Inflammasome activation by cholesterol crystals

胆固醇晶体激活炎症小体

• 批准号: 8060602
• 负责人: Eicke Latz
• 金额: $ 41.13万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8060602
• 关键词: Appearance; Arterial Fatty Streak; Arteries; Atherogenic Diet; Atherosclerosis; Biological Testing; Blood; Blood Vessels; Breeding; Cardiovascular Diseases; Caspase-1; Cathepsins; Cell Wall; Cells; Cholesterol; Chronic Disease; Cleaved cell; Clinical; Complex; Connective Tissue; Crystal Formation; Crystallization; Cytoplasmic Protein; Data; Development; Disease; Elements; Epidemiology; Extracellular Space; Foam Cells; Growth Factor; Health; Human; Image; Imaging Techniques; Immune; Immune response; Immunofluorescence Immunologic; In Vitro; Infection; Inflammation; Inflammatory; Interleukin-1; Interleukin-12; Interleukin-18; Knockout Mice; Knowledge; Lead; Lesion; Link; Lipids; Liquid substance; Low Density Lipoprotein Receptor; Low-Density Lipoproteins; Malignant Neoplasms; Mediating; Metabolic; Microbe; Microscopy; Modeling; Molecular; Molecular Target; Morbidity - disease rate; Mus; Pathologic; Pathology; Pathway interactions; Play; Prevalence; Process; Reaction; Resolution; Risk; Role; Signal Transduction; Societies; Staging; Structure; Testing; Tissues; base; cytokine; cytosolic receptor; economic impact; feeding; immune activation; improved; in vivo; inhibitor/antagonist; insight; macrophage; mortality; new therapeutic target; novel; particle; pathogen; prevent; protein complex; receptor; socioeconomics

DESCRIPTION (provided by applicant): Atherosclerosis is a chronic disease of arterial blood vessels and is fundamentally linked to abnormally high blood cholesterol levels. Atherosclerotic lesions develop after excessive amounts of lipids accumulate in arterial walls. Macrophages in atherosclerotic lesions take up and store large amounts of lipids during which they are activated to produce inflammatory cytokines and growth factors. The local saturation of free cholesterol can lead to crystal formation inside macrophages and in the extracellular space. Inflammatory immune responses in atherosclerotic lesions are key pathogenic factors for the development of clinical disease. However, the factors leading to the activation of inflammation in atherosclerotic lesions remain unknown. Immune cells recognize and respond to conditions that are of danger to the host, such as infections, cancer, tissue damage or metabolic derangements. Immune cells express receptors that can recognize foreign molecules from microbes as well as altered self-molecules, which appear under pathologic conditions. It has recently been shown that crystallization of normally soluble material is perceived as a danger to the host and can lead to the activation of the cytosolic receptor complex NALP3 inflammasome. We found that cholesterol crystals, which are abundantly present in atherosclerotic lesions, could activate the NALP3 inflammasome in immune cells leading to caspase-1 mediated maturation and release of the pro-inflammatory cytokines IL-12 and IL-18. Our hypothesis is that cholesterol crystals act as an endogenous danger signal and activate the NALP3 inflammasome. We postulate that cholesterol crystal-induced immune activation is fundamental for the development of inflammation in atherosclerotic lesions and could influence the initiation and progression of atherosclerotic disease. We propose to study the molecular mechanisms of cholesterol crystal recognition by analyzing mice with targeted lesions in components of the inflammasome pathway. Macrophages from knock-out mice will be analyzed in vitro and cholesterol crystal-induced inflammation will be tested in vivo. To better understand how crystals can enter macrophages and where signaling is initiated, we will make use of confocal imaging techniques that image crystals together with fluorescent structures at high spatial resolution. We will test the biological relevance of NALP3 inflammasome activation using a mouse atherosclerosis model with double knock-out mice that lack the LDL receptor and components of the inflammasome (NALP3 and ASC) pathway. We will further assess the prevalence of crystals in different human artherosclerotic lesion types together with cellular and inflamasome activation markers to gain insights into the relevance of crystals in human atherosclerotic disease. Detailed knowledge of the molecular mechanisms of cholesterol crystal recognition by immune cells will aid in the identification of novel therapeutic targets directed against the onset and progression of atherosclerosis, which could have broad clinical and socio-economic impact. PUBLIC HEALTH RELEVANCE: This project will lead to a detailed understanding of how immune cells are activated by cholesterol crystals. Understanding the molecular mechanisms of cholesterol crystal recognition can lead to novel molecular targets for therapies that prevent inflammation in atherosclerotic lesions, which can improve or prevent atherosclerotic disease.

描述（由申请人提供）：动脉粥样硬化是动脉血管的慢性疾病，从根本上讲与异常高的血液胆固醇水平有关。在动脉壁中积聚了过多的脂质后，动脉粥样硬化病变会出现。动脉粥样硬化病变中的巨噬细胞占用并存储大量脂质，在此期间它们被激活以产生炎症性细胞因子和生长因子。游离胆固醇的局部饱和可以导致巨噬细胞内部和细胞外空间内形成晶体。动脉粥样硬化病变中的炎症免疫反应是临床疾病发展的关键致病因素。但是，导致动脉粥样硬化病变中炎症激活的因素尚不清楚。免疫细胞识别并应对对宿主有危险的疾病，例如感染，癌症，组织损伤或代谢危险。免疫细胞表达可以从微生物中识别出外国分子以及在病理条件下出现的自我分子改变的受体。最近已经显示，正常可溶物材料的结晶被认为是对宿主的危险，并可能导致胞质受体复合物nalp3炎症体的激活。我们发现，在动脉粥样硬化病变中大量存在的胆固醇晶体可以激活免疫细胞中的NALP3炎性体，从而导致CASPase-1介导的成熟并释放促炎细胞因子IL-12和IL-18。我们的假设是胆固醇晶体充当内源性危险信号并激活Nalp3炎症体。我们假设胆固醇晶体诱导的免疫激活对于动脉粥样硬化病变的炎症发展至关重要，并且可能影响动脉粥样硬化疾病的起始和进展。我们建议通过在炎性途径成分中用靶向病变分析小鼠来研究胆固醇晶体识别的分子机制。将在体外分析敲除小鼠的巨噬细胞，并将在体内测试胆固醇晶体诱导的炎症。为了更好地了解晶体如何进入巨噬细胞以及发起信号的位置，我们将利用共聚焦成像技术，将图像晶体与高空间分辨率的荧光结构一起。我们将使用小鼠动脉粥样硬化模型和双敲除小鼠的生物学相关性测试Nalp3炎症体激活的生物学相关性，该模型缺乏炎症体（NALP3和ASC）途径的LDL受体和成分。我们将进一步评估不同人类动脉粥样硬化病变类型中晶体的流行率，以及细胞和肿瘤体激活标记，以洞悉人动脉粥样硬化疾病中晶体的相关性。对免疫细胞胆固醇晶体识别的分子机制的详细了解将有助于鉴定针对动脉粥样硬化的发作和进展的新型治疗靶标，这可能会对临床和社会经济影响广泛。公共卫生相关性：该项目将导致对胆固醇晶体如何激活免疫细胞的详细了解。了解胆固醇晶体识别的分子机制可以导致用于预防动脉粥样硬化病变炎症的疗法的新型分子靶标，这些疗法可以改善或预防动脉粥样硬化疾病。