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Stem Cell Research & Therapy Sep 2023CDC42 is a member of Rho GTPase family, acting as a molecular switch to regulate cytoskeleton organization and junction maturation of epithelium in organ development....
BACKGROUND
CDC42 is a member of Rho GTPase family, acting as a molecular switch to regulate cytoskeleton organization and junction maturation of epithelium in organ development. Tooth root pattern is a highly complicated and dynamic process that dependens on interaction of epithelium and mesenchyme. However, there is a lack of understanding of the role of CDC42 during tooth root elongation.
METHODS
The dynamic expression of CDC42 was traced during tooth development through immunofluorescence staining. Then we constructed a model of lentivirus or inhibitor mediated Cdc42 knockdown in Herwig's epithelial root sheath (HERS) cells and dental papilla cells (DPCs), respectively. Long-term influence of CDC42 abnormality was assessed via renal capsule transplantation and in situ injection of alveolar socket.
RESULTS
CDC42 displayed a dynamic spatiotemporal pattern, with abundant expression in HERS cells and apical DPCs in developing root. Lentivirus-mediated Cdc42 knockdown in HERS cells didn't disrupt cell junctions as well as epithelium-mesenchyme transition. However, inhibition of CDC42 in DPCs undermined cell proliferation, migration and odontogenic differentiation. Wnt/β-catenin signaling as the downstream target of CDC42 modulated DPCs' odontogenic differentiation. The transplantation and in situ injection experiments verified that loss of CDC42 impeded root extension via inhibiting the proliferation and differentiation of DPCs.
CONCLUSIONS
We innovatively revealed that CDC42 was responsible for guiding root elongation in a mesenchyme-specific manner. Furthermore, CDC42-mediated canonical Wnt signaling regulated odontogenic differentiation of DPCs during root formation.
Topics: Female; Humans; Wnt Signaling Pathway; Cell Differentiation; Epithelial Cells; Epithelial-Mesenchymal Transition; Tooth Root
PubMed: 37726858
DOI: 10.1186/s13287-023-03486-2 -
Frontiers in Cell and Developmental... 2023As the dentition forms and becomes functional, the alveolar bone is remodelled. Metalloproteinases are known to contribute to this process, but new regulators are...
As the dentition forms and becomes functional, the alveolar bone is remodelled. Metalloproteinases are known to contribute to this process, but new regulators are emerging and their contextualization is challenging. This applies to Myb, a transcription factor recently reported to be involved in bone development and regeneration. The regulatory effect of Myb on expression has mostly been investigated in tumorigenesis, where Myb impacted the expression of , , , and . The aim of this investigation was to evaluate the regulatory influence of the Myb on gene expression, impacting osteogenesis and mandibular bone formation. For that purpose, knock-out mouse model was used. Gene expression of bone-related and the key osteoblastic transcription factors Runx2 and Sp7 was analysed in Myb knock-out mice mandibles at the survival limit. Out of the metalloproteinases under study, Mmp13 was significantly downregulated. The impact of Myb on the expression of was confirmed by the overexpression of Myb in calvarial-derived cells causing upregulation of Expression of in the context of other Mmps during mandibular/alveolar bone development was followed along with and . The most significant changes were observed in the expression of . These MMPs and MYB were further localized by immunohistochemistry and were identified in pre/osteoblastic cells as well as in pre/osteocytes. In conclusion, these results provide a comprehensive insight into the expression dynamics of bone related Mmps during mandibular/alveolar bone formation and point to Myb as another potential regulator of Mmp13.
PubMed: 37701782
DOI: 10.3389/fcell.2023.1168866 -
In Vitro Cellular & Developmental... Aug 2023How to repair dentin-pulp injury effectively has always been a clinical problem, and the comparative study of repair process between different injuries is unknown....
