体外培养骨髓间充质干细胞诱导分化为神经样细胞的研究

目的探讨DMSO+BHA体外培养骨髓间充质干细胞诱导分化为神经样细胞的可行性。方法 DMSO+BHA诱导BMSCs向神经样细胞分化,免疫组织细胞化学染色法检测相关蛋白表达。结果神经方向诱导后细胞形态学发生变化,且NSE、Nestin及GFAP染色均为阳性。结论 DMSO+BHA可成功诱导BMSCs向神经样细胞方向分化。     

骨髓间充质干细胞诱导分化为神经样细胞的离子通道：是否有电生理特性？

背景：以往研究证实,骨髓间充质干细胞经体外诱导先分化为神经干细胞,然后分化为神经样细胞,但是对于分化的神经样细胞是否具有电生理特性尚不明确。 目的：观察骨髓间充质干细胞诱导分化为神经样细胞的离子通道是否具有电生理特性？ 设计、时间及地点：观察性实验,于2005-03在华中科技大学同济医学院附属同济医院神经内科实验室完成。 材料：4周龄Wistar大鼠37只,雌雄不拘,体质量150 g左右。 方法：取Wistar大鼠股骨和胫骨,进行骨髓间充质干细胞原代培养,传至第15~20代融合状态的间充质干细胞置于预诱导培养基中培养24 h后,换用诱导培养基。在倒置显微镜下连续观察间充质干细胞的形态变化,分别采用免疫组织化学和Western Blot对未经诱导分化的间充质干细胞和诱导后第3天的间充质干细胞进行检测。利用电生理膜片箝技术检测50个骨髓间充质干细胞诱导分化后的神经样细胞。 主要观察指标：记录到的钾电流、GABA电流。 结果：①诱导分化前呈梭形细胞,在加入预诱导培养基后未出现明显的形态变化,换用诱导培养基1 h,胞体开始收缩,出现少数较小的卵圆形或纺锤形细胞,诱导24 h后,约60%细胞变成双极形、多极形和锥形,出现类似神经元细胞的形态。②免疫细胞化学检测未经诱导分化的间充质干细胞无NeuN、Nestin、GFAP表达,诱导分化后第3天的间充质干细胞NeuN表达明显增强,有Nestin表达,无GFAP表达。③Western Blot检测在未诱导分化时和预诱导24 h,无NeuN、Nestin表达,Nestin表达在诱导分化后6 h呈强阳性,在诱导分化24 h和48 h逐渐减弱。NeuN在诱导分化后6 h有表达,在诱导分化后24 h和48 h表达增强。④在检测的50个细胞中,共有25个细胞检测到ATP电流(50%)、GABA电流13个(26%)、总钾电流46(92%)、复极化钾电流46(92%)。 结论：在诱导分化的神经样细胞上存在功能性离子通道,具有电生理特性。     

成年大鼠骨髓基质干细胞诱导分化为神经元样细胞不同方法比较的研究

目的 研究成年大鼠骨髓基质干细胞(BMSCs)诱导分化为神经元样细胞不同的方法，寻找它向神经细胞分化的最佳条件。方法 取纯度较高的BMSCs，通过不同的神经营养因子诱导法和抗氧化剂诱导法，进行抗巢蛋白(nestin)、神经元特异烯醇化酶(NSE)、神经胶质纤维酸性蛋白(GFAP)、酪氨酸羟化酶(TH)免疫细胞化学染色，观察相应的阳性细胞数。结果 诱导第3天A组(EGF：表皮生长因子，bFGF：碱性成纤维细胞生长因子，RA：全反式维甲酸)，B组(GDNF：胶质细胞系源性神经营养因子，BDNF：脑源性神经营养因子)，C组(EGF，bFGF，GDNF，BDNF和RA)的Nestin阳性细胞数较多，其中以C组最多，而D组(抗氧化剂)Nestin阳性细胞数少于前三组。A，B，C组的NSE，GFAP染色阳性细胞数较D组少，但D组有部分细胞发生死亡。诱导第7天A，B，C组的NSE，GFAP阳性细胞数较第3天时明显增多，C组最多，B组其次，Nestin阳性细胞数比例较第3天时明显减少。而D组的NSE，GFAP阳性细胞数少于其第3天时；C组诱导成神经细胞比例较高，阴性对照组和空白对照组极少或无阳性细胞。此外，神经营养因子诱导法生成神经样细胞的比例都多于胶质样细胞。结论 抗氧化剂诱导法分化诱导快，而神经营养因子诱导法分化诱导效率高，诱导后细胞生长状态明显好于前者，各种神经营养因子联合作用影响BMSCs的增殖和分化。     

