Priority Research Paper Volume 12, Issue 21 pp 20946—20967

Sirtuin 6 deficiency induces endothelial cell senescence via downregulation of forkhead box M1 expression

Figure 4. SIRT6 expression is downregulated in mouse senescent aorta, and endothelial-specific Sirt6 knockout in mouse deteriorates oxidative stress-induced senescence in the aorta. (A) Images from SA β-gal staining of thoracic aorta from C57/BL6 mice injected with PBS or PQ. (B) Graph showing the relative SA β-gal-positive areas in PBS- and PQ-treated thoracic aortas. SA β-gal-positive areas were quantified using ImageJ. The experiment was repeated twice. Data represent the mean percentage ± SD (n = 4). *P < 0.05 vs. control treatment. (C) Double immunofluorescence staining showing SIRT6 and CD31 expression in control and PQ-treated thoracic aortas. The sections were co-stained with anti-SIRT6 and anti-CD31 antibodies. DAPI was used to stain nuclei. Arrows indicate nuclei of endothelial cells. Scale bars represent 10 μm. (D) Double immunofluorescence staining confirming Sirt6 knockout in Sirt6f/fTie2cre/+ mouse thoracic aortas. The sections were co-stained with anti-SIRT6 and anti-CD31 antibodies. DAPI was used to stain nuclei. Arrows indicate nuclei of endothelial cells. Scale bars represent 10 μm. (E) Dissecting microscope images of thoracic aortas stained for SA β-gal. The thoracic aortas were obtained from Sirt6f/f and Sirt6f/fTie2cre/+ mice injected with PBS or PQ. (F) Relative SA β-gal-positive areas in the mouse thoracic aortas from Sirt6f/f and Sirt6f/fTie2cre/+ mice injected with PBS or PQ. The percentage of SA β-gal-positive areas was quantified using ImageJ. The experiment was repeated twice. Data are shown as the mean ± SD (n = 4). *P < 0.05 vs. control Sirt6f/f. #P < 0.05 vs. Sirt6f/f treated with PQ.