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Taqi D, Moussa H, Schwinghamer T, Ducret M, Dagdeviren D, Retrouvey JM, Rauch F, Tamimi F. Osteogenesis imperfecta tooth level phenotype analysis: Cross-sectional study. Bone 2021; 147:115917. [PMID: 33741542 PMCID: PMC8278321 DOI: 10.1016/j.bone.2021.115917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/16/2021] [Accepted: 03/11/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Dental anomalies in Osteogenesis imperfecta (OI), such as tooth discoloration, pulp obliteration (calcified dental pulp space), and taurodontism (enlarged dental pulp space) vary between and within patients. To better understand the associations and variations in these anomalies, a cross-sectional study was designed to analyze the dental phenotype in OI patients at the individual tooth type. METHOD A cohort of 171 individuals with OI type I, III and IV, aged 3-55 years, were recruited and evaluated for tooth discoloration, pulp obliteration, and taurodontism at the individual tooth level, using intraoral photographs and panoramic radiographs. RESULTS Genetic variants were identified in 154 of the participants. Patients with Helical α1 and α2 glycine substitutions presented the highest prevalence of tooth discoloration, while those with α1 Haploinsufficiency had the lowest (<10%). C-propeptide variants did not cause discoloration but resulted in the highest pulp obliteration prevalence (~%20). The prevalence of tooth discoloration and pulp obliteration was higher in OI types III and IV and increased with age. Tooth discoloration was mainly observed in teeth known to have thinner enamel (i.e. lower anterior), while pulp obliteration was most prevalent in the first molars. A significant association was observed between pulp obliteration and tooth discoloration, and both were associated with a lack of occlusal contact. Taurodontism was only found in permanent teeth and affected mostly first molars, and its prevalence decreased with age. CONCLUSION The dental phenotype evaluation at the tooth level revealed that different genetic variants and associated clinical phenotypes affect each tooth type differently, and genetic variants are better predictors of the dental phenotype than the type of OI. Our results also suggest that tooth discoloration is most likely an optical phenomenon inversely proportional to enamel thickness, and highly associated with pulp obliteration. In turn, pulp obliteration is proportional to patient age, it is associated with malocclusion and likely related to immature progressive dentin deposition. Taurodontism is an isolated phenomenon that is probably associated with delayed pulpal maturation.
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Affiliation(s)
- Doaa Taqi
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada.
| | - Hanan Moussa
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; Faculty of Dentistry, Benghazi University, Libya.
| | | | - Maxime Ducret
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; Faculty of Dentistry, Lyon University, Lyon, France.
| | - Didem Dagdeviren
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada.
| | - Jean-Marc Retrouvey
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; School of Dentistry, University of Missouri, Kansas City, USA.
| | - Frank Rauch
- Shriners Hospital for Children, Montreal, Quebec, Canada.
| | - Faleh Tamimi
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; College of Dental Medicine, QU Health, Qatar University, Doha, Qatar.
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Ferreira BC, Freire AR, Araujo R, do Amaral-Silva GK, Okamoto R, Prado FB, Rossi AC. β-catenin and Its Relation to Alveolar Bone Mechanical Deformation - A Study Conducted in Rats With Tooth Extraction. Front Physiol 2020; 11:549. [PMID: 32581840 PMCID: PMC7291952 DOI: 10.3389/fphys.2020.00549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/30/2020] [Indexed: 12/29/2022] Open
Abstract
The aim of this study was to analyze the relationship between alveolar bone deformation and β-catenin expression levels in response to the mechanical load changed by dental extraction in adult rats. Twenty-four male rats (Rattus norvegicus albinus), Wistar linage, at 2 months of age, were used. The right upper incisor tooth was extracted, and euthanasia occurred in periods 5 (n = 6), 7 (n = 6), and 14 (n = 6) days after Day 0. In the control group (n = 6), the dentition was maintained. The euthanasia occurred within 14 days after day 0. After euthanasia, the rats of all groups had their left jaw with tooth removed and separated in the middle. The pieces were undergone routine histological processing and then the immunohistochemical marking were performed to label expression of the primary β-catenin antibody, which was evaluated by qualitative and quantitative analysis. One head by each group (control and experimental) was submitted to computerized microtomography. After the three-dimensional reconstruction of the skull of the rat in each group, the computational simulation for finite elements analysis were performed to simulate a bite in the incisors. In finite element analysis, the strain patterns were evaluated after the application of bite force. The results were analyzed considering the areas in which changes in the amount of deformations were detected. The action of the bite force in the experimental condition, resulted in a uniform distribution of the amount of deformations, in addition to lower amount of deformation areas, differentiating from the control group. Comparing with the control group, the levels of β-catenin signaled in the lingual bone of the middle third of the alveolar bone were raised in the periods of 5 and 14 days. The increased β-catenin positive staining intensity was concentrated on osteocytes and gaps of osteocytes. The findings of the present study were in accordance with our hypothesis that the condition of dental extraction can cause the expression of β-catenin and alter the regimes of bone deformation.
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Affiliation(s)
- Beatriz Carmona Ferreira
- Laboratory for Mechanobiology Research, Biosciences Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Alexandre Rodrigues Freire
- Laboratory for Mechanobiology Research, Biosciences Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Rafael Araujo
- São Leopoldo Research Institute, São Leopoldo Mandic University, Campinas, Brazil
| | - Gleyson Kleber do Amaral-Silva
- Oral Pathology Laboratory, Oral Diagnosis Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Roberta Okamoto
- Laboratory for Study of Mineralized Tissue, Basic Sciences Department, School of Dentistry of Araçatuba, São Paulo State University, Araçatuba, Brazil
| | - Felippe Bevilacqua Prado
- Laboratory for Mechanobiology Research, Biosciences Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Ana Cláudia Rossi
- Laboratory for Mechanobiology Research, Biosciences Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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Laboux O, Dion N, Arana-Chavez V, Ste-Marie LG, Nanci A. Microwave Irradiation of Ethanol-fixed Bone Improves Preservation, Reduces Processing Time, and Allows Both Light and Electron Microscopy on the Same Sample. J Histochem Cytochem 2016; 52:1267-75. [PMID: 15385573 DOI: 10.1177/002215540405201003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Methylmethacrylate (MMA) embedding is routinely used for histomorphometry of undecalcified bone preserved by prolonged immersion in ethanol, a procedure that yields poor ultrastructural detail. Because microwave irradiation (MWI) facilitates penetration of fixatives, we have investigated whether it can improve preservation by ethanol. Rat tibiae, some labeled with tetracycline, and a human iliac crest biopsy were immersed in 70% ethanol and dehydrated, both under MWI, for a total processing time of ~7 hr. Controls were not irradiated, and all specimens were embedded in MMA at 4C. They were then processed for histomorphometry, histochemistry, structural analysis, and immunolabeling. The results showed that histological preservation was improved with MWI. Static bone formation and resorption parameters and rate of mineral apposition were similar to those of conventionally processed specimens. Mineral distribution, as visualized by von Kossa staining and backscattered electron imaging, was not affected. Alkaline phosphatase and tartrate-resistant acid phosphatase activity, as well as immunolocalization of bone sialoprotein and osteopontin, were readily visualized. Ultrastructurally, osteopontin exhibited a typical distribution in mineralization foci, between calcified collagen fibrils, and at cement lines. These data show that MWI improves preservation and permits application of a broad spectrum of analytical methodologies on the same bone sample while considerably reducing processing time.
