Caspase-3 inhibition and LIF both inhibit myogenic differentiation and caspase-3 activity. (A) Phase contrast images of myoblast cultures either with or without 10 ng/mL LIF or 100 μM Ac-DEVD-CHO (DEVD-CHO) treatment after 24 hours of differentiation showed qualitatively less myotubes present with LIF and Ac-DEVD-CHO and the combination of both compared to control. (B) Colormetric assay for caspase-3 proteolytic activity in cultures lysed 24 hours after differentiation. Caspase-3 activity is reduced with LIF, Ac-DEVD-CHO and the combination of LIF and Ac-DEVD-CHO. (C) Creatine kinase activity from the same lysates is also decreased with LIF, Ac-DEVD-CHO and the combination of LIF and Ac-DEVD-CHO indicating that inhibition of differentiation correlates with inhibition of caspase-3 proteolytic activity. Asterisk (*) indicates P < 0.05 and ns indicates P > 0.05 with one-way ANOVA and Bonferroni's post-hoc test for all treatments compared to each other (n = 4).