Lentivirus Mediating FGF13 Enhances Axon Regeneration after Spinal Cord Injury by Stabilizing Microtubule and Improving Mitochondrial Function

Fibroblast growth factor 13 (FGF13), a nonsecretory protein of the FGF family, plays a crucial role in developing cortical neurons by stabilizing the microtubule. In previous studies, we showed that regulation of microtubule dynamics was instrumental for both growth cone initiation and for promoting regrowth of injured axon. However, the expression and effect of FGF13 in spinal cord or after spinal cord injury (SCI) remains undefined. Here, we demonstrated a role of FGF13 in regulating microtubule dynamics and in enhancing axon regeneration after SCI. Administration of FGF13 not only promoted neuronal polarization, axon formation, and growth cone initiation in vitro, but it also facilitated functional recovery following SCI. In addition, we found that upregulation of FGF13 in primary cortical neurons was accompanied by enhanced mitochondrial function, which is essential for axon regeneration. Our study has defined a novel mechanism underlying the beneficial effect of FGF13 on axon regeneration, pointing out that FGF13 may serve as a potential candidate for treating SCI or other central nervous system (CNS) injury.