Human odontoblasts express functional TRPV2 channels

Background: The transient receptor potential (TRP) ion channels play a critical role in sensory physiology, where they act as transducers of thermal, mechanical and chemical stimuli. We have previously shown the functional expression of several TRP channels by human odontoblast-like cells and proposed their significance in odontoblast sensory perception. Functional expression of the mechano-sensitiveTRPV2 channel by human odontoblasts would further support a role for TRP channels in odontoblast physiology. Objective: The objective of the current study was to determine the functional expression of TRPV2 by human odontoblasts. Methods: Human dental pulp cells were cultured in the presence of 2 mM β-glycerophoshate to induce an odontoblast phenotype. TRPV2 gene expression was determined by qPCR employing custom designed FAM TRPV2 specific primers and probes (Roche, UK) and the Light Cycler 480 Probes Master (Roche). TRPV2 protein expression was determined following SDS-PAGE and Western blotting of cell lysate preparations. Functional expression of TRPV2 was investigated by Ca2+ microfluorimetry. Results: qPCR data indicated robust expression of TRPV2 in odontoblast-like cells. Western blotting revealed a discrete immunoreactive protein band indicating expression of TRPV2 in cell lysates. In functional assays, the chemical agonist of TRPV2, cannabidiol, was shown to elicit [Ca2+]i transients, that were reduced to baseline in the presence of the TRPV2 antagonist Tranilast, suggesting channel functionality in odontoblast-like cells. Conclusion: These results provide the first evidence for the functional expression of TRPV2 in human odontoblast-like cells, providing further support for the role of TRP channels in odontoblast physiology.