How to repair dentin-pulp injury effectively has always been a clinical problem, and the comparative study of repair process between different injuries is unknown. Dental pulp stem cells (DPSCs) often are selected as seed cells for the study of dentin-pulp injury repair due to excellent advantages in odontogenesis and pulp differentiation. Although many previous researches have indicated that the Wnt protein and Wnt/β-catenin signaling pathway were crucial for dental growth, development, and injury repair, the specific mechanism remained unknown. In this study, different dentine-pulp injury models of adult mice were established successfully by abrasion and cutting methods. The gross morphology and micro-CT were used to observe the repair of injured mice incisor in different groups. We found that the repair time of each group was different. The repair time of the cutting group was longer than the abrasion group and the qRT-PCR detection showed that the expression of DSPP in the cutting group was higher than that in the abrasion group, but there was no significant difference in proliferation among the groups. In vivo and cell experiments showed that activation of Wnt/β-catenin signaling pathway can promote the proliferation and odontoblast differentiation of DPSCs. In addition, by using RNAscope staining, we observed that Wnt10a was mainly expressed in the proliferative region and partially expressed in the odontoblast region. The Western blotting results showed that in the early stage of repair, the expression of Wnt10a increased with the extension of days after injury in both abrasion and cutting group and the increase of Wnt10a was tested obviously on the 5th day after injury. But on the 7th day after injury, the expression of Wnt10a was still obvious in the cutting group, while the expression of Wnt10a was significantly reduced in the abrasion group, which was close to the control group. It is suggested that Wnt10a acts as a repair-related protein and has an important role in tooth injury repair. Wnt10a was activated by R-spondin and LiCl, and Wnt10a-siRNA DPSCs were constructed to inhibit Wnt10a. The results showed that Wnt10a/β-catenin signaling pathway promoted the proliferation and odontoblast differentiation of DPSCs. It plays a crucial role in the repair process of different injuries. This study enriched the mechanisms of Wnt10a /β-catenin signaling pathways in different types of dentin-pulp injury repair, which could provide experimental evidences for the target gene screening and also give some new ideas for the subsequent research on the molecular mechanisms of tooth regeneration.
Topics: Animals; Mice; beta Catenin; Wnt Signaling Pathway; Blotting, Western; Cell Differentiation; Dentin; Nerve Tissue Proteins; Wnt Proteins
PubMed: 37700204
DOI: 10.1007/s11626-023-00785-z -
PeerJ 2023The retinoic acid (RA) pathway was shown to be important for tooth development in mammals, and suspected to play a key role in tooth evolution in teleosts. The general...
The retinoic acid (RA) pathway was shown to be important for tooth development in mammals, and suspected to play a key role in tooth evolution in teleosts. The general modalities of development of tooth and "tooth-like" structures (collectively named odontodes) seem to be conserved among all jawed vertebrates, both with regard to histogenesis and genetic regulation. We investigated the putative function of RA signalling in tooth and scale initiation in a cartilaginous fish, the small-spotted catshark . To address this issue, we identified the expression pattern of genes from the RA pathway during both tooth and scale development and performed functional experiments by exposing small-spotted catshark embryos to exogenous RA or an inhibitor of RA synthesis. Our results showed that inhibiting RA synthesis affects tooth but not caudal primary scale development while exposure to exogenous RA inhibited both. We also showed that the reduced number of teeth observed with RA exposure is probably due to a specific inhibition of tooth bud initiation while the observed effects of the RA synthesis inhibitor is related to a general delay in embryonic development that interacts with tooth development. This study provides data complementary to previous studies of bony vertebrates and support an involvement of the RA signalling pathway toolkit in odontode initiation in all jawed vertebrates. However, the modalities of RA signalling may vary depending on the target location along the body, and depending on the species lineage.
Topics: Female; Animals; Tretinoin; Signal Transduction; Elasmobranchii; Odontogenesis; Tooth Germ; Mammals
PubMed: 37692112
DOI: 10.7717/peerj.15896 -
BMC Oral Health Sep 2023There is a difference between patient self-assessment and professional assessment of oral health needs; therefore, the aim of the study was to investigate patients'...
BACKGROUND
There is a difference between patient self-assessment and professional assessment of oral health needs; therefore, the aim of the study was to investigate patients' individual needs and awareness of replacing missing teeth with prostheses and then to compare this information with professionally assessed clinical prosthetic needs in the Eastern Province of Saudi Arabia.
