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/摘要坏死性筋膜炎（NF）或“吃肉疾病”是一种迅速发展的细菌感染，严重真皮和潜在软组织的坏死。 NF的治疗需要全身性抗生素和侵略性手术清创术。即使使用这些治疗方法，NF也考虑了发病率和死亡率。那，更好了解NF的病理生理学以及鉴定新的治疗策略以减轻疾病需要进程。最近的工作表明，促炎信号可以增加或减少细胞抗胆固醇依赖性细胞赛（CDC），关键微生物毒素的耐药性，使细胞渗透细胞并破坏组织。发现吞噬细胞的CDC“抗性或敏感状态”的诱导为取决于细胞胆固醇稳态的快速重编程。而且，破坏了巨噬细胞重新编程其脂质代谢状态会破坏炎症的诱导状态信号。这是宿主细胞中的炎性脂质代谢回路是致病性的决定因素 CDC的潜力是坏死性皮肤感染的主要病毒因子。在此应用程序中，我们结合了具有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（气体）感染的致病潜力。具体目标1将确定 CH25H-LXR代谢轴如何介导细胞免受CDC的保护毒性。特别是，我们将发现发现LXR信号通路的激活深刻保护吞噬细胞免受CDC介导的膜完整性损失。结合脂质组学，转录组学，成像和功能丧失模型的功能测定，我们将分子剖析脂质 LXR介导的保护不受CDC介导的细胞毒性所必需的代谢途径。具体目标2将专注于促进我们对皮肤中细胞类型的理解必要的，并且足以满足LXR诱导的防止CDC组织损伤。我们将应用高级分析技术与鼠标模型相结合脂质代谢改变的改变，以确定诱导a的细胞类型和脂质代谢途径对皮肤中CDC的抗性状态。特定目标3确定哪种宿主脂质代谢途径至关重要抗局部或NF样实验性气体皮肤感染模型。我们的数据表明失调胆固醇代谢增强了CDC介导的组织损伤，但激活LXR途径会影响A 保护状态。在此目标中，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中的稳态改变了实验NF模型的发病机理，可以用作辅助治疗。我们预计这些研究将在分子水平上定义感染组织中的脂质代谢如何影响组织损伤导致CDC孔形成毒素，并可能提供概念证明证据表明靶向脂质体内稳态是一种衰减坏死感染发病机理的富有成效方法。