Biphasic role for Wnt/β-catenin signaling in cardiac specification in zebrafish and embryonic stem cells
- Shuichi Ueno*,†,
- Gilbert Weidinger†,‡,§,
- Tomoaki Osugi*,†,
- Aimee D. Kohn‡,
- Jonathan L. Golob*,†,
- Lil Pabon*,†,
- Hans Reinecke*,†,
- Randall T. Moon†,‡,¶, and
- Charles E. Murry*,†,‖
- *Department of Pathology, Center for Cardiovascular Biology;
- ‡Department of Pharmacology, Howard Hughes Medical Institute; and
- †Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA 98109
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Communicated by Joseph A. Beavo, University of Washington School of Medicine, Seattle, WA, April 6, 2007 (received for review August 3, 2006)
Abstract
Understanding pathways controlling cardiac development may offer insights that are useful for stem cell-based cardiac repair. Developmental studies indicate that the Wnt/β-catenin pathway negatively regulates cardiac differentiation, whereas studies with pluripotent embryonal carcinoma cells suggest that this pathway promotes cardiogenesis. This apparent contradiction led us to hypothesize that Wnt/β-catenin signaling acts biphasically, either promoting or inhibiting cardiogenesis depending on timing. We used inducible promoters to activate or repress Wnt/β-catenin signaling in zebrafish embryos at different times of development. We found that Wnt/β-catenin signaling before gastrulation promotes cardiac differentiation, whereas signaling during gastrulation inhibits heart formation. Early treatment of differentiating mouse embryonic stem (ES) cells with Wnt-3A stimulates mesoderm induction, activates a feedback loop that subsequently represses the Wnt pathway, and increases cardiac differentiation. Conversely, late activation of β-catenin signaling reduces cardiac differentiation in ES cells. Finally, constitutive overexpression of the β-catenin-independent ligand Wnt-11 increases cardiogenesis in differentiating mouse ES cells. Thus, Wnt/β-catenin signaling promotes cardiac differentiation at early developmental stages and inhibits it later. Control of this pathway may promote derivation of cardiomyocytes for basic research and cell therapy applications.
Footnotes
- ¶To whom correspondence may be addressed at: Howard Hughes Medical Institute, University of Washington School of Medicine, Box 357370, Seattle, WA 98195. E-mail: rtmoon{at}u.washington.edu
- ‖To whom correspondence may be addressed at: Center for Cardiovascular Biology, University of Washington School of Medicine, 815 Mercer Street, Seattle, WA 98109. E-mail: murry{at}u.washington.edu
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Author contributions: S.U., G.W., and T.O. contributed equally to this work; S.U., G.W., T.O., L.P., H.R., R.T.M., and C.E.M. designed research; S.U., G.W., and T.O. performed research; G.W., A.D.K., and J.L.G. contributed new reagents/analytic tools; S.U., G.W., T.O., L.P., H.R., and C.E.M. analyzed data; and S.U., G.W., J.L.G., L.P., R.T.M., and C.E.M. wrote the paper.
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↵ §Present address: Biotechnological Center and Center for Regenerative Therapies, Technical University of Dresden, 01377 Dresden, Germany.
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The authors declare no conflict of interest.
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See Commentary on 9549.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0702859104/DC1.
- Abbreviations:
- BIO,
- 6-bromoindirubicin-3′-oxime;
- EB,
- embryoid body;
- hpf,
- hours postfertilization;
- MHC,
- myosin heavy chain.
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Freely available online through the PNAS open access option.
- © 2007 by The National Academy of Sciences of the USA
