Human Molecular Genetics Advance Access originally published online on May 10, 2008
Human Molecular Genetics 2008 17(16):2424-2432; doi:10.1093/hmg/ddn142
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ccm1 cell autonomously regulates endothelial cellular morphogenesis and vascular tubulogenesis in zebrafish
1 Hubrecht Institute-KNAW and University Medical Centre Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands 2 Institut für Pathologie, Liebermeisterstr 8, 72076 Tübingen, Germany
* To whom correspondence should be addressed. Tel: +31 302121800; Fax: +31 302516464; Email: s.schulte{at}niob.knaw.nl
Received March 17, 2008; Accepted May 6, 2008
Cerebral cavernous malformations (CCMs) are a prevalent class of vascular anomalies characterized by thin-walled clusters of malformed blood vessels in the brain. Heritable forms are caused by mutations in CCM1, CCM2 and CCM3, but despite the importance of these factors in vascular biology, an understanding of their molecular and cellular functions remains elusive. Here we describe the characterization of a zebrafish embryonic model of CCM. Loss of ccm1 in zebrafish embryos leads to severe and progressive dilation of major vessels, despite normal endothelial cell fate and number. Vascular dilation in ccm1 mutants is accompanied by progressive spreading of endothelial cells and thinning of vessel walls despite ultrastructurally normal cell–cell contacts. Zebrafish ccm2 mutants display comparable vascular defects. Finally, we show that ccm1 function is cell autonomous, suggesting that it is endothelial cellular morphogenesis that is regulated by CCM proteins during development and pathogenesis.