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Cureus May 2024The management of teeth with open apices poses unique challenges in endodontics, requiring effective strategies to promote continued root development and maintain pulp...
The management of teeth with open apices poses unique challenges in endodontics, requiring effective strategies to promote continued root development and maintain pulp vitality. This abstract explores the utilization of bioactive materials in the treatment of open apices, specifically focusing on their role in achieving optimal outcomes. Bioactive materials, such as Biodentine (Septodont, Saint-Maur-des-Fossés, France), have gained prominence for their favourable physiochemical properties, biocompatibility, and ability to stimulate dentinogenesis. The application of a bioactive material as an apical plug not only addresses immediate concerns but also contributes to long-term health and stability. This abstract reviews relevant literature, discusses clinical cases, and emphasizes the importance of tailoring treatment plans to the individual characteristics of open apex cases. The findings underscore the promising role of bioactive materials in reshaping the landscape of endodontic interventions for teeth with open apices, highlighting their potential to enhance both clinical and radiographic success.
PubMed: 38947694
DOI: 10.7759/cureus.61296 -
International Journal of Molecular... Jun 2024Epigenetic modulation, including histone modification, alters gene expression and controls cell fate. Histone deacetylases (HDACs) are identified as important regulators...
Epigenetic modulation, including histone modification, alters gene expression and controls cell fate. Histone deacetylases (HDACs) are identified as important regulators of dental pulp cell (DPC) mineralisation processes. Currently, there is a paucity of information regarding the nature of histone modification and HDAC expression in the dentine-pulp complex during dentinogenesis. The aim of this study was to investigate post-translational histone modulation and HDAC expression during DPC mineralisation and the expression of Class I/II HDACs during tooth development and in adult teeth. HDAC expression (isoforms -1 to -6) was analysed in mineralising primary rat DPCs using qRT-PCR and Western blot with mass spectrometry being used to analyse post-translational histone modifications. Maxillary molar teeth from postnatal and adult rats were analysed using immunohistochemical (IHC) staining for HDACs (1-6). HDAC-1, -2, and -4 protein expression increased until days 7 and 11, but decreased at days 14 and 21, while other HDAC expression increased continuously for 21 days. The Class II mineralisation-associated HDAC-4 was strongly expressed in postnatal sample odontoblasts and DPCs, but weakly in adult teeth, while other Class II HDACs (-5, -6) were relatively strongly expressed in postnatal DPCs and adult odontoblasts. Among Class I HDACs, HDAC-1 showed high expression in postnatal teeth, notably in ameloblasts and odontoblasts. HDAC-2 and -3 had extremely low expression in the rat dentine-pulp complex. Significant increases in acetylation were noted during DPC mineralisation processes, while trimethylation H3K9 and H3K27 marks decreased, and the HDAC-inhibitor suberoylanilide hydroxamic acid (SAHA) enhanced H3K27me3. These results highlight a dynamic alteration in histone acetylation during mineralisation and indicate the relevance of Class II HDAC expression in tooth development and regenerative processes.
Topics: Animals; Acetylation; Rats; Histone Deacetylases; Dentinogenesis; Dentin; Dental Pulp; Protein Processing, Post-Translational; Histones; Molar; Odontoblasts; Male
PubMed: 38928274
DOI: 10.3390/ijms25126569 -
International Journal of Hyperthermia :... 2024Dentin hypersensitivity (DH) is a prevalent condition, but long-term effective treatments are scarce. Differentiation of odontoblast-like cells is promising for inducing...
PURPOSE
Dentin hypersensitivity (DH) is a prevalent condition, but long-term effective treatments are scarce. Differentiation of odontoblast-like cells is promising for inducing tertiary dentinogenesis and ensuring sustained therapeutic efficacy against DH. This study examined the effects and mechanism of action of mild heat stress (MHS) on the differentiation of odontoblast-like MDPC-23 cells.
