Comprehensive proteomic analysis of buffalo milk extracellular vesicles

Extracellular vesicles are secretory vesicles involved in cell-to-cell communication via their encapsulated cargo of proteins, lipids, and nucleic acids. Bovine milk provides a rich source of extracellular vesicles (mEVs) that have been studied as therapeutics and drug delivery systems. Therefore, insight into the mEV cargo, such as its proteome, may help in understanding the molecular mechanism underlying the potential health benefits attributed to the mEVs. Hence, mEVs were isolated from healthy buffalo milk after screening the milk somatic cell count. The total proteins of mEVs were analyzed using LC-MS, and 331 proteins were found commonly present among three buffalo milk samples. These proteins were primarily derived from extracellular regions and lysosomes. The major biological roles associated with the proteins were immune response, metabolism, and cell cycle regulation. The molecular functions of the proteins were transporter activity, catalytic activity, and GTPase activity. Further, comparative analysis with the previously available bovine mEVs proteome data showed 114 proteins to be newly identified in the buffalo mEVs. The biological pathways associated with these proteins may play a major role in muscle development. These findings shed a light on the potential health benefits of buffalo mEVs as therapeutics as well as drug delivery vehicles.