Extracellular vesicles from hypoxia-preconditioned mesenchymal stem cells alleviates myocardial injury by targeting thioredoxin-interacting protein-mediated hypoxia-inducible factor-1α pathway

Figure 3 Evaluation of the temporal relationship of the cardioprotective effects of hypoxia-preconditioned extracellular vesicles. A: Temporal relationship of the cardioprotective effects of hypoxia-preconditioned extracellular vesicles (HP-EVs) in vivo. Myocardial infarction (MI) models were established with left coronary artery ligation for 0.5, 1, 2, 4, and 8 h followed by 12 h of reperfusion. Evans Blue/2,3,5-triphenyltetrazolium chloride staining was used to evaluate the area of viable myocardium in the HP-EV and MI groups (n = 5); B: Temporal relationship of the HP-EV cardioprotective effects in vitro. Hypoxia injury models were established for 0.5, 1, 2, 4, and 8 h of hypoxia followed by 12 h of reoxygenation. Cell Counting Kit-8 assay was used to evaluate the cell survival rate in the HP-EV and hypoxia groups (x axis was time of hypoxia, y axis was the value of absorbance of experimental/control group, which reflected the survival rate of cells in the experimental condition; n = 5). The arrows indicate the most significant difference, and the corresponding time points were adopted for subsequent research. MI: Myocardial infarction; HP-EV: Hypoxia-preconditioned extracellular vesicles.