砷剂对胶质瘤细胞的促凋亡作用

目的 研究三氧化二砷(As2O3)对不同胶质瘤细胞系的作用以及机制.方法 应用MTT法观察As2O3对细胞生长的影响,并用透射电镜、Hoechst 33342/PI双染荧光和TUNEL观察C6胶质瘤细胞与9L胶质肉瘤细胞凋亡的形态变化;Annexin-v-FITC/PI双标记法检测细胞凋亡率.结果 MTF法发现As2O3在0.5-8.0μmol/L的浓度均可显著抑制C6与9L胶质瘤细胞株的生长;透射电镜、Hoechst 33342/PI双染荧光和TUNEL观察均显示两种胶质瘤细胞发生了显著的凋亡形态改变;Annexin-v-FITC/PI法检测显示随As2O3浓度的增大和时间的延长,C6与9L胶质瘤细胞株的凋亡率明显上升,而在相同时间及浓度下9L胶质瘤细胞株凋亡率要小于C6胶质瘤细胞株.结论 As3O3可诱导C6和9L胶质瘤细胞株产生凋亡,并且其作用具有选择性.     

三氧化二砷诱导9L胶质瘤细胞凋亡的实验研究

目的研究三氧化二砷（As2O3）对鼠胶质瘤生长的影响及其机制。方法应用不同浓度As2O3,分别处理9L胶质瘤细胞株不同时间,采用四甲基噻唑蓝比色（MTT）法观察As2O3对9L胶质瘤细胞生长的影响,以透射电镜、Hoechst 33342/PI双染荧光及流式细胞仪检测9L胶质瘤细胞凋亡。结果不同浓度的As2O3均可显著抑制9L胶质瘤细胞株的生长。As2O3作用可引起9L胶质瘤细胞的凋亡,且随As2O3浓度的增大和作用时间的延长,9L胶质瘤细胞的凋亡率明显上升。结论As2O3在体外可显著抑制9L胶质瘤细胞生长,其机制与诱导肿瘤细胞凋亡有关,且其凋亡率随As2O3作用的时间延长和剂量的增加而增加。     

三氧化二砷对正常星形胶质细胞的影响

本实验研究了三氧化二砷(As2O3)对大鼠正常神经胶质细胞的生长抑制作用,并与其对9L胶质瘤细胞的抑制作用进行对比,以明确As3O3在诱导9L胶质瘤细胞凋亡的同时,是否会对正常神经细胞产生影响,从而为临床应用As2O3治疗脑胶质瘤提供实验依据.     

白藜芦醇抑制SHG-44胶质瘤细胞生长实验研究

目的探讨白藜芦醇(Res)在体外诱导脑胶质瘤SHG-44细胞凋亡并抑制其生长的作用。方法四甲基偶氮唑蓝(MTT)比色法测量不同剂量的Res作用6h、24h和48h后对SHG-44胶质瘤细胞增殖的影响。HE染色、Hoechst33342荧光染色观察细胞形态改变,DNAladder检测细胞DNA裂解情况,流式细胞仪用异硫氰酸荧光素标记的膜联蛋白V(AnnexinV-FITC)和碘化丙啶(PI)双染检测凋亡率,并测定细胞周期的改变。结果Res明显抑制SHG-44细胞的生长和增殖(P<0.01),呈浓度及时间依赖性反应;Res所致的SHG-44胶质瘤细胞凋亡为浓度依赖关系,随着浓度的增高,凋亡更明显。此凋亡细胞周期主要发生G1期比例升高,S、G2期比例降低。结论Res明显抑制SHG-44细胞生长并诱导其发生凋亡和细胞周期改变,为Res用于治疗脑胶质细胞瘤提供了实验依据。     

