Calcium Regulation in Heart Failure with Preserved versus Reduced Ejection Fraction

保留射血分数与降低射血分数的心力衰竭中的钙调节

• 批准号: 10161855
• 负责人: Eugenio Cingolani
• 金额: $ 74.88万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10161855
• 关键词: Action Potentials; Adrenergic Agents; Animals; Arrhythmia; Binding; Biological Assay; Calcium; Cardiac; Cardiac Myocytes; Cardiology; Cell physiology; Cells; Characteristics; Clinic; Clinical; Competence; Connexins; Coronary; Coupling; Dahl Hypertensive Rats; Data; Defect; Development; Diastole; Disease; EFRAC; Electrophysiology (science); Excision; Exhibits; Failure; Fibrosis; Functional disorder; Future; Gene Expression; Generations; Goals; Heart; Heart Abnormalities; Heart Atrium; Heart failure; Human; Hypertension; Image; Incidence; Individual; Infarction; Investigation; Ion Channel; Ligation; Microfilaments; Modeling; Muscle Cells; Myocarditis; Optics; Pacemakers; Pathologic; Patients; Phase; Phenotype; Phosphoric Monoester Hydrolases; Phosphotransferases; Play; Post-Translational Protein Processing; Property; Proteomics; Publishing; Pump; Rattus; Regulation; Relaxation; Reporting; Resolution; Rest; Role; Ryanodine Receptors; Sarcoplasmic Reticulum; Shotguns; Sinoatrial Node; Sinus; Skin; Sodium; Sprague-Dawley Rats; Stress; Symptoms; Techniques; Testing; Therapeutic; Tissues; Treatment Failure; Ventricular; Ventricular Arrhythmia; base; cellular targeting; chronotropic; confocal imaging; coronary fibrosis; effective therapy; heart function; hemodynamics; improved; innovation; mortality; next generation; novel; patch clamp; preservation; response; reuptake; sudden cardiac death; targeted treatment; transcriptome sequencing; uptake; voltage

PROJECT SUMMARY/ABSTRACT Despite the fact that Heart Failure with Preserved Ejection Fraction (HFpEF) accounts for >50% of HF in the U.S., there are no effective therapies for this disease, in contrast to HF with Reduced Ejection Fraction (HFrEF). Similarly, while studies of Ca regulation and excitation-contraction (EC) coupling in HFrEF have led to important therapies to improve contractile function and reduce arrhythmia, the same cannot be said for HFpEF. The lack of fundamental understanding of Ca regulation in HFpEF is a major impediment to the development of rational and effective therapies for this disease in humans. We propose to use the Dahl Salt-sensitive (DS) rat model of hypertension-induced HFpEF, which exhibits the major hemodynamic and clinical features of human HFpEF, to identify and investigate distinctive features of cellular Ca regulation, EC coupling and myofilament Ca response, which influence contractility, diastolic relaxation and rhythm. Results will be compared with a complementary rat model of post-infarction HFrEF. Our goal is to test the overall hypothesis that abnormalities in Ca regulation, not previously demonstrated in a phenotypically-verified HFpEF rat model, are not only distinct from HFrEF but also collectively contribute to the hemodynamic and electrophysiological abnormalities that characterize HFpEF. We have three aims: Aim 1: EC Coupling & Contractility in HFpEF vs HFrEF: In this aim, we will use patch clamp and simultaneous confocal imaging of Ca dynamics to test the hypothesis that Ca-induced Ca release (CICR) is markedly enhanced in HFpEF by changes in the activity of specific Ca-regulating ion channels and transporters residing in the cardiac couplon, including Ca and Na channels, sodium-calcium exchange (NCX) and ryanodine receptors. Aim 2: Diastolic Calcium & Ventricular Relaxation in HFpEF vs HFrEF: We will test the overall hypothesis that the key abnormality of diastolic Ca regulation in HFpEF, i.e. defective SR Ca reuptake and NCX Ca efflux, is only apparent upon β-adrenergic stimulation, whereas Ca uptake is abnormal at rest in HFrEF. We will use live confocal imaging to dissect the role of Ca uptake mechanisms (e.g. SERCA) and extrusion (e.g. NCX) in the declining phase of the Ca transient, and assess the effects of posttranslational modifications identified by our proteomics screen. Myofilament assays will reveal the extent whereby changes in Ca binding properties and force generation versus passive stiffness contribute to abnormal relaxation. Aim 3: Disturbances of Atrial & Ventricular Rhythm in HFpEF vs HFrEF: Using implantable telemeters, whole heart dual voltage and calcium mapping, and single sinoatrial node (SAN) cell patch clamp, we will test the hypothesis that abnormal Ca regulation plays a critical role in chronotropic incompetence and arrhythmia in HFpEF. We will focus our studies on the role of altered SAN gene expression indicated by next generation RNA sequencing. In conclusion, this project will provide an advanced understanding of the differences between Ca regulation in HFpEF and HFrEF that may generate novel HFpEF therapies based on that entity’s unique cellular physiology.

