Figure 1. Effect of high glucose on PRR and its downstream targets. A: High glucose increased the transcripts level of PRR, VEGF, VEGFR2, and miR-21. ARPE-19 cells were incubated with perindopril (10 µM) for 24 h and then treated with 33 mM glucose (high glucose) for 48 h. Cells incubated in 5.5 mM glucose (NG) were used as control. B: Knockdown of PRR significantly decreased high glucose–induced upregulation of the expression of VEGF, VEGFR2, and miR-21. Perindopril-treated cells were transfected with 20 nM of control siRNA or PRR siRNA in the presence of high glucose. Cells were harvested for total RNA, and each mRNA/miRNA was measured with quantitative real-time PCR (qRT-PCR). The levels of each transcript were normalized to that of HPRT/snU6. The ratio was then normalized to that of the control and was plotted as a percentage of control. Values are presented as mean ± standard error of the mean (SEM); n = 4; *p<0.05, **p<0.001 versus control (set to 100%).