STUDY OF ADHESION MOLECULES, CYTOSKELETON AND SIGNAL TRANSDUCTION PATHWAY ON INJURY OF ENDOTHELIAL CELLS FOR ISOLATED PRESERVED LUNGS

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。XO通常不存在于中性粒细胞，而存在于内皮细胞。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，我们测量了反式- ...更多信息 图2示出了跨培养的肺血管内皮细胞片的内皮电阻（TER）。本实验连续测定了大鼠肺血管内皮细胞体外培养细胞片汇合时的TER值，并对几种激动剂和拮抗剂进行了检测。PKC激动剂可剂量依赖性地降低细胞的TER值，而PKC激动剂的赋形剂DMSO则不起作用。这些发现支持了离体大鼠肺的实验结果。我们还染色肺血管内皮细胞中的肌动蛋白纤维。肌动蛋白纤维存在于胞浆的周边区域，在没有任何刺激的情况下，它们被PKC激动剂解聚并绕核移动。这些结果表明，肺血管内皮细胞在受到某些刺激时，通过PKC解聚肌动蛋白纤维而改变其形态，最终增加肺微血管通透性。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. Moreover, 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- … More endothelial electrical resistance (TER) across the cultured pulmonary vascular endothelial cell sheets. We continuously measured TER of the cultured cell sheets from rat pulmonary vascular endothelial cells when they were confluent and the tested the several kinds of agonists and antagonists to the cultured cell sheets. The TERs of the cultured cell sheets were decreased by PKC agonists by dose dependent manner, meanwhile DMSO, a vehicle of PKC agonist, failed. These findings supported the results from the experiment of isolated rat lungs. We also stained actin fibers in the pulmonary vascular endothelial cells. Actin fibers existed at the peripheral area of the cytosol without any stimulations, however, they were depolymerized and moved around nucleus by PKC agonist. These findings suggest that the pulmonary vascular endothelial cells were changed their morphology by depolymerizing actin fibers by PKC when they were activated by some stimulations, and finally pulmonary microvascular permeability was increased. Less