ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of dual oxidase-1 (DUOX-1) inducing airway hyperresponsiveness in human bronchial epithelium.</p><p><b>METHODS</b>The human bronchial epithelial cells were divided into several groups: control group, tumor necrosis factor-α (TNF-α) group, methyl-β-cyclodextrin (M-β-CD)+TNF-α group, desipramine (DES)+ TNF-α group, diphenylene iodonium (DPI) + TNF-α group and apocynin (APO)+TNF-α group. Fractionation was performed by sucrose gradient centrifugation and the protein DUOX-1 was measured by western blotting. The lipid raft clusters and its colocalization with DUOX-1 were confocal analysed. The intracellular reactive oxygen species (ROS) accumulation was measured by fluorescence of reactive oxygen probe of intracellular measurement. Sigmastat 3.02 software was used to analyze the data.</p><p><b>RESULTS</b>(1) Detection of ROS, control group: 1.00 ± 0.00; TNF-α group: 1.95 ± 0.16; M-β-CD+TNF-α group: 0.91 ± 0.16; DES+TNF-α group: 1.49 ± 0.20; DPI+TNF-α group: 1.03 ± 0.16; APO+TNF-α group: 1.47 ± 0.26. The difference was statistically significant (F = 3.83, P < 0.05). (2) Extracts in rafts to lipid rafts region represents the ratio of total protein, protein content DUOX-1 each group, control group: 0.21 ± 0.02; TNF-α group: 0.49 ± 0.04; M-β-CD+TNF-α group: 0.08 ± 0.02; DES+TNF-α group: 0.09 ± 0.03; the difference was statistically significant (F = 3.96, P < 0.05). (3) DUOX-1 protein fluorescence values, control group: 1.72 ± 0.21; TNF-α group: 8.11 ± 1.23; M-β-CD+TNF-α group: 1.51 ± 0.32; DES+TNF-α group: 1.43 ± 0.11; the difference was statistically significant (F = 4.87, P < 0.05). (4) DUOX-1 gene detection, control group: 1.00 ± 0.00 ScrRNA+TNF-α group: 1.75 ± 0.04; DUOX-1siRNA+TNF-αgroup: 1.15 ± 0.02; the difference was statistically significant (F = 4.19, P < 0.05).</p><p><b>CONCLUSION</b>TNF-α can induce DUOX-1 expression increasing in lipid raft, then the DUOX-1 can be activated to increase reactive oxygen species level; acidic sphingomyelinase inhibitor desipramine can inhibit this process, the results disclose that the process will depend on the ceramide of lipid raft.</p>