ESC-EVs alleviate the senescence through miR-15b-5p- and miR-290a-5p. (A) RT-qPCR analysis of senescence-related genes in P7 MEFs, ESC-EVs treated P7 MEFs with the addition of inhibitors of miR-15b-5p or miR-290a-5p or both. (B) Western blot analysis of the level of Ccn2, AKT, p-AKT, mTOR, p-mTOR and p21 in P7 MEFs, ESC-EVs treated P7 MEFs with the addition of inhibitors of miR-15b-5p or miR-290a-5p or both. (C) Immunofluorescence analysis of p21and p53 in P7 MEFs, ESC-EVs treated P7 MEFs with the addition of inhibitors of miR-15b-5p or miR-290a-5p or both. Scale bar represents 100 μm. (D) Quantification of the percentage of p21 and p53 positive MEFs respectively. (E) Immunofluorescence analysis of Ki67 and γ-H2AX in P7 MEFs, ESC-EVs treated P7 MEFs with the addition of inhibitors of miR-15b-5p or miR-290a-5p or both. Scale bar represents 100 μm. (F) Quantification of the percentage of Ki67 and γ-H2AX positive MEFs respectively. (G) SA-β-gal staining of P7 MEFs, ESC-EVs treated P7 MEFs with the addition of inhibitors of miR-15b-5p or miR-290a-5p or both. Scale bar represents 100 μm. Data are presented as mean ± SEM. n = 3. Student's t-test: ns, not significance; *p < 0.05 and **p < 0.01.