APOE and calcification: As compared with diabetic ApoE−/− mice, PARP-1 deletion significantly attenuated diabetic atherosclerotic calcification (3.14 ± 0.78% vs. 15.83 ± 1.46%, p < 0.01, Fig. 1b), reduced the content of aortic calcium (0.84 ± 0.06 vs. 1.95 ± 0.07 fold-change, p < 0.01, Fig. 1c), and decreased vessel stiffening (3.80 ± 0.15 vs. 4.84 ± 0.17, p < 0.01, Fig. 1d).