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Microscopy (Oxford, England) Jan 2022Cell-to-cell communication orchestrates various cell and tissue functions. This communication enables cells to form cellular networks with each other through direct... (Review)
Review
Cell-to-cell communication orchestrates various cell and tissue functions. This communication enables cells to form cellular networks with each other through direct contact via intercellular junctions. Because these cellular networks are closely related to tissue and organ functions, elucidating the morphological characteristics of cellular networks could lead to the development of novel therapeutic approaches. The tooth, periodontal ligament (PDL) and alveolar bone form a complex via collagen fibres. Teeth depend on the co-ordinated activity of this complex to maintain their function, with cellular networks in each of its three components. Imaging methods for three-dimensional (3D) mesoscopic architectural analysis include focused ion beam/scanning electron microscopy (FIB/SEM), which is characterized by its ability to select observation points and acquire data from complex tissue after extensive block-face imaging, without the need to prepare numerous ultrathin sections. Previously, we employed FIB/SEM to analyse the 3D mesoscopic architecture of hard tissue including the PDL, which exists between the bone and tooth root. The imaging results showed that the cementum, PDL and alveolar bone networks are in contact and form a heterogeneous cellular network. This cellular network may orchestrate mechanical loading-induced remodelling of the cementum-PDL-alveolar bone complex as the remodelling of each complex component is coordinated, as exemplified by tooth movement due to orthodontic treatment and tooth dislocation due to occlusal loss. In this review, we summarize and discuss the 3D mesoscopic architecture of cellular networks in the cementum, PDL and alveolar bone as observed in our recent mesoscopic and morphological studies.
Topics: Bone and Bones; Dental Cementum; Periodontal Ligament
PubMed: 34850074
DOI: 10.1093/jmicro/dfab051 -
Journal of Clinical Periodontology Dec 2017Tumour necrosis factor (TNF)-α is a pathological factor causing the characteristic symptoms of periodontal disease and rheumatoid arthritis. In this study, we describe...
AIM
Tumour necrosis factor (TNF)-α is a pathological factor causing the characteristic symptoms of periodontal disease and rheumatoid arthritis. In this study, we describe the phenotypes of human TNF-α transgenic mice (hTNFtg) with respect to their periodontium and the temporomandibular joint (TMJ).
MATERIAL AND METHODS
Periodontal structures, TMJ and skull shape of hTNFtg mice and wild-type (WT) littermates were assessed by microcomputed tomography, automated segmentation, geometric morphometrics and histologic ground sections.
RESULTS
We show that hTNFtg mice have an eroded lamina dura and reduced periodontal ligament space compared to (WT) littermates. Transgenic mice further exhibit severe destruction of the TMJ. Geometric morphometrics revealed that hTNFtg mice have a more laterally positioned TMJ with a concomitantly enlarged zygomatic process. Mandibular and maxillary teeth occluded properly.
CONCLUSIONS
Our findings suggest that chronic inflammation in hTNFtg mice causes destructive changes of the periodontium and the TMJ.
Topics: Animals; Arthritis, Rheumatoid; Bone Resorption; Humans; Inflammation; Mice; Mice, Transgenic; Osteoclasts; Periodontal Ligament; Periodontium; Phenotype; Skull; Temporomandibular Joint; Tumor Necrosis Factor-alpha; X-Ray Microtomography; Zygoma
PubMed: 28833486
DOI: 10.1111/jcpe.12799 -
Periodontal ligament stem cells in the periodontitis niche: inseparable interactions and mechanisms.Journal of Leukocyte Biology Sep 2021Periodontitis is characterized by the periodontium's pathologic destruction due to the host's overwhelmed inflammation to the dental plaque. The bacterial infections and... (Review)
Review
Periodontitis is characterized by the periodontium's pathologic destruction due to the host's overwhelmed inflammation to the dental plaque. The bacterial infections and subsequent host immune responses have shaped a distinct microenvironment, which generally affects resident periodontal ligament stem cells (PDLSCs). Interestingly, recent studies have revealed that impaired PDLSCs may also contribute to the disturbance of periodontal homeostasis. The putative vicious circle underlying the interesting "positive feedback" of PDLSCs in the periodontitis niche remains a hot research topic, whereas the inseparable interactions between resident PDLSCs and the periodontitis niche are still not fully understood. This review provides a microscopic view on the periodontitis progression, especially the quick but delicate immune responses to oral dysbacterial infections. We also summarize the interesting crosstalk of the resident PDLSCs with their surrounding periodontitis niche and potential mechanisms. Particularly, the microenvironment reduces the osteogenic properties of resident PDLSCs, which are closely related to their reparative activity. Reciprocally, these impaired PDLSCs may disrupt the microenvironment by aggravating the host immune responses, promoting aberrant angiogenesis, and facilitating the osteoclastic activity. We further recommend that more in-depth studies are required to elucidate the interactions of PDLSCs with the periodontal microenvironment and provide novel interventions for periodontitis.
