Figure 1. PGC-1α Deficiency Augments Vascular Aging and Atherosclerosis Coinciding with Telomere Dysfunction and Shortening and DNA Damage through TERT Downregulation.
(A) The aortas from PGC-1α+/+ApoE−/− and PGC-1α−/−ApoE−/− mice (18-month old males, standard diet, n=5) were excised for SA-βG staining.
(B) The aortic arch from PGC-1α−/−ApoE−/− and control mice (18-month old males, n=5) was dissected for examination of atherosclerotic lesion formation.
(C) The aortas from PGC-1α−/−ApoE−/− and control mice (12-month old, n=4) were analyzed for protein expression by western blot (above) or for telomerase activity by TRAP assay (bottom), respectively.
(D) The aortas from PGC-1α+/+ApoE−/− mice of various ages (12 months vs 20 months old, n=4) were isolated for analysis of protein expression and telomerase activity.
(E and F) Telomere lengths of aortas (E) isolated from PGC-1+/+ or PGC-1−/− ApoE+/+ mice or MASMs (F) from PGC-1+/+ or PGC-1−/− ApoE−/− mice were measured by the Southern blot analysis of terminal restriction fragments.
(G and H) Oxidative DNA damage in mice aortas (G) or MASMs (H) was measured by competitive ELISA.
(I and J) DNA strand breaks in individual aortic cells isolated from PGC-1α−/− ApoE+/+ mice aortas (I) or PGC-1α−/−ApoE−/− MASMs (J) were detected by alkaline single cell gel electrophoresis (comet assays). DNA damage extent was shown as the visual scoring units and tail moment.
(K–P) PGC-1α−/−ApoE−/− MASMs were infected with Ad. PGC-1α constitutive active form (PGC-1α-CA) or TERT or control Lac Z for 1 day. Quantitative analysis of senescence was performed using FDG (K). Telomerase activity (L) and telomere length (M) were determined as described in Methods. DNA strand breaks (N) in individual cells were analyzed by comet assays. Genomic DNA was used for analysis of oxidative DNA damage by measuring 8-OH-dG production (O). Protein expression was determined by western blot (P). *P<0.05, **P<0.01, vs. control or as indicated, ns denotes no statistically significant difference. All data represent mean ± SEM. Also see Figure S1.
