CNTF对神经干细胞体外增殖的影响

目的 探讨睫状神经营养因子(ciliary neurotrophic factor,CNTF)对神经干细胞体外增殖的影响.方法 原代培养新生SD大鼠的室下区神经干细胞并鉴定,经传代纯化后,用不同浓度CNTF (0.1、0.5、1、5、10、20、30 ng/ml)处理5～7 d,MTT实验检测神经干细胞增殖活性.不完全...     

大鼠神经干细胞体外培养

目的:介绍一种较成熟的大鼠神经干细胞体外培养方法。方法:取新生大鼠(1d之内)侧脑室前角周围的脑组织,用EDTA:胰蛋白酶(1:1)消化,制成单细胞悬液,以2-5×105个细胞/ml接种于无血清培养基中。观察其增殖、分化情况,并用nestin、GFAP、NSE免疫细胞化学对细胞进行定性。结果:培养细胞呈悬浮生长,具有增殖能力,倍增时间为2d,nestin阳性。诱导分化后细胞贴壁生长,体积增大,并发出形态各异的突起。可见GFAP和NSE阳性细胞。结论:培养细胞经鉴定为神经干细胞。本方法简单、易操作,可行性强。     

脂质体介导EGFP基因转染神经干细胞实验研究

目的用增强绿色荧光蛋白基因(EGFP)的表达载体pIRES2-EGFP转染神经干细胞(neural stem cells,NSCs),检测该真核表达载体对NSCs的转染效率及EGFP的表达状态,为用NSCs为载体基因治疗中枢神经系统疾病提供实验依据。方法体外扩增、酶切鉴定pIRES2-EGFP质粒;悬浮培养NSCs;阳离子脂质体lipofectam ineTM2000介导增强绿色荧光蛋白质粒转染NSCs;庆大霉素的氨基糖苷(G418)筛选重组子;荧光显微镜观察转染效率及表达情况;免疫细胞化学鉴定重组子。结果转染后6 h,荧光蛋白偶见表达,24 h表达量明显增加,48 h达到最高峰,1个月后抗性细胞有克隆球形成。结论脂质体介导报告基因—pIRES2-EGFP转染NSCs的方法简单、效率高、易成功,是一较为理想的基因转染方法。     

不同浓度重组人促红细胞生成素对神经干细胞体外培养增殖的影响

背景：重组人促红细胞生成素是一种糖蛋白,近年的研究表明其对神经细胞的许多功能活动均具有调节作用。 目的：观察不同浓度重组人促红细胞生成素对神经干细胞体外培养增殖的影响。方法：提取新生SD大鼠神经干细胞,用含不同浓度(5,50,500 U/mL)重组人促红细胞生成素和20 μg/L碱性成纤维细胞生长因子的无血清培养基进行培养,以不含重组人促红细胞生成素无血清培养基为对照组。细胞培养7 d后计算神经干细胞克隆形成率,培养10 d后计数NSE和GFAP免疫阳性细胞数。结果与结论：添加重组人促红细胞生成素组细胞增殖较快,最终神经球的数量多于对照组,以50 U/mL重组人促红细胞生成素组作用显著;50 U/mL重组人促红细胞生成素组的生长速度显著快于对照组。50 U/mL重组人促红细胞生成素组中NSE和GFAP免疫阳性细胞明显多于对照组(P < 0.01)。结果表明重组人促红细胞生成素对神经干细胞体外培养增殖有促进作用,尤以适中浓度(50 U/mL) 作用更加明显。关键词：重组人促红细胞生成素;神经干细胞;碱性成纤维细胞生长因子;体外培养;增殖     

