MG132诱导HL-60细胞表达共刺激分子CD86及其对混合淋巴细胞反应的影响

本研究探讨蛋白酶体抑制剂MG132诱导HL-60细胞表达共刺激分子CD80、CD86及其对混合淋巴细胞反应的作用.流式细胞仪检测MG132诱导HL-60细胞表达共刺激分子CD80、CD86及细胞活力;逆转录聚合酶链反应（RT-PCR）分析CD80和CD86 mRNA表达情况;MG132诱导HL-60细胞表达共刺激分子CD86后,用75 GyCo-60照射HL-60细胞,杀死HL-60细胞,保留抗原性作为刺激细胞,用健康人外周血单个核细胞作为反应细胞,用不同浓度HL-60细胞刺激健康人单个核细胞,HL-60细胞对健康人单个核细胞的增殖作用.结果表明：MG132上调HL-60细胞表达CD86,MG132诱导HL-60细胞的凋亡率呈浓度依耐性和时间依耐性.结论：高浓度的MG132对HL-60细胞有直接杀灭作用,低浓度MG132诱导HL-60细胞表达共刺激分子CD86,对健康人单个核细胞有增殖作用.MG132诱导HL-60细胞表达共刺激分子CD86,能促进健康人单个核细胞的增殖.     

牙髓干细胞的研究与进展

综合分析牙髓干细胞的研究现状及发展方向，以期更好地分离鉴定牙髓干细胞，提高牙髓干细胞的体外增殖活性。通过对入选文献进行分析整理，将牙髓干细胞从干细胞理论、牙髓干细胞概念、牙髓干细胞生物学特性及牙髓干细胞培养4方面进行分析。虽然目前对牙髓干细胞的生物学特性、培养方法及应用前景已有一定了解，但牙髓干细胞的体外培养扩增、鉴定和分子机制等问题尚未完全清楚，这对牙髓干细胞的应用起到决定性作用。牙髓组织取材容易，利用牙髓干细胞研究牙齿器官发育、牙髓损伤修复的分子机制，以期最终能寻找更好地解决牙髓组织损伤修复的治疗方法。     

牙髓干细胞的研究与进展

综合分析牙髓干细胞的研究现状及发展方向，以期更好地分离鉴定牙髓干细胞，提高牙髓干细胞的体外增殖活性。通过对入选文献进行分析整理，将牙髓干细胞从干细胞理论、牙髓干细胞概念、牙髓干细胞生物学特性及牙髓干细胞培养4方面进行分析。虽然目前对牙髓干细胞的生物学特性、培养方法及应用前景已有一定了解，但牙髓干细胞的体外培养扩增、鉴定和分子机制等问题尚未完全清楚，这对牙髓干细胞的应用起到决定性作用。牙髓组织取材容易，利用牙髓干细胞研究牙齿器官发育、牙髓损伤修复的分子机制，以期最终能寻找更好地解决牙髓组织损伤修复的治疗方法。     

人牙髓干细胞的体外培养及神经样诱导分化

背景：牙髓组织来源干细胞的发现及概念的确立有助于从细胞水平上认识牙齿发育和再生修复机制。目的：了解人牙髓干细胞向神经元样细胞诱导分化能力和诱导分化条件。方法：取健康青年人的第三磨牙的牙髓组织后,制成单细胞悬液,加入含有体积分数为15%胎牛血清α-MEM培养基在6孔板培养,传代培养后加入丁羟基茴香醚、forskolin、β-巯基乙醇、碱性成纤维细胞生长因子诱导剂进行培养。结果与结论：免疫荧光和反转录-聚合酶链反应检测显示,诱导2周后人牙髓细胞除了stro-1,Col-Ⅰ,牙本质涎蛋白表达阳性外,还有巢蛋白,神经元特异性烯醇化酶的表达也是阳性,而牙龈纤维细胞表达均为阴性。说明人牙髓组织中存在成体干细胞,在一定的诱导培养条件下,牙髓干细胞有向神经元样细胞分化的潜能。     

