Mechanisms of cardiomyocyte dysfunction in pediatric septic shock

小儿感染性休克心肌细胞功能障碍的机制

• 批准号: 10580624
• 负责人: Andrew John Lautz
• 金额: $ 19.2万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10580624
• 关键词: Address; Adult; Animal Model; Antibiotics; Back; Biological; Biology; CRISPR/Cas technology; CXCR; Cardiac; Cardiac Myocytes; Cardiac Surgery procedures; Cell Death; Cells; Child; Childhood Injury; Collection; Data; Depressed mood; Development; Disease; Echocardiography; Excision; Exposure to; Failure; Foundations; Functional disorder; Future; Gene Expression Profile; Generations; Genetic; Genetic Transcription; Goals; Grant; Heart Injuries; Human; IL8RA gene; IL8RB gene; Intensive Care; Interleukin 8A Receptor; Interleukin-8; Knock-out; Laboratories; Mediating; Mitochondria; Modeling; Molecular; Mus; Myocardial Depressant Factor; Myocardial dysfunction; Operative Surgical Procedures; Pathogenesis; Pathway interactions; Patient Care; Patients; Pattern; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Physicians; Play; Predisposition; Process; Recombinants; Research; Role; Scientist; Sepsis; Septic Shock; Serum; Severity of illness; Signal Transduction; Technology; Tissue Sample; Tissues; Training; Translating; Translational Research; Whole Blood; biobank; career development; experimental study; exposed human population; human model; immunoregulation; improved; improved outcome; induced pluripotent stem cell; induced pluripotent stem cell derived cardiomyocytes; mortality; mouse model; neutralizing antibody; next generation; novel; organ injury; pediatric patients; pediatric sepsis; programs; prospective; response; septic; therapeutic target; transcriptome sequencing; translational model

PROJECT SUMMARY / ABSTRACT Title: Mechanisms of cardiomyocyte dysfunction in pediatric septic shock Despite decades of research in pediatric sepsis, mortality remains at approximately 25% for children with septic shock. Sepsis-associated myocardial dysfunction (SAMD) is common in children and has an association with mortality that is not simply a reflection of the severity of illness. As no disease-modifying therapies exist for SAMD, there is a critical need to understand the biologic basis of cardiomyocyte dysfunction in sepsis. Furthermore, there is a need for novel human modeling with patient-derived materials given the failure to translate molecular discoveries in murine models of sepsis to improvements in human organ injury. Our objectives are to establish human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) as a model for cardiomyocyte dysfunction in pediatric sepsis and to examine the roles of host genetic background and serum factors in the pathogenesis of SAMD. We have built upon our large, established biobank of serum from children with sepsis to study the cardiomyocyte response to septic serum banked from children who did and who did not have SAMD. We have found that the contractility of hiPSC-CMs is depressed by serum banked from children with SAMD but not by control septic serum from children without SAMD. This depressant effect was reversible after removal of the serum, suggesting this was not reflective of cell death. Furthermore, we identified a significant association of interleukin-8 (IL-8) with SAMD in children with septic shock and found that recombinant human IL-8 depresses hiPSC-CM contractility. Our proposal will address three important questions as specific aims: First, we will determine whether hiPSC-CMs and cardiomyocytes derived from the same children share common functional and transcriptional patterns of responses when exposed to banked septic serum. We will provide a comprehensive comparison of hiPSC-CMs to ex vivo cardiomyocytes by isolating cardiomyocytes from discarded surgical tissue from children undergoing cardiac surgery and by generating hiPSC-CMs from these same patients. Second, we will determine the degree to which host genetic background contributes to cardiomyocyte dysfunction in SAMD. We will develop hiPSC- CMs from pediatric patients with and without SAMD to determine responses to septic serum to identify patterns of functional and transcriptional responses associated with susceptibility to SAMD. Third, we will dissect the role of IL-8 signaling in cardiomyocyte dysfunction in sepsis. We will employ a combination of IL-8 modulation in serum and IL-8 receptor (CXCR1 and CXCR2) knockouts in hiPSC-CMs, providing evidence for IL-8 blockade as a potential therapeutic target in SAMD. This career development proposal will build on my background in translational research in myocardial dysfunction to gain new expertise in cardiomyocyte functional analysis, hiPSC generation and differentiation, and next-generation RNA sequencing technology to facilitate my transition to independence as a physician-scientist focused on elucidating and targeting mechanisms of pediatric SAMD.

项目摘要/摘要 标题：儿童感染性休克心肌细胞功能障碍的机制 尽管对儿童败血症进行了数十年的研究，但患有以下疾病的儿童死亡率仍保持在25%左右 感染性休克。脓毒症相关性心肌功能障碍(SAMD)在儿童中很常见，并与 死亡率不仅仅是疾病严重程度的反映。因为目前还没有治疗疾病的疗法 SAMD，迫切需要了解脓毒症时心肌细胞功能障碍的生物学基础。 此外，还需要使用患者衍生材料进行新的人体建模，因为 将小鼠脓毒症模型中的分子发现转化为人类器官损伤的改善。我们的 目的建立人诱导多能干细胞(HiPSC)来源的心肌细胞(hiPSC-CMS) 作为小儿脓毒症心肌细胞功能障碍的模型，并研究宿主基因的作用 SAMD的发病背景和血清因素。我们建立在我们庞大的、成熟的 脓毒症患儿血清生物库研究败血症血清库对心肌细胞的反应 患有SAMD和没有SAMD的儿童。我们发现，HiPSC-CMS的收缩性能受到抑制 用SAMD患儿的血清储存，而不用对照的非SAMD患儿的败血症血清储存。这 在去除血清后，抑制作用是可逆的，这表明这不能反映细胞死亡。 此外，我们发现白介素8(IL-8)与败血症儿童SAMD显著相关。 休克，并发现重组人IL-8抑制HiPSC-CM的收缩。我们的提案将解决 具体目标有三个重要问题：第一，我们将确定HiPSC-CMS和心肌细胞 来自相同儿童的人在以下情况下具有共同的功能和转录模式的反应 暴露在储存的败血症血清中。我们将提供HiPSC-CMS与体外的全面比较 从接受心脏手术的儿童废弃手术组织中分离心肌细胞 手术和从这些相同的患者中产生HiPSC-CMS。第二，我们将确定 哪些宿主遗传背景与SAMD的心肌细胞功能障碍有关。我们将发展HiPSC- 有无SAMD的儿科CMS患者对败血症血清的反应以确定模式 与SAMD易感性相关的功能和转录反应。第三，我们将剖析 IL-8信号在脓毒症心肌细胞功能障碍中的作用。我们将采用IL-8调制的组合 在血清和HiPSC-CMS中的IL-8受体(CXCR1和CXCR2)敲除中，为IL-8提供证据 阻滞剂作为SAMD的潜在治疗靶点。这份职业发展建议将建立在我的 心肌功能障碍的翻译研究背景以获得心肌细胞的新专业知识 功能分析、hiPSC的生成和分化以及下一代RNA测序技术 作为一名专注于阐明和确定目标的内科科学家，促进我向独立的过渡 儿童SAMD的发病机制。