Abstract：
Cigarette smoke (CS) is a major risk factor for chronic lung diseases and promotes activation of pattern recognition receptors in the bronchial epithelium. NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a pattern recognition receptor whose activation leads to caspase-1 cleavage, maturation/release of IL-1β and IL-18, and eventually pyroptosis. Whether the NLRP3 inflammasome participates in CS-induced inflammation in bronchial epithelial cells is still unclear. Herein, we evaluated the involvement of NLRP3 in CS-induced inflammatory responses in human primary bronchial epithelial cells. To this purpose, human primary bronchial epithelial cells were stimulated with CS extracts (CSE) and lytic cell death, caspase activation (-1, -8, -3/7), cytokine release (IL-1β, IL-18, and IL-8), NLRP3, pro-IL-1β/pro-IL-18 mRNA, and protein expression were measured. The impact of inhibitors of NLRP3 (MCC950), caspases, and the effect of the antioxidant N-acetyl cysteine were evaluated. We found that CSE increased pro-IL-1β expression and induced activation of caspase-1 and release of IL-1β and IL-18. These events were independent of NLRP3 and we found that NLRP3 was not expressed. N-acetyl cysteine reverted CSE-induced caspase-1 activation. Overall, our findings support that the bronchial epithelium may play a central role in the release of IL-1 family cytokines independently of NLRP3 in the lungs of smokers.
摘要：
香烟烟雾（CS）是慢性肺部疾病的主要危险因素，并促进支气管上皮中模式识别受体的激活。NOD样受体家族,含pyrin结构域3（NLRP3）是一种模式识别受体，其激活导致caspase-1裂解，IL-1β和IL-18的成熟/释放，最终焦亡。NLRP3炎症小体是否参与CS诱导的支气管上皮细胞炎症尚不清楚。在这里，我们评估了NLRP3在CS诱导的人原发性支气管上皮细胞炎症反应中的作用.为此,用CS提取物（CSE）和裂解细胞死亡刺激人原代支气管上皮细胞，半胱天冬酶激活（-1，-8，-3/7），细胞因子释放(IL-1β，IL-18和IL-8），NLRP3,pro-IL-1β/pro-IL-18mRNA,和蛋白质表达进行测量。NLRP3抑制剂（MCC950）的影响，caspases,并评价抗氧化剂N-乙酰半胱氨酸的作用。我们发现CSE增加了pro-IL-1β的表达，并诱导了caspase-1的激活以及IL-1β和IL-18的释放。这些事件独立于NLRP3,我们发现NLRP3不表达。N-乙酰半胱氨酸逆转了CSE诱导的胱天蛋白酶-1活化。总的来说,我们的研究结果支持支气管上皮可能在IL-1家族细胞因子的释放中起重要作用,而与NLRP3无关.
