Science.gov

Sample records for periodontal ligament stress

  1. Expression of heat stress proteins by human periodontal ligament cells.

    PubMed

    Sauk, J J; Norris, K; Foster, R; Moehring, J; Somerman, M J

    1988-11-01

    The purpose of the present report was to document the stress response produced by physical and chemical abuses to human periodontal ligament cells, and to review some of the known functions of stress response proteins produced as a result of such treatments. For these studies human PDL cells were exposed to sublethal challenges of 43 degrees C heat, sodium arsenite and the amino acid analog L-azetidine-2-carboxylic acid (AZC). The cells were labelled with [35S]-methionine and the proteins produced were examined by autofluorography of SDS-PAGE gels. Heat challenges were shown to induce hsps with an apparent mol. wts. of 90K, 68-72K, 41-47K, and 36 K. Arsenite-treated cells produced similar hsps including a 30k protein not produced by other forms of stress. AZC treatment resulted in the production of apparent functionless hsps with apparent molecular weights of 90,000, 72,000, 68,000 and 36,000. The function of these proteins and their possible role in periodontal disease is discussed.

  2. Advanced glycation end products upregulate the endoplasmic reticulum stress in human periodontal ligament cells.

    PubMed

    Xu, Jie; Xiong, Ming; Huang, Bin; Chen, Huangqin

    2015-03-01

    The accumulation of advanced glycation end products (AGEs) appears to be the main factor responsible for modulating periodontal inflammation in diabetes. The aim of this study is to examine the effects of AGEs on inflammation in human periodontal ligament cells and to investigate the mechanism with a specific emphasis on the role of endoplasmic reticulum (ER) stress-induced nuclear factor-kappa B (NF-κB) pathway. Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The protein expressions of ER markers and NF-κB were examined by Western blot analysis. The translocation of NF-κB was observed by immunofluorescence assay. Proinflammatory chemokine production was determined by enzyme-linked immunosorbent assay. Treatment with AGEs reduced cell viability in a concentration- and time-dependent manner. AGEs induced ER stress, as evidenced by survival molecules, such as glucose-regulated protein 78 (GRP78), double-stranded RNA-activated protein kinase-like ER kinase (PERK), and activating transcription factor 6 (ATF-6), and apoptotic molecules, such as CCAAT/enhancer binding protein homologous protein (CHOP) and caspase 12. AGEs upregulated the nucleoprotein expression of NF-κB, enhanced translocation of NF-κB from the cytoplasm to the nucleus, and increased the production of proinflammatory chemokines interleukin-6 and interleukin-8. AGEs mediate inflammation of human periodontal ligament cells via the ER stress-induced NF-κB pathway.

  3. Endoplasmic reticulum stress modulates nicotine-induced extracellular matrix degradation in human periodontal ligament cells.

    PubMed

    Lee, S-I; Kang, K-L; Shin, S-I; Herr, Y; Lee, Y-M; Kim, E-C

    2012-06-01

    Tobacco smoking is considered to be one of the major risk factors for periodontitis. For example, about half the risk of periodontitis can be attributable to smoking in the USA. It is evident that smokers have greater bone loss, greater attachment loss and deeper periodontal pockets than nonsmoking patients. It has recently been reported that endoplasmic reticulum (ER) stress markers are upregulated in periodontitis patients; however, the direct effects of nicotine on ER stress in regard to extracellular matrix (ECM) degradation are unclear. The purpose of this study was to examine the effects of nicotine on cytotoxicity and expression of ER stress markers, selected ECM molecules and MMPs, and to identify the underlying mechanisms in human periodontal ligament cells. We also examined whether ER stress was responsible for the nicotine-induced cytotoxicity and ECM degradation. Cytotoxicity and cell death were measured by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay and flow cytometric annexin V and propidium iodide staining. The mRNA and protein expressions of MMPs and ER markers were examined by RT-PCR and western blot analysis. Treatment with nicotine reduced cell viability and increased the proportion of annexin V-negative, propidium iodide-positive cells, an indication of cell death. Nicotine induced ER stress, as evidenced by survival molecules, such as phosphorylated protein kinase-like ER-resident kinase, phosphorylated eukaryotic initiation factor-2α and glucose-regulated protein-78, and apoptotic molecules, such as CAAT/enhancer binding protein homologous protein (CHOP). Nicotine treatment led to the downregulation of ECM molecules, including collagen type I, elastin and fibronectin, and upregulation of MMPs (MMP-1, MMP-2, MMP-8 and MMP-9). Inhibition of ER stress by salubrinal and transfection of CHOP small interfering RNA attenuated the nicotine-induced cell death, ECM degradation and production of MMPs. Salubrinal and CHOP small

  4. LPS from P. gingivalis and Hypoxia Increases Oxidative Stress in Periodontal Ligament Fibroblasts and Contributes to Periodontitis

    PubMed Central

    Gölz, L.; Memmert, S.; Rath-Deschner, B.; Jäger, A.; Appel, T.; Baumgarten, G.; Götz, W.; Frede, S.

    2014-01-01

    Oxidative stress is characterized by an accumulation of reactive oxygen species (ROS) and plays a key role in the progression of inflammatory diseases. We hypothesize that hypoxic and inflammatory events induce oxidative stress in the periodontal ligament (PDL) by activating NOX4. Human primary PDL fibroblasts were stimulated with lipopolysaccharide from Porphyromonas gingivalis (LPS-PG), a periodontal pathogen bacterium under normoxic and hypoxic conditions. By quantitative PCR, immunoblot, immunostaining, and a specific ROS assay we determined the amount of NOX4, ROS, and several redox systems. Healthy and inflamed periodontal tissues were collected to evaluate NOX4 and redox systems by immunohistochemistry. We found significantly increased NOX4 levels after hypoxic or inflammatory stimulation in PDL cells (P < 0.001) which was even more pronounced after combination of the stimuli. This was accompanied by a significant upregulation of ROS and catalase (P < 0.001). However, prolonged incubation with both stimuli induced a reduction of catalase indicating a collapse of the protective machinery favoring ROS increase and the progression of inflammatory oral diseases. Analysis of inflamed tissues confirmed our hypothesis. In conclusion, we demonstrated that the interplay of NOX4 and redox systems is crucial for ROS formation which plays a pivotal role during oral diseases. PMID:25374447

  5. Cadherin-11 modulates cell morphology and collagen synthesis in periodontal ligament cells under mechanical stress.

    PubMed

    Feng, Lishu; Zhang, Yimei; Kou, Xiaoxing; Yang, Ruili; Liu, Dawei; Wang, Xuedong; Song, Yang; Cao, Haifeng; He, Danqing; Gan, Yehua; Zhou, Yanheng

    2017-03-01

    To examine the role of cadherin-11, an integral membrane adhesion molecule, in periodontal ligament cells (PDLCs) under mechanical stimulation. Human PDLCs were cultured and subjected to mechanical stress. Cadherin-11 expression and cell morphology of PDLCs were investigated via immunofluorescence staining. The mRNA and protein expressions of cadherin-11 and type I collagen (Col-I) of PDLCs were evaluated by quantitative real-time polymerase chain reaction and Western blot, respectively. Small interfering RNA was used to knock down cadherin-11 expression in PDLCs. The collagen matrix of PDLCs was examined using toluidine blue staining. Cadherin-11 was expressed in PDLCs. Mechanical stress suppressed cadherin-11 expression in PDLCs with prolonged force treatment time and increased force intensity, accompanied by suppressed β-catenin expression. Simultaneously, mechanical stress altered cell morphology and repressed Col-I expression in a time- and dose-dependent manner in PDLCs. Moreover, knockdown of cadherin-11 with suppressed β-catenin expression resulted in altered PDLC morphology and repressed collagen expression, which were consistent with the changes observed under mechanical stress. Results of this study suggest that cadherin-11 is expressed in PDLCs and modulates PDLC morphology and collagen synthesis in response to mechanical stress, which may play an important role in the homeostasis and remodeling of the PDL under mechanical stimulation.

  6. Mechanical stress induces production of angiogenic regulators in cultured human gingival and periodontal ligament fibroblasts.

    PubMed

    Yoshino, Hiroyuki; Morita, Ikuo; Murota, Sei-Itsu; Ishikawa, Isao

    2003-08-01

    As periodontal tissues are constantly exposed to mechanical stress during mastication, the relationship between mechanical stimulation and biochemical phenomena has been extensively investigated. The aim of the present study was to assess the change in the production of angiogenic regulators produced by human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPLF), cultured on a flexible substrate, before and after application of cyclic tensile stretching. Both cell types were stretched in a Flexercell Strain Unit to 7, 14 and 21% elongation, at a frequency of 12 cycles/min. Medium cultured with HGF or HPLF was examined by enzyme-linked immunosorbent assay (ELISA) for vascular endothelial growth factor (VEGF), Western blotting of pigment epithelium-derived factor (PEDF) and in vitro angiogenesis assay. The residual cells were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) for both VEGF and PEDF mRNA expression. Stretching increased the VEGF mRNA level and VEGF secretion in both HGF and HPLF. The concentration of VEGF in the conditioned medium of the stretched HPLF was almost the same as that of stretched HGF. In the in vitro angiogenesis assay, the conditioned medium of HPLF after stretching showed a dramatic increase in tube formation. In contrast, stretched HGF did not show enhanced tube formation, despite the increase in VEGF secretion by stretched HGF. The mRNA levels of PEDF, an inhibitor of angiogenesis, were higher in HGF than HPLF. The protein level of PEDF in HGF was also higher than that in HPLF. These findings suggest that under mechanical stress HPLF promotes angiogenesis via expression of VEGF, whereas under the same conditions angiogenesis is not promoted in HGF, due to the expression of PEDF.

  7. Periodontal ligament injection: alternative solutions.

    PubMed Central

    Gray, R. J.; Lomax, A. M.; Rood, J. P.

    1990-01-01

    This study was undertaken to investigate whether plain lidocaine, 3% plain mepivacaine and 3% prilocaine with felypressin were suitable epinephrine-free local anesthetic solutions for use in periodontal ligament anesthesia as alternatives to lidocaine with 1:80,000 epinephrine. Two hundred and seven patients received one of the four test solutions via a periodontal ligament injection and the success rate of anesthesia was confirmed using an electric pulp stimulator. Although neither mepivacaine nor prilocaine were as effective as lidocaine with epinephrine, the success rates of these three solutions were not statistically different. A single periodontal ligament injection of any of the solutions tested resulted in a low incidence of anesthesia. The success rate of lidocaine without epinephrine was consistently poor. PMID:2097910

  8. Stress Induced in the Periodontal Ligament under Orthodontic Loading (Part I): A Finite Element Method Study Using Linear Analysis

    PubMed Central

    Hemanth, M; deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

    2015-01-01

    Background: Orthodontic tooth movement is a complex procedure that occurs due to various biomechanical changes in the periodontium. Optimal orthodontic forces yield maximum tooth movement whereas if the forces fall beyond the optimal threshold it can cause deleterious effects. Among various types of tooth movements intrusion and lingual root torque are associated with causing root resoprtion, especially with the incisors. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with intrusion and lingual root torque using finite element method (FEM). Materials and Methods: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with intrusive and lingual root torque movements by a 3D FEM using ANSYS software using linear stress analysis. Results: It was observed that with the application of intrusive load compressive stresses were distributed at the apex whereas tensile stress was seen at the cervical margin. With the application of lingual root torque maximum compressive stress was distributed at the apex and tensile stress was distributed throughout the PDL. Conclusion: For intrusive and lingual root torque movements stress values over the PDL was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using linear properties. PMID:26464555

  9. Stress Induced in the Periodontal Ligament under Orthodontic Loading (Part I): A Finite Element Method Study Using Linear Analysis.

    PubMed

    Hemanth, M; Deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

    2015-08-01

    Orthodontic tooth movement is a complex procedure that occurs due to various biomechanical changes in the periodontium. Optimal orthodontic forces yield maximum tooth movement whereas if the forces fall beyond the optimal threshold it can cause deleterious effects. Among various types of tooth movements intrusion and lingual root torque are associated with causing root resoprtion, especially with the incisors. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with intrusion and lingual root torque using finite element method (FEM). A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with intrusive and lingual root torque movements by a 3D FEM using ANSYS software using linear stress analysis. It was observed that with the application of intrusive load compressive stresses were distributed at the apex whereas tensile stress was seen at the cervical margin. With the application of lingual root torque maximum compressive stress was distributed at the apex and tensile stress was distributed throughout the PDL. For intrusive and lingual root torque movements stress values over the PDL was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using linear properties.

  10. Stress Induced in Periodontal Ligament under Orthodontic Loading (Part II): A Comparison of Linear Versus Non-Linear Fem Study

    PubMed Central

    Hemanth, M; Deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

    2015-01-01

    Background: Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties. Materials and Methods: A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses. Results: For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced. Conclusion: This shows that the force level required for non-linear analysis is lesser than that of linear analysis. PMID:26435629

  11. Stress Induced in Periodontal Ligament under Orthodontic Loading (Part II): A Comparison of Linear Versus Non-Linear Fem Study.

    PubMed

    Hemanth, M; Deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

    2015-09-01

    Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties. A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses. For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced. This shows that the force level required for non-linear analysis is lesser than that of linear analysis.

  12. Role of Mechanical Stress-induced Glutamate Signaling-associated Molecules in Cytodifferentiation of Periodontal Ligament Cells*

    PubMed Central

    Fujihara, Chiharu; Yamada, Satoru; Ozaki, Nobuhiro; Takeshita, Nobuo; Kawaki, Harumi; Takano-Yamamoto, Teruko; Murakami, Shinya

    2010-01-01

    In this study, we analyzed the effects of tensile mechanical stress on the gene expression profile of in vitro-maintained human periodontal ligament (PDL) cells. A DNA chip analysis identified 17 up-regulated genes in human PDL cells under the mechanical stress, including HOMER1 (homer homolog 1) and GRIN3A (glutamate receptor ionotropic N-methyl-d-aspartate 3A), which are related to glutamate signaling. RT-PCR and real-time PCR analyses revealed that human PDL cells constitutively expressed glutamate signaling-associated genes and that mechanical stress increased the expression of these mRNAs, leading to release of glutamate from human PDL cells and intracellular glutamate signal transduction. Interestingly, exogenous glutamate increased the mRNAs of cytodifferentiation and mineralization-related genes as well as the ALP (alkaline phosphatase) activities during the cytodifferentiation of the PDL cells. On the other hand, the glutamate signaling inhibitors riluzole and (+)-MK801 maleate suppressed the alkaline phosphatase activities and mineralized nodule formation during the cytodifferentiation and mineralization. Riluzole inhibited the mechanical stress-induced glutamate signaling-associated gene expressions in human PDL cells. Moreover, in situ hybridization analyses showed up-regulation of glutamate signaling-associated gene expressions at tension sites in the PDL under orthodontic tooth movement in a mouse model. The present data demonstrate that the glutamate signaling induced by mechanical stress positively regulates the cytodifferentiation and mineralization of PDL cells. PMID:20576613

  13. An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I.

    PubMed

    Hemanth, M; Raghuveer, H P; Rani, M S; Hegde, Chathura; Kabbur, Karthik J; Vedavathi, B; Chaithra, D

    2015-09-01

    Orthodontic tooth movement occurs due to various biomechanical changes in the periodontium. Forces within the optimal range yield maximum tooth movement with minimum deleterious effects. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with extrusion and rotational movements using the finite element method FEM. A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with linear material properties. It was observed that with the application of extrusive load, the tensile stresses were seen at the apex, whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third, whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. For extrusive movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Profitt as optimum forces for orthodontic tooth movement using linear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

  14. Evaluating Stress Distribution Pattern in Periodontal Ligament of Maxillary Incisors during Intrusion Assessed by the Finite Element Method

    PubMed Central

    Salehi, Parisa; Gerami, Alayar; Najafi, Amirhosein; Torkan, Sepideh

    2015-01-01

    Statement of the Problem The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping. Purpose The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated. Materials and Method Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews. Results In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice. Conclusion From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth. PMID:26636119

  15. An Analysis of the Stress induced in the Periodontal Ligament during Extrusion and Rotation Movements- Part II: A Comparison of Linear vs Nonlinear FEM Study.

    PubMed

    Hemanth, M; Raghuveer, H P; Rani, M S; Hegde, Chathura; Kabbur, Karthik J; Chaithra, D; Vedavathi, B

    2015-10-01

    Optimal orthodontic forces are those which stimulate tooth movement with minimal biological trauma to the tooth, periodontal ligament (PDL) during and alveolar bone. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. The mechanical behavior of the PDL is known to be nonlinear elastic and thus a nonlinear simulation of the PDL provides precision to the calculated stress values. Therefore in this study, the stress patterns in the PDL were evaluated with extrusion and rotational movements using the nonlinear finite element method (FEM). A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modelling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with nonlinear material properties. It was observed that with the application of extrusive load, the tensile stresses were seen at the apex whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. For rotational and extrusion movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using nonlinear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

  16. Periodontal Regeneration Using Periodontal Ligament Stem Cell-Transferred Amnion

    PubMed Central

    Iwasaki, Kengo; Yokoyama, Naoki; Tanaka, Yuichi; Taki, Atsuko; Honda, Izumi; Kimura, Yasuyuki; Takeda, Masaki; Akazawa, Keiko; Oda, Shigeru; Izumi, Yuichi; Morita, Ikuo

    2014-01-01

    Periodontal disease is characterized by the destruction of tooth supporting tissues. Regeneration of periodontal tissues using ex vivo expanded cells has been introduced and studied, although appropriate methodology has not yet been established. We developed a novel cell transplant method for periodontal regeneration using periodontal ligament stem cell (PDLSC)-transferred amniotic membrane (PDLSC-amnion). The aim of this study was to investigate the regenerative potential of PDLSC-amnion in a rat periodontal defect model. Cultured PDLSCs were transferred onto amniotic membranes using a glass substrate treated with polyethylene glycol and photolithography. The properties of PDLSCs were investigated by flow cytometry and in vitro differentiation. PDLSC-amnion was transplanted into surgically created periodontal defects in rat maxillary molars. Periodontal regeneration was evaluated by microcomputed tomography (micro-CT) and histological analysis. PDLSCs showed mesenchymal stem cell-like characteristics such as cell surface marker expression (CD90, CD44, CD73, CD105, CD146, and STRO-1) and trilineage differentiation ability (i.e., into osteoblasts, adipocytes, and chondrocytes). PDLSC-amnion exhibited a single layer of PDLSCs on the amniotic membrane and stability of the sheet even with movement and deformation caused by surgical instruments. We observed that the PDLSC-amnion enhanced periodontal tissue regeneration as determined by micro-CT and histology by 4 weeks after transplantation. These data suggest that PDLSC-amnion has therapeutic potential as a novel cell-based regenerative periodontal therapy. PMID:24032400

  17. Periodontal regeneration using periodontal ligament stem cell-transferred amnion.

    PubMed

    Iwasaki, Kengo; Komaki, Motohiro; Yokoyama, Naoki; Tanaka, Yuichi; Taki, Atsuko; Honda, Izumi; Kimura, Yasuyuki; Takeda, Masaki; Akazawa, Keiko; Oda, Shigeru; Izumi, Yuichi; Morita, Ikuo

    2014-02-01

    Periodontal disease is characterized by the destruction of tooth supporting tissues. Regeneration of periodontal tissues using ex vivo expanded cells has been introduced and studied, although appropriate methodology has not yet been established. We developed a novel cell transplant method for periodontal regeneration using periodontal ligament stem cell (PDLSC)-transferred amniotic membrane (PDLSC-amnion). The aim of this study was to investigate the regenerative potential of PDLSC-amnion in a rat periodontal defect model. Cultured PDLSCs were transferred onto amniotic membranes using a glass substrate treated with polyethylene glycol and photolithography. The properties of PDLSCs were investigated by flow cytometry and in vitro differentiation. PDLSC-amnion was transplanted into surgically created periodontal defects in rat maxillary molars. Periodontal regeneration was evaluated by microcomputed tomography (micro-CT) and histological analysis. PDLSCs showed mesenchymal stem cell-like characteristics such as cell surface marker expression (CD90, CD44, CD73, CD105, CD146, and STRO-1) and trilineage differentiation ability (i.e., into osteoblasts, adipocytes, and chondrocytes). PDLSC-amnion exhibited a single layer of PDLSCs on the amniotic membrane and stability of the sheet even with movement and deformation caused by surgical instruments. We observed that the PDLSC-amnion enhanced periodontal tissue regeneration as determined by micro-CT and histology by 4 weeks after transplantation. These data suggest that PDLSC-amnion has therapeutic potential as a novel cell-based regenerative periodontal therapy.

  18. Physiological features of periodontal regeneration and approaches for periodontal tissue engineering utilizing periodontal ligament cells.

    PubMed

    Benatti, Bruno Braga; Silvério, Karina Gonzales; Casati, Márcio Zaffalon; Sallum, Enílson Antônio; Nociti, Francisco Humberto

    2007-01-01

    Experimental studies have shown that the potential of periodontal regeneration seems to be limited by the regenerative capacity of the cells involved. The regeneration of damaged periodontal tissues is mediated by various periodontal cells and is regulated by a vast array of extracellular matrix informational molecules that induce both selective and nonselective responses in different cell lineages and their precursors. In this paper, we first review periodontal ligament tissue and its different cell subpopulations including fibroblasts and paravascular stem cells, and their functions during the development and homeostasis of periodontal tissues. Because conventional periodontal regeneration methods remain insufficient to obtain a complete and reliable periodontal regeneration, the concept of periodontal tissue engineering has been based on the generation of the conditions necessary to improve the healing of periodontal tissues. Additionally, the potential of periodontal ligament cells for use in periodontal tissue engineering to overcome the limitations of conventional periodontal regenerative therapies is discussed, followed by an update of the recent progress and future directions of research utilizing periodontal ligament cells for predictable periodontal regeneration.

  19. Allogeneic Periodontal Ligament Stem Cell Therapy for Periodontitis in Swine

    PubMed Central

    Ding, Gang; Liu, Yi; Wang, Wei; Wei, Fulan; Liu, Dayong; Fan, Zhipeng; An, Yunqing; Zhang, Chunmei; Wang, Songlin

    2010-01-01

    Periodontitis is one of the most widespread infectious diseases in humans. It is the main cause of tooth loss and associated with a number of systemic diseases. Until now, there is no appropriate method for functional periodontal tissue regeneration. Here, we establish a novel approach of using allogeneic periodontal ligament stem cells (PDLSCs) sheet to curing periodontitis in a miniature pig periodontitis model. Significant periodontal tissue regeneration was achieved in both the autologous and the allogeneic PDLSCs transplantation group at 12 weeks post-PDLSCs transplantation. Based on clinical assessments, computed tomography (CT) scanning, and histological examination, there was no marked difference between the autologous and allogeneic PDLSCs transplantation groups. In addition, lack of immunological rejections in the animals that received the allogeneic PDLSCs transplantation was observed. Interestingly, we found that human PDLSCs fail to express human leukocyte antigen (HLA)-II DR and costimulatory molecules. PDLSCs were not able to elicit T-cell proliferation and inhibit T-cell proliferation when stimulated with mismatched major histocompatibility complex molecules. Furthermore, we found that prostaglandin E2 (PGE2) plays a crucial role in PDLSCs-mediated immunomodulation and periodontal tissue regeneration in vitro and in vivo. Our study demonstrated that PDLSCs possess low immunogenicity and marked immunosuppression via PGE2-induced T-cell anergy. We developed a standard technological procedure of using allogeneic PDLSCs to cure periodontitis in swine. Stem Cells 2010;28:1829–1838 PMID:20979138

  20. Biological Events in Periodontal Ligament and Alveolar Bone Associated with Application of Orthodontic Forces

    PubMed Central

    Feller, L.; Khammissa, R. A. G.; Schechter, I.; Thomadakis, G.; Fourie, J.; Lemmer, J.

    2015-01-01

    Orthodontic force-induced stresses cause dynamic alterations within the extracellular matrix and within the cytoskeleton of cells in the periodontal ligament and alveolar bone, mediating bone remodelling, ultimately enabling orthodontic tooth movement. In the periodontal ligament and alveolar bone, the mechanically induced tensile strains upregulate the expression of osteogenic genes resulting in bone formation, while mechanically induced compressive strains mediate predominantly catabolic tissue changes and bone resorption. In this review article we summarize some of the currently known biological events occurring in the periodontal ligament and in the alveolar bone in response to application of orthodontic forces and how these facilitate tooth movement. PMID:26421314

  1. Cementum and Periodontal Ligament Regeneration.

    PubMed

    Menicanin, Danijela; Hynes, K; Han, J; Gronthos, S; Bartold, P M

    2015-01-01

    The unique anatomy and composition of the periodontium make periodontal tissue healing and regeneration a complex process. Periodontal regeneration aims to recapitulate the crucial stages of wound healing associated with periodontal development in order to restore lost tissues to their original form and function and for regeneration to occur, healing events must progress in an ordered and programmed sequence both temporally and spatially, replicating key developmental events. A number of procedures have been employed to promote true and predictable regeneration of the periodontium. Principally, the approaches are based on the use of graft materials to compensate for the bone loss incurred as a result of periodontal disease, use of barrier membranes for guided tissue regeneration and use of bioactive molecules. More recently, the concept of tissue engineering has been integrated into research and applications of regenerative dentistry, including periodontics, to aim to manage damaged and lost oral tissues, through reconstruction and regeneration of the periodontium and alleviate the shortcomings of more conventional therapeutic options. The essential components for generating effective cellular based therapeutic strategies include a population of multi-potential progenitor cells, presence of signalling molecules/inductive morphogenic signals and a conductive extracellular matrix scaffold or appropriate delivery system. Mesenchymal stem cells are considered suitable candidates for cell-based tissue engineering strategies owing to their extensive expansion rate and potential to differentiate into cells of multiple organs and systems. Mesenchymal stem cells derived from multiple tissue sources have been investigated in pre-clinical animal studies and clinical settings for the treatment and regeneration of the periodontium.

  2. Wnt signaling regulates homeostasis of the periodontal ligament

    PubMed Central

    Lim, W.H.; Liu, B.; Cheng, D.; Williams, B.O.; Mah, S.J.; Helms, J.A.

    2014-01-01

    Background and Objective In health, the periodontal ligament maintains a constant width throughout an organism’s lifetime. The molecular signals responsible for maintaining homeostatic control over the periodontal ligament are unknown. The purpose of this study was to investigate the role of Wnt signaling in this process by removing an essential chaperone protein, Wntless (Wls) from odontoblasts and cementoblasts, and observing the effects of Wnt depletion on cells of the periodontal complex. Material and Methods The Wnt responsive status of the periodontal complex was assessed using two strains of Wnt reporter mice, Axin2LacZ/+ mice and Lgr5LacZ/+. The function of this endogenous Wnt signal was evaluated by conditionally eliminating the Wntless (Wls) gene using an Osteocalcin Cre driver. The resulting OCN-Cre;Wlsfl/fl mice were examined using micro-CT and histology, immunohistochemical analyses for Osteopontin, Runx2 and Fibromodulin, in situ hybridization for Osterix, and alkaline phosphatase activity. Results The adult periodontal ligament is Wnt responsive. Elimination of Wnt signaling in the periodontal complex of OCN-Cre;Wlsfl/fl mice results in a wider periodontal ligament space. This pathologically increased periodontal width is due to a reduction in the expression of osteogenic genes and proteins, which results in thinner alveolar bone. A concomitant increase in fibrous tissue occupying the periodontal space was observed along with a disruption in the orientation of the periodontal ligament. Conclusion The periodontal ligament is a Wnt dependent tissue. Cells in the periodontal complex are Wnt responsive and eliminating an essential component of the Wnt signaling network leads to a pathological widening of the periodontal ligament space. Osteogenic stimuli are reduced and a disorganized fibrillary matrix results from depletion of Wnt signaling. Collectively, these data underscore the importance of Wnt signaling in homeostasis of the periodontal ligament

  3. C/EBP β Mediates Endoplasmic Reticulum Stress Regulated Inflammatory Response and Extracellular Matrix Degradation in LPS-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Bai, Yudi; Wei, Yi; Wu, Lian; Wei, Jianhua; Wang, Xiaojing; Bai, Yuxiang

    2016-03-22

    Periodontitis is an oral inflammatory disease that not only affects the integrity of local tooth-supporting tissues but also impacts systemic health. A compositional shift in oral microbiota has been considered as the main cause of periodontitis; however, the potential mechanism has not been fully defined. Herein, we investigated the role of CCAAT/enhancer-binding protein β (C/EBP β), a member of the C/EBP family of transcription factors, in human periodontal ligament cells (hPDLCs) exposed to Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). RT-PCR and Western blotting analysis showed that the expression of C/EBP β was significantly increased in hPDLCs stimulated with LPS stimuli. Overexpression of C/EBP β by the recombinant adenoviral vector pAd/C/EBP β markedly increased the expression of the pro-inflammatory cytokines IL-6 and IL-8, and matrix metalloproteinases (MMP)-8 and -9 in hPDLCs in response to LPS. Furthermore, the activation of endoplasmic reticulum (ER) stress was confirmed in LPS-stimulated hPDLCs by measuring the expression of the ER stress marker molecules protein kinase-like ER kinase (PERK), eIF2α, GRP78/Bip, and C/EBP homologous protein (CHOP). The ER stress inhibitor salubrinal repressed, but inducer tunicamycin enhanced, the production of IL-6, IL-8, MMP-8, and MMP-9 in hPDLCs. Additionally, ER stress inducer tunicamycin significantly increased the expression level of C/EBP β in hPDLCs. Blocking of C/EBP β by siRNA resulted in a significant decrease in the secretion of IL-6 and IL-8 and expression of MMP-8 and MMP-9 induced by tunicamycin treatment in hPDLCs. Taken together, ER stress appears to play a regulatory role in the inflammatory response and extracellular matrix (ECM) degradation in hPDLCs in response to LPS stimuli by activating C/EBP β expression. This enhances our understanding of human periodontitis pathology.

  4. Cyclic Tensile Stress During Physiological Occlusal Force Enhances Osteogenic Differentiation of Human Periodontal Ligament Cells via ERK1/2-Elk1 MAPK Pathway

    PubMed Central

    Li, Lu; Han, Minxuan; Li, Sheng

    2013-01-01

    Physiological occlusal force constitutively exists in the oral environment and is important for periodontal homeostasis and remodeling. Cyclic tensile stress (CTS) triggers the biological response of periodontal ligament (PDL). However, a few reports have studied the correlation between CTS during physiological occlusal force and PDL cell activities such as osteogenic differentiation. In the present study, human PDL cells (hPDLCs) were subjected to 10% elongation CTS loading at 0.5 Hz for 24 h, which represents the physiological conditions of occlusal force. Gene expression microarray was used to investigate the mechano-induced differential gene profile and pathway analysis in vitro. The osteogenic relative factors, that is, SPP1, RUNX2, and SP7, were assessed by real-time PCR and Western blot. The involvement of mitogen-activated protein kinase (MAPK) signaling pathways was investigated by Western blot with a specific inhibitor. The expressions of SPP1, RUNX2, SP7, p-ERK1/2, and p-Elk1 were up-regulated after 10% CTS exposure. However, these up-regulated expressions were prevented by ERK1/2 inhibitor U0126 in the physiological occlusal force-applied hPDLCs. These results showed that 10% CTS could enhance osteogenic differentiation of hPDLCs via ERK1/2-Elk1 MAPK pathway, indicating that CTS during physiological occlusal force is a potent agent for PDL remodeling. PMID:23781879

  5. [Ginsenoside Rg1 regulates the proliferation and migration of human periodontal ligament cells via Akt/eNOS signaling under nicotine stress].

    PubMed

    Liu, Cai-Hong; DU, Li

    2017-02-01

    To explore the effects and molecular mechanisms of ginsenoside Rg1 on the proliferation and migration of human periodontal ligament cells (HPDLCs) under nicotine stress. HPDLCs were isolated and cultured by method of explant cell culture. The cells were cultured under nicotine stress for 7 days, and treated respectively with ginsenoside Rg1 (0.01 μmol/L), ginsenoside Rg1 and LY294002 (PI3K inhibitor, 0.5 μmol/L), ginsenoside Rg1 and Tricirbine (Akt inhibitor, 5 μmol/L), ginsenoside Rg1 and L-NAME (Akt inhibitor, 1 mmol/L) from 3rd day after nicotine stress to 7th day. MTT assay and Transwell assay were used to evaluate the proliferation and migration of HPDLCs in each group. Western blot and quantitative real-time PCR methods were used for testing the changes of PI3K/Akt/eNOS signaling expression. SPSS 20.0 software package was used for statistical analysis. The proliferation and migration were significantly inhibited by nicotine treatment. PI3K levels were upregulated, but Akt1/2 and eNOS levels were remarkedly reduced by nicotine. Ginsenoside Rg1 attenuated the effects of nicotine on proliferation, migration and Akt/eNOS signaling. Tricirbine and L-NAME could reduce the inhibitory effects of ginsenoside Rg1 toward nicotine. Ginsenoside Rg1 regulates the proliferation and migration of HPDLCs under nicotine stress via Akt/eNOS signaling.

  6. Finite element analysis of equine incisor teeth. Part 2: investigation of stresses and strain energy densities in the periodontal ligament and surrounding bone during tooth movement.

    PubMed

    Schrock, P; Lüpke, M; Seifert, H; Staszyk, C

    2013-12-01

    This study investigated the hypothetical contribution of biomechanical loading to the onset of equine odontoclastic tooth resorption and hypercementosis (EOTRH) and to elucidate the physiological age-related positional changes of the equine incisors. Based on high resolution micro-computed tomography (μCT) datasets, 3-dimensional models of entire incisor arcades and the canine teeth were constructed representing a young and an old incisor dentition. Special attention was paid to constructing an anatomically correct model of the periodontal ligament (PDL). Using previously determined Young's moduli for the equine incisor PDL, finite element (FE) analysis was performed. Resulting strains, stresses and strain energy densities (SEDs), as well as the resulting regions of tension and compression within the PDL and the surrounding bone were investigated during occlusion. The results showed a distinct distribution pattern of high stresses and corresponding SEDs in the PDL and bone. Due to the tooth movement, peaks of SEDs were obtained in the PDL as well as in the bone on the labial and palatal/lingual sides of the alveolar crest. At the root, highest SEDs were detected in the PDL on the palatal/lingual side slightly occlusal of the root tip. This distribution pattern of high SEDs within the PDL coincides with the position of initial resorptive lesions in EOTRH affected teeth. The position of high SEDs in the bone can explain the typical age-related alteration of shape and angulation of equine incisors.

  7. Periodontal ligament stem cells: an update and perspectives.

    PubMed

    Chamila Prageeth Pandula, P K; Samaranayake, L P; Jin, L J; Zhang, Chengfei

    2014-05-01

    Chronic periodontitis is a serious infectious and inflammatory oral disease of humans worldwide. Conventional treatment modalities are effective for controlling periodontal disease. However, the regeneration of damaged periodontal tissues remains a major challenge in clinical practice due to the complex structure of the periodontium. Stem cell-based regenerative approaches combined with the usage of emerging biomaterials are entering a new era in periodontal regeneration. The present review updates the current knowledge of periodontal ligament stem cell-based approaches for periodontal regeneration, and elaborates on the potentials for clinical application.

  8. Decellularized Periodontal Ligament Cell Sheets with Recellularization Potential

    PubMed Central

    Farag, A.; Vaquette, C.; Theodoropoulos, C.; Hamlet, S.M.; Hutmacher, D.W.; Ivanovski, S.

    2014-01-01

    The periodontal ligament is the key tissue facilitating periodontal regeneration. This study aimed to fabricate decellularized human periodontal ligament cell sheets for subsequent periodontal tissue engineering applications. The decellularization protocol involved the transfer of intact human periodontal ligament cell sheets onto melt electrospun polycaprolactone membranes and subsequent bi-directional perfusion with NH4OH/Triton X-100 and DNase solutions. The protocol was shown to remove 92% of DNA content. The structural integrity of the decellularized cell sheets was confirmed by a collagen quantification assay, immunostaining of human collagen type I and fibronectin, and scanning electron microscopy. ELISA was used to demonstrate the presence of residual basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) in the decellularized cell sheet constructs. The decellularized cell sheets were shown to have the ability to support recellularization by allogenic human periodontal ligament cells. This study describes the fabrication of decellularized periodontal ligament cell sheets that retain an intact extracellular matrix and resident growth factors and can support repopulation by allogenic cells. The decellularized hPDL cell sheet concept has the potential to be utilized in future “off-the-shelf” periodontal tissue engineering strategies. PMID:25270757

  9. Quasi-linear viscoelastic behavior of the human periodontal ligament.

    PubMed

    Toms, Stephanie R; Dakin, Greg J; Lemons, Jack E; Eberhardt, Alan W

    2002-10-01

    Previous studies have not produced a comprehensive mathematical description of the nonlinear viscoelastic stress-strain behavior of the periodontal ligament (PDL). In the present study, the quasi-linear viscoelastic (QLV) model was applied to mechanical tests of the human PDL. Transverse sections of cadaveric premolars were subjected to relaxation tests and loading to failure perpendicular to the plane of section. Distinct and repeatable toe and linear regions of stress-strain behavior were observed. The amount of strain associated with the toe region differed as a function of anatomical location along the tooth root. Stress relaxation behavior was comparable for different anatomical locations. Model predicted peak tissue stresses for cyclic loading were within 11% of experimental values, demonstrating that the QLV approach provided an improved, accurate quantification of PDL mechanical response. The success of the QLV approach supports its usefulness in future efforts of experimental characterization of PDL mechanical behavior.

  10. Periodontal ligament cells under intermittent tensile stress regulate mRNA expression of osteoprotegerin and tissue inhibitor of matrix metalloprotease-1 and -2.

    PubMed

    Tsuji, Kiyomi; Uno, Keiji; Zhang, Gui Xia; Tamura, Masato

    2004-01-01

    We studied the mRNA expression of osteoprotegerin (OPG), receptor activator of NF-kappa B ligand (RANKL), tissue inhibitor of matrix metalloprotease (TIMP)-1 and -2, and matrix metalloprotease (MMP)-1 and -2 by human periodontal ligament (PDL) cells under intermittent tensile stress using a Flexercell Strain Unit. Analysis by reverse transcriptase-polymerase chain reaction showed that mechanical force upregulated OPG mRNA. We also demonstrated that the protein concentration of OPG in conditioned medium increased upon loading with tensile stress, as determined by enzyme-linked immunosorbent assay. TIMP-1 and -2 mRNA levels also increased, whereas levels of RANKL, MMP-1, and MMP-2 mRNA were barely affected. We further examined the effect of loading with tensile stress and addition of Salmonella abortus equi lipopolysaccharide (LPS) on the mRNA expression of PDL cells. The amount of OPG mRNA induced by mechanical strain was found to decrease with the addition of LPS to cultures. The induction of OPG mRNA expression by stretching was inhibited in the presence of indomethacin or genistein, whereas TIMP-1 mRNA expression induced by stretching was inhibited by the addition of cycloheximide, suggesting that tensile stress regulates cyclooxygenase activities, tyrosine phosphorylation, and de novo protein synthesis in PDL cells through the induction of OPG and TIMP-1 mRNA expression. These results provide evidence that the mechanical stimulus of stretching is responsible for the observed regulation of bone resorption and tissue degradation in PDL tissue.

  11. Resolvin D1 protects periodontal ligament

    PubMed Central

    Mustafa, Manal; Zarrough, Ahmed; Bolstad, Anne Isine; Lygre, Henning; Mustafa, Kamal; Hasturk, Hatice; Serhan, Charles; Kantarci, Alpdogan

    2013-01-01

    Resolution agonists are endogenous mediators that drive inflammation to homeostasis. We earlier demonstrated in vivo activity of resolvins and lipoxins on regenerative periodontal wound healing. The goal of this study was to determine the impact of resolvin D1 (RvD1) on the function of human periodontal ligament (PDL) fibroblasts, which are critical for wound healing during regeneration of the soft and hard tissues around teeth. Primary cells were cultured from biopsies obtained from three individuals free of periodontal diseases. Peripheral blood mononuclear cells were isolated by density gradient centrifugation from whole blood of healthy volunteers. PGE2, leukotriene B4 (LTB4), and lipoxin A4 (LXA4) in culture supernatants were measured by ELISA. The direct impact of RvD1 on PDL fibroblast proliferation was measured and wound closure was analyzed in vitro using a fibroblast culture “scratch assay.” PDL fibroblast function in response to RvD1 was further characterized by basic FGF production by ELISA. IL-1β and TNF-α enhanced the production of PGE2. Treatment of PDL cells and monocytes with 0.1–10 ng/ml RvD1 (0.27–27 M) reduced cytokine induced production of PGE2 and upregulated LXA4 production by both PDL cells and monocytes. RvD1 significantly enhanced PDL fibroblast proliferation and wound closure as well as basic FGF release. The results demonstrate that anti-inflammatory and proresolution actions of RvD1 with upregulation of arachidonic acid-derived endogenous resolution pathways (LXA4) and suggest resolution pathway synergy establishing a novel mechanism for the proresolution activity of the ω-3 docosahexaenoic acid-derived resolution agonist RvD1. PMID:23864609

  12. P2X7 receptor-Pannexin1 interaction mediates stress-induced interleukin-1 beta expression in human periodontal ligament cells.

    PubMed

    Kanjanamekanant, K; Luckprom, P; Pavasant, P

    2014-10-01

    Pannexin 1 (Panx1) has been found to form nonjunctional hemichannels. It is also proposed to combine with the P2X7 receptor, forming a complex involved in adenosine triphosphate (ATP)-induced interleukin-1beta (IL-1β) release in macrophages. Previously, we reported that mechanical stress induced IL-1β expression via the ATP/P2X7 receptor-dependent pathway in human periodontal ligament (HPDL) cells and that ATP was released through the connexin 43 (Cx43) hemichannel. In the present work, we examined the role of Panx1 in stress-induced IL-1β induction in HPDL cells. Cultured HPDL cells were treated with compressive loading or ATP to stimulate IL-1β expression. Inhibitors, antagonists and the small interfering RNA technique were used to investigate the involvement of Panx1 in IL-1β induction. Co-immunoprecipitation (Co-IP) and immunostaining were used to determine the association of Panx1 with the P2X7 receptor. The IL-1β release mechanism was analyzed using inhibitors. Blocking Panx1 significantly decreased ATP release, as well as IL-1β up-regulation, upon stimulation with stress or ATP. Co-IP revealed the association of Panx1 and the P2X7 receptor in HPDL cells, which was increased in response to mechanical loading. Pretreatment with vesicular trafficking inhibitors significantly reduced the amount of IL-1β released from stimulated cells, suggesting that IL-1β might be released through vesicles. We clearly illustrated the contribution of Panx1 in ATP release, as well as in IL-1β induction in HPDL cells. The association of Panx1 and the P2X7 receptor might be required for IL-1β induction, and their possible novel role in IL-1β vesicular release was indicated. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Periodontal ligament-derived cells for periodontal regeneration in animal models: a systematic review.

    PubMed

    Bright, R; Hynes, K; Gronthos, S; Bartold, P M

    2015-04-01

    Implantation of periodontal ligament stem cells is emerging as a potential periodontal regenerative procedure. This systematic review considers the evidence from animal models investigating the use of periodontal ligament stem cells for successful periodontal regeneration. PubMed, Embase, MEDLINE and Google Scholar were searched to December 2013 for quantitative studies examining the outcome of implanting periodontal ligament stem cells into experimental periodontal defects in animals. Inclusion criteria were: implantation of periodontal ligament stem cells into surgically created periodontal defects for periodontal regeneration; animal models only; source of cells either human or animal; and published in English. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From the literature search, 43 studies met the inclusion criteria. A wide variety of surgical defects were created in four species of animal (dog, rat, pig and sheep). Owing to wide variability in defect type, cell source and cell scaffold, no meta-analysis was possible. Outcome measures included new bone, new cementum and new connective tissue formation. In 70.5% of the results, statistically significant improvements of these measures was recorded. These results are notable in that they indicate that irrespective of the defect type and animal model used, periodontal ligament stem cell implantation can be expected to result in a beneficial outcome for periodontal regeneration. It is recommended that there is sufficient evidence from preclinical animal studies to warrant moving to human studies to examine the efficacy, safety, feasibility (autologous vs. allogeneic transplantation) and delivery of periodontal ligament stem cells for periodontal regeneration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Identification of multipotent stem cells from adult dog periodontal ligament.

    PubMed

    Wang, Wen-Jun; Zhao, Yu-Ming; Lin, Bi-Chen; Yang, Jie; Ge, Li-Hong

    2012-08-01

    Periodontal diseases, which are characterized by destruction of the connective tissues responsible for restraining the teeth within the jaw, are the main cause of tooth loss. Periodontal regeneration mediated by human periodontal ligament stem cells (hPDLSCs) may offer an alternative strategy for the treatment of periodontal disease. Dogs are a widely used large-animal model for the study of periodontal-disease progression, tissue regeneration, and dental implants, but little attention has been paid to the identification of the cells involved in this species. This study aimed to characterize stem cells isolated from canine periodontal ligament (cPDLSCs). The cPDLSCs, like hPDLSCs, showed clonogenic capability and expressed the mesenchymal stem cell markers STRO-1, CD146, and CD105, but not CD34. After induction of osteogenesis, cPDLSCs showed calcium accumulation in vitro. Moreover, cPDLSCs also showed both adipogenic and chondrogenic potential. Compared with cell-free controls, more cementum/periodontal ligament-like structures were observed in CB-17/SCID mice into which cPDLSCs had been transplanted. These results suggest that cPDLSCs are clonogenic, highly proliferative, and have multidifferentiation potential, and that they could be used as a new cellular therapeutic approach to facilitate successful and more predictable regeneration of periodontal tissue using a canine model of periodontal disease.

  15. Stress increases periodontal inflammation

    PubMed Central

    RIVERA, CÉSAR; MONSALVE, FRANCISCO; SUAZO, IVÁN; BECERRA, JAVIERA

    2012-01-01

    This study aimed to examine the effect of chronic restraint stress (RS) on the severity of experimental periodontal disease in rats. A total of 32 male Sprague Dawley (SD) rats were divided into four groups: i) Rats receiving two treatment regimens, chronic stress induced by movement restriction in acrylic cylinders for 1–1.5 h daily and induction of experimental periodontal disease, using a nylon ligature which was placed around the first left mandibular molars (n=8); ii) induction of periodontal disease, without RS (n=8); iii) RS (n=8) and iv) control (n=8). After 15 days, blood samples were obtained, and blood glucose levels and the corticosterone concentration were measured as stress markers. The severity of periodontal disease was analyzed according to the level of gingival and bone inflammation, leading to compromise of the teeth involved. Chronic stress was induced with movement restriction (P≤0.05, Mann-Whitney U-test) and increased the severity (P≤0.05, Mann-Whitney U-test) of experimental perio dontal disease in rats, according to the level of gingival and bone inflammation around the first left mandibular molars. The results of the present study showed that RS modulates periodontal inflammation and that the rat model described herein is suitable for investigating the association between stress and periodontal disease. PMID:23226743

  16. A Nano-indentation Identification Technique for Viscoelastic Constitutive Characteristics of Periodontal Ligaments

    PubMed Central

    Ashrafi, H.; Shariyat, M.

    2016-01-01

    Introduction Nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. A majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. The constitutive characterization of soft tissues is among very important subjects in clinical medicine and especially, biomechanics fields. Periodontal ligament plays an important role in initiating tooth movement when loads are applied to teeth with orthodontic appliances. It is also the most accessible ligament in human body as it can be directly manipulated without any surgical intervention. From a mechanical point of view, this ligament can be considered as a thin interface made by a solid phase, consisting mainly of collagen fibers, which is immersed into a so-called ground substance. However, the viscoelastic constitutive effects of biological tissues are seldom considered rigorous during Nano-indentation tests. Methods In the present paper, a mathematical contact approach is developed to enable determining creep compliance and relaxation modulus of distinct periodontal ligaments, using constant–rate indentation and loading time histories, respectively. An adequate curve-fitting method is presented to determine these characteristics based on the Nano-indentation of rigid Berkovich tips. Generalized Voigt-Kelvin and Wiechert models are used to model constitutive equations of periodontal ligaments, in which the relaxation and creep functions are represented by series of decaying exponential functions of time. Results Time-dependent creep compliance and relaxation function have been obtained for tissue specimens of periodontal ligaments. Conclusion To improve accuracy, relaxation and creep moduli are measured from two tests separately. Stress relaxation effects appear more rapidly than creep in the periodontal ligaments. PMID:27672630

  17. Marker of cemento-periodontal ligament junction associated with periodontal regeneration.

    PubMed

    Hara, Ryohko; Wato, Masahiro; Tanaka, Akio

    2005-06-01

    The purpose of this study was to identify factors promoting formation of the cemento-periodontal ligament junction. Regeneration of the cemento-periodontal ligament junction is an important factor in recovery of the connective tissue attachment to the cementum and it is important to identify all specific substances that promote its formation. To clarify the substances involved in cemento-periodontal ligament junction formation, we produced a monoclonal antibody (mAb) to human cemento-periodontal ligament junction (designated as the anti-TAP mAb) and examined its immunostaining properties and reactive antigen. Hybridomas producing monoclonal antibody against human cemento-periodontal ligament junction antigens were established by fusing P3U1 mouse myeloma cells with spleen cells from BALB/c mice immunized with homogenized human cemento-periodontal ligament junction. The mAb, the anti-TAP mAb for cemento-periodontal ligament junction, was then isolated. The immunoglobulin class and light chain of the mAb were examined using an isotyping kit. Before immunostaining, antigen determination using an enzymatic method or heating was conducted. Human teeth, hard tissue-forming lesions, and animal tissues were immunostained by the anti-TAP mAb. The anti-TAP mAb was positive in human cemento-periodontal ligament junction and predentin but negative in all other human and animal tissues examined. In the cemento-osseous lesions, the anti-TAP mAb was positive in the peripheral area of the cementum and cementum-like hard tissues and not in the bone and bone-like tissues. The anti-TAP mAb showed IgM (kappa) and recognized phosphoprotein. The anti-TAP mAb is potentially useful for developing new agents promoting cementogenesis and periodontal regeneration.

  18. Mechanoresponsive Properties of the Periodontal Ligament.

    PubMed

    Huang, L; Liu, B; Cha, J Y; Yuan, G; Kelly, M; Singh, G; Hyman, S; Brunski, J B; Li, J; Helms, J A

    2016-04-01

    The periodontal ligament (PDL) functions as an enthesis, a connective tissue attachment that dissipates strains created by mechanical loading. Entheses are mechanoresponsive structures that rapidly adapt to changes in their mechanical loading; here we asked which features of the PDL are sensitive to such in vivo loading. We evaluated the PDL in 4 physiologically relevant mechanical environments, focusing on mitotic activity, cell density, collagen content, osteogenic protein expression, and organization of the tissue. In addition to examining PDLs that supported teeth under masticatory loading and eruptive forces, 2 additional mechanical conditions were created and analyzed: hypoloading and experimental tooth movement. Collectively, these data revealed that the adult PDL is a remarkably quiescent tissue and that only when it is subjected to increased loads--such as those associated with mastication, eruption, and orthodontic tooth movement-does the tissue increase its rate of cell proliferation and collagen production. These data have relevance in clinical scenarios where PDL acclimatization can be exploited to optimize tooth movement.

  19. Review of common conditions associated with periodontal ligament widening

    PubMed Central

    Mortazavi, Hamed

    2016-01-01

    Purpose The aim of this article is to review a group of lesions associated with periodontal ligament (PDL) widening. Materials and Methods An electronic search was performed using specialized databases such as Google Scholar, PubMed, PubMed Central, Science Direct, and Scopus to find relevant studies by using keywords such as “periodontium”, “periodontal ligament”, “periodontal ligament space”, “widened periodontal ligament”, and “periodontal ligament widening”. Results Out of nearly 200 articles, about 60 were broadly relevant to the topic. Ultimately, 47 articles closely related to the topic of interest were reviewed. When the relevant data were compiled, the following 10 entities were identified: occlusal/orthodontic trauma, periodontal disease/periodontitis, pulpo-periapical lesions, osteosarcoma, chondrosarcoma, non-Hodgkin lymphoma, progressive systemic sclerosis, radiation-induced bone defect, bisphosphonate-related osteonecrosis, and osteomyelitis. Conclusion Although PDL widening may be encountered by many dentists during their routine daily procedures, the clinician should consider some serious related conditions as well. PMID:28035300

  20. Collagen implants do not preserve periodontal ligament homeostasis in periodontal wounds.

    PubMed

    Nguyen, L; Lekic, P; McCulloch, C A

    1997-07-01

    An improved understanding of the differentiation of periodontal ligament cells could facilitate the development of new treatment approaches for overcoming the loss of specialized cell types caused by periodontitis. To study healing of wounded periodontal tissues and the differentiation of mineralizing connective tissue cells in periodontal ligament, we have examined the influence of wound size and collagen implantation on the regeneration of periodontium and on immunohistochemical staining for osteopontin and bone sialoprotein. Four groups of Wistar rats were wounded by drilling through the alveolar bone and by extirpation of the periodontal ligament. Wounds were 0.6 or 1.8 mm in diameter and defects were either implanted with collagen gels or were treated without implants. Rats were killed at 1 wk or 2 months after wounding and tissue sections were stained with monoclonal antibodies against rat osteopontin and bone sialoprotein. Collagen implants strongly increased staining for osteopontin and bone sialoprotein in defects at 1 wk. By 2 months alveolar bone healed completely regardless of the wound size but in large defects, periodontal ligament width was significantly reduced with or without implants. In large wounds at 2 months, collagen implants inhibited bone regeneration and there was stronger staining for osteopontin and bone sialoprotein in the bone replacing the implant, indicating that collagen prolonged bone remodelling. We conclude that implantation of exogenous collagen affects alveolar bone healing but does not preserve the width of the regenerated periodontal ligament. Therefore collagen does not appear to contribute to homeostasis in the periodontium following wounding.

  1. Periodontal Ligament Stem Cell-Mediated Treatment for Periodontitis in Miniature Swine

    PubMed Central

    Liu, Yi; Zheng, Ying; Ding, Gang; Fang, Dianji; Zhang, Chunmei; Bartold, Peter Mark; Gronthos, Stan; Shi, Songtao; Wang, Songlin

    2009-01-01

    Periodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases. PMID:18238856

  2. Clodronate inhibits PGE(2) production in compressed periodontal ligament cells.

    PubMed

    Liu, L; Igarashi, K; Kanzaki, H; Chiba, M; Shinoda, H; Mitani, H

    2006-08-01

    Periodontal ligament (PDL) cells play an essential role in orthodontic tooth movement. We recently reported that clodronate, a non-N-containing bisphosphonate, strongly inhibited tooth movement in rats, and thus could be a useful adjunct for orthodontic treatment. However, it is not clear how clodronate affects the responses of PDL cells to orthodontic force. In this study, we hypothesized that clodronate prevents the mechanical stress-induced production of prostaglandin E(2) (PGE(2)), interleukin-1beta (IL-1beta), and nitric oxide (NO) in human PDL cells. A compressive stimulus caused a striking increase in PGE(2) production, while the responses of IL-1beta and NO were less marked. Clodronate concentration-dependently inhibited the stress-induced production of PGE(2). Clodronate also strongly inhibited stress-induced gene expression for COX-2 and RANKL. These results suggest that the inhibitory effects of clodronate on tooth movement and osteoclasts may be due, at least in part, to the inhibition of COX-2-dependent PGE(2) production and RANKL expression in PDL cells.

  3. Differentiation of Human Embryonic Stem Cells on Periodontal Ligament Fibroblasts.

    PubMed

    Elçin, Y Murat; İnanç, Bülend; Elçin, A Eser

    2016-01-01

    Human embryonic stem cells' (hESCs) unlimited proliferative potential and differentiation capability to all somatic cell types makes them one of the potential cell sources in cell-based tissue engineering strategies as well as various experimental applications in fields such as developmental biology, pharmacokinetics, toxicology, and genetics. Periodontal tissue engineering is an approach to reconstitute the ectomesenchymally derived alveolar bone, periodontal ligament apparatus, and cementum tissues lost as a result of periodontal diseases. Cell-based therapies may offer potential advantage in overcoming the inherent limitations associated with contemporary regenerative procedures, such as dependency on defect type and size and the pool and capacity of progenitor cells resident in the wound area. Further elucidation of developmental mechanisms associated with tooth formation may also contribute to valuable knowledge based upon which the future therapies can be designed. Protocols for the differentiation of pluripotent hESCs into periodontal ligament fibroblastic cells (PDLF) as common progenitors for ligament, cementum, and alveolar bone tissue represent an initial step in developing hESC-based experimental and tissue engineering strategies. The present protocol describes methods associated with the guided differentiation of hESCs by the use of coculture with adult PDLFs and the resulting change of morphotype and phenotype of the pluripotent embryonic stem cells toward fibroblastic and osteoblastic lineages.

  4. Influence of periodontal ligament simulation on bond strength and fracture resistance of roots restored with fiber posts.

    PubMed

    Marchionatti, Ana Maria Estivalete; Wandscher, Vinícius Felipe; Broch, Juliana; Bergoli, César Dalmolin; Maier, Juliana; Valandro, Luiz Felipe; Kaizer, Osvaldo Bazzan

    2014-01-01

    Considering that periodontal ligament simulation may influence the stress distribution over teeth restored with intraradicular retainers, this study aimed to assess the combined effect of mechanical cycling and periodontal ligament simulation on both the bond strength between fiber posts and root dentin and the fracture resistance of teeth restored using glass fiber posts. Ninety roots were randomly distributed into 3 groups (n=10) (C-MC: control; P-MC: polyether; AS-MC: addition silicone) to test bond strength and 6 groups (n=10) (C: control; P: polyether; AS: addition silicone, without mechanical cycling, and C-MC, P-MC and AS-MC with mechanical cycling) to test fracture strength, according to the material used to simulate the periodontal ligament. For the bond strength test, fiber posts were cemented, cores were built, mechanical cycling was applied (2×10(6) cycles, 88 N, 2.2 Hz, and 45º incline), and the teeth cut into 3 slices (2 mm), which were then subjected to the push-out test at 1 mm/min. For the fracture strength test, fiber posts were cemented, cores were built, and half of the groups received mechanical cycling, followed by the compressive strength (45° to the long axis and 1 mm/min) performed on all groups. Periodontal ligament simulation did not affect the bond strength (p=0.244) between post and dentin. Simulation of periodontal ligament (p=0.153) and application of mechanical cycling (p=0.97) did not affect fracture resistance. The materials used to simulate the periodontal ligament did not affect fracture or bond strength, therefore periodontal ligament simulation using the tested materials could be considered optional in the conditions of the study.

  5. Influence of periodontal ligament simulation on bond strength and fracture resistance of roots restored with fiber posts

    PubMed Central

    MARCHIONATTI, Ana Maria Estivalete; WANDSCHER, Vinícius Felipe; BROCH, Juliana; BERGOLI, César Dalmolin; MAIER, Juliana; VALANDRO, Luiz Felipe; KAIZER, Osvaldo Bazzan

    2014-01-01

    Objective Considering that periodontal ligament simulation may influence the stress distribution over teeth restored with intraradicular retainers, this study aimed to assess the combined effect of mechanical cycling and periodontal ligament simulation on both the bond strength between fiber posts and root dentin and the fracture resistance of teeth restored using glass fiber posts. Material and Methods Ninety roots were randomly distributed into 3 groups (n=10) (C-MC: control; P-MC: polyether; AS-MC: addition silicone) to test bond strength and 6 groups (n=10) (C: control; P: polyether; AS: addition silicone, without mechanical cycling, and C-MC, P-MC and AS-MC with mechanical cycling) to test fracture strength, according to the material used to simulate the periodontal ligament. For the bond strength test, fiber posts were cemented, cores were built, mechanical cycling was applied (2×106 cycles, 88 N, 2.2 Hz, and 45º incline), and the teeth cut into 3 slices (2 mm), which were then subjected to the push-out test at 1 mm/min. For the fracture strength test, fiber posts were cemented, cores were built, and half of the groups received mechanical cycling, followed by the compressive strength (45° to the long axis and 1 mm/min) performed on all groups. Results Periodontal ligament simulation did not affect the bond strength (p=0.244) between post and dentin. Simulation of periodontal ligament (p=0.153) and application of mechanical cycling (p=0.97) did not affect fracture resistance. Conclusions The materials used to simulate the periodontal ligament did not affect fracture or bond strength, therefore periodontal ligament simulation using the tested materials could be considered optional in the conditions of the study. PMID:25466478

  6. Biochemical markers of the periodontal ligament.

    PubMed

    Castro, Cecilia Estela; Koss, Myriam Adriana; López, María Elena

    2003-01-01

    For many years the diagnosis of Periodontal Disease has been based on clinical and radiographic methods. Other more recent methods have the objective of studying the inflammatory response of the host. That way, immunologic and biological methods determine the free mediators in the periodontal infection. The components of the gingivo-crevicular liquid or fluid are used to identify or to diagnose the active disease, to anticipate the risk of acquiring the disease and to determine its progress. For it to be clinically useful important changes should be registered the way a specific site turns active or that a previously disease affected site improves its conditions as a result of periodontal therapy. The response of the neutrophillic granulocytes play an important role in the detection of Periodontal Disease. The unspecific defense system in the gingivo-crevicular fluid can be determined through cytokines and/or interleukines that serve to identify sites at risk on the patient. In Periodontal Disease, the cytokines are not only defense mediators of the gingival sulcus fluid, but are also an indicator of tissue destruction. The liberation of high levels of lysosomal enzymes by neutrophils, proteolytic enzymes as the collagenases, or intercytoplasmatic enzymes as dehydrogenase lactate and aspartate amino transferase can equally help monitor the progress of the Periodontal Disease.

  7. Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering

    PubMed Central

    Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

    2016-01-01

    Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration—culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch. PMID:26989897

  8. Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering.

    PubMed

    Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

    2016-01-01

    Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration-culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch.

  9. Effect of vitamin C administration on hydrogen peroxide-induced cytotoxicity in periodontal ligament cells.

    PubMed

    Wu, Wenlei; Yang, Nanfei; Feng, Xiujing; Sun, Tingzhe; Shen, Pingping; Sun, Weibin

    2015-01-01

    Periodontitis is a disease, which is associated with chronic inflammation and leads to significant destruction of periodontal tissues. Periodontal ligament cells (PDLCs) constitute the largest cell population in PDL tissues and a considerable body of evidence has demonstrated an association between oxidative stress and the progression of periodontitis. However, the effects on PDLCs exposed to hydrogen peroxide (H2O2) and the molecular mechanisms by which H2O2 affects periodontitis remain to be elucidated. In the present study, the potential cytotoxic effect of H2O2 and the antioxidative function of vitamin C (Vc) in PDLCs were investigated. The results demonstrated that H2O2 treatment decreased the viability of PDLCs. The decreased PDLC viability was primarily induced by apoptosis, which was evidenced by cleaved caspases-3, caspases-9 and poly (ADP-ribose) polymerase. Following optimal Vc addition, the proapoptotic effects of H2O2 were partially antagonized. Taken together, the present study demonstrated that H2O2 primarily induced the apoptosis of PDLCs and that these adverse effects were partially rescued following treatment with Vc. These results revealed how H2O2 promotes the progression of periodontitis and provide an improved understanding of the reversal effect of antioxidant treatment. Therefore, optimal Vc administration may provide a potentially effective technique in periodontal therapy.

  10. Biomechanical characterization of the periodontal ligament: Orthodontic tooth movement.

    PubMed

    Uhlir, Richard; Mayo, Virginia; Lin, Pei Hua; Chen, Si; Lee, Yan-Ting; Hershey, Garland; Lin, Feng-Chang; Ko, Ching-Chang

    2017-03-01

    To quantify the biomechanical properties of the bovine periodontal ligament (PDL) in postmortem sections and to apply these properties to study orthodontic tooth intrusion using finite element analysis (FEA). We hypothesized that PDL's property inherited heterogeneous (anatomical dependency) and nonlinear stress-strain behavior that could aid FEA to delineate force vectors with various rectangular archwires. A dynamic mechanical analyzer was used to quantify the stress-strain behavior of bovine PDL. Uniaxial tension tests using three force levels (0.5, 1, and 3 N) and samples from two anatomical locations (circumferential and longitudinal) were performed to calculate modulus. The Mooney-Rivlin hyperelastic (MRH) model was applied to the experimental data and used in an FEA of orthodontic intrusion rebounded via a 0.45-mm step bend with three archwire configurations of two materials (stainless steel and TMA). Force levels and anatomical location were statistically significant in their effects on modulus (P < .05). The apical part had a greater stiffness than did the middle part. The MRH model was found to approximate the experimental data well (r = 0.99), and it demonstrated a reasonable stress-strain outcome within the PDL and bone for FEA intrusion simulation. The force acting on the tooth increased five times from the 0.016 × 0.022-inch TMA to the 0.019 × 0.025-inch stainless steel. The PDL is a nonhomogeneous tissue in which the modulus changed in relation to location. PDL nonlinear constitutive model estimated quantitative force vectors for the first time to compare intrusive tooth movement in 3-D space in response to various rectangular archwires.

  11. Periodontitis promotes the proliferation and suppresses the differentiation potential of human periodontal ligament stem cells.

    PubMed

    Zheng, Wei; Wang, Shi; Wang, Jianguo; Jin, Fang

    2015-10-01

    The aim of the present study was to investigate the periodontitis-associated changes in the number, proliferation and differentiation potential of human periodontal ligament stem cells (PDLSCs). Cultures of human periodontal ligament cells (PDLCs) were established from healthy donors and donors with periodontitis. The numbers of stem cell were characterized using flow cytometry. PDLSCs were isolated from the PDLCs by immunomagnetic bead selection. Colony‑forming abilities, osteogenic and adipogenic potential, gene expression of cementoblast phenotype, alkaline phosphatase activity and in vivo differentiation capacities were then evaluated. Periodontitis caused an increase in the proliferation of PDLSCs and a decrease in the commitment to the osteoblast lineage. This is reflected by changes in the expression of osteoblast markers. When transplanted into immunocompromised mice, PDLSCs from the healthy donors exhibited the capacity to produce cementum PDL‑like structures, whereas, the inflammatory PDLSCs transplants predominantly formed connective tissues. In conclusion, the data from the present study suggest that periodontitis affects the proliferation and differentiation potential of human PDLSCs in vitro and in vivo.

  12. Periodontal Ligament Stem Cells in the Periodontitis Microenvironment Are Sensitive to Static Mechanical Strain

    PubMed Central

    Liu, Jia; Liu, Shiyu; Gao, Jie; Qin, Wen; Song, Yang

    2017-01-01

    During orthodontic treatment, periodontium remodeling of periodontitis patients under mechanical force was abnormal. We have previously confirmed the function impairment of periodontal ligament stem cells (PDLSCs) in the periodontitis microenvironment which might be involved in this pathological process. However, the response of PDLSCs in periodontitis microenvironment to mechanical force remains unclear. Therefore, in the present study, we introduced a Flexcell tension apparatus and investigated the response of PDLSCs obtained from periodontal tissues of periodontitis patients (PPDLSCs) and of those obtained from healthy periodontal tissues (HPDLSCs) to different magnitudes of static mechanical strain (SMS). PPDLSCs showed increased proliferation, decreased osteogenic activity, activated osteoclastogenesis, and greater secretion of inflammatory cytokines. Different magnitudes of SMS exerted distinct effects on HPDLSCs and PPDLSCs. An SMS of 12% induced optimal effects in HPDLSCs, including the highest proliferation, the best osteogenic ability, the lowest osteoclastogenesis, and the lowest secretion of inflammatory cytokines, while the optimal SMS for PPDLSCs was 8%. Excessive SMS damaged PPDLSCs function, including decreased proliferation, an imbalance between osteogenesis and osteoclastogenesis, and an activated inflammatory response. Our data suggest that PPDLSCs are more sensitive and less tolerant to SMS, and this may explain why mechanical force results in undesirable effects in periodontitis patients. PMID:28316629

  13. The structure and function of periodontal ligament cells in acellular cementum in rat molars.

    PubMed

    Yamamoto, T; Domon, T; Takahashi, S; Islam, N; Suzuki, R; Wakita, M

    1998-12-01

    To elucidate the structure and function of periodontal ligament cells at the periodontal ligament-cementum interface in advanced acellular cementogenesis, the cervical regions of molars in rats aged 6 weeks were observed by light and electron microscopy. The light and transmission electron microscopy showed the periodontal ligament cells to be elongated between dense, well-developed principal fibers. The transmission and scanning electron microscopy showed that these cells extended wing-like projections from the lateral surface, forming cylindrical compartments surrounding the principal fibers. In addition, finger-like projections extended toward the cementum from the cementum-facing ends. The main results suggest the following: at the periodontal ligament-cementum interface, the periodontal ligament cells maintain the architecture of the principal fibers by means of extracellular compartments. The arrangement of finger-like projections results in the formation of acellular cementum containing only Sharpey's fibers as a fibrous component.

  14. Tenomodulin Expression in the Periodontal Ligament Enhances Cellular Adhesion

    PubMed Central

    Komiyama, Yuske; Ohba, Shinsuke; Shimohata, Nobuyuki; Nakajima, Keiji; Hojo, Hironori; Yano, Fumiko; Takato, Tsuyoshi; Docheva, Denitsa; Shukunami, Chisa; Hiraki, Yuji; Chung, Ung-il

    2013-01-01

    Tenomodulin (Tnmd) is a type II transmembrane protein characteristically expressed in dense connective tissues such as tendons and ligaments. Its expression in the periodontal ligament (PDL) has also been demonstrated, though the timing and function remain unclear. We investigated the expression of Tnmd during murine tooth eruption and explored its biological functions in vitro. Tnmd expression was related to the time of eruption when occlusal force was transferred to the teeth and surrounding tissues. Tnmd overexpression enhanced cell adhesion in NIH3T3 and human PDL cells. In addition, Tnmd-knockout fibroblasts showed decreased cell adhesion. In the extracellular portions of Tnmd, the BRICHOS domain or CS region was found to be responsible for Tnmd-mediated enhancement of cell adhesion. These results suggest that Tnmd acts on the maturation or maintenance of the PDL by positively regulating cell adhesion via its BRICHOS domain. PMID:23593173

  15. Periodontal Ligament Stem Cells Regulate Apoptosis of Neutrophils

    PubMed Central

    Wang, Qing; Ding, Gang; Xu, Xin

    2017-01-01

    Abstract Periodontal ligament stem cells (PDLSCs) are promising cell resource for the cell-based therapy for periodontitis and regeneration of bio-root. In this study, we investigated the effect of PDLSCs on neutrophil, a critical constituent of innate immunity, and the underlying mechanisms. The effect of PDLSCs on the proliferation and apoptosis of resting neutrophils and IL-8 activated neutrophils was tested under cell-cell contact culture and Transwell culture, with or without anti-IL-6 neutralizing antibody. We found that PDLSCs could promote the proliferation and reduce the apoptosis of neutrophils whether under cell-cell contact or Transwell culture. Anti-IL-6 antibody reduced PDLSCs-mediated inhibition of neutrophil apoptosis. IL-6 at the concentration of 10ng/ml and 20ng/ml could inhibit neutrophil apoptosis statistically. Collectively, PDLSCs could reduce the apoptosis of neutrophils via IL-6.

  16. A nonlinear poroelastic model for the periodontal ligament

    NASA Astrophysics Data System (ADS)

    Favino, Marco; Bourauel, Christoph; Krause, Rolf

    2016-05-01

    A coupled elastic-poroelastic model for the simulation of the PDL and the adjacent tooth is presented. A poroelastic constitutive material model for the periodontal ligament (PDL) is derived. The solid phase is modeled by means of a Fung material law, accounting for large displacements and strains. Numerical solutions are performed by means of a multigrid Newton method to solve the arising large nonlinear system. Finally, by means of numerical experiments, the biomechanical response of the PDL is studied. In particular, the effect of the hydraulic conductivity and of the mechanical parameters of a Fung potential is investigated in two realistic applications.

  17. Periodontitis

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001059.htm Periodontitis To use the sharing features on this page, please enable JavaScript. Periodontitis is inflammation and infection of the ligaments and ...

  18. Promise of periodontal ligament stem cells in regeneration of periodontium.

    PubMed

    Maeda, Hidefumi; Tomokiyo, Atsushi; Fujii, Shinsuke; Wada, Naohisa; Akamine, Akifumi

    2011-07-28

    A great number of patients around the world experience tooth loss that is attributed to irretrievable damage of the periodontium caused by deep caries, severe periodontal diseases or irreversible trauma. The periodontium is a complex tissue composed mainly of two soft tissues and two hard tissues; the former includes the periodontal ligament (PDL) tissue and gingival tissue, and the latter includes alveolar bone and cementum covering the tooth root. Tissue engineering techniques are therefore required for regeneration of these tissues. In particular, PDL is a dynamic connective tissue that is subjected to continual adaptation to maintain tissue size and width, as well as structural integrity, including ligament fibers and bone modeling. PDL tissue is central in the periodontium to retain the tooth in the bone socket, and is currently recognized to include somatic mesenchymal stem cells that could reconstruct the periodontium. However, successful treatment using these stem cells to regenerate the periodontium efficiently has not yet been developed. In the present article, we discuss the contemporary standpoints and approaches for these stem cells in the field of regenerative medicine in dentistry.

  19. Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration

    PubMed Central

    Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

    2015-01-01

    Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration. PMID:26150714

  20. Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration.

    PubMed

    Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

    2015-01-01

    Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration.

  1. Characterization of a novel periodontal ligament-specific periostin isoform.

    PubMed

    Yamada, S; Tauchi, T; Awata, T; Maeda, K; Kajikawa, T; Yanagita, M; Murakami, S

    2014-09-01

    Periostin is a mesenchymal cell marker predominantly expressed in collagen-rich fibrous connective tissues, including heart valves, tendons, perichondrium, periosteum, and periodontal ligament (PDL). Knockdown of periostin expression in mice results in early-onset periodontitis and failure of cardiac healing after acute myocardial infarction, suggesting that periostin is essential for connective tissue homeostasis and regeneration. However, its role(s) in periodontal tissues has not yet been fully defined. In this study, we describe a novel human isoform of periostin (PDL-POSTN). Isoform-specific analysis by reverse-transcription polymerase chain-reaction (RT-PCR) revealed that PDL-POSTN was predominantly expressed in the PDL, with much lower expression in other tissues and organs. A PDL cell line transfected with PDL-POSTN showed enhanced alkaline phosphatase (ALPase) activity and calcified nodule formation, compared with cells transfected with the full-length periostin isoform. A neutralizing antibody against integrin-αv inhibited both ALPase activity and calcified nodule formation in cells transfected with PDL-POSTN. Furthermore, co-immunoprecipitation assays revealed that PDL-POSTN bound to integrin αvβ3 more strongly than the common isoform of periostin, resulting in strong activation of the integrin αvβ3-focal adhesion kinase (FAK) signaling pathway. These results suggest that PDL-POSTN positively regulates cytodifferentiation and mineralization in PDL cells through integrin αvβ3.

