Exosomes are nanometer-sized vesicles with the function of intercellular 
communication, and they are released by various cell types. To reveal the 
knowledge about the exosomes from osteoblast, and explore the potential 
functions of osteogenesis, we isolated microvesicles from supernatants of mouse 
Mc3t3 by ultracentrifugation, characterized exosomes by electron microscopy and 
immunoblotting and presented the protein profile by proteomic analysis. The 
result demonstrated that microvesicles were between 30 and 100 nm in diameter, 
round shape with cup-like concavity and expressed exosomal marker tumor 
susceptibility gene (TSG) 101 and flotillin (Flot) 1. We identified a total 
number of 1069 proteins among which 786 proteins overlap with ExoCarta database. 
Gene Oncology analysis indicated that exosomes mostly derived from plasma 
membrane and mainly involved in protein localization and intracellular 
signaling. The Ingenuity Pathway Analysis showed pathways are mostly involved in 
exosome biogenesis, formation, uptake and osteogenesis. Among the pathways, 
eukaryotic initiation factor 2 pathways played an important role in 
osteogenesis. Our study identified osteoblast-derived exosomes, unveiled the 
content of them, presented potential osteogenesis-related proteins and pathways 
and provided a rich proteomics data resource that will be valuable for further 
studies of the functions of individual proteins in bone diseases.