Fig. 4.

UCMSC-derived ApoEVs inhibited LPS/ATP-induced macrophage pyroptosis in a high-glucose environment. a Immunofluorescence staining shows UCMSC-derived ApoEVs phagocytosed by F4/80-positive macrophages in vitro. Scale bar, 50 μm in low-magnification images, 20 μm in high-magnification images. b Representative image of SEM analysis of macrophages treated with LPS/ATP and UCMSC-derived ApoEVs. Scale bar, 5 μm in low-magnification images, 1 μm in high-magnification images. c Quantification of supernatant LDH under different stimulation conditions, N = 3 per group, 3 duplication per sample. d The detection of inflammatory factors IL-1β and IL-18 released by macrophages under different stimulation conditions by ELISA, N = 3 per group, 3 duplication per sample. e The protein levels of NLRP3, caspase-1, cleaved caspase-1, gasdermin D, cleaved gasdermin D of macrophages treated with different concentrations of UCMSC-derived ApoEVs examined by Western Blots, N = 3 per group. Corresponding uncropped full-length gels and blots are presented in Additional file 5C. f Semi-quantification of protein expression of NLRP3, cleaved caspase-1, and cleaved gasdermin D. g Immunofluorescence staining shows NLRP3, cleaved caspase-1, and gasdermin D had significant co-localization with F4/80-positive macrophages in vitro. Scale bar, 20 μm. h Semi-quantification of NLRP3, cleaved caspase-1, and gasdermin D positive count and relative fluorescence intensity. N = 3 per group, 3 ROIs per sample. Data shown as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; NS not significant. LDH lactate dehydrogenase; CASP1 caspase-1; GSDMD gasdermin D