Fig. 7: Human heart organoids faithfully recapitulate hallmarks of pregestational diabetes-induced congenital heart disease.

a Brightfield images following the development of 10 hHOs under normal glycemic conditions (NHOs, left) and under diabetic conditions (PGDHOs, right) over two weeks of differentiation. b Area of hHOs under a light microscope over the first two weeks of differentiation (value = mean ± s.d.; n = 12; 2-way ANOVA Sidak’s multiple comparisons test, exact p-values: day 0: p > 0.99, day 2: p = 0.017, day 4: p = 0.94, day 6: p = 0.99, day 8: p = 0.0008, day 10: p = 0.0003, days 12 and 14: p < 0.0001). c Electrophysiology was performed on NHOs and PGDHOs at 15 days. Arrows indicate arrhythmic events. d Seahorse analysis for oxygen consumption rate (OCR), and e extracellular acidification rate (ECAR) of normal and diabetic hHOs (Value = mean ± s.d; n = 3 organoids per condition). f Ultrastructural analysis by TEM of NHOs and PGDHOs showing endoplasmic reticulum (ER), gap junctions (Gj), glycogen granules (Gy), lipid droplets (Ld), mitochondria (Mi), nucleus (N), and sarcomeres (S); scale bars: 2 µm. g Confocal immunofluorescence images at differentiation day 15 for cardiac (TNNT2, red) and epicardial (WT1, green) formation, scale bar: 500 µm. h Confocal imaging for ventricular (MYL2, green) and atrial (MYL7, red) chamber formation under normal and diabetic-like conditions, scale bar: 500 µm. 2-DG: 2-deoxy-d-glucose, ECAR: extracellular acidification rate, NHOs: normal heart organoids, OCR: oxygen consumption rate, PGDHOs: pregestational diabetes heart organoids, Rot/AA: Rotenone and Antimycin A. Source data are provided as a Source Data file.