scholarly journals Morphometric Approach to Pulp Fibroblast Development in Tooth Germ

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Irina-Draga Căruntu ◽  
Sergiu Daniel Săvinescu ◽  
Cornelia Amălinei
Keyword(s):  
Form Factor ◽  
Dental Pulp ◽  
Tooth Development ◽  
Tooth Germ ◽  
Mean Value ◽  
Relative Distance ◽  
Color Segmentation ◽  
Histological Criteria ◽  
The Individual ◽  
Tooth Germs

This paper builds a morphometric framework for the analysis of dental pulp fibroblast evolution during tooth development. We investigated 15 tooth germs (cases) organized, by histological criteria, in three groups corresponding to cap, early bell, and late bell stages, respectively. Each group comprised five cases. The morphometric description used the following parameters: areaA, perimeterP—automatically extracted by a color segmentation technique, and form factor (FF)—calculated as4πA/P2. The designed framework operated at inter- and intragroup levels. The intergroup analysis quantified the differences between groups, in the sense of a relative distance (RD) adequately defined by mean-value scaling. We showed that the stage of early bell is approximately 5 times closer to late bell than to cap. The quantification procedure required concomitant information aboutA,Pparameters (asP versus Adependences, orFFvalues), whereas the procedure failed forAorPseparately used. The intragroup analysis quantified the similarity of the cases belonging to the same stage. We proved that, unlike the intergroup tests, the individual exploitation of all three descriptorsA,P, andFFis effective, yielding highly compatible results. Within any group, most cases presented RDs less than 10% from the group mean value, regardless of the descriptor type.

BMP4 rescues a non-cell-autonomous function of Msx1 in tooth development

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4711-4718 ◽  
Author(s):  
M. Bei ◽  
K. Kratochwil ◽  
R.L. Maas
Keyword(s):  
Dental Pulp ◽  
Tooth Development ◽  
Survival Function ◽  
Tooth Germ ◽  
Tooth Formation ◽  
Kidney Capsule ◽  
Dependent Signal ◽  
Dental Epithelium ◽  
Tooth Germs

The development of many organs depends on sequential epithelial-mesenchymal interactions, and the developing tooth germ provides a powerful model for elucidating the nature of these inductive tissue interactions. In Msx1-deficient mice, tooth development arrests at the bud stage when Msx1 is required for the expression of Bmp4 and Fgf3 in the dental mesenchyme (Bei, M. and Maas, R. (1998) Development 125, 4325–4333). To define the tissue requirements for Msx1 function, we performed tissue recombinations between wild-type and Msx1 mutant dental epithelium and mesenchyme. We show that through the E14.5 cap stage of tooth development, Msx1 is required in the dental mesenchyme for tooth formation. After the cap stage, however, tooth development becomes Msx1 independent, although our experiments identify a further late function of Msx1 in odontoblast and dental pulp survival. These results suggest that prior to the cap stage, the dental epithelium receives an Msx1-dependent signal from the dental mesenchyme that is necessary for tooth formation. To further test this hypothesis, Msx1 mutant tooth germs were first cultured with either BMP4 or with various FGFs for two days in vitro and then grown under the kidney capsule of syngeneic mice to permit completion of organogenesis and terminal differentiation. Previously, using an in vitro culture system, we showed that BMP4 stimulated the growth of Msx1 mutant dental epithelium (Chen, Y., Bei, M. Woo, I., Satokata, I. and Maas, R. (1996). Development 122, 3035–3044). Using the more powerful kidney capsule grafting procedure, we now show that when added to explanted Msx1-deficient tooth germs prior to grafting, BMP4 rescues Msx1 mutant tooth germs all the way to definitive stages of enamel and dentin formation. Collectively, these results establish a transient functional requirement for Msx1 in the dental mesenchyme that is almost fully supplied by BMP4 alone, and not by FGFs. In addition, they formally prove the postulated downstream relationship of BMP4 with respect to Msx1, establish the non-cell-autonomous nature of Msx1 during odontogenesis, and disclose an additional late survival function for Msx1 in odontoblasts and dental pulp.

scholarly journals Expression, localization and synthesis of small leucine-rich proteoglycans in developing mouse molar tooth germ

