Juan Larraín

Investigation

Our interest is to understand the cellular and molecular mechanisms that regulate cell fate and body plan during early development of the vertebrate embryo, using Xenopus as model system. The formation and patterning of three germ layers (ecto-, endo-, and mesoderm) and the generation of the asymmetric axes (dorso-ventral, antero-posterior and left-right) starts already in the oocyte and are established before the end of gastrulation. These processes depend crucially on a highly regulated cell-cell communication. We are studying the influence of the extracellular space on how the signals are interpreted. These include structural modifications and interactions with extracellular elements. A relatively unexplored aspect deals with the role of proteoglycans (PGs) during early development. We are attempting to identify the PGs expressed and to define their function at the cellular and molecular level. We are currently studying biglycan, involved in the regulation of the chordin-BMP4 signalling pathway, and syndecan-4, a novel component of the non-canonical Wnt pathway that regulates convergent extension movements.
Unravelling the mechanism used by the embryo to determine the different cell fates could provide valuable information for handling in vitro differentiation of adult stem cells, a field that has increasing importance in regenerative therapies. What we learn from the embryo could be applied in the manipulation of pluripotential cells isolated from the bone marrow and umbilical cord.

Selected References

Author(s)	Title	Date
Muñoz, R., Moreno, M., Oliva, C., Orbenes, C., Larraín, J.	Syndecan-4 regulates non-canonical Wnt signaling and is essential for convergent and extension movements in Xenopus embryos. Nat. Cell Biol. 8, 492-500.(2006)	0
Moreno, M., Muñoz, R., Aroca, F., Labarca, M., Brandan,E. and Larraín	J. Biglycan is a new extracellular component of the Chordin-BMP4 signalling pathway. EMBO, J. 24: 1397-1405 (2005).	0
Larrain, J., Oelgeschlager, M., Keptura, N.I., Reversade, B., Zakin, L. and De Robertis E.M.	Proteolysis of Chordin as a switch for the dual activities of Twisted gastrulation on BMP. Development 128, 4439-4447 (2001).	0
Oelgeschlager, M., Larrain, J., Geissert, D., and De Robertis, E.M.	The evo¬lutionarily conserved BMP-binding protein Twisted gastrulation promotes BMP signalling. Nature 405: 757-63 (2000).	0
De Robertis, E. M., Larrain, J., Oelgeschlager, M., Wessely, O.	The estab¬lishment of Spemann’s organizer and patterning of the vertebrate embryo. Nature Review Genetics 1: 171-81 (2000).	0

Juan Larraín

Academic CV

Investigation

Academic CV

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