Regulation and Function of Urocortins and their Receptors

尿皮质素及其受体的调节和功能

基本信息

批准号：
8447444
负责人：
Aditi Bhargava
金额：
$ 31.78万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2015-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8447444
关键词：
Abbreviations Adrenal Glands Affect Agonist Anxiety Arrestins Brain region Cell Line Cell membrane Cells Chronic Clostridium difficile Colitis Colon Confocal Microscopy Corticotropin-Releasing Hormone Corticotropin-Releasing Hormone Receptors Crohn&apos s disease Data Development Disease Dose Double-Stranded RNA Down-Regulation Dynamin Employee Strikes Endocytosis Exhibits Extravasation Family Feeding behaviors Financial compensation Gastrointestinal Motility Gastrointestinal tract structure Genes Genetic Genetic Models Glucocorticoids Hormonal Hypothalamic structure Ileitis Immune Immune response Immune system Immunofluorescence Immunologic Immunohistochemistry Inflammation Inflammation Mediators Inflammatory Inflammatory Bowel Diseases Inflammatory disease of the intestine Interleukin-10 Intestines Knock-out Knockout Mice Ligands Link Liquid substance Measures Mediating Mediator of activation protein Messenger RNA Modeling Modification Molecular Moods Mus Neuraxis Neurons Neuropeptides Neurosecretory Systems Organ Outcome Pathway interactions Patients Peptide Receptor Peptides Piroxicam Pituitary Hormones Plasma Play Process Production Protein Isoforms Proteins Quality of life RNA Interference Recycling Regulation Research Role Scaffolding Protein Severities Signal Transduction Stress Sulfonic Acids System Testing Therapeutic Tissues Toxin Trinitrobenzenes Ubiquitin Weight Gain autonomic nerve biological adaptation to stress cytokine defined contribution desensitization gastrointestinal gastrointestinal function hypothalamic-pituitary-adrenal axis ileum immunoreactivity improved innovation life time cost mortality psychologic receptor receptor function receptor recycling response single molecule stressor trafficking urocortin

项目摘要

PROJECT SUMMARY/ABSTRACT The corticotropin-releasing factor (CRF) family of neuropeptides (CRF and urocortins [Ucn] 1-3) and their receptors (CRFR1, CRFR2) are essential mediators of stress in the central nervous system. Therefore a systemic inhibition of their function is not an attractive therapeutic model. Components of this peptide/receptor family are prominently expressed within the intestine, where their local functions remain to be defined. Our preliminary data from CRFR2 heterozygous mice suggests that perturbation of the CRFR2 system renders the mice more susceptible to sudden stress and immune challenges. Our results suggest that new treatments for intestinal inflammatory diseases may require either antagonists or agonists of CRF receptors, depending upon the affected intestinal region and the type of inflammatory disease. A striking feature we observed during colitis was reciprocal changes in mRNA and protein levels of Ucn ligands and their receptors. These differential changes can alter Ucn-induced trafficking of receptors from and to the plasma membrane. However, the molecular mechanisms of this divergent trafficking to recycling or degradatory pathways remain unexplored. Thus, our hypothesis is that Ucn isoforms, differentially signaling through CRF receptors, govern intestinal inflammation at the molecular, cellular and organ levels. The aims of this proposal are to: Specific Aim 1. To define the systemic role of the Ucn/CRFR system in intestinal inflammation. We will use pharmacological and genetic approaches to define the systemic role of the Ucn/CRFR system in intestinal inflammation. We will determine if CRFR2 knockout and heterozygous mice exhibit differential sensitivity to inflammation and agonist treatment as compared with their wild type littermates. We will determine alterations in colitis severity by measuring changes in body weight gain, mortality, histological damage, and fluid leak. Specific Aim 2. To define the contributions of colon-specific Ucns and CRFRs in intestinal inflammation using RNA interference (RNAi). To determine the colon-specific role of the Ucn/CRFR system, we will establish the use RNAi to knockdown expression of Ucns and CRFR2 locally in the colon. We will determine the spatial and temporal effects of RNAi in the colon, and assess whether colon-specific knockdown of Ucns and CRFRs is sufficient to ameliorate or exacerbate colitis, using end points defined in Specific Aim 1. Specific Aim 3. To define the mechanism and function of Ucn1-induced trafficking of CRFR1. We will examine the influence of Ucn1 stimulation on the subcellular localization of CRFR1 using confocal microscopy and immunofluorescence. We will explore the ability of the adaptor/scaffolding proteins (¿-arrestins and dynamin) to desensitize and resensitize CRFRs. We will assess Ucn1 regulation of CRFR1 activity by measuring Ucn1-stimulated intracellular Ca2+ mobilization. Thus, manipulation of the urocortins and their receptors provides an effective starting point for understanding their GI functions, which could contribute to the development of new treatments for inflammatory bowel disease.

项目概要/摘要神经肽促肾上腺皮质激素释放因子 (CRF) 家族（CRF 和尿皮质素 [Ucn] 1-3）及其受体（CRFR1、CRFR2）是中枢神经系统应激的重要介质。其功能的全身抑制并不是一种有吸引力的治疗模型。家族在肠道内显着表达，其局部功能仍有待确定。来自 CRFR2 杂合子小鼠的初步数据表明，CRFR2 系统的扰动会导致小鼠更容易受到突然的压力和免疫挑战，我们的结果表明新的治疗方法。肠道炎症性疾病可能需要 CRF 受体拮抗剂或激动剂，具体取决于受影响的肠道区域和炎症性疾病的类型是我们在结肠炎期间观察到的一个显着特征。是 Ucn 配体及其受体的 mRNA 和蛋白质水平的相互变化。变化可以改变 UCN 诱导的受体往返于质膜的运输。这种不同运输到回收或降解途径的分子机制仍未被探索。因此，我们的假设是 Ucn 亚型通过 CRF 受体发出差异信号，控制分子、细胞和器官水平的肠道炎症该提案的目的是：具体目标 1. 明确 Ucn/CRFR 系统在肠道炎症中的全身作用。使用药理学和遗传学方法来定义 Ucn/CRFR 系统在肠道中的系统作用我们将确定 CRFR2 敲除小鼠和杂合小鼠是否表现出对炎症的不同敏感性。与野生型同窝小鼠相比，我们将确定炎症和激动剂治疗的变化。通过测量体重增加、死亡率、组织学损伤和液体渗漏的变化来评估结肠炎的严重程度。具体目标 2. 确定结肠特异性 Ucns 和 CRFRs 在肠道中的贡献使用 RNA 干扰 (RNAi) 确定 Ucn/CRFR 系统的结肠特异性作用。我们将建立使用 RNAi 来敲低结肠局部 Ucns 和 CRFR2 的表达。确定 RNAi 在结肠中的空间和时间效应，并评估结肠特异性敲低是否有效使用特定目标 1 中的最终定义点，Ucns 和 CRFR 的组合足以改善或加重结肠炎。具体目标 3. 明确 Ucn1 诱导的 CRFR1 贩运的机制和功能。使用共聚焦显微镜检查 Ucn1 刺激对 CRFR1 亚细胞定位的影响我们将探索接头/支架蛋白（¿-抑制蛋白和免疫荧光）的能力。 dynamin）使 CRFR 脱敏和重新敏化我们将通过以下方式评估 Ucn1 对 CRFR1 活性的调节。测量 Ucn1 刺激的细胞内 Ca2+ 动员，从而控制尿皮质素及其作用。受体为了解其胃肠功能提供了有效的起点，这可能有助于开发炎症性肠病的新疗法。