2020 ◽  
Vol 64 (1) ◽  
Author(s):  
Angammana Randilini ◽  
Kaoru Fujikawa ◽  
Shunichi Shibata
Keyword(s):  
Organ Culture ◽  
Developmental Stages ◽  
Tooth Development ◽  
Expression Patterns ◽  
Tooth Germ ◽  
Molar Tooth ◽  
Cervical Region ◽  
Metabolic Labeling ◽  
Tooth Formation ◽  
Tooth Germs

The gene expression and protein synthesis of small leucine-rich proteoglycans (SLRPs), including decorin, biglycan, fibromodulin, and lumican, was analyzed in the context of the hypothesis that they are closely related to tooth formation. In situ hybridization, immunohistochemistry, and organ culture with metabolic labeling of [35S] were carried out in mouse first molar tooth germs of different developmental stages using ICR mice at embryonic day (E) 13.5 to postnatal day (P) 7.0. At the bud and cap stage, decorin mRNA was expressed only in the surrounding mesenchyme, but not within the tooth germ. Biglycan mRNA was then expressed in the condensing mesenchyme and the dental papilla of the tooth germ. At the apposition stage (late bell stage), both decorin and biglycan mRNA were expressed in odontoblasts, resulting in a switch of the pattern of expression within the different stages of odontoblast differentiation. Decorin mRNA was expressed earlier in newly differentiating odontoblasts than biglycan. With odontoblast maturation and dentin formation, decorin mRNA expression was diminished and localized to the newly differentiating odontoblasts at the cervical region. Simultaneously, biglycan mRNA took over and extended its expression throughout the new and mature odontoblasts. Both mRNAs were expressed in the dental pulp underlying the respective odontoblasts. At P7.0, both mRNAs were weakly expressed but maintained their spatial expression patterns. Immunostaining showed that biglycan was localized in the dental papillae and pulp. In addition, all four SLRPs showed clear immunostaining in predentin, although the expressions of fibromodulin and lumican mRNAs were not identified in the tooth germs examined. The organ culture data obtained supported the histological findings that biglycan is more predominant than decorin at the apposition stage. These results were used to identify biglycan as the principal molecule among the SLRPs investigated. Our findings indicate that decorin and biglycan show spatial and temporal differential expressions and play their own tissue-specific roles in tooth development.

scholarly journals Runx3 negatively regulates Osterix expression in dental pulp cells

2007 ◽  
Vol 405 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Li Zheng ◽  
Koichiro Iohara ◽  
Masaki Ishikawa ◽  
Takeshi Into ◽  
Teruko Takano-Yamamoto ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Dental Pulp ◽  
Tooth Development ◽  
Tooth Germ ◽  
Dental Pulp Cells ◽  
Mobility Shift ◽  
Pulp Cells ◽  
Mobility Shift Assay ◽  
Responsive Element

Osterix, a zinc-finger-containing transcription factor, is required for osteoblast differentiation and bone formation. Osterix is also expressed in dental mesenchymal cells of the tooth germ. However, transcriptional regulation by Osterix in tooth development is not clear. Genetic studies in osteogenesis place Osterix downstream of Runx2 (Runt-related 2). The expression of Osterix in odontoblasts overlaps with Runx3 during terminal differentiation in vivo. Runx3 down-regulates Osterix expression in mouse DPCs (dental pulp cells). Therefore the regulatory role of Runx3 on Osterix expression in tooth development was investigated. Enforced expression of Runx3 down-regulated the activity of the Osterix promoter in the human embryonic kidney 293 cell line. When the Runx3 responsive element on the Osterix promoter, located at −713 to −707 bp (site 3, AGTGGTT) relative to the cap site, was mutated, this down-regulation was abrogated. Furthermore, electrophoretic mobility-shift assay and chromatin immunoprecipitation assays in mouse DPCs demonstrated direct functional binding of Runx3 to the Osterix promoter. These results demonstrate the transcriptional regulation of Osterix expression by Runx3 during differentiation of dental pulp cells into odontoblasts during tooth development.

scholarly journals The concurrent stimulation of Wnt and FGF8 signaling induce differentiation of dental mesenchymal cells into odontoblast-like cells

