Characterization of the osteogenic potential of mesenchymal stem cells from human periodontal ligament based on cell surface markers

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/CD140a, 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.

Overview of noncoding RNAs involved in the osteogenic differentiation of periodontal ligament stem cells

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.

Therapeutic potential of periodontal ligament stem cells

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.

Effects of lysophosphatidic acid on human periodontal ligament stem cells from teeth extracted from dental patients

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.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhance the Osteoblastic Differentiation of Periodontal Ligament Stem Cells Under High Glucose Conditions Through the PI3K/AKT Signaling Pathway

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.

Human periodontal ligament stem cells repair mental nerve injury

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 sig-nificantaly 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 in-jection, 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.

Mass acquisition of human periodontal ligament stem cells

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.

Effects of Aging on the Proliferation and Differentiation Capacity of Human Periodontal Ligament Stem Cells

periodontal ligament stem cells; aging; proliferation; osteogenic differentiation Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells （PDLSC） derived from different aged donors, and to evaluate the effects of aging on the biological characteristics of PDLSC. Methods Periodontal ligament tissues were obtained from 24 surgically extracted human premolars during orthodontics therapy. The specimens were divided into three groups according to the donor’s age. Group A： 18-20 years, group B： 30-35 years, group C： 45-50 years. PDLSC were isolated and cultured using a tissue-block-based enzymolytic method by limiting dilution assay. The colony forming efficiency of PDLSC for three experimental groups was determined. Senescence-Associated β-Galactosidase （SA-β-G） expression in the three groups was examined using β-galactosidase staining working solution. Cell cycle and apoptosis of the PDLSC were examined by the flow cytometry. Alkaline phosphatase （ALP） activity was evaluated by ALP staining. The expression of osteoplastic differentiation related genes Runt-related transcription factor-2 （Runx-2）, Collagen Type 1 （col-1）, and ALP of PDLSC were examined by quantitative real-time RT-PCR. Results The colony forming efficiency of PDLSC in Group A, B and C was 36.67%, 22.67% and 9.33%, respectively, which decreased with donors’ age （P〈0.05）. SA-β-G expression of the senescent PDLSC in group A, B and C were 4.14%, 16.39%, 50.38%, respectively （P〈0.05）. Cells in G2/S phase was 38.73%, 29.88%, 18.25% （P〈0.05）, and the apoptosis rate was 1.57%, 4.56%, 5.84% （P〈0.05）, in group A, B and C respectively. The ALP staining in the three groups decreased with the increase of donors’ ages, and the expression of Runx-2, col-1 and ALP decreased gradually from group A to group C （all P〈0.05）, which indicated the osteogenic differentiation capacity of PDLSC decreased while donor aging. Conclusion Human PDLSC could be successfully isolated from periodontal ligament tissues of different aged donors. However, the proliferation and osteogenic differentiation capacity of PDLSC decreased while donor aging.

PDLSCs-Exo对炎性环境中牙周膜干细胞增殖能力及活性氧水平的影响

目的探讨牙周膜干细胞(periodontal ligament stem cells,PDLSCs)来源的外泌体(exosome,Exo)对炎性环境中牙周膜干细胞增殖及活性氧水平的影响。方法分离培养牙周膜干细胞,提取牙周膜干细胞来源的外泌体,并将其添加至正常及含有10μg/mL脂多糖(lipopolysaccharide,LPS)的牙周膜干细胞培养基中,实验对象分为PDLSCs组、PDLSCs+LPS组、PDLSCs+Exo组、PDLSCs+LPS+Exo组,检测各组牙周膜干细胞对外泌体的摄取能力、增殖能力、细胞内活性氧水平及炎性因子水平。结果在10μg/m L LPS刺激下,牙周膜干细胞增殖能力下降。组间对比,PDLSCs+LPS组较PDLSCs组、PDLSCs+Exo组、PDLSCs+LPS+Exo组增殖能力显著下降,差异有统计学意义(P<0.05);PDLSCs+LPS+Exo组增殖能力较PDLSCs+Exo组降低,差异有统计学意义(P<0.05);细胞内活性氧及炎性因子对比,PDLSCs+LPS组较其余三组细胞内活性氧水平增高,差异有统计学意义(P<0.05)。结论牙周膜干细胞来源的外泌体能够改善LPS刺激导致的牙周膜干细胞增殖活性降低,降低胞内活性氧及炎性因子水平,并提高牙周膜干细胞的抗氧化能力。

