Identification of ligand and function of novel group of free fatty acid receptors by using genome information.

本研究取得的成果总结如下。进行了最初计划的以下研究项目。（1）游离脂肪酸受体家族的克隆（1）我们从基因组数据库中克隆了孤儿G蛋白偶联受体GPR 120，并成功地进行了去杂化，因此GPR 120的天然配体为游离脂肪酸。在本研究中，我们通过充分利用基因组数据库（人，小鼠和大鼠），对所有其他游离脂肪酸受体（GPR 40，GPR 41，GPR 43）进行了克隆。（2）体内外功能分析工具的开发成功地制备了针对每种游离脂肪酸受体的特异性抗体。此外，收集了每个受体的组织分布的详细信息。此外，利用HTS信号转导分析平台对各种化合物进行了筛选，发现了对各受体具有特异性的天然产物，并克隆了各受体的小鼠基因组，阐明了结构，并对其进行了初步的研究。 ...更多信息 我们试图培育基因工程动物（尤其是基因敲除小鼠），并最终成功地培育出部分受体家族基因敲除小鼠。（3）GPR 120的功能分析利用表达GPR 120的天然细胞系STC-1细胞进行体外功能分析，阐明GPR 120在调节胰岛素分泌的重要因子-肠促胰岛素分泌素GLP-1的分泌中起关键作用。此外，我们阐明了GPR 120介导的GLP-1分泌是通过钙和ERK信号传导机制。此外，这种GPR 120受体介导的信号转导抑制了这种肠内分泌细胞中的凋亡。特异性抗体、化学探针和基因敲除小鼠等）进一步分析游离脂肪酸受体家族的生理作用。在此基础上，这些游离脂肪酸受体家族的生理和病理生理作用将得到进一步阐明，并有望在未来发现新的药物。少

The result achieved for this research is summarized as following. The following research items planned at first were performed.(1)Cloning of free fatty acid receptor family(1)We cloned orphan G protein-coupled receptor GPR120 from genome database, and successfully de-orphanized ; hence, the natural ligand of GPR120 was free fatty acid. In this research, we performed cloning of all the other free fatty acid receptors (GPR40,GPR41,GPR43) by fully taking advantage of the genome database (human, mouse, and rat).(2)Development of tools for in vivo/in vitro functional analysisWe succeeded in making specific antibodies agains to each free fatty acid receptor. Moreover, detailed information of tissue distribution of each receptor was collected. In addition, various compounds were screened by using a HTS signal transduction analysis platform, and found natural products specific to each receptor was found. Furthermore, we cloned mouse genomes of each receptor, and clarified the structure, and tr … More ied to generate genetically engineered animals (especially, knockout mouse), and eventually for part of the receptor family, we succeeded in generating knockout mouse.(3)GPR120 function analysisThe in vitro function was analyzed by using native cell line STC-1 cell which are expressing GPR120, and we clarified that GPR120 plays a key role in regulating the secretion of incretin hormone GLP-1, which is important factor for insulin secretion. Moreover, we clarified that the GPR120-mediated secretion of GLP-1 is via the calcium and ERK signaling mechanism. Also, this GPR120 receptor-mediated signal transduction suppresses the apoptosis in this enteroendocrine cells.SummaryWe successfully prepared a various tools (e.g., specific antibodies, chemical probes, and knockout mice, etc.) to further analyze the physiological roles of free fatty acid receptor family. Based on this preparations, the physiological and pathophysiological role of these free fatty acid receptor family will be further clarified, and novel drug discovery can be expected in the future. Less