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International Journal of Oral Science Nov 2023Tooth root development involves intricate spatiotemporal cellular dynamics and molecular regulation. The initiation of Hertwig's epithelial root sheath (HERS) induces... (Review)
Review
Tooth root development involves intricate spatiotemporal cellular dynamics and molecular regulation. The initiation of Hertwig's epithelial root sheath (HERS) induces odontoblast differentiation and the subsequent radicular dentin deposition. Precisely controlled signaling pathways modulate the behaviors of HERS and the fates of dental mesenchymal stem cells (DMSCs). Disruptions in these pathways lead to defects in root development, such as shortened roots and furcation abnormalities. Advances in dental stem cells, biomaterials, and bioprinting show immense promise for bioengineered tooth root regeneration. However, replicating the developmental intricacies of odontogenesis has not been resolved in clinical treatment and remains a major challenge in this field. Ongoing research focusing on the mechanisms of root development, advanced biomaterials, and manufacturing techniques will enable next-generation biological root regeneration that restores the physiological structure and function of the tooth root. This review summarizes recent discoveries in the underlying mechanisms governing root ontogeny and discusses some recent key findings in developing of new biologically based dental therapies.
Topics: Female; Humans; Tooth Root; Odontogenesis; Epithelial Cells; Cell Differentiation; Biocompatible Materials
PubMed: 38001110
DOI: 10.1038/s41368-023-00258-9 -
Journal of Endodontics Jun 2022Odontoblasts, terminally differentiated dentin-forming cells with their processes that penetrate into dentin, have been considered potential sensory cells. Current...
INTRODUCTION
Odontoblasts, terminally differentiated dentin-forming cells with their processes that penetrate into dentin, have been considered potential sensory cells. Current research suggests that odontoblasts sense external stimuli and transmit pain signals. PIEZO1, as a specific mechanically activated ion channel, may play an important role in mechanical transduction in odontoblasts. In this study, we devoted to investigating the functions and underlying molecular mechanisms of PIEZO1 ion channels in odontoblast mechanotransduction.
METHODS
Human dental pulp stem cells were cultured in vitro and induced to differentiate into odontoblast-like cells (OLCs). The expression of PIEZO1 protein in pulp, dental pulp stem cells, and OLCs was detected by immunohistochemistry or immunofluorescence. The mechanical sensitivity of OLCs was detected by a constructed fluid shear stress model and examined by calcium fluorescence intensity. A single-cell mechanical stimulation model was used to detect the PIEZO1 electrophysiological properties of OLCs. Yoda1 (a PIEZO1-specific agonist), GsMTx4 (a PIEZO1 antagonist), and non-calcium ion extracellular solution were utilized to confirm PIEZO1 mechanotransduction in OLCs in both fluid shear stress and single-cell mechanical stimulation assays. The amount of ATP released by OLCs was measured under stimulation with Yoda1 and GsMTx4. Rat trigeminal ganglion neurons were cultured in vitro and detected by whole-cell patch-clamp recording under ATP stimulation.
RESULTS
PIEZO1 ion channels were positively expressed in OLCs and odontoblastic bodies and processes but weakly expressed in dental pulp cells. After the treatment of OLCs with shearing stress or Yoda1, the fluorescence intensity of intracellular calcium ions increased rapidly but did not noticeably change after treatment with GsMTx4 or the non-calcium ion extracellular solution. When single-cell mechanical stimuli were applied to OLCs, the evoked inward currents were recorded by patch-clamp electrophysiology. The inward currents increased and current inactivation became slower after Yoda1 treatment, but these currents almost completely disappeared after the addition of GsMTx4. The amount of ATP released by OLCs increased significantly after Yoda1 stimulation, while GsMTx4 reversed the release of ATP. Whole-cell patch-clamp detection showed that ATP evoked slow inward currents and increased the frequency of action potentials of trigeminal ganglion neurons.
CONCLUSIONS
Taken together, these findings indicated that odontoblasts evoked a fast inward current via PIEZO1 ion channels after the application of external mechanical stimuli and released ATP to transmit signals to adjacent cells. Thus, PIEZO1 ion channels in odontoblasts mediate mechanotransduction under various pathophysiological conditions in dentin.
