NLRP3 Inflammasome and Host Protection against Bacterial Infection

The inflammasome is a multi-protein complex that induces maturation of inflammatory cytokines interleukin (IL)-1β and IL-18 through activation of caspase-1. Several nucleotide binding oligomerization domain-like receptor family members, including NLRP3, recognize unique microbial and danger components and play a central role in inflammasome activation. The NLRP3 inflammasome is critical for maintenance of homeostasis against pathogenic infections. However, inflammasome activation acts as a double-edged sword for various bacterial infections. When the IL-1 family of cytokines is secreted excessively, they cause tissue damage and extensive inflammatory responses that are potentially hazardous for the host. Emerging evidence has shown that diverse bacterial pathogens or their components negatively regulate inflammasome activation to escape the immune response. In this review, we discuss the current knowledge of the roles and regulation of the NLRP3 inflammasome during bacterial infections. Activation and regulation of the NLRP3 inflammasome should be tightly controlled to prevent virulence and pathology during infections. Understanding the roles and regulatory mechanisms of the NLRP3 inflammasome is essential for developing potential treatment approaches against pathogenic infections.     

Mechanisms of NLRP3 inflammasome activation and its role in NSAID-induced enteropathy

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce cytokines, including tumor necrosis factor-α and interleukins (ILs), in the small intestine via a Toll-like receptor 4 (TLR4)-dependent pathway, leading to intestinal ulceration. Activation of the inflammasome promotes pro-caspase-1 cleavage, leading to pro-IL-1β maturation. We examined the role of NLRP3 inflammasome in NSAID-induced enteropathy. Small intestinal damage developed 3 h after indomethacin administration, accompanied by increases in IL-1β and NLRP3 mRNA expression and mature caspase-1 and IL-1β levels. In vivo blocking of IL-1β using neutralizing antibodies attenuated indomethacin-induced damage, whereas exogenous IL-1β aggravated it. NLRP3^−/− and caspase-1^−/− mice exhibited resistance to the damage with reduction of mature IL-1β production. This resistance was abolished by exogenous IL-1β. TLR4 deficiency prevented intestinal damage and inhibited upregulation of NLRP3 and IL-1β mRNAs and maturation of pro-caspase-1 and pro-IL-1β, whereas TLR4 activation by its agonists exerted opposite effects. Apyrase, an adenosine triphosphate (ATP) scavenger, or Brilliant Blue G, a purinergic P2X₇ receptor antagonist, inhibited the damage as well as caspase-1 activation and IL-1β processing, despite there being sufficient amounts of pro-IL-1β and NLRP3. These results suggest that NLRP3 inflammasome-derived IL-1β plays a crucial role in NSAID-induced enteropathy and that both TLR4- and P2X₇-dependent pathways are required for NLRP3 inflammasome activation.     

Mitochondria: Sovereign of inflammation?

NLRP3 inflammasome-dependent inflammatory responses are triggered by a variety of signals of host danger, including infection, tissue damage and metabolic dysregulation. How these diverse activators cause inflammasome activation is poorly understood. Recent data suggest that the mitochondria integrate these distinct signals and relay this information to the NLRP3 inflammasome. Dysfunctional mitochondria generate ROS, which is required for inflammasome activation. On the contrary, the NLRP3 inflammasome is negatively regulated by autophagy, which is a catabolic process that removes damaged or otherwise dysfunctional organelles, including mitochondria. In addition to the processing and secretion of pro-inflammatory cytokines such as IL-1β, NLRP3 inflammasome activation also influences cellular metabolic pathways such as glycolysis and lipogenesis. Mapping the connections between mitochondria, metabolism and inflammation is of great interest, as malfunctioning of this network is associated with many chronic inflammatory diseases.     

Oxidized mitochondrial DNA activates the NLRP3 inflammasome during apoptosis

We report that in the presence of signal 1 (NF-κB), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1β (IL-1β). NLRP3 secondary signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The antiapoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1β production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1β secretion could be competitively inhibited by the oxidized nucleoside 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome.     

