Extracellular vesicles are signaling organelles that are released by many cell types and is highly conserved in both prokaryotes and eukaryotes. Based on the mechanism of biogenesis, these membranous vesicles can be classified as exosomes, shedding microvesicles and apoptotic blebs. It is becoming clearer that these extracellular vesicles mediate signal transduction in both autocrine and paracrine fashion by the transfer of proteins and RNA. Whilst the role of extracellular vesicles including exosomes in pathogenesis is well established, very little is known about their function in normal physiological conditions.
Recent evidences allude that extracellular vesicles can mediate both protective and pathogenic effects depending on the precise state. In this review, the authors discuss the involvement of extracellular vesicle as mediators of signal transduction in neurodegenerative diseases and cancer. In addition, the role of extracellular vesicles in mediating Wnt and PI3K signaling pathways is also discussed. Additional findings on the involvement of extracellular vesicles in homeostasis and disease progression will promote a better biological understanding, advance future therapeutic and diagnostic applications.