title: Promotional effects of vasoactive intestinal peptide on the development of rodent Hertwig's epithelial root sheath.
abstract: Hertwig's epithelial root sheath (HERS), a bilayered epithelial cell sheath located at the cervical loop of the enamel organ in a developing tooth, is at the forefront of root formation. However, little is known about the exact mechanisms that regulate the development of HERS. The neuropeptide vasoactive intestinal peptide (VIP) is involved in the development of various tissues and cells. In this study, we investigated the roles of VIP in HERS development. VIP-immunoreactive nerve fibers were found in the dental pulp and around the root apex of the tooth, while the expression of VIP receptor 1 (VPAC1) was observed in HERS. The expression level of VPAC1 correlated with the development of HERS and was elevated at postnatal days 14 and 21. Using ex vivo cultures of neonatal tooth germs, VIP enhanced the elongation and proliferation of HERS. In vitro, VIP also promoted the proliferation of cells from the HERS-derived cell line, HERS01a cells, and upregulated the mRNA expression of cytokeratin 14 and vimentin (typical molecular markers of HERS) in these cells. These results suggest that VIP may be an essential factor for HERS development.
authors.affiliation: Pulp Biology and Endodontics             Molecular Craniofacial Embryology             GCOE Program, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo             Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Iwate, Japan.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawashima
authors.forename: Naoki
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Harada
authors.forename: Masato S
authors.initials: MS
authors.lastname: Ota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Suda
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D004658:Enamel Organ / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D053547:Keratin-14 / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D016513:Mice, SCID; D012333:RNA, Messenger / Q000378:metabolism; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I / Q000378:metabolism; D014092:Tooth Root / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology / Q000502:physiology*; D014746:Vimentin / Q000235:genetics / Q000378:metabolism
chemical_list: D053547:Keratin-14; D012333:RNA, Messenger; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D014746:Vimentin; D014660:Vasoactive Intestinal Peptide