低氧条件下气道上皮细胞增加巨噬细胞趋化和炎症因子的分泌

目的：探讨低氧条件下气道上皮细胞对巨噬细胞趋化和炎症因子表达的影响。方法：将0，100，200，400，800 μmol/L氯化钴(CoCl2)处理或转染缺氧诱导因子(hypoxia-inducible factor，HIF)-1α siRNA的人支气管上皮细胞HBE与人单核细胞THP-1诱导分化的M1或M2巨噬细胞共培养，采用Transwell小室趋化实验记录巨噬细胞趋化数量，ELISA法检测巨噬细胞上清中TNF-α，IFN-γ，IL-4，IL-13，IL-10浓度，RT-qPCR检测HBE细胞HIF-1α和巨噬细胞Cav-1mRNA的表达。结果：共培养8和12 h，HBE细胞诱导巨噬细胞趋化，并且呈时间和CoCl2浓度依赖性；转染HIF-1αsiRNA的HBE相对于未转染组对共培养的M1或M2巨噬细胞趋化诱导明显减弱(P<0.01)，在相同培养条件下，M2巨噬细胞趋化性高于M1巨噬细细胞。巨噬细胞上清中TNF-α，IFN-γ，IL-4，IL-13，IL-10水平呈时间和CoCl2浓度依赖性升高，共培养8和12 h，TNF-α和IFN-γ浓度增加较IL-4，IL-13，IL-10浓度增加更明显；共培养24 h，IL-4，IL-13，IL-10浓度增加程度高于TNF-α和IFN-γ。与转染HIF-1α siRNA的HBE共培养的巨噬细胞上清中各细胞因子水平较未转染组均明显降低(P<0.05或0.01)，其中TNF-α，IFN-γ降低更明显。共培养8和12 h，HBE细胞HIF-1α和巨噬细胞Cav-1 mRNA表达均呈CoCl2浓度依赖性增加；转染HIF-1α siRNA后，HBE细胞HIF-1α和巨噬细胞Cav-1 mRNA表达量均明显减少。结论：低氧环境下气道上皮细胞可增加巨噬细胞趋化因子和致炎因子的表达，HIF-1α和Cav-1可能是这些过程的重要介质。

Airway epithelial cells increase macrophage chemotaxis and inflammatory cytokine secretion under hypoxic conditions

Objective: To investigate the effects of airway epithelial cells on macrophages chemotaxis andinfl ammatory cytokine expression under hypoxic conditions.Methods: Human bronchial epithelial cells (HBE) treated with diff erent concentrations (0, 100,200, 400, 800 μmol/L) of CoCl2 or transfected with HIF-1α siRNA were co-cultured with THP-1-derived M1 macrophages or M2 macrophages. The chemotactic effects on macrophages wereanalyzed by Transwell assay. The levels of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatantsof macrophages were detected by ELISA, and HIF-1α or Cav-1 mRNA expression in HBE ormacrophages was detected by RT-qPCR.Results: HBE cells promoted macrophages chemotaxis in a time- and concentration-dependentmanner. Compared to un-transfected group, the chemotactic ability of HBE transfected with HIF-1α siRNA was significantly weakened (P<0.01). Under the same culture conditions, the chemotaxisof M2 macrophages was greater than that in THP1-derived M1 macrophages. The concentrations ofTNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were increased in a timeandconcentration-dependent manner. The concentrations of TNF-α and IFN-γ were increasedfurther after co-culturing for 8 and 12 h; while IL-4, IL-13 and IL-10 concentrations were increasedfurther during 24 h of co-culture. The levels of cytokines in the supernatants of macrophages coculturedwith HBE and transfected with HIF-1α siRNA were significantly lower than those in untransfectedcells (P<0.05 or P<0.01). The reduction of TNF-α or IFN-γ was more obvious. Theexpression of HIF-1α or Cav-1 mRNA in HBE or macrophages was increased in a concentrationdependentmanner after 8 or 12 h co-culture, which was significantly reduced when HBE wastransfected with HIF-1α siRNA.Conclusion: Airway epithelial cells can enhance macrophages chemotaxis and pro-inflammatorycytokines expressions under hypoxic condition. HIF-1α and Cav-1 may be the important mediatorsin these processes.