Abstract
Purpose: :
To characterize the cytotoxic, pro-inflammatory, pro-oxidative and pro-angiogenic effects of oxysterols (7β-hydroxycholesterol (7β-OH), 7 ketocholesterol (7C) and 25-hydroxycholesterol (25-OH) in human retinal pigment epithelial cells (ARPE-19) and to evaluate the protective effects of fatty acids ω3 (DHA, EPA), PPAR- agonist (fenofibrate) and resveratrol.
Methods: :
ARPE-19 cells were treated with 7β-OH, 7C and 25-OH. Cell viability was measured using the MTT assay and the trypan blue exclusion method. Membrane permeability was assessed by flow cytometry with propidium iodide. Overproduction of reactive oxygenated species (ROS) was quantified with hydroethidine (HE). Interleukins 8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) concentration was evaluated with an ELISA test. Immunofluorescence staining was used to visualize cells producing IL-8.
Results: :
7β-OH and 7C were cytotoxic, increased ROS production and did not stimulate IL-8 and MCP-1 secretion. Only 7β-OH induced VEGF secretion. 25-OH had no cytotoxic effects but highly increased ROS production, IL-8, MCP-1 and VEGF secretion. In cultured human retinal pigment epithelial cells exposed to oxysterols, DHA was cytoprotector, EPA and fenofibrate had anti-inflammatory and anti-angiogenic activities. Resveratrol and EPA/resveratrol combination had a light anti-angiogenic effect.
Conclusions: :
The oxysterols evaluated in this study had cytotoxic, pro-inflammatory, pro-oxidative and pro-angiogenic activities in cultured human retinal pigment epithelial cells. Fatty acids ω3 (DHA, EPA), PPAR- agonist (fenofibrate) and resveratrol had protective effects against the oxysterols possibly involved in ARMD lesions.
Keywords: retinal degenerations: cell biology