The expression and function of vascular endothelial growth factor in retinal pigment epithelial (RPE) cells is regulated by 4-hydroxynonenal (HNE) and glutathione S-transferaseA4-4
- Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)
Highlights: Black-Right-Pointing-Pointer Low concentration of HNE (0.1-1.0 {mu}M) induced secretion of VEGF in RPE cells. Black-Right-Pointing-Pointer VEGF secreted medium of RPE cells promoted proliferation of endothelial cells. Black-Right-Pointing-Pointer VEGFR2 expression was attenuated with increasing concentrations of HNE. Black-Right-Pointing-Pointer These effects of HNE could be blocked by the over expression of GSTA4-4 in cells. -- Abstract: It is well established that 4-hydroxynonenal (HNE) plays a major role in oxidative stress-induced signaling and the toxicity of oxidants. Surprisingly our recent studies also demonstrate that low levels of HNE generated during oxidative stress promote cell survival mechanisms and proliferation. Since the expression and secretion of VEGF is known to be affected by Oxidative stress, during present studies, we have examined dose dependent effect of HNE on VEGF expression and secretion in a model of retinal pigment epithelial (RPE) cells in culture. Results of these studies showed that while inclusion of 0.1 {mu}M HNE in the medium caused increased secretion of VEGF, its secretion and expression was significantly suppressed in the presence of >5 {mu}M HNE in the media. These concentration dependent hormetic effects of HNE on VEGF secretion could be blocked by the over expression of GSTA4-4 indicating that these effects were specifically attributed to HNE and regulated by GSTA4-4. VEGF secreted into the media showed angiogenic properties as indicated by increased migration and tube formation of HUVEC in matrigel when grown in media from RPE cells treated with 1 {mu}M HNE. The corresponding media from GSTA4-4 over expressing RPE cells had no effect on migration and tube formation of HUVEC in matrigel. These results are consistent with earlier studies showing that at low concentrations, HNE promotes proliferative mechanisms and suggest that HNE induces VEGF secretion from RPE cells that acts in a paracrine fashion to induce angiogenic signaling mechanism in the endothelial cells. These findings may suggest a role of HNE and GSTA4-4 in oxidative stress induced proliferative retinopathies.
- OSTI ID:
- 22207629
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 417, Issue 1; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
Similar Records
K20E, an oxidative-coupling compound of methyl caffeate, exhibits anti-angiogenic activities through down-regulations of VEGF and VEGF receptor-2
Survivin knockdown increased anti-cancer effects of (-)-epigallocatechin-3-gallate in human malignant neuroblastoma SK-N-BE2 and SH-SY5Y cells