Cells, 2022 · DOI: 10.3390/cells11152320 · Published: July 27, 2022
When an axon is severed, such as from a spinal cord injury, the cell body responds in one of two ways: activating a regenerative response allowing the axon to regrow, or undergoing retrograde death or atrophy. Intra-axonal protein synthesis and degradation play an important role in axon regeneration, allowing the growing axon tip to rapidly respond to its needs despite its long distance from the perikaryon. Lampreys, unlike mammals, can regenerate supraspinal axons after complete spinal cord transection. Researchers micro-aspirated axoplasms from growing, static, and retracting axon tips of spinal cord transected lampreys and performed single-cell RNA-seq to understand the role of local protein synthesis in regenerative vs. degenerative responses.
The selective upregulation of specific MAPK pathways, such as map3k2/map2k4/p38α, may be an effective strategy to improve axon regeneration.
This research provides a comprehensive view of a complex signaling network involving different subsets and isoforms in axon elongation and retraction, advancing the understanding of post-injury axon dynamics.
Genes closely associated with axon retraction (e.g., dcaf17, prkcq, cdk7, rxfp3, oprm1, grm7, and sdc2) may also be involved in signaling regenerative failure and delayed cell death.