Figure 6.
YAP Converts Pancreatic Acinar Cells to Duct-like Organoids
(A and B) Representative images of a pancreatic duct fragment growing in pancreatic organoid medium at the indicated times (A) and after four passages in fresh Matrigel (B). Pictures are representative of three independent experiments performed with four technical replicates. Scale bars, 290 μm.
(C and D) Serial images of a single acinar cell derived from R26-rtTA; tetO-YAPS127A growing as cyst-like organoids at the indicated time points after Doxy addition (C) and after four passages in fresh Matrigel in the absence of Doxy (D). Pictures are representative of five independent experiments performed with four technical replicates. Scale bars, 70 μm in (C) and 290 μm in (D).
(E and F) Lineage tracing experiments using the Ptf1a-CreERTM driver. Images are bright-field and GFP fluorescence pictures of transgenic YAP-expressing exocrine cells at the indicated time points of Doxy treatment (E) and after passaging in absence of Doxy (F). See also Figure S6I for a schematic of the experiment. Scale bars, 70 μm in (E) and 130 μm in (F).
(G) Single-cell gene expression profile of pancreatic cultures of the R26-rtTA; tetO-YAPS127A genotype during the YAP-induced conversion of acinar cells to yDucts. Rows are evaluated genes, and columns are individual cells. Day 0, starting acini (without doxycycline); day 2, cultures that experienced 48 hr of doxycycline; day 4, cultures that experienced 96 hr of doxycycline. The heatmap represents expression levels as log2 ratio normalized to 18S rRNA.
(H) Organoids from duct fragments (Ducts, bottom, as in B) and YAP-induced organoids (yDucts, center) expressed the ductal marker SOX9 and were negative for the exocrine marker Amylase (data not shown) by immunofluorescence. Acinar cells (top) are shown as a control. Scale bar, 80 μm.
(I) Unsupervised hierarchical clustering of gene expression profiles in acini, yDucts, and Ducts. Each column represents one separated biological sample. Genes are ordered according to the decreasing average expression level in acini. Representative genes upregulated in acinar cells (red) or in Ducts and yDucts (green) are shown on the left.
See also Figure S6.