Topics: Adenosine Triphosphate; Animals; Calcium; Ion Channels; Mechanotransduction, Cellular; Membrane Proteins; Odontoblasts; Rats
PubMed: 35219748
DOI: 10.1016/j.joen.2022.02.005 -
Organogenesis Dec 2022The development and repair of dentin are strictly regulated by hundreds of genes. Abnormal dentin development is directly caused by gene mutations and dysregulation....
The development and repair of dentin are strictly regulated by hundreds of genes. Abnormal dentin development is directly caused by gene mutations and dysregulation. Understanding and mastering this signal network is of great significance to the study of tooth development, tissue regeneration, aging, and repair and the treatment of dental diseases. It is necessary to understand the formation and repair mechanism of dentin in order to better treat the dentin lesions caused by various abnormal properties, whether it is to explore the reasons for the formation of dentin defects or to develop clinical drugs to strengthen the method of repairing dentin. Molecular biology of genes related to dentin development and repair are the most important basis for future research.
Topics: Dentin; Dentinogenesis; Odontoblasts; Odontogenesis
PubMed: 35023442
DOI: 10.1080/15476278.2021.2022373 -
Frontiers in Cell and Developmental... 2021Embryonic development and stem cell differentiation are orchestrated by changes in sequential binding of regulatory transcriptional factors to their motifs. These...
Embryonic development and stem cell differentiation are orchestrated by changes in sequential binding of regulatory transcriptional factors to their motifs. These processes are invariably accompanied by the alternations in chromatin accessibility, conformation, and histone modification. Odontoblast lineage originates from cranial neural crest cells and is crucial in dentinogenesis. Our previous work revealed several transcription factors (TFs) that promote odontoblast differentiation. However, it remains elusive as to whether chromatin accessibility affects odontoblast terminal differentiation. Herein, integration of single-cell RNA-seq and bulk RNA-seq revealed that odontoblast differentiation using dental papilla cells at E18.5 was comparable to the crown odontoblast differentiation trajectory of OC (osteocalcin)-positive odontogenic lineage. Before odontoblast differentiation, ATAC-seq and H3K27Ac CUT and Tag experiments demonstrated high accessibility of chromatin regions adjacent to genes associated with odontogenic potential. However, following odontoblastic induction, regions near mineralization-related genes became accessible. Integration of RNA-seq and ATAC-seq results further revealed that the expression levels of these genes were correlated with the accessibility of nearby chromatin. Time-course ATAC-seq experiments further demonstrated that odontoblast terminal differentiation was correlated with the occupation of the basic region/leucine zipper motif (bZIP) TF family, whereby we validated the positive role of ATF5 . Collectively, this study reports a global mapping of open chromatin regulatory elements during dentinogenesis and illustrates how these regions are regulated via dynamic binding of different TF families, resulting in odontoblast terminal differentiation. The findings also shed light on understanding the genetic regulation of dentin regeneration using dental mesenchymal stem cells.
PubMed: 34901015
DOI: 10.3389/fcell.2021.769193 -
Current Issues in Molecular Biology Dec 2023The embryonic development of neural crest cells and subsequent tissue differentiation are intricately regulated by specific transcription factors. Among these, , a... (Review)
Review
The embryonic development of neural crest cells and subsequent tissue differentiation are intricately regulated by specific transcription factors. Among these, , a member of the gene family, stands out. Located on chromosome 22q13, the gene encodes a transcription factor crucial for the differentiation, migration, and maintenance of tissues derived from neural crest cells. It plays a pivotal role in developing various tissues, including the central and peripheral nervous systems, melanocytes, chondrocytes, and odontoblasts. Mutations in have been associated with congenital disorders such as Waardenburg-Shah Syndrome, PCWH syndrome, and Kallman syndrome, underscoring its clinical significance. Furthermore, SOX10 is implicated in neural and neuroectodermal tumors, such as melanoma, malignant peripheral nerve sheath tumors (MPNSTs), and schwannomas, influencing processes like proliferation, migration, and differentiation. In mesenchymal tumors, SOX10 expression serves as a valuable marker for distinguishing between different tumor types. Additionally, SOX10 has been identified in various epithelial neoplasms, including breast, ovarian, salivary gland, nasopharyngeal, and bladder cancers, presenting itself as a potential diagnostic and prognostic marker. However, despite these associations, further research is imperative to elucidate its precise role in these malignancies.
