Anti-inflammatory effects of resolvin-D1 on human corneal epithelial cells: in vitro study

Nir Erdinest,Haim Ovadia,Abraham Solomon,Ran Kormas

doi:10.1186/1476-9255-11-6

Abstract

BackgroundThis study evaluated the anti-inflammatory effects of Resolvin-D1 (RV-D1) and its mechanism of action in human corneal epithelial (HCE) cells.MethodsHCE cells were incubated with different concentrations of RV-D1 for different time periods. Oleic acid (OA) and Dexamethasone (DM) served as negative and positive controls, respectively. Cells were stimulated with polyriboinosinic:polyribocytidylic acids (poly I:C). The protein contents and mRNA expression levels of Tumor necrosis factor-α (TNF-α), Interleukin (IL)-6, IL-1β and IL-8 were evaluated with multiplex fluorescent bead immunoassay (FBI) and real time-PCR, respectively. In addition, the expression of inhibitory factor-κBα (I-κBα) was evaluated with real time-PCR.ResultsThe protein level of pro-inflammatory cytokines TNF-α, IL-6, IL-1β and IL-8 significantly increased after stimulation with Poly I:C. RV-D1 treatment at concentration of 1 μM decreased the protein level of TNF-α to 20.76 ± 9.3% (P < 0.05), IL-6 to 43.54 ± 14.16% (P < 0.001), IL-1β to 46.73 ± 15.93% (P > 0.05) and IL-8 to 51.15 ± 13.01% (P < 0.05) compared with cells stimulated with poly I:C alone. Similarly, the mRNA levels of TNF-α, IL-6, IL-1β and IL-8 were significantly reduced after treatment with RV-D1. A highly significant dose response curve was demonstrated for RV-D1 treated HCE cells for TNF-α and IL-1β.DM treatment decreased the protein content for all of the pro-inflammatory cytokines, similar results were demonstrated at the mRNA level. The anti-inflammatory effects of RV-D1 were similar to those of DM for TNF-α, IL-6 and IL-8.ConclusionsRV-D1 may serve as a potent anti-inflammatory agent in ocular surface inflammation, as evaluated in cultured HCE cells. The anti-inflammatory effects of RV-D1 were comparable to those of DM, and were mediated through nuclear factor kappa B (NF-κB) signal transduction.

Highlights

This study evaluated the anti-inflammatory effects of Resolvin-D1 (RV-D1) and its mechanism of action in human corneal epithelial (HCE) cells
We have recently shown that alpha-linolenic acid (ALA), an omega-3 poly-unsaturated fatty acid, has potent anti-inflammatory effects on stimulated human corneal epithelial cells
Stimulation of HCE cells HCE cells incubated with polyribocytidylic acids (poly I):C expressed up to 4-fold higher levels of IL-6 (P < 0.05), 7-fold higher IL-1β (P < 0.01), 13-fold higher Tumor necrosis factor-α (TNF-α) (P < 0.01), and 3-fold higher IL-8 (P < 0.05) in HCE cells compared with incubation in medium only (Figures 1A-D)

Summary

Introduction

This study evaluated the anti-inflammatory effects of Resolvin-D1 (RV-D1) and its mechanism of action in human corneal epithelial (HCE) cells. Chronic inflammation of the ocular surface is a common characteristic of many common diseases such as the dry eye syndrome (DES), allergic conjunctivitis and contact lens intolerance [1,2,3]. Topical corticosteroids have shown efficacy in treating DES with a Recently, there has been a large amount of interest in using poly-unsaturated fatty acids (PUFAs) as a treatment for ocular surface inflammatory disease [9]. A recent study has indicated that dietary or oral supplementation of PUFA may improve symptoms of DES and contact lens intolerance [10]. A study by Rashid et al using a dry eye mouse model has shown that topical administration of omega-3 fatty acids decreased dry eye signs and inflammatory changes at both cellular and molecular levels [12]

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