慢病毒介导人神经营养素3基因在许旺细胞中的表达

背景：神经营养素3是目前发现的在脊髓损伤修复中作用最强的神经营养因子,它能有效促进再生轴突穿越胶质瘢痕组织,从而修复脊髓损伤。 目的：构建含有人神经营养素3基因的重组慢病毒载体(LV-hNT3),观察转染后人神经营养素3基因在许旺细胞中的表达。 设计、时间及地点：观察性实验,于2007-06/2008-03在长海医院中心实验室完成。 材料：取新生3 d的SD乳鼠双侧坐骨神经,用于许旺细胞的培养及鉴定;慢病毒三质粒系统pGC-E1-EGFP,pHelper 1.0和pHelper 2.0为上海吉凯基因化学技术有限公司产品。 方法：通过双限制性内切酶消化和连接的方法构建pGC-E1-hNT3-EGFP质粒,接着该质粒转化感受态的大肠杆菌E.coli DH5α,通过PCR及基因测序鉴定阳性克隆,再经Lipofectamine 2000将pGC-E1-hNT3-EGFP,pHelper 1.0和pHelper 2.0三质粒系统共转染293 T细胞包装病毒,按照病毒感染复数=1,4,8,10,12加入预先混好重组病毒完全培养液2 mL,通过增强型绿色荧光蛋白的表达测定收集的病毒滴度。将慢病毒转染许旺细胞,以未经转染的许旺细胞和经空载的慢病毒转染的许旺细胞为对照组。 主要观察指标：慢病毒转染许旺细胞后,检测转染效率,通过实时荧光聚合酶链反应和蛋白免疫印迹检测人神经营养素3在许旺细胞中的表达。 结果：实验中重组质粒的外源基因序列与GeneBank中的人神经营养素3阅读框架序列完全一致;浓缩后病毒滴度为5×107 TU/L,LV-hNT3感染许旺细胞后,许旺细胞发出明亮的绿色荧光,当感染复数=10时转染效率最高达85%,实时荧光PCR检测表明人神经营养素3 mRNA在人神经营养素3-许旺细胞中高效表达,而对照组中未表达,蛋白免疫印迹证实人神经营养素3在许旺细胞中表达。 结论：实验构建的含有人神经营养素3基因的慢病毒载体能感染许旺细胞并且高效表达人神经营养素3。     

慢病毒载体VP22-EGFP的构建及其对大鼠神经干细胞转染及表达的研究

目的 研究VP22穿梭蛋白对神经干细胞(neural stem cell,NSC)转染效率的影响.方法 通过酶切质粒pUL49ep获得VP22片段后克隆到含有增强型绿色荧光蛋白(enhanced greenfluorescent protein,EGFP)的慢病毒(Lentivirus)pHIV-EGFP质粒载体上,并采用PCR及基因测序技术对VP22基因进行鉴定.病毒包装采用三质粒系统共转染293T细胞后感染经体外原代培养、扩增的SD大鼠胎脑NSC,荧光显微镜下观察EGFP在NSC中的表达,流式细胞仪检测EGFP的表达,PCR检测基因组中VP22-EGFP基因的表达,MTT法测定转染前后单纯NSC、含有EGFP及含有VP22-EGFP的NSC的增殖活性.结果 PCR和DNA测序证实,外源基因VP22成功插入到质粒载体pHIV-EGFP的骨架结构中的启动子CMV和EGFP序列之间;荧光显微镜下均见有绿色荧光蛋白的表达;流式细胞仪测定结果:Lentivirus-EGFP及Lentivirus-VP22-EGFP转染的NSC的EGFP的表达率分别为(23.1±1.8)%及(34.9±2.9)%(P<0.01);PCR结果显示VP22整合入NSC的基因组DNA中;MTT结果显示转染前后单纯NSC、含有EGFP及含有VP22-EGFP的NSC的细胞生长曲线无明显改变.结论 VP22能够提高慢病毒对NSC的转染效率,且不影响其生长特性.表明VP22作为一种短链蛋白可以与编码的治疗基因形成融合蛋白增强基因治疗的疗效,在基因修饰的工程化干细胞中具有良好应用前景.     

人胚胎神经干细胞的体外培养

目的：从人胚胎皮层分离神经干细胞,寻找其在体外培养的适合条件,方法：使用具有丝裂原作用的多种细胞生长因子。结合无血清细胞培养技术。从人胚胎皮层分离具有增殖能力的细胞群,在连续传代过程中,验证其自我更新能力和多分化潜能,免疫荧光染色检测Nestin抗原和分化后特异性成熟神经细胞抗原的表达,并且流式细胞仪检测神经干细胞分化结果。结果：协同使用bFGF和EGF从人胚胎皮层分离的细胞群,具有自我更新能力和多分化潜能,表达胚胎早期细胞抗原-Nestin,加入LIF后细胞增殖速度加快,分化为神经元的比例增高,而单独采用bFGF、EGF或LIF培养的细胞迅速衰退,仅能培养3-5代。结论：协同使用丝裂原生长因子从人胚胎皮层分离的细胞时中枢神经系统的干细胞;bFGF、EGF和LIF协同使用是体外培养神经干细胞的较佳条件。     

