Fig. 2
ExoUMSCs mitigates the senescence phenotype of Old MSCs in vitro. a Representative images of exosomes derived from UMSCs (ExoUMSCs) under transmission electron microscope. Right panel is an amplified view of the selected area on the left. b Western blot analysis of exosomal specific markers (Alix, CD63, and CD9) for ExoUMSCs (100 μg of exosomal protein was loaded), and cell lysis as negative control. c Representative fluorescence images of exosome internalization into OMSCs under confocal microscopy. ExoUMSCs was marked with red florescence dye Dil and co-cultured with OMSCs. Red fluorescence represents exosomes uptaken by cells. d Representative images of β-gal staining for OMSCs with or without treatment with ExoUMSCs and quantification of β-gal-positive cells out of total cells in A. e Western blot analysis age-related protein markers in OMSCs before and after treatment with ExoUMSCs. The proteins were quantified in the bar graph. f Time course of cell proliferation for OMSCs with or without treatment of ExoUMSCs was analyzed by CCK-8 assay. g Flow cytometry analysis for cell cycle. Left side of peak in purple color represents cells in G1 phase, Middle part in green color represents cells in S phase, right peak in pink is the cells in G2 phase. h Edu staining images of OMSCs with or without treatment of ExoUMSCs. Pink represents Edu-positive cells. The nuclea of all cells were stained with Hochest showing blue. Scale bar, 100 μm. Edu+ cells out of total cells were quantified in bar graph. Each experiment was repeated three times. *P < 0.05 vs OMSCs