NLRP3 Inflammasome¶

Overview¶

The NLRP3 inflammasome is a multi-protein intracellular complex that acts as a master trigger for the acute inflammatory response in gout. It is composed of three core proteins: NLRP3 (the sensor), ASC (the adaptor), and pro-caspase-1 (the executioner). When activated, it cleaves pro-IL-1β into active interleukin-1β (IL-1β), a potent pro-inflammatory cytokine that drives the explosive pain and swelling of a gout flare. (Source: gout-deep-dive.md, nlrp3-exploit-map.md)

The inflammasome is not unique to gout—it evolved to respond to pathogenic danger signals. However, monosodium urate (MSU) crystals, which deposit in joints during hyperuricemia, directly trigger NLRP3 assembly through lysosomal rupture, potassium efflux, and reactive oxygen species (ROS) generation. In gout, the innate immune system mistakes metabolic crystals for microbial threats, producing an outsized inflammatory cascade. (Source: gout-deep-dive.md)

The NLRP3 Activation Cascade: Seven Chokepoints (with Sub-Branches)¶

The NLRP3 inflammasome pathway operates as a sequential cascade with seven primary vulnerability points (chokepoints), several with mechanistically distinct sub-branches. Each is a potential therapeutic target — gout can be attacked at multiple nodes simultaneously rather than through a single intervention. The CP0–CP6b vocabulary below is referenced throughout the corpus; the NLRP3 Exploit Map owns the full per-chokepoint catalog.

The v1.2 restructure (April 2026) added CP0 (complement priming, C5a-dominant, upstream of NF-κB), sub-branches CP1a (TNFSF14/LIGHT priming amplifier) and CP1b (C5a→ROS), CP5b (active resolution via ALX/FPR2 SPMs, alongside CP5a receptor blockade), and promoted 5-LOX/LTB4 neutrophil chemotaxis to a first-class CP6a chokepoint. (source: nlrp3-exploit-map.md)

Chokepoint	The step	Canonical exploit
CP0 — Complement priming (C5a-dominant)	MSU activates complement → C5a→C5aR1 → ROS primes NLRP3, upstream of NF-κB	Avacopan (oral C5aR1 antagonist; platform gap — no fermentable modulator)
CP1 (CP1a/CP1b) — NF-κB priming	TLR/LPS → NF-κB transcribes NLRP3, pro-IL-1β, pro-IL-18, ASC. CP1a = TNFSF14/LIGHT amplifier; CP1b = C5a→ROS	Sulforaphane (Nrf2); also berberine, curcumin, KPV, EGCG, TNFSF14 blockade
CP2 — NLRP3 activation / ASC assembly	K⁺ efflux + mtROS drive NLRP3 oligomerization and ASC nucleation	BHB (direct oligomerization block); also oridonin, tranilast, theaflavins, NAC
CP3 — ASC speck assembly / caspase-1 recruitment	Microtubule transport assembles ASC specks → recruits pro-caspase-1	Colchicine (microtubule depolymerization)
CP4 — Caspase-1 activation / substrate cleavage	Active caspase-1 cleaves pro-IL-1β and GSDMD (the executioner step)	VX-765/belnacasan (selective caspase-1 inhibitor)
CP5a — IL-1β/IL-18 secretion and signaling	Mature IL-1β binds IL-1R1 → neutrophil recruitment, pain, systemic flare	Anakinra (IL-1R1 antagonist); canakinumab; inhaled mRNA-IL-1RA (chassis-pending)
CP5b — Active resolution via ALX/FPR2	SPMs (resolvins, protectins, maresins) signal neutrophil withdrawal + efferocytosis	Omega-3 EPA/DHA precursors → RvD1/MaR1 (Animal Model gout evidence)
CP6a — Neutrophil amplification via 5-LOX/LTB4	5-LOX produces LTB4 → neutrophil chemotaxis sustains the flare	Zileuton (5-LOX inhibitor); quercetin (5-LOX IC50 300 nM); AKBA
CP6b — GSDMD pore / pyroptotic amplification	Caspase-1-cleaved GSDMD-N oligomerizes into pores → pyroptosis releases IL-1β + alarmins	Disulfiram (Cys191 covalent block); DMF

For the full per-chokepoint exploit catalog (mechanism detail, all compound entries, dosing, ChEMBL cross-check verdicts, coverage audit), see NLRP3 Exploit Map. Compound-specific dossiers: colchicine, oridonin, BHB/ketones, theaflavins, zileuton, disulfiram, complement C5a, SPM resolution pathway, cannabinoids & terpenes.