  2. Effects of nicotine on periodontal ligament fibroblasts in vitro.

    PubMed

    Giannopoulou, C; Geinoz, A; Cimasoni, G

    1999-01-01

    Cigarette smoking is associated with increased incidence of periodontal disease and poor response to therapy. In the present study, we examined the effects of nicotine on several functions of periodontal ligament fibroblasts (PDLF): proliferation, attachment, alkaline phosphatase production and chemotaxis. Nicotine concentrations varying from 5 ng/ml to 250 microg/ml were tested. Proliferation of cells was studied by the incorporation of 3H-thymidine, and a dose-dependent inhibition was observed with concentrations > or =100 ng/ml. Similar results were observed when studying the attachment of the cells on plastic surfaces, using a colorimetric method. The inhibition of attachment was even more evident after 6 h incubation of the cells with nicotine. The activity of alkaline phosphatase, as determined with the substrate p-nitrophenyl phosphate, in both conditioned medium (CM) and cellular extract (CE), was also significantly decreased in a concentration-related fashion. Finally, the chemotaxis of PDLE as examined by a modification of the Boyden's blind-well chamber technique, was inhibited in a dose-dependent manner. The degree of inhibition varied from 15% with the lowest concentration of nicotine (50 ng/ml), to almost 90% with the highest (5 microg/ml). The results show that nicotine can have direct adverse effects on various functions of the periodontal cells.

  3. The immunomodulatory properties of periodontal ligament stem cells isolated from inflamed periodontal granulation.

    PubMed

    Li, Chenghua; Wang, Xinwen; Tan, Jun; Wang, Tao; Wang, Qintao

    2014-01-01

    Periodontitis is currently the main cause of tooth loss and as yet there is no appropriate method for establishing a functional and predictable periodontal regeneration. Tissue engineering involving seed cells provides a new prospect for periodontal regeneration. While periodontal ligament stem cells (PDLSCs) are a good choice for seed cells, it is not always possible to obtain the patients' own PDLSCs. We and others have found a type of stromal cells from inflamed periodontal granulation. These cells displayed similar differentiation properties to PDLSCs. Inflammation has a profound influence on the immunomodulatory properties of mesenchymal stem cells, which may affect therapeutic outcome. In this study, we assessed the immunomodulatory characteristics of these inflamed human (ih)PDLSCs. Along with the similarity in cell surface marker expressions, they also displayed immunomodulatory properties comparable to those in healthy human (hh)PDLSCs. Both hhPDLSCs and ihPDLSCs can suppress the proliferation and secretion of IFN-γ in peripheral blood mononuclear cells by indirect soluble mediators and direct cell-cell contact. Albeit with some quantitative variances, the gene expressions of inducible nitric oxide synthases, indoleamine 2,3 dioxygenase, cyclooxygenase-2, TNF-α-induced protein 6 and IL-10 in ihPDLSCs displayed similar patterns as those in hhPDLSCs. Taken together, our results suggest that ihPDLSCs can provide a promising alternative to hhPDLSCs in terms of evident similarities in immunomodulatory properties as well as their easier accessibility and availability.

  4. The influence of root surface distance to alveolar bone and periodontal ligament on periodontal wound healing

    PubMed Central

    2016-01-01

    Purpose The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure. Methods Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis. Results New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth. Conclusions After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit. PMID:27800213

  5. Response of periodontal ligament fibroblasts and gingival fibroblasts to pulsating fluid flow: nitric oxide and prostaglandin E2 release and expression of tissue non-specific alkaline phosphatase activity.

    PubMed

    van der Pauw, M T; Klein-Nulend, J; van den Bos, T; Burger, E H; Everts, V; Beertsen, W

    2000-12-01

    The capacity of the periodontal ligament to alter its structure and mass in response to mechanical loading has long been recognized. However, the mechanism by which periodontal cells can detect physical forces and respond to them is largely unknown. Besides transmission of forces via cell-matrix or cell-cell interactions, the strain-derived flow of interstitial fluid through the periodontal ligament may mechanically activate the periodontal cells, as well as ensure transport of cell signaling molecules, nutrients and waste products. Mechanosensory cells, such as endothelial and bone cells, are reported to respond to a flow of fluid with stimulated prostaglandin E2 (PGE2) and nitric oxide production. Therefore, we examined the PGE2 and nitric oxide response of human periodontal ligament and gingival fibroblasts to pulsating fluid flow and assessed the expression of tissue non-specific alkaline phosphatase activity. Periodontal ligament and gingival fibroblasts were subjected to a pulsating fluid flow (0.7 +/- 0.02 Pa, 5 Hz) for 60 min. PGE2 and nitric oxide concentrations were determined in the conditioned medium after 5, 10, 30 and 60 min of flowing. After fluid flow the cells were cultured for another 60 min without mechanical stress. Periodontal ligament fibroblasts, but not gingival fibroblasts, responded to fluid flow with significantly elevated release of nitric oxide and decreased expression of tissue non-specific alkaline phosphatase activity. In both periodontal ligament and gingival fibroblasts, PGE2 production was significantly increased after 60 min of flowing. Periodontal ligament fibroblasts, but not gingival fibroblasts, produced significantly higher levels of PGE2 during the postflow culture period. We conclude that human periodontal ligament fibroblasts are more responsive to pulsating fluid flow than gingival fibroblasts. The similarity of the early nitric oxide and PGE2 responses to fluid flow in periodontal fibroblasts with bone cells and

  6. Cytological Kinetics of Periodontal Ligament in an Experimental Occlusal Trauma Model

    PubMed Central

    Takaya, Tatsuo; Mimura, Hiroaki; Matsuda, Saeka; Nakano, Keisuke; Tsujigiwa, Hidetsugu; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

    2015-01-01

    Using a model of experimental occlusal trauma in mice, we investigated cytological kinetics of periodontal ligament by means of histopathological, immunohistochemical, and photographical analysis methods. Periodontal ligament cells at furcation areas of molar teeth in the experimental group on day 4 showed a proliferation tendency of periodontal ligament cells. The cells with a round-shaped nucleus deeply stained the hematoxylin and increased within the day 4 specimens. Ki67 positive nuclei showed a prominent increase in the group on days 4 and 7. Green Fluorescent Protein (GFP) positivity also revealed cell movement but was slightly slow compared to Ki67. It indicated that restoration of mechanism seemed conspicuous by osteoclasts and macrophages from bone-marrow-derived cells for the periodontal ligament at the furcation area. It was suggested that the remodeling of periodontal ligament with cell acceleration was evoked from the experiment for the group on day 4 and after day 7. Periodontal ligament at the furcation area of the molar teeth in this experimental model recovered using the cells in situ and the bone-marrow-derived cells. PMID:26180510

  7. Oligonucleotide array analysis of cyclic tension-responsive genes in human periodontal ligament fibroblasts.

    PubMed

    Yamashiro, Keisuke; Myokai, Fumio; Hiratsuka, Koichi; Yamamoto, Tadashi; Senoo, Kyoko; Arai, Hideo; Nishimura, Fusanori; Abiko, Yoshimitsu; Takashiba, Shogo

    2007-01-01

    Mechanical stress results in differential gene expression that is critical to convert the stimulus into biochemical signals. Under physiological stress such as occlusal force, human periodontal ligament fibroblasts (HPLF) are associated with homeostasis of periodontal tissues however the changes in response to mechanotransduction remain uncharacterized. We hypothesized that cyclic tension-responsive (CT) genes may be used to identify a set of fundamental pathways of mechanotransduction. Our goal was to catalogue CT genes in cultured HPLF. HPLF were subjected to cyclic tension up to 16h, and total RNA was isolated from both tension-loaded and static HPLF. The oligonucleotide arrays analysis revealed significant changes of mRNA accumulation for 122 CT genes, and their kinetics were assigned by the K-means clustering methods. Ingenuity Pathway Analysis was completed for HPLF mechanotransduction using 50 CT genes. This analysis revealed that cyclic tension immediately down-regulated all nuclear transcription factors except v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) reacting as an early responsive gene. In turn, transcription factors such as tumor protein p53 binding protein 2 (TP53BP2), and extra-nuclear molecules such as adrenergic receptor beta2 (ADRB2) were up-regulated after 1-2h, which may result in fundamental HPLF functions to adapt to cyclic tension. Subsequent inhibition assays using Y27632, a pharmacologic inhibitor of Rho-associated kinase (ROCK), suggested that HPLF has both ROCK-dependent and ROCK-independent CT genes. Mechanical stress was found to effect the expression of numerous genes, in particular, expression of an early responsive gene; FOS initiates alteration of HPLF behaviors to control homeostasis of the periodontal ligament.

  8. Human periodontal ligament cell sheets cultured on amniotic membrane substrate.

    PubMed

    Adachi, K; Amemiya, T; Nakamura, T; Honjyo, K; Kumamoto, S; Yamamoto, T; Bentley, A J; Fullwood, N J; Kinoshita, S; Kanamura, N

    2014-09-01

    Periodontal ligament (PDL) cells and their substrates play key roles in periodontal regeneration. However, there has been no report on the use of amniotic membrane (AM) as a substrate for culturing PDL cells. In the current study, we conducted an analysis of PDL cells cultivated on AM to determine the distribution of factors responsible for maintaining the characteristics of PDL. Amniotic membrane was obtained from women undergoing cesarean sections, whereas PDL tissue was obtained from human maxillary third molars. The harvested PDL cells were maintained in explant culture for three or four passages, following which they were cultured on AM. After 3 weeks of culture, the PDL cells had grown well on AM. Immunofluorescence showed that these cells were capable of proliferating and potentially maintaining their PDL-like properties. In addition, strong cell-cell adhesion structures, namely desmosomes and tight junctions, were shown to be present between cells. Electron microscopy images showed that the cultured PDL cells had differentiated and proliferated on AM with lateral conjugation and adhesion to AM. We conclude that AM may represent a suitable substrate for culturing PDL cells and that PDL cells cultured on AM show sheet formation. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Mechano-transduction in periodontal ligament cells identifies activated states of MAP-kinases p42/44 and p38-stress kinase as a mechanism for MMP-13 expression

    PubMed Central

    2010-01-01

    Background Mechano-transduction in periodontal ligament (PDL) cells is crucial for physiological and orthodontic tooth movement-associated periodontal remodelling. On the mechanistic level, molecules involved in this mechano-transduction process in PDL cells are not yet completely elucidated. Results In the present study we show by western blot (WB) analysis and/or indirect immunofluorescence (IIF) that mechanical strain modulates the amount of the matrix metalloproteinase MMP-13, and induces non-coherent modulation in the amount and activity of signal transducing molecules, such as FAK, MAP-kinases p42/44, and p38 stress kinase, suggesting their mechanistic role in mechano-transduction. Increase in the amount of FAK occurs concomitant with increased levels of the focal contact integrin subunits β3 and β1, as indicated by WB or optionally by IIF. By employing specific inhibitors, we further identified p42/44 and p38 in their activated, i.e. phosphorylated state responsible for the expression of MMP-13. This finding may point to the obedience in the expression of this MMP as extracellular matrix (ECM) remodelling executioner from the activation state of mechano-transducing molecules. mRNA analysis by pathway-specific RT-profiler arrays revealed up- and/or down-regulation of genes assigning to MAP-kinase signalling and cell cycle, ECM and integrins and growth factors. Up-regulated genes include for example focal contact integrin subunit α3, MMP-12, MAP-kinases and associated kinases, and the transcription factor c-fos, the latter as constituent of the AP1-complex addressing the MMP-13 promotor. Among others, genes down-regulated are those of COL-1 and COL-14, suggesting that strain-dependent mechano-transduction may transiently perturbate ECM homeostasis. Conclusions Strain-dependent mechano-/signal-transduction in PDL cells involves abundance and activity of FAK, MAP-kinases p42/44, and p38 stress kinase in conjunction with the amount of MMP-13, and integrin

  10. Endocannabinoids and inflammatory response in periodontal ligament cells.

    PubMed

    Özdemir, Burcu; Shi, Bin; Bantleon, Hans Peter; Moritz, Andreas; Rausch-Fan, Xiaohui; Andrukhov, Oleh

    2014-01-01

    Endocannabinoids are associated with multiple regulatory functions in several tissues. The main endocannabinoids, anandamide (AEA) and 2-arachidonylglycerol (2-AG), have been detected in the gingival crevicular fluid of periodontitis patients, but the association between periodontal disease or human periodontal ligament cells (hPdLCs) and endocannabinoids still remain unclear. The aim of the present study was to examine the effects of AEA and 2-AG on the proliferation/viability and cytokine/chemokine production of hPdLCs in the presence/absence of Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS). The proliferation/viability of hPdLCs was measured using 3,4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT)-assay. Interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) levels were examined at gene expression and protein level by real-time PCR and ELISA, respectively. AEA and 2-AG did not reveal any significant effects on proliferation/viability of hPdLCs in the absence of P. gingivalis LPS. However, hPdLCs viability was significantly increased by 10-20 µM AEA in the presence of P. gingivalis LPS (1 µg/ml). In the absence of P. gingivalis LPS, AEA and 2-AG did not exhibit any significant effect on the expression of IL-8 and MCP-1 expression in hPdLCs, whereas IL-6 expression was slightly enhanced by 10 µM 2-AG and not affected by AEA. In P.gingivalis LPS stimulated hPdLCs, 10 µM AEA down-regulated gene-expression and protein production of IL-6, IL-8, and MCP-1. In contrast, 10 µM 2-AG had an opposite effect and induced a significant up-regulation of gene and protein expression of IL-6 and IL-8 (P<0.05) as well as gene-expression of MCP-1 in P. gingivalis LPS stimulated hPdLCs. Our data suggest that AEA appears to have an anti-inflammatory and immune suppressive effect on hPdLCs' host response to P.gingivalis LPS, whereas 2-AG appears to promote detrimental inflammatory processes. In conclusion, AEA and 2

  11. Development and parameter identification of a visco-hyperelastic model for the periodontal ligament.

    PubMed

    Huang, Huixiang; Tang, Wencheng; Tan, Qiyan; Yan, Bin

    2017-01-31

    The present study developed and implemented a new visco-hyperelastic model that is capable of predicting the time-dependent biomechanical behavior of the periodontal ligament. The constitutive model has been implemented into the finite element package ABAQUS by means of a user-defined material subroutine (UMAT). The stress response is decomposed into two constitutive parts in parallel which are a hyperelastic and a time-dependent viscoelastic stress response. In order to identify the model parameters, the indentation equation based on V-W hyperelastic model and the indentation creep model are developed. Then the parameters are determined by fitting them to the corresponding nanoindentation experimental data of the PDL. The nanoindentation experiment was simulated by finite element analysis to validate the visco-hyperelastic model. The simulated results are in good agreement with the experimental data, which demonstrates that the visco-hyperelastic model developed is able to accurately predict the time-dependent mechanical behavior of the PDL.

  12. Morinda citrifolia leaves enhance osteogenic differentiation and mineralization of human periodontal ligament cells.

    PubMed

    Boonanantanasarn, Kanitsak; Janebodin, Kajohnkiart; Suppakpatana, Prapan; Arayapisit, Tawepong; Rodsutthi, Jit-aree; Chunhabundit, Panjit; Boonanuntanasarn, Surintorn; Sripairojthikoon, Wanida

    2014-01-01

    This present study investigated the potential of Morinda citrifolia leaf aqueous extract to induce osteogenic differentiation and matrix mineralization of human periodontal ligament (hPDL) cells. Human periodontal ligament cells were cultured in complete medium, ascorbic acid with β-glycerophosphate, or Morinda citrifolia leaf aqueous extract. Morinda citrifolia leaf aqueous extract significantly increased alkaline phosphatase activity compared to culturing in complete medium or ascorbic acid with β-glycerophosphate. Matrixcontaining mineralized nodules were formed only when the cells were cultured in the presence of Morinda citrifolia leaf aqueous extract. These nodules showed positive alizarin red S staining and were rich in calcium and phosphorus according to energy dispersive X-ray analysis. In conclusion, Morinda citrifolia leaf extract promoted osteogenic differentiation and matrix mineralization in human periodontal ligament cells, a clear indication of the therapeutic potential of Morinda citrifolia leaves in bone and periodontal tissue regeneration.

  13. Morinda citrifolia leaves enhance osteogenic differentiation and mineralization of human periodontal ligament cells.

    PubMed

    Boonanantanasarn, Kanitsak; Janebodin, Kajohnkiart; Suppakpatana, Prapan; Arayapisit, Tawepong; Rodsutthi, Jit-aree; Chunhabundit, Panjit; Boonanuntanasarn, Surintorn; Sripairojthikoon, Wanida

    2012-01-01

    This present study investigated the potential of Morinda citrifolia leaf aqueous extract to induce osteogenic differentiation and matrix mineralization of human periodontal ligament (hPDL) cells. Human periodontal ligament cells were cultured in complete medium, ascorbic acid with β-glycerophosphate, or Morinda citrifolia leaf aqueous extract. Morinda citrifolia leaf aqueous extract significantly increased alkaline phosphatase activity compared to culturing in complete medium or ascorbic acid with β-glycerophosphate. Matrixcontaining mineralized nodules were formed only when the cells were cultured in the presence of Morinda citrifolia leaf aqueous extract. These nodules showed positive alizarin red S staining and were rich in calcium and phosphorus according to energy dispersive X-ray analysis. In conclusion, Morinda citrifolia leaf extract promoted osteogenic differentiation and matrix mineralization in human periodontal ligament cells, a clear indication of the therapeutic potential of Morinda citrifolia leaves in bone and periodontal tissue regeneration.

  14. Effect of storage media on the proliferation of periodontal ligament fibroblasts

    SciTech Connect

    Lauer, H.C.; Mueller, J.G.; Gross, J.; Horster, M.F.

    1987-07-01

    The effect of storage media, which are routinely used in replantation, upon the proliferative capacity of periodontal ligament fibroblasts, was compared with the effect of a tissue culture medium. The periodontal tissue was obtained from mandibular central incisors of White New Zealand rabbits. The experiments were performed in fibroblasts derived during second subculture. The storage media were physiologic salt solution, Ringer's solution and Rivanol; the tissue culture medium was alpha-minimum essential medium without nucleosides. The incubation period was 1 hour. (/sup 3/H)-thymidine incorporation and cell counts were taken to indicate changes in the proliferative capacity of the fibroblasts. The tissue culture experiments showed that the proliferative ability of the periodontal ligament fibroblasts was dependent upon the composition of the storage medium. Physiologic salt solution, Ringer's solution and Rivanol were unable to maintain the metabolism of the fibroblasts. alpha-MEM medium, however, was capable of stimulating proliferation of the periodontal ligament fibroblasts.

  15. Comparison of Periodontal Ligament Stem Cells Isolated from the Periodontium of Healthy Teeth and Periodontitis-Affected Teeth

    PubMed Central

    Soheilifar, Sara; Amiri, Iraj; Bidgoli, Mohsen; Hedayatipanah, Morad

    2016-01-01

    Objectives: Stem cell (SC) therapy is a promising technique for tissue regeneration. This study aimed to compare the viability and proliferation ability of periodontal ligament stem cells (PDLSCs) isolated from the periodontium of healthy and periodontitis-affected teeth to obtain an autologous, easily accessible source of SCs for tissue regeneration in periodontitis patients. Materials and Methods: The PDLSCs were isolated from the roots of clinically healthy premolars extracted for orthodontic purposes and periodontally involved teeth with hopeless prognosis (with and without phase I periodontal treatment). Cells were cultured and viability and proliferation ability of third passage cells in each group were evaluated using the methyl thiazol tetrazolium assay. The results were statistically analyzed using t-test. Results: No SCs could be obtained from periodontitis-affected teeth without phase I periodontal treatment. The viability of cells was 0.86±0.13 OD/540 in healthy group and 0.4±0.25 OD/540 in periodontitis-affected group (P=0.035). The proliferation ability (population doubling time) of cells obtained from healthy teeth was 4.22±1.23 hours. This value was 2.3±0.35 hours for those obtained from periodontitis-affected teeth (P=0.02). Conclusions: Viability and proliferation ability of cells isolated from the periodontium of healthy teeth were significantly greater than those of cells isolated from the periodontitis-affected teeth. PMID:28127319

  16. Mechano-regulation of Collagen Biosynthesis in Periodontal Ligament

    PubMed Central

    Kaku, Masaru; Yamauchi, Mitsuo

    2014-01-01

    Purpose Periodontal ligament (PDL) plays critical roles in the development and maintenance of periodontium such as tooth eruption and dissipation of masticatory force. The mechanical properties of PDL are mainly derived from fibrillar type I collagen, the most abundant extracellular component. Study selection The biosynthesis of type I collagen is a long, complex process including a number of intra- and extracellular post-translational modifications. The final modification step is the formation of covalent intra- and intermolecular cross-links that provide collagen fibrils with stability and connectivity. Results It is now clear that collagen post-translational modifications are regulated by groups of specific enzymes and associated molecules in a tissue-specific manner; and these modifications appear to change in response to mechanical force. Conclusions This review focuses on the effect of mechanical loading on collagen biosynthesis and fibrillogenesis in PDL with emphasis on the post-translational modifications of collagens, which is an important molecular aspect to understand in the field of prosthetic dentistry. PMID:25311991

  17. A new method for evaluating the threshold of periodontal ligament mechanoreceptor by slow speed mechanical stimulation.

    PubMed

    Oki, Kazuhiro; Hamanaka, Mai; Arima, Taro; Takahashi, Shuhei; Hasegawa, Kouichi; Minagi, Shogo

    2003-10-01

    This study aimed to establish a reliable method for detecting the threshold for perception of force applied to tooth and to report the basic properties of force threshold in the normal dentition subjects. The perception of mechanical stimulation exerted to tooth is formed by input from periodontal ligament mechanoreceptors and intradental mechanoreceptors. Periodontal ligament mechanoreceptors respond to a wide range speed of stimulus, whereas intradental mechanoreceptors are activated only by a rapid stimulation. Reliable properties of perception have not been reported because of the difficulties to regulate velocity and degree of the stimulus. Eighteen healthy subjects were observed in this study (mean age: 27.2 +/- 5.7 years). A loading device to generate slow speed loading was fabricated and measured as follows: (i) the fluctuation of the force threshold within a day, (ii) day-to-day fluctuation, (iii) changes in the force threshold by a transient mechanical loading. In the normal dentition, it was observed that the fluctuation within a day and day to day of the pressure sense showed no significant differences; however, a transient mechanical loading caused the sensitivity of the periodontal ligament to decrease significantly. The device examining the force threshold resulted from periodontal ligament mechanoreceptors was useful in evaluating the sensitivity of the periodontal ligament.

  18. Osteoblast histogenesis in periodontal ligament and tibial metaphysis during simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Fielder, Paul J.; Morey, Emily R.; Roberts, W. Eugene

    1986-01-01

    Utilizing the nuclear morphometric assay for osteoblast histogenesis, the effect of simulated weightlessness (SW) on the relative numbers of the periodontal ligament (PDL) osteoblast progenitors and on the total number of osteogenic cells was determined in rats. Weightlessness was simulated by subjecting rats to continuous 30-deg head-down posture using a modified back-harness device of Morey (1979). The response of a partially unloaded, weight-bearing bone, tibial primary spongiosa (PS), was compared to a normally loaded, nonweight-bearing PDL bone. Data indicated a similar differentiation sequence in PS and PDL, which suggests that these bones might be sensitive to the same systemic factors. Preosteoblast numbers were seen to decrease in both nonweight-bearing and weight-bearing bones during SW (compared with rats not exposed to SW), indicating the importance of systemic mediators, such as cephalad fluid shift, physiological stress, and/or growth retardation.

  19. Effects of fluoride on proliferation and mineralization in periodontal ligament cells in vitro

    PubMed Central

    Li, K.Q.; Jia, S.S.; Ma, M.; Shen, H.Z.; Xu, L.; Liu, G.P.; Huang, S.Y.; Zhang, D.S.

    2016-01-01

    Fluoride, which is often added to toothpaste or mouthwash in order to protect teeth from decay, may be a novel therapeutic approach for acceleration of periodontal regeneration. Therefore, we investigated the effects of fluoride on proliferation and mineralization in human periodontal ligament cells in vitro. The periodontal ligament cells were stimulated with various concentrations of NaF added into osteogenic inductive medium. Immunohistochemistry of cell identification, cell proliferation, alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time-polymerase chain reaction (RT-PCR) were performed. Moderate concentrations of NaF (50-500 μmol/L) had pro-proliferation effects, while 500 μmol/L had the best effects. ALP activity and calcium content were significantly enhanced by 10 μmol/L NaF with osteogenic inductive medium. Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. We conclude that moderate concentrations of NaF can stimulate proliferation and mineralization in periodontal ligament cells. These in vitro findings may provide a novel therapeutic approach for acceleration of periodontal regeneration by addition of suitable concentrations of NaF into the medication for periodontitis treatment, i.e., into periodontal packs and tissue patches. PMID:27409336

  20. Effects of fluoride on proliferation and mineralization in periodontal ligament cells in vitro.

    PubMed

    Li, K Q; Jia, S S; Ma, M; Shen, H Z; Xu, L; Liu, G P; Huang, S Y; Zhang, D S

    2016-07-11

    Fluoride, which is often added to toothpaste or mouthwash in order to protect teeth from decay, may be a novel therapeutic approach for acceleration of periodontal regeneration. Therefore, we investigated the effects of fluoride on proliferation and mineralization in human periodontal ligament cells in vitro. The periodontal ligament cells were stimulated with various concentrations of NaF added into osteogenic inductive medium. Immunohistochemistry of cell identification, cell proliferation, alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time-polymerase chain reaction (RT-PCR) were performed. Moderate concentrations of NaF (50-500 μmol/L) had pro-proliferation effects, while 500 μmol/L had the best effects. ALP activity and calcium content were significantly enhanced by 10 μmol/L NaF with osteogenic inductive medium. Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. We conclude that moderate concentrations of NaF can stimulate proliferation and mineralization in periodontal ligament cells. These in vitro findings may provide a novel therapeutic approach for acceleration of periodontal regeneration by addition of suitable concentrations of NaF into the medication for periodontitis treatment, i.e., into periodontal packs and tissue patches.

  1. Application of eGFP to label human periodontal ligament stem cells in periodontal tissue engineering.

    PubMed

    Wen, Yong; Lan, Jing; Huang, Haiyun; Yu, Meijiao; Cui, Jun; Liang, Jin; Jiang, Baoqi; Xu, Xin

    2012-09-01

    To establish human periodontal ligament stem cells (hPDLSC) with high and stable expression of enhanced green fluorescent protein (eGFP) and to obtain an ideal vector expression system that suitable for gene therapy in periodontal tissue engineering. hPDLSCs were transfected with eGFP for 48h via different MOI (25, 50, 100, 200 and 400) by lentiviral vector, the transfection efficiency was evaluated by fluorescent microscopy and flow cytometry, and transfected hPDLSCs proliferation was evaluated by MTT. Pluripotent, differentiation capacity and ALP expression status were determined further. Osteoblast-associated genes expressions for osteogenesis were evaluated by quantitative-PCR. In addition, rat molar periodontal fenestration defect model was used for evaluating periodontal tissue engineering. The transfection efficiency after 48h were 44.7%, 60.9%, 71.7%, 85.8%, and 86.9% respectively. There was no significant effect of transfection (at different MOI levels of 25, 50, 100, and 200) on the proliferation of hPDLSCs (designated as eGFP-hPDLSCs) compared with hPDLSCs (P>0.05). However, proliferation of eGFP hPDLSCs at MOI 400 became slower (P<0.05). Both eGFP hPDLSCs and hPDLSCs were able to differentiate into osteocytes and adipocytes under certain conditioned media. At 7 days, expression levels of COL-1, RUNX2 in hPDLSCS were higher than those in eGFP hPDLSCs (P<0.05); expression levels of ALP and OPN in eGFP hPDLSCs were similar to those in hPDLSCs (P>0.05). Newly regenerated bone formation was observed in the defect model used. Among the transfection conditions, 48h transfection at MOI 200 is optimal for labelling hPDLSCs with eGFP in a lentiviral vector. There is no change in capability of the eGFP hPDLSCs osteogenesis. The lentiviral vector with eGFP is an appropriate expression vector system and hPDLSCs are ideal seeding cells for gene therapy in periodontal tissue engineering. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Effect of F-spondin on cementoblastic differentiation of human periodontal ligament cells

    SciTech Connect

    Kitagawa, Masae; Kudo, Yasusei; Iizuka, Shinji; Ogawa, Ikuko; Abiko, Yoshimitsu; Miyauchi, Mutsumi; Takata, Takashi . E-mail: ttakata@hiroshima-u.ac.jp

    2006-10-27

    Cementum is a mineralized tissue produced by cementoblasts covering the roots of teeth that provides for the attachment of periodontal ligament to roots and surrounding alveolar bone. To study the mechanism of proliferation and differentiation of cementoblasts is important for understanding periodontal physiology and pathology including periodontal tissue regeneration. However, the detailed mechanism of the proliferation and differentiation of human cementoblasts is still unclear. We previously established human cementoblast-like (HCEM) cell lines. We thought that comparing the transcriptional profiles of HCEM cells and human periodontal ligament (HPL) cells derived from the same teeth could be a good approach to identify genes that influence the nature of cementoblasts. We identified F-spondin as the gene demonstrating the high fold change expression in HCEM cells. Interestingly, F-spondin highly expressing HPL cells showed similar phenotype of cementoblasts, such as up-regulation of mineralized-related genes. Overall, we identified F-spondin as a promoting factor for cementoblastic differentiation.

  3. Micro-Raman spectroscopy for monitoring changes in periodontal ligaments and gingival crevicular fluid.

    PubMed

    Camerlingo, Carlo; d'Apuzzo, Fabrizia; Grassia, Vincenzo; Perillo, Letizia; Lepore, Maria

    2014-11-27

    Micro-Raman Spectroscopy is an efficient method for analyzing biological specimens due to its sensitivity to subtle chemical and structural changes. The aim of this study was to use micro-Raman spectroscopy to analyze chemical and structural changes in periodontal ligament after orthodontic force application and in gingival crevicular fluid in presence of periodontal disease. The biopsy of periodontal ligament samples of premolars extracted for orthodontic reasons and the gingival crevicular fluid samples collected by using absorbent paper cones; were analyzed by micro-Raman spectroscopy. Changes of the secondary protein structure related to different times of orthodontic force application were reported; whereas an increase of carotene was revealed in patients affected by periodontal inflammation.

  4. Micro-Raman Spectroscopy for Monitoring Changes in Periodontal Ligaments and Gingival Crevicular Fluid

    PubMed Central

    Camerlingo, Carlo; d'Apuzzo, Fabrizia; Grassia, Vincenzo; Perillo, Letizia; Lepore, Maria

    2014-01-01

    Micro-Raman Spectroscopy is an efficient method for analyzing biological specimens due to its sensitivity to subtle chemical and structural changes. The aim of this study was to use micro-Raman spectroscopy to analyze chemical and structural changes in periodontal ligament after orthodontic force application and in gingival crevicular fluid in presence of periodontal disease. The biopsy of periodontal ligament samples of premolars extracted for orthodontic reasons and the gingival crevicular fluid samples collected by using absorbent paper cones; were analyzed by micro-Raman spectroscopy. Changes of the secondary protein structure related to different times of orthodontic force application were reported; whereas an increase of carotene was revealed in patients affected by periodontal inflammation. PMID:25436655

  5. Hypoxia augments lipopolysaccharide-induced cytokine expression in periodontal ligament cells.

    PubMed

    Jian, Congxiang; Li, Chenjun; Ren, Yu; He, Yong; Li, Yunming; Feng, Xiaodan; Zhang, Gang; Tan, Yinghui

    2014-10-01

    Periodontitis is a chronic inflammatory disease characterized by the destruction of tooth supporting tissues. Hypoxia, the mainly changes of the plateau environment, can induce severe periodontitis by animal experiments. There is, however, very little information on hypoxia and lipopolysaccharide (LPS) induced cytokine expression in periodontal ligament (PDL) cells. In this article, we characterized hypoxia or P. gingivalis lipopolysaccharide (Pg LPS) induced tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 expression by human periodontal ligament (hPDL) cells. We found that hypoxia augmented Pg LPS induced TNF-α, IL-1β, and IL-6 expression in hPDL cells. We also demonstrated that nuclear factor kappa B pathway was involved in hypoxia augmenting Pg LPS induced cytokine expression in hPDL cells. Thus, our results suggest that the hypoxic environment may enhance the immune function of hPDL cells that is induced by Pg LPS.

  6. Development of tissue-engineered human periodontal ligament constructs with intrinsic angiogenic potential.

    PubMed

    Nagai, Nobuhiro; Hirakawa, Ayumi; Otani, Nao; Munekata, Masanobu

    2009-01-01

    One approach to treat periodontal diseases is grafting of tissue-engineered periodontal ligaments. Therefore, periodontal ligaments were constructed by layering cell sheets. A cell sheet was prepared by enzymatic digestion of salmon collagen gel on which human periodontal ligament fibroblasts (HPLFs) were co-cultured with or without human umbilical vein endothelial cells (HUVECs). Three cell sheets were layered and then cultured in angiogenic media, in which the HUVECs were found to form capillary-like structures when co-cultured on the HPLFs. The layered HPLFs sheets with HUVEC co-culture (PL-EC construct) demonstrated longer survival, higher alkaline phosphatase activities and lower osteocalcin production than layered HPLFs sheets without HUVEC co-culture (PL construct). Hematoxylin-eosin and Masson's trichrome staining of histological sections showed that cell density, mass and extracellular matrix deposition of the PL-EC construct were higher than those of the PL construct. Furthermore, CD31 immunostaining revealed the formation of capillary-like structures throughout the PL-EC construct. In conclusion, we successfully developed tissue-engineered periodontal ligament constructs with intrinsic angiogenic potential using cell sheet engineering and HUVEC co-culture.

  7. Various methods for isolation of multipotent human periodontal ligament cells for regenerative medicine.

    PubMed

    Tran, Ha Le Bao; Doan, Vu Nguyen; Le, Huong Thi Ngoc; Ngo, Lan Thi Quynh

    2014-08-01

    Periodontal ligament (PDL) is a specialized connective tissue that connects cementum and alveolar bone to maintain and support the teeth in situ and preserve tissue homeostasis. Recent studies have revealed the existence of stem cells in human dental tissues including periodontal ligament that play an important role, not only in the maintenance of the periodontium but also in promoting periodontal regeneration. In this study, human periodontal ligament cells (hPDLCs) were isolated by outgrowth and enzymatic dissociation methods. Expression of surface markers on PDLCs as human mesenchymal stem cells (MSCs) was identified by flow cytometry. In addition, proliferation and differentiation capacity of cultured cells to osteoblasts, adipocytes were evaluated. As a result, we successfully cultured cells from the human periodontal ligament tissues. PDLCs express mesenchymal stem cell (MSC) markers such as CD44, CD73, and CD90 and do not express CD34, CD45, and HLA-DR. PDLCs also possess the multipotential to differentiate into various types of cells, such as osteoblast and adipocytes, in vitro. Therefore, these cells have high potential to serve as materials for tissue engineering, especially dental tissue engineering.

  8. Nitric oxide production during the osteogenic differentiation of human periodontal ligament mesenchymal stem cells.

    PubMed

    Orciani, Monia; Trubiani, Oriana; Vignini, Arianna; Mattioli-Belmonte, Monica; Di Primio, R; Salvolini, Eleonora

    2009-01-01

    The critical tissues that require regeneration in the periodontium are of mesenchymal origin; therefore, the ability to identify, characterize and manipulate mesenchymal stem cells within the periodontium is of considerable clinical significance. In particular, recent findings suggest that periodontal ligament cells may possess many osteoblast-like properties. In the present study, periodontal ligament mesenchymal stem cells obtained from healthy volunteers were maintained in culture until confluence and then induced to osteogenic differentiation. Intracellular calcium ([Ca2+](i)) concentration and nitric oxide, important signalling molecules in the bone, were measured along with cell differentiation. Alkaline phosphatase activity was assayed and bone nodule-like structures were evaluated by means of morphological and histochemical analysis. Our results showed that the periodontal ligament mesenchymal stem cells underwent an in vitro osteogenic differentiation, resulting in the appearance of active osteoblast-like cells together with the formation of calcified deposits. Differentiating cells were also characterized by an increase of [Ca2+](i) and nitric oxide production. In conclusion, our data show a link between nitric oxide and the osteogenic differentiation of human periodontal ligament mesenchymal stem cells, thus suggesting that local reimplantation of expanded cells in conjugation with a nitric oxide donor could represent a promising method for treatment of periodontal defects.

  9. PERK-eIF2α-ATF4 pathway mediated by endoplasmic reticulum stress response is involved in osteodifferentiation of human periodontal ligament cells under cyclic mechanical force.

    PubMed

    Yang, Shuang-Yan; Wei, Fu-Lan; Hu, Li-Hua; Wang, Chun-Ling

    2016-08-01

    To prevent excess accumulation of unfolded proteins in endoplasmic reticulum (ER), eukaryotic cells have signaling pathways from the ER to the cytosol or nucleus. These processes are known as the endoplasmic reticulum stress (ERS) response. Protein kinase R like endoplasmic reticulum kinase (PERK) is a major transducer of the ERS response and it directly phosphorylate α-subunit of eukaryotic initiation factor 2 (eIF2α), resulting in translational attenuation. Phosphorylated eIF2α specifically promoted the translation of the activating transcription factor 4 (ATF4). ATF4 is a known important transcription factor which plays a pivotal role in osteoblast differentiation and bone formation. Furthermore, ATF4 is a downstream target of PERK. Studies have shown that PERK-eIF2α-ATF4 signal pathway mediated by ERS was involved in osteoblastic differentiation of osteoblasts. We have known that orthodontic tooth movement is a process of periodontal ligament cells (PDLCs) osteodifferentiation and alveolar bone remodeling under mechanical force. However, the involvement of PERK-eIF2α-ATF4 signal pathway mediated by ERS in osteogenic differentiation of PDLCs under mechanical force has not been unclear. In our study, we applied the cyclic mechanical force at 10% elongation with 0.5Hz to mimic occlusal force, and explored whether PERK-eIF2α-ATF4 signaling pathway mediated by ERS involved in osteogenic differentiation of PDLCs under mechanical force. Firstly, cyclic mechanical force will induce ERS and intensify several osteoblast marker genes (ATF4, OCN, and BSP). Next, we found that PERK overexpression increased eIF2α phosphorylation and expression of ATF4, furthermore induced BSP, OCN expression, thus it will promote osteodifferentiation of hPDLCs; mechanical force could promote this effect. However, PERK(-/-) cells showed the opposite changes, which will inhibit osteodifferentiation of hPDLCs. Taken together, our study proved that PERK-eIF2α-ATF4 signaling pathway

  10. Comparative study of human dental follicle cell sheets and periodontal ligament cell sheets for periodontal tissue regeneration.

    PubMed

    Guo, Shujuan; Guo, Weihua; Ding, Yi; Gong, Jian; Zou, Qing; Xie, Dan; Chen, Yali; Wu, Yafei; Tian, Weidong

    2013-01-01

    Periodontal ligament cell (PDLC) sheets have been shown to contribute to periodontal tissue regeneration. Dental follicle cells (DFCs), acknowledged as the precursor cells of PDLCs, have demonstrated stemness, embryonic features, heterogeneity, and pluripotency. Therefore, we hypothesized that DFC sheets might be more effective and suitable for periodontal tissue regeneration than PDLC sheets. In this study, we compared the biological characteristics of DFC sheets and PDLC sheets in vitro. To investigate the potential for periodontal tissue regeneration in vivo, complexes composed of two types of cell sheets combined with dentin matrix were implanted subcutaneously into nude mice for 6 weeks. Our results showed that, when forming cell sheets, DFCs secreted richer extracellular matrix than PDLCs. And compared to DFCs, DFC sheets expressed high levels of calcification-related genes, including alkaline phosphatase (alp), bone sialoprotein (bsp), osteopontin (opn), runt-related transcription factor (runx2), as well as the periodontal ligament-specific genes collagen III (col III) and periostin, while the gene expression of bsp, osteocalcin (ocn), and opn were greatly increased in PDLC sheets, when compared to PDLCs. col I expression did not change significantly. However, cementum protein 23 (cp-23) expression increased several fold in PDLC sheets compared to PDLCs but decreased in DFC sheets compared to DFCs. DFC and PDLC sheets were both positive for Collagen I (Col I), cementum attachment protein (CAP), ALP, BSP, OCN, and OPN protein expression, and Col I, ALP, BSP, and OPN expression were increased after cell sheets were formed. Furthermore, the levels of laminin and fibronectin were higher in DFCs and DFC sheets than that of PDLCs and PDLC sheets, respectively. In vivo, DFC and PDLC sheets could both regenerate periodontal tissue-like structures, but DFC sheets demonstrated stronger periodontal regeneration potential than PDLC sheets. Therefore, DFC sheets derived

  11. The effects of modeling simplifications on craniofacial finite element models: the alveoli (tooth sockets) and periodontal ligaments.

    PubMed

    Wood, Sarah A; Strait, David S; Dumont, Elizabeth R; Ross, Callum F; Grosse, Ian R

    2011-07-07

    Several finite element models of a primate cranium were used to investigate the biomechanical effects of the tooth sockets and the material behavior of the periodontal ligament (PDL) on stress and strain patterns associated with feeding. For examining the effect of tooth sockets, the unloaded sockets were modeled as devoid of teeth and PDL, filled with teeth and PDLs, or simply filled with cortical bone. The third premolar on the left side of the cranium was loaded and the PDL was treated as an isotropic, linear elastic material using published values for Young's modulus and Poisson's ratio. The remaining models, along with one of the socket models, were used to determine the effect of the PDL's material behavior on stress and strain distributions under static premolar biting and dynamic tooth loading conditions. Two models (one static and the other dynamic) treated the PDL as cortical bone. The other two models treated it as a ligament with isotropic, linear elastic material properties. Two models treated the PDL as a ligament with hyperelastic properties, and the other two as a ligament with viscoelastic properties. Both behaviors were defined using published stress-strain data obtained from in vitro experiments on porcine ligament specimens. Von Mises stress and strain contour plots indicate that the effects of the sockets and PDL material behavior are local. Results from this study suggest that modeling the sockets and the PDL in finite element analyses of skulls is project dependent and can be ignored if values of stress and strain within the alveolar region are not required. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. A low-level diode laser therapy reduces the lipopolysaccharide (LPS)-induced periodontal ligament cell inflammation

    NASA Astrophysics Data System (ADS)

    Huang, T. H.; Chen, C. C.; Liu, S. L.; Lu, Y. C.; Kao, C. T.

    2014-07-01

    The purpose of this study was to investigate the cytologic effects of inflammatory periodontal ligament cells in vitro after low-level laser therapy. Human periodontal ligament cells were cultured, exposed to lipopolysaccharide and subjected to low-level laser treatment of 5 J cm-2 or 10 J cm-2 using a 920 nm diode laser. A periodontal ligament cell attachment was observed under a microscope, and the cell viability was quantified by a mitochondrial colorimetric assay. Lipopolysaccharide-treated periodontal ligament cells were irradiated with the low-level laser, and the expression levels of several inflammatory markers, iNOS, TNF-α and IL-1, and pErk kinase, were analyzed by reverse transcription polymerase chain reaction and western blot. The data were collected and analyzed by one-way analysis of variance; p < 0.05 indicated a statistically significant difference. The low-level laser treatment of periodontal ligament cells increased their ability to attach and survive. After irradiation, the expression levels of iNOS, TNF-α and IL-1 in lipopolysaccharide-exposed periodontal ligament cells decreased over time (p < 0.05). In periodontal ligament cells, low-level diode laser treatment increased the cells’ proliferative ability and decreased the expression of the examined inflammatory mediators.

  13. Oscillatory shear loading of bovine periodontal ligament--a methodological study.

    PubMed

    Sanctuary, Colin S; Wiskott, H W Anselm; Botsis, John; Scherrer, Susanne S; Belser, Urs C

    2006-06-01

    This study examined the stress response of bovine periodontal ligament (PDL) under sinusoidal straining. The principle of the test consisted in subjecting transverse tooth, PDL and bone sections of known geometries to controlled oscillatory force application. The samples were secured to the actuator by support plates fabricated using a laser sintering technique to fit their contours to the tooth and the alveolar bone. The actuator was attached to the root slices located in the specimen's center. Hence the machine was able to push or pull the root relative to its surrounding alveolar bone. After determining an optimal distraction amplitude, the samples were cyclically loaded first in ramps and then in sinusoidal oscillations at frequencies ranging from 0.2 to 5 Hz. In the present study the following observations were made: (1) Imaging and the laser sintering technique can be used successfully to fabricate custom-made support plates for cross-sectional root-PDL-bone sections using a laser sintering technique, (2) the load-response curves were symmetric in the apical and the coronal directions, (3) both the stress response versus phase angle and the stress response versus. strain curves tended to "straighten" with increasing frequency, and (4) the phase lag between applied strain and resulting stress was small and did not differ in the intrusive and the extrusive directions. As no mechanical or time-dependent anisotropy was demonstrable in the intrusive and extrusive directions, such results may considerably simplify the development of constitutive laws for the PDL.

  14. Cytotoxicity evaluation of root repair materials in human-cultured periodontal ligament fibroblasts

    PubMed Central

    Samyuktha, Voruganti; Ravikumar, Pabbati; Nagesh, Bolla; Ranganathan, K.; Jayaprakash, Thumu; Sayesh, Vemuri

    2014-01-01

    Aim: To evaluate the cytotoxicity of three root repair materials, mineral trioxide aggregate (MTA), Endosequence Root Repair Material and Biodentine in human periodontal ligament fibroblasts. Materials and Methods: Periodontal ligament fibroblasts were cultured from healthy premolar extracted for orthodontic purpose. Cells in the third passage were used in the study. The cultured fibroblast cells were placed in contact with root repair materials: (a) Biodentine, (b) MTA, (c) Endosequence, (d) control. The effects of these three materials on the viability of Periodontal ligament (PDL) fibroblasts were determined by trypan blue dye assay after 24 hours and 48-hour time period. Cell viability was determined using inverted phase contrast microscope. Statistical Analysis: Cell viability was compared for all the experimental groups with Wilcoxons matched pair test. Results: At the 24-hour examination period, all the materials showed increased cell viability. At 48-hour time period, there is slight decrease in cell viability. Mineral trioxide aggregate showed statistically significant increase in the cell viability when compared to other root repair materials. Conclusion: Mineral trioxide aggregate was shown to be less toxic to periodontal ligament fibroblasts than Endosequence Root Repair Material and Biodentine. PMID:25298650

  15. Domain of Dentine Sialoprotein Mediates Proliferation and Differentiation of Human Periodontal Ligament Stem Cells

    PubMed Central

    Yang, Guobin; Wang, Feng; Li, Wentong; Yang, Yuan; Guo, Feng; Gao, Qingping; Shoff, Lisa; Chen, Zhi; Gay, Isabel C.; Donly, Kevin J.; MacDougall, Mary; Chen, Shuo

    2013-01-01

    Classic embryological studies have documented the inductive role of root dentin on adjacent periodontal ligament differentiation.  The biochemical composition of root dentin includes collagens and cleavage products of dentin sialophosphoprotein (DSPP), such as dentin sialoprotein (DSP).  The high abundance of DSP in root dentin prompted us to ask the question whether DSP or peptides derived thereof would serve as potent biological matrix components to induce periodontal progenitors to further differentiate into periodontal ligament cells. Here, we test the hypothesis that domain of DSP influences cell fate. In situ hybridization and immunohistochemical analyses showed that the COOH-terminal DSP domain is expressed in mouse periodontium at various stages of root development. The recombinant COOH-terminal DSP fragment (rC-DSP) enhanced attachment and migration of human periodontal ligament stem cells (PDLSC), human primary PDL cells without cell toxicity. rC-DSP induced PDLSC cell proliferation as well as differentiation and mineralization of PDLSC and PDL cells by formation of mineralized tissue and ALPase activity. Effect of rC-DSP on cell proliferation and differentiation was to promote gene expression of tooth/bone-relate markers, transcription factors and growth factors. The results for the first time showed that rC-DSP may be one of the components of cell niche for stimulating stem/progenitor cell proliferation and differentiation and a natural scaffold for periodontal regeneration application. PMID:24400037

  16. Analysis of gene expression profile of periodontal ligament cells subjected to cyclic compressive force.

    PubMed

    Wu, Jiapei; Li, Yu; Fan, Xiaofeng; Zhang, Chaoliang; Wang, Yu; Zhao, Zhihe

    2011-11-01

    Cyclic compressive force is an important mechanical stimulus on periodontal ligament (PDL). The differential expression of genes in PDL cells is thought to be involved in the remodeling of periodontal tissues subjected to mechanical stress. However, little is known about differentially expressed genes in PDL cells under cyclic compressive force. In our study, human PDL cells were subjected to 4000 μ strain compressive stress loading at 0.5 Hz for 2 h. The effect of mechanical stress on PDL cells proliferation was observed by flow cytometry. Microarray analysis was used to investigate the mechano-induced differential gene profile in PDL cells. Differential expression was confirmed by quantitative real-time polymerase chain reaction (RT-PCR) analysis on genes of interest and explored at two more force loading times (6 h, 12 h). After mechanical loading, cell proliferation was repressed. The microarray data showed that 217 out of 35,000 genes were differentially expressed; among the 217 genes, 207 were up-regulated whereas 10 were down-regulated (p < 0.05). Gene ontology analysis suggested that majority of differentially expressed genes were located in the nucleus and functioned as transcription factors involved in a variety of biological processes. Five genes of interest (IL6, IL8, ETS1, KLF10, and DLC1) were found to be closely related to negative regulation of cell proliferation. The PCR results showed increased expression after 2 h loading, then a decline with extended loading time. The signaling pathways involved were also identified. These findings expand understanding of molecular regulation in the mechano-response of PDL cells.

  17. Altering ligament water content affects ligament pre-stress and creep behaviour.

    PubMed

    Thornton, G M; Shrive, N G; Frank, C B

    2001-09-01

    The water content of a ligament can be altered by injury and surgical intervention in vivo, and inadvertently or purposely during in vitro tests. We investigated how altering the water content of the rabbit medial collateral ligament (MCL) affected its resulting creep behaviour (defined as an increase in strain from sequential cyclic and static creep tests). The water content of normal MCLs 4) was compared to that of MCLs soaked for 1 h in a sucrose solution (n = 4) or phosphate buffered saline (PBS; n = 8). Sucrose exposure decreased hydration and PBS exposure increased hydration. In addition, soaking in PBS caused a shift in ligament zero (the position where there was 0.1 N of tension on the ligament). Following the same single solution treatment, additional MCLs were creep tested at 4.1 MPa using a load based on the ligament cross-sectional area measured before solution treatment: sucrose (n = 4), PBS new "ligament zero" (n = 5). and PBS old "ligament zero" (n = 6). Normal MCLs were also tested at 4.1 MPa (n = 7) in a humidity chamber that maintained normal ligament water content. Additional MCLs were treated with both solutions in series (n = 12) to examine the reversibility of the mechanical changes caused by single solution treatment. This was the first investigation to show that ligament creep behaviour was clearly affected by the initial state of hydration: creep decreased with decreased hydration and creep increased with increased hydration. Another unique finding was that ligaments with increased hydration had decreased ligament functional length and increased ligament pre-stress. The creep behaviour of these ligaments was decreased if they were loaded from the pre-stressed state compared to the unloaded state. These results suggest that maintenance of physiological water content is important for in vitro mechanical testing of ligaments and controlling the low-load stress state of ligaments in situ.

  18. Gomisin N Decreases Inflammatory Cytokine Production in Human Periodontal Ligament Cells.

    PubMed

    Hosokawa, Yoshitaka; Hosokawa, Ikuko; Shindo, Satoru; Ozaki, Kazumi; Matsuo, Takashi

    2017-04-01

    Gomisin N, which is a lignan isolated from Schisandra chinensis, has some pharmacological effects. However, the anti-inflammatory effects of gomisin N on periodontal disease are uncertain. The aim of this study was to examine the effect of gomisin N on inflammatory mediator production in tumor necrosis factor (TNF)-α-stimulated human periodontal ligament cells (HPDLC). Gomisin N inhibited interleukin (IL)-6, IL-8, CC chemokine ligand (CCL) 2, and CCL20 production in TNF-α-stimulated HPDLC in a dose-dependent manner. Moreover, we revealed that gomisin N could suppress extracellular signal-regulated kinase (ERK) and c-Jun N terminal kinase (JNK) phosphorylation in TNF-α-stimulated HPDLC though protein kinase B (Akt) phosphorylation was not suppressed by gomisin N treatment. In summary, gomisin N might exert anti-inflammatory effects by attenuating cytokine production in periodontal ligament cells via inhibiting the TNF-α-stimulated ERK and JNK pathways activation.

  19. Role of the epithelial cell rests of Malassez in the development, maintenance and regeneration of periodontal ligament tissues.

    PubMed

    Xiong, Jimin; Gronthos, Stan; Bartold, P Mark

    2013-10-01

    Periodontitis is a highly prevalent inflammatory disease that results in damage to the tooth-supporting tissues, potentially leading to tooth loss. Periodontal tissue regeneration is a complex process that involves the collaboration of two hard tissues (cementum and alveolar bone) and two soft tissues (gingiva and periodontal ligament). To date, no periodontal-regenerative procedures provide predictable clinical outcomes. To understand the rational basis of regenerative procedures, a better understanding of the events associated with the formation of periodontal components will help to establish reliable strategies for clinical practice. An important aspect of this is the role of the Hertwig's epithelial root sheath in periodontal development and that of its descendants, the epithelial cell rests of Malassez, in the maintenance of the periodontium. An important structure during tooth root development, the Hertwig's epithelial root sheath is not only a barrier between the dental follicle and dental papilla cells but is also involved in determining the shape, size and number of roots and in the development of dentin and cementum, and may act as a source of mesenchymal progenitor cells for cementoblasts. In adulthood, the epithelial cell rests of Malassez are the only odontogenic epithelial population in the periodontal ligament. Although there is no general agreement on the functions of the epithelial cell rests of Malassez, accumulating evidence suggests that the putative roles of the epithelial cell rests of Malassez in adult periodontal ligament include maintaining periodontal ligament homeostasis to prevent ankylosis and maintain periodontal ligament space, to prevent root resorption, to serve as a target during periodontal ligament innervation and to contribute to cementum repair. Recently, ovine epithelial cell rests of Malassez cells have been shown to harbor clonogenic epithelial stem-cell populations that demonstrate similar properties to mesenchymal stromal

  20. Mechanical design, analysis, and laboratory testing of a dental implant with axial flexibility similar to natural tooth with periodontal ligament.

    PubMed

    Pektaş, Ömer; Tönük, Ergin

    2014-11-01

    At the interface between the jawbone and the roots of natural teeth, a thin, elastic, shock-absorbing tissue, called the periodontal ligament, forms a cushion which provides certain flexibility under mechanical loading. The dental restorations supported by implants, however, involve comparatively rigid connections to the jawbone. This causes overloading of the implant while bearing functional loading together with neighboring natural teeth, which leads to high stresses within the implant system and in the jawbone. A dental implant, with resilient components in the upper structure (abutment) in order to mimic the mechanical behavior of the periodontal ligament in the axial direction, was designed, analyzed in silico, and produced for mechanical testing. The aims of the design were avoiding high levels of stress, loosening of the abutment connection screw, and soft tissue irritations. The finite element analysis of the designed implant revealed that the elastic abutment yielded a similar axial mobility with the natural tooth while keeping stress in the implant at safe levels. The in vitro mechanical testing of the prototype resulted in similar axial mobility predicted by the analysis and as that of a typical natural tooth. The abutment screw did not loosen under repeated loading and there was no static or fatigue failure.

  1. Mechanical Strength and Viscoelastic Response of the Periodontal Ligament in Relation to Structure

    PubMed Central

    Komatsu, Koichiro

    2010-01-01

    The mechanical strength of the periodontal ligament (PDL) was first measured as force required to extract a tooth from its socket using human specimens. Thereafter, tooth-PDL-bone preparations have extensively been used for measurement of the mechanical response of the PDL. In vitro treatments of such specimens with specific enzymes allowed one to investigate into the roles of the structural components in the mechanical support of the PDL. The viscoelastic responses of the PDL may be examined by analysis of the stress-relaxation. Video polarised microscopy suggested that the collagen molecules and fibrils in the stretched fibre bundles progressively align along the deformation direction during the relaxation. The stress-relaxation process of the PDL can be well expressed by a function with three exponential decay terms. Analysis after in vitro digestion of the collagen fibres by collagenase revealed that the collagen fibre components may play an important role in the long-term relaxation component of the stress-relaxation process of the PDL. The dynamic measurements of the viscoelastic properties of the PDL have recently suggested that the PDL can absorb more energy in compression than in shear and tension. These viscoelastic mechanisms of the PDL tissue could reduce the risk of injury to the PDL. PMID:20948569

  2. DKK1 rescues osteogenic differentiation of mesenchymal stem cells isolated from periodontal ligaments of patients with diabetes mellitus induced periodontitis.

    PubMed

    Liu, Qi; Hu, Cheng-Hu; Zhou, Cui-Hong; Cui, Xiao-Xia; Yang, Kun; Deng, Chao; Xia, Jia-Jia; Wu, Yan; Liu, Lu-Chuan; Jin, Yan

    2015-08-17

    Multiple studies have shown that diabetes mellitus is an established risk factor for periodontitis. Recently mesenchymal stem cells derived from periodontal ligament (PDLSCs) have been utilized to reconstruct tissues destroyed by chronic inflammation. However, impact of periodontitis with diabetes mellitus on PDLSCs and mechanisms mediating effects of complex microenvironments remain poorly understood. In this study, we found multiple differentiation potential of PDLSCs from chronic periodontitis with diabetes mellitus donors (D-PDLSCs) was damaged significantly. Inhibition of NF-κB signaling could rescue osteogenic potential of PDLSCs from simple chronic periodontitis patients (P-PDLSCs), whereas did not promote D-PDLSCs osteogenesis. In addition, we found expression of DKK1 in D-PDLSCs did not respond to osteogenic signal and decreased osteogenic potential of D-PDLSCs treated with DKK1 could be reversed. To further elucidate different character between P-PDLSCs and D-PDLSCs, we treated PDLSCs with TNF-α and advanced glycation end products (AGEs), and find out AGEs which enhance effect of TNF-α in PDLSCs might mediate special personality of D-PDLSCs. The adverse effect of AGEs in PDLSCs could be reversed when PDLSCs were treated with DKK1. These results suggested DKK1 mediating WNT signaling might be a therapy target to rescue potential of PDLSCs in periodontitis with diabetes mellitus.

  3. DKK1 rescues osteogenic differentiation of mesenchymal stem cells isolated from periodontal ligaments of patients with diabetes mellitus induced periodontitis

    PubMed Central

    Liu, Qi; Hu, Cheng-Hu; Zhou, Cui-Hong; Cui, Xiao-Xia; Yang, Kun; Deng, Chao; Xia, Jia-Jia; Wu, Yan; Liu, Lu-Chuan; Jin, Yan

    2015-01-01

    Multiple studies have shown that diabetes mellitus is an established risk factor for periodontitis. Recently mesenchymal stem cells derived from periodontal ligament (PDLSCs) have been utilized to reconstruct tissues destroyed by chronic inflammation. However, impact of periodontitis with diabetes mellitus on PDLSCs and mechanisms mediating effects of complex microenvironments remain poorly understood. In this study, we found multiple differentiation potential of PDLSCs from chronic periodontitis with diabetes mellitus donors (D-PDLSCs) was damaged significantly. Inhibition of NF-κB signaling could rescue osteogenic potential of PDLSCs from simple chronic periodontitis patients (P-PDLSCs), whereas did not promote D-PDLSCs osteogenesis. In addition, we found expression of DKK1 in D-PDLSCs did not respond to osteogenic signal and decreased osteogenic potential of D-PDLSCs treated with DKK1 could be reversed. To further elucidate different character between P-PDLSCs and D-PDLSCs, we treated PDLSCs with TNF-α and advanced glycation end products (AGEs), and find out AGEs which enhance effect of TNF-α in PDLSCs might mediate special personality of D-PDLSCs. The adverse effect of AGEs in PDLSCs could be reversed when PDLSCs were treated with DKK1. These results suggested DKK1 mediating WNT signaling might be a therapy target to rescue potential of PDLSCs in periodontitis with diabetes mellitus. PMID:26278788

  4. Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro.

    PubMed

    Amin, Harsh D; Olsen, Irwin; Knowles, Jonathan C; Dard, Michel; Donos, Nikolaos

    2013-01-01

    The adult periodontal ligament (PDL) is considered to contain progenitor cells that are involved in the healing of periodontal wounds. Treatment with enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs), has been shown to be of some clinical benefit in eliciting periodontal regeneration in vivo. Although there is extensive information available about the effects of EMD on periodontal regeneration, the precise influence of this material on alveolar bone and the formation of blood vessels and proprioceptive sensory nerves, prominent features of functionally active periodontal tissue, remain unclear. The aim of the present study was therefore to examine the effects of EMD on the ability of human periodontal ligament cells (HPCs) to undergo multi-lineage differentiation in vitro. Our results showed that HPCs treated with EMD under non-selective growth conditions did not show any evidence of osteogenic, adipogenic, chondrogenic, neovasculogenic, neurogenic and gliogenic "terminal" differentiation. In contrast, under selective lineage-specific culture conditions, EMD up-regulated osteogenic, chondrogenic and neovasculogenic genes and "terminal" differentiation, but suppressed adipogenesis, neurogenesis and gliogenesis. These findings thus demonstrate for the first time that EMD can differentially modulate the multi-lineage differentiation of HPCs in vitro.

  5. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    PubMed

    Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

    2016-09-01

    Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. © The Author(s) 2015.

  6. Assessment of cell sheets derived from human periodontal ligament cells: a pre-clinical study.

    PubMed

    Washio, Kaoru; Iwata, Takanori; Mizutani, Manabu; Ando, Tomohiro; Yamato, Masayuki; Okano, Teruo; Ishikawa, Isao

    2010-09-01

    Periodontal-ligament-derived cells (PDL cells) have stem-cell-like properties and, when implanted into periodontal defects in vivo, can induce periodontal regeneration including the formation of new bone, cementum, and periodontal ligament. We have previously demonstrated that PDL cell sheets, harvested from temperature-responsive cell culture dishes, have a great potential for periodontal regeneration. The purpose of this study has been to validate the safety and efficacy of human PDL (hPDL) cell sheets for use in clinical trials. hPDL tissues from three donors were enzymatically digested, and the obtained cells were cultured with media containing autologous serum in a cell-processing center (CPC). The safety and efficacy of hPDL cell sheets were evaluated both in vitro and in vivo. In vitro studies showed that the hPDL cell sheets had high alkaline phosphatase activity and periostin expression (known PDL markers) and no contamination with microorganisms. In vivo studies revealed that hPDL cell sheets, implanted with dentin blocks, induced the formation of cementum and PDL-like tissue in immunodeficient mice. The hPDL cells presented no evidence of malignant transformation. Thus, hPDL cell sheets created in CPCs are safe products and possess the potential to regenerate periodontal tissues.

  7. Distribution of mesencephalic nucleus and trigeminal ganglion mechanoreceptors in the periodontal ligament of the cat.

    PubMed Central

    Linden, R W; Scott, B J

    1989-01-01

    1. In anaesthetized cats recordings have been made in the mesencephalic nucleus of the fifth cranial nerve and the trigeminal ganglion from neurones that respond when forces are applied to the mandibular canine tooth. The site of the mechanoreceptors in the periodontal ligament and their distribution around the tooth root have been determined. 2. Receptors with their cell bodies in the mesencephalic nucleus were found to be situated in the periodontal ligament in a discrete area intermediate between the fulcrum and apex of the tooth, while those in the trigeminal ganglion were situated in the whole area of the periodontal ligament between the fulcrum and apex of the tooth. 3. All of the located mechanoreceptors responded maximally when that part of the ligament in which they lay was put under tension. 4. The directional sensitivities of the mechanoreceptors suggested that there was an uneven distribution around the tooth root of receptors with cell bodies in the mesencephalic nucleus. In contrast mechanoreceptors with cell bodies in the trigeminal ganglion were distributed more equally around the tooth root. The rationale for the differences requires further investigation. PMID:2795482

  8. Dynamic tensile properties of bovine periodontal ligament: A nonlinear viscoelastic model.

    PubMed

    Oskui, Iman Z; Hashemi, Ata

    2016-03-21

    As a support to the tooth, the mechanical response of the periodontal ligament (PDL) is complex. Like other connective tissues, the PDL exhibits non-linear and time-dependent behavior. The viscoelasticity of the PDL plays a significant role in low and high loading rates. Little information, however, is available on the short-term viscoelastic behavior of the PDL. Also, due to the highly non-linear stress-strain response, it was hypothesized that the dynamic viscoelastic properties of the PDL would be greatly dependent on the preload. Therefore, the present study was designed to explore the dynamic tensile properties of the bovine PDL as a function of loading frequency and preload. The in vitro dynamic tensile tests were performed over a wide range of frequencies (0.01-100Hz) with dynamic force amplitude of 1N and different preloads of 3, 5 and 10N. The generalized Maxwell model was utilized to describe the non-linear viscoelastic behavior of the PDL. The low loss factor of the bovine PDL, measured between 0.04 and 0.08, indicates low energy dissipation due to the high content of collagen fibers. Moreover, the influence of viscous components in the linear region of the stress-strain curve (10N preload) was lower than those of the toe region (3N preload). The data reported in this study could be used in developing accurate computational models of the PDL.

  9. NASA-approved rotary bioreactor enhances proliferation and osteogenesis of human periodontal ligament stem cells.

    PubMed

    Li, Shi; Ma, Zhaofeng; Niu, Zhongying; Qian, Hong; Xuan, Dongying; Hou, Rui; Ni, Longxing

    2009-11-01

    Previous studies have suggested that periodontal ligament stem cells (PDLSCs) play crucial role in regeneration of periodontal defects, and recently tissue engineering based on PDLSCs to enhance periodontal regeneration has been the focus of periodontal research. A theoretical way to achieve this goal would be to provide a "stimulatory'' environment to rapidly expand PDLSCs in vitro to expedite tissue engineering of periodontium. We hypothesize that three-dimensional (3D) dynamic simulated microgravity (SMG) culture system have effect on periodontal stem cells, and would benefit periodontal stem cells proliferation and differentiation, but up to now, there are no related reports on this aspect. In this study, we investigated the biological effect of three-dimensional dynamic SMG induced by rotary cell culture system (RCCS) on human periodontal ligament stem cells (hPDLSCs) in vitro. hPDLSCs were isolated from surgically extracted human teeth and enriched by collecting multiple colonies. hPDLSCs were inoculated on Cytodex 3 microcarriers and cultured in RCCS. The results showed that SMG affected the biology of hPDLSCs as indicated by promotion of proliferation and viability, alterations of morphology, and disorganization of microfilament system. Besides, SMG-treated hPDLSCs presented increased matrix mineralization and up-regulated expression of mineralization associated genes after incubation in osteogenic medium. For it is the first time to investigate effects of SMG on PDLSCs, the research may lend insight into variations of cell response in 3D environment, and contribute to achievement of desirable periodontal regeneration utilizing PDLSCs-based tissue engineering approaches.

  10. Finite element analysis of equine incisor teeth. Part 1: determination of the material parameters of the periodontal ligament.

    PubMed

    Schrock, P; Lüpke, M; Seifert, H; Borchers, L; Staszyk, C

    2013-12-01

    In equine dentistry, periodontal diseases are frequently found in aged horses. Excessive strains and stresses within the periodontal ligament (PDL) occurring during the masticatory cycle may be predisposing factors especially in old horses with short, worn teeth. The finite element (FE) analysis is a valuable tool to investigate such strains and stresses in biological materials but a precondition for a realistic and reliable FE analysis is accurate knowledge of material parameters. As no data exist concerning the PDL of equine incisor teeth, this study was undertaken to determine the equine specific, age related and load dependent Young's modulus of equine incisors. To determine the biomechanical behaviour of the PDL, the incisor jaw-regions of horses of different ages were sectioned into 5mm thick slice samples and the incisors experimentally intruded (i.e. axially displaced into the alveolus) while recording the load-displacement relationship. Based on high resolution micro-computer tomography (μCT)-datasets, reliable and detailed 3-dimensional models of the slice samples were constructed focusing on precisely modelling the anatomy of the PDL. FE calculations were then performed and set-actual comparisons of the FE results with the experimentally measured displacements enabled the Young's modulus of the PDL to be determined. The results of this study reflect the typical non-linear behaviour of the collagen fibres of the PDL and present a high load dependency of the PDL's Young's modulus. Further investigations calculating the strains and stresses within the periodontal ligament, teeth and surrounding bone of the entire rostral aspect of the jaw are warranted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Effects of platelet-rich fibrin on human periodontal ligament fibroblasts and application for periodontal infrabony defects.

    PubMed

    Chang, Y-C; Zhao, J-H

    2011-12-01

    Platelet-rich fibrin (PRF) by Choukroun's technique is derived from an autogenous preparation of concentrated platelets. Little is known about the effects of PRF on periodontal ligament fibroblasts (PDLFs) and the application of PRF for periodontal regeneration. PDLFs were derived from healthy individuals undergoing extraction for orthodontic reasons. Blood collection was carried out from healthy volunteers. PRF was obtained from a table centrifuge centrifuged at 3000 rpm for 12 minutes. The effects of PRF on PDLFs were determined by measuring the expression of phosphorylated extracellular signal-regulated protein kinase (p-ERK), osteoprotegerin (OPG) and alkaline phosphatase (ALP) activity. Moreover, we retrospectively examined the feasibility and safety of reconstructing the periodontal infrabony defects with PRF in six patients. PRF was found to increase ERK phosphorylation and OPG in PDLFs in a time-dependent manner (p < 0.05). ALP activity was also significantly upregulated by PRF (p < 0.05). Application of PRF in infrabony defects exhibited pocket reduction and clinical attachment gain after six months. Periapical radiography revealed radiographic defect filled in grafted teeth. The enhancement of p-ERK, OPG and ALP expression by PRF may provide benefits for periodontal regeneration. Clinical and radiologic analysis showed that the use of PRF is an effective modality for periodontal infrabony defects. © 2011 Australian Dental Association.

  12. Crucial role of Notch signaling in osteogenic differentiation of periodontal ligament stem cells in osteoporotic rats.

    PubMed

    Li, Ying; Li, S Q; Gao, Y M; Li, Jin; Zhang, Bin

    2014-06-01

    Estrogen deficiency-induced osteoporosis typically occurs in postmenopausal women and has been strongly associated with periodontal diseases. Periodontal ligament stem cells (PDLSCs) isolated from the periodontal ligament can differentiate into many types of specialized cells, including osteoblast-like cells that contribute to periodontal tissue repair. The Notch signaling pathway is highly conserved and associated with self-renewal potential and cell-fate determination. Recently, several studies have focused on the relationship between Notch signaling and osteogenic differentiation. However, the precise mechanisms underlying this relationship are largely unknown. We have successfully isolated PDLSCs from both ovariectomized (OVX) and sham-operated rats. Both the mRNA and protein levels of Notch1 and Jagged1 were upregulated when PDLSCs were cultured in osteogenic induction media. Mineralization assays showed decreased calcium deposits in OVX-PDLSCs treated with a γ-secretase inhibitor compared with control cells. Thus Notch signaling is important in maintaining the osteogenic differentiation of PDLSCs in osteoporotic rats, which help in the development of a potential therapeutic strategy for periodontal disease in postmenopausal women. © 2014 International Federation for Cell Biology.

  13. The periodontal ligament (PDL) injection: an alternative to inferior alveolar nerve block.

    PubMed

    Malamed, S F

    1982-02-01

    The periodontal ligament (PDL) injection for mandibular anesthesia in isolated regions was evaluated, using both a conventional syringe and two devices designed for this procedure. A high success rate was achieved, with a low incidence of adverse reaction and highly favorable comment from both patients and administrators. Duration of pulpal anesthesia following the technique described proved adequate for most dental procedures. The newer devices appear to have some advantage over the conventional syringe technique. However, the PDL injection technique can readily be used with any conventional syringe. Further study is recommended to determine the response of periodontal and pulpal tissues.

  14. Tissue engineering of cementum/periodontal-ligament complex using a novel three-dimensional pellet cultivation system for human periodontal ligament stem cells.

    PubMed

    Yang, Zhenhua; Jin, Fang; Zhang, Xiaojun; Ma, Dandan; Han, Chun; Huo, Na; Wang, Yinxiong; Zhang, Yunfei; Lin, Zhu; Jin, Yan

    2009-12-01

    Limitations of conventional regeneration modalities underscore the necessity of recapitulating development for periodontal tissue engineering. In this study, we proposed a novel three-dimensional pellet cultivation system for periodontal ligament stem cells (PDLSCs) to recreate the biological microenvironment similar to those of a regenerative milieu. Monodispersed human PDLSCs were cultured in medium with ascorbic acid and conditioned medium from developing apical tooth germ cells and were subsequently harvested from culture plate as a contiguous cell sheet with abundant extracellular matrix. The detached cell-matrix membrane spontaneously contracted to produce a single-cell pellet. The PDLSCs embedded within this cell-matrix complex exhibited several phenotypic characteristics of cementoblast lineages, as indicated by upregulated alkaline phosphatase activity, accelerated mineralization, and the expression of bone sialoprotein and osteocalcin genes. When this PDLSC pellets were transplanted into immunocompromised mice, a regular aligned cementum/PDL-like complex was formed. These results suggest that the combination of apical tooth germ cell-conditioned medium and endogenous extracellular matrix could maximally mimic the microenvironment of root/periodontal tissue development and enhance the reconstruction of physiological architecture of a cementum/PDL-like complex in a tissue-mimicking way; on the other hand, such PDLSC pellet may also be a promising alternative to promote periodontal defect repair for future clinical applications.

  15. Periodontal Ligament and Alveolar Bone in Health and Adaptation: Tooth Movement

    PubMed Central

    Jiang, Nan; Guo, Weihua; Chen, Mo; Zheng, Ying; Zhou, Jian; Kim, Sahng Gyoon; Embree, Mildred C.; Song, Karen Songhee; Marao, Heloisa F.; Mao, Jeremy J.

    2015-01-01

    The periodontal ligament (PDL) and alveolar bone are two critical tissues for understanding orthodontic tooth movement. The current literature is replete with descriptive studies of multiple cell types and their matrices in the PDL and alveolar bone, but is deficient with how stem/progenitor cells differentiate into PDL and alveolar bone cells. Can one type of orthodontic force with a specific magnitude and frequency preferably activate osteoblasts, whereas another force type activates osteoclasts? This chapter will discuss the biology of not only mature cells and their matrices in the periodontal ligament and alveolar bone, but also stem/progenitor cells that differentiate into fibroblasts, osteoblasts and osteoclasts. Key advances in tooth movement rely on further understanding of osteoblast and fibroblast differentiation from mesenchymal stem/progenitor cells, and osteoclastogenesis from the hematopoietic/monocyte lineage. PMID:26599112

  16. Jawbone microenvironment promotes periodontium regeneration by regulating the function of periodontal ligament stem cells

    PubMed Central

    Zhu, Bin; Liu, Wenjia; Liu, Yihan; Zhao, Xicong; Zhang, Hao; Luo, Zhuojing; Jin, Yan

    2017-01-01

    During tooth development, the jawbone interacts with dental germ and provides the development microenvironment. Jawbone-derived mesenchymal stem cells (JBMSCs) maintain this microenvironment for root and periodontium development. However, the effect of the jawbone microenvironment on periodontium tissue regeneration is largely elusive. Our previous study showed that cell aggregates (CAs) of bone marrow mesenchymal stem cells promoted periodontium regeneration on the treated dentin scaffold. Here, we found that JBMSCs enhanced not only the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) but also their adhesion to titanium (Ti) material surface. Importantly, the compound CAs of PDLSCs and JBMSCs regenerated periodontal ligament-like fibers and mineralized matrix on the Ti scaffold surface, both in nude mice ectopic and minipig orthotopic transplantations. Our data revealed that an effective regenerative microenvironment, reconstructed by JBMSCs, promoted periodontium regeneration by regulating PDLSCs function on the Ti material. PMID:28053317

  17. Periodontal Ligament and Alveolar Bone in Health and Adaptation: Tooth Movement.

    PubMed

    Jiang, Nan; Guo, Weihua; Chen, Mo; Zheng, Ying; Zhou, Jian; Kim, Sahng Gyoon; Embree, Mildred C; Songhee Song, Karen; Marao, Heloisa F; Mao, Jeremy J

    2016-01-01

    The periodontal ligament (PDL) and alveolar bone are two critical tissues for understanding orthodontic tooth movement. The current literature is replete with descriptive studies of multiple cell types and their matrices in the PDL and alveolar bone, but is deficient with how stem/progenitor cells differentiate into PDL and alveolar bone cells. Can one type of orthodontic force with a specific magnitude and frequency activate osteoblasts, whereas another force type activates osteoclasts? This chapter will discuss the biology of not only mature cells and their matrices in the periodontal ligament and alveolar bone, but also stem/progenitor cells that differentiate into fibroblasts, osteoblasts and osteoclasts. Key advances in tooth movement rely on further understanding of osteoblast and fibroblast differentiation from mesenchymal stem/progenitor cells, and osteoclastogenesis from the hematopoietic/monocyte lineage.

