RNA-Seq Analysis of Human Trigeminal and Dorsal Root Ganglia with a Focus on Chemoreceptors

PLoS One. 2015 Jun 12;10(6):e0128951. doi: 10.1371/journal.pone.0128951. eCollection 2015.

Abstract

The chemosensory capacity of the somatosensory system relies on the appropriate expression of chemoreceptors, which detect chemical stimuli and transduce sensory information into cellular signals. Knowledge of the complete repertoire of the chemoreceptors expressed in human sensory ganglia is lacking. This study employed the next-generation sequencing technique (RNA-Seq) to conduct the first expression analysis of human trigeminal ganglia (TG) and dorsal root ganglia (DRG). We analyzed the data with a focus on G-protein coupled receptors (GPCRs) and ion channels, which are (potentially) involved in chemosensation by somatosensory neurons in the human TG and DRG. For years, transient receptor potential (TRP) channels have been considered the main group of receptors for chemosensation in the trigeminal system. Interestingly, we could show that sensory ganglia also express a panel of different olfactory receptors (ORs) with putative chemosensory function. To characterize OR expression in more detail, we performed microarray, semi-quantitative RT-PCR experiments, and immunohistochemical staining. Additionally, we analyzed the expression data to identify further known or putative classes of chemoreceptors in the human TG and DRG. Our results give an overview of the major classes of chemoreceptors expressed in the human TG and DRG and provide the basis for a broader understanding of the reception of chemical cues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / metabolism*
  • Gene Expression Regulation
  • Humans
  • RNA / biosynthesis*
  • RNA / genetics
  • Receptors, Odorant / biosynthesis*
  • Receptors, Odorant / genetics
  • Sequence Analysis, RNA
  • Trigeminal Ganglion / cytology
  • Trigeminal Ganglion / metabolism*

Substances

  • Receptors, Odorant
  • RNA

Grants and funding

Caroline Flegel was funded by Heinrich und Alma Vogelsang Stiftung. Hanns Hatt was funded by DFG-Sonderforschungsbereich 642 “GTP- and ATP dependent membrane processes.” The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.