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。     

Leptin受体在人牙髓干细胞中表达的实验研究

目的:研究体外培养人牙髓干细胞表型特征及生物学性状,检测Leptin受体在牙髓干细胞表面的表达.方法:采用组织块法和酶消化法分离培养人牙髓十细胞;免疫组化法、免疫荧光法检测细胞表面分子的表达;体外诱导分化实验检测细胞多向分化能力.免疫组化法检测Leptin受体在人牙髓干细胞表面的表达.结果:分离获得的牙髓干细胞波形丝蛋白和CD146表达阳性,具有向脂肪细胞和成骨细胞分化的潜能;Leptin受体在牙髓干细胞表面阳性表达.结论:分离培养的牙髓干细胞具有干细胞的表型特征及生物学性状,Leptin受体可表达于牙髓干细胞.     

外周神经胶质细胞：牙髓干细胞的新来源

来源于早期外胚间充质组织头部的神经嵴细胞迁移衍生出牙髓间充质干细胞,随后这些细胞产生牙髓细胞和成牙本质细胞。神经胶质细胞是另外一个神经嵴细胞衍生迁移而形成的细胞系。神经胶质细胞有广泛的分化发育潜能,研究发现神经胶质细胞可以分化为神经细胞和牙髓间充质干细胞,并且神经胶质细胞的不同分化发育阶段间可以互相转变。通常认为,大多数组织中的间充质干细胞来源于血管周细胞,但有研究发现相当一部分牙髓间充质干细胞来源于外周神经相关的神经胶质。本文通过对神经嵴细胞、牙髓间充质干细胞和神经胶质细胞的分化发育以及神经胶质细胞的衍生细胞的概述,介绍牙髓再生领域一种新的更有前景的牙髓间充质干细胞来源。     

人恒牙牙髓干细胞分化为脂肪细胞的体外实验研究

目的验证人恒牙牙髓组织来源的牙髓干细胞在体外向脂肪细胞的定向分化,并对分化后的细胞进行鉴定。方法从正畸治疗减数拔除的恒前磨牙中分离牙髓组织,应用酶消化法获得牙髓细胞。单抗Stro-1标记、免疫磁珠阳性分选系统分选获得牙髓干细胞,第3代牙髓干细胞用成脂肪向诱导培养基向脂肪细胞诱导分化。用油红O染色鉴定成脂肪向分化,RT-PCR检测脂肪细胞的特异相关或标志基因。以同期培养的未诱导的普通培养基培养的DPSCs做阴性对照;以同期培养的骨髓间充质干细胞成脂肪向分化的结果做阳性对照。结果人恒牙牙髓干细胞经成脂肪向培养基诱导后表现出脂肪细胞特性,油红O染色结果为阳性,RT-PCR检测成脂肪向分化相关基因过氧化物酶增殖物激活受体γ2、脂肪酶结合蛋白aP2和脂蛋白脂酶均有阳性表达。结论人恒牙牙髓干细胞在体外具有分化为脂肪细胞的潜能。     

Definitive differentiation from human dental pulp stem cells to adipocyte in vitro

目的 验证人恒牙牙髓组织来源的牙髓干细胞在体外向脂肪细胞的定向分化,并对分化后的细胞进行鉴定.方法 从正畸治疗减数拔除的恒前磨牙中分离牙髓组织,应用酶消化法获得牙髓细胞.单抗Stro-1标记、免疫磁珠阳性分选系统分选获得牙髓干细胞,第3代牙髓干细胞用成脂肪向诱导培养基向脂肪细胞诱导分化.用油红O染色鉴定成脂肪向分化,RT-PCR检测脂肪细胞的特异相关或标志基因.以同期培养的未诱导的普通培养基培养的DPSCs做阴性对照;以同期培养的骨髓间充质干细胞成脂肪向分化的结果做阳性对照.结果 人恒牙牙髓干细胞经成脂肪向培养基诱导后表现出脂肪细胞特性,油红O染色结果为阳性,RT-PCR检测成脂肪向分化相关基因过氧化物酶增殖物激活受体γ2、脂肪酶结合蛋白aP2和脂蛋白脂酶均有阳性表达.结论 人恒牙牙髓干细胞在体外具有分化为脂肪细胞的潜能.     