  18. Early responses of periodontal ligament cells to mechanical stimulus in vivo.

    PubMed

    Kawarizadeh, A; Bourauel, C; Götz, W; Jäger, A

    2005-10-01

    Previous studies have indicated that human periodontal ligament cells undergo osteoblastic differentiation via the ERK pathway under mechanical stress in vitro. This study aimed to verify this principle in vivo. The right upper first molars of 25 anesthetized rats were loaded with constant forces of 0.1 N for up to 8 hrs. The untreated contralateral side served as a control. Paraffin-embedded sections were analyzed by immunohistochemistry for proliferating cell nuclear antigen (PCNA), runt-related transcription factor 2 (Runx2/Cbfa1), and phosphorylated extracellular signal-regulated kinases 1/2 (pERK1/2). In selected areas under tension, the proportions of Runx2-positive and pERK1/2-positive cells increased within 8 hrs of loading, whereas these proportions in selected areas under pressure were significantly lower than those in control teeth. Moreover, there were no significant changes in the number of PCNA-positive cells. Thus, mechanical stimulus up-regulates Runx2, and this regulation may be achieved via the ERK pathway.

  19. In vitro time-dependent response of periodontal ligament to mechanical loading.

    PubMed

    Sanctuary, Colin S; Wiskott, H W Anselm; Justiz, Jörn; Botsis, John; Belser, Urs C

    2005-12-01

    This study examined the time-dependent response of bovine periodontal ligament (PDL). Applying linear viscoelastic theory, the objective was 1) to examine the linearity of the PDL's response in terms of its scaling and superposition property and 2) to generate the phase lag-vs.-frequency spectrum graph. PDL specimens were tested under three separate straining conditions: 1) tension ramp tests conducted at different strain rates, 2) pulling step-straining to 0.3 in discrete tests and to 0.3 and 0.6 in one continuous run, and 3) tension-compression sinusoidal oscillations. To this effect, bar-shaped specimens of bovine roots that comprised portions of dentin, PDL tissue, and alveolar bone were produced and strained in a microtensile machine. The experimental data demonstrated that neither the scaling nor the superposition properties were verified and that the viscoelastic response of the PDL was nonlinear. The PDL's elastic response was essentially stiffening, and its viscous component was pseudoplastic. The tangent of the PDL's strain-stress phase lag was in the 0-0.1 range in the tensile direction and in the 0.35-0.45 range in the compressive direction. In line with other biological tissues, the phase lag was largely independent of frequency. By use of the data generated, a mathematical model is outlined that reproduces both the elastic stiffening and viscous thinning of the PDL's response.

  20. Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells.

    PubMed

    Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

    2016-08-01

    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

  1. Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells

    NASA Astrophysics Data System (ADS)

    Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

    2016-08-01

    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

  2. Function of Chemokine (CXC Motif) Ligand 12 in Periodontal Ligament Fibroblasts

    PubMed Central

    Yashiro, Yuichi; Nomura, Yoshiaki; Kanazashi, Mikimoto; Noda, Koji; Hanada, Nobuhiro; Nakamura, Yoshiki

    2014-01-01

    The periodontal ligament (PDL) is one of the connective tissues located between the tooth and bone. It is characterized by rapid turnover. Periodontal ligament fibroblasts (PDLFs) play major roles in the rapid turnover of the PDL. Microarray analysis of human PDLFs (HPDLFs) and human dermal fibroblasts (HDFs) demonstrated markedly high expression of chemokine (CXC motif) ligand 12 (CXCL12) in the HPDLFs. CXCL12 plays an important role in the migration of mesenchymal stem cells (MSCs). The function of CXCL12 in the periodontal ligament was investigated in HPDLFs. Expression of CXCL12 in HPDLFs and HDFs was examined by RT-PCR, qRT-PCR and ELISA. Chemotactic ability of CXCL12 was evaluated in both PDLFs and HDFs by migration assay of MSCs. CXCL12 was also immunohistochemically examined in the PDL in vivo. Expression of CXCL12 in the HPDLFs was much higher than that in HDFs in vitro. Migration assay demonstrated that the number of migrated MSCs by HPDLFs was significantly higher than that by HDFs. In addition, the migrated MSCs also expressed CXCL12 and several genes that are familiar to fibroblasts. CXCL12 was immunohistochemically localized in the fibroblasts in the PDL of rat molars. The results suggest that PDLFs synthesize and secrete CXCL12 protein and that CXCL12 induces migration of MSCs in the PDL in order to maintain rapid turnover of the PDL. PMID:24806431

  3. Function of chemokine (CXC motif) ligand 12 in periodontal ligament fibroblasts.

    PubMed

    Yashiro, Yuichi; Nomura, Yoshiaki; Kanazashi, Mikimoto; Noda, Koji; Hanada, Nobuhiro; Nakamura, Yoshiki

    2014-01-01

    The periodontal ligament (PDL) is one of the connective tissues located between the tooth and bone. It is characterized by rapid turnover. Periodontal ligament fibroblasts (PDLFs) play major roles in the rapid turnover of the PDL. Microarray analysis of human PDLFs (HPDLFs) and human dermal fibroblasts (HDFs) demonstrated markedly high expression of chemokine (CXC motif) ligand 12 (CXCL12) in the HPDLFs. CXCL12 plays an important role in the migration of mesenchymal stem cells (MSCs). The function of CXCL12 in the periodontal ligament was investigated in HPDLFs. Expression of CXCL12 in HPDLFs and HDFs was examined by RT-PCR, qRT-PCR and ELISA. Chemotactic ability of CXCL12 was evaluated in both PDLFs and HDFs by migration assay of MSCs. CXCL12 was also immunohistochemically examined in the PDL in vivo. Expression of CXCL12 in the HPDLFs was much higher than that in HDFs in vitro. Migration assay demonstrated that the number of migrated MSCs by HPDLFs was significantly higher than that by HDFs. In addition, the migrated MSCs also expressed CXCL12 and several genes that are familiar to fibroblasts. CXCL12 was immunohistochemically localized in the fibroblasts in the PDL of rat molars. The results suggest that PDLFs synthesize and secrete CXCL12 protein and that CXCL12 induces migration of MSCs in the PDL in order to maintain rapid turnover of the PDL.

  4. Dentists' level of knowledge of the treatment plans for periodontal ligament injuries after dentoalveolar trauma.

    PubMed

    Pedrini, Denise; Panzarini, Sônia Regina; Poi, Wilson Roberto; Sundefeld, Maria Lúcia Marçal Mazza; Tiveron, Adelisa Rodolfo Ferreira

    2011-01-01

    This study investigated the level of knowledge held by dentists about the possible treatment plan procedures for periodontal ligament injuries after dentoalveolar trauma. A 5-item self-applied questionnaire was prepared with questions referring to the professional profile of the interviewees and to the treatment plan they would propose for periodontal ligament injuries secondary to dentoalveolar trauma. The questionnaires were filled out by 693 dentists attending the 23rd Annual Meeting of the Brazilian Society for Dental Research, and the data obtained were subjected to descriptive analysis. Either the chi-square test or Fisher's exact test was applied to assess associations among variables, at a 5% level of significance. The results revealed that dentists experienced difficulty in establishing a treatment plan for subluxation, and for extrusive, lateral and intrusive luxations. In general, holding a dental specialty degree had no influence on the knowledge about treatment plan procedures for the most severe injuries. It could be concluded that the dentists participating in this study, whether specialists or not, did not have sufficient knowledge to treat most of the periodontal ligament injuries resulting from dentoalveolar trauma adequately.

  5. Chronic stress enhances progression of periodontitis via α1-adrenergic signaling: a potential target for periodontal disease therapy.

    PubMed

    Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan

    2014-10-17

    This study assessed the roles of chronic stress (CS) in the stimulation of the sympathetic nervous system and explored the underlying mechanisms of periodontitis. Using an animal model of periodontitis and CS, the expression of tyrosine hydroxylase (TH) and the protein levels of the α1-adrenergic receptor (α1-AR) and β2-adrenergic receptor (β2-AR) were assessed. Furthermore, human periodontal ligament fibroblasts (HPDLFs) were stimulated with lipopolysaccharide (LPS) to mimic the process of inflammation. The proliferation of the HPDLFs and the expression of α1-AR and β2-AR were assessed. The inflammatory-related cytokines interleukin (IL)-1β, IL-6 and IL-8 were detected after pretreatment with the α1/β2-AR blockers phentolamine/propranolol, both in vitro and in vivo. Results show that periodontitis under CS conditions enhanced the expression of TH, α1-AR and β2-AR. Phentolamine significantly reduced the inflammatory cytokine levels. Furthermore, we observed a marked decrease in HPDLF proliferation and the increased expression of α1-ARfollowing LPS pretreatment. Pretreatment with phentolamine dramatically ameliorated LPS-inhibited cell proliferation. In addition, the blocking of α1-ARsignaling also hindered the upregulation of the inflammatory-related cytokines IL-1β, IL-6 and IL-8. These results suggest that CS can significantly enhance the pathological progression of periodontitis by an α1-adrenergic signaling-mediated inflammatory response. We have identified a potential therapeutic target for the treatment of periodontal disease, particularly in those patients suffering from concurrent CS.

  6. Oxidative Stress and Periodontal Disease in Obesity.

    PubMed

    Dursun, Erhan; Akalin, Ferda Alev; Genc, Tolga; Cinar, Nese; Erel, Ozcan; Yildiz, Bulent Okan

    2016-03-01

    Periodontal disease is a chronic inflammatory disease of the jaws and is more prevalent in obesity. Local and systemic oxidative stress may be an early link between periodontal disease and obesity. The primary aim of this study was to detect whether increased periodontal disease susceptibility in obese individuals is associated with local and systemic oxidative stress. Accordingly; we analyzed periodontal status and systemic (serum) and local (gingival crevicular fluid [GCF]) oxidative status markers in young obese women in comparison with age-matched lean women.Twenty obese and 20 lean women participated. Periodontal condition was determined by clinical periodontal indices including probing depth, clinical attachment level, gingival index, gingival bleeding index, and plaque index. Anthropometric, hormonal, and metabolic measurements were also performed. Blood and GCF sampling was performed at the same time after an overnight fasting. Serum and GCF total antioxidant capacity (TAOC), and total oxidant status (TOS) levels were determined, and oxidative stress index (OSI) was calculated.Clinical periodontal analyses showed higher gingival index and gingival bleeding index in the obese group (P = 0.001 for both) with no significant difference in probing depth, clinical attachment level, and plaque index between the obese and the lean women. Oxidant status analyses revealed lower GCF and serum TAOC, and higher GCF and serum OSI values in the obese women (P < 0.05 for all). GCF TOS was higher in the obese women (P < 0.05), whereas there was a nonsignificant trend for higher serum TOS in obese women (P = 0.074). GCF TAOC values showed a negative correlation with body mass index, whereas GCF OSI was positively correlated with fasting insulin and low-density lipoprotein-cholesterol levels (P < 0.05 for all). Clinical periodontal indices showed significant correlations with body mass index, insulin, and lipid levels, and also oxidant status markers

  7. Oxidative Stress and Periodontal Disease in Obesity

    PubMed Central

    Dursun, Erhan; Akalın, Ferda Alev; Genc, Tolga; Cinar, Nese; Erel, Ozcan; Yildiz, Bulent Okan

    2016-01-01

    Abstract Periodontal disease is a chronic inflammatory disease of the jaws and is more prevalent in obesity. Local and systemic oxidative stress may be an early link between periodontal disease and obesity. The primary aim of this study was to detect whether increased periodontal disease susceptibility in obese individuals is associated with local and systemic oxidative stress. Accordingly; we analyzed periodontal status and systemic (serum) and local (gingival crevicular fluid [GCF]) oxidative status markers in young obese women in comparison with age-matched lean women. Twenty obese and 20 lean women participated. Periodontal condition was determined by clinical periodontal indices including probing depth, clinical attachment level, gingival index, gingival bleeding index, and plaque index. Anthropometric, hormonal, and metabolic measurements were also performed. Blood and GCF sampling was performed at the same time after an overnight fasting. Serum and GCF total antioxidant capacity (TAOC), and total oxidant status (TOS) levels were determined, and oxidative stress index (OSI) was calculated. Clinical periodontal analyses showed higher gingival index and gingival bleeding index in the obese group (P = 0.001 for both) with no significant difference in probing depth, clinical attachment level, and plaque index between the obese and the lean women. Oxidant status analyses revealed lower GCF and serum TAOC, and higher GCF and serum OSI values in the obese women (P < 0.05 for all). GCF TOS was higher in the obese women (P < 0.05), whereas there was a nonsignificant trend for higher serum TOS in obese women (P = 0.074). GCF TAOC values showed a negative correlation with body mass index, whereas GCF OSI was positively correlated with fasting insulin and low-density lipoprotein-cholesterol levels (P < 0.05 for all). Clinical periodontal indices showed significant correlations with body mass index, insulin, and lipid levels, and also oxidant status

  8. Beneficial effects of adiponectin on periodontal ligament cells under normal and regenerative conditions.

    PubMed

    Nokhbehsaim, Marjan; Keser, Sema; Nogueira, Andressa Vilas Boas; Cirelli, Joni Augusto; Jepsen, Søren; Jäger, Andreas; Eick, Sigrun; Deschner, James

    2014-01-01

    Type 2 diabetes and obesity are increasing worldwide and linked to periodontitis, a chronic disease which is characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium. The mechanisms underlying the association of diabetes mellitus and obesity with periodontal destruction and compromised periodontal healing are not well understood, but decreased plasma levels of adiponectin, as found in diabetic and obese individuals, might be a critical mechanistic link. The aim of this in vitro study was to examine the effects of adiponectin on periodontal ligament (PDL) cells under normal and regenerative conditions, and to study the regulation of adiponectin and its receptors in these cells. Adiponectin stimulated significantly the expression of growth factors and extracellular matrix, proliferation, and in vitro wound healing, reduced significantly the constitutive tumor necrosis factor-α expression, and caused a significant upregulation of its own expression. The beneficial actions of enamel matrix derivative on a number of PDL cell functions critical for periodontal regeneration were partially enhanced by adiponectin. The periodontopathogen Porphyromonas gingivalis inhibited the adiponectin expression and stimulated the expression of its receptors. In conclusion, reduced levels of adiponectin, as found in type 2 diabetes and obesity, may compromise periodontal health and healing.

  9. Semaphorin 3A Induces Mesenchymal-Stem-Like Properties in Human Periodontal Ligament Cells

    PubMed Central

    Maeda, Hidefumi; Hasegawa, Daigaku; Gronthos, Stan; Bartold, Peter Mark; Menicanin, Danijela; Fujii, Shinsuke; Yoshida, Shinichiro; Tomokiyo, Atsushi; Monnouchi, Satoshi; Akamine, Akifumi

    2014-01-01

    Periodontal ligament stem cells (PDLSCs) have recently been proposed as a novel option in periodontal regenerative therapy. However, one of the issues is the difficulty of stably generating PDLSCs because of the variation of stem cell potential between donors. Here, we show that Semaphorin 3A (Sema3A) can induce mesenchymal-stem-like properties in human periodontal ligament (PDL) cells. Sema3A expression was specifically observed in the dental follicle during tooth development and in parts of mature PDL tissue in rodent tooth and periodontal tissue. Sema3A expression levels were found to be higher in multipotential human PDL cell clones compared with low-differentiation potential clones. Sema3A-overexpressing PDL cells exhibited an enhanced capacity to differentiate into both functional osteoblasts and adipocytes. Moreover, PDL cells treated with Sema3A only at the initiation of culture stimulated osteogenesis, while Sema3A treatment throughout the culture had no effect on osteogenic differentiation. Finally, Sema3A-overexpressing PDL cells upregulated the expression of embryonic stem cell markers (NANOG, OCT4, and E-cadherin) and mesenchymal stem cell markers (CD73, CD90, CD105, CD146, and CD166), and Sema3A promoted cell division activity of PDL cells. These results suggest that Sema3A may possess the function to convert PDL cells into mesenchymal-stem-like cells. PMID:24380401

  10. Cooperative effects of FGF-2 and VEGF-A in periodontal ligament cells.

    PubMed

    Yanagita, M; Kojima, Y; Kubota, M; Mori, K; Yamashita, M; Yamada, S; Kitamura, M; Murakami, S

    2014-01-01

    We previously demonstrated that topical application of fibroblast growth factor (FGF)-2 enhanced periodontal tissue regeneration. Although angiogenesis is a crucial event for tissue regeneration, the mechanism(s) by which topically applied FGF-2 induces angiogenesis in periodontal tissues has not been fully clarified. In this study, we investigated whether FGF-2 could induce vascular endothelial growth factor (VEGF)-A expression in periodontal ligament (PDL) cells and whether cell-to-cell interactions between PDL cells and endothelial cells could stimulate angiogenesis. FGF-2 induced VEGF-A secretion from MPDL22 cells (mouse periodontal ligament cell line) in a dose-dependent manner. Transwell and wound-healing assays revealed that co-stimulation with FGF-2 plus VEGF-A synergistically stimulated the migration of MPDL22 cells. Interestingly, co-culture of MPDL22 cells with bEnd5 cells (mouse endothelial cell line) also stimulated VEGF-A production from MPDL22 cells and tube formation by bEnd5 cells. Furthermore, time-lapse analysis revealed that MPDL22 cells migrated close to the tube-forming bEnd5 cells, mimicking pericytes. Thus, FGF-2 induces VEGF-A expression in PDL cells and induces angiogenesis in combination with VEGF-A. Cell-to-cell interactions with PDL cells also facilitate angiogenesis.

  11. Hyperocclusion stimulates the expression of collagen type XII in periodontal ligament.

    PubMed

    Tsuzuki, Takashi; Kajiya, Hiroshi; T-Goto, Kazuko; Tsutsumi, Takashi; Nemoto, Tetsuomi; Okabe, Koji; Takahashi, Yutaka

    2016-06-01

    It is known that excessive mechanical force exerted by hyperocclusion induces occlusal trauma. However, the mechanism of the process remains unclear. In the present study, we employed an in vivo hyperocclusion rodent model to examine morphological and biological mechanisms of occlusal trauma in periodontal ligament tissue. To investigate alveolar bone resorption, tooth sections were stained to detect osteoclasts. To investigate the relationship between hyperocclusion and the regeneration of the cell matrix, we examined the effect of hyperocclusal force on the expression of collagens using immunohistochemistry and quantitative PCR methods. The arrangement of collagen fibers in the furcation area of the teeth was undisturbed before hyperocclusion (control). Type I collagen was localized in the extracellular area at the furcation and there was faint expression and localization of type XII collagen in the periodontal ligament. The number of osteoclasts significantly increased in the furcation and lingual cervical regions on day 4 after hyperocclusion was induced. Type XII collagens were gradually up-regulated following the induction of hyperocclusion, in a time-dependent manner. Although type I collagen mRNA expression was stable before and after hyperocclusion, type XII collagen mRNA was significantly up-regulated on day 2 and day 4 after hyperocclusion treatment. Our findings indicate that hyperocclusal force predominantly up-regulates the expression of type XII collagen in periodontal tissue, but not type I collagen, suggesting that there is a mechanism for regeneration of periodontal tissues as a response to occlusal trauma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Positive relationship between stress and periodontal disease?

    PubMed

    McCracken, Giles

    2009-01-01

    Medline and the Cochrane Oral Health Group Specialist Trials Register were utilised to find relevant studies. Articles were examined independently by two reviewers, and all review articles and animal studies were excluded. Studies published in the English language were included if they controlled for the potential effect of confounding factors, had adequate criteria to define periodontal disease, and it was possible to establish evaluate stress levels and the methodological quality of the study. Data were extracted by two reviewers independently and verified by a third. A qualitative summary of the findings was presented. One prospective clinical trial, seven case-control studies and six cross-sectional studies were included. Eight studies found a positive outcome between psychosocial factors or stress and periodontal disease; four studies observed a positive outcome for some characteristics and a negative outcome for others; whereas two studies found a negative outcome between psychosocial factors or stress and periodontal disease. Within the limitations of this systematic review, the majority of studies showed a positive relationship between stress or psychological factors and periodontal disease. In the future, however, well-designed and more representative studies should be considered to confirm these factors as a risk for periodontal disease.

  13. Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling.

    PubMed

    Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan; Zhao, Lisheng

    2016-03-25

    Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS.

  14. Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population.

    PubMed

    Sequeira, Catarina-Dourado; Teixeira, Alexandra; Caldas, Inês-Morais; Afonso, Américo; Pérez-Mongiovi, Daniel

    2014-12-01

    The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament.

  15. Optimizing the reconstruction filter in cone-beam CT to improve periodontal ligament space visualization: An in vitro study.

    PubMed

    Houno, Yuuki; Hishikawa, Toshimitsu; Gotoh, Ken-Ichi; Naitoh, Munetaka; Mitani, Akio; Noguchi, Toshihide; Ariji, Eiichiro; Kodera, Yoshie

    2017-09-01

    Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

  16. Optimizing the reconstruction filter in cone-beam CT to improve periodontal ligament space visualization: An in vitro study

    PubMed Central

    Houno, Yuuki; Gotoh, Ken-ichi; Naitoh, Munetaka; Mitani, Akio; Noguchi, Toshihide; Ariji, Eiichiro; Kodera, Yoshie

    2017-01-01

    Purpose Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

  17. Prevotella intermedia induces matrix metalloproteinase-9 expression in human periodontal ligament cells.

    PubMed

    Guan, Su-Min; Shu, Lei; Fu, Shan-Min; Liu, Bin; Xu, Xiu-Li; Wu, Jun-Zheng

    2008-06-01

    Matrix metalloproteinases (MMPs) play pivotal roles in inflammatory diseases including chronic periodontitis. The effects of Prevotella intermedia, a major periodontal pathogen, on MMP-9 production in primary human periodontal ligament (hPDL) cells were examined in the present study. MMP-9 mRNA expression was measured by semiquantitative reverse transcriptase PCR and its protein secretion was assayed by gelatin zymography. Prevotella intermedia ATCC 25611 supernatant time and dose-dependently induced MMP-9 expression. In contrast, Porphyromanas gingivalis ATCC 33277 supernatants, Escherichia coli lipopolysacchride and IL-1beta exhibited no stimulatory effects on MMP-9 production in hPDL cells. Mitogen-activated protein kinases [MAPK, including extracellular signal-related kinases (ERK), c-jun N-terminal kinases (JNK) and p38] inhibitors exerted no effect on the P. intermedia-induced MMP-9 production, indicating that P. intermedia induced MMP-9 production through an MAPK-independent pathway. Our results demonstrated that P. intermedia may contribute to periodontal tissue destruction during chronic periodontitis by inducing MMP-9 production in hPDL cells.

  18. Acemannan sponges stimulate alveolar bone, cementum and periodontal ligament regeneration in a canine class II furcation defect model.

    PubMed

    Chantarawaratit, P; Sangvanich, P; Banlunara, W; Soontornvipart, K; Thunyakitpisal, P

    2014-04-01

    Periodontal disease is a common infectious disease, found worldwide, causing the destruction of the periodontium. The periodontium is a complex structure composed of both soft and hard tissues, thus an agent applied to regenerate the periodontium must be able to stimulate periodontal ligament, cementum and alveolar bone regeneration. Recent studies demonstrated that acemannan, a polysaccharide extracted from Aloe vera gel, stimulated both soft and hard tissue healing. This study investigated effect of acemannan as a bioactive molecule and scaffold for periodontal tissue regeneration. Primary human periodontal ligament cells were treated with acemannan in vitro. New DNA synthesis, expression of growth/differentiation factor 5 and runt-related transcription factor 2, expression of vascular endothelial growth factor, bone morphogenetic protein-2 and type I collagen, alkaline phosphatase activity, and mineralized nodule formation were determined using [(3)H]-thymidine incorporation, reverse transcription-polymerase chain reaction, enzyme-linked immunoabsorbent assay, biochemical assay and alizarin red staining, respectively. In our in vivo study, premolar class II furcation defects were made in four mongrel dogs. Acemannan sponges were applied into the defects. Untreated defects were used as a negative control group. The amount of new bone, cementum and periodontal ligament formation were evaluated 30 and 60 d after the operation. Acemannan significantly increased periodontal ligament cell proliferation, upregulation of growth/differentiation factor 5, runt-related transcription factor 2, vascular endothelial growth factor, bone morphogenetic protein 2, type I collagen and alkaline phosphatase activity, and mineral deposition as compared with the untreated control group in vitro. Moreover, acemannan significantly accelerated new alveolar bone, cementum and periodontal ligament formation in class II furcation defects. Our data suggest that acemannan could be a candidate

  19. Movement of fibroblasts in the periodontal ligament of the mouse incisor is related to eruption

    SciTech Connect

    Beertsen, W.; Hoeben, K.A.

    1987-05-01

    Movement of fibroblasts in the periodontal ligament of the lower incisor of the mouse was studied by pulse-labeling with tritiated thymidine and proline. /sup 3/H-Thymidine was administered to mark the nuclei of the cells in the proliferative compartment near the basal end of the tooth; 3H-proline gave rise to a narrow band of radioactivity in the dentin, which served as a reference line for measurement of eruption. One or three weeks after injection in each animal, the lower right incisor was prevented from further eruption by being pinned to its alveolar process. The animals were killed 0, 1, or 2 weeks later, and their mandibles processed for LM-radioautography. It was found that in the left incisors, which were not inhibited in their eruption, labeled cells in the tooth-half of the periodontal ligament moved incisally at a rate similar to the eruption rate. In the pinned incisors, no further incisal migration could be established. It is concluded that fibroblast migration in the tooth-half of the ligament is strictly coupled to the eruptive process.

  20. Mechanical responses of the periodontal ligament based on an exponential hyperelastic model: a combined experimental and finite element method.

    PubMed

    Huang, Huixiang; Tang, Wencheng; Yan, Bin; Wu, Bin; Cao, Dan

    2016-01-01

    The V-W exponential hyperelastic model is adopted to describe the instantaneous elastic response of the periodontal ligament (PDL). The general theoretical framework of constitutive modeling is described based on nonlinear continuum mechanics, and the elasticity tensor used to develop UMAT subroutine is formulated. Nanoindentation experiment is performed to characterize mechanical properties of an adult pig PDL specimen. Then the experiment is simulated by using the finite element (FE) analysis. Meanwhile, the optimized material parameters are identified by the inverse FE method. The good agreement between the simulated results and experimental data demonstrates that the V-W model is capable of describing the mechanical behavior of the PDL. Therefore, the model and its implementation into FE code are validated. By using the model, we simulate the tooth movement under orthodontic loading to predict the mechanical responses of the PDL. The results show that local concentrations of stress and strain in the PDL are found.

  1. Dental follicle cells rescue the regenerative capacity of periodontal ligament stem cells in an inflammatory microenvironment.

    PubMed

    Liu, Jia; Wang, Liying; Liu, Wenjia; Li, Qiang; Jin, Zuolin; Jin, Yan

    2014-01-01

    Periodontal ligament stem cells (PDLSCs) are one of the best candidates for periodontal regeneration. Their function could be impaired in periodontitis microenvironment. Dental follicle cells (DFCs), serving as precursor cells and mesenchymal stem cells, have intimate connection with PDLSCs. However, it is still unknown whether DFCs could provide a favorable microenvironment to improve the proliferation and differentiation capacity of PDLSCs from healthy subjects (HPDLSCs) and patients diagnosed with periodontitis (PPDLSCs). HPDLSCs, PPDLSCs and DFCs were harvested and identified using microscopic and flow cytometric analysis. Then, the coculture systems of DFCs/HPDLSCs and DFCs/PPDLSCs were established with 0.4 µm transwell, in which all the detection indexs were obtained from HPDLSCs and PPDLSCs. The expression of stemness-associated genes was detected by real-time PCR, and the proliferation ability was assessed using colony formation and cell cycle assays. The osteogenic differentiation capacity was evaluated by real-time PCR, western blot, ALP activity, Alizarin Red S staining and calcium level analysis, while the adipogenic differentiation capacity was determined by real-time PCR and Oil Red O staining. The cell sheet formation in vitro was observed by HE staining and SEM, and the implantation effect in vivo was evaluated using HE staining and Masson's trichrome staining. PPDLSCs had a greater proliferation capability but lower osteogenic and adipogenic potential than HPDLSCs. DFCs enhanced the proliferation and osteogenic/adipogenic differentiation of HPDLSCs and PPDLSCs to different degrees. Moreover, coculture with DFCs increased cell layers and extracellular matrix of HPDLSCs/PPDLSCs cell sheets in vitro and improved periodontal regeneration by HPDLSCs/PPDLSCs in vivo. Our data suggest that the function of PPDLSCs could be damaged in the periodontitis microenvironment. DFCs appear to enhance the self-renewal and multi-differentiation capacity of both

  2. Hydrolyzed tilapia fish collagen induces osteogenic differentiation of human periodontal ligament cells.

    PubMed

    Liu, Chao; Sun, Jiao

    2015-12-14

    Alveolar bone regeneration has aroused worldwide attention and plays an important role in oral clinics. In recent years, the application of biomaterials to induce osteogenic differentiation of periodontal ligament cells has become the hot topic in the field of alveolar bone regeneration. At present, most existing biomaterials lack osteoinductivity, while extrinsic inducers carry the risk of unwanted side effects. The objective of this work was to study the in vitro functionality of a newly developed hydrolyzed tilapia fish collagen (HFC) for periodontal tissue regeneration. HFC was extracted from the scales of tilapia, human periodontal ligament cells (hPDL cells) were cultured with HFC without the addition of any inducing reagent, and the effects of HFC on cell viability and osteogenic differentiation were investigated. The results revealed that HFC promoted the cell viability of hPDL cells. Furthermore, the upregulation of osteogenic markers ALP, COL I, RUNX2, and OCN at the gene level and the production of osteogenic-related proteins (alkaline phosphatase and osteocalcin) proved the success of osteogenic differentiation of hPDL cells treated with HFC. In addition, we revealed that the effect of HFC was mediated by ERK signaling pathways. Taken together, the data presented in this paper suggested for the first time that HFC is a promising bioactive ingredient for biomaterials used in alveolar bone regeneration.

  3. Effects of Plants on Osteogenic Differentiation and Mineralization of Periodontal Ligament Cells: A Systematic Review.

    PubMed

    Costa, Cláudio Rodrigues Rezende; Amorim, Bruna Rabelo; de Magalhães, Pérola; De Luca Canto, Graziela; Acevedo, Ana Carolina; Guerra, Eliete Neves Silva

    2016-04-01

    This systematic review aimed to evaluate the effects of plants on osteogenic differentiation and mineralization of human periodontal ligament cells. The included studies were selected using five different electronic databases. The reference list of the included studies was crosschecked, and a partial gray literature search was undertaken using Google Scholar and ProQuest. The methodology of the selected studies was evaluated using GRADE. After a two-step selection process, eight studies were identified. Six different types of plants were reported in the selected studies, which were Morinda citrifolia, Aloe vera, Fructus cnidii, Zanthoxylum schinifolium, Centella asiatica, and Epimedium species. They included five types of isolated plant components: acemannan, osthole, hesperetin, asiaticoside, and icariin. In addition, some active substances of these components were identified as polysaccharides, coumarins, flavonoids, and triterpenes. The studies demonstrated the potential effects of plants on osteogenic differentiation, cell proliferation, mineral deposition, and gene and protein expression. Four studies showed that periodontal ligament cells induce mineral deposition after plant treatment. Although there are few studies on the subject, current evidence suggests that plants are potentially useful for the treatment of periodontal diseases. However, further investigations are required to confirm the promising effect of these plants in regenerative treatments. Copyright © 2016 John Wiley & Sons, Ltd.

  4. The Effect of Tumour Necrosis Factor-α on Periodontal Ligament Stem Cell Differentiation and the Related Signaling Pathways.

    PubMed

    Liu, Xiaochen; Tan, Guang-Rong; Yu, Mengfei; Cai, Xia; Zhou, Yi; Ding, Huifen; Xie, Han; Qu, Fan; Zhang, Runju; Lam, Carolina Un; Cui, Peng; Fu, Baiping

    2016-01-01

    Periodontal regeneration plays an integral role in the treatment of periodontal diseases, with important clinical significance for the preservation and functional recovery of affected teeth. Periodontal ligament stem cells (PDLSCs), which were found in the periodontal ligament tissues possessing properties of pluripotency and self-renewing, could repair damaged periodontium with great promise. However, in a chronic inflammatory micro-environment, these cells suffered from reduced capacity to differentiate and regenerate. There has been a growing appreciation that tumour necrosis factor-α (TNF-α) in periodontal tissues drives cellular responses to chronic periodontitis. Several new advances, including an increased understanding of the mechanism of interaction between TNF-α and PDLSCs provides insight into inflamed cell regeneration, which in turn reveal strategies to improve the effectiveness of therapy. Here we gave a comprehensive review on the role of TNF-α in chronic periodontitis, its effect on PDLSCs differentiation and periodontal regeneration, related signaling pathways and concluded with future perspectives of research on PDLSCs-based periodontal tissue regeneration.

  5. Differential gene expression of periodontal ligament cells after loading of static compressive force.

    PubMed

    Lee, Yeon-Hee; Nahm, Dong-Seok; Jung, Youn-Kwan; Choi, Je-Yong; Kim, Sahng Gyoon; Cho, Michael; Kim, Myung-Hee; Chae, Chang-Hoon; Kim, Seong-Gon

    2007-03-01

    Compressive force is an important mechanical stimulus on the periodontal ligament (PDL) and is closely related to therapeutic tooth movement. In this study, early or late response genes related to the compressive stress in PDL cells were evaluated. Particularly, the expression of interleukin (IL)-6, IL-8, and alkaline phosphatase (ALP) was studied. The primary cultured cells from PDL were grown in a three-dimensional collagen gel, and received a continuous static compressive force (1.76 g/cm(2)). The expressed genes were screened by cDNA microarray assays for 2 or 12 hours after the initiation of the mechanical force application. The genes of interest that showed significant changes in expression in the cDNA microarray assay were analyzed further by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), enzyme-linked immunoabsorbent assays (ELISA), and ALP assays. ALP, IL-6, and IL-8 were selected among the genes that significantly changed expression (/M/ >0.7) and subsequently were confirmed by quantitative RT-PCR. The secreted protein concentrations for IL-6, IL-8, and ALP activity were measured at 72 hours after application of continuous static compressive force. The protein level of IL-6 was significantly increased at 72 hours (P <0.001), but there was no significant change in IL-8 (P >0.05). ALP activity was decreased approximately 41.5% compared to the control (P = 0.015). Considering that IL-6 is a potent osteoclast activator and the compressive side of PDL during orthodontic tooth movement shows the resorption of calcified tissue, the changed expression of IL-6 and ALP in response to the static compressive force in PDL cells may contribute to the orthodontic tooth movement or alveolar bone remodeling.

  6. Influence of different intensities of vibration on proliferation and differentiation of human periodontal ligament stem cells

    PubMed Central

    Zhang, Chunxiang; Lu, Yanqin; Zhang, Linkun; Liu, Yang; Zhou, Yi; Chen, Yangxi

    2015-01-01

    Introduction To understand the effects of low-magnitude, high-frequency (LMHF) mechanical vibration at different intensities on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation. Material and methods The effect of vibration on hPDLSC proliferation, osteogenic differentiation, tenogenic differentiation and cytoskeleton was assessed at the cellular, genetic and protein level. Results The PDLSC proliferation was decreased after different magnitudes of mechanical vibration; however, there were no obvious senescent cells in the experimental and the static control group. Expression of osteogenesis markers was increased. The expression of alkaline phosphatase (ALP) and osteocalcin (OCN) mRNA was up-regulated at 0.1 g, 0.3 g, 0.6 g and 0.9 g magnitude, with the peak at 0.3 g. The type I collagen (Col-I) level was increased after vibration exposure at 0.1 g, 0.3 g, and 0.6 g, peaking at 0.3 g. The expression levels of both mRNA and protein of Runx2 and osterix (OSX) significantly increased at a magnitude of 0.1 g to 0.9 g, reached a peak at 0.3 g and then decreased slowly. The scleraxis, tenogenic markers, and mRNA expression decreased at 0.05 g, 0.1 g, and 0.3 g, and significantly increased at 0.6 g and 0.9 g. Compared with the static group, the F-actin stress fibers of hPDLSCs became thicker and clearer following vibration. Conclusions The LMHF mechanical vibration promotes PDLSC osteogenic differentiation and implies the existence of a magnitude-dependent effect of vibration on determining PDLSC commitment to the osteoblast lineage. Changes in the cytoskeleton of hPDLSCs after vibration may be one of the mechanisms of the biological effects. PMID:26170859

  7. Biomechanical time dependency of the periodontal ligament: a combined experimental and numerical approach.

    PubMed

    Papadopoulou, Konstantina; Hasan, Istabrak; Keilig, Ludger; Reimann, Susanne; Eliades, Theodore; Jäger, Andreas; Deschner, James; Bourauel, Christoph

    2013-12-01

    The analysis of the non-linear and time-dependent viscoelasticity of the periodontal ligament (PDL) enables a better understanding of the biomechanical features of the key regulator tissue for tooth movement. This is of great significance in the field of orthodontics as targeted tooth movement remains still one of the main goals to accomplish. The investigation of biomechanical aspects of the PDL function, a difficult area of research, helps towards this direction. After analysing the time-dependent biomechanical properties of pig PDL specimens in an in vitro experimental study, it was possible to confirm that PDL has a viscoelastic anisotropic behaviour. Three-dimensional finite element models of mini-pig mandibular premolars with surrounding tissues were developed, based on micro-computed tomography (μCT) data of the experimental specimens. Tooth mobility was numerically analysed under the same force systems as used in the experiment. A bilinear material parameter set was assumed to simulate tooth displacements. The numerical force/displacement curves were fitted to the experimental curves by repeatedly calculating tooth displacements of 0.2mm varying the loading velocities and the parameters, which describe the nonlinearity. The experimental results showed a good agreement with the numerical calculations. Mean values of Young's moduli E1, E2 and ultimate strain ε12 were derived for the elastic behaviour of the PDL for all loading velocities. E1 and E2 values increased with increasing the velocity, while ε12 remained relatively stable. A bilinear approximation of material properties of the PDL is a suitable description of measured force/displacement diagrams. The numerical results can be used to describe mechanical processes, especially stress-strain distributions in the PDL, accurately. Further development of suitable modelling assumptions for the response of PDL under load would be instrumental to orthodontists and engineers for designing more predictable

  8. [Changes in the microvascular pattern of the periodontal ligament in an experimental tooth extrusion].

    PubMed

    Kobayashi, K

    1989-08-01

    Forty eight adult cats were employed to investigate the serial changes of vascular patterns of the periodontal ligament on tooth extrusion. The right upper canines have been successively extruded (initial load 40 gr) with a open coil spring. The experimental periods were set on 1, 2, 3, 4 and 6 weeks respectively. On each experimental period, the microvascular casts of the periodontal ligament and alveolar bone around the experimental tooth were prepared for the scanning electron microscopy, utilizing the acrylic plastic injection method (Taniguchi and Ohta, et al. 1952 and 1955). And the serial sections of the surrounding tissues of the experimental tooth were made. In order to elucidate the mode of the tooth movement, the load of applied force and the distance of extrusion were measured. Results obtained were as follows: 1. The experimental tooth was extruded rapidly during first two weeks. The speed reduced gradually afterwards. 2. The new vascularization was seen around the apex first, then widely spread in the periodontal ligament. And the remarkable trabecula-shaped bone formation were observed around the venous networks of the root apex after two week period. 3. The tissue reactions after the tooth extrusion delayed in comparison with the movement of the tooth. 4. Although the tissue reactions of the root apex of the extruded tooth were originally similar to the one in the transverse tooth movement, slight differences were found in timing of the tissue change and shape of the capillary network. The findings of the tissue change showed that the light force was indicated in extrusion of the tooth. And the range of action of the force applied should be limited in orthodontic clinic.

  9. Osteogenic differentiation regulated by Rho-kinase in periodontal ligament cells.

    PubMed

    Yamamoto, Tadashi; Ugawa, Yuki; Yamashiro, Keisuke; Shimoe, Masayuki; Tomikawa, Kazuya; Hongo, Shoichi; Kochi, Shinsuke; Ideguchi, Hidetaka; Maeda, Hiroshi; Takashiba, Shogo

    2014-01-01

    The periodontal ligament is a multifunctional soft connective tissue, which functions not only as a cushion supporting the teeth against occlusal force, but is also a source of osteogenic cells that can regenerate neighboring hard tissues. Periodontal ligament cells (PDL cells) contain heterogeneous cell populations, including osteogenic cell progenitors. However, the precise mechanism underlying the differentiation process remains elusive. Cell differentiation is regulated by the local biochemical and mechanical microenvironment that can modulate gene expression and cell morphology by altering actin cytoskeletal organization mediated by Rho-associated, coiled-coil containing protein kinase (ROCK). To determine its role in PDL cell differentiation, we examined the effects of ROCK on cytoskeletal changes and kinetics of gene expression during osteogenic differentiation. PDL cells were isolated from human periodontal ligament on extracted teeth and cultured in osteogenic medium for 14 days. Y-27632 was used for ROCK inhibition assay. Osteogenic phenotype was determined by monitoring alkaline phosphatase (ALP) activity and calcium deposition by Alizarin Red staining. ROCK-induced cytoskeletal changes were examined by immunofluorescence analysis of F-actin and myosin light chain 2 (MLC2) expression. Real-time PCR was performed to examine the kinetics of osteogenic gene expression. F-actin and phospho-MLC2 were markedly induced during osteogenic differentiation, which coincided with upregulation of ALP activity and mineralization. Subsequent inhibition assay indicated that Y-27632 significantly inhibited F-actin and phospho-MLC2 expression in a dose-dependent manner with concomitant partial reversal of the PDL cell osteogenic phenotype. PCR array analysis of osteogenic gene expression indicated that extracellular matrix genes, such as fibronectin 1, collagen type I and III, and biglycan, were significantly downregulated by Y27632. These findings indicated crucial

  10. Periodontal ligament and intraosseous anesthetic injection techniques: alternatives to mandibular nerve blocks.

    PubMed

    Moore, Paul A; Cuddy, Michael A; Cooke, Matthew R; Sokolowski, Chester J

    2011-09-01

    and Overview. The provision of mandibular anesthesia traditionally has relied on nerve block anesthetic techniques such as the Halsted, the Gow-Gates and the Akinosi-Vazirani methods. The authors present two alternative techniques to provide local anesthesia in mandibular teeth: the periodontal ligament (PDL) injection and the intraosseous (IO) injection. The authors also present indications for and complications associated with these techniques. The PDL injection and the IO injection are effective anesthetic techniques for managing nerve block failures and for providing localized anesthesia in the mandible. Dentists may find these techniques to be useful alternatives to nerve block anesthesia.

  11. A Comparative Study of Canine Retraction by Distraction of the Periodontal Ligament and Dentoalveolar Distraction Methods.

    PubMed

    Kateel, Shashidhara Kamath; Agarwal, Amit; Kharae, Gagan; Nautiyal, Vijay Prakash; Jyoti, Anant; Prasad, P Narayana

    2016-06-01

    Canine distraction was introduced as an alternative treatment to retract the canines in minimum possible period of 3 weeks. It involved rapid canine retraction through distraction of the periodontal ligament. Another technique for rapid canine distalization involved osteotomies surrounding the canines to achieve rapid movement of the canines in the dentoalveolar segment known as dentoalveolar distraction. The present study is intended to assess and evaluate canine retraction by the above two mentioned methods of distraction osteogenesis. Eight orthodontic patients who required first premolar extractions were selected and 16 canines were distracted into the extraction space, using a distraction screw. The distraction procedure was completed in 15.38 ± 1.51 days on the side of periodontal ligament distraction while it took 14.50 ± 2.45 days on the side of dentoalveolar distraction. No significant anchorage loss was seen in both the sides. The distal displacement of the canines was 6.63 ± 0.90 mm on the periodontal distraction side at the rate of 0.43 ± 0.05 mm/day and 6.91 ± 1.16 mm on the side of dentoalveolar distraction at the rate of 0.48 ± 0.08 mm/day. An angulation change of 14.94° ± 7.58° was observed in canine inclination in periodontal distraction side while change of 14.88° ± 3.15° was seen in the dentoalveolar distraction side. No significant differences in the various parameters were found between both the techniques of canine retraction by distraction osteogenesis, while reducing orthodontic treatment duration by 6-9 months without any unfavorable short-term effects on the periodontium.

  12. Osteogenic induction of human periodontal ligament fibroblasts under two- and three-dimensional culture conditions.

    PubMed

    Inanc, Bülend; Elcin, A Eser; Elcin, Y Murat

    2006-02-01

    Human periodontal ligament fibroblasts (hPDLF) play a key role in the regeneration of periodontal compartment during guided tissue regeneration procedures. This property is attributed to the progenitor cell subsets residing in the area. The aim of this study was to investigate whether hPDLFs could undergo an osteogenic differentiation under two- and three-dimensional (2D and 3D) culture conditions upon osteogenic induction. hPDLFs were isolated from six healthy donors, cultured, and expanded according to standard protocols. Then, three osteogenic culture conditions (dexamethasone, ascorbic acid, and beta-glycerophosphate) were established: 1) 2D culture as single-cell monolayer, 2) 3D-static culture on mineralized poly(DL-lactic-co-glycolic acid) (PLGA) scaffold, and 3) 3D culture on mineralized PLGA scaffold inside the NASA-approved bioreactor stimulating microgravity conditions. After 21 days of osteogenic induction, the majority of monolayer cultures had undergone differentiation toward osteogenic lineage, as indicated by morphological changes, mineralization assay, and some phenotypical properties. However, immunohistochemistry revealed that the scaffold cultures expressed higher levels of osteogenic marker proteins compared with that of the monolayers. Secondly, hPDLF-PLGA constructs in bioreactor showed an increased expression of osteopontin and osteocalcin compared with that of static 3D culture after 21 days. Results indicate that human periodontal ligament contains a subpopulation of cells capable of undergoing osteogenic differentiation and presumably contributing to regeneration of bone defects in the adjacent area. Human PDLF-seeded mineralized PLGA scaffold in microgravity bioreactor may be used to support osteogenic differentiation in vitro. Thus, this system may offer new potential benefits as a tool for periodontal tissue engineering.

  13. In vivo differentiation of human periodontal ligament cells leads to formation of dental hard tissue.

    PubMed

    Wolf, M; Lossdörfer, S; Abuduwali, N; Meyer, R; Kebir, S; Götz, W; Jäger, A

    2013-11-01

    Following trauma, periodontal disease, or orthodontic tooth movement, residual periodontal ligament (PDL) cells at the defect site are considered mandatory for successful regeneration of the injured structures. Recent developments in tissue engineering focus, as one pillar, on the transplantation of PDL cells to support periodontal regeneration processes. Here, we examined the ability of osteogenically predifferentiated PDL cells to undergo further osteoblastic or cementoblastic differentiation and to mineralize their extracellular matrix when transplanted in an in vivo microenvironment. Using collagen sponges as carriers, osteogenically predifferentiated human PDL cells were transplanted subcutaneously into six immunocompromised CD-1® nude mice. Following explantation after 28 days, osteogenic and cementogenic marker protein expression was visualized immunohistochemically. After 28 days, transplanted PDL cells revealed both cellular, cytoplasmatic and extracellular immunoreactivity for the chosen markers alkaline phosphatase, osteopontin, PTH-receptor 1, and osteocalcin. Specific osteogenic and cementoblastic differentiation was demonstrated by RUNX2 and CEMP1 immunoreactivity. Early stages of mineralization were demonstrated by calcium and phosphate staining. Our results reinforce the previously published reports of PDL cell mineralization in vivo and further demonstrate the successful induction of specific osteogenic and cementogenic differentiation of transplanted human PDL cells in vivo. These findings reveal promising possibilities for supporting periodontal remodeling and regeneration processes with PDL cells being potential target cells with which to influence the process of orthodontically induced root resorption.

  14. Prevotella intermedia upregulates MMP-1 and MMP-8 expression in human periodontal ligament cells.

    PubMed

    Guan, Su-Min; Shu, Lei; Fu, Shan-Min; Liu, Bin; Xu, Xiu-Li; Wu, Jun-Zheng

    2009-10-01

    Prevotella intermedia, a major periodontal pathogen, plays important roles in the initiation and development of periodontitis by stimulating the release of proinflammatory cytokines, proteinases and matrix metalloproteinases (MMPs). Our previous study demonstrated that P. intermedia induced MMP-9 expression in human periodontal ligament (hPDL) cells. In this study, we examined the effects of P. intermedia on other MMPs' expression. Semi-quantitative reverse transcriptase (RT)-PCR analysis revealed that P. intermedia ATCC 25611 supernatant increased MMP-1 and MMP-8 mRNA expression in a concentration- and time-dependent manner. Enzyme-linked immunosorbent assay and Western blot results confirmed the RT-PCR results at the protein level. Cyclooxygenase inhibitor indomethacin significantly attenuated the upregulatory effects of P. intermedia on MMP-1 and MMP-8 expression. Extracellular signal-related kinase inhibitor PD98059 and c-Jun N-terminal kinase inhibitor SP600125 considerably decreased the upregulated level of MMP-1, whereas p38 inhibitor SB203580 markedly inhibited MMP-8 expression, suggesting that prostaglandin E(2) and mitogen-activated protein kinase signaling pathways are involved in P. intermedia-induced MMP-1 and MMP-8 upregulation. Our results indicate that P. intermedia might contribute to periodontal connective tissue and bone matrix destruction through upregulating MMP production.

  15. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts.

    PubMed

    Li, D X; Deng, T Z; Lv, J; Ke, J

    2014-12-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80 ± 5.50%, P<0.01) and increased apoptosis (11.31 ± 1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction.

  16. Anti-Inflammatory and Antiosteoclastogenic Activities of Parthenolide on Human Periodontal Ligament Cells In Vitro

    PubMed Central

    Zhang, Xufang; Mao, Xueli

    2014-01-01

    Periodontitis is an inflammatory disease that causes osteolysis and tooth loss. It is known that the nuclear factor kappa B (NF-κB) signalling pathway plays a key role in the progression of inflammation and osteoclastogenesis in periodontitis. Parthenolide (PTL), a sesquiterpene lactone extracted from the shoots of Tanacetum parthenium, has been shown to possess anti-inflammatory properties in various diseases. In the study reported herein, we investigated the effects of PTL on the inflammatory and osteoclastogenic response of human periodontal ligament-derived cells (hPDLCs) and revealed the signalling pathways in this process. Our results showed that PTL decreased NF-κB activation, I-κB degradation, and ERK activation in hPDLCs. PTL significantly reduced the expression of inflammatory (IL-1β, IL-6, and TNF-α) and osteoclastogenic (RANKL, OPG, and M-CSF) genes in LPS-stimulated hPDLCs. In addition, PTL attenuated hPDLC-induced osteoclastogenic differentiation of macrophages (RAW264.7 cells), as well as reducing gene expression of osteoclast-related markers in RAW264.7 cells in an hPDLC-macrophage coculture model. Taken together, these results demonstrate the anti-inflammatory and antiosteoclastogenic activities of PTL in hPDLCs in vitro. These data offer fundamental evidence supporting the potential use of PTL in periodontitis treatment. PMID:25610476

  17. Biomaterials in periodontal regenerative surgery: effects of cryopreserved bone, commercially available coral, demineralized freeze-dried dentin, and cementum on periodontal ligament fibroblasts and osteoblasts.

    PubMed

    Devecioğlu, Didem; Tözüm, Tolga F; Sengün, Dilek; Nohutcu, Rahime M

    2004-10-01

    The ultimate goal of periodontal therapy is to achieve successful periodontal regeneration. The effects of different biomaterials, allogenic and alloplastic, used in periodontal surgeries to achieve regeneration have been studied in vitro on periodontal ligament (PDL) cells and MC3T3-E1 cells. The materials tested included cryopreserved bone allograft (CBA), coralline hydroxyapatite (CH), demineralized freeze-dried dentin (DFDD), and cementum. CBA and CH revealed an increase in initial PDL cell attachment, whereas CH resulted in an increase in long-term PDL cell attachment. Mineral-like nodule formation was observed significantly higher in DFDD compared to other materials tested for osteoblasts. Based on the results of this in vitro study, we conclude that the materials used are all biocompatible with human PDL cells and osteoblasts, which have pivotal importance in periodontal regeneration.

  18. Periodontal treatment decreases plasma oxidized LDL level and oxidative stress.

    PubMed

    Tamaki, Naofumi; Tomofuji, Takaaki; Ekuni, Daisuke; Yamanaka, Reiko; Morita, Manabu

    2011-12-01

    Periodontitis induces excessive production of reactive oxygen species in periodontal lesions. This may impair circulating pro-oxidant/anti-oxidant balance and induce the oxidation of low-density lipoprotein (LDL) in blood. The purpose of this study was to monitor circulating oxidized LDL and oxidative stress in subjects with chronic periodontitis following non-surgical periodontal treatment. Plasma levels of oxidized LDL and oxidative stress in 22 otherwise healthy non-smokers with chronic periodontitis (mean age 44.0 years) were measured at baseline and at 1 and 2 months after non-surgical periodontal treatment. At baseline, chronic periodontitis patients had higher plasma levels of oxidized LDL and oxidative stress than healthy subjects (p < 0.001). Periodontal treatment was associated with a significant reduction in plasma levels of oxidized LDL (oxLDL)(p < 0.001) and oxidative stress (p < 0.001). At 2 months after periodontal treatment, the degree of change in the oxLDL was positively correlated with that in the oxidative stress (r = 0.593, p = 0.004). These observations indicate that periodontitis patients showed higher levels of circulating oxLDL and oxidative stress than healthy subjects. In addition, improved oral hygiene and non-surgical periodontal treatment were effective in decreasing oxLDL, which was positively associated with a reduction in circulating oxidative stress.

  19. Effect of cyclical forces on the periodontal ligament and alveolar bone remodeling during orthodontic tooth movement.

    PubMed

    Kalajzic, Zana; Peluso, Elizabeth Blake; Utreja, Achint; Dyment, Nathaniel; Nihara, Jun; Xu, Manshan; Chen, Jing; Uribe, Flavio; Wadhwa, Sunil

    2014-03-01

    To investigate the effect of externally applied cyclical (vibratory) forces on the rate of tooth movement, the structural integrity of the periodontal ligament, and alveolar bone remodeling. Twenty-six female Sprague-Dawley rats (7 weeks old) were divided into four groups: CTRL (unloaded), VBO (molars receiving a vibratory stimulus only), TMO (molars receiving an orthodontic spring only), and TMO+VB (molars receiving an orthodontic spring and the additional vibratory stimulus). In TMO and TMO+VB groups, the rat first molars were moved mesially for 2 weeks using Nickel-Titanium coil spring delivering 25 g of force. In VBO and TMO+VB groups, cyclical forces at 0.4 N and 30 Hz were applied occlusally twice a week for 10 minutes. Microfocus X-ray computed tomography analysis and tooth movement measurements were performed on the dissected rat maxillae. Tartrate-resistant acid phosphatase staining and collagen fiber assessment were performed on histological sections. Cyclical forces significantly inhibited the amount of tooth movement. Histological analysis showed marked disorganization of the collagen fibril structure of the periodontal ligament during tooth movement. Tooth movement caused a significant increase in osteoclast parameters on the compression side of alveolar bone and a significant decrease in bone volume fraction in the molar region compared to controls. Tooth movement was significantly inhibited by application of cyclical forces.

  20. Biomechanical force induces the growth factor production in human periodontal ligament-derived cells.

    PubMed

    Ichioka, Hiroaki; Yamamoto, Toshiro; Yamamoto, Kenta; Honjo, Ken-Ichi; Adachi, Tetsuya; Oseko, Fumishige; Mazda, Osam; Kanamura, Narisato; Kita, Masakazu

    2016-01-01

    Although many reports have been published on the functional roles of periodontal ligament (PDL) cells, the mechanisms involved in the maintenance and homeostasis of PDL have not been determined. We investigated the effects of biomechanical force on growth factor production, phosphorylation of MAPKs, and intracellular transduction pathways for growth factor production in human periodontal ligament (hPDL) cells using MAPK inhibitors. hPDL cells were exposed to mechanical force (6 MPa) using a hydrostatic pressure apparatus. The levels of growth factor mRNA and protein were examined by real-time RT-PCR and ELISA. The phosphorylation of MAPKs was measured using BD™ CBA Flex Set. In addition, MAPKs inhibitors were used to identify specific signal transduction pathways. Application of biomechanical force (equivalent to occlusal force) increased the synthesis of VEGF-A, FGF-2, and NGF. The application of biomechanical force increased the expression levels of phosphorylated ERK and p38, but not of JNK. Furthermore, the levels of VEGF-A and NGF expression were suppressed by ERK or p38 inhibitor. The growth factors induced by biomechanical force may play a role in the mechanisms of homeostasis of PDL.

  1. Establishment of immortalized dental follicle cells for generating periodontal ligament in vivo.

    PubMed

    Yokoi, T; Saito, M; Kiyono, T; Iseki, S; Kosaka, K; Nishida, E; Tsubakimoto, T; Harada, H; Eto, K; Noguchi, T; Teranaka, T

    2007-02-01

    The dental follicle is a mesenchymal tissue that surrounds the developing tooth germ. During tooth root formation, periodontal components, viz., cementum, periodontal ligament (PDL), and alveolar bone, are created by dental follicle progenitors. Here, we report the presence of PDL progenitors in mouse dental follicle (MDF) cells. MDF cells were obtained from mouse incisor tooth germs and immortalized by the expression of a mutant human papilloma virus type 16 E6 gene lacking the PDZ-domain-binding motif. MDF cells expressing the mutant E6 gene (MDF( E6-EGFP ) cells) had an extended life span, beyond 150 population doublings (PD). In contrast, normal MDF cells failed to proliferate beyond 10 PD. MDF( E6-EGFP ) cells expressed tendon/ligament phenotype-related genes such as Scleraxis (Scx), growth and differentiation factor-5, EphA4, Six-1, and type I collagen. In addition, the expression of periostin was observed. To elucidate the differentiation capacity of MDF( E6-EGFP ) cells in vivo, the cells were transplanted into severe combined immunodeficiency mice. At 4 weeks, MDF( E6-EGFP ) cell transplants had the capacity to generate a PDL-like tissue that expressed periostin, Scx, and type XII collagen and the fibrillar assembly of type I collagen. Our findings suggest that MDF( E6-EGFP ) cells can act as PDL progenitors, and that these cells may be a useful research tool for studying PDL formation and for developing regeneration therapies.

  2. The pro-apoptotic and pro-inflammatory effects of calprotectin on human periodontal ligament cells.

    PubMed

    Zheng, Yunfei; Hou, Jianxia; Peng, Lei; Zhang, Xin; Jia, Lingfei; Wang, Xian'e; Wei, Shicheng; Meng, Huanxin

    2014-01-01

    Calprotectin, a heterodimer of S100A8 and S100A9 subunits, is associated with inflammatory disorders such as rheumatoid arthritis and cystic fibrosis. Although calprotectin levels are increased significantly in the gingival crevicular fluid (GCF) of periodontitis patients, its effects on periodontal ligament cells (PDLCs) remain largely unknown. The aim of this study was to evaluate calprotectin levels in the GCF of generalized aggressive periodontitis (AgP) patients and to investigate the effects of recombinant human calprotectin (rhS100A8/A9) and its subunits (rhS100A8 and rhS100A9) in PDLCs. Both the concentration and amount of crevicular calprotectin were significantly higher in the AgP group compared with healthy controls. In addition, the GCF calprotectin levels were correlated positively with clinical periodontal parameters including bleeding index, probing depth, and clinical attachment loss. rhS100A8/A9 promoted cell apoptosis, whereas rhS100A8 and rhS100A9 individually exerted little effect on apoptosis in PDLCs. rhS100A9 and rhS100A8/A9 increased the activation of nuclear factor-κB (NF-κB) by promoting the nuclear translocation of p65 in PDLCs, subsequently inducing expression of the pro-inflammatory cytokines IL-6, IL-8, TNFα, and COX2. Treatment with an NF-κB inhibitor partially reversed the rhS100A9- and rhS100A8/A9-induced upregulation of the pro-inflammatory cytokines. rhS100A9, and not rhS100A8, was mainly responsible for the pro-inflammatory role of calprotectin. Collectively, our results suggest that calprotectin promotes apoptosis and the inflammatory response in PDLCs via rhS100A9. These findings might help identify novel treatments for periodontitis.

  3. In vitro proliferation of periodontal ligament-like tissue on extracted teeth.

    PubMed

    Iwata, T; Mino, C; Kawata, T

    2017-03-01

    Transplantation of autologous teeth is a routine component of orthodontic treatment. The aim of this study was to develop a method for the regeneration of damaged periodontal ligament (PDL) on extracted teeth using a three-dimensional culture system. We used the maxillary first premolars or third molars extracted from patients for orthodontic treatment. The extracted teeth were stained with toluidine blue to measure the residual PDL area. After confirming damage of the periodontal tissue on the root surface of the extracted teeth, we tried to regenerate the periodontal tissue. Other extracted teeth were inserted into a cell strainer filled with cellulose-based carrier materials to regenerate the periodontal tissue. The strainer was then placed in a 90-mm culture dish filled with culture medium and incubated at 37°C and 5% CO2 for about 1 month. The cultured teeth were observed under a stereomicroscope and examined by scanning electron microscopy (SEM), and were stained to detect alkaline phosphatase (ALP) activity. Toluidine blue staining revealed that the residual periodontal membrane covered an average of 50.4% of the root surface area of each tooth. After culturing extracted teeth with our culture system, globular structures were found on the entire tooth root surface by stereomicroscopy, and PDL-like filamentous tissue was also detected by SEM. The entire tooth root surfaces of the cultured teeth were positive for ALP activity. We have developed a useful culture method to stimulate the proliferation of cells in PDL-like tissue on the roots of extracted teeth. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. GGsTOP increases migration of human periodontal ligament cells in vitro via reactive oxygen species pathway

    PubMed Central

    JIANG, YING; WANG, XIANG; LI, YING; MU, SEN; ZHOU, SHUANG; LIU, YI; ZHANG, BIN

    2016-01-01

    GGsTOP is a novel and selective inhibitor of gamma-glutamyl transferase (GGT), a cell-surface enzyme that has a key role in glutathione homeostasis and the maintenance of cellular reactive oxygen species (ROS). ROS are essential for wound healing. However, little is known about the molecular mechanisms underlying the inhibition of GGT by GGsTOP in human periodontal ligament cells (hPLCs). The present study assessed GGT expression in mouse periodontal ligament tissues, GGT activity in hPLCs, and the potential physiological effect of GGsTOP on hPLC migration. Immunohistochemical analysis confirmed that GGT was widely expressed in mouse periodontal ligament tissue. Treatment with GGsTOP was associated with greater proliferation and migration of hPLCs, and higher levels of cellular ROS compared with untreated hPLCs. However, the increase in intracellular ROS was attenuated in hPLCs co-cultured with the anti-oxidant N-acetylcysteine (NAC), a precursor of glutathione. The higher ROS levels associated with GGsTOP treatment were in parallel with increases in the levels of type I collagen and alpha smooth muscle actin, which was inhibited in hPLCs co-cultured with NAC. Thus, GGsTOP may promote hPLC migration and participate in the maintenance of the periodontal ligament apparatus via the ROS pathway. PMID:27035100

  5. GGsTOP increases migration of human periodontal ligament cells in vitro via reactive oxygen species pathway.

    PubMed

    Jiang, Ying; Wang, Xiang; Li, Ying; Mu, Sen; Zhou, Shuang; Liu, Yi; Zhang, Bin

    2016-05-01

    GGsTOP is a novel and selective inhibitor of gamma-glutamyl transferase (GGT), a cell-surface enzyme that has a key role in glutathione homeostasis and the maintenance of cellular reactive oxygen species (ROS). ROS are essential for wound healing. However, little is known about the molecular mechanisms underlying the inhibition of GGT by GGsTOP in human periodontal ligament cells (hPLCs). The present study assessed GGT expression in mouse periodontal ligament tissues, GGT activity in hPLCs, and the potential physiological effect of GGsTOP on hPLC migration. Immunohistochemical analysis confirmed that GGT was widely expressed in mouse periodontal ligament tissue. Treatment with GGsTOP was associated with greater proliferation and migration of hPLCs, and higher levels of cellular ROS compared with untreated hPLCs. However, the increase in intracellular ROS was attenuated in hPLCs co‑cultured with the anti‑oxidant N‑acetylcysteine (NAC), a precursor of glutathione. The higher ROS levels associated with GGsTOP treatment were in parallel with increases in the levels of type I collagen and alpha smooth muscle actin, which was inhibited in hPLCs co‑cultured with NAC. Thus, GGsTOP may promote hPLC migration and participate in the maintenance of the periodontal ligament apparatus via the ROS pathway.

  6. Recombinant Human Plasminogen Activator Inhibitor-1 Promotes Cementogenic Differentiation of Human Periodontal Ligament Stem Cells

    PubMed Central

    Jin, Hexiu; Choung, Han-Wool; Lim, Ki-Taek; Jin, Bin; Jin, Chengbiao; Chung, Jong-Hoon

    2015-01-01

    The periodontium, consisting of gingiva, periodontal ligament (PDL), cementum, and alveolar bone, is necessary for the maintenance of tooth function. Specifically, the regenerative abilities of cementum with inserted PDL are important for the prevention of tooth loss. Periodontal ligament stem cells (PDLSCs), which are located in the connective tissue PDL between the cementum and alveolar bone, are an attractive candidate for hard tissue formation. We investigated the effects of recombinant human plasminogen activator inhibitor-1 (rhPAI-1) on cementogenic differentiation of human PDLSCs (hPDLSCs) in vitro and in vivo. Untreated and rhPAI-1-treated hPDLSCs mixed with hydroxyapatite/tricalcium phosphate (HA/TCP) and dentin matrix were transplanted subcutaneously into the dorsal surface of immunocompromised mice to assess their capacity for hard tissue formation at 8 and 10 weeks posttransplantation. rhPAI-1 accelerated mineral nodule formation and increased the mRNA expression of cementoblast-associated markers in hPDLSCs. We also observed that rhPAI-1 upregulated the levels of osterix (OSX) and cementum protein 1 (CEMP1) through Smad2/3 and p38 pathways, whereas specific inhibitors of Smad3 and p38 inhibited the enhancement of mineralization of hPDLSCs by rhPAI-1. Furthermore, transplantation of hPDLSCs with rhPAI-1 showed a great ability to promote cementogenic differentiation. Notably, rhPAI-1 induced hPDLSCs to regenerate cementum-like tissue with PDL fibers inserted into newly formed cementum-like tissue. These results suggest that rhPAI-1 may play a key role in cementogenic differentiation of hPDLSCs. rhPAI-1 with hPDLSCs may be a good candidate for future clinical applications in periodontal tissue regeneration and possibly in tooth root bioengineering. PMID:25808697

  7. [Cytocompatibility of chitosan-based thermosensitive hydrogel to human periodontal ligament cell].

    PubMed

    Ji, Qiu-xia; Yu, Xin-bo; Xu, Quan-chen; Wu, Hong

    2012-12-01

    The aim of this investigation was to evaluate the cytocompatibility of an in situ chitosan-quaternized chitosan/α, β-glycerophosphate (CS-HTCC/GP) thermosensitive hydrogel in vitro. The primary cells were isolated from human periodontal ligament and cultured. The role of different concentrations of CS-HTCC/GP extract to HPDLCs was evaluated by MTT assay and alkaline phosphatase (ALP) activity. Also, the ultra-architecture of HPDLCs was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. SPSS13.0 software package was used for statistical analysis. By immunocytochemical method, the cells were stained positively to antibodies against vimentin, and negatively to antibodies against cytokeratin, which indicated that they were external embryo mesenchymal cell without epithelial cell mixure. CS-HTCC/GP thermosensitive hydrogel promoted proliferation of HPDLCs,especially at 3d and 5d, the results was significantly different (P<0.001). ALP activity was significantly greater in group 2 and 3 than in group 4 after 5d (P<0.001). Also, no negative influence to ultrastructure of HPDLCs was found through SEM and TEM. The results indicate that CS-HTCC/GP thermosensitive hydrogel exhibits excellent cytocompatibility and has potential to be used as an in situ injectable local periodontal drug delivery vehicle and a tissue-engineering scaffold for periodontal disease therapy.

  8. Escin inhibits lipopolysaccharide-induced inflammation in human periodontal ligament cells.

    PubMed

    Liu, Shutai; Wang, Huaizhou; Qiu, Caiqing; Zhang, Jing; Zhang, Taowen; Zhou, Wenjuan; Lu, Zhishan; Rausch-Fan, Xiaohui; Liu, Zhonghao

    2012-11-01

    Periodontitis is a chronic inflammatory disease associated with gram-negative subgingival microflora infection. Accumulating experimental evidence suggests that escin exerts anti-inflammatory and anti-edematous effects. This study was designed to investigate the in vitro effects of escin on the inflammatory reaction of human periodontal ligament cells (hPDLs). hPDLs were stimulated with lipopolysaccharide (LPS). The cells were treated with various concentrations of escin. The viability of hPDLs was evaluated using the MTT method. The expression of Toll-like receptor 2 (TLR2) in hPDLs and the levels of IL-1β, TNF-α and IL-6 in the supernatant were measured. Escin significantly attenuated LPS-induced cytotoxicity in a concentration-dependent manner in hPDLs. Treatment with escin partly blocked the expression of TLR2. Escin also lowered the increase of pro-inflammatory cytokines (IL-1β, TNF-α and IL-6) induced by LPS. The present findings show that escin exerts a protective effect against LPS-induced inflammation in hPDLs. It was also shown that escin is a promising medicine for the treatment of periodontitis.

  9. [A preliminary study on the autophagy level of human periodontal ligament cells regulated by nicotine].

    PubMed

    Yang, Du; Shuai, Yuan; Zhifei, Zhou; Lizheng, Wu; Lulu, Wang; Xing'an, Wu; Xiaojing, Wang

    2017-04-01

    To explore the effect of nicotine on the autophagy level of human periodontal ligament cells (hPDLCs). Periodontal tissues collected from premolars for orthodontic treatment reasons were used to culture hPDLCs. Western blot analysis was performed to test the most optimal time and concentration of nicotine on the autophagy level of the hPDLCs. Transmission electron microscope and immunofluorescence observation were carried out to detect the form of autophagosomes and expression of autophagy related protein LC3 in hPDLCs under this optimal condition. Protein expression of LC3Ⅱ was up regulated with the 12 h nicotine stimulating. Besides that, the up regulation of the protein expression of LC3Ⅱ was concentration dependent and nicotine with a concentration of 1×10⁻⁵ mol·L⁻¹ was the most optimal condition. Transmission electron microscope and immunofluorescence observations indicated that nicotine would activate the autophagy level of hPDLCs by increasing the number of autophagosomes and up regulating the expression of autophagy related protein LC3. Nicotine could increase autophagy level of hPDLCs, thus affecting the occurrence and development of smoking related periodontitis.

  10. Tensile strength suppresses the osteogenesis of periodontal ligament cells in inflammatory microenvironments

    PubMed Central

    Sun, Chaofan; Liu, Fen; Cen, Shendan; Chen, Lijiao; Wang, Yi; Sun, Hao; Deng, Hui; Hu, Rongdang

    2017-01-01

    The present study aimed to investigate the role of orthodontic force in osteogenesis differentiation, matrix deposition and mineralization in periodontal ligament cells (PDLCs) cells in inflammatory microenvironments. The mesenchymal origin of PDLCs was confirmed by vimentin and cytokeratin staining. PDLCs were exposed to inflammatory cytokines (5 ng/ml IL-1β and 10 ng/ml TNF-α) and/or tensile strength (0.5 Hz, 12% elongation) for 12, 24 or 48 h. Cell proliferation and tensile strength-induced cytokine expression were assessed by MTT assay and ELISA, respectively. Runt-related transcription factor 2 (RUNX2) and type I collagen (COL-I) expression were analysed by reverse transcription-quantitative polymerase chain reaction and western blot analysis. Additionally, alkaline phosphatase activity was measured, and the mineralization profile was evaluated by alizarin red S staining. PDLCs exposed to tensile strength in inflammatory microenvironments exhibited reduced proliferation and mineralization potential. Treatment with the inflammatory cytokines IL-1β and TNF-α increased RUNX2 expression levels; however, decreased COL-I expression levels, indicating that bone formation and matrix deposition involve different mechanisms in PDL tissues. Notably, RUNX2 and COL-I expression levels were decreased in PDLCs exposed to a combination of an inflammatory environment and loading strength. The decreased osteogenic potential in an inflammatory microenvironment under tensile strength suggests that orthodontic force may amplify periodontal destruction in orthodontic patients with periodontitis. PMID:28560407

  11. Tensile strength suppresses the osteogenesis of periodontal ligament cells in inflammatory microenvironments.

    PubMed

    Sun, Chaofan; Liu, Fen; Cen, Shendan; Chen, Lijiao; Wang, Yi; Sun, Hao; Deng, Hui; Hu, Rongdang

    2017-07-01

    The present study aimed to investigate the role of orthodontic force in osteogenesis differentiation, matrix deposition and mineralization in periodontal ligament cells (PDLCs) cells in inflammatory microenvironments. The mesenchymal origin of PDLCs was confirmed by vimentin and cytokeratin staining. PDLCs were exposed to inflammatory cytokines (5 ng/ml IL‑1β and 10 ng/ml TNF‑α) and/or tensile strength (0.5 Hz, 12% elongation) for 12, 24 or 48 h. Cell proliferation and tensile strength‑induced cytokine expression were assessed by MTT assay and ELISA, respectively. Runt‑related transcription factor 2 (RUNX2) and type I collagen (COL‑I) expression were analysed by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Additionally, alkaline phosphatase activity was measured, and the mineralization profile was evaluated by alizarin red S staining. PDLCs exposed to tensile strength in inflammatory microenvironments exhibited reduced proliferation and mineralization potential. Treatment with the inflammatory cytokines IL‑1β and TNF‑α increased RUNX2 expression levels; however, decreased COL‑I expression levels, indicating that bone formation and matrix deposition involve different mechanisms in PDL tissues. Notably, RUNX2 and COL‑I expression levels were decreased in PDLCs exposed to a combination of an inflammatory environment and loading strength. The decreased osteogenic potential in an inflammatory microenvironment under tensile strength suggests that orthodontic force may amplify periodontal destruction in orthodontic patients with periodontitis.

