Periodontal diseases are infectious diseases that are characterized by progressive damage to dental support tissue.The major goal of periodontal therapy is to regenerate the periodontium destroyed by periodontal disea...Periodontal diseases are infectious diseases that are characterized by progressive damage to dental support tissue.The major goal of periodontal therapy is to regenerate the periodontium destroyed by periodontal diseases.Human periodontal ligament(PDL)tissue possesses periodontal regenerative properties,and periodontal ligament stem cells(PDLSCs)with the capacity for osteogenic differentiation show strong potential in clinical application for periodontium repair and regeneration.Noncoding RNAs(ncRNAs),which include a substantial portion of poly-A tail mature RNAs,are considered“transcriptional noise.”Recent studies show that ncRNAs play a major role in PDLSC differentiation;therefore,exploring how ncRNAs participate in the osteogenic differentiation of PDLSCs may help to elucidate the underlying mechanism of the osteogenic differentiation of PDLSCs and further shed light on the potential of stem cell transplantation for periodontium regeneration.In this review paper,we discuss the history of PDLSC research and highlight the regulatory mechanism of ncRNAs in the osteogenic differentiation of PDLSCs.展开更多
Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding th...Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding the cell numbers for medical use is the key to transitioning PDLSCs from the bench to the clinic. Lysophosphatidic acid(LPA), which is present in the human body and saliva, is a signaling molecule derived from phospholipids. In this study, we examined the effects of LPA on sternness maintenance in human PDLSCs. Several spindle-shaped and fibroblast-like periodontal ligament stem-like cell lines were established from PDLSC isolation. Among these cell lines, the most morphologically appropriate cell line was characterized. The expression levels of OCT4, NANOG(a stem cell marker), and CD90(a mesenchymal stem cell marker) were high. However, CD73(a negative marker of mesenchymal stem cells) expression was not observed. Notably, immunofluorescence analysis identified the expression of STRO-1, CD146(a mesenchymal stem cell marker), and sex determining region Y-box 2 at the protein level. In addition, lipid droplets were stained by Oil red O after the induction of adipogenesis for 21 days, and mineralized nodules were stained by Alizarin Red S after the induction of osteogenesis for 14 days. Alkaline phosphate staining also demonstrated the occurrence of osteogenesis. In summary, we established a human PDLSC line, which could be applied as a cell source for tissue regeneration in dental patients. However, further studies are needed to determine the detailed effects of LPA on PDLSCs.展开更多
Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years.Humanβ-defensin 3,a broad-spectrum antimicrobial peptide has been proven to have a variet...Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years.Humanβ-defensin 3,a broad-spectrum antimicrobial peptide has been proven to have a variety of biological functions in periodontitis;however,relatively few reports have addressed the effects of human periodontal ligament cells(h PDLCs)on osteogenic differentiation.In this study,we evaluated the osteogenic effects of h PDLCs with an adenoviral vector encoding humanβ-defensin 3 in an inflammatory microenvironment.Then humanβ-defensin 3 gene-modified rat periodontal ligament cells were transplanted into rats with experimental periodontitis to observe their effects on periodontal bone repair.We found that the humanβ-defensin 3 gene-modified h PDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition.Furthermore,the p38 MAPK pathway was activated in this process.In vivo,humanβ-defensin 3 gene-transfected rat PDLCs promoted bone repair in SD rats with periodontitis,and the p38 mitogen-activated protein kinase(MAPK)pathway might also have been involved.These findings demonstrate that humanβ-defensin 3 accelerates osteogenesis and that humanβ-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.展开更多
Inflammatory periodontal disease known as periodontitis is one of the most common conditions that affect human teeth and often leads to tooth loss.Due to the complexity of the periodontium,which is composed of several...Inflammatory periodontal disease known as periodontitis is one of the most common conditions that affect human teeth and often leads to tooth loss.Due to the complexity of the periodontium,which is composed of several tissues,its regeneration and subsequent return to a homeostatic state is challenging with the therapies currently available.Cellular therapy is increasingly becoming an alternative in regenerative medicine/dentistry,especially therapies using mesenchymal stem cells,as they can be isolated from a myriad of tissues.Periodontal ligament stem cells(PDLSCs)are probably the most adequate to be used as a cell source with the aim of regenerating the periodontium.Biological insights have also highlighted PDLSCs as promising immunomodulator agents.In this review,we explore the state of knowledge regarding the properties of PDLSCs,as well as their therapeutic potential,describing current and future clinical applications based on tissue engineering techniques.展开更多
