Fatty Acid Signaling via GPCRs in Primary Cilia Controls Adipogenesis and Insulin Secretion, Regulating Obesity and Diabetes

原发纤毛中 GPCR 的脂肪酸信号控制脂肪生成和胰岛素分泌，调节肥胖和糖尿病

基本信息

批准号：
10531880
负责人：
PETER Kent JACKSON
金额：
$ 50.41万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-12-15 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10531880
关键词：
Acceleration Adenylate Cyclase Adipocytes Adipose tissue Aging Agonist Antibodies B-Lymphocytes BODIPY Beta Cell Biological Assay Blood Vessels Bromodeoxyuridine CRISPR screen Calcium Cells Cilia Cyclic AMP Diabetes Mellitus Dinoprostone Disease Progression Dyes Early identification Event FFAR1 gene Fatty Acids Fatty acid glycerol esters Formulation G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors Gender Genes Genetic Glucagon Glucose Glucose Intolerance Growth Growth Factor High Fat Diet Histologic Hormones Human Human Genetics Hypertrophy Hypoxia IGF1 gene In Vitro Inflammation Inflammatory Insulin Insulin Resistance Islets of Langerhans Knock-out Knockout Mice Ligands Link Lipid Inclusion Lipids Mesenchymal Metabolic Metabolism Modeling Mus Nutritional Obesity Omega-3 Fatty Acids Organism Pathway interactions Patients Pharmacology Platelet-Derived Growth Factor alpha Receptor Production Prostaglandin E Receptor Prostaglandins Proteomics Publishing Regulation Reporter S phase Saturated Fatty Acids Sex Differences Signal Pathway Signal Transduction Structure of beta Cell of islet System Tamoxifen Testing Tissue Expansion Tissues Translation Initiation Translations adipocyte differentiation adult stem cell cell type diabetic diabetic patient dietary differentiation protocol feeding genetic testing genome wide screen genome-wide glucagon-like peptide 1 human disease immune activation improved insulin secretion insulin signaling insulinoma islet lipid biosynthesis mouse model multiple omics obese patients phosphoric diester hydrolase programs receptor sensor stem cell population stem cells synergism therapeutically effective trafficking

项目摘要

This project focuses on understanding how dietary fluxes from w-3 fatty acids activate the FFAR4 receptor, expressed in primary cilia, in both preadipocytes to trigger adipogenesis and in pancreatic b cells to enhance insulin secretion. The proposal extends from a recent discovery in the Jackson lab of a dramatic requirement for primary cilia in de novo adipogenesis and for the accumulation of fat mass in mice (Cell 2019). Using a knockout of TULP3, a critical regulator of ciliary GPCR trafficking, the group has established a requirement for ciliary GPCR signaling and screened 36 candidates to discover that the w-3 fatty acid (FA) receptor FFAR4/GPR120 is critical. Using FFAR4 and ciliary markers, the group finds that ciliated FFAR4+ preadipocytes comprise a perivascular stem cell population in all fat pads. Further, DHA-FFAR4 signaling synergizes with insulin signaling to direct adipogenic fate change and that FFAR4 agonists rapidly activate localized cAMP in the cilium. To better define the steps in adipogenesis downstream of FFAR4, two genome-wide CRISPR screens for genes important in adipogenesis were conducted, one using a traditional adipogenesis formulation and the other activated by FFAR4 agonists. These screens recapitulated most known requirements for adipogenesis and provided a wealth of new genes important for the adipogenic program. Among these there is a strong requirement for new factors controlling translation initiation and cap-independent translation. Finally, looking for the importance of FFAR4 in other metabolic systems, the group discovered that all pancreatic islet cell types are ciliated, but that both b and a cells express FFAR4 in cilia. Detailed pharmacology and genetics show that FFAR4 agonists can drive glucose stimulated insulin secretion (GSIS) in isolated b cells or islets at levels comparable to known secretagogues like GLP-1. FFAR4 agonists also stimulate glucagon secretion in a cells. Both effects require ciliary trafficking. The first Aim will focus on validating and explaining new adipogenesis factors found in the screen. This will focus on identifying specific adenylate cyclases, phosphodiesterases, cAMP effectors, and translational control genes. Aim 2 will focus on FFAR4 signaling in pancreatic b cells to understand the mechanisms of how FFAR4 and cAMP drive insulin secretion and how another w-3 fatty acid receptor, FFAR1, drives calcium influx to cooperate with FFAR4. Finally, in Aim 3, the focus is to use mouse models systematically knocking out both FFAR4 and FFAR1 to examine the cooperation of these pathways in obesity, insulin secretion and diabetes. This aim will also examine human patient adipose tissue to determine if FFAR4+ ciliary in preadipocytes are lost in aging, diabetic or obese patients, also comparing sex differences. Overall, Aim 3 will test whether FFAR4 or ciliary loss is an important driver of diabetic disease progression, setting up critical tests of FFAR4 and other GPCRs for normalizing adipogenesis and improving insulin secretion in aging, diabetic patients.

