STRETCH INDUCED ACTIVATION OF MAP KINASES IN THE LUNG

成人呼吸窘迫综合征（ARDS）的治疗需要 使用正压机械通气， 吸入氧气，为重要器官提供充足的氧气。以来 ARDS是一种非同质性疾病，某些区域受影响较小， 因此更加顺从。这些区域可能因机械性过度扩张而导致 呼吸机呼吸。这种呼吸诱导性肺损伤的特征是 通过非心源性肺水肿、炎性细胞因子的释放和 中性粒细胞的流入。人们对肺的影响知之甚少 细胞水平的组织过度膨胀。白细胞介素8（IL-8）是一种 炎性细胞因子和肺中中性粒细胞的化学引诱物。的 MAP激酶，包括应激活化蛋白激酶（SAPK）、p38和 ERK-1/2，调节细胞对细胞外刺激的反应，如 氧化应激、热休克、生长因子和辐射。我们假设 肺细胞牵张诱导的IL-8产生依赖于活化 应激反应性MAP激酶，SAPK和/或p38。审查 拉伸在细胞水平的影响我们使用细胞拉伸装置， 对柔性细胞培养膜施加均匀的双轴应变。肺 细胞，包括II型肺泡细胞和肺动脉内皮 细胞在纤连蛋白包被的硅酮弹性膜上生长。的 所施加的应变在12至24周/分钟下从2%变化至25%。 我们的初步数据显示，拉伸激活了SAPKs和p38， 增加IL-8的产生。两者的联合药理学阻断 SAPK和p38激活阻断牵张诱导的IL-8产生。这 该提案寻求：1）定义MAP激酶，包括SAPK，p38， 和ERK-1/2，在调节牵张诱导的IL-8的产生，通过 编码显性抑制突变体的重组腺病毒的用途 SAPKs和p38激活; 2）确定MAP激酶激活的作用 IL-8 mRNA的转录调控; 3）确定细胞的 牵张诱导的MAP激酶激活， MAP激酶途径中的活化剂被细胞拉伸激活。

The treatment of adult respiratory distress syndrome (ARDS) requires the use of positive pressure mechanical ventilation with high levels of inspired oxygen to provide adequate oxygenation to vital organs. Since ARDS is an inhomogeneous disease, some areas are less affected and therefore more compliant. These areas may be mechanically overdistended by ventilator breaths. This ventilatory induced lung injury is characterized by non-cardiogenic pulmonary edema, release of inflammatory cytokines and influx of neutrophils. Little is understood about the effects of lung tissue overdistention at the cellular level. Interleukin 8 (IL-8) is an inflammatory cytokine and chemoattractant for neutrophils in the lung. The MAP kinases, including stress activated protein kinase (SAPK), p38 and ERK-1/2, regulate cellular response to extracellular stimuli, such as oxidant stress, heat shock, growth factors and radiation. We hypothesize that lung cell stretch induced IL-8 production is dependent on activation of the stress responsive MAP kinases, SAPK and/or p38. To examine the effects of stretch at the cellular level we use a cell stretch device that applies uniform biaxial strain to flexible cell culture membranes. Lung cells, including type II alveolar cells and pulmonary artery endothelial cells, are grown on fibronectin coated silicone elastomeric membranes. The applied strain varies from two to 25 percent at 12 to 24 cycles/minute. Our preliminary data show that stretch activates the SAPKs and p38, and increases production of IL-8. Combined pharmacological blockade of both SAPK and p38 activation blocked stretch-induced IL-8 production. This proposal seeks to: 1) define the role MAP kinases, including SAPK, p38, and ERK-1/2, in regulation of stretch induced IL-8 production, through the use of recombinant adenoviruses encoding dominant inhibitory mutants of SAPKs and p38 activation; 2) determine the effect of MAP kinase activation on transcription regulation of IL-8 mRNA and 3) define the pathway of cell stretch-induce MAP kinase activation by determining the upstream activators in the MAP kinase pathways are activated by cell stretch.