TGF-β2 downregulates osteogenesis under inflammatory conditions in dental follicle stem cells

Bone formation is important for the reconstruction of bone-related structures in areas that have been damaged by inflammation.Inflammatory conditions such as those that occur in patients with rheumatoid arthritis, cystic fibrosis, and periodontitis have been shown to inhibit osteoblastic differentiation. This study focussed on dental follicle stem cells(DFSCs), which are found in developing tooth germ and participate in the reconstruction of alveolar bone and periodontal tissue in periodontal disease. After bacterial infection of inflamed dental tissue, the destruction of bone was observed. Currently, little is known about the relationship between the inflammatory environment and bone formation. Osteogenic differentiation of inflamed DFSCs resulted in decreased alkaline phosphatase(ALP) activity and alizarin red S staining compared to normal DFSCs. Additionally, in vivo transplantation of inflamed and normal DFSCs demonstrated severe impairment of osteogenesis by inflamed DFSCs. Protein profile analysis via liquid chromatography coupled with tandem mass spectrometry was performed to analyse the differences in protein expression in inflamed and normal tissue. Comparison of inflamed and normal DFSCs showed significant changes in the level of expression of transforming growth factor(TGF)-β2. Porphyromonas gingivalis(P.g.)-derived lipopolysaccharide(LPS) was used to create in vitro inflammatory conditions similar to periodontitis. The osteogenic differentiation of LPS-treated DFSCs was suppressed, and the cells displayed low levels of TGF-β1 and high levels of TGF-β2. DFSCs treated with TGF-β2 inhibitors showed significant increases in alizarin red S staining and ALP activity. TGF-β1 expression was also increased after inhibition of TGF-β2. By examining inflamed DFSCs and LPS-triggered DFSCs, these studies showed both clinically and experimentally that the increase in TGF-β2 levels that occurs under inflammatory conditions inhibits bone formation.

Clinical application prospects and transformation value of dental follicle stem cells in oral and neurological diseases

Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.

Hypoxia promotes growth of stem cells in dental follicle cell populations

Adult stem cells (ASC) have been found in many tis-sues and are of great therapeutic potential due to their capability of differentiation. However, ASC comprise only a small fraction of the tissues. In order to use ASC for therapeutic purposes, it is important to obtain relatively pure stem cells in large quantities. Current methods for stem cell purification are mainly based on marker-dependent cell sorting techniques, which have various technical difficulties. In this study, we have attempted to develop novel conditions to favor the growth of the dental follicle stem cells (DFSC) such that the resultant cell populations are enriched in stem cells. Specifically, a heterogeneous dental follicle cell (H-DFC) population containing stem cells and homogenous non-stem cell dental follicle cell population were cultured at 1% or 5% hypoxic conditions. Only the heterogeneous population could increase proliferation in the hypoxic condition whereas the homogenous DFC did not change their proliferation rate. In addition, when the resultant cells from the heterogonous population were subjected to differentiation, they appeared to have a higher capacity of adipogenesis and osteogenesis as compared to the controls grown in the normal at-mosphere (normoxic condition). These hypoxia- treated cells also express higher levels of some stem cell markers. Together, these data suggest that stem cells are enriched by culturing the heterogeneous cell populations in a reduced O2 condition.

