Substance P: A central mediator of cardiac fibrosis and diastolic dysfunction

P物质：心脏纤维化和舒张功能障碍的中心介质

• 批准号: 9324421
• 负责人: Scott P Levick
• 金额: $ 38.5万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9324421
• 关键词: Adverse effects; Amino Acids; Angiotensin II; Belief; Biological Process; Bone Marrow; Cardiac; Cell Adhesion; Cells; Chronic; Coronary; Coronary artery; Data; Development; Dissection; EFRAC; Endothelial Cells; Endothelin-1; Extracellular Matrix; Failure; Fibroblasts; Fibrosis; Functional disorder; Future; Genes; Goals; Heart; Heart Rate; Heart failure; In Vitro; Left; Length; MMP14 gene; Mediating; Mediator of activation protein; Molecular; Mus; Myocardial; Myofibroblast; Nerve; Neuropeptides; Nociception; Pathway interactions; Phenotype; Physiological; Population; Process; Protein Isoforms; Receptor Activation; Regulation; Role; Secondary to; Signal Transduction; Small Interfering RNA; Stream; Stress; Subfamily lentivirinae; Substance P; Substance P Receptor; TNF gene; Tail; Testing; Therapeutic; Tryptase; Up-Regulation; Vasodilation; adverse outcome; afferent nerve; cell type; coronary fibrosis; gene therapy; hemodynamics; in vivo; innovation; interest; knock-down; mast cell; novel; pressure; receptor; reconstitution; response; therapeutic target; treatment strategy

We recently demonstrated that the sensory nerve neuropeptide substance P (SP) is required for the development of cardiac fibrosis in response to elevations in myocardial stress, specifically pressure overload (PO). Due to its localization to sensory nerves projecting to coronary arteries, SP is likely one of the first mediators released in response to changes in coronary pressure/flow. This places SP up-stream of multiple pro-fibrotic cascades, and we have identified several cell-specific effects initiated by SP in response to PO. Therefore, targeting SP holds real therapeutic potential, however, dissection of these cell-specific pathways is firstly required. What makes SP an even more attractive therapeutic target is the existence of two isoforms of its receptor, the neurokinin-1 receptor (NK-1R). We believe that the full length NK-1R mediates the physiological actions of SP, while the truncated isoform mediates the pro-fibrotic effects. Thus, it may be possible to selectively target the adverse effects of SP, while leaving the physiological actions intact. This proposal will examine the role of these NK-1R isoforms in mediating the cell-specific actions of SP on two cell types involved in cardiac fibrosis; the cardiac fibroblast and the mast cell. Our overall hypothesis is that SP acts via the truncated NK-1R to modulate cell-specific molecular pathways to promote cardiac fibrosis and diastolic dysfunction. Specific aim 1 will examine the synergistic actions of SP and endothelin-1 on cardiac fibroblast phenotype and function. This includes investigating truncated NK-1R activation of the membrane type 1 matrix metalloproteinase/TGF-β1 pathway in vitro. Myofibroblast-specific NK-1R-/- mice will be used to examine the role of myofibroblast-specific NK-1Rs in vivo under conditions of PO. Specific aim 2 will identify the importance of mast cell-specific NK-1Rs in mediating the release of mast cell-derived pro-fibrotic molecules including tryptase and TNF-α. Reconstitution of mast cell-deficient mice with bone marrow-derived mast cells from NK-1R-/- mice will help determine the significance of the NK-1R in vivo under conditions of PO. Lentivirus transduction of mast cells will be used to elucidate molecular pathways activated by the truncated NK-1R in mast cells. This proposal is significant and innovative because it will establish a neuropeptide as a mediator of cardiac fibrosis and diastolic dysfunction, as well as identifying cell-specific mechanisms by which SP promotes fibrosis. Of high significance is the existence of the two NK-1R isoforms, of which we believe the truncated isoform mediates the pro-fibrotic actions of SP. Thus, this proposal will identify a unique, actionable therapeutic target for diastolic dysfunction since antagonists or gene therapy approaches specific to the truncated NK-1R could be developed.

我们最近证实，感觉神经神经肽P物质(SP)是 心肌应激升高，特别是压力超负荷时的心肌纤维化进展 (PO)。由于其定位于投射到冠状动脉的感觉神经，SP可能是最早的 根据冠脉压力/流量的变化而释放介质。这将SP置于多个 促肝纤维化的级联反应，我们已经确定了SP对PO的反应启动的几种细胞特异性效应。 因此，靶向SP具有真正的治疗潜力，然而，对这些细胞特异性通路的剖析是 首先是必需的。使SP成为更具吸引力的治疗靶点的原因是存在两种亚型的 它的受体是神经激肽-1受体(NK-1R)。我们认为，全长NK-1R介导了 SP的生理作用，而截断的异构体则介导促纤维化作用。因此，它可能是 有可能选择性地针对SP的不利影响，同时保持生理作用不变。这 提案将研究这些NK-1R亚型在介导SP对两个细胞的细胞特异性作用中的作用 参与心肌纤维化的类型；心脏成纤维细胞和肥大细胞。我们的总体假设是SP 通过截短的NK-1R调节细胞特异性分子通路促进心肌纤维化和 舒张期功能障碍。特定目标1将研究SP和内皮素-1在心脏中的协同作用 成纤维细胞的表型和功能。这包括研究被截断的膜NK-1R活性 I型基质金属蛋白酶/转化生长因子-β-1途径的体外研究肌成纤维细胞特异性NK-1R-/-小鼠将用于 在PO条件下检测肌成纤维细胞特异性NK-1Rs在体内的作用。具体目标2将确定 肥大细胞特异性NK-1Rs在介导肥大细胞源性促纤维化分子释放中的重要性 包括类胰蛋白酶和肿瘤坏死因子-α。应用骨髓源性肥大细胞重建肥大细胞缺陷小鼠 从NK-1R-/-小鼠体内提取的NK-1R将有助于确定在PO条件下体内NK-1R的意义。慢病毒 肥大细胞的转导将用于阐明截短的NK-1R激活的分子通路。 肥大细胞。这项提议具有重大意义和创新性，因为它将建立一种神经肽作为一种 心肌纤维化和舒张期功能障碍，以及识别细胞特异性机制 促进纤维化。具有重要意义的是两种NK-1R亚型的存在，我们认为 截短的异构体介导SP的促纤维化作用。因此，这项提案将确定一个独特的、可操作的 舒张期功能障碍的治疗靶点，因为拮抗剂或基因治疗方法针对 截短型NK-1R可以被开发出来。