Modulators of Cardiomyopathic Diseases

心肌病调节剂

• 批准号: 9914116
• 负责人: Jose Renato Pinto
• 金额: $ 37.15万
• 依托单位: FLORIDA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9914116
• 关键词: ATP phosphohydrolase; Ablation; Address; Affect; Affinity; Agonist; Arrhythmia; Binding; Biochemical; Biological Assay; Biophysics; Blood; Buffers; Cardiac; Cardiac Muscle Contraction; Cardiac Myocytes; Cardiac Myosins; Cardiac ablation; Cardiomyopathies; Cells; Complex; Coupled; Data; Development; Disease; Echocardiography; Electrocardiogram; Electrons; Elements; Excision; Functional disorder; Genes; Goals; Growth; Health; Heart; Heart Diseases; Heart failure; Histopathology; Human; Hypersensitivity; Image; Knock-in; Knock-in Mouse; Knockout Mice; Lead; Light; Link; Mass Spectrum Analysis; Measurement; Mechanics; Microfilaments; Mitochondria; Molecular; Monitor; Morphology; Movement; Mus; Muscle; Muscle Fibers; Mutant Strains Mice; Mutation; Myocardium; Myosin Light Chain Kinase; N Domain; Organism; Outcome; Pathogenicity; Pathologic; Pathologic Processes; Pathology; Patients; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Post-Translational Protein Processing; Process; Property; Proteins; Relaxation; Role; Skin; Structure; Susceptibility Gene; Tamoxifen; Testing; Therapeutic; Thin Filament; Time; Tropomyosin; Troponin; Troponin C; Troponin I; Troponin T; Trypsin; Work; X ray diffraction analysis; base; biological systems; biophysical techniques; citrate carrier; desensitization; design; disease phenotype; experimental study; genetic approach; improved; in vivo; insight; micrography; mouse model; mutant; new therapeutic target; novel; pressure; public health relevance; reconstitution; response; sensor; targeted treatment; trait; ATP phosphohydrolase; Ablation; Address; Affect; Affinity; Agonist; Arrhythmia; Binding; Biochemical; Biological Assay; Biophysics; Blood; Buffers; Cardiac; Cardiac Muscle Contraction; Cardiac Myocytes; Cardiac Myosins; Cardiac ablation; Cardiomyopathies; Cells; Complex; Coupled; Data; Development; Disease; Echocardiography; Electrocardiogram; Electrons; Elements; Excision; Functional disorder; Genes; Goals; Growth; Health; Heart; Heart Diseases; Heart failure; Histopathology; Human; Hypersensitivity; Image; Knock-in; Knock-in Mouse; Knockout Mice; Lead; Light; Link; Mass Spectrum Analysis; Measurement; Mechanics; Microfilaments; Mitochondria; Molecular; Monitor; Morphology; Movement; Mus; Muscle; Muscle Fibers; Mutant Strains Mice; Mutation; Myocardium; Myosin Light Chain Kinase; N Domain; Organism; Outcome; Pathogenicity; Pathologic; Pathologic Processes; Pathology; Patients; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Post-Translational Protein Processing; Process; Property; Proteins; Relaxation; Role; Skin; Structure; Susceptibility Gene; Tamoxifen; Testing; Therapeutic; Thin Filament; Time; Tropomyosin; Troponin; Troponin C; Troponin I; Troponin T; Trypsin; Work; X ray diffraction analysis; base; biological systems; biophysical techniques; citrate carrier; desensitization; design; disease phenotype; experimental study; genetic approach; improved; in vivo; insight; micrography; mouse model; mutant; new therapeutic target; novel; pressure; public health relevance; reconstitution; response; sensor; targeted treatment; trait