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Affiliation(s)
- Olivier Laboux
- Department of Stomatology, Faculty of Dentistry, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, Canada H3C 3J7.
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Ferreira LB, Bradaschia-Correa V, Moreira MM, Marques NDM, Arana-Chavez VE. Evaluation of bone repair of critical size defects treated with simvastatin-loaded poly(lactic-co-glycolic acid) microspheres in rat calvaria. J Biomater Appl 2014; 29:965-76. [PMID: 25209881 DOI: 10.1177/0885328214550897] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE Statins are hypolipemiant drugs with osteoinductive effect. We evaluated the potential of simvastatin loaded into poly(lactic-co-glycolic acid) (PLGA) microspheres to heal critical size defects in rat calvaria. METHODS PLGA scaffolds (50:50 ratio) were synthesized as pure membranes or as microspheres loaded with 2.5% simvastatin. Critical size defects (5-mm diameter) were created in the parietal bone of 3-month-old male Wistar rats; they were either left filled with blood clot (C group), covered with a PLGA membrane (M group) or with PLGA microspheres loaded with simvastatin (MSI group) or not (MM group), and then covered with the PLGA membrane. The defects were evaluated after 30 or 60 days by light and electron microscopy, immunohistochemistry for osteopontin (OPN), bone sialoprotein (BSP) and osteoadherin (OSAD), and immunocytochemistry for OPN. RESULTS Scanning electron microscopy showed that the calvarial defects treated with MSI were almost completely healed after 60 days, while groups M and C presented less bone formation, whereas the bone matrix formed into the defects of MSI group was more organized and mature. The immunolabeling for OPN and BSP on the matrix in groups C and M showed typical areas of primary bone unlike the MSI that presented weak labeling at the formed area. In the MSI group, there was an intense immunostaining for OSAD in osteoid, as well as in osteocyte cytoplasm. The immunocytochemistry showed intense labeling for OPN with homogeneous distribution in the interfibrillar spaces in all groups after 30 days and after 60 days; however, while C and M groups exhibited similar aspect, the MSI specimens showed weak labeling. The ultrastructural evaluation showed the interaction between the biomaterial and the surrounding tissue where some cells established intimate contact with microspheres. CONCLUSIONS The repair of critical size bone defects was accelerated and enhanced by the implantation of simvastatin-loaded PLGA microspheres.
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Affiliation(s)
- Lorraine B Ferreira
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Vivian Bradaschia-Correa
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Mariana M Moreira
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Natasha D M Marques
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Victor E Arana-Chavez
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Rothbarth CP, Bradaschia-Correa V, Ferreira LB, Arana-Chavez VE. Effects of the bisphosphonate alendronate on molars of young rats after lateral luxation. Dent Traumatol 2014; 30:415-22. [PMID: 24890501 DOI: 10.1111/edt.12116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2014] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND AIM The bisphosphonate alendronate (ALN) was employed with the aim of investigating its effects on dental and periodontal tissues after lateral luxation of developing molars. MATERIAL AND METHODS Twenty-one-day-old Wistar rats had their second upper molars laterally luxated. Daily 2.5 mg kg(-1) ALN injections started at the day of the luxation; controls received sterile saline solution. The teeth were analyzed 7, 14, and 21 days after the procedure. On the days cited, the maxillae were fixed, decalcified, and embedded in paraffin or Spurr resin. The paraffin sections were stained with H&E, incubated for TRAP histochemistry or immunolabeled for osteopontin (OPN). Spurr ultrathin sections were examined in a transmission electron microscope. RESULTS After 21 days, the root apex of luxated molars without ALN was wide open and disorganized and also covered by an irregular layer of cellular cementum, which was not observed in ALN-treated animals. Ankylosis sites were observed in ALN rats in both luxated and non-luxated teeth. The TRAP-positive osteoclasts were more numerous in ALN group, despite their latent ultrastructural appearance without the presence of resorption apparatus compared to controls. OPN immunolabeling revealed a thick immunopositive line in the dentin that must be resultant from the moment of the luxation, while ALN-treated specimens did not present alterations in dentin. CONCLUSION The present findings indicate that alendronate inhibits some alterations in dentin and cementum formation induced by dental trauma.
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Affiliation(s)
- Cláudia Pires Rothbarth
- Department of Biomaterials and Oral Biology, University of São Paulo School of Dentistry, São Paulo, Brazil; Department of Dentistry, Federal University of Pará, Belém, Brazil
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Webster P. Microwave-assisted processing and embedding for transmission electron microscopy. Methods Mol Biol 2014; 1117:21-37. [PMID: 24357357 DOI: 10.1007/978-1-62703-776-1_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Microwave processors can provide a means of rapid processing and resin embedding for biological specimens that are to be sectioned and examined by transmission electron microscopy. This chapter describes a microwave-assisted protocol for processing, dehydrating and embedding biological material, taking them from living specimens to blocks embedded in sectionable resin in 4 h or less.
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Affiliation(s)
- Paul Webster
- Center for Electron Microscopy and Microanalysis (CEMMA), University of Souther California, Los Angeles, CA, USA
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Aïoun J, Chat S, Bordat C, Péchoux C. Antigen recovery and preservation using the microwave irradiation of biological samples for transmission electron microscopy analysis. Micron 2013; 52-53:16-23. [PMID: 23962686 DOI: 10.1016/j.micron.2013.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 07/10/2013] [Accepted: 07/19/2013] [Indexed: 11/15/2022]
Abstract
Most studies using microwave irradiation (MWI) for the preparation of tissue samples have reported an improvement in structural integrity. However, there have been few studies on the effect of microwave (MW) on antigen preservation during sample preparation prior to immunolocalization. This report documents our experience of specimen preparation using an automatic microwave apparatus to obtain antigen preservation and retrieval. We tested the effects of MW processing vs. conventional procedures on the morphology and antigenicity of two different tissues: the brain and mammary gland, whose chemical composition and anatomical organization are quite different. We chose to locate the transcription factor PPARβ/δ using immunocytochemistry on brain tissue sections from hamsters. Antigen retrieval protocols involving MWI were used to restore immunoreactivity. We also studied the efficiency of the ultrastructural immunolocalization of both PPARγ and caveolin-1 following MWI vs. conventional treatment, on mammary gland tissue from mice at 10 days of lactation. Our findings showed that the treatment of tissue samples with MWI, in the context of a process lasting just a few hours from fixation to immunolocalization, enabled similar, or even better, results than conventional protocols. The quantification of immunolabeling for cav-1 indicated an increase in density of up to three-fold in tissues processed in the microwave oven. Furthermore, MW treatment permitted the localization of PPARβ/δ in glutaraldehyde-fixed specimens, which was impossible in the absence of MWI. This study thus showed that techniques involving the use of microwaves could largely improve both ultrastructure and immunodetection.
