Regenerating periodontal bone defect surrounding periodontal tissue is crucial for orthodontic or dental implant treatment. The declined osteogenic ability of periodontal ligament stem cells (PDLSCs) induced by inflammation stimulus contributes to reduced capacity to regenerate periodontal bone, which brings about a huge challenge for treating periodontitis. Here, inspired by the adhesive property of mussels, we have created adhesive and mineralized hydrogel microspheres loaded with traditional compound cordycepin (MMS-CY). MMS-CY could adhere to the surface of alveolar bone, then promote the migration capacity of PDLSCs and thus recruit them to inflammatory periodontal tissues. Furthermore, MMS-CY rescued the impaired osteogenesis and ligament-forming capacity of PDLSCs, which were suppressed by the inflammation stimulus. Moreover, MMS-CY also displayed the excellent inhibitory effect on the osteoclastic activity. Mechanistically, MMS-CY inhibited the premature senescence induced by the inflammation stimulus through the nuclear factor erythroid 2-related factor (NRF2) pathway and reducing the DNA injury. Utilizing in vivo rat periodontitis model, MMS-CY was demonstrated to enhance the periodontal bone regeneration by improving osteogenesis and inhibiting the osteoclastic activity. Altogether, our study indicated that the multi-pronged approach is promising to promote the periodontal bone regeneration in periodontitis condition by reducing the inflammation-induced stem cell senescence and maintaining bone homeostasis.
Animals ; Bone Regeneration/drug effects* ; Rats ; Periodontal Ligament/cytology* ; Microspheres ; NF-E2-Related Factor 2 ; Hydrogels ; Periodontitis/therapy* ; Osteogenesis/drug effects* ; Disease Models, Animal ; Stem Cells ; Male ; Rats, Sprague-Dawley ; Humans

The repair of the periodontal membrane is essential for the successful management of periodontal disease and dental trauma. Emdogain^® (EMD) is widely used in periodontal therapy due to its ability to promote repair. Despite substantial research, the cellular and molecular mechanisms underlying EMD's effects, particularly at the single-cell resolution, remain incompletely understood. This study established a delayed tooth replantation model in rats to investigate these aspects. Tooth loss rate and degree of loosening were evaluated at 4 and 8 weeks. Micro-CT, HE staining, TRAP staining, and immunofluorescence staining were evaluated to assess EMD's efficacy. Single-cell sequencing analyses generated single-cell maps that explored enrichment pathways, cell communication, and potential repair mechanisms. Findings indicated that EMD could reduce the rate of tooth loss, promote periodontal membrane repair, and reduce root and bone resorption. Single-cell analysis revealed that EMD promotes the importance of Vtn+ fibroblasts, enhancing matrix and tissue regeneration functions. Additionally, EMD stimulated osteogenic pathways, reduced osteoclastic activity, and promoted angiogenesis-related pathways, particularly bone-related H-type vessel expression in endothelial cells. Gene modules associated with angiogenesis, osteogenesis, and odontoblast differentiation were identified, suggesting EMD might facilitate osteogenesis and odontoblast differentiation by upregulating endothelium-related genes. Immune cell analysis indicated that EMD did not elicit a significant immune response. Cell communication analysis suggested that EMD fostered pro-regenerative networks driven by interactions between mesenchymal stem cells, fibroblasts, and endothelial cells. In conclusion, EMD proves to be an effective root surface therapy agent that supports the restoration of delayed replantation teeth.
Animals ; Tooth Replantation/methods* ; Rats ; Dental Enamel Proteins/pharmacology* ; Single-Cell Analysis ; Rats, Sprague-Dawley ; X-Ray Microtomography ; Osteogenesis/drug effects* ; Male ; Periodontal Ligament/drug effects*

