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Intracellular signal transduction mechanisms of airway epithelial cells in allergic conditions

过敏状态下气道上皮细胞的细胞内信号转导机制

基本信息

批准号：
16591705
负责人：
TAKEUCHI Kazuhiko
金额：
$ 2.11万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16591705/
关键词：
NF-κB thrombin mucin leukotrienes signal transduction PAR cellular structural proteins permeability G-protein PKC MEK

项目摘要

Recently, it is believed that epithelial cells play important roles in allergic conditions as in allergic rhinitis. We tried to elucidate the intracellular signal transduction mechanisms by which mediators have effects on functional changes in epithelial cells.1.Mechanism by which leukotrienes activate mucin gene transcriptionLeukotriene D_4 (LTD_4) has been shown to induce mucus secretion in the airway. However, nothing has previously been known about the effect of LTD_4 on mucin gene expression. Reporter gene assay was mainly used for analysis. We found that NF-κB is required for LTD_4-induced MUC2 gene transcription in a CysLT_1R-dependent manner. Taken together, our findings suggest that LTD_4 up-regulates MUC2 gene transcription via a signaling pathway involving CysLT_1R, G-protein, PKC, MEK, ERK and NF-κB.2.Mechanism by which thrombin increases permeability in epithelial cellsRecently, thrombin was reported to be increased in the airway of patients with asthma, and thrombin has b … More een shown to increase the permeability of endothelial cell monolayers. Therefore, we suspected that thrombin affects airway permeability. Calu-3 cell monolayers were established on microporous membranes of tissue culture cell inserts. We examined the effects of topically applied thrombin or thrombin receptor activating peptide (TRAP) on : (1) transepithelial permeability (luminal to serosal transfer) of radiolabeled mannitol and albumin, (2) changes in electrical resistance, and (3) actin fiber content as assessed by fluorescence microscopy. Compared with untreated control cultures, treatment of the monolayers for 24 h with thrombin or TRAP significantly decreased the electrical resistance and increased the permeability to mannitol and albumin. In addition, these treatments enhanced the appearance of actin stress fibers, and small gaps became visible at areas of cell-cell contact. Thrombin appears to increase epithelial permeability by receptor-mediated reorganization of the actin network in airway epithelial cells. This is likely to contribute to the impairment of the airway barrier function. Less

最近，人们认为上皮细胞在变态反应性疾病和变应性鼻炎中发挥着重要作用。我们试图阐明细胞内介质影响上皮细胞功能变化的信号转导机制。1.白三烯激活粘蛋白基因转录的机制白三烯D_4(LTD_4)已被证明诱导呼吸道粘液分泌。然而，LTD_4对粘蛋白基因表达的影响尚不清楚。报告基因分析主要用于分析。我们发现，在LTD_4诱导的MUC2基因转录中，NF-κB是必需的，这种转录依赖于CysLT_1R。综上所述，我们的研究结果表明，LTD_4通过涉及CysLT_1R、G蛋白、蛋白激酶C、蛋白酪氨酸激酶、ERK和核因子-κB_2的信号通路上调MUC2基因的转录。2.凝血酶增加上皮细胞通透性的机制最近报道，哮喘患者呼吸道内凝血酶增加，凝血酶有…更多的被证明增加内皮细胞单层的通透性。因此，我们怀疑凝血酶影响呼吸道通透性。在组织培养细胞贴片的微孔膜上建立了CALU-3细胞单层。我们观察了局部应用凝血酶或凝血酶受体激活肽(TRAP)对以下方面的影响：(1)放射性标记甘露醇和白蛋白的跨上皮通透性(腔至浆膜转移)，(2)电阻的变化，以及(3)荧光显微镜下评估的肌动蛋白纤维含量。与未经处理的对照组相比，经凝血酶或TRAP处理24 h的单层细胞的电阻显著降低，对甘露醇和白蛋白的通透性增加。此外，这些处理增加了肌动蛋白应激纤维的出现，在细胞与细胞接触的区域可以看到小的缝隙。凝血酶似乎通过受体介导的呼吸道上皮细胞肌动蛋白网络的重组来增加上皮的通透性。这可能会导致呼吸道屏障功能的损害。较少