2021 ◽  
Author(s):  
Motoyoshi Kimura ◽  
Akiko Saito ◽  
Shoko Onodera ◽  
Takashi Nakamura ◽  
Makoto Suematsu ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Tooth Development ◽  
Tooth Germ ◽  
Mesenchymal Cells ◽  
Dentin Matrix Protein ◽  
Fibroblast Growth Factor 8 ◽  
Related Transcription Factor ◽  
Tooth Germs ◽  
Canonical Wnt ◽  
Stimulation Of

AbstractFibroblast growth factor 8 (FGF8) is known to be a potent stimulator of canonical Wnt/β-catenin activity, an essential factor for tooth development. In this study, we analyzed the effects of co-administration of FGF8 and a CHIR99021 (GSK3β inhibitor) on differentiation of dental mesenchymal cells into odontoblasts. Utilizing Cre-mediated EGFP reporter mice, dentin matrix protein 1 (Dmp1) expression was examined in mouse neonatal molar tooth germs. At birth, expression of Dmp1-EGFP was not found in mesenchymal cells but rather epithelial cells, after which Dmp1-positive cells gradually emerged in the mesenchymal area along with disappearance in the epithelial area. Primary cultured mesenchymal cells from neonatal tooth germ specimens showed loss of Dmp1-EGFP positive signals, whereas addition of Wnt3a or the CHIR99021 significantly regained Dmp1 positivity within approximately 2 weeks. Other odontoblast markers such as dentin sialophosphoprotein (Dspp) could not be clearly detected. Concurrent stimulation of primary cultured mesenchymal cells with the CHIR99021 and FGF8 resulted in significant upregulation of odonto/osteoblast proteins. Furthermore, increased expression levels of runt-related transcription factor 2 (Runx2), osterix, and osteocalcin were also observed. The present findings indicate that coordinated action of canonical Wnt/β-catenin and FGF8 signals is essential for odontoblast differentiation of tooth germs in mice.

Delayed Development of Maxillary Second Premolar: Case Report and Literature Review

2021 ◽  
Vol 45 (1) ◽  
pp. 63-65
Author(s):  
Chen Ying ◽  
You Wen Zhe ◽  
Xia bin
Keyword(s):  
Case Report ◽  
Literature Review ◽  
Tooth Development ◽  
Tooth Germ ◽  
Panoramic Radiograph ◽  
Delayed Development ◽  
Tooth Germs

Delayed tooth development (DTD) is the development progress of a tooth germ that takes place later due to local or general causes. This case report reviews a 16-year-old Asian adolescent whose bilateral upper second premolar germs were at Nolla’s 6 stage as shown on a panoramic radiograph. It is unusual that tooth germs of the maxillary second premolar are developed after 11 years of age. To reduce the chance of misdiagnosis, clinicians should consider the possibility of DTD if a tooth germ does not present in radiographs.

The Shh signalling pathway in tooth development: defects in Gli2 and Gli3 mutants

Development ◽  
1998 ◽  
Vol 125 (15) ◽  
pp. 2803-2811 ◽  
Author(s):  
Z. Hardcastle ◽  
R. Mo ◽  
C.C. Hui ◽  
P.T. Sharpe
Keyword(s):  
Tooth Development ◽  
Tooth Germ ◽  
Signalling Pathway ◽  
Abnormal Development ◽  
Maxillary Incisor ◽  
Expression Of Genes ◽  
Hedgehog Signalling Pathway ◽  
Tooth Germs ◽  
Sonic Hedgehog Signalling ◽  
Incisor Development

