Fig. 1
From: Recent evidence from omic analysis for redox signalling and mitochondrial oxidative stress in COPD
Sources of reactive oxidant species (ROS) within the lung. The high levels of ROS reported in the lung and airways of COPD subjects is derived from both exogenous and exogenous sources. Exogenous sources include cigarette smoking, environmental pollution, pathogens and inflammation. ROS is generated endogenously through mitochondria including mitochondrial ROS (mtROS), peroxisome activation, hypoxia and inflammation. ROS affects the function of many intracellular organelles such as proteasome, inflammasome, lysosome and the endoplasmic reticulum (ER) via the unfolded protein response (UPR) to elicit detrimental effects on cellular functions