Tankyrase inhibition promotes endocrine commitment of hPSC-derived pancreatic progenitors

To improve ß-like cell differentiation from human pluripotent stem cells (hPSCs), we aimed to substitute a mechanistically elusive compound – nicotinamide (NA), which promotes pancreatic progenitor (PP) commitment, with a pathway-specific compound. By performing a low-throughput chemical screening, we demonstrated that tankyrase inhibitors (TNKSi) can replace NA and efficiently generate PPs. Surprisingly, highly selective TNKSi, such as WIKI4, generate PPs that give rise to islet-like populations with improved ß-like cell frequencies and glucose responsiveness compared to NA-derived PPs. Characterization of differentially expressed genes (DEG) between WIKI4 and NA treatment revealed that WIKI4-derived PPs expressed higher levels of genes associated with integrin signalling and actin cytoskeleton pathways. Our findings show that compared to NA, WIKI4 treatment promotes changes in cell shape and motility. Together, our results provide novel insights into pancreatic differentiation and a model that better recapitulates native events associated with pancreas and endocrine commitment. Overall design: H1 Human pluripotent stem cells were differentiated to stage 3 PDX1 + endoderm according to our published protocol (Nostro et al, Stem Cell Reports 2015) and differentiated to stage 4 Pancreatic Progenitors using a combination of Noggin, EGF and either Nicotinamide (NA) or WIKI4 (WIKI). Day 13 pancreatic progenitors were collected for bulk RNA sequencing