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Research Square Sep 2023BMP2 signaling plays a pivotal role in odontoblast differentiation and maturation during odontogenesis. Teeth lacking Bmp2 exhibit a morphology reminiscent of...
BMP2 signaling plays a pivotal role in odontoblast differentiation and maturation during odontogenesis. Teeth lacking Bmp2 exhibit a morphology reminiscent of dentinogenesis imperfecta (DGI), associated with mutations in dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) genes. Mechanisms by which BMP2 signaling influences expressions of DSPP and DMP1 and contributes to DGI remain elusive. To study the roles of BMP2 in dentin development, we generated Bmp2 conditional knockout (cKO) mice. Through a comprehensive approach involving RNA-seq, immunohistochemistry, promoter activity, ChIP, and Re-ChIP, we investigated downstream targets of Bmp2. Notably, the absence of Bmp2 in cKO mice led to dentin insufficiency akin to DGI. Disrupted Bmp2 signaling was linked to decreased expression of Dspp and Dmp1, as well as alterations in intracellular translocation of transcription factors Dlx3 and Sp7. Intriguingly, upregulation of Dlx3, Dmp1, Dspp, and Sp7, driven by BMP2, fostered differentiation of dental mesenchymal cells and biomineralization. Mechanistically, BMP2 induced phosphorylation of Dlx3, Sp7, and histone acetyltransferase GCN5 at Thr and Tyr residues, mediated by Akt and Erk kinases. This phosphorylation facilitated protein nuclear translocation, promoting interactions between Sp7 and Dlx3, as well as with GCN5 on Dspp and Dmp1 promoters. The synergy between Dlx3 and Sp7 bolstered transcription of Dspp and Dmp1. Notably, BMP2-driven GCN5 acetylated Sp7 and histone H3, while also recruiting RNA polymerase II to Dmp1 and Dspp chromatins, enhancing their transcriptions. Intriguingly, BMP2 suppressed the expression of histone deacetylases. we unveil hitherto uncharted involvement of BMP2 in dental cell differentiation and dentine development through pAkt/pErk42/44/Dlx3/Sp7/GCN5/Dspp/Dmp1.
PubMed: 37790473
DOI: 10.21203/rs.3.rs-3299295/v1 -
Dentistry Journal Aug 2022The SIBLING proteins are a family of non-collagenous proteins (NCPs) previously thought to be expressed only in dentin but have been demonstrated in other mineralized...
The SIBLING proteins are a family of non-collagenous proteins (NCPs) previously thought to be expressed only in dentin but have been demonstrated in other mineralized and non-mineralized tissues. They are believed to play vital roles in both osteogenesis and dentinogenesis. Since they are tightly regulated lifelong processes and involve a peak of mineralization, three different age groups were investigated. Fifteen wild-type (WT) mice were euthanized at ages 1, 3, and 6 months. Hematoxylin and eosin staining (H&E) was performed to localize various microscopic structures in the mice mandibles and tibias. The immunostaining pattern was compared using antibodies for dentin sialoprotein (DSP), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP), and osteopontin (OPN). Immunostaining of DSP in tibia showed its most noticeable staining in the 3-month age group. DSP was expressed in alveolar bone, cellular cementum, and PDL. A similar expression of DMP1 was seen in the tibia and dentin. BSP was most noticeably detected in the tibia and acellular cementum. OPN was mainly expressed in the bone. A lower level of OPN was observed at all age groups in the teeth. The immunostaining intensity was the least detected for all proteins in the 6-month tibia sample. The expression patterns of the four SIBLING proteins showed variations in their staining intensity and temporospatial patterning concordant with skeletal and dental maturity. These findings suggest some role in this tightly regulated mineralization process.
PubMed: 36005242
DOI: 10.3390/dj10080144 -
Cureus Oct 2022Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity. These anomalies manifest as discrepancies in the...
BACKGROUND
Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity. These anomalies manifest as discrepancies in the number, color, size, and shape of the teeth. These dental anomalies can either be acquired, congenital, or developmental. Their early detection and management are necessary as they affect aesthetics and occlusion. The study had the aim of gauging the prevalence of developmental anomalies in the permanent dentition of Indian subjects.
METHODS
A total of 1192 participants recruited from the institute for study purposes, comprising males and females, were examined clinically and radiographically, and their dental casts were also evaluated. These subjects were assessed for anomalies in position, structure, number, and/or shape. Anomalies in the position include transmigration, transportation, and/or ectopic position; anomalies in the structure, including dentinogenesis imperfecta or amelogenesis imperfecta; anomalies in number, including hyperdontia or hypodontia; and anomalies in shape, including peg laterals, taurodontism, fusion, dens evaginatus, talon cusp, and/or microdontia.
