Changes in the distribution of tenascin during tooth development

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 289-296 ◽  
Author(s):  
I. Thesleff ◽  
E. Mackie ◽  
S. Vainio ◽  
R. Chiquet-Ehrismann
Keyword(s):  
Tooth Development ◽  
Polyclonal Antibodies ◽  
Staining Intensity ◽  
Mesenchymal Cells ◽  
Hard Tissue ◽  
Connective Tissues ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Extracellular Matrix Molecule ◽  
Dental Papilla Cells

Tenascin is an extracellular matrix molecule that was earlier shown to be enriched in embryonic mesenchyme surrounding the budding epithelium in various organs including the tooth. In the present study tenascin was localized by immunohistology throughout the course of tooth development in the mouse and rat using polyclonal antibodies against chick tenascin. The results indicate that tenascin is expressed by the lineage of dental mesenchymal cells throughout tooth ontogeny. The intensity of staining with tenascin antibodies in the dental papilla mesenchyme was temporarily reduced at cap stage when the tooth grows rapidly and undergoes extensive morphogenetic changes. During the bell stage of morphogenesis, the staining intensity increased and tenascin was accumulated in the dental pulp even after completion of crown development and eruption. Tenascin was present in the dental basement membrane at the time of odontoblast differentiation. The dental papilla cells ceased to express tenascin upon differentiation into odontoblasts and tenascin was completely absent from dentin. It can be speculated that the remarkable expression of tenascin in the dental mesenchymal cells as compared to other connective tissues is associated with their capacity to differentiate into hard-tissue-forming cells.

scholarly journals HDAC6 Regulates the Fusion of Autophagosome and Lysosome to Involve in Odontoblast Differentiation

2020 ◽  
Vol 8 ◽  
Author(s):  
Yunyan Zhan ◽  
Haisheng Wang ◽  
Lu Zhang ◽  
Fei Pei ◽  
Zhi Chen
Keyword(s):  
Tooth Development ◽  
Expression Patterns ◽  
Autophagic Flux ◽  
Differentiation Capacity ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Odontoblastic Differentiation ◽  
Dental Papilla Cells

Odontoblast differentiation is an important process during tooth development in which pre-odontoblasts undergo elongation, polarization, and finally become mature secretory odontoblasts. Many factors have been found to regulate the process, and our previous studies demonstrated that autophagy plays an important role in tooth development and promotes odontoblastic differentiation in an inflammatory environment. However, it remains unclear how autophagy is modulated during odontoblast differentiation. In this study, we found that HDAC6 was involved in odontoblast differentiation. The odontoblastic differentiation capacity of human dental papilla cells was impaired upon HDAC6 inhibition. Moreover, we found that HDAC6 and autophagy exhibited similar expression patterns during odontoblast differentiation both in vivo and in vitro; the expression of HDAC6 and the autophagy related proteins ATG5 and LC3 increased as differentiation progressed. Upon knockdown of HDAC6, LC3 puncta were increased in cytoplasm and the autophagy substrate P62 was also increased, suggesting that autophagic flux was affected in human dental papilla cells. Next, we determined the mechanism during odontoblastic differentiation and found that the HDAC6 substrate acetylated-Tubulin was up-regulated when HDAC6 was knocked down, and LAMP2, LC3, and P62 protein levels were increased; however, the levels of ATG5 and Beclin1 showed no obvious change. Autophagosomes accumulated while the number of autolysosomes was decreased as determined by mRFP-GFP-LC3 plasmid labeling. This suggested that the fusion between autophagosomes and lysosomes was blocked, thus affecting the autophagic process during odontoblast differentiation. In conclusion, HDAC6 regulates the fusion of autophagosomes and lysosomes during odontoblast differentiation. When HDAC6 is inhibited, autophagosomes can't fuse with lysosomes, autophagy activity is decreased, and it leads to down-regulation of odontoblastic differentiation capacity. This provides a new perspective on the role of autophagy in odontoblast differentiation.

WWP2 Promotes Odontoblastic Differentiation by Monoubiquitinating KLF5

2020 ◽  
pp. 002203452097086
Author(s):  
J. Fu ◽  
H. Zheng ◽  
Y. Xue ◽  
R. Jin ◽  
G. Yang ◽  
...  
Keyword(s):  
Tooth Development ◽  
Marker Genes ◽  
Alizarin Red ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Odontoblastic Differentiation ◽  
C Terminus ◽  
Elevated Expression ◽  
Dentin Formation ◽  
Dental Papilla Cells

