Extracellular matrix (ECM) biomineralization is regulated by a complex sequence of metabolic events. Humoral serum-derived factors are implicated as requirements for ECM biomineralization, including vitamin D metabolites, trace elements, steroid hormones, polypeptide hormones and a variety of hormone-like proteins. Previous studies determined that 10- 20% fetal calf serum-supplemented medium provided conditions to support late fetal, neonatal and early postnatal (e.g. hamster, mouse) molar tooth dentine and enamel ECM biomineralization in organ culture; serumless medium did not support biomineralization. We now propose studies to test the hypothesis that early embryonic mouse molar tooth organs express an intrinsic developmental program for both dentine and enamel biomineralization in vitro when cultured using serumless, chemically-define (BGJb) medium. Our strategy assumes that reciprocal epithelial-mesenchymal interactions provide """"""""metabolic cooperativity"""""""" sufficient of generate dentine and enamel mineralization without exogenous factors. Comparison of the timing, position and development patterns of biomineralization during organ culture in serumless medium with that expressed during in vivo mandibular first molar organogenesis will provide definition for this model. This in vitro system will then be used to examine effects of fluoride and heavy metal ions on dentinogenesis and amelogenesis, emphasizing putative influences on cell division and dentine-and enamel-specific protein translation and post-translational processing. Methods include anhydrous fixation coupled with transmission electron microscopy and electron probe microanalysis, histochemistry, immunocytochemistry, metabolic labeling and high resolution two-dimensional gel electrophoresis, autoradiography, immunodetection assays, Northern hybridization, in situ hybridization and quantitative morphometric analyses. We propose to continue studies designed to determine the intrinsic developmental program for dentine and enamel biomineralization.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE006425-06
Application #
3219996
Study Section
Oral Biology and Medicine Study Section (OBM)
Project Start
1984-03-01
Project End
1990-02-28
Budget Start
1989-03-01
Budget End
1990-02-28
Support Year
6
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
Schools of Dentistry/Oral Hygn
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90033
Caton, Javier; Bringas Jr, Pablo; Zeichner-David, Margarita (2005) IGFs increase enamel formation by inducing expression of enamel mineralizing specific genes. Arch Oral Biol 50:123-9
Takahashi, K; Yamane, A; Bringas, P et al. (1998) Induction of amelogenin and ameloblastin by insulin and insulin-like growth factors (IGF-I and IGF-II) during embryonic mouse tooth development in vitro. Connect Tissue Res 38:269-78;discussion 295-303
Slavkin, H C; Diekwisch, T G (1997) Molecular strategies of tooth enamel formation are highly conserved during vertebrate evolution. Ciba Found Symp 205:73-80; discussion 81-4
Slavkin, H C; Diekwisch, T (1996) Evolution in tooth developmental biology: of morphology and molecules. Anat Rec 245:131-50
Hu, J C; Zhang, C; Slavkin, H C (1995) The role of platelet-derived growth factor in the development of mouse molars. Int J Dev Biol 39:939-45
Diekwisch, T G; Berman, B J; Gentner, S et al. (1995) Initial enamel crystals are not spatially associated with mineralized dentine. Cell Tissue Res 279:149-67
Nakamura, M; Bringas Jr, P; Nanci, A et al. (1994) Translocation of enamel proteins from inner enamel epithelia to odontoblasts during mouse tooth development. Anat Rec 238:383-96
Diekwisch, T; David, S; Bringas Jr, P et al. (1993) Antisense inhibition of AMEL translation demonstrates supramolecular controls for enamel HAP crystal growth during embryonic mouse molar development. Development 117:471-82
Slavkin, H C (1993) Rieger syndrome revisited: experimental approaches using pharmacologic and antisense strategies to abrogate EGF and TGF-alpha functions resulting in dysmorphogenesis during embryonic mouse craniofacial morphogenesis. Am J Med Genet 47:689-97;discussion 687-8
Shum, L; Sakakura, Y; Bringas Jr, P et al. (1993) EGF abrogation-induced fusilli-form dysmorphogenesis of Meckel's cartilage during embryonic mouse mandibular morphogenesis in vitro. Development 118:903-17

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