Exosomal microRNAs have great potential in the neurorestorative therapy for traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of brain impairment, resulting in acute neural impairment and chronic long-term disability worldwide. Until now, no therapeutics developed can improve the neurological recovery and clinical prognosis of TBI. Latest studies have indicated that the cell-based therapy can improve neurological recovery by promoting intrinsic neurogenesis and neurite growth after TBI in animal experiments and clinical researches. However, subsequent studies have further demonstrated that the benefits of cell-based therapy are mediated by exosomes released from the administered cells, and microRNAs (miRNAs) cargos in exosomes are largely responsible for the therapeutic effects. Moreover, accumulating studies have found that exosomal miRNAs not only play key roles in the pathophysiological process of TBI, but also act as prominent candidates for the neurorestorative therapy for TBI. These evidences indicate that exosomal miRNAs might have great potential in the neurorestorative therapy for TBI. In this review, we will discuss the latest advances about exosomal miRNAs in the brain and the role of exosomal miRNAs in the neurorestorative therapy for TBI. And, we will investigate the possible mechanisms of exosomal miRNAs therapy for TBI, as well as the opportunities and challenges in the translation of exosomal miRNAs therapy to clinical applications for TBI.