Figure 4.

Senescent exosomes have reduced angiogenesis-promoting effect both in vivo and in vitro. (A) Representative images of immunofluorescence staining for CD31 in paraffin-embedded sections of Matrigel plugs (red staining). Arrows indicate positive staining for CD31. For Matrigel plug assay, Matrigel and HUVECs were mixed with c-exo, s-exo (100 μg exosomes; 2 × 10⁷ HUVECs per 200 mL Matrigel), or PBS and subcutaneously injected into C57BL/6mice. Matrigel plugs were obtained 10 days later. Scale bar: 200 μm (top panel) and 50 μm (low panel). (B) Tube formation in HUVECs cultured with PBS, c-exo, and s-exo was observed after 8 h of co-culture. (C) Quantification of tube length. (D) Quantification of angiogenesis-associated genes in HUVECs cultured with PBS, c-exo, and s-exo.