Figure 2. IWR specifically induces cardiomyocytes.
(A) Dose response curves for cardiogenesis by IWR with exposure at different time points show IWR is most active when added at day 4. (B) In the optimal window, IWR has an EC50 for cardiogenesis of about 2241 nM. (C) Flow cytometry analysis for the MYH6-mCherry reporter of vehicle or IWR treated cells, gated against a negative control. Numbers reflect the percentage of MYH6 positive cells. (D) Time course RT-qPCR analysis of IWR treated monolayer samples (Red, squares) versus DMSO treated samples (blue, diamonds) normalized to the DMSO day 5 sample. Early markers for cardiogenic mesoderm include T (BRACHYURY), MESP1 and KDR, cardiac progenitor markers tested were MEF2C and NKX2.5, and cardiomyocyte markers studied were MYH6, TNNT2 and ACTN2. Other mesoderm lineages tested were endothelium (CD31) and smooth muscle (ACTA2 and TAGLN). Error bars represent SEM of 3 biological replicates. Asterisk (*) indicates p<0.05 compared to the corresponding DMSO control. (E) Schematic overview of the lineage diversification of a cardiovascular mesoderm progenitor. Wnt inhibition specifically drives mesoderm progenitors to cardiomyocytes.