Role of PAR-1 and PAR-2 in Cardiac Remodeling

PAR-1 和 PAR-2 在心脏重构中的作用

• 批准号: 7666964
• 负责人: Nigel Mackman
• 金额: $ 37.09万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7666964
• 关键词: Binding; Blood Coagulation Factor; Calcineurin; Calcineurin Pathway; Cardiac; Cardiac Myocytes; Coagulation Process; Development; Dominant-Negative Mutation; Endothelial Cells; Endothelium; Extravasation; Fibroblasts; Fibrosis; Figs - dietary; Generations; Goals; Heart; Heart Diseases; Heart Hypertrophy; Human; Hypertrophy; In Vitro; Ischemia; Lead; Left ventricular structure; Mediating; Modeling; Morbidity - disease rate; Mus; Myocardial Infarction; Myocardium; PAR-1 Receptor; PAR-2 Receptor; Pathway interactions; Peptide Hydrolases; Permeability; Plasma; Proteinase-Activated Receptors; Relative (related person); Reperfusion Injury; Reperfusion Therapy; Research Personnel; Role; Signal Pathway; Thrombin; Thromboplastin; Western World; base; in vivo; inhibitor/antagonist; mortality; novel; overexpression; programs; recombinase; research study

DESCRIPTION (provided by applicant): Heart disease resulting from pathological cardiac remodeling and hypertrophy is a leading cause of morbidity and mortality in the western world. Protease activated receptors (PARs) are expressed in cardiomyocytes and cardiac fibroblasts. However, their role in cardiac remodeling has not been studied in vivo. Importantly, we demonstrated that PAR-1-/- mice have reduced cardiac remodeling and left ventricle dilation at 2 weeks compared with wild type littermates in a cardiac ischemia-reperfusion (I/R) injury model. Furthermore, we showed that cardiomyocyte-specific overexpression of either PAR-1 or PAR-2 induced cardiac hypertrophy in mice. In addition, we found that PAR-1 and PAR-2 expression was increased in hearts from humans and mice with cardiac hypertrophy. Finally, in vitro studies showed that the activation of PAR-1 or PAR-2 on cardiomyocytes induced hypertrophy. Based on these results, we hypothesize that both PAR-1 and PAR-2 on cardiomyocytes and cardiac fibroblasts contribute to cardiac remodeling after I/R injury. The proposal has two Specific Aims. Specific Aim 1 will determine the role of PAR-1 and PAR-2 in cardiac remodeling after I/R injury. For these experiments, we will use both PAR-1-/- and PAR-2-/- mice, as well as PAR-1 and PAR-2 specific inhibitors. PAR-1flox/flox mice will be generated and crossed with mice expressing the Cre recombinase in either cardiomyocytes or cardiac fibroblasts. These mice will be used to determine the relative contribution of PAR-1 expressed on cardiomyocytes compared with cardiac fibroblasts to cardiac remodeling. Specific Aim 2 will evaluate the role of the MEK5-ERK5, MEK1-ERK1/2 and calcineurin signaling pathways in PAR-1- and PAR-2-dependent hypertrophy of cultured cardiomyocytes by inhibiting these pathways with pharmacologic inhibitors and dominant negative mutants. In addition, we will characterize the different signaling pathways that mediate hypertrophy in the hearts of mice overexpressing either PAR-1 or PAR-2 on cardiomyocytes. These studies will elucidate the role of PAR-1 and PAR-2 in cardiac remodeling after I/R injury and will determine the mechanism by which PAR-1 or PAR-2 activation induces cardiac hypertrophy. The results may lead to the development of PAR-1 and PAR-2 inhibitors that may be used as novel therapies for the treatment of pathological cardiac remodeling and hypertrophy in humans.

描述（由申请人提供）：病理心脏重塑和肥大引起的心脏病是西方世界发病和死亡率的主要原因。蛋白酶活化受体（PAR）在心肌细胞和心脏成纤维细胞中表达。但是，它们在心脏重塑中的作用尚未在体内研究。重要的是，我们证明了PAR-1 - / - 小鼠的心脏重塑降低，并且与心脏缺血性灌注（I/R）损伤模型中的野生型同窝仔相比，在2周时左心室扩张。此外，我们表明了小鼠PAR​​-1或PAR-2诱导心脏肥大的心肌细胞特异性过表达。此外，我们发现患有心脏肥大的人的心脏和小鼠的心脏中有PAR-1和PAR-2的表达增加。最后，体外研究表明，在心肌细胞诱导肥大上PAR-1或PAR-2的激活。基于这些结果，我们假设在心肌细胞和心脏成纤维细胞上的PAR-1和PAR-2都在I/R损伤后有助于心脏重塑。该提案有两个具体的目标。具体目标1将确定I/R损伤后PAR-1和PAR-2在心脏重塑中的作用。对于这些实验，我们将同时使用PAR-1 - / - 和PAR-2 - / - 小鼠，以及PAR-1和PAR-2特异性抑制剂。 PAR-1FLOX/FLOX小鼠将与表达CRE重组酶或心肌细胞或心脏成纤维细胞中的CRE重组酶交叉。这些小鼠将用于确定与心脏成纤维细胞对心脏重塑相比，对心肌细胞表达的PAR-1的相对贡献。具体目标2将通过用药理抑制剂和显性阴性突变体抑制这些途径，评估MEK5-ERK5，MEK1-ERK1/2和钙调神经蛋白信号通路的作用。此外，我们将表征在心肌细胞上过表达PAR-1或PAR-2的小鼠心脏中介导肥大的不同信号通路。这些研究将阐明I/R损伤后PAR-1和PAR-2在心脏重塑中的作用，并确定PAR-1或PAR-2激活诱导心脏肥大的机制。结果可能会导致PAR-1和PAR-2抑制剂的发展，这些抑制剂可能被用作治疗人类病理心脏重塑和肥大的新型疗法。