The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth ...The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth movement,and connect tooth roots with bone.Severe periodontitis,deep caries,and trauma cause irreversible damage to this tissue,eventually leading to tooth loss through the destruction of tooth retention.Many patients suffer from these diseases worldwide,and its prevalence increases with age.To address this issue,regenerative medicine for damaged PDL tissue as well as the surrounding tissues has been extensively investigated regarding the potential and effectiveness of stem cells,scaffolds,and cytokines as well as their combined applications.In particular,PDL stem cells(PDLSCs)have been well studied.In this review,I discuss comprehensive studies on PDLSCs performed in vivo and contemporary reports focusing on the acquisition of large numbers of PDLSCs for therapeutic applications because of the very small number of PDLSCs available in vivo.展开更多
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 hi...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/CD140 a, 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^+/CD140a^+, 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.展开更多
Objective High glucose(HG)can influence the osteogenic differentiation ability of periodontal ligament stem cells(PDLSCs).Human umbilical cord mesenchymal stem cell-derived exosomes(hUCMSC-exo)have broad application p...Objective High glucose(HG)can influence the osteogenic differentiation ability of periodontal ligament stem cells(PDLSCs).Human umbilical cord mesenchymal stem cell-derived exosomes(hUCMSC-exo)have broad application prospects in tissue healing.The current study aimed to explore whether hUCMSC-exo could promote the osteogenic differentiation of hPDLSCs under HG conditions and the underlying mechanism.Methods We used a 30 mmol/L glucose concentration to simulate HG conditions.CCK-8 assay was performed to evaluate the effect of hUCMSC-exo on the proliferation of hPDLSCs.Alkaline phosphatase(ALP)staining,ALP activity,and qRT-PCR were performed to evaluate the pro-osteogenic effect of hUCMSC-exo on hPDLSCs.Western blot analysis was conducted to evaluate the underlying mechanism.Results The results of the CCK-8 assay,ALP staining,ALP activity,and qRT-PCR assay showed that hUCMSC-exo significantly promoted cell proliferation and osteogenic differentiation in a dosedependent manner.The Western blot results revealed that hUCMSC-exo significantly increased the levels of p-PI3K and p-AKT in cells,and the effect was inhibited by LY294002(PI3K inhibitor)or MK2206(AKT inhibitor),respectively.Moreover,the increases in osteogenic indicators induced by hUCMSC-exo were significantly suppressed by LY294002 and MK2206.Conclusion hUCMSC-exo promote the osteogenic differentiation of hPDLSCs under HG conditions through the PI3K/AKT signaling pathway.展开更多
Objective 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 te...Objective 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.Methods 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.Results 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.Conclusion 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.展开更多
Periodontitis is a highly prevalent,chronic,non-specific,and immunologically devastating disease of periodontal tissues,caused by microbial infection.This study aims to examine the efficacy and protective mechanism of...Periodontitis is a highly prevalent,chronic,non-specific,and immunologically devastating disease of periodontal tissues,caused by microbial infection.This study aims to examine the efficacy and protective mechanism of triclosan(TCS),a bisphenolic,non-cationic component of oral care products,against periodontal inflammation induced by lipopolysaccharide purified from Porphyromonas gingivalis(LPS-PG).TCS markedly downregulated interleukin-6(IL-6),IL-8,and IL-15 in human periodontal ligament fibroblasts(HPDLFs)treated with LPS-PG.By using a liquid chromatography-tandem mass spectrometry(LC-MS/MS)approach,318 differentially expressed proteins(161 upregulated and 157 downregulated)were identified in TCS-pretreated HPDLFs.TCS upregulated HSPA5 and HSP90B1 but downregulated HSPA2.Besides,TCS upregulated miR-548i in HPDLFs,which downregulated IL-15.These results indicate that TCS attenuates the activation of HPDLFs and downregulates the inflammatory cytokines through various mechanisms,thus highlighting its protective role in periodontal inflammation.展开更多
α-smooth muscle actin(α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment....α-smooth muscle actin(α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament(PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1(TGF-β1) and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells(h PDLCs). The h PDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.展开更多
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 pro...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.展开更多
