Amyotrophic lateral sclerosis (ALS) is the most common disease of motoneurons, or motor neurons, in adults. It affects 6-7 people per 100,000 in Europe and 2-3 people per 100,000 worldwide. ALS is characterised by progressive damage to the motor neurons that are responsible for muscle function. So far, it has not been possible to develop a treatment that can significantly prolong the time and improve the quality of life of people with ALS. As a consequence, most patients die within 2-5 years of the first symptoms of the disease, and 50% survive only 30 months after the onset of clinical symptoms. In this situation, new therapeutic strategies for the treatment of ALS are being sought.This problem was tackled by Dr Sylwia DÄ…browska from the Mossakowski Medical Research Institute of the Polish Academy of Sciences, carrying out the Bekker NAWA project at the University of Verona in collaboration with prof. Raffaella Mariotti's group. The researchers investigated the therapeutic effect of exosomes, structures derived from stem cells, in the treatment of ALS. In particular, the immunomodulatory and neuroprotective properties of exosomes derived from adipose tissue mesenchymal stem cells were analysed in in vitro and in vivo models of ALS. The study demonstrated that exosomes decreased inflammatory responses and increased neuronal survival in in vitro models of ALS. Furthermore, the experiments showed that exosomes improved motor performance in mice, protected motoneurons from degeneration and reduced inflammation in the mouse spinal cord in an in vivo model of ALS. The results obtained demonstrated that stem cell-derived exosomes exhibit neuroprotective and immunomodulatory effects in in vitro and in vivo models of ALS; these results may serve to develop innovative therapies for neurodegenerative diseases, such as amyotrophic lateral sclerosis, in the future.