PEX基因修饰骨髓间质干细胞对C6胶质瘤细胞增殖和凋亡的影响

目的探讨PEX基因修饰的骨髓间质干细胞（mesenchymal stem cells,MSC）对C6胶质瘤细胞的作用及机制。方法分子克隆技术构建PEX基因真核表达载体并转染MSC,G418筛选获取稳定表达PEX基因的MSC（MSC-PEX）,将不同数量的MSC-PEX细胞与C6胶质瘤细胞进行共培养试验,用水溶性四氮唑法（WST-1）观察MSC-PEX对C6胶质瘤细胞增殖的影响,用Annexin-Ⅴ-FITC/PI双染荧光观察C6胶质瘤细胞凋亡的形态学变化,并用Annexin-Ⅴ-FITC/PI双标记法通过流式细胞仪检测胶质瘤细胞凋亡率。结果成功获得稳定表达PEX基因的MSC-PEX,MSC-PEX抑制C6胶质瘤细胞的生长作用较明显,Annexin-Ⅴ-FITC/PI双染荧光发现C6胶质瘤细胞发生凋亡形态改变;流式细胞仪检测显示：MSC-PEX转染组和DMEM对照组的凋亡率分别为16.7%和1.3%,差异有统计学意义（P〈0.05）。结论PEX基因修饰的骨髓间质干细胞抑制胶质瘤细胞增殖并诱导其凋亡,为胶质瘤的治疗奠定理论基础。     

白藜芦醇抑制胶质瘤细胞生长与诱导细胞凋亡实验研究

目的探讨白藜芦醇(Res)对脑胶质瘤细胞(C6细胞株)和正常成纤维细胞(3T3细胞株)体外增殖的影响,进而观察Res诱导C6和3T3细胞系的凋亡作用.方法用不同浓度的Res处理C6和3T3细胞,以四甲基偶氮唑蓝(MTT)比色法检测Res对C6和3T3细胞的增殖作用,通过HE染色、扫描电子显微镜(SEM)、原位末端标记法(TUNEL)和流式细胞仪Annexin Ⅴ荧光染色,观察细胞的形态学结构改变,并定量检测细胞凋亡.结果 Res抑制了C6细胞的生长与增殖( P < 0.01 ),呈浓度依赖性反应;Res能明显诱导C6细胞凋亡,经210 μmol/L、120 μmol/L Res处理24 h后及对照组的C6细胞,其凋亡率分别为29.7%、14.6%及2.1%;相应的3T3细胞凋亡率分别为4.3%、3.5%、2.6%. 结论 Res能通过诱导C6细胞凋亡而抑制其生长与增殖,但对3T3细胞无此作用.本研究为临床应用Res治疗脑胶质细胞瘤提供了实验依据.     

mTOR通路抑制剂依维莫司对不同胶质瘤细胞自噬作用的影响

目的 探讨mTOR抑制剂依维莫司对人脑胶质瘤细胞自噬作用的影响. 方法 体外培养胶质瘤细胞株87-MG、U251、SHG-44,给予不同浓度的依维莫司(0.1、0.5、1、10、20、100nmol/L)作用4-6d后用MTT法检测细胞的增殖并分析各细胞株的半数抑制浓度(IC50)值.Hoechst33342/PI荧光双染检测IC50的依维莫司作用48 h后细胞凋亡;单丹磺酰尸胺(MDC)荧光染色检测细胞自噬囊泡的形成;流式细胞术检测细胞周期的变化.Western blotting测定IC50的依维莫司作用24h后细胞磷酸化mTOR、p70S6K、4E-BP-1蛋白及非磷酸化mTOR、p70S6K蛋白的表达. 结果 MTT结果显示U87-MG、SHG-44、U251细胞的生长均受到明显抑制,IC50分别为0.1、0.5、10nmol/L;Hoechst 33342/PI荧光双染结果显示细胞没有发生明显的凋亡,可能为细胞白噬;MDC染色显示IC50的依维莫司作用后,细胞中荧光颗粒增加,荧光强度增强;流式细胞术检测显示3种细胞均有特异性的G0/G1期细胞阻滞;Western blotting检测显示随着依维莫司剂量的增加,胶质瘤细胞中磷酸化mTOR、p70S6K、4E-BP-1的表达水平均明显减少,非磷酸化4E-BP-1的表达水平减少,而非磷酸化p70S6K无明显变化. 结论 mTOR抑制剂依维莫司可以促进胶质瘤细胞的自噬,mTOR通路可能为潜在的新的胶质瘤的治疗靶点.     