静态机械牵张力对HPDLSCs和PPDLSCs破骨相关基因表达的影响

目的:探讨健康牙周组织来源的牙周膜干细胞(HPDLSCs)和牙周病组织来源的牙周膜干细胞(PPDLSCs)在静态机械牵张力作用下破骨相关基因表达的异同。方法:采用低密度接种法分离培养HPDLSCs和PPDLSCs,应用流式细胞仪对两种细胞的表面间充质干细胞标记物表达进行检测,使用Flexcell Tension Unit对HPDLSCs和PPDLSCs进行不同力值静态机械牵张力(SMS)加载,实时定量RT-PCR检测HPDLSCs和PPDLSCs中破骨相关基因RANKL和C-fos的表达。结果:间充质干细胞表面标记物STRO-1、CD146、CD90、CD29在HPDLSCs和PPDLSCs中均强阳性表达,且HPDLSCs中的表达显著高于PPDLSCs(P<0.05)。在未加载SMS情况下,PPDLSCs中RANKL和C-fos的表达水平明显高于HPDLSCs(P<0.05);当加载SMS≤12%形变量时,HPDLSCs中两种破骨相关基因的表达水平较未加力时无明显变化(P>0.05),而形变量达到14%时,二者的表达显著上调(P<0.05);在PPDLSCs组,当SMS≤8%形变量时,RANKL和C-fos的表达无明显变化(P>0.05),而SMS≥10%形变量时,可明显激活两种破骨基因的表达(P<0.05)。结论:HPDLSCs和PPDLSCs对SMS的反应不同,过大的静态牵张力会导致PPDLSCs表达破骨相关基因增强。

钽涂层对hPDLSCs增殖及成骨分化的影响

目的 探究钽涂层表面对人牙周膜干细胞(human periodontal ligament stem cells, hPDLSCs)增殖及成骨分化的影响。方法 对hPDLSCs进行分离、培养和细胞鉴定。纯钛试件抛光清洗后,经喷砂、酸蚀处理,以等离子喷涂技术制备钽涂层。以抛光钛表面(P组)为对照组,喷砂酸蚀钛(SLA组)、钽涂层钛(Ta组)为实验组。通过扫描电镜、能谱仪分析各组钛表面的微形貌、元素组成;将hPDLSCs接种于各组试件表面,通过CCK-8法测定细胞的增殖情况,经成骨诱导培养后行碱性磷酸酶活性检测和茜素红染色,qPCR检测成骨基因表达。结果 在钛试件上成功制备了钽涂层;成功分离培养并鉴定hPDLSCs;CCK-8实验结果显示,在培养3、5、7 d后,Ta组OD值明显高于SLA组及P组(P<0.05);ALP检测结果显示,在第7天时,三组间的差距无统计学意义;第14天时,Ta组ALP活性明显高于P组和SLA组(P<0.01)。茜素红染色显示,三组材料表面都有红色钙化结节形成,SLA组和Ta组的矿化结节明显多于P组。qPCR结果显示Ta组表面细胞ALP、RUNX2、OCN基因表达水平显著高于P组(P<0.01),RUNX2、OCN基因表达显著高于SLA组(P<0.01)。结论 SLA钛表面钽涂层对hPDLSCs的增殖、成骨分化具有促进作用。

Overview of the main biological mechanisms linked to changes in periodontal ligament stem cells and the inflammatory microenvironment

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.

Comparative analysis of different feeder layers with 3T3 fibroblasts for culturing rabbits limbal stem cells

AIM： To explore the possibility of human umbilical cord mesenchymal stem cells（h UCMSCs）, human umbilical vein endothelial cells（h UVECs）, human dental pulp stem cells（h DPSCs） and human periodontal ligament stem cells（h PDLSCs） serving as feeder cells in co-culture systems for the cultivation of limbal stem cells.METHODS： Different feeder layers were cultured in Dulbecco＇s modified Eagle＇s medium（DMEM）/F12 and were treated with mitomycin C. Rabbits limbal stem cells（LSCs） were co-cultured on h UCMSCs, h UVECs, h DPSCs, h PDLSCs and NIH-3T3, and then comparative analysis were made between each group to see their respective colony-forming efficiency（CFE） assay and immunofluorescence（IPO13,CK3/12）.RESULTS： The efficiency of the four type cells in supporting the LSCs morphology and its cellular differentiation was similar to that of NIH-3T3 fibroblasts as demonstrated by the immunostaining properties analysis, with each group exhibiting a similar strong expression pattern of IPO13, but lacking CK3 and CK12 expression in terms of immunostaining. But h UCMSCs, h DPSCs and h PDLSCs feeder layers were superior in promoting colony formation potential of cells when compared to h UVECs and feedercell-free culture.CONCLUSION： hUCMSCs, hDPSCs and hPDLSCs can be a suitable alternative to conventional mouse NIH-3T3 feeder cells, so that risk of zoonotic infection can be diminished.