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Affiliation(s)
- Josiane Aïoun
- Institut National de la Recherche Agronomique (INRA), Unité de Recherche UR902 Nutrition et Régulation Lipidique des Fonctions Cérébrales, Jouy-en-Josas, France
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Yamamoto-Silva FP, Bradaschia-Correa V, Lima LA, Arana-Chavez VE. Ultrastructural and immunohistochemical study of early repair of alveolar sockets after the extraction of molars from alendronate-treated rats. Microsc Res Tech 2013; 76:633-40. [DOI: 10.1002/jemt.22210] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/15/2013] [Accepted: 03/02/2013] [Indexed: 11/10/2022]
Affiliation(s)
| | - Vivian Bradaschia-Correa
- Department of Biomaterials and Oral Biology; School of Dentistry; University of São Paulo; São Paulo; Brazil
| | - Luiz A.P.A. Lima
- Department of Stomatology; School of Dentistry; University of São Paulo; São Paulo; Brazil
| | - Victor E. Arana-Chavez
- Department of Biomaterials and Oral Biology; School of Dentistry; University of São Paulo; São Paulo; Brazil
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Carpentier A, Abreu S, Trichet M, Satiat-Jeunemaitre B. Microwaves and tea: new tools to process plant tissue for transmission electron microscopy. J Microsc 2012; 247:94-105. [PMID: 22681535 DOI: 10.1111/j.1365-2818.2012.03626.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Optimizing sample processing, reducing the duration of the preparation of specimen, and adjusting procedures to adhere to new health and safety regulations, are the current challenges of plant electron microscopists. To address these issues, plant processing protocols for TEM, combining the use of polyphenolic compounds as substitute for uranyl acetate with microwave technology are being developed. In the present work, we optimized microwave-assisted processing of different types of plant tissue for ultrastuctural and immunocytochemical studies. We also explored Oolong tea extract as alternative for uranyl acetate for the staining of plant samples. We obtained excellent preservation of cell ultrastructure when samples were embedded in epoxy resin, and of cell antigenicity, when embedded in LR-White resin. Furthermore, Oolong tea extract successfully replaced uranyl acetate as a counterstain on ultrathin sections, and for in block staining. These novel protocols reduce the time spent at the bench, and improve safety conditions for the investigator. The preservation of the cell components when following these approaches is of high quality. Altogether, they offer significant simplification of the procedures required for electron microscopy of plant ultrastructure.
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Affiliation(s)
- Anaïs Carpentier
- Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355/IFR87, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), 91198, Gif-sur-Yvette Cedex, France
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Martinez EF, Donato TAG, Arana-Chavez VE. In vitro effects of ascorbic acid and β-glycerophosphate on human gingival fibroblast cells. Tissue Cell 2012; 44:325-31. [PMID: 22677409 DOI: 10.1016/j.tice.2012.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 02/03/2012] [Accepted: 04/20/2012] [Indexed: 01/09/2023]
Abstract
Ascorbic acid (AA) and β-glycerophosphate (βG) are considered in vitro osteogenic factors important to the differentiation of osteoblastic progenitor and dental pulp cells into mineralized tissue-forming cells. So, the present study investigated in vitro if these mineralizing inducible factors (AA and βG) could influence differentiation of human gingival fibroblasts when compared with human pulp cells and osteogenic cells derived from rat calvaria cultured. The expression of osteopontin (OPN) and osteoadherin (OSAD) was analyzed by indirect immunofluorescence, immunocytochemistry as well as Western-blotting. In addition, the main ultrastructural aspects were also investigated. No mineralized matrix formation occurred on gingival fibroblasts induced with AA+βG. On these cells, no expression of OPN and OSAD was observed when compared with pulp cells, pulp cells induced with AA+βG as well as osteogenic cells. Ultrastructure analysis additionally showed that gingival fibroblasts exhibited typical fibroblast morphology with no nodule formation. The present findings showed that AA and βG could not promote a mineralized cell differentiation of human gingival fibroblasts and confirm that human dental pulp cells, as the osteogenic cells, are capable to form a mineralized extracellular.
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Affiliation(s)
- Elizabeth F Martinez
- Laboratory of Oral Biology, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227, CEP 05508-900, São Paulo, SP, Brazil.
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Kurth T, Wiedmer S, Entzeroth R. Improvement of Ultrastructural Preservation of Eimeria Oocysts by Microwave-assisted Chemical Fixation or by High Pressure Freezing and Freeze Substitution. Protist 2012; 163:296-305. [DOI: 10.1016/j.protis.2011.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 05/14/2011] [Indexed: 11/24/2022]
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Maciel-Oliveira N, Bradaschia-Correa V, Arana-Chavez VE. Early alveolar bone regeneration in rats after topical administration of simvastatin. ACTA ACUST UNITED AC 2011; 112:170-9. [DOI: 10.1016/j.tripleo.2010.08.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 08/24/2010] [Indexed: 10/18/2022]
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Neves JDS, Omar NF, Narvaes EAO, Gomes JR, Novaes PD. Influence of different decalcifying agents on EGF and EGFR immunostaining. Acta Histochem 2011; 113:484-8. [PMID: 20598354 DOI: 10.1016/j.acthis.2010.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 04/08/2010] [Accepted: 04/11/2010] [Indexed: 11/28/2022]
Abstract
This study was designed to verify the influence of three demineralizing agents on EGF and EGFR immunostaining as well as on tissue morphology. We chose submandibular glands that are a source of EGF and its receptor and which could be analyzed using a control in which the decalcification step was not carried out. After sacrifice of adult male Wistar rats by perfusion fixation, the submandibular glands and mandibles were excised and placed together in each of the following solutions: (a) 5% nitric acid in 4% formaldehyde; (b) 4.13% EDTA pH 7.4; (c) 5% trichloroacetic acid. Mandibles served as a parameter for decalcification time in each demineralizing solution. A control group was performed with submandibular glands that were not placed in any demineralizing solution. After mandibles were completely decalcified, glands were processed by embedding in Paraplast® and immunohistochemical staining was made to detect EGF and EGFR. It was observed that decalcification did not produce noticeable differences in terms of EGF and EGFR immunoreactivity, but had an effect on the quality of the morphology and staining. Our results indicate there is no problem performing immunostaining of EGF and EGFR in tissues that require decalcification. 4.13% EDTA (pH 7.4) is the best choice for decalcification in cases that are not urgent.
