Activation of caspase-8 in SMA MN cultures.

<p>(<b>A</b>) Western blot analysis of MN patterned SMA-iPSCs cell lysates at 8 weeks show reduced SMN and MN markers Islet-1 and HB9, but increased activation of caspase-8 compared to control iPSCs. There was no difference in expression levels of Bax, Bcl-2, and AIF. GAPDH was used as a loading control. (<b>B</b>) Immunocytochemistry detected an increase in cleaved caspase-8 in 13iSMA MN cultures<b>.</b> White arrows indicate doubled labeled HB9 positive MNs that are also positive for cleaved caspase-8. (<b>C</b>) An increase in caspase-8 activation in 13iSMA MNs was confirmed with the Caspase Glo-8 assay, measuring caspase-8 activity by release of luminescence upon activation of caspase-8 and a cleavage of a target peptide. Data are represented as mean ± SEM, n = 3 experiments.