ATRIAL MYOCYTE FUNCTION--STRETCH AND THE CAVEOLAE

心房肌细胞功能——伸展和小窝

• 批准号: 2378848
• 负责人: ERNEST PAGE
• 金额: $ 30.82万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2378848
• 关键词: atrial natriuretic peptide; atrium; biological signal transduction; caveolas; cytoskeletal proteins; electron microscopy; heart cell; heart function; immunofluorescence technique; lipid bilayer membrane; muscle cells; phosphorylation; protein structure; second messengers; stretch receptors; tissue /cell culture

DESCRIPTION: (Adapted from Application) In the heart and its constituent muscle cells, stretch is a crucial physiological stimulus and regulator for both normal muscle contraction and the secretion of atrial natriuretic peptide (ANP) hormone and angiotensin II. Stretch is also a major determinant in the development of cardiac hypertrophy, cardiac arrhythmias, and heart failure, three serious abnormalities which occur frequently in many common heart diseases. While stretch and its normal and abnormal consequences can be measured, the structures which act as sensors and transducers for stretch in normal heart muscle cells have not been identified or characterized. Recent research on noncardiac tissues suggests that plasma membrane-associated vesicles called caveolae function as novel signal transduction systems for multiple stimuli including stretch. The long-term goal of this project is to characterize the structural, functional and biochemical properties of cardiac myocyte caveolae that enable caveolae to act as combined stretch sensors and stretch transducers in intact heart muscle, and to relate these properties to the structure, protein composition, and phosphorylation of caveolae and caveolae-associated proteins isolated from primary cultures of atrial myocytes from adult rats. The specific aims are (1) to test in intact atria and cultured atrial myocytes the hypothesis that atrial myocyte caveolae are implicated in variations in the stretch-dependence of ANP secretion and that such variations correlate with (a) presence of amount of atrial peptide in caveolae, and (b) with changes in phosphorylation of the caveolar coat protein caveolin, and/or other caveolae-associated proteins including cytoskeletal proteins that interact with caveolae; (2) to use experimental techniques that cause caveolae to be either open or closed to the interstitial space, or. alternatively, open or closed to the cytosol, or that promote either the insertion or withdrawal of caveolar necks into or out of the plasmalemmal lipid bilayer, in order to test hypotheses about the regulation, involvement of cytoskeletal proteins, and physiological determinants of these events; (3) (a) to identify, isolate, and localize in situ (by a combination of biochemical, immunofluorescence, and immunoelectron microscopic techniques) the glycophosphatidylinositol-linked proteins and other proteins inside cardiac myocyte caveolae, as well as proteins associated with the cytosolic surface of these caveolae; and (b) to test whether stretch, stimulation of specific plasma membrane receptors, stimulation or inhibition of relevant second messenger pathways, or changes in external or cytosolic Ca2+ concentration release intracaveolar proteins from cardiac myocyte caveolae.

描述：（改编自应用程序）心脏及其 组成肌肉细胞，拉伸是一种至关重要的生理刺激 和调节器的正常肌肉收缩和分泌 心房亚钠肽（ANP）激素和血管紧张素II。 拉紧 也是心脏肥大发展的主要决定因素， 心律不齐和心力衰竭，三个严重异常 在许多常见的心脏病中经常发生。 伸展时 可以测量其正常和异常后果，结构 在正常心肌中充当传感器和传感器 细胞尚未鉴定或表征。 最近的研究 非心脏组织表明质膜相关囊泡 称为Caveolae的功能是新型信号转导系统 多个刺激包括拉伸。 该项目的长期目标 是为了表征结构，功能和生化特性 可使小窝起作用的心肌肌细胞小窝 在完整心肌中拉伸传感器和拉伸传感器，然后 将这些特性与结构，蛋白质组成和 分离的小窝和小窝相关蛋白的磷酸化 从成年大鼠的心房肌细胞的原发性培养物。 具体 目的是（1）在完整的心房和培养的心肌细胞中测试 假设心房肌细胞小窝与变化有关 ANP分泌的拉伸依赖性和这种变化 与（a）口腔中的（a）存在量的房屋肽相关，并且 （b）随着Caveolar涂层蛋白的磷酸化变化 小窝蛋白和/或其他小窝相关的蛋白质，包括 与小窝相互作用的细胞骨架蛋白； （2）使用 导致小窝开放或关闭的实验技术 到室间空间，或。 或者，开放或封闭 细胞质，或促进caveolol的插入或戒断 为了测试 关于调节的假设，细胞骨架蛋白的参与， 这些事件的生理决定因素； （3）（a）识别， 分离物，并原位定位（通过生化的结合 免疫荧光和免疫电子显微镜技术） 糖磷脂酰肌醇连接蛋白和其他蛋白质内部 心肌细胞小窝，以及与之相关的蛋白质 这些口腔的胞质表面； （b）测试是否伸展， 刺激特定质膜受体，刺激或 抑制相关的第二通路途径或外部变化 或胞质Ca2+浓度从 心肌细胞小窝。