Nogo-66受体分子在体外培养的星形胶质细胞中的表达

目的检测Nogo-66受体（NgR）在体外培养的大鼠星形胶质细胞中的表达。方法利用RT—PCR、WesteiTl Blot和间接免疫荧光染色技术，检测原代培养并纯化的星形胶质细胞中NgR mRNA和蛋白分子的表达。结果利用RT—PCR技术，从星形胶质细胞总RNA中扩增出特异的NgR条带；利用Western Blot技术，从星形胶质细胞抽提物中检测到64kD特异性的NgR反应条带；间接免疫荧光染色和Cotffocal显微镜进一步显示，星形胶质细胞中的NgR免疫反应物主要位于细胞内。同时，来源于大鼠的C6胶质瘤细胞也证明表达NgR蛋白。结论体外培养的星形胶质细胞中表达NgR分子，这为证明NgR在体内胶质细胞中的表达提供了更直接的证据。     

烟碱型乙酰胆碱受体在离体海马小胶质细胞上的表达与定位

目的 探讨烟碱型乙酰胆碱受体(α7-nAChR)在体外培养海马小胶质细胞上的表达和定位.方法 取新生SD大鼠的海马组织,进行胶质细胞的混合培养,然后分离纯化小胶质细胞,采用免疫荧光染色检测CD11b/c进行小胶质细胞的鉴定;采用RT-PCR和免疫荧光双标分别检测α7-nAChR在小胶质细胞中的表达和定位.结果 免疫荧光染色显示分离纯化的细胞表达小胶质细胞特异性抗体CD11b/c;RT-PCR能扩增出长度为450 bp的α7-nAChR目的 条带,免疫荧光双标检测显示小胶质细胞CD11b/c和α7-nAChR染色阳性,分别呈红色和绿色荧光,叠加后呈棕黄色,且细胞膜荧光信号较强.结论 α7-nAChR在体外培养的海马小胶质细胞中能正常表达,定位在细胞膜的功能性α7-nAChR较丰富.     

星形胶质细胞活化与表皮生长因子受体表达的相关性研究

目的观察活化后星形胶质细胞(astrocyte,AST)的表皮生长因子受体(epithelial growth factor recep-tor,EGFR)表达变化。方法分离培养星形胶质细胞,实验分为对照组、活化组、抑制组,以睫状神经营养因子(cili-ary neurotrophic factor,CNTF)活化星形胶质细胞,并用EGFR抑制剂染料木黄酮(Genistein)干预活化星形胶质细胞,通过免疫荧光化学、RT-PCR分别观察胶原纤维酸性蛋白(glial fibrillary acidic protein,GFAP)及EGFR mRNA表达变化。结果星形胶质细胞活化后,不仅GFAP表达增高,EGFR表达亦明显增高,与对照组比较有显著差异(P0.01);应用EGFR抑制剂Genistein干预后,星形胶质细胞活化被抑制,GFAP表达下降,与活化组比较有显著差异(P0.01)。结论形胶质细胞活化后,EGFR表达明显上调;抑制EGFR表达,可抑制星形胶质细胞活化。     

雌激素受体α免疫阳性星形胶质细胞在阿尔茨海默病病人海马中分布的改变

目的:观察雌激素受体α(estrogen receptorα,ERα)免疫阳性星形胶质细胞在阿尔茨海默病(Alzheimerdisease,AD)病人组和老年对照组海马中的分布变化.方法:采用免疫荧光细胞化学双标方法和激光共聚焦扫描显微镜.结果:ERα免疫阳性星形胶质细胞主要分布在齿状回的门和海马的分子层、放射层及始层.GFAP(glial fibrillary acidic protein)免疫阳性细胞、ERα胞核染色的和ERα胞质染色的星形胶质细胞(number/mm2)在AD组的CA1均显著增加(P分别小于0.001,0.05,0.05),但其ERα核着色或质着色的星形胶质细胞占GFAP免疫阳性星形胶质细胞的百分数,在对照组(2.56%,n=13;16.68%,n=13)和AD病人组(2.15%,n=13;26.00%,n=13)之间无显著差异(P＞0.05).结论:这些结果表明,在AD的发病过程中雌激素可能通过ERα介导对海马星形胶质细胞的作用.     

