目的:探讨柚皮素对炎症反应时气道上皮细胞黏液高分泌的影响。方法:通过人中性粒细胞弹性蛋白酶(HNE)刺激人肺腺癌细胞A549,构建炎症反应时气道黏液高分泌模型,分别以柚皮素和磷脂酰肌醇3-激酶(PI3K)抑制剂LY294002进行干预,观察黏蛋白5AC(MUC5AC)、PI3K、PKB、P-PKB及核因子-κB(NF-κB)的表达。培养细胞经甲基偶氮唑盐法测定活性后分为对照组、HNE处理组、LY294002组、柚皮素组和柚皮素+LY294002组。逆转录PCR方法检测各组MUC5ACmRNA变化;Western blot法检测PI3K、PKB、P-PKB和NF-κB蛋白的表达;酶联免疫吸附测定法观察MUC5AC蛋白表达的变化,并用细胞免疫激光共聚焦显微镜观察柚皮素作用前后黏蛋白的分布。结果:HNE处理组MUC5AC的mRNA和蛋白的吸光度面积积分值较对照组明显降低;PI3K、PKB、P-PKB和NF-κB蛋白表达均较对照组明显升高;给予柚皮素预处理后,与HNE刺激组相比均明显下调;而柚皮素+LY294002组MUC5ACmRNA和蛋白均较单独LY294002处理组更为明显。结论:柚皮素可通过抑制PI3K/PKB信号途径,抑制NF-κB的活化,从而发挥抑制气道黏液高分泌的作用。
Objection:To investigate the effects of naringenin on airway mucous hypersecretion and on the signal transduction pathway of phosphatidylinositol 3-kinase/protein kinase B(PI3K/PKB).Methods:The cell model of mucous hypersecretion was made by human lung A549 cell stimulated by human neutrophil elastae(HNE),and treated with naringenin and LY294002,a blocking agent of PI3K,respectively.The expression of mucin(MUC)5AC,PI3K,PKB,P-PKB and nuclear factor-κB(NF-κB)were detected.The cell activity after naringenin treatment was assessed by methylthiazolyl tetrazolium method.The cells were divided into 5 groups:a negative control group,an HNE treatment group,a naringenin pre-treatment group,a LY294002 pre-treatment group and a naringenin + LY294002 group.The changes of MUC5AC mRNA was examined by the use of reverse transcriptase-polymerase chain reaction(RT-PCR).The protein expression changes of PI3K,PKB,P-PKB and NF-κB were measured by Western blot.The protein expression changes of MUC5AC were detected by enzyme-linked immunosorbent assay,while the protein morphological changes of MUC5AC were observed by immunofluorescence and confocal laser technology.Results:The expression levels of MUC5ACmRNA and its protein were decreased significantly as compared with the control group.The protein expression changes of PI3K,PKB,P-PKB and NF-κB were increased significantly as compared with the control group.After the cells were pre-treated with naringenin,the above measurements were decreased significantly as compared with the HNE group.The decrease was more significant in the naringenin+ LY294002 group.Conclusions:Naringenin inhibited activiation of NF-κB and attenuated airway mucous hypersecretion via the signal transduction pathway of PI3K/PKB.