Hemodynamics: Heterogeneous Endothelial Gene Expression

内皮细胞被公认为影响血管生理和病理的机械传导界面。动脉粥样硬化的患病率与复杂的干扰流在体内相关的区域早已被认识到，但这些网站的易感因素，并加强优先动脉粥样硬化知之甚少。我们认为，血流动力学的力量决定了动脉粥样硬化的易感性，在这些网站的内皮细胞的区域表型的调节。利用微阵列对正常成年猪主动脉进行的初步分析研究表明，不同区域的内皮基因表达存在差异 易于发展动脉粥样硬化病变（血流紊乱）和那些通常不受影响的区域。项目5将阐述以下假设：在病变易感部位，内皮表型处于平衡状态，通过促炎基因的表达引发动脉粥样硬化，但受到抗氧化机制和其他阻止动脉粥样硬化起始/早期发展的基因上调的保护。暴露于一种或多种风险因素（除血流动力学外）被认为是导致血管病理发展的失衡所必需的。在与FDA月桂，MD的设备和放射卫生动物设施中心的合作中，我们将进行第一次多基因 内皮细胞在确定的血流动力学位置的体内表达研究。将在正常成年猪动脉中定义区域内皮表型，并确定重要风险因素高胆固醇血症、性别和激素操作对动脉粥样硬化致敏区域的影响。血流动力学在区域易感性中的关键作用将通过在颈总动脉中产生流动扰动来进行测试，颈总动脉是一个通常暴露于不受干扰的层流并且抵抗动脉粥样硬化形成的位置;我们建议这种干预将导致易感表型。 将在体外测量血液动力学对抗氧化剂、凝血、炎症和其他基因分类的影响，其中将分析暴露于振荡和单向流的猪内皮细胞的转录谱。使用小干扰RNA，将产生特异性基因“敲低”（基因沉默），以确定对体外血液动力学反应的影响，包括通过微阵列分析与后续蛋白质和蛋白质组学研究评价的表型扰动。

The endothelium is well recognized as a mechanotranduction interface influencing vessel physiology and pathology. The prevalence of atherogenesis in regions associated with complex disturbed flows in vivo has long been recognized yet the factors that predispose such sites and potentiate preferential atherosclerosis there are poorly understood. We propose that hemodynamic forces determine the susceptibility to atherosclerosis by regulation of the regional phenotype of endothelium at such sites. Preliminary profiling studies in the normal adult porcine aorta using microarray have shown differences in endothelial gene expression between areas prone to develop atherosclerotic lesions (disturbed flow) and those areas that are typically spared. Project 5 will address the hypothesis that at lesion-susceptible locations, the endothelial phenotype is in an equilibrium state that is primed to develop atherosclerosis by expression of pro-inflammatory genes but is protected by the up-regulation of anti-oxidant mechanisms and other genes that prevent the initiation/early development of atherosclerosis. Exposure to one or more risk factors (additional to hemodynamics) is proposed to be necessary for imbalances that lead to the development of vascular pathology. In a collaboration with the Center for Devices and Radiological Health animal facility at the FDA Laurel, MD, we will conduct the first multi-gene expresssion studies of endothelium in vivo in defined hemodynamic locations. Regional endothelial phenotypes will be defined in normal adult porcine arteries, and the effects of the important risk factors hypercholesterolemia, gender, and hormonal manipulations upon atherosclerosis-primed regions will be determined. The critical role of hemodynamics in regional susceptibility will be tested by creating flow disturbances in the common carotid artery, a location that is normally exposed to undisturbed laminar flow and which is resistant to atherogenesis; we propose that a susceptible phenotype will result from such intervention. The effects of hemodynamic forces upon anti-oxidant, coagulation, inflammatory and other gene classifications will be measured in vitro where transcription profiles of porcine endothelial cells exposed to oscillating and unidirectional flow will be analyzed. Using small interfering RNA, specific gene 'knock-downs' will be created (gene silencing) to determine the effect upon hemodynamic responses in vitro including perturbations of the phenotype as evaluated by microarray profiling with follow-up protein and proteomic studies.