Effect of elevated dATP on contractile function and the Frank-Starling relationship in models of dilated cardiomyopathy

dATP 升高对扩张型心肌病模型收缩功能和 Frank-Starling 关系的影响

基本信息

批准号：
9108544
负责人：
Farid Moussavi-Harami
金额：
$ 16.12万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-15 至 2021-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9108544
关键词：
Actins Address Adult Affinity Anabolism Animal Model Beryllium Binding Calcium Cardiac Cardiac Myocytes Clinic Coronary Arteriosclerosis DNA Sequence Alteration Data Deoxyadenosines Dextrans Dilated Cardiomyopathy Disease model Electrostatics Enzymes Epidemic Etiology Family suidae Fluorides Genetic Genetic Models Goals Heart Heart failure Human Impairment In Vitro Infarction Kinetics Laboratories Length Mechanics Mediating Medical Methods Modeling Molecular Morbidity - disease rate Mus Muscle Cells Mutation Myocardium Myofibrils Myosin ATPase Nucleotides Pathway interactions Patients Power stroke Process Protocols documentation Publishing Rattus Recombinants Relaxation Ribonucleotide Reductase Sampling Sarcomeres Staging Stretching Striated Muscles Sturnus vulgaris Systolic heart failure Testing Therapeutic Intervention Thin Filament Toxin Training Transgenic Organisms Translational Research Tropomyosin Work Workload adeno-associated viral vector adenoviral-mediated alpha Tropomyosin base effective therapy efficacy testing improved in vivo inorganic phosphate insight mortality novel novel strategies novel therapeutics outcome forecast overexpression pre-clinical prevent public health relevance research study response tool tripolyphosphate

Actins Address Adult Affinity Anabolism Animal Model Beryllium Binding Calcium Cardiac Cardiac Myocytes Clinic Coronary Arteriosclerosis DNA Sequence Alteration Data Deoxyadenosines Dextrans Dilated Cardiomyopathy Disease model Electrostatics Enzymes Epidemic Etiology Family suidae Fluorides Genetic Genetic Models Goals Heart Heart failure Human Impairment In Vitro Infarction Kinetics Laboratories Length Mechanics Mediating Medical Methods Modeling Molecular Morbidity - disease rate Mus Muscle Cells Mutation Myocardium Myofibrils Myosin ATPase Nucleotides Pathway interactions Patients Power stroke Process Protocols documentation Publishing Rattus Recombinants Relaxation Ribonucleotide Reductase Sampling Sarcomeres Staging Stretching Striated Muscles Sturnus vulgaris Systolic heart failure Testing Therapeutic Intervention Thin Filament Toxin Training Transgenic Organisms Translational Research Tropomyosin Work Workload adeno-associated viral vector adenoviral-mediated alpha Tropomyosin base effective therapy efficacy testing improved in vivo inorganic phosphate insight mortality novel novel strategies novel therapeutics outcome forecast overexpression pre-clinical prevent public health relevance research study response tool tripolyphosphate