三氧化二砷对人胶质瘤U251细胞生长及端粒酶活性的影响

目的探讨三氧化二砷（As2O3）对人胶质瘤U251细胞的生长及端粒酶活性的影响。方法采用倒置显微镜和透射电镜观察As2O3处理后U251细胞形态变化;四甲基偶氮唑蓝比色法观察As2O3对U251细胞增殖的影响;流式细胞术检测细胞凋亡;端粒重序列扩增酶联免疫吸附实验（TRAP-ELISA）结合聚丙烯酰胺凝胶电泳（TRAP-PAGE）银染法检测As2O3处理后U251细胞端粒酶活性变化。结果倒置显微镜下观察到：As2O3处理后的U251细胞逐渐变圆、脱壁,细胞间接触变松,细胞质中颗粒增多,增殖变慢,细胞周围碎片增多;透射电镜下见较多典型凋亡细胞。1～8μmol/LAs2O3明显抑制U251细胞增殖,诱导其凋亡;并使端粒酶活性逐渐下降,该作用呈浓度和时间依赖性。结论 As2O3对人胶质瘤U251细胞株生长具有显著抑制作用,其机制可能与As2O3能够抑制U251细胞的端粒酶活性密切相关。     

三氧化二砷对人脑SHG-44胶质瘤细胞作用的体外实验研究

目的 探讨三氧化二砷(As2O3)对人脑SHG-44胶质瘤细胞株的增殖抑制及诱导凋亡机制.方法 将不同浓度的As2O3与体外培养的SHG-44胶质瘤细胞相互作用后,采用MTT比色法检测As2O3对胶质瘤细胞的增殖抑制;倒置显微镜、荧光显微镜下观察吉姆萨及Hochest33258染色后细胞凋亡的形态学改变;流式细胞仪检测细胞凋亡及对SHG-44胶质瘤细胞周期影响.结果 MTT比色法检测到As2O3对SHG-44胶质瘤细胞增殖具有明显的抑制作用,并呈剂量依赖性和时间依赖性;倒置显微镜及荧光显微镜下可观察到给药组细胞生长密度低以及出现细胞凋亡的特征性改变;流式细胞仪检测到给药组细胞凋亡比率明显高于空白对照组(P＜0.05),并具有剂量依赖性及时间依赖性,同时将胶质瘤细胞阻滞在S期,抑制了细胞周期的进程.结论 As2O3对SHG-44胶质瘤细胞增殖具有明显的抑制作用、可诱导SHG-44胶质瘤细胞的凋亡,并抑制细胞周期进程.     

TRAIL对原代培养胶质瘤细胞的凋亡诱导作用

目的研究TRAIL对原代培养的胶质瘤细胞的凋亡诱导作用,探讨其临床应用的实际价值。方法对22例脑胶质瘤和5例正常脑组织进行原代培养,用流式细胞仪检测TRAIL作用后肿瘤细胞和正常胶质细胞的凋亡率。结果成功培养出18例胶质瘤细胞和4例正常胶质细胞。800ng mlTRAIL作用48h后,凋亡率在80%以上的5例,50%～80%9例,50%以上14例,占总数的77.78%,50%以下的4例;正常胶质细胞无明显凋亡发生。结论TRAIL能有效地选择性地杀死某些胶质瘤细胞,对正常胶质细胞则无损害作用,TRAIL为胶质瘤的安全治疗提供了一个新的备选方法。     

胚鼠室管膜及成鼠骨髓神经干细胞分离培养及分化鉴定实验研究

目的 :探寻胚鼠室管膜和成鼠骨髓分离培养神经干细胞 (NSC)的可行性。方法 :将分离的胚脑室管膜组织或成年骨髓细胞分别特殊培养。以细胞克隆及免疫细胞化学方法判断NSC增殖并鉴定NSC、神经元和神经胶质细胞。结果 :两种组织来源细胞在相应培养条件下NSC均有快速增殖。可得到具有长突起并建立有网状联系的神经元及胶质细胞。结论 :由胚鼠室管膜和成鼠骨髓诱导分化NSC是可行的     