The expression of genes involved in the Sonic Hedgehog signalling pathway, including Shh, Ptc, Smo, Gli1, Gli2 and Gli3, were found to be expressed in temporal and spatial patterns during early murine tooth development, suggestive of a role in early tooth germ initiation and subsequent epithelial-mesenchymal interactions. Of these Ptc, Smo, Gli1, Gli2 and Gli3 were expressed in epithelium and mesenchyme whereas Shh was only detected in epithelium. This suggests that Shh is involved in both lateral (epithelial-mesenchymal) and planar (epithelial-epithelial) signalling in early tooth development. Ectopic application of Shh protein to mandibular mesenchyme induced the expression of Ptc and Gli1. Addition of exogenous Shh protein directly into early tooth germs and adjacent to tooth germs, resulted in abnormal epithelial invagination, indicative of a role for Shh in epithelial cell proliferation. In order to assess the possible role of this pathway, tooth development in Gli2 and Gli3 mutant embryos was investigated. Gli2 mutants were found to have abnormal development of maxillary incisors, probably resulting from a mild holoprosencephaly, whereas Gli3 mutants had no major tooth abnormalities. Gli2/Gli3 double homozygous mutants did not develop any normal teeth and did not survive beyond embryonic day 14.5; however, Gli2(−/−); Gli3(+/−) did survive until birth and had small molars and mandibular incisors whereas maxillary incisor development was arrested as a rudimentary epithelial thickening. These results show an essential role for Shh signalling in tooth development that involves functional redundancy of downstream Gli genes.

scholarly journals STRUCTURE OF TOOTH RUDIMENTS AND MINERAL METABOLISM PATTERN AT VIBRATION EFFECTIN THE EXPERIMENT

2018 ◽  
Vol 14 (2) ◽  
pp. 121-125
Author(s):  
Елена Апраксина ◽  
Elena Apraksina ◽  
Светлана Залавина ◽  
Svetlana Zalavina ◽  
Павел Жлезный ◽  
...  
Keyword(s):  
Structural Changes ◽  
Mineral Metabolism ◽  
Vibrational Excitation ◽  
Tooth Germ ◽  
Essential Elements ◽  
The Body ◽  
Vibration Exposure ◽  
Professional Activities ◽  
The Individual ◽  
Tooth Germs

Object. Vibration exposure is the most common adverse technogenic factor in the work and living conditions of many people. A significant impact on the state of the oral cavity have many socio-hygienic factors; the nature of their impact, their variability depends on the individual, the environmental situation in the region, the social conditions of people, as well as their professional activities. The undeniable fact is that production factors have an impact on both somatic health and dental status. These circumstances explain the importance of studying the development of the structure of dental rudiments, taking into account the mineral metabolism in the conditions of various anthropogenic influences, including the action of General industrial vibration. Purpose of the study. Explore features of the histogenesis of teeth based on mineral metabolism during vibrational excitation. Materials and methods. Wistar rats was performed with a vibration 9 to day 18 of pregnancy. We studied the morphology of the tooth germs in the fetus. Analytical studies of the mineral composition of the liver were performed by IRS-nuclear laboratory NGO "CBM" (Moscow) in the method of Dr. A.V. Skalniy. In the liver, the concentration female elements: Ca, Cd, Cu, Fe, Mg, P, Pb, Se, Zn. Results. The features in the structure of tooth germs and mineral metabolism in the mother-fetus system with vibrational excitation. Identified structural changes reveal a violation of microcirculation, the development of hypoxia in the tissues of the tooth germ and accelerated dentinogenesis. Change the concentration of minerals in the body - significantly reduces the concentration of essential elements of Ca, Fe, Mg and significantly increased the content of Cu, Cd, Pb. Conclusion. The observed changes in the morphology of tooth germs and mineral metabolism, are a reflection of altered homeostasis system the mother-fetus arising under the influence of vibration exposure.

SERUM THYROTROPHIN AND THE RESPONSE TO THYROTROPHIN RELEASING HORMONE IN SYMPTOMLESS AUTOIMMUNE THYROIDITIS AND IN BORDERLINE AND OVERT HYPOTHYROIDISM

1974 ◽  
Vol 75 (2) ◽  
pp. 274-285 ◽  
Author(s):  
A. Gordin ◽  
P. Saarinen ◽  
R. Pelkonen ◽  
B.-A. Lamberg
Keyword(s):  
Autoimmune Thyroiditis ◽  
Elevated Serum ◽  
Mean Value ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
The Mean ◽  
The Individual ◽  
Serum Tsh

