Lipid peroxidation contributes to hydrogen peroxide induced cytotoxicity in renal epithelial cells

Abstract

We have examined the role of lipid peroxidation in the cytotoxicity of H2O2 in OK cells containing markedly differing amounts of cell membrane polyunsaturated fatty acids (PUFA). In OK cells grown in a serum free medium, PUFA were undetectable. The membranes of these cells contained predominantly oleic, stearic and palmitic acids. When cultured in medium containing 10% calf serum, OK cells contained measurable amounts of PUFA [linoleic (5 +/- 1%) and arachidonic acids (8 +/- 1%)]. When the serum containing medium was supplemented with 60 mM linoleic acid, the membrane content of both linoleic (21 +/- 1%) as well as arachidonic acid (15 +/- 1%) as substantially increased. The severity of injury induced by H2O2 in OK cells was substantially altered by the PUFA content of the cell membrane. Exposure of OK cells to 1.25 mM H2O2 for one hour resulted in more cell death (determined by a trypan blue assay) in cells grown in serum supplemented with linoleic acid with "normal" PUFA content (90 +/- 2%) than in cells with "reduced" levels of PUFA grown in unsupplemented calf serum (81 +/- 3%). Cells gown in defined, serum free medium with undetectable levels of PUFA suffered the least H2O2-induced lethal cell injury (47 +/- 8%). Comparable differences in the cytotoxicity of H2O2 among cells with differing PUFA content were found using a clonogenic assay of cell viability. Malondialdehyde (MDA) accumulation induced by 1.25 mM H2O2 was greater in cells with "normal" PUFA content (702 +/- 103 pM/microgram cell DNA/hr) than in cells with "reduced" PUFA (328 +/- 112 pM/100 microgram DNA/hr) and was undetectable in cells grown in defined, serum free medium. In summary, the content of PUFA of cells in culture is profoundly influenced by culture conditions. Our data provide novel and direct evidence that peroxidation of cell membranes contributes directly to the severity of cell injury and death induced by H2O2.

Efeitos do butirato nos níveis de peroxidação lipídica em células da mucosa cólica sem trânsito fecal: estudo experimental em ratos

“…A quebra da barreira funcional possibilitaria, então, a translocação de bactérias da luz intestinal para a camada submucosa estéril 18,21 . Na tentativa de combater a invasão bacteriana, leucócitos ativados migrariam para o estroma da parede intestinal, dando origem ao processo inflamatório que caracteriza a doença 21,30,31 . Nesse estudo, verificou-se que os maiores níveis de estresse oxidativo relacionavam-se às alterações histológicas e bioquí-micas características da CE, e que aumentavam com o decorrer do tempo de exclusão 21,32 .…”

“…Pesquisa recente demonstrou que, no epitélio cólico desprovido de trânsito, existe redução no conteúdo e modificações do local de expressão das proteínas e-caderina e β-catenina, principais constituintes das junções aderentes intercelulares 38 . Todas essas alterações histológicas encontram-se relacionadas à maior produção de RLO 15,27,31,32 . Assim sendo, o estresse oxidativo na CE, além de atrofiar as criptas cólicas, pode romper duas importantes linhas de defesa epitelial: a barreira de muco e as junções aderentes.…”

Oxidant‐Induced Cell Death in Renal Epithelial Cells: Differential Effects of Inorganic and Organic Hydroperoxides

“…However, the role of lipid peroxidation in the pathogenesis of oxidantinduced cell injury in renal tubular cells remains controversial. Although several studies have suggested that lipid peroxidation plays a critical role in the oxidant-induced renal cell injury (Salahudeen 1995;Sheridan et al 1996), dissociation of lipid peroxidation from the oxidant-induced cell injury has been shown in various cell types including renal epithelial cells (Chen et al 1990;Farber et al 1990;Kirkland 1991;Guidarelli et al 1995;Zager & Burkhart 1998).…”

Antioxidative effects of fermented sesame sauce against hydrogen peroxide-induced oxidative damage in LLC-PK1 porcine renal tubule cells

“…MDA, a major end product of the reaction between free radicals and cellular polyunsaturated fatty acids (PUFAs), is an appropriate factor for evaluating the degree of ROS-induced cell damage. Previous studies have demonstrated that renal cell damage caused by H2O2 is directly associated with increased peroxidation of PUFAs in the cell membrane [15,38,39]. However, treatment with antioxidants such as α-tocopherol, 21-aminosteroid, 2-methyl aminochroman, or hydroxyrosol and its metabolites is able to ameliorate H2O2-induced renal cell damage through the inhibition of MDA generation [38][39][40].…”

“…Previous studies have demonstrated that renal cell damage caused by H2O2 is directly associated with increased peroxidation of PUFAs in the cell membrane [15,38,39]. However, treatment with antioxidants such as α-tocopherol, 21-aminosteroid, 2-methyl aminochroman, or hydroxyrosol and its metabolites is able to ameliorate H2O2-induced renal cell damage through the inhibition of MDA generation [38][39][40]. Our results suggested that H2O2 (500 μM) significantly increased the total intercellular ROS levels, resulting in the production of MDA in the LLC-PK1 cells.…”