少突胶质细胞与2型星形胶质细胞中S-100 β表达差异性的研究

目的研究少突胶质细胞(oligodendrocytes,OL)与2型星形胶质细胞(type-2astrocyte,T2A)中S-100的表达。方法根据各种胶质细胞的生长时间的差异及细胞的黏附性不同,通过机械振荡法和差速贴壁法获得纯化的O-2A祖细胞;免疫细胞化学染色法观察S-100β在O-2A谱系细胞中的表达情况。结果O-2A祖细胞在含有PDGF、bFGF的培养液中培养3d,分化成T2A,培养5d分化成OL;OL中S-100β免疫反应呈现阳性,T2A中不表达S-100β。结论O-2A谱系细胞中的S-100β的表达与O-2A祖细胞向OL分化有关。     

少突胶质谱系细胞的生物学特性

目的研究少突胶质谱系细胞定向分化过程中的增殖及形态学的变化,为进一步研究脑室周围白质软化的临床治疗奠定基础。方法依据各种胶质细胞黏附性及生长时间的差异,通过机械振荡法和差速贴壁法从原代培养中获得纯化的O-2A祖细胞,接种于含有血小板源性生长因子和碱性成纤维细胞生长因子的培养液观察其增殖情况,再以三碘甲状腺原氨酸和睫状神经营养因子定向诱导分化,并观察分化过程中细胞的形态学变化,免疫细胞化学鉴定。结果纯化的O-2A祖细胞接种后指数式增殖呈团,细胞界限不清,表达NG2,至第4天细胞不再增多进入分裂终期;进入分化过程的少突胶质谱系细胞突起逐渐分级、交互,免疫化学鉴定依次表达O4、Gal C及MBP。结论 O-2A祖细胞具有良好的增殖能力,沿着少突胶质谱系细胞定向分化伴随形态学及表面表达抗原的变化。     

Neuregulin对少突胶质细胞的作用

少突胶质细胞是中枢神经系统的髓鞘形成细胞（myelin-forming cell），神经纤维髓鞘的形成是中枢神经系统（Central Nervous System，CNS）发育成熟的标志之一。     

显示小胶质细胞和少突胶质细胞镀银法的改良

在中枢神经系统的神经胶质细胞中,小胶质细胞和少突胶质细胞无论在正常的生理活动或损伤的修复过程,均有重要的作用。目前尚有一些未定论的问题需待解决。因此,对这两种细胞的研究也就显得尤为重要。虽然显示小胶质细胞和少突胶质细胞的方法较多,但这些方法在具体应用时常有一些不尽人意之处。为了满足教学和科研的要求,我们对多种显示方法进行了摸索和对比,并选定Penfield氏改进的Del Rio-Hor-lega氏法进行了重要的研究和改进。(1)在进入碳酸银溶液之前,用DAB(3.3’-diaminobenzidine)和H_2O_2处理;(2)增加碳酸银配方中碳酸钠的浓度至饱和;(3)将原法中碳酸银作用的时间和温度延长和提高。经过改良后的方法,稳定,显出率和成功率高,是显示小胶     

蛋白脂蛋白在两型星形胶质细胞和少突胶质细胞中的表达

目的:探讨蛋白脂蛋白(PLP)在分化成熟的两型星形胶质细胞和少突胶质细胞中的表达。方法:用激光共聚焦双重免疫荧光标记技术检测PLP在分化成熟的两型星形胶质细胞和少突胶质细胞中的表达情况。结果:在O-2A谱系来源的成熟2型星形胶质细胞和少突胶质细胞中PLP抗体标记为阳性,而在T1A谱系来源的成熟1型星形胶质细胞中则未检测到PLP的表达,从而在蛋白质水平验证本室研究两型星形胶质细胞基因表达谱差异基因芯片结果中PLP mRNA在T2A中高表达,而在T1A中低表达的现象。结论:PLP等脂代谢相关基因可能在O-2A谱系发生和分化过程中起重要作用,O-2A谱系与神经髓鞘发生以及脑内脂质代谢内在机制密切相关。     