NLRP3 inflammasome activation and cell death

The NLRP3 inflammasome is a cytosolic multiprotein complex composed of the innate immune receptor protein NLRP3, adapter protein ASC, and inflammatory protease caspase-1 that responds to microbial infection, endogenous danger signals, and environmental stimuli. The assembled NLRP3 inflammasome can activate the protease caspase‐1 to induce gasdermin D-dependent pyroptosis and facilitate the release of IL-1β and IL-18, which contribute to innate immune defense and homeostatic maintenance. However, aberrant activation of the NLRP3 inflammasome is associated with the pathogenesis of various inflammatory diseases, such as diabetes, cancer, and Alzheimer’s disease. Recent studies have revealed that NLRP3 inflammasome activation contributes to not only pyroptosis but also other types of cell death, including apoptosis, necroptosis, and ferroptosis. In addition, various effectors of cell death have been reported to regulate NLRP3 inflammasome activation, suggesting that cell death is closely related to NLRP3 inflammasome activation. In this review, we summarize the inextricable link between NLRP3 inflammasome activation and cell death and discuss potential therapeutics that target cell death effectors in NLRP3 inflammasome-associated diseases.     

Initiation and perpetuation of NLRP3 inflammasome activation and assembly

The NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome is a multiprotein complex that orchestrates innate immune responses to infection and cell stress through activation of caspase-1 and maturation of inflammatory cytokines pro-interleukin-1β (pro-IL-1β) and pro-IL-18. Activation of the inflammasome during infection can be protective, but unregulated NLRP3 inflammasome activation in response to non-pathogenic endogenous or exogenous stimuli can lead to unintended pathology. NLRP3 associates with mitochondria and mitochondrial molecules, and activation of the NLRP3 inflammasome in response to diverse stimuli requires cation flux, mitochondrial Ca²⁺ uptake, and mitochondrial reactive oxygen species accumulation. It remains uncertain whether NLRP3 surveys mitochondrial integrity and senses mitochondrial damage, or whether mitochondria simply serve as a physical platform for inflammasome assembly. The structure of the active, caspase-1-processing NLRP3 inflammasome also requires further clarification, but recent studies describing the prion-like properties of ASC have advanced the understanding of how inflammasome assembly and caspase-1 activation occur while raising new questions regarding the propagation and resolution of NLRP3 inflammasome activation. Here, we review the mechanisms and pathways regulating NLRP3 inflammasome activation, discuss emerging concepts in NLRP3 complex organization, and expose the knowledge gaps hindering a comprehensive understanding of NLRP3 activation.     

Negative regulation of NLRP3 inflammasome by SIRT1 in vascular endothelial cells

NLRP3 inflammasome not only functions as a critical effector in innate immunity, but also triggers the production of proinflammatory cytokines involved in inflammation-associated diseases. Sirtuin 1 (SIRT1) plays an important role in the regulation of cellular inflammation. However, whether the activation of NLRP3 inflammasome is regulated by SIRT1 remains unknown. In this study, we investigated the regulatory effect of SIRT1 on NLRP3 inflammasome and the underlying mechanisms. We found that lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced the activation of NLRP3 inflammasome in human umbilical vein endothelial cells (HUVECs). Activation of SIRT1 inhibited NLRP3 inflammasome activation and subsequent caspase-1 cleavage as well as interleukin (IL)-1β secretion, whereas SIRT1 knockdown obviously enhanced the activation of NLRP3 inflammasome in HUVECs. Importantly, gene silencing of SIRT1 abrogated the inhibitory effect of SIRT1 activator on NLRP3 inflammasome formation and IL-1β production in HUVECs stimulated with LPS plus ATP. Further study indicated that cluster of differentiation 40 (CD40) may be involved in the regulation of NLRP3 inflammasome by SIRT1. In vivo studies indicated that implantation of the periarterial carotid collar increased the arterial expression levels of CD40 and CD40 Ligand (CD40L), but inhibited arterial SIRT1 expression in the rabbits. Moreover, treatment with SIRT1 activator decreased CD40 and CD40L levels in collared arteries. Meanwhile, serum IL-1β level, the marker of inflammasome activation, was also inhibited by SIRT1 activation. Taken together, these findings revealed a novel regulatory mechanism of NLRP3 inflammasome by SIRT1, which may be related to suppression of CD40.     

