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

Figure 4 Intravenous administration of extracellular vesicles derived from mesenchymal stromal cells alleviated various age-related phenotypic changes in mice. A: The liver indices of the mice; B: Representative images of hematoxylin and eosin-stained liver tissue in the control, model, and mice were treated with extracellular vesicles derived from mesenchymal stromal cells after induction with D-galactose groups (n = 3). Black arrow: Hydropic degeneration in hepatocytes; green arrow: Congestion in the central vein; yellow arrow: Cytoplasmic vacuoles of different sizes, indicating degeneration of hepatocyte vacuoles; blue arrow: Nuclear fragmentation with scant lymphocytic infiltration and focal necrosis. The scale bar of the hematoxylin and eosin scan = 200 μm; the scale bar of the enlarged image = 50 μm; C: Malondialdehyde levels in the liver; D: Total superoxide dismutase (SOD) levels in the liver; E: Catalase levels in the liver; F-H: Quantitative polymerase chain reaction was performed to determine the expression of the oxidation-related genes Mn-SOD (F), Cu/Zn-SOD (G), and catalase (H) in the three groups; I and J: Quantitative polymerase chain reaction was performed to determine the expression of the aging-related genes interleukin-1β (I) and P21 (J) in the three groups. Control: Untreated mice served as the normal baseline; model: D-galactose-induced aging mice; MSC-EVs: Mice were treated with extracellular vesicles derived from mesenchymal stromal cells after induction with D-galactose. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. EVs: Extracellular vesicles; MSC-EVs: Extracellular vesicles derived from mesenchymal stromal cells; MDA: Malondialdehyde; T-SOD: Total superoxide dismutase; CAT: Catalase; IL-1β: Interleukin-1β.