PubMed: 38132479
DOI: 10.3390/cimb45120633 -
Purinergic Signalling Dec 2021Pannexin 3 (PANX3) is a member of the pannexin family of single membrane channel-forming glycoproteins. Originally thought to have a limited localization in cartilage,... (Review)
Review
Pannexin 3 (PANX3) is a member of the pannexin family of single membrane channel-forming glycoproteins. Originally thought to have a limited localization in cartilage, bone, and skin, PANX3 has now been detected in a variety of other tissues including skeletal muscle, mammary glands, the male reproductive tract, the cochlea, blood vessels, small intestines, teeth, and the vomeronasal organ. In many cell types of the musculoskeletal system, such as osteoblasts, chondrocytes, and odontoblasts, PANX3 has been shown to regulate the balance of proliferation and differentiation. PANX3 can be induced during progenitor cell differentiation, functioning at the cell surface as a conduit for ATP and/or in the endoplasmic reticulum as a calcium leak channel. Evidence in osteoblasts and monocytes also highlight a role for PANX3 in purinergic signalling through its function as an ATP release channel. PANX3 is critical in the development and ageing of bone and cartilage, with its levels temporally regulated in other tissues such as skeletal muscle, skin, and the cochlea. In diseases such as osteoarthritis and intervertebral disc degeneration, PANX3 can have either protective or detrimental roles depending on if the disease is age-related or injury-induced. This review will discuss PANX3 function in tissue growth and regeneration, its role in cellular differentiation, and how it becomes dysregulated in disease conditions such as obesity, Duchenne's muscular dystrophy, osteosarcoma, and non-melanoma skin cancer, where most of the findings on PANX3 function can be attributed to the characterization of Panx3 KO mouse models.
Topics: Adenosine Triphosphate; Animals; Bone and Bones; Cartilage; Cell Differentiation; Chondrocytes; Connexins; Humans; Receptors, Purinergic; Signal Transduction
PubMed: 34250568
DOI: 10.1007/s11302-021-09805-7 -
Biomolecules Nov 2022The primary cilium is a solitary, sensory organelle that extends from the surface of nearly every vertebrate cell, including craniofacial cells. This organelle converts... (Review)
Review
The primary cilium is a solitary, sensory organelle that extends from the surface of nearly every vertebrate cell, including craniofacial cells. This organelle converts chemical and physical external stimuli into intracellular signaling cascades and mediates several well-known signaling pathways simultaneously. Thus, the primary cilium is considered a cellular signaling nexus and amplifier. Primary cilia dysfunction directly results in a collection of diseases and syndromes that typically affect multiple organ systems, including the face and teeth. Despite this direct connection, primary cilia are largely unexplored in craniofacial research. In this review, I briefly summarize craniofacial abnormalities tied to the primary cilium and examine the existing information on primary cilia in craniofacial development and repair. I close with a discussion on preliminary studies that motivate future areas of exploration that are further supported by studies performed in long bone and kidney cells.
Topics: Humans; Cilia; Signal Transduction; Craniofacial Abnormalities; Kidney
PubMed: 36551151
DOI: 10.3390/biom12121724 -
Biology May 2023Human dental pulp stem cells (hDPSCs) are adult mesenchymal stem cells (MSCs) obtained from dental pulp and derived from the neural crest. They can differentiate into... (Review)
Review
Human dental pulp stem cells (hDPSCs) are adult mesenchymal stem cells (MSCs) obtained from dental pulp and derived from the neural crest. They can differentiate into odontoblasts, osteoblasts, chondrocytes, adipocytes and nerve cells, and they play a role in tissue repair and regeneration. In fact, DPSCs, depending on the microenvironmental signals, can differentiate into odontoblasts and regenerate dentin or, when transplanted, replace/repair damaged neurons. Cell homing depends on recruitment and migration, and it is more effective and safer than cell transplantation. However, the main limitations of cell homing are the poor cell migration of MSCs and the limited information we have on the regulatory mechanism of the direct differentiation of MSCs. Different isolation methods used to recover DPSCs can yield different cell types. To date, most studies on DPSCs use the enzymatic isolation method, which prevents direct observation of cell migration. Instead, the explant method allows for the observation of single cells that can migrate at two different times and, therefore, could have different fates, for example, differentiation and self-renewal. DPSCs use mesenchymal and amoeboid migration modes with the formation of lamellipodia, filopodia and blebs, depending on the biochemical and biophysical signals of the microenvironment. Here, we present current knowledge on the possible intriguing role of cell migration, with particular attention to microenvironmental cues and mechanosensing properties, in the fate of DPSCs.
