糖皮质激素受体在鼻息肉上皮细胞中转录调控occludin的研究

Study of glucocorticoid receptort ranscriptional regulation of occludin in the nasal polyp epithelial cells

目的探讨糖皮质激素受体(glucocorticoid receptor,GR)在鼻息肉上皮细胞中转录调控紧密连接蛋白occludin的机制。方法离体细胞培养鼻息肉与正常人鼻黏膜上皮细胞各8例,使用实时定量聚合酶链反应(RTqPCR)以及蛋白质免疫印迹(Western blot,WB)检测occludin mRNA和蛋白表达变化;检测地塞米松处理鼻息肉上皮细胞后occludin蛋白表达;生物信息学分析GR与occludin启动子区域结合位点,双荧光素酶法测定occludin启动子活性强度,染色质沉淀法了解GR与occludin启动子区域的结合情况。结果 occluding mRNA和蛋白在鼻息肉上皮细胞组中较对照正常黏膜组中表达降低(t=3.931,P <0.05);地塞米松处理后能够提高occludin在鼻息肉上皮细胞中的表达量及转录活性(t=7.452,P<0.05);GR能够与occludin的启动子区域结合。结论地塞米松在鼻息肉上皮细胞中通过其受体转录调控occludin的表达,可能是糖皮质激素治疗鼻息肉的机制之一。

OBJECTIVE To investigate the mechanism of glucocorticoid receptor（GR） transcriptional regulation of a tight junction protein（occludin） in the nasal polyp epithelial cells. METHODS Eight cases of nasal polypide epithelial cells and normal human nasal mucosal epithelial cells were cultured in vitro. Expression of occludin mRNA and protein were detected by qRT-PCR and Western blot. The expression of occludin protein was detected after the nasal polyp epithelial cells were treated by dexamethasone. The binding sites between GR and occludin promoter regions are analyzed by bioinformatics. Occludin promoter activities are measured by dual luciferase assay. Chromatin immunoprecipitation（ChIP） was used to understand the binding of GR and occludin promoter regions. RESULTS The expression of tight junction protein occludin mRNA and protein in nasal polyp epithelial cell groups was lower than that in normal control groups（t=3.931, P〈0.05）. Dexamethasone can enhance the expression and transcriptional activity of occludin in human nasal epithelial cells（t=7.452, P〈0.05）. GR can be combined with the boot subregion of the occludin. CONCLUSION Dexamethasone regulates the expression of occludin through its receptor in epithelial cells of nasal polyps, which may be one of the mechanisms of glucocorticoid treatment of nasal polyps.