Fig 1: U18 induces up-regulation of sigma-2 receptor (S2R) mRNA in ARPE19 cells.Experiments were performed as described in Fig 1 except for the various conditions indicated in this figure. For each data point or bar, triplicate samples were used. Before staining, the cells were cultured and treated as described in Fig 1. (A) Time course of U18 treatment of ARPE19 cells (two repeat experiments). The data indicate that S2R mRNA levels were maximally increased by U18 (5 μM) at 24 h after treatment. (B, C) Effects of cytokines and different concentrations of U18 and JQ1 on S2R mRNA expression. PDGF-AA, 20 ng/ml; PDGF-BB, 20 ng/ml; TGFβ1, 20 ng/ml. PDGF-AA (Cat. no. 1055AA050), and PDGF-BB (Cat. no. 520BB050) were from R&D Systems. Human recombinant TGFβ1 was from Thermo Fisher Scientific (Cat. no. PHG9214). The data indicate that treatments with 5 and 10 μM U18 were equally effective in inducing S2R mRNA up-regulation, and 1 μM JQ1 was as potent as 10 μM in blocking U18-induced S2R up-regulation.