The Experts below are selected from a list of 573 Experts worldwide ranked by ideXlab platform
Tuula Salo - One of the best experts on this subject based on the ideXlab platform.
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alpha smooth muscle actin within epithelial islands is predictive of ameloblastic carcinoma
Oral Oncology, 2009Co-Authors: Ibrahim O Bello, Kalle Alanen, P J Slootweg, Tuula SaloAbstract:Summary Ameloblastoma is the most common clinically significant odontogenic tumor. It is considered benign but locally invasive and associated with variable clinico-pathological behavior. Ameloblastic carcinoma is a malignant tumor having features of ameloblastoma in addition to cytologic atypia with or without metastasis. It is aggressive and associated with poor prognosis. The aim of this study was to examine which epithelial and stromal markers are predictive of histologically diagnosed ameloblastic carcinoma and can sufficiently differentiate it from solid/multicystic ameloblastoma (SA). We examined immunohistochemically Ki-67, epithelial membrane antigen (EMA), alpha-smooth muscle actin (α-SMA), calponin, p63 and DNA content using image (ICM) and flow cytometry (FCM) in three ameloblastic carcinomas and up to 18 SAs. The important findings were that Ki-67 labeling index was significantly higher in ameloblastic carcinoma than SA while EMA, calponin, p63, ICM and FCM did not sufficiently differentiate the two groups of lesions. Expression of α-SMA was consistently obtained within the epithelial island cells of ameloblastic carcinoma and not in SA, although the marker was well expressed in the stroma of both lesions. We therefore conclude that the presence of α-SMA within the epithelial islands is highly predictive of ameloblastic carcinoma.
Suzana Cantanhede Orsini Machado De Sousa - One of the best experts on this subject based on the ideXlab platform.
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expression of odontogenic ameloblast associated protein amelotin Ameloblastin and amelogenin in odontogenic tumors immunohistochemical analysis and pathogenetic considerations
Journal of Oral Pathology & Medicine, 2012Co-Authors: Marcelo Macedo Crivelini, Renata Callestini Felipini, Glauco Issamu Miyahara, Suzana Cantanhede Orsini Machado De SousaAbstract:Screening for expression of amelogenesis-related proteins represents a powerful molecular approach to characterize odontogenic tumors and investigate their pathogenesis. In this study, we have examined the presence and distribution of odontogenic ameloblast-associated protein (ODAM), amelotin (AMTN), Ameloblastin (AMBN), and amelogenin (AMEL) by immunohistochemistry in samples of adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor (CEOT), developing odontoma, ameloblastoma, calcifying cystic odontogenic tumor (CCOT), ameloblastic fibroma (AF), myxoma, odontogenic fibroma (OF), and reduced enamel epithelia (REE). Positive results were obtained in those tumors with epithelial component, except for AF, OF, and ameloblastoma. ODAM was found around mineralized structures (dystrophic calcifications) and CEOT's amyloid, whereas AMTN stained the eosinophilic material of AOTs. The CCOT transitory cells to ghost cells were strongly positive with all proteins except AMEL, and the REE as well as odontomas showed immunoexpression for ODAM, AMTN, AMBN, and AMEL similar to those found in normal rat tooth germs. Based on these results, some histopathogenetic theories were formulated.
Satoshi Fukumoto - One of the best experts on this subject based on the ideXlab platform.
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Expression of collagen IV, laminin β1γ1, and Ameloblastin in incisors from WT and Itgβ1CKO mice.
2015Co-Authors: Emiko Fukumoto, Aya Yamada, Takashi Nakamura, Kenji Yuasa, Tsutomu Iwamoto, Satoshi FukumotoAbstract:A. The lower incisor of a wild type (WT) mouse was analyzed using immunostaining with anti-collagen IV and anti-laminin β1γ1 antibodies. Laminin β1γ1 was expressed in the basal membrane, papillary layer, and immature ameloblasts. B, C. The lower incisors of WT and Itgβ1 conditional knockout (CKO) mouse were immunostained by anti-Ameloblastin and anti-laminin β1γ1 antibodies. Ameloblastin was detected in the incisor of a WT but not a Itgβ1CKO mouse. Laminin β1γ1 was detected in Itgβ1CKO (asterisk) but not WT incisors. iee, inner enamel epithelium; am, ameloblasts; od, odontoblasts.
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Real-time PCR analysis of expression of mRNAs encoding ameloblast markers in primary cultures of ameloblasts.