丙戊酸诱导大鼠骨髓间充质干细胞向神经样细胞分化中对Oct-4的影响

目的探讨丙戊酸诱导大鼠骨髓间充质干细胞向成神经样细胞分化中对Oct-4的影响。方法体外分离SD大鼠骨髓间充质干细胞,将其分为两组:对照组,不加丙戊酸,细胞加入预诱导液(含1μmol/Lβ-ME,10%FBS的DMEM/F12)培养24 h,然后换诱导液(含200μmol/L BHA,2%DMSO的DMEM/F 12)诱导5 h。实验组,诱导前12 h,在细胞培养液中加入丙戊酸。用倒置相差显微镜观察细胞形态,免疫细胞化学法检测NSE、GFAP、Oct-4蛋白的表达。Western blot检测细胞内NSE及GFAP蛋白Oct-4的表达。结果倒置显微镜下观察可见骨髓间质干细胞呈纺锤状,诱导后出现突出,向周围伸出明显突起,呈现神经细胞样形态,且实验组的细胞突起数量和长度多于对照组;Western blot检测实验组的NSE、GFAP蛋白表达高于对照组,Oct-4的表达实验组高于对照组。结论丙戊酸能诱导骨髓间充质干细胞分化成神经样细胞,同时其增强了Oct-4在BMSCs体外定向诱导分化中的表达。     

碱性成纤维细胞生长因子等体外诱导成人骨髓间充质干细胞分化为神经元样细胞的研究

目的 成人骨髓间充质干细胞(hMSCs)体外定向诱导分化为神经元样细胞。方法 采用Percoll分离液离心分离hMSCs，体外扩增，分别采用含碱性成纤维细胞生长因子(bFGF)和2-巯基乙醇(2-ME)等无血清DMEM诱导hMSCs分化为神经元。免疫组化鉴定神经元烯醇化酶(NSE)、神经丝蛋白(NF)、胶质纤维酸性蛋白(GFAP)。结果 hMSCs在体外扩增传至5代后，流式细胞仪显示99．5％，97．8％，98．8％hMSCs表面抗原CD29、CD44、CD90表达阳性。接种到12孔板，3d后加入bFGF和2-ME联合或2-ME单种诱导剂诱导后，hMSCs胞体收缩，突起伸出；免疫组化显示诱导出的神经元样细胞NSE、NF表达阳性，GFAP阴性。结论 成人骨髓间干细胞在体外可以分化为神经元样细胞。     

参芪液对成人骨髓问质干细胞的诱导分化作用

目的探讨参芪液体外对成人骨髓间质干细胞(MSC)定向诱导分化为神经元的作用.方法从成人肋骨分离MSC,体外培养扩增,并传代至第5代.含10 mg/mL碱性成纤维细胞生长因子(bFGF)的培养液预诱导24h,再用含不同浓度参芪液的无血清DMEM诱导MSC分化为神经元.免疫组化鉴定神经元烯醇化酶(NSE)、神经丝蛋白(NF)、胶质纤维酸性蛋白(GFAP)的表达.结果成人骨髓间质干细胞在体外扩增5代后,加入参芪液诱导,可见MJSC胞体收缩,突起伸出.免疫组化显示诱导出的神经元样细胞NSE、NF阳性,GFAP阴性.神经分化的定量分析显示NSE、NF阳性细胞分别为(79.5±2.5)%和(76.5±2.3)%.结论参芪液在体外可以诱导成人骨髓间质干细胞分化为神经元样细胞.     