The inhibitor effect of RKIP on inflammasome activation and inflammasome-dependent diseases

Aberrant inflammasome activation contributes to the pathogenesis of various human diseases, including atherosclerosis, gout, and metabolic disorders. Elucidation of the underlying mechanism involved in the negative regulation of the inflammasome is important for developing new therapeutic targets for these diseases. Here, we showed that Raf kinase inhibitor protein (RKIP) negatively regulates the activation of the NLRP1, NLRP3, and NLRC4 inflammasomes. RKIP deficiency enhanced caspase-1 activation and IL-1β secretion via NLRP1, NLRP3, and NLRC4 inflammasome activation in primary macrophages. The overexpression of RKIP in THP-1 cells inhibited NLRP1, NLRP3, and NLRC4 inflammasome activation. RKIP-deficient mice showed increased sensitivity to Alum-induced peritonitis and Salmonella typhimurium-induced inflammation, indicating that RKIP inhibits NLRP3 and NLRC4 inflammasome activation in vivo. Mechanistically, RKIP directly binds to apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and competes with NLRP1, NLRP3, or NLRC4 to interact with ASC, thus interrupting inflammasome assembly and activation. The depletion of RKIP aggravated inflammasome-related diseases such as monosodium urate (MSU)-induced gouty arthritis and high-fat diet (HFD)-induced metabolic disorders. Furthermore, the expression of RKIP was substantially downregulated in patients with gouty arthritis or type 2 diabetes (T2D) compared to healthy controls. Collectively, our findings suggest that RKIP negatively regulates NLRP1, NLRP3, and NLRC4 inflammasome activation and is a potential therapeutic target for the treatment of inflammasome-related diseases.     

The inflammasome: an integrated view

An inflammasome is a multiprotein complex that serves as a platform for caspase-1 activation and caspase-1-dependent proteolytic maturation and secretion of interleukin-1β (IL-1β). Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied but also the most elusive. It is unique in that it responds to numerous physically and chemically diverse stimuli. The potent proinflammatory and pyrogenic activities of IL-1β necessitate that inflammasome activity is tightly controlled. To this end, a priming step is first required to induce the expression of both NLRP3 and proIL-1β. This event renders the cell competent for NLRP3 inflammasome activation and IL-1β secretion, and it is highly regulated by negative feedback loops. Despite the wide array of NLRP3 activators, the actual triggering of NLRP3 is controlled by integration a comparatively small number of signals that are common to nearly all activators. Minimally, these include potassium efflux, elevated levels of reactive oxygen species (ROS), and, for certain activators, lysosomal destabilization. Further investigation of how these and potentially other as yet uncharacterized signals are integrated by the NLRP3 inflammasome and the relevance of these biochemical events in vivo should provide new insight into the mechanisms of host defense and autoinflammatory conditions.     

Damage control: Management of cellular stress by the NLRP3 inflammasome

The NLRP3 inflammasome plays a critical role in regulating inflammatory and cell death pathways in response to a diverse array of stimuli. Activation of the NLRP3 inflammasome results in activation of the cysteine protease caspase‐1 and the subsequent processing and secretion of the proinflammatory cytokines IL‐1β and IL‐18. In this issue of the European Journal of Immunology, Licandro et al. [Eur. J. Immunol. 2013. 43, 2126–2137] show that the NLRP3 inflammasome contributes to oxidative DNA damage. In addition, activation of the NLRP3 inflammasome modulates a number of pathways involved in DNA damage repair, cell cycle, and apoptosis, suggesting a novel role for the NLRP3 inflammasome in DNA damage responses following cellular stress.     