HIV-1来源的慢病毒载体转染大鼠脊髓神经干细胞

目的 介绍人类免疫缺陷病毒（Human immunodenciency virus-1，HIV-1）载体的构建技转染大鼠脊髓神经干细胞的实验方法。方法 将含有绿色荧光蛋白（green fluorescence protein，GFP）的4种质粒通过293T细胞构建成GFP—HIV载体。用Elisa法及Hela细胞分别验证其高浓度技强感染力后将其转染大鼠脊髓神经干细胞。结果 GFP—HIV载体浓度达56672．93pg／ml，荧光显微镜FHela细胞胞浆内充满深浅不一的绿荧光，大鼠脊髓神经干细胞球发强烈的绿荧光：结论此实验方法操作简单、快捷，具有高效性及安全性。HIV载体将是基因治疗的理想工具。     

慢病毒转染胶质细胞源性神经营养因子脂肪干细胞脑移植的研究

目的 探讨慢病毒转染胶质细胞源性神经营养因子(GDNF)的脂肪干细胞(ADSCs)脑移植的应用价值.方法 分离、培养SD大鼠ADSCs,用高滴度慢病毒将GDNF转染入细胞,观察细胞形态及用免疫荧光法观察神经标志物的表达.用立体定向仪将转染ADSCs植入大鼠的纹状体,移植1个月和2个月后,用荧光显微镜观察ADSCs脑内存活和分布状况,用Western blot检测GDNF蛋白的表达,并与正常对照组比较.结果 慢病毒转染ADSCs形态类似神经元,胞浆神经元特异性烯醇化酶(NSE)表达阳性.ADSCs移植到大鼠纹状体1个月后,移植部位有大量存活的ADSCs,2个月后,仍有部分存活细胞,并向远处移行,GDNF蛋白水平显著高于正常对照组(均P<0.01).结论 慢病毒转染GDNF的ADSCs可为干细胞移植治疗中枢神经系统疾病提供新的供体.     

慢病毒转染胶质细胞源性神经营养因子基因的胎儿骨髓间充质干细胞的研究

目的 探讨胎儿骨髓间充质干细胞(fBMMSCs)经慢病毒转染胶质细胞源性神经营养因子(GDNF)基因后GDNF的表达情况.方法 利用贴壁培养法,从流产胎儿的股骨骨髓中分离培养fBMMSCs,并进行扩增.取第5代fBMMSCs,用慢病毒载体转染GDNF基因.应用免疫组化法及ELISA法检测被转染的fBMMSCs GDNF的表达情况.结果 被转染GDNF基因的fBMMSCs GDNF表达阳性,且培养液中GDNF含量随培养时间延长而增高.结论 被慢病毒转染GDNF基因的fBMMSCs能表达GDNF.     

枸杞多糖对精原干细胞体外增殖的影响

背景：精原干细胞移植对不育具有潜在的临床应用价值,体外建立精原干细胞的培养系统获得数量较多的精原干细胞,仍是目前研究中亟待解决的问题。 目的：观察枸杞多糖对精原干细胞体外增殖的影响。 方法：采用两步酶消化法获取出生4~6 d雄性C57BL/6小鼠睾丸Sertoli细胞与精原干细胞,将精原干细胞接种在Sertoli细胞饲养层上,再加入枸杞多糖或联合细胞因子添加到细胞培养液中。1周后以流式细胞仪检测细胞周期及细胞活性率,并检测各组精原干细胞GFRa-1、Thy-1、c-kit的阳性率。 结果与结论：单独加入枸杞多糖后精原干细胞数量明显增加,增殖明显,联合加入胶质细胞源性神经营养因子与白血病抑制因子精原干细胞增殖更加明显(P < 0.05)。并发现体外培养1周后的精原干细胞仍保持其睾丸组织内的精原干细胞特征,大多仍维持在未分化状态。表明在枸杞多糖或枸杞多糖联合胶质细胞源性神经营养因子及白血病抑制因子作用下,可促进精原干细胞体外增殖。     

稳定增殖神经干细胞的实验研究

目的探讨稳定、可靠建立神经干细胞体外增殖的方法,并对增殖培养的细胞进行鉴定。方法获取胚胎大鼠的脑组织,通过加入神经生长因子和采用保留细胞联系技术操作,使脑组织中的神经干细胞在体外克隆增殖并稳定传代。以免疫荧光方法对增殖克隆的神经干细胞球进行鉴定。结果神经干细胞不断增殖形成神经干细胞球且神经干细胞能快速稳定传代增殖。培养的细胞为神经干细胞特异性巢蛋白(nestin)染色阳性细胞。结论在神经生长因子的作用下,利用保留细胞联系技术操作,神经干细胞可以在体外快速、稳定克隆增殖并传代。     

