Human Odontoblasts Express Transient Receptor Protein and Acid-Sensing Ion Channel Mechanosensor Proteins

Diverse proteins of the denegerin/epithelial sodium channel (DEG/ENa+C) superfamily, in particular those belonging to the acid-sensing ion channel (ASIC) family, as well as some members of the transient receptor protein (TRP) channel, function as mechanosensors or may be required for mechanosensation in a diverse range of species and cell types. Therefore, we investigated the putative mechanosensitive function of human odontoblasts using immunohistochemistry to detect ENa+C subunits (alpha, beta, and gamma) and ASIC (1, 2, 3, and 4) proteins, as well as TRPV4, in these cells. Positive and specific immunoreactivity in the odontoblast soma and/or processes was detected for all proteins studied except alpha-ENa+C. The intensity of immunostaining was high for beta-ENa+C and ASIC2, whereas it was low for ASIC1, ASIC3, gamma-ENa+C, and TRPV4, being absent for alpha-ENa+C and ASIC4. These results suggest that human odontoblasts in situ express proteins related to mechanosensitive channels that probably participate in the mechanisms involved in teeth sensory transmission. Microsc. Res. Tech. 74:457-463, 2011. (C) 2010 Wiley-Liss, Inc.