RESULTS
A statistically significant difference was seen in unilateral microdontia and dentinogenesis imperfecta between males and females, with attained p-values of 0.003 and 0.06, respectively. The results of the present study showed that 9.89% (n = 118) study subjects, whereas 1% (n = 12) study subjects had two dental anomalies in their permanent dentitions, with no subject presenting more than two dental anomalies, showing that various dental anomalies have a low prevalence in the Indian population.
CONCLUSION
The present study has led to the conclusion that the prevalence of dental anomalies is low in Indian subjects. However, these anomalies should be detected and treated early to prevent them from causing further complications.
PubMed: 36397922
DOI: 10.7759/cureus.30156 -
Scientific Reports Oct 2021Non-syndromic inherited defects of tooth dentin are caused by two classes of dominant negative/gain-of-function mutations in dentin sialophosphoprotein (DSPP): 5'...
Non-syndromic inherited defects of tooth dentin are caused by two classes of dominant negative/gain-of-function mutations in dentin sialophosphoprotein (DSPP): 5' mutations affecting an N-terminal targeting sequence and 3' mutations that shift translation into the - 1 reading frame. DSPP defects cause an overlapping spectrum of phenotypes classified as dentin dysplasia type II and dentinogenesis imperfecta types II and III. Using CRISPR/Cas9, we generated a Dspp mouse model by introducing a FLAG-tag followed by a single nucleotide deletion that translated 493 extraneous amino acids before termination. Developing incisors and/or molars from this mouse and a Dspp mouse were characterized by morphological assessment, bSEM, nanohardness testing, histological analysis, in situ hybridization and immunohistochemistry. Dspp dentin contained dentinal tubules but grew slowly and was softer and less mineralized than the wild-type. Dspp incisor enamel was softer than normal, while molar enamel showed reduced rod/interrod definition. Dspp dentin formation was analogous to reparative dentin: it lacked dentinal tubules, contained cellular debris, and was significantly softer and thinner than Dspp and Dspp dentin. The Dspp incisor enamel appeared normal and was comparable to the wild-type in hardness. We conclude that 5' and 3' Dspp mutations cause dental malformations through different pathological mechanisms and can be regarded as distinct disorders.
Topics: Animals; Dental Enamel; Dentin; Dentinogenesis Imperfecta; Disease Models, Animal; Extracellular Matrix Proteins; Female; Frameshift Mutation; Humans; Male; Mice; Mice, Transgenic; Phenotype; Phosphoproteins; Sialoglycoproteins; Tooth
PubMed: 34667213
DOI: 10.1038/s41598-021-00219-4 -
ACS Omega Jun 2018Current standard of care for treating infected dental pulp, root canal therapy, retains the physical properties of the tooth to a large extent, but does not aim to...
Current standard of care for treating infected dental pulp, root canal therapy, retains the physical properties of the tooth to a large extent, but does not aim to rejuvenate the pulp tissue. Tissue-engineered acellular biomimetic hydrogels have great potential to facilitate the regeneration of the tissue through the recruitment of autologous stem cells. We propose the use of a dentinogenic peptide that self-assembles into β-sheet-based nanofibers that constitute a biodegradable and injectable hydrogel for support of dental pulp stem cells. The peptide backbone contains a β-sheet-forming segment and a matrix extracellular phosphoglycoprotein mimic sequence at the C-terminus. The high epitope presentation of the functional moiety in the self-assembled nanofibers may enable recapitulation of a functional niche for the survival and proliferation of autologous cells. We elucidated the hierarchical self-assembly of the peptide through biophysical techniques, including scanning electron microscopy and atomic force microscopy. The material property of the self-assembled hydrogel was probed though oscillatory rheometry, demonstrating its thixotropic nature. We also demonstrate the cytocompatibility of the hydrogel with respect to fibroblasts and dental pulp stem cells. The self-assembled peptide platform holds promise for guided dentinogenesis and it can be tailored to a variety of applications in soft tissue engineering and translational medicine in the future.
PubMed: 30023936
DOI: 10.1021/acsomega.8b00347 -
Biological Procedures Online Sep 2021In the area of oral and maxillofacial surgery, regenerative endodontics aims to present alternative options to conventional treatment strategies. With continuous... (Review)
Review
BACKGROUND
In the area of oral and maxillofacial surgery, regenerative endodontics aims to present alternative options to conventional treatment strategies. With continuous advances in regenerative medicine, the source of cells used for pulp tissue regeneration is not only limited to mesenchymal stem cells as the non-mesenchymal stem cells have shown capabilities too. In this review, we are systematically assessing the recent findings on odontoblastic differentiation induction with scaffold and non-scaffold approaches.
