Abstract
Purpose:
Alcohol consumption has a high prevalence in most countries and it is the drug with the highest use and abuse in many societies, causing numerous social and medical problems, including serious damage on central nervous system function. Ethanol exerts its deleterious effects metabolically via oxidative and nonoxidative pathways, involving free radical production and lipid peroxidation, potentially leading to an imbalance between oxidants and antioxidants, resulting in an increased oxidative stress. In the visual system, it is known that long-term ethanol consumption causes clinical manifestations that have been attributed to nutritional deficits rather than a direct effect of ethanol. Our group has demonstrated that chronic ethanol consumption induces toxicity by increasing oxidative stress in rat retina associated with an impairment of ERG and Bcl-2 overexpression (Sancho-Tello et al., 2008). Thus, these alterations in the rat retina allow the proposal of a real ‘alcoholic retinopathy’. In order to assess its existence, we tested the effect of alcohol exposure on a specific retinal cell type, a human Retinal Pigmented Epithelium cell line (ARPE-19).
Methods:
We tested 3 different concentrations of ethanol in ARPE cells (250 mM, 500 mM and 750 mM) during 24h. To find out the effects of alcohol exposure in ARPE cells, we performed cell viability assays (MTT and Anexin V/Propidium Iodide using flow cytometry). We also checked oxidative stress markers (GSH, 4HNE, Nrf2, bcl-2) by immunofluorescence and cell death markers (Caspase 3/ cleaved caspase 3 and Bax) by Western blot. Finally, we studied the cytoarchitecture of ARPE-exposed cells by Transmission Electron Microscopy.
Results:
Ethanol exposure leads to an increase of oxidative stress markers and to an impairment of cell viability in a concentration dependent manner. Moreover, cell death markers were also affected by ethanol treatment.
Conclusions:
In summary, we described the deleterious effects of ethanol on a human RPE cell model. These results agreed with our previous studies suggesting the existence of a 'real' alcoholic retinopathy in mammals.
Keywords: 701 retinal pigment epithelium •
634 oxidation/oxidative or free radical damage