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Affiliation(s)
- Juliana Dos Santos Neves
- Department of Morphology, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
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Yang H, Zhao X, Xu Y, Wang L, He Q, Lundberg YW. Matrix recruitment and calcium sequestration for spatial specific otoconia development. PLoS One 2011; 6:e20498. [PMID: 21655225 PMCID: PMC3105080 DOI: 10.1371/journal.pone.0020498] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 04/28/2011] [Indexed: 11/19/2022] Open
Abstract
Otoconia are bio-crystals anchored to the macular sensory epithelium of the utricle and saccule in the inner ear for motion sensing and bodily balance. Otoconia dislocation, degeneration and ectopic calcification can have detrimental effects on balance and vertigo/dizziness, yet the mechanism underlying otoconia formation is not fully understood. In this study, we show that selected matrix components are recruited to form the crystal matrix and sequester Ca(2+) for spatial specific formation of otoconia. Specifically, otoconin-90 (Oc90) binds otolin through both domains (TH and C1q) of otolin, but full-length otolin shows the strongest interaction. These proteins have much higher expression levels in the utricle and saccule than other inner ear epithelial tissues in mice. In vivo, the presence of Oc90 in wildtype (wt) mice leads to an enrichment of Ca(2+) in the luminal matrices of the utricle and saccule, whereas absence of Oc90 in the null mice leads to drastically reduced matrix-Ca(2+). In vitro, either Oc90 or otolin can increase the propensity of extracellular matrix to calcify in cell culture, and co-expression has a synergistic effect on calcification. Molecular modeling and sequence analysis predict structural features that may underlie the interaction and Ca(2+)-sequestering ability of these proteins. Together, the data provide a mechanism for the otoconial matrix assembly and the role of this matrix in accumulating micro-environmental Ca(2+) for efficient CaCO(3) crystallization, thus uncover a critical process governing spatial specific otoconia formation.
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Affiliation(s)
- Hua Yang
- Vestibular Neurogenetics Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Xing Zhao
- Vestibular Neurogenetics Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Yinfang Xu
- Vestibular Neurogenetics Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Lili Wang
- Vestibular Neurogenetics Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Quanyuan He
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Yunxia Wang Lundberg
- Vestibular Neurogenetics Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, United States of America
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Shimada Y, Ichinose S, Sadr A, Burrow MF, Tagami J. Localization of matrix metalloproteinases (MMPs-2, 8, 9 and 20) in normal and carious dentine. Aust Dent J 2010; 54:347-54. [PMID: 20415934 DOI: 10.1111/j.1834-7819.2009.01161.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Dentine matrix metalloproteinases (MMPs) may participate in the destruction of dentine following demineralization by bacterial acids. This study investigated the localization of MMPs in carious dentine. METHODS Frozen sections of dentine caries were prepared without demineralization and immersed in monoclonal antibody against MMP-2, -8, -9 and -20. The sections were labelled by IgG conjugated with gold colloidal particles, and observed under FE-SEM. Labelling indexes (number of gold particles/mum(2)) of outer and inner carious dentine, respectively, with and without bacterial infection, were compared with that of normal dentine. RESULTS MMP-2 was distributed in both carious and normal dentine; the level of MMP-2 showed no significant difference among the outer caries, inner caries, and normal dentine. The labelling indexes of MMP-8 and MMP-9 both significantly decreased at the inner carious dentine compared with the level of normal dentine, but intensified again at the outer caries region. The labelling index of MMP-20 was the highest at normal dentine. CONCLUSIONS The localization of MMPs was visibly detected using immunogold labelling. The localization of MMP-2 showed no significant difference among the three regions, while MMP-8 and MMP-9 showed significant reduction at the inner caries layer, and MMP-20 reduced toward the outer caries.
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Affiliation(s)
- Y Shimada
- Department of Cariology and Operative Dentistry, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.
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Aguiar MC, Arana-Chavez VE. Immunocytochemical detection of dentine matrix protein 1 in experimentally induced reactionary and reparative dentine in rat incisors. Arch Oral Biol 2010; 55:210-4. [PMID: 20138611 DOI: 10.1016/j.archoralbio.2010.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 01/04/2010] [Accepted: 01/15/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Although the general mechanisms of dentinogenesis are understood, several aspects regarding tertiary dentine formation still deserve investigation, especially regarding the presence and distribution of some noncollagenous matrix proteins. As dentine matrix protein 1 (DMP 1) is present in primary dentine, it is possible that this protein may also be present in the dentine matrix secreted after injury, but there are no immunocytochemical studies attempting its detection in tertiary dentine. The aim of this study was to examine the ultrastructural immunolocalization of DMP 1 in the tertiary dentine after extrusion of the rat incisor. STUDY DESIGN Upper incisors were extruded 3mm and then repositioned into their sockets. After several periods, the incisors were fixed and processed for transmission electron microscopy and for immunocytochemistry for DMP 1. RESULTS Extrusion yielded both types of tertiary dentine, which varied in aspect and related cells. DMP 1 was found in the mineralized matrix of all types of dentine, presenting high affinity for collagen, but rare colloidal gold particles over predentine. DMP 1 was evident in the supranuclear region and inside the nucleus of some odontoblast-like cells. CONCLUSION The observed association between DMP 1 and collagen seem to be essential for reactionary and reparative dentine formation.
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Affiliation(s)
- Marcio Cajazeira Aguiar
- Division of Oral Biology, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, Cidade Universitaria, 05508-900 São Paulo, SP, Brazil
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Santos J, Carrilho M, Tervahartiala T, Sorsa T, Breschi L, Mazzoni A, Pashley D, Tay F, Ferraz C, Tjäderhane L. Determination of Matrix Metalloproteinases in Human Radicular Dentin. J Endod 2009; 35:686-9. [DOI: 10.1016/j.joen.2009.02.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/08/2009] [Accepted: 02/17/2009] [Indexed: 10/20/2022]
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Abstract
In the course of attempting to define the bone "secretome" using a signal-trap screening approach, we identified a gene encoding a small membrane protein novel to osteoblasts. Although previously identified in silico as ifitm5, no localization or functional studies had been undertaken on this gene. We characterized the expression patterns and localization of this gene in vitro and in vivo and assessed its role in matrix mineralization in vitro. The bone specificity and shown role in mineralization led us to rename the gene bone restricted ifitm-like protein (Bril). Bril encodes a 14.8-kDa 134 amino acid protein with two transmembrane domains. Northern blot analysis showed bone-specific expression with no expression in other embryonic or adult tissues. In situ hybridization and immunohistochemistry in mouse embryos showed expression localized on the developing bone. Screening of cell lines showed Bril expression to be highest in osteoblasts, associated with the onset of matrix maturation/mineralization, suggesting a role in bone formation. Functional evidence of a role in mineralization was shown by adenovirus-mediated Bril overexpression and lentivirus-mediated Bril shRNA knockdown in vitro. Elevated Bril resulted in dose-dependent increases in mineralization in UMR106 and rat primary osteoblasts. Conversely, knockdown of Bril in MC3T3 osteoblasts resulted in reduced mineralization. Thus, we identified Bril as a novel osteoblast protein and showed a role in mineralization, possibly identifying a new regulatory pathway in bone formation.
