Extracellular Vesicle Injection Improves Myocardial Function and Increases Angiogenesis in a Swine Model of Chronic Ischemia

Figure 1. Flow diagram demonstrating the methods.

Figure 2. Metabolic parameters of pigs at ameroid and harvest procedures. A, There was no difference in BMI at the initial ameroid placement procedure or the harvest procedure between the control and MVM groups. B, There was no change in glucose tolerance test between groups at the ameroid procedure. There was improved glucose tolerance at 60 minutes in the MVM group compared with the control group 5 weeks later at the harvest procedure. BG indicates blood glucose; BMI, body mass index; CON, control group; MVM, myocardial extracellular vesicle injection group.

Figure 3. Myocardial extracellular vesicle injection increases blood flow to ischemic myocardial tissue: absolute blood flow (mL/[min·g]) was increased in the ischemic ventricle in the MVM group compared with the control group. There was an increase in myocardial perfusion ratio (left circumflex artery/left anterior descending) in the MVM group compared with the control group. CON indicates control group; LAD, left anterior descending artery; LCx, left circumflex artery; MVM, myocardial extracellular vesicle group.

Figure 4. Myocardial extracellular vesicle injection increases arteriolar and capillary density in ischemic myocardial tissue. A, Pigs in the MVM group had increased capillary and arteriolar density in the ischemic myocardial tissue compared with the control groups. B, Representative images of myocardial tissue at ×20 high‐power field. DAPI is blue, CD31 is green, α‐SMA is red. CON indicates control group; MVM, myocardial extracellular vesicle group.

Figure 5. Myocardial extracellular vesicle injection does not affect collagen expression in myocardial tissue. There was no difference in percentage collagen expression between the MVM and CON groups in the ischemic tissue or normal ventricle. There was no difference in ischemic ventricle vs normal ventricle collagen ratio between groups. CON indicates control group; MVM, myocardial extracellular vesicle group.

Figure 6. Myocardial extracellular vesicle injection increases proangiogenic protein expression in ischemic myocardial tissue. A, There was no significant difference in expression of p‐MAPK or MAPK between the MVM and control group. There was an increase in expression of the p‐MAPK/MAPK ratio in the MVM group compared with the control group. There was no significant difference in expression of p‐eNOS or eNOS between the MVM and control group. There was an increase in expression of the p‐eNOS/eNOS ratio in the MVM group compared with the control group. There was an increase in expression of AKT. There was no difference inexpression of p‐AKT or the p‐AKT/AKT ratio in the MVM group compared with the control group. B, Representative images from Western blots. CON indicates control group; MVM, myocardial extracellular vesicle group.

Figure 7. Myocardial extracellular vesicle injection increases myocardial blood flow and cardiac function. In the setting of chronic myocardial ischemia, myocardial injection of human mesenchymal cell–derived extracellular vesicles increases blood flow to the ischemic myocardial tissue by induction of capillary and arteriolar growth via upregulation of the MAPK and AKT/eNOS pathways, resulting in increased cardiac output and stroke volume.