牙髓干细胞在周围神经损伤修复中的研究进展

周围神经损伤(peripheral nerves injury,PNI)是口腔临床常见病,极易造成患者功能丧失和美观异常,牙髓干细胞(dental pulp stem cells,DPSCs)结合组织工程在PNI修复中的应用是目前研究热点.DPSCs具有来源丰富、提取简单、免疫原性低以及体外增殖率高等优点,其可分化成雪...     

人牙髓干细胞来源外泌体促进周围神经损伤修复的实验研究

目的:研究人牙髓干细胞(human dental pulp stem cells,hDPSCs)来源外泌体对周围神经损伤修复的作用.方法:将36只成年SD大鼠随机分为2组,实验组为坐骨神经损伤后hDPSCs来源外泌体注射组,对照组为坐骨神经损伤后PBS注射组.分别于损伤后第3、7、14天观察大鼠的行为学改变,取材后进行...     

牙髓干细胞修复再生同质异体大鼠牙髓牙本质复合体的研究

目的:观察第3代同质异体牙髓干细胞(dental pulp stem cell,DPSCs) 定植于冠髓被摘除的大鼠髓腔后,再生修复牙髓牙本质复合体的能力。方法:18只SD大鼠随机分为实验组和对照组,两组均全麻下摘除大鼠上颌双侧第一磨牙冠髓,实验组同期髓腔定植体外培养的同质异体大鼠牙髓干细胞,对照组冠髓摘除后不进行任何处理,术后均使用光固化树脂充填封闭髓腔。两组动物均于术后2、4、6周处死,取其上颌骨进行大体观察,X线观察,组织学观察,牙本质的厚度测量。结果:实验组4周时,肉眼可见牙髓充血减少;6周时,X线显示牙本质厚度增加,根尖孔闭合;6周时,光镜下显示明显新生牙本质形成,成牙本质细胞栅栏状排列;牙本质厚度测量结果显示,实验组牙本质厚度2周时增厚,4周增厚更明显,持续至6周,优于对照组(P<0.05)。结论:牙髓干细胞髓腔内定植,可以促进牙髓牙本质复合体修复再生,具有潜在的临床应用价值。     

牙髓干细胞修复周围神经损伤的研究进展

周围神经损伤(peripheral nerve injury,PNI)严重影响患者的生命质量及身心健康,并且损伤后的修复在临床上仍面临巨大挑战,PNI与再生修复研究是当今各相关学科研究的热点问题。细胞疗法在组织再生与修复中具有不可替代的作用。施万细胞是周围神经修复的理想细胞,但来源有限等缺点限制了其临床应用。牙髓干细胞来源于神经嵴,为神经再生提供了新的细胞来源。本文就牙髓干细胞修复PNI的研究现状进行综述。     

牙髓干细胞修复周围神经损伤的研究进展

周围神经损伤(peripheral nerve injury,PNI)严重影响患者的生命质量及身心健康,并且损伤后的修复在临床上仍面临巨大挑战,PNI与再生修复研究是当今各相关学科研究的热点问题。细胞疗法在组织再生与修复中具有不可替代的作用。施万细胞是周围神经修复的理想细胞,但来源有限等缺点限制了其临床应用。牙髓干细胞来源于神经嵴,为神经再生提供了新的细胞来源。本文就牙髓干细胞修复PNI的研究现状进行综述。     

人乳牙牙髓干细胞和成人牙髓干细胞研究进展

近年来,成体干细胞不断地从不同的组织中被分离出来,该类细胞具有多向分化潜能、较强的增殖能力和持久的自我更新能力,具备充当组织工程种子细胞的天然优势。2000年和2003年,研究者先后从成人牙髓组织和人乳牙牙髓组织中分离出具有干细胞特征的细胞,这两种细胞的发现对牙组织工程将产生重要的意义。现就这两种成体干细胞的研究进展做一综述,并展望其应用前景。     

三维培养的牙髓干细胞参与牙髓损伤修复能力的实验研究

目的：将体外建立的细胞因子BMP-2作用下牙髓干细胞（DPSC）三维培养体系应用于大鼠牙髓损伤模型中,观察DPSC对牙髓组织损伤修复的能力。方法：已构建的三维培养DPSC的细胞团添加BMP-2体外持续培养7 d,BrdU标记及检测鉴定后,将其置于建立的大鼠牙髓损伤模型洞内,移植4周后HE染色,改良Mallory三色法染色观察,免疫组化检测BrdU标记的细胞分布。结果：移植后4周,DPSC三维细胞培养的牙髓盖髓实验中有骨样牙本质基质形成,没有观察到组织的炎症和坏死。在基质中可以看到骨性成牙本质样细胞,带有长的突起的成牙本质样细胞在骨性牙本质中形成管状牙本质。结论：损伤的牙髓表面植入添加BMP处理的DPSC细胞团能够产生修复性牙本质。     

