Myocardial Infarct in Aging Animals and dATP Therapy

老龄动物心肌梗死和 dATP 治疗

基本信息

批准号：
9565690
负责人：
MICHAEL REGNIER
金额：
$ 68.26万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-30 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9565690
关键词：
Actins Affect Age Aging Animal Model Animals Binding Biological Assay Canis familiaris Cardiac Cardiac Myocytes Cells Coupled Data Development Dilated Cardiomyopathy Elderly Enzymes Exercise Tolerance Family suidae Fatigue Functional disorder Goals Health Health Benefit Health Care Costs Heart Heart failure Home Nursing Care Human Impairment Infarction Kinetics Lead Left Left Ventricular Function Life Longevity Measures Mediating Metabolic Metabolism Mitochondria Modeling Morphology Mus Muscle Muscle Weakness Muscle function Myocardial Infarction Myocardium Myofibrils Myopathy Myosin ATPase Nucleotides Organ Pathologic Patients Performance Performance at work Physiology Populations at Risk Preparation Property Protein Isoforms Proteomics Public Health Quality of life Relaxation Reporting Resistance Respiration Ribonucleotide Reductase Risk Rodent Role Running Skeletal Muscle Skeletal Muscle Myosins Skin Speed Striated Muscles System Testing Tissues Transgenic Organisms Ventricular Viral Viral Vector Work adeno-associated viral vector age related aged aging population exercise capacity exercise intolerance experimental study gene therapy heart function heart metabolism improved improved mobility interdisciplinary approach juvenile animal mature animal metabolic profile metabolomics muscle aging muscle metabolism novel novel therapeutics nucleotide metabolism older patient overexpression promoter resistance exercise response skeletal treadmill vector young adult

项目摘要

ABSTRACT The goal of this project is two-fold: 1) to determine how age compounds the effect of myocardial infarct (MI) on heart function and how this affects skeletal muscle function and exercise tolerance; and 2) to determine the ability of 2 deoxy-ATP (dATP) to affect heart and skeletal muscle performance, metabolism and exercise tolerance in age and MI induced heart failure. Most studies of performance decline with MI are done with young animal models, to look at infarct specific effects. However, MI occurs most often in the elderly, and it is not clear the extent to which this compounds pathologic effects at the system, organ and cell levels. Thus, we will study how age impacts the effects of MI on heart and skeletal muscle contractile and metabolic function. We will then use this model to study cardiac-specific vs. cardiac + skeletal muscle elevation of dATP. We have previously reported that dATP enhances contraction in demembranated cardiac and skeletal muscle by increasing myosin binding to actin (crossbridge formation) and crossbridge cycling. We have also reported that cellular levels of dATP can be elevated in the heart and skeletal muscle via transgenic or viral vector-mediated or over-expression of the enzyme Ribonucleotide Reductase (RNR). Both of these approaches enhance left ventricular (LV) heart function and increases the magnitude and speed of cardiomyocyte contraction & relaxation in normal hearts and rescues LV function of infarcted hearts of rodents and pigs. These previous MI studies were done in young adult animal and we did not determine how cardiac-specific elevation of dATP affected skeletal muscle or exercise tolerance. In preliminary data we demonstrate that 1) both demembranated cardiac and skeletal muscle from old mice have enhanced contraction when dATP (vs. ATP) is the substrate for contraction, 2) transgenic young mice with elevated heart and skeletal muscle [dATP] have greater exercise capacity, faster treadmill running and fatigue resistance, and 3) elevated cardiac RNR and dATP may protect against transition from an oxidative to glycolytic cardiac metabolic profile following MI (in young mice) and rescue this `more youthful' oxidative profile in old mice. In the proposed experiments we will determine if AAV-RNR vectors can improve cardiac and skeletal muscle performance, exercise capacity and metabolic performance of old mice with and without MI. We will compare vectors with cardiac-specific vs. striated muscle-specific expression of RNR. Thus our proposal offers a unique model to study how specifically targeting the heart to improve its performance can have secondary beneficial effects in skeletal muscle. Function will be measured at whole organ, cell and myofibril levels for both cardiac and skeletal muscle and coupled with measures of metabolic efficiency and activity, mitochondrial function, and metabolomics and proteomic analysis. This multi- scale analysis, using interdisciplinary approaches, will provide information for mechanistic interpretations. The results from these studies will determine feasibility of our approach (AAV-RNR mediated elevation of dATP in muscle) for treatment of heart failure and other age-related declines in cardiac function and exercise tolerance.

摘要该项目的目标是两个方面：1）确定年龄如何使心肌效应复合心脏功能的梗死（MI）以及这如何影响骨骼肌肉功能和运动耐受性；和2）到确定2个脱氧ATP（DATP）影响心脏和骨骼肌肉表现，代谢和年龄的运动耐受性和MI引起的心力衰竭。大多数对MI的绩效下降研究都完成了使用年轻的动物模型，以查看梗塞的特定效果。但是，MI最常发生在老年人中，并且目前尚不清楚这种在系统，器官和细胞水平上复合病理作用的程度。因此，我们将研究年龄如何影响MI对心脏和骨骼肌肉收缩和代谢功能的影响。然后，我们将使用此模型研究DATP的心脏特异性与心脏 +骨骼肌升高。我们有以前报道说，DATP通过增加与肌动蛋白（Crossbridge组）和Crossbridge循环的结合。我们还报告了 DatP的细胞水平可以通过转基因或病毒载体介导的心脏和骨骼肌升高或核糖核苷酸还原酶（RNR）的过表达。这两种方法都增强了心室（LV）心脏功能，并增加心肌细胞收缩和放松的幅度和速度在正常的心脏中，并挽救了啮齿动物和猪的梗塞心脏的LV功能。这些先前的MI研究是在年轻的成年动物中完成的，我们没有确定DATP的心脏特异性升高如何影响骨骼肌或运动耐受性。在初步数据中，我们证明了1）两者都伸长心脏当datp（vs. atp）是基板时收缩，2）心脏和骨骼肌升高的转基因小鼠[DATP]运动更大容量，更快的跑步机跑步和抗疲劳性以及3）升高的心脏RNR和DATP可以保护反对从氧化剂到糖酵解心脏代谢特征（在年轻小鼠）和救援后的过渡这种“更年轻”的氧化型在老鼠中。在提出的实验中，我们将确定是否aav-rnr 向量可以改善心脏和骨骼肌表现，运动能力和代谢性能有和没有Mi的老鼠。我们将将矢量与心脏特异性与横纹肌肉特异性进行比较 RNR的表达。因此，我们的建议提供了一个独特的模型，可以研究如何专门针对心脏提高其性能可以在骨骼肌中产生次要有益作用。功能将在心脏和骨骼肌的整个器官，细胞和肌原纤维水平，并与代谢效率和活性，线粒体功能以及代谢组学和蛋白质组学分析。这个多使用跨学科方法的比例分析将为机械解释提供信息。这这些研究的结果将确定我们方法的可行性（AAV-RNR介导的DatP升高肌肉）治疗心力衰竭和其他与年龄相关的心脏功能和运动耐受性下降。