Disease relevance of Enamel Organ

• Specifically, the null mouse does not process amelogenin properly, possesses an altered enamel matrix and rod pattern, has hypoplastic enamel that delaminates from the dentin, and has a deteriorating enamel organ morphology as development progresses [1].
• Are there structural alterations in the enamel organ of offspring of rats with alloxan-induced diabetes mellitus [2]?
• CK13 in craniopharyngioma versus related odontogenic neoplasms and human enamel organ [3].

High impact information on Enamel Organ

• Extracellular proteolysis alters tooth development in transgenic mice expressing urokinase-type plasminogen activator in the enamel organ [4].
• In odontogenesis, Cbfa1 is not involved in the early signaling networks regulating tooth initiation and early morphogenesis but regulates key epithelial-mesenchymal interactions that control advancing morphogenesis and histodifferentiation of the epithelial enamel organ [5].
• During tooth development, enamel organ epithelial cells express a tissue-specific gene product (amelogenin) which presumably functions to control calcium hydroxyapatite crystal growth patterns during enamel biomineralization [6].
• During early tooth development, TGF-beta inhibits proliferation of enamel organ epithelial cells but the underlying molecular mechanisms are largely unknown [7].
• Amelogenin transcripts were also detected in isolated late cap stage (E15) enamel organ epithelium dissected free of dental papilla mesenchyme and cultured within a substitute basement membrane gel, but not in identical cap stage enamel organ epithelium cultured on plastic or a laminin-coated filter [8].

Biological context of Enamel Organ

• It also suggests that a pathway through which point mutations in the amelogenin protein can adversely impact on the formation of the enamel organ is by disturbing self-assembly of the organic matrix [9].
• Amelogenin transcripts were also found in early cap stage (E14) isolated enamel organ epithelium cultured within a basement membrane gel, but were not detected in enamel organ epithelium isolated from earlier stages of odontogenesis and cultured within a basement membrane gel [8].
• Molecular cloning and mRNA tissue distribution of a novel matrix metalloproteinase isolated from porcine enamel organ [10].
• Finally, the presence of EGF in the follicle, as well as enamel organ, could provide an endogenous source of EGF to regulate tooth eruption, either by an autocrine or a paracrine effect [11].
• Cytochemical studies with glutaraldehyde-fixed enamel organs revealed that reaction product from hydrolysis of beta-NADP+ and other analogues containing the phosphate group attached at the natural 2'-position was localized within the intermediate saccules of the ameloblast Golgi apparatus [12].

Anatomical context of Enamel Organ

• Neither intercellular calcium concentration between ameloblasts nor over-all calcium levels of the enamel organ were lowered during a period of inhibition of enamel mineralization by injected fluoride [13].
• Vim mRNA was not found in the fetal oral epithelia, dental lamina or the enamel organ, but a distinct immunoreactivity with monoclonal antibodies to Vim was seen in the stellate reticulum cells of the enamel organ [14].
• The findings indicate that the enamel organ exists as a diffusion-limiting membrane to the movement of fluoride from the extracellular fluid compartment to the developing enamel [15].
• Effect of glutaraldehyde and decalcifying agents on acid phosphomonoester hydrolase activity in the enamel organ of the rat incisor: a biochemical study comparing enamel organ with liver [16].
• The results suggest that the dendritic cells play a role in eliminating amelogenin from the enamel organ [17].

Associations of Enamel Organ with chemical compounds

• Role of the enamel organ in limiting fluoride uptake during the maturation phase of enamel development [18].
• The removal of the enamel organ or metabolic inhibition with iodoacetate caused significant increases in enamel fluoride uptake at both stages of enamel formation [15].
• Recently, a novel serine proteinase named enamel matrix serine proteinase-1 (EMSP1) was cloned from enamel organ epithelia [19].
• The enamel organ of the growing rat incisor was fixed with a mixture of formaldehyde and glutaraldehyde and processed for ultracytochemical demonstration of Ca- and Mg-activated membrane ATPase by a one-step lead technique at alkaline pH [20].
• Perlecan, a basement membrane-type heparan sulfate proteoglycan, in the enamel organ: its intraepithelial localization in the stellate reticulum [21].

Gene context of Enamel Organ

• In the enamel organs, however, the MT1-MMP message level became reduced only during the late secretory stage [22].
• Then, by 72 hpf, eve1 expression was restricted to the differentiating ameloblasts of the enamel organ during early differentiation stage, and this expression decreased as soon as matrix was deposited [23].
• The amounts of the molecules in the cytoplasm and the nucleus showed regional variations in the enamel organ, whereas cell surface-associated beta-catenin was ubiquitous [24].
• P-cadherin also gave a stronger signal in the enamel knot than in other parts of the enamel organ [24].
• Subcellular localization of beta-catenin and cadherin expression in the cap-stage enamel organ of the mouse molar [24].

Analytical, diagnostic and therapeutic context of Enamel Organ

• Northern blot analysis of stage-specific enamel organs (early secretory, late secretory, or maturation stage) and their corresponding pulp organs revealed that MT1-MMP expression increased as the dentin matured [22].
• We analyzed the subcellular distribution of beta-catenin in the cap-stage enamel organ and compared it with the expression of E- and P-cadherin by using confocal laser microscopy [24].
• Biochemical analysis of rat incisor enamel organ homogenates, indicated tissue fixation resulted in an 82% reduction in DPP II activity, although the specific activity of DPP II was not affected [25].
• Morphologic changes in the rat enamel organ following a single intraperitoneal injection of sodium fluoride [26].
• These results indicate that there are structural defects in the enamel organ of rats born to mothers with alloxan-induced diabetes which could induce the enamel hypoplasia observed by scanning electron microscopy and which may reflect the metabolic alterations seen in this condition [2].

References