Effects of reactive oxygen species on cultured rat mesangial cells and isolated rat glomeruli
Duque, I.; García-Escribano, C.; Rodríguez-Puyol, M.; Díez-Marqués, M.L.; López-Novoa, J.M.; Arribas, I.; Hernando, L.; Rodríguez-Puyol, D.
American Journal of Physiology 263(3 Pt 2): F466-F473
1992
ISSN/ISBN: 0002-9513 PMID: 1415575 Document Number: 398138
The effects of reactive oxygen species (ROS) on cultured rat mesangial cells were studied by measuring planar call surface area (PCSA) after incubation with xanthine plus xanthine oxidase (XXO), in the presence of superoxide dismutase (SOD; 5 mu-g/ml) or catalase (CAT; 20 mu-g/ml), or after incubation with H-2O-2. Myosin light chain (MLC) phosphorylation was assessed in cells prelabeled with o-(32P)phosphoric acid and incubated with H-2O-2, after protein separation with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A possible intermediate role for platelet-activating factor (PAF) was analyzed by preincubation of the cells with a PAF antagonist BN 52021 (BN, 5 times 10-5 M) and by measuring PAF-specific (3H)acetate incorporation and immunoassayable PAF. XXO significantly decreased PCSA (14%), an effect abolished by CAT but not by SOD. H-2O-2 induced a similar effect, in a dose-dependent and time-dependent manner. MLC phosphorylation increased by 81 +- 15% after H-2O-2 incubation, and this effect was blocked by BN. BN also completely blocked the effect of H-2O-2 on PCSA. PAF-specific (3H)acetate incorporation increased in the presence of H-2O-2 (from 6,886 +- 2,030 to 58,703 +- 16,063 counts cntdot min-1 cntdot mg-1) as well as the immunoassayable PAF production by cells (from 0.90 +- 0.19 to 6.71 +- 2.27 ng/mg). These results suggest that ROS, particularly H-2O-2, could modulate the surface area of mesangial cells, modifying the ultrafiltration coefficient, thus explaining the decrease in glomerular filtration rate in those pathological situations characterized by an increased ROS synthesis. PAF could be involved in the genesis of these effects.