少(寡)突胶质细胞迁移研究进展

少 (寡 )突胶质细胞是中枢神经系统的髓鞘形成细胞。作为绝缘层的髓磷脂包卷神经元轴突有利于轴突的正常快速电传导 [1 ]。它在胚胎早期起源于室层 ( ventricular zone,VZ)和室下层 ( subventricular zone,SVZ) [2 - 4 ]。在脊髓 ,少突胶质细胞由神经管腹侧的室层产生 ,然后向两侧及背侧迁移 [5 - 7]。在胚胎晚期和新生儿早期 ,少突胶质细胞前体经一定距离的迁移后形成有髓神经纤维的髓鞘。近年来在多发性硬化、脑白质发育不良等脱髓鞘疾病或髓鞘形成障碍治疗的研究中 ,细胞移植已成为一大热点 [8- 1 0 ]。而移植入受体的少突胶质细胞或其…     

新生大鼠大脑皮层少突胶质细胞/Ⅱ型星形胶质祖细胞原代培养及形态

目的:研究不同诱导条件对大鼠大脑皮层O2A祖细胞生长活性的影响。方法:采用两次恒温摇床振荡培养法,倒置显微镜结合免疫荧光染色法鉴定细胞种类并判断纯度,透射电镜观察细胞超微结构。结果:O2A祖细胞胞体呈圆形,常有单极或双极突起.形成克隆球,A285标记阳性,免疫荧光鉴定细胞纯度可达90%以上。O2A祖细胞具有双向分化的能力,在不同诱导条件下可分化为星形胶质细胞或少突胶质细胞。电镜观察O2A祖细胞呈圆形或椭圆形,核仁可见,胞质内细胞器少,核周见成束胞质丝。结论:选择合适的培养基对O2A祖细胞纯化培养及诱导分化极其重要。     

SOX蛋白与少突胶质细胞的发育

SOX蛋白是一类在动物中发现的转录因子,它们属于高移动组分(h igh mob ility group,HMG)超家族的DNA结合蛋白。它们参与性别决定、骨组织发育、神经系统发育及晶状体发育等多种胚胎发育过程。近年发现,在脊髓中形成髓鞘的少突胶质细胞表达SOX E家族的成员SOX8,SOX9和SOX10。这3个转录因子与少突胶质细胞的发育关系密切:SOX9参与少突胶质细胞的早期定向;SOX10主要影响少突胶质细胞的终末分化和髓鞘形成;SOX8与SOX9、SOX10有协同作用,既参与早期定向又参与终末分化,但作用较弱。     

少突胶质细胞生物学特性与中枢神经系统疾病

少突胶质细胞是中枢神经系统中唯一的成髓鞘细胞,膜上分布有大量的兴奋性氨基酸受体和转运体,与神经元及其他胶质细胞构成神经网络;少突胶质细胞可分泌神经营养因子、生长因子和多种轴突生长抑制因子,在生理与病理状态下发挥重要作用。少突胶质细胞与多发性硬化症、缺血性脑白质疏松症、创伤性脊髓损伤、Alzheimer病等疾病密切相关。     

大鼠少突胶质细胞的纯化培养与鉴定

目的探讨新生2dSprague—Dawley（SD）大鼠脑少突胶质细胞的分离方法和生长条件，为少突胶质细胞损伤后髓鞘形成障碍或脱髓鞘疾病的研究奠定基础。方法根据星形胶质细胞和少突胶质细胞的生长时间差异、细胞生长方式及细胞对培养层粘附等特性的不同，采用两次恒温摇床振荡分离纯化法和条件限定培养基培养获取并鉴定高纯度的大鼠少突胶质细胞。结果培养出突起有如蜘蛛网状的成熟少突胶质细胞，半乳糖脑苷脂（Galactocerebroside，Gal）阳性。结论两次恒温摇床振荡分离纯化法和条件限定培养基培养可获取高纯度的大鼠少突胶质细胞。     

