Cronobacter sakazakii induces necrotizing enterocolitis by regulating NLRP3 inflammasome expression via TLR4
Cronobacter sakazakii induces necrotizing enterocolitis by regulating NLRP3 inflammasome expression via TLR4
复制标题
坂崎克罗诺杆菌通过 TLR4 调节 NLRP3 炎性体表达，诱导坏死性小肠结肠炎。
DOI：
10.1099/jmm.0.001181
复制
发表时间：
2020-01-01
影响因子：
3
通讯作者：
Fan, Hongying
中科院分区：
文献类型：
--
作者：
Chen, Zhenhui;Zhang, Yiduo;Fan, Hongying
介绍。新生儿感染坂崎克罗诺杆菌可导致严重的肠道损伤和坏死性小肠结肠炎 (NEC)。炎症小体和Toll样受体介导其他肠道病原体引起的肠道损伤，引起NEC，但具体机制尚不清楚。我们评估了坂崎梭菌诱导 NEC 的分子机制。方法学。通过细胞死亡试验、NLRP3炎症小体和下游因子的蛋白质印迹和实时PCR分析以及细胞和肠道损伤的观察，评估坂崎棒杆菌处理对两种细胞系和NEC Sprague-Dawley大鼠模型的影响。结果。阪崎梭菌在体外引起细胞损伤，并在动物模型中引起肠道损伤。 NLRP3、caspase-1、TLR4 和 MyD88 以及下游因子 IL-1β 在 C. sakazakii 感染的 J774A.1 和 HT-29 细胞中上调。 Western blotting结果显示，阪崎棒杆菌感染的J774A.1和HT-29细胞以及NEC大鼠模型中N端gasdermin D（GSDMD）的表达水平高于对照组。坂崎棒杆菌及其成分通过TLR4/MyD88信号通路促进NF-κB表达，从而调节NLRP3炎症小体并介导GSDMD裂解，导致焦亡诱导的肠道损伤。结论。我们发现坂崎棒杆菌通过 TLR4/MyD88 上调 NF-κB，促进 NLRP3 炎症小体的激活，导致下游 caspase-1 的上调、IL-1β 的释放、GSDMD 介导的焦亡和 NEC 的发展。这些发现阐明了坂崎梭菌促进 NEC 的机制。
Introduction. Neonatal infection with Cronobacter sakazakii can cause severe intestinal damage and necrotizing enterocolitis (NEC). The inflammasome and Toll-like receptors mediate intestinal damage caused by other intestinal pathogens causing NEC, but the exact mechanism is unclear.Aim. We evaluated the molecular mechanisms underlying C. sakazakii-induced NEC.Methodology. The effects of C. sakazakii treatment on two cell lines and a Sprague-Dawley rat model of NEC were evaluated by a cell death assay, western blot and real-time PCR analyses of the NLRP3 inflammasome and downstream factors, and observation of cell and intestinal damage.Results. C. sakazakii caused cellular damage in vitro, as well as intestinal damage in an animal model. NLRP3, caspase-1, TLR4 and MyD88, as well as the downstream factor IL-1β, were upregulated in C. sakazakii-infected J774A.1 and HT-29 cells. Western blotting showed that C. sakazakii-infected J774A.1 and HT-29 cells and the NEC rat model had higher expression levels of N-terminal gasdermin D (GSDMD) compared with those in the control groups. C. sakazakii and its components promote NF-κB expression via the TLR4/MyD88 signalling pathway, thereby regulating the NLRP3 inflammasome and mediating GSDMD cleavage, resulting in pyroptosis-induced intestinal damage.Conclusion. We found that C. sakazakii upregulates NF-κB via TLR4/MyD88 to promote activation of the NLRP3 inflammasome, leading to the up-regulation of downstream caspase-1, release of IL-1β, GSDMD-mediated pyroptosis and development of NEC. These findings clarify the mechanisms by which C. sakazakii contributes to NEC.