项目总结/摘要 尽管射血分数保留性心力衰竭（HFpEF）占HF的>50%， 美国，与射血分数降低的HF（HFrEF）相反，对于这种疾病没有有效的治疗方法。 类似地，虽然HFrEF中的Ca调节和兴奋-收缩（EC）偶联的研究已经导致了重要的 然而，尽管HFpEF治疗可以改善收缩功能和减少心律失常，但HFpEF不能这样说。缺乏 对HFpEF中钙调节的基本理解是发展合理的 和有效的治疗方法。我们建议使用Dahl盐敏感（DS）大鼠模型， 高血压诱导的HFpEF表现出人类HFpEF的主要血流动力学和临床特征， 识别和研究细胞Ca调节、EC偶联和肌丝Ca反应的独特特征， 其影响收缩性、舒张性松弛和节律。结果将与补充大鼠进行比较 梗死后HFrEF模型。我们的目标是检验总体假设，即钙调节异常， 先前在表型验证的HFpEF大鼠模型中证实，不仅与HFrEF不同，而且 共同导致表征HFpEF的血液动力学和电生理学异常。我们 我们有三个目的：目的1：HFpEF与HFrEF的EC偶联和收缩：在这个目的中，我们将使用膜片钳 和钙动力学的同步共聚焦成像，以检验钙诱导的钙释放（CICR）是 在HFpEF中通过特异性钙调节离子通道和转运蛋白活性的变化而显著增强 存在于心脏耦合子中，包括Ca和Na通道、钠钙交换（NCX）和兰尼定 受体。目的2：HFpEF与HFrEF的舒张期钙和心室舒张：我们将测试总体 假设HFpEF中舒张期Ca调节的关键异常，即SR Ca再摄取缺陷和NCX Ca流出仅在β-肾上腺素能刺激时明显，而HFrEF中静息时Ca摄取异常。我们 将使用实时共聚焦成像来剖析Ca摄取机制（例如SERCA）和挤出（例如， NCX）在钙瞬变下降阶段，并评估翻译后修饰的影响 通过我们的蛋白质组学筛选鉴定。肌丝测定将揭示钙结合变化的程度， 性能和力产生与被动刚度的关系导致异常松弛。目标3：干扰 HFpEF与HFrEF的心房和心室节律：使用植入式遥测仪，全心脏双电压 和钙映射，和单窦房结（SAN）细胞膜片钳，我们将测试的假设， 钙调节异常在HFpEF的变时性功能不全和心律失常中起关键作用。我们将 将我们的研究集中在下一代RNA测序所表明的SAN基因表达改变的作用上。在 结论，本项目将提供一个先进的理解钙调节之间的差异， HFpEF和HFrEF可以基于该实体独特的细胞生理学产生新的HFpEF疗法。