Signaling by the respiratory burst in macrophages.
During phagocytosis or stimulation with a wide variety of agents, macrophages and other phagocytic cells produce reactive oxygen species (ROS) through activation of a multicomponent NADPH oxidase. ROS production through related NADPH oxidases has recently been demonstrated in several other cell types. Furthermore, the physiological generation of ROS production has now been clearly implicated in activating signaling pathways resulting in a broad array of physiological responses from cell proliferation to gene expression and apoptosis. This brief review suggests that: 1) hydrogen peroxide and superoxide, but not the hydroxyl radical, function as second messengers; 2) antioxidant enzymes function in the "turn-off" phase of signal transduction; 3) the chemistry of thiols is critical in redox signaling; and 4) the primary physiological role of the respiratory burst in macrophages may be in redox signaling rather than microbicidal activity.
Forman
H J
HJ
Department of Environmental Health Sciences, School of Public Health, University of Alabama at Birmingham, 35294, USA. hforman@uab.edu
Torres
M
M
D000818:Animals; D006801:Humans; D016676:Macrophages, Alveolar / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism / Q000494:pharmacology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013438:Sulfhydryl Compounds / Q000737:chemistry
D016877:Oxidants; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D019255:NADPH Oxidases; D010100:Oxygen