Lack of effect of α-tocopherol on in vitro angiogenesis Teresa Navarra, Serena Del Turco, Angela Papa, Debora Battaglia, Guido Lazzerini, Giuseppina Basta ⁎ CNR Institute of Clinical Physiology, San Cataldo Research Area, Via Moruzzi, 1, 56124 Pisa, Italy Received 6 October 2005; revised 7 April 2006; accepted 11 April 2006 Available online 5 June 2006 Abstract Oxidative stress and angiogenesis are important elements in the pathogenesis of atherosclerosis and cancer. Because of its antioxidant properties, α-tocopherol has long proposed as prevention of diseases associated with oxidative stress. We explore whether α-tocopherol modulates some cell responses induced by angiogenic and proliferative stimuli. For this purpose, we evaluate the effect in human vein endothelial cells (HUVECs), of α-tocopherol treatment (5–40 μmol/L) for 72 h on the production of reactive oxygen species (ROS), induction of matrix metalloproteinases (MMPs), expression of vascular endothelial–cadherin (VE-cadherin) and α 2 - integrin, cell migration, cell proliferation, and tube formation. α-Tocopherol significantly inhibits intracellular ROS production induced by TNF-α (P < 0.01) or PMA (P < 0.001). However, α-tocopherol does not interfere with mRNA expression of VE-cadherin, α 2 -integrin, MMP-1, MMP-2, and MMP-9. Similarly, α-tocopherol does not modulate cell migration and capillary-like tube formation although at the concentration of 20 and 40 μmol/L it potentiated PMA-induced DNA synthesis (P < 0.05). Our results suggest that although α-tocopherol supplementation reduces endothelial cell oxidative stress, it does not alter the cell response to angiogenic stimuli. © 2006 Elsevier Inc. All rights reserved. Keywords: Angiogenesis; Reactive oxygen species; α-Tocopherol; VE-cadherin; Matrix metalloproteinases Introduction It is well accepted that reactive oxygen species (ROS) are causing agents in the pathogenesis of various diseases, among which atherosclerosis and cancer (Storz, 2005; Witztum, 1994). A number of stimuli induce intracellular ROS production, such as superoxide and H 2 O 2 , that are involved in triggering diverse intracellular signaling pathways (“redox-sensitive” signaling pathways) that have a central role in conditions such as endothelial activation and inflammation, cell growth, apoptosis, and angiogenesis. Because ROS trigger and mediate the angiogenic answer in a highly coordinated manner (Maulik and Das, 2002; Shono et al., 1996), the development of new blood vessels could represent a probable process linking atherosclerosis and cancer. Progressive angiogenesis in athero- sclerotic lesions has been considered one of the causes of plaque expansion, plaque vulnerability, and a risk of significant disease complications such as plaque rupture and vascular thrombosis (van der Wal and Brcker, 1999). Tumor angiogenesis is considered as a negative prognostic variable for various malignant neoplasms (Cavallaro and Christofori, 2000). Angio- genesis is a complex process involving extensive interplay among cells, soluble factors, and extracellular matrix compo- nents. Critical events of angiogenesis appear to be degradation of basement membrane components via matrix metalloproteases (MMPs) (Pepper, 2001), endothelial cell migration, prolifera- tion, and tube formation (Carmeliet, 2000). Migration and cell– extracellular matrix interactions depend upon sustained α 2 - integrin engagement (Klekotka et al., 2001). Moreover, vascular endothelial–cadherin (VE-cadherin) that mediate intercellular contact regulates tubulogenesis by preventing the disassembly of nascent blood vessels (Crosby et al., 2005). Because H 2 O 2 Microvascular Research 72 (2006) 12 – 19 www.elsevier.com/locate/ymvre ⁎ Corresponding author. Fax: +39 050 315 2166. E-mail address: lapina@ifc.cnr.it (G. Basta). 0026-2862/$ - see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.mvr.2006.04.003