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@#Periodontal ligament stem cells (PDLSCs) have the potential for multidirectional differentiation and are the preferred seed cells for periodontal tissue regeneration. In recent years, a large number of studies have confirmed that PDLSCs also possess broad immunomodulatory properties. Therefore, in-depth exploration of their specific molecular mechanisms is of great significance for the treatment of periodontitis. The aim of this paper is to summarize the research progress on the regulation of PDLSCs on various immune cells and the effect of the inflammatory environment on the immune characteristics of PDLSCs to provide an important theoretical basis for the allotransplantation of PDLSCs and improve the therapeutic effect of periodontal tissue regeneration. Studies have shown that PDLSCs possess a certain degree of immunosuppressive effect on both innate and acquired immune cells, and inflammatory stimulation may lead to the impairment of the immunoregulatory properties of PDLSCs. However, current studies are mainly limited to in vitro cell tests and lack in-depth studies on the immunomodulatory effects of PDLSCs in vivo. In vivo studies based on cell lineage tracing and conditional gene knockout technology may become the main directions for future research.
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The present study aimed to compare the adhesion and proliferation of human periodontal ligament fibroblasts (hPDL) in transverse sections of the teeth sealed with two different obturation techniques, BioRoot RCS/hydraulic obturation (HO) and AH-Plus/continuous-wave condensation (CWC). The techniques were tested using an in vitro model to simulate the interaction between periodontal tissues and the materials. The root canals were instrumented and sterilized. A total of 15 samples were obturated with BioRoot RCS/HO and 15 samples with AH-Plus/CWC. Then, roots were sectioned to obtain obturated teeth slices, and hPDL cells were seeded onto the root slices. The results were obtained at intervals of 4 and 24h for cell adhesion; and at 3,7,14, and 21 days for cell proliferation. Empty cell culture plates were use as controls. The cell adhesion was increased at 4 and 24h for both groups, with an increased response observed in the BioRoot RCS/HO group (p<0.05). The difference in cell proliferation was also found between experimental groups. After 14 days of culture, BioRoot RCS/HO group showed an increase response than control and AH-Plus/CWC groups (p<0.05), and after 21 days both groups behaved better than control group, with an increased response observed in the BioRoot RCS/HO group. This study demonstrated that both root canal sealers allow the attach and growth of periodontal ligament fibroblasts, with an increased biological response in the BioRoot RCS/HO group.
El presente estudio se enfocó en comparar la adhesión y proliferación de fibroblastos de ligamento periodontal humano (hPDL) en secciones transversales de raíces previamente obturadas con dos técnicas de obturación diferentes: obturación hidráulica empleando cono único de gutapercha y BioRoot RCS como sellador (HO), y obturación de condensación de onda continua y AH-Plus como sellador (CWC). Los selladores se usaron en un modelo in vitro que simula la interacción entre los tejidos periodontales y los materiales de obturación. Los conductos radiculares fueron instrumentados, esterilizados y obturados. La muestra se compuso de un total de 15 raíces con la técnica BioRoot RCS/HO y 15 raíces con la técnica AH-Plus/CWC. Las células de hPDL fueron sembradas en condiciones estándar de cultivo sobre las raíces seccionadas. Los resultados fueron obtenidos a intervalos de 4 y 24h para adhesión celular, y a los 3,5,7,14 y 21 días de cultivo para proliferación celular. La adhesión celular a las 4 y 24 horas mostró ser diferente para ambas técnicas en comparación con el grupo control, siendo más importante en el grupo BioRoot RCS/HO. La diferencia en la proliferación entre grupos se observó a los 14 días de cultivo, únicamente para el grupo BioRoot RCS/HO; Sin embargo para el día 21 ambas técnicas mostraron mayor proliferación celular que el grupo control, con mejor respuesta para el grupo BioRoot RCS/HO. Este estudio ha demostrado que ambos selladores de conductos permiten la adhesión y crecimiento de fibroblastos de ligamento periodontal, siendo el grupo BioRoot RCS/HO el que mostró mayor biocompatibilidad.