After teeth are replanted,there are two possible healing responses:periodontal ligament healing or ankylosis with subsequent replacement resorption.The purpose of this study was to compare the fatigue resistance of ve...After teeth are replanted,there are two possible healing responses:periodontal ligament healing or ankylosis with subsequent replacement resorption.The purpose of this study was to compare the fatigue resistance of vertically fractured teeth after bonding the fragments under conditions simulating both healing modes.Thirty-two human premolars were vertically fractured and the fragments were bonded together with Super-Bond C&B.They were then randomly distributed into four groups(BP,CP,CA,BA).The BP and CP groups were used to investigate the periodontal ligament healing mode whilst the BA and CA groups simulated ankylosis.All teeth had root canal treatment performed.Metal crowns were constructed for the CP and CA groups.The BP and BA groups only had composite resin restorations in the access cavities.All specimens were subjected to a 260 N load at 4 Hz until failure of the bond or until 2 x 106 cycles had been reached if no fracture occurred.Cracks were detected by stereomicroscope imaging and also assessed via dye penetration tests.Finally,interfaces of the resin luting agent were examined by scanning electron microscope.The results confirmed that the fatigue resistance was higher in the groups with simulated periodontal ligament healing.Periodontal reattachment showed important biomechanical role in bonded and replanted vertically fractured teeth.展开更多
Human periodontal ligament cells (hPDLCs), with the potential for multi-directional differentiation and reproduction, are the target cells of orthodontic tooth movement. The aim of this study was to examine the effect...Human periodontal ligament cells (hPDLCs), with the potential for multi-directional differentiation and reproduction, are the target cells of orthodontic tooth movement. The aim of this study was to examine the effect of mechanical tension force and lipopolysaccharides (LPS) on hPDLCs and whether they induce proliferative and differentiated characters in vitro. Tension force was applied to hPDLCs stimulated with and without LPS for 24 hrs. Real-time polymerase chain reaction (qPCR) was carried out to analyze the mRNA expression of Cyclin 2 (CCND2), WNT1 inducible signaling pathway protein 1 (WISP1), runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP). Analysis of variance (ANOVA) was used for statistical analysis. Significant differences were indicated by P < 0.05. The results showed that tension force promoted the mRNA expression of both the proliferation-related genes (CCND2 and WISP1) and differentiation-related genes (RUNX2 and ALP), and that both were enhanced by the simulation of LPS. In addition, the relative expression ratios CCND2/RUNX2 and CCND2/ALP both increased significantly after the application of tension, and this effect was further enhanced by LPS. All results indicated that with the assessed level of mechanical force loading, tension could promote both the proliferation and differentiation of hPDLCs, which could be enhanced by LPS, and that proliferation is promoted to a greater extent than differentiation. These findings may be valuable for understanding the importance of the application of suitable mechanical force in periodontal remodeling, especially in the process of orthodontic tooth movement with inflammation.展开更多
Periodontitis is a chronic inflammatory disease resulting in the loss of periodontal tissues and ultimately teeth,thus posing a substantial public-health burden worldwide[1].With the widespread increase in mesenchymal...Periodontitis is a chronic inflammatory disease resulting in the loss of periodontal tissues and ultimately teeth,thus posing a substantial public-health burden worldwide[1].With the widespread increase in mesenchymal stem cell(MSC)therapy and the discovery of MSCs in periodontal ligaments[2],periodontal ligament stem cells(PDLSCs)have been used to reconstruct periodontal tissue and repair bone defects[2,3].Furthermore.展开更多
Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG)in cultured human periodontal ligament(HPDL)cells.Methods Small interfering ...Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG)in cultured human periodontal ligament(HPDL)cells.Methods Small interfering RNA(siRNA)eukaryotic expression vector targeted transforming growth factor βⅡ receptor(TGF-β RⅡ)was constructed and transfected into T cells.HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide(LPS)and baicalin.The obtained solution was divided into six groups according to the components(group Ⅰ:HPDL cells+LPS+T cells transfected with siRNA1+baicalin;group Ⅱ:HPDL cells+LPS+T cells transfected with siRNA1;group Ⅲ:HPDL cells+LPS+T cells+baicalin;group Ⅳ:HPDL cells+LPS+T cells;group Ⅴ:HPDL cells+baicalin;group Ⅵ:HPDL cells)and was cultured for 48 hours.RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells.Results The ratio of RANKL/OPG in group Ⅰ was lower than that in group Ⅱ(P<0.01)and higher than that in group Ⅲ(P<0.01);The ratio of RANKL/OPG in group Ⅲ was lower than that in group Ⅳ(P<0.01);the ratio of RANKL/OPG in group Ⅳ was higher than that in group Ⅵ(P<0.01);the ratio of RANKL/OPG in group Ⅴ was lower than that in group Ⅵ(P<0.05).Conclusion ① Baicalin could decrease the ratio of RANKL/OPG in HPDL cells.② The TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells.③ Baicalin acts not only through TGF-β to regulate RANKL/OPG in HPDL cells,but also through other pathways.展开更多
Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous ...Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous Schwann cells in promoting the regeneration of injured peripheral nerve.To validate this hypothesis, human periodontal ligament stem cells(1 × 106) were injected into the crush-injured left mental nerve in rats. Simultaneously, autologous Schwann cells(1 × 106) and PBS were also injected as controls. Real-time reverse transcriptase polymerase chain reaction showed that at 5 days after injection, mRNA expression of low affinity nerve growth factor receptor was significantaly increased in the left trigeminal ganglion of rats with mental nerve injury. Sensory tests,histomorphometric evaluation and retrograde labeling demonstrated that at 2 and 4 weeks after injection, sensory function was significantly improved, the numbers of retrograde labeled sensory neurons and myelinated axons were significantly increased, and human periodontal ligament stem cells and autologous Schwann cells exhibited similar therapeutic effects. These findings suggest that transplantation of human periodontal ligament stem cells show a potential value in repair of mental nerve injury.展开更多
The periodontal ligament (PDL) is a soft bio-logical tissue which shows a strongly nonlinear and time dependent mechanical behavior. Re-cent experiments on rabbit PDL revealed that the rate of stress relaxation is str...The periodontal ligament (PDL) is a soft bio-logical tissue which shows a strongly nonlinear and time dependent mechanical behavior. Re-cent experiments on rabbit PDL revealed that the rate of stress relaxation is strain dependent. This nonlinear behavior of PDL cannot be de-scribed well by the separable quasi linear vis-coelasticity theory which is usually used in tis-sue biomechanics. Therefore, PDL requires a more general description which considers this nonlinearity and time dependency. The purpose of this study was to model strain dependent stress relaxation behavior of PDL using modi-fied superposition method. It is shown herein that modified superposition method describes viscoelastic nonlinearties well and shows a good compatibility with available experimental PDL data. Hence, the modified superposition model is suggested to describe periodontal ligament data, because it can suitably demon-strate both elastic nonlinearity and strain-dependent stress relaxation behavior of PDL.展开更多
Aim: To investigate the expression levels of receptor activator of NF-κB ligand (RANKL) and oste-oprotegerin (OPG) in human periodontal ligament fibroblasts when stimulated with heat in infective conditions. Methods:...Aim: To investigate the expression levels of receptor activator of NF-κB ligand (RANKL) and oste-oprotegerin (OPG) in human periodontal ligament fibroblasts when stimulated with heat in infective conditions. Methods: Periodontal ligament fibroblasts were subjected to various temperature increases for 5 min with or without 10 ng/mL lipopolysaccharide (LPS) and then maintained at 37℃ for 6 h. After that, the expression levels of RANKL and OPG were investigated using real-time RT-PCR and ELISA. As a positive or negative control, the cells were cultured at 37℃ with or without 10 ng/mL LPS. Data were analyzed using one-way ANOVA at a significant level of p = 0.05. Results: The mRNA expression levels of RANKL and OPG were both down-regulated when the cells were heated in infective conditions. The release of sRANKL was increased at low temperatures in such infection;while at high temperatures heat treatment down-regulated the release of sRANKL induced by LPS. The relative RANKL/OPG expression ratios were increased at low temperatures in infective conditions. Conclusions: The interactions between heat and LPS would affect the balance between RANKL and OPG in periodontal ligament fibroblasts when they were heated in infective conditions. Such infection may be the reason why bone resorption occurs in the local area after warm vertical compaction.展开更多
The purpose of the present study was to histopathologically and immunohistochemically investigate the distribution of proteoglycans in human periodontal ligament (PDL). Specimens from osteotomy and tooth extraction ha...The purpose of the present study was to histopathologically and immunohistochemically investigate the distribution of proteoglycans in human periodontal ligament (PDL). Specimens from osteotomy and tooth extraction having healthy PDL were studied. Histologically, PDL consisted of fibrous tissues, involving a compact arrangement area and edematous or myxoid area. Immuno-histochemically, versican binding region (12C5), versican link protein (8A4) and biotinylated hyaluronic acid binding protein (B-HABP) were distributed in PDL. In addition, positive immunore-activity for 12C5 and 8A4 was stronger in the compact arrangement area than in the edematous or myxoid area. Reactivity for B-HABP was stronger in the edematous or myxoid area than in the compact fibrous area. These results suggest that versican and link protein are associated with fibrous tissues, whereas hyaluronic acid is related to the formation of edematous and/or myxoid tissue in human PDL. These substances may play a role in periodontal homeostasis by protecting against mechanical stress.展开更多
基金Supported by National Natural Science Foundation of ChinaNo.81600882 and 81870755+4 种基金China Postdoctoral Science FoundationNo. 2019M663009President Foundation of Nanfang HospitalSouthern Medical UniversityNo.2019B002.
