Different Effects of Insulin-Like Growth Factor-1 and Insulin-Like Growth Factor-2 on Myogenic Differentiation of Human Mesenchymal Stem Cells

Figure 6

IGF-2 knockdown decreased muscle differentiation markers, while adding IGFBP-6 partially increased the markers. (a) OCT4 levels were reduced with IGF-2 knockdown until day 3 and increased at day 14. Adding IGFBP-6 alongside IGF-2 siRNA reduced OCT4 protein levels at all-time points compared to siRNA scrambled control. In contrast, (b) SOX2 levels did not change with IGF-2 knockdown. But when IGFBP-6 was added with IGF-2 silencing, the levels were reduced from 1 to 3 days compared to control and IGF-2 knockdown. Protein levels of muscle differentiation markers: (c) MyoD and (d) MHC decreased with IGF-2 siRNA and IGFBP-6 supplementation increased the levels. Protein levels were quantified by densitometry and normalized to β-actin. Data is presented as the mean ± SEM of 3 independent experiments. Two-way ANOVA with Bonferroni’s multiple comparison test was performed to determine , , and compared to scrambled siRNA control, or ^# and ^### compared to IGF-2 siRNA.

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