Neonatal necrotizing enterocolitis attenuates adult asthma via eosinophil ferroptosis

Abstract

Background: Necrotizing enterocolitis (NEC) is a severe gastrointestinal disorder primarily affecting preterm infants. Early-life exposure to NEC may influence asthma severity in adulthood through various mechanisms, yet significant research gaps remain in animal model studies of this relationship. This study aims to elucidate preliminary findings that early NEC exposure may attenuate subsequent asthma-related inflammation via animal models and proposes eosinophil ferroptosis as a potential mechanism underlying this effect.

Methods: NEC was induced in neonatal C57/BL6 mice, followed by ovalbumin (OVA)-sensitized asthma model induction in adulthood. Comprehensive evaluations were performed using lung histopathology, immune cell profiling, lipidomics, and transcriptomics. Transmission electron microscopy, lipid peroxidation assays, and ferroptosis-related protein expression analyses were employed to validate eosinophil ferroptosis. Ferroptosis modulators were tested in NEC/asthma mice. Ferroptosis activator/inhibitor-pretreated eosinophils were infused into asthmatic mice lungs through bronchial instillation to assess their impact on asthma severity in vivo.

Results: NEC-exposed mice exhibited alveolar simplification and inflammatory exudation as primary lung pathological changes. Persistent lipid metabolic dysregulation and reduced pulmonary eosinophils were observed in NEC-exposed mice, persisting into adulthood asthma. In adult asthma models, NEC pretreatment significantly alleviated airway inflammation, mucus secretion, and collagen deposition. NEC exerted protective effects by inducing eosinophil ferroptosis, characterized by mitochondrial atrophy, elevated lipid peroxidation, and altered ferroptosis-related protein expression. Transcriptomic analysis revealed downregulated inflammatory pathway genes and upregulated cilia motility-related genes in NEC-exposed asthmatic mice. Ferroptosis inhibitors significantly suppressed intestinal inflammation in NEC and pulmonary inflammation in asthmatic mice, while inhibiting eosinophil ferroptosis. Conversely, ferroptosis activators exacerbated both intestinal and pulmonary inflammation and eosinophil ferroptosis. Eosinophils pretreated with ferroptosis activators, when reinfused into asthmatic mice, synergized with dexamethasone to reduce asthma airway inflammation severity.

Conclusion: Early NEC exposure may attenuate asthma severity by triggering eosinophil ferroptosis. This study is the first to propose ferroptosis as a potential link between NEC and asthma alleviation, with causality further validated using ferroptosis modulators and eosinophil-specific ferroptosis regulation experiments. These findings establish a mechanistic framework, providing theoretical support for exploring eosinophil ferroptosis as a new therapeutic target for asthma.

Keywords: Asthma; Eosinophil; Ferroptosis; Necrotizing enterocolitis.