星形胶质细胞谱系及星形细胞瘤起源的研究

各种神经胶质细胞中数目最多、分布最广的星形细胞担负了神经胶质细胞的大部分功能。根据对两种神经组织标志物─ＧＦＡＰ、Ａ－２Ｂ－５抗体的反应不同，将星形细胞分为１型（ＧＦＡＰ＋Ａ－２Ｂ－５－）和２型（ＧＦＡＰ＋、Ａ－２Ｂ－５＋）。研究指出两型星细胞来源于不同祖细胞，而存在两个谱系，星形细胞胶质瘤与星形细胞具有同样的谱系源。对小胶质细胞在星形细胞发生和分化中的作用亦予以阐述。     

Nestin 和GFAP在缺氧大鼠视网膜神经胶质细胞中的表达及高氧治疗的作用

目的： 探讨巢蛋白（nestin）和胶质纤维酸性蛋白（GFAP）在缺氧大鼠视网膜神经胶质细胞中的表达情况及高氧治疗对其表达的影响。方法: 制作大鼠缺氧模型及缺氧后高氧治疗模型,行眼球矢状位切片及视网膜铺片,行GS/nestin、GS/GFAP、GFAP/nestin免疫荧光双标染色。结果: 正常大鼠视网膜中几乎看不到nestin阳性染色,GFAP阳性染色仅位于星形胶质细胞上。缺氧后,在Müller细胞和星形胶质细胞上出现了nestin的表达,GFAP的表达没有明显变化。高氧治疗后,nestin在Müller细胞上的表达明显减弱,但在星形胶质细胞上仍有较强的表达。GFAP仍然只在星形胶质细胞上表达。结论: Müller细胞和星形胶质细胞针对缺氧损伤和高氧处理发生不同的细胞骨架蛋白重塑,这与它们和视网膜神经节细胞以及视网膜血管在解剖和功能关系上的差异有关。     

人胎视网膜血管发育的研究

人胎视网膜血管发育的研究李爱冬羊惠君（华西医科大学解剖教研室）为了研究人胎视网膜血管发育及调节因素，明确胎儿视网膜血管存在的缺陷，本文作者收集了８－３８周胎儿视网膜１３４例和成人视网膜４例，作免疫组化染色和光镜观察。结果显示：①梭形细胞在１２－１３周...     

小鼠视网膜神经免疫系统的组织发生

目的 探讨小鼠视网膜神经免疫系统中小胶质细胞和血视网膜屏障（BRB）的发育过程,及视网膜神经免疫系统的组织发生。方法 选取不同年龄点的昆明小鼠各5～10只,应用免疫荧光染色、DiI散射标记、明胶墨汁灌注和透射电子显微镜技术,对视网膜上小胶质细胞和BRB的发育进行研究。 结果 在孕10 d（E10）时,视网膜上就已经出现了小胶质细胞,并且均匀分布于整个视网膜,随着发育小胶质细胞的形态由阿米巴样变成分支状。出生后小胶质细胞数量不断增多,在出生5 d（P5）时达到最大值,之后细胞数量有所下降,P30后趋于稳定。视网膜上血管的发生是在出生后由视乳头开始呈辐射状向四周扩散的,在P10左右浅层血管网覆盖整个视网膜,之后不断向下延伸形成深层血管网。随着年龄增长,血管体密度呈下降趋势。BRB在P30时发育成熟,主要由管腔光滑的内皮细胞、厚度均一的基底膜、薄层星形胶质细胞的终足和周细胞构成。 结论 小胶质细胞随着发育变得更加成熟,数量变化呈抛物线状;P30时,BRB的各个组成部分已发育完善,各结构之间关系密切。视网膜神经免疫系统的重要组成部分--小胶质细胞和BRB,具有一定的抗感染能力,能够有效地抵抗病原菌的感染。     

