Lipid mediators are detectable in the nasal epithelium and differ by asthma status in female subjects

Abstract

Background: Lipid mediators, bioactive products of polyunsaturated fatty acid metabolism, contribute to inflammation initiation and resolution in allergic diseases; however, their presence in lung-related biosamples has not been fully described.

Objective: We aimed to quantify lipid mediators in the nasal airway epithelium and characterize preliminary associations with asthma.

Methods: Using liquid chromatography-mass spectrometry, we conducted a pilot study to quantify 56 lipid mediators from nasal epithelial samples collected from 11 female participants of an outpatient asthma clinic and community controls (aged 30-55 years). We examined the presence of each compound using descriptive statistics to test whether lipid mediators could distinguish subjects with asthma (n = 8) from control subjects (n = 3) using linear regression and partial least squares discriminant analysis.

Results: Fifteen lipid mediators were detectable in all samples, including resolvin (Rv) D5 (RvD5), with the highest median concentrations (in pg/μg protein) of 13-HODE (126.481), 15-HETE (32.869), and 13-OxoODE (13.251). From linear regression adjusted for age, prostaglandin E₂ (PGE2) had a trend (P < .1) for higher concentrations in patients with severe asthma compared to controls (mean difference, 0.95; 95% confidence interval, -0.04 to 1.95). Asthma patients had higher scores on principal component 3 compared to controls (mean difference, 2.42; 95% confidence interval, 0.89 to 3.96), which represented lower levels of proresolving 15-HEPE, 19,20-DiHDPA, RvD5, 14-HDHA, 17-HDHA, and 13-HOTrE. Most of these compounds were best at discriminating asthma cases from controls in partial least squares discriminant analysis.

Conclusion: Lipid mediators are detectable in the nasal epithelium, and their levels distinguish asthma cases from controls.

Keywords: AA; DHA; EPA; Lipids; PUFAs; asthma; nasal airway epithelium; oxylipins; proresolving lipids; resolvins.