Fig. 8

ESC-Exos activated Nrf2 signaling by downregulating the expression of Keap1 via transferring miR-200a. a Detection of the expression of the indicated miRNAs in ESC-Exos by qRT-PCR analysis. b Aged HUVECs incubated with ESC-Exos for 6 h and the expression level of miR-200a were determined by qPCR analysis. n = 3 per group. ***P < 0.001. c The Keap1 3′-UTR contains one putative miR-200a binding site. The first eight nucleotides of miR-200a are complementary to the binding site in the 3′-UTR. All of these eight nucleotides were mutated to abrogate miR-200a binding. d Dual-luciferase reporter assay of miR-200a with 3′-UTR vectors (WT or MUT) of human Keap1 in HUVECs was performed. We found that miR-200a directly targets the 3′-UTR of Keap1. e Levels of miR-200a in exosomes from treated ESCs were analyzed by qRT-PCR. ***P < 0.001 Exos versus NCI-Exo; ^###P < 0.001 NCI-Exo versus 200aI-Exos. f Western blot analysis of Nrf2, Keap1, P21, and P16 protein levels. Aged HUVECs were treated with NCI-ESC-Exos or 200aI-ESC-Exos, while aged HUVECs without treatment were set as the control. n = 3 per group. g, h SA-β-gal staining. The SA-β-gal activity and percentages of SA-β-gal-positive cells were quantified. n = 3 per group. ***P < 0.001 Aged-NCI-Exos versus Aged group; ^###P < 0.001 Aged-NCI-Exos versus Aged-200aI-Exos. Scale bar, 50 μm. i Schematic diagram depicts rejuvenative effects of exosomes derived from embryonic stem cells. Exosomes secreted by ESCs induce enhanced angiogenesis and promoted pressure ulcer repair in aged mice. ESC-Exos-delivered miR-200a rejuvenates senescent endothelial cells by downregulating Keap1 and recovering Nrf2 activation