Transcriptional Profiling of Somatostatin Interneurons in the Spinal Dorsal Horn

Sci Rep. 2018 May 1;8(1):6809. doi: 10.1038/s41598-018-25110-7.

Abstract

The spinal dorsal horn (SDH) is comprised of distinct neuronal populations that process different somatosensory modalities. Somatostatin (SST)-expressing interneurons in the SDH have been implicated specifically in mediating mechanical pain. Identifying the transcriptomic profile of SST neurons could elucidate the unique genetic features of this population and enable selective analgesic targeting. To that end, we combined the Isolation of Nuclei Tagged in Specific Cell Types (INTACT) method and Fluorescence Activated Nuclei Sorting (FANS) to capture tagged SST nuclei in the SDH of adult male mice. Using RNA-sequencing (RNA-seq), we uncovered more than 13,000 genes. Differential gene expression analysis revealed more than 900 genes with at least 2-fold enrichment. In addition to many known dorsal horn genes, we identified and validated several novel transcripts from pharmacologically tractable functional classes: Carbonic Anhydrase 12 (Car12), Phosphodiesterase 11 A (Pde11a), and Protease-Activated Receptor 3 (F2rl2). In situ hybridization of these novel genes showed differential expression patterns in the SDH, demonstrating the presence of transcriptionally distinct subpopulations within the SST population. Overall, our findings provide new insights into the gene repertoire of SST dorsal horn neurons and reveal several novel targets for pharmacological modulation of this pain-mediating population and treatment of pathological pain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 3',5'-Cyclic-GMP Phosphodiesterases / genetics
  • 3',5'-Cyclic-GMP Phosphodiesterases / metabolism
  • Animals
  • Carbonic Anhydrases / genetics
  • Carbonic Anhydrases / metabolism
  • Cell Nucleus / metabolism
  • Cell Nucleus / ultrastructure
  • Gene Expression Profiling
  • Genes, Reporter
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Interneurons / metabolism*
  • Interneurons / ultrastructure
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Nerve Tissue Proteins / classification
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Nociceptive Pain / genetics
  • Nociceptive Pain / metabolism
  • Nociceptive Pain / physiopathology
  • Posterior Horn Cells / metabolism
  • Posterior Horn Cells / ultrastructure
  • RNA, Messenger / classification
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Receptors, Thrombin / genetics
  • Receptors, Thrombin / metabolism
  • Somatostatin / genetics*
  • Somatostatin / metabolism
  • Spinal Cord Dorsal Horn / cytology
  • Spinal Cord Dorsal Horn / metabolism*
  • Transcription, Genetic*

Substances

  • Nerve Tissue Proteins
  • RNA, Messenger
  • Receptors, Thrombin
  • protease-activated receptor 3
  • Green Fluorescent Proteins
  • Somatostatin
  • 3',5'-Cyclic-GMP Phosphodiesterases
  • Pde11a protein, mouse
  • Carbonic Anhydrases
  • carbonic anhydrase XII