The Src Family Kinases Hck and Fgr Regulate Neutrophil Responses to N-formyl-methionyl-leucyl-phenylalanine
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The chemotactic peptide formyl-methionyl-leucyl-phenilalanine (fMLP) triggers intracellular protein tyrosine phosphorylation leading to neutrophil activation. Deficiency of the Src family kinases Hck and Fgr have previously been found to regulate fMLP-induced degranulation. In this study, we further investigate fMLP signaling in hck-/-fgr-/- neutrophils and find that they fail to activate a respiratory burst and display reduced F-actin polymerization in response to fMLP. Additionally, albeit migration of both hck-/-fgr-/-mouse neutrophils and human neutrophils incubated with the Src family kinase inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2) through 3-microm pore size Transwells was normal, deficiency, or inhibition, of Src kinases resulted in a failure of neutrophils to migrate through 1-microm pore size Transwells. Among MAPKs, phosphorylation of ERK1/2 was not different, phosphorylation of p38 was only partially affected, and phosphorylation of JNK was markedly decreased in fMLP-stimulated hck-/-fgr-/- neutrophils and in human neutrophils incubated with PP2. An increase in intracellular Ca(2+) concentration and phosphorylation of Akt/PKB occurred normally in fMLP-stimulated hck-/-fgr-/- neutrophils, indicating that activation of both phosphoinositide-specific phospholipase C and PI3K is independent of Hck and Fgr. In contrast, phosphorylation of the Rho/Rac guanine nucleotide exchange factor Vav1 and the Rac target p21-activated kinases were markedly reduced in both hck-/-fgr-/- neutrophils and human neutrophils incubated with a PP2. Consistent with these findings, PP2 inhibited Rac2 activation in human neutrophils. We suggest that Hck and Fgr act within a signaling pathway triggered by fMLP receptors that involves Vav1 and p21-activated kinases, leading to respiratory burst and F-actin polymerization.
Wang X, Guo L, Zhang W Genes (Basel). 2024; 15(3).
PMID: 38540431 PMC: 10970270. DOI: 10.3390/genes15030372.
Volkov D, Stepanova V, Rubtsov Y, Stepanov A, Gabibov A Acta Naturae. 2023; 15(3):17-26.
PMID: 37908772 PMC: 10615191. DOI: 10.32607/actanaturae.25438.
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Vorobjeva N, Chelombitko M, Sudina G, Zinovkin R, Chernyak B Cells. 2023; 12(18).
PMID: 37759432 PMC: 10526294. DOI: 10.3390/cells12182210.
Chen M, Menon M, Wang W, Fu J, Yi Z, Sun Z Nat Commun. 2023; 14(1):4297.
PMID: 37463911 PMC: 10354075. DOI: 10.1038/s41467-023-40086-3.
Wang F, Peters R, Jia J, Mudd M, Salemi M, Allers L Dev Cell. 2023; 58(10):866-884.e8.
PMID: 37054706 PMC: 10205698. DOI: 10.1016/j.devcel.2023.03.014.