牙髓干细胞研究进展

干细胞是一类具有自我更新和分化潜能的细胞，它包括胚胎干细胞和成体干细胞。牙髓干细胞具有成体干细胞所界定的两大特征：较强的自我更新能力和分化潜能。牙髓干细胞因具有临床取材容易并可特异性地分化为牙体矿化结构等特性，目前正受到广泛关注。     

生物治疗在牙髓损伤修复中的应用研究

安全有效的活髓保存治疗方法一直是牙体牙髓病学研究的热点,但现有的治疗方法都存在许多不足。生物治疗近年来发展迅速,其中基因治疗和干细胞治疗能有效促进组织的修复与再生,在牙髓损伤修复中已有不少应用研究,本文就这方面的研究进展作一综述。     

人牙髓干细胞的体外培养和鉴定

目的　研究第三恒磨牙来源的人牙髓干细胞的表型和生物学性状。方法　从成人健康阻生牙中获取牙髓,酶消化法分离获得牙髓干细胞,计算细胞克隆形成率(CFU-F);免疫组化、RT-PCR法检测细胞的表面分子表达; 流式细胞仪测定细胞周期;体外分化诱导实验检测细胞的多向分化能力。结果　分离获得的牙髓干细胞在体外具有一定的克隆形成能力,诱导条件下部分牙髓干细胞可向脂肪、肌细胞和成牙本质细胞方向分化,符合干细胞的特征。结论　成功的从人第三恒磨牙牙髓中分离得到牙髓干细胞。     

Determinants of Dental Pulp Stem Cell Heterogeneity

IntroductionThe aim of this review is to provide a narrative review on the determinants of dental pulp stem cell (DPSC) heterogeneity that may affect the regenerative properties of these cells.MethodsPubMed, Scopus, and MEDLINE (Ovid) literature searches were done on human dental pulp stem cell heterogeneity. The focus was on human dental pulp stem cells with a primary focus on DPSC heterogeneity.ResultsDPSCs display significant heterogeneity as illustrated by the various subpopulations reported, including differences in proliferation and differentiation capabilities and the impact of various intrinsic and extrinsic factors.ConclusionsThe lack of consistent and reliable results in the clinical setting may be due to the heterogeneous nature of DPSC populations. Standardization in isolation techniques and criteria to characterize DPSCs should lead to less variability in results reported and improve comparison of findings between studies. Single-cell RNA sequencing holds promise in elucidating DPSC heterogeneity and may contribute to the establishment of standardized techniques.     

The Role of Small Extracellular Vesicles Derived from Lipopolysaccharide-preconditioned Human Dental Pulp Stem Cells in Dental Pulp Regeneration

IntroductionRegenerative endodontics has created a desirable shift in the treatment paradigm despite current limitations of regenerative outcomes. Mesenchymal stem cells (MSCs) facilitate tissue regeneration and repair in a mild inflammatory environment. Small extracellular vesicles (sEVs) derived from MSCs play an imperative role in the paracrine modulation of regenerative responses modulated by MSCs. However, it remains unknown whether MSCs enhance dental pulp regeneration or whether this enhancement is mediated by sEVs in a mild inflammatory environment. The present study aimed to elucidate the effects of sEVs originated from lipopolysaccharide (LPS)-preconditioned human dental pulp stem cells (hDPSCs) on dental pulp regeneration.MethodsAll sEVs were isolated from hDPSCs cultured with or without LPS (ie, N-sEVs and L-sEVs, respectively). The effect of N-sEVs and L-sEVs on proliferation, migration, angiogenesis, and differentiation of rat bone marrow MSCs was identified in vitro. Moreover, N-sEVs or L-sEVs were implanted into rat pulpless root canal models, and the regenerated tissue in root canals was assessed via hematoxylin-eosin staining, Masson staining, and immunohistochemistry after 30 days of transplantation.ResultsBoth N-sEVs and L-sEVs could modulate BMSC proliferation, migration, angiogenesis, and differentiation. Both kinds of sEVs enhanced the structure of the regenerated tissue closer to that of a normal dental pulp in vivo. L-sEVs had a more significant effect than N-sEVs.ConclusionssEVs released by hDPSCs in a mild inflammatory microenvironment are capable of facilitating the regeneration of dental pulp through functional healing instead of scar healing, which has potential applications in regenerative endodontics.     

