Hypoxia-preconditioned mesenchymal stem cell-derived exosomes attenuate myocardial ischemia/reperfusion injury by miR-29b-3p via PINK1/Parkin-mediated mitophagy

Figure 3 Profiling and identification of upregulated microRNAs in exosome and hypoxia-preconditioned mesenchymal stem cell-derived exosome. A: Schematic diagram of next-generation sequencing; B and C: Twenty-two microRNAs (miRNAs) that were differently expressed between exosome (Exo) and hypoxia-preconditioned mesenchymal stem cell-derived Exo as displayed in the volcano plot (C) and hierarchical clustering heat map (B); D: Verification for the miRNA expressions in Exo and hypoxia-preconditioned mesenchymal stem cell-derived Exo by quantitative PCR analysis; E and F: Representative flow cytometry plots show the effects of highly expressed miRNAs identified (Figure 3D) on cell apoptosis (E) and quantitative analysis of apoptosis rate (F); G and H: Flow cytometric analysis of dihydroethidium-stained myocardial cells (G) and quantitative analysis of oxidative stress in myocardial cells (H); I: Dihydroethidium staining of myocardial cells. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, ^dP < 0.0001. Con: Control; DAPI: 4’,6-diamidino-2-phenylindole; DHE: Dihydroethidium; Exo: Normoxic exosomes; HPC-Exo: Hypoxia-preconditioned mesenchymal stem cells-derived exosomes; MFI: Mean fluorescent intensity; miR: MicroRNA; miRNAs: MicroRNAs; NC: Negative control; NGS: Next-generation sequencing; NS: Not significant; PI: Propidium iodide; q-PCR: Quantitative PCR; H/R: Hypoxia/reperfusion.