脂氧素A4抑制内毒素诱导的人支气管上皮细胞环氧合酶2及前列腺素E2的表达

目的: 探讨脂氧素A₄对人支气管上皮细胞(HBECs)环氧合酶2(COX-2)表达的影响。方法: 应用不同浓度(0.1、1、10 mg/L)的内毒素(LPS)刺激HBECs 9 h,或者用1 mg/L LPS分别刺激HBECs不同时点(3 h、6 h、9 h)后,测定HBECs的COX-2 mRNA表达和细胞上清液前列腺素E₂(PGE₂)水平。应用不同浓度 (0、100、400 μmol/L) 的脂氧素A₄作用于经过LPS(1 mg/L)刺激培养9 h的HBECs,采用酶联免疫吸附法(ELISA)检测细胞上清液PGE₂的水平, 同时分别应用RT-PCR和Western blotting分别检测HBECs COX-2 mRNA及蛋白的表达。结果: LPS刺激培养条件下HBECs的COX-2 mRNA表达及其上清液PGE₂水平增加,并呈时间、剂量依赖性。脂氧素A₄能抑制LPS刺激培养HBECs COX-2蛋白和mRNA的表达及上清液PGE₂的水平,并呈剂量依赖性。结论: 脂氧素A₄能抑制LPS诱导的HBECs COX-2表达及上清液PGE₂的水平。

doi:10.3969/j.issn.1000-4718.2012.03.016Lipoxin A4 reduces lipopolysaccharide-induced expression of cyclooxygenase 2 and prostaglandin E2 in human bronchial epithelial cells

AIM:To explore the effects of lipoxin A₄ on the expression of cyclooxygenase 2（COX-2 ） in human bronchial epithelial cells（HBECs）.METHODS:HBECs were incubated with various concentrations（0.1,1 and 10 mg/L） of lipopolysaccharide（LPS） for 9 h,or 1 mg/L LPS for different time（3 h,6 h and 9 h）.The levels of COX -2 mRNA in HBECs and prostaglandin E₂（PGE₂） in the culture supernatant were measured.In addition,the HBECs were exposed to lipoxin A₄ at concentration of 0,100 and 400μmol/L after stimulated with LPS at concentration of 1 mg/L for 9 h,and the supernatant of the culture cells was collected for determining the content of PGE₂ by ELISA.The cells were also harvested,and the mRNA and protein levels of COX -2 were analyzed by RT-PCR and Western blotting,respectively. RESULTS:LPS increased the mRNA expression of COX-2 and production of PGE₂ in a dose and time dependent manners in HBECs.Induction of COX-2 mRNA and protein by LPS were inhibited by lipoxin A₄ in a dose-dependent manner. Lipoxin A₄ also significantly decreased LPS-induced production of PGE₂.CONCLUSION:Lipoxin A4 down-regulates LPS-induced expression of COX-2 and consequently inhibits the production of PGE₂ in HBECs.