Cysteamine suppresses human peripheral blood mononuclear cells – human corneal endothelial cell reaction via reactive oxygen species reduction

PURPOSE: To investigate the effect of cysteamine (CYS) on mixed peripheral blood mononuclear cells (PBMCs) - human corneal endothelial cell (HCEC) reaction (MLER). METHODS: PBMC stimulation assay was performed using cultured HCEC. MLERs were treated with various concentrations of CYS (0–20 mM). The proliferation rate and secretion profiles of transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6) of PBMCs stimulated by cultured HCEC were determined using bromodeoxyuridine proliferation assay and enzyme-linked immunosorbent assay, respectively. RESULTS: CYS suppressed PBMC proliferation in a dose-dependent manner (p<0.001). The intracellular reactive oxygen species (ROS) levels decreased with an increase in CYS concentration (p<0.001). The levels of TGF-β1 and IL-6 decreased in a dose-dependent manner as well (p=0.011 and 0.003, respectively). CONCLUSIONS: This study showed that CYS decreased PBMC proliferation, IL-6 and TGF-β1 levels via ROS formation. Our results suggest that CYS could suppress inflammation associated with PBMCs to corneal endothelial cells.