Subject(s)
Humans , Pit and Fissure Sealants/analysis , Materials Testing , Periodontal Ligament , Receptors, Aryl HydrocarbonABSTRACT
Objective@# To explore the effects of red LED light mediated by the Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (KEAP1-NRF2/HO-1) pathway on osteogenic differentiation and oxidative stress damage of human periodontal ligament stem cells (hPDLSCs) induced by high glucose, which provides a basis for the application of red light-emitting diode (LED) light in cell antioxidative damage.@*Methods@#hPDLSCs were identified by flow cytometric analysis, alkaline phosphatase (ALP) staining and Alizarin red-S staining; hPDLSCs were pretreated in a high glucose environment for 48 hours and irradiated with 1, 3, or 5 J/cm2 red LED light. A CCK-8 assay was performed to choose the radiant exposure that had the strongest effect on promoting the cell proliferation rate for subsequent experiments. hPDLSCs were divided into a control group, a high glucose group and a high glucose+light exposure group. ALP staining, ALP activity, Alizarin red-S staining and quantitative calcified nodules were used to detect the osteogenic differentiation of hPDLSCs; qRT-PCR and Western blot were used to detect the gene and protein expression levels of ALP, runt-related transcription factor 2 (RUNX2) and osterix (OSX); the relative mRNA expression levels of antioxidant enzyme-related genes superoxide dismutase 2 (SOD2) and catalase (CAT) in hPDLSCs were detected by qRT-PCR; reactive oxygen species (ROS) levels were detected by fluorescence microscopy and flow cytometry; the tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels in cell supernatants were detected by ELISA; the NRF2-specific inhibitor ML385 was used to inhibit the NRF2 pathway; ALP staining and ALP activity were used to detect the markers of early osteogenic differentiation; qRT-PCR was used to detect the gene expression of ALP, RUNX2 and OSX; and the protein expression levels of KEAP1, NRF2 and HO-1 were detected by Western blot.@*Results @# Identified, and irradiant exposure of 5 J/cm2 was chosen for subsequent experiments. Red LED light irradiation (5 J/cm2) improved the osteogenic differentiation of hPDLSCs induced by high glucose (P<0.05), increased the mRNA and protein levels of ALP, RUNX2 and OSX (P<0.05), upregulated the mRNA expression levels of SOD2 and CAT (P<0.05), reduced the levels of ROS (P<0.05), and reduced TNF-α and IL-1β levels in the cell supernatants (P<0.05). When ML385 was added to inhibit the NRF2 pathway, the ALP activity of cells was decreased (P<0.05); the gene expression levels of ALP, RUNX2 and OSX were downregulated (P<0.05); the protein level of KEAP1 was upregulated (P<0.05); and the protein levels of NRF2 and HO-1 were downregulated (P<0.05)@*Conclusion@#Red LED light may promote the proliferation and osteoblastic differentiation of hPDLSCs induced by high glucose through the KEAP1-NRF2/HO-1 pathway and reduce the oxidative stress damage to hPDLSCs induced by high glucose.
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@#Ankylosis of primary molars is a kind of eruption abnormality of the teeth, where the periodontal membrane disappears, owing to a bony union between bone and root. Studies have shown that the common proportion of ankylosed primary molars is 1.3%~8.9% with an equal occurrence. In the primary dentition, the mandibular first primary molar is the most commonly affected tooth, while in the middle mixed dentition stage of development, the second primary molar is more affected. Its etiology may be related to genetics, signaling pathways of mineralization metabolism of local alveolar bone or cementum, cytokines secreted by epithelial rest cells of Malassez, and enhanced inflammatory reactions during physiological absorption of roots. Ankylosis of primary molars can be diagnosed by clinical symptoms and imaging and is classified as mild, moderate and severe according to the degree of infraocclusion. As it may cause a series of complications, such as occlusal disturbances, delayed exfoliation and incomplete alveolar process development, multidisciplinary treatment, including in the departments of pediatric dentistry, orthodontics, periodontics and prosthodontics, should be adopted, and long-term treatment is determined based on the patient's age, severity of infraocclusion, and presence of permanent teeth. This review summarizes the etiology, diagnosis, complications and treatment of ankylosed primary molars to provide a reference for the clinical diagnosis and treatment of decidual molar fixation.
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Periodontitis is a complex chronic inflammatory disease. The invasion of pathogens induces the inflammatory microenvironment in periodontitis. Cell behavior changes in response to changes in the microenvironment, which in turn alters the local inflammatory microenvironment of the periodontium through factors secreted by cells. It has been confirmed that periodontal ligament stem cells (PDLSCs) are vital in the development of periodontal disease. Moreover, PDLSCs are the most effective cell type to be used for periodontium regeneration. This review focuses on changes in PDLSCs, their basic biological behavior, osteogenic differentiation, and drug effects caused by the inflammatory microenvironment, to provide a better understanding of the influence of these factors on periodontal tissue homeostasis. In addition, we discuss the underlying mechanism in detail behind the reciprocal responses of PDLSCs that affect the microenvironment.