人牙髓干细胞在聚乳酸-聚乙醇酸共聚物支架上粘附与增殖的研究

目的：研究成人牙髓干细胞（HDPSCs）在聚乳酸-聚乙醇酸共聚物（PLGA）支架上粘附与增殖的情况。方法：采用酶消化法分离、培养人牙髓干细胞,免疫组化法及体外诱导分化对细胞进行鉴定。将人牙髓干细胞与PLGA支架材料进行复合培养,扫描电镜（SEM）观察支架材料形态,细胞粘附、增殖及基质分泌情况;细胞计数检测其增殖力。结果：细胞接种2、5、10d,扫描电镜及细胞计数均显示HDPSCs与PLGA支架材料粘附紧密,生长状态良好,细胞明显增殖（P〈0.05）,有丰富的细胞外基质形成。结论：PLGA是一种适宜人牙髓干细胞粘附与增殖的支架材料。     

牙髓干细胞在组织再生及细胞治疗中的研究进展

<正>在人体发育过程中,组织器官高度分化,行使不同功能,组成复杂的人体结构。一部分组织器官仍保留着一定再生功能。如上皮组织、肝组织等,而大部分组织器官只具有部分再生能力。如骨、软骨、神经组织。这些组织器官在创伤、感染、肿瘤等疾病破坏后再生能力较弱,给医学带来极大的挑战。近年来,组织再生及细胞治疗的发展为解决上述问题展现出美好的前景。干细胞用于组织再生及细胞治     

Characterization of Dental Pulp Stem Cells Isolated from Canine Premolars

Introduction

Dogs are commonly used animal models for regenerative endodontics research. Although several studies have used stem cells isolated from dog teeth to investigate the dentin/pulp regeneration in vivo, less attention has been paid for the characterization of these cells. Therefore, this study aimed to characterize the dental pulp stem cells isolated from dog teeth (cDPSCs) in order to further define the dog as an animal model for regenerative endodontics.

Methods

Stem cells were isolated from freshly extracted premolars of 10-month-old Beagles. The isolated cells were investigated for their stem cell properties by analysis of their clonogenic and growth characteristics; expression of mesenchymal stem cell markers; and evaluation of their osteo/odontogenic, adipogenic, and neurogenic potential.

Results

A colony formation assay showed the existence of a clonogenic cell population in cDPSCs isolated. The growth curves revealed a higher proliferation rate of cDPSCs compared with hBMMSCs. cDPSCs expressed mesenchymal stem cell markers STRO-1, CD146, and Nanog. However, they were negative for CD73, CD105, and CD45. cDPSCs were able to differentiate into odontoblast-like cells as shown by increased alkaline phosphatase activity, dentin sialoprotein expression, and formation of mineralized nodules. cDPSCs also showed the neurogenic and adipogenic differentiation potential at a lower level compared with those of hDPSCs and hBMMSCs.

Conclusions

The results of this study confirmed the stem cell properties of cDPSCs at a comparable level to those of hDPSCs and hBMMSCs. Overall, the data presented in this study provide evidence in supportive of using cDPSCs and dogs as an animal model in dental tissue engineering via stem cell-based approaches.     

Mesenchymal Stem Cells Derived from Human Inflamed Dental Pulp Exhibit Impaired Immunomodulatory Capacity In Vitro

IntroductionDental pulp stem cells (DPSC) are very attractive in regenerative medicine. In this study, we focused on the characterization of the functional properties of mesenchymal stem cells derived from DPSCs. Currently, it is unknown whether inflammatory conditions present in an inflamed dental pulp tissue could alter the immunomodulatory properties of DPSCs. This study aimed to evaluate the immunomodulatory capacity in vitro of DPSCs derived from healthy and inflamed dental pulp.MethodsDPSCs from 10 healthy and inflamed dental pulps (irreversible pulpitis) were characterized according to the minimal criteria of the International Society for Cell Therapy, proliferation, differential potential, and colony-forming units. Furthermore, the immunomodulatory capacity of DPSCs was tested on the proliferation of T lymphocytes by flow cytometry and the in vitro enzyme activity of indoleamine 2, 3-dioxygenase.ResultsThere were no significant differences in the DPSC characteristics and properties such as immunophenotype, tridifferentiation, colony-forming units, and proliferation of the DPSCs derived from normal and inflamed pulp tissue. Furthermore, there were significant differences in the immunomodulatory capacity of DPSCs obtained from human healthy dental pulp and with the diagnosis of irreversible pulpitis.ConclusionsOur results showed that DPSCs isolated from inflamed dental pulp showed typical characteristics of MSCs and diminished immunosuppressive capacity in vitro in comparison with MSCs derived from healthy dental pulp. Further investigation in vivo is needed to clarify the mechanism of this diminished immunosuppressive capacity.     

