猫骨髓基质细胞诱导为神经干细胞的实验研究

目的观察猫骨髓基质细胞体外培养及诱导分化情况。方法从猫的骨髓中分离得到骨髓基质细胞(Bone Marrow Stromal cells．BMSC），在体外给予神经干细胞培养基培养，增殖后用分化诱导因子(维甲酸，Retinoic acid，RA)进行诱导分化．倒置相差显微镜下观察活细胞及免疫细胞化学染色情况。结果猫骨髓基质细胞在体外培养中胞体增大，镜下可见丰富的胞浆颗粒，继之出芽，贴壁生长，可形成克隆团，同时可传代培养。这些具有克隆能力的骨髓基质细胞能表达神经干细胞特异性抗原nestin，而且能分化出胶质细胞样细胞和神经元样细胞。结论猫骨髓基质细胞具有干细胞特征，在合适的条件下可扩增、形成克隆并诱导分化出神经胶质细胞和神经元特征细胞，它们可考虑作为神经系统功能缺失细胞移植治疗的种子细胞来源。     

骨髓基质细胞对人胚胎神经干细胞分化极性的诱导

目的 :建立骨髓基质细胞及人胚胎神经干细胞共培养系统并观察其对神经干细胞的诱导分化作用。方法 :来源于人胚胎脑组织不同脑区的神经干细胞分别与骨髓基质细胞建立起各自的共培养系统并在其中纯化 ,以CM、CO CM、BMSC对神经干细胞进行诱导分化 ,并通过免疫荧光及免疫细胞化学技术检测神经元的诱导率。结果 :骨髓基质细胞及其共培养系统培养液能够明显地提高神经元的分化率。结论 :共培养系统诱发了神经干细胞与骨髓基质细胞的自分泌与旁分泌的作用并改变了神经干细胞的分化极性     

成鼠骨髓基质细胞向神经干细胞诱导分化的实验研究

目的研究成鼠骨髓基质细胞体外培养的生长行为和分化情况。方法利用EGF、FGF-b等增殖及分化诱导因子和神经干细胞培养液进行培养,分化诱导,用细胞免疫组化染色进行细胞鉴定。结果成鼠骨髓基质细胞在体外培养中能形成细胞克隆团,具有增殖能力,并可分化出胶质细胞样细胞和神经元样细胞。结论骨髓基质细胞具有较强的自我更新及多向分化能力,在适宜的诱导分化条件下,可诱导为神经干细胞,分化出神经元和胶质细胞。     

人脑组织匀浆液诱导大鼠骨髓间质干细胞分化为神经细胞

目的 研究人脑组织匀浆液诱导大鼠骨髓间质干细胞向神经元细胞分化能力。方法从大鼠骨髓分离培养骨髓间质干细胞．经体外增殖，用人脑组织匀浆液诱导骨髓间质干细胞向神经元样细胞分化，应用免疫细胞化学方法对分化的细胞进行鉴定。结果大鼠骨髓间质干细胞可在体外增殖，经人脑组织匀浆液诱导，骨髓间质干细胞可向神经元样细胞分化，且分化率较高，24小时为45％，48小时为78．2％，72小时为88．3％。分化后的细胞表达神经元标志物-神经微丝(NF)和神经元特异性烯醇化酶(NSE)。结论人脑组织匀浆液可诱导大鼠骨髓间质干细胞向神经元细胞分化，从而为骨髓间质干细胞脑内移植与及其分化，以及神经功能的修复提供了基础。     

