Thrombin Stimulates Cytokine Production By Human Retinal Pigment Epithelial Cells

Abstract

Purpose: : Proliferative vitreoretinopathy (PVR) is an inflammatory scarring process and is the mayor cause of recurrent retinal detachment (RD) and an unfavorable functional outcome after retinal detachment surgery. A better understanding of the pathophysiological processes involved in PVR would help to identify novel prevention options. Activation of the coagulation system might contribute to PVR and therefore we examined the effect of thrombin on cytokine production by retinal pigment epithelial (RPE) cells.

Methods: : Cultured human RPE cells (ARPE-19) were stimulated with different concentrations (0.5-10 units/ml) of thrombin for 24 hours and supernatants were analyzed for IL-6 and IL-8 by ELISA. In order to gain a broader cytokine profile, in a second experiment, ARPE-19 cells were stimulated with thrombin (5 units/ml), supernatants from four individual experiments were pooled and analyzed on a quantitative human cytokine antibody array, which enables simultaneous detection of 120 cytokines. Cytokines of interest were confirmed by RQ-PCR or ELISA.

Results: : The coagulant thrombin induced IL-6 and IL-8 production by ARPE-19 in a dose-dependant manner. Besides IL-6 and IL-8, thrombin enhanced the production of other cytokines such as IL-11, IL-17, MCP-1, MCP-3, and M-CSF. ELISA analysis of culture supernatants as well as mRNA studies confirmed the data obtained by the quantitative human cytokine antibody array analysis.

Conclusions: : The coagulation cascade protein thrombin stimulates cytokine production by RPE cells and therefore can contribute to PVR-associated inflammation. Thrombin antagonists may be of use in the prevention of PVR.

Keywords: proliferative vitreoretinopathy