人参皂苷Rg1诱导骨髓间充质干细胞分化为神经样细胞的作用

目的研究人参皂苷Rg1在体外能否诱导Wistar大鼠骨髓间充质干细胞分化为神经元样细胞。方法通过贴壁法分离大鼠骨髓间充质干细胞,体外培养扩增,人参皂苷Rg1诱导分化,光镜下观察细胞形态,免疫细胞化学检测神经元特异性烯醇化酶（NSE）和神经胶质纤维酸性蛋白（GFAP）的表达,RT-PCR检测细胞NGF mRNA的表达。结果大鼠骨髓间充质干细胞可通过贴壁法成功分离并可以在体外大量扩增。人参皂苷Rg1诱导72h后,部分骨髓间充质干细胞（35．57％±3．59％）转变为神经元样细胞,免疫细胞化学染色NSE呈阳性,分化的神经元样细胞可能表达NGF mRNA。结论人参皂苷Rg1可以在体外诱导大鼠骨髓间充质干细胞分化为神经元样细胞,并且可能表达NGF mRNA。     

神经节苷脂诱导骨髓间充质干细胞分化为神经细胞的作用的研究

目的探讨神经节苷脂(GM1)诱导骨髓间充质干细胞(BMSCs)分化为神经细胞的作用。方法通过贴壁法分离大鼠BMSCs,体外扩增3代,加入GM1诱导分化。用倒置显微镜观察诱导分化后BMSCs的形态,免疫组化染色检测其神经元特异性烯醇化酶(NSE)和神经胶质纤维酸性蛋白(GFAP)的表达。逆转录PCR检测BMSCs神经生长因子(NGF)mRNA和脑源性神经营养因子(BDNF)mRNA的表达水平,并与胎牛血清(FBS)对照组和空白对照组的BMSCs比较。结果GM1诱导组BMSCs胞体变圆,突起增加,部分突起相互联结成网状,NSE阳性表达细胞为(29.47%±3.26)%,GFAP阳性表达细胞为(2.32±0.18)%,FBS组和空白对照组分别为(6.97±0.56)%和(10.6±0.75)%的细胞NSE表达阳性,(1.41±0.35)%和(1.21±0.35)%的细胞GFAP表达阳性。GM1诱导组NGFmRNA和BDNFmRNA水平显著高于FBS对照组(均P<0.01)和空白对照组(均P<0.05)。结论GM1在体外能诱导BMSCs分化为神经元样细胞。     

碱性成纤维生长因子等诱导间质干细胞分化为神经元样细胞的研究

目的　体外定向诱导成人骨髓间质干细胞 (MSC)分化为神经元样细胞。方法　采用Ficoll Paque液 (10 77g/L)离心分离成人MSC ,体外扩增 ,分别采用含碱性成纤维细胞生长因子 (bFGF)和叔丁对甲氧酚 (BHA)或硫代甘油等试剂的无血清DMEM诱导MSC分化为神经元。免疫组化鉴定神经元烯醇化酶 (NSE)、神经丝蛋白 (NF)、胶质纤维酸性蛋白 (GFAP)、巢蛋白 (nestin)的表达。结果　成人骨髓间质干细胞在体外扩增原代可获得 5× 10 5,10代可获得 2× 10 10 个细胞。加入bFGF和BHA等诱导剂或硫代甘油诱导后 ,MSC胞体收缩 ,突起伸出 ;免疫组化显示诱导出的神经元样细胞NSE、NF、nestin表达阳性 ,GFAP阴性。结论　成人骨髓间质干细胞在体外可以分化为神经元样细胞。     