文摘Periodontal diseases are infectious diseases that are characterized by progressive damage to dental support tissue.The major goal of periodontal therapy is to regenerate the periodontium destroyed by periodontal diseases.Human periodontal ligament(PDL)tissue possesses periodontal regenerative properties,and periodontal ligament stem cells(PDLSCs)with the capacity for osteogenic differentiation show strong potential in clinical application for periodontium repair and regeneration.Noncoding RNAs(ncRNAs),which include a substantial portion of poly-A tail mature RNAs,are considered“transcriptional noise.”Recent studies show that ncRNAs play a major role in PDLSC differentiation;therefore,exploring how ncRNAs participate in the osteogenic differentiation of PDLSCs may help to elucidate the underlying mechanism of the osteogenic differentiation of PDLSCs and further shed light on the potential of stem cell transplantation for periodontium regeneration.In this review paper,we discuss the history of PDLSC research and highlight the regulatory mechanism of ncRNAs in the osteogenic differentiation of PDLSCs.
基金supported,in part,by a grant from the"Korea Research Fellowship(KRF)Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2015HlD3A1066175)"the"NRF Grant funded by the Ministry of Science and ICT(NRF-2016RIDIAIB-03933191,NRF-2017RIA2B4002546)"+1 种基金the"Global Research and Development Center(GRDC)Program through the NRF funded by the Ministry of Science and ICT(NRF-2017KlA4A3014959)""Korea Institute of Planning and Evaluation for Technology in Food,Agriculture,Forestry and Fisheries(IPET)through Agri-Bio industry Technology Development Program,funded by Ministry of Agriculture,Food and Rural Affairs(MAFRA)(318016-5)",Republic of Korea
文摘Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding the cell numbers for medical use is the key to transitioning PDLSCs from the bench to the clinic. Lysophosphatidic acid(LPA), which is present in the human body and saliva, is a signaling molecule derived from phospholipids. In this study, we examined the effects of LPA on sternness maintenance in human PDLSCs. Several spindle-shaped and fibroblast-like periodontal ligament stem-like cell lines were established from PDLSC isolation. Among these cell lines, the most morphologically appropriate cell line was characterized. The expression levels of OCT4, NANOG(a stem cell marker), and CD90(a mesenchymal stem cell marker) were high. However, CD73(a negative marker of mesenchymal stem cells) expression was not observed. Notably, immunofluorescence analysis identified the expression of STRO-1, CD146(a mesenchymal stem cell marker), and sex determining region Y-box 2 at the protein level. In addition, lipid droplets were stained by Oil red O after the induction of adipogenesis for 21 days, and mineralized nodules were stained by Alizarin Red S after the induction of osteogenesis for 14 days. Alkaline phosphate staining also demonstrated the occurrence of osteogenesis. In summary, we established a human PDLSC line, which could be applied as a cell source for tissue regeneration in dental patients. However, further studies are needed to determine the detailed effects of LPA on PDLSCs.
基金supported by the National Natural Science Foundation Project(No.81771078 and No.81570982)Jiangsu Provincial Medical Innovation Team(No.CXTDB2017014)the Nanjing Clinical Research Center for Oral Diseases(No.2019060009)。
文摘Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years.Humanβ-defensin 3,a broad-spectrum antimicrobial peptide has been proven to have a variety of biological functions in periodontitis;however,relatively few reports have addressed the effects of human periodontal ligament cells(h PDLCs)on osteogenic differentiation.In this study,we evaluated the osteogenic effects of h PDLCs with an adenoviral vector encoding humanβ-defensin 3 in an inflammatory microenvironment.Then humanβ-defensin 3 gene-modified rat periodontal ligament cells were transplanted into rats with experimental periodontitis to observe their effects on periodontal bone repair.We found that the humanβ-defensin 3 gene-modified h PDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition.Furthermore,the p38 MAPK pathway was activated in this process.In vivo,humanβ-defensin 3 gene-transfected rat PDLCs promoted bone repair in SD rats with periodontitis,and the p38 mitogen-activated protein kinase(MAPK)pathway might also have been involved.These findings demonstrate that humanβ-defensin 3 accelerates osteogenesis and that humanβ-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.
