Immunolocalization and distribution of functional temperature-sensitive TRP channels in salivary glands.
Transient receptor potential (TRP) cation channels are unique cellular sensors involved in multiple cellular functions. Their role in salivary secretion remains to be elucidated. The expression and localization of temperature-sensitive TRP channels in salivary (submandibular, sublingual and parotid) glands were analyzed by immunohistochemistry and quantitative real-time reverse transcription plus the polymerase chain reaction (RT-PCR). The effects of various TRP channel agonists on carbachol (CCh)-induced salivary secretion in the submandibular gland and on the intracellular Ca(2+) concentration ([Ca(2+)]i) in a submandibular epithelial cell line were also investigated. Immunohistochemistry revealed the expression of TRP-melastatin subfamily member 8 (TRPM8) and TRP-ankyrin subfamily member 1 (TRPA1) in myoepithelial, acinar and ductal cells in the sublingual, submandibular and parotid glands. In addition, TRP-vanilloid subfamily member 1 (TRPV1), TRPV3 and TRPV4 were also expressed in myoepithelial, acinar and ductal cells in all three types of gland. Quantitative real-time RT-PCR results demonstrated the mRNA expression of TRPV1, TRPV3, TRPV4, TRPM8 and TRPA1 in acinar and ductal cells in these salivary glands. Perfusion of the entire submandibular gland with the TRPV1 agonist capsaicin (1 μM) via the submandibular artery significantly increased CCh-induced salivation, whereas perfusion with TRPM8 and TRPA1 agonists (0.5 μM WS12 and 100 μM allyl isothiocyanate) decreased it. Application of agonists for each of the thermosensitive TRP channels increased [Ca(2+)]i in a submandibular epithelial cell line. These results indicate that temperature-sensitive TRP channels are localized and distributed in acinar, ductal and myoepithelial cells in salivary glands and that they play a functional role in the regulation and/or modulation of salivary secretion.
Oral Health Science Center hrc8, Tokyo Dental College, Chiba, 261-8502, Japan.
Ubaidus
U
Sobhan
Masaki
M
Sato
Takashi
T
Shinomiya
Migiwa
M
Okubo
Maki
M
Tsumura
Takashi
T
Muramatsu
Mitsuru
M
Kawaguchi
Masakazu
M
Tazaki
Yoshiyuki
Y
Shibukawa
D000818:Animals; D002118:Calcium / Q000378:metabolism; D015870:Gene Expression; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D020318:Rats, Long-Evans; D017208:Rats, Wistar; D012469:Salivary Glands / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D050053:TRPM Cation Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D050916:TRPV Cation Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D050051:Transient Receptor Potential Channels / Q000032:analysis* / Q000235:genetics / Q000378:metabolism
D012333:RNA, Messenger; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; D050053:TRPM Cation Channels; D050916:TRPV Cation Channels; C505767:TRPV3 protein, rat; D050051:Transient Receptor Potential Channels; C480976:Trpa1 protein, rat; C498947:Trpm8 protein, rat; C493922:Trpv1 protein, rat; C486577:Trpv4 protein, rat; D002118:Calcium