The consumption of NAD liberates hexokinase 2 from mitochondria, activating the NLRP3 inflammasome 4209

Abstract Description The NLRP3 inflammasome, an arbiter of host defense and inflammatory disease pathology, governs the secretion of pro-inflammatory cytokines IL-1β and IL-18. Although a range of stimuli can activate the NLRP3 inflammasome, a unifying upstream signal remains elusive. Here, we identify NAD consumption as a crucial and common step in NLRP3 inflammasome activation within macrophages. We demonstrate a time-dependent decrease in NAD levels following stimulation with NLRP3 activators. Supplementation with NAD or its precursor enhances NLRP3 inflammasome activation, while NAD depletion attenuates it. Mechanistically, we implicate NAD-consuming enzymes, including CD38 and PARP1-PARG pathway, as their respective inhibitors significantly reduce inflammasome activity. Furthermore, we observe an increase in ADP-ribose (ADPR), a product of NAD catabolism by these enzymes, during NLRP3 activation. Notably, ADPR alone is sufficient to trigger NLRP3 inflammasome activation by directly interacting with the mitochondrial voltage-dependent anion channel (VDAC), displacing hexokinase 2 and promoting VDAC oligomerization—key steps in NLRP3 inflammasome activation. These findings advance our understanding of NLRP3 inflammasome activation and position NAD metabolism as a viable therapeutic target for NLRP3-driven inflammatory diseases. Funding Sources A.J.W. received funds from National Institutes of Health grant R01AI148465. D.M.U. received funds from National Institutes of Health grant R01GM085796. Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)