METHODS
This was a cross-sectional study conducted in the Eastern Province of Saudi Arabia. The study subjects were recruited from Imam Abdulrahman bin Faisal University in Dammam City, Primary Health Care Centers in Alhasa City and from health education campaigns in the same area. All the patients were provided with a questionnaire related to the effect of missing teeth and replacement options, then underwent a clinical examination performed by a well-trained investigator. Statistical analyses were performed using JMP data analysis software (JMP®, Version 16. SAS Institute Inc., Cary, NC, 1989-2021.) RESULTS: A total of 102 participants were included. Most of the participants (94.2%) reported their need to replace missing teeth. Most of the participants stated that losing teeth (teeth) affected their ability to chew food and their appearance (82.6% and 61.6%, respectively). Dental caries was the main reason behind teeth extraction in 77.9% of the study sample. Fixed partial prosthesis was the first treatment option preferred by 33.7%, followed by implant-supported prosthesis with 25.6% to replace the missing teeth. Only 3.5% of participants preferred not to restore the missing teeth. Professional screening showed that 48.8% of the participants had one missing anterior tooth or more, which dictates the need for esthetic restoration, and 58.1% of the participants had three missing posterior teeth or more, which dictates the need for functional restoration.
CONCLUSIONS
Patient knowledge and attitudes toward replacing missing teeth in terms of their functional and esthetic needs were variable among the population in comparison to the professional assessment of patient needs. Dentists plays a major role in raising the level of awareness about missing teeth replacement. The results of this study serve as baseline data for any related future studies.
Topics: Humans; Cross-Sectional Studies; Dental Caries; Tooth Replantation; Odontogenesis; Anodontia; Tooth Loss; Attitude
PubMed: 37670303
DOI: 10.1186/s12903-023-03355-7 -
Stem Cell Research & Therapy Aug 2023Redox signaling and energy metabolism are known to be involved in controlling the balance between self-renewal and proliferation/differentiation of stem cells. In this...
BACKGROUND
Redox signaling and energy metabolism are known to be involved in controlling the balance between self-renewal and proliferation/differentiation of stem cells. In this study we investigated metabolic and redox changes occurring during in vitro human dental pulp stem cells (hDPSCs) osteoblastic (OB) differentiation and tested on them the impact of the reactive oxygen species (ROS) signaling.
METHODS
hDPSCs were isolated from dental pulp and subjected to alkaline phosphatase and alizarin red staining, q-RT-PCR, and western blotting analysis of differentiation markers to assess achievement of osteogenic/odontogenic differentiation. Moreover, a combination of metabolic flux analysis and confocal cyto-imaging was used to profile the metabolic phenotype and to evaluate the redox tone of hDPSCs.
RESULTS
In differentiating hDPSCs we observed the down-regulation of the mitochondrial respiratory chain complexes expression since the early phase of the process, confirmed by metabolic flux analysis, and a reduction of the basal intracellular peroxide level in its later phase. In addition, dampened glycolysis was observed, thereby indicating a lower energy-generating phenotype in differentiating hDPSCs. Treatment with the ROS scavenger Trolox, applied in the early-middle phases of the process, markedly delayed OB differentiation of hDPSCs assessed as ALP activity, Runx2 expression, mineralization capacity, expression of stemness and osteoblast marker genes (Nanog, Lin28, Dspp, Ocn) and activation of ERK1/2. In addition, the antioxidant partly prevented the inhibitory effect on cell metabolism observed following osteogenic induction.
CONCLUSIONS
Altogether these results provided evidence that redox signaling, likely mediated by peroxide species, influenced the stepwise osteogenic expansion/differentiation of hDPSCs and contributed to shape its accompanying metabolic phenotype changes thus improving their efficiency in bone regeneration and repair.
Topics: Humans; Osteogenesis; Dental Pulp; Reactive Oxygen Species; Bone Regeneration; Energy Metabolism; Oxidation-Reduction; Niacinamide; Alkaline Phosphatase
PubMed: 37608350
DOI: 10.1186/s13287-023-03447-9 -
BMC Oral Health Aug 2023Molar-root incisor malformation (MRIM) is a seldom reported condition characterised by disturbances in root development of first permanent molars. This systematic review...
OBJECTIVES
Molar-root incisor malformation (MRIM) is a seldom reported condition characterised by disturbances in root development of first permanent molars. This systematic review aimed to collate the clinical characteristics of individuals diagnosed with MRIM.
