Figure 2.

Levels of PER2, CLOCK, PER1, REV-ERBα, and REV-ERBβ in lungs from nonsmokers, smokers, and patients with COPD by Western blot. (A) Levels of PER2, CLOCK, PER1, REV-ERBα, and REV-ERBβ in lung tissues from nonsmokers, smokers, and patients with COPD were measured by Western blot. Each group represents the results of at least three independent experiments, and the representative REV-ERBα bands are from different gels, which are demarcated by the lines. (B) The relative band intensity normalized to β-actin or glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is shown in a histogram. Data are shown as mean ± SEM (n = 3–4). **P < 0.01 and ***P < 0.001 versus nonsmokers.