The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Hidemitsu Harada - One of the best experts on this subject based on the ideXlab platform.
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cell dynamics in cervical loop Epithelium during transition from crown to root implications for hertwig s epithelial root sheath formation
Journal of Periodontal Research, 2013Co-Authors: Masaaki Sakano, Keishi Otsu, Satoshi Fukumoto, Aya Yamada, Hidemitsu HaradaAbstract:Background and Objective Some clinical cases of hypoplastic tooth root are congenital. Because the formation of Hertwig's epithelial root sheath (HERS) is an important event for root development and growth, we have considered that understanding the HERS developmental mechanism contributes to elucidate the causal factors of the disease. To find integrant factors and phenomenon for HERS development and growth, we studied the proliferation and mobility of the cervical loop (CL). Material and Methods We observed the cell movement of CL by the DiI labeling and organ culture system. To examine cell proliferation, we carried out immunostaining of CL and HERS using anti-Ki67 antibody. Cell motility in CL was observed by tooth germ slice organ culture using green fluorescent protein mouse. We also examined the expression of paxillin associated with cell movement. Results Imaging using DiI labeling showed that, at the apex of CL, the Epithelium elongated in tandem with the growth of Outer Enamel Epithelium (OEE). Cell proliferation assay using Ki67 immunostaining showed that OEE divided more actively than inner Enamel Epithelium (IEE) at the onset of HERS formation. Live imaging suggested that mobility of the OEE and cells in the apex of CL were more active than in IEE. The expression of paxillin was observed strongly in OEE and the apex of CL. Conclusion The more active growth and movement of OEE cells contributed to HERS formation after reduction of the growth of IEE. The expression pattern of paxillin was involved in the active movement of OEE and HERS. The results will contribute to understand the HERS formation mechanism and elucidate the cause of anomaly root.
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cessation of fgf10 signaling resulting in a defective dental epithelial stem cell compartment leads to the transition from crown to root formation
Development, 2006Co-Authors: Tamaki Yokohamatamaki, Hideyo Ohuchi, Satoshi Wakisaka, Hayato Ohshima, Naoki Fujiwara, Yunosuke Takada, Yasuo Ichimori, Hidemitsu HaradaAbstract:Mouse, rat and human molars begin to form root after the completion of crown formation. In these teeth, fibroblast growth factor (Fgf) 10 disappears in the transitional stage from crown formation to root. By contrast, rodent incisors and vole molars demonstrate continuous growth, owing to the formation and maintenance of a stem cell compartment by the constant expression of Fgf10. To clarify the relationship between root formation and disappearance of Fgf10, we carried out two experiments for the loss and gain of Fgf10 function. First, we examined postnatal growth in the incisors of Fgf10-deficient mice, which have the defect of a dental epithelial stem cell compartment referred to as ;apical bud', after implantation under the kidney capsule. The growth at the labial side in the mutant mice mimics the development of limited-growth teeth. 5'-Bromo-2'-deoxyuridine (BrdU) labeling and cytokeratin (CK) 14 and Notch2 immunostaining suggested that the inhibition of inner Enamel Epithelium growth and the more-active proliferation of the Outer Enamel Epithelium and/or stellate reticulum result in Hertwig's epithelial root sheath formation. Second, we examined the effects of Fgf10 overexpression in the transitional stage of molar germs, which led to the formation of apical bud involving in the inhibition of HERS formation. Taken together, these results suggest that the disappearance of Fgf10 signaling leads to the transition from crown to root formation, owing to the loss of a dental epithelial stem cell compartment.
Thomas G H Diekwisch - One of the best experts on this subject based on the ideXlab platform.
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daughters of the Enamel organ development fate and function of the stratum intermedium stellate reticulum and Outer Enamel Epithelium
Stem Cells and Development, 2016Co-Authors: Hui Liu, Xiulin Yan, Mirali Pandya, Xianghong Luan, Thomas G H DiekwischAbstract:The tooth Enamel organ (EO) is a complex epithelial cell assembly involved in multiple aspects of tooth development, including amelogenesis. The present study focuses on the role of the nonameloblast layers of the EO, the stratum intermedium, the stellate reticulum, and the Outer Enamel Epithelium (OEE). The secretory stage stratum intermedium was distinguished by p63-positive epithelial stem cell marks, highly specific alkaline phosphatase labeling, as well as multiple desmosomes and gap junctions. At the location of the presecretory stage stellate reticulum, the pre-eruption EO prominently featured the papillary layer (PL) as a keratin immunopositive network of epithelial strands between tooth crowns and oral Epithelium. PL cell strands contained numerous p63-positive epithelial stem cells, while BrdU proliferative cells were detected at the Outer boundaries of the PL, suggesting that the stellate reticulum/PL epithelial cell sheath proliferated to facilitate an epithelial seal during tooth eruption. Comparative histology studies demonstrated continuity between the OEE and the general lamina of continuous tooth replacement in reptiles, and the Outer layer of Hertwig's epithelial root sheath in humans, implicating the OEE as the formative layer for continuous tooth replacement and tooth root extension. Cell fate studies in organ culture verified that the cervical portion of the mouse molar EO gave rise to Malassez rest-like cell islands. Together, these studies indicate that the nonameloblast layers of the EO play multiple roles during odontogenesis, including the maintenance of several p63-positive stem cell reservoirs, a role during tooth root morphogenesis and tooth succession, a stabilizing function for the ameloblast layer, the facilitation of ion transport from the EO capillaries to the Enamel layer, as well as safe and seamless tooth eruption.