HSP25 Affects the Proliferation and Differentiation of Rat Dental Follicle Cells

Aim To detect the expression of HSP25 in rat dental follicles both in vivo and vitro, and explore the underlying mechanism of HSP25 on the proliferation and differentiation of rat dental follicle cells （DFCs）. Methodology Immunohistochemistry was performed to detect the expression of HSP25 in mandibles of postnatal rats on days 1, 3, 5, 7, 9 and 11 in vivo. In vitro, the expression of HSP25 in DFCs was detected by an indirect immunofluorescence assay. Thiazolyl blue tetrazolium bromide （MTT） assay, flow cytometry and alkaline phosphatase （ALP） assay were used to identify the time-course effect mediated by different concentrations of recombinant murine HSP25 of 0, 1, 10, 50 and 100 ng/mL on rat DFCs. Results Expression of HSP25 was not detected in dental follicles of the rats until day 5 after birth, but became up-regulated in a time-dependent manner till day 11. HSP25 was detected in the cytoplasm of cultured rat DFCs. No significant difference could be observed in the proliferation of DFCs after stimulation with different concentrations of HSP25 on days 1, 2 and 3 （P〉0.05）. HSP25 at concentrations of 50 ng/mL and 100 ng/mL up-regulated the ALP activity of DFCs on day 9 （P〈0.05）. Conclusion HSP25-immunoreactivity increased chronologically during the development of dental follicles. The protein had no significant effect on cell proliferation but may play a role in cementoblast/osteoblast differentiation of DFCs.

Response Proliferative Capacity of Undifferentiated Stem Cells of Obtained Human Adult Dental Follicle

Objective: The aim of this study was correlation proliferative activity, markers express stem cells, and lipid peroxides of undifferentiated stem cells of human adult dental follicle (DF) following culture. Methods: For this study, we used 8 samples from DF of impacted third molars to maintain culture conditions and evaluated the growth curve, cell viability, production of lipid peroxidation, cell cycle phases, and proliferative index during 25 days of culture. Results: Cells after culture showed characteristics of fibroblast-like type following 25th day of culture. The results of lipid peroxidation showed that stem cells in culture produce 13 nmoles/ml malondialdehyde at the start of culture, increasing until the 12th day and then began a decline that lasted until the 25th day. We revealed that DFSCs presented a significantly higher percentage of cells in S + G2/M phases by the 15th day of culture compared with cells at the start of culture. Cell surface markers revealed that cell lines were negative for HLA-DR and positive for CD90, CD44, and CD105. The expression of p21 protein, involved in the regulation of the cell cycle, showed a significant increase from the 15th to 25th day of culture. Results of cell division rates show a significant increase between the 6th and 15th day of culture. Conclusions: We conclude that the culture remained stable during the 25 days of culture, presenting the markers of stem cells and markers of control, progression, and cell proliferation that there was an increased production of lipid peroxides between the 6th and 12th days;this increase is related to the increased numbers of cells that also occurs during this period. Then, there is a significantly decline in the production of lipid peroxides and the number of cells, which is accompanied by an increase in cell unviability.

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.

A ROS-responsive hydrogel incorporated with dental follicle stem cell-derived small extracellular vesicles promotes dental pulp repair by ameliorating oxidative stress

Pulpitis,an inflammatory disease of dental pulp tissues,ultimately results in the loss of pulp defense properties.Existing clinical modalities cannot effectively promote inflamed pulp repair.Oxidative stress is a major obstacle inhibiting pulp repair.Due to their powerful antioxidative capacity,mesenchymal stem cell-derived small extracellular vesicles(MSC-sEVs)exhibit potential for treating oxidative stress-related disorders.However,whether MSC-sEVs shield dental pulp tissues from oxidative damage is largely unknown.Here,we showed that dental follicle stem cell-derived sEVs(DFSC-sEVs)have antioxidative and prohealing effects on a rat LPS-induced pulpitis model by enhancing the survival,proliferation and odontogenesis of H_(2)O_(2)-injured dental pulp stem cells(DPSCs).Additionally,DFSC-sEVs restored the oxidative/antioxidative balance in DPSC mitochondria and had comparable effects on ameliorating mitochondrial dysfunction with the mitochondrion-targeted antioxidant Mito-Tempo.To improve the efficacy of DFSC-sEVs,we fabricated an intelligent and injectable hydrogel to release DFSC-sEVs by combining sodium alginate(SA)and the ROS sensor RhB-AC.The newly formed SA-RhB hydrogel efficiently encapsulates DFSC-sEVs and exhibits controlled release of DFSC-sEVs in a HClO/ClO^(-)concentration-dependent manner,providing a synergistic antioxidant effect with DFSC-sEVs.These results suggest that DFSC-sEVs-loaded SA-RhB is a promising minimally invasive treatment for pulpitis by enhancing tissue repair in the pulp wound microenvironment.