Trichothecene mycotoxins activate NLRP3 inflammasome through a P2X7 receptor and Src tyrosine kinase dependent pathway

Inflammasome is an intracellular molecular platform of the innate immunity that is a key mediator of inflammation. The inflammasome complex detects pathogens and different danger signals, and triggers cysteine protease caspase-1-dependent processing of pro-inflammatory cytokines IL-1β, and IL-18 in dendritic cells and macrophages. Previously, we have shown that water-damaged building associated trichothecene mycotoxins, including roridin A, trigger IL-1β and IL-18 secretion in human macrophages. However, the molecular basis as well as mechanism behind this trichothecene-induced cytokine secretion has remained uncharacterized. Here, we show that the trichothecene-induced IL-1β secretion is dependent on NLRP3 inflammasome in human primary macrophages. Pharmacological inhibition and small interfering RNA approach showed that the trichothecene-induced NLRP3 inflammasome activation is mediated through ATP-gated P2X₇ receptor. Moreover, we show that trichothecene-triggered NLRP3 inflammasome activation is dependent on Src tyrosine kinase activity. In addition, gene silencing of c-Cbl, a negative autophagy-related regulator of c-Src, resulted in enhanced secretion of IL-1β and IL-18 in response to trichothecene mycotoxin stimulation in human macrophages. In conclusion, our results suggest that roridin A, a fungal trichothecene mycotoxin, acts as microbial danger signals that trigger activation of NLRP3 inflammasome through P2X₇R and Src tyrosine kinase signaling dependent pathway in human primary macrophages.     

NLRP3 inflammasome activation regulated by NF-κB and DAPK contributed to paraquat-induced acute kidney injury

Paraquat can result in dysfunction of multiple organs after ingestion in human. However, the mechanisms of nucleotide-binding domain and leucine-rich repeat containing protein 3 (NLRP3) inflammasome activation in acute kidney injury have not been clearly demonstrated. The aim of this study was to determine the effect of NLRP3 inflammasome activation and its regulation by nuclear factor-kappa B (NF-κB) and death-associated protein kinase (DAPK). Male Wistar rats were treated with intraperitoneal injection of paraquat at 20 mg/kg, and NF-κB inhibitor BAY 11-7082 was pretreated at 10 mg/kg 1 h before paraquat exposure. Additionally, rat renal tubular epithelial cells (NRK-52E) were transfected with small interfering RNA (siRNA) against DAPK to evaluate its role in NLRP3 inflammasome activation. DAPK and NLRP3 inflammasome were evaluated by immunohistochemistry staining or Western blot; the pro-inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were measured via ELISA. The results showed that NF-κB, DAPK, and NLRP3 inflammasome were activated in paraquat (PQ)-treated rat kidney; the secretion of pro-inflammatory cytokines was significantly increased. These toxic effects were attenuated by NF-κB inhibitor. Besides, the activation of NLRP3 inflammasome and secretion of IL-1β and IL-18 in paraquat-treated rat renal tubular epithelial cells were inhibited by siRNA against DAPK. In conclusion, NLRP3 inflammasome activation regulated by NF-κB and DAPK played an important role in paraquat-induced acute kidney injury.     

Extracellular ADP augments microglial inflammasome and NF-κB activation via the P2Y12 receptor

The NLRP3 inflammasome is a molecular complex that translates signals from pathogens and tissue damage into inflammatory responses, and plays crucial roles in numerous neurological diseases. Activation of the NLRP3 inflammasome leads to caspase-1 dependent cleavage of pro-IL-1β to form mature IL-1β. By acting on the P2X7 purinergic receptor, extracellular ATP is one of the major stimuli that activates the NLRP3 inflammasome. Although microglia express multiple purinergic receptors, their roles in inflammasome-mediated inflammation are largely unknown. We studied the role of the P2Y12 receptor, a metabotropic P2Y receptor enriched in microglia, on inflammation in vitro. Inhibition of the microglial P2Y12 receptor by PSB0739 or siRNA knockdown suppressed IL-1β release. P2Y12 receptor-deficient microglia displayed markedly attenuated IL-1β mRNA expression and release. P2Y12 receptor blockade also suppressed IL-6 production. Both IL-1β and IL-6 responses were augmented by extracellular ADP or ADP-βS and were abrogated by PSB0739. Mechanistically, ADP-βS potentiated NF-κB activation. In addition, ADP altered mitochondrial membrane potential in combination with ATP and increased the number of caspase-1 positive cells through the P2Y12 receptor. These results elucidate a novel inflammatory mechanism by which extracellular ADP acts on the P2Y12 receptor to activate NF-κB and the NLRP3 inflammasome to enhance microglial inflammation.     

