CCKAR在胰岛B细胞中的偏向性信号转导及针对CCKAR的功能选择性APTAMER的筛选

胃肠激素受体CCKAR是缩胆囊素的受体，调控胆囊收缩和胰酶分泌等生理活动。近年来，CCKAR成为治疗代谢综合征尤其是糖尿病的重要药物靶蛋白。但是对CCKAR在胰腺B细胞中信号通路及生理功能由于缺乏有效研究手段知之甚少，阻碍了相关药物研发。本项目将联合细胞生物学,电生理和化学生物学手段，应用新发展的受体-效应器融合蛋白技术，及基因敲除和化学诱导等动物模型,深入研究CCKAR对胰腺B细胞功能调控及其信号途径。本项目的研究不仅可阐明CCKAR的下游效应器偏向性信号途径如何调节胰岛素分泌，葡萄糖敏感性和胰腺B细胞凋亡;还通过新建立针对 GPCR超家族的功能性Aptamer筛选方法，获得CCKAR的偏向性Aptamer,并评估其做为代谢综合征治疗药物的潜力。此外，作为本项目的一部分，我们还研究CCKAR基因多态性对胰岛信号途径的影响,为发展基于CCKAR多态性的个性化疗法奠定基础。

The Cholecystokinin A receptor (CCKAR) is a widely expressed G protein-coupled receptor which has been identified in gallbladder, pancreas and neuronal system. CCKAR regulates smooth muscle contraction of gall bladder, pancreatic enzyme secretion and satiety in nervous system. Recently, research revealed that CCK promoted insulin secretion in diabetes patients and the CCKAR deficient OLETF male rat developed type2 diabetes. Therefore CCKAR received a great deal of attention for its potential as a diabetes therapeutic target, while we know very little about CCKAR mediated cellular signaling in pancreatic beta cells and how CCKAR signaling regulates pancreatic beta cell function. In this proposal, we set out to use multiple approaches, including cell biology, electrophysiology and chemical biology methods, the recent developed receptor-effector fusion protein technique, together with CCKAR deficient OLETF rat, beta-arrestin knock out mice and STZ induced diabetes mice model to study the CCKAR signaling in pancreatic beta cells and their important role in regulation of pancreatic beta cell functions. Further, we will develop a new functional GPCR apatmer selection method, to acquire aptamers specifically targeting to CCKAR selective functions. We are going to evaluate therapeutic potential for these acquired aptamers through testing them in cell signaling, pancreatic beta cell functions and animal models. Finally, we are going to investigate the cell signaling and pancreatic beta cell functions of CCKAR polymorphism, which will lay the foundation for future personal therapy development.