Suzuki Shinya, Takeuchi Kazuhiko, Ishinaga Hajime, Basbaum Carol, Majima Yuichi
Department of Otorhinolaryngology, Head and Neck Surgery, Mie University Graduate School of Medicine, Edobashi, Tsu, Mie, Japan.
Pharmacology. 2008;81(3):221-8. doi: 10.1159/000112866. Epub 2008 Jan 7.
BACKGROUND/AIMS: Leukotriene (LT) D(4) has been shown to induce mucus secretion in the airways. Excessive mucus secretion characterizes airway inflammatory disease such as asthma, allergic rhinitis. However, little is known about the effect of LTD(4) on mucin gene expression. The aim of this study was to investigate the effect of LTD(4) on MUC2 gene expression in cultured epithelial cells (HM3-MUC2 cells).
HM3-MUC2 cells were treated with LTD(4) for 2 or 6 h. Reporter gene assay was mainly used for analysis.MUC2 protein levels were measured using an enzyme-linked immunosorbent assay.
LTD(4) significantly increased MUC2 gene transcriptional activity in a dose-dependent manner. Pranlukast, which is a selective antagonist of CysLT(1) receptor, inhibited LTD(4)-induced MUC2 gene transcriptional activity in a dose-dependent manner. LTD(4)-induced MUC2 gene transcriptional activity was also suppressed by a G-protein inhibitor (pertussis toxin),a protein kinase C (PKC) inhibitor (bisindolylmaleimide), a mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor (PD98059), an extracellular signal regulated kinase-2 (ERK-2) inhibitor (AG126) and a nuclear factor kappaB (NF-kappaB) inhibitor. In addition, pranlukast inhibited LTD(4)-induced NF-kappaB activity.
These results suggest that LTD(4 )upregulates MUC2 gene transcription via a signaling pathway involving CysLT(1) receptor, G-protein, PKC, MEK, ERK and NF-kappaB.
背景/目的：白三烯（LT）D4已被证明可诱导气道黏液分泌。气道炎症性疾病如哮喘、过敏性鼻炎的特征是黏液分泌过多。然而，关于LTD4对黏蛋白基因表达的影响知之甚少。本研究的目的是探讨LTD4对培养的上皮细胞（HM3-MUC2细胞）中MUC2基因表达的影响。
用LTD4处理HM3-MUC2细胞2或6小时。主要采用报告基因分析法进行分析。使用酶联免疫吸附测定法测量MUC2蛋白水平。
LTD4以剂量依赖性方式显著增加MUC2基因转录活性。普仑司特是半胱氨酰白三烯（CysLT）1受体的选择性拮抗剂，以剂量依赖性方式抑制LTD4诱导的MUC2基因转录活性。LTD4诱导的MUC2基因转录活性也受到G蛋白抑制剂（百日咳毒素）、蛋白激酶C（PKC）抑制剂（双吲哚马来酰胺）、丝裂原活化蛋白/细胞外信号调节激酶激酶（MEK）抑制剂（PD98059）、细胞外信号调节激酶-2（ERK-2）抑制剂（AG126）和核因子κB（NF-κB）抑制剂的抑制。此外，普仑司特抑制LTD4诱导的NF-κB活性。
这些结果表明，LTD4通过涉及CysLT1受体、G蛋白、PKC、MEK、ERK和NF-κB的信号通路上调MUC2基因转录。