  12. Assessment of Surface Markers Derived from Human Periodontal Ligament Stem Cells: An In Vitro Study

    PubMed Central

    Kadkhoda, Zainab; Rafiei, Sahar Chokami; Azizi, Bahare; Khoshzaban, Ahad

    2016-01-01

    Objectives: Periodontal tissue regeneration for treatment of periodontal disease has not yet been mastered in tissue engineering. Stem cells, scaffold, and growth factors are the three main basic components of tissue engineering. Periodontal ligament (PDL) contains stem cells; however, the number, potency and features of these cells have not yet been understood. This study aimed to isolate and characterize the properties of PDL stem cells. Materials and Methods: In this experimental study, samples were isolated from the PDL of extracted teeth of five patients and then stained immunohistochemically for detection of cell surface markers. Cells were then examined by immuno-flow cytometry for mesenchymal markers as well as for osteogenic and adipogenic differentiation. Results: The isolated cell population had fibroblast-like morphology and flow cytometry revealed that the mesenchymal surface markers were (means): CD90 (84.55), CD31 (39.97), CD166 (33.77), CD105 (31.19), CD45 (32/44), CD44 (462.11), CD34 (227.33), CD38 (86.94), CD13 (34.52) and CD73 (50.39). The PDL stem cells also differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively. Conclusions: PDL stem cells expressed mesenchymal stem cell (MSC) markers and differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively. PMID:28127326

  13. Calcitriol Suppressed Inflammatory Reactions in IL-1β-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Hosokawa, Yoshitaka; Hosokawa, Ikuko; Shindo, Satoru; Ozaki, Kazumi; Matsuo, Takashi

    2015-12-01

    Vitamin D has important roles on control of calcium and phosphate levels in the body. However, the role of vitamin D on the pathogenesis of periodontal disease is still uncertain. Therefore, we examined the effect of the hormonal form of vitamin D, calcitriol, on inflammatory responses of human periodontal ligament cells (HPDLC). We detected vitamin D receptor expression in non-stimulated HPDLC. Calcitriol inhibited interleukin (IL)-6, IL-8, CC chemokine ligand (CCL) 20, CXC chemokine ligand (CXCL) 10, and matrix metalloproteinase (MMP)-3 release from IL-1β-stimulated HPDLC. Tissue inhibitor of metalloproteinase (TIMP)-1 production did not change by calcitriol. Moreover, we found c-jun N-terminal kinase (JNK) phosphorylation and IκB-α degradation in IL-1β-stimulated HPDLC were inhibited by calcitriol, and JNK and nuclear factor (NF)-κB inhibitors could decrease IL-6, IL-8, CCL20, CXCL10, and MMP-3 productions in IL-1β-treated HPDLC. These findings suggest that vitamin D could modulate inflammatory response in periodontal tissues.

  14. Gravity loading induces adenosine triphosphate release and phosphorylation of extracellular signal-regulated kinases in human periodontal ligament cells.

    PubMed

    Ito, Mai; Arakawa, Toshiya; Okayama, Miki; Shitara, Akiko; Mizoguchi, Itaru; Takuma, Taishin

    2014-11-01

    The periodontal ligament (PDL) receives mechanical stress (MS) from dental occlusion or orthodontic tooth movement. Mechanical stress is thought to be a trigger for remodeling of the PDL and alveolar bone, although its signaling mechanism is still unclear. So we investigated the effect of MS on adenosine triphosphate (ATP) release and extracellular signal-regulated kinases (ERK) phosphorylation in PDL cells. Mechanical stress was applied to human PDL cells as centrifugation-mediated gravity loading. Apyrase, Ca(2+)-free medium and purinergic receptor agonists and antagonists were utilized to analyze the contribution of purinergic receptors to ERK phosphorylation. Gravity loading and ATP increased ERK phosphorylation by 5 and 2.5 times, respectively. Gravity loading induced ATP release from PDL cells by tenfold. Apyrase and suramin diminished ERK phosphorylation induced by both gravity loading and ATP. Under Ca(2+)-free conditions the phosphorylation by gravity loading was partially decreased, whereas ATP-induced phosphorylation was unaffected. Receptors P2Y4 and P2Y6 were prominently expressed in the PDL cells. Gravity loading induced ATP release and ERK phosphorylation in PDL fibroblasts, and ATP signaling via P2Y receptors was partially involved in this phosphorylation, which in turn would enhance gene expression for the remodeling of PDL tissue during orthodontic tooth movement. © 2013 Wiley Publishing Asia Pty Ltd.

  15. Effects of bisphosphonate on matrix metalloproteinase enzymes in human periodontal ligament cells.

    PubMed

    Nakaya, H; Osawa, G; Iwasaki, N; Cochran, D L; Kamoi, K; Oates, T W

    2000-07-01

    The host response is a critical component in the pathogenesis of periodontitis. In fact, the clinical benefits associated with regulating the host response have been demonstrated in studies using several different classes of drugs. Biophosphates are one host-modulating class of drugs that has demonstrated this ability. These drugs are clinically effective at reducing bone resorption and have shown the ability to inhibit host degradative enzymes, specifically the matrix metalloproteinases (MMPs). Therefore, the purpose of this study was to investigate the regulatory effects of a bisphosphonate, tiludronate, on MMP levels and activity in human periodontal cells. MMP-1 and MMP-3 were assessed in cultured human periodontal ligament cells treated with a bisphosphonate, tiludronate. Reverse transcription-polymerase chain reaction was used to identify mRNA levels for both enzymes, and also for tissue inhibitors (TIMP-1). Enzyme immunoassay (EIA) and immunocytochemistry were used to assess MMP proteins in these cell cultures. Enzyme activity was assessed using FITC-conjugated substrates and quantitated using spectrophotofluorometry. Tiludronate significantly inhibited both MMP-1 and MMP-3 activity in a concentration-dependent manner. A maximal reduction in activity of 35% was achieved for each of the enzymes at a 10(-4) M concentration. Tiludronate did not have a significant effect on the mRNA levels for MMP-1, MMP-3, or TIMP-1. Similarly, there were no effects noted for either MMP-1 or MMP-3 on the protein level. This study demonstrates an inhibitory effect of tiludronate on the activity of both MMP-1 and MMP-3. These effects appear to occur without altering either mRNA or protein levels for these enzymes, supporting a possible mechanism of action that involves the ability of bisphosphonates to chelate cations from the MMPs. Furthermore, these results support the continued investigation of these drugs as potential therapeutic agents in periodontal disease.

  16. Electrospun fibrous scaffolds combined with nanoscale hydroxyapatite induce osteogenic differentiation of human periodontal ligament cells.

    PubMed

    Wu, Xiaonan; Miao, Leiying; Yao, Yingfang; Wu, Wenlei; Liu, Yu; Chen, Xiaofeng; Sun, Weibin

    2014-01-01

    Periodontal repair is a complex process in which regeneration of alveolar bone is a vital component. The aim of this study was to develop a biodegradable scaffold with good biocompatibility and osteoinductive ability. Two types of composite fibrous scaffolds were produced by electrospinning, ie, type I collagen/poly(ε-caprolactone) (COL/PCL) and type I collagen/poly(ε-caprolactone)/nanoscale hydroxyapatite (COL/PCL/nHA) with an average fiber diameter of about 377 nm. After a simulated body fluid (SBF) immersion test, the COL/PCL/nHA-SBF scaffold developed a rough surface because of the calcium phosphate deposited on the fibers, suggesting that the presence of nHA promoted the mineralization potential of the scaffold. Energy dispersive X-ray spectroscopy clearly showed the calcium and phosphorus content in the COL/PCL/nHA and COL/PCL/nHA-SBF scaffolds, confirming the findings of nHA and calcium phosphate precipitation on scanning electron micrographs. Water contact analysis revealed that nHA could improve the hydrophilic nature of the COL/PCL/nHA-SBF scaffold. The morphology of periodontal ligament cells cultured on COL/PCL-SBF and COL/PCL/nHA-SBF was evaluated by scanning electron microscopy. The results showed that cells adhered to either type of scaffold and were slightly spindle-shaped in the beginning, then extended gradually with stretched filopodia, indicating an ability to fill the fiber pores. A Cell Counting Kit-8 assay showed that both scaffolds supported cell proliferation. However, real-time quantitative polymerase chain reaction analysis showed that expression of the bone-related markers, alkaline phosphatase and osteocalcin, was upregulated only on the COL/PCL/nHA-SBF scaffold, indicating that this scaffold had the ability to induce osteogenic differentiation of periodontal ligament cells. In this study, COL/PCL/nHA-SBF produced by electrospinning followed by biomimetic mineralization had combined electrospun fibers with nHA in it. This scaffold has

  17. Electrospun fibrous scaffolds combined with nanoscale hydroxyapatite induce osteogenic differentiation of human periodontal ligament cells

    PubMed Central

    Wu, Xiaonan; Miao, Leiying; Yao, Yingfang; Wu, Wenlei; Liu, Yu; Chen, Xiaofeng; Sun, Weibin

    2014-01-01

    Periodontal repair is a complex process in which regeneration of alveolar bone is a vital component. The aim of this study was to develop a biodegradable scaffold with good biocompatibility and osteoinductive ability. Two types of composite fibrous scaffolds were produced by electrospinning, ie, type I collagen/poly(ε-caprolactone) (COL/PCL) and type I collagen/poly(ε-caprolactone)/nanoscale hydroxyapatite (COL/PCL/nHA) with an average fiber diameter of about 377 nm. After a simulated body fluid (SBF) immersion test, the COL/PCL/nHA-SBF scaffold developed a rough surface because of the calcium phosphate deposited on the fibers, suggesting that the presence of nHA promoted the mineralization potential of the scaffold. Energy dispersive X-ray spectroscopy clearly showed the calcium and phosphorus content in the COL/PCL/nHA and COL/PCL/nHA-SBF scaffolds, confirming the findings of nHA and calcium phosphate precipitation on scanning electron micrographs. Water contact analysis revealed that nHA could improve the hydrophilic nature of the COL/PCL/nHA-SBF scaffold. The morphology of periodontal ligament cells cultured on COL/PCL-SBF and COL/PCL/nHA-SBF was evaluated by scanning electron microscopy. The results showed that cells adhered to either type of scaffold and were slightly spindle-shaped in the beginning, then extended gradually with stretched filopodia, indicating an ability to fill the fiber pores. A Cell Counting Kit-8 assay showed that both scaffolds supported cell proliferation. However, real-time quantitative polymerase chain reaction analysis showed that expression of the bone-related markers, alkaline phosphatase and osteocalcin, was upregulated only on the COL/PCL/nHA-SBF scaffold, indicating that this scaffold had the ability to induce osteogenic differentiation of periodontal ligament cells. In this study, COL/PCL/nHA-SBF produced by electrospinning followed by biomimetic mineralization had combined electrospun fibers with nHA in it. This scaffold has

  18. Allogeneic Transplantation of Periodontal Ligament-Derived Multipotent Mesenchymal Stromal Cell Sheets in Canine Critical-Size Supra-Alveolar Periodontal Defect Model

    PubMed Central

    Tsumanuma, Yuka; Iwata, Takanori; Kinoshita, Atsuhiro; Washio, Kaoru; Yoshida, Toshiyuki; Yamada, Azusa; Takagi, Ryo; Yamato, Masayuki; Okano, Teruo; Izumi, Yuichi

    2016-01-01

    Abstract Periodontitis is a chronic inflammatory disease that induces the destruction of tooth-supporting tissues, followed by tooth loss. Although several approaches have been applied to periodontal regeneration, complete periodontal regeneration has not been accomplished. Tissue engineering using a combination of cells and scaffolds is considered to be a viable alternative strategy. We have shown that autologous transplantation of periodontal ligament-derived multipotent mesenchymal stromal cell (PDL-MSC) sheets regenerates periodontal tissue in canine models. However, the indications for autologous cell transplantation in clinical situations are limited. Therefore, this study evaluated the safety and efficacy of allogeneic transplantation of PDL-MSC sheets using a canine horizontal periodontal defect model. Canine PDL-MSCs were labeled with enhanced green fluorescent protein (EGFP) and were cultured on temperature-responsive dishes. Three-layered cell sheets were transplanted around denuded root surfaces either autologously or allogeneically. A mixture of β-tricalcium phosphate and collagen gel was placed on the bone defects. Eight weeks after transplantation, dogs were euthanized and subjected to microcomputed tomography and histological analyses. RNA and DNA were extracted from the paraffin sections to verify the presence of EGFP at the transplantation site. Inflammatory markers from peripheral blood sera were quantified using an enzyme-linked immunosorbent assay. Periodontal regeneration was observed in both the autologous and the allogeneic transplantation groups. The allogeneic transplantation group showed particularly significant regeneration of newly formed cementum, which is critical for the periodontal regeneration. Serum levels of inflammatory markers from peripheral blood sera showed little difference between the autologous and allogeneic groups. EGFP amplicons were detectable in the paraffin sections of the allogeneic group. These results suggest

  19. Healing of sites within the dog periodontal ligament after application of cold to the periodontal attachment apparatus.

    PubMed

    Tal, H; Kozlovsky, A; Pitaru, S

    1991-08-01

    The potential of periodontal ligament-derived tissues to regenerate periodontal attachment after cryosurgical trauma to the PDL in dogs was evaluated. The buccal alveolar plate of each canine tooth was exposed by a semi-lunar excision. A 3 mm thick cryoprobe, cooled to -81 degrees C, was placed on the bone 5 mm apical to the crest for 10 s. This induced cellular devitalization in the bone directly in contact with the probe and the PDL under it. The freezing-thawing cycle was repeated 3 times. Control sites were sham-operated at room temperature. Histologic sections from the center of the lesions were obtained from 1 h, 48 h and 30 d specimens. 1-h control and experimental histologic sections were similar. At 48 h post-surgery, the cellular component of the frozen PDL could not be identified and inflammatory response was minimal. The collagenous framework, however, appeared to form a continuum between the alveolar bone and cementum. Lacunae in the bone at the frozen segment were empty. The injured PDL was surrounded by normal PDL. Control specimens appeared normal. At 30 d, the PDL space in the frozen segments was populated by PDL-like tissue which did not differ significantly from the PDL coronal or apical to it. Collagen fibers appeared to be attached to the cementum on one side and to the alveolar bone on the other. Bone resorption or ankylosis was not observed in the experimental sites. It is suggested that the extracellular matrix in the devitalized area was preserved, supporting regeneration of the cryolesion.

  20. Experimentally Determined Mechanical Properties of, and Models for, the Periodontal Ligament: Critical Review of Current Literature

    PubMed Central

    Fill, Ted S.; Carey, Jason P.; Toogood, Roger W.; Major, Paul W.

    2011-01-01

    Introduction. This review is intended to highlight and discuss discrepancies in the literature of the periodontal ligament's (PDL) mechanical properties and the various experimental approaches used to measure them. Methods. Searches were performed on biomechanical and orthodontic publications (in databases: Compendex, EMBASE, MEDLINE, PubMed, ScienceDirect, and Scopus). Results. The review revealed that significant variations exist, some on the order of six orders of magnitude, in the PDL's elastic constants and mechanical properties. Possible explanations may be attributable to different experimental approaches and assumptions. Conclusions. The discrepancies highlight the need for further research into PDL properties under various clinical and experimental loading conditions. Better understanding of the PDL's biomechanical behavior under physiologic and traumatic loading conditions might enhance the understanding of the PDL's biologic reaction in health and disease. Providing a greater insight into the response of the PDL would be instrumental to orthodontists and engineers for designing more predictable, and therefore more efficacious, orthodontic appliances. PMID:21772924

  1. Adhesion and Proliferation of Human Periodontal Ligament Cells on Poly(2-methoxyethyl acrylate)

    PubMed Central

    Aoki, Makiko; Sato, Chikako; Ishihata, Hiroshi; Tanaka, Masaru

    2014-01-01

    Human periodontal ligament (PDL) cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate) (PMEA) is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except for poly(2-hydroxyethyl methacrylate) and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(n-butyl methacrylate)]. The initial adhesion of the PDL cells on PMEA was comparable with that on polyethylene terephthalate (PET). In addition, the PDL cells on PMEA spread well and exhibited proliferation behavior similar to that observed on PET. In contrast, platelets hardly adhered to PMEA. PMEA is therefore expected to be an excellent scaffold for tissue engineering and for culturing tissue-derived cells in a blood-rich environment. PMID:25165689

  2. [Cytotoxicity of MTA, Dycal and GIC on human periodontal ligament cells in vitro].

    PubMed

    Xia, Lie; Jiang, Long; Zhu, Ya-qin

    2007-12-01

    To compare the cytotoxicity of three endodontic materials (MTA, Dycal and GIC) on human periodontal ligament cells (HPDLCs) in vitro. HPDLCs proliferation was evaluated using methylthiazol tetrazolium (MTT) assay for three endodontic materials in different concentration. SAS6.12 software package was used to analyse the results. There was no statistically significant difference in three subgroups of MTA group (P>0.05). Statistically significant differences were found in Dycal group (P<0.05). In GIC group, there was no statistically significant difference between the control and 10 mg/ml subgroup (P>0.05). At the same time, statistically significant differences were found in between the control and 20 mg/ml or 40 mg/ml subgroup (P<0.05). Dycal and GIC are more cytotoxic than MTA. MTA is superior to Dycal and GIC in biocompatibility.

  3. Effect of chlorophyllin on normothermic storage of human periodontal ligament cells.

    PubMed

    Chung, Won-Gyun; Lee, Eun Ju; Lee, Seung-Jong; Lee, Seung-Ae; Kim, Jin

    2004-06-01

    The purpose of the present study was to evaluate whether chlorophyllin could serve as an effective constituent of a storage medium to enhance the human periodontal ligament (PDL) cell viability. Freshly isolated PDL cells from premolars extracted from healthy people were stored at 37 degrees C for 6 h in various solutions: F-medium and Hank's balanced salt solution (HBSS), supplemented with chlorophyllin. From MTT viability assays, the highest cell viability was found in the PDL cells stored in HBSS supplemented with 500 nM chlorophyllin, and the chlorophyllin-treated cells showed a dose-dependent response to concentration. Additionally, the results from flow cytometry showed that 77 to 80% of the PDL cells were in the G0/G1 phases of the cell cycle, which suggested that most were in a stable stage. These result showed that HBSS, supplemented with chlorophyllin, may be a useful solution for preserving the viability of PDL cells.

  4. The effects of the periodontal ligament on mandibular stiffness: a study combining finite element analysis and geometric morphometrics.

    PubMed

    Gröning, F; Fagan, M J; O'Higgins, P

    2011-04-29

    It is generally accepted that the periodontal ligament (PDL) plays a crucial role in transferring occlusal forces from the teeth to the alveolar bone. Studies using finite element analysis (FEA) have helped to better understand this role and show that the stresses and strains in the alveolar bone are influenced by whether and how PDL is included in FE models. However, when the overall distribution of stresses and strains in crania and mandibles are of interest, PDL is often not included in FE models, although little is known about how this affects the results. Here we study the effect of representing PDL as a layer of solid material with isotropic homogeneous properties in an FE model of a human mandible using a novel application of geometric morphometrics. The results show that the modelling of the PDL affects the deformation and thus strain magnitudes not only of the alveolar bone around the biting tooth, but that the whole mandible deforms differently under load. As a result, the strain in the mandibular corpus is significantly increased when PDL is included, while the strain in the bone beneath the biting tooth is reduced. These results indicate the importance of the PDL in FE studies. Thus we recommend that the PDL should be included in FE models of the masticatory apparatus, with tests to assess the sensitivity of the results to changes in the Young's modulus of the PDL material. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Combined effects of proinflammatory cytokines and intermittent cyclic mechanical strain in inhibiting osteogenicity in human periodontal ligament cells.

    PubMed

    Sun, Chaofan; Chen, Lijiao; Shi, Xinlian; Cao, Zhensheng; Hu, Bibo; Yu, Wenbin; Ren, Manman; Hu, Rongdang; Deng, Hui

    2016-09-01

    Mechanical strain plays an important role in bone formation and resorption during orthodontic tooth movement. The mechanism has not been fully studied, and the process becomes complex with increased amounts of periodontal patients seeking orthodontic care. Our aims were to elucidate the combined effects of proinflammatory cytokines and intermittent cyclic strain (ICS) on the osteogenic capacity of human periodontal ligament cells. Cultured human periodontal ligament cells were exposed to proinflammatory cytokines (interleukin-1β 5 ng/mL and tumor necrosis factor-α 10 ng/mL) for 1 and 5 days, and ICS (0.5 Hz, 12% elongation) was applied for 4 h per day. The autocrine of inflammatory cytokines was measured by enzyme-linked immunosorbent assay. The expression of osteoblast markers runt-related transcription factor 2 and rabbit collagen type I was determined using real-time polymerase chain reaction and Western blot. The osteogenic capacity was also detected by alkaline phosphatase (ALP) staining, ALP activity, and alizarin red staining. We demonstrated that ICS impaired the osteogenic capacity of human periodontal ligament cells when incubated with proinflammatory cytokines, as evidenced by the low expression of ALP staining, low ALP activity, reduced alizarin red staining, and reduced osteoblast markers. These data, for the first time, suggest that ICS has a negative effect on the inductive inhibition of osteogenicity in human PDL cells mediated by proinflammatory cytokines. © 2016 International Federation for Cell Biology.

  6. In vitro viability of human periodontal ligament cells in green tea extract

    PubMed Central

    Ghasempour, Maryam; Moghadamnia, Ali Akbar; Abedian, Zeynab; Amir, Mahdi Pour; Feizi, Farideh; Gharekhani, Samane

    2015-01-01

    Context: Delayed replantation of avulsed teeth may be successful if the majority of periodontal ligament cells (PDL) survive. A proper transport medium is required when immediate replantation is not possible. Green tea extract (GTE) may be effective in preserving the cells because of its special properties. Aims: This study was done to evaluate the potential of GTE in periodontal ligament cells preservation. Materials and Methods: Fifty-four extracted human teeth with closed apices were randomly divided into three groups each with 18 teeth as follow: GTE, water (negative control), and Hank's balanced salt solution (HBSS) (positive control). The specimens were immersed in the media for 1, 3, and 15 hours at 4°C (n = 6) and treated with collagenase 1A for 45 minutes. Cell viability was determined using the trypan blue exclusion technique. Statistical Analysis: Data were analyzed by one-way analysis of variance (ANOVA), post hoc Tukey and paired t-test at significance level of P < 0.05. Results: Means (standard deviation, SD) of viable cells in HBSS, water, and GTE were estimated 348.33 ± 88.49, 101 ± 14.18, and 310.56 ± 56.97 at 1 hours; 273.4 ± 44.80, 64.16 ± 16.44, and 310.2 ± 11.21 at 3 hours; and 373.72 ± 67.81, 14.41 ± 2.88 and 315.24 ± 34.48 at 15 hours; respectively. No significant differences were found between HBSS and GTE at all the time intervals. Both these solutions could preserve the cells more than water significantly. Conclusion: GTE and HBSS were equally effective in preserving the cells and were significantly superior to water. PMID:25657527

  7. Biocompatibility of three new calcium silicate-based endodontic sealers on human periodontal ligament stem cells.

    PubMed

    Collado-González, M; García-Bernal, D; Oñate-Sánchez, R E; Ortolani-Seltenerich, P S; Lozano, A; Forner, L; Llena, C; Rodríguez-Lozano, F J

    2017-09-01

    To evaluate the biocompatibility of three calcium silicate-based endodontic sealers, Bioroot BC Sealer (Septodont, Saint-Maur-des-Fosses, France), Endoseal MTA (EndoSeal, Maruchi, Seoul, Korea) and Nano-ceramic Sealer (B&L Biotech, Fairfax, VA, USA) (NCS), on human periodontal ligament stem cells (hPDLSCs). Human periodontal ligament stem cells were cultured in the presence of various endodontic sealer eluates for 24 h. Cell viability was determined using the MTT assay. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. Also, an in vitro scratch wound-healing model was used to determine their effects in cell migration. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test was performed (P < 0.05). At 24 h, cell spreading was evident in the presence of Bioroot BC Sealer (BR) and Nano-ceramic Sealer (NCS), but not Endoseal MTA (ES). At 72 h, BR and NCS exhibited high and moderate cell proliferation, respectively, whereas ES revealed low rates of cell proliferation (P < 0.05). Similar results were obtained in a cell death assay. In addition, hPDLSCs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of BR. Finally, SEM studies revealed a good degree of proliferation, cell spreading and attachment, especially when using BR and NCS discs. BR and NCS were associated with better cytocompatibility than ES. Further in vitro and in vivo investigations are required to confirm the suitability of these calcium silicate-based endodontic sealers for clinical application. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Influence of E-smoking liquids on human periodontal ligament fibroblasts

    PubMed Central

    2014-01-01

    Introduction Over the last years, electronic cigarettes (ECs) have become more popular, particularly in individuals who want to give up smoking tobacco. The aim of the present study was to assess the influence of the different e-smoking liquids on the viability and proliferation of human periodontal ligament fibroblasts. Method and materials For this study six test solutions with components from ECs were selected: lime-, hazelnut- and menthol-flavored liquids, nicotine, propylene glycol, and PBS as control group. The fibroblasts were incubated up to 96 h with the different liquids, and cell viability was measured by using the PrestoBlue® reagent, the ATP detection and the migration assay. Fluorescence staining was carried out to visualize cell growth and morphology. Data were statistically analyzed by two-tailed one-way ANOVA. Results The cell viability assay showed that the proliferation rates of the cells incubated with nicotine or the various flavored liquids of the e-cigarettes were reduced in comparison to the controls, though not all reductions were statistically significant. After an incubation of 96 h with the menthol-flavored liquid the fibroblasts were statistically significant reduced (p < 0.001). Similar results were found for the detection of ATP in fibroblasts; the incubation with menthol-flavored liquids (p < 0.001) led to a statistically significant reduction. The cell visualization tests confirmed these findings. Conclusion Within its limits, the present in vitro study demonstrated that menthol additives of e-smoking have a harmful effect on human periodontal ligament fibroblasts. This might indicate that menthol additives should be avoided for e-cigarettes. PMID:25224853

  9. Stem Cells Derived from Tooth Periodontal Ligament Enhance Functional Angiogenesis by Endothelial Cells

    PubMed Central

    Yeasmin, Shamima; Ceccarelli, Jacob; Vigen, Marina; Carrion, Bita; Putnam, Andrew J.; Tarle, Susan A.

    2014-01-01

    In regenerative medicine approaches involving cell therapy, selection of the appropriate cell type is important in that the cells must directly (differentiation) or indirectly (trophic effects) participate in the regenerative response. Regardless of the mode of action of the cells, angiogenesis underlies the success of these approaches. Stem cells derived from tooth tissues, specifically the periodontal ligament of teeth (periodontal ligament stem cells [PDLSCs]), have recently been identified as a good source of multipotent cells for cell therapies. PDLSCs have demonstrated properties similar to mesenchymal stem cells (MSCs), yet, unlike MSCs, their vascular potential has not been previously demonstrated. Thus, the aim of this study was to determine if PDLSCs could modulate angiogenesis. In comparison to MSCs and stem cells derived from tooth pulp tissues (SHEDs), we first determined if PDLSCs released soluble proangiogenic factors with the capacity to induce vessel formation by endothelial cells (ECs). Next, the ability of PDLSCs to modulate angiogenesis was examined through their cotransplantation with ECs in subcutaneous sites of immunocompromised mice. Finally, the stability of the PDLSC-mediated vasculature was determined through evaluation of the maturity and functionality of the vessels formed following PDLSC transplantation. It was determined that PDLSCs produced appreciable levels of vascular endothelial growth factor and basic fibroblast growth factor-2, and additionally, were able to initiate in vitro angiogenesis of ECs comparable to MSC- and SHED-mediated angiogenesis. In vivo cotransplantation of ECs with PDLSCs significantly (>50% increase) enhanced the number of blood vessels formed relative to transplantation of ECs alone. Finally, vessels formed following PDLSC cotransplantation were more mature and less permeable than those formed after transplantation of EC alone. These data demonstrate for the first time that PDLSCs have vascular potential

  10. Mechanical loading influences the effects of bisphosphonates on human periodontal ligament fibroblasts.

    PubMed

    Jacobs, Collin; Walter, Christian; Ziebart, Thomas; Dirks, Isabelle; Schramm, Sabrina; Grimm, Sarah; Krieger, Elena; Wehrbein, Heinrich

    2015-04-01

    There is increasing evidence that bisphosphonates affect orthodontic tooth movement. The object of the study was to investigate the changes produced by tensile strain on human periodontal ligament fibroblasts (HPdLFs) treated with clodronate or zoledronate. HPdLF were cultured with 5 and 50 μM clodronate or zoledronate for 48 h and applied to tensile strain (TS) (5 and 10 %) for 12 h in vitro. Viability was verified by MTT assay and apoptosis rate via caspase 3/7 assay. Gene expression of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) was investigated using real-time PCR. OPG was also analyzed by ELISA and RANKL by immunocytochemical staining. Zoledronate (50 μM) reduced the viability of HPdLF (76 vs 100 %) and combined with 5 % TS to 53 %. TS of 10 % and clodronate reduced viability to 79 % with increased caspase 3/7 activity. Clodronate (5 μM) led to a slight increase of OPG gene expression, zoledronate (5 μM) to a slight decrease. Combined with 5 % TS, both increased OPG gene expression (2-3-fold) and OPG synthesis. Zoledronate increased gene expression of RANKL (4-fold). Combined with 5 % of TS, this increase was abolished. TS of 10 % in combination amplified increase of RANKL ending up with a 9-fold gene expression by clodronate and high RANKL protein synthesis. This study shows for the first time that mechanical loading alters the effects of bisphosphonates on viability, apoptosis rate, and OPG/RANKL system of HPdLF dependent on the applied strength. Low forces and bisphosphonates increase factors for bone apposition, whereas high forces combined with bisphosphonates stimulate osteoclastogenesis. Mechanical loading of periodontal ligament with high strengths should be avoided during bisphosphonate therapy.

  11. Expression of fibronectin and integrins in cultured periodontal ligament epithelial cells.

    PubMed

    Uitto, V J; Larjava, H; Peltonen, J; Brunette, D M

    1992-05-01

    The process of attachment of epithelial cells obtained from the porcine periodontal ligament (cell rests of Malassez) to different extracellular matrix proteins and their expression of fibronectin and integrin receptors were studied by means of immunocytochemistry, in situ hybridization, and time-lapse cinemicrography techniques. The cell lines of periodontal ligament epithelial cells (PLE cells) attached to and spread rapidly on fibronectin, vitronectin, and type I collagen. One of the cell lines also attached to laminin, while the other cell line showed poor attachment to both laminin and Matrigel, a basement membrane material. By use of the in situ hybridization technique, some PLE cells were found to express the fibronectin gene strongly. Immunocytochemical staining localized fibronectin in extracellular fibrils and intracellular granules. Fibronectin was also found in the tracks left behind by the cells migrating on the substratum. Arg-gly-asp-ser peptide inhibited the attachment of the PLE cells to fibronectin, laminin, type I collagen, and vitronectin by 47%, 43%, 83%, and 94%, respectively, suggesting that the cell-matrix interactions were partly mediated by receptors related to the integrin family. Antibodies against the beta 1-integrin subunit stained the cell bodies and the plasma membrane projections of spreading cells. After 24 h or longer in culture, beta 1-integrins were localized to the regions of cell-cell contact. Cinemicrography of the arg-gly-asp-ser-peptide-treated cells demonstrated that the spreading and migration of isolated cells were prevented by the peptide. The peptide did not appear to dissociate the cell-cell contacts or interfere with migration of spread-cell colonies.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Stem cells derived from tooth periodontal ligament enhance functional angiogenesis by endothelial cells.

    PubMed

    Yeasmin, Shamima; Ceccarelli, Jacob; Vigen, Marina; Carrion, Bita; Putnam, Andrew J; Tarle, Susan A; Kaigler, Darnell

    2014-04-01

    In regenerative medicine approaches involving cell therapy, selection of the appropriate cell type is important in that the cells must directly (differentiation) or indirectly (trophic effects) participate in the regenerative response. Regardless of the mode of action of the cells, angiogenesis underlies the success of these approaches. Stem cells derived from tooth tissues, specifically the periodontal ligament of teeth (periodontal ligament stem cells [PDLSCs]), have recently been identified as a good source of multipotent cells for cell therapies. PDLSCs have demonstrated properties similar to mesenchymal stem cells (MSCs), yet, unlike MSCs, their vascular potential has not been previously demonstrated. Thus, the aim of this study was to determine if PDLSCs could modulate angiogenesis. In comparison to MSCs and stem cells derived from tooth pulp tissues (SHEDs), we first determined if PDLSCs released soluble proangiogenic factors with the capacity to induce vessel formation by endothelial cells (ECs). Next, the ability of PDLSCs to modulate angiogenesis was examined through their cotransplantation with ECs in subcutaneous sites of immunocompromised mice. Finally, the stability of the PDLSC-mediated vasculature was determined through evaluation of the maturity and functionality of the vessels formed following PDLSC transplantation. It was determined that PDLSCs produced appreciable levels of vascular endothelial growth factor and basic fibroblast growth factor-2, and additionally, were able to initiate in vitro angiogenesis of ECs comparable to MSC- and SHED-mediated angiogenesis. In vivo cotransplantation of ECs with PDLSCs significantly (>50% increase) enhanced the number of blood vessels formed relative to transplantation of ECs alone. Finally, vessels formed following PDLSC cotransplantation were more mature and less permeable than those formed after transplantation of EC alone. These data demonstrate for the first time that PDLSCs have vascular potential

  13. Cyclic stretch and compression forces alter microRNA-29 expression of human periodontal ligament cells.

    PubMed

    Chen, Yinghua; Mohammed, Arshad; Oubaidin, Maysaa; Evans, Carla A; Zhou, Xiaofeng; Luan, Xianghong; Diekwisch, Thomas G H; Atsawasuwan, Phimon

    2015-07-15

    MicroRNAs (miRs) play an important role in the development and remodeling of tissues through the regulation of large cohorts of extracellular matrix (ECM) genes. The purpose of the present study was to determine the response of miR-29 family expression to loading forces and their effects on ECM gene expression in periodontal ligament cells, the key effector cell population during orthodontic tooth movement. In a comparison between miRs from human periodontal ligament cells (PDLCs) and alveolar bone cells (ABCs) from healthy human subjects, the ABC cohort of miRs was substantially greater than the corresponding PDLC cohort. Cyclic mechanical stretch forces at 12% deformation at 0.1Hz for 24h decreased expression of miR-29 family member miRs about 0.5 fold while 2g/cm(2) compression force for 24h increased miR-29 family member expression in PDLCs 1.8-4 folds. Cyclic stretch up-regulated major ECM genes in PDLCs, such as COL1A1, COL3A1 and COL5A1, while the compression force resulted in a down-regulation of these ECM genes. Direct interactions of miR-29 and Col1a1, Col3a1 and Col5a1 were confirmed using a dual luciferase reporter gene assay. In addition, transient transfection of a miR-29b mimic in mouse PDLCs down-regulated Col1a1, Col3a1 and Col5a1 while the transfection of miR-29b inhibitor up-regulated these genes compared to control transfection indicating that these target ECM genes directly responded to the altered level of miR-29b. These results provided a possible explanation for the effects of the miR-29 family on loaded PDLCS and their roles in extracellular matrix gene expression.

  14. In Vitro Cytotoxicity Evaluation of Three Root-End Filling Materials in Human Periodontal Ligament Fibroblasts.

    PubMed

    Coaguila-Llerena, Hernán; Vaisberg, Abraham; Velásquez-Huamán, Zulema

    2016-01-01

    The aim of this study was to evaluate in vitro the cytotoxicity on human periodontal ligament fibroblasts of three root-end filling materials: MTA Angelus®, EndoSequence Root Repair Material Putty® and Super EBA®. A primary culture of human periodontal ligament fibroblasts was previously obtained in order to evaluate the cytotoxicity of the three extracts from the root-end filling materials after 2 and 7 days of setting. Serial dilutions of these extracts (1:1, 1:2, 1:4 and 1:8) were evaluated at 1, 3 and 7 days using the methyl-thiazol-tetrazolium (MTT) colorimetric assay. Cell viability was evaluated as percentage of the negative control group, which represented 100% cell viability. Statistical analyses were done with t-test, ANOVA and Kruskal-Wallis test at a significance level of 5%. It was found that the main difference among root-end filling materials was in the higher dilutions (p<0.05), but there was a similar behavior in lower dilutions (p>0.05). Cell viability of MTA Angelus® was superior for 2-day setting (p<0.05), compared with the other two root-end fillings. There were no statistically significant differences between 7-day set MTA Angelus® and EndoSequence Root Repair Material Putty®. Super EBA® showed the lowest percentage of cell viability at higher dilutions (p<0.05). Therefore, MTA Angelus® and EndoSequence Root Repair Material Putty® were less cytotoxic in the highest dilution (1:1) compared with Super EBA®.

  15. In vitro Osteogenic impulse effect of Dexamethasone on periodontal ligament stem cells.

    PubMed

    Roozegar, Mohamad Ali; Mohammadi, Tayebeh Malek; Havasian, Mohamad Reza; Panahi, Jafar; Hashemian, Amirreza; Amraei, Mansur; Hoshmand, Behzad

    2015-01-01

    Periodontium is a complex organ composed of mineralized epithelial and connective tissue. Dexamethasone could stimulate proliferation of osteoblast and fibroblasts. This study aimed to assess the osteogenic effect of dexamethasone on periodental ligament (PDL) stem cells. PDL stem cells were collected from periodontal ligament tissue of root of extracted premolar of young and healthy people. The stem cells were cultured in α-MEM Medium in three groups, one group with basic medium contains (α- MEM and FBS 10 % and 50 mmol of β_ gelisrophosphat and L_ ascorbic acid µg/ml), the second group: basic medium with dexamethasone and the third one: basic medium without any osteogenic stimulant. Mineralization of cellular layer was analyzed with Alizarin red stain method. Osteogenic analysis was done by Alkaline phosphates and calcium test. These analysis indicated that the amount of intra-cellular calcium and alkaline phosphates in the Dexamethasone group was far more than the control and basic group (P<0.05). The results of Alizarin red stain indicated more mineralization of cultured cells in Dexamethasone group (P<0.05). The study results showed that Dexamethasone has significant osteogenic effect on PDL stem cells and further studies are recommended to evaluate its effect on treatment of bone disorders.

  16. In vitro Osteogenic impulse effect of Dexamethasone on periodontal ligament stem cells

    PubMed Central

    Roozegar, Mohamad Ali; Mohammadi, Tayebeh Malek; Havasian, Mohamad Reza; Panahi, Jafar; Hashemian, Amirreza; Amraei, Mansur; Hoshmand, Behzad

    2015-01-01

    Periodontium is a complex organ composed of mineralized epithelial and connective tissue. Dexamethasone could stimulate proliferation of osteoblast and fibroblasts. This study aimed to assess the osteogenic effect of dexamethasone on periodental ligament (PDL) stem cells. PDL stem cells were collected from periodontal ligament tissue of root of extracted premolar of young and healthy people. The stem cells were cultured in α-MEM Medium in three groups, one group with basic medium contains (α- MEM and FBS 10 % and 50 mmol of β_ gelisrophosphat and L_ ascorbic acid µg/ml), the second group: basic medium with dexamethasone and the third one: basic medium without any osteogenic stimulant. Mineralization of cellular layer was analyzed with Alizarin red stain method. Osteogenic analysis was done by Alkaline phosphates and calcium test. These analysis indicated that the amount of intra-cellular calcium and alkaline phosphates in the Dexamethasone group was far more than the control and basic group (P<0.05). The results of Alizarin red stain indicated more mineralization of cultured cells in Dexamethasone group (P<0.05). The study results showed that Dexamethasone has significant osteogenic effect on PDL stem cells and further studies are recommended to evaluate its effect on treatment of bone disorders. PMID:25848170

  17. Mechanical removal of necrotic periodontal ligament by either Robinson bristle brush with pumice or scalpel blade. Histomorphometric analysis and scanning electron microscopy.

    PubMed

    Esper, Helen Ramon; Panzarini, Sônia Regina; Poi, Wilson Roberto; Sonoda, Celso Koogi; Casatti, Cláudio Aparecido

    2007-12-01

    One of the important factors accounting for successful delayed replantation of avulsed teeth is seemingly the type of root surface treatment. Removal of necrotic cemental periodontal ligament remnants may prevent the occurrence of external root resorption, which is the major cause of loss of teeth replanted in such conditions. The purpose of this study was to compare the efficacy of two mechanical techniques for removal of root-adhered periodontal ligament. Preservation or removal of the cementum layer concomitantly with these procedures was also assessed. Forty-five roots of healthy premolars extracted for orthodontic purposes were selected. After extraction, the teeth were kept dry at room temperature for 1 h and then immersed in saline for rehydration for an additional 10 min. Thereafter, the roots were assigned to three groups, as follows: group 1 (control)--the cemental periodontal ligament was preserved; group 2--removal of the periodontal ligament by scraping root surface with a scalpel blade (SBS); group 3--periodontal ligament remnants were removed using a Robinson bristle brush at low-speed with pumice/water slurry (RBP). The specimens were analysed histomorphometrically and examined by scanning electron microscopy. The quantitative and qualitative analyses of the results showed that the RBP technique was significantly more effective than the SBS technique for removal of the periodontal ligament remnants adhered to root surface. Both techniques preserved the cementum layer.

  18. Cyclic tension promotes osteogenic differentiation in human periodontal ligament stem cells.

    PubMed

    Shen, Tao; Qiu, Lin; Chang, Huijun; Yang, Yanchun; Jian, Congxiang; Xiong, Jian; Zhou, Jixiang; Dong, Shiwu

    2014-01-01

    Orthodontic forces result in alveolar bone resorption and formation predominantly on the pressure and tension sides of the tooth roots, respectively. Human periodontal ligament stem cells (PDLSCs) have demonstrated the capacity to differentiate into osteoblasts, and they play important roles in maintaining homeostasis and regenerating periodontal tissues. However, little is known about how PDLSCs contribute to osteoblastogenesis during orthodontic tooth movement on the tension side. In this study, we applied a 12% cyclic tension force to PDLSCs cultured in osteoinductive medium. The osteogenic markers Runx2, ALP, and OCN were detected at the mRNA and protein levels at different time points using real-time PCR and western blot analyses. We discovered that the mRNA and protein levels of Runx2, ALP and OCN were significantly up-regulated after 6, 12 and 24 hours of mechanical loading on PDLSCs compared to levels in unstimulated PDLSCs (P < 0.05). This study demonstrates, for the first time, the effects of mechanical tensile strain on the osteogenic differentiation of PDLSCs, as examined with a Flexcell FX-4000T Tension Plus System. Our findings suggested that cyclic tension could promote the osteogenic differentiation of PDLSCs. Furthermore, the effects of orthodontic force on alveolar bone remodeling might be achieved by PDLSCs.

  19. Bilayered construct for simultaneous regeneration of alveolar bone and periodontal ligament.

    PubMed

    Nivedhitha Sundaram, M; Sowmya, S; Deepthi, S; Bumgardener, Joel D; Jayakumar, R

    2016-05-01

    Periodontitis is an inflammatory disease that causes destruction of tooth-supporting tissues and if left untreated leads to tooth loss. Current treatments have shown limited potential for simultaneous regeneration of the tooth-supporting tissues. To recreate the complex architecture of the periodontium, we developed a bilayered construct consisting of poly(caprolactone) (PCL) multiscale electrospun membrane (to mimic and regenerate periodontal ligament, PDL) and a chitosan/2wt % CaSO4 scaffold (to mimic and regenerate alveolar bone). Scanning electron microscopy results showed the porous nature of the scaffold and formation of beadless electrospun multiscale fibers. The fiber diameter of microfiber and nanofibers was in the range of 10 ± 3 µm and 377 ± 3 nm, respectively. The bilayered construct showed better protein adsorption compared to the control. Osteoblastic differentiation of human dental follicle stem cells (hDFCs) on chitosan/2wt % CaSO4 scaffold showed maximum alkaline phosphatase at seventh day followed by a decline thereafter when compared to chitosan control scaffold. Fibroblastic differentiation of hDFCs was confirmed by the expression of PLAP-1 and COL-1 proteins which were more prominent on PCL multiscale membrane in comparison to control membranes. Overall these results show that the developed bilayered construct might serve as a good candidate for the simultaneous regeneration of the alveolar bone and PDL.

  20. Proapoptotic fibronectin fragment induces the degradation of ubiquitinated p53 via proteasomes in periodontal ligament cells

    PubMed Central

    Ghosh, Abhijit; Joo, Nam Eok; Chen, Tina Chunyuan; Kapila, Yvonne L.

    2009-01-01

    Background and Objective The extracellular matrix (ECM) plays a key role in signaling necessary for tissue remodeling and cell survival. However, signals from disease-altered ECMs, as that present in inflammatory diseases like periodontitis and arthritis, may lead to apoptosis or programmed cell death of resident cells. Previously, we found that a disease-associated fibronectin fragment triggers apoptosis of primary human periodontal ligament (PDL) cells via a novel apoptotic pathway in which the tumor suppressor, p53, is transcriptionally downregulated. Materials and Methods We used immunofluorescence, transfection assays, western blotting and ELISAs to show that p53 is degraded by a proteasomal pathway in response to a proapoptotic disease-associated fibronectin fragment. Results We now show that under these same apoptotic conditions p53 is further downregulated by post-translational ubiquitination and subsequent targeting to the proteasome for degradation. Pretreatment of cells with the proteasomal inhibitors MG132 and lactacystin rescued the cells from apoptosis. p53 levels in cells transfected with ubiquitin siRNA were resistant to degradation induced by the proapoptotic fibronectin fragment, showing that ubiquitination is important for the proapoptotic fibronectin fragment-induced degradation of p53. Conclusions These data show that a proapoptotic fibronectin matrix induces ubiquitination and degradation of p53 in the proteasome as part of a novel mechanism of apoptosis associated with inflammatory diseases. PMID:20337881

  1. Evaluation of the resolving potency of a novel reconstruction filter on periodontal ligament space with dental cone-beam CT: a quantitative phantom study

    NASA Astrophysics Data System (ADS)

    Houno, Yuuki; Hishikawa, Toshimitsu; Gotoh, Ken-ichi; Naitoh, Munetaka; Ariji, Eiichiro; Kodera, Yoshie

    2014-03-01

    Diagnosis of the alveolar bone condition is important for the treatment planning of periodontal disease. Especially the determination of periodontal ligament space is the most important remark because it represents the periodontal tissue support for tooth retention. However, owing to the image blur of the current cone-beam CT (CBCT) imaging technique, the periodontal ligament space is difficult to visualize. In this study, we developed an original periodontal ligament phantom (PLP) and evaluated the image quality of simulated periodontal ligament space using a novel reconstruction filter for CBCT that emphasized high frequency component. PLP was composed from two resin blocks of different materials, the bone equivalent block and the dentine equivalent block. They were assembled to make continuously changing space from 0.0 to 1.0 millimeter that mimics periodontal ligament space. PLP was placed in water and the image was obtained by using Alphard-3030 dental cone-beam CT (Asahi Roentgen Industry Co., Ltd.). Then we reconstructed the projection data with a novel reconstruction filter. The axial images were compared with conventional reconstructed images. In novel filter reconstruction images, 0.4 millimeter of the space width was steadily detected by calculation of pixel value, on the other hand 0.6 millimeter was in conventional images. With our method, the resolving potency of conebeam CT images was improved.

  2. Development of a novel intraoral measurement device to determine the biomechanical characteristics of the human periodontal ligament.

    PubMed

    Drolshagen, M; Keilig, L; Hasan, I; Reimann, S; Deschner, J; Brinkmann, K T; Krause, R; Favino, M; Bourauel, C

    2011-07-28

    Periodontal diseases like gingivitis and periodontitis have damaging effects on the periodontium and commonly affect the mechanical properties of the periodontal ligament (PDL), which in the end might lead to loss of teeth. Monitoring tooth mobility and changes of the material properties of the PDL might help in early diagnosis of periodontal diseases and improve their prognosis. It was the aim of this study to develop a novel intraoral device to determine the biomechanical characteristics of the periodontal ligament. This includes the measurement of applied forces and resulting tooth displacement in order to investigate the biomechanical behaviour of the periodontium with varying loading protocols with respect to velocity and tooth displacement. The developed device uses a piezoelectric actuator to apply a displacement to a tooth's crown, and the resulting force is measured by an integrated force sensor. To measure the tooth displacement independently and non-invasively, two magnets are fixed on the teeth. The change in the magnetic field caused by the movement of the magnets is measured by a total of 16 Hall sensors. The displacement of the tooth is calculated from the movement of the magnets. The device was tested in vitro on premolars of four porcine mandibular segments and in vivo on two volunteers. The teeth were loaded with varying activation curves. Comparing the force progression of different activation velocities, the forces decreased with decreasing velocity. Intensive testing demonstrated that the device fulfils all requirements. After acceptance of the ethical committee, further testing in clinical measurements is planned.

  3. Extracellular matrix derived from periodontal ligament cells maintains their stemness and enhances redifferentiation via the Wnt pathway.

    PubMed

    Zhang, Ji-Chun; Song, Zhong-Chen; Xia, Yi-Ru; Shu, Rong

    2017-09-07

    Large numbers of viable cells cannot be obtained from periodontal ligament tissues of patients with periodontitis. Therefore, it is imperative to establish an ex vivo environment that can support cell proliferation and delay senescence. Here, we have successfully reconstructed a native extracellular matrix (ECM), derived from early-passage human periodontal ligament cells (PDLCs) using the NH4 OH/Triton X-100 protocol. The ECM was investigated by scanning electron microscopy and immunostaining for specific ECM proteins (collagen I and fibronectin). Late-passage ECM-expanded PDLCs exhibited a much higher proliferation index and lower levels of reactive oxygen species (ROS), confirmed by the increased expression of pluripotent markers. and enhanced osteogenic capacity. Interestingly, the Wnt pathway was suppressed during the ECM expansion-mediated increase in pluripotency, but was activated in an osteogenic differentiation environment, as confirmed by treatment with the XAV-939 β-catenin inhibitor or the SP600125 c-Jun N-terminal kinase (JNK) inhibitor. Cell sheets formed by ECM-expanded PDLCs exhibited an enhanced periodontal tissue regeneration capacity compared to those formed on tissue culture polystyrene (TCP) surfaces in vivo. Taken together, the cell-free ECM provides a tissue-specific cell niche for the ex vivo expansion of PDLCs while retaining stemness and osteogenic potential, partially via the Wnt pathway. This represents a promising matrix for future applications in periodontal tissue regeneration therapy. This article is protected by copyright. All rights reserved. © 2017 Wiley Periodicals, Inc.

  4. Effect of intermittent PTH(1-34) on human periodontal ligament cells transplanted into immunocompromised mice.

    PubMed

    Wolf, Michael; Lossdörfer, Stefan; Abuduwali, Nuersailike; Meyer, Rainer; Kebir, Sied; Götz, Werner; Jäger, Andreas

    2012-09-01

    Residual periodontal ligament (PDL) cells in the damaged tissue are considered a prerequisite for a successful regeneration of the periodontal architecture with all its components, including gingiva, PDL, cementum, and bone. Among other approaches, current concepts in tissue engineering aim at a hormonal support of the regenerative capacity of PDL cells as well as at a supplementation of lost cells for regeneration. Here, we investigated how far an anabolic, intermittent parathyroid hormone (iPTH) administration would enhance the osteoblastic differentiation of PDL cells and the cellular ability to mineralize the extracellular matrix in an in vivo transplantation model. PDL cells were predifferentiated in a standard osteogenic medium for 3 weeks before subcutaneous transplantation into CD-1 nude mice using gelatin sponges as carrier. Daily injections of 40 μg/kg body weight PTH(1-34) or an equivalent dose of vehicle for 4 weeks were followed by explantation of the specimens and an immunohistochemical analysis of the osteoblastic marker proteins alkaline phosphatase (ALP), osteopontin, and osteocalcin. Signs of biomineralization were visualized by means of alizarin red staining. For verification of the systemic effect of iPTH application, blood serum levels of osteocalcin were determined. The osteogenic medium stimulated the expression of ALP and PTH1-receptor mRNA in the cultures. After transplantation, iPTH resulted in an increased cytoplasmic and extracellular immunoreactivity for all markers investigated. In contrast to only sporadic areas of mineralization under control conditions, several foci of mineralization were observed in the iPTH group. Blood serum levels of osteocalcin were elevated significantly with iPTH. These data indicate that the osteoblastic differentiation of human PDL cells and their ability for biomineralization can be positively influenced by iPTH in vivo. These findings hold out a promising prospect for the support of periodontal

  5. Effect of Intermittent PTH(1–34) on Human Periodontal Ligament Cells Transplanted into Immunocompromised Mice

    PubMed Central

    Wolf, Michael; Abuduwali, Nuersailike; Meyer, Rainer; Kebir, Sied; Götz, Werner; Jäger, Andreas

    2012-01-01

    Residual periodontal ligament (PDL) cells in the damaged tissue are considered a prerequisite for a successful regeneration of the periodontal architecture with all its components, including gingiva, PDL, cementum, and bone. Among other approaches, current concepts in tissue engineering aim at a hormonal support of the regenerative capacity of PDL cells as well as at a supplementation of lost cells for regeneration. Here, we investigated how far an anabolic, intermittent parathyroid hormone (iPTH) administration would enhance the osteoblastic differentiation of PDL cells and the cellular ability to mineralize the extracellular matrix in an in vivo transplantation model. PDL cells were predifferentiated in a standard osteogenic medium for 3 weeks before subcutaneous transplantation into CD-1 nude mice using gelatin sponges as carrier. Daily injections of 40 μg/kg body weight PTH(1–34) or an equivalent dose of vehicle for 4 weeks were followed by explantation of the specimens and an immunohistochemical analysis of the osteoblastic marker proteins alkaline phosphatase (ALP), osteopontin, and osteocalcin. Signs of biomineralization were visualized by means of alizarin red staining. For verification of the systemic effect of iPTH application, blood serum levels of osteocalcin were determined. The osteogenic medium stimulated the expression of ALP and PTH1-receptor mRNA in the cultures. After transplantation, iPTH resulted in an increased cytoplasmic and extracellular immunoreactivity for all markers investigated. In contrast to only sporadic areas of mineralization under control conditions, several foci of mineralization were observed in the iPTH group. Blood serum levels of osteocalcin were elevated significantly with iPTH. These data indicate that the osteoblastic differentiation of human PDL cells and their ability for biomineralization can be positively influenced by iPTH in vivo. These findings hold out a promising prospect for the support of periodontal

  6. Enhanced bone-forming activity of side population cells in the periodontal ligament.

    PubMed

    Ninomiya, Tadashi; Hiraga, Toru; Hosoya, Akihiro; Ohnuma, Kiyoshi; Ito, Yuzuru; Takahashi, Masafumi; Ito, Susumu; Asashima, Makoto; Nakamura, Hiroaki

    2014-04-01

    Regeneration of alveolar bone is critical for the successful treatment of periodontal diseases. The periodontal ligament (PDL) has been widely investigated as a source of cells for the regeneration of periodontal tissues. In the present study where we attempted to develop an effective strategy for alveolar bone regeneration, we examined the osteogenic potential of side population (SP) cells, a stem cell-containing population that has been shown to be highly abundant in several kinds of tissues, in PDL cells. Isolated SP cells from the rat PDL exhibited a superior ability to differentiate into osteoblastic cells compared with non-SP (NSP) and unsorted PDL cells in vitro. The mRNA expressions of osteoblast markers and bone morphogenetic protein (BMP) 2 were significantly upregulated in SP cells and were further increased by osteogenic induction. To examine the bone-forming activity of SP cells in vivo, PDL SP cells isolated from green fluorescent protein (GFP)-transgenic rats were transplanted with hydroxyapatite (HA) disks into wild-type animals. SP cells exhibited a high ability to induce the mineralized matrix compared with NSP and unsorted PDL cells. At 12 weeks after the implantation, some of the pores in the HA disks with SP cells were filled with mineralized matrices, which were positive for bone matrix proteins, such as osteopontin, bone sialoprotein, and osteocalcin. Furthermore, osteoblast- and osteocyte-like cells on and in the bone-like mineralized matrices were GFP positive, suggesting that the matrices were directly formed by the transplanted cells. These results suggest that PDL SP cells possess enhanced osteogenic potential and could be a potential source for cell-based regenerative therapy for alveolar bone.

  7. The biomechanical characteristics of the bone-periodontal ligament-cementum complex

    PubMed Central

    Ho, Sunita P.; Kurylo, Michael P.; Fong, Tiffany; Lee, Stephen; Wagner, Hanoch D.; Ryder, Mark; Marshall, G. W.

    2010-01-01

    The relative motion between the tooth and alveolar bone is facilitated by the soft-hard tissue interfaces which include periodontal ligament-bone (PDL-bone) and periodontal ligament-cementum (PDL-cementum). The soft-hard tissue interfaces are responsible for attachment and are critical to the overall biomechanical efficiency of the bone-tooth complex. In this study, the PDL-bone and PDL-cementum attachment sites in human molars were investigated to identify the structural orientation and integration of the PDL with bone and cementum. These attachment sites were characterized from a combined materials and mechanics perspective and were related to macro-scale function. High resolution complimentary imaging techniques including atomic force microscopy, scanning electron microscopy and micro-scale X-ray computed tomography (Micro XCT™) illustrated two distinct orientations of PDL; circumferential-PDL (cir-PDL) and radial-PDL (rad-PDL). Within the PDL-space, the primary orientation of the ligament was radial (rad-PDL) as is well known. Interestingly, circumferential orientation of PDL continuous with rad-PDL was observed adjacent to alveolar bone and cementum. The integration of the cir-PDL was identified by 1 to 2 μm diameter PDL-inserts or Sharpey’s fibers in alveolar bone and cementum. Chemically and biochemically the cir-PDL adjacent to bone and cementum was identified by relatively higher carbon and lower calcium including the localization of small leucine rich proteins responsible for maintaining soft-hard tissue cohesion, stiffness and hygroscopic nature of PDL-bone and PDL-cementum attachment sites. The combined structural and chemical properties provided graded stiffness characteristics of PDL-bone (Er range for PDL: 10 – 50 MPa; bone: 0.2 – 9.6 GPa) and PDL-cementum (Er range for cementum: 1.1 – 8.3 GPa), which was related to the macro-scale function of the bone-tooth complex. PMID:20541802

  8. The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering

    PubMed Central

    Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

    2016-01-01

    Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

  9. Development of the oxytalan fiber system in the rat molar periodontal ligament evaluated by light- and electron-microscopic analyses.

    PubMed

    Inoue, Kouji; Hara, Yaiko; Sato, Tetsuji

    2012-09-01

    In the elastic fiber system of the periodontal ligaments only oxytalan fibers can be identified, whereas all three types of fibers, oxytalan, elaunin and elastic fibers, are present in the gingiva. However, little information is available concerning their organization in the developing periodontal ligament. In the present study, growth and distribution of the oxytalan fiber system were examined in the developing periodontal ligament of rat molars using the specific staining for oxytalan, elastic and collagen fibers, and electron-microscopic analyses. Oxytalan staining clearly confirmed the earliest oxytalan fibers in a bell-staged tooth germ at embryonic day 18, which were tiny violet-colored fibers in the dental follicle. Their cross images were made up of dot-like microfibrils of 10-15nm in diameter close to fibroblasts in the dental follicle of the rat molars aged 1 day. These microfibrils appeared to be linked to one another through delicate filaments in 3-nm-diameter. At the beginning of root formation, the cross figures of oxytalan fibers were found as dot-like structures around the root sheath as well as in areas very close to blood vessels. As development proceeded, longer oxytalan fibers were produced in the apico-occlusal direction along with blood vessels. In addition, the immunoreactive products to anti-amyloid β protein on the surface of blood vessels suggest that this molecule might be involved in the adhesion of oxytalan fibers to vascular basement membranes. Thus, the oxytalan fiber system might regulate periodontal ligament function through tensional variations registered on the walls of the vascular structures.

  10. An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: I. Normal fibroblasts

    SciTech Connect

    Cho, M.I.; Garant, P.R.

    1981-12-01

    Analysis of electron microscopic radioautographs revealed a maximum labeling with /sup 3/H-proline of rough endoplasmic reticulum (RER) at 3 minutes, Golgi saccules 1 and 2 at 10 minutes, Golgi saccules type 3 at 20 minutes, and presecretory and secretory granules at 30 minutes. Labeling of the extra-cellular collagen matrix occurred at 30 minutes and increased with time. These observations suggest that pro-a-chains of collagen in periodontal ligament fibroblasts are synthesized in the RER and transported to the Golgi apparatus within 10 minutes. These chains then undergo parallel alignment in Golgi saccules type 2 and form segment-long-spacing-like crystallites in Golgi saccules type 3 between 10 and 20 minutes. The peak labeling of presecretory granules and mature secretory granules in small amounts at 30 minutes and the rapid increase in labeling of extracellular collagen matrix which begins at 30 minutes, indicates that the formation of secretory granules requires approximately 30 minutes and that a rapid system of secretory granule translocation exists in periodontal ligament fibroblasts. This evidence further supports the previously published morphologic evidence for a microtubule-dependent system of collagen secretion in periodontal ligament fibroblasts (Cho and Garant, 1981b).

  11. In vitro cytotoxicity of white MTA, MTA Fillapex® and Portland cement on human periodontal ligament fibroblasts.

    PubMed

    Yoshino, Patrícia; Nishiyama, Celso Kenji; Modena, Karin Cristina da Silva; Santos, Carlos Ferreira; Sipert, Carla Renata

    2013-01-01

    The aim of this study was to compare the in vitro cytotoxicity of white mineral trioxide aggregate (MTA), MTA Fillapex® and Portland cement (PC) on human cultured periodontal ligament fibroblasts. Periodontal ligament fibroblast culture was established and the cells were used for cytotoxic tests after the fourth passage. Cell density was set at 1.25 X10 4 cells/well in 96-well plates. Endodontic material extracts were prepared by placing sealer/cement specimens (5x3mm) in 1mL of culture medium for 72 h. The extracts were then serially two-fold diluted and inserted into the cell-seeded wells for 24, 48 and 72 h. MTT assay was employed for analysis of cell viability. Cell supernatants were tested for nitric oxide using the Griess reagent system. MTA presented cytotoxic effect in undiluted extracts at 24 and 72 h. MTA Fillapex® presented the highest cytotoxic levels with important cell viability reduction for pure extracts and at ½ and ¼ dilutions. In this study, PC did not induce alterations in fibroblast viability. Nitric oxide was detected in extract-treated cell supernatants and also in the extracts only, suggesting presence of nitrite in the soluble content of the tested materials. In the present study, MTA Fillapex displayed the highest cytotoxic effect on periodontal ligament fibroblasts followed by white MTA and PC.

  12. HtrA1 may regulate the osteogenic differentiation of human periodontal ligament cells by TGF-β1.

    PubMed

    Li, Ran; Zhang, Qi

    2015-04-01

    Periodontal ligament cells (PDLCs) in periodontal ligament (PDL) can differentiate into osteoblasts, while physiologically PDL remains non-mineralized space although located two hard tissues. But the exact mechanism of which is still unclear. High-temperature requirement protein A1 (HtrA1) is a key mineralization regulator and could inhibit the osteogenesis by transforming growth factor-β (TGF-β) signaling. However, the role of HtrA1 in PDLCs osteogenic differentiation has yet to be clarified. We assume HtrA1 may play an important role in maintaining the balance of PDL mineralization, and may regulate human periodontal ligament cells (hPDLCs) osteogenic differentiation by TGF-β1. Firstly we confirmed the mRNA expression of HtrA1 and TGF-β1 in hPDLCs by RT-PCR, then QDs-based immunofluorescence demonstrated the co-localization of them in the cytoplasm, and co-immunoprecipitation further confirmed the interaction between them. Lentivirus-mediated HtrA1 overexpression enhanced the osteogenic differentiation of hPDLCs, as well as up-regulation of TGF-β1. In contrast, knockdown of HtrA1 suppressed the osteogenic differentiation with down-regulation of TGF-β1. These findings suggested that HtrA1 plays a positive role in hPDLCs osteogenic differentiation and may regulate this process by TGF-β1.

  13. A biphasic scaffold design combined with cell sheet technology for simultaneous regeneration of alveolar bone/periodontal ligament complex.

    PubMed

    Vaquette, Cédryck; Fan, Wei; Xiao, Yin; Hamlet, Stephen; Hutmacher, Dietmar W; Ivanovski, Saso

    2012-08-01

    This study describes the design of a biphasic scaffold composed of a Fused Deposition Modeling scaffold (bone compartment) and an electrospun membrane (periodontal compartment) for periodontal regeneration. In order to achieve simultaneous alveolar bone and periodontal ligament regeneration a cell-based strategy was carried out by combining osteoblast culture in the bone compartment and placement of multiple periodontal ligament (PDL) cell sheets on the electrospun membrane. In vitro data showed that the osteoblasts formed mineralized matrix in the bone compartment after 21 days in culture and that the PDL cell sheet harvesting did not induce significant cell death. The cell-seeded biphasic scaffolds were placed onto a dentin block and implanted for 8 weeks in an athymic rat subcutaneous model. The scaffolds were analyzed by μCT, immunohistochemistry and histology. In the bone compartment, a more intense ALP staining was obtained following seeding with osteoblasts, confirming the μCT results which showed higher mineralization density for these scaffolds. A thin mineralized cementum-like tissue was deposited on the dentin surface for the scaffolds incorporating the multiple PDL cell sheets, as observed by H&E and Azan staining. These scaffolds also demonstrated better attachment onto the dentin surface compared to no attachment when no cell sheets were used. In addition, immunohistochemistry revealed the presence of CEMP1 protein at the interface with the dentine. These results demonstrated that the combination of multiple PDL cell sheets and a biphasic scaffold allows the simultaneous delivery of the cells necessary for in vivo regeneration of alveolar bone, periodontal ligament and cementum.

  14. α11β1 Integrin-Dependent Regulation of Periodontal Ligament Function in the Erupting Mouse Incisor

    PubMed Central

    Popova, Svetlana N.; Barczyk, Malgorzata; Tiger, Carl-Fredrik; Beertsen, Wouter; Zigrino, Paola; Aszodi, Attila; Miosge, Nicolai; Forsberg, Erik; Gullberg, Donald

    2007-01-01

    The fibroblast integrin α11β1 is a key receptor for fibrillar collagens. To study the potential function of α11 in vivo, we generated a null allele of the α11 gene. Integrin α11−/− mice are viable and fertile but display dwarfism with increased mortality, most probably due to severely defective incisors. Mutant incisors are characterized by disorganized periodontal ligaments, whereas molar ligaments appear normal. The primary defect in the incisor ligament leads to halted tooth eruption. α11β1-defective embryonic fibroblasts displayed severe defects in vitro, characterized by (i) greatly reduced cell adhesion and spreading on collagen I, (ii) reduced ability to retract collagen lattices, and (iii) reduced cell proliferation. Analysis of matrix metalloproteinase in vitro and in vivo revealed disturbed MMP13 and MMP14 synthesis in α11−/− cells. We show that α11β1 is the major receptor for collagen I on mouse embryonic fibroblasts and suggest that α11β1 integrin is specifically required on periodontal ligament fibroblasts for cell migration and collagen reorganization to help generate the forces needed for axial tooth movement. Our data show a unique role for α11β1 integrin during tooth eruption. PMID:17420280

  15. Trophic factors from adipose tissue-derived multi-lineage progenitor cells promote cytodifferentiation of periodontal ligament cells

    SciTech Connect

    Sawada, Keigo; Takedachi, Masahide; Yamamoto, Satomi; Morimoto, Chiaki; Ozasa, Masao; Iwayama, Tomoaki; Lee, Chun Man; Okura, Hanayuki; Matsuyama, Akifumi; Kitamura, Masahiro; Murakami, Shinya

    2015-08-14

    Stem and progenitor cells are currently being investigated for their applicability in cell-based therapy for periodontal tissue regeneration. We recently demonstrated that the transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) enhances periodontal tissue regeneration in beagle dogs. However, the molecular mechanisms by which transplanted ADMPCs induce periodontal tissue regeneration remain to be elucidated. In this study, trophic factors released by ADMPCs were examined for their paracrine effects on human periodontal ligament cell (HPDL) function. ADMPC conditioned medium (ADMPC-CM) up-regulated osteoblastic gene expression, alkaline phosphatase activity and calcified nodule formation in HPDLs, but did not significantly affect their proliferative response. ADMPCs secreted a number of growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), hepatocyte growth factor and vascular endothelial growth factor. Among these, IGFBP6 was most highly expressed. Interestingly, the positive effects of ADMPC-CM on HPDL differentiation were significantly suppressed by transfecting ADMPCs with IGFBP6 siRNA. Our results suggest that ADMPCs transplanted into a defect in periodontal tissue release trophic factors that can stimulate the differentiation of HPDLs to mineralized tissue-forming cells, such as osteoblasts and cementoblasts. IGFBP6 may play crucial roles in ADMPC-induced periodontal regeneration. - Highlights: • ADMPC-derived humoral factors stimulate cytodifferentiation of HPDLs. • ADMPCs secret growth factors including IGFBP6, VEGF and HGF. • IGFBP6 is involved in the promotion effect of ADMPC-CM on HPDL cytodifferentiation.

  16. Trophic factors from adipose tissue-derived multi-lineage progenitor cells promote cytodifferentiation of periodontal ligament cells.

    PubMed

    Sawada, Keigo; Takedachi, Masahide; Yamamoto, Satomi; Morimoto, Chiaki; Ozasa, Masao; Iwayama, Tomoaki; Lee, Chun Man; Okura, Hanayuki; Matsuyama, Akifumi; Kitamura, Masahiro; Murakami, Shinya

    2015-08-14

    Stem and progenitor cells are currently being investigated for their applicability in cell-based therapy for periodontal tissue regeneration. We recently demonstrated that the transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) enhances periodontal tissue regeneration in beagle dogs. However, the molecular mechanisms by which transplanted ADMPCs induce periodontal tissue regeneration remain to be elucidated. In this study, trophic factors released by ADMPCs were examined for their paracrine effects on human periodontal ligament cell (HPDL) function. ADMPC conditioned medium (ADMPC-CM) up-regulated osteoblastic gene expression, alkaline phosphatase activity and calcified nodule formation in HPDLs, but did not significantly affect their proliferative response. ADMPCs secreted a number of growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), hepatocyte growth factor and vascular endothelial growth factor. Among these, IGFBP6 was most highly expressed. Interestingly, the positive effects of ADMPC-CM on HPDL differentiation were significantly suppressed by transfecting ADMPCs with IGFBP6 siRNA. Our results suggest that ADMPCs transplanted into a defect in periodontal tissue release trophic factors that can stimulate the differentiation of HPDLs to mineralized tissue-forming cells, such as osteoblasts and cementoblasts. IGFBP6 may play crucial roles in ADMPC-induced periodontal regeneration.

  17. Combination of platelet-rich plasma within periodontal ligament stem cell sheets enhances cell differentiation and matrix production.

    PubMed

    Xu, Qiu; Li, Bei; Yuan, Lin; Dong, Zhiwei; Zhang, Hao; Wang, Han; Sun, Jin; Ge, Song; Jin, Yan

    2017-03-01

    The longstanding goal of periodontal therapy is to regenerate periodontal tissues. Although platelet-rich plasma (PRP) has been gaining increasing popularity for use in the orofacial region, whether PRP is useful for periodontal regeneration is still unknown. The purpose of this study was to determine whether a mixture of periodontal ligament stem cell (PDLSC) sheets and PRP promoted bone regeneration, one of the most important measurement indices of periodontal tissue regenerative capability in vitro and in vivo. In this study, we evaluated the effects of different doses of PRP on the differentiation of human PDLSCs. Then cell sheet formation, extracellular matrix deposition and osteogenic gene expression in response to different doses of PRP treatment during sheet grafting was investigated. Furthermore, we implanted PDLSC sheets treated with 1% PRP subcutaneously into immunocompromised mice to evaluate their bone-regenerative capability. The results revealed that 1% PRP significantly enhanced the osteogenic differentiation of PDLSCs. Based on the production of extracellular matrix proteins, the results of scanning electron microscopy and the expression of the osteogenic genes ALP, Runx2, Col-1 and OCN, the provision of 1% PRP for PDLSC sheets was the most effective PRP administration mode for cell sheet formation. The results of in vivo transplantation showed that 1% PRP-mediated PDLSC sheets exhibited better periodontal tissue regenerative capability than those obtained without PRP intervention. These data suggest that a suitable concentration of PRP stimulation may enhance extracellular matrix production and positively affect cell behaviour in PDLSC sheets. Copyright © 2014 John Wiley & Sons, Ltd.

  18. The impact of Wnt signalling and hypoxia on osteogenic and cementogenic differentiation in human periodontal ligament cells

    PubMed Central

    Li, Shuigen; Shao, Jin; Zhou, Yinghong; Friis, Thor; Yao, Jiangwu; Shi, Bin; Xiao, Yin

    2016-01-01

    Cementum is a periodontal support tissue that is directly connected to the periodontal ligament. It shares common traits with bone tissues, however, unlike bone, the cementum has a limited capacity for regeneration. As a result, following damage the cementum rarely, if ever, regenerates. Periodontal ligament cells (PDLCs) are able to differentiate into osteoblastic and cementogenic lineages according to specific local environmental conditions, including hypoxia, which is induced by inflammation or activation of the Wnt signalling pathway by local loading. The interactions between the Wnt signalling pathway and hypoxia during cementogenesis are of particular interest to improve the understanding of periodontal tissue regeneration. In the present study, osteogenic and cementogenic differentiation of PDLCs was investigated under hypoxic conditions in the presence and absence of Wnt pathway activation. Protein and gene expression of the osteogenic markers type 1 collagen (COL1) and runt-related transcription factor 2 (RUNX2), and cementum protein 1 (CEMP1) were used as markers for osteogenic and cementogenic differentiation, respectively. Wnt signalling activation inhibited cementogenesis, whereas hypoxia alone did not affect PDLC differentiation. However, hypoxia reversed the inhibition of cementogenesis that resulted from overexpression of Wnt signalling. Cross-talk between hypoxia and Wnt signalling pathways was, therefore, demonstrated to be involved in the differentiation of PDLCs to the osteogenic and cementogenic lineages. In summary, the present study suggests that the differentiation of PDLCs into osteogenic and cementogenic lineages is partially regulated by the Wnt signalling pathway and that hypoxia is also involved in this process. PMID:27840938

  19. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    NASA Astrophysics Data System (ADS)

    Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

    2012-12-01

    A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface with HPDLCs. The Col-immobilized titanium surface could be used for forming ligament-like tissues around titanium dental implants.

