Leukotriene receptors are differently expressed in fibroblast from peripheral versus central airways in asthmatics and healthy controls.

Leukotrienes are involved in airway inflammation, and are believed to stimulate airway remodeling in asthma. The aim of the project was to investigate the expression of leukotriene receptors in peripheral and central airway fibroblasts. Peripheral and central airway fibroblasts, from asthmatics and healthy controls, were investigated for the amount of cysteinyl-leukotriene receptors (CysLT(1) and CysLT(2)), leukotriene B(4) receptors (BLT(1) and BLT(2)), IL-13 receptor-α(1) (IL-13Rα(1)) and the IL-4 receptor (IL-4R). The mRNA expression of CysLT(1) in fibroblasts from peripheral airways was higher compared to central airways. There was no difference in CysLT(2) between peripheral and central airways. On the contrary, BLT(1) and BLT(2) were lower in fibroblasts from peripheral airways compared to central. The expression of CysLT(1) was higher than CysLT(2) in fibroblasts from peripheral airways, and the expression of BLT(1) was higher than BLT(2) in both peripheral and central airways. Both BLT(1) and BLT(2) were higher in asthmatics compared to healthy controls, while CysLT(1) and CysLT(2) did not differ. The expression of IL-13Rα(1) was higher in asthmatics compared to controls, and correlated to the BLTs. All fibroblasts stained for the different receptor proteins. Leukotriene receptors are differently expressed in fibroblasts from peripheral compared to central airways, which may explain a suggested cysteinyl-leukotriene driven remodeling mainly in the peripheral airways.