TRANSDUCTION OF HEMODYNAMIC SIGNALS INTO VASCULAR CELLS

开发有效的预防和治疗方案 心血管疾病，重要的是要了解控制 血管内皮的功能状态。血液流动的变化和 压力改变内皮细胞(EC)的功能状态， 自然地受到就地物理力量的影响。因此，定义了 物理力量在维持正常和健康中的确切作用 产生病态的EC行为很重要。剪切力，力 与EC相切的血液流动被认为是 对血管内皮损伤最大的机械力。是否 剪应力的脉动变化不同于恒定的刺激 剪应力是未知的。本研究将分析其作用机制。 EC对恒定剪应力的自适应响应，并与 对脉动剪应力的响应。 血流动力学信息是如何通过细胞膜传递的 然后这个信息是如何被传递到细胞的其他部分的 被调查。细胞如何根据蛋白质的变化做出反应 将对合成进行研究。具体目标遵循一系列 刺激和反应，检验以下假设：1.即 剪应力信息的传递由离子的变化组成 导致膜超极化的通道，2.增加 胞内钙是切变信号转导的第二信使 应力信号，以及3.剪切应力改变了合成速率 特定的蛋白质。将对这些蛋白质进行鉴定，并研究其动力学 这些蛋白质在剪切力作用下的变化将被研究。 长期目标是了解EC蛋白的适应性反应。 切应力，并研究转导事件如何改变 这些蛋白质的合成。 这些研究将涉及膜的连续测量。 用荧光染料和荧光染料测定电位和胞内钙 同位素外流。放射性标记蛋白质将通过二维凝胶进行研究 电泳，荧光照相，凝胶的数字分析，分级， 抗体反应性和多肽测序。 内皮细胞异常可能导致动脉粥样硬化、血栓形成、 止血障碍，以及炎症、免疫反应性和 肿瘤发生学。切应力如何改变EC功能磨机阐明这些 疾病过程。

To develop effective preventative and therapeutic regimens for cardiovascular disease, it is important to understand control of the functional state of the vascular endothelium. Changes in blood flow and pressure alter the functional state of the endothelial cells (EC), which are naturally subjected to physical forces in situ. Thus definition of the precise roles of physical forces in maintaining normal and in producing pathological EC behavior is important. Shear stress, the force tangential to the EC resulting from blood flow is considered to be the mechanical force that is most injurious to the endothelium. Whether pulsatile variations in shear stress differ as a stimulus from steady shear stress is unknown. This research will analyze the mechanisms of adaptive EC responses to steady shear stress, and compare these with responses to pulsatile shear stress. How hemodynamic information is transduced across the cell membrane and how this information is then conveyed to other parts of the cell will be investigated. How the cell responds in terms of changes in protein synthesis will be investigated. Specific Aims follow a sequence of stimulus and response, testing the following hypotheses: 1. that transduction of shear stress information consists of alterations in ion channels leading to membrane hyperpolarization, 2. that an increase in cytosolic calcium acts as a second messenger for transduction of shear stress signals, and 3. that shear stress changes synthetic rates of specific proteins. The proteins will be identified and the kinetics of change in these proteins produced by shear stress will be investigated. The long term goal is to understand the adaptive response of EC proteins to shear stress, and to investigate how transduction events alter synthesis of these proteins. These studies will involve continuous measurement of membrane potential and cytosolic calcium using spectrofluorometric dyes and isotopic efflux. Radiolabelled proteins will be studied by 2-D gel electrophoresis, fluorography, digital analysis of gels, fractionation, antibody reactivity, and peptide sequencing. EC abnormalities may contribute to atherosclerosis, thrombosis, hemostatic disorders, as well as to inflammation, immune reactivity and tumorigenesis. How shear stress alters EC function mill elucidate these disease processes.