Epithelial Na+ channels and stomatin are expressed in rat trigeminal mechanosensory neurons

• Published in: Cell and tissue research Vol. 299; no. 3; pp. 327 - 334
• Main Authors: Fricke, B, Lints, R, Stewart, G, Drummond, H, Dodt, G, Driscoll, M, von Düring, M
• Format: Journal Article
• Language: English
• Published: Germany 01.03.2000
• Subjects: Animals; Antibodies; Blood Proteins - analysis; Blood Proteins - genetics; Blood Proteins - immunology; Epithelial Cells - chemistry; Epithelial Sodium Channels; Gene Expression - physiology; Immunohistochemistry; Mechanoreceptors - chemistry; Nerve Fibers, Myelinated - chemistry; Neurons, Afferent - chemistry; Neurons, Afferent - ultrastructure; Rats; Rats, Wistar; RNA, Messenger - analysis; Signal Transduction - physiology; Sodium Channels - analysis; Sodium Channels - genetics; Sodium Channels - immunology; Space life sciences; Trigeminal Nerve - cytology; Vibrissae - innervation
• ISSN: 0302-766X; 1432-0878
• DOI: 10.1007/s004410050031

Caenorhabditis elegans MEC-4 and MEC-10 are subunits of the degenerin/epithelial Na+ channel (DEG/ENaC) ion channel superfamily thought to be associated with MEC-2 (a stomatin-like protein) in a mechanotransducing molecular complex in specialized touch sensory neurons. A key question is whether analogous molecular complexes in higher organisms transduce mechanical signals. To address this question, we selected mechanoreceptors of the rat vibrissal follicle-sinus complex in the mystacial pad and the trigeminal ganglia for an immunocytochemical and molecular biological study. RT-PCR of poly(A+) mRNA of rat trigeminal ganglia indicated that alpha-, beta-, and gamma-ENaC and stomatin mRNA are expressed in rat trigeminal ganglia. Using immunocytochemistry, we found that alpha-, beta-, and gamma-ENaC subunits and stomatin are localized in the perikarya of the trigeminal neurons and in a minor fraction of their termination site in the vibrissal follicle-sinus complex, where longitudinal lanceolate endings are immunopositive. We conclude that alpha-, beta-, and gamma-ENaC subunits as well as the candidate interacting protein stomatin are coexpressed in a mammalian mechanoreceptor, a location consistent with a possible role in mechanotransduction.