HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Data Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by McLean, A. B. Articles by Dalton, S. Search for Related Content PubMed PubMed Citation Articles by McLean, A. B. Articles by Dalton, S.

EMBRYONIC STEM CELLS: CHARACTERIZATION SERIES

Activin A Efficiently Specifies Definitive Endoderm from Human Embryonic Stem Cells Only When Phosphatidylinositol 3-Kinase Signaling Is Suppressed

^aDepartment of Biochemistry and Molecular Biology and Paul D. Coverdell Center for Biomedical and Health Sciences and
^cInstitute of Bioinformatics, University of Georgia, Athens, Georgia, USA;
^bNovocell Inc., San Diego, California, USA

Key Words. Human ESCs • Differentiation • Self-renewal • Phosphatidylinositol 3-kinase

Correspondence: Stephen Dalton, Ph.D., Department of Biochemistry and Molecular Biology and Paul D. Coverdell Center for Biomedical and Health Sciences, 3 Institute of Bioinformatics, University of Georgia, Green Street, Athens, Georgia 30602, USA. Telephone: 706-583-0480; Fax: 706-583-0480; e-mail: sdalton{at}uga.edu

Received April 13, 2006; accepted for publication September 7, 2006.


Human ESCs (hESCs) respond to signals that determine their pluripotency, proliferation, survival, and differentiation status. In this report, we demonstrate that phosphatidylinositol 3-kinase (PI3K) antagonizes the ability of hESCs to differentiate in response to transforming growth factor ß family members such as Activin A and Nodal. Inhibition of PI3K signaling efficiently promotes differentiation of hESCs into mesendoderm and then definitive endoderm (DE) by allowing them to be specified by Activin/Nodal signals present in hESC cultures. Under conditions where hESCs are grown in mouse embryo fibroblast-conditioned medium under feeder-free conditions, 70%–80% are converted into DE following 5 days of treatment with inhibitors of the PI3K pathway, such as LY 294002 and AKT1-II. Microarray and quantitative polymerase chain reaction-based gene expression profiling demonstrates that definitive endoderm formation under these conditions closely parallels that following specification with elevated Activin A and low fetal calf serum (FCS)/knockout serum replacement (KSR). Reduced insulin/insulin-like growth factor (IGF) signaling was found to be critical for cell fate commitment into DE. Levels of insulin/IGF present in FCS/KSR, normally used to promote self-renewal of hESCs, antagonized differentiation. In summary, we show that generation of hESC-DE requires two conditions: signaling by Activin/Nodal family members and release from inhibitory signals generated by PI3K through insulin/IGF. These findings have important implications for our understanding of hESC self-renewal and early cell fate decisions.

This article has been cited by other articles:

				M Mimeault and S K Batra Recent progress on normal and malignant pancreatic stem/progenitor cell research: therapeutic implications for the treatment of type 1 or 2 diabetes mellitus and aggressive pancreatic cancer Gut, October 1, 2008; 57(10): 1456 - 1468. [Abstract] [Full Text] [PDF]

				D. C. Hay, J. Fletcher, C. Payne, J. D. Terrace, R. C. J. Gallagher, J. Snoeys, J. R. Black, D. Wojtacha, K. Samuel, Z. Hannoun, et al. Highly efficient differentiation of hESCs to functional hepatic endoderm requires ActivinA and Wnt3a signaling PNAS, August 26, 2008; 105(34): 12301 - 12306. [Abstract] [Full Text] [PDF]

				T. Ishii, K. Fukumitsu, K. Yasuchika, K. Adachi, E. Kawase, H. Suemori, N. Nakatsuji, I. Ikai, and S. Uemoto Effects of extracellular matrixes and growth factors on the hepatic differentiation of human embryonic stem cells Am J Physiol Gastrointest Liver Physiol, August 1, 2008; 295(2): G313 - G321. [Abstract] [Full Text] [PDF]

				N. Shiraki, K. Umeda, N. Sakashita, M. Takeya, K. Kume, and S. Kume Differentiation of mouse and human embryonic stem cells into hepatic lineages. Genes Cells, July 1, 2008; 13(7): 731 - 746. [Abstract] [Full Text] [PDF]

				S. Agarwal, K. L. Holton, and R. Lanza Efficient Differentiation of Functional Hepatocytes from Human Embryonic Stem Cells Stem Cells, May 1, 2008; 26(5): 1117 - 1127. [Abstract] [Full Text] [PDF]

				N. Shiraki, T. Yoshida, K. Araki, A. Umezawa, Y. Higuchi, H. Goto, K. Kume, and S. Kume Guided Differentiation of Embryonic Stem Cells into Pdx1-Expressing Regional-Specific Definitive Endoderm Stem Cells, April 1, 2008; 26(4): 874 - 885. [Abstract] [Full Text] [PDF]

				D. C. Hay, D. Zhao, J. Fletcher, Z. A. Hewitt, D. McLean, A. Urruticoechea-Uriguen, J. R. Black, C. Elcombe, J. A. Ross, R. Wolf, et al. Efficient Differentiation of Hepatocytes from Human Embryonic Stem Cells Exhibiting Markers Recapitulating Liver Development In Vivo Stem Cells, April 1, 2008; 26(4): 894 - 902. [Abstract] [Full Text] [PDF]

				C. Freund, D. Ward-van Oostwaard, J. Monshouwer-Kloots, S. van den Brink, M. van Rooijen, X. Xu, R. Zweigerdt, C. Mummery, and R. Passier Insulin Redirects Differentiation from Cardiogenic Mesoderm and Endoderm to Neuroectoderm in Differentiating Human Embryonic Stem Cells Stem Cells, March 1, 2008; 26(3): 724 - 733. [Abstract] [Full Text] [PDF]

				L. Wang, T. C. Schulz, E. S. Sherrer, D. S. Dauphin, S. Shin, A. M. Nelson, C. B. Ware, M. Zhan, C.-Z. Song, X. Chen, et al. Self-renewal of human embryonic stem cells requires insulin-like growth factor-1 receptor and ERBB2 receptor signaling Blood, December 1, 2007; 110(12): 4111 - 4119. [Abstract] [Full Text] [PDF]