Topics: Cell Communication; Humans; Immunity; Models, Biological; Periodontal Ligament; Periodontitis; Stem Cells
PubMed: 34043832
DOI: 10.1002/JLB.4MR0421-750R -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Oct 2017The clinical management of periodontal disease is a global concern, and the regeneration of periodontal tissue defects due to periodontitis faces a huge challenge in the...
The clinical management of periodontal disease is a global concern, and the regeneration of periodontal tissue defects due to periodontitis faces a huge challenge in the field of regenerative dentistry. Although conventional periodontal therapies focusing on in flammation control could stop or delay the progression of the disease, periodontal regeneration remains an elusive but laudable goal. Since late 1980s, concerted efforts have been made to accelerate and augment periodontal repair by using guided tissue regeneration (GTR), guided bone regeneration (GBR) and a wide range of other regenerative paradigms. Those advances have largely improved the clinical outcomes of periodontal therapies. In the past several years of 21st century, many progresses were made in the developments of stem cell therapy and tissue engineering, including remarkable biological discoveries in the laboratory as well as great curative successes in preclinical scenarios. The use of the principles, techniques and procedures of tissue engineering in periodontology showed great potential to regenerate new functional periodontal tissues such as alveolar bone, periodontal ligament, root cementum and finally and predictably the normal structure and functionality of the periodontium around a previously diseased tooth.
Topics: Bone Regeneration; Dental Cementum; Disease Progression; Guided Tissue Regeneration, Periodontal; Humans; Periodontal Diseases; Periodontal Ligament; Periodontics; Periodontitis; Periodontium; Regeneration; Stem Cell Transplantation; Tissue Engineering; Tooth Socket
PubMed: 29972934
DOI: 10.3760/cma.j.issn.1002-0098.2017.10.006 -
Cells Jan 2024Orthodontic tooth movement (OTM) is thought to be impeded by bisphosphonate (BP) therapy, mainly due to increased osteoclast apoptosis and changes in the periodontal...
Orthodontic tooth movement (OTM) is thought to be impeded by bisphosphonate (BP) therapy, mainly due to increased osteoclast apoptosis and changes in the periodontal ligament (PdL), a connecting tissue between the alveolar bone and teeth. PdL cells, mainly fibroblasts (PdLFs), are crucial regulators in OTM by modulating force-induced local inflammatory processes. Recently, we identified the TGF-β/BMP superfamily member GDF15 as an important modulator in OTM, promoting the pro-inflammatory mechanoresponses of PdLFs. The precise impact of the highly potent BP zoledronate (ZOL) on the mechanofunctionality of PdLFs is still under-investigated. Therefore, the aim of this study was to further characterize the ZOL-induced changes in the initial inflammatory mechanoresponse of human PdLFs (hPdLFs) and to further clarify a potential interrelationship with GDF15 signaling. Thus, two-day in vitro treatment with 0.5 µM, 5 µM and 50 µM of ZOL altered the cellular properties of hPdLFs partially in a concentration-dependent manner. In particular, exposure to ZOL decreased their metabolic activity, the proliferation rate, detected using Ki-67 immunofluorescent staining, and survival, analyzed using trypan blue. An increasing occurrence of DNA strand breaks was observed using TUNEL and an activated DNA damage response was demonstrated using H2A.X (phosphoS139) staining. While the osteogenic differentiation of hPdLFs was unaffected by ZOL, increased cellular senescence was observed using enhanced p21 and β-galactosidase staining. In addition, cytokine-encoding genes such as , , and , which are associated with a senescence-associated secretory phenotype, were up-regulated by ZOL. Subsequently, this change in the hPdLF phenotype promoted a hyperinflammatory response to applied compressive forces with an increased expression of the pro-inflammatory markers , and , as well as the activation of monocytic THP1 cells. GDF15 appeared to be particularly relevant to these changes, as siRNA-mediated down-regulation balanced these hyperinflammatory responses by reducing IL-1β and IL-6 expression (IL1B -value < 0.0001; IL6 -value < 0.001) and secretion (IL-1β -value < 0.05; IL-6 -value < 0.001), as well as immune cell activation (-value < 0.0001). In addition, ZOL-related reduced RANKL/OPG values and inhibited osteoclast activation were enhanced in -deficient hPdLFs (both -values < 0.0001; all statistical tests: one-way ANOVA, Tukey's post hoc test). Thus, GDF15 may become a promising new target in the personalized orthodontic treatment of bisphosphonatepatients.
