In this study, we used five karyotypically normal human embryonic stem cell (hESC) lines to investigate molecular mechanisms of hESC differentiation bias towards definitive endoderm (DE). We quantified DE differentiation efficiency using both a classic adherent differentiation and an in vitro model of early gastrulation-associated fate patterning in geometrically-confined micropatterned colonies, and identified VUB04 as a hESC line with significantly lower DE differentiation efficiency when compared to the other lines.
As our DE differentiation protocol employs a strong activator of WNT signalling, we hypothesize that differentially expressed genes in VUB04 prevent its proper activation for endodermal specification. Bulk mRNA-sequencing at the undifferentiated stage showed that the main pluripotency genes were expressed at comparable levels between hESC lines, however, pathway enrichment analysis pointed at deregulation of MAPK/ERK signalling in VUB04. GO-term analysis of mRNA-sequencing samples 6 and 24 hours after the onset of DE differentiation showed that VUB04 fails to upregulate genes responsible for gastrulation, endoderm formation and BMP signalling.
We are currently modifying expression levels of candidate genes selected from a list of 120 genes which were differentially expressed in VUB04 at all three mRNA-sequencing timepoints, and investigating if they have regulatory effects on DE differentiation. Our work provides preliminary insight into the molecular mechanisms of how hESC may manifest DE differentiation bias and provides experimental validation of an in vitro platform that can be employed for high-throughput screens of hPSC differentiation propensities.
|Publication status||Unpublished - 26 Oct 2018|
|Event||Annual meeting of the Belgian Society for Stem Cell Research - Leuven, Belgium|
Duration: 26 Oct 2018 → 26 Oct 2018
|Conference||Annual meeting of the Belgian Society for Stem Cell Research|
|Period||26/10/18 → 26/10/18|