兔牙髓细胞的体外增殖及鉴定

背景:牙髓干细胞的多分化潜能、高扩增速率和容易获取使之成为引人注目的间充质干细胞来源。目的:观察兔牙髓细胞增殖特性并进行细胞表面标志物的鉴定。方法:体外分离培养兔牙髓细胞,采用酶解组织块法培养细胞至第3代观察细胞形态变化、计数细胞活率、细胞克隆形成率、细胞生长曲线、细胞增殖周期以及细胞表面标志物的鉴定。结果与结论:酶解组织块法可以较快的收获各代兔牙髓细胞。第3代到第6代细胞活率分别比为94.7%∶95.8%∶95.2%∶95.3%,细胞的克隆形成率为18个/2000;细胞的生长曲线基本符合间充质细胞特征,细胞周期G0/G1期大于80%;免疫细胞化学vimentin、CD44、osteonectin、Dsp均为阳性表达。证实兔牙髓细胞中可分离培养出牙髓干细胞,并能在体外有效增殖。     

干细胞因子促进牙髓干细胞增殖与骨向分化能力

背景:干细胞因子作为对干细胞的增殖分化具有一定促进作用的因子,是否影响牙髓干细胞的生物学特性从而在牙齿再生中发挥重要作用尚不清楚.目的:观察干细胞因子对人牙髓干细胞增殖与骨向分化能力的影响.方法:采用酶消化法培养因正畸需要拔H{的健康人牙的牙髓组织,接种于培养板,加入含1,10 μmol/L干细胞因子的培养液,以正常培养液作为对照.MTT法检测细胞增殖,real-time PCR检测成骨相关基因骨唾液蛋白、骨钙素Mrna的表达,碱性磷酸酶试剂盒检测碱性磷酸酶活性.结果与结论:干细胞因子对牙髓干细胞的增殖具有促进作用,干细胞因子上调了骨唾液蛋白、骨钙素Mrna的表达,增强了牙髓干细胞的碱性磷酸酶活性,且具有随浓度增加促进作用增强的趋势.提示干细胞因子可以促进人牙髓干细胞的增殖及骨向分化能力.     

不同发育阶段小鼠纹状体神经干细胞的体外增殖和分化情况比较

目的：分析胚胎、新生以及成年小鼠纹状体神经干细胞的体外培养和分化条件，并比较其体外增殖和分化情况。方法：实验于2005-02／05在解放军第四军医大学西京医院神经内科实验室完成。选取孕14d小鼠、出生24h内的新生小鼠和4月龄的成年小鼠各1只用于实验。①神经干细胞的原代培养：分别将孕14d小鼠、新生小鼠和成年小鼠处死后取出纹状体组织，轻轻吹打制成单个细胞悬液，接种于无血清的D／F12培养基中，每六七天机械分离克隆传代1次。②神经干细胞的鉴定：采用有限稀释法获得神经干细胞单克隆，继续培养得到大量来自单个细胞的亚克隆。对神经球行免疫荧光染色鉴定。③通过四甲基偶氮唑盐比色法及免疫荧光染色比较胚胎鼠、新生鼠及成年小鼠的神经干细胞的增殖和分化情况。结果：①成功地从胚胎鼠、新生鼠以及成年小鼠的纹状体中分离培养出神经干细胞。②胚胎鼠、新生鼠及成年小鼠的神经干细胞分化为神经元的比例均为7％～11％，分化为星形胶质细胞的比例均为76％～88％，差异无显著性意义（P〉0．01）。③与成年小鼠比较，胚胎鼠和新生鼠的神经干细胞增殖旺盛（P〈0．01），而胚胎鼠和新生鼠之间差异无显著性意义。结论：随着小鼠年龄的增加纹状体神经干细胞的增殖能力逐渐减弱，但仍保持着分化为神经元和胶质子细胞的能力。胚胎和新生鼠源性的神经干细胞均具有较强的增殖能力，为寻找理想的移植细胞提供了思路。     

