Regulation of GPIHBP1-dependent and independent triglyceride clearance

GPIHBP1 依赖性和独立性甘油三酯清除率的调节

基本信息

批准号：
9895855
负责人：
BRANDON Scott Joseph DAVIES
金额：
$ 38.13万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9895855
关键词：
ANGPTL3 gene ANGPTL4 gene Address Angiopoietins Binding Binding Proteins Biological Assay Blood Vessels Blood capillaries Capillary Endothelial Cell Cardiac Cell Culture System Cell Culture Techniques Clinical Complex Data Deposition Dyslipidemias Endothelial Cells Fatty Acids Fenestrated Capillary Fibrates GPI Membrane Anchors Goals High Density Lipoproteins Human Hydrolysis Hyperlipidemia Hypertriglyceridemia In Vitro Individual Inflammatory Response Injections Insulin Resistance Knockout Mice Knowledge Lead Life Lipase Lipids Lipolysis Liver Mediating Metabolic Diseases Metabolic syndrome Methods Mission Modeling Mus N-terminal Non-Insulin-Dependent Diabetes Mellitus Obesity Pathway interactions Pharmaceutical Preparations Phenotype Plasma Process Proteins Public Health Recombinant Proteins Regulation Research Serum Skeletal Muscle Surface Testing Therapeutic Tissues Triglyceride Metabolism Triglycerides United States National Institutes of Health base burden of illness cardiovascular risk factor design improved in vivo in vivo Model innovation lipoprotein lipase lipoprotein triglyceride mouse model novel novel strategies novel therapeutic intervention prevent restoration uptake

项目摘要

PROJECT SUMMARY Clinical hypertriglyceridemia is common and is only partially responsive to available drugs. Conversely, excess triglyceride delivery to individual tissues can lead to skeletal muscle insulin resistance, cardiac lipotoxicity, or severe inflammatory responses. Given the importance of proper triglyceride delivery, it is imperative that we understand the mechanisms that regulate this process. Two proteins normally required for triglyceride clearance are lipoprotein lipase (LPL) and GPIHBP1. LPL is required for the actual hydrolysis of plasma triglyceides, liberating fatty acids for tissue uptake. The endothelial cell protein GPIHBP1 is required to properly localize LPL to the vascular lumen where lipolysis takes place. The long term goal of the proposed research is to understand and ultimately modulate the delivery of triglyceride-derived fatty acids to specific tissues. The objectives in this application are to advance our understanding of how the angiopoietin-like (ANGPTL) proteins, ANGPTL3 and ANGPTL4, modulate triglyceride clearance. ANGPTL3 and ANGPTL4 can both inhibit LPL in vitro, and ANGPTL3 or ANGPTL4 deficiency leads to lower plasma triglyceride levels. However, if and how ANGPTL3 and ANGPTL4 directly modulate LPL/GPIHBP1-mediated triglyceride clearance is not clear. Moreover, the plasma triglyceride levels in mice deficient in both GPIHBP1 and ANGPTL4 indicate that ANGPTL4 may regulate an uncharacterized, GPIHBP1-independent triglyceride clearance pathway. These issues will be addressed by pursuing two specific aims: 1) Define the mechanisms by which ANGPTL3 and ANGPTL4 modulate GPIHBP1-dependent triglyceride clearance; and 2) Identify novel mechanisms of GPIHBP1- independent triglyceride clearance. The studies in aim 1 employ cell culture–based binding and lipase activity assays, as well as in vivo injection of recombinant proteins and tissue-specific knockout mice to investigate how ANGPTL proteins interact with GPIHBP1/LPL complexes on the surface of endothelial cells. The second aim will address the remarkably lower triglycerides in Angptl4–/–Gpihbp1–/– mice. Triglyceride clearance and fatty acid uptake assays will be used to identify the tissues to which triglycerides get cleared. Expression, protein, and lipase activity analysis will be used to identify the proteins responsible for this clearance. The approaches in the proposed research are innovative because they combine standard methods with novel mouse models to address previously untested questions about how triglyceride clearance is regulated. The proposed studies are significant because they will elucidate how and where ANGPTL3 and ANGPTL4 modulate levels of functional LPL to influence triglyceride delivery and will uncover novel mechanisms of triglyceride clearance that do not require vascular LPL, ultimately permitting new strategies designed to prevent or treat dyslipidemia.