MATERIALS AND METHODS
A systematic search strategy using PubMed, Embase, Web of Science, and SCOPUS databases was performed through to March 2023. Inclusion criteria were case reports or case series including a diagnosis consistent with MRIM. Critical appraisal for all included studies utilised the Joanna Briggs Institute (JBI) critical appraisal checklist for case reports and case series and collation of clinical characteristics was performed in JBI System for the Unified Management, Assessment and Review of Information program.
RESULTS
The search identified 157 studies from which 35 satisfied the inclusion criteria. After full-text review, a total of 23 papers described the MRIM dental anomaly and were included in this paper. A total of 130 reported cases were retrieved, with age ranging 3-32 years, and males affected 1.16:1 females. Presence of neurological conditions, premature birth history, medication, and surgery within first years of life were synthesised and described.
CONCLUSIONS
The aetiology of MRIM is yet to be determined but epigenetic changes from significant medical history in the first years of life are likely to influence the development of this root malformation. First permanent molars were most commonly affected, but clinicians should be aware that permanent central incisors, primary teeth and other permanent teeth may also be affected.
Topics: Adolescent; Adult; Child; Child, Preschool; Female; Humans; Male; Pregnancy; Young Adult; Awareness; Databases, Factual; Incisor; Molar; Tooth Abnormalities; Odontogenesis; Tooth Root
PubMed: 37596569
DOI: 10.1186/s12903-023-03275-6 -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Aug 2023To investigate the characteristics of exosomes derived from dental pulp stem cells (DPSCs) in the direction of odontogenic differentiation, to analyze the differences in...
OBJECTIVE
To investigate the characteristics of exosomes derived from dental pulp stem cells (DPSCs) in the direction of odontogenic differentiation, to analyze the differences in microRNA expression profile between exosomes derived from undifferentiated and odontogenic DPSCs, and to analyze their possible signal transduction pathways.
METHODS
(1) DPSCs were cultured in minimum Eagle' s medium (-MEM), and odontogenic DPSCs were cultured in odontogenic differentiation medium for 21 days, using alizarin red staining and alkaline phosphatase staining to identify the odontogenic differentiation. Exosomes from the cell supernatant were isolated respectively, named as dental pulp stem cells-exosomes (DPSCs-Exo) and dental pulp stem cells-odontogenic-exosomes (DPSCs-OD-Exo). The exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis and Western blot. (2) The microRNA expression profiles of DPSCs-Exo and DPSCs-OD-Exo were investigated by microRNA microarray. To validate the result of the microRNA microarray, real-time quantitative polymerase chain reaction (real-time PCR) assay was applied on 3 most significantly differential expressed microRNA. Pathway analysis was taken to detect enriched pathways associated with the predicted target genes of microRNA.
RESULTS
(1) The DPSCs were isolated and cultured showed typical fibroblast-like morphology. The odontogenic differentiated DPSCs were spindle-shaped, polygonal, and uniform in size. Odontogenic differentiation group showed a large number of dark deposits in alizarin red staining and the cells were darkly stained in alkaline phosphatase staining, while the cells in normal culture medium group did not show obvious dyeing. The DPSCs-Exo and DPSCs-OD-Exo had the same morphology, both showed bilayer membrane and cup-shape. The peak sizes of DPSCs-Exo and DPSCs-OD-Exo were (114.67±9.07) nm and (134.00±8.54) nm, respectively. The difference between the two was statistically significant. DPSCs-Exo and DPSCs-OD-Exo both expressed the markers of exosomes, tumor susceptibility gene (TSG)101 and CD63. (2) microRNA microarray results showed that the expression profiles of DPSCs-Exo and DPSCs-OD-Exo were different. Nineteen increased by more than two times, and one decreased by 64%. Real-time PCR results showed that the expression levels of microRNA-1246, microRNA-1246-100-5p and microRNA-1246-494-3p in DPSCs-OD-Exo were significantly up-regulated. The difference was statistically significant. microRNA target prediction database and gene signaling pathway database were used to analyze differentially expressed microRNA, and it was predicted that differentially expressed microRNA could target axis inhibition protein 2() gene and Wnt/β-catenin signaling pathway.
CONCLUSION
DPSCs-OD-Exo and DPSCs-Exo had differences in their microRNA expression profile. Those differentially expressed microRNA may be involved in the regulation of DPSCs odontogenic differentiation.