不同胚层来源成体干细胞修复周围神经损伤

背景:成体干细胞疗法是周围神经损伤修复与再生领域的研究热点之一。中胚层被视为成体干细胞的理想来源,间充质干细胞具有获得率高、来源广、增殖快等优异性能。而外胚层来源成体干细胞,尤其是神经嵴干细胞,具有神经源性,越来越受到研究人员的关注。目的:对来自外胚层和中胚层的多功能成体干细胞在周围神经损伤修复与再生中的作用及机制进行简要综述,探究不同来源成体干细胞的研究进展与应用前景,并结合临床研究,探讨成体干细胞疗法潜在的应用价值以及亟待解决的问题。方法:第一作者于2024年2月应用计算机在PubMed和SinoMed数据库检索2001年12月至2024年2月相关文献,以“ectodermal stem cells,mesenchymal stem cells,peripheral nerve injury,repair,regeneration”为英文检索词,以“外胚层干细胞、间充质干细胞、周围神经损伤、修复、再生”为中文检索词,最终纳入69篇文献进行分析论述。结果与结论:①外胚层来源成体干细胞具有优异的分化和再生潜能,尤其是毛囊神经嵴干细胞、嗅干细胞、牙外胚层干细胞等,具有神经源性,可在体外表达神经特异性标志物,但目前缺少临床试验研究。②中胚层来源成体干细胞种类多、易获得及纯化,其中骨髓间充质干细胞和脐带间充质干细胞在周围神经损伤修复的应用疗效及安全性方面有相关临床试验支持,能改善感觉及运动神经传导,且在随访中未出现并发症和明显不良反应。骨髓间充质干细胞的获取需行侵入性外科手术且要求患者与捐赠者骨髓配型吻合,应用受到一定限制;而脐带间充质干细胞虽无需侵入性获取,但分离较困难且表型不稳定。③内胚层来源成体干细胞常难以在体外生长,应用受限,目前应用于临床的可能性低。④综合来看,骨髓间充质干细胞仍为周围神经损伤干细胞治疗的首选细胞,适用于无外科手术禁忌且符合配型要求的情况,其次为脐带间充质干细胞,辅以分离方法的改进和表型稳定性的提高策略。⑤牙外胚层干细胞以及脂肪间充质干细胞具有较高应用潜能,有待进一步临床试验,其他外胚层、中胚层来源成体干细胞各以其优异特性在动物及细胞实验研究中具有显著优势。

芒柄花素促进牙囊干细胞成骨向分化

目的:研究芒柄花素对牙囊干细胞(human dental follicle stem cells,hDFSCs)成骨分化的影响。方法:首先对hDFSCs进行分离、培养及鉴定,并使用含不同浓度芒柄花素(0、0.1、1、10μmol/L)培养基培养细胞。通过CCK-8实验、结晶紫染色和活/死细胞荧光染色评估细胞的活性状况;通过细胞骨架荧光染色观察细胞骨架状况;采用RT-qPCR检测细胞成骨相关基因的表达变化;利用碱性磷酸酶(alkaline phosphatase,ALP)染色及活性检测法评估细胞成骨分化过程中ALP活性的影响;通过茜素红染色法评估细胞成骨分化过程中钙化结节数量的影响。结果:hDFSCs具有干细胞特性;不同浓度的芒柄花素对hDFSCs活性无显著性影响;1μmol/L的芒柄花素可显著促进Runx2、OCN、Col-Iα1的mRNA表达;并能够提高的细胞内ALP活性和钙化结节的数量。结论:1μmol/L芒柄花素可促进hDFSCs的成骨分化。

小鼠牙囊细胞的体外分离培养鉴定及异质性研究

目的:建立小鼠牙囊细胞体外分离培养的方法,并对其起源进行鉴定,同时检测其生物学特性。方法:用1%的胰蛋白酶消化分离7天龄Balb/c小乳鼠的下颌第一磨牙牙胚的牙囊组织进行体外培养,波形蛋白和角蛋白鉴定细胞起源,HE染色观察细胞的形态,Gomori改良钙钴法进行细胞的碱性磷酸酶(alkalinephosphatase,ALPase)染色,免疫组化法检测细胞Ⅰ型胶原和骨钙素(osteocalcin,OCN)的表达。结果:分离培养的细胞具有多形性,现有3种基本的细胞类型:立方形或多角形;长梭形;非常细长的细胞形状,前2种细胞胞核内有2～4个清晰的核仁,胞质内有大量颗粒,且有大量的线状伪足。波形蛋白染色阳性,角蛋白染色阴性,ALPase染色显示72.7%的牙囊细胞内的AL鄄Pase呈强阳性;免疫组化染色显示48.8%的牙囊细胞Ⅰ型胶原及8.75%的牙囊细胞的OCN表达阳性。结论:所培养的牙囊细胞源自间充质,含有多种细胞表型,具有异质性。

大鼠牙囊细胞体外培养技术的建立及其鉴定

目的 建立体外培养大鼠牙囊细胞的方法 ,观察牙囊细胞体外生长的生物学特性。方法 分离乳鼠下颌第一、第二磨牙牙胚的牙囊组织 ,应用组织培养的方法进行牙囊细胞原代和传代培养。显微镜观察培养细胞的形态 ,电镜观察体内牙囊组织和体外培养的牙囊细胞的超微结构。免疫组化法检测细胞波形蛋白、Ⅰ型胶原、纤维连接蛋白的表达。结果 分离组织培养 2 4h后 ,梭形细胞和多角形细胞从组织块中游出 ,经消化排除法获得纯化的牙囊细胞。显微镜下牙囊细胞为成纤维细胞样 ,电镜下牙囊细胞无桥粒 ,胞浆中含有高密度电子颗粒和大量粗面内质网 (RER)。免疫组化染色显示牙囊细胞表达波形蛋白、Ⅰ型胶原和纤维连接蛋白。结论 运用组织培养和细胞生物学技术可以成功获得原代和传代培养的大鼠牙囊细胞 。

人牙囊细胞的分离培养和生物学特性

目的 :应用酶消化法体外培养人牙囊细胞并研究其生物学特性。方法 :分离合法引产人胚胎乳牙胚的牙囊组织 ,消化法获得人牙囊细胞 ,HE染色观察细胞形态、免疫组织化学染色技术检测波形丝蛋白、Ⅰ型胶原表达 ,RT -PCR检测细胞的骨钙素、骨涎蛋白、碱性磷酸酶的表达。结果 :原代培养的人牙囊细胞呈成纤维细胞形态 ,有部分上皮成分混杂 ,经纯化后可排除 ;在牙囊细胞中Ⅰ型胶原和波形丝蛋白的表达呈阳性 ,定位于细胞的胞质中 ;RT -PCR结果显示骨涎蛋白、骨钙素、碱性磷酸酶表达。结论 :体外培养的人牙囊细胞具有成纤维细胞的特性 ,具有合成Ⅰ型胶原的能力 ;不同程度表达Ⅰ型胶原、骨钙素、骨涎蛋白、碱性磷酸酶等矿化相关蛋白。

