Radioautographic Study of the Incorporation of (3H)-Choline Into the Phospholipids of Secretory Ameloblasts and Enamel of Normal and Essential-Fatty-Acid-Deficient Rats

Goldberg, Michel; Lécolle, Sylvie; Bissila-Mapahou, P.; Septier, D.; Carreau, Jean-Paul

doi:10.1177/08959374960100020401

Cited by 8 publications

(1 citation statement)

References 46 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the lack of a leader peptide, the presence of tuftelin and TIP39 in the extracellular matrix can be explained in the following way. Secretory ameloblasts appear to shed part of their Tomes' processes, including membrane phospholipids (32,33). Intentional deposition of protein and lipid into the developing enamel, and in particular at the rod and interod boundaries, may serve to pattern the Blue indicates the sites of hybridization for the TIP39 cRNA probe (A) to its corresponding mRNA in ameloblasts (Am), odontoblasts (Od), and cells of the stratum intermedium (Si).…”

Section: Discussionmentioning

confidence: 99%

A Tuftelin-interacting Protein (TIP39) Localizes to the Apical Secretory Pole of Mouse Ameloblasts

Paine¹,

Paine²,

Luo³

et al. 2000

Journal of Biological Chemistry

View full text Add to dashboard Cite

Enamel biomineralization is a complex process that involves interactions between extracellular matrix proteins. To identify proteins interacting with tuftelin, a potential nucleator of enamel crystallites, the yeast twohybrid system was applied to a mouse tooth expression library and a tuftelin-interacting protein (TIP) was isolated for further characterization. Polyclonal antibodies were prepared against two recombinant variants of this protein. Both antibodies identified a major protein product in tooth organs at 39 kDa, and this protein has been called TIP39. Northern analysis showed TIP39 messenger RNA in multiple organs, a pattern similar to that of tuftelin messenger RNA. In situ hybridization of mandibles of 1-day-old mice detected TIP39 RNA in secretory ameloblasts and odontoblasts. Immunolocalization of TIP39 and tuftelin in cultured ameloblast-like cells showed that these two proteins colocalize. Within the developing tooth organ, TIP39 and tuftelin immunolocalized to the apical pole of secretory ameloblasts (Tomes' processes) and to the newly secreted extracellular enamel matrix. TIP39 amino acid sequence appears to be highly conserved with similarities to proteins in species as diverse as yeast and primates. Available sequence data and the findings reported here suggest a role for TIP39 in the secretory pathway of extracellular proteins.

show abstract

Section: Discussionmentioning

confidence: 99%

A Tuftelin-interacting Protein (TIP39) Localizes to the Apical Secretory Pole of Mouse Ameloblasts

Paine¹,

Paine²,

Luo³

et al. 2000

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

Effects of Essential Fatty Acid Deficiency on Periodontal Tissue Adaptation to Spontaneous Tooth Migration

Vermelin¹,

Baroukh²,

Llorens³

et al. 2005

Calcif Tissue Int

View full text Add to dashboard Cite

Essential fatty acids (EFAs) play a significant role in bone metabolism. Herein we studied the adaptation of alveolar bone to physiologic tooth drift in young rats deprived of essential fatty acids from birth. Reductions in femur size and trabecular bone volume reflected body growth impairment. Along the alveolar wall, osteoclastic resorption and bone formation were depressed, disrupting the adaptive deformation of the tooth socket to ongoing migration. As a result, the periodontal ligament narrowed considerably, and further adaptation was achieved through root resorption. Essential fatty acid deficiency (EFAD), did not affect precursor recruitment or differentiation in the periodontal ligament (PDL), but caused redistribution of nonspecific-esterase (NSE)-positive osteoclast precursors and tartrate-resistant acid phosphatase (TRAP)-positive pre-osteoclasts between the bone compartment (which was depleted) and the root compartment (which was enriched). EFAD had also a marked effect on the PDL vasculature; the number of vessels was reduced, whereas their size was markedly increased. As a whole, our results show that EFAD disturbs alveolar bone adaptation to drift, but that a reaction (detrimental to root integrity) prevents root collision with the bone surface, thereby preserving the PDL as a source of precursor cells for bone and cementum homeostasis. Moreover, our results confirm that although alveolar bone resorption is arachidonic acid-dependent, the factors activating root resorption are different.

show abstract

[3H]Choline Uptake and Turnover into Membrane and Extracellular Matrix Phospholipids, Visualized by Radioautography in Rat Incisor Dentin and Enamel

Goldberg¹,

Lécolle²,

Vermelin³

et al. 1999

Calcif Tissue Int

View full text Add to dashboard Cite

In order to study the uptake and fate of [3H]choline into cellular and extracellular phospholipids in the forming part of mandibular rat incisors, radioautography was carried out after treatment with the iodoplatinate reaction which retains phospholipids. Thirty minutes and 1 hour after the intravenous injection of the radiolabeled precursor, grain density in secretory odontoblasts and ameloblasts was not significantly above background labeling whereas dentin was actually labeled. Therefore, at this early period, odontoblasts cannot be responsible for the secretion of phospholipids incorporated into dentin, and intercellular diffusion of components originating from blood could explain this early dentin labeling. After 2 hours, odontoblasts and ameloblasts were labeled. In cells, grain density reached a maximum at 4 hours, reduced at 24 hours, and strongly decreased at 4 days. In predentin and enamel, grain density peaked at 24 hours and diminished at 4 days. However, in the forming enamel 4 days after the injection, labeling was twice as high as in any other compartment. Altogether, the results highlighted two distinct pathways for phospholipids in dental mineralized dental tissues: a first one shows evidence of early incorporation of [3H]choline into dentin resulting from intercellular diffusion independently from odontoblasts secretion, whereas inside the forming enamel, higher labeling and longer retention of choline-containing membrane components were detected between 4 hours and 4 days. This suggests an accumulation of membranes that are not subjected to rapid turnover in contrast with other dental compartments.

show abstract

Radioautographic Study of the Incorporation of (3H)-Choline Into the Phospholipids of Secretory Ameloblasts and Enamel of Normal and Essential-Fatty-Acid-Deficient Rats

Cited by 8 publications

References 46 publications

A Tuftelin-interacting Protein (TIP39) Localizes to the Apical Secretory Pole of Mouse Ameloblasts

A Tuftelin-interacting Protein (TIP39) Localizes to the Apical Secretory Pole of Mouse Ameloblasts

Effects of Essential Fatty Acid Deficiency on Periodontal Tissue Adaptation to Spontaneous Tooth Migration

[3H]Choline Uptake and Turnover into Membrane and Extracellular Matrix Phospholipids, Visualized by Radioautography in Rat Incisor Dentin and Enamel

Contact Info

Product

Resources

About