Fig. 4.

Cytoprotection by αKlotho in an in vitro hydrogen peroxide (H₂O₂) model of oxidative damage. A: dose-response of H₂O₂ on lactate dehydrogenase (LDH) release as a marker of cell death. A549 lung epithelial cells were incubated with the indicated H₂O₂ dose for 4 h. *P < 0.0001 vs. 0 nmol/l H₂O₂, †P < 0.0001 vs. 50 nmol/l H₂O₂, ‡P < 0.001 vs. 100 nmol/l H₂O₂, §P < 0.05 vs. 200 nmol/l H₂O₂, #P < 0.05 vs. 300 nmol/l H₂O₂. B: dose-response of purified recombinant αKlotho on H₂O₂-induced A549 cell death. ^aP < 0.05 vs. 0 or 10 pM αKlotho concentration. Average of 3 independent experiments (means ± SD). Statistical significance was assessed by ANOVA.