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

Rit Vatsyayan, Poorna Chandra Rao Lelsani, Pankaj Chaudhary, Sushil Kumar, Sanjay Awasthi, Yogesh C. Awasthi

Research output: Contribution to journalArticle

23 Scopus citations

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 0.1μM HNE in the medium caused increased secretion of VEGF, its secretion and expression was significantly suppressed in the presence of >5μM 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 1μM 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.

Original languageEnglish
Pages (from-to)346-351
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume417
Issue number1
DOIs
StatePublished - 6 Jan 2012

Keywords

  • 4-Hydroxy-t-2-nonenal
  • Glutathione S-transferasesA4-4
  • Lipid peroxidation
  • Retinal pigment epithelium cells
  • Vascular endothelial growth factor
  • Vascular endothelial growth factor receptor

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