title: Role of extracellular signal-regulated kinase and phosphatidylinositol-3 kinase in chemoattractant and LPS delay of constitutive neutrophil apoptosis.
abstract: The present study examined the role of mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3 kinase-stimulated Akt (PI-3K/Akt) in the regulation of constitutive human neutrophil apoptosis by bacterial lipopolysaccharide (LPS) and two chemoattractants, fMLP and leukotriene B(4) (LTB(4)). LPS and LTB(4) inhibited apoptosis, while fMLP had no effect. Inhibition of extracellular signal-regulated kinase (ERK) with PD098059 significantly inhibited the anti-apoptotic effect of both LPS and LTB(4), while inhibition of p38 kinase with SB203580 had no effect. Inhibition of PI-3K with wortmannin and LY294002 significantly attenuated the anti-apoptotic effect of LTB(4), but not LPS. LPS, fMLP, and LTB(4) stimulated similar levels of ERK and Akt activation. LTB(4) and LPS inhibited neutrophil apoptosis when added simultaneously with fMLP, and LTB(4) and LPS demonstrated an additive effect. We conclude that the ERK and/or PI-3K/Akt pathways are necessary, but not sufficient, for LPS and LTB(4) to delay apoptosis, but other anti-apoptotic pathways remain to be identified.
authors.affiliation: Molecular Signaling Group, Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40202, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Klein
authors.forename: A
authors.initials: A
authors.lastname: Buridi
authors.forename: P Y
authors.initials: PY
authors.lastname: Coxon
authors.forename: M J
authors.initials: MJ
authors.lastname: Rane
authors.forename: T
authors.initials: T
authors.lastname: Manning
authors.forename: R
authors.initials: R
authors.lastname: Kettritz
authors.forename: K R
authors.initials: KR
authors.lastname: McLeish
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D002867:Chromones / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007975:Leukotriene B4 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000276:immunology*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000031:analogs & derivatives / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000201:enzymology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011725:Pyridines / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000730:Androstadienes; D002867:Chromones; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D007975:Leukotriene B4; D008070:Lipopolysaccharides; D020928:Mitogen-Activated Protein Kinases; D009025:Morpholines; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011725:Pyridines; D010566:Virulence Factors, Bordetella; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C042932:formylmethionyl-leucyl-phenylalanine methyl ester; C494918:AKT1 protein, human; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one