Figure 4.

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.