Tas2R expression and function in the murine tracheal epithelium
Fri-S6-003
Presented by: Alexander Perniss
Objectives: As shown by single cell sequencing and corresponding reporter mice various Tas2R are expressed by murine tracheal brush cells. Activation of tracheal brush cells by specific pathogen-associated formyl peptides results in an acetylcholine (ACh) dependent increase in mucociliary clearance (MC). In this study, we asked if Tas2R expression within the trachea is restricted to brush cells and if stimulation of Tas2R also leads to a release of ACh by brush cells and thereby alters MC.
Methods: Expression of all known murine Tas2R in the whole trachea and mechanically abraded tracheal epithelium was analyzed by RT-PCR (n = 3-6 each). As a readout for MC particle transport speed (PTS) was measured in response to 11 different Tas2R agonists in WT (C57BL/6J) and brush cell-deficient mice (Pou2f3-/-).
Results: Messenger-RNA-transcripts for 34 of 35 murine Tas2R were present in samples of whole tracheas of WT mice. In contrast to that, mRNA for only 18 of 35 Ta2R was detected in abraded tracheal epithelium of WT mice. Three Tas2R-agonists (cycloheximide (100 µM), allylisothiocyanate (300 µM) and 3-oxo-C12-HSL (100 µM)) increased PTS independent of brush cells by 12%, 54% and 24%, respectively, since the effect persisted in Pou2f3-/--mice.
Conclusions: RT-PCR experiments suggest an alternative source of Tas2R expression in the trachea besides brush cells. Tested Tas2R agonists increased PTS independent of brush cells, pointing towards a brush cell-independent expression of Tas2R or to Tas2-independent actions on MC of these agonists.
Methods: Expression of all known murine Tas2R in the whole trachea and mechanically abraded tracheal epithelium was analyzed by RT-PCR (n = 3-6 each). As a readout for MC particle transport speed (PTS) was measured in response to 11 different Tas2R agonists in WT (C57BL/6J) and brush cell-deficient mice (Pou2f3-/-).
Results: Messenger-RNA-transcripts for 34 of 35 murine Tas2R were present in samples of whole tracheas of WT mice. In contrast to that, mRNA for only 18 of 35 Ta2R was detected in abraded tracheal epithelium of WT mice. Three Tas2R-agonists (cycloheximide (100 µM), allylisothiocyanate (300 µM) and 3-oxo-C12-HSL (100 µM)) increased PTS independent of brush cells by 12%, 54% and 24%, respectively, since the effect persisted in Pou2f3-/--mice.
Conclusions: RT-PCR experiments suggest an alternative source of Tas2R expression in the trachea besides brush cells. Tested Tas2R agonists increased PTS independent of brush cells, pointing towards a brush cell-independent expression of Tas2R or to Tas2-independent actions on MC of these agonists.