TRPV2 expression in rat oral mucosa

Abstract

The oral mucosa is a highly specialised, stratified epithelium that confers protection from infection and physical, chemical and thermal stimuli. The non-keratinised junctional epithelium surrounds each tooth like a collar and is easily attacked by foreign substances from the oral sulcus. We found that TRPV2, a temperature-gated channel, is highly expressed in junctional epithelial cells, but not in oral sulcular epithelial cells or oral epithelial cells. Dual or triple immunolabelling with immunocompetent cell markers also revealed TRPV2 expression in Langerhans cells and in dendritic cells and macrophages. Electron microscopy disclosed TRPV2 immunoreactivity in the unmyelinated and thinly myelinated axons within the connective tissue underlying the epithelium. TRPV2 labelling was also observed in venule endothelial cells. The electron-dense immunoreaction in junctional epithelial cells, macrophages and neural axons occurred on the plasma membrane, on invaginations of the plasma membrane and in vesicular structures. Because TRPV2 has been shown to respond to temperature, hypotonicity and mechanical stimuli, gingival cells expressing TRPV2 may act as sensor cells, detecting changes in the physical and chemical environment, and may play a role in subsequent defence mechanisms.

Distribution and Expression of Non-Neuronal Transient Receptor Potential (TRPV) Ion Channels in Rosacea

“…Recently, it was revealed that TRPV2 in macrophages is essential for phagocytosis (Link et al, 2010), as well as tumor necrosis factor-a and IL-6 production (Yamashiro et al, 2010). TRPV2 expression was also shown in monocyte-related cell types such as Langerhans cells (Shimohira et al, 2009; Link et al, 2010) and phagocytic retinal pigment epithelial cells where TRPV2 may regulate vascular endothelial growth factor-A secretion (Cordeiro et al, 2010). The precise characterization of TRPV2-expressing immune cells in rosacea has to await further investigation.…”

Mechanotransduction by TRP Channels: General Concepts and Specific Role in the Vasculature

“…Hypotonicity [78,170], stretch (cell membrane stretch) [10,89] 17p11.2 TRPV4/ENSG00000111199 Hypotonicity [55,63,[171][172][173][174][175][176][177], shear (flow chamber) [61,175,178] (isolated perfused carotid artery) [65,66], stretch (silicon chamber) [179] (uniaxial cyclic stretch or static stretch) [180] (cytometric experiments) [181] (overventilation [72] or elevated hydrostatic pressure [60] in isolated murine lungs) Gong et al [54] subsequently identified that mutation of Inactive (IAV), the only other TRPV homologue in Drosophila, results in lack of NAN expression in proximal cilia, and vice versa, suggesting that both IAV and NAN may contribute to a heteromultimeric transduction channel in vivo. While these data clearly implicate a role of NAN in chordotonal mechanotransduction, it is important to note that they do not prove a direct sensory role of the channel, which may equally constitute an essential component of the early downstream signaling pathway.…”

Transient receptor potential (TRP) channels as drug targets for diseases of the digestive system

“…In contrast to TRPV1, TRPV2 occurs primarily in medium and large diameter afferent neurons (Zhang et al, 2004). In the rat oral mucosa, TRPV2 is not only present in subepithelial nerve fibers, but also in junctional epithelial cells surrounding each tooth, Langerhans cells, dendritic cells, macrophages and endothelial cells of venules, but not in oral epithelial cells (Shimohira et al, 2009). In the rat and guinea-pig small intestine, TRPV2 is found in nerve fibers within the muscularis and myenteric plexus as well as in myenteric cell bodies (Kashiba et al, 2004; Zhang et al, 2004).…”