Fig. 4.

HIF-1α-EVs effectively preserved cardiac function in a rat MI model. (A) Dil-labeled exosomes were injected into the infarcted heart of rats for 6 ​h. Representative images of post-MI heart sections stained with Dil-labeled Exo (red), α-actin (green), and DAPI (blue). Scale bar ​= ​50 ​μm (B) Representative echocardiogram of rat heart in different groups at 28 days post-MI. (C and D) Significantly enhanced LVEF and LVFS in rats transplanted with MSCs-EVs and HIF-1α-EVs compared with control groups. (E) HE staining at the border zone on Day 28 after MI. (F) Masson Trichrome staining at the border zone on Day 28 after MI. (G) Quantitative data for the fibrotic area. (H) Quantification of IL-6 expression level in the infarct border zone of rat heats. Continuous variables were described by means ​± ​SEM. n=5–6 for each group. ∗P< 0.05, ∗∗P< 0.01, ∗∗∗P< 0.001, ∗∗∗∗P< 0.0001 vs. PBS group; #P< 0.05, ##P< 0.01 vs. NC-EVs group. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)