  20. In vitro clonogenic capacity of periodontal ligament fibroblasts cultured with Emdogain.

    PubMed

    Ashkenazi, Malka; Shaked, Ilanit

    2006-02-01

    The aim of the present study was to evaluate the efficiency of Emdogain (EMD) in preserving the size of the periodontal ligament progenitor pool (clonogenic capacity) and in promoting their proliferation. Periodontal ligament fibroblasts (PDLF) were obtained from explants of young permanent healthy tooth. After initial outgrowth (10 days to 2 weeks following explantation), the culture medium of experimental flasks was replaced with medium supplemented with 100 microg ml(-1) EMD, whereas the other served as controls and were fed with regular medium. Following 5 weeks, the cells were washed (3x), harvested (trypsin + EDTA), and evaluated for their viability. Viable cells from each group were inoculated into six 96-well plates at a concentration of one viable cell per two wells and were allowed to grow for 5 weeks. The percentage of cells with clonogenic capacity was determined as the number of colonies formed/number of cells seeded x 100 in the experimental and control groups. Three degrees of dish area coverage were utilized: up to 25%, between 25% and 75% and higher than 75%. This experiment was repeated four times from four different donors. A total of 2328 cells were evaluated, half of which, were cultured with EMD. The mean percentage of cells (from all donors) who exhibited any clonogenic capacity in the presence of EMD was comparable with that of cells cultured in the absence of EMD: 26.6 +/- 14.3% when compared with 34.6 +/- 20.6% respectively (P = 0.186). Similarly, the percentage of clones that proliferated to cover up to 25% of the well area was comparable in the two groups 7.5 +/- 8.6 for EMD-treated clones and 7.1 +/- 7.8 for untreated clones (P = 0.674). The percentage of clones that proliferated to cover 25% up to 75% of the well area was greater EMD-treated clones as compared with the untreated cells: 8.1 +/- 6.7% vs 3.8 +/- 3%. However this difference was not statistically significant (P = 0.277). In contrast, the percentage of clones that covered

  1. Validation of human periodontal ligament-derived cells as a reliable source for cytotherapeutic use.

    PubMed

    Iwata, Takanori; Yamato, Masayuki; Zhang, Zheng; Mukobata, Shigeki; Washio, Kaoru; Ando, Tomohiro; Feijen, Jan; Okano, Teruo; Ishikawa, Isao

    2010-12-01

    Periodontal ligament (PDL) is a reliable cell source for periodontal regeneration. In this study, an optimal protocol for the extraction, expansion, and characterization of human PDL (hPDL) cells was examined for clinical trials. hPDL tissues were obtained from 41 surgically extracted teeth and digested with enzymes. Human adipose-derived stem cells (hADSCs), bone marrow-derived mesenchymal stem cells (hBMMSCs), and gingival fibroblasts (hGFs) were used for comparison. For each sample, the proliferative capacity, colony-forming ability, alkaline phosphatase activity, differentiation ability, the cell surface antigens, gene expression, and regenerative potential were examined. hPDL cells were more successfully extracted with collagenase/dispase [29/30 (96.7%)] than with trypsin/EDTA [8/11 (72.7%)], and exhibited osteogenic potential both in vitro and in vivo. The proliferation of hPDL cells was rapid at a low cell density. hPDL cells frequently differentiated into cementoblastic/osteoblastic lineage (∼60%). In contrast, their adipogenic and chondrogenic potentials were lower than those of hADSCs and hBMMSCs. Some genes (NCAM1, S100A4, and periostin) were preferentially expressed in hPDL cells compared with those of hBMMSCs and hGFs. Immunohistochemical studies revealed the expressions of S100A4 and periostin in hPDL tissue. A protocol for the successful cultivation and validation of hPDL cells is proposed for clinical settings. © 2010 John Wiley & Sons A/S.

  2. Soluble CD14 Enhances the Response of Periodontal Ligament Stem Cells to P. gingivalis Lipopolysaccharide

    PubMed Central

    Andrukhov, Oleh; Andrukhova, Olena; Özdemir, Burcu; Haririan, Hady; Müller-Kern, Michael; Moritz, Andreas; Rausch-Fan, Xiaohui

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) are lacking membrane CD14, which is an important component of lipopolysaccharide (LPS) signaling through toll-like receptor (TLR) 4. In the present study we investigated the effect of soluble CD14 on the response of human PDLSCs to LPS of Porphyromonas (P.) gingivalis. Human PDLSCs (hPDLSCs) were stimulated with P. gingivalis LPS in the presence or in the absence of soluble CD14 (sCD14) and the production of interleukin (IL)-6, chemokine C-X-C motif ligand 8 (CXCL8), and chemokine C-C motif ligand 2 (CCL2) was measured. The response to P. gingivalis LPS was compared with that to TLR4 agonist Escherichia coli LPS and TLR2-agonist Pam3CSK4. The response of hPDLSCs to both P. gingivalis LPS and E. coli LPS was significantly enhanced by sCD14. In the absence of sCD14, no significant difference in the hPDLSCs response to two kinds of LPS was observed. These responses were significantly lower compared to that to Pam3CSK4. In the presence of sCD14, the response of hPdLSCs to P. gingivalis LPS was markedly higher than that to E. coli LPS and comparable with that to Pam3CSK4. The response of hPdLSCs to bacterial LPS is strongly augmented by sCD14. Local levels of sCD14 could be an important factor for modulation of the host response against periodontal pathogens. PMID:27504628

  3. Exposure of periodontal ligament progenitor cells to lipopolysaccharide from Escherichia coli changes osteoblast differentiation pattern

    PubMed Central

    ALBIERO, Mayra Laino; AMORIM, Bruna Rabelo; MARTINS, Luciane; CASATI, Márcio Zaffalon; SALLUM, Enilson Antonio; NOCITI, Francisco Humberto; SILVÉRIO, Karina Gonzales

    2015-01-01

    Periodontal ligament mesenchymal stem cells (PDLMSCs) are an important alternative source of adult stem cells and may be applied for periodontal tissue regeneration, neuroregenerative medicine, and heart valve tissue engineering. However, little is known about the impact of bacterial toxins on the biological properties of PDLSMSCs, including self-renewal, differentiation, and synthesis of extracellular matrix. Objective : This study investigated whether proliferation, expression of pro-inflammatory cytokines, and osteogenic differentiation of CD105-enriched PDL progenitor cell populations (PDL-CD105+ cells) would be affected by exposure to bacterial lipopolysaccharide from Escherichia coli (EcLPS). Material and Methods : Toll-like receptor 4 (TLR4) expression was assessed in PDL-CD105+ cells by the immunostaining technique and confirmed using Western blotting assay. Afterwards, these cells were exposed to EcLPS, and the following assays were carried out: (i) cell viability using MTS; (ii) expression of the interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) genes; (iii) osteoblast differentiation assessed by mineralization in vitro, and by mRNA levels of run-related transcription factor-2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN) determined by quantitative PCR. Results : PDL-CD105+ cells were identified as positive for TLR4. EcLPS did not affect cell viability, but induced a significant increase of transcripts for IL-6 and IL-8. Under osteogenic condition, PDL-CD105+ cells exposed to EcLPS presented an increase of mineralized matrix deposition and higher RUNX2 and ALP mRNA levels when compared to the control group. Conclusions : These results provide evidence that CD105-enriched PDL progenitor cells are able to adapt to continuous Escherichia coli endotoxin challenge, leading to an upregulation of osteogenic activities. PMID:26018305

  4. Expression of osteoblastic phenotype in periodontal ligament fibroblasts cultured in three-dimensional collagen gel

    PubMed Central

    ALVES, Luciana Bastos; MARIGUELA, Viviane Casagrande; GRISI, Márcio Fernando de Moraes; de SOUZA, Sérgio Luiz Scaombatti; NOVAES, Arthur Belém; TABA, Mário; de OLIVEIRA, Paulo Tambasco; PALIOTO, Daniela Bazan

    2015-01-01

    Objective : To investigate the influence of a three-dimensional cell culture model on the expression of osteoblastic phenotype in human periodontal ligament fibroblast (hPDLF) cultures. Material and Methods : hPDLF were seeded on bi-dimensional (2D) and three-dimensional (3D) collagen type I (experimental groups) and and on a plastic coverslip (control) for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity were performed. Also, cell morphology and immunolabeling for alkaline phosphatase (ALP) and osteopontin (OPN) were assessed by epifluorescence and confocal microscopy. The expression of osteogenic markers, including alkaline phosphatase, osteopontin, osteocalcin (OC), collagen I (COL I) and runt-related transcription factor 2 (RUNX2), were analyzed using real-time polymerase chain reaction (RT-PCR). Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Results : Experimental cultures produced an increase in cell proliferation. Immunolabeling for OPN and ALP in hPDLF were increased and ALP activity was inhibited by three-dimensional conditions. OPN and RUNX2 gene expression was significantly higher on 3D culture when compared with control surface. Moreover, ALP and COL I gene expression were significantly higher in three-dimensional collagen than in 2D cultures at 7 days. However, at 14 days, 3D cultures exhibited ALP and COL I gene expression significantly lower than the control, and the COL I gene expression was also significantly lower in 3D than in 2D cultures. Significant calcium mineralization was detected and quantified by alizarin red assay, and calcified nodule formation was not affected by tridimensionality. Conclusion : This study suggests that the 3D cultures are able to support hPDLF proliferation and favor the differentiation and mineralized matrix formation, which may be a potential periodontal regenerative therapy. PMID:26018313

  5. [Oxidative stress and antioxitant therapy of chronic periodontitis].

    PubMed

    Shen, Y X; Guo, S J; Wu, Y F

    2016-07-01

    Chronic periodontitis is a progressive, infectious inflammation disease, caused by the dysbiosis of oral resident flora, leading to the destruction of periodontium. The onset of pathogenic microorganisms is the etiological factor of periodontitis, while the immuno-inflammatory response affects the progression of the disease. Under chronic periodontitis, oxidative stress occurs when excessive reactive oxygen species are produced and exceed the compensative capacity of the organism. Oxidative stress leads to the destruction of periodontium, in a direct way(damaging the biomolecule) or an indirect way(enhancing the produce of inflammatory cytokine and destructive enzymes). Therefore, as the antagonist of the reactive oxygen species, antioxidants may be helpful to treat the chronic periodontitis. This paper reviewed relevant literatures about the destructive role of excessive reactive oxygen species and protective role of antioxidants in chronic periodontitis.

  6. Comparison of mesenchymal stem cells derived from gingival tissue and periodontal ligament in different incubation conditions.

    PubMed

    Yang, Hao; Gao, Li-Na; An, Ying; Hu, Cheng-Hu; Jin, Fang; Zhou, Jun; Jin, Yan; Chen, Fa-Ming

    2013-09-01

    Gingival tissue-derived mesenchymal stem cells (MSCs) were recently identified and characterized as having multipotential differentiation and immunomodulatory properties in vitro and in vivo, and they represent new postnatal stem cell types for cytotherapy and regenerative medicine. However, the utility of gingival MSCs (GMSCs) as alternatives to periodontal ligament stem cells (PDLSCs), which have been demonstrated to be effective but with limited cell availability and reduced clinical feasibility, for periodontal regeneration in a previously diseased/inflamed environment remains obscure. In this study, patient-matched human GMSCs and PDLSCs were evaluated in terms of their colony-forming ability, proliferative capacity, cell surface epitopes, multi-lineage differentiation potentials, and related gene expression when incubated in different designed culture conditions, with or without the presence of inflammatory cytokines. An in vivo ectopic transplantation model using transplants from inflammatory cytokine-treated or untreated cells was applied to assess bone formation. We found that cells derived from both tissues expressed MSC markers, including CD146, CD105, CD90, CD29, and STRO-1. Both cells successfully differentiated under osteogenic, adipogenic, and chondrogenic microenvironments; PDLSCs displayed a more effective differentiation potential in all of the incubation conditions compared to GMSCs (P < 0.01). Although inflammatory cytokine-treated GMSCs and PDLSCs are inferior to normally cultured, patient and tissue-matched cells in terms of their osteogenic capacity and regenerative potential (P < 0.05), they retain the capacity for osteoblastic and adipose differentiation, as well as ectopic bone formation, similar to what has been demonstrated for other MSCs. Interestingly, GMSCs exhibited fewer inflammation-related changes in terms of osteogenic potential in vitro and bone formation in vivo compared to PDLSCs (P < 0.01). These results suggest

  7. Low-Intensity Pulsed Ultrasound Stimulation Facilitates Osteogenic Differentiation of Human Periodontal Ligament Cells

    PubMed Central

    Hu, Bo; Zhang, Yuanyuan; Zhou, Jie; Li, Jing; Deng, Feng; Wang, Zhibiao; Song, Jinlin

    2014-01-01

    Human periodontal ligament cells (hPDLCs) possess stem cell properties, which play a key role in periodontal regeneration. Physical stimulation at appropriate intensities such as low-intensity pulsed ultrasound (LIPUS) enhances cell proliferation and osteogenic differentiation of mesechymal stem cells. However, the impacts of LIPUS on osteogenic differentiation of hPDLCs in vitro and its molecular mechanism are unknown. This study was undertaken to investigate the effects of LIPUS on osteogenic differentiation of hPDLCs. HPDLCs were isolated from premolars of adolescents for orthodontic reasons, and exposed to LIPUS at different intensities to determine an optimal LIPUS treatment dosage. Dynamic changes of alkaline phosphatase (ALP) activities in the cultured cells and supernatants, and osteocalcin production in the supernatants after treatment were analyzed. Runx2 and integrin β1 mRNA levels were assessed by reverse transcription polymerase chain reaction analysis after LIPUS stimulation. Blocking antibody against integrinβ1 was used to assess the effects of integrinβ1 inhibitor on LIPUS-induced ALP activity, osteocalcin production as well as calcium deposition. Our data showed that LIPUS at the intensity of 90 mW/cm2 with 20 min/day was more effective. The ALP activities in lysates and supernatants of LIPUS-treated cells started to increase at days 3 and 7, respectively, and peaked at day 11. LIPUS treatment significantly augmented the production of osteocalcin after day 5. LIPUS caused a significant increase in the mRNA expression of Runx2 and integrin β1, while a significant decline when the integrinβ1 inhibitor was used. Moreover, ALP activity, osteocalcin production as well as calcium nodules of cells treated with both daily LIPUS stimulation and integrinβ1 antibody were less than those in the LIPUS-treated group. In conclusion, LIPUS promotes osteogenic differentiation of hPDLCs, which is associated with upregulation of Runx2 and integrin β1, which

  8. Attachment, proliferation and differentiation of periodontal ligament cells on various guided tissue regeneration membranes.

    PubMed

    Takata, T; Wang, H L; Miyauchi, M

    2001-10-01

    The purpose of this study was to evaluate the biological effects of guided tissue regeneration (GTR) membrane materials, per se, on the periodontal tissue regeneration. Rat periodontal ligament (PDL)-derived cells were used to study the attachment, proliferation and differentiation, in vitro, on various GTR membranes. Five commercially available membranes bovine type I collagen (BioMend; BM), bovine type I atelocollagen (Tissue Guide; TG), polylactic acid (Epi-Guide; EG), co-polymer of polylactic acid and polyglycolic acid (Resolute; RL) and expanded polytetrafluoroethylene: e-PTFE (Gore Tex; GT)-were examined. A 3 x 3 mm section of the membrane was fixed to the bottom of a 35 x 10 mm style culture dish and plated with 2 ml of cell suspension at an initial density of 5 x 10(4) cells/ml in culture medium with 10% fetal bovine serum. For cell growth analysis, the specimens were fixed with 10% buffered formalin and stained with hematoxylin at 1.5 hours and 1, 3 and 5 days after cell seeding. The number of cells included in a unit area of 0.25 mm2 were counted under light microscopy. As a comparative scaffold of cell proliferation, a plastic cover for cell culture slip (Celldesk; CD) was used. For analysis of cell differentiation, activity of alkaline phosphatase (ALP) and calcification were histochemically revealed after 2-week cultivation. The initial number of PDL cells attached to the membrane at 1.5 hours after cell seeding was different among membranes. RL, TG and EG had the same level of attached cell numbers as that on CD, while the cell numbers on GT and BM were significantly lower than that on CD (p < 0.01). The rate of cell proliferation with time also differed among the membranes examined. RL and BM demonstrated a significantly higher number of cells at 5 days than at 1.5 hours (p < 0.01). TG had increased numbers of cells at 3 and 5 days after cell seeding. However, there was no statistical difference between the cell numbers at 1.5 hours and 5 days after

  9. Anti-inflammatory effects of hypoxic-preconditioned human periodontal ligament cells secretome in an experimental model of multiple sclerosis: a key role of IL-37.

    PubMed

    Giacoppo, Sabrina; Thangavelu, Soundara Rajan; Diomede, Francesca; Bramanti, Placido; Conti, Pio; Trubiani, Oriana; Mazzon, Emanuela

    2017-08-23

    Recent research has widely investigated the anti-inflammatory effects of mesenchymal stem cells and their secretory products, termed secretome, in the treatment of multiple sclerosis (MS). The present study examined the capacity of the conditioned medium (CM) collected from human periodontal ligament cells under hypoxic condition medium (H-hPDLSCs-CM) to suppress experimental autoimmune encephalomyelitis (EAE), a murine model of MS. To induce EAE, female C57BL/6 mice were immunized with myelin oligodendroglial glycoprotein peptide35-55 At the onset of symptoms, H-hPDLSCs-CM was infused via the tail vein of mice. Our results demonstrate the efficacy of H-hPDLSCs-CM treatment in diminishing clinical and histologic disease score. A key finding from this study is the marked expression of anti-inflammatory cytokine IL-37, paralleled by the suppression of proinflammatory cytokines in mice with EAE that were treated with H-hPDLSCs-CM. In addition, a consequent modulation of oxidative stress, autophagic, and apoptotic markers was observed in mice with EAE after hPDLSCs-CM administration. In addition, to provide additional evidence of the molecular mechanisms that underlie H-hPDLSCs-CM, we investigated its therapeutic action in scratch injury-exposed NSC-34 neurons, an in vitro model of injury. This model reproduces severe inflammation and oxidative stress conditions as observed after EAE damage. In vitro results corroborate the ability of hPDLSCs-CM to modulate inflammatory, oxidative stress, and apoptotic pathways. Taken together, our findings suggest H-hPDLSCs-CM as a new pharmacologic opportunity for the management of MS.-Giacoppo, S., Thangavelu, S. R., Diomede, F., Bramanti, P., Conti, P., Trubiani, O., Mazzon, E. Anti-inflammatory effects of hypoxic-preconditioned human periodontal ligament cells secretome in an experimental model of multiple sclerosis: a key role of IL-37. © The Author(s).

  10. The secretome of periodontal ligament stem cells from MS patients protects against EAE.

    PubMed

    Rajan, Thangavelu Soundara; Giacoppo, Sabrina; Diomede, Francesca; Ballerini, Patrizia; Paolantonio, Michele; Marchisio, Marco; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2016-12-07

    Manipulation of stem cells or stem cells-derived secretome has emerged as a novel alternative therapeutic option for multiple sclerosis (MS). Here we show that human periodontal ligament stem cells (hPDLSCs)-derived conditioned medium (hPDLSCs-CM) and purified exosomes/microvesicles (hPDLSCs-EMVs) obtained from Relapsing Remitting (RR)-MS patients and healthy donors block experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing anti-inflammatory and immunosuppressive effects in spinal cord and spleen, and reverse disease progression by restoring tissue integrity via remyelination in the spinal cord. We show that hPDLSCs-CM and hPDLSCs-EMVs reduce pro-inflammatory cytokines IL-17, IFN-γ, IL-1β, IL-6, TNF-α, and induce anti-inflammatory IL-10. In addition, apoptosis related STAT1, p53, Caspase 3, and Bax expressions were attenuated. Our findings unravel the immunosuppressive effects of hPDLSCs-CM and hPDLSCs-EMVs in EAE mice, and suggest simple alternative autologous source for patient-customized cell-free targeting treatment in MS patients.

  11. Effects of non-thermal atmospheric plasma on human periodontal ligament mesenchymal stem cells

    NASA Astrophysics Data System (ADS)

    Miletić, M.; Mojsilović, S.; Okić Đorđević, I.; Maletić, D.; Puač, N.; Lazović, S.; Malović, G.; Milenković, P.; Petrović, Z. Lj; Bugarski, D.

    2013-08-01

    Here we investigate the influences of non-thermal atmospheric plasma on human mesenchymal stem cells isolated from periodontal ligament (hPDL-MSCs). A specially redesigned plasma needle was used as the source of low-temperature plasma and its effects on different hPDL-MSC functions were investigated. Cell cultures were obtained from extracted normal impacted third molars and characterized for their phenotype and multi-potential differentiation. The hPDL-MSCs possessed all the typical MSC properties, including clonogenic ability, high proliferation rate, specific phenotype and multilineage differentiation. The data regarding the interaction of plasma with hPDL-MSCs demonstrated that plasma treatment inhibited the migration of hPDL-MSCs and induced some detachment, while not affecting their viability. Additionally, plasma significantly attenuated hPDL-MSCs' proliferation, but promoted their osteogenic differentiation. The results of this study indicated that a non-thermal plasma offers specific activity with non-destructive properties that can be advantageous for future dental applications.

  12. Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells

    PubMed Central

    Xiong, Jimin; Menicanin, Danijela; Marino, Victor

    2016-01-01

    The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein “spots” were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

  13. ABCG2 is a selectable marker for enhanced multilineage differentiation potential in periodontal ligament stem cells.

    PubMed

    Szepesi, Áron; Matula, Zsolt; Szigeti, Anna; Várady, György; Szabó, Gyula; Uher, Ferenc; Sarkadi, Balázs; Német, Katalin

    2015-01-15

    Periodontal ligament stem cells (PDLSCs) provide an important source for tissue regeneration and may become especially useful in the formation of osteogenic seeds. PDLSCs can be cultured, expanded, and differentiated in vitro; thus, they may be applied in the long-term treatment of the defects in the dental regions. Here we studied numerous potential markers allowing the selection of human PDLSCs with a maximum differentiation potential. We followed the expression of the ATP-binding cassette subfamily G member 2 (ABCG2) membrane transporter protein and isolated ABCG2-expressing cells by using a monoclonal antibody, recognizing the transporter at the cell surface in intact cells. The expression of the ABCG2 protein, corresponding to the so-called side-population phenotype in various tissue-derived stem cells, was found to be a useful marker for the selection of PDLSCs with enhanced osteogenic, chondrogenic, and adipogenic differentiation. These findings may have important applications in achieving efficient dental tissue regeneration by using stem cells from extracted teeth.

  14. ABCG2 Is a Selectable Marker for Enhanced Multilineage Differentiation Potential in Periodontal Ligament Stem Cells

    PubMed Central

    Szepesi, Áron; Matula, Zsolt; Szigeti, Anna; Várady, György; Szabó, Gyula; Uher, Ferenc; Sarkadi, Balázs

    2015-01-01

    Periodontal ligament stem cells (PDLSCs) provide an important source for tissue regeneration and may become especially useful in the formation of osteogenic seeds. PDLSCs can be cultured, expanded, and differentiated in vitro; thus, they may be applied in the long-term treatment of the defects in the dental regions. Here we studied numerous potential markers allowing the selection of human PDLSCs with a maximum differentiation potential. We followed the expression of the ATP-binding cassette subfamily G member 2 (ABCG2) membrane transporter protein and isolated ABCG2-expressing cells by using a monoclonal antibody, recognizing the transporter at the cell surface in intact cells. The expression of the ABCG2 protein, corresponding to the so-called side-population phenotype in various tissue-derived stem cells, was found to be a useful marker for the selection of PDLSCs with enhanced osteogenic, chondrogenic, and adipogenic differentiation. These findings may have important applications in achieving efficient dental tissue regeneration by using stem cells from extracted teeth. PMID:25101689

  15. Effect of propolis on survival of periodontal ligament cells: new storage media for avulsed teeth.

    PubMed

    Ozan, Fatih; Polat, Zübeyde Akin; Er, Kürsat; Ozan, Ulkü; Değer, Orhan

    2007-05-01

    Propolis is a multifunctional material used by bees in the construction and maintenance of their hives. Propolis possesses several biologic activities such as anti-inflammatory, antibacterial, antioxidant, antifungal, antiviral, and tissue regenerative, among others. The purpose of this study was to determine the ability of propolis to serve as a temporary storage medium for the maintenance of periodontal ligament (PDL) cell viability of avulsed teeth. PDL cells were obtained from healthy third molars and cultured in Dulbecco's Modified Eagles Medium (DMEM). Cultures were subjected to 10% propolis solution, 20% propolis solution, long-shelf life light milk with lower fat content (milk), Hank's Balanced Salt Solution, tap water as the negative control, and DMEM as the positive control. Tissue culture plates were incubated with experimental media at 37 degrees C for 1, 3, 6, 12, or 24 hours. PDL cell viability was assessed by trypan blue exclusion. Statistical analysis of the data was accomplished by using one-way analysis of variance complemented by the Tukey test. The level of significance was 5% (p<0.05). The results showed that 10% propolis was a more effective storage medium than other groups. In conclusion, propolis can be recommended as a suitable transport medium for avulsed teeth.

  16. Influence of orthodontic forces on the distribution of proteoglycans in rat hypofunctional periodontal ligament.

    PubMed

    Esashika, Mayumi; Kaneko, Sawa; Yanagishita, Masaki; Soma, Kunimichi

    2003-06-01

    During orthodontic treatment, it is often necessary to move the hypofunctional teeth. In this study, we revealed an influence of orthodontic forces in the hypofunctional periodontal ligament, and focused on the distribution of proteoglycans, major extracellular matrix molecules. Five-week-old rats were divided into normal group and hypofunctional group. To induce occlusal hypofunction, occluding teeth of the mandibular first molar were extracted. At 8-week-old, orthodontic force by 15 or 2 gf titanium-nickel alloy closed coil spring was applied to the mandibular first molar toward the mesial direction. Immunohistochemical analysis was performed using antibodies for chondroitin sulfate (CS) and heparan sulfate (HS). In normal group, CS was observed throughout the extracellular matrix, while HS was observed on the endothelial cells and the osteoclastic cells on compressive side. In hypofunctional group without orthodontic appliance, CS and HS were detected in less amounts. With 15 gf, CS was observed at the compressive area where no cells and fibers were present, and HS was observed at the periphery of this area. With 2 gf, however, the distribution of CS and HS was similar to the normal control. These findings indicate that CS and HS were affected by orthodontic forces, and suggest their distinct functions in tissue remodeling.

  17. Bone repair by periodontal ligament stem cellseeded nanohydroxyapatite-chitosan scaffold

    PubMed Central

    Ge, Shaohua; Zhao, Ning; Wang, Lu; Yu, Meijiao; Liu, Hong; Song, Aimei; Huang, Jing; Wang, Guancong; Yang, Pishan

    2012-01-01

    Background A nanohydroxyapatite-coated chitosan scaffold has been developed in recent years, but the effect of this composite scaffold on the viability and differentiation of periodontal ligament stem cells (PDLSCs) and bone repair is still unknown. This study explored the behavior of PDLSCs on a new nanohydroxyapatite-coated genipin-chitosan conjunction scaffold (HGCCS) in vitro as compared with an uncoated genipin-chitosan framework, and evaluated the effect of PDLSC-seeded HGCCS on bone repair in vivo. Methods Human PDLSCs were cultured and identified, seeded on a HGCCS and on a genipin-chitosan framework, and assessed by scanning electron microscopy, confocal laser scanning microscopy, MTT, alkaline phosphatase activity, and quantitative real-time polymerase chain reaction at different time intervals. Moreover, PDLSC-seeded scaffolds were used in a rat calvarial defect model, and new bone formation was assessed by hematoxylin and eosin staining at 12 weeks postoperatively. Results PDLSCs were clonogenic and positive for STRO-1. They had the capacity to undergo osteogenic and adipogenic differentiation in vitro. When seeded on HGCCS, PDLSCs exhibited significantly greater viability, alkaline phosphatase activity, and upregulated the bone-related markers, bone sialoprotein, osteopontin, and osteocalcin to a greater extent compared with PDLSCs seeded on the genipin-chitosan framework. The use of PDLSC-seeded HGCCS promoted calvarial bone repair. Conclusion This study demonstrates the potential of HGCCS combined with PDLSCs as a promising tool for bone regeneration. PMID:23091383

  18. Comparative Gene-Expression Analysis of the Dental Follicle and Periodontal Ligament in Humans

    PubMed Central

    Kim, Seong-Oh; Song, Je-Seon; Lee, Jae-Ho; Lee, Syng-Ill; Jung, Han-Sung; Choi, Byung-Jai

    2013-01-01

    The human dental follicle partially differentiates into the periodontal ligament (PDL), but their biological functions are different. The gene-expression profiles of the dental follicle and PDL were compared using the cDNA microarray technique. Microarray analysis identified 490 genes with a twofold or greater difference in expression, 365 and 125 of which were more abundant in the dental follicle and PDL, respectively. The most strongly expressed genes in the dental follicle were those related to bone development and remodeling (EGFL6, MMP8, FRZB, and NELL1), apoptosis and chemotaxis (Nox4, CXCL13, and CCL2), and tooth and embryo development (WNT2, PAX3, FGF7, AMBN, AMTN, and SLC4A4), while in the PDL it was the tumor-suppressor gene WIF1. Genes related to bone development and remodeling (STMN2, IBSP, BMP8A, BGLAP, ACP5, OPN, BMP3, and TM7SF4) and wound healing (IL1, IL8, MMP3, and MMP9) were also more strongly expressed in the PDL than in the dental follicle. In selected genes, a comparison among cDNA microarray, real-time reverse-transcription polymerase chain reaction, and immunohistochemical staining confirmed similar relative gene expressions. The gene-expression profiles presented here identify candidate genes that may enable differentiation between the dental follicle and PDL. PMID:24376796

  19. Comparative gene-expression analysis of the dental follicle and periodontal ligament in humans.

    PubMed

    Lee, Hyo-Seol; Lee, Jongeun; Kim, Seong-Oh; Song, Je-Seon; Lee, Jae-Ho; Lee, Syng-Ill; Jung, Han-Sung; Choi, Byung-Jai

    2013-01-01

    The human dental follicle partially differentiates into the periodontal ligament (PDL), but their biological functions are different. The gene-expression profiles of the dental follicle and PDL were compared using the cDNA microarray technique. Microarray analysis identified 490 genes with a twofold or greater difference in expression, 365 and 125 of which were more abundant in the dental follicle and PDL, respectively. The most strongly expressed genes in the dental follicle were those related to bone development and remodeling (EGFL6, MMP8, FRZB, and NELL1), apoptosis and chemotaxis (Nox4, CXCL13, and CCL2), and tooth and embryo development (WNT2, PAX3, FGF7, AMBN, AMTN, and SLC4A4), while in the PDL it was the tumor-suppressor gene WIF1. Genes related to bone development and remodeling (STMN2, IBSP, BMP8A, BGLAP, ACP5, OPN, BMP3, and TM7SF4) and wound healing (IL1, IL8, MMP3, and MMP9) were also more strongly expressed in the PDL than in the dental follicle. In selected genes, a comparison among cDNA microarray, real-time reverse-transcription polymerase chain reaction, and immunohistochemical staining confirmed similar relative gene expressions. The gene-expression profiles presented here identify candidate genes that may enable differentiation between the dental follicle and PDL.

  20. Ultrastructural visualization of carbohydrates in oxytalan fibers in monkey periodontal ligaments.

    PubMed

    Takagi, M; Yagasaki, H; Baba, T; Baba, H

    1985-10-01

    Fullmer's oxytalan fibers appear to be special connective tissue fibers belonging to elastic system fibers. We have ultrastructurally examined carbohydrates in oxytalan fibers in monkey periodontal ligaments after glutaraldehyde fixation and ethylenediaminetetraacetic acid (EDTA) decalcification using: Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for thin-section staining of vicinal glycol-containing complex carbohydrates, and the concanavalin A-ferritin (Con A-ferritin) and Con A-horseradish peroxidase (Con-A-HRP) en bloc staining methods specific for alpha-D-mannosyl and alpha-D-glucosyl groups. PA-TCH-SP stained collagen fibrils weakly to moderately and stained oxytalan fibers moderately. Con A-ferritin and Con A-HRP stained collagen fibrils weakly or moderately and stained oxytalan fibers intensely within the superficial region of specimen blocks. The penetration of staining reagents was improved by prior saponin treatment and/or chondroitinase ABC digestion. Thus, these studies demonstrate that PA-TCH-SP and Con A staining of carbohydrates is very useful in identifying oxytalan fibers at the ultrastructural level and that more carbohydrate components are present in oxytalan fibers than in collagen fibrils.

  1. Evaluation of Periodontal Ligament Cell Viability in Three Different Storage Media: An in Vitro Study

    PubMed Central

    Sharma, Sanjay; Reddy, Y. G.; Mittal, Rakesh; Agarwal, Vishal; Singh, Chanchal; Singh, Amandeep

    2015-01-01

    Objectives: This study was undertaken to evaluate the viability of periodontal ligament (PDL) cells of avulsed teeth in three different storage media. Materials and Methods: Forty-five premolars extracted for orthodontic therapeutic purposes were randomly and equally divided into three groups based on storage media used [Group I: milk (control); Group II: aloe vera (experimental); Group III: egg white (experimental)]. Following extractions, the teeth were placed in one of the three different storage media for 30 minutes, following which the scrapings of the PDL from these teeth were collected in Falcon tubes containing collagenase enzyme in 2.5 mL of phosphate buffered saline. The tubes were subsequently incubated for 30 minutes and centrifuged for five minutes at 800 rpm. The obtained PDL cells were stained with Trypan Blue and were observed under optical microscope. The percentage of viable cells was calculated. Results: Aloe vera showed the highest percentage of viable cells (114.3±8.0), followed by egg white (100.9±6.3) and milk (101.1±7.3). Conclusion: Within the limitations of this study, it appears that aloe vera maintains PDL cell viability better than egg white or milk. PMID:26877742

  2. The Biomechanical Function of Periodontal Ligament Fibres in Orthodontic Tooth Movement

    PubMed Central

    McCormack, Steven W.; Witzel, Ulrich; Watson, Peter J.; Fagan, Michael J.; Gröning, Flora

    2014-01-01

    Orthodontic tooth movement occurs as a result of resorption and formation of the alveolar bone due to an applied load, but the stimulus responsible for triggering orthodontic tooth movement remains the subject of debate. It has been suggested that the periodontal ligament (PDL) plays a key role. However, the mechanical function of the PDL in orthodontic tooth movement is not well understood as most mechanical models of the PDL to date have ignored the fibrous structure of the PDL. In this study we use finite element (FE) analysis to investigate the strains in the alveolar bone due to occlusal and orthodontic loads when PDL is modelled as a fibrous structure as compared to modelling PDL as a layer of solid material. The results show that the tension-only nature of the fibres essentially suspends the tooth in the tooth socket and their inclusion in FE models makes a significant difference to both the magnitude and distribution of strains produced in the surrounding bone. The results indicate that the PDL fibres have a very important role in load transfer between the teeth and alveolar bone and should be considered in FE studies investigating the biomechanics of orthodontic tooth movement. PMID:25036099

  3. The biomechanical function of periodontal ligament fibres in orthodontic tooth movement.

    PubMed

    McCormack, Steven W; Witzel, Ulrich; Watson, Peter J; Fagan, Michael J; Gröning, Flora

    2014-01-01

    Orthodontic tooth movement occurs as a result of resorption and formation of the alveolar bone due to an applied load, but the stimulus responsible for triggering orthodontic tooth movement remains the subject of debate. It has been suggested that the periodontal ligament (PDL) plays a key role. However, the mechanical function of the PDL in orthodontic tooth movement is not well understood as most mechanical models of the PDL to date have ignored the fibrous structure of the PDL. In this study we use finite element (FE) analysis to investigate the strains in the alveolar bone due to occlusal and orthodontic loads when PDL is modelled as a fibrous structure as compared to modelling PDL as a layer of solid material. The results show that the tension-only nature of the fibres essentially suspends the tooth in the tooth socket and their inclusion in FE models makes a significant difference to both the magnitude and distribution of strains produced in the surrounding bone. The results indicate that the PDL fibres have a very important role in load transfer between the teeth and alveolar bone and should be considered in FE studies investigating the biomechanics of orthodontic tooth movement.

  4. The secretome of periodontal ligament stem cells from MS patients protects against EAE

    PubMed Central

    Rajan, Thangavelu Soundara; Giacoppo, Sabrina; Diomede, Francesca; Ballerini, Patrizia; Paolantonio, Michele; Marchisio, Marco; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2016-01-01

    Manipulation of stem cells or stem cells-derived secretome has emerged as a novel alternative therapeutic option for multiple sclerosis (MS). Here we show that human periodontal ligament stem cells (hPDLSCs)-derived conditioned medium (hPDLSCs-CM) and purified exosomes/microvesicles (hPDLSCs-EMVs) obtained from Relapsing Remitting (RR)-MS patients and healthy donors block experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing anti-inflammatory and immunosuppressive effects in spinal cord and spleen, and reverse disease progression by restoring tissue integrity via remyelination in the spinal cord. We show that hPDLSCs-CM and hPDLSCs-EMVs reduce pro-inflammatory cytokines IL-17, IFN-γ, IL-1β, IL-6, TNF-α, and induce anti-inflammatory IL-10. In addition, apoptosis related STAT1, p53, Caspase 3, and Bax expressions were attenuated. Our findings unravel the immunosuppressive effects of hPDLSCs-CM and hPDLSCs-EMVs in EAE mice, and suggest simple alternative autologous source for patient-customized cell-free targeting treatment in MS patients. PMID:27924938

  5. Intraseptal vs. periodontal ligament anaesthesia for maxillary tooth extraction: quality of local anaesthesia and haemodynamic response.

    PubMed

    Brkovic, Bozidar M B; Savic, Miroslav; Andric, Miroslav; Jurisic, Milan; Todorovic, Ljubomir

    2010-12-01

    There is no data concerning the use of the intraseptal anaesthesia (ISA) for single tooth extraction. The aims of this study were to compare the clinical efficacy and haemodynamic responses of the ISA with the periodontal ligament anaesthesia (PLA) for single tooth extraction. Thirty-five randomly selected healthy patients (ASA I) undergoing maxillary lateral incisors extraction entered the study. Onset of anaesthesia, the width of the anaesthetic field and duration of anaesthesia were recorded by pinprick testing. Intensity of anaesthesia was evaluated on a visual analogue scale. Haemodynamic parameters were recorded simultaneously at different time points after anaesthesia injection. The two techniques of local anaesthesia did not show statistically significant differences regarding the success rate and onset of anaesthesia, while the duration of the ISA on the buccal site was significantly longer in comparison with the PLA. The intensity of the achieved anaesthesia, estimated by the experienced pain during procedure, pointed out that pain was recorded in 24% of cases in the ISA group, and in 19% in the PLA group without significant differences. Postoperative pain was found to be smaller in the ISA group (70.9% of treated sites) than in the PLA group (81.3% of treated sites); however, this difference was not significant. Although the heart rate increased in both groups, there were no significant differences in the patients' haemodynamic response between the ISA and the PLA. The results of the present study indicate that both techniques are useful and suitable for the routine tooth extraction.

  6. Experiment and hydro-mechanical coupling simulation study on the human periodontal ligament.

    PubMed

    Wei, Zhigang; Yu, Xiaoliu; Xu, Xiangrong; Chen, Xinyuan

    2014-03-01

    In this paper, a new method involving an experiment in vivo and hydro-mechanical coupling simulations was proposed to investigate the biomechanical property of human periodontal ligament (PDL). Teeth were loaded and their displacements were measured in vivo. The finite element model of the experiment was built and hydro-mechanical coupling simulations were conducted to test some PDL's constitutive models. In the simulations, the linear elastic model, the hyperfoam model, and the Ogden model were assumed for the solid phase of the PDL coupled with a model of the fluid phase of the PDL. The displacements of the teeth derived from the simulations were compared with the experimental data to validate these constitutive models. The study shows that a proposed constitutive model of the PDL can be reliably tested by this method. Furthermore, the influence of species, areas, and the fluid volume ratio on PDL's mechanical property should be considered in the modeling and simulation of the mechanical property of the PDL.

  7. In vitro phagocytosis of exogenous collagen by fibroblasts from the periodontal ligament: an electron microscopic study.

    PubMed Central

    Svoboda, E L; Brunette, D M; Melcher, A H

    1979-01-01

    There have been numerous electron microscopic reports of apparent phagocytosis of collagen by fibroblasts and other cells in vivo. We have developed an in vitro system which, to the best of our knowledge, will permit for the first time the study of regulatory mechanisms governing phagocytosis and digestion of collagen fibres. Cells were cultured from explants of monkey periodontal ligament, subcultured, and grown to confluence in alpha-MEM plus 15% fetal calf serum plus antibiotics. The confluent cells were then cultured together with minced rat tail tendon collagen in alpha-MEM lacking proline, lysine, glycine and fetal calf serum for up to 7 days, after which they were processed for electron microscopy. Intracellular collagen profiles could be seen in cultured cells that were associated with exogenous collagen fibrils as early as 24 hours after addition of the collagen. Through electron microscopic examination of serial sections of the culture, we have demonstrated: (1) that fibroblasts can phagocytose collagen; (2) that the observed intracellular collagen is not the result of aggregation of endogenous synthesized collagen; (3) that it is not possible to base a decision as to whether a collagen fibril has been phagocytosed in whole or in part by the type of vesicle with which it is associated; (4) that cleavage of collagen into small pieces may not be a necessary prelude to its phagocytosis. Images Fig. 1 Fig. 2 Fig. 4 (cont.) Fig. 4 Fig. 6 (cont.) Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:108237

  8. Periodontal ligament hydrostatic pressure with areas of root resorption after application of a continuous torque moment.

    PubMed

    Hohmann, Ansgar; Wolfram, Uwe; Geiger, Martin; Boryor, Andrew; Sander, Christian; Faltin, Rolf; Faltin, Kurt; Sander, Franz Guenter

    2007-07-01

    To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated. A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied in vivo to the aforementioned teeth. After extraction, FEMs of these double-rooted teeth were created based on high-resolution microcomputed tomographics (micro CT, voxel size: 35 microns). This high volumetric resolution made the recognition of very small resorption lacunae possible. Scanning electron micrographs of the root surfaces were created as well. This enabled the investigation of advantages and disadvantages of the different imaging techniques from the viewpoint of the examination of root resorption. Using the FEMs, the same loading conditions as applied in vivo were simulated. The results of clinical examination and simulations were compared using the identical roots of the teeth. The regions that showed increased hydrostatic pressure (>0.0047 MPa) correlated well with the locations of root resorption for each tooth. Increased torque resulted in increased high-pressure areas and increased magnitudes of hydrostatic pressure, correlating with the experiments. If hydrostatic pressure exceeds typical human capillary blood pressure in the PDL, the risk of root resorption increases.

  9. [Experiment on inducing human periodontal ligament stem cells into adipose cells].

    PubMed

    He, Hui-xia; Liu, Hong-chen; Wang, Dong-sheng; Cao, Jun-kai; Zhang, Hai-zhong; E, Ling-ling

    2010-04-01

    To explore the capability of human periodontal ligament stem cells (PDLSCs) differentiating into adipose cells in vitro and to determine their changes in cell morphology, structure and function during differentiation. PDLSCs isolated by magnetic-activated cell selection were treated continuously with adipogenic medium for 21 d. Then the cell morphology, ultrastructure, adipose specific markers of low density lipoprotein (LPL) and peroxisome proliferator activated receptor-gamma (PPAR-gamma) were analyzed by inverted contrast microscope, trans mission electron microscope (TEM), flow cytometry, immunofluorescence, RT-PCR and Western blot, respectively. These adipose-like cells were also identified by oil red O staining to determine the formation of lipid droplet, and the non-induced cells were used as control. After continuous induction, the treated cells differentiated into adipose-like cells with round shape, and large amount of lipid drop in cytoplasm. 96.54% of the PDLSCs were found to differentiate into adipose cells as showed by flow cytometry, the specific markers of LPL mRNA and PPAR-gamma mRNA, and oil red O staining, respectively. Further, PPAR-gamma protein was detected in the induced cells in a time-dependent manner. Human PDLSCs have the potential of differentiating into adipose cells under appropriate condition, and the differentiated cells exhibited characteristics of adipose cells both from cell morphology and from their functions.

  10. In vitro toxicity of formocresol, ferric sulphate, and grey MTA on human periodontal ligament fibroblasts.

    PubMed

    Al-Haj Ali, S N; Al-Jundi, S H; Ditto, D J

    2015-02-01

    This was to assess and compare the in vitro toxicity of formocresol, ferric sulphate and MTA on cultured human periodontal ligament (PDL) fibroblasts. PDL cells were obtained from sound first permanent molars and cultured in Dulbecco's modified Eagle's medium. PDL cells were subjected to different concentrations of formocresol, ferric sulphate, and grey MTA for 24, 48, and 72 h at 37 °C. Cells that were not exposed to the tested materials served as the negative control. In vitro toxicity was assessed using MTT assay. Statistical analysis of data was accomplished using ANOVA and Tukey statistical tests (p<0.05). The overall toxicity ranking of the tested materials was as follows: formocresol>ferric sulphate>grey MTA. Only grey MTA had comparable cell viability to the negative control, the other tested materials were significantly inferior at the three exposure periods (p<0.05). Regarding the viability of PDL fibroblasts, MTA stands as the most promising substitute to formocresol. However, considering MTA's unavailability and high price in Jordan, ferric sulphate may be the best alternative to formocresol in pulpotomy of primary teeth.

  11. Effect of Four Different Media on Periodontal Ligament Cells Viability of Dry- Stored Dog Teeth

    PubMed Central

    Moazzami, Fariborz; Asheghi, Bahar; Sahebi, Safoura

    2017-01-01

    Statement of the Problem: The maintenance of viable periodontal ligament cells is the most important issue in the long-term preservation of avulsed teeth. Purpose: The aim of this study was to assess aloe vera as a new storage media in maintaining the cell viability of dry-stored teeth in comparison with soy milk, Hank`s balanced salt solution (HBSS), and milk. Materials and Method: Twenty one extracted dog premolar teeth were dried for 30 minutes and stored in soy milk, HBSS, milk, and aloe vera extract (50%) for 45 minutes (n=6 for each). Furthermore, positive and two negative control groups (n=6), corresponding to 0 min, 30 min, and 2-hour drying times were also prepared respectively. The number of viable cells was counted following storage using Trypan blue exclusion. Data were statistically analyzed using the one-way ANOVA and post hoc Tukey-HSD test. Results: Statistical analysis showed no significant differences in cell viability among aloe vera, soymilk, and HBSS- stored teeth; however, they were all superior to milk. Conclusion: Aloe vera extract can be recommended as a suitable storage media for avulsed teeth. PMID:28280756

  12. [Comparison between gingival and periodontal ligament fibroblasts from the same subject].

    PubMed

    Palioto, Daniela Bazan; Della Coletta, Ricardo; Martelli Júnior, Hercílio; Joly, Julio Cesar; Graner, Edgard; de Lima, Antonio Fernando Martorelli

    2002-01-01

    The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.

  13. Bioactivity of periodontal ligament stem cells on sodium titanate coated with graphene oxide

    PubMed Central

    Zhou, Qi; Yang, Pishan; Li, Xianlei; Liu, Hong; Ge, Shaohua

    2016-01-01

    As a biocompatible and low cytotoxic nanomaterial, graphene oxide (GO) has captured tremendous interests in tissue engineering. However, little is known about the behavior of dental stem cells on GO. This study was to evaluate the bioactivity of human periodontal ligament stem cells (PDLSCs) on GO coated titanium (GO-Ti) substrate in vitro as compared to sodium titanate (Na-Ti) substrate. By scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), methylthiazol tetrazolium (MTT) assay, alkaline phosphatase (ALP) activity, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, we investigated the attachment, morphology, proliferation and osteogenic differentiation of PDLSCs on these two substrates. When seeded on GO-Ti substrate, PDLSCs exhibited significantly higher proliferation rate, ALP activity and up-regulated gene expression level of osteogenesis-related markers of collagen type I (COL-I), ALP, bone sialoprotein (BSP), runt related transcription factor 2 (Runx2) and osteocalcin (OCN) compared with those on Na-Ti substrate. Moreover, GO promoted the protein expression of BSP, Runx2 and OCN. These findings suggest that the combination of GO and PDLSCs provides a promising construct for regenerative dentistry. PMID:26763307

  14. Occlusal stimuli regulate interleukin-1 beta and FGF-2 expression in rat periodontal ligament.

    PubMed

    Boonpratham, Supatchai; Kanno, Zuisei; Soma, Kunimichi

    2007-03-01

    While many studies reported the structural changes in the periodontal ligament (PDL) under hypofunctional conditions, the associations of cytokine growth factors are still unclear. They are known to take part in inflammation, and may affect the biological properties of hypofunctional tooth. To investigate the hypofunctional PDL and the recovery from this condition, we focused on interleukin-1 beta (IL-1beta) and basic fibroblast growth factor (FGF-2). Male Wistar rats were divided into occluded, non-occluded, and recovery groups. An anterior bite plate was used to eliminate the occlusal contact of molars in the non-occluded group, and was then removed for the recovery group. After occlusal stimuli were eliminated for 7 and 14 days, and after 3 and 7 days of recovery from 7 days in the hypofunctional condition, the PDLs of the lower first molars were investigated immunohistochemically. The lack of occlusal stimuli caused atrophic changes in the PDL with the upregulation of IL-1beta and decreased expression of FGF-2, while decreased IL-1beta and enhanced FGF-2 expression were observed in the recovery process. These results suggest that occlusal stimuli regulate IL-1beta and FGF-2 expression, and the nature of this regulation may differ from that in the healing process of an inflammatory reaction.

  15. Mosasaurs and snakes have a periodontal ligament: timing and extent of calcification, not tissue complexity, determines tooth attachment mode in reptiles.

    PubMed

    LeBlanc, Aaron R H; Lamoureux, Denis O; Caldwell, Michael W

    2017-09-12

    Squamates present a unique challenge to our understanding of dental evolution in amniotes because they are the only extant tooth-bearing group for which a ligamentous tooth attachment is considered to be absent. This has led to the assumption that mammals and crocodilians have convergently evolved a ligamentous tooth attachment, composed of root cementum, periodontal ligament, and alveolar bone, whereas squamates are thought to possess a single bone of attachment tissue that fuses teeth to the jaws. The identity and homology of tooth attachment tissues between squamates, crocodilians, and mammals have thus been a focal point of debate for decades. We provide a novel interpretation of the mineralized attachment tissues in two focal taxa in this debate, mosasaurids and snakes, and compare dental tissue histology with that of the extant crocodilian Caiman sclerops. We identify a periodontal ligament in these squamates that usually exists temporarily as a soft connective tissue anchoring each tooth to the alveolar bone. We also identify two instances where complete calcification of the periodontal ligament does not occur: in a durophagous mosasaur, and in the hinged teeth of fossil and modern snakes. We propose that the periodontal ligament rapidly calcifies in the majority of mosasaurids and snakes, ankylosing the tooth to the jaw. This gives the appearance of a single, bone-like tissue fusing the tooth to the jaw in ankylosed teeth, but is simply the end stage of dental tissue ontogeny in most snakes and mosasaurids. © 2017 Anatomical Society.

  16. Effects of cathepsin K on Emdogain-induced hard tissue formation by human periodontal ligament stem cells.

    PubMed

    Liu, Fen; Zhou, Zhi-Fei; An, Ying; Yu, Yang; Wu, Rui-Xin; Yin, Yuan; Xue, Yang; Chen, Fa-Ming

    2016-07-12

    Recent studies have shown that patients with pycnodysostosis caused by cathepsin K (CTSK) genetic mutations exhibit significantly abnormal periodontal hard tissue structure. This finding suggests that CTSK may play a role in regulating the development of alveolar bone and cementum. However, the source of CTSK in the periodontal environment and the role of CTSK in periodontal regeneration, particularly hard tissue regeneration and development, remain unclear. After the isolation, cultivation, identification, and multi-lineage induction of human periodontal ligament stem cells (hPDLSCs), the present study used light and scanning electron microscopy, reverse-transcription quantitative polymerase chain reaction, western blotting, micro-computed tomography, immunohistochemical assays and ectopic hard tissue formation experiments to examine CTSK expression in hPDLSCs. The results indicated that CTSK expression was significantly upregulated in hPDLSCs during Emdogain induction but underwent minimal change during osteogenic or adipogenic induction. The present study also showed that the downregulation of CTSK expression inhibited osteogenic/cementogenic differentiation and ectopic hard tissue formation of hPDLSCs. It is therefore concluded that hPDLSCs expressed CTSK and that CTSK levels were significantly upregulated during Emdogain induction. Furthermore, CTSK promoted not only the osteogenic/cementogenic differentiation of hPDLSCs but also their ability to form ectopic hard tissue. These new findings may enhance the understanding of periodontal hard tissue development and functional regeneration. However, the specific underlying mechanisms require further investigation. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Human periodontal ligament cells facilitate leukocyte recruitment and are influenced in their immunomodulatory function by Th17 cytokine release.

    PubMed

    Konermann, A; Beyer, M; Deschner, J; Allam, J P; Novak, N; Winter, J; Jepsen, S; Jäger, A

    2012-01-01

    The objective of this in vitro study was to examine the immunomodulatory impact of human periodontal ligament (PDL) cells on the nature and magnitude of the leukocyte infiltrate in periodontal inflammation, particularly with regard to Th17 cells. PDL cells were challenged with pro-inflammatory cytokines (IL-1ß, IL-17A, and IFN-γ) and analyzed for the expression of cytokines involved in periodontal immunoinflammatory processes (IL-6, MIP-3 alpha, IL-23A, TGFß1, IDO, and CD274). In order to further investigate a direct involvement of PDL cells in leukocyte function, co-culture experiments were conducted. The expression of the immunomodulatory cytokines studied was significantly increased under pro-inflammatory conditions in PDL cells. Although PDL cells did not stimulate leukocyte proliferation or Th17 differentiation, these cells induced the recruitment of leukocytes. The results of our study suggest that PDL cells might be involved in chronic inflammatory mechanisms in periodontal tissues and thus in the transition to an adaptive immune response in periodontitis.

  18. Genipin inhibits MMP-1 and MMP-3 release from TNF-a-stimulated human periodontal ligament cells.

    PubMed

    Shindo, Satoru; Hosokawa, Yoshitaka; Hosokawa, Ikuko; Ozaki, Kazumi; Matsuo, Takashi

    2014-12-01

    Genipin, the aglycon of geniposide found in gardenia fruit has long been considered for treatment of inflammatory diseases in traditional oriental medicine. Genipin has recently been reported to have some pharmacological functions, such as antimicrobial, antitumor, and anti-inflammatory effects. The aim of this study was to examine whether genipin could modify matrix metalloproteinase (MMP)-1 and MMP-3, which are related to the destruction of periodontal tissues in periodontal lesion, expression in tumor necrosis factor (TNF)-α-stimulated human periodontal ligament cells (HPDLCs). Genipin prevented TNF-α-mediated MMP-1 and MMP-3 productions in HPDLCs. Moreover, genipin could suppress not only extracellular signal-regulated kinase (ERK) and Jun-N-terminal kinase (JNK) phosphorylations but also AMP-activated protein kinase (AMPK) phosphorylation in TNF-α-stimulated HPDLCs. Inhibitors of ERK and AMPK could inhibit both MMP-1 and MMP-3 productions. Moreover, we revealed the ERK inhibitor suppressed AMPK phosphorylation in TNF-α-stimulated HPDLCs. These data provide a new mechanism through which genipin could be used for the treatment of periodontal disease to prevent MMPs expression in periodontal lesion.

  19. IL-4 Modulates CCL11 and CCL20 Productions from IL-1β-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Hosokawa, Yoshitaka; Hosokawa, Ikuko; Shindo, Satoru; Ozaki, Kazumi; Matsuo, Takashi

    2016-01-01

    IL-4 is a multifunctional cytokine that is related with the pathological conditions of periodontal disease. However, it is uncertain whether IL-4 could control T cells migration in periodontal lesions. The aim of this study was to examine the effects of IL-4 on CCL11, which is a Th2-type chemokine, and CCL20, which is related with Th17 cells migration, productions from human periodontal ligament cells (HPDLCs). CCL20 and CCL11 productions from HPDLCs were monitored by ELISA. Western blot analysis was performed to detect phosphorylations of signal transduction molecules in HPDLCs. IL-1β could induce both CCL11 and CCL20 productions in HPDLCs. IL-4 enhanced CCL11 productions from IL-1β-stimulated HPDLCs, though IL-4 inhibited CCL20 production. Western blot analysis showed that protein kinase B (Akt) and signal transducer and activator of transcription (STAT)6 pathways were highly activated in IL-4/IL-1β-stimulated HPDLCs. Akt and STAT6 inhibitors decreased CCL11 production, but enhanced CCL20 production in HPDLCs stimulated with IL-4 and IL-1β. These results mean that IL-4 enhanced Th2 cells migration in periodontal lesion to induce CCL11 production from HPDLCs. On the other hand, IL-4 inhibits Th17 cells accumulation in periodontally diseased tissues to inhibit CCL20 production. Therefore, IL-4 is positively related with the pathogenesis of periodontal disease to control chemokine productions in periodontal lesions. © 2016 The Author(s) Published by S. Karger AG, Basel.

  20. Cytotoxic Effects of One-step Self-etching Dental Adhesives on Human Periodontal Ligament Fibroblasts In Vitro.

    PubMed

    Sun, Fangfang; Mao, Peng; Wang, Cong; Shi, Chaowen; Nie, Rongrong; Han, Ningning; Han, Xiaodong

    2016-01-01

    To evaluate the potential cytotoxic effects of four one-step self-etching dental adhesives [Adper Easy One (AEO), iBond (IB), Clearfil S³ Bond (CSB), and G-Bond (GB)] on cultured human periodontal ligament fibroblasts. Cured adhesives were immersed in complete DMEM or deionized water and maintained at 37°C for 24 h, followed by sterilization. The deionized water-based extract was used for Fourier transform infrared spectroscopy analysis. The DMEM-based extract was diluted into various concentrations for cytotoxicity tests. The viability, integrity, and apoptosis of cultured human periodontal ligament fibroblasts upon treatment with the extracts were determined using the CCK-8 assay, microscopy, and flow cytometry. All of the four adhesives induced cell viability loss, cell morphology alteration, and cell death. GB showed the greatest cytotoxicity by inducing cell apoptosis and necrosis, while IB had the weakest cytotoxic effect on the cultured cells. All tested dental adhesives have significant adverse effects on cell viability. Therefore, precautions should be taken to protect the periodontal tissues when dental adhesives are applied in the clinic.

  1. Wnt5a Induces Collagen Production by Human Periodontal Ligament Cells Through TGFβ1-Mediated Upregulation of Periostin Expression.

    PubMed

    Hasegawa, Daigaku; Wada, Naohisa; Maeda, Hidefumi; Yoshida, Shinichiro; Mitarai, Hiromi; Tomokiyo, Atsushi; Monnouchi, Satoshi; Hamano, Sayuri; Yuda, Asuka; Akamine, Akifumi

    2015-11-01

    Wnt5a, a member of the noncanonical Wnt proteins, is known to play important roles in the development of various organs and in postnatal cell functions. However, little is known about the effects of Wnt5a on human periodontal ligament (PDL) cells. In this study, we examined the localization and potential function of Wnt5a in PDL tissue. Immunohistochemical analysis revealed that Wnt5a was expressed predominantly in rat PDL tissue. Semi-quantitative reverse-transcription polymerase chain reaction and Western blotting analysis demonstrated that human PDL cells (HPDLCs) expressed Wnt5a and its receptors (Ror2, Fzd2, Fzd4, and Fzd5). Removal of occlusal pressure by extraction of opposing teeth decreased Wnt5a expression in rat PDL tissue, and the expression of Wnt5a and its receptors in HPDLCs was upregulated by exposure to mechanical stress. Stimulation with Wnt5a significantly enhanced the proliferation and migration of HPDLCs. Furthermore, Wnt5a suppressed osteoblastic differentiation of HPDLCs cultivated in osteogenic induction medium, while it significantly enhanced the expression of PDL-related genes, such as periostin, type-I collagen, and fibrillin-1 genes, and the production of collagen in HPDLCs cultivated in normal medium. Both knockdown of periostin gene expression by siRNA and inhibition of TGFβ1 function by neutralizing antibody suppressed the Wnt5a-induced PDL-related gene expression and collagen production in HPDLCs. Interestingly, in HPDLCs cultured with Wnt5a, TGFβ1 neutralizing antibody significantly suppressed periostin expression, while periostin siRNA had no effect on TGFβ1 expression. These results suggest that Wnt5a expressed in PDL tissue plays specific roles in inducing collagen production by PDL cells through TGFβ1-mediated upregulation of periostin expression. © 2015 Wiley Periodicals, Inc.

  2. Altered distribution of HMGB1 in the periodontal ligament of periostin-deficient mice subjected to Waldo's orthodontic tooth movement.

    PubMed

    Li, Juan; Feng, Wei; Liu, Bo; Sun, Bao; Han, Xiuchun; Du, Juan; Sun, Jing; Yimin; Cui, Jian; Guo, Jie; Kudo, Akira; Amizuka, Norio; Li, Minqi

    2015-06-01

    Periostin is essential for the integrity and function of the periodontal ligament (PDL), and periostin knockout is related to an enhanced inflammatory status in PDL. High mobility group box 1 (HMGB1), a late inflammatory cytokine, is up-regulated in PDL cells in response to mechanical stress. This study aimed to investigate the effect of periostin deficiency (Pn-/-) on HMGB1 expression in PDL during orthodontic tooth movement. We used 8-week-old male mice homozygous for the disrupted periostin gene and their wild-type (WT) littermates. Tooth movement was performed according to Waldo's method, in which 0.5-mm-thick elastic bands were inserted between the first and second upper molars of anesthetized mice. After 3 days of mechanical loading, mice were fixed by transcardial perfusion of 4% paraformaldehyde in phosphate buffer, and the maxilla was extracted for histochemical analyses. Compared with the WT group, Pn-/- mice showed higher basal expression of HMGB1 in the absence of mechanical loading. Following 3 days of orthodontic tooth movement, the PDL in the compression side of both groups was almost replaced by cell-free hyaline zones, and Pn-/- mice showed a much wider residual PDL than WT mice. In the tension side, the number of HMGB1-positive cells in PDL in both Pn-/- and WT groups increased remarkably without a significant difference between the two groups. Our findings suggest an inhibitory effect of periostin on HMGB1 production by PDL and confirmed the critical role of periostin in integrity of PDL collagen fibrils during orthodontic tooth movement, although mechanical loading is the predominant stimulant of HMGB1 expression relative to periostin deficiency.

  3. Periodontal ligament cells cultured under steady-flow environments demonstrate potential for use in heart valve tissue engineering.

    PubMed

    Martinez, Catalina; Rath, Sasmita; Van Gulden, Stephanie; Pelaez, Daniel; Alfonso, Abraham; Fernandez, Natasha; Kos, Lidia; Cheung, Herman; Ramaswamy, Sharan

    2013-02-01

    A major drawback of mechanical and prosthetic heart valves is their inability to permit somatic growth. By contrast, tissue-engineered pulmonary valves potentially have the capacity to remodel and integrate with the patient. For this purpose, adult stem cells may be suitable. Previously, human periodontal ligament cells (PDLs) have been explored as a reliable and robust progenitor cell source for cardiac muscle regeneration (Pelaez, D. Electronic Thesis and Dissertation Database, Coral Gables, FL, May 2011). Here, we investigate the potential of PDLs to support the valve lineage, specifically the concomitant differentiation to both endothelial cell (EC) and smooth muscle cell (SMC) types. We were able to successfully promote PDL differentiation to both SMC and EC phenotypes through a combination of stimulatory approaches using biochemical and mechanical flow conditioning (steady shear stress of 1 dyne/cm(2)), with flow-based mechanical conditioning having a predominant effect on PDL differentiation, particularly to ECs; in addition, strong expression of the marker FZD2 and an absence of the marker MLC1F point toward a unique manifestation of smooth muscle by PDLs after undergoing steady-flow mechanical conditioning alone, possible by only the heart valve and pericardium phenotypes. It was also determined that steady flow (which was performed using a physiologically relevant [for heart valves] magnitude of ~5-6 dynes/cm(2)) augmented the synthesis of the extracellular matrix collagen proteins. We conclude that under steady-flow dynamic culture environments, human PDLs can differentiate to heterogeneous cell populations that are relevant to heart valve tissue engineering. Further exploration of human PDLs for this purpose is thus warranted.

  4. Multiscale biomechanical responses of adapted bone-periodontal ligament-tooth fibrous joints

    PubMed Central

    Jang, Andrew T.; Merkle, Arno; Fahey, Kevin; Gansky, Stuart A.; Ho, Sunita P.

    2015-01-01

    Reduced functional loads cause adaptations in organs. In this study, temporal adaptations of bone-ligament-tooth fibrous joints to reduced functional loads were mapped using a holistic approach. Systematic studies were performed to evaluate organ-level and tissue-level adaptations in specimens harvested periodically from rats given powder food for 6 months (N = 60 over 8,12,16,20, and 24 weeks). Bone-periodontal ligament (PDL)-tooth fibrous joint adaptation was evaluated by comparing changes in joint stiffness with changes in functional space between the tooth and alveolar bony socket. Adaptations in tissues included mapping changes in the PDL and bone architecture as observed from collagen birefringence, bone hardness and volume fraction in rats fed soft foods (soft diet, SD) compared to those fed hard pellets as a routine diet (hard diet, HD). In situ biomechanical testing on harvested fibrous joints revealed increased stiffness in SD groups (SD:239-605 N/mm) (p<0.05) at 8 and 12 weeks. Increased joint stiffness in early development phase was due to decreased functional space (at 8wks change in functional space was −33 µm, at 12wks change in functional space was −30 µm) and shifts in tissue quality as highlighted by birefringence, architecture and hardness. These physical changes were not observed in joints that were well into function, that is, in rodents older than 12 weeks of age. Significant adaptations in older groups were highlighted by shifts in bone growth (bone volume fraction 24wks: Δ-0.06) and bone hardness (8wks: Δ−0.04 GPa, 16 wks: Δ−0.07 GPa, 24wks: Δ−0.06 GPa). The response rate (N/s) of joints to mechanical loads decreased in SD groups. Results from the study showed that joint adaptation depended on age. The initial form-related adaptation (observed change in functional space) can challenge strain-adaptive nature of tissues to meet functional demands with increasing age into adulthood. The coupled effect between functional space in

  5. Multiscale biomechanical responses of adapted bone-periodontal ligament-tooth fibrous joints.

    PubMed

    Jang, Andrew T; Merkle, Arno P; Fahey, Kevin P; Gansky, Stuart A; Ho, Sunita P

    2015-12-01

    Reduced functional loads cause adaptations in organs. In this study, temporal adaptations of bone-ligament-tooth fibrous joints to reduced functional loads were mapped using a holistic approach. Systematic studies were performed to evaluate organ-level and tissue-level adaptations in specimens harvested periodically from rats (N=60) given powder food for 6 months over 8,12,16,20, and 24 weeks. Bone-periodontal ligament (PDL)-tooth fibrous joint adaptation was evaluated by comparing changes in joint stiffness with changes in functional space between the tooth and alveolar bony socket. Adaptations in tissues included mapping changes in the PDL and bone architecture as observed from collagen birefringence, bone hardness and volume fraction in rats fed soft foods (soft diet, SD) compared to those fed hard pellets as a routine diet (hard diet, HD). In situ biomechanical testing on harvested fibrous joints revealed increased stiffness in SD groups (SD:239-605 N/mm) (p<0.05) at 8 and 12 weeks. Increased joint stiffness in early development phase was due to decreased functional space (at 8 weeks change in functional space was -33 μm, at 12 weeks change in functional space was -30 μm) and shifts in tissue quality as highlighted by birefringence, architecture and hardness. These physical changes were not observed in joints that were well into function, that is, in rodents older than 12 weeks of age. Significant adaptations in older groups were highlighted by shifts in bone growth (bone volume fraction 24 weeks: Δ-0.06) and bone hardness (8 weeks: Δ-0.04 GPa, 16 weeks: Δ-0.07 GPa, 24 weeks: Δ-0.06 GPa). The response rate (N/s) of joints to mechanical loads decreased in SD groups. Results from the study showed that joint adaptation depended on age. The initial form-related adaptation (observed change in functional space) can challenge strain-adaptive nature of tissues to meet functional demands with increasing age into adulthood. The coupled effect between functional

  6. Stress and periodontal disease: The link and logic!!

    PubMed Central

    Goyal, Sachin; Gupta, Garima; Thomas, Betsy; Bhat, K. M.; Bhat, G. S.

    2013-01-01

    Stress is an equated response to constant adverse stimuli. At one point or another everybody suffers from stress. Stress is compatible with good health, being necessary to cope with the challenges of everyday life. Problems start when the stress response is inappropriate to the intensity of the challenge. Psychological stress can down regulate the cellular immune response. Communication between the central nervous system and the immune system occurs via a complex network of bidirectional signals linking the nervous, endocrine, and immune systems. Stress disrupts the homeostasis of this network, which in turn, alters immune function. Direct association between periodontal disease and stress remains to be proven, which is partly due to lack of an adequate animal models and difficulty to quantifying the amount and duration of stress and also there are many factors influencing the incidence and severity of periodontal disease. Nevertheless, more recent studies indicate that psychosocial stress represents a risk indicator for periodontal disease and should be addressed before and during treatment. This paper discusses how stress may modulate host response to bacteria and influence the course and progression of periodontal disease. PMID:24459366

  7. Stress and periodontal disease: The link and logic!!

    PubMed

    Goyal, Sachin; Gupta, Garima; Thomas, Betsy; Bhat, K M; Bhat, G S

    2013-01-01

    Stress is an equated response to constant adverse stimuli. At one point or another everybody suffers from stress. Stress is compatible with good health, being necessary to cope with the challenges of everyday life. Problems start when the stress response is inappropriate to the intensity of the challenge. Psychological stress can down regulate the cellular immune response. Communication between the central nervous system and the immune system occurs via a complex network of bidirectional signals linking the nervous, endocrine, and immune systems. Stress disrupts the homeostasis of this network, which in turn, alters immune function. Direct association between periodontal disease and stress remains to be proven, which is partly due to lack of an adequate animal models and difficulty to quantifying the amount and duration of stress and also there are many factors influencing the incidence and severity of periodontal disease. Nevertheless, more recent studies indicate that psychosocial stress represents a risk indicator for periodontal disease and should be addressed before and during treatment. This paper discusses how stress may modulate host response to bacteria and influence the course and progression of periodontal disease.

  8. The effect of rate of force application on the threshold of periodontal ligament mechanoreceptors in the cat canine tooth.

    PubMed

    Linden, R W; Millar, B J

    1988-01-01

    Mechanical stimuli in the form of ramp-plateau forces were applied to the tip of the crown of the left mandibular canine tooth in cats anaesthetized with alpha-chloralose. Electrophysiological recordings were made from functionally single fibres teased from the inferior alveolar nerve. The force threshold was determined for 34 periodontal ligament mechanoreceptors at different controlled rates of force application. Force threshold was dependent on the rate of force application to the crown tip. Rate sensitivity was present for all receptors across the range from rapidly to slowly adapting; the degree of rate sensitivity was graded according to the adaptation rate of the receptor. The results suggest that the velocity of mechanical stimulus application to teeth needs to be considered in studies involving periodontal mechanoreceptor responses and their reflexes.

  9. Effect of temperature and seven storage media on human periodontal ligament fibroblast viability.

    PubMed

    de Souza, Beatriz Dulcineia Mendes; Bortoluzzi, Eduardo Antunes; Reyes-Carmona, Jessie; Dos Santos, Luciane Geanini Pena; Simões, Claudia Maria de Oliveira; Felippe, Wilson Tadeu; Felippe, Mara Cristina Santos

    2017-04-01

    Natural resources, such as coconut water, propolis, and egg whites, have been examined as possible storage media for avulsed teeth. However, there is a lack of research focused on the efficacy of these three products together compared with Hank's balanced salt solution and milk. The aim of this study was to evaluate the capacity of seven storage media to maintain the viability of human periodontal ligament fibroblasts (PDLFs). PDLFs were kept at 5°C and 20°C, in skimmed milk (SMilk), whole milk (WMilk), recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth(®) system's HBSS (Save), natural coconut water (Coconut), Propolis, and egg white (Egg) for 3, 6, 24, 48, 72, 96, and 120 h, through the analysis of tetrazolium salt-based colorimetric (MTT) assay. At 5°C, SMilk and WMilk were better than HBSS in maintaining cell viability, from 24 h onward. At 20°C, HBSS was the best storage medium at 96 and 120 h. At both temperatures, from 6 h onward, Coconut, Propolis and Egg were less effective than SMilk, WMilk, and HBSS. In general, the performance of Coconut, Propolis and Egg were not influenced by storage temperature. However, the lowest temperature undermined the effectiveness of HBSS from 24 h and favored SMilk and WMilk, from 96 and 48 h onward, respectively. Save and water were the worst storage media. SMilk was the best storage medium, followed by WMilk and HBSS. Coconut, Propolis, and Egg can be indicated for the conservation of PDLF up to 3 h. The lower temperature (5°C) undermined the effectiveness of HBSS and favored SMilk and WMilk. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. The preservative effect of Thai propolis extract on the viability of human periodontal ligament cells.

