Plasma-circulating microRNAs have been implicated as novel early biomarkers for myocardial infarction (MI) due to their high specificity for cardiac injury. For swift clinical translation of this potential biomarker, it is important to understand their temporal and spatial characteristics upon MI. Therefore, researchers at the University Medical Center Utrecht studied the temporal release, potential source, and transportation of circulating miRNAs in different models of ischemia reperfusion (I/R) injury. They demonstrated that extracellular vesicles are released from the ischemic myocardium upon I/R injury. Moreover, they provided evidence that cardiac and muscle-specific miRNAs are transported by extracellular vesicles and are rapidly detectable in plasma. Since these vesicles are enriched for the released miRNAs and their detection precedes traditional damage markers, they hold great potential as specific early biomarkers for MI.
Characterization of mouse plasma-derived extracellular microvesicles
a Western blot of flotillin-1 on isolated and sucrose gradient-purified EV in healthy control, sham-operated, and I/R injury mice (t = 150 min), n = 3, b showed that flotillin-1 in EV with a floating density of 1.08–1.12 g/ml was relatively increased. Sample loading was corrected for initial plasma volume and the level of healthy control mice was set to 1. c Electron microscopy image of isolated plasma EV. d Protein quantification of cardiac-derived (Langendorff perfused heart) EV with and without LAD ligation-induced cardiac ischemia (n = 2 vs. n = 2). e Electron microscopy image of isolated Langendorff perfused heart-derived EV.