Topic: The Role of Nanovesicles in Neurodifferentiation, Neurohomeostasis, Neuropathophysiology and Neurotumorigenesis

Exosomes are nanosized extracellular vesicles secreted by virtually all cell types - including stem cells, cells of the nervous system, and tumoral cells - playing a crucial role in cell-to-cell communication by carrying proteins, RNA molecules, DNA fragments, lipids, and other cellular components. 

Exosomes can have either protecting or damaging effects, depending on their contents. For example, exosomes released by healthy nervous system cells can vehiculate various neuroprotective factors, such as growth factors and anti-inflammatory molecules, promoting nerve regeneration and shielding against further damage. On the other hand, exosomes from other cell types, such as activated immune cells or microglial cells, can exacerbate nerve damage by promoting inflammation and oxidative stress. Therefore, exosomes can interact with recipient cells, influencing their function. 

This ability to alter the behavior of recipient cells extends to neurotumors, where exosomes from tumoral cells contain a variety of bioactive molecules that can be transferred to recipient cells within the neoplastic microenvironment or at distant sites in the body, promoting tumor promotion and progression, helping to shape supportive tumoral niches and pre-metastatic niches in distant organs, and thus facilitating the spread of tumor cells to multiple sites. Furthermore, in neurotumors, exosomes play additional roles such as manipulating the immune system's ability to recognize and destroy cancer cells and contributing to drug resistance development. 

Hence, exosomes represent a fascinating area of research. Researchers are exploring the potential use of engineered exosomes as drug-delivery vehicles for targeted therapies, or using exosomes derived from healthy cells to restore tissue homeostasis. 

This Special Issue welcomes research articles, reviews,  and others focused on the study and use of exosomes to improve our understanding of neurodifferentiation, neurohomeostasis, neuropathophysiology, and neurotumorigenesis, with an emphasis on elucidating the mechanisms by which exosomes may offer new opportunities for the development of novel therapeutic strategies.