Olaparib Blocks Oxidative Stress‐Dependent NLRP3 Inflammasome in Pediatric Acute Lung Injury by Metabolic Reprogramming via AMPK ‐Driven Autophagic Flux

ABSTRACT Pediatric acute lung injury (ALI) is a life‐threatening syndrome defined by dysregulated pulmonary inflammation and impaired alveolar gas exchange, with limited therapeutic interventions. This study aims to evaluate the therapeutic efficacy and mechanistic basis of Olaparib, a clinically approved PARP inhibitor, using in vitro and in vivo models of pediatric ALI. In LPS/ATP‐stimulated THP‐1‐derived macrophages, Olaparib induced metabolic reprogramming, as indicated by a reduced NAD + /NADH ratio and an elevated AMP/ATP ratio, leading to activation of the AMPK/ULK1 signaling pathway. This activation enhanced autophagic flux, as evidenced by increased LC3‐II conversion, p62 degradation, and analysis of the mRFP‐GFP‐LC3 reporter. Enhanced autophagy was associated with attenuation of oxidative stress, including reductions in mitochondrial and intracellular reactive oxygen species and malondialdehyde levels, and suppression of NLRP3 inflammasome activation, as evidenced by decreased cleaved caspase‐1, IL‐1β, and IL‐18. In a juvenile murine model of LPS‐induced ALI, Olaparib administration reduced histopathological lung injury, inflammatory cell infiltration, and pulmonary edema. It also restored alveolar–capillary barrier integrity by upregulating junctional proteins, including ZO‐1, claudin‐5, and VE‐cadherin, and reduced apoptosis. The protective effects of Olaparib on autophagy, oxidative stress, inflammasome activity, and lung tissue repair were attenuated by pharmacological inhibition of AMPK using compound C. In conclusion, these findings demonstrate that Olaparib ameliorates pediatric ALI through AMPK‐dependent induction of autophagic flux via metabolic reprogramming, attenuating oxidative stress and inhibiting NLRP3 inflammasome activation. These results support the therapeutic potential of Olaparib in pediatric ALI.