Connexin Distribution in Physiological Versus Pathological Cardiac Hypertrophy

生理性与病理性心脏肥大中的连接蛋白分布

• 批准号: 8391535
• 负责人: Michael R Zile
• 金额: --
• 依托单位: RALPH H JOHNSON VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8391535
• 关键词: Accounting; Address; Adenoviruses; Adrenergic Agents; Adrenergic Agonists; Adrenergic Receptor; Adult; Affinity; Agonist; Aliquot; Animal Model; Animals; Applications Grants; Arrestins; Arrhythmia; Atrial Heart Septal Defects; Attenuated; Basic Science; Binding; Biopsy; Cadherins; Canis familiaris; Cardiac; Cardiac Myocytes; Caring; Catheterization; Cell Adhesion; Cell Nucleolus; Cell Nucleus; Cell surface; Cells; Characteristics; Chronic; Clinical; Complex; Confocal Microscopy; Congenital Heart Defects; Connexin 43; Connexins; Connexon; Control Animal; Cyclic AMP; Cytoplasm; Cytoskeleton; Data; Dependence; Diffuse; Diffusion; Distal; Docking; Down-Regulation; Dynein ATPase; Echocardiography; Electrocardiogram; Electrons; Elements; Environment; Event; Exhibits; Failure; Family; Family Felidae; Felis catus; Functional disorder; Funding; Gap Junctions; Genes; Genetic Transcription; Genetic screening method; Goals; Golgi Apparatus; Grant; Grant Review; Growth; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Homeostasis; Human; Hypertrophy; Immunoblotting; Infection; Interphase Cell; Intervention; Intracellular Transport; Kinesin; Lead; Left; Left ventricular structure; Life; Life Cycle Stages; Location; Lung; Lysosomes; MAP4; Maps; Measurement; Measures; Mechanics; Mediating; Medical center; Membrane; Membrane Transport Proteins; Messenger RNA; Metalcaptase; Methods; Microfilaments; Microtubule Depolymerization; Microtubule Proteins; Microtubule-Associated Proteins; Microtubules; Minor; Modeling; Molecular; Morphology; Motion; Motor; Mus; Myocardial; Myocardium; Myofibrils; Nocodazole; Normal Cell; Normal Range; Optics; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phenotype; Phosphoric Monoester Hydrolases; Phosphotransferases; Physiological; Plus End of the Microtubule; Positioning Attribute; Prevention; Principal Investigator; Process; Program Reviews; Progress Reports; Property; Propranolol; Protein Biosynthesis; Protein Dephosphorylation; Protein Isoforms; Protein phosphatase; Proteins; Protocols documentation; Pulmonary artery structure; Recruitment Activity; Research; Research Support; Ribonucleoproteins; Ribosomal RNA; Ribosomes; Right ventricular structure; Right-On; Role; Sarcolemma; Science; Series; Site; Specificity; Staining method; Stains; Stimulus; Stress; Structure; System; Systolic Pressure; Telemetry; Testing; Therapeutic Intervention; Thinking; Time; Tissues; Transfection; Transgenic Mice; Translating; Translational Research; Translations; Transport Process; Transport Vesicles; Treatment Efficacy; Tubulin; Up-Regulation; Ventricular; Vesicle; Work; adrenergic; base; beta-adrenergic receptor; constriction; density; extracellular; gap junction channel; gene therapy; hemodynamics; improved; interest; macromolecule; member; messenger ribonucleoprotein; overexpression; p21-activated kinase 1; palliative; particle; pressure; prevent; programs; receptor; receptor internalization; receptor recycling; research study; response; small molecule; success; trans-Golgi Network