音猬因子诱导恒河猴间充质干细胞向神经样细胞的分化**☆◆

背景：骨髓间充质干细胞诱导分化为神经细胞，是神经系统疾病细胞治疗的有效手段，但目前的时效尚不完善。 目的：应用神经发育音猬因子诱导恒河猴骨髓间充质干细胞向神经样细胞分化。 方法：应用经典的维甲酸方案与音猬因子方案两种方法诱导恒河猴骨髓间充质干细胞分化为神经样细胞，采用密度梯度离心法分离培养恒河猴骨髓间充质干细胞，倒置相差显微镜观察生长情况，MTT法测定细胞生长曲线，流式细胞仪鉴定细胞表型，免疫组织化学鉴定分化细胞标志，透射电镜和扫描电镜观察分化细胞超微结构。 结果与结论：体外分离培养的恒河猴骨髓间充质干细胞，经流式细胞仪表型鉴定，具有较高均一性。通过音猬因子诱导方案诱导处理7 d后，分化细胞多数表现为NSE、NF-M、Tau和Nestin染色阳性，经图像统计分析发现经音猬因子诱导方案神经干细胞标志物Nestin阳性率显著高于维甲酸诱导方案(P < 0.01)，另一方面经维甲酸诱导方案诱导的细胞表现GFAP阳性率高于音猬因子诱导方案，差异具有显著性意义(P < 0.05)。提示音猬因子诱导方案是一种诱导恒河猴骨髓间充质干细胞向神经样细胞分化的有效途径。     

损伤脑组织匀浆诱导骨髓间质干细胞向神经细胞分化的研究

目的探讨损伤脑组织匀浆液对骨髓间质干细胞的诱导分化作用。方法体外分离、培养骨髓间质干细胞,经体外增殖,用损伤脑组织匀浆液诱导其分化,应用免疫细胞化学方法对分化的细胞进行鉴定。结果大鼠骨髓间质干细胞可在体外增殖,经损伤脑组织匀浆液诱导,骨髓间质干细胞形态学改变明显,部分细胞突起可见锥样改变,在细胞密集处可突起交织成网。免疫细胞化学法染色显示分化细胞呈NSE阳性表达占23.2%±6.09%,GFAP阳性表达占14.3%±3.27%。结论损伤脑组织匀浆液可诱导大鼠骨髓间质干细胞向神经细胞分化,部分为神经元,部分为神经胶质细胞。     

丹参诱导鼠骨髓间充质细胞向神经元分化

目的：研究丹参对鼠骨髓间充质细胞的分化作用。方法：丹参注射液诱导鼠骨髓间充质细胞向神经元方向分化，采用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：丹参可诱导鼠骨髓间充质细胞向神经细胞分化，分化的细胞早期表达巢蛋白和Musashi1蛋白，后期则表达神经元的标志物神经元特异性醇化酶和神经微丝M，在最适合的诱导条件下约50％-60％的细胞表达这两种神经元的标志物。结论：骨髓组织中存在能分化为神经元的干细胞，丹参能够诱导这种干细胞向神经元分化，这种细胞可能成为中枢神经系统自体细胞移植的另一个干细胞的来源。     

大鼠骨髓基质干细胞体外分离、培养及分化的相关实验研究

目的探索大鼠骨髓基质干细胞(BMSC)体外分离、培养及纯化的合适实验条件,并探讨其在体外定向诱导分化为神经元样细胞的可行性。方法通过密度梯度离心法从成年大鼠骨髓中分离出BMSC,而后通过贴壁培养法培养及纯化,观察其生长特性;对纯化后的BMSC使用碱性成纤维生长因子(bFGF)和表皮生长因子(EGF)进行定向诱导分化,并进行免疫细胞化学鉴定。结果体外培养的BMSC传4代后,纯度最高,可达(95.23±3.06)%;其诱导分化7 d后,(75.43±7.63)%的细胞表现为-βTubulinⅢ阳性的神经元样细胞,(33.01±6.73)%的细胞则为GFAP阳性的胶质细胞。结论BMSC在体外培养条件下生长良好,经bFGF和EGF诱导后可大量分化为神经元样细胞和神经胶质细胞。     