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Humans , Periodontal Ligament , Osteogenesis , Stem Cells , Periodontitis/metabolism , Cell Differentiation/physiology , Cells, CulturedABSTRACT
To compare the viability of periodontal ligament (PDL) cells stored in Hanks Balanced Salt Solution (HBSS) with those in readily available transport media over a variable period of time. Methods: Periodontal ligament cells harvested from premolars freshly extracted for orthodontic reasons were cultured for exponential growth. The cells were exposed to egg white, evaporated milk, water and Hanks Balanced Salt Solution (HBSS) at room temperature. Their viability was evaluated after 30 minutes, 1 hour and 3 hours with the tetrazolium salt-based colorimetric assay (MTT assay). Statistical analysis was done using the IBM® SPSS version 23.0 software. Comparison between the Mean Optical Densities (MODs) of the cells stored in HBSS and other media at each time interval was done using the independent t test. Repeated measure ANOVA and Tukey post-hoc test were also carried out to compare the MOD of cells within each medium over time. The level of significance was set at p <0.05. Result: The PDL cells stored in egg white had higher MODs than those in HBSS at 30 minutes and 1 hour. Conversely, the MODs of the cells stored in milk and water were lower than those in HBSS at all the studied points. There was a significant difference in the viability of the cells stored in HBSS and water at all the time points (p<0.05). Conclusion: For up to an hour, egg white was found to perform better than HBSS in supporting the viability of PDL cell
Subject(s)
Periodontal Ligament , Tooth Avulsion , Milk , Egg White , Saline SolutionABSTRACT
Abstract Protease-activated receptor-2 (PAR2) is associated with the pathogenesis of many chronic diseases with inflammatory characteristics, including periodontitis. This study aimed to evaluate how the activation of PAR2 can affect the osteogenic activity of human periodontal ligament stem cells (PDLSCs) in vitro. PDLSCs collected from three subjects were treated in osteogenic medium for 2, 7, 14, and 21 days with trypsin (0.1 U/mL), PAR2 specific agonist peptide (SLIGRL-NH2) (100 nM), and PAR2 antagonist peptide (FSLLRY-NH2) (100 nM). Gene (RT-qPCR) expression and protein expression (ELISA) of osteogenic factors, bone metabolism, and inflammatory cytokines, cell proliferation, alkaline phosphatase (ALP) activity, alizarin red S staining, and supernatant concentration were assessed. Statistical analysis of the results with a significance level of 5% was performed. Activation of PAR2 led to decreases in cell proliferation and calcium deposition (p < 0.05), calcium concentration (p < 0.05), and ALP activity (p < 0.05). Additionally, PAR2 activation increased gene and protein expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) (p < 0.05) and significantly decreased the gene and protein expression of osteoprotegerin (p <0. 05). Considering the findings, the present study demonstrated PAR2 activation was able to decrease cell proliferation, decreased osteogenic activity of PDLSCs, and upregulated conditions for bone resorption. PAR2 may be considered a promising target in periodontal regenerative procedures.
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OBJECTIVES@#This study aimed to clarify the effects of Foxp3 silencing on the expression of inflammatory cytokines in human periodontal ligament cells (hPDLFs) in an inflammatory environment and on cell proliferation and invasiveness, as well as to explore the role of Foxp3 gene in the development of periodontitis.@*METHODS@#An small interfering RNA (siRNA) construct specific for Foxp3 was transfected into hPDLFs. Foxp3 silencing efficiency was verified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, and the siRNA with the optimum silencing effect of Foxp3 gene was screened. Using lipopolysaccharide to simulate an inflammatory environment in vitro, CCK-8 detected the effect of silencing Foxp3 on hPDLFs proliferation under inflammatory conditions. Wound-healing experiments and transwell assays were conducted to detect the effect of silencing Foxp3 on hPDLF migration under inflammatory conditions. The expression of the inflammatory cytokines interleukin (IL)-6 and IL-8 was detected by RT-PCR and Western blotting under inflammatory conditions.@*RESULTS@#After siRNA transfection, RT-PCR and Western blotting analyses showed that the expression of Foxp3 mRNA in the Foxp3-si3 group decreased significantly (t=21.03, P<0.000 1), and the protein expression of Foxp3 also decreased significantly (t=12.8, P<0.001). In the inflammatory environment, Foxp3 gene silencing had no significant effect on hPDLFs proliferation (P>0.05), and Foxp3 gene silencing promoted hPDLFs migration (P<0.05). Moreover, the expression of IL-6 and IL-8 increased (P<0.05).@*CONCLUSIONS@#In an inflammatory environment, Foxp3 gene silencing promoted hPDLFs migration but had no significant effect on hPDLFs proliferation. The expression of inflammatory factors expressed in hPDLFs increased after Foxp3 gene silencing, indicating that Foxp3 gene inhibited inflammation in periodontitis.