MHC五聚体方法检测基因疫苗体外诱导的抗原特异性细胞毒T淋巴细胞

目的 探讨MHC五聚体方法检测在体外用抗B细胞淋巴瘤基因疫苗(简称基因疫苗)刺激PBMC生成抗原特异性CTL的效率.方法 用于细胞培养的4份血液标本来自2例B淋巴细胞肿瘤患者(1例为滤泡性淋巴瘤患者,另1例为毛细胞白血病患者)和2名健康对照者.分别检测上述标本中PBMC受基因疫苗刺激后CTL生成情况.PBMC贴壁培养获得DC前体,在重组细胞因子GM-CSF和IL4的支持下诱导培养DC,采用基因枪方法将基因疫苗质粒导入DC,RT-PCB方法检测转染后细胞IgHV1-GM-CSF mRNA的转录,ELISA方法检测细胞因子GM-CSF的表达,并验证转染是否获得有效表达.转染后的DC再与从PBMC中获得的淋巴细胞共培养,诱导抗原特异性的CTL;共进行2次DC刺激,共计培养24 d,分别在培养前、培养第7天、第17天及第24天收获培养细胞,培养分为转染基因疫苗组和转染对照质粒组,流式细胞术分析培养细胞中CD3+ CD8+细胞亚群的水平;用针对基因疫苗抗原肽抗原表位的MHC五聚体荧光抗体检测CTL产生水平.结果 基因枪颗粒轰击方法转染DC后,RT-PCR结果显示转染得到了表达;转染基因疫苗组的DC中GM-CSF含量为(28±6)ng/106个细胞,而转染对照质粒组的DC中GM-CSF含量为(10±3)ng/106个细胞,差异有统计学意义(t=5.191,P<0.01).分析培养后的T淋巴细胞亚群,显示随着培养时间的延长,CD3+CD8+细胞亚群比例明显增加,转染对照质粒组在培养前、培养第7天、第17天和第24天的比例分别为(34.24±2.72)%,(46.06±3.08)%,(65.34±4.26)%,(73.86±4.85)%,而在转染基因疫苗组,其比例分别为(32.28±2.08)%,(45.32±3.81)%,(63.37±4.21)%,(75.01±3.20)%.两因素方差分析显示培养不同时间点的CD3+CD8+细胞亚群比例差异有统计学意义(F培养时间=176.966,P<0.01),但转染因素本身对其产生的影响差异无统计学意义(F转染因素=0.657,P>0.05).MHC五聚体检测结果显示转染基因疫苗组的DC能够诱导针对该表位的抗原特异性CTL产生,CTL水平随着DC的刺激逐渐增高;在培养第24天,健康对照者最高获得2.03%的CTL,滤泡性淋巴瘤患者的CTL达4.36%,而毛细胞白血病患者为3.89%.结论 MHC五聚体方法能够有效检测基因疫苗诱导的抗原特异性CTL;该方法对于抗肿瘤细胞免疫的检测、肿瘤患者的细胞免疫状态及早期预后判定可能是一项有前景的临床检验方法.     

人牙髓干细胞增殖与瞬时受体电位M7通道的作用

背景：瞬时受体电位M7通道广泛存在于机体组织和细胞,对细胞存活、增殖和维持细胞镁离子平衡是必须的.目的：探讨瞬时受体电位M7通道对人牙髓干细胞增殖的作用.方法：酶消化法分离培养人牙髓干细胞,运用不同浓度（50,100μmol/L）瞬时受体电位M7通道抑制剂2-氨基乙基二苯硼酸酯作用于人牙髓干细胞72 h后,Western-blot 检测2-氨基乙基二苯硼酸酯对瞬时受体电位M7通道蛋白水平的影响,MTT法观察其对人牙髓干细胞增殖的影响;构建特异抑制瞬时受体电位M7通道表达慢病毒载体,运用慢病毒感染人牙髓干细胞.进行RT-PCR和Western-blot沉默效果分析,在1,3,5,7 d进行MTT法检测特异沉默瞬时受体电位M7通道后对细胞增殖的影响.结果与结论：50,100μmol/L 2-氨基乙基二苯硼酸酯均能抑制瞬时受体电位M7通道蛋白水平的表达并且能明显抑制人牙髓干细胞增殖（P 〈0.01）,特异性沉默瞬时受体电位M7通道表达后,在不同时间段人牙髓干细胞增殖能力均明显降低（P 〈0.01）.提示瞬时受体电位M7通道对维持人牙髓干细胞增殖能力有重要作用.     

