title: CP-64131, an aminobenzazepine with cytokine-like properties, stimulates human neutrophil functions through the p38-MAPK pathway.
abstract: CP-64131 (CP), an aminobenzazepine with cytokine-like, physiologic effects similar to granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage (GM)-CSF, increases the number of neutrophils and stimulates marrow recovery after doxirubicin ablation. CP can also function as a neutrophil agonist, like formyl-Met-leu-Phe (fMLP). In these studies, we show that CP is unique in that it stimulates the p38-mitogen-activated protein kinase (MAPK) pathway but not extracellular signal-regulated kinase (ERK)1/2 or c-jun N-terminal kinase MAPKs in human neutrophils from peripheral blood. This is in contrast to other neutrophil agonists such as fMLP, interleukin (IL)-8, or GM-CSF, which stimulate multiple MAPK pathways. Like fMLP and IL-8, CP is capable of stimulating superoxide (O2-) production, CD11b expression, and cell polarization in human neutrophils. CP-stimulated O2- production is completely dependent on p38-MAPK activation, as determined by sensitivity to the p38-MAPK inhibitor SB203580. In contrast, SB203580 only partially inhibits expression of CD11b and has no effect on cell polarization stimulated by CP. Therefore, CP treatment of neutrophils activates p38-MAPK but has effects independent of p38-MAPK activation. In human embryonic kidney 293 cells, a human kidney epithelial cell line CP stimulates p38-MAPK and modestly activates ERK1/2. The findings define CP as a novel, small molecule, which has little cellular toxicity in vitro. CP has the ability to activate specific MAPK pathways in different cell types and should prove to be an effective agonist in combination with inhibitors to study biological responses regulated by MAPKs.
authors.affiliation: Bonfils Blood Center, 717 Yosemite Street, Denver, CO 80230, USA.
authors.forename: Marsha S
authors.initials: MS
authors.lastname: Anderson
authors.forename: Cindy
authors.initials: C
authors.lastname: Knall
authors.forename: Gail
authors.initials: G
authors.lastname: Thurman
authors.forename: Don
authors.initials: D
authors.lastname: Mann
authors.forename: Nancy
authors.initials: N
authors.lastname: Cusack
authors.forename: Gary L
authors.initials: GL
authors.lastname: Johnson
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Ambruso
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D001552:Benzazepines / Q000494:pharmacology*; D039481:CD11b Antigen / Q000187:drug effects; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000276:Adjuvants, Immunologic; D001552:Benzazepines; D039481:CD11b Antigen; D013481:Superoxides; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases