Systematic assessment of small RNA profiling in human ex-tracellular vesicles
Presenting author: Jing Wang, Department of Biostatistics, Vanderbilt University Medical Center
Extracellular vesicles (EVs) are produced and released by most cells and are now recognized to play a role in intercellular communication through the delivery of molecular cargo. Small RNA sequencing (small RNA-seq) has been widely used to characterize the small RNA content in EVs. However, there is a lack of a systematic assessment of the quality, technical biases, RNA composition, and RNA biotypes enrichment for small RNA profiling of EVs across cell types, biofluids, and conditions. We collected and reanalyzed small RNA-seq datasets for 2,756 samples from 83 studies involving 55 with EVs only and 28 with both EVs and matched donor cells. We found EV extraction methods varied in reproducibility of isolating small RNAs with effects on small RNA composition. Comparing proportional abundances of RNA biotypes between EVs and matched donor cells, we discovered rRNA and tRNA fragments relatively enriched but miRNAs and snoRNA depleted in EVs. Except export of eight miRNAs being context-independent, the selective release of most miRNAs into EVs was study-specific. This work guides quality control and the selection of EV isolation methods and enhances the interpretation of small RNA contents and preferential loading in EVs.