Bioactive injectable aggregates with nanofibrous microspheres and human dental pulp stem cells: A translational strategy in dental endodontics

Regeneration of the pulp–dentin complex with stem cells is a potential alternative to conventional root canal treatments. Human dental pulp stem cells (hDPSCs) have been extensively studied because of their ability to proliferate and differentiate into mineralized dental and non‐dental tissues. Here we combined hDPSCs with two types of injectable poly‐l ‐lactic acid (PLLA) microsphere with a nanofibrous or smooth surface to form bioactive injectable aggregates, and examined their ability to promote pulp regeneration in the root canal in an in vivo model. We investigated the biocompatibility, biosafety and odontogenic potential of fibrous (F‐BIM) and smooth bioactive injectable microspheres (S‐BIM) in vitro and in vivo. Our results demonstrated that PLLA microspheres and hDPSCs were able to form bioactive injectable aggregates that promoted dentin regeneration in both in vitro and in vivo models. Our results suggest that F‐BIM and S‐BIM may induce dentinogenesis upon in vivo grafting, and propose that the potential usefulness of the microsphere–hDPSC aggregates described here should be evaluated in clinical settings. Copyright © 2017 John Wiley & Sons, Ltd.     

The odontogenic potential of STRO-1 sorted rat dental pulp stem cells in vitro

The presence of heterogeneous cell populations in dental pulp may count for the considerable variation in the outcome of in vitro and in vivo experiments. Here, we intended to determine whether a minor cell sub-population of high proliferation and odontogenic potential existed among a larger compartment of perhaps more committed progenitors. In this study, the STRO-1 antigen, defining a mesenchymal stem cell or progenitor subpopulation, was used for separating rat dental pulp cells with fluorescence-activated cell sorting (FACS). Subsequently, the STRO-1 positive cells were tested for their ability to differentiate towards an odontoblast-like phenotype. Three cell populations (STRO-1 positive, STRO-1 negative, and non-sorted cells) were cultured in odontogenic medium containing dexamethasone and beta-glycerophosphate. Cultures were analyzed by light- and scanning electron microscopy (SEM), and assessed for proliferation, ALP activity, and calcium content. Results showed that the STRO-1 positive cell population was able to differentiate into the odontoblast phenotype, similar to the non-sorted population. The negative cells however showed a fibroblast-like phenotype. SEM and real-time PCR confirmed such results. In conclusion, the STRO-1 selection proved applicable for rat-derived material, to obtain a cell population which is more homogeneous. This positive cell fraction was capable of differentiating into the odontogenic pathway, whereas the negative fraction was not. However, the effect was not always advantageous, when compared to non-sorted cells.     