组蛋白去甲基化酶FBXL11抑制牙髓干细胞成骨和成牙本质分化

目的 研究组蛋白去甲基化酶FBXL11对牙髓干细胞定向分化能力的影响.方法 成骨分化诱导培养基诱导牙髓干细胞体外成骨/成牙本质分化.逆转录病毒转染构建过表达FBXL11的牙髓干细胞稳定转染细胞,进行FBXL11获得性功能研究.碱性磷酸酶活性实验及碱性磷酸酶染色检测成骨/成牙本质分化早期分化指标-碱性磷酸酶活性.茜素红染色及钙离子定量分析检测牙髓干细胞体外成骨/成牙本质分化能力.实时定量RT-PCR检测FBXL11及成骨/成牙本质分化相关基因-骨涎蛋白、骨桥蛋白和骨钙素的表达.结果 成骨诱导牙髓干细胞抑制FBXL11的表达.过表达FBXL11明显抑制牙髓干细胞的碱性磷酸酶活性、牙髓干细胞体外矿化能力以及骨涎蛋白和骨桥蛋白的表达.结论 组蛋白去甲基化酶FBXL11具有抑制牙髓干细胞成骨和成牙本质分化的潜能.     

人恒牙牙髓干细胞体外定向诱导分化为成骨细胞的研究

目的:研究人恒牙牙髓组织来源的牙髓干细胞在体外分化为成骨细胞的能力,探讨其作为骨组织工程种子细胞的可行性.方法:从正畸治疗减数拔除的恒前磨牙中分离牙髓组织,应用酶消化法获得牙髓细胞.单抗Stro-1标记、免疫磁珠阳性分选系统分选获得牙髓干细胞,第3代牙髓干细胞用成骨向诱导培养基向成骨细胞诱导分化.用碱性磷酸酶染色和Vo...     

猪牙胚细胞条件培养基可诱导人牙髓干细胞的牙向分化

牙源性干细胞的分化受其所处的局部微环境所调控。以往研究表明牙胚细胞条件培养基可诱导牙髓干细胞向成牙的细胞谱系分化。然而，采用人牙胚细胞条件培养基诱导在实际操作中不可行，所以推测异种的牙胚细胞条件培养基可能对人牙髓干细胞产生类似的效应。本研究采用猪的牙胚细胞条件培养基（pTGC-cM）来诱导人牙髓干细胞，评估其诱导前后的细胞形态学、集落形成、体外多向分化、与成牙相关的蛋白和基因表达、体内分化能力等。     

牙髓干细胞及其在组织工程中的研究进展

牙髓干细胞是具有自我更新能力和多向分化潜能,在一定条件下可向特定的细胞类型分化,产生数个亚系的前体细胞。牙髓干细胞在组织工程和临床应用中,可达到组织和器官再造的目的,具有广阔的前景。下面就牙髓干细胞的基本生物学特性、特异性表面标记及其在组织工程中的应用作一综述。     

SV40-LT基因使牙髓干细胞永生化的研究

目的:分离牙髓干细胞,用含有SV40-LT抗原的慢病毒感染牙髓干细胞以建立永生化细胞株并进行鉴定。方法:消化法获得牙髓干细胞;用慢病毒粒子HBLV-SV40LT-3*flag-PURO感染目的细胞,抗生素筛选出稳定传代的细胞株,并进行干性测定。结果:原代与永生化的牙髓干细胞(iDPSCs)在分化能力及表面标记物的检测无差异;Real-time PCR结果显示,感染组细胞中SV40-LT基因的转录水平显著提高;Western blot结果显示,实验组均可检测到标签蛋白Flag的表达。结论:含有SV40-LT基因片段的慢病毒可使人牙髓干细胞发生永生化,永生化后的细胞仍具有多向分化潜能。     

牙髓干细胞的生物学性能及临床应用研究进展

牙髓干细胞是一类具有自我更新、多向分化、高度增殖能力的外胚间充质干细胞,可为组织器官修复和多种疾病治疗提供细胞来源.本文通过总结相关文献,对牙髓干细胞的一般生物学特性进行论述,并探讨其成骨/成牙本质、成肌/成血管和神经再生的机制,以及其在糖尿病和眼部疾患的临床前应用.同时结合了国内外有关牙髓干细胞的最新临床应用进展,给...     

