Ascending dorsal column sensory neurons respond to spinal cord injury and downregulate genes related to lipid metabolism

Sci Rep. 2021 Jan 11;11(1):374. doi: 10.1038/s41598-020-79624-0.

Abstract

Regeneration failure after spinal cord injury (SCI) results in part from the lack of a pro-regenerative response in injured neurons, but the response to SCI has not been examined specifically in injured sensory neurons. Using RNA sequencing of dorsal root ganglion, we determined that thoracic SCI elicits a transcriptional response distinct from sciatic nerve injury (SNI). Both SNI and SCI induced upregulation of ATF3 and Jun, yet this response failed to promote growth in sensory neurons after SCI. RNA sequencing of purified sensory neurons one and three days after injury revealed that unlike SNI, the SCI response is not sustained. Both SCI and SNI elicited the expression of ATF3 target genes, with very little overlap between conditions. Pathway analysis of differentially expressed ATF3 target genes revealed that fatty acid biosynthesis and terpenoid backbone synthesis were downregulated after SCI but not SNI. Pharmacologic inhibition of fatty acid synthase, the enzyme generating palmitic acid, decreased axon growth and regeneration in vitro. These results support the notion that decreased expression of lipid metabolism-related genes after SCI, including fatty acid synthase, may restrict axon regenerative capacity after SCI.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cells, Cultured
  • Down-Regulation / genetics
  • Embryo, Mammalian
  • Female
  • Ganglia, Spinal / metabolism
  • Ganglia, Spinal / pathology
  • Lipid Metabolism / genetics*
  • Mice
  • Mice, Inbred C57BL
  • Nerve Regeneration / genetics
  • Sensory Receptor Cells / metabolism
  • Sensory Receptor Cells / pathology
  • Sensory Receptor Cells / physiology*
  • Spinal Cord / metabolism
  • Spinal Cord / pathology
  • Spinal Cord Injuries* / genetics
  • Spinal Cord Injuries* / metabolism
  • Spinal Cord Injuries* / pathology
  • Spinal Nerve Roots / metabolism
  • Spinal Nerve Roots / pathology