title: Enhanced tissue expression and elevated circulating level of phospholipase A(2) receptor during murine endotoxic shock.
abstract: Phospholipase A(2) receptor (PLA(2)R) mediates a variety of biological responses elicited by mammalian secretory phospholipase A(2) (sPLA(2)). In mice, group IB sPLA(2) (sPLA(2)-IB) acts as an endogenous ligand of PLA(2)R, and analysis of PLA(2)R-deficient mice has demonstrated a critical role of the sPLA(2)-IB/PLA(2)R system in the production of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) in the development of endotoxic shock. Here, we generated specific antibodies against a recombinant soluble form of PLA(2)R and examined its expression in the lung and spleen where a remarkable elevation of TNF-alpha expression has been observed during endotoxemia. Immunohistochemical analysis revealed the expression of PLA(2)R in type II alveolar epithelial cells and a subset of splenic lymphocytes, and its expression levels were markedly enhanced at 1 h after endotoxin challenge. Analysis with a newly developed sandwich enzyme-linked immunosorbent assay system revealed the presence of a soluble form of PLA(2)R in plasma of wild-type mice compared with its absence in plasma of PLA(2)R-deficient mice. After exposure to endotoxin, its circulating level was significantly elevated to the maximum level at 2-3 h after the treatment. These results suggest that tissue expression and the circulating level of PLA(2)R are elevated during murine endotoxemia, which might be relevant to its potential roles in the production of proinflammatory mediators during the development of inflammatory conditions.
authors.affiliation: Shionogi Research Laboratories, Shionogi & Co., Ltd., Fukushima-ku, Osaka, 553-0002, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yokota
authors.forename: M
authors.initials: M
authors.lastname: Ikeda
authors.forename: K
authors.initials: K
authors.lastname: Higashino
authors.forename: K
authors.initials: K
authors.lastname: Nakano
authors.forename: N
authors.initials: N
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Arita
authors.forename: K
authors.initials: K
authors.lastname: Hanasaki
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016466:CHO Cells; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D054501:Group II Phospholipases A2; D007150:Immunohistochemistry; D007249:Inflammation / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000378:metabolism; D051379:Mice; D010741:Phospholipases A / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D054507:Receptors, Phospholipase A2; D011994:Recombinant Proteins / Q000276:immunology; D012772:Shock, Septic / Q000097:blood / Q000378:metabolism*; D013154:Spleen / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D008070:Lipopolysaccharides; C516357:Pla2r1 protein, mouse; D011956:Receptors, Cell Surface; D054507:Receptors, Phospholipase A2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D010741:Phospholipases A; D054501:Group II Phospholipases A2