Differential expression of keratinocyte-derived extracellular vesicle miRNAs discriminate exosomes from apoptotic bodies and microvesicles

Extracellular vesicles (EVs) are mammalian cell-derived nano-scale structures enclosed by a lipid bilayer that were previously considered to be cell debris with little biological value. However, EVs are now recognized to possess biological function, acting as a packaging, transport and delivery mechanism by which functional molecules (i.e. miRNAs) can be transferred to target cells over some distance. To examine the miRNA from keratinocyte-derived EVs, we isolated three distinct populations of EVs from both HaCaT and primary human keratinocytes (PKCs) and characterized their biophysical, biochemical and functional features by using microscopy, immunoblotting, nanoparticle tracking, and next generation sequencing. We identified 1048; 906; and, 704 miRNAs, respectively, in apoptotic bodies (APs), microvesicles (MVs) and exosomes (EXs) released from HaCaT, and 608; 506; and, 622 miRNAs in APs, MVs and EXs released from PKCs. In which, there were 623 and 437 identified miRNAs common to three HaCaT-derived EVs and PKC-derived EVs, respectively. In addition, we found hundreds of exosomal miRNAs that were previously un-reported and that differences in the abundance levels of the identified EV miRNAs could discriminate between the three EV populations. These data contribute to EV-identified miRNA database, especially keratinocyte-derived EV miRNA content. Overall design: miRNAs were profiled in extracellular vesicles (exosomes, microvesicles and apoptotic bodies) derived from primary keratinocytes.