Synaptotagmin 4 Supports Spontaneous Axon Sprouting after Spinal Cord Injury

J Neurosci. 2024 Oct 23;44(43):e1593232024. doi: 10.1523/JNEUROSCI.1593-23.2024.

Abstract

Injuries to the central nervous system (CNS) can cause severe neurological deficits. Axonal regrowth is a fundamental process for the reconstruction of compensatory neuronal networks after injury; however, it is extremely limited in the adult mammalian CNS. In this study, we conducted a loss-of-function genetic screen in cortical neurons, combined with a Web resource-based phenotypic screen, and identified synaptotagmin 4 (Syt4) as a novel regulator of axon elongation. Silencing Syt4 in primary cultured cortical neurons inhibits neurite elongation, with changes in gene expression involved in signaling pathways related to neuronal development. In a spinal cord injury model, inhibition of Syt4 expression in cortical neurons prevented axonal sprouting of the corticospinal tract, as well as neurological recovery after injury. These results provide a novel therapeutic approach to CNS injury by modulating Syt4 function.

Keywords: axon regeneration; corticospinal tract; spinal cord.

MeSH terms

  • Animals
  • Axons* / metabolism
  • Axons* / physiology
  • Cells, Cultured
  • Cerebral Cortex / metabolism
  • Female
  • Mice
  • Mice, Inbred C57BL
  • Nerve Regeneration / physiology
  • Qa-SNARE Proteins* / metabolism
  • Spinal Cord Injuries* / genetics
  • Spinal Cord Injuries* / metabolism
  • Spinal Cord Injuries* / pathology
  • Spinal Cord Injuries* / physiopathology
  • Synaptotagmins* / genetics
  • Synaptotagmins* / metabolism

Substances

  • Synaptotagmins
  • Stx4a protein, mouse
  • Qa-SNARE Proteins