参芪液对成人骨髓间质干细胞的诱导分化作用

目的　探讨参芪液体外对成人骨髓间质干细胞 (MSC)定向诱导分化为神经元的作用。方法　从成人肋骨分离MSC ,体外培养扩增 ,并传代至第 5代。含 10mg/mL碱性成纤维细胞生长因子 (bFGF)的培养液预诱导 2 4h ,再用含不同浓度参芪液的无血清DMEM诱导MSC分化为神经元。免疫组化鉴定神经元烯醇化酶 (NSE)、神经丝蛋白 (NF)、胶质纤维酸性蛋白 (GFAP)的表达。结果　成人骨髓间质干细胞在体外扩增 5代后 ,加入参芪液诱导 ,可见MSC胞体收缩 ,突起伸出。免疫组化显示诱导出的神经元样细胞NSE、NF阳性 ,GFAP阴性。神经分化的定量分析显示NSE、NF阳性细胞分别为 (79 5± 2 5 ) %和 (76 5± 2 3 ) %。结论　参芪液在体外可以诱导成人骨髓间质干细胞分化为神经元样细胞     

神经干细胞与脑胶质瘤干细胞☆

所有的肿瘤组织并不是由均一的肿瘤细胞所组成的,不同的细胞具有不同的增殖、浸润和转移能力,亦即肿瘤的异质性。其中存在少数担当着干细胞角色的肿瘤细胞,具有干细胞的基本特性,包括自我更新能力、无限的增殖能力和多向分化潜能,为肿瘤干细胞。神经干细胞具有很强的自我更新机制,获得较少突变即有可能恶性转化,而且干细胞存活时间较长,这意味着干细胞比成熟细胞发生细胞复制的错误几率更大,因外界环境的刺激而发生突变的机会更多,最终形成脑胶质瘤干细胞,同时调节神经干细胞增殖和自我更新的基因在脑胶质瘤的脑胶质瘤干细胞中也表达,这也是支持神经干细胞是脑胶质瘤干细胞来源的;也有推测认为它可能起源于已分化的细胞,由这些细胞突变发生去分化得来,并通过基因突变而获得了干细胞自我更新的特性,从而形成脑胶质瘤干细胞。通过探讨神经干细胞与脑胶质瘤干细胞,为脑胶质瘤的治疗提供依据。     

Quite amusing stem cells:Muse cells

<正>Stem cells may be the future of therapeutics for stroke due to their regenerative and immunomodulatory capabilities.Major barriers faced when employing stem cells,however,include faulty migration,low cell survival,and diminished proliferation.M ultilineage-differentiating stress ensuring (Muse) cells,a subset of mesenchymal stem cells,overcome these barriers.Muse cells aid in neuroregeneration,have immense regenerative potential,and are pluripotent,non-tumorigenic,and immunomodulatory.I...     

神经干细胞诱导骨髓基质细胞向神经元样细胞分化

目的：研究骨髓基质细胞向神经元样细胞分化的条件。方法：神经十细胞诱导骨髓基质细胞向神经元样细胞分化，免疫细胞化学方法对分化的和未分化的细胞进行鉴定。结果：神经于细胞可诱导骨髓基质细胞向神经元样细胞分化，分化的细胞表达神经元的标志物神经元特异性烯醇化酶(NSE)。结论：骨髓组织中存在能分化为神经元的于细胞，可能成为中枢神经系统自体移植的于细胞的来源。     

Oligodendroglioma-like cells (clear cells) in ependymoma

A brain tumor of a 22-year-old man was composed mostly of round cells with perinuclear halos (clear cells), forming clusters intersected by small blood vessels. In some areas, the tumor cells showed perivascular arrangement and epithelial pattern. Phosphotungstic-acid hematoxylin stain and immunoperoxidase stain for glial fibrillary acidic protein (GFAP) technique failed to stain the clear cells. Electron microscopy of the clear cells revealed them to be classical ependymoma cells with well developed intercellular junctions, microvilli and cilia. As no reporters in the past showed the evidence to clarify the nature of the clear cells, this case is considered a good example to support the viewpoint that the clear cells (oligodendroglioma-like cells) commonly observed in ependymomas are in reality ependymoma cells. It is stressed that the diagnosis of "mixed glioma" or "oligoependymoma" should be made with sufficient caution despite the recent advances of GFAP technique.     

