Caveolae and adipocyte lipid metabolism

小凹和脂肪细胞脂质代谢

基本信息

批准号：
8843840
负责人：
PAUL F PILCH
金额：
$ 40.82万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-05 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8843840
关键词：
ANXA2 gene Address Adipocytes Adipose tissue Affect Age Animals Annexins Area Binding Biochemical Biological Assay Biology Blood Glucose Body Weight CAV1 gene Cardiovascular system Caveolae Cell Culture Techniques Cell Line Cell membrane Cell physiology Cell surface Cells Characteristics Cholesterol Cholesterol Homeostasis Communities Complex Cyclodextrins Cytoskeleton Cytosol Data Employee Strikes Event Excision Familial generalized lipodystrophy Family Fasting Fatty Acids Fatty acid glycerol esters Functional disorder Genes Goals Health Hormonal Hormones Human Human Biology Impairment In Vitro Insulin Insulin Resistance Integral Membrane Protein Isoproterenol Knock-out Knockout Mice Lipids Lipodystrophy Lipolysis Liposomes Mass Spectrum Analysis Membrane Membrane Proteins Metabolic Metabolism Modeling Molecular Monitor Mus Mutation Myocardium Organ Organism Pathology Pathway interactions Peripheral Phenotype Phosphorylation Physiological Physiology Population Protein Isoforms Proteins Proteome Protocols documentation Recovery Regulation Research Role Scaffolding Protein Sphingolipids Structure System Testing Time Tissues Ubiquitination Western Blotting Work caveolin 1 cell type feeding glucose tolerance human disease in vivo inhibitor/antagonist interest lipid metabolism male multicatalytic endopeptidase complex novel perilipin response small hairpin RNA sterol esterase

项目摘要

DESCRIPTION (provided by applicant): Caveolae and adipocyte lipid metabolism Caveolae are prominent features of the adipocyte plasma membrane comprising ca. 50% of the cell surface area, thus begging the question of why they are so abundant and what their functions are in this metabolically important cell type. Caveolar structures are 50-100 nm sac-like invaginations projecting from the plasma membrane into the cytosol. They are comprised of small integral membrane proteins, caveolins 1 & 2, and peripheral membrane proteins of the cavin family (cavin-1- 3). They concentrate high levels of cholesterol and sphingolipids which are needed to maintain their structural integrity. Loss of adipocyte caveolae components, in vitro and in vivo, by gene manipulation/inactivation results in abnormalities of adipocyte metabolism. It is the long-term goal of this proposal to understand how the relevant proteins and lipids interact to form caveolae, and how caveolae impact the metabolic and biochemical functions of the fat cell, which has phenotypic consequences for the organism. Specific Aim 1 will address the mechanism(s) by which lipid metabolism is dysregulated in vitro and in vivo in adipocytes deficient in caveolae. Preliminary data support the hypothesis that cavin-1 and/or cavin-2 serve as regulatory factor(s) in hormonally- stimulated lipolysis, and we will experimentally address this hypothesis in animals and in cell culture models lacking specific caveolae components. Cholesterol depletion collapses caveolae concomitantly with remodeling of the cortical cytoskeleton and degradation of cavin-2 by the proteosome. In Aim 2, we will manipulate caveolae by this and other protocols to determine how caveolae sense cholesterol, and how caveolae influence plasma membrane organization and function. We will test the hypothesis that ubiquitination is requisite for caveolae formation. In Aim 3, we propose to phenotypically analyze mice lacking cavin-1 in adipocytes to assess the contribution of this tissue to the metabolic abnormalities seen in the global cavin-1 knockout, and we will metabolically characterize mice lacking cavin-3, which have a reduced adipose mass. We will also phenotype and analyze cavin-2 knockout mice. The multi-organ phenotype of caveolae-deficient mice appears identical to that of humans harboring inactivating mutations in caveolae components, and therefore the physiological relevance of these studies to human biology is considerable. The adipocyte studies will also inform the research community interested in caveolae in other relevant systems and tissues, for example, in cardiovascular biology.

描述（由申请人提供）：小凹和脂肪细胞脂质代谢小凹是脂肪细胞质膜的显着特征，其包含约50% 的细胞表面积，因此引出了一个问题：为什么它们如此丰富，以及它们在这种代谢重要的细胞类型中的功能是什么。小凹结构是 50-100 nm 的囊状内陷，从质膜突出到细胞质中。它们由小的整合膜蛋白、caveolins 1 和 2 以及 Cavin 家族的外周膜蛋白 (cavin-1-3) 组成。它们浓缩了维持其结构完整性所需的高水平胆固醇和鞘脂。在体外和体内，通过基因操作/失活导致脂肪细胞小窝成分的损失导致脂肪细胞代谢异常。该提案的长期目标是了解相关蛋白质和脂质如何相互作用形成小凹，以及小凹如何影响脂肪细胞的代谢和生化功能，这对生物体具有表型影响。具体目标 1 将解决在小窝缺陷的脂肪细胞中体外和体内脂质代谢失调的机制。初步数据支持cavin-1和/或cavin-2在激素刺激的脂肪分解中作为调节因子的假设，我们将在动物和缺乏特定小窝成分的细胞培养模型中通过实验解决这一假设。胆固醇消耗使小窝塌陷，同时皮质细胞骨架重塑和蛋白酶体降解cavin-2。在目标 2 中，我们将通过此协议和其他协议来操纵小凹，以确定小凹如何感知胆固醇，以及小凹如何影响质膜组织和功能。我们将检验泛素化对于小凹形成所必需的假设。在目标 3 中，我们建议对脂肪细胞中缺乏 cavin-1 的小鼠进行表型分析，以评估该组织对整体 Cavin-1 敲除中观察到的代谢异常的贡献，并且我们将从代谢上表征缺乏 cavin-3 的小鼠，这些小鼠具有减少脂肪量。我们还将对 Cavin-2 敲除小鼠进行表型分析。小凹缺陷小鼠的多器官表型似乎与小凹成分失活突变的人类相同，因此这些研究与人类生物学的生理相关性相当大。脂肪细胞研究还将为对其他相关系统和组织中的小凹感兴趣的研究界提供信息，例如心血管生物学。