Notch信号分子于小鼠牙髓干细胞样细胞表达的研究

目的　研究Notch基因在小鼠牙髓干细胞样细胞表达。方法　采用酶消化培养法获得小鼠的单个牙髓细胞悬液,调整细胞密度为1×104个/孔细胞,干细胞培养液培养14 d,挑选细胞克隆扩增,提取细胞的总RNA,反转录聚合酶联反应(RT-PCR)检测Notch基因的表达。结果　小鼠牙髓细胞呈集落状生长,克隆形成率约为1·6 ~2·5 个/104细胞,所形成的集落细胞结合紧密,细胞胞体小、胞核大,RT-PCR结果显示Notch的mRNA在牙髓干细胞样细胞中有表达。结论　培养的集落状生长的小鼠牙髓细胞具有干细胞增殖快的特性,Notch基因于牙髓干细胞中表达,表明Notch信号参与了牙髓干细胞样细胞的早期分化的调控过程。     

Effect of EDTA on Attachment and Differentiation of Dental Pulp Stem Cells

Introduction

In regenerative endodontics, it is believed that EDTA induces odontoblast differentiation by releasing growth factors from the dentin matrix. The aim of this study was to evaluate the effect of EDTA on the attachment and differentiation of dental pulp stem cells (DPSCs). We also investigated whether the behavioral changes of DPSCs could be caused by biochemical components released from EDTA-treated dentin.

Methods

Cells were obtained from human third molars, and the stem-like nature of the cells was investigated by flow cytometric analysis. DPSCs were seeded on EDTA-treated and untreated dentin slices. After 3 days of culture, cell attachment was evaluated by cell density, fibronectin 1 gene expression level using quantitative real-time polymerase chain reaction, and scanning electron microscopy. After 21 days of culture, the expression of differentiation genes was investigated by quantitative real-time polymerase chain reaction, and calcification was observed using alizarin red S staining. To investigate the EDTA-induced growth factor release, DPSCs were cultured with or without direct contact with the EDTA-treated dentin surface.

Results

After 3 days of culture, both the cell density and fibronectin expression level were significantly higher in the EDTA-treated dentin group. After 3 weeks, the DPSCs on the EDTA-treated dentin surfaces showed higher expression levels of dentin sialophosphoprotein and dentin matrix protein 1, whereas the DPSCs cultured without direct contact with the EDTA-treated dentin surfaces did not exhibit these findings.

Conclusions

Our results showed that EDTA induced cell attachment and odontoblastic/osteoblastic differentiation, which was observed only in the group in which the DPSCs were placed in direct contact with the EDTA-treated dentin surfaces. These findings suggest that EDTA is beneficial for achieving successful outcomes in regenerative endodontics.     

2-Hydroxyethyl Methacrylate Inhibits Migration of Dental Pulp Stem Cells

Introduction

Cell migration is an important step in pulpal wound healing. Although components in the resin-based dental materials are known to have adverse effects on pulp wound healing including proliferation and mineralization, their effects on cell migration have been scarcely examined. Here, we investigated the effects of 2-hydroxyethyl methacrylate (HEMA) on the migration of dental pulp stem cells (DPSC) in vitro.

Methods

Cell viability was assessed using the MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay, and cell migration was evaluated using the wound scratch assay and transwell migration assay at noncytotoxic doses. The Western blot was used to examine pathways associated with migration such as focal adhesion kinase, mitogen-activated protein kinase, and glycogen synthase kinase 3.

Results

There were no drastic changes in the cell viability below 3 mmol/L HEMA. When DPSCs were treated with HEMA at 0.5, 1.0, and 2.5 mmol/L, cell migration was diminished. HEMA-treated DPSCs exhibited the loss of phosphorylated focal adhesion kinase in a dose-dependent manner. The HEMA-mediated inhibition of cell migration was associated with phosphorylation of p38 but not glycogen synthase kinase 3, Extracellular signal-related kinase (ERK), or c-Jun N-terminal kinase (JNK) pathways. When we inhibited the p38 signaling pathway using a p38 inhibitor, the migration of DPSCs was suppressed.

Conclusions

HEMA inhibits the migration of dental pulp cells in vitro, suggesting that poor pulpal wound healing under resin-based dental materials may be caused, in part, by the inhibition of cell migration by HEMA.