    PubMed

    Prueksakorn, Attaporn; Puasiri, Subin; Ruangsri, Supanigar; Makeudom, Anupong; Sastraruji, Thanapat; Krisanaprakornkit, Suttichai; Chailertvanitkul, Pattama

    2016-12-01

    Tooth avulsion causes an injury to the periodontal ligament (PDL). The success of tooth replantation depends on the quantity and quality of PDL cells. The aim of this study was to examine the preservative and proliferative effects of Thai propolis extract, previously shown to exert anti-inflammatory and antioxidant activities, on human PDL cells. Ninety-six premolars were left to air dry for 30 min and stored in Hank's balanced salt solution (HBSS), milk, or various concentrations of propolis extract from 0.25 to 10 mg ml(-1) for 3 h. PDL cells were isolated by collagenase and trypsin digestion, and their viability was determined by a trypan blue dye exclusion assay. PDL tissues were also scraped off the root surface and cultured to determine cell growth and morphology. The alamarBlue(®) and BrdU assays were performed to determine the cytotoxic and proliferative effects of the extract on cultured PDL cells, respectively. A non-toxic dose of 2.5 mg ml(-1) of propolis extract yielded the greatest percentage of cell viability (78.84 ± 3.34%), which was significantly higher than those of the other concentrations (P < 0.001). Nevertheless, this percentage was not significantly different from that of HBSS (80.14 ± 2.44%; P = 1.00), but was significantly higher than that of milk (71.27 ± 2.79%; P < 0.001). The cells grown from PDL explants looked like fibroblasts. However, 2.5 mg ml(-1) of the extract did not induce PDL cell proliferation. Thai propolis extract at 2.5 mg ml(-1) appears to be the most effective dose for preserving the viability of PDL cells, and this was comparable to HBSS. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Differentiation and characteristics of undifferentiated mesenchymal stem cells originating from adult premolar periodontal ligaments

    PubMed Central

    Kwon, Dae-Woo; Im, Insook; Kim, Yong-Deok; Hwang, Dae-Seok; Holliday, L Shannon; Donatelli, Richard E; Son, Woo-Sung; Jun, Eun-Sook

    2012-01-01

    Objective The purpose of this study was to investigate the isolation and characterization of multipotent human periodontal ligament (PDL) stem cells and to assess their ability to differentiate into bone, cartilage, and adipose tissue. Methods PDL stem cells were isolated from 7 extracted human premolar teeth. Human PDL cells were expanded in culture, stained using anti-CD29, -CD34, -CD44, and -STRO-1 antibodies, and sorted by fluorescent activated cell sorting (FACS). Gingival fibroblasts (GFs) served as a positive control. PDL stem cells and GFs were cultured using standard conditions conducive for osteogenic, chondrogenic, or adipogenic differentiation. Results An average of 152.8 ± 27.6 colony-forming units was present at day 7 in cultures of PDL stem cells. At day 4, PDL stem cells exhibited a significant increase in proliferation (p < 0.05), reaching nearly double the proliferation rate of GFs. About 5.6 ± 4.5% of cells in human PDL tissues were strongly STRO-1-positive. In osteogenic cultures, calcium nodules were observed by day 21 in PDL stem cells, which showed more intense calcium staining than GF cultures. In adipogenic cultures, both cell populations showed positive Oil Red O staining by day 21. Additionally, in chondrogenic cultures, PDL stem cells expressed collagen type II by day 21. Conclusions The PDL contains multipotent stem cells that have the potential to differentiate into osteoblasts, chondrocytes, and adipocytes. This adult PDL stem cell population can be utilized as potential sources of PDL in tissue engineering applications. PMID:23323245

  12. The Plastic Nature of the Human Bone-Periodontal Ligament-Tooth Fibrous Joint

    PubMed Central

    Ho, Sunita P.; Kurylo, Michael P.; Grandfield, Kathryn; Hurng, Jonathan; Herber, Ralf-Peter; Ryder, Mark I.; Altoe, Virginia; Aloni, Shaul; Feng, Jian Q. (Jerry); Webb, Samuel; Marshall, Grayson W.; Curtis, Donald; Andrews, Joy C.; Pianetta, Piero

    2014-01-01

    This study investigates bony protrusions within a narrowed periodontal ligament space (PDL-space) of a human bone-PDL-tooth fibrous joint by mapping structural, biochemical, and mechanical heterogeneity. Higher resolution structural characterization was achieved via complementary atomic force microscopy (AFM), nano transmission X-ray microscopy (nano-TXM), and micro tomography (Micro XCT™). Structural heterogeneity was correlated to biochemical and elemental composition, illustrated via histochemistry and microprobe X-ray fluorescence analysis (μ-XRF), and mechanical heterogeneity evaluated by AFM-based nanoindentation. Results demonstrated that the narrowed PDL-space was due to invasion of bundle bone (BB) into PDL-space. Protruded BB had a wider range with higher elastic modulus values (2-8 GPa) compared to lamellar bone (0.8-6 GPa), and increased quantities of Ca, P and Zn as revealed by μ-XRF. Interestingly, the hygroscopic 10-30 μm interface between protruded BB and lamellar bone exhibited higher X-ray attenuation similar to cement lines and lamellae within bone. Localization of the small leucine rich proteoglycan biglycan (BGN) responsible for mineralization was observed at the PDL-bone interface and around the osteocyte lacunae. Based on these results, it can be argued that the LB-BB interface was the original site of PDL attachment, and that the genesis of protruded BB identified as protrusions occurred as a result of shift in strain. We emphasize the importance of bony protrusions within the context of organ function and that additional study is warranted. PMID:24063947

  13. Comparative Gene Expression Analysis of the Human Periodontal Ligament in Deciduous and Permanent Teeth

    PubMed Central

    Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; Park, Wonse; Choi, Hyung-Jun

    2013-01-01

    There are histological and functional differences between human deciduous and permanent periodontal ligament (PDL) tissues. The aim of this study was to determine the differences between these two types of tissue at the molecular level by comparing their gene expression patterns. PDL samples were obtained from permanent premolars (n = 38) and anterior deciduous teeth (n = 31) extracted from 40 healthy persons. Comparative cDNA microarray analysis revealed several differences in gene expression between the deciduous and permanent PDL tissues. These findings were verified by qRT-PCR (quantitative reverse-transcription–polymerase chain reaction) analysis, and the areas where genes are expressed were revealed by immunohistochemical staining. The expressions of 21 genes were up-regulated in deciduous relative to PDL tissues, and those of 30 genes were up-regulated in permanent relative to deciduous PDL tissues. The genes that were up-regulated in deciduous PDL tissues were those involved in the formation of the extracellular matrix (LAMC2, LAMB3, and COMP), tissue development (IGF2BP, MAB21L2, and PAX3), and inflammatory or immune reactions leading to tissue degradation (IL1A, CCL21, and CCL18). The up-regulated genes in permanent PDL tissues were related to tissue degradation (IL6 and ADAMTS18), myocontraction (PDE3B, CASQ2, and MYH10), and neurological responses (FOS, NCAM2, SYT1, SLC22A3, DOCK3, LRRTM1, LRRTM3, PRSS12, and ARPP21). The analysis of differential gene expressions between deciduous and permanent PDL tissues aids our understanding of histological and functional differences between them at the molecular level. PMID:23593441

  14. The Circular RNA Landscape of Periodontal Ligament Stem Cells During Osteogenesis.

    PubMed

    Zheng, Yunfei; Li, Xiaobei; Huang, Yiping; Jia, Lingfei; Li, Weiran

    2017-09-01

    The present study aims to investigate the distinct expression pattern of circular RNAs (circRNAs) in periodontal ligament stem cells (PDLSCs) during osteogenesis. PDLSCs were isolated and cultured in osteogenic medium. Total RNA was extracted from cells at day 0 (D0), day 3 (D3), day 7 (D7), and day 14 (D14) and submitted to RNA-sequencing to detect expression profiles of circRNAs, messenger RNAs (mRNAs), and microRNAs (miRNAs). Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to validate expression of circRNAs and miRNAs. Differential expression analysis and gene ontology analysis were performed. A circRNA-miRNA-mRNA network was constructed to reveal the potential regulatory role of circRNAs. A total of 12,693 circRNA transcripts were detected, and circRNAs displayed stage-specific expression. Expression of four well-known circRNAs was validated by qRT-PCR. In total, 118 circRNAs were differentially expressed at D3, 128 circRNAs were differentially expressed at D7, and 139 circRNAs were differentially expressed at D14 compared with D0. Host genes of differentially expressed circRNAs were enriched in cytoplasmic or membrane-bound vesicles and extracellular matrix, indicating their potential roles in modulating biogenesis of extracellular vesicles. Moreover, mRNAs that were potentially regulated by circRNAs were enriched in bone-formation-associated processes, including extracellular matrix organization, cell differentiation, and bone morphogenetic protein signaling pathway. Expression profiles of circRNAs were significantly altered during osteogenic differentiation of PDLSCs, providing a clue for future studies on the role of circRNAs in osteoblast differentiation.

  15. SPARC/Osteonectin Functions to Maintain Homeostasis of the Collagenous Extracellular Matrix in the Periodontal Ligament

    PubMed Central

    Trombetta, Jessica M.; Bradshaw, Amy D.

    2010-01-01

    Expression of secreted protein acidic and rich in cysteine (SPARC)/osteonectin, a collagen-binding matricellular protein, is frequently associated with tissues with high rates of collagen turnover, such as bone. In the oral cavity, expression of SPARC/osteonectin has been localized to the periodontal ligament (PDL), a collagen-rich tissue with high rates of collagen turnover. The PDL is critical for tooth position within the alveolar bone and for absorbing forces generated by chewing. To characterize the function of SPARC/osteonectin in PDL, SPARC/osteonectin expression in murine PDL was evaluated by immunochemistry at 1, 4, 6, and >18 months. Highest levels of SPARC/osteonectin were detected at 1 and >18 months, with decreased levels associated with adult (4–6 months) PDL. To determine whether the absence of SPARC/osteonectin expression influenced cellular and fibrillar collagen content in PDL, PDL of SPARC-null mice was evaluated using histological stains and compared with that of wild-type (WT). Our results demonstrated decreased numbers of nuclei in PDL of SPARC-null mice at 1 month. In addition, decreased collagen volume fractions were found at 1 and >18 months and decreases in thick collagen fiber volume fraction were detected at 4, 6, and >18 months in SPARC-null PDL. The greatest differences in cell number and in collagen content between SPARC-null and WT PDL coincided with ages at which levels of SPARC/osteonectin expression were highest in WT PDL, at 1 and >18 months. These results support the hypothesis that SPARC/osteonectin is critical in the control of tissue collagen content and indicate that SPARC/osteonectin is necessary for PDL homeostasis. (J Histochem Cytochem 58:871–879, 2010) PMID:20566756

  16. Effects of Activin A on the phenotypic properties of human periodontal ligament cells.

    PubMed

    Sugii, Hideki; Maeda, Hidefumi; Tomokiyo, Atsushi; Yamamoto, Naohide; Wada, Naohisa; Koori, Katsuaki; Hasegawa, Daigaku; Hamano, Sayuri; Yuda, Asuka; Monnouchi, Satoshi; Akamine, Akifumi

    2014-09-01

    Periodontal ligament (PDL) tissue plays an important role in tooth preservation by structurally maintaining the connection between the tooth root and the bone. The mechanisms involved in the healing and regeneration of damaged PDL tissue, caused by bacterial infection, caries and trauma, have been explored. Accumulating evidence suggests that Activin A, a member of the transforming growth factor-β (TGF-β) superfamily and a dimer of inhibinβa, contributes to tissue healing through cell proliferation, migration, and differentiation of various target cells. In bone, Activin A has been shown to exert an inhibitory effect on osteoblast maturation and mineralization. However, there have been no reports examining the expression and function of Activin A in human PDL cells (HPDLCs). Thus, we aimed to investigate the biological effects of Activin A on HPDLCs. Activin A was observed to be localized in HPDLCs and rat PDL tissue. When PDL tissue was surgically damaged, Activin A and IL-1β expression increased and the two proteins were shown to be co-localized around the lesion. HPDLCs treated with IL-1β or TNF-α also up-regulated the expression of the gene encoding inhibinβa. Activin A promoted chemotaxis, migration and proliferation of HPDLCs, and caused an increase in fibroblastic differentiation of these cells while down-regulating their osteoblastic differentiation. These osteoblastic inhibitory effects of Activin A, however, were only noted during the early phase of HPDLC osteoblastic differentiation, with later exposures having no effect on differentiation. Collectively, our results suggest that Activin A could be used as a therapeutic agent for healing and regenerating PDL tissue in response to disease, trauma or surgical reconstruction.

  17. Storage media enhance osteoclastogenic potential of human periodontal ligament cells via RANKL-independent signaling.

    PubMed

    Zhan, Xuan; Zhang, Chengfei; Dissanayaka, Waruna L; Cheung, Gary S P; Jin, Lijian; Yang, Yangqi; Yan, Fuhua; Tong, Edith H Y

    2013-02-01

    Hank's balanced salt solution (HBSS) and milk have gained wide acceptance as storage media for avulsed tooth. However, the effect of the media and storage time on the periodontal ligament (PDL) cells involvement in the development of root resorption is still unclear. The purpose of this study was to evaluate whether precultured PDL cells in HBSS, milk, or modified Eagle's medium alpha (α-MEM) would affect osteoclastogenesis. PDL cells were precultured in HBSS, milk, or α-MEM for 1 h or 6 h before being co-cultured with RAW 264.7 cells for an additional 3 days for mRNA analysis and 11 days for osteoclastogenesis assay. Cyclooxygenase-2 (COX-2) mRNA was detected immediately in PDL cells precultured in the three storage media. The expression was up-regulated markedly in all co-cultures when compared with RAW cells alone. As a result of the co-culture, interleukin-1β (IL-1β) expression was detectable in both PDL and RAW cells. TRAP+ multinucleated, osteoclast-like cells developed in all co-cultures; the number of TRAP+ cells was highest (P < 0.05) in the co-cultures that PDL cells precultured in milk for 6 h. The mRNA level of receptor activator of nuclear factor-kappa B ligand (RANKL) was not detected in PDL cells. Osteoprotegerin (OPG) mRNA expression reduced with increased preculture time, but the difference was not significant (P > 0.05). PDL cells kept in the three storage media led to TRAP+ multinucleated, osteoclast-like cells formation via RANKL-independent signaling. The ability to induce osteoclastogenesis may be considered as one of the factors to evaluate the ability of storage medium to maintain PDL viability after tooth avulsion. © 2012 John Wiley & Sons A/S.

  18. Endogenous hydrogen sulfide is involved in osteogenic differentiation in human periodontal ligament cells.

    PubMed

    Cen, Sheng-Dan; Yu, Wen-Bin; Ren, Man-Man; Chen, Li-Jiao; Sun, Chao-Fan; Ye, Zhi-Li; Deng, Hui; Hu, Rong-Dang

    2016-08-01

    Endogenous hydrogen sulfide (H2S) has recently emerged as an important intracellular gaseous signaling molecule within cellular systems. Endogenous H2S is synthesized from l-cysteine via cystathionine β-synthase and cystathionine γ-lyase and it regulates multiple signaling pathways in mammalian cells. Indeed, aberrant H2S levels have been linked to defects in bone formation in experimental mice. The aim of this study was to examine the potential production mechanism and function of endogenous H2S within primary human periodontal ligament cells (PDLCs). Primary human PDLCs were obtained from donor molars with volunteer permission. Immunofluorescent labeling determined expression of the H2S synthetase enzymes. These enzymes were inhibited with D,L-propargylglycine or hydroxylamine to examine the effects of H2S signaling upon the osteogenic differentiation of PDLCs. Gene and protein expression levels of osteogenic markers in conjunction with ALP staining and activity and alizarin red S staining of calcium deposition were used to assay the progression of osteogenesis under different treatment conditions. Cultures were exposed to Wnt3a treatment to assess downstream signaling mechanisms. In this study, we show that H2S is produced by human PDLCs via the cystathionine β-synthase/cystathionine γ-lyase pathway to promote their osteogenic differentiation. These levels must be carefully maintained as excessive or deficient H2S levels temper the observed osteogenic effect by inhibiting Wnt/β-catenin signaling. These results demonstrate that optimal concentrations of endogenous H2S must be maintained within PDLCs to promote osteogenic differentiation by activating the Wnt/β-catenin signaling cascade. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Human periodontal ligament stem cells cultured onto cortico-cancellous scaffold drive bone regenerative process.

    PubMed

    Diomede, F; Zini, N; Gatta, V; Fulle, S; Merciaro, I; D'Aurora, M; La Rovere, R M; Traini, T; Pizzicannella, J; Ballerini, P; Caputi, S; Piattelli, A; Trubiani, O

    2016-09-16

    The purpose of this work was to test, in vitro and in vivo, a new tissue-engineered construct constituted by porcine cortico-cancellous scaffold (Osteobiol Dual Block) (DB) and xeno-free ex vivo culture of human Periodontal Ligament Stem Cells (hPDLSCs). hPDLSCs cultured in xeno-free media formulation preserved the stem cells' morphological features, the expression of stemness and pluripotency markers, and their ability to differentiate into mesenchymal lineage. Transmission electron microscopy analysis suggested that after one week of culture, both noninduced and osteogenic differentiation induced cells joined and grew on DB secreting extracellular matrix (ECM) that in osteogenic induced samples was hierarchically assembled in fibrils. Quantitative RT-PCR (qRT-PCR) showed the upregulation of key genes involved in the bone differentiation pathway in both differentiated and undifferentiated hPDLSCs cultured with DB (hPDLSCs/DB). Functional studies revealed a significant increased response of calcium transients in the presence of DB, both in undifferentiated and differentiated cells stimulated with calcitonin and parathormone, suggesting that the biomaterial could drive the osteogenic differentiation process of hPDLSCs. These data were confirmed by the increase of gene expression of L-type voltage-dependent Ca2+ (VDCCL), subunits α1C and α2D1 in undifferentiated cells in the presence of DB. In vivo implantation of the hPDLSCs/DB living construct in the mouse calvaria evidenced a precocious osteointegration and vascularisation process. Our results suggest consideration of DB as a biocompatible, osteoinductive and osteoconductive biomaterial, making it a promising tool to regulate cell activities in biological environments and for a potential use in the development of new custom-made tissue engineering.

  20. Allogenic human serum, a clinical grade serum supplement for promoting human periodontal ligament stem cell expansion.

    PubMed

    Arpornmaeklong, Premjit; Sutthitrairong, Chotika; Jantaramanant, Piyathida; Pripatnanont, Prisana

    2016-12-13

    Exposing human periodontal ligament stem cells (hPDLSCs) to animal proteins during cell expansion would compromise quality and safety of the hPDLSCs for clinical applications. The current study aimed to evaluate the replacement of animal-based serum by human serum for the expansion of hPDLSCs. hPDLSCs were cultured in culture media supplemented with four types of serums: Group A: fetal bovine serum (FBS); Group B: allogeneic human male AB serum (HS); Group C: in-house autologous (Auto-HS); and Group D: in-house allogeneic human serums (Allo-HS). Exhibitions of mesenchymal stem cell characteristics of hPDLSCs were examined. Then, growth and osteogenic (OS) differentiation potential of hPDLSCs in FBS and HS at passages 5 and 15 were compared to investigate the effects of serum supplements on growth and expansion stability of the expanded hPDLSCs. After that, growth and OS differentiation of hPDLSCs in Auto- and Allo-HS were investigated. Flow cytometrical analyses, functional differentiations, cell growth kinetic, cytogenetic analysis, alkaline phosphatase and calcium content assays, and oil red O and von Kossa staining were performed. Results showed that at passage 5, HS promoted growth and OS differentiation of hPDLSCs and extensive cell expansion, decreased growth and differentiation potential of the expanded hPDLSCs, particularly in HS. Growth and OS differentiation of hPDLSCs in Auto-HS and Allo-HS were not different. In summary, allogeneic human serum could be a replacement to FBS for hPDLSC expansion. In vitro cell expansion of hPDLSCs should be minimal to ensure optimal cell quality. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. [The expression of transcription factor Osterix in human periodontal ligament cells].

    PubMed

    Ueda-Maeda, Mamiko

    2006-03-01

    Periodontal ligament (PDL) has a heterogeneous cell population, where some of the cells may be capable of differentiating into either cementoblasts or osteoblasts. Recently, C 2 H 2 zinc finger transcription factor Osterix has been reported. Osterix is one of the master regulators of bone cell differentiation and it has two different isoforms. According to a recent report, osteogenic differentiation of murine embryonic stem cells can be induced by overexpression of Osterix. The purpose of this study was to investigate about the expression of Osterix on human PDL (hPDL), and whether the osteogenic differentiation of hPDL cells can be induced by overexpression of Osterix. hPDL cells were obtained from healthy human teeth indicated for extraction for orthodontic treatment. All procedure used in this study was approved by the local ethical committee of Tokyo Medical and Dental University. To investigate expression of Osterix mRNA in hPDL tissues and cells, RT-PCR experiments were performed. Two different isoform Osterix expression vectors were made and transiently transfected into hPDL cells. Osteogenic differentiation was assessed by RT-PCR for genes associated with the osteoblast lineage such as Osteopontin, Osteocalcin, and Bone Sialoprotein. RT-PCR analyses showed that osterix mRNA was expressed in both hPDL tissue and cells. The expression of Osterix short isoform was higher than that of the long isoform. Overexpression of Osterix induced upregulated expression of Bone Sialoprotein mRNA. In expression levels of Osteopontin and Osteocalcin mRNA, compared to the control, no difference was observed. In conclusion, Osterix plays important roles in the osteoblastic differentiation in hPDL cells and modulates the mineralization.

  2. Caffeine may enhance orthodontic tooth movement through increasing osteoclastogenesis induced by periodontal ligament cells under compression.

    PubMed

    Yi, Jianru; Yan, Boxi; Li, Meile; Wang, Yu; Zheng, Wei; Li, Yu; Zhao, Zhihe

    2016-04-01

    Caffeine is the kernel component of coffee and has multiple effects on bone metabolism. Here we aimed to investigate the effects of caffeine intake on orthodontic tooth movement (OTM). (1) In the in vivo study, two groups comprising 15 randomly assigned rats each underwent orthodontic treatment. One group ingested caffeine at 25mg/kg body weight per day and the other, plain water. After 3 weeks, the degree of tooth movement and effect on the periodontium were assessed. (2) In the in vitro study, we established a model mimicking the essential bioprocess of OTM, which contained a periodontal ligament tissue model (PDLtm), and a co-culture system of osteoblasts (OBs) and osteoclast precursors (pre-OCs). After being subjected to static compressive force with or without caffeine administration, the conditioned media from the PDLtm were used for the OB/pre-OC co-cultures to induce osteoclastogenesis. (1) In vivo, the caffeine group displayed a significantly greater rate of tooth movement than the control. The alveolar bone mineral density and bone volume fraction were similar between the two groups; however, immunohistochemical staining showed that the caffeine group had significantly more TRAP(+) osteoclasts and higher RANKL expression in the compressed periodontium. (2) In vitro, caffeine at 0.01mM significantly enhanced the compression-induced expression of RANKL and COX-2, as well as prostaglandin E2 production in the PDLtm. Furthermore, the "caffeine+compression"-conditioned media induced significantly more TRAP(+) OC formation when compared with compression alone. Daily intake of caffeine, at least at some specific dosage, may enhance OTM through increasing osteoclastogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Static and dynamic responses of periodontal ligament mechanoreceptors and intradental mechanoreceptors.

    PubMed

    Dong, W K; Shiwaku, T; Kawakami, Y; Chudler, E H

    1993-05-01

    1. The response properties of 39 periodontal ligament mechanoreceptors (PDLMs) and 12 intradental mechanoreceptors (IMs) related to the intact mandibular canine tooth were isolated by extracellular recording methods from the ipsilateral trigeminal semilunar ganglion. 2. The stimulus threshold and response magnitude of individual PDLMs depended on the direction of steady force applied to the intact canine tooth. Canine PDLMs as a population, however, did not have a preferred stimulus direction. IMs were activated only by a rapid mechanical transient applied to the intact tooth in any direction. The stimulus threshold and response magnitude of each IM were approximately equipotent in all stimulus directions. 3. Application of quantifiable ramp-and-hold stimulation showed that PDLMs can encode the intensity of steady forces as well as the rate of force ramps. Increasing the ramp rates decreased the total ramp discharge but increased the peak discharge frequency. IMs encoded only the rate of force ramps that were applied by percussion. Higher ramp rates increased both the total discharges and peak discharge frequency of IMs. 4. The dynamic response properties of PDLMs and IMs were clearly differentiated by sinusoidal vibratory stimulation. The maximum frequencies for entrainment of IM discharge at the stimulus cycle length (251 +/- 103 Hz, mean +/- SD) and at any periodicity including multiples of the stimulus cycle length (295 +/- 100 Hz) were significantly higher than the maximum frequencies for PDLM discharge entrainment at the stimulus cycle length (103 +/- 53 Hz) and at any periodicity (133 +/- 62 Hz). 5. The functional similarities of PDLMs and IMs, respectively, to slowly adapting type II mechanoreceptors and Pacinian corpuscle receptors in the skin are discussed. Our present findings, which complement earlier anatomic and behavioral evidence, strongly suggest that IMs subserve nonnociceptive and nonpain functions. Both PDLMs and IMs may provide a continuum of

  4. Remote noxious stimuli modulate jaw reflexes evoked by activation of periodontal ligament mechanoreceptors in man.

    PubMed

    Mason, Andrew G; Scott, Brendan J J; van der Glas, Hilbert W; Linden, Roger W A; Cadden, Samuel W

    2002-11-01

    The purpose of the study was to investigate whether jaw reflexes evoked by selective stimulation of periodontal ligament me canoreceptors are susceptible to modulation by remote noxious stimulation. Experiments were performed on 10 volunteer subjects. Skin surface recordings were made from the jaw-closing masseter muscle. The subjects activated the muscle to approximately 10% of maximum by biting on a rubber impression of their molar teeth while they received visual feedback of the electromyogram (EMG) of the muscle. Reflexes were produced by the application of gentle mechanical stimuli to an upper central incisor tooth. The stimuli were in the form of 'ramp and hold' forces with a 5 ms rise-time and a 1.5 N plateau which lasted 350 ma. The resulting reflexes were recorded both under control conditions and while the subjects received a remote noxious stimulus (immersion of a hand in water at 3 degrees C). In all 10 subjects, the stimuli produced a single period of inhibition of masseteric activity (latency, 12.8 t 04 ms; duration, 18.1+/-1.3 ms; means +/- S.E.M.), which was usually followed by a period of increased masseteric activity. The period of inhibition constituted a downward wave in full-wave rectified, averaged signals. The integrals of such waves were significantly smaller (by 17+/- 6.5 %; P = 0.027; Student's t test) when the reflex was evoked during remote noxious stimulation rather than under control conditions. As such reflexes are beLieved to play a modulatory role during normal oral function this finding maybe relevant to disorders of mastication associated with pain.

  5. Hydro-mechanical coupling in the periodontal ligament: a porohyperelastic finite element model.

    PubMed

    Bergomi, Marzio; Cugnoni, Joël; Galli, Matteo; Botsis, John; Belser, Urs C; Wiskott, H W Anselm

    2011-01-04

    Harmonic tension-compression tests at 0.1, 0.5 and 1 Hz on hydrated bovine periodontal ligament (PDL) were numerically simulated. The process was modeled by finite elements (FE) within the framework of poromechanics, with the objective of isolating the contributions of the solid- and fluid phases. The solid matrix was modeled as a porous hyperelastic material (hyperfoam) through which the incompressible fluid filling the pores flowed in accordance with the Darcy's law. The hydro-mechanical coupling between the porous solid matrix and the fluid phase circulating through it provided an apparent time-dependent response to the PDL, whose rate of deformation depended on the permeability of the porous solid with respect to the interstitial fluid. Since the PDL was subjected to significant deformations, finite strains were taken into account and an exponential dependence of PDL permeability on void ratio - and therefore on the deformation state - was assumed. PDL constitutive parameters were identified by fitting the simulated response to the experimental data for the tests at 1 Hz. The values thus obtained were then used to simulate the tests at 0.1 and 0.5 Hz. The results of the present simulation demonstrate that a porohyperelastic model with variable permeability is able to describe the two main aspects of the PDL's response: (1) the dependency on strain-rate-the saturated material can develop volumetric strains by only exchanging fluid and (2) the asymmetry between tension and compression, which is due to the effect of both the permeability and the elastic properties on deformation.

  6. Effects ofrhBMP-2gene transfectionto periodontal ligament cells on osteogenesis.

    PubMed

    Jian, Cong-Xiang; Fan, Quan-Shui; Hu, Yong-He; He, Yong; Li, Ming-Zhe; Zheng, Wei-Yin; Ren, Yu; Li, Chen-Jun

    2017-04-10

    Objective: This study aims to investigate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the osteogenesis of periodontal ligament (PDL) cells. Method: The expression vector of rhBMP-2 (pcDNA3.1-rhBMP-2) was established. PDL cells were obtained through the enzymatic digestion and tissue explant methods and verified by immunohistochemistry. Cells were classified into an experimental (cells were transfected with pcDNA3.1/rhBMP-2-EGFP), blank (cells with no transfection) and control group (cells were transfected with empty plasmid). rhBMP-2 expression was assessed via western blotting analysis. The mineralization ability, alkaline phosphatase activity and level of related osteogenic biomarkers were detected to evaluate the osteogenic characteristics of PDL cells. Results: The rhBMP-2 expression vector (pcDNA3.1-rhBMP-2) was successfully established. Primary PDL cells displayed a star or long spindle shape. The cultured cells were long spindle shaped, had a plump cell body and homogeneous cytoplasm and the ellipse nucleus contained two or three nucleoli. Cells displayed a radial, sheaf-like or eddy-like arrangement after adherence growth. Immunohistochemical staining confirmed that cells originated from mesenchymal opposed to epithelium. The experimental group exhibited an enhanced mineralization ability, higher alkaline phosphatase activity and increased expression of rhBMP-2 and osteogenic biomarkers (runx2, collagen type I and osteocalcin) than the blank and control group. Conclusion: This study demonstrated that rhBMP-2 transfection enhances the osteogenesis of PDL cells and provides a possibility for the application of rhBMP-2 expression products in dental disease treatment.

  7. The plastic nature of the human bone-periodontal ligament-tooth fibrous joint.

    PubMed

    Ho, Sunita P; Kurylo, Michael P; Grandfield, Kathryn; Hurng, Jonathan; Herber, Ralf-Peter; Ryder, Mark I; Altoe, Virginia; Aloni, Shaul; Feng, Jian Q; Webb, Samuel; Marshall, Grayson W; Curtis, Donald; Andrews, Joy C; Pianetta, Piero

    2013-12-01

    This study investigates bony protrusions within a narrowed periodontal ligament space (PDL-space) of a human bone-PDL-tooth fibrous joint by mapping structural, biochemical, and mechanical heterogeneity. Higher resolution structural characterization was achieved via complementary atomic force microscopy (AFM), nano-transmission X-ray microscopy (nano-TXM), and microtomography (MicroXCT™). Structural heterogeneity was correlated to biochemical and elemental composition, illustrated via histochemistry and microprobe X-ray fluorescence analysis (μ-XRF), and mechanical heterogeneity evaluated by AFM-based nanoindentation. Results demonstrated that the narrowed PDL-space was due to invasion of bundle bone (BB) into PDL-space. Protruded BB had a wider range with higher elastic modulus values (2-8GPa) compared to lamellar bone (0.8-6GPa), and increased quantities of Ca, P and Zn as revealed by μ-XRF. Interestingly, the hygroscopic 10-30μm interface between protruded BB and lamellar bone exhibited higher X-ray attenuation similar to cement lines and lamellae within bone. Localization of the small leucine rich proteoglycan biglycan (BGN) responsible for mineralization was observed at the PDL-bone interface and around the osteocyte lacunae. Based on these results, it can be argued that the LB-BB interface was the original site of PDL attachment, and that the genesis of protruded BB identified as protrusions occurred as a result of shift in strain. We emphasize the importance of bony protrusions within the context of organ function and that additional study is warranted.

  8. Mesenchymal stem cell characteristics of dental pulp and periodontal ligament stem cells after in vivo transplantation.

    PubMed

    Lei, Ming; Li, Kun; Li, Bei; Gao, Li-Na; Chen, Fa-Ming; Jin, Yan

    2014-08-01

    Mesenchymal stem cells (MSCs) isolated from human postnatal dental pulp and periodontal ligament (PDL) tissues can give rise to multilineage differentiation in vitro and generate related dental tissues in vivo. However, the cell properties of human dental pulp stem cells (DPSCs) and PDL stem cells (PDLSCs) after in vivo implantation remain largely unidentified. In this study, cells were re-isolated from in vivo-generated dental pulp-like and PDL-like tissues (termed re-DPCs and re-PDLCs, respectively) as a result of ectopic transplantation of human DPSC and PDLSC sheets. The cell characteristics in terms of colony-forming ability, cell surface antigens and multi-differentiation potentials were all evaluated before and after implantation. It was found that re-DPCs and re-PDLCs were of human and mesenchymal origin and positive for MSC markers such as STRO-1, CD146, CD29, CD90 and CD105; and, to some extent, re-DPCs could maintain their colony forming abilities. Moreover, both cell types were able to form mineral deposits and differentiate into adipocytes and chondrocytes; however, quantitative analysis and related gene expression determination showed that the osteo-/chondro-differentiation capabilities of re-DPCs and re-PDLCs were significantly reduced compared to those of DPSCs and PDLSCs, respectively (P < 0.05); re-PDLCs showed a greater reduction potential than re-DPCs. We conclude that DPSCs and PDLSCs may maintain their MSC characteristics after in vivo implantation and, compared to PDLSCs, DPSCs appear much more stable under in vivo conditions. These findings provide additional cellular and molecular evidence that supports expanding the use of dental tissue-derived stem cells in cell therapy and tissue engineering.

  9. Functional differences in mesenchymal stromal cells from human dental pulp and periodontal ligament.

    PubMed

    Vasandan, Anoop Babu; Shankar, Shilpa Rani; Prasad, Priya; Sowmya Jahnavi, Vulugundam; Bhonde, Ramesh Ramachandra; Jyothi Prasanna, Susarla

    2014-02-01

    Clinically reported reparative benefits of mesenchymal stromal cells (MSCs) are majorly attributed to strong immune-modulatory abilities not exactly shared by fibroblasts. However, MSCs remain heterogeneous populations, with unique tissue-specific subsets, and lack of clear-cut assays defining therapeutic stromal subsets adds further ambiguity to the field. In this context, in-depth evaluation of cellular characteristics of MSCs from proximal oro-facial tissues: dental pulp (DPSCs) and periodontal ligament (PDLSCs) from identical donors provides an opportunity to evaluate exclusive niche-specific influences on multipotency and immune-modulation. Exhaustive cell surface profiling of DPSCs and PDLSCs indicated key differences in expression of mesenchymal (CD105) and pluripotent/multipotent stem cell-associated cell surface antigens: SSEA4, CD117, CD123 and CD29. DPSCs and PDLSCs exhibited strong chondrogenic potential, but only DPSCs exhibited adipogenic and osteogenic propensities. PDLSCs expressed immuno-stimulatory/immune-adhesive ligands like HLA-DR and CD50, upon priming with IFNγ, unlike DPSCs, indicating differential response patterns to pro-inflammatory cytokines. Both DPSCs and PDLSCs were hypo-immunogenic and did not elicit robust allogeneic responses despite exposure to IFNγ or TNFα. Interestingly, only DPSCs attenuated mitogen-induced lympho-proliferative responses and priming with either IFNγ or TNFα enhanced immuno-modulation capacity. In contrast, primed or unprimed PDLSCs lacked the ability to suppress polyclonal T cell blast responses. This study indicates that stromal cells from even topographically related tissues do not necessarily share identical MSC properties and emphasizes the need for a thorough functional testing of MSCs from diverse sources with respect to multipotency, immune parameters and response to pro-inflammatory cytokines before translational usage.

  10. Expression and effects of epidermal growth factor on human periodontal ligament cells.

    PubMed

    Teramatsu, Yoko; Maeda, Hidefumi; Sugii, Hideki; Tomokiyo, Atsushi; Hamano, Sayuri; Wada, Naohisa; Yuda, Asuka; Yamamoto, Naohide; Koori, Katsuaki; Akamine, Akifumi

    2014-09-01

    Repair of damaged periodontal ligament (PDL) tissue is an essential challenge in tooth preservation. Various researchers have attempted to develop efficient therapies for healing and regenerating PDL tissue based on tissue engineering methods focused on targeting signaling molecules in PDL stem cells and other mesenchymal stem cells. In this context, we investigated the expression of epidermal growth factor (EGF) in normal and surgically wounded PDL tissues and its effect on chemotaxis and expression of osteoinductive and angiogenic factors in human PDL cells (HPDLCs). EGF as well as EGF receptor (EGFR) expression was observed in HPDLCs and entire PDL tissue. In a PDL tissue-injured model of rat, EGF and IL-1β were found to be upregulated in a perilesional pattern. Interleukin-1β induced EGF expression in HPDLCs but not EGFR. It also increased transforming growth factor-α (TGF-α) and heparin-binding EGF-like growth factor (HB-EGF) expression. Transwell assays demonstrated the chemotactic activity of EGF on HPDLCs. In addition, EGF treatment significantly induced secretion of bone morphogenetic protein 2 and vascular endothelial growth factor, and gene expression of interleukin-8 (IL-8), and early growth response-1 and -2 (EGR-1/2). Human umbilical vein endothelial cells developed well-formed tube networks when cultured with the supernatant of EGF-treated HPDLCs. These results indicated that EGF upregulated under inflammatory conditions plays roles in the repair of wounded PDL tissue, suggesting its function as a prospective agent to allow the healing and regeneration of this tissue.

  11. Proteome of Human Stem Cells from Periodontal Ligament and Dental Pulp

    PubMed Central

    Sulpizio, Marilisa; Di Giuseppe, Fabrizio; Pierdomenico, Laura; Marchisio, Marco; Giancola, Raffaella; Giammaria, Gianluigi; Miscia, Sebastiano; Caputi, Sergio; Di Ilio, Carmine; Angelucci, Stefania

    2013-01-01

    Background Many adult tissues contain a population of stem cells with the ability to regenerate structures similar to the microenvironments from which they are derived in vivo and represent a promising therapy for the regeneration of complex tissues in the clinical disorder. Human adult stem cells (SCs) including bone marrow stem cells (BMSCs), dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) have been characterized for their high proliferative potential, expression of characteristic SC-associated markers and for the plasticity to differentiate in different lineage in vitro. Methodology/Principal Findings The aim of this study is to define the molecular features of stem cells from oral tissue by comparing the proteomic profiles obtained with 2-DE followed by MALDI-TOF/TOF of ex-vivo cultured human PDLSCs, DPSCs and BMSCs. Our results showed qualitative similarities in the proteome profiles among the SCs examined including some significant quantitative differences. To enrich the knowledge of oral SCs proteome we performed an analysis in narrow range pH 4–7 and 6–9, and we found that DPSCs vs PDLSCs express differentially regulated proteins that are potentially related to growth, regulation and genesis of neuronal cells, suggesting that SCs derived from oral tissue source populations may possess the potential ability of neuronal differentiation which is very consistent with their neural crest origin. Conclusion/Significance This study identifies some differentially expressed proteins by using comparative analysis between DPSCs and PDLSCs and BMSCs and suggests that stem cells from oral tissue could have a different cell lineage potency compared to BMSCs. PMID:23940696

  12. Cardiomyogenesis of periodontal ligament-derived stem cells by dynamic tensile strain.

    PubMed

    Pelaez, Daniel; Acosta Torres, Zenith; Ng, Tsz Kin; Choy, Kwong Wai; Pang, Chi Pui; Cheung, Herman S

    2017-02-01

    Cellular therapies for the treatment of myocardial infarction have proven to be an invaluable tool in recent years and provide encouraging evidence for the possibility to restore normal heart function. However, questions still remain as to the optimal cell source, pre-conditioning methods and delivery techniques for such an application. This study explores the use of a population of stem cells arising from the neural crest and isolated from adult human periodontal ligament along with short-term mechanical strain as an inducer of cardiomyogenesis and possibly pre-conditioning stimulus for cellular cardiomyoplasty. Cells were subjected to a short-term dynamic mechanical tension in our custom-built bioreactor and analyzed for cardiomyogenic commitment. Mechanical strain elicited a cardiomyogenic response from the cells following just 2 h of stimulation. Mechanical strain activated and translocated cardiac-specific transcription factors GATA4, MEF2C and Nkx2.5, and induced expression of the sarcomeric actin and cardiac troponin T proteins. Mechanical strain induced production of significantly higher levels of nitric oxide when compared to static controls. Elimination of elevated ROS levels by free radical scavengers completely abolished the cardiomyogenic response of the cells. MicroRNA profile changes in stretched cells were detected for 39 miRNAs with 16 of the differentially expressed miRNAs related to heart development. The use of stem cells in combination with mechanical strain prior to their delivery in vivo may pose a valuable alternative for the treatment of myocardial infarction and merits further exploration for its capacity to augment the already observed beneficial effects of cellular therapies.

  13. Effect of Root Filling on Stress Distribution in Premolars with Endodontic-Periodontal Lesion: A Finite Elemental Analysis Study.

    PubMed

    Belli, Sema; Eraslan, Oğuz; Eskitascioglu, Gürcan

    2016-01-01

    Endodontic-periodontal (EP) lesions require both endodontic and periodontal therapies. Impermeable sealing of the root canal system after cleaning and shaping is essential for a successful endodontic treatment. However, complete healing of the hard and soft tissue lesions takes time, and diseased bone, periodontal ligament, and tooth fibrous joints are reported to have an increased failure risk for a given load. Considering that EP lesions may affect the biomechanics of teeth, this finite elemental analysis study aimed to test the effect of root fillings on stress distribution in premolars with EP lesions. Three finite elemental analysis models representing 3 different types of EP lesions (primary endodontic disease [PED], PED with secondary periodontic involvement, and true combined) were created. The root canals were assumed as nonfilled or filled with gutta-percha, gutta-percha/apical mineral trioxide aggregate (MTA) plug, and MTA-based sealer. Materials used were assumed to be homogenous and isotropic. A 300-N load was applied from the buccal cusp of the crown with a 135° angle. The Cosmoworks structural-analysis program (SolidWorks Corp, Waltham, MA) was used for analysis. Results were presented considering von Mises criteria. Stresses at the root apex increased with an increase in lesion dimensions. Root filling did not affect stress distribution in the PED model. An MTA plug or MTA-based sealer created more stress areas within the root compared with the others in the models representing PED with periodontic involvement and true combined lesions. Stresses at the apical end of the root increase with increases in lesion dimensions. MTA-based sealers or an MTA plug creates more stresses when there is periodontic involvement or a true combined lesion. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Tri-Layered Nanocomposite Hydrogel Scaffold for the Concurrent Regeneration of Cementum, Periodontal Ligament, and Alveolar Bone.

    PubMed

    Sowmya, S; Mony, Ullas; Jayachandran, P; Reshma, S; Kumar, R Arun; Arzate, H; Nair, Shantikumar V; Jayakumar, R

    2017-04-01

    A tri-layered scaffolding approach is adopted for the complete and concurrent regeneration of hard tissues-cementum and alveolar bone-and soft tissue-the periodontal ligament (PDL)-at a periodontal defect site. The porous tri-layered nanocomposite hydrogel scaffold is composed of chitin-poly(lactic-co-glycolic acid) (PLGA)/nanobioactive glass ceramic (nBGC)/cementum protein 1 as the cementum layer, chitin-PLGA/fibroblast growth factor 2 as the PDL layer, and chitin-PLGA/nBGC/platelet-rich plasma derived growth factors as the alveolar bone layer. The tri-layered nanocomposite hydrogel scaffold is cytocompatible and favored cementogenic, fibrogenic, and osteogenic differentiation of human dental follicle stem cells. In vivo, tri-layered nanocomposite hydrogel scaffold with/without growth factors is implanted into rabbit maxillary periodontal defects and compared with the controls at 1 and 3 months postoperatively. The tri-layered nanocomposite hydrogel scaffold with growth factors demonstrates complete defect closure and healing with new cancellous-like tissue formation on microcomputed tomography analysis. Histological and immunohistochemical analyses further confirm the formation of new cementum, fibrous PDL, and alveolar bone with well-defined bony trabeculae in comparison to the other three groups. In conclusion, the tri-layered nanocomposite hydrogel scaffold with growth factors can serve as an alternative regenerative approach to achieve simultaneous and complete periodontal regeneration. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Effect of icariin on cell proliferation and the expression of bone resorption/formation-related markers in human periodontal ligament cells.

    PubMed

    Pei, Zhenhua; Zhang, Fengqiu; Niu, Zhongying; Shi, Shenggen

    2013-11-01

    Periodontitis is a common destructive inflammatory disease that leads to changes in the tooth-supporting tissues. Human periodontal ligament cells are essential in periodontal tissue regeneration. The traditional Chinese medicine icariin promoted bone formation, stimulated the osteogenic differentiation of preosteoblastic cells and inhibited osteoclast differentiation and bone resorption. Thus, in the present study, the effect of icariin on cell proliferation and the expression of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), core binding factor α1 (Cbfa1) and osteocalcin (OC) was investigated in human periodontal ligament cells, by an MTT assay, qPCR and western blot analysis. The results demonstrated that icariin promoted cell proliferation in a dose- and time-dependent manner, upregulated OPG, Cbfa1 and OC expression, and downregulated RANKL production and the RANKL/OPG expression ratio. This suggested the potential value of icariin in treating alveolar bone resorption and promoting periodontal tissue regeneration, due to its ability to stimulate the proliferation and osteogenic differentiation of human periodontal ligament cells and inhibit osteoclast differentiation.

  16. Oxidative Stress: A Link between Diabetes Mellitus and Periodontal Disease.

    PubMed

    Monea, Adriana; Mezei, Tibor; Popsor, Sorin; Monea, Monica

    2014-01-01

    Objective. To investigate oxidative stress (OS) and histological changes that occur in the periodontium of subjects with type 2 diabetes mellitus without signs of periodontal disease and to establish if oxidative stress is a possible link between diabetes mellitus and periodontal changes. Materials and Methods. Tissue samples from ten adult patients with type 2 diabetes mellitus (T2D) and eight healthy adults were harvested. The specimens were examined by microscope using standard hematoxylin-eosin stain, at various magnifications, and investigated for tissue levels of malondialdehyde (MDA) and glutathione (GSH). Results. Our results showed that periodontal tissues in patients with T2D present significant inflammation, affecting both epithelial and connective tissues. Mean MDA tissue levels were 3.578 ± 0.60 SD in diabetics versus 0.406 ± 0.27 SD in controls (P < 0.0001), while mean GSH tissue levels were 2.48 ± 1.02 SD in diabetics versus 9.7875 ± 2.42 SD in controls (P < 0.0001). Conclusion. Diabetic subjects had higher MDA levels in their periodontal tissues, suggesting an increased lipid peroxidation in T2D, and decreased GSH tissue levels, suggesting an alteration of the local antioxidant defense mechanism. These results are in concordance with the histological changes that we found in periodontal tissues of diabetic subjects, confirming the hypothesis of OS implication, as a correlation between periodontal disease incidence and T2D.

  17. Lactone form 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) stimulate the osteoblastic differentiation of mouse periodontal ligament cells via the ERK pathway.

    PubMed

    Kim, I S; Jeong, B C; Kim, O S; Kim, Y J; Lee, S E; Lee, K N; Koh, J T; Chung, H J

    2011-04-01

    Recent studies reported that the lactone forms of 3-hydroxy- 3-methylglutaryl-coenzyme A reductase inhibitors, which are also known as statins, have a bone stimulatory effect. However, there are few reports on the effect of statins on periodontal ligament cells. This study examined the statin-induced osteoblastic differentiation of mouse periodontal ligament cells as well as its mechanism. Mouse periodontal ligament cells were cultured with lovastatin or simvastatin, and their viability was measured. The levels of alkaline phosphatase (ALP), osteocalcin, bone sialoprotein and bone morphogenetic protein-2 mRNA expression were evaluated by RT-PCR. The osteoblastic differentiation was characterized by the ALP activity and Alizarin Red-S staining for calcium deposition. The activity of the osteocalcin gene (OG2) and synthetic osteoblast-specific elements (6× OSE) promoter with statins was also measured using a luciferase assay. For the signal mechanism of statins, the ERK1/2 MAPK activity was determined by western blot analysis. A statin treatment at concentrations < 1 μM did not affect the cell viability. Lovastatin or simvastatin at 0.1 μM increased the levels of ALP, osteocalcin, bone sialoprotein and bone morphogenetic protein-2 mRNA in mouse periodontal ligament cells. In addition, the ALP activity, mineralized nodule formation and OG2 and OSE promoter activity were higher in the lovastatin- or simvastatin-treated cells than the control cells. Western blot analysis confirmed that the statins stimulated the phosphorylation of ERK1/2. Lovastatin and simvastatin may stimulate the osteoblastic differentiation of periodontal ligament cells via the ERK1/2 pathway. This suggests that the statins may be useful for regenerating periodontal hard tissue. © 2010 John Wiley & Sons A/S.

  18. Comparative in vitro study of the effectiveness of Green tea extract and common storage media on periodontal ligament fibroblast viability

    PubMed Central

    Adeli, Fahimeh; Zabihi, Ebrahim; Abedian, Zeinab; Gharekhani, Samane; Pouramir, Mahdi; Khafri, Soraya; Ghasempour, Maryam

    2016-01-01

    Objective: Green tea extract (GTE) was shown to be effective in preserving periodontal ligament fibroblasts (PDLFs) of avulsed teeth. This study aimed at determining the potential of GTE in preserving the viability of PDLFs comparing with different storage media. Materials and Methods: Periodontal ligament cells were obtained from freshly extracted healthy impacted third molars and cultured in Dulbecco's Modified Eagle Medium (DMEM). Cell viability was determined by storing the cells in seven media; DMEM, tap water, Hank's balanced salt solution (HBSS), whole milk, hypotonic sucrose solution, GTE, and GTE + sucrose for 1, 2, 4, and 24 h at 37°C using tetrazolium salt-based colorimetric (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay. Statistical analysis was performed by one-way analysis of variance and post hoc tests. Results: GTE showed significantly higher protective effect than HBSS at 2, 4, and 24 h (P = 0.009, P = 0.02, P = 0.016), DMED at 2 h (P = 0.003), and milk at 4 h (P = 0.039). Conclusion: Although with undesirable osmolality and pH, GTE had a good ability in preserving the PDLFs comparing with other studied media. PMID:27403063

  19. DNA Demethylation Rescues the Impaired Osteogenic Differentiation Ability of Human Periodontal Ligament Stem Cells in High Glucose

    PubMed Central

    Liu, Zhi; Chen, Tian; Sun, Wenhua; Yuan, Zongyi; Yu, Mei; Chen, Guoqing; Guo, Weihua; Xiao, Jingang; Tian, Weidong

    2016-01-01

    Diabetes mellitus, characterized by abnormally high blood glucose levels, gives rise to impaired bone remodeling. In response to high glucose (HG), the attenuated osteogenic differentiation capacity of human periodontal ligament stem cells (hPDLSCs) is associated with the loss of alveolar bone. Recently, DNA methylation was reported to affect osteogenic differentiation of stem cells in pathological states. However, the intrinsic mechanism linking DNA methylation to osteogenic differentiation ability in the presence of HG is still unclear. In this study, we found that diabetic rats with increased DNA methylation levels in periodontal ligaments exhibited reduced bone mass and density. In vitro application of 5-aza-2′-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to decrease DNA methylation levels in hPDLSCs, rescued the osteogenic differentiation capacity of hPDLSCs under HG conditions. Moreover, we demonstrated that the canonical Wnt signaling pathway was activated during this process and, under HG circumstances, the 5-aza-dC-rescued osteogenic differentiation capacity was blocked by Dickkopf-1, an effective antagonist of the canonical Wnt signaling pathway. Taken together, these results demonstrate for the first time that suppression of DNA methylation is able to facilitate the osteogenic differentiation capacity of hPDLSCs exposed to HG, through activation of the canonical Wnt signaling pathway. PMID:27273319

  20. Stimulation of Periodontal Ligament Stem Cells by Dentin Matrix Protein 1 Activates Mitogen-Activated Protein Kinase and Osteoblast Differentiation

    PubMed Central

    Chandrasekaran, Sangeetha; Ramachandran, Amsaveni; Eapen, Asha; George, Anne

    2013-01-01

    Background Periodontitis can ultimately result in tooth loss. Many natural and synthetic materials have been tried to achieve periodontal regeneration, but the results remain variable and unpredictable. We hypothesized that exogenous treatment with dentin matrix protein 1 (DMP1) activates specific genes and results in phenotypic and functional changes in human periodontal ligament stem cells (hPDLSCs). Methods hPDLSCs were isolated from extracted teeth and cultured in the presence or absence of DMP1. Quantitative polymerase chain reactions were performed to analyze the expression of several genes involved in periodontal regeneration. hPDLSCs were also processed for immunocytochemical and Western blot analysis using phosphorylated extracellular signal-regulated kinase (pERK) and ERK antibodies. Alkaline phosphatase and von Kossa staining were performed to characterize the differentiation of hPDLSCs into osteoblasts. Field emission scanning electron microscopic analysis of the treated and control cell cultures were also performed. Results Treatment with DMP1 resulted in the upregulation of genes, such as matrix metalloproteinase-2, alkaline phosphatase, and transforming growth factor β1. Activation of ERK mitogen-activated protein kinase signaling pathway and translocation of pERK from the cytoplasm to the nucleus was observed. Overall, DMP1-treated cells showed increased expression of alkaline phosphatase, increased matrix, and mineralized nodule formation when compared with untreated controls. Conclusion DMP1 can orchestrate a coordinated expression of genes and phenotypic changes in hPDLSCs by activation of the ERK signaling pathway, which may provide a valuable strategy for tissue engineering approaches in periodontal regeneration. PMID:22612367

  1. Histological analysis of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low-level laser therapy.

    PubMed

    Maia, Luiz Guilherme Martins; Alves, Angela Valéria Farias; Bastos, Talita Santos; Moromizato, Lucas Sandes; Lima-Verde, Isabel Bezerra; Ribeiro, Maria Amália Gonzaga; Gandini Júnior, Luiz Gonzaga; de Albuquerque-Júnior, Ricardo Luiz Cavalcanti

    2014-06-05

    The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT). The movement of the upper molar was performed in 60 male Wistar rats divided into four groups (n=15): CTR (control), DBT (diabetic), CTR/LT (irradiated control) and DBT/LT (irradiated diabetic). Diabetes was induced with alloxan (150 mg/kg, i.p.). LLLT was applied with GaAlAs laser at 780 nm (35 J/cm(2)). After 7, 13 and 19 days, the periodontal ligament and alveolar bone were histologically analyzed. The mean of osteoblasts (p<0.01) and blood vessels (p<0.05) were significantly decreased in DBT compared with CTR at 7 days, whereas the mean of osteoclasts was lower at 7 (p<0.001) and 13 days (p<0.05). In DBT/LT, only the mean of osteoclasts was lower than in CTR (p<0.05) at 7 days, but no difference was observed at 13 and 19 days (p>0.05). The collagenization of the periodontal ligament was impaired in DBT, whereas DBT/LLT showed density/disposition of the collagen fibers similar to those observed in CTR. LLLT improved the periodontal ligament and alveolar bone remodeling activity in diabetic rats during dental movement. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. [Alteration mechanisms of oxidative stress at periodontal tissues of rats in a simulated periodontitis and elaborate methods of their correction].

    PubMed

    Хмиль, Елена В; Ляшенко, Лилия И; Янко, Наталия В; Хмиль, Дмитрий А; Каськова, Людмила Ф

    2016-01-01

    one of the peroxidation stress mechanisms is inducible NO synthase (iNOS) expression involved in the pathogenesis of periodontitis. to access the influence of isoform NO synthase (NOS) on alteration mechanisms of oxidative stress at periodontal tissues of 50 mature rats in a simulated periodontitis (SP). a SP at rats was induced by a high-carbohydrate, high-fat (HCHF) diet. Тreated SP rat groups were intragastrically administered with selective neuronal NOS (nNOS) inhibitor 7-nitroindazole, selective inducible NOS (iNOS) inhibitor aminoguanidine, and nitric oxide synthase substrate L-arginine. Oxidative stress level in the homogenated soft periodontal tissues was evaluated by TBARS (thiobarbituric acid reactive substances) level before and after 1,5 hours of incubation. Antioxidant response was evaluated by the increase in concentration of TBARS for incubation, аnd by antioxidant enzyme activity - superoxide dismutase and catalase. nNOS activity increase in a SP considerably limits oxidative stress activation at periodontal tissues, decreases antioxidant response, but heightens catalase activity. iNOS functional activity stimulates oxidative stress at periodontal tissues of rats, decreases antioxidant response. L-arginine in a MS effectively repaired antioxidant response at periodontal tissues that probably will give positive result at complex treatment of periodontitis and MS generally. in the near future, the appropriate regulation of NO activity by using NOS-active agents may provide a novel strategy for the periodontal disease prevention and correction in a MS.

  3. [Alteration mechanisms of oxidative stress at periodontal tissues of rats in a simulated periodontitis and elaborate methods of their correction].

    PubMed

    Хмиль, Елена В; Ляшенко, Лилия И; Янко, Наталия В; Хмиль, Дмитрий А; Каськова, Людмила Ф

    one of the peroxidation stress mechanisms is inducible NO synthase (iNOS) expression involved in the pathogenesis of periodontitis. to access the influence of isoform NO synthase (NOS) on alteration mechanisms of oxidative stress at periodontal tissues of 50 mature rats in a simulated periodontitis (SP). a SP at rats was induced by a high-carbohydrate, high-fat (HCHF) diet. Тreated SP rat groups were intragastrically administered with selective neuronal NOS (nNOS) inhibitor 7-nitroindazole, selective inducible NOS (iNOS) inhibitor aminoguanidine, and nitric oxide synthase substrate L-arginine. Oxidative stress level in the homogenated soft periodontal tissues was evaluated by TBARS (thiobarbituric acid reactive substances) level before and after 1,5 hours of incubation. Antioxidant response was evaluated by the increase in concentration of TBARS for incubation, аnd by antioxidant enzyme activity - superoxide dismutase and catalase. nNOS activity increase in a SP considerably limits oxidative stress activation at periodontal tissues, decreases antioxidant response, but heightens catalase activity. iNOS functional activity stimulates oxidative stress at periodontal tissues of rats, decreases antioxidant response. L-arginine in a MS effectively repaired antioxidant response at periodontal tissues that probably will give positive result at complex treatment of periodontitis and MS generally. in the near future, the appropriate regulation of NO activity by using NOS-active agents may provide a novel strategy for the periodontal disease prevention and correction in a MS.

  4. Conditioned media from differentiating craniofacial bone marrow stromal cells influence mineralization and proliferation in periodontal ligament stem cells.

    PubMed

    Jin, Zhenyu; Feng, Yuan; Liu, Hongwei

    2016-10-01

    Previous reports have mainly focused on the behavioral responses of human periodontal ligament stem cells (hPDLSCs) in interaction with tibia bone marrow stromal cells (BMSCs). However, there is little study on the biologic features of hPDLSCs under the induction of maxilla BMSCs (M-BMSCs) at different phases of osteogenic differentiation. We hypothesized that M-BMSCs undergoing osteogenic differentiation acted on the proliferation, differentiation, and bone-forming capacity of hPDLSCs. In this paper, primary hPDLSCs and human M-BMSCs (hM-BMSCs) were expanded in vitro. After screening of surface markers for characterization, hPDLSCs were cocultured with different phases of differentiating hM-BMSCs. Cell proliferation and alkaline phosphatase activity were examined, and mineralization-associated markers such as osteocalcin and runt-related transcription factor 2 of hPDLSCs in coculture with uninduced/osteoinduced hM-BMSCs were evaluated. hPDLSCs in hM-BMSCs-conditioned medium (hM-BMSCs-CM) group showed a reduction in proliferation compared with untreated hPDLSCs, while osteoinduced hM-BMSCs for 10 day-conditioned medium (hM-BMSCs-CM-10ds) and osteoinduced hM-BMSCs for 15 day-conditioned medium (hM-BMSCs-CM-15ds) enhance the proliferation of hPDLSCs. hM-BMSCs of separate differentiation stages temporarily inhibited osteogenesis of hPDLSCs in the early days. Upon extending time periods, uninduced/osteoinduced hM-BMSCs markedly enhanced osteogenesis of hPDLSCs to different degrees. The transplantation results showed hM-BMSCs-CM-15ds treatment promoted tissue regeneration to generate cementum/periodontal ligament-like structure characterized by hard-tissue formation. This research supported the notion that hM-BMSCs triggered osteogenesis of hPDLSCs suggesting important implications for periodontal engineering.

  5. Biomechanics of a Bone-Periodontal Ligament-Tooth Fibrous Joint

    PubMed Central

    Lin, Jeremy D.; Özcoban, Hüseyin; Greene, Janelle; Jang, Andrew T.; Djomehri, Sabra; Fahey, Kevin; Hunter, Luke; Schneider, Gerold A; Ho, Sunita P.

    2013-01-01

    This study investigates bone-tooth association under compression to identify strain amplified sites within the bone-periodontal ligament (PDL)-tooth fibrous joint. Our results indicate that the biomechanical response of the joint is due to a combinatorial response of constitutive properties of organic, inorganic, and fluid components. Second maxillary molars within intact maxillae (N=8) of 5-month-old rats were loaded with a μ-XCT-compatible in situ loading device at various permutations of displacement rates (0.2, 0.5, 1.0, 1.5, 2.0 mm/min) and peak reactionary load responses (5, 10, 15, 20 N). Results indicated a nonlinear biomechanical response of the joint, in which the observed reactionary load rates were directly proportional to displacement rates (velocities). No significant differences in peak reactionary load rates at a displacement rate of 0.2 mm/min were observed. However, for displacement rates greater than 0.2 mm/min, an increasing trend in reactionary rate was observed for every peak reactionary load with significant increases at 2.0 mm/min. Regardless of displacement rates, two distinct behaviors were identified with stiffness (S) and reactionary load rate (LR) values at a peak load of 5 N (S5 N=290–523 N/mm) being significantly lower than those at 10 N (LR5 N=1–10 N/s) and higher (S10N–20 N=380–684 N/mm; LR10N–20 N=1–19 N/s). Digital image correlation revealed the possibility of a screw-like motion of the tooth into the PDL-space, i.e., predominant vertical displacement of 35 μm at 5 N, followed by a slight increase to 40 μm at 10 N and 50 μm at 20 N of the tooth and potential tooth rotation at loads above 10 N. Narrowed and widened PDL spaces as a result of tooth displacement indicated areas of increased apparent strain within the complex. We propose that such highly strained regions are “hot spots” that can potentiate local tissue adaptation under physiological loading and adverse tissue adaptation under pathological loading

  6. Effects of human relaxin on orthodontic tooth movement and periodontal ligaments in rats

    PubMed Central

    Madan, Monica S.; Liu, Zee J.; Gu, Gao M.; King, Gregory J.

    2010-01-01

    Introduction The rate-limiting step in orthodontic treatment is often the rapidity with which teeth move. Using biological agents to modify the rate of tooth movement has been shown to be effective in animals. Relaxin is a hormone present in both males and females. Its main action is to increase the turnover of fibrous connective tissues. Thus, relaxin might increase the amount and rate of tooth movement through its effect on the periodontal ligament (PDL). The purpose of this study was to measure the effect of relaxin on orthodontic tooth movement and PDL structures. Methods Bilateral orthodontic appliances designed to tip maxillary molars mesially with a force of 40 cN were placed in 96 rats. At day 0, the animals were randomized to either relaxin or vehicle treatment. Twelve rats in each group were killed at 2, 4, 7, and 9 days after appliance activation. Cephalograms were taken at appliance placement and when the rats were killed. Tooth movement was measured cephalometrically in relation to palatal implants. Fractal analysis and visual analog scale assessments were used to evaluate the effect of relaxin on PDL fiber organization at the tension sites in histologic sections. The in-vitro testing for PDL mechanical strength and tooth mobility was performed by using tissue from an additional 20 rats that had previously received the same relaxin or vehicle treatments for 1 or 3 days (n = 5). Results Both groups had statistically significant tooth movement as functions of time. However, relaxin did not stimulate significantly greater or more rapid tooth movement. Fractal and visual analog scale analyses implied that relaxin reduced PDL fiber organization. In-vitro mechanical testing and tooth mobility assessments indicated that the PDL of the mandibular incisors in the relaxin-treated rats had reduced yield load, strain, and stiffness. Moreover, the range of tooth mobility of the maxillary first molars increased to 130% to 170%, over vehicle-treated rats at day 1

  7. Co-culture with periodontal ligament stem cells enhances osteogenic gene expression in de-differentiated fat cells.

    PubMed

    Tansriratanawong, Kallapat; Tamaki, Yuichi; Ishikawa, Hiroshi; Sato, Soh

    2014-10-01

    In recent decades, de-differentiated fat cells (DFAT cells) have emerged in regenerative medicine because of their trans-differentiation capability and the fact that their characteristics are similar to bone marrow mesenchymal stem cells. Even so, there is no evidence to support the osteogenic induction using DFAT cells in periodontal regeneration and also the co-culture system. Consequently, this study sought to evaluate the DFAT cells co-culture with periodontal ligament stem cells (PDLSCs) in vitro in terms of gene expression by comparing runt-related transcription factor 2 (RUNX2) and Peroxisome proliferator-activated receptor gamma 2 (PPARγ2) genes. We isolated DFAT cells from mature adipocytes and compared proliferation with PDLSCs. After co-culture with PDLSCs, we analyzed transcriptional activity implying by DNA methylation in all adipogenic gene promoters using combined bisulfite restriction analysis. We compared gene expression in RUNX2 gene with the PPARγ2 gene using quantitative RT-PCR. After being sub-cultured, DFAT cells demonstrated morphology similar to fibroblast-like cells. At the same time, PDLSCs established all stem cell characteristics. Interestingly, the co-culture system attenuated proliferation while enhancing osteogenic gene expression in RUNX2 gene. Using the co-culture system, DFAT cells could trans-differentiate into osteogenic lineage enhancing, but conversely, their adipogenic characteristic diminished. Therefore, DFAT cells and the co-culture system might be a novel cell-based therapy for promoting osteogenic differentiation in periodontal regeneration.

  8. Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate.

    PubMed

    Wu, Jyun-Yi; Chen, Chia-Hsin; Yeh, Li-Yin; Yeh, Ming-Long; Ting, Chun-Chan; Wang, Yan-Hsiung

    2013-06-01

    Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the proliferation and osteogenic differentiation of human PDL (hPDL) cells. Cultured hPDL cells were irradiated (660 nm) daily with doses of 0, 1, 2 or 4 J⋅cm(-2). Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Our data showed that LPLI at a dose of 2 J⋅cm(-2) significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J⋅cm(-2) showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate (cAMP) is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.

  9. The difference on the osteogenic differentiation between periodontal ligament stem cells and bone marrow mesenchymal stem cells under inflammatory microenviroments.

    PubMed

    Zhang, Jing; Li, Zhi-Gang; Si, Ya-Meng; Chen, Bin; Meng, Jian

    2014-01-01

    Periodontitis is a major cause of tooth loss in adults and periodontal ligament stem cells (PDLSCs) is the most favorable candidate for the reconstruction of tissues destroyed by periodontal diseases. However, pathological alterations caused by inflammatory insults might impact the regenerative capacities of these cells. Bone-marrow-derived human mesenchymal stem cells (hBMSCs) would accelerate alveolar bone regeneration by transplantation, compared to PDLSCs. Therefore, a better understanding of the osteogenic differentiation between PDLSCs and BMSCs in inflammatory microenviroments is therefore warranted. In this study, human PDLSCs were investigated for their stem cell characteristics via analysis of cell surface marker expression, colony forming unit efficiency, osteogenic differentiation and adipogenic differentiation, and compared to BMSCs. To determine the impact of both inflammation and the NF-κβ signal pathway on osteogenic differentiation, cells were challenged with TNF-α under osteogenic induction conditions and investigated for mineralization, alkaline phosphatase (ALP) activity, cell proliferation and relative genes expression. Results showed that PDLSCs exhibit weaker mineralization and ALP activity compared to BMSCs. TNF-α inhibited genes expression of osteogenic differentiation in PDLSCs, while, it stimulates gene expressions (BSP and Runx2) in BMSCs. Enhanced NF-κβ activity in PDLSCs decreases expression of Runx2 but it does not impede the osteogenic differentiation of BMSCs. Taken together, these results may suggest that the BMSCs owned the stronger immunomodulation in local microenvironment via anti-inflammatory functions, compared to PDLSCs.

  10. Periodontitis

    MedlinePlus

    ... This is called gingivitis, the mildest form of periodontal disease. Ongoing inflammation eventually causes pockets to develop between ... you to a specialist in the treatment of periodontal disease (periodontist). Diagnosis of periodontitis is generally simple. Diagnosis ...

  11. Coping with stress: its influence on periodontal disease.

    PubMed

    Wimmer, Gernot; Janda, Michaela; Wieselmann-Penkner, Karin; Jakse, Norbert; Polansky, Raoul; Pertl, Christof

    2002-11-01

    Various forms of stress behavior were documented and in patients with periodontitis their relationship with periodontal disease was investigated. Eighty-nine patients with different forms of chronic periodontitis were included in this retrospective case-control study. They were all undergoing periodontal treatment at the Department of Dental Prosthetics, University of Graz, or a private dental practice. The control group consisted of 63 persons employed in health care at the Clinic of Graz. All participants completed a stress coping questionnaire of 114 items and 19 actional and intrapsychic stress coping modes. The questionnaire served as a psychodiagnostic survey aimed at collecting data on stress coping strategies. Clinical attachment loss (CAL) served as the clinical parameter. With the help of a factor analysis with a factorization and Varimax rotation, 5 factors were extracted from the 19 subtests. The reliability of the questionnaire was less than 0.70 only for subtests "escape" and "pharmaceutical drugs." Otherwise the internal consistency ranged between 0.74 and 0.92, and the retest reliability between 0.72 and 0.84. Subsequent assessment with the t test for independent random samples at the 5% level showed that patients differ significantly from controls in regard of factor 2 (active coping, P = 0.40) and 3 (distractive coping, P = 0.033), and that they differ very significantly from controls in regard of factor 4 (defensive coping, P = 0.000) and 5 (coping through aggression and pharmaceutical drugs, P = 0.007). In the statistical analysis of factors with regard to the severity of periodontal disease, the patients were divided into 2 groups (mild to moderate and severe). The t test for independent random samples showed significance for factor 4 (defensive coping) in that patients with a defensive coping style had greater attachment loss (pF4 = 0.04). The data corroborate the thesis that periodontitis patients with inadequate stress behavior strategies

  12. Rho plays a key role in TGF-β1-induced proliferation and cytoskeleton rearrangement of human periodontal ligament cells.

    PubMed

    Wang, Li; Wang, Tingle; Song, Meng; Pan, Jinsong

    2014-02-01

    Human periodontal ligament cells (hPDLCs) form specialised connective tissues that influence the lifespan of the tooth. Periodontal disease is a chronic infectious disease of the periodontal supporting tissues caused by a variety of factors, particularly the loss of hPDLCs. Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine known to play an important role in periodontal disease, but little is known about the effects of TGF-β1 on human PDL cells. To determine how TGF-β1 mediates the changes in hPDLCs, we characterised the effects of TGF-β1 treatment on hPDLCs. We then elucidated the signalling pathway that mediates these effects. Serum-starved hPDLCs were incubated with 10ng/mL TGF-β1, and their proliferation was examined using the Cell Counting Kit-8, while their morphological changes were examined by phase-contrast microscopy. F-actin reorganisation was visualised by phalloidin staining and confocal microscopy. Protein expression was analysed by western blotting. We found that TGF-β1 treatment induced proliferation and cytoskeletal reorganisation, decreased Rho-GDIa protein expression, activated ROCK protein expression, and increased the phosphorylation of LIM kinase and cofilin. Proliferation and cytoskeletal rearrangement were suppressed by pre-treatment with the ROCK inhibitor Y-27632; additionally, expression of ROCK protein and phosphorylation of LIM kinase and cofilin were decreased by Y-27632, while Rho-GDIa knockdown by targeted siRNA transfection causes opposite effects. Therefore, we propose that TGF-β1 induces proliferation and cytoskeletal rearrangement in hPDLCs via Rho GTPase-dependent pathways that modulate ROCK, LIM kinase, and cofilin activity.

  13. Bone morphogenetic protein-2, -6, and -7 differently regulate osteogenic differentiation of human periodontal ligament stem cells.

    PubMed

    Hakki, Sema S; Bozkurt, Buket; Hakki, Erdogan E; Kayis, Seyit Ali; Turac, Gizem; Yilmaz, Irem; Karaoz, Erdal

    2014-01-01

    The utility of adult stem cells for bone regeneration may be an attractive alternative in the treatment of extensive injury, congenital malformations, or diseases causing large bone defects. To create an environment that is supportive of bone formation, signals from molecules such as the bone morphogenetic proteins (BMPs) are required to engineer fully viable and functional bone. We therefore determined whether BMP-2, -6, and -7 differentially regulate the (1) proliferation, (2) mineralization, and (3) mRNA expression of bone/mineralized tissue associated genes of human periodontal ligament stem cells (hPDLSCs), which were obtained from periodontal ligament tissue of human impacted third molars. hPDLSCs from six participants were isolated and characterized using histochemical and immunohistochemical methods. A real-time cell analyzer was used to evaluate the effects of BMP-2, -6, and -7 on the proliferation of hPDLSCs. hPDLSCs were treated with Dulbecco's modified Eagle's medium containing different concentrations of BMP-2, -6, and -7 (10, 25, 50, 100 ng/mL) and monitored for 264 hours. After dose-response experiments, 50 and 100 ng/mL concentrations of BMPs were used to measure bone/mineralized tissue-associated gene expression. Type I collagen, bone sialoprotein, osteocalcin, osteopontin, and osteoblastic transcription factor Runx2 mRNA expression of hPDLSCs treated with BMP-2, -6, and -7, were evaluated using quantitative RT-PCR. Biomineralization of hPDLSCs was assessed using von Kossa staining. This study demonstrated that BMPs at various concentrations differently regulate the proliferation, mineralization, and mRNA expression of bone/mineralized tissue associated genes in hPDLSCs. BMPs regulate hPDLSC proliferation in a time and dose-dependent manner when compared to an untreated control group. BMPs induced bone/mineralized tissue-associated gene mRNA expression and biomineralization of hPDLSCs. The most pronounced induction occurred in the BMP-6 group in

  14. Expression of Phospholipase D in Periodontitis and Its Role in the Inflammatory and Osteoclastic Response by Nicotine- and Lipopolysaccharide-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Shin, Seung-Yun; Kim, Young-Suk; Lee, So-Youn; Bae, Won-Jung; Park, Yong-Duk; Hyun, Yong-Cheol; Kang, KyungLhi; Kim, Eun-Cheol

    2015-12-01

    The aim of the present study is to investigate the expression of phospholipase D (PLD) 1 and PLD2 in periodontal patients and in human periodontal ligament cells (HPDLCs) exposed to nicotine plus lipopolysaccharide (LPS) from Porphyromonas gingivalis (Toll-like receptor 2 ligand). Furthermore, the effects of PLD isoform inhibition on the inflammatory response and osteoclast differentiation and its mechanisms were determined. Proinflammatory mediators were examined by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. To silence the gene expression of the PLD isoforms, cells were transfected with small interfering RNA (siRNA) targeting PLD1 or PLD2. Mouse bone marrow-derived macrophages (BMMs) were used as osteoclast precursor cells for in vitro osteoclastogenesis. Western blot analysis and immunofluorescence were used to assess signaling pathways. Chronic smokers with periodontitis exhibited significantly higher PLD1 and PLD2 messenger RNA (mRNA) expression than non-smokers with periodontitis and healthy controls. Nicotine and LPS upregulated PLD1 and PLD2 mRNA expression in a dose-dependent manner in HPDLCs. Pharmacologic and siRNA-mediated inhibition of PLD1 and PLD2 attenuated the nicotine- and LPS-induced upregulation of inducible nitric oxide (NO) synthase and cyclooxygenase-2, production of NO, and prostaglandin E2, and mRNA expression and secretion of tumor necrosis factor-α, interleukin (IL)-1β, and IL-8. The conditioned media from HPDLCs treated with PLD isoform inhibitors or siRNA against PLD inhibited receptor activator of nuclear factor-κB (NF-κB) ligand-mediated osteoclast differentiation, as well as protein expression of nuclear factor of activated T cells c1 and c-Fos, in BMMs. In addition, PLD isoform inhibitors and siRNA inhibited the nicotine- and LPS-induced activation of phosphoinositide 3-kinase, protein kinase C, p38, extracellular signal-regulated kinase, c-Jun N-terminal protein kinase, mitogen

  15. Changes in the masticatory muscles, periodontal tissues, and the pharyngeal ring in Wistar rats in chronic psychophysical stress.

    PubMed

    Antonova, I N

    2008-11-01

    Experimental studies performed on 120 male Wistar rats using morphometric and histological methods demonstrated changes in oral cavity tissues on exposure to chronic psychophysical stress (dosed swimming). The masticatory muscles showed foci of non-infective inflammation, dystrophic changes in muscle fibers, and contractures. The periodontal ligament showed impairments to the microcirculation with congestion of the venous bed, local bleeding into the tissue, changes in the directions of bundles of collagen fibers, and deformation of bundles. The tissues of the pharyngeal ring showed decreases in lymphocyte content, progressive loosening of connective tissue, and decreases in non-degranulated mast cell numbers, as compared with controls. The intensity of these changes depended on the level of physical loading and the individual adaptive capacity of the animals. These structural changes in the tissues may be the etiopathogenetic basis of the development of chronic inflammatory periodontal diseases.