OBJECTIVES: To explore the promoting effect of ginsenoside Rb3 (Rb3) on osteogenesis in periodontitis environment, and to explain its mechanism. METHODS: Human periodontal ligament stem cells (hPDLSCs) were cultured by tissue block method and identified by flow cytometry. Cell counting kit-8 (CCK8) method and calcein acetoxymethyl ester/propidium iodide staining were used to detect the effect of Rb3 on the viability of hPDLSCs cells. In vitro cell experiments were divided into control group, 10 μg/mL lipopolysaccharides (LPS) group, 10 μg/mL LPS+100 μmol/L Rb3 group and 10 μg/mL LPS+200 μmol/L Rb3 group. Alkaline phosphatase (ALP) staining was used to detect the ALP activity of hPDLSCs in each group after osteogenesis induction. The expression of hPDLSCs interleukin-6 (IL-6), interleukin-8 (IL-8), runt-related transcription factor 2 (RUNX2) and transforming growth factor-β (TGF-β)genes in each group after osteogenesis was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. Western blot was used to detect the protein expression of hPDLSCs phosphorrylated extracellular signal-regulated kinase (p-ERK) in each group. Sprague-Dawley rats were randomly divided into the control group, ligation group and ligation+Rb3 group. The left molar-maxillary tissue was subjected to micro-computed tomography (micro-CT) scanning. After the scanning, the left molar-maxilla was made into periodontal tissue sections. Hematoxylin-eosin (HE) staining was used to detect the infiltration and loss of adhesion of inflammatory cells. Masson staining was used to detect the destruction of gingival collagen fibers. Immunofluorescence staining was used to detect the protein expression of RUNX2 and p-ERK. The expression of TGF-β in rat gingival tissue was detected by qRT-PCR. The protein expression of IL-6 in peripheral serum of rats was detected by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to detect the proportion of Treg cells in rat heart blood. The experimental data were statistically analyzed by Graph Pad Prism10.1.2 software. RESULTS: Rb3 had no effect on the cell activity of hPDLSCs. The results of qRT-PCR and ALP staining showed that Rb3 could inhibit the gene expression of IL-6 and IL-8 in inflammatory hPDLSCs, promote TGF-β gene and promote the osteogenic differentiation of inflammatory hPDLSCs. Western blot showed that Rb3 inhibited the protein expression of inflammatory hPDLSCs p-ERK. The results from micro-CT, Masson staining, and HE staining demonstrated that Rb3 promotes alveolar bone formation in rats with periodontitis, while simultaneously inhibiting the destruction of periodontal fibrous tissue, reducing attachment loss, and suppressing inflammatory cell infiltration. The results of flow cytometry showed that Rb3 could promote the differentiation of Treg cells in peripheral blood of periodontitis rats. The results of ELISA and qRT-PCR showed that Rb3 could inhibit the protein expression of IL-6 and promote the gene expression of TGF-β in periodontitis rats. Immunofluorescence results showed that Rb3 could promote the protein expression of RUNX2 and inhibit the protein expression of p-ERK in periodontitis rats. CONCLUSIONS Rb3 can reduce the inflammatory reaction of periodontal tissues in periodontitis rats, and promote the osteogenic differentiation of hPDLSCs by regulating p-ERK pathways.
Animals ; Ginsenosides/pharmacology* ; Osteogenesis/drug effects* ; Periodontitis/metabolism* ; Rats ; Periodontal Ligament/cytology* ; Humans ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Stem Cells/drug effects* ; Interleukin-6/metabolism* ; Rats, Sprague-Dawley ; Interleukin-8/metabolism* ; Cells, Cultured ; MAP Kinase Signaling System/drug effects* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Male ; Phosphorylation ; Lipopolysaccharides ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Alkaline Phosphatase/metabolism*

OBJECTIVES: Investigating the protective effect of naringenin (NAR) on the osteogenic potential of human periodontal ligament stem cells (hPDLSCs) under oxidative stress and its related mechanisms. METHODS: The oxidative damage model of hPDLSCs was established using hydrogen peroxide (H₂O₂) andthe hPDLSCs were treated with different concentrations of NAR and 0.5 μmol/L forkhead box protein O-1 (FOXO1) inhibitor AS1842856. After that, the cell counting kit-8 (CCK8) was used to determine the optimal concentrations of H₂O₂ and NAR. The alkaline phosphatase (ALP) staining and real time fluorescent quantitative reverse transcription polymerase chain reaction (qRT-PCR) were employed to assess the expression of ALP, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) in hPDLSCs of each group. The enzyme-linked immunosorbent assay (ELISA) and 2',7'-dichlorofluorescin diacetate (DCFH-DA) staining were utilized to evaluate the expression of reactive oxygen species (ROS), malondialdehyde (MDA) and lactate dehydrogenase (LDH) in hPDLSCs. Meanwhile, qRT-PCR and western blot were used to detect the expression levels of FOXO1 and β-catenin, both are pathway related genes and proteins. RESULTS: H₂O₂ exposure led to an increase in oxidative damage in hPDLSCs, characterized by a rise in intracellular ROS levels and increased expression of MDA and LDH (P<0.05). At the same time, the osteogenic differentiation ability of hPDLSCs decreased, as evidenced by lighter ALP staining and reduced expression levels of osteogenic differentiation-related genes ALP, RUNX2 and OCN (P<0.05). Co-treatment with NAR alleviated the oxidative damage in hPDLSCs, enhanced their antioxidant capacity, and restored their osteogenic ability. The FOXO1 inhibitor AS1842856 downregulated the expression of β-catenin (P<0.05) and significantly diminished both the antioxidant effect of NAR and its ability to restore osteogenesis (P<0.05). CONCLUSIONS NAR can enhance the antioxidant capacity of hPDLSCs by activating the FOXO1/β-catenin signaling pathway within hPDLSCs, thereby mitigating oxidative stress damage and alleviating the loss of osteogenic capacity.
Humans ; Oxidative Stress/drug effects* ; Periodontal Ligament/cytology* ; Hydrogen Peroxide ; Forkhead Box Protein O1/metabolism* ; Stem Cells/cytology* ; Flavanones/pharmacology* ; beta Catenin/metabolism* ; Osteogenesis/drug effects* ; Signal Transduction ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Alkaline Phosphatase/metabolism* ; Osteocalcin/metabolism* ; Cells, Cultured ; Cell Differentiation/drug effects*