Ultrastructural study of the granule cell domain of the cochlear nucleus in rats: Mossy fiber endings and their targets

The principal projection neurons of the cochlear nucleus receive the bulk of their input from the auditory nerve. These projection neurons reside in the core of the nucleus and are surrounded by an external shell, which is called the granule cell domain. Interneurons of the cochlear granule cell domain are the target for nonprimary auditory inputs, including projections from the superior olivary complex, inferior colliculus, and auditory cortex. The granule cell domain also receives projections from the cuneate and trigeminal nuclei, which are first-order nuclei of the somatosensory system. The cellular targets of the nonprimary projections are mostly unknown due to a lack of information regarding postsynaptic profiles in the granule cell areas. In the present paper, we examined the synaptic relationships between a heterogeneous class of large synaptic terminals called mossy fibers and their targets within subdivisions of the granule cell domain known as the lamina and superficial layer. By using light and electron microscopic methods in these subdivisions, we provide evidence for three different neuron classes that receive input from the mossy fibers: granule cells, unipolar brush cells, and a previously undescribed class called chestnut cells. The distinct synaptic relations between mossy fibers and members of each neuron class further imply fundamentally separate roles for processing acoustic signals. © 1996 Wiley-Liss, Inc.     

Retinal neurons of the California ground squirrel,Spermophilus beecheyi: A Golgi study

Although the optic nerve fibers of the cone-dominant ground squirrel retina have been well studied physiologically, the morphological details of the retinal neurons have not. To that end, retinal neurons of the California ground squirrel have been studied in Golgi-impregnated wholemounts. Two types of horizontal cell have been identified: H1 has an axon and axon terminal, whereas H2 is axonless. The dendritic field of H1 cells enlarges in a nonuniform manner with increasing displacement from the central retina. The smallest examples lie centrally in the visual streak, and the largest occur in the superior periphery. Eight types of bipolar cell are distinguished by morphological differences in dendritic branching pattern and field size in the outer plexiform layer, cell body size, and layering within the inner nuclear layer and by the morphology and stratification of axon terminals in the inner plexiform layer. A large bistratified bipolar cell (B8) is introduced here; the other 7 types closely resemble those in the retinas of other sciurid species described by R.W. West (1976, J. Comp. Neurol. 168:355–378; 1978, Vision Res. 18:129–136). The B1 type is proposed as a blue cone bipolar cell. Amacrine cells are classified into 27 cell types. Six of these occur as mirror-image pairs across the inner plexiform layer, the soma of one of each pair being “displaced” to the ganglion cell layer. The best described of these pairs is the very elaborate starburst amacrine cell, A5, which stains regularly in these wholemounted retinas. Changes in dendritic field size of both A5 subtypes with retinal location are quantified. The morphology of three amacrine cell types identified in Spermophilus beecheyi suggests that their possible counterparts in S. mexicanus (West, 1976) were, as displaced amacrine cells, misidentified as ganglion cells. Amacrine cell types that may play roles in the rod pathway, the blue cone pathway, and ganglion cell directional selectivity are discussed. No type of interplexiform cell was observed. Ganglion cells are classified into 19 cell types, 9 of which probably correspond to the ganglion cells described by West (1976) in the Mexican ground squirrel. The bistratified G11 cell is proposed as an ON-OFF directionally selective type. © 1996 Wiley-Liss, Inc.     

A quantitative morphometric analysis of rat spinal cord remyelination following transplantation of allogenic Schwann cells

