Fig. 4

Col-EVs treatment alleviated apoptosis in vivo and in vitro. a Immunohistochemical staining of cleaved caspase-3 at day3 after AKI. Scale bar, 50 μm. b Quantification of cleaved caspase-3⁺ staining area in each group. Data were represented as mean ± SEM (n = 5; ^*P < 0.05 vs. sham; ^#P < 0.05 vs. PBS; ^$P < 0.05 vs. Col). c Representative immunofluorescence images of γ-H2AX (red) expression in HK-2 cells. Scale bar, 50 μm. d Quantification of γ-H2AX⁺ cells in each group. Data were represented as mean ± SEM. *P < 0.05 vs. control; ^#P < 0.05 vs. PBS; ^$P < 0.05 vs. Col.