Gastruloids enable modeling of the earliest stages of human cardiac and hepatic vascularization

Here we show that spatially micropatterned human pluripotent stem cell (hPSC)-derived gastruloids enable in vitro modeling of the earliest developmental stages of cardiac vascularization, roughly corresponding to the first three weeks of in vivo human development (Carnegie Stages 9 and 10). Using clues from developmental biology, we identified a growth factor/small molecule cocktail, that when added to micropatterned hPSCs, generated a spatially organized, branched, and lumenized vascular network within a multi-lineage cVO comprising endocardial, myocardial, epicardial, and neuronal cell types. Overall design: Our single cell RNA-seq (scRNA-seq) data includes one (1) Control (standard cardiac differentiation) and four (4) groups of cVOs (standard cardiac differentiation + vascular factors). Our bulk RNA-seq (bRNA-seq) includes data for cardiac and hepatic systems. In the cardiac system, there are three groups and a total of 39 samples: 1. hESC-3R at D0 only (3 replicates/timepoint x 1 timepoint = 3 total samples); 2. Control at Days 2, 5, 8, 10, 12, and 16 of differentiation (3 replicates/timepoint x 6 timepoints = 18 total samples); 3. cVO at Days 2, 5, 8, 10, 12, and 16 of differentiation (3 replicates/timepoint x 6 timepoints = 18 total samples). In the hepatic system, there are four groups and a total of 12 samples: 1. hESC-3R at D0 only (3 replicates/timepoint x 1 timepoint = 3 total samples) *Note: this group/replicates were used both for cardiac and hepatic systems; 2. Control at Day 20 of differentiation (3 replicates/timepoint x 1 timepoint = 3 total samples); 3. hVO-D3 at Day 20 of differentiation (3 replicates/timepoint x 1 timepoint = 3 total samples); 4. hVO-D6 at Day 20 of differentiation (3 replicates/timepoint x 1 timepoint = 3 total samples). Our single cell RNA-seq (scRNA-seq) data includes one (1) Control (standard cardiac differentiation) and four (4) groups of cVOs (standard cardiac differentiation + vascular factors).