METHODS
We used a heating device to accurately control the temperature and duration, mimicking the thermal microenvironment of odontoblast-like cells. Using this device, the effects of MHS on cell viability and differentiation were examined. Cell viability was assessed using the MTT assay. The expression and nucleoplasmic ratio of the yes-associated protein (YAP) were examined by western blotting and immunofluorescence. The gene expression levels of heat shock proteins (HSPs) and dentin matrix protein-1 (DMP1) were measured using qPCR. Dentin sialophosphoprotein (DSPP) expression was evaluated using immunofluorescence and immunoblotting. Verteporfin was used to inhibit YAP activity.
RESULTS
Mild heat stress (MHS) enhanced the odontoblast differentiation of MDPC-23 cells while maintaining cell viability. MHS also increased YAP activity, as well as the levels of HSP25 mRNA, HSP70 mRNA, HSP90α mRNA, DMP1 mRNA, and DSPP protein. However, after YAP inhibition, both cell viability and the levels of HSP90α mRNA, DMP1 mRNA, and DSPP protein were reduced.
CONCLUSION
YAP plays a crucial role in maintaining cell viability and promoting odontoblast differentiation of MDPC-23 cells under MHS. Consequently, MHS is a potential therapeutic strategy for DH, and boosting YAP activity could be beneficial for maintaining cell viability and promoting odontoblast differentiation.
Topics: Odontoblasts; Cell Differentiation; Heat-Shock Response; Animals; YAP-Signaling Proteins; Mice; Cell Line; Adaptor Proteins, Signal Transducing; Cell Survival
PubMed: 38925872
DOI: 10.1080/02656736.2024.2369749 -
Journal of Dental Research Jun 2024Located at the interface of the dentin-pulp complex, the odontoblasts are specialized cells responsible for dentin synthesis and nociceptive signal detection in response...
Located at the interface of the dentin-pulp complex, the odontoblasts are specialized cells responsible for dentin synthesis and nociceptive signal detection in response to external stimuli. Recent studies have shown that the mechanosensitive ion channel PIEZO1 is involved in bone formation and remodeling through the influx of calcium ions, and it is abundantly expressed in odontoblasts. However, the specific role of PIEZO1 in reactionary dentinogenesis and the underlying mechanisms remain elusive. In this study, we found intense PIEZO1 expression in the plasma membrane and cytoplasm of odontoblasts in healthy human third molars, mouse mandibular molars, and human odontoblast-like cells (hOBLCs). In hOBLCs, PIEZO1 positively regulated DSPP, DMP1, and COL1A1 expression through the Ca/PI3K-Akt/SEMA3A signaling pathway. In addition, exogenous SEMA3A supplementation effectively reversed reduced mineralization capacity in -knockdown hOBLCs. In vivo, Piezo1 expression peaked at day 7 and returned to baseline at day 21 in a wild-type mice dentin injury model, with Sema3a presenting a similar expression pattern. To investigate the specific role of PIEZO1 in odontoblast-mediated reactionary dentinogenesis, mice with a conditional knockout of in odontoblasts were generated, and no significant differences in teeth phenotypes were observed between the control and conditional knockout () mice. Nevertheless, mice exhibited reduced reactionary dentin formation and decreased Sema3a and Dsp positive staining after dentin injury, indicating impaired dental pulp repair by odontoblasts. In summary, these findings suggest that PIEZO1 enhances the mineralization capacity of hOBLCs in vitro via the Ca/PI3K-Akt/SEMA3A signaling pathway and contributes to reactionary dentinogenesis in vivo.
PubMed: 38910430
DOI: 10.1177/00220345241257866 -
Journal of Clinical Research in... Jun 2024Osteogenesis imperfecta (OI) is a group of phenotypically and genetically heterogeneous connective tissue disorders that share similar skeletal anomalies causing bone...
INTRODUCTION
Osteogenesis imperfecta (OI) is a group of phenotypically and genetically heterogeneous connective tissue disorders that share similar skeletal anomalies causing bone fragility and deformation. This study aimed to investigate the molecular genetic etiology and determine the relationship between genotype and phenotype in OI patients with targeted next-generation sequencing (NGS).
METHOD
In patients with OI, a targeted NGS analysis panel (Illumina TruSight One) containing genes involved in collagen/bone synthesis was performed on the Illumina Nextseq550 platform.