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Zhao X, Jones SM, Thoreson WB, Lundberg YW. Osteopontin is not critical for otoconia formation or balance function. J Assoc Res Otolaryngol 2008; 9:191-201. [PMID: 18459000 DOI: 10.1007/s10162-008-0117-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 02/29/2008] [Indexed: 10/22/2022] Open
Abstract
Unlike the structural and mechanical role of bone crystals, the inertial mass of otoconia crystals provides a shearing force to stimulate the mechanoreceptors of the utricle and saccule (the gravity receptor organ) under the stimuli of linear motion. It is not clear whether otoconia, composed primarily of CaCO3 and glycoproteins, go through similar calcification processes as bone. We have recently shown that otoconin-90 (Oc90) regulates the growth of otoconia crystals as osteopontin does bone crystals. Here, we analyzed the role of this non-collagenous bone matrix protein, osteopontin, in otoconia formation and balance function utilizing its knockout mice, whose inner ear phenotype has not been examined. Despite the presence of the protein in wild-type otoconia and vestibular hair cells, morphological, ultrastructural, and protein and calcium composition analyses of osteopontin null otoconia show that the protein is not needed for crystal formation, and no evidence of compensatory protein deposition is found. Employment of a wide spectrum of balance behavioral tests demonstrates that the protein is not critical for balance function either, which is confirmed by the normal function of the gravity receptor organ directly measured with linear vestibular-evoked potentials (VsEPs). When compared with findings on other otoconins, the data manifest a hierarchy of importance of proteins in crystallization and indicate mechanistic similarities and differences between bone and otoconia calcification.
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Affiliation(s)
- Xing Zhao
- Genetics Department, Boys Town National Research Hospital, Omaha, NE 68131, USA
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20
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Mazzoni A, Pashley DH, Tay FR, Gobbi P, Orsini G, Ruggeri A, Carrilho M, Tjäderhane L, Di Lenarda R, Breschi L. Immunohistochemical identification of MMP‐2 and MMP‐9 in human dentin: Correlative FEI‐SEM/TEM analysis. J Biomed Mater Res A 2008; 88:697-703. [DOI: 10.1002/jbm.a.31920] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Annalisa Mazzoni
- Department of SAU and FAL, University of Bologna, Bologna, Italy
| | - David H. Pashley
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
| | - Franklin R. Tay
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
| | - Pietro Gobbi
- Institute of Morphological Sciences; University of Urbino “Carlo Bo”, Urbino, Italy
| | - Giovanna Orsini
- Department of Biomorphology, University of Chieti‐Pescara, Chieti, Italy
| | | | - Marcela Carrilho
- Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912‐1129
- Department of Restorative Dentistry, Dental Materials Area, University of Campinas, Piracicaba School of Dentistry, Piracicaba/SP, Brazil
| | - Leo Tjäderhane
- Institute of Dentistry, University of Helsinki, Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital (HUCH), Helsinki, Finland
| | - Roberto Di Lenarda
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
| | - Lorenzo Breschi
- Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Trieste, Italy
- IGM‐CNR, Unit of Bologna c/o IOR, Bologna, Italy
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Bradaschia-Correa V, Massa LF, Arana-Chavez VE. Effects of alendronate on tooth eruption and molar root formation in young growing rats. Cell Tissue Res 2007; 330:475-85. [PMID: 17901984 DOI: 10.1007/s00441-007-0499-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 08/28/2007] [Indexed: 10/22/2022]
Abstract
Tooth eruption consists of the movement of teeth from the bony crypt in which they initiate their development to the occlusal plane in the oral cavity. Interactions between the tooth germ and its surrounding alveolar bone occur in order to offer spatial conditions for its development and eruption. This involves bone remodeling during which resorption is a key event. Bisphosphonates are a group of drugs that interfere with the resorption of mineralized tissues. With the purpose of investigating the effects of sodium alendronate (a potent bisphosphonate inhibitor of osteoclast activity) on alveolar bone during tooth development and eruption, we gave newborn rats daily doses of this drug for 4, 14, and 30 days. Samples of the maxillary alveolar process containing the tooth germs were processed for light, transmission, and scanning electron microscopy and were also submitted to tartrate-resistant acid phosphatase histochemistry and high-resolution colloidal-gold immunolabeling for osteopontin. Inhibition of osteoclast activity by sodium alendronate caused the absence of tooth eruption. The lack of alveolar bone remodeling resulted in primary bone with the presence of latent osteoclasts and abundant osteopontin at the interfibrillar regions. The developing bone trabeculae invaded the dental follicle and reached the molar tooth germs, provoking deformities in enamel surfaces. No root formation was observed. These findings suggested that alendronate effectively inhibited tooth eruption by interfering with the activation of osteoclasts, which remained in a latent stage.
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Affiliation(s)
- Vivian Bradaschia-Correa
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, Brazil
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22
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Aguiar MC, Arana-Chavez VE. Ultrastructural and immunocytochemical analyses of osteopontin in reactionary and reparative dentine formed after extrusion of upper rat incisors. J Anat 2007; 210:418-27. [PMID: 17428203 PMCID: PMC2100295 DOI: 10.1111/j.1469-7580.2007.00708.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Reactionary dentine and reparative dentine are two strategies used by the dentine-pulp complex to respond to injury. The reactionary dentine is secreted by original odontoblasts, while the reparative dentine is formed by odontoblast-like cells. Osteopontin (OPN) is a non-collagenous protein usually present in the repair of mineralized tissues. It is likely to be present in newly formed dentine but there are no studies attempting to detect it in reactionary and reparative dentine. The aim of the present study was to examine the ultrastructural characteristics, as well as the presence and distribution of OPN in reactionary and reparative dentine by provoking extrusion of the rat incisor. The right upper incisors of 3-month-old male rats were extruded 3 mm and then repositioned into their original sockets. At 3, 7, 10, 15, 20, 30 and 60 days after surgery, the incisors were fixed in glutaraldehyde-formaldehyde and then processed for scanning and transmission electron microscopy and for immunocytochemistry for OPN. After extrusive trauma, the dentine-pulp interface showed the presence of reactionary and reparative dentine, which varied in aspect, thickness and related cells. OPN was not detected in the physiological and reactionary dentine, while it was strongly immunoreactive in the matrix that surrounded the entrapped cells of reparative dentine. In addition, original odontoblasts subjacent to the physiological dentine contained OPN in their Golgi region. The present findings showed that reparative dentine shares some structural characteristics with primary bone, especially in relation to its OPN content. The odontoblast-like cells resemble osteoblasts rather than odontoblasts.
