Effects of shear stress on regulation of epithelial permeability

剪切应力对上皮通透性调节的影响

• 批准号: 7651284
• 负责人: Venkataramana K Sidhaye
• 金额: $ 13.55万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-03 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7651284
• 关键词: Actins; Air; Apical; Area; Asthma; Breathing; Calcium; Cations; Cells; Coughing; Critical Care; Cytoskeleton; DNA Sequence Rearrangement; Data; Development; Disease; Endothelial Cells; Environment; Environmental air flow; Epidermal Growth Factor; Epithelial; Epithelial Cells; Event; Exercise; Foundations; Frequencies; Goals; Height; Hepatocyte; Human; Infection; Inflammation; Ion Channel; Kidney; L-Type Calcium Channels; Lung; Mechanics; Medicine; Membrane; Metabolic acidosis; MicroRNAs; Modeling; Mus; Nifedipine; Nitric Oxide; Organ; Pathologic; Pathway interactions; Permeability; Physiological; Physiology; Play; Production; Property; Proteins; Regulation; Relative (related person); Reporting; Research Personnel; Respiration; Respiratory physiology; Rest; Role; Signal Transduction; Source; Stimulus; Structure of respiratory epithelium; Surface; TRPV channel; Techniques; Tidal Volume; Tight Junctions; Trachea; Tubular formation; Vanilloid; Vascular Endothelial Cell; Water; abstracting; airway epithelium; airway surface liquid; aquaporin 5; career; claudin-1 protein; cytokine; experience; genetic manipulation; human NOS3 protein; in vitro Model; inhibitor/antagonist; interest; novel; particle; programs; receptor; release of sequestered calcium ion into cytoplasm; response; shear stress; skills; tool; voltage gated channel; water channel

DESCRIPTION (provided by applicant): The goal of this K08 application is to facilitate development of essential skills that will allow the PI to become a successful academician and achieve independent scientific investigator status. The respiratory epithelium serves as a barrier, a regulator of the content of airway surface liquid, and a source of cytokines and other products that regulate airway physiology. In addition to cyclic extensions and contraction, airway epithelial cells are exposed to lumenal shear stress, defined as the frictional force per unit surface area, generated by airflow. The shear stress sensed by airway epithelia is continuously changing under both physiologic and pathologic conditions. We have exciting novel data suggesting that shear stress in airway epithelial cells leads to changes in airway epithelial permeability. Therefore, dynamic modulation of the airway epithelial barrier could be an important mechanism by which epithelial cells transduce lumenal information into subepithelial responses. Our preliminary studies indicate that shear stress induces TRPV4 activation with subsequent L-type voltage gated channel activation with subsequent increases in intracellular calcium. The increase in intracellular calcium in airway epithelial cells leads to concerted changes in epithelial paracellular permeability by modulating actin rearrangement and NO production, as well as in transmembrane permeability by modulating AQP5 abundance. We propose to study the role of shear stress in altering both paracellular and transmembrane permeability as well as dissect the underlying mechanisms regulating these effects. In SA#1we will investigate the effects of shear stress on airway epithelial permeability using primary cultured human airway epithelial cells (NHBE) and.ex vivo isolated mouse trachea. In SA#2 we will define the role for and the mechanisms (TRPV4, L-type channel) of shear-induced calcium flux in modulating epithelial permeability using pharmacologic inhibition and genetic manipulation. In SA#3 we will study the role od shear-induced increases in calcium on NO production and its effect on permeability. Through these complimentary techniques and coursework, the PI will develop new skills and generate novel data regarding the effects of mechanical shear stress on airway epithelial cell regulation and function, a little-examined area likely to be of immense importance to normal lung function, as well as conditions of altered shear including exercise and asthma. (End of Abstract)

描述（由申请人提供）： 该K08申请的目标是促进基本技能的发展，使PI成为一名成功的院士并获得独立的科学研究者地位。呼吸道上皮作为一个屏障，气道表面液体的内容物的调节器，和细胞因子和其他产品的来源，调节气道生理。除了周期性伸展和收缩之外，气道上皮细胞还暴露于由气流产生的内腔剪切应力，该剪切应力定义为每单位表面积的摩擦力。在生理和病理条件下，气道上皮感受到的切应力都在不断变化。我们有令人兴奋的新数据表明，气道上皮细胞的剪切应力导致气道上皮通透性的变化。因此，气道上皮屏障的动态调节可能是上皮细胞将腔信息转化为上皮下反应的重要机制。我们的初步研究表明，剪切应力诱导TRPV4激活，随后L型电压门控通道激活，随后增加细胞内钙。气道上皮细胞中细胞内钙离子的增加通过调节肌动蛋白重排和NO产生导致上皮细胞旁通透性的协同变化，以及通过调节AQP5丰度导致跨膜通透性的协同变化。我们建议研究剪切应力在改变细胞旁和跨膜渗透性中的作用，并剖析调节这些作用的潜在机制。在SA#1中，我们将使用原代培养的人气道上皮细胞（NHBE）和离体小鼠气管研究切应力对气道上皮通透性的影响。在SA#2中，我们将定义剪切诱导的钙流在使用药理学抑制和遗传操作调节上皮通透性中的作用和机制（TRPV4，L型通道）。在SA#3中，我们将研究剪切诱导的钙增加对NO产生的作用及其对渗透性的影响。通过这些免费的技术和课程，PI将开发新的技能，并产生关于机械剪切应力对气道上皮细胞调节和功能的影响的新数据，这是一个很少检查的领域，可能对正常肺功能以及包括运动和哮喘在内的剪切力改变的条件非常重要。(End摘要）