Hypoxia-Induced NLRP3 Inflammasome Activation in a Cellular Model for Pulmonary Arterial Hypertension
Notice bibliographique
Résumé
Abstract Rationale: Pulmonary arterial hypertension (PAH) is a severe disease marked by vascular remodeling and right heart failure, with limited treatments available. Studies suggest macrophage pyroptosis, driven by NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome activation, contributes to inflammation in PAH. While NLRP3 involvement in PAH has been established, the trigger for activation remains unknown. Hypoxia, commonly used in PAH models, has been linked to reactive oxygen species (ROS) production, which may activate NLRP3 and drive pyroptosis via gasdermin D (GSDMD) lipidation. We hypothesized that hypoxia-induced ROS enhances macrophage pyroptosis in PAH. Methods: Mouse bone marrow-derived macrophages (BMDMs) were cultured under normoxic or hypoxic conditions (2% O₂ for 24 hours) with or without lipopolysaccharide (LPS) and nigericin (Ng) to induce pyroptosis. Cell death was assessed via lactate dehydrogenase (LDH) release and Zombie Red staining. Extracellular IL-1β and high-mobility group box 1 (HMGB1) were measured as markers of inflammasome activation and pyroptosis. Expression of NLRP3 and IL-1β was analyzed by qPCR. MCC950 (NLRP3 inhibitor), the ROS scavenger N-acetylcysteine (NAC), and the pan-lipidation inhibitor 2-bromopalmitate (2BP) were tested. GSDMD, HIF-1α or STAT1 knockout (KO) BMDMs were evaluated. Plasma from PAH patients and healthy controls was analyzed for LDH activity as an indicator of cell lysis. Results: LDH release was significantly elevated in plasma from PAH patients as compared to controls, consistent with increased lytic cell death. In hypoxia-exposed BMDMs, inflammasome activation and pyroptotic cell death were increased under LPS+Ng treatment, as shown by elevated LDH release, Zombie Red staining, and IL-1β and HMGB1 secretion. Hypoxia also upregulated NLRP3 and IL-1β at mRNA levels. Pyroptosis was abolished by MCC950 in both normoxia and hypoxia, confirming that NLRP3 is required for this response. GSDMD KO BMDMs exhibited reduced pyroptosis, indicating that GSDMD is crucial for hypoxia-induced pyroptosis. Hypoxia-induced NLRP3 activation was dependent on HIF-1α, but not STAT1. Hypoxia alone and in combination with LPS increased ROS levels in macrophages, which was suppressed by NAC. NAC also blocked LDH release and pyroptosis markers, including caspase-1 and GSDMD activation. Additionally, 2BP reduced pyroptotic markers, implicating lipidation in the hypoxia-driven pyroptotic pathway. Conclusion: Our data demonstrate that hypoxia induces ROS production, enhances NLRP3 inflammasome expression and activation, thereby amplifying macrophage pyroptosis through ROS- and lipidation-dependent mechanisms. This newly described pathway provides insights into PAH pathogenesis and suggests hypoxia may be an important NLRP3 stimulus in vivo.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».