Figure 2: DR is protective against cellular senescence.

(a) Representative images showing γH2A.X (green) and telomere fluorescent in situ hybridization (FISH; red) in hepatocyte nuclei of the indicated animals at 15 months of age. White arrows indicate TAF. Panel ‘MAGN’ shows co-localization of γH2A.X and telomeres at higher magnification. (10 images per liver are taken containing 15–20 hepatocytes each, scale bar 4 μm). (b) Percentage of hepatocytes with ≥3 TAF (n=5, 100–150 hepatocytes per n). (c) Representative images showing peri/centromeric satellite DNA signals (SADS). These signals are tightly compacted in cycling cells but distant in senescent cells. Micrographs showing single hepatocyte nuclei with centromere FISH (green) and DAPI staining (blue) in the indicated groups at 15 months of age. White arrows indicate SADS, which are shown in higher magnification at the right. (10 images per liver are taken containing 10–20 hepatocytes each, scale bar 4 μm). (d) Percentage of hepatocytes with ≥4 SADS (n=4, 100–150 hepatocytes per n). (e) Percentage of karyomegalic hepatocytes in all experimental groups (n=5, 100–140 hepatocytes per n). (f) Cluster analysis of RNA abundance as analysed by RNA-seq analysis identified 709 transcripts that follow the pattern of Oil Red O and TAF. (g) Transcripts identified in f were subjected to GO-term analysis for biological process using PANTHER. Ten pathways were over-represented (false discovery rate ≤5%), including lipid modification and inflammatory/immune system response. All data are mean±s.d. with 4–5 animals per group. Significant differences (one-way analysis of variance) are indicated with *P≤0.05 and **P≤0.001.