Protective Effects of Anti-C5a in Sepsis

抗 C5a 对脓毒症的保护作用

• 批准号: 7982444
• 负责人: Peter A Ward
• 金额: $ 31.1万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7982444
• 关键词: Action Potentials; Affect; Anaphylatoxins; Animals; Antibodies; Appearance; C5a anaphylatoxin receptor; Calcium; Cardiac; Cardiac Myocytes; Cardiac Output; Cardiomyopathies; Cardiovascular system; Characteristics; Clinical; Complement 5a; Complication; Coupling; Data; Defect; Development; Dose; Echocardiography; Exposure to; FDA approved; Failure; Functional disorder; Generic Drugs; Heart; Heart failure; Human; In Vitro; Individual; Interleukin-12; Interleukin-17; Interleukin-6; Intervention; Knockout Mice; Ligation; Literature; Location; Measures; Mediator of activation protein; Molecular; Mus; Muscle Cells; North America; Organ failure; Pathogenesis; Patients; Performance; Peripheral Resistance; Plasma; Puncture procedure; Rodent; Role; Sepsis; Septic Shock; Signal Pathway; Stroke Volume; Time; Ventricular; base; chemokine; cytokine; in vivo; mortality; mouse model; neutralizing antibody; protective effect; public health relevance; receptor; receptor upregulation; response; septic; statistics

DESCRIPTION (provided by applicant): We will continue our studies to define molecular mechanisms related to development of septic cardiomyopathy in rodents after cecal ligation and puncture (CLP), with an emphasis on the roles of C5a anaphylatoxin and its receptors, C5aR and C5L2. Aim 1 will define the requirements for C3, C5, C5a receptors (C5aR, C5L2) and IL-17 for spontaneous release of cardiosuppressive cytokines (IL-12, TNF1, IL-6) from sham and CLP cardiomyocytes (CMs). These data will be compared to the presence of cytokines in heart homogenates and plasma from CLP mice. Aim 2 will determine the time course after CLP for upregulation of receptors for C5a and the cardiosuppressive cytokines (IL-12, TNF1 and IL-6) on CMs. Aim 3 will assess electrophysiological responses (action potentials, Ca2+ transients, and K+ and Ca2+ currents) as well as functional responses (by measuring intracellular calcium transients and myocyte contraction) in CMs obtained from sham and CLP rodents as a function of time after CLP. In addition, sham and CLP CMs will be studied for changes in electrophysiological and contractile responses after in vitro exposure to C5a in an effort to define molecular mechanisms by which C5a causes contractile dysfunction in CMs. Aim 4 will assess the ability of C5a to induce changes in CMs (as described in Aim 3), using sham and CLP CMs to which varying concentrations of C5a or cardiosuppressive cytokines, or both, have been added. We will determine if there is a synergy in development of electrophysiological dysfunction with combination of C5a and cardiosuppressive cytokines. Aim 5 will employ non-invasive echocardiography approaches to assess systolic and diastolic function and systemic vascular resistance, as well as other parameters, in CLP mice as compared to sham mice. We will attempt to define the roles of C3, C5, C5a and IL-17 receptors in CM dysfunction. These studies will also feature CLP mice that have been treated with neutralizing antibodies to C5a or IL-17. A C5aR knockout mouse model will also be utilized to define the role of the C5a signaling pathways in the pathogenesis of septic cardiomyopathy. Collectively, these studies should define the roles of C5a and its receptors as well as cardiosuppressive cytokines in the development of septic cardiomyopathy and how this complication can be averted or treated. PUBLIC HEALTH RELEVANCE: Sepsis continues to be a daunting problem in humans with a single FDA approved intervention. Depending on location and clinical details, the mortality rate may be as high as 50-60%, an especially alarming statistic in view of 600,000 or more patients with sepsis in North America each year. It is clear that we have incomplete understanding of sepsis. Until this obstacle is resolved through an understanding of the molecular determinants of sepsis, treatment will be supportive and extremely costly.

描述（由申请人提供）：我们将继续研究，以定义与盲肠结扎和穿刺后啮齿动物的发育相关的分子机制（CLP），重点是C5A过敏毒素及其受体C5AR和C5L2的作用。 AIM 1将定义C3，C5，C5A受体（C5AR，C5L2）和IL-17的需求，以自发释放来自Sham和Clp Cardiomyocytes（CMS）的心脏抑制细胞因子（IL-12，TNF1，IL-6）。这些数据将与CLP小鼠的心脏匀浆和血浆中的细胞因子的存在进行比较。 AIM 2将确定CLP上C5A和CMM中C5A受体（IL-12，TNF1和IL-6）受体上调的时间过程。 AIM 3将评估电生理反应（动作电位，Ca2+瞬变，K+和Ca2+电流）以及在CLP啮齿动物中获得的CMS中的CMS中的功能反应（通过测量细胞内钙瞬变和肌细胞收缩）作为CLP后时间的函数。此外，在体外暴露于C5A后，将研究假和CLP CM的电生理和收缩反应的变化，以定义C5A在CMS中引起收缩功能障碍的分子机制。 AIM 4将使用SHAM和CLP CMS评估C5A诱导CMS变化的能力（如AIM 3中所述），并添加了不同浓度的C5A或心脏抑制细胞因子或两者兼而有之。我们将确定电生理功能障碍与C5A和心脏抑制细胞因子的结合是否存在协同作用。与假小鼠相比，AIM 5将采用非侵入性超声心动图方法评估CLP小鼠的收缩和舒张功能以及全身血管抗性以及其他参数。我们将尝试定义C3，C5，C5A和IL-17受体在CM功能障碍中的作用。这些研究还将以中和C5A或IL-17进行中和抗体治疗的CLP小鼠。 C5AR敲除小鼠模型也将用于定义C5A信号通路在化粪池心肌病的发病机理中的作用。总的来说，这些研究应定义C5A及其受体的作用以及心脏抑制性细胞因子在败血性心肌病的发展中以及如何避免或治疗这种并发症。 公共卫生相关性：在单一FDA批准的干预措施的人类中，败血症仍然是一个艰巨的问题。根据位置和临床细节，死亡率可能高达50-60％，鉴于每年有600,000名或更多的败血症患者，这是一个特别令人震惊的统计数据。显然，我们对败血症没有完全理解。在理解败血症的分子决定因素之前，在解决这一障碍之前，治疗将是支持和昂贵的。