INTESTINAL ADENOSINE A2B RECEPTOR

说明(改编自应用程序) 该项目的总体目标是更好地定义 肠上皮细胞-中性粒细胞相互作用与液体和 电解质分泌。许多肠道疾病，尤其是急性红斑症 炎症性肠病(IBD)的特点是移行 中性粒细胞穿过肠上皮进入肠腔形成“隐窝” 脓肿‘。隐窝脓肿是活动性IBD和感染性结肠炎的病因学 并与疾病的严重程度和临床症状相关。我们有 以前的研究表明，中性粒细胞迁移到肠腔会引起 电源性氯化物分泌(分泌性腹泻)及其主要影响因素 这种氯离子分泌反应是中性粒细胞衍生的促分泌剂5‘AMP。 肠上皮细胞表达一种胞外核苷酸酶，可将5‘AMP转化为 腺苷，然后与肠上皮腺苷2b(A2B)相互作用 受体可以刺激氯的分泌。因此，A2B受体发挥着中枢作用。 在中性粒细胞诱导的氯离子分泌中的作用。一个 了解A2B受体的调节和信号机制可能 因此，为IBD的这一组成部分设计新的治疗方法。在……里面 本提案拟对肠道A2B受体的生物学特性进行研究 应用两种肠道上皮细胞模型：T84细胞和Caco-2 BBE细胞 用A2B受体转染组。A2B受体是唯一的腺苷受体 在T84细胞中，Caco-2 BBE细胞缺乏A2B受体。首先，我会研究一下 表面表达的极性、分布、周转动力学、结构 配体结合、脱敏和G蛋白识别的要求。 其次，我将分析细胞外核酸酶和A2B受体的存在。 信号膜微域，如小凹。这些微域代表 富含鞘糖脂的质膜内陷，已被 显示含有信号蛋白。第三，我将研究腺苷的作用 中性粒细胞上皮细胞调节和反馈调节中的受体 相互作用包括轮回和趋化因子的分泌。

DESCRIPTION (adapted from the application) The overall aim of this project is to better define the characteristics of intestinal epithelial cell-neutrophil interaction as it relates to fluid and electrolyte secretion. Many intestinal disorders, particularly the acute flare of inflammatory bowel disease (IBD), are characterized by migration of neutrophils across the intestinal epithelium into the lumen to form 'crypt abscess'. Crypt abscesses are pathognomic of active IBD and infectious colitis and correlate with severity of disease as well as clinical symptoms. We have previously shown that neutrophil migration into the intestinal lumen elicits electrogenic chloride secretion (secretory diarrhea) and the major effector of this chloride secretory response is the neutrophil-derived secretagogue, 5'AMP. Intestinal epithelia express an ectonucleotidase, which converts 5' AMP to adenosine which then interacts with intestinal epithelial adenosine 2b (A2b) receptor to elicit chloride secretion. Thus the A2b receptor plays a central role in orchestrating chloride secretion induced by neutrophils. An understanding of the regulation and signaling mechanism of A2b receptor may therefore lead to designing of novel treatments for this component of IBD. In this proposal, I intend to characterize the biology of intestinal A2b receptor using two intestinal epithelial cell models: T84 cells and Caco-2 bbe cells transfected with the A2b receptor. A2b receptor is the only adenosine receptor in T84 cells while Caco-2 bbe cells lack A2b receptor. First, I will study the polarity of surface expression, distribution, kinetics of turnover, structural requirements for ligand binding, desensitization, and G-protein recognition. Second, I will analyze the existence of ectonucleotidase and A2b receptor in signaling membrane microdomain such as caveolae. These microdomains represent invagination of plasma membrane enriched in glycosphingolipid, which have been shown to contain signaling proteins. Third, I will study the role of adenosine receptor in the modulation and feedback regulation of neutrophil-epithelial interaction including transmigration and chemokine secretion.