Inositol hexasulphate, a casein kinase inhibitor, alters the distribution of dentin matrix protein 1 in cultured embryonic mouse tooth germs.
Immunohistochemical studies using a polyclonal antibody, raised against the recombinant form of dentin matrix protein 1 (DMP1), show that DMP1 was detected mainly in odontoblasts in cultured mouse embryonic tooth germs. However, in restricted areas, DMP1 staining was also observed in secretory ameloblasts, in the stratum intermedium and stellate reticulum, but only when the odontoblasts located in front of them were unstained. When the embryonic tooth germs were cultured in the presence of inositol hexasulfate, a casein kinase I and II inhibitor, staining of odontoblasts was weak or nil, whereas, in contrast, ameloblasts and enamel organ were strongly immunolabelled, suggesting an enhanced translocation of DMP1 after secretion to the secretory ameloblasts and/or stratum intermedium and stellate reticulum. Moreover, DMP1--was shown to be a good substrate for gelatinase A (MMP-2), but not to gelatinase B (MMP- 9). We hypothesized that DMP1--or the sub-fractions cleaved by the MMP--could behave as diffusible signaling molecule (s) rather than as a true dentin extracellular matrix component.
Septier
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Laboratoire de Biologie et Physiopathologie Crâniofaciales, Faculté de Chirurgie Dentaire, Université René, Descartes (Paris V), Montrouge, France.
Torres-Quintana
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MA
Menashi
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S
George
A
A
Goldberg
M
M
D000565:Ameloblasts / Q000187:drug effects / Q000648:ultrastructure; D000818:Animals; D000918:Antibody Specificity; D047388:Casein Kinases; D004396:Coloring Agents; D004591:Electrophoresis, Polyacrylamide Gel; D004658:Enamel Organ / Q000187:drug effects / Q000648:ultrastructure; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000648:ultrastructure; D016326:Extracellular Matrix Proteins; D007150:Immunohistochemistry; D007294:Inositol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D020778:Matrix Metalloproteinase 2 / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000494:pharmacology; D051379:Mice; D009804:Odontoblasts / Q000187:drug effects / Q000648:ultrastructure; D009924:Organ Culture Techniques; D010750:Phosphoproteins / Q000187:drug effects* / Q000378:metabolism; D047428:Protein Kinase Inhibitors; D015398:Signal Transduction / Q000502:physiology; D014083:Tooth Germ / Q000187:drug effects* / Q000648:ultrastructure
D004396:Coloring Agents; C513308:Dmp1 protein, mouse; D004791:Enzyme Inhibitors; D016326:Extracellular Matrix Proteins; D007527:Isoenzymes; D010750:Phosphoproteins; D047428:Protein Kinase Inhibitors; C013063:inositol hexasulfate; D007294:Inositol; D047388:Casein Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9