Efficacy of extracellular vesicles derived from mesenchymal stromal cells in regulating senescence: In vitro and in vivo insights

Figure 2 Extracellular vesicle derived from mesenchymal stromal cell treatment rejuvenated human dermal fibroblasts. A: The results of the Cell Counting Kit-8 assay demonstrated the proliferation of human dermal fibroblasts (HDFs) after treatment with extracellular vesicles derived from mesenchymal stromal cells (MSC-EVs) for 72 hours; B: Transwell migration assays (left) and subsequent quantitative analysis were performed using ImageJ software (right) for HDFs treated with MSC-EVs; C: Scratch assays provided qualitative (left) and quantitative (right) evidence for an increase in the migration of HDFs after treatment with MSC-EVs. In vitro wound healing assays revealed that the migration of HDFs increased after treatment with MSC-EVs at 6 and 22 hours after administration. Specifically, at the 22-hour mark, the wound healing rate of the MSC-EV-treated cells (85.00%) was significantly greater than that of the phosphate buffered saline-treated control cells (57.33%); D: Representative images of senescence-associated β-galactosidase-stained samples and quantification of HDFs. Quantitative assessments revealed that the percentage of senescence-associated β-galactosidase-positive cells after treatment with MSC-EVs (30%) was considerably lower than that recorded in the untreated control group of the passage 30 cohort (49%); E-H: Real time quantitative polymerase chain reaction analyses of the expression of the senescence and inflammatory markers P21, interleukin-1β, the extracellular matrix remodeling enzyme matrix metallopeptidase 1, and collagen type I. The data represent the mean ± SD of three replicates. ^aP < 0.05, ^bP < 0.01. For the control condition, human dermal fibroblasts were incubated with a comparable volume of phosphate buffered saline instead of extracellular vesicles derived from mesenchymal stromal cells. The images were quantitatively analyzed using ImageJ software. MSC-EVs: Extracellular vesicles derived from mesenchymal stromal cells; SA-β-gal: Senescence-associated β-galactosidase; EVs: Extracellular vesicles; IL-1β: Interleukin-1β; MMP-1: Matrix metallopeptidase 1; COL-1: Collagen type I.