Figure 6.

Transfer of exosomes improved cardiac function, attenuated cardiac fibrosis, and increased angiogenesis following induction of myocardial infarction (MI) in rats. Exosomes or PBS were injected 30 min prior to MI induction, and then three additional injections were given on days 2, 4, and 6 after MI. A. Cardiac function was evaluated 28 days after treatment by echocardiography and measurements of the ejection fraction (EF) and fraction shortening (FS) were performed. **, P < 0.01 versus PBS group. n = 10 for each group. B. Rats were euthanized and the hearts were excised for histological analysis. Representative images are shown for the Masson stain, which showed a decreased cardiac fibrosis area in exosome-treated animals. C. A collagen content assay was performed for both groups, and showed decreased collagen formation in the exosome group. ****, P < 0.0001 versus PBS group. D. Samples were stained for CD31 (red) and DAPI (blue), and representative images are shown for both groups. Increased staining for CD31 was identified in the exosome-treated group. White arrows indicate neo-angiogenesis. Scale bar: 100 µm.