WW domain-containing E3 Ub-protein ligase 2 (WWP2) belongs to the homologous to E6AP C-terminus (HECT) E3 ligase family. It has been explored to regulate osteogenic differentiation, chondrogenesis, and palatogenesis. Odontoblasts are terminally differentiated mesenchymal cells, which contribute to dentin formation in tooth development. However, it remained unknown whether WWP2 participated in odontoblast differentiation. In this study, WWP2 was found to be expressed in mouse dental papilla cells (mDPCs), odontoblasts, and odontoblastic-induced mDPCs by immunohistochemistry and Western blotting. Besides, WWP2 expression was decreased in the cytoplasm but increased in the nuclei of differentiation-induced mDPCs. When Wwp2 was knocked down, the elevated expression of odontoblast marker genes ( Dmp1 and Dspp) in mDPCs induced by differentiation medium was suppressed. Meanwhile, a decrease of alkaline phosphatase (ALP) activity was observed by ALP staining, and reduced formation of mineralized matrix nodules was demonstrated by Alizarin Red S staining. Overexpression of WWP2 presented opposite results to knockdown experiments, suggesting that WWP2 promoted odontoblastic differentiation of mDPCs. Further investigation found that WWP2 was coexpressed and interacted with KLF5 in the nuclei, leading to ubiquitination of KLF5. The PPPSY (PY2) motif of KLF5 was essential for its physical binding with WWP2. Also, cysteine 838 (Cys838) of WWP2 was the active site for ubiquitination of KLF5, which did not lead to proteolysis of KLF5. Then, KLF5 was confirmed to be monoubiquitinated and transactivated by WWP2, which promoted the expression of KLF5 downstream genes Dmp1 and Dspp. Deletion of the PY2 motif of KLF5 or mutation of Cys838 of WWP2 reduced the upregulation of Dmp1 and Dspp. Besides, lysine (K) residues K31, K52, K83, and K265 of KLF5 were verified to be crucial to WWP2-mediated KLF5 transactivation. Taken together, WWP2 promoted odontoblastic differentiation by monoubiquitinating KLF5.

scholarly journals IPO7 Promotes Odontoblastic Differentiation of Mouse Dental Papilla Cells by Selectively Importing Odontogenic Transcription Factors

2020 ◽  
Author(s):  
Yue Zhang ◽  
Hao Zhang ◽  
Guohua Yuan ◽  
Guobin Yang
Keyword(s):  
Transcription Factors ◽  
Biological Process ◽  
Expression Patterns ◽  
Nucleocytoplasmic Transport ◽  
Immunoprecipitation Assay ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Odontoblastic Differentiation ◽  
Dentin Formation ◽  
Dental Papilla Cells

Abstract Background: An important biological process for dentin formation and mineralization is odontoblast differentiation, which is precisely governed by a series of transcription factors (TFs). Importin 7 (IPO7) is a member of the Karyopherin β-superfamily mediating nucleocytoplasmic transport of proteins. In this study, we aimed to study the mechanisms by which IPO7 participates in odontoblastic differentiation. Methods: The expression patterns of IPO7 was investigated by immunofluorescence staining. Besides, mouse dental papilla cells (mDPCs) were extracted and cultured. After silencing Ipo7 in mDPCs, odontoblastic differentiation and the effect on odontogenic TFs were evaluated. Using nuclear and cytoplasmic extraction and co-immunoprecipitation assay, we aimed to confirm that IPO7 imports some odontogenic transcriptions factors to promote odontoblastic differentiation.Results: We found that IPO7 was increasingly expressed from the pre-odontoblasts to mature odontoblasts from PN2 to PN9. IPO7 enhanced odontoblast differentiation in mDPCs and imported essential TFs for odontoblastic differentiation, such as Distal-less homeobox 3 (DLX3), Osterix (OSX), Krüppel-like factor 4 (KLF4) and P-SMAD1/5 except for RUNX2. Besides, only RUNX2 showed no obvious interaction with IPO7.Conclusion: In conclusion, our data demonstrated that IPO7 enhances odontoblast differentiation in mDPCs by selectively importing odontogenic TFs.

Enamel Knots as Signaling Centers Linking Tooth Morphogenesis and Odontoblast Differentiation

2001 ◽  
Vol 15 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Irma Thesleff ◽  
Soile Keranen ◽  
Jukka Jernvall
Keyword(s):  
Tooth Development ◽  
Experimental Studies ◽  
Cell Lineage ◽  
Signaling Molecules ◽  
Enamel Knot ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Dental Epithelium ◽  
Tooth Morphogenesis ◽  
Enamel Knots