Topics: Humans; Fibroblasts; Growth Differentiation Factor 15; Interleukin-6; Osteogenesis; Periodontal Ligament; Zoledronic Acid
PubMed: 38247838
DOI: 10.3390/cells13020147 -
Human periodontal ligament stem cells and hormesis: Enhancing cell renewal and cell differentiation.Pharmacological Research Nov 2021This paper provides a detailed assessment of hormetic dose responses by human periodontal ligament stem cells (hPDLSCs). Hormetic dose responses were induced by a broad... (Review)
Review
This paper provides a detailed assessment of hormetic dose responses by human periodontal ligament stem cells (hPDLSCs). Hormetic dose responses were induced by a broad range of chemicals, including dietary supplements (e.g., curcumin, ginsenoside Rg1), pharmaceutical/commercial substances (e.g., metformin) and endogenous agents (e.g., periostin, TNF-α) for cell proliferation/viability and osteogenic/adipocyte differentiation. This paper clarifies underlying mechanistic foundations of the hPLDSC hormetic dose responses and explores their therapeutic implications. Emerging evidence based on assessments of multiple types of stem cells shows hormetic dose responses to be widespread, reflecting considerable generality and a highly conserved evolutionary trait.
Topics: Cell Differentiation; Cell Proliferation; Hormesis; Humans; Periodontal Ligament; Stem Cells
PubMed: 34563662
DOI: 10.1016/j.phrs.2021.105914 -
Life Sciences Sep 2018Flavonoids are plant-derived polyphenolic compounds claimed to help alleviate a variety of conditions, including diabetes, infectious endocarditis, and cancer. They have... (Review)
Review
Flavonoids are plant-derived polyphenolic compounds claimed to help alleviate a variety of conditions, including diabetes, infectious endocarditis, and cancer. They have attracted substantial research interest as nutraceuticals owing to their diverse bioactivities. Periodontitis is a high-incidence inflammatory disease affecting the dentition-supporting periodontium. Although the etiology of periodontitis is diverse, microbial species in dental plaque are considered its main pathogenic agents. Here, we provide a review of flavonoid study findings relevant for periodontitis treatment and prevention. Cell biology and in vivo rodent model studies have revealed a multiple of flavonoid effects on periodontal cells and tissues, including regulation of inflammatory responses in periodontal components and potential preserving effects in periodontal ligament and alveolar bone tissues. Mechanistic studies have indicated that flavonoids may counteract the proinflammatory effects exerted by pathogen-associated molecular patterns (PAMP) proteins through Toll-like receptor (TLR) responses. Potentially beneficial effects of flavonoids have been reported for various periodontium cells, including epithelial gingival cells, gingival fibroblasts, and periodontal ligament fibroblasts, as well as for alveolar bone maintaining osteoblasts. The findings indicate that flavonoids are highly promising clinical agents for the prevention and reduction of periodontitis, which can be delivered easily to patients via mouthwash, toothpaste, and food products.