Reactome Pathway Audit (Release 96)¶

The official Reactome report for R-HSA-844456 is now preserved as raw provenance at reference/papers/R-HSA-844456_.pdf. Reactome is useful here as a curated pathway map, not as primary experimental evidence. It confirms several NLRP3 activation nodes already relevant to Open Enzyme:

P2X7 / pannexin-1 activation trigger: extracellular ATP activates P2X7, potassium efflux, and pannexin-1-associated pore formation upstream of NLRP3 activation (Reactome events R-HSA-877178, R-HSA-877187, R-HSA-877198; In Vitro pathway curation, including Pelegrin and Surprenant 2006 PMID: 17036048).
SGT1:HSP90 chaperone dependency: SGT1 and HSP90 bind inactive NLRP3 and support signaling competence (Reactome events R-HSA-874087, R-HSA-873951; In Vitro / cell biology, Mayor et al. 2007 PMID: 17435760).
TXNIP/HMOX1 regulatory axis: Reactome models TXNIP binding to NLRP3 and includes negative regulation by cytosolic HMOX1 (Reactome event R-HSA-1250272; HMOX1 paper requires primary-source verification before adding detailed structural claims; the corrected PubMed record is PMID: 30333233, not 30121650).
Pyrin/ASC interaction: Reactome includes Pyrin binds ASC (R-HSA-877361) and its summation states that pyrin-ASC binding can interfere with NLRP3 association with ASC. Treat this as an already-modeled pathway note, not a novel Open Enzyme contribution. Detailed residue/interface claims should stay out of the wiki until primary-source grep verification is complete.

Contribution opportunity is therefore narrower than the first Antigravity draft implied. The plausible Reactome gaps from Open Enzyme's corpus are small-molecule/regulatory edges around already modeled events: oridonin as a covalent NLRP3/NEK7-blocking inhibitor (PMID: 29959312), tranilast as a direct NACHT-domain inhibitor (PMID: 29531021), and BHB/ketones as a ketone-body inhibitor of potassium efflux and ASC oligomerization (PMID: 25686106). These should be proposed as targeted curation additions only after checking the current Reactome graph for each compound name, synonym, ChEBI entity, and target event.

Chokepoint 5 — endogenous IL-1Ra biology (anakinra is not a foreign molecule)¶

This is the canonical explainer for why recombinant IL-1Ra has such a clean safety profile — referenced from chassis-pending-interventions.md §4. The acute-flare anakinra protocol (100 mg SC daily × 3 days, ~$900/flare, cumulative-steroid-burden framing) and the inhaled mRNA-IL-1RA pulse comparator live canonically in gout-action-guide.md §"Active flare" and chassis-pending-interventions.md §4 respectively; the exploit map's CP5a section carries the full mechanism entries.

Humans naturally produce IL-1Ra (~17 kDa, encoded by IL1RN, secreted primarily by macrophages and neutrophils as a feedback brake on IL-1 signaling). Endogenous IL-1Ra competes with IL-1α and IL-1β for the same IL-1R1 receptor — when bound, it occupies the receptor without triggering downstream signaling. The IL-1β / IL-1Ra ratio determines net signaling: at homeostatic baseline, endogenous IL-1Ra is in ~100× molar excess over IL-1β, keeping signaling damped. Inflammatory states (gout flare, autoimmune, sepsis) tip the ratio by driving IL-1β production faster than IL-1Ra, exceeding the endogenous brake. Therapeutic anakinra is the same protein the body makes, just at supplemental dose — which is why the safety profile is so clean (essentially zero immunogenicity, no ADCC/CDC off-target effects, simple competitive-antagonism mechanism). The same "endogenous brake" framing is why mRNA-encoded IL-1Ra is a cleaner payload than an mRNA-encoded anti-IL-1β monoclonal: IL-1Ra is small (no glycosylation, no disulfides, no heavy/light chain assembly), broader-mechanism (blocks IL-1α AND IL-1β at the same receptor), and immunogenicity-free as a recombinant version of an endogenous protein. (source: chassis-pending-interventions.md, gout-action-guide.md, nlrp3-exploit-map.md)

