A dialogue between neutrophils and monocytes for effective resolution of inflammation following acute myocardial injury

中性粒细胞和单核细胞之间的对话有效解决急性心肌损伤后的炎症

• 批准号: 10522283
• 负责人: Prabhakara Reddy Nagareddy
• 金额: $ 61.78万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10522283
• 关键词: Ablation; Acute; Agonist; Anti-Inflammatory Agents; Antibodies; CD36 gene; Cardiac; Cause of Death; Cell Line; Cells; Cessation of life; Clinical; Cytometry; Early Intervention; Excision; Exhibits; Exposure to; Fluorescence; Grant; Heart; Heart Injuries; Heart failure; Inflammation; Inflammatory; Inflammatory Response; Interleukin-1 beta; Knowledge; Label; Leukocytes; Maps; Mediating; Molecular; Mus; Myocardial Infarction; Neutrophilic Infiltrate; Outcome; PTPRC gene; Pathway interactions; Patients; Pattern; Persons; Pharmacology; Phase; Phenocopy; Phenotype; Play; RXR; Receptor Signaling; Recombinants; Reporter; Reporting; Resolution; Role; S100A8 gene; SR-A proteins; Scheme; Signal Transduction; System; Tamoxifen; Testing; Time; Toll-like receptors; Up-Regulation; base; cell type; defined contribution; experience; genetic approach; healing; heart function; improved; improved outcome; insight; macrophage; monocyte; myocardial injury; neutrophil; novel; paracrine; phagocytosis receptor; programs; receptor expression; scavenger receptor; single-cell RNA sequencing; tissue repair; transcriptome sequencing; transcriptomics; uptake; wound healing

Project Summary After myocardial infarction (MI), the ensuing inflammatory response spearheaded by neutrophils is essential for removal of cellular debris and tissue repair; but if unregulated, it may confer more long-term harm than actual benefit. We know elevated neutrophil count is a strong predictor of heart failure and death in MI patients, yet strategies aimed at suppressing neutrophil function have not been successful in improving outcome. This is due to the lack of knowledge of neutrophil function and its cross-talk with other pro- and anti-inflammatory signaling components in the heart post-MI. We recently reported that the initial wave of infiltrating neutrophils amplify the inflammatory response post-MI by deploying key damage associated molecular patterns (DAMPs) such as S100A8/A9. Here, we provide promising findings to show that while S100A8/A9 participates in instigating inflammation, they may also have a potential role in the resolution of inflammation. We performed global transcriptomic analysis (RNA seq) of cardiac leukocytes obtained at day 3 post-MI, and found a robust upregulation of class A scavenger receptors (SRs) such as Msr1 and Marco via MafB, and phagocytosis receptors (Mertk, CD36 via Nr4a1) that are crucial for the clearance of DAMPs and dead cells, respectively. We further show that S100A8/A9 could upregulate SRs and Mertk by engaging the toll-like-receptor (TLR4) on Ly6Chi monocytes, the second-in-line cell type to infiltrate the infarcted heart. These novel findings support the premise that neutrophil-derived S100A8/A9 orchestrate the resolution of inflammation by engaging monocytes for effective clearance of DAMPs, as well as facilitating the maturation of monocytes into macrophages to enhance efferocytosis and final resolution of inflammation after MI. We will test this hypothesis using two specific aims: In Aim 1, we will define the mechanisms underlying the interaction between S100A8/A9 and Ly6Chi monocytes for the initial clearance of DAMPs. We will specifically focus on characterizing the time-dependent phenotypic and transcriptomic changes in monocytes following their interaction with neutrophils or S100A8/A9 using mass cytometry (CyTOF) and single-cell RNA sequencing. We will then decipher the role of the TLR4-MafB-SR signalling cascade in the endocytic uptake of DAMPs including S100A8/A9 during the initial phase of inflammation. In Aim 2, we will define the paracrine function of S100A8/A9 in orchestrating the transition of Ly6Chi to Ly6Clo monocytes/ macrophages for the final clearance of dead cells and the resolution of inflammation. Here, we will use lineage-tracing studies to map the conversion of Ly6Chi to Ly6Clo monocytes and study the role of Nr4a1, and the impact of neutrophils or S100A8/A9 on such conversion. For each strategy, the clearance of DAMPs, dead cells, cardiac remodeling and function will be studied as endpoints. The outcome of our studies will yield new insights into the mechanisms by which neutrophil-derived S100A8/A9 induce pro-resolving signals, and also unravel novel targets to suppress inflammation associated with MI.

项目摘要 心肌梗死（MI）之后，随后由中性粒细胞支撑的炎症反应对于 去除细胞碎屑和组织修复；但是，如果不受监管，它可能比实际的长期危害更大 益处。我们知道，中性粒细胞计数升高是MI患者心力衰竭和死亡的有力预测指标，但 旨在抑制中性粒细胞功能的策略尚未成功改善结果。这是应得的 对于缺乏中性粒细胞功能的知识及其与其他促疾病信号的串扰 MI后心脏中的成分。我们最近报道，浸润性嗜中性粒细胞的初始波会扩大 MI后通过部署关键损害相关的分子模式（潮湿），例如 S100A8/A9。在这里，我们提供了有希望的发现，以表明当S100A8/A9参与煽动时 炎症，它们也可能在炎症的解决中起潜在的作用。我们执行了全球 在MI后第3天获得的心脏白细胞的转录组分析（RNA SEQ），并发现了强大的 通过MAFB和吞噬作用的A类清道夫受体（SR）的上调（SRS） 受体（MERTK，CD36通过NR4A1）分别对于清除潮湿和死细胞至关重要。我们 进一步表明，S100A8/A9可以通过在Ly6Chi上与Toll-Like-pector（TLR4）接触SRS和MERTK上调和MERTK 单核细胞，是渗入梗塞心脏的第二intin-in-clim细胞类型。这些新颖的发现支持前提 中性粒细胞衍生的S100A8/A9通过使单核细胞与 有效清除潮湿，并促进单核细胞成熟到巨噬细胞中以增强 MI后炎症的炎性细胞增多症和最终分辨率。我们将使用两个具体目标检验这一假设： AIM 1，我们将定义S100A8/A9和LY6CHI单核细胞之间相互作用的基础机制 潮湿的初始清除率。我们将专门专注于表征时间依赖性表型和 单核细胞与中性粒细胞相互作用或使用质量相互作用的转录组变化 细胞仪（细胞仪）和单细胞RNA测序。然后，我们将破译TLR4-MAFB-SR的作用 在潮湿的内吞吸收（包括S100A8/A9）中的信号传导级联 炎。在AIM 2中，我们将定义S100A8/A9的旁分泌功能 ly6chi至ly6clo单核细胞/巨噬细胞，用于最终清除死细胞和炎症的分辨率。 在这里，我们将使用谱系追踪研究来绘制Ly6chi向Ly6clo单核细胞的转化并研究该作用 NR4A1，以及中性粒细胞或S100A8/A9对这种转化的影响。对于每个策略，清除 潮湿，死细胞，心脏重塑和功能将作为终点研究。我们研究的结果 将产生有关中性粒细胞衍生的S100A8/A9的机制的新见解。 并解散了抑制与MI相关的炎症的新型靶标。