Subject(s)
Humans , Cell Proliferation/genetics , Cells, Cultured , Cytokines/metabolism , Fibroblasts/metabolism , Forkhead Transcription Factors/metabolism , Gene Silencing , Interleukin-6/metabolism , Interleukin-8/metabolism , Periodontal Ligament/metabolism , Periodontitis/metabolism , RNA, Small Interfering/metabolism , Transcription Factors/metabolismABSTRACT
OBJECTIVES@#This work aimed to investigate the molecular mechanism of cyclic tensile stress (CTS) stimulating autophagy in human periodontal ligament cells (hPDLCs).@*METHODS@#hPDLCs were isolated and cultured from normal periodontal tissues. hPDLCs were loaded with tensile stress by force four-point bending extender to simulate the autophagy of hPDLCs induced by orthodontic force du-ring orthodontic tooth movement. XMU-MP-1 was used to inhibit the Hippo signaling pathway to explore the role of the Hippo-YAP signaling pathway in activating hPDLC autophagy by tensile stress. The expression levels of autophagy-related genes (Beclin-1, LC3, and p62) in hPDLCs were detected by real-time quantitative polymerase chain reaction. Western blot was used to detect the expression levels of autophagy-related proteins (Beclin-1, LC3-Ⅱ/LC3-Ⅰ, and p62) and Hippo-YAP pathway proteins (active-YAP and p-YAP) in hPDLCs. Immunofluorescence was used to locate autophagy-related proteins (LC3-Ⅱand p62) and Hippo-YAP pathway proteins (active-YAP) of hPDLCs.@*RESULTS@#CTS-activated autophagy in hPDLCs and expression of autophagy-related proteins initially increased and then decreased; it began to increase at 30 min, peaked at 3 h, and decreased (P<0.05). CTS increased the expression of active-YAP protein and decreased the expression of p-YAP protein (P<0.05). When XMU-MP-1 inhibited the Hippo-YAP signaling pathway (P<0.05), active-YAP protein was promoted to enter the nucleus and autophagy expression was enhanced (P<0.05).@*CONCLUSIONS@#The Hippo-YAP signaling pathway is involved in the regulation of autophagy activation in hPDLCs under CTS.
Subject(s)
Humans , Hippo Signaling Pathway , Periodontal Ligament/metabolism , Beclin-1/metabolism , Cells, Cultured , AutophagyABSTRACT
OBJECTIVES@#This study aimed to investigate how naringenin (Nar) affected the anti-inflammatory, vascula-rization, and osteogenesis differentiation of human periodontal ligament stem cells (hPDLSCs) stimulated by lipopolysaccharide (LPS) and to preliminarily explore the underlying mechanism.@*METHODS@#Cell-counting kit-8 (CCK8), cell scratch test, and Transwell assay were used to investigate the proliferation and migratory capabilities of hPDLSCs. Alkaline phosphatase (ALP) staining, alizarin red staining, lumen-formation assay, enzyme-linked immunosorbent assay, quantitative timed polymerase chain reaction, and Western blot were used to measure the expression of osteopontin (OPN), Runt-related transcription factor 2 (RUNX2), vascular endothlial growth factor (VEGF), basic fibroblast growth factor (bFGF), von Willebrand factor (vWF), tumor necrosis factor-α (TNF-α), and interleukin (IL)-6.@*RESULTS@#We observed that 10 μmol/L Nar could attenuate the inflammatory response of hPDLSCs stimulated by 10 μg/mL LPS and promoted their proliferation, migration, and vascularization differentiation. Furthermore, 0.1 μmol/L Nar could effectively restore the osteogenic differentiation of inflammatory hPDLSCs. The effects of Nar's anti-inflammatory and promotion of osteogenic differentiation significantly decreased and inflammatory vascularization differentiation increased after adding AMD3100 (a specific CXCR4 inhibitor).@*CONCLUSIONS@#Nar demonstrated the ability to promote the anti-inflammatory, vascularization, and osteogenic effects of hPDLSCs stimulated by LPS, and the ability was associated with the stromal cell-derived factor/C-X-C motif chemokine receptor 4 signaling axis.
Subject(s)
Humans , Anti-Inflammatory Agents/pharmacology , Cell Differentiation , Cell Proliferation , Cells, Cultured , Chemokine CXCL12 , Lipopolysaccharides/pharmacology , Osteogenesis , Periodontal Ligament/metabolism , Receptors, Chemokine/metabolism , Stem Cells , Interleukin-8/metabolismABSTRACT
OBJECTIVE To explore the regulatory effects of baicalin on the proliferation and migration of human periodontal ligament stem cells （hPDLSCs） induced by lipopolysaccharide （LPS） and Janus protein tyrosine kinase 2 （JAK2）/signal transduction and transcription activator 3 （STAT3） signaling pathways. METHODS hPDLSCs were divided into control group， LPS group， different concentration baicalin groups （0.1， 1 and 10 mg/L）. ELISA method and CCK-8 assay were used to determine the contents of cell inflammatory factors [interleukin 6 （IL-6）， IL-1β and tumor necrosis factor-α （TNF-α）] and cell viability， so as to screen the optimal concentration of baicalin for follow-up pathway validation experiments. The cells were then divided into control group， LPS group， optimal baicalin concentration group and inhibitor group （10 μg/mL LPS+1 mg/L baicalin +3 μmol/L JAK2/STAT3 pathway inhibitor AG490）. After treated for 24 h， the proliferation rate of hPDLSCs， apoptosis rate， migration rate， invasion cell number， mRNA and protein expressions of Cyclin D1 and caspase-3， the expression of JAK2/STAT3 pathway-related proteins were all detected. RESULTS According to cell inflammatory factors and cell viability， 1 mg/L was selected as the optimal concentration of baicalin. Compared with control group， cell proliferation rate， migration rate， invasion cell number， Cyclin D1 mRNA and protein expression were significantly decreased in LPS group， while cell apoptosis rate， caspase-3 mRNA and protein expression， p-JAK2 and p-STAT3 protein expression were significantly increased （P＜0.05）. After treated with 1 mg/L baicalin， the above indexes were reversed significantly （P＜0.05）. The improvement of above indexes in the inhibitor group was more obvious （P＜0.05）. CONCLUSIONS Baicalin can promote the proliferation， migration and invasion of LPS-induced hPDLSCs and inhibit their apoptosis and inflammation by blocking the JAK2/STAT3 pathway.
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Context: The proliferation and differentiation of human periodontal ligament stem cells (hPDLSC) into other cell types are also mediated by mechanical stresses; they might offer therapeutic benefits in tissue regeneration and angiogenesis. Objectives: The study was planned to assess the proliferation, clonogenic potential, and osteogenic differentiation of human periodontal ligament stem cells (PDLSC) following the application of light and heavy orthodontic forces. Materials and Methods: A couple forces of 50 gm (light force) were applied on the 1st premolar on the one side and 250 gm (heavy force) on the contralateral side in the upper arch of patients requiring orthodontic treatment with extraction of all 1st premolars. After 30 days, periodontal tissues were scrapped from extracted teeth for the establishment of PDLSC in vitro. PDLC from the lower premolar teeth where no orthodontic force was applied acted as the control group. Morphology, viability, proliferating rate and population doubling time, clonogenicity, and alkaline phosphatase activity were analysed. Result: The osteogenic potential was confirmed by Alizarin red staining and the expression of the osteogenic markers by qRT?PCR. The morphology, growth kinetics, potency, and osteogenic lineage characteristics inferred the application of high force reduced the proliferative ability and osteogenesis of PDLSC, though the difference was not significant. Conclusion: The established PDLSCs demonstrated their MSC?like properties based on morphology, growth kinetics, colony forming ability, and AP activity. The culture?expanded PDLSCs showed their differentiation potential into osteocytes. The application of high force reduced the proliferative ability and osteogenesis of PDLSCs, variations were not significant.differentiation
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Background: A number of media that create the best possible conditions to maintain periodontal ligament (PDL) cell viability after dental avulsion have been reported. Aim: The aim of this study is to evaluate ice apple water (IAW), Aloe vera, and propolis as a storage medium to preserve the viability of human PDL fibroblasts. Methods: An in vitro comparative type of study was performed on a PDL cell culture model. PDL fibroblasts obtained from the roots of healthy premolars were cultured in Dulbecco's Modified Eagle's Medium (DMEM) and treated with ice apple water (IAW), 7% propolis extract (PE), 30% Aloe vera extract (AVE), positive control DMEM supplemented with fetal bovine serum, negative control (NC) without any agent, and incubated at 37°C for 1 h, 3 h, and 24 h. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay after every test period. Optical density was measured at a wavelength of 490 nm. Statistical Analysis Used: The effects of the test storage media were evaluated by one-way analysis of variance test, followed by post hoc Tukey's multiple comparison test (P < 0.05). Results: Seven percent PE demonstrated the highest capacity of maintaining PDL cell viability at 1 h and 24 h. IAW showed a statistically significantly lower percentage of viable cells at all three test periods as compared to 7% PE. After 3 h, 30% AVE demonstrated maximum viable cells. Conclusions: Within the limitations of this study, propolis at a concentration of 7% was the most effective medium for maintaining PDL cell viability.