该项目的重点是了解W-3脂肪酸的饮食通量如何激活FFAR4 在两种前纤毛细胞中表达的受体，以触发脂肪生成和胰腺B细胞，以增强胰岛素分泌。该提案从最近在杰克逊实验室的发现中发现了对从头脂肪生成中原发性纤毛的巨大需求以及小鼠脂肪质量的积累（Cell 2019）。该组使用纤毛GPCR贩运的关键调节器Tulp3的敲除，已经确定了纤毛GPCR信号传导的要求，并筛选了36个候选者，以发现W-3脂肪酸（FA）受体FFAR4/GPR120至关重要。使用FFAR4和睫状标记，该组发现纤毛FFAR4+前脂肪细胞包含所有脂肪垫中的血管周干细胞群。此外，DHA-FFAR4信号传导与胰岛素信号传导协同作用，以导致脂肪生成的命运变化，FFAR4激动剂迅速激活纤毛中的局部营地。为了更好地定义FFAR4下游的脂肪生成的步骤，对在脂肪生成中重要的基因进行了两个基因组CRISPR筛选，一种是使用传统的脂肪形成制剂，另一个使用FFAR4激动剂激活。这些屏幕概括了最著名的要求对于脂肪生成，并为掺杂程序提供了大量新基因。其中有很大的要求，需要控制翻译启动和无限依赖性翻译的新因素。最后，该小组在其他代谢系统中寻找FFAR4的重要性，发现所有胰岛细胞类型都是纤毛的，但是B和A细胞在Cilia中都表达FFAR4。详细的药理学和遗传学表明，FFAR4激动剂可以在分离的B细胞或胰岛中驱动葡萄糖刺激的胰岛素分泌（GSIS），其水平与GLP-1（如GLP-1）相当。 FFAR4激动剂还刺激细胞中的胰高血糖素分泌。两种影响都需要睫毛贩运。第一个目标将着重于验证和解释屏幕中发现的新的脂肪形成因子。这将着重于识别特定的腺苷酸环化酶，磷酸二酯酶，营地效应子和翻译控制基因。 AIM 2将集中于胰腺B细胞中的FFAR4信号传导，以了解FFAR4和CAMP驱动胰岛素分泌的机制以及另一个W-3脂肪酸受体FFAR1如何驱动钙涌入与FFAR4合作。最后，在AIM 3中，重点是使用小鼠模型系统地敲除FFAR4和FFAR1来检查肥胖，胰岛素分泌和糖尿病中这些途径的合作。该目标还将检查人类患者脂肪组织，以确定在衰老，糖尿病患者或肥胖患者中丢失了前脂肪细胞中的FFAR4+睫状体，也比较性别差异。总体而言，AIM 3将测试FFAR4还是睫状损失是糖尿病疾病进展的重要驱动力，对FFAR4和其他GPCR进行了关键测试，以使脂肪形成并改善糖尿病患者衰老的胰岛素分泌。