Stauprimide priming of human embryonic stem cells toward definitive endoderm

ABSTRACT

In vitro production of a definitive endoderm [DE] is an important issue in stem cell-related differentiation studies and it can assist with the production of more efficient endoderm derivatives for therapeutic applications. Despite tremendous progress in DE differentiation of human embryonic stem cells [hESCs], researchers have yet to discover universal, efficient and cost-effective protocols. In this experimental study, we have treated hESCs with 200 nM of Stauprimide [Spd] for one day followed by activin A [50 ng/ml; A50] for the next three days [Spd-A50]. In the positive control group, hESCs were treated with Wnt3a [25 ng/ml] and activin A [100 ng/ml] for the first day followed by activin A for the next three days [100 ng/ml; W/A100-A100]. Gene expression analysis showed up regulation of DE-specific marker genes [SOX17, FOXA2 and CXCR4] comparable to that observed in the positive control group. Expression of the other lineage specific markers did not significantly change [p<0.05]. We also obtained the same gene expression results using another hESC line. The use of higher concentrations of Spd [400 and 800 nM] in the Spd-A50 protocol caused an increase in the expression SOX17 as well as a dramatic increase in mortality rate of the hESCs. A lower concentration of activin A [25 ng/ml] was not able to up regulate the DE-specific marker genes. Then, A50 was replaced by inducers of definitive endoderm; IDE1/2 [IDE1 and IDE2], two previously reported small molecule [SM] inducers of DE, in our protocol [Spd-IDE1/2]. This replacement resulted in the up regulation of visceral endoderm [VE] marker [SOX7] but not DE-specific markers. Therefore, while the Spd-A50 protocol led to DE production, we have shown that IDE1/2 could not fully replace activin A in DE induction of hESCs These findings can assist with the design of more efficient chemically-defined protocols for DE induction of hESCs and lead to a better understanding of the different signaling networks that are involved in DE differentiation of hESCs