Fig 2.

Reduced proliferation and increased senescence in fibroblasts from moderate and severe COPD subjects. (A) Proliferation index (Alarma Blue assay) showing significantly reduced proliferative capacity of fibroblasts cultured from the COPD GOLD stage 2–3 group compared with the control and GOLD stage 1 groups. (B) Significantly increased percentage of SA-β-Gal positive fibroblasts from COPD GOLD stage 2–3 subjects compared to control and GOLD stage 1 subjects. SA-β-Gal: senescence-associated β-galactosidase. **P < 0.01; ***P < 0.001.