Proteomics Analyses Reveal Functional Differences between Exosomes of Mesenchymal Stem Cells Derived from The Umbilical Cord and Those Derived from The Adipose Tissue.

[OBJECTIVE] We aimed to identify the differentially expressed proteins (DEPs) and functional differences between exosomes derived from mesenchymal stem cells (MSCs) derived from umbilical cord (UC) or adipose tissue (AD).

[MATERIALS AND METHODS] In this experimental study, the UC and AD were isolated from healthy volunteers. Then, exosomes from UC-MSCs and AD-MSCs were isolated and characterized. Next, the protein compositions of the exosomes were examined via liquid chromatography tandem mass spectrometry (LC-MS/MS), followed by evaluation of the DEPs between UC-MSC and AD-MSC-derived exosomes. Finally, functional enrichment analysis was performed.

[RESULTS] One hundred and ninety-eight key DEPs were identified, among which, albumin (ALB), alpha-II-spectrin (SPTAN1), and Ras-related C3 botulinum toxin substrate 2 (RAC2) were the three hub proteins present at the highest levels in the protein-protein interaction network that was generated based on the shared DEPs. The DEPs were mainly enriched in gene ontology (GO) items associated with immunity, complement activation, and protein activation cascade regulation corresponding to 24 pathways, of which complement and coagulation cascades as well as platelet activation pathways were the most significant.

[CONCLUSION] The different functions of AD- and UC-MSC exosomes in clinical applications may be related to the differences in their immunomodulatory activities.