The NLRP3 inflammasome is linked to sterile and pathogen-dependent inflammation, and its dysregulation underlies many chronic diseases. Mitochondria have been implicated as regulators of the NLRP3 inflammasome through several mechanisms including generation of mitochondrial reactive oxygen species (ROS). Here, we report that mitochondrial electron transport chain (ETC) complex I, II, III and V inhibitors all prevent NLRP3 inflammasome activation. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI1) or Ciona intestinalis alternative oxidase, which can complement the functional loss of mitochondrial complex I or III, respectively, without generation of ROS, rescued NLRP3 inflammasome activation in the absence of endogenous mitochondrial complex I or complex III function. Metabolomics revealed phosphocreatine (PCr), which can sustain ATP levels, as a common metabolite that is diminished by mitochondrial ETC inhibitors. PCr depletion decreased ATP levels and NLRP3 inflammasome activation. Thus, the mitochondrial ETC sustains NLRP3 inflammasome activation through PCr-dependent generation of ATP, but via a ROS-independent mechanism.

NLRP3 炎症小体与无菌和病原体依赖性炎症有关，其失调是许多慢性疾病的基础。线粒体通过多种机制（包括产生线粒体活性氧 (ROS)）作为 NLRP3 炎症小体的调节因子。在此，我们报道线粒体电子传递链 (ETC) 复合物 I、II、III 和 V 抑制剂均可阻止 NLRP3 炎性体激活。酿酒酵母NADH 脱氢酶 (NDI1) 或玻璃海鞘替代氧化酶的异位表达，可以分别补充线粒体复合物 I 或 III 的功能损失，而不产生 ROS，在缺乏内源性线粒体复合物 I 或复合物的情况下挽救 NLRP3 炎性体激活三、功能。代谢组学揭示了磷酸肌酸 (PCr)，它可以维持 ATP 水平，是一种常见的代谢物，可被线粒体 ETC 抑制剂减少。 PCR 耗竭降低了 ATP 水平和 NLRP3 炎性体激活。因此，线粒体 ETC 通过 PCr 依赖性的 ATP 生成来维持 NLRP3 炎症小体的激活，但通过 ROS 独立的机制。