Comparative Analyses of Human Exosome Proteomes.

Exosomes are responsible for cell-to-cell communication and serves as a valuable drug delivery vehicle. However, exosome heterogeneity, non-standardized isolation methods and proteomics/bioinformatics approaches limit its clinical applications. To better understand exosome heterogeneity, biological function and molecular mechanism of its biogenesis, secretion and uptake, techniques in proteomics or bioinformatics were applied to investigate human embryonic kidney cell (293T cell line)-derived exosome proteome and enable an integrative comparison of exosomal proteins and protein-protein interaction (PPI) networks of eleven exosome proteomes extracted from diverse human samples, including 293T (two datasets), dermal fibroblast, mesenchymal stem cell, thymic epithelial primary cell, breast cancer cell line (MDA-MB-231), patient neuroblastoma cell, plasma, saliva, serum and urine. Mapping of exosome biogenesis/secretion/uptake-related proteins onto exosome proteomes highlights exosomal origin-specific routes of exosome biogenesis/secretion/uptake and exosome-dependent intercellular communication. The finding provides insight into comparative exosome proteomes and its biogenesis, secretion and uptake, and potentially contributes to clinical applications.