Regulation of the NADPH oxidase activity and anti-microbial function of neutrophils by arachidonic acid.
Arachidonic acid (AA), a second-messenger molecule released from membrane phospholipids by phospholipase A(2) in activated cells, is a stimulator of neutrophil responses, including the oxygen-dependent respiratory burst. The polyunsaturated fatty acid is also the precursor of biologically active eicosanoids. There are several mechanisms by which AA stimulates the respiratory burst. These include the direct binding of AA to S100 proteins which regulate the assembly of the NADPH oxidase as well as the activation of key signaling molecules which control the respiratory burst. Arachidonic acid also stimulates it own release from membrane phospholipids and this contributes to optimal respiratory burst activity. Thus, increased levels of AA at sites of inflammation will influence the magnitude and course of the inflammatory response, not only by directly affecting the function of infiltrating neutrophils and other leukocytes, but also through its metabolites generated by lipoxygenases and cyclooxygenases.
Hii
Charles S
CS
Department of Immunopathology, Children, Youth and Women's Health Services, 72 King William Road, North Adelaide, South Australia 5006, Australia. charles.hii@adelaide.edu.au
Ferrante
Antonio
A
D016718:Arachidonic Acid / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000502:physiology; D004951:Esterification; D005227:Fatty Acids / Q000493:pharmacokinetics; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008954:Models, Biological; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology* / Q000378:metabolism / Q000382:microbiology / Q000502:physiology; D010741:Phospholipases A / Q000502:physiology; D015398:Signal Transduction; D013481:Superoxides / Q000378:metabolism
D005227:Fatty Acids; D013481:Superoxides; D016718:Arachidonic Acid; D019255:NADPH Oxidases; D010741:Phospholipases A