α-黑素细胞刺激素体外对星形胶质细胞产生NO和前炎性细胞因子的影响

目的：研究α－黑素细胞刺激素（α－ＭＳＨ）对ＬＰＳ诱导星形胶质细胞产生ＮＯ和前炎性细胞因子的影响。探讨α－ＭＳＨ的抗炎作用机制。方法：分别用ＬＰＳ或α－ＭＳＨ＋ＬＰＳ处理体外培养的大鼠脑星形胶质细胞,用Ｇｒｉｅｓｓ试剂测定ＮＯ,以ＭＴＴ显色法检测ＩＬ－１、ＩＬ－６和ＴＮＦ－α,采用半定量ＲＴ－ＰＣＲ检测ＭＩＦｍＲＮＡ表达。结果：体外培养的星形胶质细胞在ＬＰＳ刺激下产生ＮＯ、ＩＬ－１、ＩＬ－６、ＴＮＦ－α和表达ＭＩＦｍＲＮＡ表达。结果：体外的星形胶质细胞在ＬＰＳ刺激下产生ＮＯ、ＩＬ－１、ＩＬ－６、ＴＮＦ－α和表达ＭＩＦｍＲＮＡ显著增高;若同时给予ＬＰＳ和α－ＭＳＨ,可明显降低ＮＯ、ＩＬ－１、ＩＬ－６和ＴＮＦ－α的产生以及ＭＩＦｍＲＮＡ表达。结论：Ｒ昧α－ＭＳＨ抑制星形胶质细胞产生ＮＯ和前炎性细胞因子与其抑制中枢神     

GFAP标记人胎视网膜星形胶质细胞的观察

采用胶质原纤维酸性蛋白（Glial Fibrillary Acidic Protein,GFAP)单克隆抗体在人胎视网膜全铺片上标记了星形胶质细胞（Astrocyte)，观察到地视网膜中心区（后根部）星形胶质细胞的突起束与神经节细胞轴突束平行排列，它们自视神经盘处向视网膜周边部呈放射状走行，在向周期行进过程中突起束逐渐变稀变细，至视网膜周边部突起束已模糊不易辩认，某些突起束还沿着残留的玻璃体动脉延伸一段距离，见到的单个星形胶质细胞，呈纤维性型特性。     

视网膜神经血管发育及其相互影响研究进展

视网膜神经和血管分别按照各自的时间和空间顺序发育。视网膜血管发育可受到各种因素的影响,其中血管内皮生长因子(VEGF)和色素上皮衍生因子(PEDF)是目前发现功能最强的眼内血管新生促进因子和抑制因子,而视网膜中的星形胶质细胞和Müller细胞则可以影响血管的生长发育。视网膜神经和血管的发育过程存在相互联系。     

CNTF及其受体在不同类型星形胶质细胞中的表达

目的：研究CNTF及其受体在不同类型星形胶质细胞中的表达分布。方法：星形胶质细胞的原代分离培养结合地高辛标记的RNA探针及寡核苷酸探原原位杂交技术。结果：0－2A前体细胞和纤维型星形胶质细胞中CNTFmRNA表达,大多数原浆型星形胶质细胞CNTF表达低,只有约5％的原浆型星形胶质细胞群可见较高,CNTNFmRNA的表达。原浆型与纤维型星形胶质细胞中CNTFRαmRNA表达相同。结论CNTF在不同类型星形胶质细胞中的表达水平不同。但其受体的表达水平无差别。     

胶质纤维酸性蛋白基因调控及其在胶质瘤诱导分化中的作用

胶质纤维酸性蛋白（ｇｌｉａｌｆｉｂｒｉｌａｒｙａｃｉｄｉｃｐｒｏｔｅｉｎ，ＧＦＡＰ）是星形细胞胞质内特异性蛋白，它在星形细胞源性胶质瘤的诊断上已发挥出重要作用。不仅如此，人们对ＧＦＡＰ表达与胶质细胞分化和瘤细胞生物学特性的关系、ＧＦＡＰ基因的结构和功...     

