Abstract
Abstract: :
Purpose: To determine the mechanisms of thrombin effects on chemokine production of human retinal pigment epithelial (HRPE) cells: monocytes co-cultures. Methods: Enzyme-linked immunosorbent assays (ELISA) were performed to determine interleukin (IL)-8, monocyte chemoattractant protein-1 (MCP-1) by HRPE cells, monocytes, and HRPE cell: monocyte co-cultures stimulated with thrombin. HRPE cell: monocyte co-cultures were also co-incubated with anti-tumor necrosis factor-α (TNF-α), IL-1ß, and/or CD14 antibodies. Results: Thrombin enhanced IL-8 and MCP-1 production by HRPE cells, monocytes, and HRPE cell: monocyte co-cultures, by apparently enhancing cell-cell contact mechanisms. Thrombin-induced chemokines by co-cultures were inhibited by anti-TNF-α antibody and anti-CD14 antibody, but not by anti-IL-1ß antibody. TNF-α was detected in cell lysates of monocytes detached from HRPE cells after co-culture stimulation with thrombin. Co-incubation with both anti-TNF-α antibody and anti-CD14 antibody inhibited thrombin-induced chemokines prominently. Conclusion: Our results indicate that thrombin may cause leukocyte recruitment by inducing HRPE cell and monocyte chemokine and by enhancing HRPE cell: monocyte interactions, in part due to monocyte TNF-α induction and CD14, suggesting important mechanisms for ocular inflammation during blood-retina barrier breakdown and intraocular hemorrhage.
Keywords: 567 retinal pigment epithelium • 340 cell-cell communication • 560 retinal culture