文摘Inflammatory periodontal disease known as periodontitis is one of the most common conditions that affect human teeth and often leads to tooth loss.Due to the complexity of the periodontium,which is composed of several tissues,its regeneration and subsequent return to a homeostatic state is challenging with the therapies currently available.Cellular therapy is increasingly becoming an alternative in regenerative medicine/dentistry,especially therapies using mesenchymal stem cells,as they can be isolated from a myriad of tissues.Periodontal ligament stem cells(PDLSCs)are probably the most adequate to be used as a cell source with the aim of regenerating the periodontium.Biological insights have also highlighted PDLSCs as promising immunomodulator agents.In this review,we explore the state of knowledge regarding the properties of PDLSCs,as well as their therapeutic potential,describing current and future clinical applications based on tissue engineering techniques.
基金Supported by Japan Society for the Promotion of Science,No.JP17H01598.
文摘The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth movement,and connect tooth roots with bone.Severe periodontitis,deep caries,and trauma cause irreversible damage to this tissue,eventually leading to tooth loss through the destruction of tooth retention.Many patients suffer from these diseases worldwide,and its prevalence increases with age.To address this issue,regenerative medicine for damaged PDL tissue as well as the surrounding tissues has been extensively investigated regarding the potential and effectiveness of stem cells,scaffolds,and cytokines as well as their combined applications.In particular,PDL stem cells(PDLSCs)have been well studied.In this review,I discuss comprehensive studies on PDLSCs performed in vivo and contemporary reports focusing on the acquisition of large numbers of PDLSCs for therapeutic applications because of the very small number of PDLSCs available in vivo.
基金supported by National Institute of Dental and Craniofacial Research grant T90DE022734
文摘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/CD140 a, 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^+/CD140a^+, 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.
文摘Objective High glucose(HG)can influence the osteogenic differentiation ability of periodontal ligament stem cells(PDLSCs).Human umbilical cord mesenchymal stem cell-derived exosomes(hUCMSC-exo)have broad application prospects in tissue healing.The current study aimed to explore whether hUCMSC-exo could promote the osteogenic differentiation of hPDLSCs under HG conditions and the underlying mechanism.Methods We used a 30 mmol/L glucose concentration to simulate HG conditions.CCK-8 assay was performed to evaluate the effect of hUCMSC-exo on the proliferation of hPDLSCs.Alkaline phosphatase(ALP)staining,ALP activity,and qRT-PCR were performed to evaluate the pro-osteogenic effect of hUCMSC-exo on hPDLSCs.Western blot analysis was conducted to evaluate the underlying mechanism.Results The results of the CCK-8 assay,ALP staining,ALP activity,and qRT-PCR assay showed that hUCMSC-exo significantly promoted cell proliferation and osteogenic differentiation in a dosedependent manner.The Western blot results revealed that hUCMSC-exo significantly increased the levels of p-PI3K and p-AKT in cells,and the effect was inhibited by LY294002(PI3K inhibitor)or MK2206(AKT inhibitor),respectively.Moreover,the increases in osteogenic indicators induced by hUCMSC-exo were significantly suppressed by LY294002 and MK2206.Conclusion hUCMSC-exo promote the osteogenic differentiation of hPDLSCs under HG conditions through the PI3K/AKT signaling pathway.
文摘Objective 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.Methods 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.Results 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.Conclusion 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.
基金This work was funded by the innovative development funds of Jiangsu Province Hospital of Traditional Chinese Medicine(Y2018CX19).
文摘Periodontitis is a highly prevalent,chronic,non-specific,and immunologically devastating disease of periodontal tissues,caused by microbial infection.This study aims to examine the efficacy and protective mechanism of triclosan(TCS),a bisphenolic,non-cationic component of oral care products,against periodontal inflammation induced by lipopolysaccharide purified from Porphyromonas gingivalis(LPS-PG).TCS markedly downregulated interleukin-6(IL-6),IL-8,and IL-15 in human periodontal ligament fibroblasts(HPDLFs)treated with LPS-PG.By using a liquid chromatography-tandem mass spectrometry(LC-MS/MS)approach,318 differentially expressed proteins(161 upregulated and 157 downregulated)were identified in TCS-pretreated HPDLFs.TCS upregulated HSPA5 and HSP90B1 but downregulated HSPA2.Besides,TCS upregulated miR-548i in HPDLFs,which downregulated IL-15.These results indicate that TCS attenuates the activation of HPDLFs and downregulates the inflammatory cytokines through various mechanisms,thus highlighting its protective role in periodontal inflammation.
基金funded by National Nature Science Foundation of China (Grant Nos 30970705, 11172190, 81371171, and 81371172)
文摘α-smooth muscle actin(α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament(PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1(TGF-β1) and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells(h PDLCs). The h PDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.
基金supported by grants from the Kaohsiung Medical University of Taiwan (KMU-Q099018 and KMU-Q098025)
文摘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.
