MECHANICS AND DEFORMATION RESPONSES OF LUNG CELLS

描述（申请人摘要）：有压倒性的证据表明， 肺变形引发水肿和炎症。这些证据已经产生了 一场关于呼吸机设置选择的激烈争论， 损伤的肺，并推动了对呼吸机诱导的机制的研究。 肺损伤（VILI）。机制的数量和机制之间复杂的相互作用 它们使对整个肺的实验分析复杂化。为此我们 我建议测试我们的主要假设（变形代表一个 对上皮和内皮肺细胞的促炎刺激） 器官，以及在减少系统。在目标1下详述的研究中，我们将 明确基质变形与炎症反应的关系， 肺泡上皮细胞和肺毛细血管内皮细胞的信号反应 细胞培养。我们假设，足够振幅的周期性变形 上调炎症介质的产生和释放， 伴随间歇性非致死质膜的钙振荡 应力失效事件可能是一种信号传导机制。目标二是 为了强调细胞培养工作的生物相关性， VILI大鼠模型肺泡上皮细胞是否表达介质 炎症以及这种表达是否需要来自肺泡的输入 巨噬细胞目标3和4是通过以下方式剖析责任机制： 表征基质应变对细胞形状的影响， 细胞骨架和质膜之间的机械相互作用。我们推测 (1)变形的细胞通过插入脂质 分子从细胞内存储和（2）质膜应力和 应力破坏概率随细胞骨架刚度而变化。识别 变形应力的传递是一个迅速扩展的研究领域。 它的大部分重点是膜通道生理学和调节 脂质和蛋白质介质。信号本身（细胞形状的变化和 相关的应力分布），细胞骨架之间的相互作用 以及这些相互作用对血浆 膜应力破坏相比之下很少受到关注。这是 我们想要填补的知识上的差距。

DESCRIPTION (Applicant's abstract): There is overwhelming evidence that large lung deformations trigger edema and inflammation. This evidence has generated an intense debate about the choice of ventilator settings for patients with injured lungs and has fueled research on the mechanisms of ventilator-induced lung injury (VILI). The number of mechanisms and the complex interplay between them complicate analyses of experiments on whole lungs. For this reason, we propose to test our principal hypothesis (that deformation represents a pro-inflammatory stimulus for epithelial and endothelial lung cells) in whole organ as well as in reduced systems. In studies detailed under Aim 1, we will define the relationships between substratum deformation and the inflammatory signaling responses of alveolar epithelial and pulmonary capillary endothelial cells in culture. We postulate that cyclic deformation of sufficient amplitude up-regulates production and release of inflammatory mediators and consider calcium oscillations accompanying intermittent non-lethal plasma membrane stress failure events to be a possible signal transduction mechanism. Aim 2 is to underscore the biologic relevance of the cell culture work by testing in a rat model of VILI whether alveolar epithelial cells express mediators of inflammation and whether this expression requires input from alveolar macrophages. Aims 3 and 4 are to dissect the responsible mechanisms by characterizing the effects of substratum strain on cell shape and the mechanical interactions between cytoskeleton and plasma membrane. We postulate (1) that deformed cells minimize plasma membrane stress by inserting lipid molecules from intracellular stores and (2) that plasma membrane stress and the probability of stress failure vary with cytoskeletal stiffness. The recognition and transduction of deforming stresses is a rapidly expanding area of research. Much of its focus has been on membrane channel physiology and the regulation of lipid and protein mediators. The signal itself (the change in cell shape and the associated stress-distribution), the interactions between the cytoskeleton and the plasma membrane, and the implications of these interactions for plasma membrane stress failure have in comparison received little attention. This is the gap in knowledge that we intend to fill.