IDENTIFICATION OF THE ROLES OF VAX GENES IN MOUSE NERVE REGENERATION

Regeneration capacity differs markedly between the central nervous system (CNS) and the peripheral nervous system (PNS). CNS nerves regenerate poorly after injury, whereas PNS nerves exhibit robust regenerative ability. Most previous studies have focused on axonal survival and outgrowth in injured CNS nerves. However, accumulating evidence indicates that glial cells, which myelinate axons, also play critical roles in axon regeneration. Therefore, understanding the functions of glial cells in both PNS and CNS regeneration may provide new strategies to promote CNS nerve repair. Ventral anterior homeobox (Vax) genes are homeodomain transcription factors that are expressed in optic nerve glial cells during development but are silenced in adulthood. Vax genes are re-expressed in glial cells following injury in both the optic nerve and the sciatic nerve. Notably, Vax gene expression was transient in the sciatic nerve and disappeared as axon regeneration progressed, whereas it was persistently maintained in the injured optic nerve. These findings suggest distinct regulatory mechanisms of Vax gene expression during CNS versus PNS nerve regeneration. Here, we investigate the functional roles of Vax genes and the mechanisms regulating their expression in CNS and PNS nerve regeneration. This study may provide new insights into molecular strategies that could enable regeneration of CNS nerves following injury.