AgNORs,p53癌基因蛋白在胶质细胞增生和胶质瘤中的表达

目的：探讨核仁组成区嗜银蛋白（ＡｇＮＯＲｓ），ｐ５３蛋白在胶质细胞增生和胶质瘤中的表达。方法：运用免疫组化和形态半定量技术，对胶质细胞增生和星形细胞瘤分别标记ＡｇＮＯＲｓ（３７例），ｐ５３蛋白（３３例）的表达。结果：ＡｇＮＯＲｓ，ｐ５３蛋白在胶质细胞增生和Ⅰ级星形细胞瘤以及Ⅱ、Ⅲ、Ⅳ级星形细胞瘤中的表达存在差异性，各组间统计学处理Ｐ＜０．０１，差异有显著性。结论：ＡｇＮＯＲｓ、ｐ５３蛋白可作为鉴别胶质细胞增生和Ⅰ级星形细胞瘤有用的参考指标，两者表达随着星形细胞瘤级别增加而增强，具有正相关性，能较好地反映星形细胞瘤的恶性程度     

Astrocyte invasion and vasculogenesis in the developing ferret retina

We studied the time course of astrocyte invasion and blood vessel formation in the developing ferret retina using glial fibrillary acidic protein (GFAP)-immunohistochemistry for astrocytes and isolectin B4 histochemistry for blood vessels. As in other mammals, strongly GFAP positive astrocytes invade the ferret retina from the optic nerve. At birth, strongly GFAP positive astrocytes have reached about 22% of the distance between optic disc and outer retinal edge whereas weakly GFAP positive processes already extend to the edge of the retina. At postnatal days P30–P37 about 82% of the distance between optic disc and outer retinal edge and in the adult 88% of this distance is covered with strongly labelled astrocytes. Superficial blood vessels form from the optic disc. They reach up to about 24% of the retinal radius at birth and grow radially across the retina during further development. At P30–P37, the whole retina is covered with superficial blood vessels. The deep vascular layer forms later (around P30) through sprouting from superficial vessels. The radial pattern of astrocyte and vessel growth from the optic disc is not affected by the formation of the area centralis and visual streak.     

兔胎视网膜内P物质免疫反应神经元的发生

本文用免疫细胞化学ＡＢＣ法，研究了新西兰白兔１８、２２、２５、２６、２８和３０ｄ胎龄视网膜内Ｐ物质免疫反应（ＳＰＩＲ）神经元的发生。在胎龄１８和２２ｄ兔视网膜未见ＳＰＩＲ细胞体和纤维。在胎龄２５ｄ视网膜的节细胞层最先出现ＳＰＩＲ神经元，胞体浅染呈卵圆形，突起不明显，在神经纤维层偶见串珠状ＳＰＩＲ纤维，其平均细胞密度为１０４．６个细胞／ｍｍ￣２。到胎龄２６和２８ｄ时，在节细胞层的ＳＰＩＲ神经元的胞体渐深染，可见个别ＳＰＩＲ神经元发出粗而短的突起伸向内网层，平均细胞密度分别为３８７和７７９．５个细胞／ｍｍ２。到胎龄３０ｄ时ＳＰＩＲ神经元开始出现于内核层的内排细胞，但数量很少，胞体呈卵圆形，发出细突起伸入内同层，在节细胞层的ＳＰＩＲ神经元的突起分支增加。此时ＳＰＩＲ神经元平均细胞密度为３５７．４个细胞／ｍｍ￣２。     

Intermediate filament complement of the normal and gliotic canine retina.

