Effect of MK-4 incubation on muscle proliferation and differentiation.

<p>A) A dose response effect on muscle cell proliferation after 3 days upon MK-4 treatment, compared with control cells (vehicle EtOH only). The data is presented as the average of at least three independent cell culture experiments seeded out in triplicates, ± SEM. Asterisk indicate significant differences in treated cells compared with control cells (*p<0.05, ***p<0.001) statistics assessed by one-way ANOVA with Dunnett’s multiple comparison test. B) Relative gene expression (fold change) of muscle specific genes during 10 μM MK-4 treatment for 3 days. Bars show the relative mRNA expression (fold change) of <i>myoD</i>, <i>desmin</i>, <i>myogenin</i> and <i>myh8</i> in MK-4 cells compared to negative control cells (vehicle EtOH only) after 3 days of proliferation. The data is presented as the average of at least three independent cell culture experiments seeded out in duplicates, ± SEM. Asterisks denote significant differences (*p<0.05) between MK-4 treated cells compared to control cells assessed by un-paired two-tailed t-test. C) Fusion index was calculated based on scoring of at least four randomly chosen regions with nuclei and myotubes stained with Hoechst and desmin, as demonstrated in the left pictures. Scale bar as indicated. For each region the number of nuclei incorporated in myotubes and the total number of nuclei was scored. The fusion index (FI) was calculated as the percentage of total nuclei incorporated in myotubes, as demonstrated in the right panel. D) Relative gene expression (fold change) of muscle specific genes during 10 μM MK-4 treatment for 3 days of differentiation. Bars show the relative mRNA expression (fold change) of <i>myoD</i>, <i>desmin</i>, <i>myogenin</i> and <i>myh8</i> in MK-4 cells compared to negative control cells (vehicle EtOH only) after 3 days of differentiation. The data is presented as the average of at least three independent cell culture experiments seeded out in duplicates, ± SEM. Asterisks denote significant differences (***p<0.001) between MK-4 treated cells compared to control cells, as assessed by un-paired two-tailed t test.