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Abstract

Amelogenins are a group of heterogenous proteins first identified in developing tooth enamel and reported to be present in odontoblasts. The objective of this study was to elucidate the expression and function of amelogenins in the human dentin-pulp complex. Developing human tooth buds were immunostained for amelogenin, and mRNA was detected by in situ hybridization. The effects of recombinant amelogenins on pulp and papilla cell proliferation were measured by Brd U immunoassay, and differentiation was monitored by alkaline phosphatase expression. Amelogenin protein was found in the forming dentin matrix, and amelogenin mRNA was localized in the dentin, presumably in the odontoblast processes. Proliferation of papilla cells was enhanced by recombinant human amelogenin rH72 (LRAP+ exon 4), while pulp cells responded to both rH72 and rH58 (LRAP), with no effect by rH174. These studies suggest that odontoblasts actively synthesize and secrete amelogenin protein during human tooth development, and that low-molecular-weight amelogenins can enhance pulp cell proliferation.

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References

Albrecht U, Eichele G, Helms JA, Lu HC (1997). Visualization of gene expression patterns by in situ hybridization. In: Molecular and cellular methods in developmental toxicology. Daston GP, editor. Boca Raton, FL: CRC Press, pp. 23–48.

Bonass WA, Robinson PA, Kirkham J, Shore RC, Robinson C (1994). Molecular cloning and DNA sequence of rat amelogenin and a comparative analysis of mammalian amelogenin protein sequence divergence. Biochem Biophys Res Commun 198:755–763.

Bronckers AL, D’Souza RN, Butler WT, Lyaruu DM, van Dijk S, Gay S, et al. (1993). Dentin sialoprotein: biosynthesis and developmental appearance in rat tooth germs in comparison with amelogenins, osteocalcin and collagen type-I. Cell Tissue Res 272:237–247.

Brookes SJ, Robinson C, Kirkham J, Bonass WA (1995). Biochemistry and molecular biology of amelogenin proteins of developing dental enamel. Arch Oral Biol 40:1–14.

Couble ML, Farges JC, Bleicher F, Perrat-Mabillon B, Boudeulle M, Magloire H (2000). Odontoblast differentiation of human dental pulp cells in explant cultures. Calcif Tissue Int 66:129–138.

DenBesten PK, Li RS (1992). Characterization of amelogenin mRNA from secretory- and maturation-stage rat incisor enamel. Arch Oral Biol 37:1097–1100.

Gronthos S, Mankani M, Brahim J, Robey PG, Shi S (2000). Postnatal human dental pulp stem cells (DPSCs) in vitro and in vivo. Proc Natl Acad Sci USA 97:13625–13630.

Hochstrasser M (1998). There’s the rub: a novel ubiquitin-like modification linked to cell cycle regulation. Genes Dev 12:901–907.

Inai T, Kukita T, Ohsaki Y, Nagata K, Kukita A, Kurisu K (1991). Immunohistochemical demonstration of amelogenin penetration toward the dental pulp in the early stages of ameloblast development in rat molar tooth germs. Anat Rec 229:259–270.

10.

Janones DS, Massa LF, Arana-Chavez VE (2005). Immunocytochemical examination of the presence of amelogenin during the root development of rat molars. Arch Oral Biol 50:527–532.

11.

Karg HA, Burger EH, Lyaruu DM, Woltgens JH, Bronckers AL (1997). Gene expression and immunolocalisation of amelogenins in developing embryonic and neonatal hamster teeth. Cell Tissue Res 288:545–555.

12.

Li W, Gibson CW, Abrams WR, Andrews DW, DenBesten PK (2001). Reduced hydrolysis of amelogenin may result in X-linked amelogenesis imperfecta. Matrix Biol 19:755–760.

13.

Li W, Gao C, Yan Y, DenBesten P (2003). X-linked amelogenesis imperfecta may result from decreased formation of tyrosine rich amelogenin peptide (TRAP). Arch Oral Biol 48:177–183.

