CLONING AND CHARACTERIZATION OF CANNABINOID RECEPTORS

大麻是目前滥用最广泛的非法药物。然而， 健康和疾病中的大麻素受体系统包括大麻素作为镇痛剂的用途， 用于癌症患者的止吐剂、用于癫痫的抗惊厥剂和作为抗青光眼剂，以及 免疫调节剂。迄今为止，已经鉴定出两种大麻素受体亚型，CBt和CB2， 通过cDNA克隆，然而anandamide的复杂药理学性质以及外源性 大麻素并不完全由这两种亚型定义。花生四烯酸酰胺产生全方位的行为 在CBi受体敲除小鼠中的抗伤害效应（抗伤害感受、僵住症和受损的运动活性）。在 此外，在这些小鼠的脑细胞膜中可以引发大麻素刺激的GTP γ S活性。 最后，放射性配体结合研究表明，在脑和脊髓中存在额外的结合位点。 该项目的目标是识别和表征大麻素受体的其他亚型， 以阐明其在体内的作用。第一个具体目标是表征用于治疗的候选孤儿GPCR。 大麻素受体活性。GPR55最近被鉴定为候选大麻素受体， 我们有证据表明GPR35具有大麻素受体活性。GPR18是Narachinoylglycine的受体， 内源性大麻素GPR119是油酰乙醇胺的受体， 棕榈酰乙醇胺我们建议通过表达来表征这些候选大麻素受体， 异源细胞系，允许配体选择性和信号传导的详细表征。第二 具体目标是使用表达来鉴定具有大麻素受体活性的其它孤儿GPCR， 克隆策略在具体目标3中，我们将研究新型大麻素受体的功能作用。 这一目标的实验旨在利用我们与其他中心资助研究人员的合作， 以了解候选大麻素受体的功能作用。这些研究将有助于 涉及大麻素系统的新治疗策略的设计。此外，深入了解 大麻素受体激活的分子机制可能有助于更好地理解 人类滥用大麻

Marijuana is currently the most widely abused illegal drug. However, the functional significance of the cannabinoid receptor system in health and disease includes the use of cannabinoids as analgesics, antiemetics in cancer patients, anticonvulsants for epilepsy and as antiglaucoma agents as well as immunomodulatory agents. To date, two cannabinoid receptor subtypes, CBt and CB2, have been identified by cDNA cloning, yet the complex pharmacological properties of anandamide as well as exogenous cannabinoids are not fully defined by these two subtypes. Anandamide produces the full range of behavioral effects (antinociception, catalepsy and impaired locomotor activity) in CBi receptor knockout mice. In addition, anandamide-stimulated GTPyS activity can be elicited in brain membranes from these mice. Finally, radioligand binding studies indicate the existence of additional binding sites in brain and spinal cord. The goal of this project is to identify and characterize additional subtypes of the cannabinoid receptors in order to elucidate their role in vivo. The first specific aim is to characterize candidate orphan GPCRs for cannabinoid receptor activity. GPR55 has recently been identified as a candidate cannabinoid receptor, and we have evidence that GPR35 has cannabinoid receptor activity. GPR18 is a receptor for Narachinoylglycine, an endocannabinoid. GPR119 is a receptor for oleoylethanolamide and palmitoylethanolamide. We propose to characterize these candidate cannabinoid receptors by expression in heterologous cell lines, allowing the detailed characterization of ligand selectivity and signaling. The second specific aim will identify additional orphan GPCRs with cannabinoid receptor activity using an expression cloning strategy. In specific aim 3, we will investigate the functional role of novel cannabinoid receptors. The experiments in this aim are designed to utilize our collaborations with other Center Grant Investigators in order to understand the functional roles of the candidate cannabinoid receptors. These studies will facilitate the design of new therapeutic strategies involving the cannabinoid system. Furthermore, insight into the molecular mechanisms of activation of cannabinoid receptors may lead to a better understanding of marijuana abuse in humans.