Figure 1. SIRT1 was down-regulated in the STZ-induced DR rat model. STZ-treated rats were further treated with DMSO, 10 mg/kg CMS, 50 mg/kg CMS, and 100 mg/kg CMS. n = 15 per treatment. (A) Representative images of retinal tissues observed by HE-staining (× 400) (scale bar = 25 μm) and quantitative analysis of thickness. * p < 0.05 compared to sham-operated rats and #p < 0.05 compared to STZ-treated rats. (B) Ultrastructure of rat retinal tissues observed under a TEM (× 10000) (scale bar = 1 μm). The arrow represents the capillary BMT, which is used to measure basement membrane width. (C) Expression pattern of SIRT1 measured by RT-qPCR in rat retinal tissues, normalized to β-actin. (D) Representative Western blots of SIRT1 protein and its quantitation in rat retinal tissues, normalized to β-actin. *p < 0.05, **p < 0.01, ***p < 0.001, compared to the sham-operated rats, and #p < 0.05, ##p < 0.01, ###p < 0.001, compared to the rats injected with STZ and treated with DMSO. The results were measurement data and expressed as mean ± standard deviation. Comparisons between multiple groups were analyzed by one-way ANOVA with Tukey’s post hoc test. (n = 15). DR, diabetic retinopathy; STZ, streptozotocin; RT-qPCR, reverse transcription-quantitative polymerase chain reaction; SIRT1, Sirtuin 1; TEM, transmission electron microscopy; ANOVA, analysis of variance; n, number; GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; ONL, outer nuclear layer; OPL, outer plexiform layer DMSO, dimethyl sulfoxide.