Research supported by this grant during the previous twenty-four years has been built around extensive data showing that cardiac structure, composition, and function each respond rapidly and reversibly to changes in hemodynamic load. The first set of studies supported by this grant used isolated cells, or cardiocytes, and intact animals to demonstrate the role of load as a central regulator of cardiocyte growth. The second set of studies supported by this grant, which also used load change as the primary experimental variable, led to our discovery of a dense cardiocyte microtubule network during severe pressure-overload cardiac hypertrophy that contrib- utes to the contractile dysfunction which occurs in this setting. The initial goals for the subsequent studies of this abnormal microtubule network were to determine how it contributes to the contractile dysfunction of hypertrophied myocardium. Major findings have been that 1) it is based both on increased tubulin, and thus microtubules, and on greater microtubule stability, 2) the major car- diac microtubule-stabilizing microtubule-associated protein, MAP4, is greatly upregulated in pressure overload hypertrophy and binds extensively to microtubules, and 3) contractile dysfunction is caused by viscous loading imposed on shortening myofilaments by the dense microtubule network. However, the most important normal role of the microtubules in an interphase cell such as the cardiocyte is not to determine cellular rheological properties but rather to subserve intracellular transport of macromolecules and vesicles via the microtubule-associated kinesin and dynein families of motor proteins. Indeed, this is an absolutely essential role in the extremely diffusion-restricted cytoplasm of the adult cardiocyte. For this reason, and because of the known inhibition of microtubule-dependent intracellular transport by excessive decoration of microtubules with MAPs, we next asked if microtubule-based transport of the activated ¿-adrenergic receptor and/or mRNA - ribonucleoprotein complexes was inhibited by MAP4 binding to microtubules in pressure- overload hypertrophy. Such, in fact. was the case. Building on this most recent work, we propose to examine here the potential role of alterations in microtubule network organization and MAP4 binding in causing abnormal transport and localization of connexin43 [Cx43], a gap junction protein known to undergo functionally important alterations in quantity and localization during pathological cardiac hypertrophy. The basic research in the first objective will use isolated cells as well as oper- ated and transgenic mice to determine whether MAP4 decoration of microtubules, and the attendant densifica- tion of the microtubule network, inhibit the normal transport of Cx43 to gap junctions as well as Cx43-depen- dent electrophysiological function. The translational research in the second and third objectives will compare an equal degree & duration of pathological pressure vs. physiological volume overload hypertrophy. We will first extend the findings of the first objective to ask if MAP4 decoration of the dense microtubule network in pathological hypertrophy has a role in the altered Cx43 transport and localization that are important clinically in forming an arrhythmogenic substrate. We will then ask if ¿-receptor blockade in pathological hypertrophy, which early data indicates will prevent the abnormal microtubule phenotype, will also prevent the abnormal Cx43 phenotype in this setting. In the first objective we will use murine models, and in the second and third objectives we will use our long- standing feline models of physiological versus pathological hypertrophy. While we recognize that it is prefer- able to use a single species, in this research the initial mechanistic portion can only be done in the mouse, but the later quantitative translational portions require very reproducible animal models that can be reliably and verifiably ¿-blocked and have an equivalent degree and duration of physiological vs. pathological hypertrophy, with ex- tensively characterized cytoskeletal properties in each setting.

在过去的二十四年中，这笔赠款支持的研究已围绕大量数据构建 表明心脏结构，组成和功能各自响应 血液动力学负荷。该赠款支持的第一组研究使用了孤立的细胞或心脏细胞，并且完整 动物证明负载是心脏细胞生长的中心调节剂的作用。第二组研究 在这笔赠款的支持下，该赠款也将负载更改用作主要实验变量，导致了我们的发现 在严重的压力越过的心脏肥大期间，密集的心细胞微管网络 在这种情况下发生的收缩功能障碍的UTE。 随后研究此异常微管网络的最初目标是确定它如何 导致肥厚的心肌的收缩功能障碍。主要发现是1） 基于微管蛋白增加，因此基于微管蛋白，以及更大的微管蛋白，2） DIAC微管稳定的微连接相关蛋白MAP4在压力超负荷中非常上调 肥大并广泛与微管结合，3）收缩功能障碍是由粘性负载引起的 通过密集的微管网络缩短肌膜。 然而，微管在相互相细胞（例如心脏细胞）中最重要的正常作用是 不是确定细胞流变特性，而是要覆盖大分子的细胞内转运 通过微管相关的驱动蛋白和动力蛋白的蔬菜。确实，这是一个 在成年心细胞的极限扩散限制细胞质中，绝对重要的作用。为此原因， 并且由于已知抑制微管依赖性细胞内转运 带有地图的微纤维的，我们接下来询问基于微管的激活的运输 - 肾上腺肾上腺肾上腺肾上腺素的接收器是否 和/或mRNA-核糖核蛋白复合物被MAP4结合在压力中与微管结合 超负荷肥大。实际上，这样。是这样。 在这项最新工作的基础上，我们建议在这里检查微管变化的潜在作用 网络组织和MAP4绑定在引起异常运输和connexin43的定位[CX43]， 已知的间隙连接蛋白在功能上经历了重要的数量和定位变化 第一个目标中的基础研究将使用孤立的细胞以及运行 ATED和转基因小鼠，以确定MAP4微管的装饰以及伴随的致密性 微管网络的tion，抑制CX43向差距连接的正常运输以及CX43-DEPEN- 凹痕电生理功能。第二和第三个目标中的翻译研究将比较 病理压力与生理体积超负荷肥大的相等程度和持续时间。我们将 首先扩展了第一个目标的发现，以询问MAP4在密集微管网络中是否装饰 病理肥大在改变的CX43转运和定位中起作用，在临床上很重要 形成心律不齐的底物。然后，我们将询问是否在病理肥大中封锁了受体阻塞，这是 早期数据表明将防止异常微管表型，也将防止异常CX43 在这种情况下的表型。 在第一个目标中，我们将使用鼠模型，在第二和第三个目标中，我们将使用长期 身体肥大与病理肥大的站立猫科动物模型。虽然我们认识到这是喜欢的 它可以使用一个物种，在这项研究中，初始机械部分只能在鼠标中完成，但是 以后的定量翻译部分需要非常可靠的动物模型，这些模型可以可靠地可靠 - 烧毁，具有等效的身体和病理肥大的持续时间，并具有 在每种环境中的细胞骨架特性张紧。

项目成果

Prediction of All-Cause Mortality Based on the Direct Measurement of Intrathoracic Impedance.

• DOI: 10.1161/circheartfailure.115.002543
• 发表时间: 2016-01
• 期刊: Circulation. Heart failure
• 作者: Zile MR;Sharma V;Johnson JW;Warman EN;Baicu CF;Bennett TD
• 通讯作者: Bennett TD