Disease relevance of Tooth Germ

• METHODS: Frozen tissue sections of seven tooth germs and 22 ameloblastomas were immunohistochemically examined using anti-MMP-1, -2 and -9 and anti-TIMP-1 and -2 antibodies [1].
• Nuclear CBFA1 expression was detected scatteredly in odontogenic epithelial cells in normal and neoplastic odontogenic tissues, as well as in some mesenchymal cells in tooth germs and in some stromal cells in epithelial odontogenic tumors [2].
• Three-dimensional ultrasonography therefore has a potential for enhanced visualization of fetal tooth germs and may aid in the antenatal detection of syndromes associated with oligodontia or anodontia [3].
• With aging, bone trabeculae, which were not remodeled, penetrated into op/op tooth germs and divided them into several daughter germs, which were recognized as odontomas [4].
• Antagonism of fluoride toxicity by high levels of calcium but not of inorganic phosphate during secretory amelogenesis in the hamster tooth germ in vitro [5].

High impact information on Tooth Germ

• We show that activin betaA is expressed in presumptive tooth-germ mesenchyme and is thus a candidate for a signaling molecule in tooth development [6].
• Although development of tooth germs of uninjected op/op mice was impaired, rhM-CSF injection restored the development of molar tooth germs and led to tooth eruption as a consequence of the recovery of bone-resorbing activity [7].
• A new function of BMP4: dual role for BMP4 in regulation of Sonic hedgehog expression in the mouse tooth germ [8].
• To further test this hypothesis, Msx1 mutant tooth germs were first cultured with either BMP4 or with various FGFs for two days in vitro and then grown under the kidney capsule of syngeneic mice to permit completion of organogenesis and terminal differentiation [9].
• By adding a soluble form of Edar to tooth germs, we were able to mimic the tabby enamel knot phenotype, demonstrating the involvement of endogenous Eda in tooth development [10].

Chemical compound and disease context of Tooth Germ

• To overcome this shortcoming, second-passage cells established from calf molar tooth germs by enzymatic pretreatment of the dental papilla were transfected by electroporation with pSV3neo, coding for the oncogene simian virus 40 large t antigen and a neomycin-resistance gene [11].

Biological context of Tooth Germ

• Changes in the structure of the enamel knot signalling centre in downless tooth germs provide functional data directly linking the enamel knot with tooth cusp morphogenesis [10].
• Analysis of cell proliferation revealed that some cell types of the tooth germ did not respond to SGF by proliferation, while a stimulation by EGF was observed [12].
• In this study, we examined amelogenin gene expression in various cell layers prepared from a porcine permanent tooth germ using reverse transcription-polymerase chain-reaction (RT-PCR) [13].
• Sonic hedgehog regulates epithelial proliferation and cell survival in the developing tooth germ [14].
• Hamster tooth germs during early secretory amelogenesis were exposed in vitro for 24 h to 10(-9) M-5 x 10(-5) M actinomycin D [15].

Anatomical context of Tooth Germ

• Using the more powerful kidney capsule grafting procedure, we now show that when added to explanted Msx1-deficient tooth germs prior to grafting, BMP4 rescues Msx1 mutant tooth germs all the way to definitive stages of enamel and dentin formation [9].
• The findings of a BrdU incorporation experiment suggested that the imbalance between the proliferation activity of the inner enamel epithelium and that of the dental papilla caused by HGF translation arrest results in the abnormal structure of the tooth germ [16].
• After addition of ethanol to the ordinary fodder of pregnant mini-pigs, ultrastructural changes were found in secretory ameloblasts from tooth germs of their mid-term fetuses [17].
• No alpha 1 type IV collagen chain mRNA was detected in tooth germ epithelium or dental papilla [18].
• Treatment of the explants with bisphosphonate or vitamin K2, inhibitors of the differentiation of osteoclasts, induced the invasion by bone into the tooth germs as observed in the antisense ODN-treated explants [19].

Associations of Tooth Germ with chemical compounds

• (3) SP and the mRNA encoding SP receptors are also expressed in the developing tooth germ [20].
• Addition of ascorbic acid does not affect in vitro collagen synthesis of tooth germs from protein-energy malnourished rats [21].
• Inositol hexasulphate, a casein kinase inhibitor, alters enamel formation in cultured embryonic mouse tooth germs [22].
• Prostaglandin E2 and F2alpha in tooth germs [23].
• To evaluate the amount of calcification around tooth germs, 3D images of mandibles were reconstructed from the calcein-labeled sections of the wild-type and mutant mice [24].

Gene context of Tooth Germ

• In turn, we show that addition of BMP4 to Msx1 deficient tooth germs bypasses the requirement for Msx1 and rescues epithelial development from the bud stage to the E14.5 cap stage [25].
• Lama5-null mice develop a small tooth germ with defective cusp formation and have reduced proliferation of dental epithelium [26].
• To test the hypothesis that LEF1 signaling regulates the fate of the dental epithelial and the CNC-derived mesenchymal cells during tooth morphogenesis, we investigated and compared the cellular migration, proliferation, and apoptotic activity within the tooth germ between the wild-type and Lef1 null mutant mice [27].
• We examined the effects of PTHrP, TGF-beta, and EGF, which are all secreted by the tooth germ, on tartrate-resistant acid-phosphatase-positive (TRAP+) cell formation using co-cultures of human PDL cells and mouse spleen cells [28].
• Although Rankl expression was not detected in tooth epithelium or mesenchyme, it was expressed in pre-osteogenic mesenchymal cells close to developing tooth germs [29].

Analytical, diagnostic and therapeutic context of Tooth Germ

• In organ culture, anti-integrin alpha6 antibody and wortmannin reduce tooth germ size and shape [26].
• We compared mRNA expression of class 3 semaphorins (Sema3A, 3B, 3C and 3F) and their two receptors (Neuropilin-1 and -2) in the embryonic mouse first molar tooth germ (E10-18) by radioactive in situ hybridization [30].
• In addition, whole-mount in situ hybridizations and immunohistochemistry showed that developing tooth germs express Sonic hedgehog (Shh) [31].
• Western blotting of proteins from tooth germs identified RP59 as a band at 90 kD, co-migrating with RP59 from bone marrow and spleen [32].
• It involves the in vitro treatment of tooth germs with 4-nitroquinoline 1-oxide (4NQO) at the early bell stage and their subsequent transplantation into the kidney subcapsular space [33].

References