Fig. 1. RNA m7G methylation decreases with senescence and aging.

a Differentially expressed RNA-modifying enzymes in IMR90 cells were identified using a proteomics assay. The data was summarized from three repeats. The METTL1/WDR4 m7G modification complex was analyzed by western blotting using RS (replicative senescence) and TIS (therapy-induced senescence) (b) and KRasG12V-induced senescence (OIS) (c), unless otherwise specified, P represents proliferating IMR90 cells, Sen refers to senescent IMR90 cells. P + ETO stands for proliferating cells treated with ETO. d METTL1-WDR4 and senescence markers at different time points during IMR90 cell senescence were detected. e Mettl1/Wdr4 were measured by Western blotting in tissues from aged mice (n = 5, 2 female, 3 male), specifically in the liver and kidney. m7G levels of total RNA, tRNA, and mRNA were assessed by HPLC-MS in samples of proliferative and senescent IMR90 cells (f) and the corresponding mice liver and kidney tissues (g). The representative experiment was shown. Three repeats demonstrate similar results (b, c, d).Three independent experiments were conducted, unless otherwise specified, n = 3, P values were calculated with the two-tailed Student’s t test. Data are presented as mean ± SEM, *p  <  0.05; **p  <  0.01; ***p  <  0.001. Source data are provided as a Source Data file.