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Affiliation(s)
- Marcio Cajazeira Aguiar
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Brazil
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23
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Jimenez-Pellegrin C, Arana-Chavez VE. Root resorption repair in mandibular first premolars after rotation. A transmission electron microscopy analysis combined with immunolabeling of osteopontin. Am J Orthod Dentofacial Orthop 2007; 132:230-6. [PMID: 17693375 DOI: 10.1016/j.ajodo.2007.03.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 03/09/2007] [Accepted: 03/20/2007] [Indexed: 11/15/2022]
Abstract
INTRODUCTION A previous study with scanning electron microscopy showed that orthodontic root resorption occurs at the lateral surfaces of premolar roots for 2 to 6 weeks after orthodontic rotation. The purpose of this investigation was to observe how resorbed cementum repairs during rotation movement. METHODS Twenty-one mandibular first premolars from 12 patients, orthodontically indicated for extraction, were used. They were intra-individually divided into 2 groups: 8 teeth were not moved (control group), and 13 were rotated (experimental group). In the experimental group, a rotational force (25 g both buccally and lingually) with a precise biomechanical model, individually calibrated, was applied for 2, 3, 4, or 6 weeks. After extraction, the teeth were fixed and decalcified, and 8 were conventionally processed for transmission electron microscopy, and 13 teeth were processed for high-resolution immunocytochemistry by using an antibody against osteopontin. The samples were analyzed in a transmission electron microscope. RESULTS This examination showed areas of repair in previously resorbed lacunae in the experimental group. Both the clastic cells and the root surface showed immunolabeling for osteopontin. In addition to areas of cementum resorption and various degrees of cell and extracellular matrix degeneration, active cementoblasts and fibroblasts in several stages of differentiation and activity appeared adjacent to newly synthesized collagen fibers, thus reestablishing the function of the periodontal ligament. CONCLUSIONS We concluded that cementum repair occurs after resorption during rotation movement and that noncollagenous matrix protein osteopontin plays a role in both resorbing and repairing.
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Affiliation(s)
- Cristina Jimenez-Pellegrin
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, Brazil
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24
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Abstract
Microwave processors can provide a means of rapid processing and resin embedding for biological specimens that are to be sectioned and examined by transmission electron microscopy. This chapter describes a microwave-assisted protocol for processing, dehydrating, and embedding biological material, from living specimens to blocks embedded in sectionable resin in 4 h or less.
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Affiliation(s)
- Paul Webster
- Ahmanson Advanced Electron Microscopy and Imaging Center, House Ear Institute, Los Angeles, CA, USA
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25
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Massa LF, Bradaschia-Correa V, Arana-Chavez VE. Immunocytochemical Study of Amelogenin Deposition during the Early Odontogenesis of Molars in Alendronate-treated Newborn Rats. J Histochem Cytochem 2006; 54:713-25. [PMID: 16461365 DOI: 10.1369/jhc.5a6853.2006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Newborn rats were treated with sodium alendronate to study how enamel is formed and the effect of alendronate during early odontogenesis. Ultrastructural analysis combined with high-resolution immunocytochemistry for amelogenin was carried out. Twelve rats were subjected to daily SC injections of sodium alendronate (2.5 mg/kg/day) for 3 days on their dorsal region, whereas three rats were daily injected with saline solution as a control. Molar tooth germs from 3-day-old rats were fixed under microwave irradiation in 0.1% glutaraldehyde + 4% formaldehyde buffered at pH 7.2 with 0.1 M sodium cacodylate. The specimens were left undecalcified, postfixed with osmium tetroxide, dehydrated, and embedded in LR White resin. Ultrathin sections were incubated with a chicken anti-24-kDa rat amelogenin antibody, a secondary antibody, and finally with a protein A-gold complex. Large patches of amelogenin were present over the unmineralized mantle dentin and at early secretory ameloblasts. At more advanced stages, they were also detected at the enamel matrix, as well as in the mineralized dentin, at the periodontoblastic space of the dentinal tubules, and at the predentin. It is likely that the main effect of alendronate at early stages of odontogenesis is the increase of synthesis/secretion of amelogenin, promoting its deposition within the forming dentin and enamel.
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Affiliation(s)
- Luciana F Massa
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
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26
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Bartlett JD, Ganss B, Goldberg M, Moradian-Oldak J, Paine ML, Snead ML, Wen X, White SN, Zhou YL. Protein–Protein Interactions of the Developing Enamel Matrix. Curr Top Dev Biol 2006; 74:57-115. [PMID: 16860665 DOI: 10.1016/s0070-2153(06)74003-0] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Extracellular matrix proteins control the formation of the inorganic component of hard tissues including bone, dentin, and enamel. The structural proteins expressed primarily in the enamel matrix are amelogenin, ameloblastin, enamelin, and amelotin. Other proteins, like biglycan, are also present in the enamel matrix as well as in other mineralizing and nonmineralizing tissues of mammals. In addition, the presence of sulfated enamel proteins, and "tuft" proteins has been examined and discussed in relation to enamel formation. The structural proteins of the enamel matrix must have specific protein-protein interactions to produce a matrix capable of directing the highly ordered structure of the enamel crystallites. Protein-protein interactions are also likely to occur between the secreted enamel proteins and the plasma membrane of the enamel producing cells, the ameloblasts. Such protein-protein interactions are hypothesized to influence the secretion of enamel proteins, establish short-term order of the forming matrix, and to mediate feedback signals to the transcriptional machinery of these cells. Membrane-bound proteins identified in ameloblasts, and which interact with the structural enamel proteins, include Cd63 (cluster of differentiation 63 antigen), annexin A2 (Anxa2), and lysosomal-associated glycoprotein 1 (Lamp1). These and related data help explain the molecular and cellular mechanisms responsible for the removal of the organic enamel matrix during the events of enamel mineralization, and how the enamel matrix influences its own fate through signaling initiated at the cell surface. The knowledge gained from enamel developmental studies may lead to better dental and nondental materials, or materials inspired by Nature. These data will be critical to scientists, engineers, and dentists in their pursuits to regenerate an entire tooth. For tooth regeneration to become a reality, the protein-protein interactions involving the key dental proteins must be identified and understood. The scope of this review is to discuss the current understanding of protein-protein interactions of the developing enamel matrix, and relate this knowledge to enamel biomineralization.
