Oxidative stress-induced changes in pyridine nucleotides and chemoattractant 5-lipoxygenase products in aging neutrophils.
Neutrophils spontaneously undergo apoptosis, which is associated with increased oxidative stress. We found that there is a dramatic shift in the formation of 5-lipoxygenase products during this process. Freshly isolated neutrophils rapidly convert leukotriene B(4) (LTB(4)) and 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) to their biologically inactive omega-oxidation products. However, omega-oxidation is impaired in neutrophils cultured for 24 h, when only 25% of the cells are nonapoptotic, resulting in the persistence of LTB(4) and a dramatic shift in 5-HETE metabolism to the potent granulocyte chemoattractant 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). The reduced omega-oxidation activity seems to be due to a reduction in LTB(4) 20-hydroxylase activity, whereas the increased 5-oxo-ETE formation is caused by a dramatic increase in the 5-hydroxyeicosanoid dehydrogenase cofactor NADP(+). NAD(+), but not NADPH, also increased, as did the GSSG/GSH ratio, indicative of oxidative stress. The changes in 5-HETE metabolism and pyridine nucleotides were inhibited by antiapoptotic agents (GM-CSF, forskolin) and antioxidants (diphenylene iodonium, catalase, deferoxamine), suggesting the involvement of H(2)O(2) and possibly other reactive oxygen species. These results suggest that in severe inflammation, aging neutrophils that have evaded rapid uptake by macrophages may produce increased amounts of the chemoattractants 5-oxo-ETE and LTB(4), resulting in delayed resolution or exacerbation of the inflammatory process.
Meakins-Christie Laboratories, McGill University, Montreal, QC, Canada.
François D
FD
Graham
Karl-Rudolf
KR
Erlemann
Sylvie
S
Gravel
Joshua
J
Rokach
William S
WS
Powell
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001094:Arachidonate 5-Lipoxygenase / Q000276:immunology / Q000378:metabolism; D001095:Arachidonic Acids / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D032701:Biomimetics; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000502:physiology; D002630:Chemotactic Factors / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000276:immunology / Q000378:metabolism; D000072470:Cytochrome P450 Family 4; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000737:chemistry / Q000378:metabolism*; D007975:Leukotriene B4 / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress; D011725:Pyridines / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000737:chemistry
D000975:Antioxidants; D001095:Arachidonic Acids; D002630:Chemotactic Factors; D006893:Hydroxyeicosatetraenoic Acids; D011725:Pyridines; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D005576:Colforsin; D007975:Leukotriene B4; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; D000429:Alcohol Oxidoreductases; C099244:5-hydroxyeicosanoid dehydrogenase; D001094:Arachidonate 5-Lipoxygenase; D000072470:Cytochrome P450 Family 4; C040780:leukotriene B4 20-hydroxylase; D013482:Superoxide Dismutase; C023666:pyridine