Fig. 2

AMSC-EV and HUMSC-EV mitigated photoaging of HaCaTs in vitro. a Representative image of MSC-EV uptake by HaCaTs pretreated with or without UVB irradiation (scale bar, 20 μm). b Representative immunofluorescence staining images of positive cells of ROS (green) and DAPI (scale bar, 20 μm). c Fluorescence intensity of ROS levels. n = 3, ****P < 0.0001. d Representative images of SA-β-gal staining in HaCaTs (scale bar, 100 μm). e Quantitation of SA-β-gal positive cells in HaCaTs. f Representative immunofluorescence staining images of positive cells of γ-H2Ax (red) and DAPI (scale bar, 20 μm). g Quantitation of the mean number of γ-H2Ax foci/cell. n = 3, ****P < 0.0001. h Quantitation of HaCaTs proliferation detected by CCK8 assay with the OD value on Day 1, Day 2, Day 3, Day 4, and Day 5. n = 3, ***P < 0.001, ****P < 0.0001. i Representative images of transwell assays of HaCaTs (scale bar, 100 μm). j Quantitation of transwell assays of HaCaTs. n = 3, ****P < 0.0001. k Representative images of migration assay and the image was taken at the indicated times (scale bar, 100 μm). l Quantitation of migration assays of HaCaTs. n = 3, *P < 0.05, **P < 0.01. m Quantitation of IL-1β, IL-6, and TNF-α released by HaCaTs was detected through qRT-PCR. n = 3, ****P < 0.0001. n Quantitation of IL-1β, IL-6, and TNF-α released by HaCaTs was detected through ELISA. n = 3, **P < 0.01, ****P < 0.0001