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

我们发现中性粒细胞诱导的肺损伤是由黄嘌呤氧化酶（XO）在中性粒细胞粘附在内皮细胞上后产生的活性氧诱导的。通常，XO不存在于中性粒细胞中，而是存在于内皮细胞中。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。在离体灌注大鼠肺实验中，我们使用蛋白激酶C拮抗剂研究了细胞内信号转导系统是否参与了中性粒细胞活化引起的肺血管内皮细胞损伤。我们发现 PKC 拮抗剂以剂量依赖性方式改善由活化的中性粒细胞引起的肺血管损伤。此外，我们发现，在没有中性粒细胞的情况下，PKC 激动剂可以增加肺血管通透性。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，我们测量了培养的肺血管内皮细胞片的反式内皮电阻（TER）。高渗暴露的主要作用是 TER 的增加，表明屏障强化的诱导。高渗暴露还增加了细胞外周粘附斑激酶的活性和 E-钙粘蛋白的积累。与此同时，肌动蛋白丝的密度显着增加。 PMA（phobor myristateacetate）是一种蛋白激酶 C 激动剂，可降低 TER，表明肌动蛋白丝发生解聚。另一方面，肌动蛋白丝的解聚剂细胞松弛素 D 也降低了 TER，表明参与了肌动蛋白的解聚。尽管 TER 中的反应不受影响，但肌动蛋白对高渗暴露的反应增强，表明内皮屏障增强独立于肌动蛋白发生。然而，在表达粘着斑激酶的激酶依赖性突变体的单层细胞中，高渗透压诱导的粘着斑激酶活性增加和外周E-钙粘蛋白增强被阻断，并且TER诱导的增加明显减弱。这些发现表明，EC 暴露于高渗挑战，粘着斑激酶的参与对于建立屏障强化至关重要。较少的

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