METHODS
A comprehensive search was conducted in Pubmed, and Scopus, and relevant studies published between 2015 and 2020 were selected following the PRISMA guideline. The main inclusion criteria were that articles must be revolving on method for osteoblast differentiation in vitro study. Therefore, in vivo and human or animal clinical studies were excluded. The search outcomes identified all articles containing the word "odontoblast", "differentiation", and "mesenchymal stem cell".
RESULTS
The literature search identified 99 related studies, but only 11 articles met the inclusion criteria. These include 5 odontoblastic differentiation induction with scaffold, 6 inductions without scaffolds. The data collected were characterised into two main categories: type of cells undergo odontoblastic differentiation, and odontoblastic differentiation techniques using scaffolds or non-scaffold.
CONCLUSION
Based on the data analysis, the scaffold-based odontoblastic induction method seems to be a better option compared to the non-scaffold method. In addition of that, the combination of growth factors in scaffold-based methods could possibly enhance the differentiation. Thus, further detailed studies are still required to understand the mechanism and the way to enhance odontoblastic differentiation.
PubMed: 34521356
DOI: 10.1186/s12575-021-00155-7 -
Frontiers in Genetics 2020If dental caries (or tooth decay) progresses without intervention, the infection will advance through the dentine leading to severe pulpal inflammation (irreversible... (Review)
Review
If dental caries (or tooth decay) progresses without intervention, the infection will advance through the dentine leading to severe pulpal inflammation (irreversible pulpitis) and pulp death. The current management of irreversible pulpits is generally root-canal-treatment (RCT), a destructive, expensive, and often unnecessary procedure, as removal of the injurious stimulus alone creates an environment in which pulp regeneration may be possible. Current dental-restorative-materials stimulate repair non-specifically and have practical limitations; as a result, opportunities exist for the development of novel therapeutic strategies to regenerate the damaged dentine-pulp complex. Recently, epigenetic modification of DNA-associated histone 'tails' has been demonstrated to regulate the self-renewal and differentiation potential of dental-stem-cell (DSC) populations central to regenerative endodontic treatments. As a result, the activities of histone deacetylases (HDAC) are being recognised as important regulators of mineralisation in both tooth development and dental-pulp-repair processes, with HDAC-inhibition (HDACi) promoting pulp cell mineralisation and . Low concentration HDACi-application can promote de-differentiation of DSC populations and conversely, increase differentiation and accelerate mineralisation in DSC populations. Therapeutically, various HDACi solutions can release bioactive dentine-matrix-components (DMCs) from the tooth's extracellular matrix; solubilised DMCs are rich in growth factors and can stimulate regenerative processes such as angiogenesis, neurogenesis, and mineralisation. The aim of this mini-review is to discuss the role of histone-acetylation in the regulation of DSC populations, while highlighting the importance of HDAC in tooth development and dental pulp regenerative-mineralisation processes, before considering the potential therapeutic application of HDACi in targeted biomaterials to the damaged pulp to stimulate regeneration.
PubMed: 32117431
DOI: 10.3389/fgene.2020.00001 -
Journal of Bone and Mineral Research :... Aug 2019Transcription factors bind to cell-specific cis-regulatory elements, such as enhancers and promoters, to initiate much of the gene expression program of different...
Transcription factors bind to cell-specific cis-regulatory elements, such as enhancers and promoters, to initiate much of the gene expression program of different biological process. Odontoblast differentiation is a necessary step for tooth formation and is also governed by a complex gene regulatory network. Our previous in vitro experiments showed that Krüppel-like factor 4 (KLF4) can promote odontoblastic differentiation of both mouse dental papillary cells (mDPCs) and human dental pulp cells; however, its mechanism remains unclear. We first used Wnt1-Cre; KLF4 (Klf4 cKO) mice to examine the role of KLF4 during odontoblast differentiation in vivo and demonstrated significantly impaired dentin mineralization and enlarged pulp/root canals. Additionally, combinatory analysis using RNA-seq and ATAC-seq revealed genomewide direct regulatory targets of KLF4 in mouse odontoblasts. We found that KLF4 can directly activate the TGF-β signaling pathway at the beginning of odontoblast differentiation with Runx2 as a cofactor. Furthermore, we found that KLF4 can directly upregulate the expression levels of Dmp1 and Sp7, which are markers of odontoblastic differentiation, through binding to their promoters. Interestingly, as a transcription factor, KLF4 can also recruit histone acetylase as a regulatory companion to the downstream target genes to positively or negatively regulate transcription. To further investigate other regulatory companions of KLF4, we chose histone acetylase HDAC3 and P300. Immunoprecipitation demonstrated that KLF4 interacted with P300 and HDAC3. Next, ChIP analysis detected P300 and HDAC3 enrichment on the promoter region of KLF4 target genes Dmp1 and Sp7. HDAC3 mainly interacted with KLF4 on day 0 of odontoblastic induction, whereas P300 interacted on day 7 of induction. These temporal-specific interactions regulated Dmp1 and Sp7 transcription, thus regulating dentinogenesis. Taken together, these results demonstrated that KLF4 regulates Dmp1 and Sp7 transcription via the modulation of histone acetylation and is vital to dentinogenesis. © 2019 American Society for Bone and Mineral Research.