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Abstract This study was conducted to assess the in vitro response of human periodontal ligament stem cells (hPDLSCs) to bacterial lipopolysaccharide (LPS) activation and application of three calcium silicate-based materials (CSBM): Bio-C Sealer, MTA Fillapex and Cimmo HP. Characterization of the CSBM was performed by FTIR (n = 3). Extracts of Bio-C Sealer, MTA Fillapex and Cimmo HP were prepared and diluted (1:1, 1:4 and 1:16). Culture of hPDLSCs was established and treated or not with LPS from Escherichia coli (1 µg/mL) for 7 days. MTT assay was used to assess cell viability at 24, 48 and 72 h (n = 9). Alkaline phosphatase (ALP) activity was indirectly assayed at day 7 (n = 5). TNF-α and Il -1 0 cytokines were quantified by ELISA at 24h-cell supernatants (n = 6). Data were analyzed by ANOVA and Tukey's test (α = 0.05). The cell viability of the LPS-activated hPDLSCs were higher than untreated control (p < 0.05). The application of CSBM affected the cell viability of untreated and LPS-activated cells (p < 0.05). ALP activity was higher for Bio-C Sealer and Cimmo HP in untreated and LPS-activated cells, respectively (p < 0.05). Application of CSBM normalized the TNF-α secretion in the LPS-activated cells (p < 0.05). Only MTA Fillapex in untreated hPDLSCs presented higher values of Il -1 0 (p < 0.05). Taken collectively, the results suggests that the simulation of the inflammatory process by LPS affect the in vitro response the hPDLSCs to the application of the CSBM.
Resumo Este estudo objetivou avaliar a resposta in vitro de células-tronco do ligamento periodontal humano (hPDLSCs) à ativação por lipopolissacarídeo bacteriano (LPS) e aplicação de três materiais à base de silicato de cálcio (CSBM): Bio-C Sealer, MTA Fillapex e Cimmo HP. A caracterização dos CSBM foi realizada por FTIR (n = 3). Extratos de Bio-C Sealer, MTA Fillapex e Cimmo HP foram preparados e diluídos (1:1, 1: 4 e 1:16). A cultura de hPDLSCs foi estabelecida e tratada ou não com 1 µg / mL de LPS de Escherichia coli por 7 dias. O ensaio de MTT foi usado para avaliar a viabilidade celular em 24, 48 e 72 h (n = 9). A atividade de ALP foi avaliada indiretamente no dia 7 (n = 5). As citocinas TNF-α e Il-10 foram quantificadas por ELISA em sobrenadantes de células em 24h (n = 6). Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). A viabilidade celular das hPDLSCs ativados por LPS foi maior do que o controle (p <0,05). A aplicação dos CSBM afetou a viabilidade celular de células ativadas ou não por LPS (p <0,05). A atividade de ALP foi maior para Bio-C Sealer e Cimmo HP em células não ativadas e ativadas por LPS, respectivamente (p <0,05). A aplicação dos CSBM normalizou a secreção de TNF-α nas células ativadas por LPS (p <0,05). Apenas o MTA Fillapex em hPDLSCs não ativadas apresentou valores mais elevados de Il-10 (p <0,05). Em conclusão, os resultados sugerem que a simulação do processo inflamatório por LPS afetou a resposta in vitro de células-tronco do ligamento periodontal e de materiais à base de silicato de cálcio.