  16. Policaprolactone/polyvinylpyrrolidone/siloxane hybrid materials: Synthesis and in vitro delivery of diclofenac and biocompatibility with periodontal ligament fibroblasts.

    PubMed

    Peña, José A; Gutiérrez, Sandra J; Villamil, Jean C; Agudelo, Natalia A; Pérez, León D

    2016-01-01

    In this paper, we report the synthesis of polycaprolactone (PCL) based hybrid materials containing hydrophilic domains composed of N-vinylpyrrolidone (VP), and γ-methacryloxypropyltrimethoxysilane (MPS). The hybrid materials were obtained by RAFT copolymerization of N-vinylpyrrolidone and MPS using a pre-formed dixanthate-end-functionalized PCL as macro-chain transfer agent, followed by a post-reaction crosslinking step. The composition of the samples was determined by elemental and thermogravimetric analyses. Differential scanning calorimetry and X-ray diffraction indicated that the crystallinity of PCL decreases in the presence of the hydrophilic domains. Scanning electron microscopy images revealed that the samples present an interconnected porous structure on the swelling. Compared to PCL, the hybrid materials presented low water contact angle values and higher elastic modulus. These materials showed controlled release of diclofenac, and biocompatibility with human periodontal ligament fibroblasts. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Biological response at the cellular level within the periodontal ligament on application of orthodontic force – An update

    PubMed Central

    Meeran, Nazeer Ahmed

    2012-01-01

    Orthodontic force elicits a biological response in the tissues surrounding the teeth, resulting in remodeling of the periodontal ligament and the alveolar bone. The force-induced tissue strain result in reorganization of both cellular and extracellular matrix, besides producing changes in the local vascularity. This in turn leads to the synthesis and release of various neurotransmitters, arachidonic acid, growth factors, metabolites, cytokines, colony-stimulating factors, and enzymes like cathepsin K, matrix metalloproteinases, and aspartate aminotransferase. Despite the availability of many studies in the orthodontic and related scientific literature, a concise integration of all data is still lacking. Such a consolidation of the rapidly accumulating scientific information should help in understanding the biological processes that underlie the phenomenon of tooth movement in response to mechanical loading. Therefore, the aim of this review was to describe the biological processes taking place at the molecular level on application of orthodontic force and to provide an update of the current literature. PMID:24987618

  18. Comparison of soymilk, powdered milk, Hank's balanced salt solution and tap water on periodontal ligament cell survival.

    PubMed

    Moazami, Fariborz; Mirhadi, Hosein; Geramizadeh, Bita; Sahebi, Safoura

    2012-04-01

    The purpose of this study was to evaluate the ability of soymilk, powdered milk, and Hank's balanced salt solution (HBSS) to maintain human periodontal ligament (PDL) cell viability in vitro. PDL cells were obtained from extracted healthy third molars and cultured in Dulbecco's modified Eagles medium (DMEM). The cultures were exposed for 1, 2, 4, and 8 h to experimental solutions (tap water served as negative control and DMEM as positive control) at 37°C. The viable cells were then counted using the trypan blue exclusion technique. Data were analyzed by using one-way anova, post hoc Scheffe and two-way anova test. Statistical analysis showed that HBSS, powdered baby formula, and soymilk maintain cell viability equally well in different periods of times. Tap water cannot keep cells viable as well as other solutions. Soymilk and powdered baby formula can be recommended as suitable storage media for avulsed teeth for up to 8 h.

  19. A simple fluorescence labeling method to visualize the three-dimensional arrangement of collagen fibers in the equine periodontal ligament.

    PubMed

    Staszyk, Carsten; Gasse, Hagen

    2004-04-01

    In order to display the collagen-fiber arrangement in the equine periodontal ligament an inexpensive and easy staining procedure with fluorescein was applied to paraffin sections. After fluorescein labeling a section was suitable for successful examination with three special microscopical systems: a) fluorescence microscopy b) phase contrast microscopy and c) polarized light microscopy. Collagen fibers were clearly displayed as compact structures in the fluorescence microscope. This distinct feature of the fluorescent image generated an almost three-dimensional impression of the fiber arrangement. Phase contrast microscopy and polarized light microscopical investigations of the same section supplemented the findings with further structural details. This contributed to demonstration of the complex architecture of the PDL, i. e. the varying sizes of the fiber bundles, their specific spatial alignment, and the entheses to the dental cementum.

  20. Loss of proliferation and differentiation capacity of aged human periodontal ligament stem cells and rejuvenation by exposure to the young extrinsic environment.

    PubMed

    Zheng, Wei; Wang, Shi; Ma, Dandan; Tang, Liang; Duan, Yinzhong; Jin, Yan

    2009-09-01

    The application of periodontal ligament stem cells (PDLSCs) may be effective for periodontal regenerative therapy. As tissue regenerative potential may be negatively regulated by aging, whether aging and its microenvironment modify human PDLSCs remains a question. In this study, we compared the proliferation and differentiation capacity of PDLSCs obtained from young and aged donors. Then, we exposed aged PDLSCs to young periodontal ligament cell-conditioned medium (PLC-CM), and young PDLSCs were exposed to aged PLC-CM. Morphological appearance, colony-forming assay, cell cycle analysis, osteogenic and adipogenic induction media, gene expression of cementoblast phenotype, and in vivo differentiation capacities of PDLSCs were evaluated. PDLSCs obtained from aged donors exhibited decreased proliferation and differentiation capacity when compared with those from young donors. Young PLC-CM enhanced the proliferation and differentiation capacity of PDLSCs from aged donors. Aged PDLSCs induced by young PLC-CM showed enhanced tissue-regenerative capacity to produce cementum/periodontal ligament-like structures, whereas young PDLSCs induced by aged PLC-CM transplants mainly formed connective tissues. To our knowledge, this is the first study to mimic the developmental microenvironment of PDLSCs in vitro, and our data suggest that age influences the proliferation and differentiation potential of human PDLSCs, and that the activity of human PDLSCs can be modulated by the extrinsic microenvironment.

  1. Dynamic assessment of Capparis spinosa buds on survival of periodontal ligament cells using a real-time cell analysis method.

    PubMed

    Ozan, F; Özan, Ü; Oktay, E A; Toptas, O; Özdemir, H; KürÞat, Er

    2015-01-01

    Tooth avulsion is the most severe type of traumatic dental injuries and it results in the complete displacement of the tooth out of its socket in alveolar bone. Reimplantation of the tooth is considered to be a best treatment modality due to its biological and psychological advantages. Its prognosis depends on the extra alveolar time, the storage medium, and the patient's general health. The aim of this study was to evaluate the effect of Capparis spinosa (C. spinosa) in maintaining the viability of human periodontal ligament (PDL) cells using a real-time cell analysis method. Periodontal ligament cells were obtained from healthy human third molars extracted for orthodontic purposes. The storage media tested were: Dulbecco's Modified Eagle Medium (DMEM), C. spinosa, Hank's Balanced Salt Solution (HBSS), and light milk. A real-time cell analyzer system was used to evaluate cell viability. After seeding cell suspensions into the wells of the E-plate 96, PDL cells were treated with each of tested media and monitored for every 5 min for 26 h. Statistical analysis of the data was accomplished using one-way analysis of variance complemented by the Tukey test. The level of significance was set at P < 0.05. Dulbecco's Modified Eagle Medium (control) and C. spinosa groups had significantly higher cell index values compared with the HBSS and light milk (P < 0.05). Although, C. spinosa showed better results than DMEM (control), but this difference was not found statistically significant. Capparis spinosa can be a suitable, alternative storage medium for avulsed teeth.

  2. Application of stem cells derived from the periodontal ligament or gingival tissue sources for tendon tissue regeneration

    PubMed Central

    Moshaverinia, Alireza; Xu, Xingtian; Chen, Chider; Ansari, Sahar; Zadeh, Homayoun H.; Snead, Malcolm L.; Shi, Songtao

    2014-01-01

    Tendon injuries are often associated with significant dysfunction and disability due to tendinous tissue’s very limited self-repair capacity and propensity for scar formation. Dental-derived mesenchymal stem cells (MSCs) in combination with appropriate scaffold material present an alternative therapeutic option for tendon repair/regeneration that may be advantageous compared to other current treatment modalities. The MSC delivery vehicle is the principal determinant for successful implementation of MSC-mediated regenerative therapies. In the current study, a co-delivery system based on TGF-β3-loaded RGD-coupled alginate microspheres was developed for encapsulating periodontal ligament stem cells (PDLSCs) or gingival mesenchymal stem cells (GMSCs). The capacity of encapsulated dental MSCs to differentiate into tendon tissue was investigated in vitro and in vivo. Encapsulated dental-derived MSCs were transplanted subcutaneously into immunocompromised mice. Our results revealed that after 4 weeks of differentiation in vitro, PDLSCs and GMSCs as well as the positive control human bone marrow mesenchymal stem cells (hBMMSCs) exhibited high levels of mRNA expression for gene markers related to tendon regeneration (Scx, DCn, Tnmd, and Bgy) via qPCR measurement. In a corresponding in vivo animal model, ectopic neo-tendon regeneration was observed in subcutaneous transplanted MSC-alginate constructs, as confirmed by histological and immunohistochemical staining for protein markers specific for tendons. Interestingly, in our quantitative PCR and in vivo histomorphometric analyses, PDLSCs showed significantly greater capacity for tendon regeneration than GMSCs or hBMMSCs (P<0.05). Altogether, these findings indicate that periodontal ligament and gingival tissues can be considered as suitable stem cell sources for tendon engineering. PDLSCs and GMSCs encapsulated in TGF-β3-loaded RGD-modified alginate microspheres are promising candidates for tendon regeneration. PMID

  3. Application of stem cells derived from the periodontal ligament or gingival tissue sources for tendon tissue regeneration.

    PubMed

    Moshaverinia, Alireza; Xu, Xingtian; Chen, Chider; Ansari, Sahar; Zadeh, Homayoun H; Snead, Malcolm L; Shi, Songtao

    2014-03-01

    Tendon injuries are often associated with significant dysfunction and disability due to tendinous tissue's very limited self-repair capacity and propensity for scar formation. Dental-derived mesenchymal stem cells (MSCs) in combination with appropriate scaffold material present an alternative therapeutic option for tendon repair/regeneration that may be advantageous compared to other current treatment modalities. The MSC delivery vehicle is the principal determinant for successful implementation of MSC-mediated regenerative therapies. In the current study, a co-delivery system based on TGF-β3-loaded RGD-coupled alginate microspheres was developed for encapsulating periodontal ligament stem cells (PDLSCs) or gingival mesenchymal stem cells (GMSCs). The capacity of encapsulated dental MSCs to differentiate into tendon tissue was investigated in vitro and in vivo. Encapsulated dental-derived MSCs were transplanted subcutaneously into immunocompromised mice. Our results revealed that after 4 weeks of differentiation in vitro, PDLSCs and GMSCs as well as the positive control human bone marrow mesenchymal stem cells (hBMMSCs) exhibited high levels of mRNA expression for gene markers related to tendon regeneration (Scx, DCn, Tnmd, and Bgy) via qPCR measurement. In a corresponding in vivo animal model, ectopic neo-tendon regeneration was observed in subcutaneous transplanted MSC-alginate constructs, as confirmed by histological and immunohistochemical staining for protein markers specific for tendons. Interestingly, in our quantitative PCR and in vivo histomorphometric analyses, PDLSCs showed significantly greater capacity for tendon regeneration than GMSCs or hBMMSCs (P < 0.05). Altogether, these findings indicate that periodontal ligament and gingival tissues can be considered as suitable stem cell sources for tendon engineering. PDLSCs and GMSCs encapsulated in TGF-β3-loaded RGD-modified alginate microspheres are promising candidates for tendon regeneration. Copyright

  4. The potential role of transient receptor potential type A1 as a mechanoreceptor in human periodontal ligament cells.

    PubMed

    Tsutsumi, Takashi; Kajiya, Hiroshi; Fukawa, Teruhisa; Sasaki, Mina; Nemoto, Tetsuomi; Tsuzuki, Takashi; Takahashi, Yutaka; Fujii, Shinsuke; Maeda, Hidefumi; Okabe, Koji

    2013-12-01

    Transient receptor potential type A1 (TRPA1) is reported to be a Ca(2+) -permeable channel and is activated by cold temperatures and mechanical stimuli in the hair cells and in dorsal root ganglion. Using a DNA microarray, we found that TRPA1 was significantly up-regulated in human periodontal ligament (hPDL) cells 2 d after intermittent mechanical stimulation (iMS) loading compared with unloaded cells. Although hPDL cells are known to respond to mechanical stimulation induced by occlusal force, little is known about the expression and functional role of TRPA1 in these cells. Therefore, we investigated the effects of iMS on TRPA1 expression and its signaling pathway in hPDL cells. Intermittent mechanical stimulation loading up-regulated TRPA1 expression in hPDL cells in a time-dependent manner, but had no effect on other mechanoreceptors. Furthermore, iMS significantly increased the phosphorylation of mitogen-activated protein kinases (MAPKs), especially extracellular signal-regulated kinase 1/2 (ERK1/2) and p38, and the expression of C-C chemokine ligand 2 (CCL2). Transient receptor potential type A1 agonists also increased MAPK phosphorylation and the intracellular Ca(2+) concentration. By contrast, inhibition or silencing of TRPA1 partially suppressed iMS-induced MAPK phosphorylation. In summary, iMS during occlusion activates TRPA1 and MAPK signaling in periodontal ligament tissues, suggesting that TRPA1 regulates the mechanosensitivity of occlusal force via activation of MAPKs in hPDL cells.

  5. Matrix metalloproteinases regulate extracellular levels of SDF-1/CXCL12, IL-6 and VEGF in hydrogen peroxide-stimulated human periodontal ligament fibroblasts.

    PubMed

    Cavalla, Franco; Osorio, Constanza; Paredes, Rodolfo; Valenzuela, María Antonieta; García-Sesnich, Jocelyn; Sorsa, Timo; Tervahartiala, Taina; Hernández, Marcela

    2015-05-01

    Periodontitis is a highly prevalent infectious disease characterized by the progressive inflammatory destruction of tooth-supporting structures, leading to tooth loss. The underling molecular mechanisms of the disease are incompletely understood, precluding the development of more efficient screening, diagnostic and therapeutic approaches. We investigated the interrelation of three known effector mechanisms of the cellular response to periodontal infection, namely reactive oxygen species (ROS), matrix metalloproteinases (MMPs) and cytokines in primary cell cultures of human periodontal ligament fibroblast (hPDLF). We demonstrated that ROS increase the activity/levels of gelatinolytic MMPs, and stimulate cytokine secretion in hPDLF. Additionally, we proved that MMPs possesses immune modulatory capacity, regulating the secreted levels of cytokines in ROS-stimulated hPDLF cultures. This evidence provides further insight in the molecular pathogenesis of periodontitis, contributing to the future development of more effective therapies.

  6. A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts.

    PubMed

    Hägi, Tobias T; Klemensberger, Sabrina; Bereiter, Riccarda; Nietzsche, Sandor; Cosgarea, Raluca; Flury, Simon; Lussi, Adrian; Sculean, Anton; Eick, Sigrun

    2015-01-01

    There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and

  7. A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts

    PubMed Central

    Hägi, Tobias T.; Klemensberger, Sabrina; Bereiter, Riccarda; Nietzsche, Sandor; Cosgarea, Raluca; Flury, Simon; Lussi, Adrian; Sculean, Anton; Eick, Sigrun

    2015-01-01

    Background and Aim There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Material and Methods Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. Results After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. Conclusion The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air

  8. Effects of IL-10 and glucose on expression of OPG and RANKL in human periodontal ligament fibroblasts

    PubMed Central

    Zhang, L.; Ding, Y.; Rao, G.Z.; Miao, D.

    2016-01-01

    The effects of interleukin-10 (IL-10) and glucose on mRNA and protein expression of osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor-κB ligand (RANKL), were investigated in human periodontal ligament fibroblasts (HPDLFs). Primary HPDLFs were treated with different concentrations of IL-10 (0, 1, 10, 25, 50, and 100 ng/mL) or glucose (0, 5.5, 10, 20, 30, and 40 mmol/L). Changes in mRNA and protein expression were examined using the reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. After IL-10 treatment, mRNA and protein levels of OPG were increased, while mRNA and protein levels of RANKL were decreased (P<0.05), both in a concentration-dependent manner. Glucose stimulation had the opposite concentration-dependent effect to that of IL-10 on OPG and RANKL expression. IL-10 upregulated OPG expression and downregulated RANKL expression, whereas high glucose upregulated RANKL and downregulated OPG in HDPLFs. Abnormal levels of IL-10 and glucose may contribute to the pathogenesis of periodontal disease. PMID:27074164

  9. Bone Morphogenetic Protein-9 Enhances Osteogenic Differentiation of Human Periodontal Ligament Stem Cells via the JNK Pathway

    PubMed Central

    Wang, Xingxing; Pang, Yanan; Yang, Su; Wei, Yibo; Gao, Haochen; Wang, Dalin; Cao, Zhizhong

    2017-01-01

    Bone morphogenetic protein-9 (BMP9) shows great osteoinductive potential in bone regeneration. Periodontal ligament stem cells (PDLSCs) with multi-differentiation capability and low immunogenicity are increasingly used as seed cells for periodontal regenerative therapies. In the present study, we investigated the potent osteogenic activity of BMP9 on human PDLSCs (hPDLSCs), in which the c-Jun N-terminal kinase (JNK) pathway is possibly involved. Our results showed that JNK inhibition by the specific inhibitor SP600125 or adenovirus expressing small interfering RNA (siRNA) targeting JNK (AdR-si-JNK) significantly decreased BMP9-induced gene and protein expression of early and late osteogenic markers, such as runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN), in hPDLSCs. We also confirmed the in-vivo positive effect of JNKs on ectopic bone formation induced by hPDLSCs injected into the musculature of athymic nude mice and BMP9 ex vivo gene delivery. For the cellular mechanism, we found that BMP9 activated the phosphorylation of JNKs and Smad2/3, and that JNKs may engage in cross-talk with the Smad2/3 pathway in BMP9-mediated osteogenesis. PMID:28052093

  10. Scleraxis and osterix antagonistically regulate tensile force-responsive remodeling of the periodontal ligament and alveolar bone.

    PubMed

    Takimoto, Aki; Kawatsu, Masayoshi; Yoshimoto, Yuki; Kawamoto, Tadafumi; Seiryu, Masahiro; Takano-Yamamoto, Teruko; Hiraki, Yuji; Shukunami, Chisa

    2015-02-15

    The periodontal ligament (PDL) is a mechanosensitive noncalcified fibrous tissue connecting the cementum of the tooth and the alveolar bone. Here, we report that scleraxis (Scx) and osterix (Osx) antagonistically regulate tensile force-responsive PDL fibrogenesis and osteogenesis. In the developing PDL, Scx was induced during tooth eruption and co-expressed with Osx. Scx was highly expressed in elongated fibroblastic cells aligned along collagen fibers, whereas Osx was highly expressed in the perialveolar/apical osteogenic cells. In an experimental model of tooth movement, Scx and Osx expression was significantly upregulated in parallel with the activation of bone morphogenetic protein (BMP) signaling on the tension side, in which bone formation compensates for the widened PDL space away from the bone under tensile force by tooth movement. Scx was strongly expressed in Scx(+)/Osx(+) and Scx(+)/Osx(-) fibroblastic cells of the PDL that does not calcify; however, Scx(-)/Osx(+) osteogenic cells were dominant in the perialveolar osteogenic region. Upon BMP6-driven osteoinduction, osteocalcin, a marker for bone formation was downregulated and upregulated by Scx overexpression and knockdown of endogenous Scx in PDL cells, respectively. In addition, mineralization by osteoinduction was significantly inhibited by Scx overexpression in PDL cells without affecting Osx upregulation, suggesting that Scx counteracts the osteogenic activity regulated by Osx in the PDL. Thus, Scx(+)/Osx(-), Scx(+)/Osx(+) and Scx(-)/Osx(+) cell populations participate in the regulation of tensile force-induced remodeling of periodontal tissues in a position-specific manner.

  11. Comparison of Periodontal Ligament Injection and Inferior Alveolar Nerve Block in Mandibular Primary Molars Pulpotomy: A Randomized Control Trial

    PubMed Central

    Haghgoo, Roza; Taleghani, Ferial

    2015-01-01

    Background: Inferior alveolar nerve block is a common technique for anesthesia of the primary mandibular molars. A number of disadvantages have been shown to be associated with this technique. Periodontal ligament (PDL) injection could be considered as an alternative to inferior alveolar nerve block. The aim of this study was to evaluate the effectiveness of PDL injection in the anesthesia of primary molar pulpotomy with mandibular block. Methods: This study was performed using a sequential double-blind randomized trial design. 80 children aged 3-7 years old who required pulpotomy in symmetrical mandibular primary molars were selected. The teeth of these children were anesthetized with periodontal injection on one side of the mandible and block on the other. Pulpotomy was performed on each patient during the same appointment. Signs of discomfort, including hand and body tension and eye movement, the verbal complaint and crying (SEM scale), were evaluated by a dental assistant who was blinded to the treatment allocation of the patients. Finally, the data were analyzed using the exact Fisher test and Pearson Chi-squared exact test. Results: Success rate was 88/75 and 91/25 in the PDL injection and nerve block groups, respectively. There was no statistically significant difference between the two techniques (P = 0.250). Conclusion: Results showed that PDL injection can be used as an alternative to nerve block in pulpotomy of the mandibular primary molars. PMID:26028895

  12. Oxidative Stress Parameters in Saliva and Its Association with Periodontal Disease and Types of Bacteria

    PubMed Central

    Almerich-Silla, Jose Manuel; Montiel-Company, Jose María; Pastor, Sara; Serrano, Felipe; Puig-Silla, Miriam; Dasí, Francisco

    2015-01-01

    Objective. To determine the association between oxidative stress parameters with periodontal disease, bleeding, and the presence of different periodontal bacteria. Methods. A cross-sectional study in a sample of eighty-six patients, divided into three groups depending on their periodontal status. Thirty-three with chronic periodontitis, sixteen with gingivitis, and thirty-seven with periodontal healthy as control. Oxidative stress biomarkers (8-OHdG and MDA), total antioxidant capacity (TAOC), and the activity of two antioxidant enzymes (GPx and SOD) were determined in saliva. Subgingival plaque samples were obtained from the deepest periodontal pocket and PCR was used to determine the presence of the 6 fimA genotypes of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Treponema denticola. Results. Periodontal disease was found to be associated with increased oxidative stress parameter levels. These levels rose according to the number and type of different periodontal bacteria found in the periodontal pockets. The presence of different types of periodontal bacteria is predictive independent variables in linear regresion models of oxidative stress parameters as dependent variable, above all 8-OHdG. Conclusions. Oxidative stress parameter levels are correlated with the presence of different types of bacteria. Determination of these levels and periodontal bacteria could be a potent tool for controlling periodontal disease development. PMID:26494938

  13. ET-1 Promotes Differentiation of Periodontal Ligament Stem Cells into Osteoblasts through ETR, MAPK, and Wnt/β-Catenin Signaling Pathways under Inflammatory Microenvironment.

    PubMed

    Liang, Li; Zhou, Wei; Yang, Nan; Yu, Jifeng; Liu, Hongchen

    2016-01-01

    Periodontitis is a kind of chronic inflammatory disease that affects the tooth-supporting tissues. ET-1 is related to periodontitis and involved in the regulation of cytokines, but the mechanisms remain unclear. The aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression and differentiation in human periodontal ligament stem cells (PDLSCs). PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients and then treated with ET-1 (1, 10, or 100 nM) for 12 h, 24 h, or 72 h. The osteogenic potential of PDLSCs was tested using ALP staining. TNF-α, IL-1β, and IL-6 levels were evaluated by ELISA and western blot. Runx2, OCN, and COL1 mRNA and western levels were detected by RT-PCR and western blot, respectively. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression and osteogenic differentiation, ETR pathway, MAPKs pathway, Wnt/β-catenin pathway, and Wnt/Ca(2+) pathway were detected by RT-PCR and western blot, respectively. ET-1 promoted differentiation of PDLSCs into osteoblasts by increasing secretion of TNF-α, IL-1β, and IL-6 in a dose- and time-dependent manner. ET-1 also increased expression of Runx2, OCN, and COL1. ET-1 promotes differentiation of PDLSCs into osteoblasts through ETR, MAPK, and Wnt/β-catenin signaling pathways under inflammatory microenvironment.

  14. Enterococcus faecalis lipoteichoic acid suppresses Aggregatibacter actinomycetemcomitans lipopolysaccharide-induced IL-8 expression in human periodontal ligament cells.

    PubMed

    Im, Jintaek; Baik, Jung Eun; Kim, Kyoung Whun; Kang, Seok-Seong; Jeon, Jun Ho; Park, Ok-Jin; Kim, Hyun Young; Kum, Kee-Yeon; Yun, Cheol-Heui; Han, Seung Hyun

    2015-08-01

    Periodontitis is caused by multi-bacterial infection and Aggregatibacter actinomycetemcomitans and Enterococcus faecalis are closely associated with inflammatory periodontal diseases. Although lipopolysaccharide (LPS) of A. actinomycetemcomitans (Aa.LPS) and lipoteichoic acid of E. faecalis (Ef.LTA) are considered to be major virulence factors evoking inflammatory responses, their combinatorial effect on the induction of chemokines has not been investigated. In this study, we investigated the interaction between Aa.LPS and Ef.LTA on IL-8 expression in human periodontal ligament (PDL) cells. Aa.LPS, but not Ef.LTA, substantially induced IL-8 expression at the protein and mRNA levels. Interestingly, Ef.LTA suppressed Aa.LPS-induced IL-8 expression without affecting the binding of Aa.LPS to Toll-like receptor (TLR) 4. Ef.LTA reduced Aa.LPS-induced phosphorylation of mitogen-activated protein kinases, including ERK, JNK and p38 kinase. Furthermore, Ef.LTA inhibited the Aa.LPS-induced transcriptional activities of the activating protein 1, CCAAT/enhancer-binding protein and nuclear factor-kappa B transcription factors, all of which are known to regulate IL-8 gene expression. Ef.LTA augmented the expression of IL-1 receptor-associated kinase-M (IRAK-M), a negative regulator of TLR intracellular signaling pathways, in the presence of Aa.LPS at both the mRNA and protein levels. Small interfering RNA silencing IRAK-M reversed the attenuation of Aa.LPS-induced IL-8 expression by Ef.LTA. Collectively, these results suggest that Ef.LTA down-regulates Aa.LPS-induced IL-8 expression in human PDL cells through up-regulation of the negative regulator IRAK-M.

  15. A three-dimensional cell culture model to study the mechano-biological behavior in periodontal ligament regeneration.

    PubMed

    Oortgiesen, Daniel A W; Yu, Na; Bronckers, Antonius L J J; Yang, Fang; Walboomers, X Frank; Jansen, John A

    2012-02-01

    Periodontitis is a disease affecting the supporting structures of the teeth, which can eventually result in tooth loss. A three-dimensional (3D) tissue culture model was developed that may serve to grow a 3D construct that not only transplants into defective periodontal sites, but also allows to examine the effect of mechanical load in vitro. In the current in vitro study, green fluorescent protein labeled periodontal ligament (PDL) cells form rat incisors were embedded in a 3D matrix and exposed to mechanical loading alone, to a chemical stimulus (Emdogain; enamel matrix derivative [EMD]) alone, or a combination of both. Loading consisted of unilateral stretching (8%, 1 Hz) and was applied for 1, 3, or 5 days. Results showed that PDL cells were distributed and randomly oriented within the artificial PDL space in static culture. On mechanical loading, the cells showed higher cell numbers. Moreover, cells realigned perpendicular to the stretching force depending on time and position, with great analogy to natural PDL tissue. EMD application gave a significant effect on growth and upregulated bone sialoprotein (BSP) and collagen type-I (Col-I), whereas Runx-2 was downregulated. This implies that PDL cells under loading might tend to act similar to bone-like cells (BSP and Col-I) but at the same time, react tendon like (Runx-2). The combination of chemical and mechanical stimulation seems possible, but does not show synergistic effects. In this study, a new model was successfully introduced in the field of PDL-related regenerative research. Besides validating the 3D model to mimic an authentic PDL space, it also provided a useful and well-controlled approach to study cell response to mechanical loading and other stimuli.

  16. MicroRNA-22 Promoted Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Targeting HDAC6.

    PubMed

    Yan, Guang-Qi; Wang, Xue; Yang, Fan; Yang, Min-Liang; Zhang, Gui-Rong; Wang, Guo-Kun; Zhou, Qing

    2017-07-01

    Stem cells transplantation is a promising therapy strategy for accelerating periodontal regeneration and reconstruction. Genetic modification could induce stem cells directional differentiation to facilitate recovery of physiological functions. In this study, we investigated the role and mechanism of miR-22 on human periodontal ligament stem cells (PDLSCs). First, a cellular model of osteogenic differentiation was first established by osteogenic inductive cocktail. Real-time PCR determined that expression of miR-22 was significantly increased during PDLSCs osteogenic differentiation. Alizirin red staining showed that overexpression of miR-22 in PDLSCs induced better mineralized nodule formation. Real-time PCR and Western blot further confirmed up-regulation of osteogenic genes Runx2 and OPN in miR-22-overexpressing PDLSCs. Conversely, inhibition of miR-22 delayed the process of PDLSCs osteogenic differentiation. Furthermore, Histone deacetylase 6 (HDAC6) was identified as a target gene of miR-22. Overexpression of miR-22 not only reduced the luciferase activity of the reporter containing the 3' untranslated region of HDAC6 mRNA, but also suppressed the endogenous protein expression of HDAC6. Rescue experiment showed that the promotion role of miR-22 in osteogenic differentiation could be relieved by overexpression of HDAC6. Meanwhile, overexpression of HDAC6 alone could also delay the osteogenic differentiation process. The results demonstrated that miR-22 promoted PDLSCs osteogenic differentiation by inhibiting HDAC6 expression, suggesting that miR-22 might be developed as a target of genetic modified stem cells therapy for periodontal diseases. J. Cell. Biochem. 118: 1653-1658, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Effectiveness and safety of computer-controlled periodontal ligament injection system in endodontic access to the mandibular posterior teeth.

    PubMed

    Jing, Quan; Wan, Kuo; Wang, Xiao-jun; Ma, Lin

    2014-03-01

    To evaluate the effectiveness and safety of a computer-controlled periodontal ligament (PDL) injection system to the local soft tissues as the primary technique in endodontic access to mandibular posterior teeth in patients with irreversible pulpitis. A total of 162 Chinese patients who had been diagnosed with irreversible pulpitis in their mandibular posterior teeth without acute infection or inflammation in the periodontal tissues were enrolled in this clinical study. The patients were divided into 3 groups according to the position of the involved tooth: the premolar group (PM, n=38), first molar group (FM, n=66), and second molar group (SM, n=58). All the patients received computer-controlled PDL injection with 4% articaine and 1:100 000 epinephrine. Immediately after the injection, endodontic access was performed, and the degree of pain during the treatment was evaluated by the patients using Visual Analogue Scale for pain. The success rates were compared among the 3 groups. The responses of local soft tissues were evaluated 3-8 days and 3 weeks after the procedure. The overall success rate was 76.5%. There was a significant difference in success rates among the PM, FM, and SM groups (92.1%, 53.0%, 93.1%, respectively; χ² = 34.3, P<0.01). Both the PM and SM groups showed higher success rates than that of the FM group (v=1, χ² = 16.73, P<0.01; v=1, χ² = 24.5, P<0.01). No irreversible adverse effects on the periodontal soft tissues at the injection sites were observed in the follow-up visits in any of the groups. The computer-controlled PDL injection system demonstrates both satisfactory anesthetic effects and safety in local soft tissues as primary anesthetic technique in endodontic access to the mandibular posterior teeth in patients with irreversible pulpitis.

  18. Effect of hypoxia on the expression of RANKL/OPG in human periodontal ligament cells in vitro

    PubMed Central

    Yu, Xi-Jiao; Xiao, Chang-Jie; Du, Yan-Mei; Liu, Shuang; Du, Yi; Li, Shu

    2015-01-01

    To investigate the impact of hypoxia on the expression of receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG) in human periodontal ligament cells (hPDLCs) in vitro. hPDLCs were incubated in a hypoxic atmosphere of 2% O2, 5% CO2, 94% N2 at 37°C for 6, 12, 24 and 48 h. After that, cell proliferation assay was determined using CCK-8 technique. SP immunocytochemistry method was performed to trace the expression of hypoxia-inducible factor 1 alpha (HIF-1α) in hPDLCs. The expression levels of RANKL and OPG were investigated using real-time PCR and ELISA. As a control, the cells were incubated at normoxic conditions of 20% O2, 5% CO2, 75% N2. All results were analyzed using one-way ANOVA at a significant level of P=0.05. OPG mRNA and protein levels were down-regulated meanwhile RANKL mRNA and soluble RANKL (sRANKL) protein levels were up-regulated after stimulated by hypoxia. The relative RANKL/OPG expression ratios were increased in both mRNA and protein levels. The expression of RANKL mRNA and sRANKL protein levels was enhanced significantly (P<0.05) under the hypoxia conditions at 12 h, 24 h and 48 h while OPG mRNA and protein were reduced significantly (P<0.05) at 12 h, 24 h and 48 h. Hypoxia can affect the expression of RANKL and OPG in hPDLCs, which constitute an important pathogenic event in the alveolar bone resorption. Lack of oxygen in periodontal tissue may accelerate the development of periodontitis. PMID:26722486

  19. Verification of γ-Amino-Butyric Acid (GABA) Signaling System Components in Periodontal Ligament Cells In Vivo and In Vitro.

    PubMed

    Konermann, Anna; Kantarci, Alpdogan; Wilbert, Steven; Van Dyke, Thomas; Jäger, Andreas

    2016-11-01

    CNS key neurotransmitter γ-amino-butyric acid (GABA) and its signaling components are likewise detectable in non-neuronal tissues displaying inter alia immunomodulatory functions. This study aimed at identifying potential glutamate decarboxylase (GAD)65 and GABA receptor expression in periodontal ligament (PDL) cells in vivo and in vitro, with particular regard to inflammation and mechanical loading. Gene expression was analyzed in human PDL cells at rest or in response to IL-1ß (5 ng/ml) or TNFα (5 ng/ml) challenge via qRT-PCR. Western blot determined constitutive receptor expression, and confocal laser scanning fluorescence microscopy visualized expression changes induced by inflammation. ELISA quantified GAD65 release. Immunocytochemistry was performed for GABA component detection in vitro on mechanically loaded PDL cells, and in vivo on rat upper jaw biopsies with mechanically induced root resorptions. Statistical significance was set at p < 0.05. GABAB1, GABAB2, GABAA1, and GABAA3 were ubiquitously expressed both on gene and protein level. GABAA2 and GAD65 were undetectable in resting cells, but induced by inflammation. GABAB1 exhibited the highest basal gene expression (6.97 % ± 0.16). IL-1ß markedly increased GABAB2 on a transcriptional (57.28-fold ± 12.40) and protein level seen via fluorescence microscopy. TNFα-stimulated PDL cells released GAD65 (3.68 pg/ml ± 0.17 after 24 h, 5.77 pg/ml ± 0.65 after 48 h). Immunocytochemistry revealed GAD65 expression in mechanically loaded PDL cells. In vivo, GABA components were varyingly expressed in an inflammatory periodontal environment. PDL cells differentially express GABA signaling components and secrete GAD65. Inflammation and mechanical loading regulate these neurotransmitter molecules, which are also detectable in vivo and are potentially involved in periodontal pathophysiology.

  20. Stem cell regulatory gene expression in human adult dental pulp and periodontal ligament cells undergoing odontogenic/osteogenic differentiation.

    PubMed

    Liu, Lu; Ling, Junqi; Wei, Xi; Wu, Liping; Xiao, Yin

    2009-10-01

    During development and regeneration, odontogenesis and osteogenesis are initiated by a cascade of signals driven by several master regulatory genes. In this study, we investigated the differential expression of 84 stem cell-related genes in dental pulp cells (DPCs) and periodontal ligament cells (PDLCs) undergoing odontogenic/osteogenic differentiation. Our results showed that, although there was considerable overlap, certain genes had more differential expression in PDLCs than in DPCs. CCND2, DLL1, and MME were the major upregulated genes in both PDLCs and DPCs, whereas KRT15 was the only gene significantly downregulated in PDLCs and DPCs in both odontogenic and osteogenic differentiation. Interestingly, a large number of regulatory genes in odontogenic and osteogenic differentiation interact or crosstalk via Notch, Wnt, transforming growth factor beta (TGF-beta)/bone morphogenic protein (BMP), and cadherin signaling pathways, such as the regulation of APC, DLL1, CCND2, BMP2, and CDH1. Using a rat dental pulp and periodontal defect model, the expression and distribution of both BMP2 and CDH1 have been verified for their spatial localization in dental pulp and periodontal tissue regeneration. This study has generated an overview of stem cell-related gene expression in DPCs and PDLCs during odontogenic/osteogenic differentiation and revealed that these genes may interact through the Notch, Wnt, TGF-beta/BMP, and cadherin signaling pathways to play a crucial role in determining the fate of dental derived cell and dental tissue regeneration. These findings provided a new insight into the molecular mechanisms of the dental tissue mineralization and regeneration.

  1. Comparison of the osteogenic, adipogenic, chondrogenic and cementogenic differentiation potential of periodontal ligament cells cultured on different biomaterials.

    PubMed

    Barrera-Ortega, C C; Hoz-Rodríguez, L; Arzate, H; Fonseca-García, A; Pérez-Alvarez, J; Rodil, S E

    2017-07-01

    It has been shown that the cellular responses such as adhesion, proliferation and differentiation are influenced by the surface properties, such as the topography or the surface energy. However, less is known about the effect of the chemical composition and type of material on the differentiation potential. The objective of the present paper is to compare the differentiation potential of periodontal ligament cells (HPLC) into adipocytes, osteoblasts, chondroblasts and cementoblasts of three type of materials (metals, ceramics and polymers) without using any biological induction media, but keeping the average roughness values within a limited range of 2.0-3.0μm. The samples were produced as discs of 14×2mm; (n=30 for each type of material). Two samples of each type were chosen; stainless-steel 316L and commercially pure titanium for the metallic samples. The polymers were polymethyl methacrylate and high-density polyethylene, and finally for the ceramics; zirconia and dental porcelain were used. The surfaces properties of the samples (wettability, chemical composition and point of zero charge, PZC) were measured in order to correlate them with the biological response. To evaluate the potential of differentiation, human periodontal ligament cells obtained from extracted teeth were used since they are a promising source for periodontal tissue regeneration. Cell proliferation was initially tested to assure non-toxic effects using a viability colorimetric assay. Finally, the differentiation pattern was evaluated using real time reverse transcription quantitative polymerase chain reaction for 5, 10 and 15days without adding any induction medium. The results indicated that the relative expression of genes related to a particular phenotype were different for each surface. However, not clear correlation between the type of material or their surface properties (morphology, chemical composition, wettability or point of zero charge) and the expression pattern could be

  2. [Molecular mechanisms for the improvement of wound healing ability of periodontal ligament in Marfan's syndrome].

    PubMed

    Saito, Masahiro; Tsuji, Takashi

    2012-01-01

    Marfan's syndrome (MFS) is a systemic disorder of the connective tissues caused by insufficient fibrillin-1 microfibril formation and can cause cardiac complications, emphysema, ocular lens dislocation and severe periodontal disease. ADAMTSL6β, a microfibril-associated extracellular matrix protein that has been implicated in fibrillin-1 microfibril assembly is able to improve microfibril insufficiency in MFS mice model. These findings suggest a new therapeutic strategy for the treatment of MFS through ADAMTSL6β-mediated fibrillin-1 microfibril assembly. We here review effect on ADAMTSL6β to the improvement of microfibril insufficiency in periodontal tissue as a model.

  3. Ligament creep recruits fibres at low stresses and can lead to modulus-reducing fibre damage at higher creep stresses: a study in rabbit medial collateral ligament model.

    PubMed

    Thornton, G M; Shrive, N G; Frank, C B

    2002-09-01

    Ligaments are subjected to a range of loads during different activities in vivo, suggesting that they must resist creep at various stresses. Cyclic and static creep tests of rabbit medial collateral ligament were used as a model to examine creep over a range of stresses in the toe- and linear-regions of the stress-strain curve: 4.1 MPa (n = 7), 7.1 MPa (n = 6), 14 MPa (n = 9) and 28 MPa (n = 6). We quantified ligament creep behaviour to determine if, at low stresses, modulus would increase in a cyclic creep test and collagen fibres would be recruited in a static creep test. At higher creep stresses, a decrease in measured modulus was expected to be a potential marker of damage. The increase in modulus during cyclic creep and the increase in strain during static creep were similar between the three toe-region stresses (4.1, 7.1, 14 MPa). However, at the linear-region stress (28 MPa), both these parameters increased significantly compared to the increases at the three toe-region stresses. A concurrent crimp analysis revealed that collagen fibres were recruited during creep, evidenced by decreased area of crimped fibres at the end of the static creep test. Interestingly, a predominance of straightened fibres was observed at the end of the 28 MPa creep test, suggesting a limited potential for fibre recruitment at higher, linear-region stresses. An additional 28 MPa (n = 6) group had mechanically detectable discontinuities in their stress-strain curves during creep that were related to reductions in modulus and suggested fibre damage. These data support the concept that collagen fibre recruitment is a mechanism by which ligaments resist creep at low stresses. At a higher creep stress, which was still only about a third of the failure capacity, damage to some ligaments occurred and was marked by a sudden reduction in modulus. In the cyclic tests, with continued cycling, the modulus increased back to original values obtained before the discontinuity suggesting that other

  4. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor

    PubMed Central

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions. PMID:27274995

  5. The Adaptive Nature of the Bone-Periodontal Ligament-Cementum Complex in a Ligature-Induced Periodontitis Rat Model

    PubMed Central

    Lee, Ji-Hyun; Lin, Jeremy D.; Fong, Justine I.; Ryder, Mark I.; Ho, Sunita P.

    2013-01-01

    The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF-α and RANKL), a mineral resorption indicator (TRAP), and a cell migration and adhesion molecule for tissue regeneration (fibronectin) within the complex were localized and correlated with changes in PDL-space (functional space). At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF-α. At 8 and 15 days, the number of RANKL(+) cells decreased near the mesial alveolar bone crest (ABC) but increased at the distal ABC. TRAP(+) cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations. PMID:23936854

  6. Ulnar collateral ligament injuries of the thumb: phalangeal translation during valgus stress in human cadavera.

    PubMed

    McKeon, Kathleen E; Gelberman, Richard H; Calfee, Ryan P

    2013-05-15

    The clinical diagnosis of thumb ulnar collateral ligament disruption has been based on joint angulation during valgus stress testing. This report describes a definitive method of distinguishing between complete and partial ulnar collateral ligament injuries by quantifying translation of the proximal phalanx on the metacarpal head during valgus stress testing. Sixty-two cadaveric thumbs underwent standardized valgus stress testing under fluoroscopy with the ulnar collateral ligament intact, following an isolated release of the proper ulnar collateral ligament, and following a combined release of both the proper and the accessory ulnar collateral ligament (complete ulnar collateral ligament release). Following complete ulnar collateral ligament release, the final thirty-seven thumbs were also analyzed after the application of a valgus force sufficient to cause 45° of valgus angulation at the metacarpophalangeal joint to model more severe soft-tissue injury. Two independent reviewers measured coronal plane joint angulation (in degrees), ulnar joint line gap formation (in millimeters), and radial translation of the proximal phalanx on the metacarpal head (in millimeters) on digital fluoroscopic images that had been randomized. Coronal angulation across the stressed metacarpophalangeal joint progressively increased through the stages of the testing protocol: ulnar collateral ligament intact (average [and standard deviation], 20° ± 8.1°), release of the proper ulnar collateral ligament (average, 23° ± 8.3°), and complete ulnar collateral ligament release (average, 30° ± 8.9°) (p < 0.01 for each comparison). Similarly, gap formation increased from the measurement in the intact state (5.1 ± 1.3 mm), to that following proper ulnar collateral ligament release (5.7 ± 1.5 mm), to that following complete ulnar collateral ligament release (7.2 ± 1.5 mm) (p < 0.01 for each comparison). Radial translation of the proximal phalanx on the metacarpal head did not increase

  7. The stimulation of proliferation and differentiation of periodontal ligament cells by the ionic products from Ca7Si2P2O16 bioceramics.

    PubMed

    Zhou, Yinghong; Wu, Chengtie; Xiao, Yin

    2012-07-01

    The ultimate goal of periodontal tissue engineering is to produce predictable regeneration of alveolar bone, root cementum, and periodontal ligament, which are lost as a result of periodontal diseases. To achieve this goal, it is of great importance to develop novel bioactive materials which could stimulate the proliferation, differentiation and osteogenic/cementogenic gene expression of periodontal ligament cells (PDLCs) for periodontal regeneration. In this study, we synthesized novel Ca(7)Si(2)P(2)O(16) ceramic powders for the first time by the sol-gel method and investigated the biological performance of PDLCs after exposure to different concentrations of Ca(7)Si(2)P(2)O(16) extracts. The original extracts were prepared at 200 mg ml(-1) and further diluted with serum-free cell culture medium to obtain a series of diluted extracts (100, 50, 25, 12.5 and 6.25 mg ml(-1)). Proliferation, alkaline phosphatase (ALP) activity, Ca deposition, and osteogenesis/cementogenesis-related gene expression (ALP, Col I, Runx2 and CEMP1) were assayed for PDLCs on days 7 and 14. The results showed that the ionic products from Ca(7)Si(2)P(2)O(16) powders significantly stimulated the proliferation, ALP activity, Ca deposition and osteogenesis/cementogenesis-related gene expression of PDLCs. In addition, it was found that Ca(7)Si(2)P(2)O(16) powders had excellent apatite-mineralization ability in simulated body fluids. This study demonstrated that Ca(7)Si(2)P(2)O(16) powders with such a specific composition possess the ability to stimulate the PDLC proliferation and osteoblast/cemenoblast-like cell differentiation, indicating that they are a promising bioactive material for periodontal tissue regeneration application.

  8. Effects of BMP9 and pulsed electromagnetic fields on the proliferation and osteogenic differentiation of human periodontal ligament stem cells.

    PubMed

    Wang, Tingting; Wang, Pei; Cao, Zhizhong; Wang, Xingxing; Wang, Dalin; Shen, Yaxian; Jing, Da; Luo, Erping; Tang, Weizhong

    2017-01-01

    Periodontal ligament stem cells (PDLSCs) have been confirmed to have self-renewal capacity and multidifferentiation potential and are good candidates for periodontal tissue regeneration. Pulsed electromagnetic field (PEMF) has been demonstrated to promote osteogenesis in non-union fractures, partly by regulating mesenchymal stem cells or osteoblast activity. However, there is no report about the osteo-inductive effect of PEMF stimulation on human PDLSCs (hPDLSCs). Thus, we tested the hypothesis that PEMF biophysical stimulation alone has an influence on the proliferation and osteogenic differentiation of hPDLSCs. To detect the osteo-inductive potential of bone morphogenetic protein (BMP9), we transfected the STRO-1(+) /CD146(+) hPDLCSs with BMP9-expressing recombinant adenoviruses. We examined the proliferation and osteogenic differentiation of hPDLSCs treated with either PEMF (15 Hz, 1 h daily, different intensities), or BMP9, or both stimuli. Cell counting kit-8 (CCK-8) assay showed that PEMF of different intensities had no effect on the proliferation of hPDLSCs and did not enhance the proliferative capability of BMP9-transfected cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting showed that the combination of both PEMFs (1.8 or 2.4 mT) and BMP9 stimulation had a synergistic effect on early and intermediate osteogenic genes and protein expressions of runt-related transcription factor 2, alkaline phosphatase, osteopontin, and late mineralized extracellular matrix formation in hPDLSCs. Bioelectromagnetics. 38:63-77, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Correction of hypophosphatasia (HPP) associated mineralization deficiencies in vitro by phosphate/pyrophosphate modulation in periodontal ligament cells

    PubMed Central

    Rodrigues, Thaisângela L.; Foster, Brian L.; Silverio, Karina G.; Martins, Luciane; Casati, Marcio Z.; Sallum, Enilson A.; Somerman, Martha J.; Nociti, Francisco H.

    2013-01-01

    Background Mutations in the Alpl gene in hypophosphatasia (HPP) reduce the function of tissue nonspecific alkaline phosphatase (TNAP), resulting in increased pyrophosphate (PPi) and a severe deficiency in acellular cementum. We hypothesized that exogenous phosphate (Pi) would rescue the in vitro mineralization capacity of periodontal ligament (PDL) cells harvested from HPP-diagnosed subjects, by correcting Pi/PPi ratio and modulating expression of genes involved with Pi/PPi metabolism. Methods Ex vivo and in vitro analyses were employed to identify mechanisms involved in HPP-associated PDL/tooth root deficiencies. Constitutive expression of PPi-associated genes was contrasted in PDL versus pulp tissues obtained from healthy subjects. Primary PDL cell cultures from HPP subjects (monozygotic twin males) were established to assay alkaline phosphatase activity (ALP), in vitro mineralization, and gene expression. Exogenous Pi was provided to correct Pi/PPi ratio. Results PDL tissues obtained from healthy individuals featured higher basal expression of key PPi regulators, genes Alpl, progressive ankylosis protein (Ankh) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1), versus paired pulp tissues. A novel Alpl mutation was identified in the twin HPP subjects enrolled in this study. Compared to controls, HPP-PDL cells exhibited significantly reduced ALP and mineralizing capacity, which were rescued by addition of 1mM Pi. Dysregulated expression of PPi regulatory genes Alpl, Ankh, and Enpp1 was also corrected by adding Pi, though other matrix markers evaluated in our study remained down-regulated. Conclusions These findings underscore the importance of controlling Pi/PPi ratio toward development of a functional periodontal apparatus, and support Pi/PPi imbalance as the etiology of HPP-associated cementum defects. PMID:22014174

  10. The ionic products of bioactive glass particle dissolution enhance periodontal ligament fibroblast osteocalcin expression and enhance early mineralized tissue development.

    PubMed

    Varanasi, Venu G; Owyoung, Jeremy B; Saiz, Eduardo; Marshall, Sally J; Marshall, Grayson W; Loomer, Peter M

    2011-08-01

    This study resulted in enhanced collagen type 1 and osteocalcin expression in human periodontal ligament fibroblasts (hPDLF) when exposed to bioactive glass conditioned media that subsequently may promote early mineralized tissue development. Commercial Bioglass™ (45S5) and experimental bioactive coating glass (6P53-b), were used to make a glass conditioned media (GCM) for comparison to control medium. ICP-MS analysis showed increased concentrations of Ca(2+), PO(4) (3-), Si(4+), and Na(+), for 45S5 GCM and Mg(2+), K(+), Ca(2+), PO(4)(3-), Si(4+), and Na(+) for 6P53-b GCM (relative to control medium). Differentiating hPDLF cultures exposed to 45S5 and 6P53-b GCM showed enhanced expression of collagen type 1 (Col1α1, Col1α2), osteocalcin, and alkaline phosphatase gene expression. These GCM also enhanced osteocalcin protein expression. After 16 d of culture, 45S5 and 6P53-b GCM treated cells showed regions of deep red Alizarin staining, indicating increased Ca within their respective extracellular matrices (ECM), while control-treated cells did not exhibit these features. SEM analysis showed more developed ECM in GCM treated cultures, indicated by multiple tissue layering and abundant collagen fiber bundle formation, while control treated cells did not exhibit these features. SEM analysis showed polygonal structures suggestive of CaP in 45S5 GCM treated cultures. These results indicate the osteogenic potential of bioactive coating glass in periodontal bone defect filling applications.

  11. Sodium hydrogen sulfide inhibits nicotine and lipopolysaccharide-induced osteoclastic differentiation and reversed osteoblastic differentiation in human periodontal ligament cells.

    PubMed

    Lee, Sun-Kyung; Chung, Jong-Hyuk; Choi, Sung-Chul; Auh, Q-Schick; Lee, Young-Man; Lee, Sang-Im; Kim, Eun-Cheol

    2013-05-01

    Although previous studies have demonstrated that hydrogen sulfide (H(2)S) stimulated or inhibited osteoclastic differentiation, little is known about the effects of H(2)S on the differentiation of osteoblasts and osteoclasts. To determine the possible bioactivities of H(2)S on bone metabolism, we investigated the in vitro effects of H(2)S on cytotoxicity, osteoblastic, and osteoclastic differentiation as well as the underlying mechanism in lipopolysaccharide (LPS) and nicotine-stimulated human periodontal ligament cells (hPDLCs). The H(2)S donor, NaHS, protected hPDLCs from nicotine and LPS-induced cytotoxicity and recovered nicotine- and LPS-downregulated osteoblastic differentiation, such as alkaline phosphatase (ALP) activity, mRNA expression of osteoblasts, including ALP, osteopontin (OPN), and osteocalcin (OCN), and mineralized nodule formation. Concomitantly, NaHS inhibited the differentiation of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in mouse bone marrow cells and blocked nicotine- and LPS-induced osteoclastogenesis regulatory molecules, such as RANKL, OPG, M-CSF, MMP-9, TRAP, and cathepsin K mRNA. NaHS blocked nicotine and LPS-induced activation of p38, ERK, MKP-1, PI3K, PKC, and PKC isoenzymes, and NF-κB. The effects of H(2)S on nicotine- and LPS-induced osteoblastic and osteoclastic differentiation were remarkably reversed by MKP-1 enzyme inhibitor (vanadate) and expression inhibitor (triptolide). Taken together, we report for the first time that H(2)S inhibited cytotoxicity and osteoclastic differentiation and recovered osteoblastic differentiation in a nicotine- and periodontopathogen-stimulated hPDLCs model, which has potential therapeutic value for treatment of periodontal and inflammatory bone diseases.

  12. Evaluation of association between psychological stress and serum cortisol levels in patients with chronic periodontitis - Estimation of relationship between psychological stress and periodontal status

    PubMed Central

    Jaiswal, Roshni; Shenoy, Nina; Thomas, Biju

    2016-01-01

    Background: Stress classically describes a destructive notion that can have a bearing on one's physical and mental health. It may also add to an increased propensity to periodontal disease. Aim: To investigate the association between psychological stress and serum cortisol levels in patients with chronic periodontitis. Materials and Methods: Forty subjects were recruited from the outpatient department at the Department of Periodontics, from a college in Mangalore, divided into two groups, i.e., twenty as healthy controls and twenty were stressed subjects with chronic periodontitis. The clinical examination included the assessment of probing pocket depth, clinical attachment level and oral hygiene index-simplified. Serum cortisol levels were estimated biochemically using the enzyme-linked immunosorbent assay method and the estimation of psychological stress was done by a questionnaire. Results: Descriptive statistics such as mean and standard deviation was used to review the collected data. Independent sample t-test was used for comparison and correlation was evaluation using Pearson's correlation test. As per our observation, high serum cortisol levels and psychological stress are positively linked with chronic periodontitis establishing a risk profile showing a significant correlation (P < 0.05). Conclusion: Routine serum cortisol assessment may be a reasonable and a valuable investigative indicator to rule out stress in periodontitis patients as it should be considered as an imperative risk factor for periodontal disease. PMID:28298818

  13. Evaluation of association between psychological stress and serum cortisol levels in patients with chronic periodontitis - Estimation of relationship between psychological stress and periodontal status.

    PubMed

    Jaiswal, Roshni; Shenoy, Nina; Thomas, Biju

    2016-01-01

    Stress classically describes a destructive notion that can have a bearing on one's physical and mental health. It may also add to an increased propensity to periodontal disease. To investigate the association between psychological stress and serum cortisol levels in patients with chronic periodontitis. Forty subjects were recruited from the outpatient department at the Department of Periodontics, from a college in Mangalore, divided into two groups, i.e., twenty as healthy controls and twenty were stressed subjects with chronic periodontitis. The clinical examination included the assessment of probing pocket depth, clinical attachment level and oral hygiene index-simplified. Serum cortisol levels were estimated biochemically using the enzyme-linked immunosorbent assay method and the estimation of psychological stress was done by a questionnaire. Descriptive statistics such as mean and standard deviation was used to review the collected data. Independent sample t-test was used for comparison and correlation was evaluation using Pearson's correlation test. As per our observation, high serum cortisol levels and psychological stress are positively linked with chronic periodontitis establishing a risk profile showing a significant correlation (P < 0.05). Routine serum cortisol assessment may be a reasonable and a valuable investigative indicator to rule out stress in periodontitis patients as it should be considered as an imperative risk factor for periodontal disease.

  14. Chronic Periodontitis in Type 2 Diabetes Mellitus: Oxidative Stress as a Common Factor in Periodontal Tissue Injury

    PubMed Central

    Patil, Vijayetha P.; Gokhale, Neeraja; Acharya, Anirudh; Kangokar, Praveenchandra

    2016-01-01

    Introduction The prevalence of periodontitis is significantly higher among people with poorly controlled diabetes mellitus. Majority of tissue destruction in periodontitis is considered to be the result of an aberrant inflammatory/immune response to microbial plaque and involve prolonged release of reactive oxygen species (ROS). There is increased evidence for compromised antioxidant capacity in periodontal tissues and fluids which may be an added factor for tissue damage in periodontitis. Aim To study the possible role of Reactive oxygen species (ROS) and antioxidant status in blood among chronic periodontitis patients with and without Type 2 Diabetes mellitus. Materials and Methods The study comprised of total 100 subjects among which 25 were normal healthy controls, 25 were gingivitis patients, 25 were chronic periodontitis patients (CP) and 25 were having chronic periodontitis with type 2 diabetes (CP with DM). ROS levels were determined as MDA (Malondialdehyde) and antioxidant status as plasma total antioxidant capacity (TAC), vitamin C and erythrocyte Superoxide dismutase (SOD) and catalase activity. Results There was significant increase in MDA levels in all the patient groups compared with healthy controls (p<0.05). The decrease in TAC, Vitamin C and SOD levels among CP with DM patients as compared to controls was highly significant (p<0.01). There was a positive correlation between the probing pocket depth and MDA levels among periodontitis patients with diabetes (r=0.566, p=0.003). Conclusion There is increased oxidative stress in chronic periodontitis with and without type 2 diabetes indicating a common factor involvement in tissue damage. More severe tissue destruction in periodontitis is associated with excessive ROS generation which is positively correlated in type 2 diabetic subjects. PMID:27190790

  15. Chronic Periodontitis in Type 2 Diabetes Mellitus: Oxidative Stress as a Common Factor in Periodontal Tissue Injury.

    PubMed

    Patil, Vidya S; Patil, Vijayetha P; Gokhale, Neeraja; Acharya, Anirudh; Kangokar, Praveenchandra

    2016-04-01

    The prevalence of periodontitis is significantly higher among people with poorly controlled diabetes mellitus. Majority of tissue destruction in periodontitis is considered to be the result of an aberrant inflammatory/immune response to microbial plaque and involve prolonged release of reactive oxygen species (ROS). There is increased evidence for compromised antioxidant capacity in periodontal tissues and fluids which may be an added factor for tissue damage in periodontitis. To study the possible role of Reactive oxygen species (ROS) and antioxidant status in blood among chronic periodontitis patients with and without Type 2 Diabetes mellitus. The study comprised of total 100 subjects among which 25 were normal healthy controls, 25 were gingivitis patients, 25 were chronic periodontitis patients (CP) and 25 were having chronic periodontitis with type 2 diabetes (CP with DM). ROS levels were determined as MDA (Malondialdehyde) and antioxidant status as plasma total antioxidant capacity (TAC), vitamin C and erythrocyte Superoxide dismutase (SOD) and catalase activity. There was significant increase in MDA levels in all the patient groups compared with healthy controls (p<0.05). The decrease in TAC, Vitamin C and SOD levels among CP with DM patients as compared to controls was highly significant (p<0.01). There was a positive correlation between the probing pocket depth and MDA levels among periodontitis patients with diabetes (r=0.566, p=0.003). There is increased oxidative stress in chronic periodontitis with and without type 2 diabetes indicating a common factor involvement in tissue damage. More severe tissue destruction in periodontitis is associated with excessive ROS generation which is positively correlated in type 2 diabetic subjects.

  16. Conditioned medium of periodontal ligament mesenchymal stem cells exert anti-inflammatory effects in lipopolysaccharide-activated mouse motoneurons.

    PubMed

    Rajan, Thangavelu Soundara; Giacoppo, Sabrina; Trubiani, Oriana; Diomede, Francesca; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela

    2016-11-15

    Conditioned medium derived from mesenchymal stem cells (MSCs) shows immunomodulatory and neuroprotective effects in preclinical models. Given the difficulty to harvest MSCs from bone marrow and adipose tissues, research has been focused to find alternative resources for MSCs, such as oral-derived tissues. Recently, we have demonstrated the protective effects of MSCs obtained from healthy human periodontal ligament tissue (hPDLSCs) in murine experimental autoimmune encephalomyelitis model. In the present in vitro study, we have investigated the immunomodulatory and neuroprotective effects of conditioned medium obtained from hPDLSCs of Relapsing Remitting- Multiple sclerosis (RR-MS) patients on NSC34 mouse motoneurons stimulated with lipopolysaccharide (LPS). Immunocytochemistry and western blotting were performed. Increased level of TLR4 and NFκB, and reduced level of IκB-α were observed in LPS-stimulated motoneurons, which were modulated by pre-conditioning with hPDLSC-conditioned medium. Inflammatory cytokines (TNF-α, IL-10), neuroprotective markers (Nestin, NFL 70, NGF, GAP43), and apoptotic markers (Bax, Bcl-2, p21) were modulated. Moreover, extracellular vesicles of hPDLSC-conditioned medium showed the presence of anti-inflammatory cytokines IL-10 and TGF-β. Our results demonstrate the immunosuppressive properties of hPDLSC-conditioned medium of RR-MS patients in motoneurons subjected to inflammation. Our findings warrant further preclinical and clinical studies to elucidate the autologous therapeutic efficacy of hPDLSC-conditioned medium in neurodegenerative diseases.

  17. An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: II. Colchicine-treated fibroblasts

    SciTech Connect

    Cho, M.I.; Garant, P.R.

    1981-12-01

    Colchicine administered intravenously depolymerized microtubules and disrupted the normal organization of the Golgi apparatus in periodontal ligament fibroblasts. Radioautography with /sup 3/H-proline indicated that collagen secretion was completely inhibited during a period of approximately 4 hours following the onset of the colchicine effect. During this period of secretory inhibition, labeled collagen precursors were present within a variety of dense bodies, primarily located in a juxtanuclear location replacing the normal Golgi complex. The time course of /sup 3/H-proline labeling from 2 to 8 hours suggested that small, newly formed dense bodies fused to form larger dense bodies and pleomorphic structures (zebra bodies), within which collagen precursors appeared to undergo partial polymerization. Autophagosomes, many labeled with /sup 3/H-proline, also increased in number after colchicine administration. A gradual decline in /sup 3/H-proline label occurred from 4 to 24 hours, presumably due to exocytosis of dense bodies or by the digestion of labeled collagen precursors within autophagosomes. These results support the concept that an intact microtubular network is essential for the organized transport of collagen precursors, from the rough endoplasmic reticulum to the Golgi apparatus, and the eventual transport and exocytosis of collagen secretory granules.

  18. Three-dimensional ultrastructural analysis of cells in the periodontal ligament using focused ion beam/scanning electron microscope tomography.

    PubMed

    Hirashima, Shingo; Ohta, Keisuke; Kanazawa, Tomonoshin; Okayama, Satoko; Togo, Akinobu; Uchimura, Naohisa; Kusukawa, Jingo; Nakamura, Kei-Ichiro

    2016-12-20

    The accurate comprehension of normal tissue provides essential data to analyse abnormalities such as disease and regenerative processes. In addition, understanding the proper structure of the target tissue and its microenvironment may facilitate successful novel treatment strategies. Many studies have examined the nature and structure of periodontal ligaments (PDLs); however, the three-dimensional (3D) structure of cells in normal PDLs remains poorly understood. In this study, we used focused ion beam/scanning electron microscope tomography to investigate the whole 3D ultrastructure of PDL cells along with quantitatively analysing their structural properties and ascertaining their orientation to the direction of the collagen fibre. PDL cells were shown to be in contact with each other, forming a widespread mesh-like network between the cementum and the alveolar bone. The volume of the cells in the horizontal fibre area was significantly larger than in other areas, whereas the anisotropy of these cells was lower than in other areas. Furthermore, the orientation of cells to the PDL fibres was not parallel to the PDL fibres in each area. As similar evaluations are recognized as being challenging using conventional two-dimensional methods, these novel 3D findings may contribute necessary knowledge for the comprehensive understanding and analysis of PDLs.

  19. Alginate/hyaluronic acid hydrogel delivery system characteristics regulate the differentiation of periodontal ligament stem cells toward chondrogenic lineage.

    PubMed

    Ansari, Sahar; Diniz, Ivana M; Chen, Chider; Aghaloo, Tara; Wu, Benjamin M; Shi, Songtao; Moshaverinia, Alireza

    2017-09-15

    Cartilage tissue regeneration often presents a challenging clinical situation. Recently, it has been shown that Periodontal Ligament Stem Cells (PDLSCs) possess high chondrogenic differentiation capacity. In this study, we developed a stem cell delivery system based on alginate/hyaluronic acid (HA) loaded with TGF-β1 ligand, encapsulating PDLSCs; and investigated the chondrogenic differentiation of encapsulated cells in alginate/HA hydrogel microspheres in vitro and in vivo. The results showed that PDLSCs, as well as human bone marrow mesenchymal stem cells (hBMMSCs), as the positive control, were stained positive for both toluidine blue and alcian blue staining, while exhibiting high levels of gene expression related to chondrogenesis (Col II, Aggrecan and Sox-9), as assessed via qPCR. The quantitative PCR analyses exhibited that the chondrogenic differentiation of encapsulated MSCs can be regulated by the modulus of elasticity of hydrogel delivery system, confirming the vital role of the microenvironment, and the presence of inductive signals for viability and differentiation of MSCs. In vivo, histological and immunofluorescence staining for chondrogenic specific protein markers confirmed ectopic cartilage-like tissue regeneration inside transplanted hydrogels. PDLSCs presented significantly greater capability for chondrogenic differentiation than hBMMSCs (P < 0.05). Altogether, our findings confirmed that alginate/HA hydrogels encapsulating PDLSCs are a promising candidate for cartilage regeneration.

  20. Three-dimensional ultrastructural analysis of cells in the periodontal ligament using focused ion beam/scanning electron microscope tomography

    PubMed Central

    Hirashima, Shingo; Ohta, Keisuke; Kanazawa, Tomonoshin; Okayama, Satoko; Togo, Akinobu; Uchimura, Naohisa; Kusukawa, Jingo; Nakamura, Kei-ichiro

    2016-01-01

    The accurate comprehension of normal tissue provides essential data to analyse abnormalities such as disease and regenerative processes. In addition, understanding the proper structure of the target tissue and its microenvironment may facilitate successful novel treatment strategies. Many studies have examined the nature and structure of periodontal ligaments (PDLs); however, the three-dimensional (3D) structure of cells in normal PDLs remains poorly understood. In this study, we used focused ion beam/scanning electron microscope tomography to investigate the whole 3D ultrastructure of PDL cells along with quantitatively analysing their structural properties and ascertaining their orientation to the direction of the collagen fibre. PDL cells were shown to be in contact with each other, forming a widespread mesh-like network between the cementum and the alveolar bone. The volume of the cells in the horizontal fibre area was significantly larger than in other areas, whereas the anisotropy of these cells was lower than in other areas. Furthermore, the orientation of cells to the PDL fibres was not parallel to the PDL fibres in each area. As similar evaluations are recognized as being challenging using conventional two-dimensional methods, these novel 3D findings may contribute necessary knowledge for the comprehensive understanding and analysis of PDLs. PMID:27995978

  1. Effect of the simulated periodontal ligament on cast post-and-core removal using an ultrasonic device.

    PubMed

    Brito-Junior, Manoel; Braga, Neilor Mateus Antunes; Rodrigues, Danilo Costa; Camilo, Carla Cristina; Faria-e-Silva, André Luis

    2010-01-01

    The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. Simulation of PDL has an effect on both ultrasonic vibration and tensile testing.

  2. Effect of the simulated periodontal ligament on cast post-and-core removal using an ultrasonic device

    PubMed Central

    BRITO-JUNIOR, Manoel; BRAGA, Neilor Mateus Antunes; RODRIGUES, Danilo Costa; CAMILO, Carla Cristina; FARIA-E-SILVA, André Luis

    2010-01-01

    Objective The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. Material and Methods Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). Results The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. Conclusion Simulation of PDL has an effect on both ultrasonic vibration and tensile testing. PMID:21085812

  3. In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint

    PubMed Central

    Jang, Andrew T.; Lin, Jeremy D.; Seo, Youngho; Etchin, Sergey; Merkle, Arno; Fahey, Kevin; Ho, Sunita P.

    2014-01-01

    This study demonstrates a novel biomechanics testing protocol. The advantage of this protocol includes the use of an in situ loading device coupled to a high resolution X-ray microscope, thus enabling visualization of internal structural elements under simulated physiological loads and wet conditions. Experimental specimens will include intact bone-periodontal ligament (PDL)-tooth fibrous joints. Results will illustrate three important features of the protocol as they can be applied to organ level biomechanics: 1) reactionary force vs. displacement: tooth displacement within the alveolar socket and its reactionary response to loading, 2) three-dimensional (3D) spatial configuration and morphometrics: geometric relationship of the tooth with the alveolar socket, and 3) changes in readouts 1 and 2 due to a change in loading axis, i.e. from concentric to eccentric loads. Efficacy of the proposed protocol will be evaluated by coupling mechanical testing readouts to 3D morphometrics and overall biomechanics of the joint. In addition, this technique will emphasize on the need to equilibrate experimental conditions, specifically reactionary loads prior to acquiring tomograms of fibrous joints. It should be noted that the proposed protocol is limited to testing specimens under ex vivo conditions, and that use of contrast agents to visualize soft tissue mechanical response could lead to erroneous conclusions about tissue and organ-level biomechanics. PMID:24638035

  4. Periodontal ligament stem cells modulate root resorption of human primary teeth via Runx2 regulating RANKL/OPG system.

    PubMed

    Li, Bei; Zhang, Yu; Wang, Qingchao; Dong, Zhiwei; Shang, Linjuan; Wu, Lizheng; Wang, Xiaojing; Jin, Yan

    2014-10-15

    Physiological primary teeth exfoliation is a normal phenomenon during teeth development. However, retained primary teeth can often be observed in the patients with cleidocranial dysplasia (CCD) caused by mutation of Runx2. The potential regulative mechanism is still unknown. In the present study, periodontal ligament stem cells (PDLSCs) were derived from different resorbed stages of primary teeth and permanent teeth from normal patients and primary teeth from CCD patient. The proliferative, osteogenic and osteoclast-inductive capacities of PDLSCs from each group were detected. We demonstrated here that the proliferative ability of PDLSCs was reduced while the osteogenic and the osteoclast-inductive capacity of PDLSCs were enhanced during root resorption. The results also showed that PDLSCs from permanent teeth and CCD patient expressed low level of Runx2 and RANKL while high level of OPG. However, expression of Runx2 and RANKL were increased while expression of OPG was decreased in PDLSCs derived from resorbed teeth. Furthermore, Runx2 regulating the expression of RANKL and OPG and the osteoclast-inductive capacity of PDLSCs were confirmed by gain or loss of function assay. These data suggest that PDLSCs promote osteoclast differentiation via Runx2 upregulating RANKL and downregulating OPG, leading to enhanced root resorption that results in physiological exfoliation of primary teeth.

  5. Expression and Presence of OPG and RANKL mRNA and Protein in Human Periodontal Ligament with Orthodontic Force

    PubMed Central

    Otero, Liliana; García, Dabeiba Adriana; Wilches-Buitrago, Liseth

    2016-01-01

    OBJECTIVE The objective of this study is to investigate the expression and concentration of ligand receptor activator of NFkB (RANKL) and osteoprotegerin (OPG) in human periodontal ligament (hPDL) with orthodontic forces of different magnitudes. METHODS Right premolars in 32 patients were loaded with 4oz or 7oz of orthodontic force for 7 days. Left first premolars were not loaded. After 7 days, premolars were extracted for treatment as indicated. OPG and RANKL mRNA expressions were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and ELISA was used to assess OPG and RANKL protein concentration in compression and tension sides of PDL. Data were subjected to analysis of variance and Tukey tests. RESULTS There was statistically significant difference in RANKL concentration on comparing control teeth with tension and compression sides of the experimental teeth (P < 0.0001). The expression of mRNA RANKL was increased in the tension and compression sides with 4oz (P < 0.0001). OPG did not show statistically significant association with any group. Changes in RANKL/OPG protein ratio in experimental and control groups showed statistically significant difference (P < 0.0001). CONCLUSIONS RANKL protein levels are elevated in hPDL loaded with orthodontic forces, suggesting that RANKL protein contributes to bone modeling in response to the initial placement of orthodontic force. PMID:26823650

  6. Osteogenesis differentiation of human periodontal ligament cells by CO2 laser-treatment stimulating macrophages via BMP2 signalling pathway

    NASA Astrophysics Data System (ADS)

    Hsieh, Wen-Hui; Chen, Yi-Jyun; Hung, Chi-Jr; Huang, Tsui-Hsien; Kao, Chia-Tze; Shie, Ming-You

    2014-11-01

    Immune reactions play an important role in determining the biostimulation of bone formation, either in new bone formation or inflammatory fibrous tissue encapsulation. Macrophage cell, the important effector cells in the immune reaction, which are indispensable for osteogenesis and their heterogeneity and plasticity, render macrophages a primer target for immune system modulation. However, there are very few studies about the effects of macrophage cells on laser treatment-regulated osteogenesis. In this study, we used CO2 laser as a model biostimulation to investigate the role of macrophage cells on the CO2 laser stimulated osteogenesis. Bone morphogenetic protein 2 (BMP2) was also significantly up regulated by the CO2 laser stimulation, indicating that macrophage may participate in the CO2 laser stimulated osteogenesis. Interestingly, when laser treatment macrophage-conditioned medium were applied to human periodontal ligament cells (hPDLs), the osteogenesis differentiation of hPDLs was significantly enhanced, indicating the important role of macrophages in CO2 laser-induced osteogenesis. These findings provided valuable insights into the mechanism of CO2 laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment.

  7. In vitro cytotoxicity of hydrothermally synthesized ZnO nanoparticles on human periodontal ligament fibroblast and mouse dermal fibroblast cells.