生长因子对牙髓干细胞的矿化作用

健康牙髓中含有的具有多向分化、高效增殖和自我更新潜能的牙髓干细胞,在牙髓损伤后牙本质修复再生和牙/骨组织工程中具有至关重要的作用.本文就牙髓干细胞的矿化潜能、生长因子及其在促牙髓干细胞矿化和作用机制方面的研究进展作一综述.     

牙髓干细胞分化的研究进展

牙髓干细胞(DPSC)是一种具有高度增生、自我更新能力和多相分化潜能的成体干细胞,在一定条件下可向特定的细胞类型分化,在牙髓修复和牙齿再生中发挥着重要的作用。本文主要就DPSC成骨向分化、成牙本质向分化的研究进展作一综述。     

牙髓干细胞及其表面特异标志物

牙髓干细胞是位于牙髓组织中的一种成体干细胞,具有高度增殖与多向分化的能力。牙髓干细胞的出现,为牙髓病的治疗提供了新的治疗途径。下面就牙髓干细胞及其表面特异性标志物的研究进展作一综述。     

Isolation and characterization of dental pulp stem cells from a supernumerary tooth

Background: Dental pulp stem cells (DPSCs) were primarily derived from the pulp tissues of primary incisors and permanent third molar teeth, whereas no report to our knowledge has yet been documented on deriving DPSCs from the other tooth types. The aim of this study is to present a novel approach of harvesting stem cells from a supernumerary tooth (a mesiodens). Materials and methods: The pulp tissues from a mesiodens of a 20‐year‐old healthy male patient and the left lower deciduous canine of a healthy 10‐year‐old boy (the positive control) were extracted and cultured for DPSCs, which were examined with stem cells (Oct‐4, Nanog and Rex‐1) and differentiation (Osteonectin and Nestin) markers. Furthermore, DPSCs were directionally differentiated to osteogenic and adipogenic cell lineages. Results: Dental pulp stem cells derived from the mesiodens were capable of differentiating into adipogenic and osteogenic lineages. The mesioden’s DPSCs also expressed stem cell and differentiation markers, which suggested their stem cell origin and differentiation capability. All the aforementioned results for the mesiodens were consistent with those of the DPSCs derived from the positive control. Conclusion: We have demonstrated the feasibility of deriving DPSCs from a usually discarded tissue such as a supernumerary tooth.     

Differentiation of dental pulp stem cells into a neural lineage

We previously investigated whether dental pulp-derived cells possess similar pluripotency to bone marrow cells, and reported their capacity to differentiate into osteoblasts, as well as the characteristics of the stem cells present in dental pulp. In the present study, we hypothesized that neural stem cells would also exist in rat dental pulp, similar to bone marrow and the brain, and attempted to induce their differentiation into a neural lineage by applying an in vitro study design previously reported to induce differentiation of human bone marrow cells. Before inducing differentiation, we detected cells expressing nestin (Nes), which is known to be a marker for neural stem cells, within primary cultures of rat dental pulp-derived cells, suggesting the existence of neural stem cells in dental pulp. Quantitative analyses of the mRNA and protein expression levels revealed downregulation of both the Nes mRNA and protein levels to about 68.1% and 12.4%, respectively, after the induction of differentiation compared to the corresponding levels before induction. Conversely, the glial fibrillary acidic protein (Gfap) mRNA level was elevated by 1.3-fold after the induction of differentiation compared with the level before induction. The reduced number of Nes-positive cells and decreased Nes mRNA and protein levels after the induction of differentiation may be attributed to differentiation of neural stem cells into a neural lineage. Moreover, the increased number of Gfap-positive cells and increased Gfap mRNA level after the induction of differentiation most likely support their progressive differentiation into a glial cell lineage, since Gfap is a marker that is upregulated in glial cells. Our present data demonstrate the existence of neural stem cells in tissues other than the central nervous system, and may represent a significant step toward providing more diverse and multiple sources of stem cells for future regenerative medicine.     