OBJECTIVE: To investigate the effect of periostin on hypoxia-induced oxidative stress and apoptosis in human periodontal ligament fibroblasts and the molecular mechanism involved. METHODS: cultured human periodontal ligament fibroblasts were placed in an anaerobic gas-producing bag for hypoxia treatment for 48 h followed by treatment with periostin at low (25 ng/mL), moderate (50 ng/mL) or high (100 ng/mL) doses. MTT assay was used to measure the cell viability, and the cell apoptosis rate was determined using flow cytometry. The contents of IL-1β, IL-6 and TNF-α in the cells were determined with ELISA, and ROS levels were measured using a fluorescent plate reader. The intracellular SOD activity was detected using ELISA. The expressions of HIF-1α, P21, cyclin D1, Bax, cleaved caspase-3, Bcl-2, P38MAPK and p-p38 MAPK proteins in the cells were detected with Western blotting. RESULTS: Hypoxia treatment significantly reduced the cell viability ( < 0.05), increased P21, Bax, and cleaved caspase-3 protein levels ( < 0.05), promoted cell apoptosis ( < 0.05), and decreased cyclin D1 and Bcl-2 protein levels ( < 0.05) in the cells. Compared with the hypoxic group, the cells treated with periostin at different concentrations showed significantly increased cell viability ( < 0.05) with significantly lowered apoptotic rates ( < 0.05) and decreased expression levels of Bax and cleaved caspase-3 ( < 0.05) but significantly increased expression levels of cyclin D1 and Bcl-2 ( < 0.05). Hypoxic exposure of the cells resulted in significantly increased expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and increased levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) but decreased SOD activity ( < 0.05). Periostin treatment at different concentrations significantly lowered the expression levels of HIF-1α and p-p38 MAPK ( < 0.05) and the levels of IL-1β, IL-6, TNF-α and ROS ( < 0.05) and significantly increased SOD activity in the hypoxic cells ( < 0.05). CONCLUSIONS Periostin promotes the proliferation, inhibits apoptosis, enhances cellular antioxidant capacity, and reduces inflammatory damage in human periodontal ligament fibroblasts exposed to hypoxia possibly by inhibiting the activation of the p38 MAPK signaling pathway.
Apoptosis ; drug effects ; Cell Adhesion Molecules ; administration & dosage ; Cell Hypoxia ; Fibroblasts ; drug effects ; Humans ; Oxidative Stress ; drug effects ; Periodontal Ligament ; cytology ; Signal Transduction ; drug effects ; p38 Mitogen-Activated Protein Kinases

Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years. Human β-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 (hPDLCs) on osteogenic differentiation. In this study, we evaluated the osteogenic effects of hPDLCs with an adenoviral vector encoding human β-defensin 3 in an inflammatory microenvironment. Then human β-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 human β-defensin 3 gene-modified hPDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition. Furthermore, the p38 MAPK pathway was activated in this process. In vivo, human β-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 human β-defensin 3 accelerates osteogenesis and that human β-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.
Animals ; Anti-Infective Agents ; metabolism ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Humans ; Osteogenesis ; drug effects ; Periodontal Ligament ; drug effects ; metabolism ; Periodontitis ; drug therapy ; Rats ; Rats, Sprague-Dawley ; beta-Defensins ; metabolism ; pharmacology