Topics: Exosomes; Alkaline Phosphatase; Dental Pulp; Odontogenesis; Cell Differentiation; MicroRNAs; Stem Cells; Cells, Cultured; Cell Proliferation
PubMed: 37534653
DOI: 10.19723/j.issn.1671-167X.2023.04.020 -
World Journal of Stem Cells Jun 2023Accumulating evidence suggests that the maxillary process, to which cranial crest cells migrate, is essential to tooth development. Emerging studies indicate that plays...
BACKGROUND
Accumulating evidence suggests that the maxillary process, to which cranial crest cells migrate, is essential to tooth development. Emerging studies indicate that plays an essential role in odontogenesis. However, the underlying mechanisms have yet to be elucidated.
AIM
To establish the functionally heterogeneous population in the maxillary process, elucidate the effects of deficiency on gene expression differences.
METHODS
p75NTR knockout () mice (from American Jackson laboratory) were used to collect the maxillofacial process tissue of p75NTR knockout mice, and the wild-type maxillofacial process of the same pregnant mouse wild was used as control. After single cell suspension, the cDNA was prepared by loading the single cell suspension into the 10x Genomics Chromium system to be sequenced by NovaSeq6000 sequencing system. Finally, the sequencing data in Fastq format were obtained. The FastQC software is used to evaluate the quality of data and CellRanger analyzed the data. The gene expression matrix is read by R software, and Seurat is used to control and standardize the data, reduce the dimension and cluster. We search for marker genes for subgroup annotation by consulting literature and database; explore the effect of p75NTR knockout on mesenchymal stem cells (MSCs) gene expression and cell proportion by cell subgrouping, differential gene analysis, enrichment analysis and protein-protein interaction network analysis; understand the interaction between MSCs cells and the differentiation trajectory and gene change characteristics of p75NTR knockout MSCs by cell communication analysis and pseudo-time analysis. Last we verified the findings single cell sequencing .
RESULTS
We identified 21 cell clusters, and we re-clustered these into three subclusters. Importantly, we revealed the cell-cell communication networks between clusters. We clarified that was significantly associated with the regulation of mineralization.
CONCLUSION
This study provides comprehensive mechanistic insights into the maxillary- process-derived MSCs and demonstrates that is significantly associated with the odontogenesis in mesenchymal populations.
PubMed: 37424952
DOI: 10.4252/wjsc.v15.i6.589 -
Cellular and Molecular Life Sciences :... Jun 2023The Notch pathway is an ancient, evolutionary conserved intercellular signaling mechanism that is involved in cell fate specification and proper embryonic development....
The Notch pathway is an ancient, evolutionary conserved intercellular signaling mechanism that is involved in cell fate specification and proper embryonic development. The Jagged2 gene, which encodes a ligand for the Notch family of receptors, is expressed from the earliest stages of odontogenesis in epithelial cells that will later generate the enamel-producing ameloblasts. Homozygous Jagged2 mutant mice exhibit abnormal tooth morphology and impaired enamel deposition. Enamel composition and structure in mammals are tightly linked to the enamel organ that represents an evolutionary unit formed by distinct dental epithelial cell types. The physical cooperativity between Notch ligands and receptors suggests that Jagged2 deletion could alter the expression profile of Notch receptors, thus modifying the whole Notch signaling cascade in cells within the enamel organ. Indeed, both Notch1 and Notch2 expression are severely disturbed in the enamel organ of Jagged2 mutant teeth. It appears that the deregulation of the Notch signaling cascade reverts the evolutionary path generating dental structures more reminiscent of the enameloid of fishes rather than of mammalian enamel. Loss of interactions between Notch and Jagged proteins may initiate the suppression of complementary dental epithelial cell fates acquired during evolution. We propose that the increased number of Notch homologues in metazoa enabled incipient sister cell types to form and maintain distinctive cell fates within organs and tissues along evolution.
Topics: Pregnancy; Female; Mice; Animals; Cell Lineage; Membrane Proteins; Receptors, Notch; Serrate-Jagged Proteins; Cell Differentiation; Carrier Proteins; Mammals
PubMed: 37330998
DOI: 10.1007/s00018-023-04831-7