The transfer of microRNAs (miRs) via extracellular vesicles (EVs) is a functionally relevant mechanism of intercellular communication that regulates both organ homoeostasis and disease development. Little is known about the packaging of miRs into EVs. Previous studies have shown that certain miRs are exported by RNA-binding proteins into small EVs, while for other miRs and for large EVs, in general, the export mechanisms remain unclear. Therefore, a proteomic analysis of endothelial cell-derived large EVs was performed, which revealed that heterogeneous nuclear ribonucleoprotein U (hnRNPU) is abundantly present in EVs. The specific role of hnRNPU for vesicular miR-sorting was confirmed independently by gain- and loss-of-function experiments.
In summary the group of Felix Jansen (AG Jansen), Zietzer and Hosen et. al. could show that hnRNPU retains miR-30c-5p and other miRs and thereby prevents their export into large EVs. The data presented provide a novel and functionally relevant mechanism of vesicular miR export.
Publication
Andreas Zietzer, Mohammed Rabiul Hosen, Han Wang, Philip Roger Goody, Marc Sylvester, Eicke Latz, Georg Nickenig, Nikos Werner & Felix Jansen
The RNA-binding protein hnRNPU regulates the sorting of microRNA-30c-5p into large extracellular vesicles; Journal of Extracellular Vesicles 2020 Jul 02, 9:1, 1786967, DOI: 10.1080/20013078.2020.1786967