项目摘要临床高甘油三酯血症很常见，仅部分响应可用的药物。反过来，甘油三酸酯过多地递送到单个组织会导致骨骼肌胰岛素抵抗，心脏脂肪毒性或严重的炎症反应。考虑到适当甘油三酸酯的重要性，这是我们必须了解调节这一过程的机制。通常两种蛋白质甘油三酸酯清除所需的是脂蛋白脂肪酶（LPL）和GPIHBP1。 LPL是需要的血浆triglyces的实际水解，使脂肪酸释放了组织摄取。内皮细胞需要蛋白质GPIHBP1正确将LPL定位到发生脂解的血管内腔。拟议研究的长期目标是了解并最终调节交付甘油三酸酯衍生的脂肪酸到特定的组织。此应用程序中的对象是推动我们的了解血管生成素样（Angptl）蛋白（angptl3和angptl4）如何调节甘油三酸酯的间隙。 angptl3和angptl4既可以在体外抑制LPL，angptl3或 ANGPTL4缺乏导致血浆甘油三酸酯水平较低。但是，如果以及如何angptl3和 ANGPTL4直接调节LPL/GPIHBP1介导的甘油三酸酯间隙尚不清楚。而且，在GPIHBP1和ANGPTL4中，小鼠中的血浆甘油三酸酯水平表明Angptl4可能调节一个未示范的GPIHBP1独立甘油三酸酯清除途径。这些问题将是通过追求两个具体目标来解决：1）定义Angptl3和angptl4的机制调节GPIHBP1依赖性甘油三酸酯间隙； 2）确定GPIHBP1-的新型机制独立的甘油三酸酯清除率。 AIM 1员工细胞培养的结合和脂肪酶的研究活性以及体内注入重组蛋白和组织特异性基因敲除小鼠研究ANGPTL蛋白如何与内皮表面上的GPIHBP1/LPL复合物相互作用细胞。第二个目标将解决Angptl4 - / - GPIHBP1 - / - 小鼠中较低的甘油三酸酯。甘油三酸酯清除率和脂肪酸摄取测定将用于识别组织清除甘油三酸酯。表达，蛋白质和脂肪酶活性分析将用于识别蛋白质负责此清除。拟议研究中的方法是创新的因为它们将标准方法与新型鼠标模型相结合以解决以前未经测试的有关如何调节甘油三酸酯清除的问题。拟议的研究很重要，因为他们将阐明如何和何处angptl3和angptl4调节功能LPL的水平影响甘油三酸酯的递送，并会发现甘油三酸酯清除的新机制需要血管LPL，最终允许旨在预防或治疗血脂异常的新策略。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A novel NanoBiT-based assay monitors the interaction between lipoprotein lipase and GPIHBP1 in real time.

一种基于 NanoBiT 的新型检测实时监测脂蛋白脂肪酶和 GPIHBP1 之间的相互作用。

DOI：
10.1194/jlr.d119000388
发表时间：
2020
期刊：
Journal of lipid research
影响因子：
6.5
作者：
Shetty,ShwethaK;Walzem,RosemaryL;Davies,BrandonSJ
通讯作者：
Davies,BrandonSJ

Regulation of plasma triglyceride partitioning by adipose-derived ANGPTL4 in mice.

DOI：
10.1038/s41598-021-87020-5
发表时间：
2021-04-12
期刊：
Scientific reports
影响因子：
4.6
作者：
Spitler KM;Shetty SK;Cushing EM;Sylvers-Davie KL;Davies BSJ
通讯作者：
Davies BSJ

Chronic high-fat feeding and prolonged fasting in liver-specific ANGPTL4 knockout mice.

肝脏特异性 ANGPTL4 基因敲除小鼠的长期高脂肪喂养和长时间禁食。

DOI：
10.1152/ajpendo.00144.2021
发表时间：
2021
期刊：
American journal of physiology. Endocrinology and metabolism
影响因子：
0
作者：
Spitler,KathrynM;Shetty,ShwethaK;Cushing,EmilyM;Sylvers-Davie,KelliL;Davies,BrandonSJ
通讯作者：
Davies,BrandonSJ

ANGPTL8 promotes the ability of ANGPTL3 to bind and inhibit lipoprotein lipase.

DOI：
10.1016/j.molmet.2017.06.014
发表时间：
2017-10
期刊：
Molecular metabolism
影响因子：
8.1
作者：
Chi X;Britt EC;Shows HW;Hjelmaas AJ;Shetty SK;Cushing EM;Li W;Dou A;Zhang R;Davies BSJ
通讯作者：
Davies BSJ