大鼠牙囊细胞体外培养与表型鉴定

目的:体外培养大鼠牙囊细胞(RDFCs),鉴定其细胞来源及表型,为牙周组织再生的研究提供可靠的种子细胞来源。方法:选择出生后6-7d SD仔鼠,分离上、下颌第一、第二磨牙牙胚,取牙囊组织进行原代和传代培养。通过倒置显微镜观察细胞形态及生长情况;波形丝蛋白(Vimentin,VIM)和角蛋白(Cytokeratin,CK)鉴定其细胞来源;免疫组化染色技术检测细胞骨桥蛋白(osteopontin,OPN)、骨涎蛋白(bone sialoprotein,BSP)、Ⅰ型胶原(type Ⅰ collagen,CoL-Ⅰ)、Ⅲ型胶原(typeⅢ collagen,CoL-Ⅲ)及纤维连接蛋白(fibronectin,FN)的表达。结果:细胞形态呈多形性,有长梭形,纺锤形、不规则三角形等,波形丝蛋白染色阳性,角蛋白染色阴性。免疫组化染色显示OPN、BSP、CoL-Ⅰ、CoL-Ⅲ、FN在胞浆中呈不同程度的阳性表达。结论:大鼠牙囊细胞来源于外胚间充质,具有成纤维细胞的形态特征及成骨/成牙骨质细胞表型特征,可将牙囊细胞作为种子细胞用于牙周组织工程的再生研究。

矿化液对体外培养的人牙囊细胞碱性磷酸酶活性的影响

目的:探讨矿化液对体外培养的人牙囊细胞中碱性磷酸酶表达的影响。方法:取12～13岁患者因正畸原因拔除的下颌第三磨牙牙囊,原代培养人牙囊细胞,将第5代细胞加入矿化液培养,应用碱性磷酸酶组织化学方法染色、碱性磷酸酶试剂盒检测人牙囊细胞中碱性磷酸酶的活性。结果:培养的牙囊细胞呈长梭形、不规则多角形。免疫细胞化学染色显示抗波形丝蛋白染色阳性。矿化液诱导7d,碱性磷酸酶染色呈阳性,碱性磷酸酶活性检测第3、5、7d明显升高,与对照组均有显著性差异。结论:矿化液能增强体外培养的人牙囊细胞中碱性磷酸酶的表达。

差速传代纯化大鼠牙囊细胞

目的:建立一种简捷的分离培养和纯化大鼠牙囊细胞的方法。方法:分离出生后6dSD大鼠上下颌第一和第二磨牙完整牙胚,剥离牙囊和成釉器,剪碎后酶消化并混合培养,再利用多次差速传代纯化牙囊细胞。结果:原代细胞为牙囊细胞和成釉器细胞混合生长,差速传代培养到第4代可获得纯化的牙囊细胞。倒置显微镜下观察牙囊细胞呈长梭形或三角形,免疫组化染色抗波形丝蛋白阳性,抗角蛋白阴性。结论:利用多次差速传代可从混合培养的原代细胞中获得纯化的牙囊细胞。

BMP-2和地塞米松对体外培养大鼠牙囊细胞矿化能力的影响

目的:探讨BMP-2和地塞米松联合作用对大鼠牙囊细胞分化能力的影响,为牙囊细胞在牙周组织工程中的应用提供实验依据。方法:取生长状态良好的第3代大鼠牙囊细胞,血清饥饿同步化后,分别加入含BMP-2(100ng/ml)、地塞米松Dex(10-8mol/ml)、BMP-2(100ng/ml)+地塞米松(10-8mol/ml)的DMEM培养液,通过碱性磷酸酶(ALP)检测试剂盒、钙化结节染色分别检测不同诱导条件下对大鼠牙囊细胞分化的影响。结果:经BMP-2、Dex、BMP-2+Dex诱导后,体外培养的大鼠牙囊细胞碱性磷酸酶活性均显著高于未诱导组,各组间ALP活性与对照组相比差异有统计学意义(P<0.01)。BMP-2+Dex诱导组ALP活性最强,与BMP-2诱导组间差异有统计学意义(P<0.01),而与Dex诱导组间ALP活性则差异无统计学意义(P>0.01)。培养14d时,BMP-2+Dex诱导组牙囊细胞ALP活性增强最为显著,与BMP-2诱导组及Dex诱导组相比差异均有统计学意义(P<0.01)。矿化结节计数分析显示,各组细胞矿化结节形成的数量及面积明显存在显著的差异,BMP-2、Dex、BMP-2+Dex诱导组与未诱导组相比,其矿化结节形成量差异均有统计学意义(P<0.01),BMP-2+Dex诱导组矿化结节形成量明显大于BMP-2和Dex单独诱导组。结论:BMP-2、地塞米松均能促进牙囊细胞的分化,然而两者联合作用促分化的能力最为显著,提示其在牙周组织工程中的应用前景。

