The role of lipocalin 2 in small airway lesions of asthma

<bold>Background:</bold> The role of lipocalin 2 (LCN2) in small airway lesions of asthma remains unclear. <bold>Objective:</bold> To dig for the role and mechanisms of LCN2 in small airway lesions of asthma. <bold>Methods:</bold> Induced sputum from 20 asthmatic patients with normal small airway function (SAN), 20 asthmatic patients with SAD and 12 healthy volunteers was prospectively collected, enzyme-linked immunosorbent assay detected the cytokines of inducued sputum. Neutrophil asthma mouse model was constructed by OVA and ozone exposure. <bold>Results:</bold> Baseline sex, age, and body mass index (BMI) were matched among the three groups. The expression of LCN2 in induced sputum was significantly increased in asthma patients (567.6 ng/ml vs. 284.4 ng/ml) and was higher in asthmatic patients with SAD than in patients with SAN (747.3 ng/ml vs. 427.0 ng/ml). LCN2 negatively correlated with small airway function and positively related to neutrophil cells, interleukin (IL)-8, IL-6 and interferon (IFN)-γ. The level of LCN2 was significantly increased in the airway epithelium of asthma mouse model and positively correlated with the small airway neutrophil inflammation, airway remodeling and the disruption of the small airway epithelial barrier. <bold>Conclusion:</bold> LCN2 is closely related to small airway lesions and is expected to be an effective therapeutic target for improving small airway barrier and remodeling in asthma.