The role of the extracellular biophysical and biomechanical milieu in CHDs

细胞外生物物理和生物力学环境在先心病中的作用

• 批准号: 8507273
• 负责人: Lauren D. Black III
• 金额: $ 17.39万
• 依托单位: TUFTS UNIVERSITY MEDFORD
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8507273
• 关键词: Affect; Behavior; Biological Assay; Biomechanics; Birth; Blood flow; Calcium; Cardiac; Cardiac Myocytes; Cause of Death; Cell physiology; Cells; Child; Childhood; Collagen; Congenital Heart Defects; Congenital diaphragmatic hernia; Connective Tissue; Cues; Custom; Development; Dimensions; Disease; Embryo; Embryonic Heart; Environment; Etiology; Extracellular Matrix; Frequencies; Gene Expression; Genetic; Goals; Growth; Health; Heart; Hernia; Infant; Knowledge; Lead; Left; Left Ventricular Function; Left ventricular structure; Life; Link; Mechanics; Membrane; Methods; Modeling; Muscle Cells; Myocardium; Pathogenesis; Pathology; Perfusion; Phenotype; Play; Positioning Attribute; Procollagen; Property; Quality of life; Rattus; Regenerative Medicine; Research; Role; Sampling; Signal Transduction; Staging; Structure; System; Techniques; Testing; Thoracic cavity structure; Time; Tissue Engineering; Tissues; Tropoelastin; Ventricular; Visceral; Work; cardiac repair; cardiogenesis; extracellular; fetal; heart cell; heart function; improved; in utero; mortality; nitrofen; novel; polyacrylamide gels; repaired; research study

DESCRIPTION (provided by applicant): Congenital heart defects (CHDs) are the leading cause of death in infants and young children and those suffering from congenital diaphragmatic hernia and associated CHDs (particularly with left heart hypoplasia (LHH)), have high mortality. The dominant hypothesis is that the CHDs result from mechanical factors leading to altered blood flow in the left heart, such as compression of the left heart by visceral structures protruding into the thoracic cavity. In mild LHH, left ventricular dimensions tend to normalize after birth and hernia repair, further implicating the role of altered mechanical loads in certain forms of CHD. Decreased cardiac tropoelastin and procollagen gene expression and decreased left ventricular function in LHH compared to normal hearts suggest that significant deviations from normal ECM composition and mechanical properties of the myocardium occur. Given that ECM properties can affect various cell functions including proliferation, differentiation, and phenotype, any deviations from the normal composition and stiffness of the ECM in the progression of CHD would have a significant impact on the myocytes, resulting in profound alterations to the development and function of the myocardium. Additionally, altered flow through the developing heart will affect mechanical strain in the ventricular wall, and studies have demonstrated that changes in mechanical strain can significantly impact cell function. We hypothesize that by mimicking changes in ECM composition, stiffness, and/or mechanical strain associated with LHH, we will be able to guide embryonic myocytes towards the LHH phenotype while mimicking the healthy embryonic heart environment will lead to normal myocyte development. In Aim 1 we will use nitrofen-induced congenital diaphragmatic hernia in developing rat embryos to generate models of CHD. Healthy and diseased hearts from embryonic and fetal stages will undergo decellularization to obtain cardiac ECM which will be assayed to determine any compositional differences and alterations in mechanical stiffness. At these same life stages, we will characterize native myocyte proliferation and maturation in healthy and CHD hearts. We will then culture embryonic/fetal myocytes isolated from healthy and CHD ventricles in rationally altered 2D environments that mimic different combinations of healthy and diseased biophysical properties using an ECM-coated polyacrylamide (PA) gel system and assess whether stiffness and composition act synergistically or antagonistically, and whether "healthy" biophysical cues can drive "diseased" myocytes towards a healthy phenotype. In Aim 2, we will subject embryonic and fetal myocytes to mechanical strain of varying amplitude and frequency and assess the proliferation, maturation, and function of myocytes from healthy and CHD hearts. These studies are novel and will represent one of the first experiments to assess the role of altered biophysical and biomechanical signaling in the development of cardiac pathologies during growth in utero.

描述(申请人提供)：先天性心脏缺陷(CHDS)是婴幼儿死亡的主要原因，患有先天性隔疝及其相关的CHDS(尤其是左心发育不良(LHH))的人死亡率很高。主要的假设是，先天性心脏病是由于机械因素导致左心血流改变，如左心因内脏结构突出进入胸腔而受到压迫。在轻度LHH中，出生后和疝修补术后左室大小趋于正常化，进一步暗示机械负荷改变在某些形式的CHD中的作用。与正常心脏相比，LHH患者心脏弹性蛋白原和前胶原基因表达减少，左心功能下降，提示心肌细胞外基质成分和机械性能明显偏离正常心肌。鉴于细胞外基质的特性可以影响细胞的各种功能，包括增殖、分化和表型，在冠心病的发展过程中，任何偏离正常成分和硬度的细胞外基质都会对心肌细胞产生重大影响，导致心肌发育和功能的深刻变化。此外，心脏发育过程中血流的改变将影响室壁的机械应变，研究表明机械应变的变化可以显著影响细胞功能。我们假设，通过模拟与LHH相关的ECM成分、硬度和/或机械应变的变化，我们将能够引导胚胎心肌细胞走向LHH表型，同时模拟健康的胚胎心脏环境将导致正常的心肌细胞发育。在目标1中，我们将使用硝苯醚诱导的大鼠胚胎发育中的先天性横隔疝来建立CHD模型。来自胚胎和胎儿阶段的健康和患病心脏将进行去细胞处理，以获得心脏ECM，并将进行检测，以确定任何组成差异和机械硬度的变化。在这些相同的生命阶段，我们将描述健康和CHD心脏中天然心肌细胞的增殖和成熟。然后，我们将在合理改变的2D环境中培养从健康和CHD脑室分离的胚胎/胎儿心肌细胞，该环境使用ECM包被的聚丙烯酰胺(PA)凝胶系统模拟健康和患病的生物物理特性的不同组合，并评估僵硬和成分是协同作用还是拮抗作用，以及“健康的”生物物理线索是否可以驱动“患病”的心肌细胞走向健康的表型。在目标2中，我们将使胚胎和胎儿心肌细胞受到不同幅度和频率的机械应变，并评估来自健康心脏和冠心病心脏的心肌细胞的增殖、成熟和功能。这些研究是新的，并将是第一批实验之一，以评估改变的生物物理和生物力学信号在子宫发育过程中心脏病理发展中的作用。

项目成果

Extracellular matrix and cyclic stretch alter fetal cardiomyocyte proliferation and maturation in a rodent model of heart hypoplasia.

• DOI: 10.3389/fcvm.2022.993310
• 发表时间: 2022
• 期刊: FRONTIERS IN CARDIOVASCULAR MEDICINE
• 影响因子: 3.6
• 作者: Watson, Matthew C.;Williams, Corin;Wang, Raymond M.;Perreault, Luke R.;Sullivan, Kelly E.;Stoppel, Whitney L.;Black III, Lauren D.
• 通讯作者: Black III, Lauren D.