Investigating the role of the complement system in cardiac regeneration

研究补体系统在心脏再生中的作用

• 批准号: 10093224
• 负责人: Niranjana Natarajan
• 金额: $ 6.74万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10093224
• 关键词: Acute; Address; Adult; Agonist; Ambystoma; Animal Model; Apical; Birth; C5a anaphylatoxin receptor; Cardiac; Cardiac Myocytes; Cell Proliferation; Cell division; Cicatrix; Complement; Complement 3a; Complement 5a; Complement Activation; Complement Receptor; Complement component C5; Data; Dominant-Negative Mutation; Embryo; Endothelial Cells; Event; Excision; Exhibits; Fibrosis; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits, Gs; Gene Transfer; Genes; Genetic; Heart; Heart Diseases; Heart Injuries; Heart failure; Hour; IL6 gene; Immune response; Impairment; Inflammatory; Inflammatory Response; Injury; Innate Immune System; Knockout Mice; Laboratories; Lead; Life; Limb structure; Liver; Lymphoid Cell; Mammals; Mediating; Modeling; Molecular; Mouse Cell Line; Mus; Myocardial Infarction; Myocardium; Natural regeneration; Neonatal; Newts; Pathway interactions; Peptides; Pharmacology; Receptor Signaling; Reperfusion Injury; Resources; Retina; Role; Signal Transduction; Testing; Thrombin; Tissues; United States; Up-Regulation; Zebrafish; cardiac regeneration; complement system; deep sequencing; experimental study; immune system function; mortality; mouse model; receptor; receptor expression; receptor function; regenerative; repaired; response; tool; transcriptome sequencing; transcriptomics

Project summary: The mammalian heart has a limited regenerative potential due to the low proliferation rate of adult cardiomyocytes. However, a narrow regenerative window has been identified in the neonatal murine heart, wherein mice are able to successfully regenerate their hearts both at the tissue and functional level following injury. In a cross-species transcriptomic screen in the Lee laboratory, inflammatory response genes including complement receptors were upregulated in a conserved manner in the regenerating heart of three model organisms – axolotl, mouse and zebrafish. The most-upregulated inflammatory response genes include G-protein coupled receptors (GPCR) for complement components, complement 5a receptor (C5aR1) and complement 3a receptor (C3aR). The complement system is part of the innate immune system and functions to clear foreign material. Activation of an early immune response is a shared feature observed in the regenerating heart of model organisms, consistent with the upregulation of C5aR1 and C3aR observed. C5aR1 is a GPCR that functions as a complement receptor for C5a, generated by proteolytic cleavage of complement component 5. Pharmacologic inhibition of C5aR1 after apical resection results in an impaired cardiomyocyte proliferative response in all three model organisms studied – axolotl, mouse and zebrafish. I propose to investigate the role of complement activation in murine cardiac regeneration, to elucidate the molecular mechanisms that initiate effective repair and cardiomyocyte proliferation in the mammalian heart following injury. To understand the role of C5aR1, I will utilize global genetic deletion mouse model of C5aR1 to assess cardiac regeneration after apical resection at the cellular, tissue and functional level in C5aR1 wild-type and C5aR1 knock-out mice. I propose to assess cardiomyocyte proliferation in C5aR1 wild-type and knock-out mice to understand the sequence of molecular events in the injured heart that initiate cardiomyocyte proliferation and effective regeneration. Furthermore, I will investigate the role of C3aR in early cardiac regeneration using pharmacologic inhibition and C3aR knock-out mice. In addition, I will perform experiments in non-regenerative murine models (7- day-old mice) to investigate if acute activation of complement signaling (C3 and C5) will increase cardiomyocyte proliferation following injury. These studies will likely define a mechanistic pathway of early events critical for the initiation of cardiomyocyte proliferation in the myocardium.

项目摘要： 由于成人的增殖率低，哺乳动物心脏的再生潜力有限 心肌细胞。但是，在新生儿鼠心脏中发现了一个狭窄的再生窗口， 其中小鼠能够在组织和功能水平上成功再生其心脏 受伤后。在Lee实验室的跨物种转录组屏幕中，炎症反应 包括补体受体在内的基因以构成的方式更新 三种模型生物 - axolotl，小鼠和斑马鱼。最新的炎症反应 基因包括用于完成组件的G蛋白偶联受体（GPCR），补充5A受体 （C5AR1）和补体3A受体（C3AR）。完成系统是先天免疫的一部​​分 系统和功能清除异物。早期免疫反应的激活是共同的特征 在模型生物的再生心脏中观察到，与C5AR1和 观察到C3AR。 C5AR1是GPCR，可作为C5A的补体受体，由 完成成分的蛋白水解切割5。根尖切除后C5AR1的药理抑制作用 导致在所有三种模型生物体中的心肌细胞增殖物反应受损 - axolotl， 鼠标和斑马鱼。我建议研究完成激活在鼠心脏中的作用 再生，以阐明启动有效修复和心肌细胞的分子机制 受伤后哺乳动物心脏的增殖。要了解C5AR1的作用，我将利用全球 C5AR1的遗传缺失小鼠模型，以评估细胞上根尖切除后心脏再生， C5AR1野生型和C5AR1敲除小鼠的组织和功能水平。我建议评估 C5AR1野生型和敲除小鼠的心肌细胞增殖，以了解 受伤的心脏中的分子事件引发心肌细胞增殖和有效再生。 此外，我将使用药物抑制作用研究C3AR在早期心脏再生中的作用 和C3AR淘汰小鼠。此外，我将在非再生鼠模型中进行实验（7- 日益小鼠）研究完成信号的急性激活（C3和C5）是否会增加 受伤后心肌细胞增殖。这些研究可能会定义早期的机械途径 心肌中心肌细胞增殖至关重要的事件。