Protective Effects of Anti-C5a in Sepsis

抗 C5a 对脓毒症的保护作用

• 批准号: 8126439
• 负责人: Peter A Ward
• 金额: $ 30.94万
• 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/8126439
• 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; TNF gene; 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）：我们将继续研究以确定啮齿类动物盲肠结扎穿刺（CLP）后发生败血性心肌病相关的分子机制，重点是 C5a 过敏毒素及其受体 C5aR 和 C5L2 的作用。目标 1 将定义假手术和 CLP 心肌细胞 (CM) 自发释放心脏抑制细胞因子（IL-12、TNF1、IL-6）对 C3、C5、C5a 受体（C5aR、C5L2）和 IL-17 的要求。这些数据将与 CLP 小鼠心脏匀浆和血浆中细胞因子的存在进行比较。目标 2 将确定 CLP 后 CM 上 C5a 受体和心脏抑制细胞因子（IL-12、TNF1 和 IL-6）上调的时程。目标 3 将评估从假手术和 CLP 啮齿动物获得的 CM 中的电生理反应（动作电位、Ca2+ 瞬变以及 K+ 和 Ca2+ 电流）以及功能反应（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，还将研究假手术和 CLP CM 体外暴露于 C5a 后电生理和收缩反应的变化，以明确 C5a 导致 CM 收缩功能障碍的分子机制。目标 4 将使用添加了不同浓度的 C5a 或心脏抑制细胞因子或两者的假手术和 CLP CM 来评估 C5a 诱导 CM 变化的能力（如目标 3 中所述）。我们将确定 C5a 和心脏抑制细胞因子的组合在电生理功能障碍的发展中是否存在协同作用。目标 5 将采用非侵入性超声心动图方法来评估 CLP 小鼠与假手术小鼠的收缩和舒张功能、全身血管阻力以及其他参数。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。这些研究还将采用 C5a 或 IL-17 中和抗体治疗的 CLP 小鼠。 C5aR 敲除小鼠模型也将用于确定 C5a 信号通路在脓毒症心肌病发病机制中的作用。总的来说，这些研究应该明确 C5a 及其受体以及心脏抑制细胞因子在脓毒症心肌病发展中的作用，以及如何避免或治疗这种并发症。 公共卫生相关性：通过 FDA 批准的单一干预措施，脓毒症仍然是人类面临的一个令人畏惧的问题。根据地点和临床细节，死亡率可能高达 50-60%，鉴于北美每年有 600,000 名或更多脓毒症患者，这一统计数字尤其令人震惊。很明显，我们对脓毒症的了解并不完整。在通过了解脓毒症的分子决定因素解决这一障碍之前，治疗将是支持性的且极其昂贵。