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Abstract Objectives Diabetes has been strongly associated with periodontal diseases. The periodontal ligament (PDL) has an abundant extracellular matrix (ECM). Lysyl oxidases (LOXs) are closely associated with various diseases caused by abnormal ECM functions, however, the role of LOXs in periodontal diseases induced by diabetes remains unclear. Methodology In this study, 8-week-old Zucker diabetic fatty rats were used to establish a type 2 diabetes mellitus (T2DM) model. After 9 and 16 weeks, hematoxylin and eosin (H&E), Masson's trichrome, and immunohistochemical staining were performed. Results After 9 weeks, loose collagen fibers were found in the interradicular area of the diabetic group, in opposition to the control group. There were no significant differences in LOX expression between the diabetic and control groups (p>0.05). However, after 16 weeks, the diabetic group presented a disordered arrangement of the PDL, showing decreased collagen content and significantly increased lysyl oxidase-like protein 3 (LOXL3) expression when compared with the control group (p<0.05). This suggests that LOXL3 plays a significant role in periodontal histopathological changes in diabetic rats. Conclusion Our study showed elevated LOXL3 expression in the PDL of diabetic rats after 16 weeks, suggesting that LOXL3 may be involved in the occurrence and development of periodontal histopathological changes in diabetic rats. LOXL3 could be further used as an indicator for the early diagnosis of diabetic periodontitis in T2DM patients in clinical settings.
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ABSTRACT Objective To compare the cytotoxicity of commercial reparative endodontic cements on human periodontal ligament stem cells (hPDLSCs). Material and Methods The culture of hPDLSCs was established. Cell density was set at 2 × 104 cells/well in 96-well plates. Extracts of Biodentine, Bio-C Repair, Cimmo HD, MTA Repair HP and White MTA were prepared. Then, the extracts were diluted (pure, 1:4 and 1:16) and inserted into cell-seeded wells for 24, 48, and 72 h to assess cell viability through MTT assay. hPDLSCs incubated with culture medium alone served as a negative control group. Data were analyzed by Two-Way ANOVA and Tukey's test (α=0.05). Results At 24 h, pure extract of MTA Repair HP and Biodentine 1:16 presented higher cell viability compared to control. Lower cell viability was found for pure extract of Cimmo HD, MTA Repair HP 1:4 and 1:16, and White MTA 1:16. At 48 h, pure extract of Bio-C Repair and MTA Repair HP presented higher cell viability compared to control. At 72 h, only the pure extract of MTA Repair HP led to higher cell proliferation compared to control. Conclusion Biodentine, Bio-C Repair and MTA Repair HP were able to induce hPDLSCs proliferation. Cimmo HD and White MTA were found to be mostly cytotoxic in hPDLSCs.
Subject(s)
Periodontal Ligament/anatomy & histology , Root Canal Filling Materials , Stem Cells/immunology , Cytotoxicity Tests, Immunologic/instrumentation , Dental Cements , Immunologic Tests/instrumentation , Brazil , Cell Count , Analysis of Variance , Endodontics , Primary Cell CultureABSTRACT
@#Introduction: The cryopreservation of periodontal ligament stem cells (PDLSCs) required a good combination of CPA composition as a step in the preparation of PDLSCs. This study aimed to analyze the proliferative capacities and differentiation potentials of PDLSCs after slow-freezing cryopreservation with CPA in different combinations. Methods: The fourth passage of the primary PDL cells were examined their fibroblast-like morphology and colony forming unit-fibroblast (CFU-F), and characterized by surface markers for mesenchymal stem cells using flow cytometry. PDLSCs were divided into two groups of freshly-PDLSCs (fPDLSCs) and cryopreserved-PDLSCs (cPDLSCs). The PDLSCs were cryopreserved using slow freezing method with CPA in different combinations: 1) 90%FBS+10%DMEM (FD-group), 2) 90%DMEM+10%DMSO (DDs-group), 3) 90%FBS+10%DMSO (FDs-group), and 4) 100% Cell Banker (CB-group) as positive control. The proliferation of fPDLSCs and cPDLSCs were evaluated by trypan blue dye exclusion method. The multipotency of cells was assessed by Oil Red O, Alizarin Red, and Alcian Blue staining. Results: The primary PDL cells had fibroblast-like morphology and CFU-F ability. They expressed more than 95% positive MSC surface markers of CD90, CD73, CD150, and CD44, but showed less than 2% hematopoietic cell markers of CD11b/CD19/CD34/CD45 and HLA-DR. The cPDLSCs viability of FDs-group was 81.5% and 80% in -80oC and LN2, respectively. The fPDLSCs and cPDLSCs proliferation and doubling time were no statistically significant difference (p>0.05). They could differentiate into adipogenic, osteogenic, and chondrogenic differentiation. Conclusion: The cPDLSCs could maintain their proliferative capacities and differentiation potentials after slow-freezing cryopreservation with 90%FBS+10%DMSO in -80oC.
