Abstract
Background: Obesity is a risk factor for the development of asthma and is associated with poor control. IL-33 is involved in innate immunity and induces type 2 inflammation in the airway. However, the role of IL-33 in obesity-associated asthma has not fully understood.
Aims: In this study, we examined the effect of IL-33 in diet-induced obese mice.
Methods: Female C57BL/6J mice (4-week-old) were fed with a high fat diet (HFD; 60% kcal from fat) or a normal chow diet (control) for 20 weeks. IL-33 (1μg/50μL PBS) was instilled intranasally on Day 1-3 in HFD mice and control mice. On Day 4, the mice were anesthetized, ventilated (flexiVent; SCIREQ, Montreal, Canada), challenged with increasing doses of inhaled methacholine, and measured with resistance of respiratory system (Rrs) by forced oscillation technique. Furthermore, cell differentiation in BAL fluid and histology of the lungs were also analyzed.
Results: Body weight of HFD mice was ~ 35g, whereas that of control mice was ~20g. IL-33 increased eosinophil number in BALF in control mice. However, IL-33-induced increase in eosinophil number was much less in HFD mice than in control mice. Rrs was greater in HFD mice than in control mice under the non-treated condition. In contrast, IL-33 increased Rrs in control mice, whereas IL-33 had little effect on Rrs in HFD mice. IL-33-induced airway inflammation around bronchi and goblet cell metaplasia were less in HFD mice than in control mice.
Conclusion: HFD-induced obesity increased airway hyperresponsiveness at baseline, but attenuated IL-33-induced eosinophilic inflammation and goblet cell metaplasia. These results might reflect some features of the obesity-associated asthma.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 309.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020