title: Induction of vascular endothelial growth factor by 4-hydroxynonenal and its prevention by glutathione precursors in retinal pigment epithelial cells.
abstract: Although 4-hydroxynonenal, a highly reactive lipid peroxidation product, is implicated in several age-related disorders such as Alzheimer's and Parkinson's diseases, its role in age-related macular degeneration is not known. The purpose of this study was to determine whether 4-hydroxynonenal increases vascular endothelial growth factor (VEGF) expression in human retinal pigment epithelial cells (ARPE-19), a source of VEGF in choroidal neovascularization observed in age-related macular degeneration. In addition, it was the purpose of this study to assess whether glutathione (GSH) and GSH precursors can inhibit the effects of 4-hydroxynonenal. At 1 micro M, 4-hydroxynonenal did not alter cell viability, but elevated VEGF secretion and mRNA expression by 35% (p<0.05) and 1.9-fold (p<0.05), respectively. However, at concentrations 5 microM and above, 4-hydroxynonenal reduced VEGF secretion as well as cell viability. At 1 and 10 microM, 4-hydroxynonenal did not induce apoptosis in ARPE-19 cells. 4-Hydroxynonenal (1 microM) reduced intracellular GSH by 25% (p<0.05) and increased oxidative stress by 50% (p<0.05). GSH precursor pretreatment for 1 h, which increased intracellular GSH levels by 50% (p<0.05), as well as GSH co-treatment, inhibited the VEGF-inductive and cytotoxic effects of 4-hydroxynonenal. Thus, 4-hydroxynonenal (1 microM) induces VEGF expression and secretion in ARPE-19 cells. This effect is likely due to GSH depletion and an associated increase in intracellular oxidative stress, resulting in increased VEGF mRNA levels. 4-Hydroxynonenal-mediated VEGF secretion as well as cytotoxicity can be reversed with GSH precursor pretreatment or GSH co-treatment.
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA.
authors.forename: Surya P
authors.initials: SP
authors.lastname: Ayalasomayajula
authors.forename: Uday B
authors.initials: UB
authors.lastname: Kompella
mesh_terms: D000447:Aldehydes / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D016228:Endothelial Growth Factors / Q000096:biosynthesis*; D005136:Eye Proteins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis*; D015227:Lipid Peroxidation; D008222:Lymphokines / Q000096:biosynthesis*; D018384:Oxidative Stress / Q000502:physiology; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D000447:Aldehydes; D015853:Cysteine Proteinase Inhibitors; D016228:Endothelial Growth Factors; D005136:Eye Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D005978:Glutathione; C027576:4-hydroxy-2-nonenal