Quantitative morphometric techniques were used to assess the extent and pattern of remyelination produced by transplanting allogenic Schwann cells into demyelinated lesions in adult rat spinal cords. The effects of donor age, prior culturing of donor cells, prior lesioning of donor nerves, and host immunosuppression were evaluated by transplanting suspensions of 30,000 acutely dissociated or cultured Schwann cells from neonatal, young adult, or aged adult rat sciatic nerves into X-irradiation and ethidium bromide-induced demyelinated dorsal column lesions, with or without co-transplantation of neonatal optic nerve astrocytes. Three weeks after transplantation, spinal cords were processed for histological analysis. Under all Schwann cell transplant protocols, large areas containing many Schwann cell-like myelinated axon profiles could be readily observed throughout most of the lesion length. Within these "myelin-rich" regions, the vast majority of detectable axons showed a peripheral-like pattern of myelination. However, interaxonal spacing also increased, resulting in densities of myelinated axons that were more similar to peripheral nerve than intact dorsal columns. Freshly isolated Schwann cells remyelinated more axonal length than cultured Schwann cells, and cells from younger donors remyelinated slightly more axon length than cells from older donors, but all Schwann cell transplant protocols remyelinated tens of thousands of millimeters of axon length and remyelinated axons at similar densities. These results indicate that Schwann cells prepared under a variety of conditions are capable of eliciting remyelination, but that the density of remyelinated axons is much lower than the myelinated axon density in intact spinal cords.     

Extraordinary synapses of the unipolar brush cell: An electron microscopic study in the rat cerebellum

A neglected type of neuron, termed the unipolar brush cell, was recently characterized in the granular layer of the mammalian cerebellar cortex with several procedures, including light and electron microscopic immunocytochemistry utilizing antibodies to calretinin and neurofilament proteins. Although certain features of the unipolar brush cells were highlighted in these studies, the internal fine structure was partially obfuscated by immunoreaction product. In this study, rat cerebella were prepared for electron microscopy after perfusion fixation and Araldite embedding, and folia of the vestibulo-cerebellum, where unipolar brush cells are known to be enriched, were studied by light microscopy in semithin (0.5–1 μ) sections and by electron microscopy in ultrathin sections. Unipolar brush cells were easily identified in semithin sections immunostained with antibodies to GABA and/or glycine, and cbunterstained with toluidine blue. The unipolar brush cells have a pale cytoplasm and are GABA and glycine negative, while Golgi cells are darker and appear positive for GABA and, for the most part, also for glycine. Sets of identification criteria to differentiate unipolar brush cells from granule and Golgi cells in standard electron micrographs are presented. The unipolar brush cells possess many distinctive features that make them easily distinguishable from other cerebellar neurons and form unusually conspicuous and elaborate synapses with mossy rosettes. The unipolar brush cell has a deeply indented nucleus containing little condensed chromatin. The Golgi apparatus is large and the cytoplasm is rich in neurofilaments, microtubules, mitochondria, and large dense core vesicles, but contains few cisterns of granular endoplasmic reticulum. In addition, unipolar brush cells contain an unusual inclusion, which invariably lacks a limiting membrane and is made up of peculiar ringlet subunits. The cell body usually emits a thin axon and is provided with a single, large dendritic trunk that terminates with a paintbrush-like bunch of branchlets. Numerous nonsynaptic appendages emanate from the cell body, the dendritic stem, and the branchlets. The appendages contain rare organelles and lack neurofilaments. The branchlets contain numerous mitochondria, neurofilaments, large dense core vesicles, and clusters of clear, small, and round synaptic vesicles. They form extensive asymmetric synaptic junctions with of a or two mossy fibers, which indicates minimal convergence of excitatory inputs. Under the postsynaptic densities, the branchlet cytoplasm displays a microfilamentous web. Besides their contact with mossy rosettes, the branchlets form symmetric and asymmetric synaptic junctions with presumed Golgi cell boutons that contain pleomorphic synaptic vesicles, indicating that the unipolar brush cells receive an inhibitory modulation. Some of these junctions are unusually extensive. The branchlets also form asymmetric synapses with granule cell dendrites, in which they represent the presynaptic elements, a feature never described before in the normal cerebellum. A minority of the unipolar brush cells receive mossy fiber contacts directly on the cell body, or on short dendritic branchlets emanating directly from the cell body. Such “enmarron” synapses were previously attributed to Golgi cells. Thus, the unipolar brush cells have complex synaptic features: Besides being specialized to form a powerful link with mossy rosettes, they may also have a paracrine function, and they participate with presynaptic dendrites in the cerebellar microcircuit. © 1994 Wiley-Liss, Inc.     

