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: 9161006
• 负责人: JEFFREY A RANISH
• 金额: $ 46.02万
• 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/9161006
• 关键词: ATP binding cassette transporter 1; Address; Apolipoprotein E; Arterial Fatty Streak; Atherosclerosis; Automobile Driving; Biochemical; Carrier Proteins; Cells; Cholesterol; Complex; Data; Development; Disease; Engineered Gene; Engineering; Enhancers; Event; Foam Cells; Gene Expression; Gene-Modified; Generations; Genes; Goals; Health; Health Benefit; Heart Diseases; Homeostasis; Individual; Inflammatory; Knowledge; Lesion; Lipids; Mass Spectrum Analysis; Measures; Mediating; Mission; Modification; Molecular; Mutant Strains Mice; 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; 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展和病理的主要驱动因素。的接触 巨噬细胞对甾醇脂质和炎症 TLR 信号修饰控制脂质的基因调控网络 体内平衡，有利于泡沫细胞的形成。我们对这个问题的理解存在着根本性的差距 TLR-脂质信号串扰影响这些网络并调节泡沫的分子机制 细胞形成。长期目标是了解控制泡沫细胞形成的分子机制， 以治疗干预动脉粥样硬化为目的。阐明这些机制不仅 增进我们对疾病病理学的理解，同时也为功能相互作用提供重要的见解 可以对其进行改造以增强脂质转运蛋白的表达，作为新治疗方法的一部分 对抗动脉粥样硬化。该提案的目标是确定 NCOA5、SND1 和 SART1 如何 具有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 这些蛋白质是 LXR 转录复合物的关键成分，在基因调控中组装 脂质转运蛋白 Abca1 和 Abcg1 的元件（GRE），并且 TLR-脂质串扰促进了脂质转运蛋白 Abca1 和 Abcg1 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，该假设将通过追求 三个具体目标：（1）阐明LXR相互作用蛋白在脂质转运蛋白控制中的功能 表达、功能和泡沫细胞形成； (2) 阐明LXR相互作用磷酸化的作用 控制脂质转运蛋白表达、功能和泡沫细胞形成的蛋白质； (3) 表征 在泡沫细胞形成过程中，LXR 依赖性调节复合物在脂质转运蛋白 GRE 上组装，以及 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 脂质转运蛋白的表达和泡沫细胞的形成。第二个目标是创新的目标大众 光谱分析 (MS) 策略将用于识别磷酸化状态的信号依赖性变化 NCOA5、SND1 和 SART1，然后将使用功能研究来确定这些的影响 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 用于表征 Abca1 和 Abcg1 的 GRE 处组装的蛋白质复合物的组成 体内的泡沫细胞。此外，我们将评估 NCOA5 在促进泡沫细胞形成和 体内动脉粥样硬化。拟议的研究意义重大，因为它将提供机制来解释如何 泡沫细胞的形成在分子水平上受到调节，并提供对蛋白质和相互作用的见解 可以有针对性地重新设计基因调控网络，以防止泡沫细胞形成并抵消 动脉粥样硬化。这有可能有益于患有这种疾病的患者的健康。