14.

Liu H, Li W, Gao C, Kumagai Y, Blacher RW, DenBesten PK (2004). Dentonin, a fragment of MEPE, enhanced dental pulp stem cell proliferation. J Dent Res 83:496–499.

15.

Malumbres M, Sotillo R, Santamaria D, Galan J, Cerezo A, Ortega S, et al. (2004). Mammalian cells cycle without the D-type cyclin-dependent kinases Cdk4 and Cdk6. Cell 118:493–504.

16.

Nagano T, Oida S, Ando H, Gomi K, Arai T, Fukae M (2003). Relative levels of mRNA encoding enamel proteins in enamel organ epithelia and odontoblasts. J Dent Res 82:982–986.

17.

Nakamura M, Bringas P Jr, Nanci A, Zeichner-David M, Ashdown B, Slavkin HC (1994). Translocation of enamel proteins from inner enamel epithelia to odontoblasts during mouse tooth development. Anat Rec 238:383–396.

18.

Nakayama KI, Hatakeyama S, Nakayama K (2001). Regulation of the cell cycle at the G1-S transition by proteolysis of cyclin E and p27Kip1. Biochem Biophys Res Commun 282:853–860.

19.

Nebgen DR, Inoue H, Sabsay B, Wei K, Ho CS, Veis A (1999). Identification of the chondrogenic-inducing activity from bovine dentin (bCIA) as a low-molecular-mass amelogenin polypeptide. J Dent Res 78:1484–1494.

20.

Papagerakis P, MacDougall M, Hotton D, Bailleul-Forestier I, Oboeuf M, Berdal A (2003). Expression of amelogenin in odontoblasts. Bone 32:228–240.

21.

Salido EC, Yen PH, Koprivnikar K, Yu LC, Shapiro LJ (1992). The human enamel protein gene amelogenin is expressed from both the X and the Y chromosomes. Am J Hum Genet 50:303–316.

22.

Sawada T, Nanci A (1995). Spatial distribution of enamel proteins and fibronectin at early stages of rat incisor tooth formation. Arch Oral Biol 40:1029–1038.

23.

Simmer JP, Hu CC, Lau EC, Sarte P, Slavkin HC, Fincham AG (1994). Alternative splicing of the mouse amelogenin primary RNA transcript. Calcif Tissue Int 55:302–310.

24.

Tompkins K, George A, Veis A (2006). Two related low molecular mass polypeptide isoforms of amelogenin have distinct activities in mouse tooth germ differentiation in vitro. J Bone Miner Res 20:341–349.

25.

Torres-Quintana MA, Gaete M, Hernandez M, Farias M, Lobos N (2005). Ameloblastin and amelogenin expression in postnatal developing mouse molars. J Oral Sci 47:27–34.

26.

Uchida T, Tanabe T, Fukae M (1989). Immunocytochemical localization of amelogenins in the deciduous tooth germs of the human fetus. Arch Histol Cytol 52:543–552.

27.

Veis A, Tompkins K, Alvares K, Wei K, Wang L, Wang XS, et al. (2000). Specific amelogenin gene splice products have signaling effects on cells in culture and in implants in vivo. J Biol Chem 275:41263–41272.

28.

Viswanathan HL, Berry JE, Foster BL, Gibson CW, Li Y, Kulkarni AB, et al. (2003). Amelogenin: a potential regulator of cementum-associated genes. J Periodontol 74:1423–1431.

29.

Yokose S, Kadokura H, Tajima Y, Fujieda K, Katayama I, Matsuoka T, et al. (2000). Establishment and characterization of a culture system for enzymatically released rat dental pulp cells. Calcif Tissue Int 66:139–144.

30.

Yuan ZA, Collier PM, Rosenbloom J, Gibson CW (1996). Analysis of amelogenin mRNA during bovine tooth development. Arch Oral Biol 41:205–213.

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Amelogenins in Human Developing and Mature Dental Pulp

Abstract

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