Odontoblasts differentiate from the cells of the dental papilla, and it has been well-established that their differentiation in developing teeth is induced by the dental epithelium. In experimental studies, no other mesenchymal cells have been shown to have the capacity to differentiate into odontoblasts, indicating that the dental papilla cells have been committed to odontoblast cell lineage during earlier developmental stages. We propose that the advancing differentiation within the odontoblast cell lineage is regulated by sequential epithelial signals. The first epithelial signals from the early oral ectoderm induce the odontogenic potential in the cranial neural crest cells. The next step in the determination of the odontogenic cell lineage is the development of the dental papilla from odontogenic mesenchyme. The formation of the dental papilla starts at the onset of the transition from the bud to the cap stage of tooth morphogenesis, and this is regulated by epithelial signals from the primary enamel knot. The primary enamel knot is a signaling center which forms at the tip of the epithelial tooth bud. It becomes fully developed and morphologically discernible in the cap-stage dental epithelium and expresses at least ten different signaling molecules belonging to the BMP, FGF, Hh, and Wnt families. In molar teeth, secondary enamel knots appear in the enamel epithelium at the sites of the future cusps. They also express several signaling molecules, and their formation precedes the folding and growth of the epithelium. The differentiation of odontoblasts always starts from the tips of the cusps, and therefore, it is conceivable that some of the signals expressed in the enamel knots may act as inducers of odontoblast differentiation. The functions of the different signals in enamel knots are not precisely known. We have shown that FGFs stimulate the proliferation of mesenchymal as well as epithelial cells, and they may also regulate the growth of the cusps. We have proposed that the enamel knot signals also have important roles, together with mesenchymal signals, in regulating the patterning of the cusps and hence the shape of the tooth crown. We suggest that the enamel knots are central regulators of tooth development, since they link cell differentiation to morphogenesis.

scholarly journals C-Jun N-terminal kinase (JNK) pathway activation is essential for dental papilla cells polarization

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0233944
Author(s):  
Jiao Luo ◽  
Xiujun Tan ◽  
Ling Ye ◽  
Chenglin Wang
Keyword(s):  
Cell Function ◽  
Tooth Development ◽  
Tooth Germ ◽  
Cell Polarization ◽  
Positive Role ◽  
Jnk Pathway ◽  
Jnk Signaling ◽  
Dental Papilla ◽  
Dental Papilla Cells

During tooth development, dental papilla cells differentiate into odontoblasts with polarized morphology and cell function. Our previous study indicated that the C-Jun N-terminal kinase (JNK) pathway regulates human dental papilla cell adhesion, migration, and formation of focal adhesion complexes. The aim of this study was to further examine the role of the JNK pathway in dental papilla cell polarity formation. Histological staining, qPCR, and Western Blot suggested the activation of JNK signaling in polarized mouse dental papilla tissue. After performing an in vitro tooth germ organ culture and cell culture, we found that JNK inhibitor SP600125 postponed tooth germ development and reduced the polarization, migration and differentiation of mouse dental papilla cells (mDPCs). Next, we screened up-regulated polarity-related genes during dental papilla development and mDPCs or A11 differentiation. We found that Prickle3, Golga2, Golga5, and RhoA were all up-regulated, which is consistent with JNK signaling activation. Further, constitutively active RhoA mutant (RhoA Q63L) partly rescued the inhibition of SP600125 on cell differentiation and polarity formation of mDPCs. To sum up, this study suggests that JNK signaling has a positive role in the formation of dental papilla cell polarization.

Mdm2 Promotes Odontoblast-like Differentiation by Ubiquitinating Dlx3 and p53

2019 ◽  
Vol 99 (3) ◽  
pp. 320-328 ◽  
Author(s):  
H. Zheng ◽  
G. Yang ◽  
J. Fu ◽  
Z. Chen ◽  
G. Yuan
Keyword(s):  
Cell Types ◽  
Inhibitory Effect ◽  
Gene Knockdown ◽  
Physical Interaction ◽  
Odontoblast Differentiation ◽  
Dental Papilla ◽  
Spatiotemporal Expression ◽  
Dentin Formation ◽  
Different Cell Types ◽  
Dental Papilla Cells