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项目摘要

DESCRIPTION (provided by applicant): Dilated cardiomyopathy (DCM) is the most common form of systolic heart failure with poor prognosis and no specific treatment to address the underlying contractile deficit. DCM has various causes including coronary artery disease, toxins, metabolites and genetic mutations with all leading to a common pathway of dilation and reduced contractility. In addition to the loss of contractility, there is also impairment in the Frank-Staring relationship, an adaptive process that is described as the increase in contractile force in response to increased preload. We are proposing to investigate a novel therapy for DCM that addresses both loss of contractility and impairment in the Frank-Starling relationship. This novel therapy is achieved by increasing intracellular levels of 2-deoxy ATP (dATP) in cardiomyocytes via increasing the expression of the enzyme ribonucleotide reductase (R1R2), the rate-limiting step in de novo dNTP biosynthesis. Our previous published work has shown that that increased intracellular levels dATP in cardiomyocytes increases contraction by enhancing cross-bridge binding and cycling kinetics and improving allosteric activation of contraction. Recent data suggests that in addition to improved contraction, increased dATP level also enhances the Frank Starling relationship. I will propose specific aims to assess the effect of increased dATP on the Frank Starling relationship and contraction in two animal models of DCM. In the first aim, I will use a genetic model of DCM with a D230N mutation in alpha-tropomyosin (Tm). This allows us to test whether augmenting cross-bridge binding improves the contractile deficit caused by a thin filament mutation and suggest that our therapy can be used a wide variety of conditions. Using recombinant D230N Tm, I will test the hypothesis that this mutation reduces thin filament activation and, as a consequence, the kinetics of contractile activation and relaxation. I will then determine the effect of increasing dATP content on these deficits. Using demembranated trabecula from transgenic D230N Tm mice, I will test the hypothesis that this mutation decreases calcium sensitivity of force and length-dependent activation. I will correct these functional deficits by increasing dATP content. Using AAV6-R1R2cTnT455, an adeno-associated viral vector that restricts R1R2 over-expression to cardiac myocytes, I will test the hypothesis that increasing dATP levels improves contractility of isolated cardiomyocytes, and improves systolic function in adult D230N Tm mice and retard or prevent progression of heart failure in young mice with DCM. In the first aim, I will use post-infarct model of DCM in rats in addition to the D230N Tm mice to evaluate the effect of cross-bridge activation on length dependent activation (LDA)-the Frank Starling relationship at the sarcomere level. I will first tes the hypothesis that dATP enhances LDA in the two models of DCM. Next, I will use alternative agents to increase (dextran, EMD 50733) or decrease (BDM, beryllium fluoride, high inorganic phosphate) cross-bridge recruitment and evaluate their effect on LDA in demembranated post-infarct DCM rat trabecula. I will complete this aim by testing the hypothesis that cross-bridge activation augments LDA in human myocardium from patients with DCM. The long-term goal of this project is provide a safe and effective treatment for DCM regardless of its cause. I am proposing the necessary preclinical experiments necessary to take this novel therapy to the clinic to improve morbidity and mortality in DCM.

描述（由适用提供）：扩张的心肌病（DCM）是收缩性心力衰竭的最常见形式，预后不良，没有特定的治疗方法来解决潜在的收缩防御。 DCM有各种原因，包括冠状动脉毒品，毒素，代谢产物和基因突变，所有原因都导致了词典和降低收缩力的通用途径。除了失去收缩性外，坦率的宣传关系也有损害，这是一种自适应过程，被描述为收缩力增加，以响应提前加载的增加。我们建议调查DCM的新型疗法，该疗法既解决了坦率的关系中的收缩力和损害的损失。这种新的疗法是通过增加心肌细胞中2-脱氧ATP（DATP）水平通过增加酶核糖核苷酸还原酶（R1R2）的表达而实现的，这是NOVO DNTP生物合成的速率限制步骤。我们以前发表的工作表明，通过增强跨桥结合和循环动力学并改善收缩的变构激活，心肌细胞中的细胞内水平增加了DATP的增加。最近的数据表明，除了改善收缩外，DATP水平的提高还可以增强坦率的Starling关系。我将提出特定的目的，以评估在两个DCM动物模型中增加DATP对Frank Starling关系和收缩的影响。在第一个目标中，我将使用α-胶质素（TM）中具有D230N突变的DCM的遗传模型。这使我们能够测试增加跨桥结合是否可以改善薄丝突变引起的收缩防御，并表明我们的治疗可以使用多种疾病。使用重组D230N TM，我将测试以下假设：这种突变会减少细丝的激活，并因此而是收缩激活和放松的动力学。然后，我将确定增加DATP内容对这些防御能力的影响。使用来自转基因D230N TM小鼠的非桥接小梁，我将检验以下假设：该突变降低了力和长度依赖性激活的钙敏感性。我将通过增加DATP内容来纠正这些功能防御能力。 Using AAV6-R1R2cTnT455, an adeno-associated viral vector that restricts R1R2 over-expression to cardiac myocytes, I will test the hypothesis that increasing dATP levels improve contractility of isolated cardiomyocytes, and improves systolic function in adult D230N Tm mice and retard or prevent progression of heart failure in young mice with DCM.在第一个目的中，除了D230N TM小鼠外，我还将使用大鼠的DCM的触觉后模型来评估跨桥激活对长度依赖性激活（LDA）的影响 - 肉瘤水平上的Frank Starling关系。我首先将DATP在DCM的两个模型中增强LDA的假设。接下来，我将使用替代药物增加（葡萄剂，EMD 50733）或减少（BDM，氟化铍，高无机磷酸盐）跨桥募集，并评估其对脱离后脑脑中肿瘤的LDA的影响。我将通过检验以下假设来完成这一目标：DCM患者的跨桥激活增强了人体心肌的LDA。该项目的长期目标是为DCM提供安全有效的治疗方法，无论其原因如何。我建议将这种新型疗法带到诊所以提高DCM的发病率和死亡率所需的必要必要的临床前实验。