Reciprocal Adaptations in Sarcomere Sensitivity and Metabolic Phenotype

项目3考察了肌节重塑后收缩功能代谢支持的适应性变化。该项目与计划项目的中心主题相关，通过研究肌丝对钙[2]敏感性改变的心脏的代谢重塑，以及通过改变代谢信号相互影响肌丝活动的可能性。总体目标是确定肌丝修饰是否导致代谢中的适应性、非适应性和/或心脏保护性转变。 小路。这项工作考察了病理生理应激是否通过AMPK连接底物氧化以产生能量的竞争模式的改变而导致代谢活性的相互变化，以及通过导致酰基衍生物通过肌节蛋白的磷酸化对收缩功能的影响而导致收缩功能的相互变化。主要的假设是：收缩/调节蛋白的化学修饰，特别是肌钙蛋白和可能的调节肌球蛋白轻链的化学修饰，会影响代谢表型，从而通过改变胞浆的化学环境来相互影响肌小球的活性。我们提出了三个特定的目标：1)在压力超负荷的转基因小鼠心脏中，确定脂肪酸氧化和储存之间的平衡，表达胎儿/新生儿肌钙蛋白I的异构体，ssTn1，一个明显的应激抵抗模型，并测试在压力超负荷心脏期间发生的氧化代谢潜在的不适应变化的减弱。2)阐明在基础状态和B-肾上腺素能应激期间收缩功能的代谢支持的变化 肌丝修饰的小鼠心脏模型将或不会发展为家族性肥厚性心肌病(FHC)，并且还显示AMPK激活的改变3)通过与脱敏的肌丝的小鼠心脏模型杂交，确定从具有高钙[2]敏感性和FHC的TG小鼠手中拯救心脏时的代谢反应。这些目标将通过一种独特的方法实现，将代谢流量和酶表达的核磁共振测定与肌丝功能和 蛋白质组学。该实验计划将使研究心肌病发病机制中肌节的代谢流量、AMPK激活和钙敏感性之间的三向联系成为可能。

Project 3 examines adaptive changes in the metabolic support of contractile function subsequent to sarcomere remodeling. This project relates to the central theme of the program project, by investigating metabolic remodeling in hearts with altered myofilament sensitivity to Ca[2+], and the potential to reciprocally influence myofilament activity through altered metabolic signaling. The overall objective is to determine if myofilament modifications induce adaptive, maladaptive, and/or cardioprotective shifts in metabolic pathways. The work examines whether the pathophysiological stress induces reciprocal changes in both metabolic activity, through AMPK-linked shifts in competing modes of substrate oxidation for energy production, and contractile function, through resulting affects of acyl-derivatives on contractile function via phosphorylation of sarcomeric proteins. The primary hypothesis is that: Chemical modifications of the contractile/regulatory proteins, specifically within troponin and possibly the regulatory myosin light chain, influence metabolic phenotype which reciprocally effects sarcomere activity by altering the chemical environment of the cytosol. We propose three specific aims: 1) Determine the balance between fatty acid oxidation and storage in pressure overloaded, transgenic mouse hearts that express the fetal/neonatal isoform of troponin I, ssTnl, an apparent model of stress resistance, and test for attenuation of potentially maladaptive changes in oxidative metabolism that occur during pressure overload cardiac. 2) Elucidate alterations in the metabolic support of contractile function at baseline and during B-adrenergic stress, in mouse heart models of myofilament modifications that will or will not develop familial hypertrophic cardiomyopathy (FHC), and also display altered AMPK activation 3) Determine the metabolic responses to rescue of hearts from TG mice with high Ca[2+] sensitivity and FHC, by crossing with a mouse heart model of desensitized myofilaments. These aims will be accomplished though a unique approach, combining NMR determinations of metabolic flux and enzyme expression with experiments on myofilament function and proteomics. The experimental plan will enable study of the three-way link between metabolic flux, AMPK activation, and Ca[2+] sensitivity of the sarcomeres in the pathogenesis of cardiomyopathy.