Induction of Eotaxin–3 Expression in Human Retinal Pigmented Epithelial Cells by TNF– and VEGF–A.

Abstract

Abstract: : Purpose:To investigate the effects of tumor necrosis factor (TNF)–α and vascular endothelial growth factor (VEGF)–A alone, or in combination, on human retinal pigmented epithelial (hRPE) cell expression of the chemokine eotaxin–3, which has the exceptional property to actively repulse recruited monocytes. Methods: Serum–starved cultured hRPE cells were incubated with TNF–α, VEGF–A, or both. Eotaxin–3 mRNA expression in cell lysates was determined by reverse transcription–polymerase chain reaction analysis after 4 and 8 hours incubation. Results: hRPE cells incubated either in the absence of cytokines or with VEGF–A alone did not express detectable amounts of eotaxin–3 mRNA. Eotaxin–3 mRNA expression, which was stimulated by TNF–α alone in a time–dependent fashion peaking at 4 hours, was further upregulated by preincubation with VEGF–A. Conclusions:The synergistic effect of TNF–α and VEGF–A on eotaxin–3 mRNA expression by hRPE cells suggests a role for this chemokine in modulating macrophage trafficking in the subretinal space.

Keywords: retinal pigment epithelium • cytokines/chemokines