Figure 5. The expression of CTSB, CTSD, and CTSL in retinal vascular endothelial cells treated with high glucose. (A–F) The immunofluorescence of CTSB, CTSD, and CTSL proteins in the HG-treated simian retinal vascular endothelial cells (RF/6A) and normal controls. Scale bar = 100 μm (G) The concentrations of CTSB, CTSD, and CTSL proteins in RF/6A cell culture supernatant. (H–J) The relative expression levels of CTSB, CTSD, and CTSL genes in HG-stimulated and normal RF/6A cells. n = 6 / group. Data are expressed as mean ± SEM. * P < 0.05, ** P < 0.01. HG: high glucose.