International Journal of Cell Biology
Volume 2009 (2009), Article ID 532432, 9 pages
doi:10.1155/2009/532432
Research Article

Lowering Caveolin-1 Expression in Human Vascular Endothelial Cells Inhibits Signal Transduction in Response to Shear Stress

A. D. van der Meer,1 M. M. J. Kamphuis,1,2 A. A. Poot,1 J. Feijen,1 and I. Vermes1,2

1Institute for Biomedical Technology and Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
2Department of Clinical Chemistry, Medical Spectrum Twente, Hospital Group, P.O. Box 50000, 7500 KA Enschede, The Netherlands

Received 18 July 2008; Accepted 19 October 2008

Academic Editor: Rony Seger

Copyright © 2009 A. D. van der Meer et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Vascular endothelial cells have an extensive response to physiological levels of shear stress. There is evidence that the protein caveolin-1 is involved in the early phase of this response. In this study, caveolin-1 was downregulated in human endothelial cells by RNAi. When these cells were subjected to a shear stress of 15 dyn/cm2 for 10 minutes, activation of Akt and ERK1/2 was significantly lower than in control cells. Moreover, activation of Akt and ERK1/2 in response to vascular endothelial growth factor was significantly lower in cells with low levels of caveolin-1. However, activation of integrin-mediated signaling during cell adhesion onto fibronectin was not hampered by lowered caveolin-1 levels. In conclusion, caveolin-1 is an essential component in the response of endothelial cells to shear stress. Furthermore, the results suggest that the role of caveolin-1 in this process lies in facilitating efficient VEGFR2-mediated signaling.