Dentin is an important structural component of the tooth. Odontoblast differentiation is an essential biological process that guarantees normal dentin formation, which is precisely regulated by various proteins. Murine double minute 2 (Mdm2) is an E3 ubiquitin ligase, and it plays a pivotal role in the differentiation of different cell types, such as osteoblasts and myoblasts. However, whether Mdm2 plays a role in odontoblast differentiation remains unknown. Here, we investigated the spatiotemporal expression of Mdm2 by immunostaining and found that Mdm2 was highly expressed in the odontoblasts and slightly in the dental papilla cells of mouse incisors and molars. Gene knockdown and overexpression experiments verified that Mdm2 promoted the odontoblast-like differentiation of mouse dental papilla cells (mDPCs). Intranuclear colocalization and physical interaction between Mdm2 and distal-less 3 (Dlx3), a transcription factor important for odontoblast differentiation, was found during the odontoblast-like differentiation of mDPCs by double immunofluorescence and immunoprecipitation. Mdm2 was proved to monoubiquitinate Dlx3, which enhanced the expression of Dlx3 target gene Dspp. In addition, p53, the canonical substrate of Mdm2, was validated to be also ubiquitinated but degraded by Mdm2 during the odontoblast-like differentiation of mDPCs. Gene knockdown experiments confirmed that p53 inhibited the odontoblast-like differentiation of mDPCs. p53 and Mdm2 double knockdown partially rescued the reduced odontoblast-like differentiation by knockdown of Mdm2 alone. Taken together, our study revealed that Mdm2 promoted the odontoblast-like differentiation of mDPCs by ubiquitinating both Dlx3 and p53. On one hand, the monoubiquitination of Dlx3 by Mdm2 led to upregulation of Dspp, which is a marker of the odontoblast differentiation. On the other hand, ubiquitination of p53 by Mdm2 resulted in its degradation, which eliminated the inhibitory effect of p53 on the odontoblast-like differentiation of mDPCs.

scholarly journals C-Jun N-terminal kinase (JNK) pathway activation is essential for dental papilla cells polarization

2020 ◽  
Author(s):  
Jiao Luo ◽  
Xiujun Tan ◽  
Ling Ye ◽  
Chenglin Wang
Keyword(s):  
Cell Function ◽  
Tooth Development ◽  
Tooth Germ ◽  
Culture Method ◽  
Positive Role ◽  
Jnk Pathway ◽  
Jnk Signaling ◽  
Dental Papilla ◽  
Dental Papilla Cells

AbstractDuring tooth development, dental papilla cells could develop into odontoblasts with polarized morphology and cell function, c-Jun N-terminal kinase (JNK) signaling could participate in this process. Histological staining, qPCR and Western Blot shown that activation of JNK signaling in polarized mouse dental papilla tissue. In vitro cell culture and organ culture method found JNK inhibitor SP600125 postponed tooth germ development and reduced the polarization, migration and differentiation of mouse dental papilla cells (mDPCs) in vitro. The expression of polarity-related genes including Prickle3, Golga2, Golga5 and RhoA was consistent with JNK signaling activation, by screening of up-regulated polarity-related genes during the process of dental papilla development and mDPCs or A11 differentiation. Further, constitutively active RhoA mutant (RhoA Q63L) partly rescue the inhibition of SP600125 on cell differentiation and polarity formation of mDPCs. This study suggests that JNK signaling has a positive role in dental papilla cells polarization formation.

scholarly journals RORα Regulates Odontoblastic Differentiation and Mediates the Pro-Odontogenic Effect of Melatonin on Dental Papilla Cells

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1098
Author(s):  
Jun Kang ◽  
Haoling Chen ◽  
Fuping Zhang ◽  
Tong Yan ◽  
Wenguo Fan ◽  
...  
Keyword(s):  
Tooth Development ◽  
Critical Role ◽  
Orphan Receptor ◽  
Dental Papilla ◽  
Odontoblastic Differentiation ◽  
Alp Activity ◽  
Matrix Mineralisation ◽  
Dental Papilla Cells

Dental papilla cells (DPCs), precursors of odontoblasts, are considered promising seed cells for tissue engineering. Emerging evidence suggests that melatonin promotes odontoblastic differentiation of DPCs and affects tooth development, although the precise mechanisms remain unknown. Retinoid acid receptor-related orphan receptor α (RORα) is a nuclear receptor for melatonin that plays a critical role in cell differentiation and embryonic development. This study aimed to explore the role of RORα in odontoblastic differentiation and determine whether melatonin exerts its pro-odontogenic effect via RORα. Herein, we observed that RORα was expressed in DPCs and was significantly increased during odontoblastic differentiation in vitro and in vivo. The overexpression of RORα upregulated the expression of odontogenic markers, alkaline phosphatase (ALP) activity and mineralized nodules formation (p < 0.05). In contrast, odontoblastic differentiation of DPCs was suppressed by RORα knockdown. Moreover, we found that melatonin elevated the expression of odontogenic markers, which was accompanied by the upregulation of RORα (p < 0.001). Utilising small interfering RNA, we further demonstrated that RORα inhibition attenuated melatonin-induced odontogenic gene expression, ALP activity and matrix mineralisation (p < 0.01). Collectively, these results provide the first evidence that RORα can promote odontoblastic differentiation of DPCs and mediate the pro-odontogenic effect of melatonin.

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