金黄色葡萄球菌肠毒素B激活TACE诱导人鼻黏膜上皮细胞分泌黏蛋白

Staphylococcus Aureus Enterotoxin B Induces Human Nasal Epithelial Cells Secretion of MUC5AC via Activation of TACE

目的观察金黄色葡萄球菌肠毒素B（SEB）对人鼻黏膜上皮细胞活性氧（ROS）和肿瘤坏死因子转化酶（TACE）活性的影响，并探讨其在介导黏蛋白MUC5AC分泌中的作用。方法体外培养人鼻黏膜上皮细胞。用不同浓度的SEB孵育细胞0～24h，采用荧光共振能量转移法检测TACE的酶活性，荧光探针H2DCFDA检测鼻黏膜上皮细胞中活性氧（ROS）的含量，ELISA检测培养上清中MUC5AC的分泌水平。同时采用TACEsiRNA干扰或ROS抑制剂NAC处理细胞，观察其在介导MUC5AC分泌中的作用。结果100ng／mLSEB作用鼻黏膜上皮细胞15min后即可上调TACE的酶活性，30～60min后达到峰值，并持续至2h；SEB也能增加鼻黏膜上皮细胞内ROS的含量：采用NAPDH氧化酶抑制剂DPI处理后，ROS水平明显减少；ROS抑制剂NAC处理鼻黏膜上皮细胞后，可明显降低TACE的酶活性；30-100ng／mLSEB能显著诱导鼻黏膜上皮细胞分泌MUC5AC，采用TACEsiRNA干扰其表达或抑制剂处理后，可抑制MUC5AC分泌。结论SEB激活TACE诱导人鼻黏膜上皮细胞分泌MUC5AC。

Objective To observe the effect of staphylococcus aureus enterotoxin B （SEB） on reactive oxygen species （ROS） production and tumor necrosis factor converting enzyme （TACE） activity in human nasal epithelial cells, and explore its role in MUCSAC secretion. Methods Human nasal epithelial cells were cultured in vitro, and then were stimulated with different concentrations of SEB for 0- 24 h.The activity of TACE was measured by fluorescence resonance energy transfer method, SEB-induced production of ROS was detected by using the fluorescent probe H2DCFDA.To investivate the role of TA- CE and ROS in MUC5AC secretion,nasal epithelial cells was transfected by TACE siRNA or the ROS inhibitor NAC,and Se- cretion of MUC5AC in the culture supernatant was detected by ELISA. Result The enzymic activity of TACE was up-regu- lated followed by treatment of 100ng/mL of SEB for 15rain,peaked at 30-60min and lasted for 2 h.In addition,SEB could in- duce ROS accumulation in human nasal epithelial cells, and this ability could be abrogated by DPI, an inhibitor of NADPH ox- idase.Moreover,treatment of the ROS inhibitor NAC significantly decreased the enzymic activity of TACE.Furthermore, secre- tion of MUCSAC were abrogated when the cells were transfected the TACE siRNA or treated by its inhibitor TAPI. Conclu- sions SEB induces MUC5AC secretion via ROS and TACE in human nasal epithelial cells.