MECHANICAL INJURY TO LUNG ENDOTHELIUM

肺内皮机械损伤

• 批准号: 6233721
• 负责人: JAMES Courtney PARKER
• 金额: $ 24.02万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2001-09-23
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6233721
• 关键词: CHO cells; calcium flux; cytokine; hemodynamics; inflammation; laboratory rat; lung injury; mechanical stress; membrane channels; transfection; vascular endothelium; vascular endothelium permeability; voltage /patch clamp

DESCRIPTION (Applicant's Abstract): Mechanical injury to the lung by high airway and vascular pressures cause increased vascular permeability and fluid extravasation in a number of disease states, but the segmental localization of vascular injury and cellular pathways are unknown. However, mechanical strain induced Ca2+ entry through stretch activated cation channels (SACC) appears to initiate endothelial cell (EC) retraction and adhesion release leading to vascular leak. We propose to establish SACC involvement in mechanical lung injury using three novel approaches with vertically integrated studies at the single channel, endothelial monolayer and intact lung levels. 1) Alveolar and extra-alveolar segmental permeabilities in isolated lungs will be assessed using segmental filtration coefficients (Kf) of arterial, venous an microvascular segments and electron microscopy under conditions which differentially alter segmental wall stresses. 2) Whole-cell voltage clamp and single-channel cell-attached patch clamp measurements of Ca2+ and monovalent cation entry currents evoked by cell deformation will be compared in cultured endothelial cells from rat pulmonary artery, vein and microvascular segments and Chinese Hamster Ovary (CHO) cells with and without transfection and expression of MID 1, a SACC gene product recently cloned from the yeast, Saccharomyces cerevisiae. 3) Pressure deformation induced increases in hydraulic conductance (Lp), decreases in protein reflection coefficient and changes in equivalent pore distribution in monolayers of the three EC phenotypes will be measured with and without expression of the MID1 gene product to determine the role of SACC in initiating the increased permeability as wet as certain cellular mechanism involved in the increase. Finally, the modulation of strain induced Ca2+ entry and permeability by cyclic nucleotides, cytoskeletal tone, cytokines and oxidants will be determined in the three experimental models to determine if polymodal gating and cellular feed back regulated SACC Ca2+ entry. At the end of this research we will unequivocally establish that SACC are critical for initiating strain induced vascular permeability increases and whether polymodal gating by cellular pathways and inflammatory mediators modulate this response to increase susceptibility to mechanical injury of patients with lung disease.

描述（申请人的摘要）：高肺的机械损伤 气道和血管压力导致血管渗透性增加和流体 在许多疾病状态下进行渗出，但是 血管损伤和细胞途径尚不清楚。但是，机械应变 通过拉伸激活的阳离子通道（SACC）诱导Ca2+进入 启动内皮细胞（EC）缩回和粘附释放，导致 血管泄漏。我们建议在机械肺中建立SACC参与 使用三种新型方法在垂直整合研究的情况下进行伤害 单个通道，内皮单层和完整的肺水平。 1）牙槽和 将评估孤立肺中的肺泡外节渗透率 使用动脉静脉的分段过滤系数（KF） 在条件下的微血管段和电子显微镜 差异改变节壁应力。 2）全电池电压夹和 CA2+和单价的单通道连接贴片夹夹测量 将在培养中比较细胞变形引起的阳离子进入电流 大鼠肺动脉，静脉和微血管段的内皮细胞 有和没有转染的中国仓鼠卵巢（CHO）细胞， Mid 1的表达，最近从酵母克隆的SACC基因产物的表达， 酿酒酵母。 3）压力变形引起的增加 液压电导（LP）降低蛋白质反射系数和 三个EC的单层孔分布的变化 表型将在MID1基因表达和不表达的情况下测量 确定SACC在启动渗透率增加的作用的产品 与某些涉及增加的细胞机制一样湿。最后， 调节应变诱导的Ca2+进入和循环核苷酸的渗透性， 细胞骨架张力，细胞因子和氧化剂将在三个 实验模型，以确定多形成门控和细胞反馈是否 受管制的SACC CA2+进入。在这项研究结束时，我们将明确地 确定SACC对于启动菌株诱导血管至关重要 渗透性增加，以及通过细胞途径和 炎症介体调节这种反应，以增加对 肺部疾病患者的机械损伤。