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 All Versions of this Article: 2007-1056v1 26/12/3099    most recent 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 Google Scholar Google Scholar Articles by Levenstein, M. E. Articles by Thomson, J. A. Search for Related Content PubMed PubMed Citation Articles by Levenstein, M. E. Articles by Thomson, J. A.

EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS

Secreted Proteoglycans Directly Mediate Human Embryonic Stem Cell-Basic Fibroblast Growth Factor 2 Interactions Critical for Proliferation

^aWiCell Research Institute, Madison, Wisconsin, USA;
^bDepartment of Chemistry, University of Wisconsin, Madison, Wisconsin, USA;
^cGenome Center of Wisconsin, Madison, Wisconsin, USA;
^dWisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, USA;
^eDepartment of Anatomy, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA

Key Words. Human embryonic stem cells • Heparan sulfate proteoglycans • Stem cell-basic fibroblast growth factor interactions

Correspondence: Correspondence: James A. Thomson, V.M.D., Ph.D., Morgridge Institute for Research, c/o The Genome Center of Wisconsin, The Genetics and Biotechnology Building, 425 Henry Mall, Madison, Wisconsin 53706, USA. Telephone: 608-263-3585; Fax: 608-890-0181; e-mail: thomson{at}primate.wisc.edu; or Mark E. Levenstein, Ph.D., CDI Bioscience, 3587 Anderson Street, Suite 103, Madison, Wisconsin 53704, USA. Telephone: 608-310-9577; Fax: 608-310-9579; e-mail: markl{at}cdibios.com

Received on December 18, 2007; accepted for publication on August 26, 2008.

First published online in STEM CELLS EXPRESS  September 18, 2008.

Human embryonic stem (ES) cells can be maintained in an undifferentiated state if the culture medium is first conditioned on a layer of mouse embryonic fibroblast (MEF) feeder cells. Here we show that human ES cell proliferation is coordinated by MEF-secreted heparan sulfate proteoglycans (HSPG) in conditioned medium (CM). These HSPG and other heparinoids can stabilize basic fibroblast growth factor (FGF2) in unconditioned medium at levels comparable to those observed in CM. They also directly mediate binding of FGF2 to the human ES cell surface, and their removal from CM impairs proliferation. Finally, we have developed a purification scheme for MEF-secreted HSPG in CM. Using column chromatography, immunoblotting, and mass spectrometry-based proteomic analysis, we have identified multiple HSPG species in CM. The results demonstrate that HSPG are key signaling cofactors in CM-based human ES cell culture.

Disclosure of potential conflicts of interest is found at the end of this article.