基金supported by the Jiangsu Province's Outstanding Medical Academic Leader Program(No.LJ201110)the National Natural Scientific Foundation of China(81070839)Key Project supported by Medical Science and Technology Development Foundation,Nanjing Department of Health(ZKX10030)
文摘After teeth are replanted,there are two possible healing responses:periodontal ligament healing or ankylosis with subsequent replacement resorption.The purpose of this study was to compare the fatigue resistance of vertically fractured teeth after bonding the fragments under conditions simulating both healing modes.Thirty-two human premolars were vertically fractured and the fragments were bonded together with Super-Bond C&B.They were then randomly distributed into four groups(BP,CP,CA,BA).The BP and CP groups were used to investigate the periodontal ligament healing mode whilst the BA and CA groups simulated ankylosis.All teeth had root canal treatment performed.Metal crowns were constructed for the CP and CA groups.The BP and BA groups only had composite resin restorations in the access cavities.All specimens were subjected to a 260 N load at 4 Hz until failure of the bond or until 2 x 106 cycles had been reached if no fracture occurred.Cracks were detected by stereomicroscope imaging and also assessed via dye penetration tests.Finally,interfaces of the resin luting agent were examined by scanning electron microscope.The results confirmed that the fatigue resistance was higher in the groups with simulated periodontal ligament healing.Periodontal reattachment showed important biomechanical role in bonded and replanted vertically fractured teeth.
文摘Human periodontal ligament cells (hPDLCs), with the potential for multi-directional differentiation and reproduction, are the target cells of orthodontic tooth movement. The aim of this study was to examine the effect of mechanical tension force and lipopolysaccharides (LPS) on hPDLCs and whether they induce proliferative and differentiated characters in vitro. Tension force was applied to hPDLCs stimulated with and without LPS for 24 hrs. Real-time polymerase chain reaction (qPCR) was carried out to analyze the mRNA expression of Cyclin 2 (CCND2), WNT1 inducible signaling pathway protein 1 (WISP1), runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP). Analysis of variance (ANOVA) was used for statistical analysis. Significant differences were indicated by P < 0.05. The results showed that tension force promoted the mRNA expression of both the proliferation-related genes (CCND2 and WISP1) and differentiation-related genes (RUNX2 and ALP), and that both were enhanced by the simulation of LPS. In addition, the relative expression ratios CCND2/RUNX2 and CCND2/ALP both increased significantly after the application of tension, and this effect was further enhanced by LPS. All results indicated that with the assessed level of mechanical force loading, tension could promote both the proliferation and differentiation of hPDLCs, which could be enhanced by LPS, and that proliferation is promoted to a greater extent than differentiation. These findings may be valuable for understanding the importance of the application of suitable mechanical force in periodontal remodeling, especially in the process of orthodontic tooth movement with inflammation.
基金supported by grants from the Natural Science Foundation of Shandong Province[No.ZR2021MH051 to DING Gang]the Postgraduate Education Quality Improvement Plan of Shandong Province[No.SDYAL21150 to DING Gang]the National Natural Science Foundation of China[No.81570945 to DING Gang]
文摘Periodontitis is a chronic inflammatory disease resulting in the loss of periodontal tissues and ultimately teeth,thus posing a substantial public-health burden worldwide[1].With the widespread increase in mesenchymal stem cell(MSC)therapy and the discovery of MSCs in periodontal ligaments[2],periodontal ligament stem cells(PDLSCs)have been used to reconstruct periodontal tissue and repair bone defects[2,3].Furthermore.
基金supported by the Foundation of Stomatology Hospital,Xi'an Jiaotong University
文摘Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG)in cultured human periodontal ligament(HPDL)cells.Methods Small interfering RNA(siRNA)eukaryotic expression vector targeted transforming growth factor βⅡ receptor(TGF-β RⅡ)was constructed and transfected into T cells.HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide(LPS)and baicalin.The obtained solution was divided into six groups according to the components(group Ⅰ:HPDL cells+LPS+T cells transfected with siRNA1+baicalin;group Ⅱ:HPDL cells+LPS+T cells transfected with siRNA1;group Ⅲ:HPDL cells+LPS+T cells+baicalin;group Ⅳ:HPDL cells+LPS+T cells;group Ⅴ:HPDL cells+baicalin;group Ⅵ:HPDL cells)and was cultured for 48 hours.RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells.Results The ratio of RANKL/OPG in group Ⅰ was lower than that in group Ⅱ(P<0.01)and higher than that in group Ⅲ(P<0.01);The ratio of RANKL/OPG in group Ⅲ was lower than that in group Ⅳ(P<0.01);the ratio of RANKL/OPG in group Ⅳ was higher than that in group Ⅵ(P<0.01);the ratio of RANKL/OPG in group Ⅴ was lower than that in group Ⅵ(P<0.05).Conclusion ① Baicalin could decrease the ratio of RANKL/OPG in HPDL cells.② The TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells.③ Baicalin acts not only through TGF-β to regulate RANKL/OPG in HPDL cells,but also through other pathways.
