The role of regulator of G protein signaling Gbeta5-R7 in neuronal control of body weight

G蛋白信号调节剂Gbeta5-R7在神经元控制体重中的作用

基本信息

批准号：
10096696
负责人：
Vladlen Z Slepak
金额：
$ 52.44万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-01-28 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10096696
关键词：
Ablation Acute Adult Affect Agonist Alleles Animals Antibodies Beta Cell Body Weight Brain CRISPR/Cas technology Cardiovascular Diseases Cardiovascular system Cell Line Cell Nucleus Cell physiology Complex Controlled Environment Data Diabetes Mellitus Diagnosis Disease Energy Intake Equilibrium Etiology Event Family G-Protein-Coupled Receptors GNB5 gene GTP-Binding Protein Regulators GTP-Binding Protein beta Subunits GTP-Binding Proteins Gene Transfer Genes Genetic Goals Growth Homeostasis Hormone secretion Hormones Human Human Genetics Hypothalamic Hormones Hypothalamic structure In Situ In Vitro Injections Insulin Inulin Investigation Kidney Diseases Knock-out Lead Link Malignant Neoplasms Maps Measures Messenger RNA Metabolic Metabolic Diseases Metabolic syndrome Metabolism Molecular Mus Muscarinic Acetylcholine Receptor M3 Mutation Neuraxis Neuroendocrinology Neurologic Neurons Neurosecretory Systems Neurotransmitters Non-Insulin-Dependent Diabetes Mellitus Obesity Organ Pancreas Pathologic Pathway interactions Pattern Peripheral Pharmacology Phenotype Phosphorylation Physiological Play Population Proteins RGS Proteins Regulation Research Risk Factors Role Second Messenger Systems Series Signal Transduction Signaling Protein Slice Stimulus Stroke Structure Structure of beta Cell of islet System Testing Tissues Viral Genes Viral Vector Weight Gain biological systems cholinergic comorbidity dimer effective therapy energy balance experimental study extracellular in vivo insight insulin secretion kinase inhibitor knock-down knockout gene mutant nervous system disorder novel novel therapeutic intervention overexpression peptide hormone protein complex real-time images response

项目摘要

Obesity is a major co-morbidity factor in diabetes, cancer, cardiovascular, neurological and other diseases. Recently, a new group of human genes was linked to obesity, the genes encoding the R7 family of regulator of G protein signaling proteins (RGS6, 7, 9 and 11) and Gnb5, which encodes the atypical G protein beta subunit Gb5. This proposal studies how a deficiency in the Gnb5 and R7 genes can lead to obesity and other abnormalities in control of body weight. The ultimate goal is to discover effective treatments of disorders associated with neuroendocrine pathways regulated by these genes. The proposed research plan builds upon earlier discoveries that together constitute a strong premise for this study. Gb5 and R7 proteins form obligatory dimers, so that the Gnb5 knockout causes complete degradation of the entire Gb5-R7 complex. Ablation of one Gnb5 allele leads to obesity and metabolic syndrome in mice; this finding was later confirmed by human genetics. Subsequent mechanistic investigations in this lab identified a novel role for the Gb5-R7 complex in pancreatic beta cells where Gb5- R7 strongly promoted secretion of insulin. Brain is the main organ regulating body weight, and the expression level of Gb5-R7 is much higher in the CNS than in the pancreas or any other peripheral tissues. These considerations lead us to the hypothesis that Gb5-RGS7 regulates body weight via its function in the neurons, where, similarly to the insulin-secreting beta cells, it controls secretion of neurotransmitters and hormones. In support of this hypothesis, recent studies in the lab demonstrated that local knockout of Gnb5 in the adult mouse hypothalamus dramatically increased body and adiposity. The proposed experiments will develop this discovery through a series of experiments performed at the organismal, tissue and cellular levels. Specific Aim 1 will use the Cre-loxP approach to inactivate Gnb5 in specific hypothalamic nuclei and types of neurons and examine the effect of the knockout on body weight and metabolism. Overexpression of Gnb5 using viral gene transfer will be performed to rescue the changes caused by the knockout. Aim 2 will study co-expression of Gnb5 with GPCRs and gene encoding hypothalamic hormones and tissue slices will be examined ex vivo for signal-stimulated secretion of specific hormones. Specific Aim 3 will study Gb5-R7 its knockout (CRISPR/Cas9), knockdown and overexpression in cell lines that endogenously express Gb5-R7. Experiments will utilize pharmacological agents and structure-function analysis to interrogate molecular events in signaling and secretory pathways. The proposed investigation of the Gb5-R7 complex will elucidate the novel mechanism regulating secretion of hypothalamic hormones and significantly advance our understanding of G protein signaling, etiology of obesity and other metabolic and neuroendocrine disorders.

肥胖是糖尿病，癌症，心血管，神经和其他的主要合并症疾病。最近，一个新的人类基因与肥胖有关，该基因编码R7家族 G蛋白信号蛋白（RGS6、7、9和11）和GNB5的调节剂，该蛋白编码非典型G 蛋白质β亚基GB5。该建议研究GNB5和R7基因的缺乏如何导致肥胖和其他异常控制体重。最终目标是发现有效与这些基因调节的神经内分泌途径相关的疾病的治疗。拟议的研究计划是建立在较早发现的基础上的这项研究的前提。 GB5和R7蛋白形成强制性二聚体，因此GNB5敲除原因整个GB5-R7复合物的完全降解。一个GNB5等位基因的消融会导致肥胖和小鼠代谢综合征；后来人类遗传学证实了这一发现。随后的机械该实验室的研究确定了GB5-R7复合物在胰腺β细胞中的新作用，其中GB5-- R7强烈促进了胰岛素的分泌。大脑是调节体重的主要器官，并且中枢神经系统中GB5-R7的表达水平高于胰腺或任何其他外围组织。这些考虑因素使我们提出了这样的假设，即GB5-RGS7通过其功能来调节体重神经元，与分泌胰岛素分泌β细胞相似，它控制神经递质的分泌和激素。为了支持这一假设，实验室的最新研究表明成年小鼠下丘脑中的GNB5急剧增加了身体和肥胖。提议实验将通过在生物体进行的一系列实验来开发这一发现，组织和细胞水平。特定的目标1将使用Cre-loxp方法在特定的下丘脑核和神经元类型，并检查敲除对体重和体重的影响代谢。将使用病毒基因转移对GNB5的过表达来挽救变化由淘汰赛引起。 AIM 2将研究GNB5与GPCR和基因编码的共表达下丘脑激素和组织切片将在体内检查，以进行信号刺激的分泌特定激素。具体目标3将研究GB5-R7的淘汰（CRISPR/CAS9），敲除和内源表达GB5-R7的细胞系中的过表达。实验将利用药理代理和结构功能分析，以询问信号传导和分泌途径中的分子事件。对GB5-R7复合物的拟议研究将阐明调节分泌的新机制下丘脑激素，并显着提高我们对G蛋白信号传导的理解肥胖和其他代谢和神经内分泌疾病。