Activin A supplement in the hESCs culture enhances the endoderm differentiation efficiency.

Activin A is a critical regulator in human embryonic stem cells (hESCs) maintenance and differentiation. Different concentrations of Activin A affect hESC maintenance and differentiation in different ways. A high concentration favors anterior primitive streak and gives rise to DE if the stimulation persists. hESCs were cultured with and without 10 ng/mL Activin A supplement respectively. The two groups of cells were differentiated into endoderm cells with 100 ng/mL Activin A and other reagents. Microarray-based DNA methylation was analyzed with the Infinium Human Methylation450 BeadChip on these two groups. There was a significant difference in endoderm differentiation efficiency (average efficiency: 71 vs. 58.5%, P < 0.05). hESCs cultured with Activin A supplement had an increased propensity to form definitive endoderm cells in response to Activin A and Wnt signal. Differentially Methylated Regions (DMRs) between these two groups were found. DMRs were related to the stem cell maintenance and gene regulation by peroxisome proliferators via PPARα, indicating that hESCs maintained with Activin A supplement had stronger "stemness."

Guo S ，Mao X ，He F ，Liu H ，Ming L ... -  《-》

Efficient definitive endoderm induction from mouse embryonic stem cell adherent cultures: a rapid screening model for differentiation studies.

Definitive endoderm (DE) differentiation from mouse embryonic stem cell (mESC) monolayer cultures has been limited by poor cell survival or low efficiency. Recently, a combination of TGFβ and Wnt activation with BMP inhibition improved DE induction in embryoid bodies cultured in suspension. Based on these observations we developed a protocol to efficiently induce DE cells in monolayer cultures of mESCs. We obtained a good cell yield with 54.92% DE induction as shown by Foxa2, Sox17, Cxcr4 and E-Cadherin expression. These DE-cells could be further differentiated into posterior foregut and pancreatic phenotypes using a culture protocol initially developed for human embryonic stem cell (hESC) differentiation. In addition, this mESC-derived DE gave rise to hepatocyte-like cells after exposure to BMP and FGF ligands. Our data therefore indicate a substantial improvement of monolayer DE induction from mESCs and support the concept that differentiation conditions for mESC-derived DE are similar to those for hESCs. As mESCs are easier to maintain and manipulate in culture compared to hESCs, and considering the shorter duration of embryonic development in the mouse, this method of efficient DE induction on monolayer will promote the development of new differentiation protocols to obtain DE-derivatives, like pancreatic beta-cells, for future use in cell replacement therapies.

Mfopou JK ，Geeraerts M ，Dejene R ，Van Langenhoven S ，Aberkane A ，Van Grunsven LA ，Bouwens L ... -  《-》

Treatment of human embryonic stem cells with different combinations of priming and inducing factors toward definitive endoderm.

Tahamtani Y ，Azarnia M ，Farrokhi A ，Sharifi-Zarchi A ，Aghdami N ，Baharvand H ... -  《-》

Activin a efficiently specifies definitive endoderm from human embryonic stem cells only when phosphatidylinositol 3-kinase signaling is suppressed.

McLean AB ，D'Amour KA ，Jones KL ，Krishnamoorthy M ，Kulik MJ ，Reynolds DM ，Sheppard AM ，Liu H ，Xu Y ，Baetge EE ，Dalton S ... -  《STEM CELLS》

Combined activin A/LiCl/Noggin treatment improves production of mouse embryonic stem cell-derived definitive endoderm cells.

Induction of definitive endoderm (DE) cells is a prerequisite for the whole process of embryonic stem (ES) cells differentiating into hepatic or pancreatic progenitor cells. We have established an efficient method to induce mouse ES cell-derived DE cells in suspension embryonic body (EB) culture. Similar to previous studies, mouse ES cell-derived DE cells, which were defined as Cxcr4(+) c-Kit(+) , Cxcr4(+) E-cadherin(+) cells or Cxcr4(+) PDGFRa(-) cells, could be induced in the serum-free EBs at Day 4 of induction. The activations of Wnt, Nodal, and FGF signaling pathways in differentiating EBs promoted DE cell differentiation, while activation of BMP4 signaling inhibited the process. In the present study, we found that chemical activation of canonical Wnt signaling pathway by LiCl could synergize with Activin A-mediated Nodal signaling pathway to promote induction of DE cells, and inhibition of Bmp4 signaling by Noggin along with Activin A/LiCl further improved the efficiency of DE cell differentiation. The derived DE cells were proved for their capacities to become hepatic progenitor cells or pancreatic progenitor cells. In conclusion, we significantly improved the efficiency of generating mouse ES cell-derived DE cells by combined Activin A/LiCl/Noggin treatment. Our work will be greatly helpful to generate ES cell-derived hepatic cells and ES cell-derived pancreatic cells for future regenerative medicine.

Li F ，He Z ，Li Y ，Liu P ，Chen F ，Wang M ，Zhu H ，Ding X ，Wangensteen KJ ，Hu Y ，Wang X ... -  《-》