Intermediate filament expression of various cell types in the adult canine normal and gliotic retina was determined by an immunoperoxidase method of using monoclonal antibodies on aldehyde-fixed tissues. In the normal retina, vimentin was present in astrocytes in the nerve fibre layer, horizontal cell processes, and Müller cell fibres from the internal limiting membrane to the outer nuclear layer. Neurofilamentous axons were noted in the nerve fibre, inner plexiform layer, and outer plexiform layer, although the degree of staining intensity varied among the three molecular weight neurofilament antisera used. Glial fibrillary acidic protein (GFAP) staining was confined to the nerve fibre and ganglion cell layer; this was interpreted as representing fibrous astrocytes. Astrocyte density varied according to retinal topography with an increased number around retinal blood vessels and in the peripapillary retina. Quantitative, but not qualitative differences in staining for vimentin and the neurofilaments were noted in degenerative, gliotic retinas. In common with several other mammalian species previously studied, the canine Müller cells accumulate or express GFAP under pathological conditions involving a gliotic response.     

Two classes of astrocytes in the adult human and pig retina in terms of their expression of high affinity NGF receptor (TrkA)

Astrocytes have been implicated in axon guidance and synaptic regeneration in the retina and these processes involve activation of the high affinity nerve growth factor receptor, known as the tyrosine kinase A (TrkA) receptor. The purpose of the present study was to characterize the expression of TrkA in astrocytes of the adult pig and human retina. To this end, sections of human and pig retinas were immunolabeled with a combination of antibodies to glial fibrillary acidic protein (GFAP) and TrkA. Our study revealed that most of the GFAP-positive cells express TrkA, whereas a rare, novel subpopulation of astrocytes was found to be devoid of TrkA. Our results support the idea that astrocytes play an important neurotrophic role in the retina.     

Glial cell differentiation in neuron-free and neuron-rich regions

Summary The development of the human fetal hippocampus and dentate gyros has been studied immunocytochemically. The first glial cells to appear are vimentin-positive radial glial cells. A gradual transition from vimentin to glial fibrillary acidic protein (GFAP) reactivity in the radial glial cells occurs at week 8. The GFAP-positive radial glial cells transform into astrocytes from week 14. A population of small S-100-positive somata which morphologically and spatially are distinct from GFAP-positive radial glial cells and their transformed progeny, are found as early as week 9.5 in the hippocampus during the period of peak neurogenesis. The well-defined immunoreactivity of the morphologically homogenous cell subpopulation for S-100 protein, which has been used as an astrocytic marker in the adult hippocampus, indicates that astrocytes may differentiate at very early gestational ages in human fetuses. The S-100-positive astrocytes are thought to be derived from ventricular zone cells, which at the time of their appearance do not express any of the applied astrocytic markers (S-100, GFAP, vimentin). It is suggested that the S-100-positive astrocytic cell population interacts with the first incoming projection fibers, so modulating the pattern of connectivity.     

人胚胎视网膜内神经丝蛋白的出现和分布

用免疫组织化学ＡＢＣ法研究了２５０例４－３８周人胚胎视网膜中神经丝蛋白（ＮＦ）的出现和分布。发现第３２周胎儿视网膜神经纤维层出现ＮＦ阳性纤维。至出生时，神经纤维层卫性纤维增多、增粗，但仍未达成人的水平。人胎视网膜ＮＦ主要分布于节细胞轴突，成人除节细胞胞体和轴突外，内网层也有少数ＮＦ阳性纤维。     

Human retinal astroglia. A comparative study of adult and the 18 month postnatal developmental stage

The immunohistochemical location of glial fibrillary acidic protein (GFAP) was used to study the state of maturation of retinal astrocytes from an 18-mo-old infant and to compare it with the situation in the adult. Infant astrocytes showed intense GFAP immunoreactivity in the perikarya and possessed spindle-like enlargements in their processes, while in the adult immunoreactivity in the perikarya was scarce and the spindle-like enlargements were not evident. Two types of astrocyte were observed in adult and child retinas: elongated and star-shaped. In the adult, the star-shaped type tend to be more stylised and to have longer processes than in the infant. In the infant, numerous astrocyte cell bodies were observed over vessels, while in the adult these were scarce. In the infant, the star-shaped astrocytes made up a honeycomb plexus, but this was not fully developed. These results suggest that at 18 mo of postnatal development the retinal astrocytes are still increasing and growing into the astroglial structure found in adults.     

