Fig. 5

Cell type-specific expression of SMADs and type I and II receptors. a Expression of the inhibitory SMAD6 and SMAD7 was higher in human induced pluripotent stem cell (hiPSC)-derived endothelial cells (iECs) than in hiPSCs. Also, SMAD6 had significantly higher expression in fibrodysplasia ossificans progressiva (FOP) iECs. b Activin A gene expression levels were higher in iECs than in hiPSCs; however, there was no difference in Activin A levels between FOP and wild type (WT) by quantitative PCR or ELISA. c Gene expression analysis of WT ACVR1, ACVR1 R206H, and the ratio of R206H/WT ACVR1. WT ACVR1 expression was higher in iECs compared to hiPSCs. WT ACVR1 levels were lower in FOP cells and ACVR1 R206H was detected only in FOP cells, as expected. d ACVR2A, ACVR2B, and BMPRII gene expression analysis of WT and FOP hiPSCs, iECs, and iECs cultured in osteogenic media (OB iEC). Type II receptor expression was differentially expressed based on cell type but not on ACVR1 R206H status. WT and FOP hiPSCs, iECs, and iECs cultured in osteogenic media were run in at least three separate experiments for each group. Error bars represent the mean ± one standard deviation. Mean values were statistically different by Student’s t test: * p < 0.05, ** p < 0.01, *** p < 0.005, **** p < 0.0001