Modulation of Ca Control of Cardiac Myofibrils

心肌原纤维 Ca2+ 控制的调节

• 批准号: 8666785
• 负责人: MADHU GUPTA
• 金额: $ 39.08万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-18 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8666785
• 关键词: 3' Untranslated Regions; Acidosis; Address; Adrenergic Agents; Adult; Affect; Animal Model; Birth; Breeding; Calcium; Cardiac; Cardiac Myocytes; Cardiomyopathies; Connexin 43; DNA Binding; Data; Depressed mood; Dilated Cardiomyopathy; Down-Regulation; Embryo; Embryonic Heart; Experimental Models; Fetal Heart; Functional RNA; Functional disorder; Gene Expression; Gene Expression Regulation; Genetic; Goals; Growth; Heart; Heart Diseases; Heart failure; Hypothyroidism; In Situ; Indium; Kinetics; Knock-out; Lead; Life; Link; Mechanics; Mediating; MicroRNAs; Microfilaments; Modification; Mus; Muscle; Muscle Cells; Muscle Contraction; Mutation; Myocardial; Myocardium; Myofibrils; Myosin ATPase; Neonatal; Patients; Phenotype; Phosphorylation; Phosphotransferases; Population; Post-Translational Protein Processing; Property; Protein Isoforms; Proteins; Proteolysis; Rattus; Regenerative Medicine; Regulation; Relative (related person); Repression; Research Proposals; Research Support; Resistance; Role; Signal Transduction; Skeletal Muscle; Skin; Stress; Testing; Therapeutic; Thin Filament; Thyroid Gland; Thyroid Hormones; Transgenic Mice; Transgenic Organisms; Tropomyosin; Troponin; Troponin I; adrenergic; alpha Tropomyosin; angiogenesis; cardiogenesis; design; fetal; improved; in vivo; loss of function; mouse model; postnatal; prevent; research study; response; skeletal; transcription factor; translational medicine

DESCRIPTION (provided by applicant): Our long term goal in experiments proposed here is to identify the mechanism(s) responsible for the down-regulation of the slow skeletal troponin I (ssTnI) isoform, which occurs during post-natal maturation of the heart. Preliminary data underpin our hypothesis that the microRNA, miR-208a, is involved in silencing the cardiac expression of ssTnI after birth. Our experiments continue research supported by this proposal that demonstrated that expression of ssTnI in the adult heart of transgenic mice protects the myocardium against common stresses including familial dilated cardiomyopathy (DCM). Preliminary data demonstrate: i) increased expression of miR-208a with muscle specific miRs, miR-1 and miR-133a in developing cardiomyocytes, and ii) knockdown of miR-208a in cardiomyocytes by a 208a-antagomiR induces ssTnI expression. Our objectives are as follows: Aim #1 To determine mechanism(s) of ssTnI and miR-208a mediated regulation by (a) investigating interplay of miR-208a with thyroid hormone mediated down regulation of ssTnI, (b) analyzing the role of miR-208a in conjunction with other co-regulated miRNAs in ssTnI gene regulation, (c) investigating transcriptional mechanisms of ssTnI gene regulation, and (d) evaluating ssTnI as a direct target of miRNA- mediated regulation. Aim #2: To determine the relative impact of miR-208a KO on modifications of thin filament proteins, on myofilament response to Ca, on myocyte mechanics and Ca, and on in situ cardiac function. Aim #3. To determine whether reduced expression of miR-208a improves cardiac function in dilated cardiomyopathy (DCM) associated with an alpha-tropomyosin mutation. Our approach to Aim #1 includes i) analysis of expression of ssTnI in neonatal cardiac myocytes by gain and loss of function approaches to dissect the relative significance of thyroid related signaling in the repression of ssTnI; ii) determination the relative role of miR-208a as a repressor of ssTnI expression employing co-induction with other miRs; iii) identification of transcription factors targeted by miR-208a and determination of their DNA binding and expression; and iv) identification of targets of miR-208a in ssTnI 3'UTR. Our approaches to Aims #2 include studies comparing miR208a-KO mice to controls to determine the functional impact of altered myofilament properties as reflected in isoform population, post-translational modifications, pCa-force relations and cross- bridge kinetics. Findings from studies of skinned myocytes are integrated into myocardial function by studies of Ca2+ transients and mechanics at the level of cardiac myocytes and of dynamics of in situ beating hearts responding to stresses including those dominated by altered thin filament properties. In Aim #3 our approach is to determine whether cross-breeding a familial DCM mouse model linked to a tropomyosin mutation with the miR208a-KO mouse is able to rescue the DCM phenotype. Experiments proposed here fill a significant gap in our understanding of the control of expression of the isoform population of myocardial TnI, an essential thin filament protein, and test a significant therapeutic approach to cardiac disorders.

