Fig. 1

Comparison of differentiation of HD-corrected and HD180 iPSCs reveals a unique iBMEC differentiation trajectory. A Schematic illustration of differentiation timeline. hiPSC colonies are counted and passaged at 10,000 cells cm⁻² on Matrigel-coated plates. iBMECs are differentiated over 8 days (six-day treatment with UM/F- media and two-day treatment with RA media). B Representative phase contrast images of differentiation at day 0, 6, and 8 for HD-corrected and HD180 iPSCs. Endothelial colonies surrounded by neural tracts only form during HD-corrected iBMEC differentiation (red dotted line), despite identical density and appearance of iPSC colonies between the two iPSCs. C Representative phase contrast images following sub-culture of HD-corrected and HD180 differentiated cells highlights the differences in fraction of adherent cells. D Cell density on day 0 (hiPSCs 3 days after passing at 10,000 cm⁻²), day 8 (differentiated cells), and post-subculture (purified iBMECs). Data collected across n = 7 and 8 independent differentiations for each cell line, respectively. E iBMEC adherent fraction (ratio of adherent cells to differentiated cells) for HD-corrected and HD180 iBMECs. Data collected across n = 4 and 5 independent differentiations for each cell line, respectively. F Representative immunofluorescence images of CD31 and GLUT-1 for HD-corrected and HD180 iBMECs. G iBMEC differentiation downregulates genes associated with pluripotency (POU5F1, SOX2, MYC) independent of CAG repeat length, and upregulates genes associated with endothelial and BMEC phenotype (CDH5, SLC2A1, RARA). Data represents row z-scores for transformed bulk RNA sequencing data across n = 2 independent differentiations for HD-corrected and HD180 cells. Transcript abundances (FPKM values) shown in Additional file 2: Fig. S1A