Fig. 1.

Elovl2 is a metabolic gene that serves as marker of aging. a Correlation between DNA methylation of genes and aging. The significant sites are marked. The aging model were described in our previous work.¹¹ p values are based on a least-squares model built with the same terms and drop-one F tests. b MeDip-qPCR and qPCR of Elovl2 in human fibroblasts (n = 3). Error bars, standard error of the mean (SEM). Levels of significance were calculated with one-tailed Student’s t test. The expression and DNA methylation based on the same plates of cells, which are inked with the same color. c DNA methylation level on the CpG island in intron 1 (CGI-I1) of Elovl2 in the brain and liver of 129/sv mice. For each group 30 Sanger sequencing results from six mice were used. Error bars, SEM. Levels of significance were calculated with two-tailed Student’s t test. d Beta-galactosidase (β-GAL) staining on young (p5) human fibroblasts with or without hydrogen peroxide (H₂O₂) treatment (n = 3). Scale bar, 100 µm. Levels of significance were calculated with one-tailed Student’s t test. e qPCR showing the transcriptional changes of cellular senescence markers in normal and H₂O₂ treated human fibroblasts (n = 3). Error bars, SEM. Levels of significance were calculated with two-tailed Student’s t test. f MeDip-qPCR of Elovl2 in H₂O₂ treated human fibroblasts (n = 3). Error bars. Levels of significance were calculated with one-tailed Student’s t test. g Co-immunoprecipitation on human fibroblasts with or without H₂O₂ treatment. h Western blotting showing that the H₂O₂-induced accumulation of DNMTs to the chromatins was CHD4-dependent. i The recruitment of CHD4 and 5mC on DNA damage sites of cells irradiated with a 450 nm laser. Scale bar, 5 µm. For each group, 30 cells were treated. 26 out of 30 cells in control group show co-localization of CDH4 and 5mC to γ-H2A.X site, while 28 out of 30 cells in iCDH4 group have no accumulation of CDH4 and 5mC to γ-H2A.X site