Chemical modulation of Akt signaling enhances spinal cord regeneration in zebrafish

Central nervous system lesions often cause permanent motility defects in mammals since the injured neurons cannot regenerate. In contrast, lower vertebrates like zebrafish can regenerate lost neurons and restore motor function. This study investigates the efficacy of SC79, a pan-Akt activator, and A674563, a selective Akt1 inhibitor, as potential therapeutic agents for promoting spinal cord recovery post-injury. Spinal cord injury was induced in zebrafish larvae, and the effects of SC79 and A674563 on neuronal and glial regeneration were examined. SC79 promoted neuronal regeneration without affecting glial bridging, while A674563 induced glial bridging but reduced neuronal regeneration. The combination of SC79 and A674563 induced both glial bridging and neuronal regeneration. Optomotor response tests revealed improved motor function recovery with the combined treatment compared to individual treatments. Additionally, these chemical treatments altered the expression of 12 Akt downstream transcriptional target genes, affirming that the combination treatment preferentially regulates spinal cord regeneration through its action on Akt signaling. These findings highlight the complex interplay of Akt signaling pathways in spinal cord regeneration and suggest potential therapeutic strategies for enhancing functional recovery in spinal cord injury patients.