Expression of cVg1 mRNA during chicken embryonic development

Using degenerated PCR-primers to identify known and novel BMPs that are expressed in the developing chicken heart, we identified not only BMP2, -4, and -7 mRNA, but also the TGFbeta superfamily member cVg1. The expression pattern of cVg1 mRNA was determined during chicken development from HH4 to HH44. In early developmental stages, cVg1 mRNA is expressed in the primitive streak, paraxial mesoderm, developing somites, and developing neural tube. Subsequently, cVg1 mRNA is expressed in the developing central and peripheral nervous system, retina, auditory vesicle, notochord, lung alveoli, and olfactory mucosa. In the heart, cVg1 is initially expressed through the linear heart tube, but becomes restricted to the forming chamber myocardium, in an expression domain similar to that of atrial natriuretic factor (ANF) mRNA.     

Expression of protocadherin-1 (Pcdh1) during mouse development.

Protocadherin-1 (Pcdh1) is a member of the delta-protocadherin subgroup of non-clustered protocadherins. We studied the expression of Pcdh1 from the early embryonic to the adult stage of mouse development by semi-quantitative RT-PCR and in situ hybridization. Pcdh1 can be detected as early as embryonic day 9.5. In early embryogenesis, expression is especially prominent in blood vessels. During later development and in the adult mouse, organs derived from the embryonic gut, such as the esophagus, intestines, liver, lung, and submandibular gland, contain epithelia and other types of tissues that are Pcdh1-positive. Other positive organs include the brain, spinal cord, retina, peripheral ganglia, the inner ear, hair follicles, kidney, vagina, uterus, placenta, testis, prostate, and the seminal gland. The tight spatial and temporal regulation of Pcdh1 expression suggests that this protocadherin plays multiple roles not only during development but also in mature tissues and organs in the mouse. Developmental Dynamics 237:2496-2505, 2008. (c) 2008 Wiley-Liss, Inc.     

Expression pattern changes and function of RANKL during mouse lymph node microarchitecture development

Receptor activator of nuclear factor kappa-B ligand (RANKL) expression was examined during the development of mouse fetal peripheral lymphoid organs. A shift in the expression pattern was detected during the transition from lymphoid tissue inducer (LTi) cells to lymphoid tissue organizer (LTo) cells in the lymph node (LN) anlagen but not in the Peyer's patch anlagen. In order to understand the functional impact of these changes in the fetal expression of RANKL, the RANKL function was blocked by a blocking antibody. Excess anti-RANKL antibody was administered to pregnant mice between 13.5 and 16.5 dpc and was found to completely block LN anlagen development, suggesting that RANKL function during this period is critical for LN development. In addition, small amounts of anti-RANKL antibodies were injected directly into the amniotic space at 13.5 dpc, resulting in perturbed B-cell follicle formation and high endothelial venule differentiation after birth. These results suggest that RANKL expression on LTi cells during the early phase of LN development is critical for the development LN microarchitecture.     

Regulation of oligodendrocyte development in the vertebrate CNS

The vertebrate central nervous system (CNS) contains two major classes of macroglial cells, oligodendrocytes and astrocytes. Oligodendrocytes are responsible for the formation of myelin in the central nervous system, while the functions of astrocytes are more diverse and less well established. Recent studies have provided new insights into when, where and how these different classes of cell arise during CNS development. The founder cells of the oligodendrocyte lineage initially arise in distinct regions of the ventricular zone during early development as the result of local signals including sonic hedgehog. In the spinal cord, oligodendrocyte precursors appear to share a developmental lineage with motor neurons, although they may also develop from restricted glial precursors. Immature oligodendrocyte precursors are highly migratory. They migrate from their site of origin to developing white matter tracts using a variety of guidance cues including diffusible chemorepellents. The majority of oligodendrocyte precursor proliferation occurs in developing white matter as a result of the local expression of mitogenic signals. Oligodendrocyte precursor cell proliferation is regulated by a number of distinct growth factors that act at distinct stages in the lineage and whose activity is modulated by synergy with other molecules including chemokines. The final matching of oligodendrocyte and axon number is accomplished through a combination of local regulation of cell proliferation, differentiation and cell death. Not all oligodendrocyte precursors differentiate during development, and the adult CNS contains a significant population of precursors. Understanding the regulation of oligodendrogenesis will facilitate the use of these endogenous precursors to enhance repair in a variety of pathological conditions.     

