title: Membrane-anchored CD14 is important for induction of interleukin-8 by lipopolysaccharide and peptidoglycan in uroepithelial cells.
abstract: We investigated the induction of interleukin-8 (IL-8) by bacterial lipopolysaccharide (LPS) and peptidoglycan (PGN) in the bladder cancer cell lines T24, 5637, UM-UC-3, and HT1197. T24 and 5637 cells strongly induced IL-8 after stimulation with LPS or PGN in a dose- and time-dependent manner, whereas UM-UC-3 and HT1197 cells did so very weakly. The expression of CD14 at the mRNA, total cellular protein, and cell surface protein levels differed among these cell lines, but the expression levels of Toll-like receptors 2 and 4 (TLR2 and TLR4) were not significantly different. The CD14 expression levels were found to correlate with the inducibility of IL-8 by LPS or PGN. Treatment of T24 and 5637 cells with phosphatidylinositol-specific phospholipase C to eliminate CD14 from the cell surface dramatically suppressed the induction of IL-8. On the other hand, UM-UC-3 cells transfected with CD14 cDNA expressed membrane-anchored CD14 and showed more efficient induction of IL-8 by LPS stimulation than untransfected controls. These results suggest that the presence of the membrane-anchored, but not the soluble, form of CD14 is a strong factor in IL-8 induction in bladder epithelial cells in response to bacterial components. The presence of the membrane-anchored form of CD14 may thus be a determinant for the inflammatory response of uroepithelial cells.
authors.affiliation: Department of Urology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shimizu
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yokota
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Kunishima
authors.forename: Koh
authors.initials: K
authors.lastname: Takeyama
authors.forename: Naoya
authors.initials: N
authors.lastname: Masumori
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Matsukawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Itoh
authors.forename: Taiji
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Fujii
mesh_terms: D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D017261:Glycosylphosphatidylinositols / Q000502:physiology*; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics*; D018950:Lipopolysaccharide Receptors / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000032:analysis; D008565:Membrane Proteins; D010457:Peptidoglycan / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D001743:Urinary Bladder / Q000166:cytology
chemical_list: D017261:Glycosylphosphatidylinositols; D016209:Interleukin-8; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010457:Peptidoglycan; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors