title: Actin reorganization and morphological changes in human neutrophils stimulated by TNF, GM-CSF, and G-CSF: the role of MAP kinases.
abstract: Stimulation of human neutrophils with tumor necrosis factor-alpha (TNF), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte CSF (G-CSF) resulted in decreased fluorescence intensity of FITC-phalloidin (actin depolymerization) and morphological changes. Cytokine-induced actin depolymerization was dependent on the concentration of cytokines used as stimuli. The maximal changes were detected at 10 min after stimulation with TNF or GM-CSF and at 20 min after stimulation with G-CSF. Cytokine-induced actin depolymerization was sustained for at least 30 min after stimulation. In contrast, N-formyl-methionyl-leucyl-phenylalanine (FMLP) rapidly (within 45 s) induced an increase in the fluorescence intensity of FITC-phalloidin (actin polymerization) and morphological changes. TNF- and GM-CSF-induced actin depolymerization and morphological changes, but not FMLP-induced responses, were partially inhibited by either PD-98059, an inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase, or SB-203580, an inhibitor of p38 MAPK, and were almost completely abolished by these inhibitors in combination. G-CSF-induced responses were almost completely abolished by PD-98059 and were unaffected by SB-203580. These findings are consistent with the ability of these cytokines to activate the distinct MAPK subtype cascade in human neutrophils. Phosphorylated ERK and p38 MAPK were not colocalized with F-actin in neutrophils stimulated by cytokines or FMLP. Furthermore, FMLP-induced polarization and actin polymerization were prevented by cytokine pretreatment. These findings suggest that TNF, GM-CSF, and G-CSF induce actin depolymerization and morphological changes through activation of ERK and/or p38 MAPK and that cytokine-induced actin reorganization may be partly responsible for the inhibitory effect of these cytokines on neutrophil chemotaxis.
authors.affiliation: Department of Physiology, Osaka City University Medical School, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Kutsuna
authors.forename: Kenichi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Noriko
authors.initials: N
authors.lastname: Kamata
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kato
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Hato
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mizuno
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Ishii
authors.forename: Seiichi
authors.initials: S
authors.lastname: Kitagawa
mesh_terms: D051339:Actin Depolymerizing Factors; D000199:Actins / Q000037:antagonists & inhibitors / Q000502:physiology*; D000328:Adult; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008840:Microfilament Proteins / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism / Q000502:physiology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism* / Q000648:ultrastructure*; D010766:Phosphorylation; D011108:Polymers / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D008840:Microfilament Proteins; D011108:Polymers; D011725:Pyridines; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016179:Granulocyte Colony-Stimulating Factor; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one