Inhibition of NLRP3 inflammasome: a new protective mechanism of cinnamaldehyde in endotoxin poisoning of mice

Context: Cinnamaldehyde (CA) has a protective effect in endotoxin poisoning of mice, but there is no direct evidence for the protective effect of CA through inhibition of NLRP3 inflammasome activation in endotoxin poisoning of mice.

Objective: We aimed to investigate the protective mechanism of CA in endotoxin poisoned mice through NLRP3 inflammasome.

Materials and methods: First, we evaluated the anti-inflammatory effect of CA in phorbol-12-myristate acetate–differentiated THP-1 cells through the NLRP3 inflammasome. Second, in a mouse model of lipopolysaccharide (LPS)-induced endotoxin poisoning, CA was administrated for 5 d (once a day) before the 15?mg/kg LPS challenge. Then, the levels of IL-1β in serum were measured, and the effect of CA on the NLRP3 inflammasome activation and the expression of cathepsin B and P2X7R proteins in lung were explored.

Results: In vitro, CA decreased the levels of p20, pro-IL-1β and IL-1β in cell culture supernatants, as well as the expression of NLRP3 and IL-1β mRNA in cells. In vivo, CA decreased IL-1β production in serum. Furthermore, CA suppressed LPS-induced NLRP3, p20, Pro-IL-1β, P2X7 receptor (P2X7R) and cathepsin B protein expression in lung, as well as the expression of NLRP3 and IL-1β mRNA.

Conclusions: CA has a protective effect in the endotoxin poisoned mice through the inhibition of NLRP3 inflammasome activation. Furthermore, CA suppresses the NLRP3 inflammasome activation by inhibiting the expression of cathepsin B and P2X7R protein expression. CA can be considered as a potential therapeutic candidate for diseases involved in endotoxin poisoning such as sepsis.     

Regulation and functions of NLRP3 inflammasome during influenza virus infection

The NLRP3 inflammasome constitutes a major antiviral host defense mechanism during influenza virus infection. Inflammasome assembly in virus-infected cells facilitates autocatalytic processing of pro-caspase-1 and subsequent cleavage and secretion of proinflammatory cytokines IL-1β and IL-18. The NLRP3 inflammasome is critical for induction of both innate and adaptive immune responses during influenza virus infection. Inflammasome-dependent antiviral responses also regulate immunopathology and tissue repair in the infected lungs. The regulation of NLRP3 inflammasome assembly is an area of active research and recent studies have unraveled multiple cellular and viral factors involved in inflammasome assembly. Emerging studies have also identified the cross talk between inflammasome activation and programmed cell death pathways in influenza virus-infected cells. Here, we review the current literature regarding regulation and functions of NLRP3 inflammasome during influenza virus infection.     

Molecular Mechanism of NLRP3 Inflammasome Activation

The inflammasome is an intracellular multimolecular complex that controls caspase-1 activity in the innate immune system. NLRP3, a member of the NLR family of cytosolic pattern recognition receptors, along with the adaptor protein ASC, mediates caspase-1 activation via assembly of the inflammasome in response to various pathogen-derived factors as well as danger-associated molecules. The active NLRP3 inflammasome drives innate immune response towards invading pathogens and cellular damage, and regulates adaptive immune response. Here, we review identified agonists of the NLRP3 inflammasome and the molecular mechanism by which they induce NLRP3 inflammasome activation. Three signaling pathways involving potassium efflux, generation of reactive oxygen species, and cathepsin B release are discussed.     