2015Co-Authors: Kan Saito, Aya Yamada, Takashi Nakamura, Emiko Fukumoto, Kenji Yuasa, Tsutomu Iwamoto, Keigo Yoshizaki, Masahiro Saito, Satoshi FukumotoAbstract:A. Wild type (WT) ameloblasts were cultured with RGD or RAD peptide for 0 to 72 hours. The expression of Ameloblastin was delayed by RGD but not by RAD. B. WT and Itgβ1CKO ameloblasts were cultured for 0 to 72 hours. The expression of Ameloblastin was delayed in Itgβ1CKO ameloblasts as compared with WT. C. Analysis of the expression of mRNAs encoding ameloblast markers in WT ameloblasts cultured in the presence of an anti-β1 integrin antibody. The expression of all ameloblast markers was decreased. D. WT ameloblasts were transfected with fibronectin siRNA for 0 to 72 hours. The inhibition of fibronectin expression delayed the expression of Ameloblastin. *P < 0.01; **P < 0.05 (n = 5).
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synergistic roles of amelogenin and Ameloblastin
Journal of Dental Research, 2009Co-Authors: J Hatakeyama, Satoshi Fukumoto, Takashi Nakamura, Naoto Haruyama, Shigeki Suzuki, Y Hatakeyama, Lillian Shum, Carolyn W Gibson, Yoshihiko Yamada, Ashok B KulkarniAbstract:Amelogenin and Ameloblastin, the major enamel matrix proteins, are important for enamel mineralization. To identify their synergistic roles in enamel development, we generated Amel X−/−/Ambn−/− mice. These mice showed additional enamel defects in comparison with Amel X−/− or Ambn−/− mice. In 7-day-old Amel X−/−/Ambn−/− mice, not only was the ameloblast layer irregular and detached from the enamel surface, as in Ambn−/−, but also, the enamel width was significantly reduced in the double-null mice as compared with Amel X−/− or Ambn−/− mice. Proteomic analysis of the double-null teeth revealed increased levels of RhoGDI (Arhgdia), a Rho-family-specific guanine nucleotide dissociation inhibitor, which is involved in important cellular processes, such as cell attachment. Both Amel X−/−/Ambn−/− mice and Ambn−/− mice displayed positive staining with RhoGDI antibody in the irregularly shaped ameloblasts detached from the matrix. Ameloblastin-regulated expression of RhoGDI suggests that Rho-mediated signaling path...
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synergistic roles of amelogenin and Ameloblastin
Journal of Dental Research, 2009Co-Authors: J Hatakeyama, Satoshi Fukumoto, Takashi Nakamura, Naoto Haruyama, Shigeki Suzuki, Y Hatakeyama, Lillian Shum, Carolyn W Gibson, Yoshihiko Yamada, Ashok B KulkarniAbstract:Amelogenin and Ameloblastin, the major enamel matrix proteins, are important for enamel mineralization. To identify their synergistic roles in enamel development, we generated Amel X(-/-)/Ambn(-/-) mice. These mice showed additional enamel defects in comparison with Amel X(-/-) or Ambn(-/-) mice. In 7-day-old Amel X(-/-)/Ambn(-/-) mice, not only was the ameloblast layer irregular and detached from the enamel surface, as in Ambn(-/-), but also, the enamel width was significantly reduced in the double-null mice as compared with Amel X(-/-) or Ambn(-/-) mice. Proteomic analysis of the double-null teeth revealed increased levels of RhoGDI (Arhgdia), a Rho-family-specific guanine nucleotide dissociation inhibitor, which is involved in important cellular processes, such as cell attachment. Both Amel X(-/-)/Ambn(-/-) mice and Ambn(-/-) mice displayed positive staining with RhoGDI antibody in the irregularly shaped ameloblasts detached from the matrix. Ameloblastin-regulated expression of RhoGDI suggests that Rho-mediated signaling pathway might play a role in enamel formation.
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Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts
Journal of Cell Biology, 2004Co-Authors: Antonio Nanci, Paul H Krebsbach, Satoshi Fukumoto, Takayoshi Kiba, Bradford Hall, Noriyuki Iehara, Takashi Nakamura, Glenn Longenecker, Ashok B KulkarniAbstract:Tooth morphogenesis results from reciprocal interactions between oral epithelium and ectomesenchyme culminating in the formation of mineralized tissues, enamel, and dentin. During this process, epithelial cells differentiate into enamel-secreting ameloblasts. Ameloblastin, an enamel matrix protein, is expressed by differentiating ameloblasts. Here, we report the creation of Ameloblastin-null mice, which developed severe enamel hypoplasia. In mutant tooth, the dental epithelium differentiated into enamel-secreting ameloblasts, but the cells were detached from the matrix and subsequently lost cell polarity, resumed proliferation, and formed multicell layers. Expression of Msx2, p27, and p75 were deregulated in mutant ameloblasts, the phenotypes of which were reversed to undifferentiated epithelium. We found that recombinant Ameloblastin adhered specifically to ameloblasts and inhibited cell proliferation. The mutant mice developed an odontogenic tumor of dental epithelium origin. Thus, Ameloblastin is a cell adhesion molecule essential for amelogenesis, and it plays a role in maintaining the differentiation state of secretory stage ameloblasts by binding to ameloblasts and inhibiting proliferation.