RESULTS
Fifty-six patients (female/male: 25/31) from 46 different families were enrolled in the study. Consanguinity between parents was noted in 15 (32.6%) families. Clinically according to Sillence classification; 18(33.1%) patients were considered to type I, 1(1.7%) type II, 26(46.4%) type III and 11(19.6%) type IV. Median body weight was -1.1 (-6.8, - 2.5) SDS, and height was -2.3 (-7.6, - 1.2) SDS. Bone deformity was detected in 30 (53.5%) of the patients, while 31 (55.4%) were evaluated as mobile. Thirty-six (60.7%) patients had blue sclera, 13 (23.2%) had scoliosis, 12 (21.4%) had dentinogenesis imperfecta (DI), and 2 (3.6%) had hearing loss. Disease-causing variants in COL1A1 and COL1A2 genes were found in 24 (52.1%) and 6 (13%) families, respectively. In 8 (17.3%) of the remaining 16 (34.7%) families, the NGS panel revealed disease-causing variants in three different genes (FKBP10, SERPINF1, and P3H1). Nine (23.6%) of the variants detected in all investigated genes were not previously reported in the literature and were classified to be pathogenic according to ACMG guidelines pathogenity scores. In ten (21.7%) families, a disease-related variant was not found in a total of 13 OI genes included in the panel.
CONCLUSION
Genetic etiology was found in 38 (82.6%) of 46 families by targeted NGS analysis. In addition, 9 new variants were assessed in known OI genes which is a significant contribution to the literature.
PubMed: 38828893
DOI: 10.4274/jcrpe.galenos.2024.2022-12-8 -
Journal of Nanobiotechnology May 2024Pulp regeneration is a novel approach for the treatment of immature permanent teeth with pulp necrosis. This technique includes the combination of stem cells, scaffolds,...
BACKGROUND
Pulp regeneration is a novel approach for the treatment of immature permanent teeth with pulp necrosis. This technique includes the combination of stem cells, scaffolds, and growth factors. Recently, stem cell-derived extracellular vesicles (EVs) have emerged as a new methodology for pulp regeneration. Emerging evidence has proven that preconditioning is an effective scheme to modify EVs for better therapeutic potency. Meanwhile, proper scaffolding is of great significance to protect EVs from rapid clearance and destruction. This investigation aims to fabricate an injectable hydrogel loaded with EVs from pre-differentiated stem cells from human exfoliated deciduous teeth (SHEDs) and examine their effects on pulp regeneration.
RESULTS
We successfully employed the odontogenic induction medium (OM) of SHEDs to generate functional EV (OM-EV). The OM-EV at a concentration of 20 µg/mL was demonstrated to promote the proliferation and migration of dental pulp stem cells (DPSCs). The results revealed that OM-EV has a better potential to promote odontogenic differentiation of DPSCs than common EVs (CM-EV) in vitro through Alizarin red phalloidin, alkaline phosphatase staining, and assessment of the expression of odontogenic-related markers. High-throughput sequencing suggests that the superior effects of OM-EV may be attributed to activation of the AMPK/mTOR pathway. Simultaneously, we prepared a photocrosslinkable gelatin methacryloyl (GelMA) to construct an OM-EV-encapsulated hydrogel. The hydrogel exhibited sustained release of OM-EV and good biocompatibility for DPSCs. The released OM-EV from the hydrogel could be internalized by DPSCs, thereby enhancing their survival and migration. In tooth root slices that were subcutaneously transplanted in nude mice, the OM-EV-encapsulated hydrogel was found to facilitate dentinogenesis. After 8 weeks, there was more formation of mineralized tissue, as well as higher levels of dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1).
CONCLUSIONS
The effects of EV can be substantially enhanced by preconditioning of SHEDs. The functional EVs from SHEDs combined with GelMA are capable of effectively promoting dentinogenesis through upregulating the odontogenic differentiation of DPSCs, which provides a promising therapeutic approach for pulp regeneration.
