The Role of Exosomal microRNAs and Oxidative Stress in Neurodegenerative Diseases

Figure 2

Schematic representation of the formation and composition of extracellular vesicles. Ectosomes are generated by direct outward budding of the plasma membrane, while exosomes are derived from endosomes. The plasma membrane of the parent cell forms the endocytic vesicles (endosomes), which inward bud and recruit protein and RNA cargo to form multivesicular bodies (MVBs). Eventually, MVBs fuse with the plasma membrane to release cargo-enriched exosomes into the extracellular space or get degraded by lysosomes. The membrane-type structure of the exosome is made of a lipid bilayer. Exosomes encompass cytosol of the parent cell from which they are derived and express the extracellular domain of distinct transmembrane proteins, such as integrin, tetraspanins, major histocompatibility complex (MHC), and cluster of differentiation (CD), which reflect the type of parent cell.