甲状腺激素对大鼠骨髓间充质干细胞分化为少突胶质细胞的影响

背景：如何为脱髓鞘疾病的细胞替代治疗提供丰富的少突胶质细胞来源是急需解决的问题。 目的：实验拟采用表皮生长因子及碱性成纤维细胞因子诱导骨髓间充质干细胞向神经干细胞方向分化,撤退细胞因子后,用甲状腺激素诱导神经干细胞向少突胶质细胞分化。 设计、时间及地点：细胞观察实验,于2007-08/12在泸州医学院神经生物学研究室完成。 材料：普通级SD大鼠5只用于骨髓间充质干细胞的培养。 方法：采用密度梯度离心法从大鼠骨髓中分离培养骨髓间充质干细胞,传至第4代,用含碱性成纤维细胞生长因子、表皮生长因子、N2辅助因子、甲状腺激素T3的DMEM/F12诱导液诱导向神经干细胞分化。诱导后4 d,更换成含胎牛血清、甲状腺激素T3的DMEM/F12分化液,诱导向少突胶质细胞分化。 主要观察指标：骨髓间充质干细胞生长情况和形态变化,采用SABC法进行免疫细胞化学检测神经细胞特异性标志的表达。 结果：原代细胞接种3 d后多数贴壁,传代后细胞贴壁速度加快,增殖能力更强。诱导液处理第4天,圆形细胞聚集成簇。换成分化液后,细胞伸出树枝状细长突起,交织成网,形成少突胶质细胞样细胞。骨髓源性细胞簇表达巢蛋白阳性,示神经干细胞;从细胞簇分化的细胞,多数细胞表达半乳糖脑苷脂,部分细胞表达髓鞘碱性蛋白,示少突胶质细胞,少数细胞表达微管相关蛋白2阳性,示神经元。 结论：甲状腺激素在体外可诱导骨髓间充质干细胞向少突胶质细胞分化。     

大鼠骨髓基质细胞体外培养向神经干细胞的诱导分化

目的：已证实骨髓基质细胞可分化为中胚层组织细胞，实验予进一步探讨体外分离培养的骨髓基质细胞向神经干细胞分化的可能性，以及是否能继续定向分化为神经细胞及神经胶质细胞，为神经系统疾病细胞移植治疗提供种子细胞。 方法：实验于2007-02/09在泸州医学院神经生物学研究室进行。①动物：选择5只普通级SD大鼠，由泸州医学院实验动物中心提供，实验过程中对动物的处置符合动物伦理学标准。②实验方法：大鼠戊巴比妥钠腹腔麻醉，取双侧胫骨和股骨，磷酸盐缓冲液冲洗骨髓腔，采用密度梯度离心法从大鼠骨髓中分离培养骨髓基质细胞，胰蛋白酶与EDTA联合消化，传至第4代，用含20 μg/L碱性成纤维细胞生长因子、20 μg/L表皮生长因子、N2辅助因子的DMEM/F12培养液向神经干细胞诱导分化。③实验评估：观察原代、传代培养及诱导分化后的骨髓基质细胞生长情况和形态变化，采用SABC法进行免疫细胞化学检测神经细胞特异性标志的表达。 结果：①骨髓基质细胞形态观察：原代细胞接种1 d后开始贴壁增殖，3 d后多数贴壁，贴壁细胞呈梭形或扁平形；10 d后90%细胞融合，以长梭形为主，突起粗大，形成网状、片状；传代后细胞贴壁速度加快，增殖能力更强，7 d左右达到融合。②诱导分化后细胞生长情况和形态变化：第4代骨髓基质细胞向神经干细胞诱导分化7 d，成球的细胞脱离瓶底，悬浮在细胞液中。将细胞离心弃上清，换成血清分化液后，细胞球逐渐贴壁，球周围很快发出突起，分化为星形胶质细胞样细胞、神经元样细胞及少突胶质细胞样细胞。③神经细胞特异性标志的表达：骨髓源性细胞球表达巢蛋白，呈棕黄色，为神经干细胞；从细胞球分化的细胞抗胶质纤维酸性蛋白、微管相关蛋白2及半乳糖脑苷脂均呈阳性。 结论：骨髓基质细胞能在体外诱导分化出神经干细胞，且骨髓源性神经干细胞可进一步定向分化为神经细胞及神经胶质细胞。     

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.