Chloroquine Protects Human Corneal Epithelial Cells from Desiccation Stress Induced Inflammation without Altering the Autophagy Flux.

Shivapriya Shivakumar,Rohit Shetty,Nallathambi Jeyabalan,Murali Subramani,Arkasubhra Ghosh,Trailokyanath Panigrahi

doi:10.1155/2018/7627329

Abstract

Dry eye disease (DED) is a multifactorial ocular surface disorder affecting millions of individuals worldwide. Inflammation has been associated with dry eye and anti-inflammatory drugs are now being targeted as the alternate therapeutic approach for dry eye condition. In this study, we have explored the anti-inflammatory and autophagy modulating effect of chloroquine (CQ) in human corneal epithelial and human corneal fibroblasts cells exposed to desiccation stress, (an in-vitro model for DED). Gene and protein expression profiling of inflammatory and autophagy related molecular factors were analyzed in HCE-T and primary HCF cells exposed to desiccation stress with and without CQ treatment. HCE-T and HCF cells exposed to desiccation stress exhibited increased levels of activated p65, TNF-α, MCP-1, MMP-9, and IL-6. Further, treatment with CQ decreased the levels of active p65, TNF-α, MCP-1, and MMP-9 in cells underdesiccation stress. Increased levels of LC3B and LAMP1 markers in HCE-T cells exposed to desiccation stress suggest activation of autophagy and the addition of CQ did not alter these levels. Changes in the phosphorylation levels of MAPKinase and mTOR pathway proteins were found in HCE-T cells under desiccation stress with or without CQ treatment. Taken together, the data suggests that HCE-T cells under desiccation stress showed NFκB mediated inflammation, which was rescued through the anti-inflammatory effect of CQ without altering the autophagy flux. Therefore, CQ may be used as an alternate therapeutic management for dry eye condition.

Highlights

Dry eye disease (DED) is characterized by an abnormal instability of the tear film leading to ocular discomfort, visual disturbance, inflammation, dryness, and irritation of the eye [1]
The data suggests that human corneal epithelial cells (HCE)-T cells under desiccation stress showed NFκB mediated inflammation, which was rescued through the anti-inflammatory effect of CQ without altering the autophagy flux
human corneal epithelial cell line (HCE-T) cells treated with different concentrations of CQ (0.00006 to 0.003%) for 48 hrs were analysed for cell viability using trypan blue dye

Summary

Introduction

Dry eye disease (DED) is characterized by an abnormal instability of the tear film leading to ocular discomfort, visual disturbance, inflammation, dryness, and irritation of the eye [1]. Inflammation is a primary response of one’s body towards stress and foreign substances; it is a major risk factor for several chronic diseases including dry eye. Dry eye patients were found with higher levels of proinflammatory cytokines such as IL1α [3] along with IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF-α) in the tear film compared to normal controls [4]. Studies have shown that CQ inhibits the release of pro-inflammatory cytokines in the human blood during chronic and bacteria-induced inflammation [7]. It was been found to inhibit LPS-induced activation of TNF-α & ERK1/2 gene expression in PBMC’s [8]. In addition to its anti-inflammatory activity CQ is a known modulator of autophagy. Autophagy is a cellular mechanism through which damaged intracellular molecules and organelles are cleared

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