Fig. 4

Effect of drugs on gene expression in photoreceptor-directed fibroblasts derived from an EYS-RP patient, Pt#1. The fibroblasts of a healthy individual (N#3) and fibroblasts of a patient suffering from retinitis pigmentosa due to a homozygous mutation in the EYS gene (Pt#1) were transdifferentiated to photoreceptor-like cells by retroviral transduction of four transcription factors. Gene expression was compared 2 weeks post-transduction. Differentiation medium was supplemented with four drugs, 4-phenylbutyric acid (4-PBA), metformin (Metf), rapamycin (Rapa), N-acetyl-L-cysteine (NAC) or the vehicle (water and ethanol (EtOH)) or none (-). The gene expression with each pharmacological treatment was compared to the gene expression in photoreceptor-like cells derived from fibroblasts of healthy individual without any supplement (-). Columns represent mean ± SEM. All data points are overlaid (n = 6 (N#3 without any supplement (-)), n = 3 (N#3 with supplement and Pt#1). a = p > 0.05, b = p > 0.01, c = p > 0.001; One-way ANOVA followed by Tukey’s honest test. For the sake of simplicity, comparison with the gene expression level in N#3 without any supplement (-) is shown here. Comparison among other groups is shown in Additional file 2: Fig. S2