title: Activin A and Wnt-dependent specification of human definitive endoderm cells.
abstract: Activin/Nodal and Wnt signaling are known to play important roles in the regional specification of endoderm. Here we have investigated the effect of the length of stimulation with Activin A plus Wnt3a on the development of hepatic and pancreatic progenitors from the definitive endoderm (DE) cells derived from human pluripotent stem cells (hPSC). We show that DE-cells derived from hPSC with 3 days high Activin A and Wnt3a treatment were able to differentiate further into both tested endodermal lineages. When prolonging the DE-induction protocol from 3 to 5 or 7 days, almost pure DE-marker positive cell populations were obtained. However, these cells had an impaired pancreatic differentiation capacity, while they still developed into hepatocyte-like cells. Further propagation of the DE-cells in the presence of Wnt3a and Activin A led to the complete loss of differentiation capacity into hepatic or pancreatic lineages. When Wnt3a was removed after 24h from the initiation of the differentiation, the cells were able to differentiate into PDX1+/NKX6.1+ pancreatic progenitors even with longer DE induction time while efficiency of hepatic differentiation was lower. Our results suggest that both the length and the timing of Wnt3a treatment during DE induction are crucial for the final differentiation outcome. Although it is possible to derive apparently pure DE cells with prolonged Activin A/Wnt-stimulation, their progenitor capacity is restricted to a limited time window.
authors: Research Programs Unit, Molecular Neurology, Biomedicum Stem Cell Center, University of Helsinki, Helsinki, Finland. Electronic address: sanna.toivonen@helsinki.fi.
authors: Sanna
authors: S
authors: Toivonen
authors: Karolina
authors: K
authors: Lundin
authors: Diego
authors: D
authors: Balboa
authors: Jarkko
authors: J
authors: Ustinov
authors: Kaisa
authors: K
authors: Tamminen
authors: Jaan
authors: J
authors: Palgi
authors: Ras
authors: R
authors: Trokovic
authors: Timo
authors: T
authors: Tuuri
authors: Timo
authors: T
authors: Otonkoski
mesh_terms: D028341:Activins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D004627:Embryonic Induction; D004707:Endoderm / Q000166:cytology*; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010179:Pancreas / Q000166:cytology; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D060509:Wnt3A Protein / Q000494:pharmacology*
chemical_list: D018398:Homeodomain Proteins; C105201:NKX6-1 protein, human; D015534:Trans-Activators; C555510:WNT3A protein, human; D060509:Wnt3A Protein; C422405:activin A; C084010:pancreatic and duodenal homeobox 1 protein; D028341:Activins
keywords: Definitive endoderm; Differentiation; Human pluripotent stem cells