牙髓干细胞在组织工程研究中的应用

背景：牙髓干细胞是来源于牙髓组织中的一种成体干细胞,该种细胞具有高度增殖、自我更新的能力和多向分化潜能.通过对牙髓干细胞的深入研究,有助于人类为组织工程研究提供可能的细胞来源,进而指导临床相关治疗与预防.目的：就牙髓干细胞的研究现状及其在组织工程中的应用作一综述.方法：应用计算机检索CNKI和Pubmed数据库中2000年1月至2012年5月关于牙髓干细胞的文章,在标题和中以“牙髓干细胞,诱导,培养,分化”或“dental pulp stem cel s,culture,induced, differentiation”为检索词进行检索.选择文章内容与牙髓干细胞有关者,同一领域文献则选择近期发表或发表在权威杂志文章.初检得到205篇文献,根据纳入标准选择关于牙周局部缓释剂的44篇文献进行综述.结果与结论：相比较其他成体干细胞,牙髓干细胞的研究尚面临许多问题.但随着科学技术的日益进步,随着这些问题的深入探讨和逐步解决,牙髓干细胞的研究将日趋完善.牙髓干细胞有望成为牙组织工程、骨组织工程和神经组织工程的种子细胞,在牙髓再生、牙体的修复等方面有着广阔的应用前景.     

Purmorphamine increased adhesion,proliferation and expression of osteoblast phenotype markers of human dental pulp stem cells cultured on beta-tricalcium phosphate

ObjectivesGrowth factors play a significant role in cell proliferation and differentiation during different stages of the bone repair. However, several limitations have been brought researchers attention to an osteoinductive small molecule including Purmorphamine. In this study, we aimed to evaluate the effect of Purmorphamine on adhesion, proliferation and differentiation of human dental pulp stem cells (hDPSCs) seaded on beta-tricalcium phosphate (β-TCP) granules.MethodshDPSCs were established from extracted wisdom teeth of healthy volenteers. Cells at passage 3 were seeded on β-TCP in the presence or absence of Purmorphamine. Cell adhesion and proliferation were assessed using scanning electeron microscopy (SEM) and DNA counting assay, respectively, after 1, 3 and 5 days. Then, hDPSCs seeded on β-TCP were subjected to osteogenic medium with or without Purmorphamine. After 7 and 14 days osteogenic diffrentiation capability of hDPSCs were determined using real-time RT-PCR and alkaline phosphatase (ALP) activity assay.ResultsThe significant increase in amount of DNA was observed at day 3 and 5 in the presence of Purmorphamine. SEM imaging also was confirmed the DNA counting assay; in all given time points, hDPSC attachment and growth was significantly higher in the presence of Purmorphamine. ALP activity was increased by Purmorphamine at both 7 and 14 days of induction. Purmorphamine showed to effect on osteopontin expression at earlier stage of osteogenic differentiation, whereas for osteocalcin expression, this effect was more evident at later stage of differentiation.ConclusionPurmorphamine had a promotive effect on adhesion, proliferation and osteogenic differentiation of hDPSCs cultured on β-TCP. The outcome of the current study would help in development of in vitro culture conditions for better osteogenic differentiation of hDPSCs prior to transplantation.     

Multilineage potential of STRO-1+ rat dental pulp cells in vitro

The aim of the current study was to determine whether STRO-1 selection is an effective approach for purifying rat dental pulp stem cells, and especially whether such selection is beneficial on the multilineage differentiation capacity, i.e. whether selection will account for a higher rate of differentiation or lesser variability. In this study, two cell populations (STRO-1(+) and non-sorted cells) were cultured under conditions promoting neurogenic, adipogenic, myogenic and chondrogenic differentiation. Results of light microscopy, histochemistry, and immunohistochemistry showed that STRO-1(+) cells were capable of advancing into all four differentiation pathways under the influence of inductive media. Quantitative PCR and statistical analysis on specific differentiation markers confirmed that there were significant upregulations in STRO-1(+) cells compared to the other populations, during induction culture. On the basis of our results, we concluded that: (a) rat STRO-1(+) dental pulp stem cells are capable of differentiating towards multilineage cell types, including neural cells, adipocytes, myocytes and chondrocytes; (b) the STRO-1(+) population has a more defined multilineage potential compared to non-sorted cells, probably because of its more homogeneous nature. .     

