Dynamic Proteomics Of Exosomes From Rat Bone Marrow And Human Umbilical Cord Mesenchymal Stem Cells

Exosomes are cup-shaped extracellular vesicles(EVs)with lipid bilayers,ranging from 30 nm to 150 nm in diameter.They contain a large number of biologically active substances,including nucleic acids(DNA,m RNA,micro RNA,lnc RNA),proteins,lipids,and metabolites.The MSCs exosomes have information from the parental cells and are of even greater research interest.Exosomes can act as an important mediator of intercellular information exchange and secondly,they are readily available in body fluids and blood circulation and therefore can also be used clinically as a non-invasive liquid biopsy to identify and assess the disease.Despite the critical biological and translational medicine significance of exosomes,there is still a relative lack of truly universal protein biomarkers that can identify such EVs,and the reported abundance and intensity of CD9,CD63,and CD81 in exosomes from different sources still vary considerably,suggesting that the application of these transmembrane proteins as biomarkers in exosomes from different cells is limited of MSCs.Secondly,the corresponding characterization of the differentiation capacity of MSCs is also unclear,and therefore there is an urgent need for complementary proteomic studies of MSCs exosomes as well as of MSCs themselves.In this study,we identified and quantified exosomes from rat bone marrow and human umbilical cord MSCs using highsensitivity quantitative mass spectrometry(dia PASEF)and analyzed the proteomic composition of exosomes at the proteomic level,providing a comprehensive quantitative profile of exosomal proteins from rat bone marrow MSCs and human umbilical cord MSCs,providing reliable data to support the study of exosome proteomics.and identified a number of unique proteins in UCMSCs that may be candidate bioprotein markers for exosomes and differentially expressed proteins in different channels.In BMSCs,we identified proteins such as Thbs1 and Dcn proteins that could be used to characterize the differentiation capacity of BMSCs during their transmission,and some of these proteins may be candidate bioprotein markers for the differentiation capacity of BMSCs.In conclusion,this study reveals possible candidate biomarker proteins for MSC exosomes and possible biomarker proteins to assess the differentiation capacity of MSCs,and the quantitative proteomics of exosomes demonstrated in this study provides reliable data to support further studies in the field of exosomes.