Ethanol-Induced Oxidative Stress Modifies Inflammation and Angiogenesis Biomarkers in Retinal Pigment Epithelial Cells (ARPE-19): Role of CYP2E1 and its Inhibition by Antioxidants.

Natalia Martinez-Gil,Francisco J Romero,Javier Sancho-Pelluz,Manuel Diaz-Llopis,Miguel Flores-Bellver,Lorena Vidal-Gil,Jorge M Barcia,Rosa Maisto

doi:10.3390/antiox9090776

Abstract

The retinal pigment epithelium (RPE) plays a key role in retinal health, being essential for the protection against reactive oxygen species (ROS). Nevertheless, excessive oxidative stress can induce RPE dysfunction, promoting visual loss. Our aim is to clarify the possible implication of CYP2E1 in ethanol (EtOH)-induced oxidative stress in RPE alterations. Despite the increase in the levels of ROS, measured by fluorescence probes, the RPE cells exposed to the lowest EtOH concentrations were able to maintain cell survival, measured by the Cell Proliferation Kit II (XTT). However, EtOH-induced oxidative stress modified inflammation and angiogenesis biomarkers, analyzed by proteome array, ELISA, qPCR and Western blot. The highest EtOH concentration used stimulated a large increase in ROS levels, upregulating the cytochrome P450-2E1 (CYP2E1) and promoting cell death. The use of antioxidants such as N-acetylcysteine (NAC) and diallyl sulfide (DAS), which is also a CYP2E1 inhibitor, reverted cell death and oxidative stress, modulating also the upstream angiogenesis and inflammation regulators. Because oxidative stress plays a central role in most frequent ocular diseases, the results herein support the proposal that CYP2E1 upregulation could aggravate retinal degeneration, especially in those patients with high baseline oxidative stress levels due to their ocular pathology and should be considered as a risk factor.

Highlights

The retinal pigment epithelium (RPE) is essential for retinal health [1,2,3,4,5,6,7,8,9]
We demonstrated demonstrated that higher EtOH exposure induces cytochrome P450-2E1 (CYP2E1) upregulation, promoting cell death through that higher EtOH exposure induces CYP2E1 upregulation, promoting cell death through apoptosis apoptosis activation [47]
The current work reveals that EtOH-induced oxidative stress can upregulate upregulate CYP2E1 expression and activity by itself, inducing RPE cells alterations (Figure 5)

Summary

Introduction

The retinal pigment epithelium (RPE) is essential for retinal health [1,2,3,4,5,6,7,8,9]. Besides age and genetic predisposition, which have clearly been identified as risk factors, the environment and nutrition have been described as modifiable risk factors to avoid RPE and photoreceptor cells death at eye macula [11,12]. Another significant player in AMD is the RPE, which loses its functions, promoting retinal neurodegeneration [13,14].

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