Fig 1: IGFBP-6 inhibits extracellular IGF-2 induced by oxidative stress in primary cortical neurons. Concentrations of (A) IGF-1 and (B) IGF-2 in the supernatant of primary cortical neuron cultures incubated with hMSC-CM or hMSC-CM pretreated with anti-IGFPB-6-Ab following H2O2 treatment were analyzed using an enzyme-linked immunosorbent assay. The data are presented the mean ± standard error of the mean of at least four independent experiments. *P<0.05 and **P<0.01 vs. control; †P<0.05 vs. H2O2; #P<0.05 vs. hMSC-CM. Analysis of variance followed by the Newman-Keuls post hoc test were used. hMSC-CM, human mesenchymal stem cell-conditioned medium; IGF, insulin-like growth factor; IGFBP-6 Ab, insulin-like growth factor binding protein-6 antibody.