大鼠牙囊细胞培养方法的探讨

【目的】探讨大鼠牙囊细胞体外培养的方法。【方法】分离出大鼠牙囊组织,分别采用组织块培养法、细胞消化分散法、及改良组织块法进行牙囊细胞原代及传代培养,倒置相差显微镜下进行细胞形态学观察,透射电镜观察细胞超微结构。【结果】培养至第3天,倒置相差显微镜观察发现,采用组织块培养法,见少数细胞从组织块爬出;而细胞消化分散法则可获得数量多的牙囊细胞,但与杂质细胞混杂生长;改良组织块法见量多、相对纯的牙囊细胞。电镜下牙囊细胞无桥粒,胞浆中含有高密度电子颗粒和大量粗面内质网。组织块法、细胞消化分散法和改良组织块法牙囊细胞培养成功率分别为80%、60%和100%;分别于10 d、7 d和6 d左右进行第一次传代。【结论】改良组织块法是一种良好的大鼠牙囊细胞培养方法。

人牙囊细胞的培养及其特性

目的 :体外培养人牙囊细胞并研究其特性。方法 :取年龄为 12岁人埋藏阻生第三磨牙的牙囊 ,组织块法进行人牙囊细胞的培养 ,HE染色、扫描电镜观察人牙囊细胞的形态 ,免疫组织化学染色技术观察Ⅰ型胶原及波形蛋白在牙囊细胞中的表达及定位。结果 :培养的人牙囊细胞呈梭形、卵圆形及多角形 ,形似成纤维细胞 ;扫描电镜可见细胞多呈梭形 ,也可见多角形 ,所有细胞表面均有颗粒状物质 ,有的细胞表面多且密 ,有的细胞表面较少 ,折光性较强 ,细胞核周围分布较多 ;在牙囊细胞中Ⅰ型胶原和波形蛋白的表达呈阳性 ,定位于细胞的胞质中 ,围绕细胞核周围染色较强 ,细胞核内染色阴性。结论 :体外可以培养人牙囊细胞 ,人牙囊细胞具有成纤维细胞的特性 。

体外共培养人牙髓干细胞对人牙囊干细胞增殖、成骨分化的作用

目的通过体外建立人牙囊干细胞(human dental follicle stem cells,HDFSCs)和人牙髓干细胞(human dental pulp stem cells,HDPSCs)共培养体系,研究HDPSCs对HDFSCs增殖、成骨分化的作用。方法 1利用改良的组织块-消化联合法、免疫组化方法、流式细胞术以及多向诱导方法对HDFSCs和HDPSCs进行分离、培养、鉴定;2采用0.4μm孔径的Transwell小室构建HDFSCs和HDPSCs体外共培养体系;3CCK-8测定HDFSCs增殖活性的变化;4与HDPSCs体外共培养1周,qRTPCR检测HDFSCs几个标志性成骨基因:碱性磷酸酶(alkaline phosphatase,ALP)、人类相关转录因子2(runt-related transcription factor 2,Runx2)、骨桥蛋白(osteopontin,OPN)、骨涎蛋白(bone sialoprotein,BSP)以及Ⅰ型胶原(collagen type 1,Col-1)的表达情况。结果 1成功分离、培养、鉴定HDFSCs和HDPSCs;2从第4天开始,共培养组HDFSCs的增殖活力明显高于对照组(P<0.05);3与对照组相比,共培养组ALP、Runx2、OPN、BSP、Col-1的相对表达量均明显增高(P<0.05)。结论与HDPSCs共培养能增强HDFSCs增殖活力及成骨分化。