Institut für Umweltmedizinische Forschung (IUF) - Leibniz-Research Institute for Environmental Medicine, Duesseldorf, Germany.
Front Immunol. 2022 Jul 13;13:898039. doi: 10.3389/fimmu.2022.898039. eCollection 2022.
The NLRP3 inflammasome plays an important role in intestinal homeostasis as well as inflammation. However, studies investigating the role of the NLRP3 inflammasome in inflammatory bowel disease (IBD) report contrasting results, leaving it unclear if the NLRP3 inflammasome augments or attenuates intestinal inflammation. To investigate the role of the NLRP3/caspase-1 pathway in a model of acute intestinal inflammation, we modified a previously established triple culture model of the healthy and inflamed intestine (Caco-2/HT29-MTX-E12/THP-1). Using THP-1 knockout cell lines, we analyzed how the NLRP3 inflammasome and its downstream enzyme caspase-1 (CASP1) affect inflammatory parameters including barrier integrity and cytotoxicity, as well as gene expression and secretion of pro-inflammatory cytokines and mucus. Furthermore, we investigated differences in inflammation-mediated cytotoxicity towards enterocyte-like (Caco-2) or goblet-like (HT29-MTX-E12) epithelial cells. As a complementary approach, inflammation-related cytotoxicity and gene expression of cytokines was analyzed in intestinal tissue explants from wildtype (WT) and mice. Induction of intestinal inflammation impaired the barrier, caused cytotoxicity, and altered gene expression of pro-inflammatory cytokines and mucins , while the knockout of and in THP 1 cells led to attenuation of these inflammatory parameters. The knockout of tended to show a slightly stronger attenuating effect compared to the knockout model. We also found that the inflammation-mediated death of goblet-like cells is NLRP3/caspase-1 dependent. Furthermore, inflammation-related cytotoxicity and upregulation of pro-inflammatory cytokines was present in ileal tissue explants from WT, but not mice. The here presented observations indicate a pro-inflammatory and adverse role of the NLRP3 inflammasome in macrophages during acute intestinal inflammation.
NLRP3 炎性体在肠道稳态和炎症中发挥重要作用。然而，研究 NLRP3 炎性体在炎症性肠病（IBD）中的作用的报告结果相互矛盾，尚不清楚 NLRP3 炎性体是否增强或减弱肠道炎症。为了研究 NLRP3/caspase-1 途径在急性肠道炎症模型中的作用，我们修改了先前建立的健康和炎症肠道（Caco-2/HT29-MTX-E12/THP-1）三重培养模型。使用 THP-1 敲除细胞系，我们分析了 NLRP3 炎性体及其下游酶 caspase-1（CASP1）如何影响炎症参数，包括屏障完整性和细胞毒性，以及促炎细胞因子和粘蛋白的基因表达和分泌。此外，我们研究了炎症介导的对肠上皮样（Caco-2）或杯状细胞样（HT29-MTX-E12）上皮细胞的细胞毒性差异。作为补充方法，分析了来自野生型（WT）和 的肠道组织外植体中的炎症相关细胞毒性和细胞因子基因表达。肠道炎症的诱导损害了屏障，导致细胞毒性，并改变了促炎细胞因子和粘蛋白的基因表达，而 THP1 细胞中 和 的敲除导致这些炎症参数的减弱。与 敲除模型相比， 的敲除倾向于显示出稍微更强的减弱作用。我们还发现，杯状细胞样细胞的炎症介导死亡依赖于 NLRP3/caspase-1。此外，WT 但不是 小鼠的回肠组织外植体中存在与炎症相关的细胞毒性和促炎细胞因子的上调。这里呈现的观察结果表明，NLRP3 炎性体在急性肠道炎症期间的巨噬细胞中具有促炎和不利作用。
