Endocrine-disrupting chemical exposure augments neutrophilic inflammation in severe asthma through the autophagy pathway

Corticosteroid resistance, progressive lung function decline, and frequent asthma exacerbations are the hallmarks of neutrophilic asthma (NA). However, the potential contributors and their mechanisms of NA aggravation have not yet been fully clarified. This study was conducted to assess the precise mechanism and inflammatory effects of endocrine-disrupting chemicals using mono-n-butyl phthalate (MnBP) on an NA model. BALB/c mice from normal control and LPS/OVA-induced NA groups were treated with or without MnBP. The effects of MnBP on the airway epithelial cells (AECs), macrophages (M9), and neutrophils were investigated in vitro and in vivo. NA mice exposed to MnBP had significantly increased airway hyperresponsiveness, total and neutrophil cell counts in the bronchoalveolar lavage fluid, and the percentage of M1M9 in the lung tissues compared to those non-exposed to MnBP. In in vitro study, MnBP induced the human neutrophil activation to release neutrophil DNA extracellular traps, M9 polarizing toward M1M9, and AEC damage. Treatment with hydroxychloroquine (an autophagy in-hibitor) reduced the effects of MnBP in vivo and in vitro. The results of our study suggest that MnBP exposure may increase the risk of neutrophilic inflammation in severe asthma and autophagy pathway-targeted therapeutics can help control MnBP-induced harmful effects in asthma.

Automated summary

Corticosteroid resistance, progressive lung function decline, and frequent asthma exacerbations are characteristics of neutrophilic asthma (NA). This study provides insights into the precise mechanism and inflammatory effects of endocrine-disrupting chemicals, specifically mono-n-butyl phthalate (MnBP), on an NA model. The findings show that exposure to MnBP increases airway hyperresponsiveness, neutrophilic inflammation, and M1M9 cells in NA mice. In vitro experiments demonstrate that MnBP induces neutrophil activation, M9 polarization, and airway epithelial cell damage. Treatment with hydroxychloroquine alleviates the effects of MnBP. These results suggest that MnBP exposure increases the risk of neutrophilic inflammation in severe asthma and targeted therapies for the autophagy pathway can mitigate MnBP-induced harm.