A molecular biologic study on delayed type cell injury of the airway mucosa.

用10 μ M的白三烯D_4（LTD_4）和10 μ M的血小板活化因子（PAF）分别诱导培养的人鼻粘膜上皮细胞诱导型一氧化氮合酶mRNA（iNOSmRNA）、黄嘌呤氧化酶mRNA（XO mRNA）和环氧化酶-2 mRNA（考克斯-2 mRNA）的表达<-8><-8>。通过真实的时间-PCR研究每个mRNA。结果：（1）与PBS相比，LTD_4对iNOS mRNA、XO mRNA和考克斯-2 mRNA的诱导水平相同;（2）与PBS相比，PAF对iNOS mRNA的诱导水平相同，但对XO mRNA和考克斯-2 mRNA的诱导水平较高。（3）LTD_4可增加细胞液中iNOS蛋白的浓度，PAF则略有增加，提示LTD_4可能通过iNOS参与NO的过量产生，PAF可能通过XO参与超氧阴离子的产生。这些脂质介质产生于皮下 ...更多信息 炎症细胞如嗜酸性粒细胞、中性粒细胞和巨噬细胞;特别是PAF在嗜酸性粒细胞中产生的量更大。因此，上皮细胞可能也参与了过敏性炎症过程中NO和超氧化物的过量产生，提示炎症细胞如嗜酸性粒细胞、其它白细胞释放的LTD_4和PAF参与了超氧化物的产生，并与其它促XO的因子有关。炎症细胞产生超氧化物是众所周知的，但其机制尚未阐明。LTB_4还具有促进白细胞产生超氧阴离子的能力。因此，在过量产生NO和产生超氧化物的情况下，这些分子相互反应产生过氧亚硝酸盐，过氧亚硝酸盐具有强烈的伤害活性并攻击酪氨酸，留下痕量硝基酪氨酸。我们先前的研究显示过敏性鼻炎患者的鼻液中含有硝基酪氨酸。原代细胞因子对体外培养的人鼻上皮细胞诱导iNOS mRNA、XO mRNA和考克斯-2 mRNA表达的影响有待进一步研究。少

Induction of inducible nitric oxide synthase m RNA (iNOS mRNA), xanthine oxidase mRNA (XO mRNA) and cylooxygenase-2 mRNA (COX-2 mRNA) in cultured human nasal epithelial cells were studied by exposing to 10^<-8>M leukotrien D_4(LTD_4) and 10^<-8>M platelet activating factor (PAF), respectively and 20 hours later total RNA was extracted. Each mRNA was investigated by real time -PCR. The concentration of the iNOS protein in the cell solution was also measured in a duplicate manner.Results : (1)Comparing PBS, LTD_4 showed the same level induction of iNOS mRNA, XO mRNA and COX-2 mRNA. (2)Comparing PBS, PAF showed the same level induction of iNOS mRNA although PAF did higher level of induction of both XO mRNA and COX-2 mRNA. (3)LTD_4 augmented the concentration of the iNOS protein in the cell solution, while PAF did slightly.These results suggest that LTD_4 may take part in excessive production of NO via iNOS, and PAF may do superoxide production via XO. These lipid mediators generated in su … More ch inflamed cells as eosinophils, neutrophils and macrophages ; especially PAF is generated in eosinophils in greater amount. Therefore, epithelial cells may also relate with excess production of NO and superoxide in allergic inflammation process.These results suggest that LTD_4 and PAF released from inflamed cells such as eosinophils, other leukocytes takes part in superoxide production associated with other promoting factors of XO. It has been well known that inflamed cells produce superoxide, however, its mechanism has not been elucidated. LTB_4 has also the capacity of promoting superoxide generation in leukocytes. Therefore, under excessive generation of NO and superoxide generation, these molecules react each other generating peroxynitrite, which has strong injurious activity and attack tyrosine leaving a trace, nitrotyrosine. Our previous study showed nitrotyrosine in nasal leverage fluids of allergic patients with rhinitis. In the further study the effect of primary cytokines on induction of iNOS mRNA, XO mRNA and COX-2 mRNA in cultured human nasal epithelial cells should be elucidated. Less