The interplay between mechanoresponses and a broad range of fundamental biological processes, such as cell cycle progression, growth and differentiation, has been extensively investigated. However, metabolic regulation in mechanobiology remains largely unexplored. Here, we identified glucose transporter 1 (GLUT1)-the primary glucose transporter in various cells-as a novel mechanosensitive gene in orthodontic tooth movement (OTM). Using an in vivo rat OTM model, we demonstrated the specific induction of Glut1 proteins on the compressive side of a physically strained periodontal ligament. This transcriptional activation could be recapitulated in in vitro cultured human periodontal ligament cells (PDLCs), showing a time- and dose-dependent mechanoresponse. Importantly, application of GLUT1 specific inhibitor WZB117 greatly suppressed the efficiency of orthodontic tooth movement in a mouse OTM model, and this reduction was associated with a decline in osteoclastic activities. A mechanistic study suggested that GLUT1 inhibition affected the receptor activator for nuclear factor-κ B Ligand (RANKL)/osteoprotegerin (OPG) system by impairing compressive force-mediated RANKL upregulation. Consistently, pretreatment of PDLCs with WZB117 severely impeded the osteoclastic differentiation of co-cultured RAW264.7 cells. Further biochemical analysis indicated mutual regulation between GLUT1 and the MEK/ERK cascade to relay potential communication between glucose uptake and mechanical stress response. Together, these cross-species experiments revealed the transcriptional activation of GLUT1 as a novel and conserved linkage between metabolism and bone remodelling.
Animals ; Biomechanical Phenomena ; Blotting, Western ; Bone Remodeling ; drug effects ; Cells, Cultured ; Glucose Transporter Type 1 ; antagonists & inhibitors ; genetics ; Humans ; Hydroxybenzoates ; pharmacology ; Immunohistochemistry ; MAP Kinase Signaling System ; drug effects ; Mice ; Mice, Inbred C57BL ; Osteoprotegerin ; metabolism ; Periodontal Ligament ; cytology ; RANK Ligand ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Tooth Movement Techniques ; Transcriptional Activation

OBJECTIVETo investigate the effects of small interfering RNA (siRNA) targeting YAP on the proliferation and apoptosis of human periodontal ligament stem cells (hPDLSCs).

METHODSSynthesized sequences of siRNA were transfected into hPDLSCs by Lipofectamine™ 2000. The expression of YAP was identified by using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Proliferation activity was detected by using cell counting kit-8 (CCK-8). Changes in the cell cycle and apoptosis rate were detected by using flow cytometry. Results were analyzed by using SPSS 19.0, and P < 0.05 was considered statistically significant.

RESULTSExpression of YAP mRNA and protein were significantly downregulated after 48 h of transfection (P < 0.001). No obvious difference was found in the expression levels of YAP protein between 48 and 72 h, thus indicating that siRNA could inhibit the expression of YAP persistently and effectively. Proliferation activity was inhibited, and apoptosis rate was increased. Cell cycle was changed as the proportion of G₁and S phases increased (P < 0.01) and G₂ phase decreased (P < 0.05).

CONCLUSIONKnocking down YAP gene by siRNA could inhibit proliferation activity, induce apoptosis, and change the cell cycle of hPDLSCs. Thus, YAP could regulate the proliferation and apoptosis of hPDLSCs.

Adaptor Proteins, Signal Transducing ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Down-Regulation ; Humans ; Periodontal Ligament ; drug effects ; Phosphoproteins ; RNA, Messenger ; RNA, Small Interfering ; pharmacology ; Stem Cells ; drug effects ; Transfection

OBJECTIVETo evaluate the effects of ginsenoside Rg-1 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and to explore the possible application on the alveolar bone regeneration.

METHODSTo determine the optimum concentration, the effects of ginsenoside Rg-1 ranging from 10 to 100 μmol/L were evaluated by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide, alkaline phosphatase activity and calcium deposition. Expressions of runt-related transcription factor 2, collagen alpha-2(I) chain, osteopontin, osteocalcin protein were examined using real-time polymerase chain reaction.

RESULTSCompared with the control group, a certain concentration (10 μmol/L) of the Rg-1 solution significantly enhanced the proliferation and osteogenic differentiation of hPDLSCs (P<0.05). However, concentrations that exceeds 100 μmol/L led to cytotoxicity whereas concentrations below 10 nmol/L showed no significant effect as compared with the control.

CONCLUSIONGinsenoside Rg-1 can enhance the proliferation and osteogenic differentiation of hPDLSCs at an optimal concentration of 10 μmol/L.

Adolescent ; Alkaline Phosphatase ; metabolism ; Biomarkers ; metabolism ; Calcification, Physiologic ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cell Separation ; Cell Shape ; drug effects ; Cells, Cultured ; Flow Cytometry ; Ginsenosides ; pharmacology ; Humans ; Osteoblasts ; drug effects ; metabolism ; Osteogenesis ; drug effects ; genetics ; Periodontal Ligament ; cytology ; Real-Time Polymerase Chain Reaction ; Stem Cells ; cytology ; drug effects ; enzymology ; Time Factors ; Young Adult

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 (hPDLCs). The hPDLCs 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.
Actins ; analysis ; drug effects ; Adult ; Animals ; Biomechanical Phenomena ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cells, Cultured ; Cellular Microenvironment ; physiology ; Humans ; Male ; Myofibroblasts ; physiology ; Orthodontic Wires ; Periodontal Ligament ; chemistry ; cytology ; Pressure ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical ; Tenascin ; analysis ; drug effects ; Time Factors ; Tooth Movement Techniques ; instrumentation ; Transforming Growth Factor beta1 ; pharmacology