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-1 mRNA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-1α siRNA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 and infl 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 were analyzed by Transwell assay. The levels of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were detected by ELISA, and HIF-1α or Cav-1 mRNA expression in HBE or macrophages was detected by RT-qPCR. Results: HBE cells promoted macrophages chemotaxis in a time- and concentration-dependent manner. 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 chemotaxis of M2 macrophages was greater than that in THP1-derived M1 macrophages. The concentrations of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were increased in a timeand concentration-dependent manner. The concentrations of TNF-α and IFN-γ were increased further after co-culturing for 8 and 12 h; while IL-4, IL-13 and IL-10 concentrations were increased further during 24 h of co-culture. The levels of cytokines in the supernatants of macrophages cocultured with HBE and transfected with HIF-1α siRNA were significantly lower than those in untransfected cells (P<0.05 or P<0.01). The reduction of TNF-α or IFN-γ was more obvious. The expression of HIF-1α or Cav-1 mRNA in HBE or macrophages was increased in a concentrationdependent manner after 8 or 12 h co-culture, which was significantly reduced when HBE was transfected with HIF-1α siRNA. Conclusion: Airway epithelial cells can enhance macrophages chemotaxis and pro-inflammatory cytokines expressions under hypoxic condition. HIF-1α and Cav-1 may be the important mediators in these processes.