Nerve growth factor promotes in vitro proliferation of neural stem cells from tree shrews

Neural stem cells promote neuronal regeneration and repair of brain tissue after injury,but have limited resources and proliferative ability in vivo.We hypothesized that nerve growth factor would promote in vitro proliferation of neural stem cells derived from the tree shrews,a primate-like mammal that has been proposed as an alternative to primates in biomedical translational research.We cultured neural stem cells from the hippocampus of tree shrews at embryonic day 38,and added nerve growth factor(100 μg/L) to the culture medium.Neural stem cells from the hippocampus of tree shrews cultured without nerve growth factor were used as controls.After 3 days,fluorescence microscopy after DAPI and nestin staining revealed that the number of neurospheres and DAPI/nestin-positive cells was markedly greater in the nerve growth factor-treated cells than in control cells.These findings demonstrate that nerve growth factor promotes the proliferation of neural stem cells derived from tree shrews.     

快速老化与正常老化小鼠脑内神经干细胞增殖的差异**

背景：在老化过程中,脑内环境改变可引起脑内神经干细胞增殖能力改变。脑内神经干细胞与衰老和退行性神经病变疾病密切相关,增殖能力与年龄存在负相关,但以快速老化小鼠为衰老模型的相关研究未见报道。目的：比较快速老化与正常老化小鼠嗅球、海马、皮质神经干细胞增殖的差异。方法：分别取6只快速老化小鼠(SAMP8)和6只正常老化小鼠(SAMR1)的嗅球、海马、皮质组织,在固定、冰冻切片后,运用Ki-67/Nestin免疫荧光双标检测3个脑区的神经干细胞增殖情况。免疫荧光双标在荧光显微镜下通过Leica Qwin v3采图,在40倍物镜和10倍目镜下采图,每一张切片随机选取5 个相邻视野,通过Image-pro-Plus软件完成图像分析。结果与结论：正常老化小鼠和快速老化小鼠均有神经干细胞增殖现象,但二者存在差异,其差异主要表现在海马和嗅球两个脑区(P < 0.05)。提示快速老化可能会导致海马、嗅球神经干细胞增殖能力降低。     

Lentiviral-mediated vascular endothelial growth factor 165 gene transfer into neural stem cells promotes proliferation

We constructed a lentiviral vector carrying vascular endothelial growth factor 165, which was used to transfect neural stem cells. The transfection rate was approximately 50%, as determined by flow cytometry. Vascular endothelial growth factor protein was detected in neural stem cells and pro-moted proliferation.     

In vitro culture and differentiation of rat embryonic midbrain-derived neural stem cells

BACKGROUND: Midbrain-derived neural stem cells (mNSCs) can differentiate into functional mature dopamincrgic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson's disease. OBJECTIVE: To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING: An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital (China) from March to November 2007. MATERIALS: Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein (GFAP) antibody and cyclic nucleotide 3'-phosphohydrolase (CNPase) antibody were provided by Abeam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF2) were provided by R＆D Systems. METHODS: The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/Fl2, 1% N2 supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10 μg/mL polylysine and induced to differentiate in the DMEM/Fl2 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES: The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for βⅢ tubulin, GFAP and CNPase. RESULTS: Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tubulin. CONCLUSION: Embryonic day 14 rat mNSCs can differentiate into neuron-like cells and glial cells following induction by EGF, FGF2 and N2 additive.     

In vitro culture and differentiation of rat embryonic midbrain-derived neural stem cells*☆

BACKGROUND： Midbrain-derived neural stem cells （mNSCs） can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson＇s disease. OBJECTIVE： To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING： An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital （China） from March to November 2007. MATERIALS： Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein （GFAP） antibody and cyclic nucleotide 3＇-phosphohydrolase （CNPase） antibody were provided by Abcam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor （EGF） and fibroblast growth factor-2 （FGF2） were provided by R＆D Systems. METHODS： The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/FI 2, 1% N： supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10ug/mL polylysine and induced to differentiate in the DMEM/F12 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES： The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for β Ⅲ tubulin, GFAP and CNPase. RESULTS： Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tu