Exosomes derived from GIT1-overexpressing bone marrow mesenchymal stem cells promote traumatic spinal cord injury recovery in a rat model

This study aims to explore the effects of exosomes derived from G protein-coupled receptor kinase 2 interacting protein 1 (GIT1)-overexpressing bone marrow mesenchymal stem cell (GIT1-BMSC-Exos) on the treatment of traumatic spinal cord injury (SCI) in a rat model. All the rats underwent a T10 laminectomy. A weight-drop impact was performed using a 10-g rod from a height of 12.5 mm except the sham group. Rats with SCI were distributed into three groups randomly and then treated with tail vein injection of GIT1-BMSCs-Exos, BMSCs-Exos and PBS, respectively. The effects of GIT1-Exos on glutamate (GLU)-induced apoptosis <i>in vitro</i> were also evaluated by TUNEL staining. The results showed that rats treated with GIT1-BMSCs-Exos had better functional behavioral recovery than those treated with PBS or BMSCs-Exos only. The overexpression of GIT1 in BMSCs-Exos not only restrained glial scar formation and neuroinflammation after SCI, but also attenuated apoptosis and promoted axonal regeneration in the injured lesion area. Neuronal cell death induced by GLU was controlled remarkably <i>in vitro</i> as well. In conclusion, our study suggested that the application of GIT1-BMSCs-Exos may provide a novel avenue for traumatic SCI treatment.