Oxidative stress in COPD. Oxidative stress may be increased in COPD by a reduction in the transcription
factor Nrf2, activation of NADPH oxidases (NOX), MPO, and reduced superoxide dismutase (SOD). Oxidative stress
is a key driving mechanisms in COPD through activation of the proinflammatory transcription factor nuclear
factor-KB (NF-kB), p38 mitogen-activated protein kinase (MAPK), generation of autoantibodies to carbonylated
proteins, reduced sirtuin-1 (SIRT1), DNA damage, reduced histone deacetylase (HDAC)-2, reduced antiproteases,
and increased TGF-b.