Immunohistochemical features of the human retina and retinoblastoma

The immunohistochemical features of 24 retinoblastoma specimens from 22 patients, 15 with unilateral and 7 with bilateral disease, were examined by the labelled streptavidin biotin (LSAB) method and compared with those of specimens from the remaining morphologically normal retina. In the normal retina, S-100 protein, glial fibrillary acidic protein (GFAP) and vimentin were detected in astrocytes and/or Müller cells. Neurofilament protein was seen in axons of the ganglion cells, synaptophysin was present in both plexiform layers, bcl-2 oncoprotein was seen in ganglion cells and bipolar cells, and neuron-specific enolase (NSE) was detected in ganglion cells, bipolar cells and photoreceptor cells and in their cell processes. While retinoblastoma (Rb) protein expression was noted in ganglion cells, bipolar cells, and some photoreceptor cells, p53 protein was not expressed at all. In all retinoblastomas, strong NSE expression and weak bcl-2 expression was observed in almost all tumour cells and synaptophysin was localized in rosette-forming cells, while tumour cells were devoid of S-100, GFAP, vimentin and neurofilament protein. These findings support the view that retinoblastomas are composed of neuron-committed cells. In addition, no Rb protein expression was detected in retinoblastomas, whereas p53 expression was found in 18 cases (75%).     

Indoleamine-accumulating cell death and endogenous glial cell reaction induced by 5,7-dihydroxytryptamine in the cat retina.

We investigated the patterns of degenerative changes of indoleamine-accumulating cells (IACs) induced by 5,7-dihydroxytryptamine (5,7-DHT, 100 microg), and the glial reaction to the neurodegenerative changes of IACs in the cat retina by using light-and electron-microscopy. The neurons accumulating 5,7-DHT in the cat retina were a few ganglion cells and displaced amacrine cells located in the ganglion cell layer (GCL), and some amacrine cells in the inner nuclear layer (INL). The cell density (per unit area, 1 mm2) of the 5,7-DHT accumulating cells in the GCL and INL was 910 and 134 cells, respectively. Most 5,7-DHT accumulating cells showed dark degeneration characterized by widening of the cellular organelles at early stage, and by darkening of the cytoplasm at a late stage. In addition, amacrine cells, showing a typical filamentous degeneration, were observed in a few cases. The degenerated neurons were phagocytosed by microglial cells and astrocytes. The immunoreactivity for glial fibrillary acidic protein (GFAP) in Muller cells was increased at early stage, but thereafter abruptly decreased. In a few cases, severe degenerative changes were observed in Miller cells. These results indicate that 5,7-DHT induces severe dark degeneration of IACs, and most degenerated cells could be eliminated by microglial cells and astrocytes in the cat retina.     

Immunohistochemistry of glial fibrillary acidic protein, vimentin and S-100 protein for study of astrocytes in hippocampus of rat

The distribution of astrocytes was studied in the hippocampus of mature Wistar rats. Immunohistochemistry was performed using antibodies against glial fibrillary acidic protein (GFAP), vimentin and S-100 protein and peroxidase anti-peroxidase techniques. Material from fresh-frozen brain, post-fixed in acetone, yielded a complex picture of the glial populations when stained for GFAP. Astrocytes immunoreactive for GFAP were seen in white matter tracts but also in the large dendritic layers of the hippocampus. Frozen material also contained different types of astrocytes following staining with a monoclonal antibody to vimentin. Stellate astrocyte types in the dendritic layers contained vimentin-stained processes. In addition a form of residual radial glia was found in the dentate gyrus. Material from brains perfusion-fixed with formaldehyde remained positive for astrocytic GFAP, but was negative for vimentin. Staining for S-100 protein antibodies revealed numerous astrocytes and diffuse background staining in fixed material. This study allows one to make predictions concerning the use of astrocytic markers in experimental pathological material.