ABSTRACT Serum thyrotrophin (TSH) was determined by the double-antibody radioimmunoassay in 58 patients with primary hypothyroidism and was found to be elevated in all but 2 patients, one of whom had overt and one clinically borderline hypothyroidism. Six (29%) out of 21 subjects with symptomless autoimmune thyroiditis (SAT) had an elevated serum TSH level. There was little correlation between the severity of the disease and the serum TSH values in individual cases. However, the mean serum TSH value in overt hypothyroidism (93.4 μU/ml) was significantly higher than the mean value both in clinically borderline hypothyroidism (34.4 μU/ml) and in SAT (8.8 μU/ml). The response to the thyrotrophin-releasing hormone (TRH) was increased in all 39 patients with overt or borderline hypothyroidism and in 9 (43 %) of the 21 subjects with SAT. The individual TRH response in these two groups showed a marked overlap, but the mean response was significantly higher in overt (149.5 μU/ml) or clinically borderline hypothyroidism (99.9 μU/ml) than in SAT (35.3 μU/ml). Thus a normal basal TSH level in connection with a normal response to TRH excludes primary hypothyroidism, but nevertheless not all patients with elevated TSH values or increased responses to TRH are clinically hypothyroid.

scholarly journals Anti–USAG-1 therapy for tooth regeneration through enhanced BMP signaling

2021 ◽  
Vol 7 (7) ◽  
pp. eabf1798
Author(s):  
A. Murashima-Suginami ◽  
H. Kiso ◽  
Y. Tokita ◽  
E. Mihara ◽  
Y. Nambu ◽  
...  
Keyword(s):  
Tooth Development ◽  
Bmp Signaling ◽  
Tooth Agenesis ◽  
Tooth Regeneration ◽  
Missing Teeth ◽  
Morphogenetic Protein ◽  
Genetic Abnormalities ◽  
Direct Binding ◽  
Tooth Germs ◽  
Lipoprotein Receptor Related Protein

Uterine sensitization–associated gene-1 (USAG-1) deficiency leads to enhanced bone morphogenetic protein (BMP) signaling, leading to supernumerary teeth formation. Furthermore, antibodies interfering with binding of USAG-1 to BMP, but not lipoprotein receptor–related protein 5/6 (LRP5/6), accelerate tooth development. Since USAG-1 inhibits Wnt and BMP signals, the essential factors for tooth development, via direct binding to BMP and Wnt coreceptor LRP5/6, we hypothesized that USAG-1 plays key regulatory roles in suppressing tooth development. However, the involvement of USAG-1 in various types of congenital tooth agenesis remains unknown. Here, we show that blocking USAG-1 function through USAG-1 knockout or anti–USAG-1 antibody administration relieves congenital tooth agenesis caused by various genetic abnormalities in mice. Our results demonstrate that USAG-1 controls the number of teeth by inhibiting development of potential tooth germs in wild-type or mutant mice missing teeth. Anti–USAG-1 antibody administration is, therefore, a promising approach for tooth regeneration therapy.

scholarly journals BMP Activity Is Required for Tooth Development from the Lamina to Bud Stage

2012 ◽  
Vol 91 (7) ◽  
pp. 690-695 ◽  
Author(s):  
Y. Wang ◽  
L. Li ◽  
Y. Zheng ◽  
G. Yuan ◽  
G. Yang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Molecular Marker ◽  
Tooth Development ◽  
Tooth Germ ◽  
Bmp Signaling ◽  
Expression Of Genes ◽  
Dental Epithelium ◽  
Initiation Stage ◽  
Transgenic Embryos ◽  
Bmp Antagonist

Several Bmp genes are expressed in the developing mouse tooth germ from the initiation to the late-differentiation stages, and play pivotal roles in multiple steps of tooth development. In this study, we investigated the requirement of BMP activity in early tooth development by transgenic overexpression of the extracellular BMP antagonist Noggin. We show that overexpression of Noggin in the dental epithelium at the tooth initiation stage arrests tooth development at the lamina/early-bud stage. This phenotype is coupled with a significantly reduced level of cell proliferation rate and a down-regulation of Cyclin-D1 expression, specifically in the dental epithelium. Despite unaltered expression of genes known to be implicated in early tooth development in the dental mesenchyme and dental epithelium of transgenic embryos, the expression of Pitx2, a molecular marker for the dental epithelium, became down-regulated, suggesting the loss of odontogenic fate in the transgenic dental epithelium. Our results reveal a novel role for BMP signaling in the progression of tooth development from the lamina stage to the bud stage by regulating cell proliferation and by maintaining odontogenic fate of the dental epithelium.

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