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Oxidative stress attenuates podocyte monolayer barrier function
Author(s) -
Santos Noel M Delos,
Elias Bertha C,
Suzuki Takuya,
Jain Suneet,
Rao Radhakrishna K
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a452-b
Subject(s) - chemistry , podocyte , oxidative stress , reactive oxygen species , xanthine oxidase , apoptosis , viability assay , lactate dehydrogenase , superoxide dismutase , cytotoxicity , microbiology and biotechnology , biochemistry , biology , endocrinology , enzyme , kidney , proteinuria , in vitro
The study objective was to test the effect of ROS on podocyte epithelial barrier integrity, and to determine whether increases in paracellular flux versus cytotoxicity or apoptosis is responsible for podocyte monolayer permeability changes. An immortalized podocyte cell line was grown on porous transwells. The podocyte monolayer flux of FITC‐conjugated 70kDa anionic dextran was periodically measured for 4 hours. Superoxide (SO) was generated by adding xanthine (X) to xanthine oxidase (XO) in cell media. Other experiments were performed in the presence of superoxide dismutase (SOD) or Tempol, a SOD mimetic. Cell cytotoxicity, viability, and apoptosis was determined by measuring lactate dehydrogenase (LDH) release, mitochondrial dehydrogenase (MD) activity, and caspase 3 activity, respectively. XO in the presence of X increased the flux of anionic dextran across the podocyte monolayer barrier in a dose and time‐dependent fashion. The effect of XO+X was not altered by SOD. However, this effect was blocked by the addition of Tempol, suggesting that hydrogen peroxide may be responsible. XO+X did not significantly alter the levels of LDH, MD activity, or caspase 3 activity, indicating that increased permeability was not mediated by cytotoxicity or apoptosis. This study reveals that ROS increases podocyte epithelial permeability without inducing cell necrosis or apoptosis.