Insulin-Like Growth Factor Binding Protein-6 Alters Skeletal Muscle Differentiation of Human Mesenchymal Stem Cells

Figure 4

PMSCs cultured under skeletal muscle differentiation conditions showed increased IGFBP-6 expression and secretion. (a, b) PMSCs cultured under muscle differentiation conditions showed higher IGFBP-6 staining (red-Alexa, λ-568 nm) when compared to PMSCs under control conditions (10% FBS) at 14 days postdifferentiation. Nuclei were stained with Hoechst dye (blue, ). (c) Using Western blots, IGFBP-6 protein levels in PMSCs cultured under differentiation conditions were increased at each time point compared to control conditions. Under muscle differentiation conditions, IGFBP-6 levels peaked at 2 days postdifferentiation and gradually decreased from days 3 to 14. Protein levels were quantified by densitometry and normalized to β-actin. (d) Using ELISA, IGFBP-6 and (e) IGF-2 secretion into the media was increased under muscle differentiation conditions compared to control conditions. 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 comparing control to muscle differentiation conditions, or ^## and ^### comparing the same treatment over time.

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