title: The glossopharyngeal nerve controls epithelial expression of Sprr2a and Krt13 around taste buds in the circumvallate papilla.
abstract: Tastants reach the tip of taste bud cells through taste pores which are openings in the epithelium. We found Sprr2a is selectively expressed in the upper layer of the epithelium surrounding taste buds in the circumvallate papilla (CV) where the epithelium is organized into taste pores. Sprr2a is a member of a small proline-rich protein family, which is suggested to be involved in the restitution/migration phase of epithelial wound healing. The expression of Sprr2a was restricted to the upper layer and largely segregated with Ptch1 expression that is restricted to the basal side of the epithelium around the taste buds. Denervation resulted in the gradual loss of Sprr2a-expressing cells over 10 days similarly to that of taste bud cells which is in contrast to the rapid loss of Ptch1 expression. We also found that denervation caused an increase of Keratin (Krt)13 expression around taste buds that corresponded with the disappearance of Sprr2a and Ptch1 expression. Taste buds were surrounded by Krt13-negative cells in the CV in control mice. However, at 6 days post-denervation, taste buds were tightly surrounded by Krt13-positive cells. During taste bud development, taste bud cells emerged together with Krt13-negtive cells, and Sprr2a expression was increased along with the progress of taste bud development. These results demonstrate that regional gene expression surrounding taste buds is associated with taste bud formation and controlled by the innervating taste nerve.
authors.affiliation: Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima-shi, Kagoshima 890-8544, Japan. Electronic address: hmiura@dent.kagoshima-u.ac.jp.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Miura
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba-shi, Ibaraki 305-8642, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kusakabe
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba-shi, Ibaraki 305-8642, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Hashido
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba-shi, Ibaraki 305-8642, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hino
authors.affiliation: Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima-shi, Kagoshima 890-8544, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ooki
authors.affiliation: Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima-shi, Kagoshima 890-8544, Japan.
authors.forename: Shuitsu
authors.initials: S
authors.lastname: Harada
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D055233:Cornified Envelope Proline-Rich Proteins / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D005930:Glossopharyngeal Nerve / Q000502:physiology*; D053535:Keratin-13 / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011956:Receptors, Cell Surface / Q000378:metabolism; D013650:Taste Buds / Q000254:growth & development / Q000378:metabolism*
chemical_list: D055233:Cornified Envelope Proline-Rich Proteins; D053535:Keratin-13; C507427:Krt13 protein, mouse; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; C000606240:Ptch1 protein, mouse; D011956:Receptors, Cell Surface; C491091:Sprr2a1 protein, mouse
keywords: Cell differentiation; Precursor cell; Taste bud; Taste nerve; Taste pore