Macrophage-Derived Exosome Transfer of Mir-155 Into Cardiomyocytes and Worsened Pyroptosis in Vitro
(A) Exosomes harvested from the medium of cultured macrophages (RAW264.7) were labeled with PKH67 and added to primary cardiomyocytes for 24 h. (B) Macrophage original exosome was verified by transmission electron microscopy, ranging in size from 80 to 130 nm. (C) Western blot for Alix, CD9, and CD63 exosome markers. (D) PKH67 labeled exosomes introduced into primary cardiomyocytes. (E) qRT-PCR analysis of miR-155 relative folds to U6 expression is shown (n = 3 per group). (F) Levels of Gsdmd p30, Caspase 1, IL-1β, IL-18, and FoxO3a protein. (G) Graphic presentation shows the relative abundance levels of Gsdmd p30, caspase-1, IL-1β, IL-18, and FoxO3a after normalization with GAPDH (n = 3 per group). (H) Pyroptosis, as evidenced by caspase-1 and PI double-positive cells in flow cytometry experiments in cardiomyocytes treated with macrophage-derived exosomes in the presence or absence of miR-155 inhibitor (n = 3 per group). Scale bars: 100 nm (B). #p < 0.05 versus 5% US, *p < 0.05 versus 5% US plus macrophage exosome. PI = propidium iodide; qRT-PCR = quantitative real-time polymerase chain reaction; US = uremia serum; other abbreviations as in Figures 1 and 2.