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Editorials |
From the Vascular Development Laboratory, Cancer Research UK London Research Institute, 44 Lincolns Inn Fields, London WC2A 3PX, United Kingdom
Correspondence to Ralf H. Adams, Vascular Development Laboratory, Cancer Research UK London Research Institute, 44 Lincolns Inn Fields, London WC2A 3PX, United Kingdom. E-mail ralf.adams@cancer.org.uk
See related article, pages 480489
Key Words: axon guidance blood vessel angiogenesis Slit Robo vascular smooth muscle migration GTPase Rac1
An extract of the first 250 words of the full text is provided, because this article has no abstract. |
The vasculature and the nervous system both form extensively branched networks in the vertebrate body, incorporate into very different tissue environments, and establish connections over long distances. Although there are many obvious morphological and functional differences between blood vessels and nerve fibers, one should not ignore striking conceptual similarities in the assembly of these networks through guided growth and branching processes. There is accumulating evidence that this resemblance is not just coincidental and instead reflects that the morphogenesis of both systems use similar mechanistic principles and molecular tool kits.13 During development of the nervous system, neurons extend a long axonal process that carries a highly motile sensory structure, termed growth cone, at its distal tip. Growth cones dynamically form filopodial extensions to explore the spatial environment and recognize repulsive or attractive guidance cues acting as molecular signposts. Growth cones have the ability to interpret a multitude of these signals and decide whether it is appropriate to carry on, stall, retract, or change direction. A series of correct decisions will direct the growing axon to its proper target where it forms synaptic connections. Unlike neurons, endothelial cells do not extend long processes and instead line the inner surface of blood vessels with their cell bodies. During growth and remodeling processes, a specialized endothelial cell, termed tip cell, covers the distal end of vascular sprouts. Tip cells dynamically extend long filopodia and explore signals presented by surrounding cells and the matrix environment.4 Live imaging data obtained in zebrafish embryos and phenotypes of
Related Article:
Circ. Res. 2006 98: 480-489.
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