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Klotho Protects Lung Epithelial Cells against Oxidative DNA Damage
Author(s) -
Ravikumar Priya,
Smith Blaine,
Hsia Connie C.W.,
Moe Orson W.
Publication year - 2013
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.27.1_supplement.722.3
Subject(s) - klotho , pi , chemistry , recombinant dna , microbiology and biotechnology , medicine , andrology , oxidative stress , transfection , endocrinology , biology , biochemistry , kidney , gene
Klotho is an anti‐aging protein through pleiotropic actions. We postulate that Klotho can protect the lung against O 2 and Pi toxicity and tested the direct effects of Klotho in vitro using A549 lung epithelial cells exposed to hyperoxia (95–5% O 2 ‐CO 2 ) and increasing Pi (1 vs. 5 mM). Soluble or transmembrane full length Klotho was over‐expressed by transfection or recombinant soluble Klotho was added to the medium. DNA damage was assessed by ELISA assay of 8‐hydroxydeoxyguanosine (8‐OHdG) (OxiSelect™ Cell BioLabs Inc). Triplicate experiments were performed. The amount of 8‐OHdG (ng/ml, mean±SD) under each condition was compared by two‐way ANOVA. P ≤ 0.05 was considered significant.O 2 21% 95% Klotho − + − +Transmembrane KlothoPi 1mM 0.093±0.003 0.086±0.009 0.172±0.005 * 0.076±0.006 † Pi 5mM 0.326±0.009 0.300±0.010 † 0.563±0.013 * 0.323±0.013 †Soluble KlothoPi 1mM 0.093±0.003 0.082±0.002 † 0.166±0.005 * 0.072±0.001 * † Pi 5mM 0.322±0.011 0.292±0.005 † 0.546±0.012 * 0.324±0.011 * †Conditioned MediumPi 1mM 0.089±0.002 0.079±0.002 † 0.164±0.004 * 0.070±0.004 * † Pi 5mM 0.317±0.007 0.299±0.005 † 0.531±0.012 * 0.303±0.014 * †* 95% vs. 21% O 2 ; † Klotho vs. control at the same Pi and O 2 concentrations. All differences between Pi conditions were significant.Increasing either O 2 or Pi concentration increased 8‐OHdG production, indicating DNA damage; the effects are synergistic. In pulmonary epithelial cells , either Klotho expression or addition ameliorates hyperoxia‐induced DNA damage but has only mild effects on Pi‐induced DNA damage. These findings suggest that increasing Klotho concentration in the lung may be beneficial in the prevention of oxidant DNA damage. Support F32 HL103043 , RO1 DK091392 , DK092461 , UO1 HL111146