Proteomic profiling of various human dental stem cells-a systematic review

BACKGROUND The proteomic signature or profile best describes the functional component of a cell during its routine metabolic and survival activities.Additional complexity in differentiation and maturation is observed in stem/progenitor cells.The role of functional proteins at the cellular level has long been attributed to anatomical niches,and stem cells do not deflect from this attribution.Human dental stem cells(hDSCs),on the whole,are a combination of mesenchymal and epithelial coordinates observed throughout craniofacial bones to pulp.AIM To specify the proteomic profile and compare each type of hDSC with other mesenchymal stem cells(MSCs)of various niches.Furthermore,we analyzed the characteristics of the microenvironment and preconditioning changes associated with the proteomic profile of hDSCs and their influence on committed lineage differentiation.METHODS Literature searches were performed in PubMed,EMBASE,Scopus,and Web of Science databases,from January 1990 to December 2018.An extra inquiry of the grey literature was completed on Google Scholar,ProQuest,and OpenGrey.Relevant MeSH terms(PubMed)and keywords related to dental stem cells were used independently and in combination.RESULTS The initial search resulted in 134 articles.Of the 134 full-texts assessed,96 articles were excluded and 38 articles that met the eligibility criteria were reviewed.The overall assessment of hDSCs and other MSCs suggests that differences in the proteomic profile can be due to stem cellular complexity acquired from varied tissue sources during embryonic development.However,our comparison of the proteomic profile suffered inconsistencies due to the heterogeneity of various hDSCs.We believe that the existence of a heterogeneous population of stem cells at a given niche determines the modalities of regeneration or tissue repair.Added prominences to the differences present between various hDSCs have been reasoned out.CONCLUSION Systematic review on proteomic studies of various hDSCs are promising as an eye-opener for revisiting the proteomic profile and in-depth analysis to elucidate more refined mechanisms of hDSC functionalities.

Application of dental stem cells in three-dimensional tissue regeneration

Dental stem cells can differentiate into different types of cells.Dental pulp stem cells,stem cells from human exfoliated deciduous teeth,periodontal ligament stem cells,stem cells from apical papilla,and dental follicle progenitor cells are five different types of dental stem cells that have been identified during different stages of tooth development.The availability of dental stem cells from discarded or removed teeth makes them promising candidates for tissue engineering.In recent years,three-dimensional(3D)tissue scaffolds have been used to reconstruct and restore different anatomical defects.With rapid advances in 3D tissue engineering,dental stem cells have been used in the regeneration of 3D engineered tissue.This review presents an overview of different types of dental stem cells used in 3D tissue regeneration,which are currently the most common type of stem cells used to treat human tissue conditions.

牙龈卟啉单胞菌超声提取物对hPDLSCs表达VEGF的影响

目的:观察牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)超声提取物对人牙周膜干细胞(human per-iodontal ligament stem cells,hPDLSCs)表达血管内皮生长因子(vascular endothelial growth factor,VEGF)及基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)的影响。方法:标准厌氧培养环境下培养Pg,收集细菌菌落,离心,制备细菌的超声提取物,然后以不同的浓度加入hPDLSCs的培养液中。培养6d,分别观察第2、4、6天时hPDLSCs的增殖情况。提取蛋白并用Western Blotting法检测VEGF和MMP-9的表达。结果:与对照组相比,第2天时,10μg/ml和100μg/mlPg轻度促进hPDLSCs的生长,第4天时,10μg/ml和100μg/mlPg则明显抑制hPDLSCs的生长(P<0.05),第6天时,3种浓度的Pg均明显抑制hPDLSCs的生长(P<0.05);1μg/ml和10μg/mlPg上调VEGF的表达,100μg/mlPg明显抑制VEGF的表达;3种浓度的Pg均上调hPDLSCs中MMP-9的表达。结论:作为牙周炎病原菌,大量的Pg可能通过抑制hPDLSCs的生长增殖,抑制局部血管重建以及加速细胞外基质的降解而降低了牙周组织的自我修复能力。

