Research Paper Volume 13, Issue 1 pp 578—597

Figure 2. Effect of aging on the auto-phosphorylation of IGF-IR of bmMSCs. (A) BrdU incorporation analyses. Serum-starved Aged-1 and Aged-2 bmMSCs were examined for the IGF-I-induced DNA synthesis with or without concomitant treatment of AG1024 (1 μM). Relative DNA synthesis was calculated by compared the OD₄₅₀ readings of the treated cells to that of the untreated (U) cells. (to which a value of 1 was assigned). Data represent the mean ± S.D. from three experiments. Student’s t-test was used to analyze the differences between the groups. (B) Western blot analyses. Serum-starved Aged-1 and Adult-1 cells were treated with 0, 50, and 250 ng/ml of IGF-I for 0, 5, 10, and 20 min. The auto-phosphorylation of IGF-IR was examined. Representative blots are shown. All the signals were compared to that of the untreated cells at time 0 (to which a value of 1 was assigned). Data represent the mean ± S.D. from three experiments. A one-way ANOVA plus Scheffe’s post hoc tests were used to analyze the differences among the untreated and IGF-I-treated groups. ^*, P<0.05 versus untreated control.