Nisha Kurian 1 , Taylor S Cohen 2 , Lisa Öberg 3 , Erica De Zan 3 , Gabriel Skogberg 4 , Stefan Vollmer 3 , Engin Baturcam 3 , Petter Svanberg 5 , Britta Bonn 5 , Paul D Smith 6 , Outi Vaarala 3 , Danen M Cunoosamy 3
26 November 2019
Unlike p38 mitogen-activated protein Kinases (MAPK) that has been extensively studied in the context of lung-associated pathologies in COPD, the role of the dual-specificity mitogen-activated protein kinase kinase (MEK1/2) or its downstream signaling molecule extracellular signal-regulated kinases 1/2 (ERK1/2) in COPD is poorly understood.
The aim of this study was to address whether MEK1/2 pathway activation is linked to COPD and that targeting this pathway can improve lung inflammation through decreased immune-mediated inflammatory responses without compromising bacterial clearance.
Association of MEK1/2 pathway activation to COPD was investigated by immunohistochemistry using lung tissue biopsies from COPD and healthy individuals and through analysis of sputum gene expression data from COPD patients. The anti-inflammatory effect of MEK1/2 inhibition was assessed on cytokine release from lipopolysaccharide-stimulated alveolar macrophages. The effect of MEK1/2 inhibition on bacterial clearance was assessed using Staphylococcus aureus killing assays with RAW 264.7 macrophage cell line and human neutrophils.
We report here MEK1/2 pathway activation demonstrated by increased pERK1/2 staining in bronchial epithelium and by the presence of MEK gene activation signature in sputum samples from COPD patients. Inhibition of MEK1/2 resulted in a superior anti-inflammatory effect in human alveolar macrophages in comparison to a p38 inhibitor. Furthermore, MEK1/2 inhibition led to an increase in bacterial killing in human neutrophils and RAW 264.7 cells that was not observed with the p38 inhibitor.