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.

项目概要/摘要 标题：小儿感染性休克心肌细胞功能障碍的机制 尽管对儿科脓毒症进行了数十年的研究，但患有脓毒症的儿童死亡率仍约为 25% 败血性休克。脓毒症相关心肌功能障碍 (SAMD) 在儿童中很常见，并且与 死亡率不仅仅是疾病严重程度的反映。由于不存在缓解疾病的疗法 SAMD，迫切需要了解脓毒症心肌细胞功能障碍的生物学基础。 此外，由于无法利用患者来源的材料建立新型人体模型 将败血症小鼠模型中的分子发现转化为改善人体器官损伤。我们的 目标是建立人类诱导多能干细胞 (hiPSC) 衍生的心肌细胞 (hiPSC-CM) 作为小儿脓毒症心肌细胞功能障碍的模型并检查宿主遗传的作用 SAMD发病机制中的背景和血清因素。我们建立在我们庞大而成熟的基础上 脓毒症儿童血清生物库，用于研究心肌细胞对脓毒症血清的反应 患有和未患有 SAMD 的儿童。我们发现 hiPSC-CM 的收缩力受到抑制 是通过患有 SAMD 的儿童储存的血清进行的，而不是通过来自没有 SAMD 的儿童的对照脓毒症血清进行的。这 去除血清后，抑制作用是可逆的，表明这并不反映细胞死亡。 此外，我们发现脓毒症儿童中白细胞介素 8 (IL-8) 与 SAMD 存在显着相关性。 休克并发现重组人 IL-8 抑制 hiPSC-CM 收缩性。我们的提案将解决 作为具体目标的三个重要问题：首先，我们将确定 hiPSC-CM 和心肌细胞是否 来自相同孩子的人在以下情况下具有共同的功能和转录反应模式： 暴露于储存的脓毒症血清。我们将提供 hiPSC-CM 与离体的全面比较 通过从接受心脏手术的儿童废弃的手术组织中分离心肌细胞来制备心肌细胞 手术并从这些相同的患者身上产生 hiPSC-CM。其次，我们将确定程度 其宿主遗传背景导致 SAMD 心肌细胞功能障碍。我们将开发 hiPSC- 来自患有和不患有 SAMD 的儿科患者的 CM 可以确定对脓毒症血清的反应，从而识别模式 与 SAMD 易感性相关的功能和转录反应。第三，我们要剖析 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 hiPSC-CM 中血清和 IL-8 受体（CXCR1 和 CXCR2）敲除，为 IL-8 提供证据 阻断作为 SAMD 的潜在治疗靶点。这个职业发展建议将建立在我的基础上 心肌功能障碍转化研究背景，以获得心肌细胞方面的新专业知识 功能分析、hiPSC 生成和分化以及下一代 RNA 测序技术 促进我作为一名专注于阐明和瞄准目标的医师科学家向独立过渡 儿科 SAMD 的机制。