Expression and function of the guanylin ligand family

鸟苷配体家族的表达和功能

基本信息

批准号：
7321658
负责人：
Mitchell B Cohen
金额：
$ 30.46万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-09-30 至 2009-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7321658
关键词：
5&apos Flanking Region Acute Address Animals Arts Bicarbonates Binding Bioinformatics Biological Assay Blood Pressure Caco-2 Cells Cell Line Cells Chloride Ion Chlorides Condition Data Defect Defensins Diarrhea Diet Disease Diuresis Dominant-Negative Mutation Down-Regulation Elements Endocrine Endocrine system Enteral Enterocytes Enterotoxins Epithelial Cells Equilibrium Excretory function Exhibits Family Fibrinogen Fluid overload Functional disorder Future Gene Expression Gene Targeting Gene Transfer Guanylate Cyclase HT29 Cells Heating Homeostasis Hormones Hour Human Hypertension In Vitro Interferon Type II Interferons Intestinal Hormones Intestinal Secretions Intestines Isoenzymes Kidney Ligands Light Mediating Metabolism Modeling Molecular Molecular Profiling Mus Natriuresis Pathway interactions Peptides Phenotype Phosphotransferases Physiological Physiology Potassium Protein Isoforms Protein Kinase C Receptor Gene Regulation Research Personnel Role Signal Transduction Signal Transduction Pathway Small Intestines Sodium Sodium Chloride System Testing Therapeutic Agents Thinking Translational Research Tubular formation Up-Regulation Urine Vacuole Water Wild Type Mouse adenoviral-mediated animal tissue base citrate carrier enterotoxin receptor expression cloning genetic element guanylin in vitro Assay in vivo inhibitor/antagonist insight knockout animal novel paracrine receptor research study response salt balance salt sensitive saluretic solute therapeutic target tissue culture urinary uroguanylin water channel

项目摘要

DESCRIPTION (provided by applicant): Guanylin and uroguanylin are peptides that are expressed primarily in the mammalian intestine and were identified because of their homology to the bacterial heat stable enterotoxin (ST) and their ability to bind to the ST receptor, guanylyl cyclase C (GC-C). ST is a worldwide cause of secretory diarrhea whereas guanylin and uroguanylin are thought to modulate intestinal secretion without causing diarrhea. Therefore, a better understanding of the mechanisms and receptors through which these peptides act will likely shed light on the pathophysiology of toxigenic diarrhea. To further explore the physiologic role of guanylin and uroguanylin we created guanylin and uroguanylin gene-targeted mice. We found in preliminary experiments that uroguanylin has an important regulatory role in salt homeostasis. Therefore, the overarching hypothesis of this application is that uroguanylin and guanylin are enteric hormones forming both a local paracrine regulatory system in the intestine and a hormonal system as part of an enteric-renal axis to regulate natriuresis. We will address the following specific aims. I) Define the role of guanylin and uroguanylin as endocrine hormones regulating salt and water metabolism in gene targeted mice. We will test the hypotheses that: 1) Uroguanylin but not guanylin or GC-C deficient mice, will demonstrate impaired urinary sodium and potassium excretion. 2) Uroguanylin deficient mice will demonstrate salt sensitive hypertension. 3) These actions of uroguanylin are mediated via a novel, non-GC-C receptor. II) Determine the mechanisms regulating guanylin and uroguanylin expression. We will test the hypotheses that: 1) Basal levels of guanylin and uroguanylin expression are regulated by protein kinase C (PKC) isoforms. 2) Hypertonicity upregulates guanylin and uroguanylin by a transcriptionally-regulated, PKC-dependent mechanism. 3. Interferon-gamma (IFN-gamma) downregulates guanylin and uroguanylin via a transcriptionally-regulated mechanism. III) Define the cellular secretory defects resulting from uroguanylin loss in intestine and kidney. We will test the hypotheses that: 1) Loss of uroguanylin will result in impaired intestinal secretion of chloride. 2) In the kidney, loss of uroguanylin will result in dysregulated water and solute transport in proximal tubular cells leading to intracellular vacuole formation. 3) Loss of uroguanylin will result in compensatory upregulation of novel uroguanylin receptor gene(s) and compensatory counter-regulation of transporters and water channels expressed in enterocytes in the proximal small intestine and proximal tubule cells in the kidney. These studies will further delineate the role and action of these peptides and ST in the intestine as well as their roles as intestinal hormones in an enteric-renal axis. Furthermore, these studies will lay the groundwork for translational research involving these peptides as therapeutic agents for fluid overload states.

描述（由申请人提供）：鸟苷蛋白和尿鸟苷蛋白是主要在哺乳动物肠道中表达的肽，因其与细菌热稳定肠毒素 (ST) 的同源性以及与 ST 受体鸟苷酸环化酶 C 结合的能力而被鉴定。气相色谱-C）。 ST 是分泌性腹泻的世界性原因，而鸟苷蛋白和尿鸟苷蛋白被认为可以调节肠道分泌而不引起腹泻。因此，更好地了解这些肽的作用机制和受体将可能有助于阐明毒性腹泻的病理生理学。为了进一步探索鸟苷蛋白和尿鸟苷蛋白的生理作用，我们创建了鸟苷蛋白和尿鸟苷蛋白基因靶向小鼠。我们在初步实验中发现，尿鸟苷素在盐稳态中具有重要的调节作用。因此，本申请的总体假设是尿鸟苷蛋白和鸟苷蛋白是肠道激素，形成肠道中的局部旁分泌调节系统和作为肠肾轴的一部分来调节尿钠排泄的激素系统。我们将实现以下具体目标。 I) 定义鸟苷蛋白和尿鸟苷蛋白作为调节基因靶向小鼠盐和水代谢的内分泌激素的作用。我们将测试以下假设：1) 尿鸟苷蛋白而非鸟苷蛋白或 GC-C 缺陷小鼠将表现出尿钠和钾排泄受损。 2) 尿鸟苷蛋白缺乏的小鼠会表现出盐敏感性高血压。 3) 尿鸟苷蛋白的这些作用是通过一种新型的非 GC-C 受体介导的。 II)确定鸟苷蛋白和尿鸟苷蛋白表达的调节机制。我们将测试以下假设：1) 鸟苷蛋白和尿鸟苷蛋白表达的基础水平受蛋白激酶 C (PKC) 同种型调节。 2) 高渗性通过转录调节、PKC 依赖性机制上调鸟苷蛋白和尿鸟苷蛋白。 3. 干扰素-γ (IFN-gamma) 通过转录调节机制下调鸟苷蛋白和尿鸟苷蛋白。 III) 定义肠和肾中尿鸟苷蛋白损失导致的细胞分泌缺陷。我们将测试以下假设：1) 尿鸟苷蛋白的损失将导致肠道氯化物分泌受损。 2) 在肾脏中，尿鸟苷蛋白的损失将导致近端肾小管细胞中水和溶质运输失调，从而导致细胞内液泡形成。 3) 尿鸟苷蛋白的缺失将导致新型尿鸟苷蛋白受体基因的代偿性上调以及近端小肠肠上皮细胞和肾脏近端小管细胞中表达的转运蛋白和水通道的代偿性反调节。这些研究将进一步阐明这些肽和 ST 在肠道中的作用和作用，以及它们作为肠道激素在肠肾轴中的作用。此外，这些研究将为涉及这些肽作为液体超负荷状态治疗剂的转化研究奠定基础。