Topics: Dental Pulp; Humans; Extracellular Vesicles; Gelatin; Cell Differentiation; Odontogenesis; Animals; Stem Cells; Regeneration; Tooth, Deciduous; Methacrylates; Mice; Cell Proliferation; Mice, Nude; Cells, Cultured; Hydrogels; Cell Movement
PubMed: 38760763
DOI: 10.1186/s12951-024-02542-0 -
Journal of Cellular Biochemistry May 2024Odontoblast differentiation is a key process in dentin formation. Mouse dental papilla cells (mDPCs) are pivotal in dentinogenesis through their differentiation into...
Odontoblast differentiation is a key process in dentin formation. Mouse dental papilla cells (mDPCs) are pivotal in dentinogenesis through their differentiation into odontoblasts. Odontoblast differentiation is intricately controlled by transcription factors (TFs) in a spatiotemporal manner. Previous research explored the role of RUNX2 and KLF4 in odontoblast lineage commitment, respectively. Building on bioinformatics analysis of our previous ATAC-seq profiling, we hypothesized that KLF4 potentially collaborates with RUNX2 to exert its biological role. To investigate the synergistic effect of multiple TFs in odontoblastic differentiation, we first examined the spatiotemporal expression patterns of RUNX2 and KLF4 in dental papilla at the bell stage using immunostaining techniques. Notably, RUNX2 and KLF4 demonstrated colocalization in preodontoblast. Further, immunoprecipitation and proximity ligation assays verified the interaction between RUNX2 and KLF4 in vitro. Specifically, the C-terminus of RUNX2 was identified as the interacting domain with KLF4. Functional implications of this interaction were investigated using small hairpin RNA-mediated knockdown of Runx2, Klf4, or both. Western blot analysis revealed a marked decrease in DSPP expression, an odontoblast differentiation marker, particularly in the double knockdown condition. Additionally, alizarin red S staining indicated significantly reduced mineralized nodule formation in this group. Collectively, our findings highlight the synergistic interaction between RUNX2 and KLF4 in promoting odontoblast differentiation from mDPCs. This study contributes to a more comprehensive understanding of the regulatory network of TFs governing odontoblast differentiation.
PubMed: 38720665
DOI: 10.1002/jcb.30577 -
Journal of Endodontics May 2024Heparan sulfate (HS) is a major component of dental pulp tissue. We previously reported that inhibiting HS biosynthesis impedes endothelial differentiation of dental...
INTRODUCTION
Heparan sulfate (HS) is a major component of dental pulp tissue. We previously reported that inhibiting HS biosynthesis impedes endothelial differentiation of dental pulp stem cells (DPSCs). However, the underlying mechanisms by which exogenous HS induces DPSC differentiation and pulp tissue regeneration remain unknown. This study explores the impact of exogenous HS on vasculogenesis and dentinogenesis of DPSCs both in vitro and in vivo.
METHODS
Human-derived DPSCs were cultured in endothelial and odontogenic differentiation media and treated with HS. Endothelial differentiation of DPSCs was investigated by real-time polymerase chain reaction and capillary sprouting assay. Odontogenic differentiation was assessed through real-time polymerase chain reaction and detection of mineralized dentin-like deposition. Additionally, the influence of HS on pulp tissue was assessed with a direct pulp capping model, in which HS was delivered to exposed pulp tissue in rats. Gelatin sponges were loaded with either phosphate-buffered saline or 10-10 μg/mL HS and placed onto the pulp tissue. Following a 28-day period, tissues were investigated by histological analysis and micro-computed tomography imaging.
RESULTS
HS treatment markedly increased expression levels of key endothelial and odontogenic genes, enhanced the formation of capillary-like structures, and promoted the deposition of mineralized matrices. Treatment of exposed pulp tissue with HS in the in vivo pulp capping study induced formation of capillaries and reparative dentin.
CONCLUSIONS
Exogenous HS effectively promoted vasculogenesis and dentinogenesis of DPSCs in vitro and induced reparative dentin formation in vivo, highlighting its therapeutic potential for pulp capping treatment.
PubMed: 38719089
DOI: 10.1016/j.joen.2024.04.015 -
Journal of the American Dental... Jun 2024MSX1 sequence variants have been known to cause human tooth agenesis (TA) with or without orofacial clefts. However, their roles during the whole processes of tooth...
