Mechanical Activity and Myocyte Remodeling

机械活动和肌细胞重塑

• 批准号: 8380012
• 负责人: BRENDA RUSSELL
• 金额: $ 42.68万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8380012
• 关键词: Actins; Address; Affect; American; Area; Authorship; Beryllium; Binding; Biological Models; Cardiac; Cardiac Myocytes; Cell membrane; Cells; Collaborations; Complement; Complex; Congestive Heart Failure; Data; Dependence; Depressed mood; Development; Diagnosis; Dilated Cardiomyopathy; Disease; Elderly; Elements; Event; Failure; Family; Financial compensation; Focal Adhesion Kinase 1; Focal Adhesions; Funding; GTP-Binding Proteins; Health; Heart; Heart Hypertrophy; Heart failure; Human; Hypertrophy; In Vitro; Incidence; Integrins; Intervention; Investigation; Laboratories; Length; Longevity; Measures; Mechanics; Medical; Metabolism; Microfilaments; Modification; Molecular; Mus; Muscle Cells; Muscle Fibers; Myofibrillogenesis; Neonatal; Paper; Pathway interactions; Patients; Pattern; Phosphatidylinositol 4,5-Diphosphate; Phosphoric Monoester Hydrolases; Phosphorylation; Prevalence; Process; Protein Biosynthesis; Protein Isoforms; Protein Kinase; Protein Kinase C; Proteins; Pump; Rattus; Regulation; Research; Role; Sarcomeres; Series; Serine; Shapes; Signal Pathway; Signal Transduction; Site; Stimulus; Surface; Syndrome; Testing; Thin Filament; Tyrosine; Ventricular; base; hemodynamics; improved; mortality; novel; overexpression; programs; research study; response; rho; stressor; vector

Mechanical strain is a powerful stimulus for shape and size remodeling of cardiac myocytes in normal and pathological situations. Indeed, the major change in shape that precedes heart failure in humans is progression to cellular elongation in dilated cardiomyopathy. The overall objective of this project is to test the hypothesis that longitudinal mechanical strain regulates cell lengthening by differential phosphorylation of focal adhesion kinase (FAK) at the costamere leading to differential actin capping by CapZ at the Z-disc and thin filament addition. The Specific Aims are: Aim #1: To determine the mechanisms of anisotropic Rho family G protein phosphorylation leading to myocyte elongation. We define the subcellular events responsible for strain-induced PKCE signaling using the PKCE-over expressing (OE) mouse, and aligned 3D cultured neonatal rat ventricular myocytes (NRVM) subjected to sudden static strain as model systems. Aim #2: To test the hypothesis that PKC-dependent FAK serine phosphorylation is required for the costameric mechanosensory apparatus to detect longitudinal strain. We examine the PKC dependence of FAK serine phosphorylation in response to longitudinal vs. transverse strain in 3D NRVM cultures. Aim #3: To determine whether elongating myocytes have altered CapZ phosphorylation. We determine whether CapZ phosphorylations in normal mice differ from ventricular myocytes that are lengthening and whether there is differential CapZ phosphorylation in response to anisotropic mechanical inputs to NRVM aligned 3D culture. Aim #4: To test the hypothesis that CapZ phosphorylation and PIP2 binding alter actin capping and are required for length remodeling. We measure actin-capping dynamics of green fluorescent tagged-CapZ to determine the effect of anisotropic mechanical stimuli. We determine the mechanism of cell length remodeling by regulation of CapZ binding via phosphorylation, PIP2 and other CapZ partnering proteins. In these experiments, we use validated conditions of normal myocyte lengthening and challenge these processes with specific molecular interventions to determine the mechanisms of length remodeling.

在正常和病理情况下，机械应变是心肌细胞形状和大小重塑的强大刺激。事实上，人类心力衰竭之前形状的主要变化是扩张型心肌病的细胞伸长。该项目的总体目标是检验这样的假设：纵向机械应变通过肋部粘着斑激酶 (FAK) 的差异磷酸化来调节细胞延长，从而导致 Z 盘上的 CapZ 和细丝添加差异肌动蛋白加帽。 具体目标是： 目标#1：确定各向异性 Rho 家族 G 蛋白磷酸化导致肌细胞伸长的机制。我们使用 PKCE 过度表达 (OE) 小鼠定义了负责应变诱导 PKCE 信号传导的亚细胞事件，并将 3D 培养的新生大鼠心室肌细胞 (NRVM) 经受突然静态应变作为模型系统。 目标#2：检验以下假设：肋节机械感觉装置检测纵向应变需要 PKC 依赖性 FAK 丝氨酸磷酸化。我们检查了 3D NRVM 培养物中 FAK 丝氨酸磷酸化对纵向应变与横向应变的 PKC 依赖性。 目标#3：确定伸长的肌细胞是否改变了 CapZ 磷酸化。我们确定正常小鼠的 CapZ 磷酸化是否与延长的心室肌细胞不同，以及是否存在差异 CapZ 磷酸化以响应 NRVM 对齐 3D 培养的各向异性机械输入。 目标#4：检验 CapZ 磷酸化和 PIP2 结合改变肌动蛋白加帽并且是长度重塑所必需的假设。我们测量绿色荧光标记的 CapZ 的肌动蛋白加帽动力学，以确定各向异性机械刺激的效果。我们通过磷酸化、PIP2 和其他 CapZ 伙伴蛋白调节 CapZ 结合来确定细胞长度重塑的机制。 在这些实验中，我们使用经过验证的正常心肌细胞延长条件，并通过特定的分子干预来挑战这些过程，以确定长度重塑的机制。