Exosomes and neuroregulation

Exosomes are extracellular vesicles and regulators of tissue homeostasis, immune effectors, disease biomarkers and drug delivery vehicles. Primarily they serve as vesicular carriers for intercellular communication by bringing nucleic acids, proteins, carbohydrates and drugs to injury action sites. As such, by acting as vesicles for tissue repair and delivery for disease combating therapies they can ameliorate tissue injuries and attenuate microbial infections. On balance, they can perpetuate disease by serving as carriers for infectious agents. In contrast, they can control inflammatory responses through the delivery of tumor necrosis factor alpha (TNF-α) and interleukin-6, ultimately affecting survival during a myriad of infectious, inflammatory and degenerative diseases. Exosomes may also speed engulfment of apoptotic cells and clearance of debris, and reduce systemic inflammatory responses. How exosomes are synthesized, secreted and regulate cellular and tissue function is a key part of understanding immunity and the nervous system. To such ends this review devotes itself to an understanding of the biology and function of exosomes in both health and disease with a special focus on their role as new therapeutic delivery vehicles.