Transplanted human bone marrow cells generate new brain cells

Multiple studies have reported that adult cells of bone marrow origin can differentiate into muscle, skin, liver, lung, epithelial cells, and neurons. To determine whether such cells might produce neurons and other cells in the human brain, we examined paraffin sections from female patients who had received bone marrow transplants from male donors. Y-chromosomes were labeled using autoradiography and fluorescent in situ hybridization. Neurons and astrocytes were identified histologically and immunohistochemically in neocortex, hippocampus, striatum, and cerebellum. However, most labeled cells in both gray and white matter appeared to be glia. Others have suggested that such Y-labeling represents fusion between host and donor cells, rather than true transdifferentiation. The possibilities of fusion and microchimerism were therefore examined using buccal epithelial cells as a model system. The female patients in this study had received either bone marrow or stem cell (CD34+ enriched) transplants from their brothers. Double labeling for X- and Y-chromosomes showed that Y-labeled buccal cells could not be explained by fusion. Genotyping studies of one patient, her brother, and her son ruled out the possibility of microchimerism. Whether, and under what circumstances, some form of bone marrow transplantation might provide adequate number of cells capable of replacing lost brain cells or enhancing their function will require additional studies.     

Differentiation of radial glia-like cells from embryonic stem cells

Radial glial cells play important roles in neural development. They provide support and guidance for neuronal migration and give rise to neurons and glia. In vitro, neurons, astrocytes, and oligodendrocytes can be generated from neural and embryonic stem cells, but the generation of radial glial cells from these stem cells has not yet been reported. Since the differentiation of radial glial cells is indispensable during brain development, we hypothesize that stem cells also generate radial glial cells during in vitro neural differentiation. To test this hypothesis, we utilized five different clones of mouse embryonic (ES) and embryonal carcinoma (EC) stem cell lines to investigate the differentiation of radial glial cells during in vitro neural differentiation. Here, we demonstrate that radial glia-like cells can be generated from ES/EC cell lines. These ES/EC cell-derived radial glia-like cells are similar in morphology to radial glial cells in vivo, i.e., they are bipolar with an unbranched long process and a short process. They also express several cytoskeletal markers, such as nestin, RC2, and/or GFAP, that are characteristics of radial glial cells in vivo. The processes of these in vitro generated radial glia-like cells are organized into parallel arrays that resemble the radial glial scaffolds in neocortical development. Since radial glia-like cells were observed in all five clones of ES/EC cells tested, we suggest that the differentiation of radial glial cells may be a common pathway during in vitro neural differentiation of ES cells. This novel in vitro model system should facilitate the investigation of regulation of radial glial cell differentiation and its biological function.     

The tropism of embryoid body cells for glioma cells

It has been demonstrated that several types of adult stem cells have a common attribute of tropism for gliomas. In our study, we provided evidence that embryonic stem cell-derived embryoid body (EB) cells also exhibited a tropism for gliomas. Chemotaxis assays and organotypic hippocampal slice culture experiments showed that EB cells were attracted by the conditioned medium from C6 glioma cells and by C6 glioma cells deposited on the slice. Aggregate culture assays showed that EB cells could coaggregate with C6 glioma cells. Embryoid body cells injected intratumorally were found to distribute throughout the tumor mass. All data indicated that EB cells displayed a tropism for gliomas.