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@#Basic fibroblast growth factor (bFGF) exhibits superior biological functions by improving periodontal inflammation, promoting the migration and proliferation of periodontal-related stem cells, promoting the formation of blood vessels and periodontal ligament-like tissue, and regulating the formation of bone/cementum. It plays an important role in tooth development, repair and regeneration. bFGF can be combined with seed cells and scaffold materials for periodontal tissue regeneration, which has been verified in a number of experimental studies. However, the application of bFGF alone as a drug in clinical treatment requires further research.
ABSTRACT
Objective @# The purpose of this study was to clarify the regulatory effect and mechanism of Src homology-2 domain containing protein tyrosine phosphatase-2 (SHP2) on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation under inflammatory environment and to provide a new target for the treatment of periodontitis. @*Methods@#SHP2 was knocked down in hPDLSCs, and the transfection efficiency of SHP2 was detected by RT-qPCR and Western blot. An in vitro inflammatory environment was created using tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). The effect of SHP2 knockdown on hPDLSC viability under normal and inflammatory conditions was detected by CCK-8, and the osteogenic capacity of hPDLSCs under normal and inflammatory conditions was detected by ALP staining, ALP activity, ARS staining, RT-qPCR and Western blot. The mechanism by which SHP2 knockdown affected the MAPK pathway and its downstream NF-κB pathway under inflammatory conditions was assessed by Western blot. @*Results@# Green fluorescence was observed after transfection for 72 h, and the titer of SHP2 shRNA recombinant lentivirus was 2.9×108 TU/mL. SHP2 expression was significantly downregulated in lentivirus-transfected cells, as demonstrated by Western blot and RT-qPCR (P<0.001). SHP2 knockdown inhibited hPDLSC proliferation to a certain extent and increased the expression of early osteogenic markers under normal conditions, including increased ALP activity and increased ALP and COL-1 expression (P<0.05). However, SHP2 knockdown exerted no effect on mineralized nodule formation. In the TNF-α- and IL-1β-induced inflammatory environment, SHP2 knockdown exerted no effect on hPDLSC proliferation (P>0.05). Osteogenic markers were upregulated (P<0.05), and mineralized nodules were significantly increased (P<0.05) after SHP2 knockdown. Western blot analysis showed that p65 phosphorylation and IκB-α degradation were reduced in SHP2-knockdown hPDLSCs in the inflammatory environment. Moreover, SHP2 knockdown significantly inhibited the expression of p-p38 and p-JNK MAPK, which represent pathways upstream of the NF-κB pathway (P<0.05). @*Conclusion @# SHP2 knockdown did not affect cell viability but promoted the osteogenic potential of hPDLSCs by inhibiting the MAPK/NF-κB-mediated signaling pathway under inflammatory environment.
ABSTRACT
Objective @#To investigate the effect of silencing histone deacetylase 9 (HDAC9) expression on the proliferation and osteogenic differentiation of periodontal ligament stem cells (PDLSCs).@*Methods@# PDLSCs were isolated, cultured and identified in vitro. An siRNA construct specific for HDAC9 was transfected into PDLSCs (siHDAC9 group), and a nontargeting siRNA was used as a control (siNC group). The interference effect was determined by qRT-PCR. The cell cycle progression of PDLSCs was detected using flow cytometry. The proliferation activity of PDLSCs was detected via CCK-8 assay. Western blotting was used to detect the protein expression of proliferating cell nuclear antigen (PCNA). The mRNA expression of runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP) was investigated by qRT-PCR. The protein expression of RUNX2 was detected by western blotting. In addition, the formation of mineralized nodules was assessed by alizarin red staining. @*Results@#Compared with that in the siNC group, the mRNA expression of HDAC9 in the siHDAC9 group was lower (P < 0.01). Moreover, compared with those in the siNC group, the proliferation index (P<0.01), proliferation activity (P<0.05) and protein expression of PCNA (P<0.01) in the siHDAC9 group were all increased. Compared with the siNC group, the siHDAC9 group exhibited higher mRNA expression of RUNX2 and ALP (P < 0.05), and the protein expression of RUNX2 showed the same results (P < 0.01). The results of alizarin red staining showed that compared to the siNC group, the siHDAC9 group formed more mineralized nodules.@* Conclusion@#Silencing HDAC9 expression can promote the proliferation and osteogenic differentiation of PDLSCs.