Figure 1.

Endogenous N/OFQ expression is increased in human asthmatic airways; the NOP receptor is expressed in human airways. (A) Sputum N/OFQ levels from healthy (n = 29 subjects; n = 5 below detection limit), mild to moderate asthmatic (GINA 1–3; n = 30 patients; n = 7 below detection limit) and severe asthmatic (GINA 4–5; n = 55 patients; n = 2 below detection limit) donors; (B) correlation between sputum N/OFQ (pg·mL⁻¹) and sputum eosinophils (%) in asthmatics (mild–moderate and severe); (C) IHC staining of human airway tissues for N/OFQ (representative image, n = 3 healthy donors and n = 6 asthmatic donors), scale bars 100 μm; (D) semi‐quantitative IHC staining score (n <5 for healthy human airway tissue); (E) quantitative real‐time PCR demonstrating ppN/OFQ mRNA expression on PBEs (n = 5 healthy and n = 5 asthmatic donors); and (F) quantitative real‐time PCR demonstrating NOP receptor mRNA expression in human airway structural and immune cells (n numbers represent cells from individual donors for HASM, HBEC, HLMC and PBEs and independent experiments for HMC‐1 and EOL‐1 cell lines). Data are expressed as mean ± SEM. Comparisons made by unpaired t‐test or one‐way anova followed by appropriate post hoc tests where relevant. *P <0.05.