Figure 2.

Exosomes as therapeutic and diagnostic tools. Targeting the exosomal secretory pathway in neurodegenerative diseases has been proposed as a disease-modifying strategy, since it can reduce the propagation of proteopathic seeds and other toxic molecules. Exosomes can also serve as biomarkers, since they carry molecules relevant for diagnosis, such as disease-related proteins or unique sets of miRNAs (a proposed “signature” or “bar-code”). Finally, the resilience of exosomes in the extracellular milieu renders them as ideal vehicles for the delivery of drugs or disease-modifying molecules such as viral DNA or siRNAs, with the possibility of being targeted to specific cell types or tissues by genetic engineering of membrane proteins.