A succinate/SUCNR1-brush cell defense program in the tracheal epithelium

Sci Adv. 2023 Aug 2;9(31):eadg8842. doi: 10.1126/sciadv.adg8842. Epub 2023 Aug 2.

Abstract

Host-derived succinate accumulates in the airways during bacterial infection. Here, we show that luminal succinate activates murine tracheal brush (tuft) cells through a signaling cascade involving the succinate receptor 1 (SUCNR1), phospholipase Cβ2, and the cation channel transient receptor potential channel subfamily M member 5 (TRPM5). Stimulated brush cells then trigger a long-range Ca2+ wave spreading radially over the tracheal epithelium through a sequential signaling process. First, brush cells release acetylcholine, which excites nearby cells via muscarinic acetylcholine receptors. From there, the Ca2+ wave propagates through gap junction signaling, reaching also distant ciliated and secretory cells. These effector cells translate activation into enhanced ciliary activity and Cl- secretion, which are synergistic in boosting mucociliary clearance, the major innate defense mechanism of the airways. Our data establish tracheal brush cells as a central hub in triggering a global epithelial defense program in response to a danger-associated metabolite.

MeSH terms

  • Acetylcholine*
  • Animals
  • Epithelium / metabolism
  • Mice
  • Signal Transduction
  • Succinates / metabolism
  • Trachea* / metabolism

Substances

  • Acetylcholine
  • Succinates