Objective      Based on the identification of extracellular vesicles (EVs) isolated by ultracentrifugation

to investigate the communication channel and mechanism of mouse 3T3-fGFP fibroblast cells by uptake of mouse neural progenitor cells (mNPCs) derived exosomes (EXOs).       Methods      EVs and EXOs from mNPC C17.2 culture supernatants were purified by ultracentrifugation and total exosome isolation kit

and visualized with a transmission electron microscope (TEM) and an atomic force microscope (AFM). Biochemical identification of the EVs and EXOs was performed by SDS-PAGE electrophoresis and Western blotting. EVs were labeled with dyes

and incubated with 3T3-fGFP cells to study the cellular uptake. Pharmacological experiments were carried out to determine the main pathway.       Results      C17.2 cells did not show obvious differentiation. Under the TEM

membrane vesicle samples with bilayer membrane structure and cup shape were observed

and the diameter was about 300 nm. The average diameter of EV samples was greater than that of EXO samples. AFM showed that the height of the samples was more concentrated within 10-20 nm

and the lateral diameter was about 300 nm. Both the average height and the average diameter of the EXO samples were bigger than those of the EV samples. SDS-PAGE results showed that the 2 kinds of samples contained a variety of proteins

with similar expression intensity. Under condition of the same sample content

HSP70 expression intensity was close

but CD63

CD9 and CD81 expression was more abundant in the EV samples than in the EXO samples. EVs were internalized by 3T3-fGFP cells

trapped in the vesicles

and transported to perinuclear region

and the number was increased along with time (P0.05). Clathrin-mediated endocytosis was the main pathway for the vesicle uptake.       Conclusion      mNPC-derived EXOs involve in the communication between NPCs and 3T3-fGFP cells via clathrin-mediated endocytosis.