Multi-omics identify hallmark protein and lipid features of small extracellular vesicles circulating in human plasma

Abstract Extracellular vesicles (EVs) are an essential signalling entity in human plasma implicated in health and disease. Still, their core protein and lipid componentry, which lie at the centre of EV form and function, remain poorly defined. Here we performed high-resolution density gradient fractionation of over 140 human plasma samples to isolate circulating EVs, and systematically constructed their quantitative proteome (4,500 proteins) and lipidome (829 lipids) landscapes using mass spectrometry. We identified a highly conserved panel of 182 proteins (including ADAM10, STEAP23 and STX7) and 52 lipids (including PS, PIPs, Hex2Cer and PAs), providing a deep survey of hallmark molecular features and biological pathways characteristic to circulating EVs. We also mapped the surfaceome diversity, identifying 151 proteins on the EV surface. We further established a set of 42 proteins and 114 lipids features that served as hallmark features of non-EV particles in plasma. We submit ADAM10 and PS(36:1) as conserved EV biological markers that precisely differentiate between EV and non-EV particles. Our findings, which can be explored via an open-source Shiny web tool ( evmap.shinyapps.io/evmap/ ), will serve as a valuable repository to the research community for a clearer understanding of circulating EV biology.