Imaging fluid forces in mouse cardiovascular development

小鼠心血管发育中的流体力成像

• 批准号: 6969001
• 负责人: Mary E Dickinson
• 金额: $ 36.25万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6969001
• 关键词: angiogenesis; bioimaging /biomedical imaging; blood circulation; blood vessels; cardiogenesis; cardiovascular function; cell morphology; confocal scanning microscopy; embryology; hemodynamics; imaging /visualization /scanning; laboratory mouse; mutant; polymerase chain reaction; shear stress; yolk sac

DESCRIPTION: The mouse provides an excellent system for studying congenital cardiovascular abnormalities defects since mouse and human development are very similar and many mutants with heart and vascular anomolies have been identified (Harvey, 2002). Blood flow and the formation of the heart and vasculature coincide, and several studies suggest that mechanical stimulus, imparted by the shear stress between blood flow and the endothelial cell wall, acts as a signal for vascular remodeling (see Topper and Gimbrone, 1999 for review). Using confocal laser scanning microscopy, we have developed methods to measure blood flow velocities and calculate shear stress levels in mouse embryos (Jones et at 2004b). Here we will test the hypothesis that mechano-sensory signals are necessary for proper development of the yolk sac vasculature using three sets of in vivo, multispectral imaging experiments: First, we will study how the vascular plexus forms using celltype specific fluorescent protein expression. We will describe how endothelial cell morphologies change as vessels are assembled and flow begins. Second, we will quantify changes in shear stress during early yolk sac vessel formation and remodeling to identify forces that induces morphogenesis. Third, we will quantify hemodynamics in Myosin Light Chain 2a (MLC2a) mutant embryos (Huang et al 2003) to test whether disrupted flow and reduced shear stress can cause abnormal development of vascular cells in the yolk sac. MLC2a -/- embryos are ideal for studying the effects of shear stress because mutants have defects in vessel formation even though MLC2a is never expressed outside the heart. Through these Specific Aims, we will gather vital information about the dyanamic development of the yolk sac vasculature and will test how mechanical signals relate to changing vessel morphology. We have focused on a single mutant strain here, but the quantitative methods employed can be used to study any mutant with impaired vascular development or impaired cardiovascular function.

描述：小鼠为研究先天性心血管异常缺陷提供了一个极好的系统，因为小鼠和人类发育非常相似，并且已经确定了许多心脏和血管异常的突变体（Harvey，2002）。血流和心脏和血管的形成重合，几项研究表明，由血流和内皮细胞壁之间的剪切应力赋予的机械刺激是血管重塑的信号（请参阅Topper和Gimbrone，1999年，1999年）。使用共聚焦激光扫描显微镜，我们开发了测量血流速度并计算小鼠胚胎中的剪切应力水平的方法（Jones et 2004b）。在这里，我们将检验以下假设：使用三组体内，多光谱成像实验的机械感应信号对于正确开发蛋黄囊血管是必需的：首先，我们将研究如何使用细胞犬特异性荧光蛋白质表达血管丛形式。我们将描述内皮细胞的形态如何随着血管组装而开始流动而变化。其次，我们将在早期的蛋黄囊血管形成过程中量化剪切应力的变化并进行重塑以识别诱导形态发生的力。第三，我们将量化肌球蛋白光链2a（MLC2A）突变体胚胎（Huang等，2003）中的血液动力学，以测试流动破坏和剪切应激是否会导致蛋黄囊中血管细胞的异常发育。 MLC2A - / - 胚胎是研究剪切应力作用的理想选择，因为突变体在血管形成中存在缺陷，即使MLC2A从未在心脏之外表达。通过这些具体目标，我们将收集有关蛋黄囊脉管系统的二元开发的重要信息，并将测试机械信号与变化的血管形态的关系。我们在这里专注于单个突变菌株，但是所采用的定量方法可用于研究任何具有血管发育受损或心血管功能受损的突变体。