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Affiliation(s)
- John D Bartlett
- The Forsyth Institute, 140 The Fenway, Boston, MA 02115, USA
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27
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Massa LF, Ramachandran A, George A, Arana-Chavez VE. Developmental appearance of dentin matrix protein 1 during the early dentinogenesis in rat molars as identified by high-resolution immunocytochemistry. Histochem Cell Biol 2005; 124:197-205. [PMID: 16049693 DOI: 10.1007/s00418-005-0009-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
Dentin matrix protein 1 (DMP 1) is an acidic phosphoprotein that has been postulated to play an important role in mineralized tissue formation. We have examined rat molar tooth germs by applying a high-resolution immunocytochemical approach with the purpose to identify the temporal and spatial localization of DMP 1 at the onset of dentinogenesis. Upper molar tooth germs of 2- to 3-day-old Wistar rats were fixed in a cacodylate-buffered 0.1% glutaraldehyde + 4% formaldehyde fixative, left unosmicated and embedded in LR White resin. The sections were incubated with a polyclonal DMP 1 antibody for postembedding colloidal gold immunolabeling and examined in a Jeol 1010 transmission electron microscope. The earliest localization of DMP 1 was in the Golgi region as well as in the nucleus of differentiating odontoblasts. When mineralization spread from matrix vesicles to the surrounding matrix, DMP 1 was extracellularly detected around the mineralizing globules. In the regions of fully mineralized mantle dentin, it was present in the mineralized regions, mainly around the peritubular dentin. The appearance of DMP 1 during early dentinogenesis implies a direct role for this protein in both odontoblast differentiation and matrix mineralization.
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Affiliation(s)
- Luciana F Massa
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, 05508-900, São Paulo, Brazil
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28
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Janones DS, Massa LF, Arana-Chavez VE. Immunocytochemical examination of the presence of amelogenin during the root development of rat molars. Arch Oral Biol 2005; 50:527-32. [PMID: 15777534 DOI: 10.1016/j.archoralbio.2004.10.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Accepted: 10/12/2004] [Indexed: 10/26/2022]
Abstract
The presence of enamel proteins, especially amelogenins, during root development has been a subject of controversy for a long time. Whereas some studies have reported the presence of enamel proteins on the root surface, others were not able to detect them at these places. Since microwave (MW) processing has been shown to improve the antigen retention in mineralised tissues, we have applied MW techniques to ultrastructurally analyse the presence of amelogenin during root formation in rat molars. Upper molar tooth germs from 12 and 13-day-old Wistar rats were fixed in 0.1% glutaraldehyde + 4% formaldehyde under MW irradiation. They were then decalcified in 4.13% EDTA, dehydrated in graded concentrations of ethanol and embedded in LR White Resin. Ultrathin sections were processed for post-embedding colloidal gold immunolabelling using a chicken egg yolk antibody against a 24 kDa rat amelogenin. Then, the grids were incubated with a rabbit anti-chicken IgG secondary antibody and with a protein A-gold complex. The immunoreactivity for 24-kDa amelogenin was detected in the cytoplasm of the epithelial diaphragm cells--the most apical portion of the Hertwig's epithelial root sheath (HERS), and in less amounts on the adjacent dental papilla extracellular matrix. Amelogenin was no longer observed at advanced stages of root dentinogenesis or later, during cementogenesis. The restricted presence of amelogenin at the early stages of root formation suggests that this protein may play a role in the differentiation of ectomesenchymal cells into root odontoblasts.
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Affiliation(s)
- Daniela S Janones
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
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29
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Arana-Chavez VE. Extracellular matrix proteins and the selective resorption of deciduous tooth roots. Am J Orthod Dentofacial Orthop 2005; 127:159; author reply 159-60. [PMID: 15754470 DOI: 10.1016/j.ajodo.2004.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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30
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Torres-Quintana MA, Gaete M, Hernandez M, Farías M, Lobos N. Ameloblastin and amelogenin expression in posnatal developing mouse molars. J Oral Sci 2005; 47:27-34. [PMID: 15881226 DOI: 10.2334/josnusd.47.27] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Ameloblastin and amelogenin are structural proteins present in the enamel matrix of developing teeth. Here we report the results of in situ hybridization analyses with DNA probes of ameloblastin and amelogenin expression in the mandibular first molars of ICR/Jcl mice from postnatal day 1 to day 15. Ameloblastin mRNA expression was observed in ameloblasts at day 2 while amelogenin mRNA was detected in secretory ameloblasts at day 3. Significant expression of both molecules was observed at days 4, 5 and 6, after which the levels decreased. Amelogenin expression ended on day 10, while ameloblastin mRNA was only weakly detected on day 12. Neither amelogenin nor ameloblastin expression was observed in day 15 mouse molars. Amelogenin and ameloblastin mRNAs were restricted to ameloblasts. We conclude that amelogenin and ameloblastin expression is enamel-specific, and suggest that these genes might be involved in the mineralization of enamel. It is possible that ameloblastin could participate in the attachment of ameloblasts to the enamel surface. In this case, the downregulation of expression may indicate the beginning of the maturation stage in which the ameloblasts tend to detach from the enamel layer.
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João SMA, Arana-Chavez VE. Tight junctions in differentiating ameloblasts and odontoblasts differentially express ZO-1, occludin, and claudin-1 in early odontogenesis of rat molars. ACTA ACUST UNITED AC 2004; 277:338-43. [PMID: 15052661 DOI: 10.1002/ar.a.20021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Little is known about the expression of associated proteins during the assembly of tight junctions (TJs). We studied the distribution of ZO-1, occludin, and claudin-1 between differentiating ameloblasts and odontoblasts in molar tooth germs from 1- to 3-day-old rats by confocal laser scanning microscopy. Immunoreactivity for ZO-1 was strong at proximal and distal junctional complexes of differentiating ameloblasts, while it was weak and punctuate at the distal region of differentiating odontoblasts. Occludin was immunoreactive at distal and proximal complexes of early differentiating ameloblasts and at distal regions of differentiating odontoblasts. However, in more advanced stages, occludin was only evident at the proximal complex of ameloblasts. Claudin-1 was strongly detected at the proximal complex but it was weak at distal complex of late differentiating ameloblasts. Thus, our results showed that ZO-1, occludin, and claudin-1 are differentially expressed as TJs assemble for regulating polarity and/or paracellular permeability in differentiating ameloblasts and odontoblasts.
