Please use this identifier to cite or link to this item: http://repositorio.unifesp.br/handle/11600/30352
Title: The effects of lipopolysaccharide-induced reactive oxygen species were blunted by calcium oxalate in renal tubular epithelial cells
Authors: Borges, F. T. [UNIFESP]
Garofalo, A. S. [UNIFESP]
Dalboni, Maria Aparecida [UNIFESP]
Abreu, N. P. [UNIFESP]
Michelacci, Y. M. [UNIFESP]
Schor, N. [UNIFESP]
Universidade Federal de São Paulo (UNIFESP)
Keywords: reactive oxygen species
oxalates
calcium oxalate
urinary tract infections
lipopolysaccharides
Issue Date: 1-Jan-2008
Publisher: Karger
Citation: Nephron Experimental Nephrology. Basel: Karger, v. 108, n. 2, p. 35-44, 2008.
Abstract: Background/Aim: Previously we demonstrated that calcium oxalate ( CaOx) in LLC-PK1 cells and oxalate in MDCK cells induce tubular damage and greater glycosaminoglycan synthesis. We test the hypothesis that reactive oxygen species ( ROS) and prostaglandins mediate these effects. Methods: LLC-PK1 and MDCK cells were exposed to graded concentrations of CaOx, oxalate or both. Glycosaminoglycan synthesis was analyzed through metabolic labeling and gel electrophoresis. Cell permeability and lipid peroxidation were assessed by lactate dehydrogenase release and malondialdehyde levels. Hydrogen peroxide and superoxide anion were analyzed using 2',7'-dichlorofluorescein and luminol. Cyclooxygenase-2 expression and prostaglandin E 2 production were assessed by RT-PCR and ELISA, respectively. Results: in LLC-PK1 cells exposed to CaOx, we observed increased cell permeability, no induction of ROS or lipid peroxidation, inability to produce lipopolysaccharide-induced ROS and increases in prostaglandin E-2. Indomethacin used alone increased glycosaminoglycan synthesis but did not potentiate CaOx-induced effects. in MDCK cells exposed to oxalate we observed increased cell permeability, ROS production only at higher concentrations and inability to produce lipopolysaccharide-induced ROS. Indomethacin alone had no effect but increased oxalate-induced glycosaminoglycan synthesis. Conclusions: Prostaglandins modulate endogenous production of glycosaminoglycans in LLC-PK1 cells, as well as regulate oxalate-induced glycosaminoglycan synthesis in MDCK cells. Rather than increasing, CaOx and oxalate blunted lipopolysaccharide-induced ROS production. We could speculate that patients with recurrent nephrolithiasis may lose antimicrobial protection induced by ROS during infections. Copyright (C) 2008 S. Karger AG, Basel.
URI: http://repositorio.unifesp.br/handle/11600/30352
ISSN: 1660-2129
Other Identifiers: http://dx.doi.org/10.1159/000115027
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