Multi-Chokepoint Compounds¶

The most efficient exploits hit three or more chokepoints — BHB (CP1+CP2+CP3), berberine (CP1+CP4), oridonin (CP1+CP2), DMF (CP1+CP2+CP6b), EGCG (CP1+CP4+CP5). See the NLRP3 Exploit Map "Multi-Chokepoint Compounds" section for the per-compound chokepoint breakdown. (source: nlrp3-exploit-map.md)

Pharmaceutical NLRP3 Inhibitors¶

Approved or In Clinical Development¶

Canakinumab (Ilaris): IL-1β monoclonal antibody. FDA approved for gout in August 2023 — the first biologic ever formally indicated for gout in the US, 12 years after its initial 2011 rejection. Originally approved for CAPS/JIA. Very effective but expensive (~$300,000/year). Systemic immunosuppression risk. (Clinical Trial; J Inflamm Res 2026;19, PMID: 41867470. source: gout-clinical-pipeline.md)
Genakumab (Firsekibart): Chinese canakinumab competitor (GeneScience). Phase 3 NCT05983445 (313 patients) completed April 2024. Same anti-IL-1β mechanism. (Clinical Trial; source: gout-clinical-pipeline.md)
Anakinra (Kineret): IL-1 receptor antagonist. FDA-approved for RA and CAPS. Off-label for refractory gout. Less expensive than canakinumab but requires daily injection.
Rilonacept (Arcalyst): IL-1 trap. Rejected by FDA for gout in 2012 despite a 1,315-patient Phase 3 (NCT00856206) demonstrating efficacy. Not currently in active gout development. (Clinical Trial; source: gout-clinical-pipeline.md)
Dapansutrile (OLT1177): Oral NLRP3 inhibitor. Phase 2a in gout (N=34, Lancet Rheumatol 2020, PMID: 33005902) showed 52–68% target joint pain reduction at day 3 across four dose levels. However, no Phase 2b or Phase 3 trial in gout is registered on ClinicalTrials.gov as of April 2026. Olatec's subsequent active programs moved to heart failure (Phase 1b NCT03534297, completed 2019) and COVID-19 (Phase 2 NCT04540120, terminated 2022). Dapansutrile in gout appears stalled, not advancing. (Clinical Trial; source: gout-clinical-pipeline.md) Species-gap caveat (ChEMBL v34, 2026-04-23): Dapansutrile's curated cellular IC50 is 1.0 nM in mouse J774A.1 cells but 1.0 μM in human MDM cells — a 1,000× species gap (Eur J Med Chem 2020/2023, Bioorg Med Chem Lett 2021). The Phase 2a efficacy at 100–2,000 mg/day is consistent with human-cell μM potency at high oral doses, not with the sub-nanomolar mouse-cell potency. This reframes translational expectations for the entire oral-NLRP3-inhibitor class. (In Vitro; source: nlrp3-inhibitor-screen.md)
MCC950 (CRID3): The first specific NLRP3 inhibitor. Binds the Walker B motif in the NACHT domain, blocking ATP hydrolysis required for oligomerization. Clinical development terminated due to hepatotoxicity in Phase 1 RA trial, but it defined the druggable target and validated the mechanism. ChEMBL cross-check (2026-04-23): MCC950 / CRID3 / CP-456773 are not retrievable by common synonyms in ChEMBL v34's name search; the cited 7.5 nM IC50 (Coll et al. 2015 J Biol Chem, cell-free Walker B) has not been independently re-indexed by the MCP cross-check. Benchmark status unchanged, but the IC50 is not verified via ChEMBL. (source: nlrp3-inhibitor-screen.md)

