Aim: The pathogenesis of obesity has been associated with high intake of dietary fat, and some recent studies have explored the cellular mechanisms of oro-sensory detection of dietary fatty acids. We further assessed the role of transient receptor potential canonical (TRPC) channels in oro-sensory perception of dietary lipids.
Methods: We determined by RT-qPCR and western blotting the expression of TRPC3/6/7 channels in mouse fungiform taste bud cells (mTBC). Immunocytochemistry was used to explore whether TRPC3 channels were co-expressed with fatty acid receptors. We employed wild-type (WT) mTBC, and those transfected with small interfering RNAs (siRNAs) against TRPC3 or STIM1. Ca2+ signalling was studied in TBC from TRPC3-/- mice and their WT littermates.
Results: We demonstrate that mouse fungiform taste bud cells (mTBC) express TRPC3, but not TRPC6 or TRPC7 channels, and their inactivation by siRNA or experiments on TBC from TRPC3-/- mice brought about a decrease in fatty acid-induced gustatory Ca2+ signalling, coupled with taste bud CD36 lipid sensor. TRPC3 channel activation was found to be under the control of STIM1 in lingual mTBC. Behavioural studies showed that spontaneous preference for a dietary long-chain fatty acid was abolished in TRPC3-/- mice, and in mice wherein lingual TRPC3 expression was silenced by employing siRNA.
Conclusion: We report that lingual TRPC3 channels are critically involved in fat taste perception.
Keywords: Ca2+ signalling; TRPC3 channels; fat taste; fatty acids; lipids.
© 2020 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.