Antonio Nanci - One of the best experts on this subject based on the ideXlab platform.
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JCB: ARTICLE
2013Co-Authors: Paul H Krebsbach, Antonio Nanci, Ashok B Kulkarni, Yoshihiko YamadaAbstract:Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblast
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Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts
Journal of Cell Biology, 2004Co-Authors: Antonio Nanci, Paul H Krebsbach, Satoshi Fukumoto, Takayoshi Kiba, Bradford Hall, Noriyuki Iehara, Takashi Nakamura, Glenn Longenecker, Ashok B KulkarniAbstract:Tooth morphogenesis results from reciprocal interactions between oral epithelium and ectomesenchyme culminating in the formation of mineralized tissues, enamel, and dentin. During this process, epithelial cells differentiate into enamel-secreting ameloblasts. Ameloblastin, an enamel matrix protein, is expressed by differentiating ameloblasts. Here, we report the creation of Ameloblastin-null mice, which developed severe enamel hypoplasia. In mutant tooth, the dental epithelium differentiated into enamel-secreting ameloblasts, but the cells were detached from the matrix and subsequently lost cell polarity, resumed proliferation, and formed multicell layers. Expression of Msx2, p27, and p75 were deregulated in mutant ameloblasts, the phenotypes of which were reversed to undifferentiated epithelium. We found that recombinant Ameloblastin adhered specifically to ameloblasts and inhibited cell proliferation. The mutant mice developed an odontogenic tumor of dental epithelium origin. Thus, Ameloblastin is a cell adhesion molecule essential for amelogenesis, and it plays a role in maintaining the differentiation state of secretory stage ameloblasts by binding to ameloblasts and inhibiting proliferation.
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hertwig s epithelial root sheath enamel matrix proteins and initiation of cementogenesis in porcine teeth
Journal of Clinical Periodontology, 2004Co-Authors: Dieter D. Bosshardt, Antonio NanciAbstract:Objectives: The aim of this study was to analyze the association between Hertwig's epithelial root sheath (HERS) cells, enamel matrix proteins (EMPs), and cementogenesis. Material and Methods: Porcine teeth were examined at the beginning of root formation by light and transmission electron microscopy. Colloidal gold immunocytochemistry was used to analyze the protein expression of amelogenin and Ameloblastin. Results: Before and during disintegration of HERS, its cells displayed the cytologic features of protein synthesis and secretion. While some cells assumed an ameloblast-like phenotype, others extended their territory away from the root surface. A collagenous matrix filled the widening intercellular spaces, and tonofilaments and desmosomes were still present in cells featuring the morphologic characteristics of cementoblasts. Labeling for amelogenin was observed but Ameloblastin was not immunodetected. Labeling was associated with organic matrix deposits that were sporadically and randomly distributed both along the root surface and away from it among the dissipated epithelial cells. Conclusions: These findings suggest that HERS' cells occasionally assume a lingering ameloblastic activity at the beginning of root formation in the pig. While the results do not support the hypothesis of a causal relationship between EMPs and cementogenesis, they lend support to the concept of an epithelial origin of cementoblasts.
Paul H Krebsbach - One of the best experts on this subject based on the ideXlab platform.
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JCB: ARTICLE
2013Co-Authors: Paul H Krebsbach, Antonio Nanci, Ashok B Kulkarni, Yoshihiko YamadaAbstract:Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblast
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Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts
Journal of Cell Biology, 2004Co-Authors: Antonio Nanci, Paul H Krebsbach, Satoshi Fukumoto, Takayoshi Kiba, Bradford Hall, Noriyuki Iehara, Takashi Nakamura, Glenn Longenecker, Ashok B KulkarniAbstract:Tooth morphogenesis results from reciprocal interactions between oral epithelium and ectomesenchyme culminating in the formation of mineralized tissues, enamel, and dentin. During this process, epithelial cells differentiate into enamel-secreting ameloblasts. Ameloblastin, an enamel matrix protein, is expressed by differentiating ameloblasts. Here, we report the creation of Ameloblastin-null mice, which developed severe enamel hypoplasia. In mutant tooth, the dental epithelium differentiated into enamel-secreting ameloblasts, but the cells were detached from the matrix and subsequently lost cell polarity, resumed proliferation, and formed multicell layers. Expression of Msx2, p27, and p75 were deregulated in mutant ameloblasts, the phenotypes of which were reversed to undifferentiated epithelium. We found that recombinant Ameloblastin adhered specifically to ameloblasts and inhibited cell proliferation. The mutant mice developed an odontogenic tumor of dental epithelium origin. Thus, Ameloblastin is a cell adhesion molecule essential for amelogenesis, and it plays a role in maintaining the differentiation state of secretory stage ameloblasts by binding to ameloblasts and inhibiting proliferation.
