Exploring Optic Nerve Axon Regeneration

Abstract

Background: Traumatic optic nerve injury is a leading cause of irreversible blindness across the world and causes progressive visual impairment attributed to the dysfunction and death of retinal ganglion cells (RGCs). To date, neither pharmacological nor surgical interventions are sufficient to halt or reverse the progress of visual loss. Axon regeneration is critical for functional recovery of vision following optic nerve injury. After optic nerve injury, RGC axons usually fail to regrow and die, leading to the death of the RGCs and subsequently inducing the functional loss of vision. However, the detailed molecular mechanisms underlying axon regeneration after optic nerve injury remain poorly understood.

Methods: Research content related to the detailed molecular mechanisms underlying axon regeneration after optic nerve injury have been reviewed.

Results: The present review provides an overview of regarding potential strategies for axonal regeneration of RGCs and optic nerve repair, focusing on the role of cytokines and their downstream signaling pathways involved in intrinsic growth program and the inhibitory environment together with axon guidance cues for correct axon guidance. A more complete understanding of the factors limiting axonal regeneration will provide a rational basis, which contributes to develop improved treatments for optic nerve regeneration. These findings are encouraging and open the possibility that clinically meaningful regeneration may become achievable in the future.

Conclusion: Combination of treatments towards overcoming growth-inhibitory molecules and enhancing intrinsic growth capacity combined with correct guidance using axon guidance cues is crucial for developing promising therapies to promote axon regeneration and functional recovery after ON injury.

Keywords: Optic nerve; axon regeneration; extracellular environment; factors; guidance cues; intrinsic ability.

Fig. (1)

Intrinsic signaling pathways for axon regeneration towards optic nerve injury. Schematic drawing depicting regulatory factors and their downstream signaling pathways involved in intrinsic growth program in the axon regeneration following optic nerve injury.

Fig. (2)

Extrinsic signaling pathways for axon regeneration towards optic nerve injury. Schematic drawing depicting regulatory factors and their downstream signaling pathways involved in extrinsic growth program in the axon regeneration following optic nerve injury.