Emerging Roles of Extracellular Vesicles in the Nervous System

Abstract

Information exchange executed by extracellular vesicles, including exosomes, is a newly described form of intercellular communication

Cranial grafting of stem cell-derived microvesicles improves cognition and reduces neuropathology in the irradiated brain

“…There has been a growing realization that activated microglia play an integral role in synaptic remodeling, in part mediated by their capability to prune dendritic arbors and spines (23,24). Persistent inflammation caused by age and disease elicits chronic activation of microglia that can reshape the synaptic landscape and compromise cognition (24).…”

“…Although the mechanisms underlying the beneficial effects of stem cell transplantation are certain to be complex and multifaceted, present findings suggest that secreted MV likely play an important role in mediating trophic support derived from multipotent stem cells. MV contain a wealth of bioactive cargo ranging from long noncoding to micro-RNAs, neurotrophic factors, membrane-bound receptors, and other small molecules capable of playing a variety of neuromodulatory roles (23,24). These factors could directly or indirectly stimulate astroglial-derived plasticity or neuronal support through enhanced remyelination, neurogenesis, immunemodulation, the delivery of antioxidants, the secretion of neurotrophic factors, addition of membrane-bound receptors, the replenishment of neurotransmitter pools, or improved synaptic connectivity by attenuating intercellular signaling and the degradation of neuronal structure after irradiation (24).…”

Blood biomarkers for evaluation of perinatal encephalopathy: state of the art

“…Exosomes may serve as vehicles for targeted delivery of repair-inducing molecules and possibly as novel biomarkers (Werner and Stevens, 2015). They have been implicated in an array of signaling processes involving astrocytes, oligodendrocytes, microglia, neurons, and neural stem cells (Rajendran et al, 2014). Increased levels of exosomes have been found after traumatic brain injury in humans (Patz et al, 2013).…”

“…Increased levels of exosomes have been found after traumatic brain injury in humans (Patz et al, 2013). Injured neurons release the microtubule-associated protein Tau which is then carried by exosomes (Rajendran et al, 2014). Exosomes may represent ideal biomarker containers, as RNA and protein transported within the vesicles are protected from enzymatic degradation, and there is considerable interest in developing assays to evaluate blood-borne brain-derived exosomes, often referred to as the "liquid brain biopsy" (Werner and Stevens, 2015).…”

International Meeting Molecular Neurodegeneration: News and Views in Molecular Neuroscience in Health and Disease. Delmenhorst, Germany, July 20–22, 2015

“…Exosomes have a critical role in physiological processes, including nerve regeneration, axonal transport, synaptic function, and behavior. These vesicles also have a sinister role in the propagation of toxic amyloid proteins in neurodegenerative conditions, including prion diseases and Alzheimer's and Parkinson's diseases, in inducing neuroinflammation by exchange of information between the neurons and glia, as well as in aiding tumor progression in the brain by subversion of normal cells (Rajendran et al 2014). Oligodendrocyte-derived exosomes situated between the myelin sheath and the axon may affect axonal properties and axonal transport.…”