SD大鼠胚胎神经干细胞分离、培养及鉴定

目的 体外培养并鉴定神经干细胞，为相关实验研究奠定基础。方法 分离SD大鼠胎鼠的间脑，加入神经生长因子EGF和bFGF在神经干细胞条件培养基中克隆培养。用免疫细胞化学方法鉴定分离的神经干细胞。结果 分离培养的细胞具有不断增殖的能力，表达神经巢蛋白（nestin），并能经过诱导分化为神经元和神经胶质细胞。结论 成功建立了神经干细胞的分离培养方法，可用于进一步的实验研究。     

心肌条件培养液与5-氮胞苷诱导骨髓基质干细胞向心肌样细胞的分化

背景：骨髓基质干细胞可以明显改善心肌缺血时的心脏功能，但其直接分化为心肌细胞并参与心功能恢复的机制尚不明确。 目的：探讨心肌条件培养液与5-氮胞苷诱导骨髓基质干细胞分化为心肌样细胞的作用。 方法：全骨髓贴壁法分离培养骨髓基质干细胞，将第6代骨髓基质干细胞随机分为4组：5-氮胞苷+心肌条件培养液联合诱导组；5-氮胞苷组；心肌条件培养液组；基础培养基组(空白组)。用心肌条件培养液和5-氮胞苷诱导3周后用免疫组化法测定各组心肌肌钙蛋白表达，并采用单因素方差分析检验进行统计学分析。 结果与结论：在体外心肌条件培养液可以诱导骨髓基质干细胞向心肌细胞分化，提示其中细胞因子可能起关键作用，但心肌条件培养液的这种作用要弱于化学诱导剂5-氮胞苷的诱导作用，且联合诱导作用更强。     

Properties of the ON bistratified ganglion cell in the rabbit retina

The identity of the types of different neurons in mammalian retinae is now close to being completely known for a few mammalian species; comparison reveals strong homologies for many neurons across the order. Still, there remain some cell types rarely encountered and inadequately described, despite not being rare in relative frequency. Here we describe in detail an additional ganglion cell type in rabbit that is bistratified with dendrites in both sublaminae, yet spikes only at light onset and has no response bias to the direction of moving bars. This ON bistratified ganglion cell type is most easily distinguished by the unusual behavior of its dendritic arbors. While dendrites that arborize in sublamina b terminate at that level, those that ascend to arborize in sublamina a do not normally terminate there. Instead, when they reach the approximate radius of the dendrites in sublamina b, they dive sharply back down to ramify in sublamina b. Here they continue to course even further away from the soma at the same level as the branches wholly contained in sublamina b, thereby forming an annulus of secondary ON dendrites in sublamina b. This pattern of branching creates a bistratified dendritic field of approximately equal area in the two sublaminae initially, to which is then added an external annulus of dendrites only in sublamina b whose origin is entirely from processes descending from sublamina a. It is coupled to a population of wide‐field amacrine cells upon which the dendrites of the ganglion cell often terminate. J. Comp. Neurol. 521:1497–1509, 2013. © 2012 Wiley Periodicals, Inc.     

稳定表达人CNTF诱导PC12细胞分化作用的研究

目的:探讨CNTF对PC12细胞的诱导分化作用。方法:应用转基因技术将pcDNA-S-hCNTF质粒转入COS7细胞进行表达,并对CNTF表达进行检测,然后将hCNTF修饰过的COS7细胞与PC12细胞进行联合培养,4天后对CNTF作用后的PC12进行形态学观察,β-tubulin免疫细胞化学染色及不同培养时间4天,5天后阳性细胞的指数进行分析,同时通过MTF实验对诱导培养后的PC12细胞内增殖进行检测。结果:PC12细胞与hCHTF修饰过的COS7细胞经过4天的联合培养,细胞大部分形态呈现出类似于神经元的形态,胞体立体感较强,并且细胞长出较长的突起。另外细胞呈现β-tubulin反应阳性,并且随培养时间延长,β-tubulin阳性细胞的数目有增加的趋势(从76.6％增加到88.3％),最后,反映细胞增殖程度的OD值为0.328±0.019,明显低于对照组0.586±0.028,0.597±0.032。结论:hCNTF对PC12细胞向神经元分化有明显的促进作用。