基金supported by a grant of the Korea Healthcare Technology R&D Project,Ministry for Health,Welfare & Family Affairs,Republic of Korea,No.A101578
文摘Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous Schwann cells in promoting the regeneration of injured peripheral nerve.To validate this hypothesis, human periodontal ligament stem cells(1 × 106) were injected into the crush-injured left mental nerve in rats. Simultaneously, autologous Schwann cells(1 × 106) and PBS were also injected as controls. Real-time reverse transcriptase polymerase chain reaction showed that at 5 days after injection, mRNA expression of low affinity nerve growth factor receptor was significantaly increased in the left trigeminal ganglion of rats with mental nerve injury. Sensory tests,histomorphometric evaluation and retrograde labeling demonstrated that at 2 and 4 weeks after injection, sensory function was significantly improved, the numbers of retrograde labeled sensory neurons and myelinated axons were significantly increased, and human periodontal ligament stem cells and autologous Schwann cells exhibited similar therapeutic effects. These findings suggest that transplantation of human periodontal ligament stem cells show a potential value in repair of mental nerve injury.
文摘The periodontal ligament (PDL) is a soft bio-logical tissue which shows a strongly nonlinear and time dependent mechanical behavior. Re-cent experiments on rabbit PDL revealed that the rate of stress relaxation is strain dependent. This nonlinear behavior of PDL cannot be de-scribed well by the separable quasi linear vis-coelasticity theory which is usually used in tis-sue biomechanics. Therefore, PDL requires a more general description which considers this nonlinearity and time dependency. The purpose of this study was to model strain dependent stress relaxation behavior of PDL using modi-fied superposition method. It is shown herein that modified superposition method describes viscoelastic nonlinearties well and shows a good compatibility with available experimental PDL data. Hence, the modified superposition model is suggested to describe periodontal ligament data, because it can suitably demon-strate both elastic nonlinearity and strain-dependent stress relaxation behavior of PDL.
文摘Aim: To investigate the expression levels of receptor activator of NF-κB ligand (RANKL) and oste-oprotegerin (OPG) in human periodontal ligament fibroblasts when stimulated with heat in infective conditions. Methods: Periodontal ligament fibroblasts were subjected to various temperature increases for 5 min with or without 10 ng/mL lipopolysaccharide (LPS) and then maintained at 37℃ for 6 h. After that, the expression levels of RANKL and OPG were investigated using real-time RT-PCR and ELISA. As a positive or negative control, the cells were cultured at 37℃ with or without 10 ng/mL LPS. Data were analyzed using one-way ANOVA at a significant level of p = 0.05. Results: The mRNA expression levels of RANKL and OPG were both down-regulated when the cells were heated in infective conditions. The release of sRANKL was increased at low temperatures in such infection;while at high temperatures heat treatment down-regulated the release of sRANKL induced by LPS. The relative RANKL/OPG expression ratios were increased at low temperatures in infective conditions. Conclusions: The interactions between heat and LPS would affect the balance between RANKL and OPG in periodontal ligament fibroblasts when they were heated in infective conditions. Such infection may be the reason why bone resorption occurs in the local area after warm vertical compaction.
文摘The purpose of the present study was to histopathologically and immunohistochemically investigate the distribution of proteoglycans in human periodontal ligament (PDL). Specimens from osteotomy and tooth extraction having healthy PDL were studied. Histologically, PDL consisted of fibrous tissues, involving a compact arrangement area and edematous or myxoid area. Immuno-histochemically, versican binding region (12C5), versican link protein (8A4) and biotinylated hyaluronic acid binding protein (B-HABP) were distributed in PDL. In addition, positive immunore-activity for 12C5 and 8A4 was stronger in the compact arrangement area than in the edematous or myxoid area. Reactivity for B-HABP was stronger in the edematous or myxoid area than in the compact fibrous area. These results suggest that versican and link protein are associated with fibrous tissues, whereas hyaluronic acid is related to the formation of edematous and/or myxoid tissue in human PDL. These substances may play a role in periodontal homeostasis by protecting against mechanical stress.