PubMed: 37237554
DOI: 10.3390/biology12050742 -
BACH1 regulates the proliferation and odontoblastic differentiation of human dental pulp stem cells.BMC Oral Health Nov 2022The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic...
BACKGROUND
The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic differentiation of human dental pulp stem cells (hDPSCs) exhibits the capacity of dental pulp regeneration and dentin complex rebuilding. Exploration of the mechanisms regulating differentiation and proliferation of hDPSCs may help to investigate potential clinical applications. BTB and CNC homology 1 (BACH1) is a transcription repressor engaged in the regulation of multiple cellular functions. This study aimed to investigate the effects of BACH1 on the proliferation and odontoblastic differentiation of hDPSCs in vitro.
METHODS
hDPSCs and pulpal tissues were obtained from extracted human premolars or third molars. The distribution of BACH1 was detected by immunohistochemistry. The mRNA and protein expression of BACH1 were examined by qRT-PCR and Western blot analysis. BACH1 expression was regulated by stable lentivirus-mediated transfection. Cell proliferation and cell cycle were assessed by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay and flow cytometry. The expression of mineralization markers, alkaline phosphatase (ALP) activity and alizarin red S staining were conducted to assess the odontoblastic differentiation ability.
RESULTS
BACH1 expression was stronger in the odontoblast layer than in the cell rich zone. The total and nuclear protein level of BACH1 during odontoblastic differentiation was downregulated initially and then upregulated gradually. Knockdown of BACH1 greatly inhibited cell proliferation, arrested cell cycle, upregulated the heme oxygenase-1 (HO-1) expression and attenuated ALP activity, decreased calcium deposits and downregulated the expression of mineralization markers. Treatment of Tin-protoporphyrin IX, an HO-1 inhibitor, failed to rescue the impaired odonto/osteogenic differentiation capacity. Overexpression of BACH1 increased cell proliferation, ALP activity and the expression of mineralization markers.
CONCLUSIONS
Our findings suggest that BACH1 is an important regulator of the proliferation and odontoblastic differentiation of hDPSCs in vitro. Manipulation of BACH1 expression may provide an opportunity to promote the regenerative capacity of hDPSCs.
Topics: Humans; Basic-Leucine Zipper Transcription Factors; Cell Proliferation; Dental Pulp; Osteogenesis; Regeneration; Stem Cells
PubMed: 36424585
DOI: 10.1186/s12903-022-02588-2 -
Biology Letters Apr 2022In amniotes, daily rates of dentine formation in non-ever-growing teeth range from less than 1 to over 25 μm per day. The latter value has been suggested to represent...
In amniotes, daily rates of dentine formation in non-ever-growing teeth range from less than 1 to over 25 μm per day. The latter value has been suggested to represent the upper limit of odontoblast activity in non-ever-growing teeth, a hypothesis supported by the lack of scaling between dentine apposition rates and body mass in Dinosauria. To determine the correlates and potential controls of dentine apposition rate, we assembled a dataset of apposition rates, metabolic rates and body masses for 80 amniote taxa of diverse ecologies and diets. We used phylogenetic regression to test for scaling relationships and reconstruct ancestral states of daily dentine apposition across Amniota. We find no relationship between body mass and daily dentine apposition rate (DDAR) for non-ever-growing teeth in Amniota as a whole or within major clades. Metabolic rate, the number of tooth generations, diet and habitat also do not predict or correspond with DDARs. Similar DDARs are found in large terrestrial mammals, dinosaurs and marine reptiles, whereas primates, cetaceans and some smaller marine reptiles independently evolved exceptionally slow rates. Life-history factors may explain the evolution of dentine apposition rates, which evolved rapidly at the origin of major clades.
Topics: Animals; Dentin; Dinosaurs; Mammals; Phylogeny; Reptiles; Tooth
PubMed: 35472282
DOI: 10.1098/rsbl.2022.0092