Two-Tier Labeling: Direct Inhibitors vs. Pathway Modulators (2026-04-23)¶

The 2026-04-23 ChEMBL v34 cross-check (see nlrp3-inhibitor-screen.md appendix) surfaced a labeling rigor issue. Only two compounds in the wiki's broader NLRP3 discussion have a curated direct human NLRP3 IC50 in ChEMBL:

Dapansutrile: 1.0 μM (human MDM, Eur J Med Chem 2023) — but 1 nM in mouse J774A.1 (1,000× species gap)
Oridonin: 5.18 μM (human THP-1, Eur J Med Chem 2023)

MCC950 and tranilast have published direct NLRP3 assays in the primary literature but are not retrievable via ChEMBL's curated target-bound bioactivity table for human NLRP3 (CHEMBL1741208) by common synonyms.

Compounds with zero curated direct human NLRP3 entries in ChEMBL: quercetin, ursolic acid, tranilast, beta-caryophyllene. Their "NLRP3 inhibitor" status rests on functional IL-1β readouts in macrophage assays or upstream pathway effects (NF-κB priming, ROS, K⁺ efflux) — not direct NLRP3 binding/inhibition measurements.

Going-forward convention: Distinguish "direct NLRP3 inhibitor" (binding/inhibition IC50 measured against NLRP3 protein) from "NLRP3 pathway modulator" (functional IL-1β reduction, mechanism inferred). Both are clinically relevant — Open Enzyme ultimately cares about IL-1β output, not NLRP3 biochemistry per se — but the distinction sharpens how claims are written. (In Vitro; source: nlrp3-inhibitor-screen.md)

NLRP3 Pipeline Has Drifted Out of Gout¶

The broader NLRP3 inhibitor pipeline has moved to other indications where the biology has wider therapeutic appeal: DFV890 (Novartis, knee osteoarthritis Phase 2 completed Dec 2024), NT-0796 (NodThera, obesity + semaglutide Phase 2a active), VTX3232 (Zomagen, Parkinson's Phase 2a completed April 2025), VENT-02 (Ventus, Parkinson's Phase 1b terminated Oct 2025), Inzomelid (Inflazome/Roche, CAPS Phase 1 completed), ZYIL1 (Zydus, Phase 1 completed). No NLRP3-specific compound is in active gout-indicated trials as of April 2026. This is a strategic data point for Open Enzyme's "food-derived NLRP3 adjunct" positioning — the prescription pipeline isn't delivering for gout. (source: gout-clinical-pipeline.md)

Emerging Target: TNFSF14 (LIGHT) — CP1a Priming Amplifier¶

A 2024 Annals of the Rheumatic Diseases study (Ea et al., DOI: 10.1136/ard-2023-225305, PMID: 38373842) used the Olink 92-protein inflammation panel on gout flare vs. intercritical vs. treat-to-target patients. TNFSF14 (TNF superfamily 14, also called LIGHT) was the second-highest fold-change gout-flare biomarker after IL-6. LIGHT signals via HVEM and LTβR receptors on fibroblast-like synoviocytes, B cells, monocytes, and myeloid cells, activating NF-κB and AP-1 — a priming amplifier parallel to LPS/TLR4 (classified as CP1a in the exploit map v1.2). Ex vivo TNFSF14 blockade reduced LPS+MSU cytokine production; SNPs in TNFSF14 modulate myeloid cytokine output. CERC-002 (anti-LIGHT mAb) showed positive Phase 2 data in COVID ARDS — potential repurposing candidate. Safety caveat: LIGHT has dual roles (LIGHT-null mice have worse colitis) — episodic or LTβR-selective blockade is safer than total suppression. Natural compounds: EGCG suppresses TNFSF14-induced IL-6 and downregulates HVEM receptor expression (In Vitro); DHA shows inverse genetic association with circulating LIGHT. (Clinical Trial + In Vitro; source: gout-clinical-pipeline.md, tnfsf14-gout-target.md) See TNFSF14 Gout Target for the dedicated analysis.

