1. ¹Laboratoire de Médecine Moléculaire, Centre de Cancérologie Charles-Bruneau, Hôpital Sainte-Justine-UQAM, Montreal, Quebec, Canada
2. ²CNRS FRE 2737, Faculté de Pharmacie, Marseille, France
3. ³Laboratoire d'Oncologie Moléculaire, Département de Chimie-Biochimie, Université du Québec à Montréal, Montreal, Quebec, Canada
4. ⁴Laboratory of the Cell Biology of Hypertension, Clinical Research Institute of Montreal, University of Montreal, Montreal, Quebec, Canada

Correspondence: Prof R Béliveau, Laboratoire de Médecine Moléculaire, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montréal, Québec, Canada H3C 3P8. E-mail: oncomol@nobel.si.uqam.ca

Received 15 May 2004; Revised 3 October 2004; Accepted 22 December 2004; Published online 13 April 2005.

Abstract

The platelet-derived lysophospholipid sphingosine-1-phosphate (S1P) is present in blood plasma and is one of the most potent growth factors displaying proangiogenic activity towards endothelial cells (EC) derived from various tissues. The paracrine regulation of brain angiogenesis by platelet-derived growth factors is, however, poorly understood. In the present study, we assessed the role of S1P on brain EC migration and tubulogenesis, using rat brain-derived (RBE4) EC as an in vitro model. We show that S1P inhibits brain EC migration and tubulogenesis, while it displays proangiogenic activity towards noncerebral EC. Overexpression of the S1P receptor S1P-1 in RBE4 cells potentiated all of the S1P-mediated events. We also show that the lack of expression of MT1-MMP, a membrane-bound matrix metalloproteinase that is thought to cooperate with S1P in tubulogenic processes, may explain the antiangiogenic activity of S1P on brain vasculature. Altogether our results support the hypothesis of a tissue-specific, antiangiogenic role of S1P in the brain, which may help to stabilize the cerebral vasculature and thus have crucial impact on the setting and regulation of normal brain vascularization.