| Co-Investigator(Kenkyū-buntansha) |
TOMOYASU Makoto IWATE MEDICAL UNIVERSITY, THORACIC SURGERY, INSTRUCTOR, 医学部, 助手 (50347861)
MIZUNO Masaru IWATE MEDICAL UNIVERSITY, THE THIRD DEPT OF SURG, ASSISTANT PROFESSOR, 医学部, 講師 (90321992)
南雲 朋樹 岩手医科大学, 医学部, 助手 (70316371)
菰田 研二 岩手医科大学, 医学部, 講師 (10162067)
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| Budget Amount *help |
¥14,400,000 (Direct Cost: ¥14,400,000)
Fiscal Year 2003: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2002: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2001: ¥8,900,000 (Direct Cost: ¥8,900,000)
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| Research Abstract |
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
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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
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