Targeting host lipid metabolism to limit tissue damage in necrotizing fasciitis

靶向宿主脂质代谢以限制坏死性筋膜炎的组织损伤

基本信息

批准号：
10639904
负责人：
STEVEN J BENSINGER
金额：
$ 71.46万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2028-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10639904
关键词：
Affect Antibiotics Attenuated Automobile Driving Bacillus anthracis Bacteria Bacterial Infections Binding Biological Assay Cell membrane Cells Cessation of life Cholesterol Cholesterol Homeostasis Critical Pathways Cytolysins Cytoprotection Data Debridement Dermis Disease Disease Progression Eating Effectiveness Elements Exotoxins Fascia Fatty acid glycerol esters Functional disorder Gene Expression Genetic Goals Grant Homeostasis Hospitalization Host Defense Image Immune Infection Infectious Skin Diseases Inflammation Inflammatory Integration Host Factors Laboratories Learning Life Lipids Liver X Receptor Macrophage Mass Spectrum Analysis Measures Mediating Medical emergency Membrane Metabolic Metabolic Pathway Metabolism Methodology Microbe Modeling Molecular Morbidity - disease rate Necrosis Necrotizing fasciitis Operative Surgical Procedures Outcome Pathogenesis Pathogenicity Pathology Pathway interactions Patients Permeability Phagocytes Play Process Productivity Proteins Research Design Resistance Role Sepsis Signal Pathway Signal Transduction Skin Skin Tissue Soft Tissue Infections Streptococcus pyogenes Streptolysins Survival Rate Techniques Testing Therapeutic Therapeutic Uses Tissue Preservation Tissues Toxic effect Toxin Treatment Cost Vibrio vulnificus Virulence Virulence Factors Work advanced analytics cell type cytotoxicity design experimental group gain of function intradermal injection lipid metabolism lipidomics loss of function microbial monomer mortality mouse model neutrophil new therapeutic target novel therapeutic intervention novel therapeutics pharmacologic programs protective effect single cell sequencing soft tissue transcriptomics

项目摘要

ABSTRACT/SUMMARY Necrotizing Fasciitis (NF) or “flesh-eating disease” is a rapidly progressing bacterial infection with severe necrosis of the dermis and underlying soft tissues. Treatment of NF requires systemic antibiotics and aggressive surgical debridement. Even with these treatments, NF has considerable morbidity and mortality. Thus, a better understanding of the pathophysiology of NF and identification of new treatment strategies to attenuate disease progression is required. Recent work has revealed that pro-inflammatory signals can increase or decrease cellular resistance to the cholesterol-dependent cytolysins (CDCs), key microbial toxins that permeabilize cells and destroy tissues. The induction of a CDC “resistant or sensitive state” for phagocytes was found to be dependent on the rapid reprogramming of cellular cholesterol homeostasis. Moreover, disrupting the ability of macrophages to reprogram their lipid metabolic state disrupts the induction of protective states by inflammatory signals. Thus, an inflammatory-lipid metabolic circuit in host cells serves as a determinant of the pathogenic potential of CDCs, a major virulence factor in necrotizing skin infections. In this application, we combine advanced methodologies (e.g., mass spectrometry, single-cell sequencing, and imaging) with genetic and pharmacologic models of lipid metabolism to understand if tissue lipid metabolism is a host factor that determines the pathogenic potential of CDCs and group A strep (GAS) infections. Specific Aim 1 will determine the molecular mechanism underlying how the CH25H-LXR metabolic axis mediates the protection of cells from CDC toxicity. Specifically, we will pursue our discovery that activation of the LXR signaling pathway profoundly protects phagocytes from CDC-mediated loss of membrane integrity. Combining lipidomics, transcriptomics, imaging, and functional assays with gain- and loss-of function models, we will molecularly dissect the lipid metabolic pathways necessary for LXR-mediated protection from CDC-mediated cytotoxicity. Specific aim 2 will focus on advancing our understanding of the cell types in the skin necessary and sufficient for LXR-induced protection from CDC tissue damage. We will apply advanced analytical techniques combined with mouse models of altered lipid metabolism to determine the cell types and lipid metabolic pathways involved in inducing a resistant state to CDCs in the skin. Specific Aim 3 determines which host lipid metabolism pathways are critical for resistance to localized or NF-like experimental GAS skin infection models. Our data shows that dysregulation of cholesterol metabolism potentiates CDC-mediated tissue damage but activating the LXR pathway induces a protective state. In this aim, we extend these exciting observations and mechanistically test if modulating lipid homeostasis in host tissues alters the pathogenesis of experimental NF models and may serve as an adjunct treatment. We expect that these studies will define at the molecular level how lipid metabolism in infected tissues influences tissue damage caused the CDC pore-forming toxins and could provide proof-of-concept evidence that targeting lipid homeostasis is a productive approach to attenuating the pathogenesis of necrotizing infections.

摘要/总结坏死性筋膜炎 (NF) 或“食肉性疾病”是一种快速进展的细菌感染，可导致严重的后果真皮和底层软组织坏死的治疗需要全身抗生素和积极的治疗。即使采用这些治疗方法，神经纤维瘤病的发病率和死亡率也相当高。了解 NF 的病理生理学并确定减轻疾病的新治疗策略最近的研究表明促炎症信号可以增加或减少。细胞对胆固醇依赖性溶细胞素 (CDC) 的抵抗力，这是使细胞透化的关键微生物毒素并发现吞噬细胞诱导 CDC“抵抗或敏感状态”。依赖于细胞胆固醇稳态的快速重编程。巨噬细胞重新编程其脂质代谢状态会破坏炎症对保护状态的诱导因此，宿主细胞中的炎症-脂质代谢回路是致病的决定因素。 CDC 的潜力是坏死性皮肤感染的主要毒力因子，在此应用中，我们将其结合起来。先进的方法（例如质谱、单细胞测序和成像）与遗传和脂质代谢的药理学模型，以了解组织脂质代谢是否是决定的宿主因素 CDC 和 A 组链球菌 (GAS) 感染的致病潜力将决定具体目标 1。 CH25H-LXR代谢轴介导细胞免受CDC保护的分子机制具体来说，我们将深入研究 LXR 信号通路激活的发现。结合脂质组学、转录组学，保护吞噬细胞免受 CDC 介导的膜完整性损失。通过成像以及功能获得和丧失模型的功能测定，我们将从分子角度剖析脂质 LXR 介导的保护免受 CDC 介导的细胞毒性所必需的代谢途径。具体目标 2 将。专注于增进我们对 LXR 诱导所需和足够的皮肤细胞类型的理解我们将结合小鼠模型应用先进的分析技术。改变脂质代谢以确定细胞类型和参与诱导脂质代谢途径皮肤对 CDC 的抵抗状态决定了哪些宿主脂质代谢途径至关重要。对于局部或 NF 样实验性 GAS 皮肤感染模型的抵抗力，我们的数据表明失调。胆固醇代谢的增加会增强 CDC 介导的组织损伤，但激活 LXR 途径会诱导为了这个目的，我们扩展了这些令人兴奋的观察结果并机械测试是否调节脂质。宿主组织的稳态改变了实验性神经纤维瘤模型的发病机制，并可能作为一种辅助手段我们期望这些研究将在分子水平上确定感染组织中的脂质代谢情况。影响引起 CDC 成孔毒素的组织损伤，并可以提供概念验证证据针对脂质稳态是减轻坏死性感染发病机制的有效方法。