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a transgenic animal model resembling amelogenesis imperfecta related to Ameloblastin overexpression
Journal of Biological Chemistry, 2003Co-Authors: Michael L Paine, Paul H Krebsbach, Hongjun Wang, Wen Luo, Malcolm L SneadAbstract:Genetic diseases that affect tooth enamel are grouped under the classification amelogenesis imperfecta. Human pedigrees and experiments on transgenic and null mice have all demonstrated that mutations to the secreted proteins amelogenin, enamelin, and enamelysin result in visibly, structurally, or mechanically defective enamel. In an attempt to better define a physiologic function for Ameloblastin during enamel formation, we have produced transgenic mice that misexpress the Ameloblastin gene. These transgenic animals exhibit imperfections in their enamel that is evident at the nanoscale level. Specifically, Ameloblastin overexpression influences enamel crystallite habit and enamel rod morphology. These findings suggest enamel crystallite habit and rod morphology are influenced by the temporal and spatial expression of Ameloblastin and may implicate the role of the Ameloblastin gene locus in the etiology of a number of undiagnosed autosomally dominant cases of amelogenesis imperfecta.
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dentin sialoprotein dentin phosphoprotein enamelysin and Ameloblastin tooth specific molecules that are distinctively expressed during murine dental differentiation
European Journal of Oral Sciences, 1998Co-Authors: Catherine Beguekirn, Paul H Krebsbach, John D Bartlett, William T ButlerAbstract:: Dentin sialophosphoprotein [designated DSPP and cleaved into dentin sialoprotein (DSP) and dentin phosphoprotein (DPP)], enamelysin and Ameloblastin are each expressed in unique fashions during tooth development. It is possible that these components participate in cell differentiation and the conversion of unmineralized matrix into mineralized structures. In order to delineate the timing and the positioning of these three molecules in a physiological context, we compared their expression profiles by performing in situ hybridization experiments on consecutive sections in developing mouse tissues. Hybridization signals were uniquely detected for DSPP mRNA in odontoblasts and preameloblasts, for enamelysin mRNA in odontoblasts and in the facing ameloblast layer, and for Ameloblastin mRNA in preodontoblasts, polarizing odontoblasts and ameloblasts. Immunohistochemistry showed that DSP and Ameloblastin transcripts were translated into proteins that were deposited at the apical pole of the differentiated cells (odontoblasts and ameloblasts, respectively). The interrelated expression profiles found for these tooth-specific molecules illustrate the importance of a specific molecular network to initiate highly regulated processes such as cytodifferentiation and the subsequent mineralization.
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full length sequence localization and chromosomal mapping of Ameloblastin a novel tooth specific gene
Journal of Biological Chemistry, 1996Co-Authors: Paul H Krebsbach, Christine A Kozak, Suk Keun Lee, Yutaka Matsuki, Kenneth M YamadaAbstract:We report the full-length sequencing, cell type-specific expression, and immunolocalization of a novel gene expressed in rat incisors, which we have designated Ameloblastin. Northern blot analysis of RNA from multiple rat and mouse tissues demonstrated high levels of expression of two distinct transcripts of approximately 2.0 and 1.6 kilobase pairs that were expressed only in teeth. In situ hybridization using a digoxigenin-labeled RNA probe showed that the tissue distribution of Ameloblastin was limited to the ameloblast in rat incisors. Immunohistochemical staining of rat incisors using a polyclonal antibody raised against a fusion protein revealed a unique localization pattern. Ameloblastin was found to be expressed during the differentiation of inner enamel epithelium into ameloblasts, with intense localization in the Tomes' processes of secretory ameloblasts. In contrast to amelogenin, only modest amounts of Ameloblastin were detected in enamel matrix. The Ameloblastin gene encodes an open reading frame of 422 amino acids corresponding to a putative protein of 45 kDa. The predicted protein is acidic (pI = 5.54) and the most abundant amino acids are Pro (15.2%), Gly (9.9%), and Leu (9.9%). We have also mapped the Ameloblastin gene, Ambn, to a locus on mouse chromosome 5 near other genes associated with mineralized tissues. Thus, Ameloblastin represents a unique ameloblast-specific gene product that may be important in enamel matrix formation and mineralization.