Topics: Alveolar Process; Animals; Anti-Inflammatory Agents; Bone Development; Flavonoids; Humans; Periodontal Ligament; Periodontitis
PubMed: 30121198
DOI: 10.1016/j.lfs.2018.08.029 -
Biochimica Et Biophysica Acta.... May 2018Jaw discrepancies and malrelations affect a large proportion of the general population and their treatment is of utmost significance for individuals' health and quality... (Review)
Review
Jaw discrepancies and malrelations affect a large proportion of the general population and their treatment is of utmost significance for individuals' health and quality of life. The aim of their therapy is the modification of aberrant jaw development mainly by targeting the growth potential of the mandibular condyle through its cartilage, and the architectural shape of alveolar bone through a suture type of structure, the periodontal ligament. This targeted treatment is achieved via external mechanical force application by using a wide variety of intraoral and extraoral appliances. Condylar cartilage and sutures exhibit a remarkable plasticity due to the mechano-responsiveness of the chondrocytes and the multipotent mesenchymal cells of the sutures. The tissues respond biologically and adapt to mechanical force application by a variety of signaling pathways and a final interplay between the proliferative activity and the differentiation status of the cells involved. These targeted therapeutic functional alterations within temporo-mandibular joint ultimately result in the enhancement or restriction of mandibular growth, while within the periodontal ligament lead to bone remodeling and change of its architectural structure. Depending on the form of the malrelation presented, the above treatment approaches, in conjunction or separately, lead to the total correction of jaw discrepancies and the achievement of facial harmony and function. Overall, the treatment of craniofacial and jaw anomalies can be seen as an interplay of mechanical forces and adaptations occurring within temporo-mandibular joint and alveolar bone. The aim of the present review is to present up-to-date knowledge on the mechano-biology behind jaw growth modification and alveolar bone remodeling. Furthermore, future molecular targeted therapeutic strategies are discussed aiming at the improvement of mechanically-driven chondrogenesis and osteogenesis.
Topics: Animals; Bone Remodeling; Cell Proliferation; Humans; Mandible; Mandibular Diseases; Periodontal Ligament; Stress, Mechanical; Temporomandibular Joint
PubMed: 29454076
DOI: 10.1016/j.bbadis.2018.02.007 -
Current Drug Targets 2021The prevalence of periodontitis is around 20-50% in the global population. If it is not treated, it can cause tooth loss. Periodontal treatment aims at preserving the... (Review)
Review
The prevalence of periodontitis is around 20-50% in the global population. If it is not treated, it can cause tooth loss. Periodontal treatment aims at preserving the patient's teeth from various damages, including infection control and restoring lost periodontal tissue. The periodontium has great biological regenerative potential, and several biomaterials can be used to improve the outcome of periodontal treatment. To achieve the goal of periodontal tissue regeneration, numerous studies have used fibroblast growth factor 2 (FGF2) to stimulate the regeneration of both the soft tissue and bone. FGF2 induced a significant increment in the percentage of bone fill, bone mineral levels of the defect sites, length of the regenerated periodontal ligament, angiogenesis, connective tissue formation on the root surface, formation of dense fibers bound to the alveolar bone and newly synthesized cementum in teeth. This review will open further avenues to better understand the FGF2 therapy for periodontal regeneration.
Topics: Bone Regeneration; Fibroblast Growth Factor 2; Humans; Periodontal Diseases; Periodontal Ligament; Periodontium
PubMed: 33153420
DOI: 10.2174/1389450121999201105152639 -
PeerJ 2023Dental-derived stem cells have excellent proliferation ability and multi-directional differentiation potential, making them an important research target in tissue... (Review)
Review
Dental-derived stem cells have excellent proliferation ability and multi-directional differentiation potential, making them an important research target in tissue engineering. An increasing number of dental-derived stem cells have been discovered recently, including dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHEDs), stem cells from apical papilla (SCAPs), dental follicle precursor cells (DFPCs), and periodontal ligament stem cells (PDLSCs). These stem cells have significant application prospects in tissue regeneration because they are found in an abundance of sources, and they have good biocompatibility and are highly effective. The biological functions of dental-derived stem cells are regulated in many ways. Epigenetic regulation means changing the expression level and function of a gene without changing its sequence. Epigenetic regulation is involved in many biological processes, such as embryonic development, bone homeostasis, and the fate of stem cells. Existing studies have shown that dental-derived stem cells are also regulated by epigenetic modifications. Pulp and periodontal regeneration refers to the practice of replacing damaged pulp and periodontal tissue and restoring the tissue structure and function under normal physiological conditions. This treatment has better therapeutic effects than traditional treatments. This article reviews the recent research on the mechanism of epigenetic regulation of dental-derived stem cells, and the core issues surrounding the practical application and future use of pulp and periodontal regeneration.
Topics: Humans; Mesenchymal Stem Cells; Epigenesis, Genetic; Stem Cells; Periodontal Ligament; Periodontium
PubMed: 36620748
DOI: 10.7717/peerj.14550