 DESCRIPTION (provided by applicant): The long-term goal of this work is to identify components inside the cardiac cell that are involved with the development of cardiomyopathic diseases. This proposal focuses on cardiac troponin C (cTnC), the on-off switch of the contractile apparatus and a major cardiomyocyte intracellular Ca2+ buffer. Aimed at understanding the regulatory properties of the troponin complex in vivo and its link to abnormal intracellular Ca2+ handling governing heart disease, this proposal is of considerable health relevance. Mutations in the regulatory complex of the thin filament (tropomyosin, troponin T and troponin I) associated with phenotypic outcomes of hypertrophic (HCM) and dilated (DCM) cardiomyopathies are suggested to indirectly disrupt cardiac muscle contraction by altering the Ca2+-binding properties of cTnC. However, effects of cTnC mutants that influence Ca2+-sensitive contractile responses have yet to be tested for their pathogenic capacity in living organisms. The central hypothesis guiding this proposal is that changes in cTnC N-terminus Ca2+-binding affinity, alone, can evoke cardiac remodeling in vivo. We further posit that ablation of a dedicated high-fidelity kinase has the potential to reverse the hypercontractile state imposed by Ca2+-sensitizing HCM-linked cTnC mutants. Aim 1 will evaluate direct changes in cTnC Ca2+-binding affinity in the thin filament as a critical determinant underlying cardiomyopathic development. This Aim tests the hypothesis that cTnC mutants increasing Ca2+-binding affinity in the N-domain (regulatory) can instigate diastolic dysfunction, leading to HCM; while a designed mutant decreasing cTnC Ca2+- binding affinity will recapitulate a DCM-reminiscent phenotype. Cardiac patho-physiological, biophysical and biochemical approaches will be used to dissect the role of cTnC mutations in our newly developed knock-in (KI) mice. The antithetical effects that these cTnC mutants exert on Ca2+-binding dynamics will be investigated early, prior to development of distinctive cardiac remodeling. In addition, this projet will further define TNNC1 (cTnC- encoding gene) as a cardiomyopathy-susceptibility gene. Aim 2 will establish mechanistic and potential therapeutic links regarding normalization of myofilament Ca2+-sensitivity. This Aim examines whether conditional removal of a dedicated sarcomeric kinase will correct the myofilament Ca2+ response, diminish the hypercontractile phenotype and improve cardiac relaxation, thus reversing post-symptomatic HCM disease. The consequences of conditional removal of this kinase in KI cTnC-HCM hearts will be monitored as a function of time. The last aim can serve as a proof-of-concept for the development of targeted therapies aimed at modulating the activity of dedicated sarcomeric kinases. The novel concepts generated here will define the role of cTnC in initiating and modulating one class of cardiomyopathies, thus opening avenues for development of new tailored therapeutic approaches.

 描述（由应用程序提供）：这项工作的长期目标是识别与心肌病疾病发展有关的心脏细胞内部的组成部分。该提案的重点是心脏肌钙蛋白C（CTNC），收缩式设备的开关开关和主要的心肌细胞内CA2+缓冲液。旨在了解体内肌钙蛋白复合物的调节性能及其与异常的细胞内CA2+处理治疗心脏病的联系，该提议具有健康相关性。与肥大性（HCM）表型结局相关的薄丝调节复合物的突变（Tropomyosin，troponin t和troponin i）和扩张（DCM）心肌病被建议通过改变CAC2+-binting ctnc的ca2+ - 结合特性而间接破坏心脏肌肉的肌肉。但是，影响CA2+敏感收缩反应的CTNC突变体的影响尚未测试其在生活组织中的致病能力。指导该提议的中心假设是，仅CTNC N末端Ca2+结合亲和力的变化就可以在体内引起心脏重塑。我们进一步赞赏专用的高保真激酶的消融有可能扭转由Ca2+敏感HCM链接的CTNC突变体施加的超收缩状态。 AIM 1将评估薄丝中CTNC Ca2+结合亲和力的直接变化，这是一个关键的确定剂心肌疗法发育。该目标检验了以下假设：N域（调节）中增加Ca2+结合亲和力的CTNC突变体可以促进舒张功能障碍，从而导致HCM。虽然设计的突变体降低了CTNC Ca2+结合亲和力，但会概括DCM-振动表型。心脏病生理学，生物物理和生化方法将用于剖析CTNC突变在我们新开发的敲入（KI）小鼠中的作用。这些CTNC突变体对Ca2+结合动力学作用的相反效应将在开发独特的心脏重塑之前提前研究。此外，该projet将进一步将TNNC1（CTNC-编码基因）定义为心肌病抑制基因。 AIM 2将建立有关肌丝Ca2+敏感性正常化的机械和潜在疗法联系。此目的检查是否有条件地去除专用的肉瘤激酶会纠正肌丝Ca2+反应，减少合同表型并改善心脏放松，从而逆转后对称的HCM疾病。在Ki CTNC-HCM心脏中有条件去除该激酶的后果将随着时间的变化而受到监测。最后一个目标可以作为旨在调节专用肌肉激酶活性的有针对性疗法的概念证明。这里产生的新颖概念将定义CTNC在启动和调节一类心肌病中的作用，从而为开发新的量身定制的治疗方法开发途径。