Figure 5. Kinetics of AR and TauT mRNA expression in response to hyperosmolar stress. ARPE-19 cells were incubated for 0, 1, 2, 4, 8, 12, or 24 h with iso-osmolar medium (control) or media containing the additional presence of 100 mM NaCl (Na100) or 200 mM sucrose (Su200). Genes mRNA levels were measured with real-time quantitative PCR (RT-qPCR) as described in the Methods section. Data are expressed as (A) relative aldose reductase (AR) or (B) sodium-dependent taurine transporter (TauT) mRNA levels (in fold stimulation) over the 0 h time point set to 1. The data are the mean ± standard error of the mean (SEM; n=3) and are expressed as TauT and AR mRNA levels following normalization with the appropriate reference genes (HPRT1, B2M, ATP5B). Data were analyzed using repeated-measures ANOVA and Dunnett’s post-hoc tests. *p<0.05 indicates statistical significance compared to time 0 h.