Fig. 2: Rewiring of lipid metabolic programs upon human fetal hepatocyte organoid growth.

a Single-cell profiling of human FH organoids. b UMAP plots of the indicated markers. c Experimental strategy to temporally address the transcriptomic changes associated with human organoid growth from single FHs. d Cumulative plots of the amount of differentially expressed genes per time point post seeding, all versus 0 h (|log2FC| > 0.5, p-adj < 0.05) based on responses of n = 2 donors. e GO-term enrichment analysis on the upregulated and downregulated DEGs identified at 24 h versus 0 h based on responses of n = 2 donors. f Temporal Z-score expression of the genes identified in fetal tissue clusters 2 and 7 upon organoid growth from single FHs (single cells) across n = 2 donors. The organoid growth responses from fetal liver tissue are plotted for comparison. Mean ± SD is plotted, clusters 2 and 7: n = 2509 and 2330 genes, respectively. g, h Temporal mRNA expression profiles of selected genes involved in the cell cycle, DNA replication, and Wnt signaling (g) and selected classes of lipid metabolism genes (h). Mean fold change expression of n = 2 donors relative to 0 h is shown. i Representative brightfield images (top) and lipid staining overlaid with Phalloidin (bottom) of organoid growth from single FHs over time. Representative of n = 2 outgrowth experiments. Scale bar = 15 μm. j Quantification of the amount of steatosis positive cells during organoid growth (yellow) and the appearance of multicellular organoids (red, defined as n ≥ 2 cells/organoid) at different time points post seeding of single FHs. Mean ± SD is plotted, n = 3 fields analyzed per time point with a total of n = 137 cells (0 h), n = 135 cells (24 h), n = 289 cells (48 h), and n = 258 cells (72 h). k Schematic illustrating the transient steatosis occurring upon FH organoid growth from single fetal hepatocytes. Source data are provided as a Source data file.