Effects of cell cycle phases on the induction of dental pulp stem cells toward dopaminergic‐like cells

Parkinson's disease (PD) is characterized by tremors and cognitive issues, and is due to the death of dopaminergic (DA‐ergic) neurons in brain circuits that are responsible for producing neurotransmitter dopamine (DA). Currently, cell replacement therapies are underway to improve upon existing therapeutic approaches such as drug treatments and electrical stimulation. Among the widely available sources, dental pulp stem cells (DPSCs) from deciduous teeth have gained popularity because of their neural crest origin and inherent propensity toward neuronal lineage. Despite the various pre‐clinical studies conducted, an important factor yet to be elucidated is the influence of growth phases in a typical trans‐differentiation process. This study selected DPSCs at three distinct time points with variable growth phase proportions (G0/G1, S and G2/M) for in vitro trans‐differentiation into DA‐ergic‐like cells. Using commercially available PCR arrays, we identified distinct gene profiles pertaining to cell cycles in these phases. The differentiation outcomes were assessed in terms of morphology and gene and protein expression, as well as with functional assays. It was noted that DPSCs with the highest G0/G1 phase were comparatively the best, representing at least a 2‐fold up regulation (p < 0.05) of DA‐ergic molecular cues compared to those from the remaining time points. Further investigations in terms of protein expression and DA‐release assays also revealed a similar phenomenon (p < 0.05). These findings are expected to provide vital information for consideration in improving standard operating procedures in future cell transplantation work. Copyright © 2017 John Wiley & Sons, Ltd.     

Donor‐matched comparison of dental pulp stem cells and bone marrow‐derived mesenchymal stem cells in a rat model

Dental pulp stem cells (DPSCs) have drawn much interest for the regeneration of mineralized tissues, and several studies have compared DPSCs to bone marrow‐derived mesenchymal stem cells (BMMSCs). However, conflicting results, possibly due to donor‐associated variability, have been published and the regenerative potential of DPSCs is currently unclear. In the present study we have sought to address this problem using a donor‐matched experimental design to robustly compare the biological properties of DPSCs and BMMSCs. All experiments were performed using cells isolated from a single adult Sprague–Dawley rat. Our results show that DPSCs and BMMSCs had similar morphologies and flow cytometry profiles, were capable of forming colonies in vitro and were capable of osteogenic, chondrogenic and adipogenic differentiation. However, quantitative comparisons revealed that DPSCs had a faster population doubling time and a higher percentage of stem/progenitor cells in the population, as determined by clonogenic assays. Furthermore, while both cell populations formed mineral in vitro, DPSCs had significantly higher alkaline phosphatase activity than BMMSCs after 3 weeks in osteogenic medium. These data show several key differences between DPSCs and BMMSCs and support the possibility of using DPSCs for mineralized tissue regeneration. Copyright © 2009 John Wiley & Sons, Ltd.     

骨髓间充质干细胞对致敏小鼠淋巴细胞增殖的影响及其作用方式

本研究探讨骨髓间充质干细胞(mesenchymal stem cells,MSC)在体外对致微小鼠淋巴细胞增殖的影响及其作用方式,以便进一步了解MSC对致敏小鼠影响的可能机制.建立致敏模型后,将应用贴壁培养法体外培养的正常小鼠骨髓MSC或其培养上清液作为免疫细胞或免疫因子,致敏小鼠的淋巴细胞作为效应细胞,用植物血凝素( phytohemagglutinin,PHA)刺激淋巴细胞增殖,在体外应用MTT法检测两者的混合淋巴细胞增殖反应.结果表明,正常小鼠骨髓MSC在体外能很好地抑制致敏小鼠脾淋巴细胞增殖,同时在MSC培养上清液也能观察到类似现象,而且随着两者细胞比例或浓度比的增大,抑制作用有所加大,当两者比例为1∶1时抑制作用最大(有明显的统计学意义).结论:MSC能在体外明显抑制致敏小鼠脾淋巴细胞增殖,该作用可以通过细胞与细胞(MSC和淋巴细胞)直接接触抑制,也可通过细胞与细胞的间接作用(如MSC的培养上清液与淋巴细胞)方式发挥作用.