描述（由申请人提供）：我们在此提出的实验中的长期目标是确定在出生后心脏成熟期间发生的缓慢骨骼肌钙蛋白I（ssTnI）亚型下调的机制。初步数据支持了我们的假设，即microRNA，miR-208 a，参与沉默出生后心脏ssTnI的表达。我们的实验继续研究支持这一建议，证明ssTnI在成年转基因小鼠的心脏表达保护心肌免受常见的压力，包括家族性扩张型心肌病（DCM）。初步数据表明：i）在发育中的心肌细胞中增加miR-208 a与肌肉特异性miR、miR-1和miR-133 a的表达，和ii）通过208 a-miR-133 a敲低心肌细胞中的miR-208 a诱导ssTnI表达。我们的目标如下：目的#1通过（a）研究miR-208 a与甲状腺激素介导的ssTnI下调的相互作用，（B）分析miR-208 a与其他共调节的miRNA在ssTnI基因调控中的作用，（c）研究ssTnI基因调控的转录机制，和（d）评估ssTnI作为miRNA介导的调节的直接靶。目标二：确定miR-208 a KO对细丝蛋白修饰、肌丝对Ca反应、肌细胞力学和Ca以及原位心脏功能的相对影响。目标3。确定miR-208 a表达减少是否改善与α-原肌球蛋白突变相关的扩张型心肌病（DCM）的心功能。我们的目标#1的方法包括i）通过功能获得和丧失方法分析新生心肌细胞中ssTnI的表达，以剖析甲状腺相关信号传导在ssTnI抑制中的相对重要性; ii）使用与其它miR的共诱导来确定miR-208 a作为ssTnI表达的抑制物的相对作用; iii）鉴定miR-208 a靶向的转录因子并测定其DNA结合和表达;和我们实现目标#2的方法包括比较miR 208 a-KO小鼠与对照的研究，以确定改变的肌丝性质的功能影响，如亚型群体、翻译后修饰、pCa-力关系和跨桥动力学所反映的。从剥皮的心肌细胞的研究结果整合到心肌功能的研究Ca 2+瞬变和力学水平的心肌细胞和动力学的原位跳动的心脏响应应力，包括那些主要由改变细丝属性。在目标#3中，我们的方法是确定与原肌球蛋白突变相关的家族性DCM小鼠模型与miR 208 a-KO小鼠杂交是否能够挽救DCM表型。这里提出的实验填补了一个显着的空白，我们的理解心肌肌钙蛋白I，一个必不可少的细丝蛋白的亚型群体的表达控制，并测试一个显着的治疗方法，心脏疾病。

项目成果

Ranolazine improves cardiac diastolic dysfunction through modulation of myofilament calcium sensitivity.

• DOI: 10.1161/circresaha.111.258251
• 发表时间: 2012-03-16
• 期刊: Circulation research
• 影响因子: 20.1
• 作者: Lovelock JD;Monasky MM;Jeong EM;Lardin HA;Liu H;Patel BG;Taglieri DM;Gu L;Kumar P;Pokhrel N;Zeng D;Belardinelli L;Sorescu D;Solaro RJ;Dudley SC Jr
• 通讯作者: Dudley SC Jr

Metabolic efficiency promotes protection from pressure overload in hearts expressing slow skeletal troponin I.

• DOI: 10.1161/circheartfailure.114.001496
• 发表时间: 2015-01
• 期刊: Circulation. Heart failure
• 作者: Carley AN;Taglieri DM;Bi J;Solaro RJ;Lewandowski ED
• 通讯作者: Lewandowski ED

Inhibition of PKC phosphorylation of cTnI improves cardiac performance in vivo.

• DOI: 10.1152/ajpheart.00582.2003
• 发表时间: 2004-06
• 期刊: American journal of physiology. Heart and circulatory physiology
• 作者: Brian B. Roman;P. Goldspink;Elyse Spaite;D. Urboniene;R. McKinney;David L. Geenen;R. J. Solaro

Functional importance of the carboxyl-terminal region of striated muscle tropomyosin.

横纹肌原肌球蛋白羧基末端区域的功能重要性。

• DOI: 10.1074/jbc.m303073200
• 发表时间: 2003
• 期刊: The Journal of biological chemistry
• 作者: Jagatheesan,Ganapathy;Rajan,Sudarsan;Petrashevskaya,Natalia;Schwartz,Arnold;Boivin,Greg;Vahebi,Susan;DeTombe,Pieter;Solaro,RJohn;Labitzke,Erin;Hilliard,George;Wieczorek,DavidF
• 通讯作者: Wieczorek,DavidF

Tension production and thin-filament protein isoforms in developing rat myocardium.

大鼠心肌发育中的张力产生和细丝蛋白亚型。

• DOI: 10.1152/ajpheart.1994.267.4.h1589
• 发表时间: 1994
• 期刊: The American journal of physiology
• 作者: Reiser,PJ;Westfall,MV;Schiaffino,S;Solaro,RJ
• 通讯作者: Solaro,RJ