In vivo time-lapse imaging shows dynamic oligodendrocyte progenitor behavior during zebrafish development

Myelinating oligodendrocytes arise from migratory and proliferative oligodendrocyte progenitor cells (OPCs). Complete myelination requires that oligodendrocytes be uniformly distributed and form numerous, periodically spaced membrane sheaths along the entire length of target axons. Mechanisms that determine spacing of oligodendrocytes and their myelinating processes are not known. Using in vivo time-lapse confocal microscopy, we show that zebrafish OPCs continuously extend and retract numerous filopodium-like processes as they migrate and settle into their final positions. Process remodeling and migration paths are highly variable and seem to be influenced by contact with neighboring OPCs. After laser ablation of oligodendrocyte-lineage cells, nearby OPCs divide more frequently, orient processes toward the ablated cells and migrate to fill the unoccupied space. Thus, process activity before axon wrapping might serve as a surveillance mechanism by which OPCs determine the presence or absence of nearby oligodendrocyte-lineage cells, facilitating uniform spacing of oligodendrocytes and complete myelination.     

Expression and regulation of ROR-1 during early avian limb development

ROR-1 is a member of the ROR family of tyrosine kinase like orphan receptors and is highly conserved among various species. We have isolated the chick ROR-1 (cROR-1) and show that cROR-1 expression is high and restricted to the proximal limb region until HH-stage 25. At later stages, expression spreads towards the distal limb region. In order to determine the signals that control cROR-1 expression, factors known to be involved in limb patterning (FGFs, BMPs, SHH, retinoic acid) were applied to the developing limb. Whereas neither FGFs, BMPs, nor SHH affected cROR-1 expression, upregulation could be achieved by ectopic application of retinoic acid to the distal limb region. As retinoic acid also upregulated retinoic acid receptor beta (Rar-), we assume that cROR-1 upregulation is mediated by Rar-. We conclude that ROR-1 signaling is an independently regulated pathway, which is involved in late rather than early limb development.     

Expression of occ1 mRNA in the visual cortex during postnatal development in macaques

We previously reported that the occ1 gene is specifically expressed in the primary visual cortex of adult monkeys in an activity-dependent manner (Tochitani et al., Eur. J. Neurosci., 3, 297-307, 2001). In this report, we compared occ1 mRNA expression in the primary visual cortex during the development of newborn, 3-month-old and adult monkeys. occ1 mRNA was already expressed preferentially in the primary visual cortex of newborn monkeys, but the laminar pattern of occ1 expression in the visual cortex changed as development proceeded. This suggests the possible importance of experience-dependent developmental regulations of occ1 in the developing primary visual cortex.     

Expression and regulation of HTRA1 during chick and early mouse development

HTRA1, a member of the high temperature requirement factor A family, is a secreted serine protease that can bind to and inactivate members of the transforming growth factor-beta (TGFbeta) family, modulate insulin-like growth factor signaling and stimulate long range fibroblast growth factor (FGF) signaling in Xenopus. In vertebrates, so far homologues from mouse, human, and Xenopus have been cloned and studied. Here we report the cloning of the chicken HTRA1 homologue from a screen for FGF8 inducible genes in chick facial mesenchyme. We characterize its expression pattern from gastrulation (Hamburger and Hamilton stage 4) to day 4 of development, and in forming inner organs and limbs. We show that chick HTRA1 has a dynamic expression pattern that differs significantly from the expression of its mouse homolog. We, furthermore, demonstrate that FGF signaling is necessary and sufficient for HTRA1 expression in chick facial and forelimb mesenchyme, but is not required for HTRA1 expression in HH11 embryos.