Hui Liu - One of the best experts on this subject based on the ideXlab platform.
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daughters of the Enamel organ development fate and function of the stratum intermedium stellate reticulum and Outer Enamel Epithelium
Stem Cells and Development, 2016Co-Authors: Hui Liu, Xiulin Yan, Mirali Pandya, Xianghong Luan, Thomas G H DiekwischAbstract:The tooth Enamel organ (EO) is a complex epithelial cell assembly involved in multiple aspects of tooth development, including amelogenesis. The present study focuses on the role of the nonameloblast layers of the EO, the stratum intermedium, the stellate reticulum, and the Outer Enamel Epithelium (OEE). The secretory stage stratum intermedium was distinguished by p63-positive epithelial stem cell marks, highly specific alkaline phosphatase labeling, as well as multiple desmosomes and gap junctions. At the location of the presecretory stage stellate reticulum, the pre-eruption EO prominently featured the papillary layer (PL) as a keratin immunopositive network of epithelial strands between tooth crowns and oral Epithelium. PL cell strands contained numerous p63-positive epithelial stem cells, while BrdU proliferative cells were detected at the Outer boundaries of the PL, suggesting that the stellate reticulum/PL epithelial cell sheath proliferated to facilitate an epithelial seal during tooth eruption. Comparative histology studies demonstrated continuity between the OEE and the general lamina of continuous tooth replacement in reptiles, and the Outer layer of Hertwig's epithelial root sheath in humans, implicating the OEE as the formative layer for continuous tooth replacement and tooth root extension. Cell fate studies in organ culture verified that the cervical portion of the mouse molar EO gave rise to Malassez rest-like cell islands. Together, these studies indicate that the nonameloblast layers of the EO play multiple roles during odontogenesis, including the maintenance of several p63-positive stem cell reservoirs, a role during tooth root morphogenesis and tooth succession, a stabilizing function for the ameloblast layer, the facilitation of ion transport from the EO capillaries to the Enamel layer, as well as safe and seamless tooth eruption.
Masamichi Ohishi - One of the best experts on this subject based on the ideXlab platform.
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characterization of dental epithelial progenitor cells derived from cervical loop Epithelium in a rat lower incisor
Journal of Dental Research, 2004Co-Authors: Shintarou Kawano, Keisuke Handa, Takahiko Morotomi, Takashi Toyono, Yuji Seta, Norifumi Nakamura, Takashi Uchida, Kuniaki Toyoshima, Masahiro Saito, Masamichi OhishiAbstract:Dental epithelial progenitor cells differentiate into various cell types during development of tooth germs. To study this mechanism, we produced immortalized dental epithelial progenitor cells derived from the cervical-loop Epithelium of a rat lower incisor. The expression patterns of cytokeratin 14, nerve growth factor receptor p75, amelogenin, Notch2, and alkaline phosphatase were examined by immnohistochemistry in both lower and higher cell densities. The patterns of each were compared in the dental Epithelium of rat lower incisors. The results demonstrated that these cells could produce ameloblast lineage cells, stratum intermedium cells, stellate reticulum, and Outer Enamel Epithelium. Furthermore, fibroblast growth factor 10 stimulated proliferation of dental progenitor cells and subsequently increased the number of cells expressing alkaline phosphatase. These results suggest that fibroblast growth factor 10 plays a role in coupling mitogenesis of the cervical-loop cells and the production of stratu...
Xianghong Luan - One of the best experts on this subject based on the ideXlab platform.
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daughters of the Enamel organ development fate and function of the stratum intermedium stellate reticulum and Outer Enamel Epithelium
Stem Cells and Development, 2016Co-Authors: Hui Liu, Xiulin Yan, Mirali Pandya, Xianghong Luan, Thomas G H DiekwischAbstract:The tooth Enamel organ (EO) is a complex epithelial cell assembly involved in multiple aspects of tooth development, including amelogenesis. The present study focuses on the role of the nonameloblast layers of the EO, the stratum intermedium, the stellate reticulum, and the Outer Enamel Epithelium (OEE). The secretory stage stratum intermedium was distinguished by p63-positive epithelial stem cell marks, highly specific alkaline phosphatase labeling, as well as multiple desmosomes and gap junctions. At the location of the presecretory stage stellate reticulum, the pre-eruption EO prominently featured the papillary layer (PL) as a keratin immunopositive network of epithelial strands between tooth crowns and oral Epithelium. PL cell strands contained numerous p63-positive epithelial stem cells, while BrdU proliferative cells were detected at the Outer boundaries of the PL, suggesting that the stellate reticulum/PL epithelial cell sheath proliferated to facilitate an epithelial seal during tooth eruption. Comparative histology studies demonstrated continuity between the OEE and the general lamina of continuous tooth replacement in reptiles, and the Outer layer of Hertwig's epithelial root sheath in humans, implicating the OEE as the formative layer for continuous tooth replacement and tooth root extension. Cell fate studies in organ culture verified that the cervical portion of the mouse molar EO gave rise to Malassez rest-like cell islands. Together, these studies indicate that the nonameloblast layers of the EO play multiple roles during odontogenesis, including the maintenance of several p63-positive stem cell reservoirs, a role during tooth root morphogenesis and tooth succession, a stabilizing function for the ameloblast layer, the facilitation of ion transport from the EO capillaries to the Enamel layer, as well as safe and seamless tooth eruption.