    PubMed

    Seker, Sükran; Elçin, A Eser; Yumak, Tuğrul; Sınağ, Ali; Elçin, Y Murat

    2014-12-01

    The use of metal oxide nanoparticles (NPs) in industrial applications has been expanding, as a consequence, risk of human exposure increases. In this study, the potential toxic effects of zinc oxide (ZnO) NPs on human periodontal ligament fibroblast cells (hPDLFs) and on mouse dermal fibroblast cells (mDFs) were evaluated in vitro. We synthesized ZnO NPs (particle size; 7-8 nm) by the hydrothermal method. Characterization assays were performed with atomic force microscopy, Braun-Emmet-Teller analysis, and dynamic light scattering. The hPDLFs and mDFs were incubated with the NPs with concentrations of 0.1, 1, 10, 50 and 100 μg/mL for 6, 24 and 48h. Under the control and NP-exposed conditions, we have made different types of measurements for cell viability and morphology, membrane leakage and intracellular reactive oxygen species generation. Also, we monitored cell responses to ZnO NPs using an impedance measurement system in real-time. While the morphological changes were visualized using scanning electron microscopy, the subcellular localization of NPs was investigated by transmission electron microscopy. Results indicated that ZnO NPs have significant toxic effects on both of the primary fibroblastic cells at concentrations of ∼50-100 μg/mL. The cytotoxicity of ZnO NPs on fibroblasts depended on concentration and duration of exposure.

  8. Influence of masticatory hypofunction on the alveolar bone and the molar periodontal ligament space in the rat maxilla.

    PubMed

    Denes, Balazs J; Mavropoulos, Anestis; Bresin, Andrea; Kiliaridis, Stavros

    2013-12-01

    Previous studies have established that complete absence of masticatory function results in a narrower alveolar process and periodontal ligament (PDL). The aim of our study was to investigate, for the first time, both the alveolar process and the PDL in masticatory hypofunction. Twenty-six rats, 3 wk of age, were randomly assigned to either a hard- or a soft-diet group (n = 13 each group). The rats were killed after 6 wk and their skulls were scanned using micro-computed tomography (micro-CT). We measured the cross-sectional width of the space occupied by the PDL, as well as the cross-sectional alveolar socket surface (AS) and the cross-sectional root surface (RS). We also measured the width of the alveolar process. The alveolar process was narrower, the PDL width was thinner, and the AS was smaller in rats fed a soft diet compared with rats fed a hard diet. The PDL width was correlated to the alveolar process width and the AS. The narrower alveolar process found in rats fed a soft diet is the result of alterations to both the alveolar bone and the PDL. The correlation between them provides evidence that a reduction of occlusal loading induces a simultaneous response in both tissues. © 2013 Eur J Oral Sci.

  9. [Diagnosis of medial collateral ligament injury by stress X-ray and MRI of knee joint].

    PubMed

    Zhang, Long-Jun; Chen, Jian-Liang; Xu, Yong; Zhu, Shao-Bing

    2012-11-01

    To study the application of stress X-ray of knee joint for the diagnosis ot medial collateral ligament injury. From January 2008 to June 2011, 46 patients with medial collateral ligament injury were reviewed. Among the patients, 32 patients were male and 14 patients were female, ranging in age from 28 to 72 years, with an average of (49.46 +/- 22.54) years. Left knee joint injuries occurred in 22 patients, and 24 patients had injuries in right knee joint. Thirty-one patients were treated with surgical method, and 15 patients were treated with conservative method including 1 patient finally received operation after 3 months treatment with conservative method without effect. The injury side and normal side were observed by X-ray under stress and non-stress, as well as MRI. Operation was used to treat patients with medial gap markedly widen and the deep layer of medial collateral ligament injury in MRI. A line (line A) was drawn from medial condyle to lateral condyle of tibia platform. The line A was translated to the inner margin of condylus medialis femoris, which was line B. The perpendicular distance was measured, which was line C. The ration of space difference (R) was calculated by (space at stress force of injured side-space at non-stress force of injured side)/(space at stress force of normal side-space at non-stress force of normal side). The relationship between R and ligament injury type were investigated. There were 17 patients with injuries of superficial lamella, 21 patients with injuries of deep lamella. Eight patients had associated injuries of articular capsule and posterior cruciate ligament. When R value was between 1.51 to 5.24, the injury of superficial ligament was found in 15 patients, actual injuries were found in 17 patients. When R value between 5.28 and 13.85, the injuries of bathypelagic ligament were found in 19 patients, actual injuries were found in 21 patients. When R value was between 15.61 and 26.25, the associated injuries of

  10. Effect of initial periodontal therapy on oxidative stress markers in gingival crevicular fluid, saliva, and serum in smokers and non-smokers with chronic periodontitis.

    PubMed

    Hendek, Meltem Karsiyaka; Erdemir, Ebru Olgun; Kisa, Ucler; Ozcan, Gonen

    2015-02-01

    The aim of this case-control study with an intervention arm is to determine the effect of initial periodontal treatment on oxidative stress biomarkers in smokers and non-smokers with chronic periodontitis (CP). The study included 47 patients with CP (24 smokers [S+P+] and 23 non-smokers [S-P+]) and 46 periodontally healthy individuals (23 smokers [S+P-] and 23 non-smokers [S-P-]) for a total of 93 participants. Gingival crevicular fluid (GCF), serum, and saliva samples were obtained and clinical periodontal measurements were recorded at baseline and at the first and third months after periodontal therapy. 8-hydroxydeoxyguanosine (OHdG) and 4-hydroxynonenal (HNE) and enzyme activity of glutathione peroxidase (GSH-Px) were analyzed with enzyme-linked immunosorbent assay. The level of 8-OHdD in GCF was found to be significantly higher in both periodontitis groups compared with both periodontally healthy groups. 8-OHdG and GSH-Px in saliva in both periodontitis groups were significantly increased compared with the S-P- group. In the S+P+ group, 4-HNE in GCF was found to be significantly higher than in periodontally healthy participants. After initial periodontal treatment, the levels of 8-OHdG in GCF and saliva were significantly decreased in both periodontitis groups. Initial periodontal therapy may be helpful for diminishing oxidative stress in periodontitis.

  11. [Sclerostin expression in periodontal ligaments during movement of orthodontic teeth in rats].

    PubMed

    Yiwen, Chen; Shang, Gao; Tongtong, Xu; Jiahui, Zhang; Jincheng, Li; Huiyan, Zhang; Jinjin, Lu; Min, Hu; Zhihui, Liu

    2016-06-01

    This study aims to observe the expression of Sclerostin during movement of orthodontic teeth and determine the effect of this protein on remodeling of periodontal tissues. Twenty-four Wistar rats were chosen. Orthodontic forces were applied between the bilateral incisor and first molar to achieve mesial movement. Rats in each group were executed at different time points (0, 1, 3, 5, 7, 14 d). Morphology of periodontal tissue was observed by hematoxylin-eosin (HE) staining. The number of osteoclasts were observed by tartrate-resistant acid phosphatase (TRAP) staining. Sclerostin expression were observed by immunohistochemical staining. HE staining revealed that the resorption of alveolar bone intensified with prolonged movement. Results of immunohistochemical and TRAP staining revealed that Sclerostin expression and number of osteoclasts were related to duration of movement of orthodontic tooth. After staining for 5 days, the number of osteoclasts and Sclerostin expression reached their peak and then began to decline. The numbers of osteoclasts and the expression level of Sclerostin were higher at the compressive side than those at the tensive side. Sclerostin affected orthodontic tooth movement by inhibiting the Wnt signaling pathway and by indirectly or directly controlling bone morphogenetic protein.

  12. [Influences of Oral Health Behaviors, Depression and Stress on Periodontal Disease in Pregnant Women].

    PubMed

    Park, Hae Jin; Lee, Hae Jung; Cho, Soo Hyun

    2016-10-01

    The purpose of this study was to identify the influences of oral health behaviors, depression, and stress on periodontal disease in pregnant women. The participants in this study were 129 pregnant women. Data were collected using questionnaires which included individual characteristics, oral health care behaviors, the Center for Epidemiological Studies-Depression scale (CES-D), a global measure of perceived stress, and pregnancy stress. A dentist measured periodontal probing depth and classified stages of periodontal disease according to the Community Periodontal Index (CPI). Data were analyzed using descriptive statistics, Pearson correlation, and multiple regression. Periodontal disease had significant correlations with oral health care behaviors (r=-.56, p<.001), perceived stress (r=.44 p<.001), pregnancy stress (r=.37 p<.001), diet (r=-.33, p<.001) and depression (r=.18 p=.046). Factors influencing periodontal disease for these pregnant women were being in the 2nd (β=.27, p<.001) or 3rd trimester (β=.45, p<.001), having a pregnancy induced disease (β=.20, p=.002), performing higher oral health behaviors (β=-.30, p<.001), and having higher perceived stress (β=.17, p=.028). The explanation power of this regression model was 61.6% (F=15.52, p<.001). The findings of this study indicated that periodic assessment of periodontal disease is essential for pregnant women who are in 2nd or 3rd trimester and have pregnancy induced diseases. Enhancing oral health care behaviors and reducing perceived stress are indicated as effective strategies to reduce periodontal disease in pregnant women.

  13. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway.

    PubMed

    Mao, Lixia; Liu, Jiaqiang; Zhao, Jinglei; Chang, Jiang; Xia, Lunguo; Jiang, Lingyong; Wang, Xiuhui; Lin, Kaili; Fang, Bing

    2015-01-01

    The surface structure of bioceramic scaffolds is crucial for its bioactivity and osteoinductive ability, and in recent years, human periodontal ligament stem cells have been certified to possess high osteogenic and cementogenic differential ability. In the present study, hydroxyapatite (HA) bioceramics with micro-nano-hybrid surface (mnHA [the hybrid of nanorods and microrods]) were fabricated via hydrothermal reaction of the α-tricalcium phosphate granules as precursors in aqueous solution, and the effects of mnHA on the attachment, proliferation, osteogenic and cementogenic differentiations of human periodontal ligament stem cells as well as the related mechanisms were systematically investigated. The results showed that mnHA bioceramics could promote cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and expression of osteogenic/cementogenic-related markers including runt-related transcription factor 2 (Runx2), ALP, osteocalcin (OCN), cementum attachment protein (CAP), and cementum protein (CEMP) as compared to the HA bioceramics with flat and dense surface. Moreover, mnHA bioceramics stimulated gene expression of low-density lipoprotein receptor-related protein 5 (LRP5) and β-catenin, which are the key genes of canonical Wnt signaling. Moreover, the stimulatory effect on ALP activity and osteogenic and cementogenic gene expression, including that of ALP, OCN, CAP, CEMP, and Runx2 of mnHA bioceramics could be repressed by canonical Wnt signaling inhibitor dickkopf1 (Dkk1). The results suggested that the HA bioceramics with mnHA could act as promising grafts for periodontal tissue regeneration.

  14. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway

    PubMed Central

    Mao, Lixia; Liu, Jiaqiang; Zhao, Jinglei; Chang, Jiang; Xia, Lunguo; Jiang, Lingyong; Wang, Xiuhui; Lin, Kaili; Fang, Bing

    2015-01-01

    The surface structure of bioceramic scaffolds is crucial for its bioactivity and osteoinductive ability, and in recent years, human periodontal ligament stem cells have been certified to possess high osteogenic and cementogenic differential ability. In the present study, hydroxyapatite (HA) bioceramics with micro-nano-hybrid surface (mnHA [the hybrid of nanorods and microrods]) were fabricated via hydrothermal reaction of the α-tricalcium phosphate granules as precursors in aqueous solution, and the effects of mnHA on the attachment, proliferation, osteogenic and cementogenic differentiations of human periodontal ligament stem cells as well as the related mechanisms were systematically investigated. The results showed that mnHA bioceramics could promote cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and expression of osteogenic/cementogenic-related markers including runt-related transcription factor 2 (Runx2), ALP, osteocalcin (OCN), cementum attachment protein (CAP), and cementum protein (CEMP) as compared to the HA bioceramics with flat and dense surface. Moreover, mnHA bioceramics stimulated gene expression of low-density lipoprotein receptor-related protein 5 (LRP5) and β-catenin, which are the key genes of canonical Wnt signaling. Moreover, the stimulatory effect on ALP activity and osteogenic and cementogenic gene expression, including that of ALP, OCN, CAP, CEMP, and Runx2 of mnHA bioceramics could be repressed by canonical Wnt signaling inhibitor dickkopf1 (Dkk1). The results suggested that the HA bioceramics with mnHA could act as promising grafts for periodontal tissue regeneration. PMID:26648716

  15. A three-dimensional constitutive model for the stress relaxation of articular ligaments.

    PubMed

    Davis, Frances M; De Vita, Raffaella

    2014-06-01

    A new nonlinear constitutive model for the three-dimensional stress relaxation of articular ligaments is proposed. The model accounts for finite strains, anisotropy, and strain-dependent stress relaxation behavior exhibited by these ligaments. The model parameters are identified using published uniaxial stress-stretch and stress relaxation data on human medial collateral ligaments (MCLs) subjected to tensile tests in the fiber and transverse to the fiber directions (Quapp and Weiss in J Biomech Eng Trans ASME 120:757-763, 1998; Bonifasi-Lista et al. in J Orthop Res 23(1):67-76, 2005). The constitutive equation is then used to predict the nonlinear elastic and stress relaxation response of ligaments subjected to shear deformations in the fiber direction and transverse to the fiber direction, and an equibiaxial extension. A direct comparison with stress relaxation data collected by subjecting human MCLs to shear deformation in the fiber direction is presented in order to demonstrate the predictive capabilities of the model.

  16. cDNA cloning of S100 calcium-binding proteins from bovine periodontal ligament and their expression in oral tissues.

    PubMed

    Duarte, W R; Kasugai, S; Iimura, T; Oida, S; Takenaga, K; Ohya, K; Ishikawa, I

    1998-09-01

    The periodontal ligament (PDL) is a unique tissue that is crucial for tooth function. However, little is known of the molecular mechanisms controlling PDL function. To characterize PDL cells at the molecular level, we constructed a cDNA library from bovine PDL tissue. We then focused on the isolation of S100 calcium-binding proteins (CaBPs), because they mediate Ca2+ signaling and control important cellular processes such as differentiation and metabolism. We screened the PDL cDNA library with a mouse S100A4 cDNA, and cloned the bovine cDNAs of two S100 CaBPs (S100A4 and S100A2). In northern blotting analysis, the highest expression of S100A4 was detected in PDL from erupted teeth (PDLE). PDL from teeth under eruption (PDLU) showed a lower expression of S100A4, and its expression in gingiva was faintly detectable. S100A4 expression was also high in the pulp tissue followed by the dental papilla of the tooth germ. S100A2 expression was high in PDLE and gingiva. Interestingly, only PDLE exhibited a high expression of both S100A4 and S100A2. PDLE also expressed the highest level of beta-actin, a target cytoskeletal protein for S100A4. It is conceivable that the high expression of S100A4 in PDLE is a result of the maturation of the PDL and/or a response to mechanical stress generated by mastication. Since there was a marked difference of S100A4 expression between PDL and gingiva, we propose that S100A4 could be a useful marker for distinguishing cells from these two tissues.

  17. Role of resistin in the inflammatory response induced by nicotine plus lipopolysaccharide in human periodontal ligament cells in vitro.

    PubMed

    Kang, S K; Park, Y D; Kang, S I; Kim, D K; Kang, K L; Lee, S Y; Lee, H J; Kim, E C

    2015-10-01

    Resistin was recently reported to play a role in inflammation-related diseases such as arthritis. However, the precise role of resistin in chronic inflammatory diseases, such as periodontal disease, remains unclear. The aim of this study was to investigate the combined effects of nicotine and lipopolysaccharide (LPS) on the expression of resistin and to assess whether resistin expression influences the levels of inflammatory cytokines, extracellular matrix (ECM) molecules and MMPs in human periodontal ligament cells (PDLCs) stimulated with both nicotine and LPS. PDLCs were pretreated with isoproterenol or resistin-specific small interfering RNA (siRNA), stimulated with LPS plus nicotine for 24 h, and then monitored for the production of inflammatory mediators. The concentrations of prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method, respectively. RT-PCR and western blot analysis were used to measure the levels of mRNA and protein, respectively. Western blot analysis was also used to assess the activation of various signal-transduction pathways. Treatment with nicotine plus LPS up-regulated the expression of resistin mRNA and the production of resistin protein in PDLCs in a time- and concentration-dependent manner. Isoproterenol-mediated interference with the function of resistin, or siRNA-mediated knockdown of resistin expression, markedly attenuated the LPS plus nicotine-mediated stimulation of PGE2 and NO production, the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase proteins and the expression of proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-12] and MMPs (MMP-1, MMP-2 and MMP-9); however, these treatments restored the expression of ECM molecules. Furthermore, pretreatment with isoproterenol or resistin-specific siRNA blocked nicotine plus LPS-induced activation of phosphoinositide-3-kinase, glycogen synthase kinase-3 beta, β-catenin, p38, ERK

  18. Human umbilical vein endothelial cells synergize osteo/odontogenic differentiation of periodontal ligament stem cells in 3D cell sheets.

    PubMed

    Pandula, P K C Prgeeth; Samaranayake, L P; Jin, L J; Zhang, C F

    2014-06-01

    To investigate the expression of osteo/odontogenic differentiation markers and vascular network formation in a 3D cell sheet with varying cell ratios of periodontal ligament stem cells (PDLSCs) and human umbilical vein endothelial cells (HUVECs). Human PDLSCs were isolated and characterized by flow cytometry, and co-cultured with HUVECs for the construction of cell sheets. Both types of cells were seeded on temperature-responsive culture dishes with PDLSCs alone, HUVECs alone and various ratios of the latter cells (1 : 1, 2 : 1, 5 : 1 and 1 : 5) to obtain confluent cell sheets. The expressions of osteo/odontogenic pathway markers, including alkaline phosphatase (ALP), bone sialoprotein (BSP) and runt-related transcription factor 2 (RUNX2), were analyzed at 3 and 7 d using RT-PCR. Further ALP protein quantification was performed at 7 and 14 d using ALP assay. The calcium nodule formation was assessed qualitatively and quantitatively by alizarin red assay. Histological evaluations of three cell sheet constructs treated with different combinations (PDLSC-PDLSC-PDLSC/PDLSC-HUVEC-PDLSC/co-culture-co-culture-co-culture) were performed with hematoxylin and eosin and immunofluorescence staining. Statistical analysis was performed using t-test (p < 0.05). Significantly higher ALP gene expression was observed at 3 d in 1 : 1 (PDLSC-HUVEC) (2.52 ± 0.67) and 5 : 1 (4.05 ± 1.07) co-culture groups compared with other groups (p < 0.05); this was consistent with ALP protein quantification. However, the expression of BSP and RUNX2 genes was higher at 7 d compared to 3 d. Significant calcium mineralization was detected as quantified by alizarin red assay at 14 d in 1 : 1 (1323.55 ± 6.54 μm) and 5 : 1 (994.67 ± 4.15 μm) co-cultures as compared with monoculture cell sheets (p < 0.05). Hematoxylin and eosin and CD31 immunostaining clearly exemplified the development of a layered cell sheet structure with endothelial cell islands within the constructed PDLSC-HUVEC-PDLSC and co

  19. Periodontal-ligament-derived stem cells exhibit the capacity for long-term survival, self-renewal, and regeneration of multiple tissue types in vivo.

    PubMed

    Menicanin, Danijela; Mrozik, Krzysztof Marek; Wada, Naohisa; Marino, Victor; Shi, Songtao; Bartold, P Mark; Gronthos, Stan

    2014-05-01

    Primary periodontal ligament stem cells (PDLSCs) are known to possess multidifferentiation potential and exhibit an immunophenotype similar to that described for bone-marrow-derived mesenchymal stem cells. In the present study, bromo-deoxyuridine (BrdU)-labeled ovine PDLSCs implanted into immunodeficient mice survived after 8 weeks post-transplantation and exhibited the capacity to form bone/cementum-like mineralized tissue, ligament structures similar to Sharpey's fibers with an associated vasculature. To evaluate self-renewal potential, PDLSCs were recovered from harvested primary transplants 8 weeks post-transplantation that exhibit an immunophenotype and multipotential capacity comparable to primary PDLSCs. The re-derived PDLSCs isolated from primary transplants were implanted into secondary ectopic xenogeneic transplants. Histomorphological analysis demonstrated that four out of six donor re-derived PDLSC populations displayed a capacity to survive and form fibrous ligament structures and mineralized tissues associated with vasculature in vivo, although at diminished levels in comparison to primary PDLSCs. Further, the capacity for long-term survival and the potential role of PDLSCs in dental tissue regeneration were determined using an ovine preclinical periodontal defect model. Autologous ex vivo-expanded PDLSCs that were prelabeled with BrdU were seeded onto Gelfoam(®) scaffolds and then transplanted into fenestration defects surgically created in the periodontium of the second premolars. Histological assessment at 8 weeks post-implantation revealed surviving BrdU-positive PDLSCs associated with regenerated periodontium-related tissues, including cementum and bone-like structures. This is the first report to demonstrate the self-renewal capacity of PDLSCs using serial xenogeneic transplants and provides evidence of the long-term survival and tissue contribution of autologous PDLSCs in a preclinical periodontal defect model.

  20. Dataset of microarray analysis to identify endoglin-dependent bone morphogenetic protein-2-responsive genes in the murine periodontal ligament cell line PDL-L2.

    PubMed

    Ishibashi, Osamu; Inui, Takashi

    2014-12-01

    The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. We previously reported that endoglin was involved in the bone morphogenetic protein (BMP)-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. Further, we found that the BMP-2-induced Smad-2 phosphorylation was, at least in part, dependent upon endoglin. In this study, to elucidate the detailed mechanism underlying the BMP-2-induced signaling pathway unique to PDL cells, we performed a cDNA microarray analysis to identify endoglin-dependent BMP-2-responsive genes in PDL-L2, a mouse PDL-derived cell line. Here we provide experimental methods and obtained dataset to correspond with our data in Gene Expression Omnibus (GEO) Datasets.

  1. Luteolin and apigenin activate the Oct-4/Sox2 signal via NFATc1 in human periodontal ligament cells.

    PubMed

    Liu, Lu; Peng, Zhengjun; Huang, Haoquan; Xu, Zhezhen; Wei, Xi

    2016-10-01

    Identifying small molecules to activate the Oct-4/Sox2-derived pluripotency network represents a hopeful and safe method to pluripotency without genetic manipulation. Luteolin and apigenin, two major bioactive flavonoids, enhance reprogramming efficiency and increase expression of Oct-4/Sox2/c-Myc, albeit the detailed mechanism regulating pluripotency in dental-derived cells remains unknown. In the present study, to elucidate the effect of luteolin/apigenin on pluripotency of periodontal ligament cells (PDLCs) through interaction with downstream signals, we examined cell cycle, proliferation, apoptosis, expression of Oct-4/Sox2/c-Myc, and multilineage differentiation of PDLCs with luteolin/apigenin treatment. Moreover, we profiled the differentially expressed pluripotency genes by PCR arrays. Our results demonstrated that luteolin/apigenin restrained cell proliferation, increased apoptosis, and arrested PDLCs in G2/M and S phase. Luteolin and apigenin activated expression of Oct-4, Sox2, and c-Myc in a time- and dose-dependent pattern, and repressed lineage-specific differentiation. PCR arrays profiled multiple signals in PDLCs with luteolin/apigenin treatment, among which NFATc1 was the major upregulated gene. Notably, blocking of the NFATc1 signal with INCA-6 significantly decreased mRNA and protein expression of Oct-4, Sox2, and c-Myc in PDLCs with luteolin/apigenin treatment, indicating that NFATc1 may act as an upstream modulator of Oct-4/Sox2 signal. Taken together, this study showed that luteolin and apigenin effectively maintain pluripotency of PDLCs through activation of Oct-4/Sox2 signal via NFATc1.

  2. Evaluation of goat milk as storage media to preserve viability of human periodontal ligament cells in vitro.

    PubMed

    Ulusoy, Ayça Tuba; Kalyoncuoglu, Elif; Kaya, Senay; Cehreli, Zafer Cavit

    2016-08-01

    The purpose of this study was to evaluate the effectiveness of goat milk as a storage media for maintenance of periodontal ligament (PDL) cell viability of avulsed teeth and compare it with commonly used and/or investigated storage media. PDL cells were obtained from the root surface of healthy premolars and were cultured in Eagle's maintenance medium (EMM). Cell cultures were treated with the following storage media: tap water (negative control); EMM (positive control); Hank's balanced salt solution; ultra high temperature (UHT) long-shelf-life lactose-free cow milk; UHT long-shelf-life whole cow milk; UHT long-shelf-life skimmed cow milk; UHT long-shelf-life soy milk; UHT long-shelf-life goat milk, UHT long-shelf-life follow on milk with probiotic, 20% propolis, and egg white. Culture plates were incubated with experimental media at 20°C for 1, 3, 6, 12, and 24 h. PDL cell viability was assessed by tetrazolium salt-based colorimetric (MTT) assay at each test period. One-way anova was used to evaluate the effects of storage solutions at each time point, followed by post hoc Duncan's multiple comparison test (P = 0.05). A dendrogram was constructed to show the arrangement of hierarchical clustering. Goat milk displayed the highest capacity to maintain cell viability at all test intervals (P < 0.001). Between 3 and 24 h, milk with the probiotic showed the lowest time-dependent PDL cell viability among all test media (P < 0.001). Compared with all milks, HBSS performed significantly less effectively in maintaining PDL cell viability during the entire test period (P < 0.001). Based on PDL viability, goat milk can be recommended as a suitable storage medium for avulsed teeth. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Distribution pattern of versican, link protein and hyaluronic acid in the rat periodontal ligament during experimental tooth movement.

    PubMed

    Sato, R; Yamamoto, H; Kasai, K; Yamauchi, M

    2002-02-01

    The ability of the periodontal ligament (PDL) to rapidly remodel is the basis of orthodontic tooth movement. During the tooth movement, matrix proteoglycans (PGs) may play important roles in spatial, mechanical and biological aspects for the maintenance and repair of the PDL. The aim of this study was to characterize the distribution of a large hyaluronic acid (HA)-binding proteoglycan, versican, link protein (LP) and HA in the rat molar PDL during experimental tooth movement by histochemical and immunohistochemical methods. Experimental tooth movement was performed according to Waldo's method. Histologically, regressive changes, such as decrease of fibroblasts and collagen fibers and exudative change of edema were observed in the compressive side and progressive changes, such as proliferation of fibroblasts and collagen fibers, in the strain side one day after treatment. By 3 days after tooth movement, regressive or progressive changes were not observed in either side. Using monoclonal antibodies specific to versican core protein or LP, the positive immunoreactivity for both molecules was constantly observed throughout the PDL. After the experimental force was applied to the tooth, however, the immunostainings of versican and LP became significantly intense only in the compressive side but decreased in the strain side. The intensity in the compressive side was strongest one day after the force was applied and gradually diminished thereafter. HA of both sides did not change during experimental tooth movement. Since HA is present in the PDL, large amounts of versican and LP expressed in the compressive side may create large hydrated aggregates via their association with HA that dissipates the compressive force applied to this tissue.

  4. [A preliminary study of three-dimensional bio-printing by polycaprolactone and periodontal ligament stem cells].

    PubMed

    Xu, J; Hu, M

    2017-04-09

    Objective: To investigate the technical scheme of three-dimensional (3D) bio-printing by polycaprolactone (PCL) and periodontal ligament stem cells (PDLSC). Methods: To manufacture a 3D bio-printing body, PDLSC were used as seed cells, and polycaprolactone (PCL) was used as the 3D printing scaffold material. Print size was designed at 13.0 mm×13.0 mm, and mesh size was 0.25 mm×0.25 mm (group A) and 0.75 mm×0.75 mm (group B). Cell counting kit-8 was used to detect the proliferation of PDLSC on day 1, day 3 and day 5 respectively. The state of the cells in the 3D printing structure was observed by scanning electron microscope (SEM). Osteoblastic ability of the 3D printing mixture was observed after 14 days of culture by alizarin red mineralized nodule staining method. Results: Using PDLSC as seed cells and PCL as a scaffold to print two mesh-sized 3D bodies. The body thickness and porosity of group A and group B were 1.1 mm, 1.5 mm and 49.3%, 72.5% respectively. SEM showed that PDLSC proliferated significantly on two sets of 3D structure which was more obvious in group A. In vitro osteogenic induction, a large number of red mineralized nodules formed on the 3D structure. Conclusions: A 3D structure with a self-defined shape and size was successfully printed using 3D bio-printing equipment. PDLSC can grow and proliferate on the structure.

  5. The roles of calcium-sensing receptor and calcium channel in osteogenic differentiation of undifferentiated periodontal ligament cells.

    PubMed

    Koori, Katsuaki; Maeda, Hidefumi; Fujii, Shinsuke; Tomokiyo, Atsushi; Kawachi, Giichiro; Hasegawa, Daigaku; Hamano, Sayuri; Sugii, Hideki; Wada, Naohisa; Akamine, Akifumi

    2014-09-01

    Elevated extracellular calcium has been shown to promote the differentiation of osteoblasts. However, the way that calcium affects the osteogenic differentiation of human periodontal ligament stem/progenitor cells (PDLSCs) remains unclear. Our aim has been to investigate the proliferation and osteogenic differentiation of a calcium-exposed human PDLSC line (cell line 1-17) that we have recently established and to elucidate the roles of the calcium-sensing receptor (CaSR) and L-type voltage-dependent calcium channel (L-VDCC) in this process. Proliferation activity was investigated by WST-1 assay, and gene and protein expression was examined by quantitative reverse transcriptase plus the polymerase chain reaction and immunostaining, respectively. Calcification assay was performed by von Kossa and Alizarin red staining. Treatment with 5 mM CaCl2 significantly induced proliferation, bone-related gene expression, and calcification in cell line 1-17. During culture with 5 mM CaCl2, this cell line up-regulated the gene expression of CaSR, which was reduced after 7 days. Simultaneous treatment with NPS2143, a CaSR inhibitor, and calcium significantly further increased bone-related gene expression and calcification as compared with CaCl2 exposure alone. The L-VDCC inhibitor, nifedipine, significantly suppressed osteogenic differentiation of cell line 1-17 treated with 5 mM CaCl2 and promoted the expression of CaSR, as compared with calcium treatment alone. Thus, elevated extracellular calcium promotes the proliferation and osteogenic differentiation of a PDLSC line. Antagonizing CaSR further enhances the effect of calcium on osteogenic differentiation, with CaSR expression being regulated by L-VDCC under extracellular calcium. Extracellular calcium might therefore modulate the osteogenic differentiation of PDLSCs through reciprocal adjustments of CaSR and L-VDCC.

  6. Human periodontal ligament stem cells secretome from multiple sclerosis patients suppresses NALP3 inflammasome activation in experimental autoimmune encephalomyelitis.

    PubMed

    Soundara Rajan, Thangavelu; Giacoppo, Sabrina; Diomede, Francesca; Bramanti, Placido; Trubiani, Oriana; Mazzon, Emanuela

    2017-09-01

    Research in recent years has largely explored the immunomodulatory effects of mesenchymal stem cells (MSCs) and their secretory products, called "secretome," in the treatment of neuroinflammatory diseases. Here, we examined whether such immunosuppressive effects might be elicited due to inflammasome inactivation. To this end, we treated experimental autoimmune encephalomyelitis (EAE) mice model of multiple sclerosis (MS) with the conditioned medium or purified exosomes/microvesicles (EMVs) obtained from relapsing-remitting-MS patients human periodontal ligament stem cells (hPDLSCs) and investigated the regulation of NALP3 inflammasome. We noticed enhanced expression of NALP3, Cleaved Caspase 1, interleukin (IL)-1β, and IL-18 in EAE mouse spinal cord. Conversely, hPDLSCs-conditioned medium and EMVs significantly blocked NALP3 inflammasome activation and provided protection from EAE. Reduction in NALP3, Cleaved Caspase 1, IL-1β, and IL-18 level was noticed in conditioned medium and EMVs-treated EAE mice. Pro-inflammatory Toll-like receptor (TLR)-4 and nuclear factor (NF)-κB were elevated in EAE, while hPDLSCs-conditioned medium and EMVs treatment reduced their expression and increased IκB-α expression. Characterization of hPDLSCs-conditioned medium showed substantial level of anti-inflammatory IL-10, transforming growth factor (TGF)-β, and stromal cell-derived factor 1α (SDF-1α). We propose that the immunosuppressive role of hPDLSCs-derived conditioned medium and EMVs in EAE mice may partly attribute to the presence of soluble immunomodulatory factors, NALP3 inflammasome inactivation, and NF-κB reduction.

  7. 'Effects of novel root repair materials on attachment and morphological behaviour of periodontal ligament fibroblasts: Scanning electron microscopy observation'.

    PubMed

    Akbulut, Makbule Bilge; Uyar Arpaci, Pembegul; Unverdi Eldeniz, Ayce

    2016-12-01

    The aim of this study was to evaluate the adhesion of periodontal ligament fibroblasts (PDLs) on newly proposed root repair materials [Biodentine, MM-MTA, polymethylmethacrylate (PMMA) bone cement, and SDR], in comparison with contemporary root repair materials [IRM, Dyract compomer, ProRoot MTA (PMTA), and Vitrebond]. Five discs from each material were fabricated in sterile Teflon molds, and the specimens were aged and prewetted in cell culture media for 96 hours. Three material discs were used for scanning electron microscopy (SEM) for the assessment of the attachment, density, and morphological changes in the PDLs, while two samples were used for energy dispersive x-ray spectroscopy (SEM-EDX) to determine the elemental composition of the materials. Human PDLs were plated onto the materials at a density of 10,000/well, and incubated for 3 days. The SEM micrographs were taken at different magnifications (500× and 5000×). In the SEM, the cells were attached and well spread-out on the surfaces of the Biodentine, PMTA, and Dyract compomer, while varied cell densities and morphological alterations were observed in the Vitrebond, IRM, MM-MTA, SDR, and PMMA bone cement groups. The SEM-EDX analysis revealed a maximum calcium percentage in the PMTA specimens, as well a maximum silicon percentage in the Dyract compomer specimens. This in vitro study demonstrated that the Biodentine and Dyract compomer supported PDL cell adhesion and spreading. The PMTA presented a favorable scaffold for better attachment of the PDL cell aggregates. Therefore, the calcium and silicon content of a material may enhance the PDL cell attachment. © 2016 Wiley Periodicals, Inc.

  8. Secretome Profiling of Periodontal Ligament from Deciduous and Permanent Teeth Reveals a Distinct Expression Pattern of Laminin Chains

    PubMed Central

    Giovani, Priscila A.; Salmon, Cristiane R.; Martins, Luciane; Paes Leme, Adriana F.; Rebouças, Pedro; Puppin Rontani, Regina M.; Mofatto, Luciana S.; Sallum, Enilson A.; Nociti, Francisco H.; Kantovitz, Kamila R.

    2016-01-01

    It has been suggested that there are histological and functional distinctions between the periodontal ligament (PDL) of deciduous (DecPDL) and permanent (PermPDL) teeth. Thus, we hypothesized that DecPDL and PermPDL display differences in the constitutive expression of genes/proteins involved with PDL homeostasis. Primary PDL cell cultures were obtained for DecPDL (n = 3) and PermPDL (n = 3) to allow us to perform label-free quantitative secretome analysis. Although a highly similar profile was found between DecPDL and PermPDL cells, comparative secretome analysis evidenced that one of the most stickling differences involved cell adhesion molecules, including laminin subunit gamma 1 (LAMC1) and beta 2 (LAMB2). Next, total RNA and protein extracts were obtained from fresh PDL tissues of deciduous (n = 6) and permanent (n = 6) teeth, and Western blotting and qPCR analysis were used to validate our in vitro findings. Western blot analysis confirmed that LAMC1 was increased in DecPDL fresh tissues (p<0.05). Furthermore, qPCR data analysis revealed that mRNA levels for laminin subunit beta 1 (LAMB1), beta 3 (LAMB3), LAMC1, and gamma 2 (LAMC2) were higher in DecPDL fresh tissues, whereas transcripts for LAMB2 were increased in PermPDL (p<0.05). In conclusion, the differential expression of laminin chains in DecPDL and PermPDL suggests an involvement of laminin-dependent pathways in the control of physiological differences between them. PMID:27149379

  9. The mechanical function of the periodontal ligament in the macaque mandible: a validation and sensitivity study using finite element analysis.

    PubMed

    Panagiotopoulou, Olga; Kupczik, Kornelius; Cobb, Samuel N

    2011-01-01

    Whilst the periodontal ligament (PDL) acts as an attachment tissue between bone and tooth, hypotheses regarding the role of the PDL as a hydrodynamic damping mechanism during intraoral food processing have highlighted its potential importance in finite element (FE) analysis. Although experimental and constitutive models have correlated the mechanical function of the PDL tissue with its anisotropic, heterogeneous, viscoelastic and non-linear elastic nature, in many FE simulations the PDL is either present or absent, and when present is variably modelled. In addition, the small space the PDL occupies and the inability to visualize the PDL tissue using μCT scans poses issues during FE model construction and so protocols for the PDL thickness also vary. In this paper we initially test and validate the sensitivity of an FE model of a macaque mandible to variations in the Young's modulus and the thickness of the PDL tissue. We then tested the validity of the FE models by carrying out experimental strain measurements on the same mandible in the laboratory using laser speckle interferometry. These strain measurements matched the FE predictions very closely, providing confidence that material properties and PDL thickness were suitably defined. The FE strain results across the mandible are generally insensitive to the absence and variably modelled PDL tissue. Differences are only found in the alveolar region adjacent to the socket of the loaded tooth. The results indicate that the effect of the PDL on strain distribution and/or absorption is restricted locally to the alveolar bone surrounding the teeth and does not affect other regions of the mandible.

  10. Secretome Profiling of Periodontal Ligament from Deciduous and Permanent Teeth Reveals a Distinct Expression Pattern of Laminin Chains.

    PubMed

    Giovani, Priscila A; Salmon, Cristiane R; Martins, Luciane; Paes Leme, Adriana F; Rebouças, Pedro; Puppin Rontani, Regina M; Mofatto, Luciana S; Sallum, Enilson A; Nociti, Francisco H; Kantovitz, Kamila R

    2016-01-01

    It has been suggested that there are histological and functional distinctions between the periodontal ligament (PDL) of deciduous (DecPDL) and permanent (PermPDL) teeth. Thus, we hypothesized that DecPDL and PermPDL display differences in the constitutive expression of genes/proteins involved with PDL homeostasis. Primary PDL cell cultures were obtained for DecPDL (n = 3) and PermPDL (n = 3) to allow us to perform label-free quantitative secretome analysis. Although a highly similar profile was found between DecPDL and PermPDL cells, comparative secretome analysis evidenced that one of the most stickling differences involved cell adhesion molecules, including laminin subunit gamma 1 (LAMC1) and beta 2 (LAMB2). Next, total RNA and protein extracts were obtained from fresh PDL tissues of deciduous (n = 6) and permanent (n = 6) teeth, and Western blotting and qPCR analysis were used to validate our in vitro findings. Western blot analysis confirmed that LAMC1 was increased in DecPDL fresh tissues (p<0.05). Furthermore, qPCR data analysis revealed that mRNA levels for laminin subunit beta 1 (LAMB1), beta 3 (LAMB3), LAMC1, and gamma 2 (LAMC2) were higher in DecPDL fresh tissues, whereas transcripts for LAMB2 were increased in PermPDL (p<0.05). In conclusion, the differential expression of laminin chains in DecPDL and PermPDL suggests an involvement of laminin-dependent pathways in the control of physiological differences between them.

  11. Characterization of the osteogenic potential of mesenchymal stem cells from human periodontal ligament based on cell surface markers.

    PubMed

    Alvarez, Ruth; Lee, Hye-Lim; Wang, Cun-Yu; Hong, Christine

    2015-12-18

    Mesenchymal stem cell (MSC)-mediated therapy has been shown to be clinically effective in regenerating tissue defects. For improved regenerative therapy, it is critical to isolate homogenous populations of MSCs with high capacity to differentiate into appropriate tissues. The utilization of stem cell surface antigens provides a means to identify MSCs from various tissues. However, few surface markers that consistently isolate highly regenerative MSCs have been validated, making it challenging for routine clinical applications and making it all the more imperative to identify reliable surface markers. In this study, we used three surface marker combinations: CD51/CD140α, CD271, and STRO-1/CD146 for the isolation of homogenous populations of dental mesenchymal stem cells (DMSCs) from heterogeneous periodontal ligament cells (PDLCs). Fluorescence-activated cell sorting analysis revealed that 24% of PDLCs were CD51(+)/CD140α(+), 0.8% were CD271(+), and 2.4% were STRO-1(+)/CD146(+). Sorted cell populations were further assessed for their multipotent properties by inducing osteogenic and chondrogenic differentiation. All three subsets of isolated DMSCs exhibited differentiation capacity into osteogenic and chondrogenic lineages but with varying degrees. CD271(+) DMSCs demonstrated the greatest osteogenic potential with strong induction of osteogenic markers such as DLX5, RUNX2, and BGLAP. Our study provides evidence that surface marker combinations used in this study are sufficient markers for the isolation of DMSCs from PDLCs. These results provide important insight into using specific surface markers for identifying homogenous populations of DMSCs for their improved utilization in regenerative medicine.

  12. Angiogenic Capacity of Periodontal Ligament Stem Cells Pretreated with Deferoxamine and/or Fibroblast Growth Factor-2.

    PubMed

    Ratajczak, Jessica; Hilkens, Petra; Gervois, Pascal; Wolfs, Esther; Jacobs, Reinhilde; Lambrichts, Ivo; Bronckaers, Annelies

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) represent a good source of multipotent cells for cell-based therapies in regenerative medicine. The success rate of these treatments is severely dependent on the establishment of adequate vasculature in order to provide oxygen and nutrients to the transplanted cells. Pharmacological preconditioning of stem cells has been proposed as a promising method to augment their therapeutic efficacy. In this study, the aim was to improve the intrinsic angiogenic properties of PDLSCs by in vitro pretreatment with deferoxamine (DFX; 100μM), fibroblast growth factor-2 (FGF-2; 10ng/mL) or both substances combined. An antibody array revealed the differential expression of several proteins, including vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). ELISA data confirmed a 1.5 to 1.8-fold increase in VEGF for all tested conditions. Moreover, 48 hours after the removal of DFX, VEGF levels remained elevated (1.8-fold) compared to control conditions. FGF-2 and combination treatment resulted in a 5.4 to 13.1-fold increase in PlGF secretion, whereas DFX treatment had no effect. Furthermore, both PDLSCs as pretreated PDLSCs induced endothelial migration. Despite the significant elevated VEGF levels of pretreated PDLSCs, the induced endothelial migration was not higher by pretreated PDLSCs. We find that the observed induced endothelial cell motility was not dependent on VEGF, since blocking the VEGFR1-3 with Axitinib (0.5nM) did not inhibit endothelial motility towards PDLSCs. Taken together, this study provides evidence that preconditioning with DFX and/or FGF-2 significantly improves the angiogenic secretome of PDLSCs, in particular VEGF and PlGF secretion. However, our data suggest that VEGF is not the only player when it comes to influencing endothelial behavior by the PDLSCs.

  13. [Histological study of cell attachment and proliferation of periodontal ligament cells on the tooth surface. Effect of the fibronectin application].

    PubMed

    Takigami, T

    1989-09-01

    The purpose of this study was to examine the effect of fibronectin on cell attachment and the growth of cultured cells on the surface of the dentin. In the first experiment, dentin specimens were divided into following three groups: dentin surface polished with carborundum-point, carborundum-point and #150 sandpaper and carborundum-point, #150 sandpaper and #240 sandpaper. The roughness of the surface was measured with a profilometer (Surfcom e-st-sa) for the purpose of comparing differences among the three groups. The foregoing treated samples were added to cultures of periodontal ligament (PDL) cells and following fixation, the number of cells was counted under a light microscope and examination under a scanning electron microscope (SEM) was also performed. 1. Greater numbers of cells attached to the smooth surface (#240) than the rough surface. 2. SEM observations showed increased numbers of attached and proliferated cells on the smooth surface. In the second experiment, the dentin surfaces were polished with carborundum point, #150 and #240 sand paper. The dentin tube side was treated with fibronectin. MEM-treated samples not immersed in fibronectin were employed as controls. The foregoing treated root samples were cultured with PDL cells. Following fixation, the cells attached to the root surface were examined under the light microscope and using a SEM. 1. A significant increase in the number of the attached cells as observed after treatment with fibronectin. 2. SEM observation suggested PDL cells migrated more and proliferated more on the side treated with fibronectin. 3. Fibronectin application increased cell attachment and proliferation more on the smooth surface of dentin.

  14. Generation of Neural Crest-Like Cells From Human Periodontal Ligament Cell-Derived Induced Pluripotent Stem Cells.

    PubMed

    Tomokiyo, Atsushi; Hynes, Kim; Ng, Jia; Menicanin, Danijela; Camp, Esther; Arthur, Agnes; Gronthos, Stan; Mark Bartold, Peter

    2017-02-01

    Neural crest cells (NCC) hold great promise for tissue engineering, however the inability to easily obtain large numbers of NCC is a major factor limiting their use in studies of regenerative medicine. Induced pluripotent stem cells (iPSC) are emerging as a novel candidate that could provide an unlimited source of NCC. In the present study, we examined the potential of neural crest tissue-derived periodontal ligament (PDL) iPSC to differentiate into neural crest-like cells (NCLC) relative to iPSC generated from a non-neural crest derived tissue, foreskin fibroblasts (FF). We detected high HNK1 expression during the differentiation of PDL and FF iPSC into NCLC as a marker for enriching for a population of cells with NCC characteristics. We isolated PDL iPSC- and FF iPSC-derived NCLC, which highly expressed HNK1. A high proportion of the HNK1-positive cell populations generated, expressed the MSC markers, whilst very few cells expressed the pluripotency markers or the hematopoietic markers. The PDL and FF HNK1-positive populations gave rise to smooth muscle, neural, glial, osteoblastic and adipocytic like cells and exhibited higher expression of smooth muscle, neural, and glial cell-associated markers than the PDL and FF HNK1-negative populations. Interestingly, the HNK1-positive cells derived from the PDL-iPSC exhibited a greater ability to differentiate into smooth muscle, neural, glial cells and adipocytes, than the HNK1-positive cells derived from the FF-iPSC. Our work suggests that HNK1-enriched NCLC from neural crest tissue-derived iPSC more closely resemble the phenotypic and functional hallmarks of NCC compared to the HNK1-low population and non-neural crest iPSC-derived NCLC. J. Cell. Physiol. 232: 402-416, 2017. © 2016 Wiley Periodicals, Inc.

  15. Biocompatibility and Osteogenic Capacity of Periodontal Ligament Stem Cells on nHAC/PLA and HA/TCP Scaffolds.

    PubMed

    He, Huixia; Yu, Jinhua; Cao, Junkai; E, Lingling; Wang, Dongsheng; Zhang, Haizhong; Liu, Hongchen

    2011-01-01

    This study investigated the effects of a newly-developed scaffold, nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA), on the attachment, proliferation and osteogenic capability of dog periodontal ligament stem cells (PDLSCs) in vitro and in vivo. Hydroxyapatite/tricalcium phosphate (HA/TCP), a commonly used bone substitute, was used as a positive control. PDLSCs isolated from dog molar were incubated in an osteogenic medium to evaluate their osteogenic differentiation in vitro, and then seeded onto nHAC/PLA and HA/TCP scaffolds. In vitro cell attachment, proliferation and differentiation were assessed by scanning electron microscopy (SEM), cell counting, 3-[4,5-dimethythiazol-2-yl]-5-[3-carboxy-phenyl]-2-[4-sulfophenyl]-2H-tetrazolium and alkaline phosphate activity, and reverse transcription-polymerase chain reaction, respectively. Finally, the constructs were implanted subcutaneously into dogs to investigate their osteogenic capacity. After osteogenic induction for 21 days, PDLSCs differentiated into osteogenic lineage, as indicated by the expressions of osteoblastic differentiation genes CoL-I, OCN and OPN mRNA, and the formation of mineral deposits. When seeded onto scaffolds, the cells attached and spread well, and retained their osteogenic phenotypes on both scaffolds. Comparatively, cell number and proliferative viability on nHAC/PLA constructs were greater than those on HA/TCP constructs (P < 0.05). Histological results showed that new bone and osteoid was formed in both groups, and histomorphometric analysis demonstrated that the amount of newly formed bone in the nHAC/PLA group was higher than that in the HA/TCP group (P < 0.05). This study suggests that nHAC/PLA can be used as a potent scaffold for alveolar bone regeneration.

  16. Angiogenic Capacity of Periodontal Ligament Stem Cells Pretreated with Deferoxamine and/or Fibroblast Growth Factor-2

    PubMed Central

    Ratajczak, Jessica; Hilkens, Petra; Gervois, Pascal; Wolfs, Esther; Jacobs, Reinhilde; Lambrichts, Ivo; Bronckaers, Annelies

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) represent a good source of multipotent cells for cell-based therapies in regenerative medicine. The success rate of these treatments is severely dependent on the establishment of adequate vasculature in order to provide oxygen and nutrients to the transplanted cells. Pharmacological preconditioning of stem cells has been proposed as a promising method to augment their therapeutic efficacy. In this study, the aim was to improve the intrinsic angiogenic properties of PDLSCs by in vitro pretreatment with deferoxamine (DFX; 100μM), fibroblast growth factor-2 (FGF-2; 10ng/mL) or both substances combined. An antibody array revealed the differential expression of several proteins, including vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). ELISA data confirmed a 1.5 to 1.8-fold increase in VEGF for all tested conditions. Moreover, 48 hours after the removal of DFX, VEGF levels remained elevated (1.8-fold) compared to control conditions. FGF-2 and combination treatment resulted in a 5.4 to 13.1-fold increase in PlGF secretion, whereas DFX treatment had no effect. Furthermore, both PDLSCs as pretreated PDLSCs induced endothelial migration. Despite the significant elevated VEGF levels of pretreated PDLSCs, the induced endothelial migration was not higher by pretreated PDLSCs. We find that the observed induced endothelial cell motility was not dependent on VEGF, since blocking the VEGFR1-3 with Axitinib (0.5nM) did not inhibit endothelial motility towards PDLSCs. Taken together, this study provides evidence that preconditioning with DFX and/or FGF-2 significantly improves the angiogenic secretome of PDLSCs, in particular VEGF and PlGF secretion. However, our data suggest that VEGF is not the only player when it comes to influencing endothelial behavior by the PDLSCs. PMID:27936076

  17. Vitamin D reduces the inflammatory response by Porphyromonas gingivalis infection by modulating human β-defensin-3 in human gingival epithelium and periodontal ligament cells.

    PubMed

    De Filippis, Anna; Fiorentino, Margherita; Guida, Luigi; Annunziata, Marco; Nastri, Livia; Rizzo, Antonietta

    2017-04-03

    Periodontitis is a multifactorial polymicrobial infection characterized by a destructive inflammatory process. Porphyromonas gingivalis, a Gram-negative black-pigmented anaerobe, is a major pathogen in the initiation and progression of periodontitis; it produces several virulence factors that stimulate human gingival epithelium (HGE) cells and human periodontal ligament (HPL) cells to produce various inflammatory mediators. A variety of substances, such as vitamin D, have growth-inhibitory effects on some bacterial pathogens and have shown chemo-preventive and anti-inflammatory activity. We used a model with HGE and HPL cells infected with P. gingivalis to determine the influence of vitamin D on P. gingivalis growth and adhesion and the immunomodulatory effect on TNF-α, IL-8, IL-12 and human-β-defensin 3 production. Our results demonstrated, firstly, the lack of any cytotoxic effect on the HGE and HPL cells when treated with vitamin D; in addition, vitamin D inhibited P. gingivalis adhesion and infectivity in HGE and HPL cells. Our study then showed that vitamin D reduced TNF-α, IL-8, IL-12 production in P. gingivalis-infected HGE and HPL cells. In contrast, a significant upregulation of the human-β-defensin 3 expression in HGE and HPL cells induced by P. gingivalis was demonstrated. Our results indicate that vitamin D specifically enhances the production of the human-β-defensin 3 antimicrobial peptide and exerts an inhibitory effect on the pro-inflammatory cytokines, thus suggesting that vitamin D may offer possible therapeutic applications for periodontitis.

  18. The Cytolethal Distending Toxin Induces Receptor Activator of NF-κB Ligand Expression in Human Gingival Fibroblasts and Periodontal Ligament Cells

    PubMed Central

    Belibasakis, G. N.; Johansson, A.; Wang, Y.; Chen, C.; Kalfas, S.; Lerner, U. H.

    2005-01-01

    Actinobacillus actinomycetemcomitans is associated with localized aggressive periodontitis, a disease characterized by rapid loss of the alveolar bone surrounding the teeth. Receptor activator of NF-κB Ligand (RANKL) and osteoprotegerin (OPG) are two molecules that regulate osteoclast formation and bone resorption. RANKL induces osteoclast differentiation and activation, whereas OPG blocks this process by acting as a decoy receptor for RANKL. The purpose of this study was to investigate the effect of A. actinomycetemcomitans on the expression of RANKL and OPG in human gingival fibroblasts and periodontal ligament cells. RANKL mRNA expression was induced in both cell types challenged by A. actinomycetemcomitans extract, whereas OPG mRNA expression remained unaffected. Cell surface RANKL protein was also induced by A. actinomycetemcomitans, whereas there was no change in OPG protein secretion. A cytolethal distending toxin (Cdt) gene-knockout strain of A. actinomycetemcomitans did not induce RANKL expression, in contrast to its wild-type strain. Purified Cdt from Haemophilus ducreyi alone, or in combination with extract from the A. actinomycetemcomitans cdt mutant strain, induced RANKL expression. Pretreatment of A. actinomycetemcomitans wild-type extract with Cdt antiserum abolished RANKL expression. In conclusion, A. actinomycetemcomitans induces RANKL expression in periodontal connective tissue cells. Cdt is crucial for this induction and may therefore be involved in the pathological bone resorption during the process of localized aggressive periodontitis. PMID:15618171

  19. Mitogen-activated protein kinases and phosphatidylinositol 3-kinase are involved in Prevotella intermedia-induced proinflammatory cytokines expression in human periodontal ligament cells.

    PubMed

    Guan, Su-Min; Zhang, Ming; He, Jian-Jun; Wu, Jun-Zheng

    2009-08-28

    Chronic periodontitis is an inflammatory disease affecting periodontal connective tissues and alveolar bone. Proinflammatory mediators induced by periodontal pathogens play vital roles in the initiation and progression of the disease. In this study, we examined whether Prevotella intermedia induces proinflammatory cytokines expression in human periodontal ligament cells (hPDLs). The mRNA expression and protein production were determined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbant assay (ELISA) respectively. P. intermedia treatment dose- and time-dependently increased IL-6, IL-8 and M-CSF, but not IL-1beta and TNF-alpha mRNA expression and protein secretion. Preincubation of hPDLs with extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 kinase and phosphatidylinositol 3-kinase (PI3K) inhibitors PD98059, SP600125, SB203580 and LY294002 resulted in significant reduction in P. intermedia-induced IL-6, IL-8 and M-CSF expression. Blocking the synthesis of prostaglandin E(2) (PGE(2)) by indomethacin also abolished the stimulatory effects of P. intermedia on cytokines expression. Our results indicate that P. intermedia induces proinflammatory cytokines through MAPKs and PI3K signaling pathways, and PGE(2) is involved in the P. intermedia-induced proinflammatory cytokines upregulation.

  20. Genistein regulates the IL-1 beta induced activation of MAPKs in human periodontal ligament cells through G protein-coupled receptor 30.

    PubMed

    Luo, Li-Jun; Liu, Feng; Lin, Zhi-Kai; Xie, Yu-Feng; Xu, Jia-Li; Tong, Qing-Chun; Shu, Rong

    2012-06-01

    Periodontal ligament (PDL) cells are fibroblasts that play key roles in tissue integrity, periodontal inflammation and tissue regeneration in the periodontium. The periodontal tissue destruction in periodontitis is mediated by host tissue-produced inflammatory cytokines, including interleukin-1β (IL-1β). Here, we report the expression of G protein-coupled receptor 30 (GPR30, also known as G protein-coupled estrogen receptor 1 GPER) in human PDL cells and its regulation by IL-1β. IL-1β-induced GPR30 expression in human PDL cells leads to the activation of multiple signaling pathways, including MAPK, NF-κB and PI3K. In contrast, genistein, an estrogen receptor ligand, postpones the activation of MAPKs induced by IL-1β. Moreover, the inhibition of GPR30 by G15, a GPR30-specific antagonist, eliminates this delay. Thus, genistein plays a role in the regulation of MAPK activation via GPR30, and GPR30 represents a novel target regulated by steroid hormones in PDL cells.

  1. Effects of Intermittent Administration of Parathyroid Hormone (1-34) on Bone Differentiation in Stromal Precursor Antigen-1 Positive Human Periodontal Ligament Stem Cells

    PubMed Central

    Wang, Xiaoxiao; Wang, Yanlan; Dai, Xubin; Chen, Tianyu; Yang, Fanqiao; Dai, Shuangye; Ou, Qianmin; Wang, Yan; Lin, Xuefeng

    2016-01-01

    Periodontitis is the most common cause of tooth loss and bone destruction in adults worldwide. Human periodontal ligament stem cells (hPDLSCs) may represent promising new therapeutic biomaterials for tissue engineering applications. Stromal precursor antigen-1 (STRO-1) has been shown to have roles in adherence, proliferation, and multipotency. Parathyroid hormone (PTH) has been shown to enhance proliferation in osteoblasts. Therefore, in this study, we aimed to compare the functions of STRO-1(+) and STRO-1(−) hPDLSCs and to investigate the effects of PTH on the osteogenic capacity of STRO-1(+) hPDLSCs in order to evaluate their potential applications in the treatment of periodontitis. Our data showed that STRO-1(+) hPDLSCs expressed higher levels of the PTH-1 receptor (PTH1R) than STRO-1(−) hPDLSCs. In addition, intermittent PTH treatment enhanced the expression of PTH1R and osteogenesis-related genes in STRO-1(+) hPDLSCs. PTH-treated cells also exhibited increased alkaline phosphatase activity and mineralization ability. Therefore, STRO-1(+) hPDLSCs represented a more promising cell resource for biomaterials and tissue engineering applications. Intermittent PTH treatment improved the capacity for STRO-1(+) hPDLSCs to repair damaged tissue and ameliorate the symptoms of periodontitis. PMID:27069479

  2. Characterization and angiogenic potential of xenogeneic bone grafting materials: Role of periodontal ligament cells.

    PubMed

    Rombouts, Charlotte; Jeanneau, Charlotte; Camilleri, Josette; Laurent, Patrick; About, Imad

    2016-12-01

    Adequate revascularization is a prerequisite for successful healing of periodontal bone defects. This study characterized three different xenogeneic bone grafting materials: Gen-Os of equine and porcine origins, and anorganic Bio-Oss. We also investigated their angiogenic potential. All materials were composed of poorly crystalline calcium oxide phosphate, with Bio-Oss exhibiting a carbonated phase and larger particle size and both Gen-Os showing the presence of collagen. Both Gen-Os materials significantly enhanced vascular endothelial growth factor (VEGF) secretion by PDL cells. A significant increase in endothelial cell proliferation was observed in cultures with both Gen-Os conditioned media, but not with that of Bio-Oss. Finally, angiogenesis was stimulated by both Gen-Os conditioned media as demonstrated by an increased formation of capillary-like structures. Taken together, these findings indicate an enhanced angiogenic potential of both Gen-Os bone grafting materials when applied on PDL cells, most likely by increasing VEGF production.

  3. [Three-dimensional finite element analysis of removable partial denture with periodontally compromised abutments].

    PubMed

    Wei, Jian; Xu, Bin-ting; Li, Qing; Wang, Yi-ning

    2013-07-01

    To evaluate three-dimensional (3D) finite element (FE) modeling of different periodontally compromised unilateral distal extension removable partial denture (RPD) abutments using the data of a 3D non-contact digitizing scanner. FE models were established, and the following structures were simulated in the models: alveolar bone, mucosa, abutments, periodontal ligaments, framework and artificial teeth. The alveolar bone and periodontal ligaments around the distal abutment in the three models were designed as normal, with bone defect and with periodontal ligaments defect respectively.Vertical or buccally inclined forces of 50, 100, 100 N were applied on the artificial teeth of the RPD and the stress distributions on the supporting tissues were calculated. Under vertical loading, the maximal stress on the alveolar bone of the abutment were as follows: periodontal ligaments defect model (3.57 MPa) > bone defect model (3.21 MPa) > normal model (2.63 MPa). Under buccally inclined loading, the maximal stress on the alveolar bone of the abutment were as follows: periodontal ligaments defect model (2.50 MPa) > bone defect model (2.41 MPa) > normal model (1.79 MPa). Under buccally inclined loading, the stresses on distal aspects of the residual alveolar ridge were higher than that of the vertical loading model. 3D non-contact digitalizing scanner was useful for the finite element modeling process of removable partial denture.

  4. Visualization of Oxidative Stress Induced by Experimental Periodontitis in Keap1-Dependent Oxidative Stress Detector-Luciferase Mice.

    PubMed

    Kataoka, Kota; Ekuni, Daisuke; Tomofuji, Takaaki; Irie, Koichiro; Kunitomo, Muneyoshi; Uchida, Yoko; Fukuhara, Daiki; Morita, Manabu

    2016-11-16

    The aim of this study was to investigate whether a Keap1-dependent oxidative stress detector-luciferase (OKD-LUC) mouse model would be useful for the visualization of oxidative stress induced by experimental periodontitis. A ligature was placed around the mandibular first molars for seven days to induce periodontitis. Luciferase activity was measured with an intraperitoneal injection of d-luciferin on days 0, 1, and 7. The luciferase activity in the periodontitis group was significantly greater than that in the control group at seven days. The expressions of heme oxygenase-1 (HO-1) and malondialdehyde in periodontal tissue were significantly higher in the periodontitis group than in the control group. Immunofluorescent analysis confirmed that the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) occurred more frequently in the periodontitis group than in the control group. This study found that under oxidative stress induced by experimental periodontitis, the Nrf2/antioxidant defense pathway was activated and could be visualized from the luciferase activity in the OKD-LUC model. Thus, the OKD-LUC mouse model may be useful for exploring the mechanism underlying the relationship between the Nrf2/antioxidant defense pathway and periodontitis by enabling the visualization of oxidative stress over time.

  5. Visualization of Oxidative Stress Induced by Experimental Periodontitis in Keap1-Dependent Oxidative Stress Detector-Luciferase Mice

    PubMed Central

    Kataoka, Kota; Ekuni, Daisuke; Tomofuji, Takaaki; Irie, Koichiro; Kunitomo, Muneyoshi; Uchida, Yoko; Fukuhara, Daiki; Morita, Manabu

    2016-01-01

    The aim of this study was to investigate whether a Keap1-dependent oxidative stress detector-luciferase (OKD-LUC) mouse model would be useful for the visualization of oxidative stress induced by experimental periodontitis. A ligature was placed around the mandibular first molars for seven days to induce periodontitis. Luciferase activity was measured with an intraperitoneal injection of d-luciferin on days 0, 1, and 7. The luciferase activity in the periodontitis group was significantly greater than that in the control group at seven days. The expressions of heme oxygenase-1 (HO-1) and malondialdehyde in periodontal tissue were significantly higher in the periodontitis group than in the control group. Immunofluorescent analysis confirmed that the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) occurred more frequently in the periodontitis group than in the control group. This study found that under oxidative stress induced by experimental periodontitis, the Nrf2/antioxidant defense pathway was activated and could be visualized from the luciferase activity in the OKD-LUC model. Thus, the OKD-LUC mouse model may be useful for exploring the mechanism underlying the relationship between the Nrf2/antioxidant defense pathway and periodontitis by enabling the visualization of oxidative stress over time. PMID:27854327

  6. Association among stress, salivary cortisol levels, and chronic periodontitis.

    PubMed

    Refulio, Zoila; Rocafuerte, Marco; de la Rosa, Manuel; Mendoza, Gerardo; Chambrone, Leandro

    2013-04-01

    Chronic periodontitis (CP) seems to be associated with stress and depression, but little information on this possible association is available in the literature. Thus, the objective of this study was to evaluate the association among stress, the salivary cortisol level (SCL), and CP. Seventy systemically healthy subjects were included in the study from January to September 2011. Full medical and dental histories were obtained, and the following measurements were recorded: 1) probing depth; 2) clinical attachment level; 3) bleeding on probing; and 4) tooth mobility. Saliva samples were collected for the evaluation of SCL (via a highly sensitive electrochemiluminescence immunoassay), and all subjects also answered a questionnaire (i.e., the Zung Self-rating Depression Scale). The odds ratio (OR) with a 95% confidence interval (CI) was calculated, and one way analysis of variance and the Tukey-Kramer method were performed. A total of 36 subjects with CP (51.4%) and 34 without CP were evaluated. Of them, all of the subjects with CP and one periodontally healthy subject were diagnosed with depression. Subjects with moderate CP had statistically significantly higher levels of SCL than subjects with a diagnosis of slight CP (P=0.006). Also, subjects with severe CP showed the same outcome when compared to those with slight CP (P=0.012). In addition, 46 subjects presented high SCL whereas 24 had a normal level. CP was found to be correlated with the SCL, with an OR of 4.14 (95% CI, 1.43 to 12.01). Subjects with a high SCL and depression may show an increased risk for CP.

  7. Association among stress, salivary cortisol levels, and chronic periodontitis

    PubMed Central

    Refulio, Zoila; Rocafuerte, Marco; de la Rosa, Manuel; Mendoza, Gerardo

    2013-01-01

    Purpose Chronic periodontitis (CP) seems to be associated with stress and depression, but little information on this possible association is available in the literature. Thus, the objective of this study was to evaluate the association among stress, the salivary cortisol level (SCL), and CP. Methods Seventy systemically healthy subjects were included in the study from January to September 2011. Full medical and dental histories were obtained, and the following measurements were recorded: 1) probing depth; 2) clinical attachment level; 3) bleeding on probing; and 4) tooth mobility. Saliva samples were collected for the evaluation of SCL (via a highly sensitive electrochemiluminescence immunoassay), and all subjects also answered a questionnaire (i.e., the Zung Self-rating Depression Scale). The odds ratio (OR) with a 95% confidence interval (CI) was calculated, and one way analysis of variance and the Tukey-Kramer method were performed. Results A total of 36 subjects with CP (51.4%) and 34 without CP were evaluated. Of them, all of the subjects with CP and one periodontally healthy subject were diagnosed with depression. Subjects with moderate CP had statistically significantly higher levels of SCL than subjects with a diagnosis of slight CP (P=0.006). Also, subjects with severe CP showed the same outcome when compared to those with slight CP (P=0.012). In addition, 46 subjects presented high SCL whereas 24 had a normal level. CP was found to be correlated with the SCL, with an OR of 4.14 (95% CI, 1.43 to 12.01). Conclusions Subjects with a high SCL and depression may show an increased risk for CP. PMID:23678393

  8. Gingival fibroblasts resist apoptosis in response to oxidative stress in a model of periodontal diseases

    PubMed Central

    Cheng, R; Choudhury, D; Liu, C; Billet, S; Hu, T; Bhowmick, NA

    2015-01-01

    Periodontal diseases are classified as inflammation affecting the supporting tissue of teeth, which eventually leads to tooth loss. Mild reversible gingivitis and severe irreversible periodontitis are the most common periodontal diseases. Periodontal pathogens initiate the diseases. The bacterial toxin, lipopolysaccharide (LPS), triggers the inflammatory response and leads to oxidative stress. However, the progress of oxidative stress in periodontal diseases is unknown. The purpose of this study is to examine oxidative stress and cell damage in gingivitis and periodontitis. Our results showed that LPS increases reactive oxygen species (ROS) accumulation in gingival fibroblast (GF). However, oxidative stress resulting from excessive ROS did not influence DNA damage and cell apoptosis within 24 h. The mechanism may be related to the increased expression of DNA repair genes, Ogg1, Neil1 and Rad50. Detection of apoptosis-related proteins also showed anti-apoptotic effects and pro-apoptotic effects were balanced. The earliest damage appeared in DNA when increased γH2AX, an early biomarker for DNA damage, was detected in the LPS group after 48 h. Later, when recurrent inflammation persisted, 8-OHdG, a biomarker for oxidative stress was much higher in periodontitis model compared to the control in vivo. Staining of 8-OHdG in human periodontitis specimens confirmed the results. Furthermore, TUNEL staining of apoptotic cells indicated that the periodontitis model induced more cell apoptosis in gingival tissue. This suggested GF could resist early and acute inflammation (gingivitis), which was regarded as reversible, but recurrent and chronic inflammation (periodontitis) led to permanent cell damage and death. PMID:27551475

  9. Finite element analysis on tooth and periodontal stress under simulated occlusal loads.

    PubMed

    Zhang, H; Cui, J-W; Lu, X L; Wang, M-Q

    2017-07-01

    The tooth stress elicited by occluding contact represents critical biomechanical information about dental health during chewing. Effects of occlusal contact on tooth stress remain obscure. In this study, a mandibular first molar finite element model was built from CT images. The effects of area size, location and direction of occlusal loading on both tooth and periodontal stresses were analysed. Results showed tooth and periodontal stress had drastically different patterns. Tooth stress value was much higher than periodontal stress value under the same task. Tooth stress concentration area and its value decreased from outside to inside. The Maximum Tooth Stress (MTS) always occurred at the loading site and a larger loading area elicited a smaller MTS value. The variation of MTS was larger when the fossa bottoms were inclined loaded than when the cusp tips were inclined loaded, larger when lingually loaded than when buccally loaded and larger when mesially loaded than when distally loaded. Distal loadings generally induced smaller Maximum Periodontal Stress (MPS) variations than the mesial loadings. These findings indicated exposure of the rational site(s) to occlusal contact should be helpful to achieve proper tooth and periodontal stress, thus to diminish loading associated structure problems. © 2017 John Wiley & Sons Ltd.

  10. Oxidative Stress and IgG Antibody Modify Periodontitis-CRP Association.

    PubMed

    Singer, R E; Moss, K; Kim, S J; Beck, J D; Offenbacher, S

    2015-12-01

    In a previous report, we demonstrated the inverse association of high serum 8-isoprostane levels, a marker for oxidative stress, with decreased serum IgG antibodies to oral bacteria. The association between increased serum IgG with increased plaque and periodontitis (increased probing depths) was attenuated by high systemic oxidative stress. Other investigations have reported a role for systemic oxidative stress as a stimulus of hepatic C-reactive protein (CRP) response. These observations led us to hypothesize that the reported relationship of periodontitis to elevated serum CRP, a systemic inflammatory marker, may be modified by oxidative stress and that the levels of serum antibodies to oral bacteria might be an intermediary explanatory variable linking the association of systemic oxidative stress, periodontal disease, and levels of CRP. This hypothesis was explored as a secondary analysis of the Dental ARIC (Atherosclerosis Risk in Communities) study using serum levels of CRP, serum IgG levels to 16 oral organisms, serum levels of 8-isoprostane, and periodontal status. The findings indicate periodontitis is associated with high CRP in the presence of elevated oxidative stress that serves to suppress the IgG response. Only within the highest 8-isoprostane quartile was periodontitis (pocket depth) associated with increased serum CRP levels (P = 0.0003). Increased serum IgG antibody levels to oral bacteria were associated with lowered serum CRP levels. Thus, systemic oxidative stress, which has been demonstrated to be associated with increased levels of CRP in other studies, appears to be associated with the suppression of bacterial-specific IgG levels, which in the presence of periodontal disease can result in an enhanced systemic CRP response. Conversely, individuals with increased serum IgG antibodies to plaque bacteria exhibit lowered serum CRP levels. These 2 factors, oxidative stress and the serum IgG response, appear to function in opposing directions to

  11. Effects of Enterococcus faecalis lipoteichoic acid on receptor activator of nuclear factor-κB ligand and osteoprotegerin expression in periodontal ligament fibroblasts.

    PubMed

    Zhao, L; Chen, J; Cheng, L; Wang, X; Du, J; Wang, F; Peng, Z

    2014-02-01

    To investigate the influence of Enterococcus faecalis lipoteichoic acid (LTA) on the key bone resorption-regulating proteins, receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in human periodontal ligament fibroblasts (PDL cells). Periodontal ligament cells were subjected to various concentrations of LTA. Cell viability was then determined by methyl thiazolyl tetrazolium (MTT) assay, whilst the expression levels of RANKL and OPG were investigated by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The effect of the inhibitors [IL-1 receptor-associated kinase (IRAK)-1/4, p38 mitogen-activated protein kinase (MAPK) (SB203580)] on LTA-stimulated RANKL/OPG activation was examined. Cell viability and RANKL/OPG ratio in PDL cells were also analysed by MTT assay and Western blotting. Data were analysed using one-way anova or t-test at a significance level of P = 0.05. Cell viability was reduced significantly in the LTA group in a dose-dependent fashion (P < 0.05). In addition, LTA was found to upregulate the protein expression of RANKL, OPG and their relative ratio in PDL cells (P < 0.05). The optimal concentration of LTA used in PDL cells was determined to be 10 μg mL(-1) . Following IRAK1/4 and p38MAPK inhibition, LTA-stimulated increases of RANKL/OPG ratio were significantly reduced (P < 0.05). Enterococcus faecalis LTA could upregulate the expression of RANKL and OPG at different rates, suggesting a potential role for LTA in the bone resorption process of refractory apical periodontitis through the regulation of RANKL and OPG. In addition, IRAK1/4 and p38MAPK signalling involving RANKL/OPG may contribute to inflammatory responses from PDL cells. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  12. EFFECT OF UNBROKEN LIGAMENTS ON STRESS CORROSION CRACKING BEHAVIOR OF ALLOY 82H WELDS

    SciTech Connect

    Mills, W.J. and Brown, C.M.

    2003-02-20

    Previously reported stress corrosion cracking (SCC) rates for Alloy 82H gas-tungsten-arc welds tested in 360 C water showed tremendous variability. The excessive data scatter was attributed to the variations in microstructure, mechanical properties and residual stresses that are common in welds. In the current study, however, re-evaluation of the SCC data revealed that the large data scatter was an anomaly due to erroneous crack growth rates inferred from crack mouth opening displacement (CMOD) measurements. Apparently, CMOD measurements provided reasonably accurate SCC rates for some specimens, but grossly overestimated rates in others. The overprediction was associated with large unbroken ligaments that often form in welds in the wake of advancing crack fronts. When ligaments were particularly large, they prevented crack mouth deflection, so apparent crack incubation times (i.e. period of time before crack advance commences) based on CMOD measurements were unrealistically long. During the final states of testing, ligaments began to separate allowing the crack mouth to open rather quickly. This behavior was interpreted as a rapid crack advance, but it actually reflects the ligament separation rate, not the SCC rate. Revised crack growth rates obtained in this study exhibit substantially less scatter than that previously reported. The effects of crack orientation and fatigue flutter loading on SCC rates in 82H welds are also discussed.

  13. Ibandronate promotes osteogenic differentiation of periodontal ligament stem cells by regulating the expression of microRNAs

    SciTech Connect

    Zhou, Qiang; Zhao, Zhi-Ning; Cheng, Jing-Tao; Zhang, Bin; Xu, Jie; Huang, Fei; Zhao, Rui-Ni; Chen, Yong-Jin

    2011-01-07

    Research highlights: {yields} Ibandronate significantly promote the proliferation of PDLSC cells. {yields} Ibandronate enhanced the expression of ALP, COL-1, OPG, OCN, Runx2. {yields} The expression of a class of miRNAs, e.g., miR-18a, miR-133a, miR-141 and miR-19a, was significantly modified in PDLSC cells cultured with ibandronate. {yields} Ibandronate regulates the expression of diverse bone formation-related genes via miRNAs in PDLSCs. {yields} Ibandronate can suppress the activity of osteoclast while promoting the proliferation of osteoblast by regulating the expression of microRNAs. -- Abstract: Bisphosphonates (BPs) have a profound effect on bone resorption and are widel