title: S100A8 modulates mast cell function and suppresses eosinophil migration in acute asthma.
abstract: S100A8 is implicated in the pathogenesis of inflammatory diseases. S100A8 is upregulated in macrophages by Toll-like receptors (TLR)-3, 4, and 9 agonists in an IL-10-dependent manner, and by corticosteroids in vitro and in vivo, and scavenges oxidants generated by activated phagocytes. Because if its elevated expression in various lung disorders, we asked whether S100A8 was protective in allergic inflammation. S100A8, but not Cys(41)-Ala S100A8, in which the single reactive Cys residue was replaced by Ala, reduced mast cell (MC) degranulation and production of particular cytokines (IL-6, IL-4, and granulocyte macrophage colony-stimulating factor) in response to IgE-crosslinking in vitro, likely by inhibiting intracellular reactive oxygen species production, thereby reducing downstream linker for activation of T cells and extracellular signal regulated kinase/mitogen-activated protein kinase phosphorylation. In lungs of mice with acute asthma, S100A8, but not Cys(41)-Ala S100A8, reduced MC degranulation, production of eosinophil chemoattractants (IL-5, eotaxin, and monocyte chemoattractant protein-1), and eosinophil infiltration. Suppression of IL-6 and IL-13 could have contributed to reduced mucus production seen in lungs of S100A8-treated mice. IgE production was unaffected. In asthma, there is an imbalance of anti-oxidant systems that are generally protective. Our results strongly support a protective role for S100A8 in allergic inflammation by modulating MC activation and eosinophil recruitment, and by scavenging oxidants generated by activated leukocytes, in processes reliant on its thiol-scavenging capacity.
authors.affiliation: Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Sydney, Australia.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Ikuko
authors.initials: I
authors.lastname: Endoh
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hsu
authors.forename: Nicodemus
authors.initials: N
authors.lastname: Tedla
authors.forename: Yasumi
authors.initials: Y
authors.lastname: Endoh
authors.forename: Carolyn L
authors.initials: CL
authors.lastname: Geczy
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001249:Asthma / Q000235:genetics / Q000378:metabolism*; D040501:Calgranulin A / Q000378:metabolism*; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics; D004804:Eosinophils / Q000166:cytology*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics; D016753:Interleukin-10 / Q000235:genetics; D018793:Interleukin-13 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics; D015848:Interleukin-5 / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics; D008407:Mast Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D040501:Calgranulin A; D018932:Chemokine CCL2; D018793:Interleukin-13; D015848:Interleukin-5; D015850:Interleukin-6; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor