Implication of TRPC3 channel in gustatory perception of dietary lipids

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. Ca(2+) 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 Ca(2+) 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.

• Murtaza, B.
• Hichami, A.
• Khan, A. S.
• Plesnik, J.
• Sery, O.
• Dietrich, A.
• Birnbaumer, L.
• Khan, N. A.