Glia-derived Inhibitors of Axonal Regrowth : Implication for the Molecular Strategy of Axonal Regeneration

Axonal injury causes fatal damage to the neuron because of the poor regrowth of the injured axon. This phenomenon is one of the most critical reasons why neurological diseases are currently intractable. Recent studies have revealed that a part of the poor axonal regeneration is caused by the presence of the inhibitors to axonal regrowth, derived from glial cells surrounding the axon. Known molecules such as chondroitin sulfate proteoglycan and myelin-associated glycoprotein (MAG), derived from the astrocyte and the oligodendrocyte, respectively, are thought to be involved in the inhibition of the axonal regeneration. Here, we summarize the current findings on regarding the actions of these molecules, and survey strategies for treating the axonal injury from clinical aspects.