Topics: Acetylation; Animals; Cell Differentiation; Core Binding Factor Alpha 1 Subunit; Dental Pulp; Extracellular Matrix Proteins; Gene Expression Regulation; Histone Deacetylase 2; Histones; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Mice; Mice, Knockout; Odontoblasts; Sp7 Transcription Factor; Transcription, Genetic; Transforming Growth Factor beta
PubMed: 31112333
DOI: 10.1002/jbmr.3716 -
Frontiers in Physiology 2023Mouse and human genetic studies indicate key roles of the ligand in odontogenesis. Previous studies have identified effectors and regulators of the Wnt signaling...
Mouse and human genetic studies indicate key roles of the ligand in odontogenesis. Previous studies have identified effectors and regulators of the Wnt signaling pathway actively expressed during key stages of tooth morphogenesis. However, limitations in multiplexing and spatial resolution hindered a more comprehensive analysis of these signaling molecules. Here, profiling of transcriptomes using fluorescent multiplex hybridization and single-cell RNA-sequencing (scRNA-seq) provide robust insight into the synchronized expression patterns of , , and simultaneously during tooth development. First, we identified transcripts restricted to the epithelium at the stage of tooth bud morphogenesis, contrasting that of and localization to the dental mesenchyme. By embryonic day 15.5 (E15.5), a marked shift of expression from dental epithelium to mesenchyme was noted, while and expression remained enriched in the mesenchyme. By postnatal day 0 (P0), co-localization patterns of , , and were observed in both terminally differentiating and secreting odontoblasts of molars and incisors. Interestingly, exhibited robust expression in fully differentiated ameloblasts at the developing cusp tip of both molars and incisors, an observation not previously noted in prior studies. At P7 and 14, after the mineralization of dentin and enamel, expression was limited to odontoblasts. Meanwhile, Wnt modulators showed reduced or absent signals in molars. In contrast, strong signals persisted in ameloblasts (for ) and odontoblasts (for , , and ) towards the proximal end of incisors, near the cervical loop. Our scRNA-seq analysis used CellChat to further contextualize Wnt pathway-mediated communication between cells by examining ligand-receptor interactions among different clusters. The co-localization pattern of , , and in both terminally differentiating and secreting odontoblasts of molars and incisors potentially signifies the crucial ligand-modulator interaction along the gradient of cytodifferentiation starting from each cusp tip towards the apical region. These data provide cell type-specific insight into the role of Wnt ligands and mediators during epithelial-mesenchymal interactions in odontogenesis.
PubMed: 38274045
DOI: 10.3389/fphys.2023.1316635 -
Dentistry Journal Apr 2021Osteogenesis imperfecta (OI) is a genetic disorder characterized by increased bone fragility and low bone mass, caused mainly by mutations in collagen type I encoding...
Osteogenesis imperfecta (OI) is a genetic disorder characterized by increased bone fragility and low bone mass, caused mainly by mutations in collagen type I encoding genes. The current study aimed to evaluate dentinogenesis imperfecta (DI), oral manifestations and caries status of OI children. Sixty-eight children (41 males, 27 females) aged from 3 to 17 years old (mean 9 ± 4.13) participated in the study. Participants were classified into three OI type groups (I-2 cases, III-31 cases and IV-35 cases). Clinical examination and an orthopantomogram were used to obtain prevalences and associations of DI, caries status, malocclusion, crossbite, open bite, eruption, impaction and missing teeth with OI. The prevalence of DI among OI patients was 47.1%, more common in OI type III than type IV. The yellow-brown discoloration type was more vulnerable to attrition than the opalescent-grey one in the primary dentition. OI seemed not to have a high risk of caries; the prevalence of caries was 69.1%. A high incidence of malocclusion, crossbite and open bite was observed. In-depth oral information would provide valuable data for better dental management in OI patients. Parents and general doctors should pay more attention to dental care to prevent caries and premature tooth loss.
PubMed: 33925433
DOI: 10.3390/dj9050049