PERTICIPATION OF INTRACELLULAR SIGNAL TRANSDUCTION PATHWAY AND RE-PERFUSION LUNG INJURY AFTER LUNG TRANSPLANTATION

我们发现嗜中性粒细胞诱导的肺损伤是由中性粒细胞粘附在内皮细胞上后通过黄嘌呤氧化酶（XO）产生的活性氧引起的;通常，XO不存在于中性粒细胞中，而存在于内皮细胞中。因此，我们推测这种肺损伤是否是由内皮细胞本身的激活引起的。在离体大鼠肺灌流实验中，我们用蛋白激酶C拮抗剂研究了活化中性粒细胞对肺血管内皮细胞的损伤是否与细胞内信号转导系统有关。我们发现PKC拮抗剂以剂量依赖的方式减轻由活化的中性粒细胞引起的肺血管损伤。此外，我们发现，肺血管通透性增加的PKC激动剂没有中性粒细胞。另一方面，在细胞培养模型中，不可能测量细胞培养片的蛋白质渗透性，我们测量了trans-en ...更多信息 跨培养的肺血管内皮细胞片的内皮电阻（TER）。高渗暴露的主要效应是TER增加，表明屏障强化的诱导。高渗暴露也增加了粘着斑激酶和E-钙粘蛋白在细胞周围的积累的活性。与此同时，肌动蛋白丝的密度显着增加。PMA（phobor myristate acetate）是蛋白激酶C的激动剂，可降低TER，表明肌动蛋白丝解聚。另一方面，细胞松弛素D，肌动蛋白丝的解聚剂，也降低TER，表明肌动蛋白解聚的参与。肌动蛋白对高渗暴露的反应增强，尽管TER中的反应不受影响，表明内皮屏障增强独立于肌动蛋白发生。然而，在单层表达的激酶依赖性突变体的黏着斑激酶，高渗诱导的黏着斑激酶和外周E-钙粘蛋白增强活性的增加被阻断，并诱导增加的TER显着钝化。这些结果表明，EC暴露于高渗性的挑战，粘着斑激酶的参与是至关重要的，在建立屏障加强。少

We showed that neutrophils-induced lung injury was induced by reactive oxygen species generated via xanthine oxidase(XO) following adhesion of neutrophils on the endothelial cells; Usually, XO does not exist in the neutrophils but endothelial cells. Therefore we speculate if this kind of lung injury is induced by activation of endothelial cells themselves. In the experiments of isolated perfused rat lungs, whether intracellular signal transduction systems were involved in the injury of the pulmonary vascular endothelial cells caused by activated neutrophils, we investigated using a protein kinase C antagonist. We showed that PKC antagonist ameliorated the pulmonary vascular injury caused by activated neutrophils in a dose dependent manner. Besides, we showed that the pulmonary vascular permeability was increased by a PKC agonist without neutrophils. On the other hand, in cell culture models, it was impossible to measure protein permeability for cell culture sheets, we measured trans-en … More dothelial electrical resistance (TER) across the cultured pulmonary vascular endothelial cell sheets. The dominanat effect of hyperosmolar exposure was an increase in the TER, indicating the induction of barrier strengthening. Hyperosmolar exposure also increased activity of focal adhesion kinase and E-cadherin accumulation at the cell periphery. Concomitantly, the density of actin filaments increased markedly. PMA (phobor myristate acetate), an agonist of Protein kinase C, decreased the TER, indicating a de-polymerization of actin filaments. On the other hand, cytochalasin D, de-polymerize agents for actin filaments, also decreased TER, indicating participation of actin de-polymerization. The actin response to hyperosmolar exposure was enhanced although the response in TER was unaffected, indicating that the endothelial barrier enhancement occurred independently actin. However, in monolayers expressing a kinase-dependent mutant of focal adhesion kinase, the hyperosmolarity-induced increase in activity of focal adhesion kinase and peripheral E-cadherin enhancement were blocked and the induced increase of TER was markedly blunted. These findings indicate that EC exposed to hyperosmolar challenge, the involvement of focal adhesion kinase was critical in establishing barrier strengthening. Less