Fig. 1

a Example photomicrographs of ASM stained with (i) isotype control or (ii-iv) NOX4 in a healthy control with a less than or greater than 20 pack year history and subject with COPD respectively and (v) an example of a COPD subject with more intense staining at higher power. b NOX4 % positive staining assessed by thresholding (mean [SEM]). n = 6 (<20 pack years healthy controls), n = 4 (>20 pack years healthy controls), n = 9 (COPD). c Correlation between smoking history and NOX4 ASM expression. d NOX4 mRNA (measured in triplicate) in ASM from COPD versus healthy controls. n = 11 (healthy controls), n = 9 (COPD). e Percentage of cells expressing NOX4 in ASM from COPD and asthma subjects assessed by flow cytometry. n = 7 (asthma), n = 5 (COPD). f Geometric mean fluorescence intensity of NOX4 expression following incubation with control media or 50 ng/mL TNFα in ASM from subjects with COPD or asthma. n = 7 (asthma), n = 5 (COPD). g Detection of intracellular ROS (measured in triplicate; relative fluorescent units [RFU]) in ASM induced by hydrogen peroxide. n = 9 (healthy controls), n = 5 (asthma), n = 5 (COPD). h Detection of hydrogen peroxide-induced intracellular ROS following pre-incubation with NOX4 inhibitor. n = 10. Each point represents an individual donor: circles-healthy, square-COPD and triangle-asthma subjects