Effect of Mitochondrial Quality Control on Systemic Inflammation and Organ Dysfunction in Pediatric Sepsis

线粒体质量控制对小儿脓毒症全身炎症和器官功能障碍的影响

• 批准号: 10424551
• 负责人: SCOTT L WEISS
• 金额: $ 24.68万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10424551
• 关键词: Address; Animal Model; Antibiotics; Biogenesis; Caring; Cause of Death; Cell Respiration; Cell physiology; Cells; Cessation of life; Child; Clinical; Cytosol; Data; Enrollment; Etiology; Event; Functional disorder; Future; Genetic Transcription; Goals; Health; Hospitalization; Human; Human Herpesvirus 4; Immune; Immune response; In Vitro; Infection; Inflammasome; Inflammation; Inflammatory; Injury; Investigation; Lead; Life; Link; Lipopolysaccharides; Measures; Medical emergency; Metabolic; Mitochondria; Mitochondrial DNA; Mitochondrial Diseases; Mitochondrial RNA; Multiple Organ Failure; National Institute of Child Health and Human Development; Organ; Oxidation-Reduction; Pathologic; Pathway interactions; Patients; Pattern; Peripheral Blood Mononuclear Cell; Persons; Plasma; Prevention; Process; Proteins; Protocols documentation; Quality Control; Recovery; Refractory; Regulation; Respiration; Resuscitation; Sampling; Sepsis; Septic Shock; Severities; Shock; Speed; Stimulator of Interferon Genes; Suggestion; TLR9 gene; Testing; Therapeutic; United States; Work; body system; cytokine; experimental study; high risk; improved; in vitro Model; interest; lipoteichoic acid; lymphoblast; mitochondrial dysfunction; pediatric sepsis; protein expression; septic; systemic inflammatory response; targeted treatment; therapeutic target; translational potential

PROJECT SUMMARY / ABSTRACT Sepsis is a medical emergency of life-threatening organ dysfunction due to a dysregulated host response to infection. In the United States, over one million people are hospitalized with sepsis or septic shock every year, including >75,000 children. Multiple organ dysfunction syndrome (MODS) is the most common cause of death for children with sepsis. Although most children who develop sepsis recover with appropriate conventional care, ~20% develop MODS, and one in five of these children with sepsis-induced MODS still die. For this high-risk subset, we have no cure and care is largely supportive. Widespread alterations in the ability of mitochondria to supply sufficient energy for normal cellular activities has been implicated as a key pathologic event leading to MODS in sepsis. Using a protocol optimized to measure mitochondrial respiration and content in peripheral blood mononuclear cells (PBMC), our group discovered that children with prolonged sepsis- induced MODS are more likely to have persistent mitochondrial dysfunction. This proposal builds on our prior work to test the hypothesis that low mitochondrial respiration in PBMCs is caused by abnormal mitochondrial quality control processes (biogenesis, fission, fusion, and mitophagy) that normally restore and maintain mitochondrial health. The resulting mitochondrial dysfunction, through release of mitochondrial DNA (mtDNA) into the cytosol, can then activate inflammatory pathways that sustain inflammation and organ dysfunction in children with sepsis. In Aim 1, we will determine which changes in mitochondrial quality control are associated with recovery versus persistence of low mitochondrial respiration in children with sepsis. We will enroll 106 children with sepsis-induced MODS and measure mitochondrial respiration, redox state, content, biogenesis, fission, fusion, and mitophagy on days 1, 3, 5, and 7 of illness. In Aim 2, we will determine if the persistence of PBMC mitochondrial dysfunction activates three inflammatory pathway (cGAS-STING, TLR-9, and inflammasome) that sense release of mtDNA into the cytosol. In Aim 3, we will test whether mitochondrial dysfunction, abnormal mitochondrial quality control, or activation of inflammatory pathways are associated with the severity or duration of MODS in children with sepsis. As part of Aims 1 and 2, we will also conduct a parallel set of in vitro experiments to test the utility of lipopolysaccharide- and lipoteichoic acid-stimulation of EBV-transformed lymphoblasts as a potential translational platform for future therapeutic investigation and to establish cytosolic mtDNA as one mechanism through which mitochondria can promote inflammation in sepsis. These aims address the NICHD’s interest in “studies focused on mitochondrial dysfunction as a pathophysiologic process of MODS…with potential to advance to translational and clinical projects.” By understanding why mitochondrial dysfunction persists in some children and how this can lead to sustained inflammation and MODS, we will identify new potential therapeutic targets for children with prolonged MODS, the leading cause of death in sepsis for which we currently have no cure.

项目概要/摘要 脓毒症是一种因宿主反应失调而导致危及生命的器官功能障碍的医疗紧急情况 感染。在美国，每年有超过一百万人因败血症或败血性休克住院， 其中包括超过 75,000 名儿童。多器官功能障碍综合征（MODS）是最常见的死亡原因 对于患有败血症的儿童。尽管大多数患有脓毒症的儿童通过适当的常规治疗都能康复 大约 20% 的儿童会患上 MODS，其中五分之一患有脓毒症引起的 MODS 的儿童仍然会死亡。为了这 高风险子集，我们无法治愈，护理基本上是支持性的。能力的广泛改变 线粒体为正常细胞活动提供足够的能量已被认为是关键的病理学 导致败血症中 MODS 的事件。使用优化的方案来测量线粒体呼吸和含量 在外周血单核细胞（PBMC）中，我们的小组发现长期败血症的儿童 诱导的 MODS 更有可能出现持续性线粒体功能障碍。该提案建立在我们之前的基础上 致力于检验 PBMC 中线粒体呼吸低是由线粒体异常引起的假设 通常恢复和维持的质量控制过程（生物发生、裂变、融合和线粒体自噬） 线粒体健康。通过释放线粒体 DNA (mtDNA)，导致线粒体功能障碍 进入细胞质，然后可以激活炎症途径，维持炎症和器官功能障碍 患有败血症的儿童。在目标 1 中，我们将确定与线粒体质量控制的哪些变化相关 脓毒症儿童线粒体呼吸低下的恢复与持续。我们将报名106名 患有败血症诱发的 MODS 的儿童并测量线粒体呼吸、氧化还原状态、含量、生物发生、 患病第 1 天、第 3 天、第 5 天和第 7 天发生裂变、融合和线粒体自噬。在目标 2 中，我们将确定是否持续存在 PBMC 线粒体功能障碍激活三个炎症通路（cGAS-STING、TLR-9 和 炎症小体）感知 mtDNA 释放到细胞质中。在目标 3 中，我们将测试线粒体是否 功能障碍、线粒体质量控制异常或炎症途径激活与 败血症儿童 MODS 的严重程度或持续时间。作为目标 1 和 2 的一部分，我们还将开展 一组平行的体外实验来测试脂多糖和脂磷壁酸刺激的效用 EBV 转化的淋巴母细胞作为未来治疗研究的潜在转化平台 确定细胞质 mtDNA 作为线粒体促进脓毒症炎症的一种机制。 这些目标满足了 NICHD 对“以线粒体功能障碍为重点的研究”的兴趣。 MODS 的病理生理过程……有可能推进转化和临床项目。”经过 了解为什么线粒体功能障碍在一些儿童中持续存在，以及这如何导致持续的 炎症和 MODS，我们将为患有长期 MODS 的儿童确定新的潜在治疗靶点， 脓毒症死亡的主要原因，目前我们无法治愈。