牙髓干细胞分化过程中L型钙离子通道羧基末端的表达

目的:探讨牙髓干细胞(DPSCs)分化过程中L型钙离子通道羧基末端的表达。方法:利用酶消化法体外分离、培养大鼠牙髓干细胞;吉姆萨染色法检测大鼠牙髓干细胞的克隆形成能力;神经诱导体系下诱导牙髓干细胞向神经样细胞分化,免疫荧光染色检测细胞分化后胶质纤维酸蛋白(glial fibrillary acidic pro-tein,GFAP)的表达和细胞分化前后L型钙离子通道Cav 1.2及羧基末端的表达。结果:牙髓干细胞的克隆形成能力为每1 000个细胞形成2～17个克隆;免疫荧光染色检测诱导后细胞GFAP表达阳性;免疫荧光染色检测显示:牙髓干细胞分化前L型钙离子通道Cav 1.2羧基末端表达于细胞膜上,细胞分化后羧基末端同时表达于细胞膜上和细胞核中。结论:L型钙离子通道Cav 1.2羧基末端在牙髓干细胞分化过程中发生核转位,羧基末端可能在牙髓干细胞的分化过程中发挥着一定的作用。     

Dental pulp stem cells, niches, and notch signaling in tooth injury

Stem cells guarantee tissue repair and regeneration throughout life. The decision between cell self-renewal and differentiation is influenced by a specialized microenvironment called the 'stem cell niche'. In the tooth, stem cell niches are formed at specific anatomic locations of the dental pulp. The microenvironment of these niches regulates how dental pulp stem cell populations participate in tissue maintenance, repair, and regeneration. Signaling molecules such as Notch proteins are important regulators of stem cell function, with various capacities to induce proliferation or differentiation. Dental injuries often lead to odontoblast apoptosis, which triggers activation of dental pulp stem cells followed by their proliferation, migration, and differentiation into odontoblast-like cells, which elaborate a reparative dentin. Better knowledge of the regulation of dental pulp stem cells within their niches in pathological conditions will aid in the development of novel treatments for dental tissue repair and regeneration.     

成牙本质细胞特异分子标志物的研究进展

牙髓干细胞是一类存在于牙髓组织中,保持着高度的增殖和分化潜能,受到刺激后能向终末细胞分化的细胞。在牙髓干细胞的研究过程中,常需要根据成牙本质细胞分子标记物的表达来判断牙髓干细胞的分化进程。随着研究的进展,可供选择的成牙本质细胞分子标记物也越来越广泛。下面就成牙本质细胞分化的特异分子标记物的研究进展作一综述。     

Stem cells and the dental pulp: potential roles in dentine regeneration and repair

The dentine-pulp complex displays exquisite regenerative potential in response to injury. The postnatal dental pulp contains a variety of potential progenitor/stem cells, which may participate in dental regeneration. A population of multipotent mesenchymal progenitor cells known as dental pulp stem cells with high proliferative potential for self-renewal has been described and may be important to the regenerative capacity of the tissue. The nature of the progenitor/stem cell populations in the pulp is of importance in understanding their potentialities and development of isolation or recruitment strategies, and allowing exploitation of their use in regeneration and tissue engineering. Various strategies will be required to ensure not only effective isolation of these cells, but also controlled signalling of their differentiation and regulation of secretory behaviour. Characterization of these cells and determination of their potentialities in terms of specificity of regenerative response will form the foundation for development of new clinical treatment modalities, whether involving directed recruitment of the cells and seeding of stem cells at sites of injury for regeneration or use of the stem cells with appropriate scaffolds for tissue engineering solutions. Such approaches will provide an innovative and novel biologically based new generation of clinical treatments for dental disease.