An LXR protein interaction network controlling macrophage lipid transporter expression in response to inflammatory-lipid crosstalk

LXR 蛋白相互作用网络控制巨噬细胞脂质转运蛋白表达以响应炎症-脂质串扰

• 批准号: 9335965
• 负责人: JEFFREY A RANISH
• 金额: $ 45.65万
• 依托单位: INSTITUTE FOR SYSTEMS BIOLOGY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9335965
• 关键词: ATP binding cassette transporter 1; Address; Apolipoprotein E; Arterial Fatty Streak; Atherosclerosis; Automobile Driving; Biochemical; Cells; Cholesterol; Complex; Data; Development; Disease; Engineered Gene; Engineering; Enhancers; Event; Foam Cells; Gene Expression; Generations; Genes; Genetic Transcription; Goals; Health; Health Benefit; Heart Diseases; Homeostasis; Individual; Inflammatory; Knowledge; Lesion; Lipids; Mass Spectrum Analysis; Measures; Mediating; Mission; Modification; Molecular; Mutant Strains Mice; National Heart, Lung, and Blood Institute; Outcome; Pathology; Patients; Phosphorylation; Prevention; Proteins; Public Health; Receptor Signaling; Regulator Genes; Regulatory Element; Research; Role; Signal Pathway; Signal Transduction; Sterols; Stimulus; TLR3 gene; Testing; Therapeutic; Therapeutic Intervention; Toll-like receptors; Work; base; design; gene function; gene repression; improved; in vivo; innovation; insight; lipid transport; macrophage; mouse model; novel; novel therapeutic intervention; prevent; promoter; protein complex; protein transport; response; transcription factor; western diet

Macrophage foam cells are major drivers of the development and pathology of atherosclerosis. Exposure of macrophages to sterol lipid and inflammatory TLR signals modifies gene regulatory networks controlling lipid homeostasis, which can favor foam cell formation. There exists a fundamental gap in our understanding of the molecular mechanisms by which TLR-lipid signal crosstalk impinges upon these networks and regulates foam cell formation. The long-term goal is to understand the molecular mechanisms governing foam cell formation, for the purpose of therapeutic intervention in atherosclerosis. Elucidating these mechanisms will not only advance our understanding of disease pathology, but also provide crucial insights into functional interactions that could be engineered to enhance lipid transporter expression as part of new therapeutic approaches to counteract atherosclerosis. The objective of this proposal is to determine how NCOA5, SND1, and SART1 function to control lipid transporter gene expression, function and foam cell formation. The central hypothesis is that these proteins are critical components of LXR transcriptional complexes assembled at the gene regulatory elements (GREs) of lipid transporters Abca1 and Abcg1, and that TLR-lipid crosstalk promotes changes in the composition and activity of these complexes, through phosphorylation, that favor gene repression, cholesterol accumulation and foam cell formation. Based on preliminary data, this hypothesis will be tested by pursuing three specific aims: (1) Elucidate the function of LXR-interacting proteins in the control of lipid transporter expression, function and foam cell formation; (2) Elucidate the role of phosphorylation of LXR-interacting proteins in the control of lipid transporter expression, function and foam cell formation; and (3) Characterize LXR-dependent regulatory complexes assembled on lipid transporter GREs during foam cell formation, and assess the role of NCOA5 in atherosclerosis, in vivo. Under the first aim, biochemical, molecular, and cellular approaches will be used to address the signal-dependent role of NCOA5, SND1, and SART1 in regulating expression of lipid transporters and foam cell formation. In the second aim, an innovative targeted mass spectrometry (MS) strategy will be used to identify signal-dependent changes in the phosphorylation state of NCOA5, SND1, and SART1, which will then be pursued using functional studies to define the impact of those modifications. For the third aim, an innovative promoter enrichment quantitative MS (PE-QMS) approach will be employed to characterize the composition of protein complexes assembled at GREs of Abca1 and Abcg1 in foam cells in vivo. Moreover, we will assess the importance of NCOA5 in promoting foam cell formation and atherosclerosis in vivo. The proposed research is significant because it will provide mechanisms to explain how foam cell formation is regulated at the molecular level, and provide insights into proteins and interactions that can be targeted to re-engineer gene regulatory networks to prevent foam cell formation and counteract atherosclerosis. This has the potential to benefit the health of patients suffering from this disease.

巨噬细胞泡沫细胞是动脉粥样硬化发育和病理学的主要驱动因素。的接触 巨噬细胞到固醇脂质和炎症TLR信号修饰了控制脂质的基因调节网络 稳态，可以有利于泡沫细胞形成。我们对我们的理解存在根本差距 TLR-lipid信号串扰撞击这些网络并调节泡沫的分子机制 细胞形成。长期目标是了解有关泡沫细胞形成的分子机制， 为了治疗干预动脉粥样硬化。阐明这些机制不仅将 促进我们对疾病病理学的理解，但也为功能相互作用提供了重要的见解 可以设计以增强脂质转运蛋白表达，作为新的治疗方法的一部分 抵消动脉粥样硬化。该提议的目的是确定NCOA5，SND1和SART1如何 控制脂质转运蛋白基因表达，功能和泡沫细胞形成的功能。中心假设是 这些蛋白是在基因调节的LXR转录复合物的关键成分 脂质转运蛋白ABCA1和ABCG1的元素（GRE），TLR脂质串扰促进了促进的变化 这些复合物的组成和活性通过磷酸化，有利于基因抑制，胆固醇 积累和泡沫细胞形成。根据初步数据，将通过追求该假设来检验 三个特定目的：（1）阐明LXR相互作用蛋白在脂质转运蛋白中的功能 表达，功能和泡沫细胞形成； （2）阐明LXR相互作用的磷酸化的作用 控制脂质转运蛋白表达，功能和泡沫细胞形成的蛋白质； （3）特征 在泡沫细胞形成期间，在脂质转运蛋白GRE上组装的LXR依赖性调节络合物，并 评估NCOA5在体内动脉粥样硬化中的作用。在第一个目标下，生化，分子和细胞 方法将用于解决NCOA5，SND1和SART1在调节中的信号依赖性作用 脂质转运蛋白和泡沫细胞形成的表达。在第二个目标中，创新的目标质量 光谱法（MS）策略将用于识别信号依赖性变化的变化 NCOA5，SND1和SART1，然后将使用功能研究来定义这些影响 修改。对于第三个目标，创新的启动子富集定量MS（PE-QMS）方法将 被用来表征在ABCA1和ABCG1中组装的蛋白质复合物的组成 体内泡沫细胞。此外，我们将评估NCOA5在促进泡沫细胞形成和 动脉粥样硬化在体内。拟议的研究很重要，因为它将提供机制来解释如何 在分子水平调节泡沫细胞的形成，并提供对蛋白质和相互作用的见解 可以针对重新设计器基因调节网络，以防止泡沫细胞形成并抵消 动脉粥样硬化。这有可能使患有这种疾病的患者的健康受益。