p38 MAPK通路调控BMP9诱导hPDLSCs成骨分化的体外研究

目的:检测骨形成发生蛋白9 (bone morphogenetic proteins 9,BMP9)对人牙周膜干细胞(human periodontal ligament stem cells,hPDLSCs)的成骨诱导分化能力,并探讨p38 MAPK通路在该成骨分化中的作用。方法:培养h PDLSCs,腺病毒载体(Ad-BMP9)感染hPDLSCs后,通过碱性磷酸酶(alkaline phosphatase, ALP)活性测定与染色、定量聚合酶链反应(quantitative polymerase chain reaction, qPCR)、钙盐沉积等方法,分别检测ALP、骨桥蛋白(osteopontin,OPN)、骨钙素(osteocalcin, OCN)的表达及钙盐沉积量,评价BMP9诱骨分化的能力。在Ad-BMP9感染hPDLSCs 36 h后,检测BMP9作用hPDLSCs后对p38及MKK3/6磷酸化(p-p38, p-MKK3/6)的影响,以及p38 MAPK通路抑制剂SB203580预处理后BMP9-p38-MAPK通路对hPDLSCs成骨分化的影响。采用SPSS16.0软件包对数据进行统计学分析。结果:在Ad-BMP9作用下,ALP活性、OPN和OCN的表达均显著高于对照组(P<0.01), ALP染色与钙盐沉积结果与之吻合。Western印迹法检测发现,BMP9可增强p-p38、p-MKK3/6的表达。加入p38 MAPK通路抑制剂后,ALP、及OPN、OCN的表达均显著降低(P<0.01),钙盐沉积、基质矿化也显著减弱。结论:在hPDLSCs的分化过程中,BMP9对其具有诱骨分化能力。MKK3/6-p38 MAPK通路参与了该成骨分化过程且具有正向调节作用。

Effects of Ginsenoside Rg-1 on the Proliferation and Osteogenic Differentiation of Human Periodontal Ligament Stem Cells

Objective： TO 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. Methods： To 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-yl）-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. Results： Compared 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. Conclusion： Ginsenoside Rg-1 can enhance the proliferation and osteogenic differentiation of hPDLSCs at an optimal concentration of 10 μmol/L.

miR-17对炎症微环境中PDLSCs骨向分化特性的影响

目的探讨体外炎症微环境中,miR-17对牙周膜干细胞(periodontal ligament stem cells,PDLSCs骨向分化能力的影响。方法体外有限稀释法克隆化和密度梯度离心法分别培养牙周膜干细胞(PDLSCs)和外周血免疫细胞(PBMCs),并建立PDLSCs与免疫细胞的Transwell共培养炎症微环境体系。使用定量PCR技术检测miR-17的表达,并将PDLSCs转染miR-17模拟物Mimics和抑制剂Inhibitor后进行成骨诱导,ALP染色,定量PCR和Western Blot检测细胞成骨分化的能力。结果共培养组PDLSCs中miR-17表达降低,转染Mimics后共培养细胞成骨分化能力升高,转染Inhibitor后细胞成骨分化能力降低。结论炎症微环境中miR-17可以促进PDLSCs骨向分化。

Research progress of strontium in promoting periodontal tissue regeneration

Periodontal disease is a chronic infectious disease of the oral cavity.Its main clinical features are periodontal pocket formation and alveolar bone resorption.Scholars'research hotspot is to achieve periodontal tissue regeneration in patients.Studies have found that strontium has certain potential in promoting periodontal tissue regeneration.In recent years,scholars have been conducting research on strontium and periodontal tissue regeneration,with a view to opening a new path for periodontal disease treatment.This article reviews the research status of strontium and periodontal tissue regeneration.The review results show that strontium can induce the proliferation and differentiation of PDLSCs and promote the regeneration of lost bone tissue;it can inhibit osteoclast activity and induce osteoclast apoptosis through a variety of signaling pathways,thereby inhibiting bone resorption;Promote bone formation;Strontium also has the function of promoting early angiogenesis and suppressing immune inflammatory response.Because the current research on strontium and periodontal tissue regeneration is only focused on in vivo and in vitro experiments,there is no relevant clinical trial to apply strontium to periodontal tissue regeneration.Therefore,if strontium is used to promote periodontal tissue regeneration to achieve the treatment of periodontal disease,further research is needed.