BACKGROUND
MSX1 sequence variants have been known to cause human tooth agenesis (TA) with or without orofacial clefts. However, their roles during the whole processes of tooth development are not fully understood. This study aimed to characterize a 4-membered family with TA carrying a novel MSX1 pathogenic variant and investigate the disease mechanism.
METHODS
The authors conducted whole exome analysis to define the disease-causing sequence variant. They performed microcomputed tomography, morphometric analyses, transcriptome profiling, and molecular characterization to study the affected teeth and the gene variant.
RESULTS
The authors identified an MSX1 pathogenic variant, p.Glu232∗, in affected family members with TA and concomitant orodental anomalies, namely, prominent maxillary labial frenum, central incisor diastema, median maxillary anterior alveolar cleft, tooth fusion, mandibular molar dysmorphology, thin dentin layer, and slender dental roots. MSX1-defective teeth were not apparently microdontic but had thin dentin layers. The mandibular molars showed a homeotic transformation to maxillary counterparts. Genes involved in extracellular matrix organization and dentinogenesis, such as DMP1 and MMP20, were downregulated in dental pulp tissues of MSX1-defective teeth. The p.Glu232∗-truncated MSX1 properly localized to the nucleus but partially lost its transactivation ability. Analyzing reported cases indicated that truncation sequence variants within the homeobox domain of MSX1 caused a more severe TA phenotype than those outside of the homeobox domain, probably due to dominant negativity compared with haploinsufficiency.
CONCLUSIONS
This study provides in vivo evidence that MSX1 contributes to developmental processes of various orodental tissues in humans.
PRACTICAL IMPLICATIONS
Clinically, hypertrophic labial frenum, incisor diastema, and median maxillary anterior alveolar cleft might be considered diagnostic for MSX1-associated TA.
Topics: Humans; MSX1 Transcription Factor; Male; Female; Anodontia; Pedigree; X-Ray Microtomography; Tooth Abnormalities; Adult; Adolescent; Child; Genetic Variation
PubMed: 38713117
DOI: 10.1016/j.adaj.2024.02.010 -
European Journal of Dentistry May 2024Dental pulp, a specialized mesenchymal tissue within teeth, is pivotal in dental health and tissue repair. Capsaicin, the primary pungent component of chili peppers,...
OBJECTIVES
Dental pulp, a specialized mesenchymal tissue within teeth, is pivotal in dental health and tissue repair. Capsaicin, the primary pungent component of chili peppers, is known for its diverse pharmacological properties. While capsaicin's effects on various cell types have been studied, its impact on dental pulp cells remains relatively unexplored. This study investigated the influence of pure capsaicin extract on dental pulp cell behavior, focusing on cell viability, proliferation, migration, and alkaline phosphatase (ALP) activity.
MATERIALS AND METHODS
Capsaicin solution was prepared and diluted to various concentrations (1 nM, 0.01 µM, 0.1 µM, 1 µM, 10 µM, and 100 µM), then was tested on rat dental pulp cells (RPC-C2A). Cell viability and proliferation were assessed using the MTT assay. Boyden chamber tests and wound healing were used for evaluating cell migration. The activity of ALP was determined to show cell function during dental pulp repair.
STATISTICAL ANALYSIS
The data were analyzed using a one-way analysis of variance or an independent-sample Kruskal-Wallis, followed by multiple comparison tests.
RESULTS
Capsaicin of 100 µM exhibited cytotoxicity, whereas those with lower concentrations stimulated cell proliferation. Wound healing assays revealed increased cell migration, particularly when cultured with 1 nM capsaicin ( = 0.002). Boyden chamber assays demonstrated enhanced cell invasion without statistical significance. ALP activity of dental pulp cells increased significantly at 1 nM ( < 0.001) and 1 µM ( = 0.021) capsaicin concentrations, indicating potential dentinogenesis and pulp repair.
CONCLUSION
Capsaicin of lower concentrations, less than 10 µM, is likely to promote proliferation, migration, and ALP activity of dental pulp cells. Our findings offer potential applications for capsaicin as a medication for dental pulp repair.
PubMed: 38698615
DOI: 10.1055/s-0044-1782191