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Affiliation(s)
- Silvia M A João
- Department of Histology and Embryology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Bonafe-Oliveira L, Faltin RM, Arana-Chavez VE. Ultrastructural and histochemical examination of alveolar bone at the pressure areas of rat molars submitted to continuous orthodontic force. Eur J Oral Sci 2003; 111:410-6. [PMID: 12974685 DOI: 10.1034/j.1600-0722.2003.00067.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is usually believed that repair in alveolar bone during orthodontic movement occurs after decreasing of force. However, we have recently observed signs of repair in previously resorbed cementum from human teeth exposed to continuous forces. In order to test the hypothesis that bone resorption and deposition occur concomitantly at the pressure areas, a continuous 15 cN force was applied in a buccal direction to upper first molars from eight 2.5-month-old male Wistar rats for 3 d (n = 4) and 7 d (n = 4). As a control, two additional rats did not have their molars moved. Maxillae were fixed in 2% glutaraldehyde + 2.5% formaldehyde, under microwave irradiation, decalcified in ethylenediaminetetraacetic acid, and processed for transmission electron microscopy. Specimens from one rat from each group were processed for tartrate-resistant acid phosphatase (TRAP) histochemistry. At both the times studied, the alveolar bone surface at the pressure areas showed numerous TRAP-positive osteoclasts, which were apposed to resorption lacunae. In addition, osteoblasts with numerous synthesis organelles were present in the neighboring areas overlying an organic matrix. Thus, this study provides evidence that the application of continuous forces produces concomitant bone resorption and formation at the pressure areas in rat molars.
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Affiliation(s)
- Lucienne Bonafe-Oliveira
- Laboratory of Mineralized Tissue Biology, Department of Histology and Embryology, Institute of Biomedical Sciences, University of São Paulo, Brazil
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33
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João SMA, Arana-Chavez VE. Expression of connexin 43 and ZO-1 in differentiating ameloblasts and odontoblasts from rat molar tooth germs. Histochem Cell Biol 2003; 119:21-6. [PMID: 12548402 DOI: 10.1007/s00418-002-0482-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2002] [Indexed: 12/20/2022]
Abstract
We studied the distribution of connexin (Cx) 43 and ZO-1 by confocal laser scanning microscopy at early stages of dentinogenesis and amelogenesis. Labeling for Cx43 was observed at early stages of differentiation in both the epithelial cells and differentiating odontoblasts. Immunolabeling was detected at the distal and medial regions of undifferentiated ameloblasts and between cells from stratum intermedium and stellate reticulum. Differentiating odontoblasts exhibited immunoreaction for this antibody at their distal end. Immunoreactivity for ZO-1 was observed at regions that correspond to the proximal and distal junctional complexes of differentiating ameloblasts. Staining for ZO-1 was observed at apical regions of odontoblasts with a punctate appearance. In more advanced stages, expression of Cx43 was more evident on ameloblasts, especially at the junctional complexes. Punctate immunolabeling for Cx43 was observed at the lateral sides of differentiating ameloblasts and between the other cells of the enamel organ. Immunoreaction for ZO-1 in ameloblasts was more evident than at the previous stage. It was also observed at the distal end of differentiated odontoblasts. The present study showed that differentiating ameloblasts and odontoblasts express Cx43 and ZO-1 as early as the start of the differentiation process. In addition, the expression of these junctional proteins increases as differentiation of cells continues.
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Affiliation(s)
- Silvia M A João
- Laboratory of Mineralized Tissue Biology, Department of Histology and Embryology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, S.P., Brazil
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Moriguchi K, Utsumi M, Maeda H, Kameyama Y, Ohno N. Cytochrome oxidase activity and confocal laser scanning microscopic analysis of the hamster submandibular gland using microwave irradiated fixation. SCANNING 2002; 24:314-320. [PMID: 12507386 DOI: 10.1002/sca.4950240606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Submandibular glands of the hamster were irradiated in 2% paraformaldehyde (pFA)-0.5% pure glutaraldehyde (PGA) with a microwave (MW) processor at temperatures of 10 degrees and 37 degrees C. Electron microscopy showed that cytochrome oxidase activity was taking place in the mitochondrial intermembrane-intracristal space of the granular duct cell when the temperature of the MW-irradiated fixatives was at 10 degrees C. However, a decrease of this activity was observed when we took care to keep the temperature of the MW-irradiated fixatives at 37 degrees C. The distinct reduction of cytochrome oxidase activity allowed by MW irradiation seems to be due the thermal affects of fixatives. Of course, the possibility cannot be excluded that MW irradiation caused other undetectable membrane damage. Then, we used confocal laser scanning microscopy for the preservation check of the mitochondrial membrane for cytochemistry with MW-irradiated fixation. The fluorescence of rhodamine 123 was observed in the inner spaces of the mitochondria at temperatures of 10 degrees and 37 degrees C. When the same tissues were fixed with 2% pFA using an MW processor as the sole fixative at 10 degrees C, no mitochondrial fluorescence was observed. Cytochrome oxidase activity, by contrast, could be seen in the mitochondrial intermembrane-intracristal spaces in the same condition. Formaldehyde is not the best aldehyde for the purpose of ultrastructural preservation. On the other hand, light and electron microscopy showed that the endogenous peroxidase activity was localized in the nuclear envelope, endoplasmic reticulum, secretory granules, and Golgi apparatus of the hamster submandibular gland using 2% pFA-0.5% PGA fixative with and without MW irradiations at temperatures of 10 degrees and 37 degrees C. Some of the same cells were fixed with only 2% pFA under MW irradiation at 10 degrees C; however, marked diffuseness of the peroxidase activity was observed. Therefore, these results indicated that cytochrome oxidase activity was sensitive to heat with MW-irradiated fixation. Peroxidase activity was very resistant to heat with MW-irradiated fixation but not with pFA solo fixation, therefore, PGA had to be used.
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Affiliation(s)
- K Moriguchi
- Department of Anatomy, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
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Nakamura H, Tsuji T, Hirata A, Yamamoto T. Localization of osteoprotegerin (OPG) on bone surfaces and cement lines in rat tibia. J Histochem Cytochem 2002; 50:945-53. [PMID: 12070273 DOI: 10.1177/002215540205000708] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Osteoprotegerin (OPG), a soluble member of the tumor necrosis factor (TNF) receptor family, is an osteoclastogenesis inhibitory factor. We investigated the localization of OPG in rat tibia using a specific peptide antibody to clarify the role of OPG in bone remodeling. OPG reactivity was mainly seen on bone surfaces. In bone matrices, OPG was also localized on cartilage/bone interfaces and cement lines. However, labeling was scarcely detected in the region of contact between osteoclasts and stromal cells. Some osteoblasts and osteocytes showed weak labeling. Immunoreactivity was not seen in chondrocytes or osteoclasts. Immunoelectron microscopic observation revealed that OPG is localized on the bone surfaces under osteoclasts. These findings suggest that OPG derived from osteoblast lineage cells and/or serum may be concentrated on resorbed bone surfaces and subsequently on cement lines. OPG may play an important role in the prevention of excess bone resorption by inhibiting differentiation and activity of osteoclasts in bone remodeling.
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Affiliation(s)
- Hiroaki Nakamura
- Department of Oral Morphology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
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