Engineered Koji & Production Candidates¶

A. oryzae could be engineered to overproduce food-derived NLRP3-suppressing compounds (procyanidin/EGCG-like polyphenols), and several stack compounds have established microbial titers — ursolic acid (8.59 g/L in S. cerevisiae), quercetin (930 mg/L), carnosine (the only candidate with dual hyperuricemia + NLRP3 rat data), and native kojic acid (3–5 g/L, NLRP3 mechanism unscreened). The full production-candidate analysis (titers, potency rankings, bioavailability, stacking strategy) lives in the NLRP3 Exploit Map "AI Analysis — Microbial Production Candidates" section and 07 — NLRP3 Inhibitor Screen. (source: nlrp3-exploit-map.md)

The SIBO–Gout–Lynn Connection¶

NLRP3 activation is a shared driver of both gout and SIBO-driven intestinal inflammation, so several stack compounds (berberine, KPV, omega-3 SPMs, BHB/fasting, spermidine+trehalose) suppress both conditions through the same mechanism. See the NLRP3 Exploit Map "SIBO–Gout–Lynn Connection" section for the full per-compound dual-indication mapping. (source: nlrp3-exploit-map.md)

Key Insights¶

The Crystal Dissolution Danger Window: When urate-lowering therapy (including [[uricase|koji-uricase]]) begins dissolving existing MSU crystal deposits, crystals temporarily become smaller with more surface area. Crystal shedding from tophi can trigger acute flares. The NLRP3 stack is essential during this phase—it prevents dissolution-triggered flares while the uricase handles the underlying uric acid problem. Both strategies must run simultaneously. (Source: nlrp3-exploit-map.md, gout-deep-dive.md)

Disulfiram is Underrated: An FDA-approved drug with 70 years of safety data, costing ~$30/month, that blocks the final step of IL-1β release and prevents pyroptotic amplification. Few rheumatologists discuss it because it was discovered by immunologists studying sepsis—a market inefficiency in medical knowledge. (Source: nlrp3-exploit-map.md)

Ketosis Paradox Resolved: The conventional wisdom that ketosis is bad for gout (ketones compete with urate for renal excretion) misses that BHB simultaneously and potently suppresses NLRP3 inflammasome activation. With [[uricase|koji-uricase]] handling uric acid clearance, ketosis becomes purely beneficial—all inflammasome suppression, no uric acid penalty. (Source: nlrp3-exploit-map.md)

References¶

Source: nlrp3-exploit-map.md — Systematic black hat pen-testing of NLRP3 inflammasome pathway; v1.2 restructure (April 2026) adds CP0, CP1a/1b, CP5a/5b, CP6a/6b — seven primary chokepoints
Source: gout-deep-dive.md — Comprehensive gout pathophysiology including NLRP3 inflammasome overview and crystal-driven activation
Source: peptide-gout-addendum.md — Deep dive into peptide mechanisms including BPC-157 and TB-500 NLRP3 interactions
Source: complement-c5a-gout.md — Complement C5a as dominant NLRP3 priming signal (CP0); avacopan repurposing candidate
Source: spm-resolution-pathway.md — Active resolution via ALX/FPR2 SPMs (CP5b); RvD1 and MaR1 gout animal model evidence
Source: tnfsf14-gout-target.md — TNFSF14/LIGHT as second-highest gout-flare biomarker (CP1a); EGCG and DHA natural activity; CERC-002 clinical precedent
Source: chembl-cross-check.md — ChEMBL v34 curated cross-check of stack compounds; curcumin 24.2 μM NLRP3 IC50, berberine TDO top target, resveratrol DPP-4 top target, EGCG proteasome 86 nM
Source: theaflavins.md — Theaflavins (black-tea polyphenols): NLRP3-NEK7 disruption (CP2/CP3), direct MSU peritonitis Animal Model, URAT1/GLUT9 downregulation, TF3 TNFSF14/HVEM modulation (CP1a); Tier 2 supplement candidate added 2026-05-05
Source: zileuton.md — Zileuton (FDA-approved 5-LOX inhibitor, asthma): CP6a repurposing candidate; zero gout trials registered; hepatotoxicity monitoring required; n=1 protocol design
Source: nlrp3-inhibitor-screen.md — 2026-05-05 audit: sulforaphane upgraded to Tier 2 (Yang 2018 PMID 29340626 direct MSU gout; Greaney 2015 PMID 26269198 Nrf2-independent inflammasome inhibition); theaflavins added as Tier 2