Molecular Mechanisms of Myofilament Dysfunction in Heart Failure

心力衰竭肌丝功能障碍的分子机制

• 批准号: 7919147
• 负责人: Pieter P. de TOMBE
• 金额: $ 38.8万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7919147
• 关键词: Action Potentials; Area; Automobile Driving; Award; Biochemical; Calcium; Cardiac; Cardiac Myocytes; Cavia; Cell physiology; Cells; Characteristics; Chemicals; Collaborations; Complement; Congestive Heart Failure; Contractile Proteins; Controlled Study; Coupling; Data; Defect; Depressed mood; Development; Elements; Endocardium; Epicardium; Functional disorder; Gene Delivery; Generations; Goals; Harvest; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Homeostasis; Human; Hypertrophy; Kinetics; Lead; Left; Link; Measures; Mechanics; Metabolism; Microfilaments; Modeling; Modification; Molecular; Morphology; Muscle; Myocardium; Myofibrils; Myosin Light Chains; Paper; Pathway interactions; Patients; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Post-Translational Protein Processing; Preparation; Production; Protein Kinase; Proteins; Proteomics; Recombinant Proteins; Regulation; Relaxation; Research; Right ventricular structure; Sampling; Sarcomeres; Secondary to; Signal Pathway; Site; Staging; Structure; Structure-Activity Relationship; Techniques; Testing; Time; Troponin; Troponin T; Variant; Ventricular Dysfunction; Work; base; combat; design; hemodynamics; mortality; myosin-binding protein C; novel; novel therapeutics; pressure; programs; reconstitution; research study

Congestive heart failure (CHF) is associated with an abnormality in cardiac cell function. The molecular mechanisms that underlie this depressed function in CHF are unknown. In previous work we have shown that myofilament function is depressed in CHF in terms of depressed maximum force generating capacity, calcium responsiveness, and cross-bridge cycle kinetics. Experimental mechanical/biochemical data suggest that dys-regulated myofilament contractile protein phosphorylation causes myofilament dysfunction in CHF, possibly via altered phosphorylation of myosin light chain (MLC), myosin binding protein C (MyoBPC), and Troponin-l (Tnl). However, the precise structure-function relationship has not been determined. In this proposal for continued support we will employ a well-established model of CHF in the guinea-pig secondary to pressure overload. The guinea-pig model allows study of control, compensatory hypertrophy, and CHF in a model that closely resembles the myofilament and EC-coupling parameters as found in the human. Biochemical proteomics analysis will be used to identify pathways and proteins that are targeted in CHF and the impact of identified post-translational modifications on contractile function will be determined using a variety of biophysical techniques ranging from intact electrically stimulated isolated muscle to single myofibrils (aim 1). Contractile protein post-translational modifications and signal pathways will be manipulated via adenoviral gene delivery, kinase/phosphatase treatment and recombinant protein contractile protein exchange in permeabilized isolated myocardium (aim 1). As we recently demonstrated, regional myofilament function is not uniform in the heart and this distribution is significantly altered in heart failure. Experiments proposed in specific aim 2 will determine the signal pathways and contractile protein posttranslational modifications that underlie these phenomena. Finally, experiments proposed in aim3 will determine the dynamic and temporal coupling between the driving Ca2+ transient and the mechanical dynamic contractile protein force production; these experiments will be performed in single cardiac myofibrils. Overall, our aim is to determine the mechanisms that underlie contractile protein dysfunction in CHF. Our research will aid in the development of new therapeutic strargies to combat OHF in patients.

充血性心力衰竭（CHF）与心脏细胞功能异常有关。CHF中这种功能低下的分子机制尚不清楚。在以前的工作中，我们已经表明，肌丝功能在CHF中被抑制，在抑制的最大力产生能力，钙反应性和跨桥循环动力学方面。实验机械/生化数据表明，肌丝收缩蛋白磷酸化失调导致CHF中肌丝功能障碍，可能通过改变肌球蛋白轻链（MLC）、肌球蛋白结合蛋白C（MyoBPC）和肌球蛋白结合蛋白C（MyoBPC）的磷酸化， 肌钙蛋白-l（Tnl）。然而，精确的结构-功能关系尚未确定。在本持续支持提案中，我们将在豚鼠中采用继发于压力超负荷的CHF的成熟模型。豚鼠模型允许在与人类中发现的肌丝和EC偶联参数非常相似的模型中研究控制、代偿性肥大和CHF。将使用生化蛋白质组学分析来鉴定CHF中靶向的途径和蛋白质，并且将使用生物化学方法来确定鉴定的翻译后修饰对收缩功能的影响。 各种生物物理技术，从完整的电刺激离体肌肉到单个肌原纤维（目的1）。收缩蛋白翻译后修饰和信号通路将通过腺病毒基因递送、激酶/磷酸酶处理和重组蛋白收缩蛋白交换在透化的分离心肌中进行操纵（目的1）。正如我们最近所证实的，局部肌丝功能在心脏中是不均匀的，并且这种分布在心力衰竭中显著改变。 具体目标2中提出的实验将确定这些现象背后的信号通路和收缩蛋白翻译后修饰。最后，在aim 3中提出的实验将确定驱动Ca 2+瞬变和机械动态收缩蛋白质力产生之间的动态和时间耦合;这些实验将在单个心肌肌原纤维中进行。总体而言，我们的目标是确定CHF中收缩蛋白功能障碍的机制。我们的研究将有助于开发新的治疗策略来对抗OHF患者。