Masafumi Kuzuya1, Miguel Ramos1, Shigeru Kanda1, Teruhiko Koike1, Toshinobu ASAI1, Keiko Maeda1, Kenya Shitara1, Masabumi Shibuya1, Akihisa Iguchi1
1From the Department of Geriatrics (M.K., M.A.R., S.K., T.K., T.A., K.M., A.I.), Nagoya University Graduate School of Medicine, Nagoya, the Tokyo Research Laboratories of Kyowa Hakko Kogyo Co (K.S.), Machida, and the Department of Genetics (M.S.), Institute of Medical Science, University of Tokyo, Tokyo, Japan.
Tóm tắt
Abstract
—Although the accumulation of vascular endothelial growth factor (VEGF) has been observed in human atherosclerotic lesions, the exact role of this growth factor in atherogenesis remains unknown. We hypothesized that VEGF in the vascular wall might have a preventive effect on endothelial cell damage during atherosclerosis. To test our hypothesis, we examined whether VEGF protects against the toxicity of oxidized low density lipoprotein (Ox-LDL) in cultured endothelial cells derived from bovine aortas (BAECs). Preincubation of BAECs with VEGF prevented Ox-LDL–induced toxicity in a preincubation time– and VEGF concentration–dependent manner. Addition of
N
ω
-nitro-
l
-arginine methyl ester, a nitric oxide synthase inhibitor, did not reverse the protective effect of VEGF on Ox-LDL toxicity. Incubation of BAECs with VEGF increased intracellular glutathione (GSH) content in a time-dependent manner. Combined addition of VEGF and
l
-buthionine sulfoximine, a GSH synthesis inhibitor, reversed both GSH levels and the protective effect of VEGF on Ox-LDL–induced cytotoxicity. Placenta growth factor, which ligates to the VEGF Flt-1 receptor but not KDR/Flk-1, failed to prevent Ox-LDL toxicity and had no effect on intracellular GSH levels. An anti-KDR antibody completely blocked these beneficial activities of VEGF. These results suggest that VEGF prevents Ox-LDL–induced endothelial cell damage via an intracellular GSH-dependent mechanism through the KDR/Flk-1 receptor.
