通量筛选中鉴定的拮抗剂“命中”;以及（3）使用LOPAC 1280化学文库对FXR测定流程方案进行验证筛选。 公共卫生相关性：该提案侧重于开发筛选试验，以识别特定的FXR拮抗剂。FXR是作为胆汁酸的生理受体起作用的核受体。目前不存在选择性FXR拮抗剂，拮抗剂的鉴定将允许表征该受体在代谢调节中的作用。

DESCRIPTION (provided by applicant): Members of the human nuclear hormone receptor (NR) superfamily serve as receptors for steroids, thyroid hormones, retinoids, oxysterols, fatty acids, and bile acids. Nearly all of the NRs with identified ligands have been successful targets for drugs treating a variety of diseases including diabetes, dyslipidemia, inflammation, and cancer. FXR is a NR that functions as a physiological receptor for bile acids. FXR plays a critical role in bile acid homeostasis as well as glucose and lipid metabolism. FXR has been implicated as a drug target for the treatment of dyslipidemia (atheroscelerosis), diabetes, and gallstones. Although a few synthetic agonists have been identified for FXR, no selective antagonists have yet been characterized. Thus, the chemical tools available to characterize this receptor are limited. The proposed research is focused on development of assays to identify FXR antagonists that can be used as chemical tools to fully characterize the biological function of FXR as well as to validate this receptor as a potential drug target. In order to develop the assays required for identification of FXR antagonists the following specific aims will be addressed: (1) Develop and validate a biochemical assay to detect FXR antagonists in a high-throughput screen format.; (2) Develop and validate secondary assays for the purpose of characterizing antagonist "hits" identified in an FXR high throughput screen; and (3) Perform a validating screen of the FXR assay flow scheme using the LOPAC 1280 chemical library. PUBLIC HEALTH RELEVANCE: This proposal focuses on development of screening assays to identify specific FXR antagonists. FXR is a nuclear receptor that functions as a physiological receptor for bile acids. No selective FXR antagonists currently exist and identification of antagonists will allow for characterization of the role of this receptor in regulation of metabolism.