Fig. 1

EGR3 was upregulated in COPD lungs. a RT-qPCR was used to detect the expression of EGR3 in lungs from nonsmokers (n = 7), smokers without COPD (n = 22) and smokers with COPD (n = 26). b IHC staining of EGR3 in airway tissues of nonsmokers, smokers without COPD, smokers with COPD. c The expression of EGR3 in 16HBE cells treated with different concentrations of CSE (1, 2, 3, and 4%) for 24 h was evaluated by RT-qPCR (n = 3). d The expression of EGR3 in 16HBE cells exposed to 2.5% CSE at 0, 12, 24, 36 and 48 h was measured by RT-qPCR (n = 3). *p < 0.05, **p < 0.01