Developmental properties of the Hertwig's epithelial root sheath in mice.
Hertwig's epithelial root sheath (HERS) plays an important role in tooth root formation. In this study, we examined root formation of the first molar in mice, focusing on cell proliferation, cell death, cell migration, and the expression patterns of the signaling molecules, including glycoproteins and proteoglycans between PN8 and PN26. The number of HERS cells decreased during root formation, although HERS retained total length until PN15. The migration of HERS cells did not occur during root formation. Moreover, the immunopositive reaction of laminin beta-3 and syndecan-1 in HERS indicates that both cell adhesion and cell proliferation are essential for HERS development. Bmp-2, Bmp-4, and Msx-2 were expressed in HERS cells during root formation. We also developed an in vitro culture system for investigating the periodontium and suggest that this system provides an excellent vehicle for full exploration, and hence improved understanding, of the development and regeneration of the periodontium. Together, our results provide a comprehensive model describing the morphogenesis of early root development in vertebrates.
Department of Oral Biology, Research Center for Orofacial Hard Tissue Regeneration, Oral Science Research Center, College of Dentistry, Brain Korea 21 project for Medical Science, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea.
H
H
Yamamoto
S-W
SW
Cho
E-J
EJ
Kim
J-Y
JY
Kim
N
N
Fujiwara
H-S
HS
Jung
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000032:analysis; D002448:Cell Adhesion; D016923:Cell Death; D002455:Cell Division; D002465:Cell Movement; D046508:Culture Techniques; D004268:DNA-Binding Proteins / Q000032:analysis; D004658:Enamel Organ / Q000254:growth & development*; D004848:Epithelium / Q000254:growth & development; D006023:Glycoproteins / Q000032:analysis; D018398:Homeodomain Proteins / Q000032:analysis; D007797:Laminin / Q000032:analysis; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008813:Mice, Inbred ICR; D009024:Morphogenesis / Q000502:physiology; D009805:Odontogenesis / Q000502:physiology*; D011509:Proteoglycans / Q000032:analysis; D053668:Syndecan-1; D053667:Syndecans; D014092:Tooth Root / Q000254:growth & development*; D016212:Transforming Growth Factor beta / Q000032:analysis
C525719:Bmp2 protein, mouse; C525810:Bmp4 protein, mouse; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D006023:Glycoproteins; D018398:Homeodomain Proteins; D007797:Laminin; C084119:MSX2 protein; D008562:Membrane Glycoproteins; D011509:Proteoglycans; C508242:Sdc1 protein, mouse; D053668:Syndecan-1; D053667:Syndecans; D016212:Transforming Growth Factor beta