MicroRNA-223 regulates inflammation and brain injury via feedback to NLRP3 inflammasome after intracerebral hemorrhage

NLRP3 inflammasome, the multimeric protein complexes involved in the processing of IL-1β through Caspase-1 cleavage, facilitates the inflammatory response. The control and activation of NLRP3 after intracerebral hemorrhage have not been fully studied. In the current study, we explore the specific microRNA which could regulate the NLRP3 inflammasome and inflammation after intracerebral hemorrhage. We detected the inverse relationship between the expression of miR-223 and NLRP3. We found that NLRP3 mRNA contains conserved miR-223 binding sites in its 3′ UTR, and miR-223 could directly regulate NLRP3 expression through these 3′ UTR sites. Our results indicate that miR-223 could downregulate NLRP3 to inhibit inflammation through caspase-1 and IL-1β, reduce brain edema and improve neurological functions. Together, miR-223 may be a vital regulator of NLRP3 inflammasome activation. The results suggest that miR-223 represents a novel target reducing the inflammatory response, and offers a new therapeutical strategy following ICH.     

Inflammasome activation is required for human rhinovirus-induced airway inflammation in naive and allergen-sensitized mice

Activation of the inflammasome is a key function of the innate immune response that regulates inflammation in response to microbial substances. Inflammasome activation by human rhinovirus (RV), a major cause of asthma exacerbations, has not been well studied. We examined whether RV induces inflammasome activation in vivo, molecular mechanisms underlying RV-stimulated inflammasome priming and activation, and the contribution of inflammasome activation to RV-induced airway inflammation and exacerbation. RV infection triggered lung mRNA and protein expression of pro-IL-1β and NLRP3, indicative of inflammasome priming, as well as cleavage of caspase-1 and pro-IL-1β, completing inflammasome activation. Immunofluorescence staining showed IL-1β in lung macrophages. Depletion with clodronate liposomes and adoptive transfer experiments showed macrophages to be required and sufficient for RV-induced inflammasome activation. TLR2 was required for RV-induced inflammasome priming in vivo. UV irradiation blocked inflammasome activation and RV genome was sufficient for inflammasome activation in primed cells. Naive and house dust mite-treated NLRP3−/− and IL-1β−/− mice, as well as IL-1 receptor antagonist-treated mice, showed attenuated airway inflammation and responsiveness following RV infection. We conclude that RV-induced inflammasome activation is required for maximal airway inflammation and hyperresponsiveness in naive and allergic mice. The inflammasome represents a molecular target for RV-induced asthma exacerbations.     

Toll-Like Receptor 2 and NLRP3 Cooperate To Recognize a Functional Bacterial Amyloid,Curli

Amyloids are proteins with cross-β-sheet structure that contribute to pathology and inflammation in complex human diseases, including Alzheimer''s disease, Parkinson''s disease, type II diabetes, and secondary amyloidosis. Bacteria also produce amyloids as a component of their extracellular matrix during biofilm formation. Recently, several human amyloids were shown to activate the NLRP3 inflammasome, leading to the activation of caspase 1 and production of interleukin 1β (IL-1β). In this study, we investigated the activation of the NLRP3 inflammasome by bacterial amyloids using curli fibers, produced by Salmonella enterica serovar Typhimurium and Escherichia coli. Here, we show that curli fibers activate the NLRP3 inflammasome, leading to the production of IL-1β via caspase 1 activation. Investigation of the underlying mechanism revealed that activation of Toll-like receptor 2 (TLR2) by curli fibers is critical in the generation of IL-1β. Interestingly, activation of the NLRP3 inflammasome by curli fibers or by amyloid β of Alzheimer''s disease does not cause cell death in macrophages. Overall, these data identify a cross talk between TLR2 and NLRP3 in response to the bacterial amyloid curli and generation of IL-1β as a product of this interaction.     

Metabolic regulation of NLRP3

A shift in our understanding of macrophage biology has come about as a result of recent discoveries in the area of metabolic reprogramming of macrophages. The NLRP3 inflammasome drives the activation of caspase-1, leading to the production of IL-1β, IL-18, and a type of cell death termed pyroptosis. The NLRP3 inflammasome has been shown to sense metabolites such as palmitate, uric acid, and cholesterol crystals and is inhibited by ketone bodies produced during metabolic flux. The NLRP3 inflammasome has also been shown to be regulated by mitochondrial reactive oxygen species and components of glycolysis, such as Hexokinase. Here, we review these findings and discuss their importance for inflammation and furthermore discuss potential therapeutic benefits of targeting NLRP3.