PPAR-γ对大鼠脊髓损伤后神经功能影响的研究

目的观察PPAR-γ对大鼠脊髓损伤后GFAP(胶质纤维酸性蛋白)及新生星形胶质细胞表达的影响。方法 SD大鼠108只,分成损伤组、PPAR-γ激动剂及拮抗剂治疗组。损伤后观察BBB评分、GFAP及新生星形胶质细胞的表达。结果激动剂治疗组BBB(BBB运动功能评分)及GFAP表达较损伤组GFAP的表达在1~2 w时间点内表达增加(P0.05),拮抗剂治疗组GFAP的表达较脊髓损伤组GFAP的表达在1~4 w时间点内表达减少(P0.05)。激动剂组新生星形胶质细胞在1~2 w明显增加(P0.05),而拮抗剂治疗组表达明显减少(P0.05),有统计学差异。结论 PPAR-γ激活后促进GFAP及星形胶质细胞的表达,起到神经保护作用。     

全反式维甲酸对胶质瘤干细胞VEGF和bFGF表达的影响

目的 研究全反式维甲酸(ATRA)对胶质瘤干细胞(GSCs)血管内皮细胞生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)表达的影响. 方法 从人胶质母细胞瘤细胞系U87中分离培养GSCs,免疫荧光染色检测CD133、巢蛋白(nestin)的表达进行鉴定.将取GSCs分成3组分别培养:(1)ATRA组:培养基中含10 nmol/L ATRA;(2)空载体组:培养基中含与ATRA组等量的二甲基亚砜(DMSO);(3)对照组:单纯培养基,培养10 d后免疫荧光染色检测胶质纤维酸性蛋白(GFAP)、β-微管蛋白Ⅲ(β-tubulinⅢ)、半乳糖脑苷脂(GalC)的表达;CCK8法检测各组细胞的增殖;ELISA和RT-PCR分别检测各组GSCs VEGF、bFGF的分泌水平和mRNA的表达. 结果 二代细胞球表达神经干细胞(NSCs)的标记抗体CD133和nestin.免疫荧光染色检测显示分化后GSCs能够分化为多种同源子代细胞(分别表达星形胶质细胞、神经元、少突胶质细胞标志物GFAP、β-tubulinⅢ、Galc);培养10d后ATRA组细胞GFAP的阳性表达率高于对照组及空载体组,差异有统计学意义(P＜0.05).第3.～7天ATRA组细胞增殖速度较对照组和空载体组明显变缓,差异有统计学意义(P＜0.05);分化24 h后ATRA组GSCs VEGF、bFGF的分泌水平和mRNA的表达均少于对照组和空载体组,差异有统计学意义(P＜0.05). 结论 ATRA能诱导GSCs分化并抑制其增殖,其可能通过抑制VEGF和bFGF的表达发挥抗胶质母细胞瘤的作用.     

X线照射后体外培养星形胶质细胞VEGF和GFAP表达变化及意义

目的 研究X线照射体外培养的星形胶质细胞后血管内皮生长因子(VEGF)和胶质原纤维酸性蛋白(GFAP)表达随时间及剂量的变化,探讨星形胶质细胞与放射性脑损伤(RBI)的关系. 方法 以5、10、15、20 Gy剂量的X线照射体外原代培养的星形胶质细胞后继续培养48 h,或以20 Gy剂量照射后分别培养4、12、24、48 h,实验均设正常对照组即未照射组.免疫荧光染色检测GFAP观察各组细胞形态学的变化;DAPI染色观察星形胶质细胞的凋亡;Western blotting检测细胞GFAP、VEGF蛋白的表达情况. 结果 与正常对照组比较,不同剂量照射组星形胶质细胞增生、增多,变形,胞体肥大肿胀,分支增多,突起增粗,GFAP染色加深,且这种变化随照射剂量和时间增加而表现更明显;与正常对照组相比,各剂量照射组星形胶质细胞凋亡率差异无统计学差异(P＞0.05); Western blotting检测显示不同剂量组、20Gy剂量照射不同时间组星形胶质细胞GFAP、VEGF蛋白的表达均不同,差异有统计学意义(P＜0.05).与正常对照组相比,5、10、15、20 Gy照射组和20 Gy剂量照射后各时间组GFAP、VEGF的蛋白表达均增高,且随着照射剂量的增加GFAP、VEGF的蛋白表达亦增高,差异有统计学意义(P＜0.05).20 Gy剂量照射后4～48 h内GFAP的表达呈时间依赖性,20 Gy剂量照射后4～24 h内VEGF的表达呈时间依赖性. 结论 X线能诱导体外培养的星形胶质细胞活化,GFAP及VEGF的表达呈时间及剂量依赖性增高,VEGF异常高表达可能是造成RBI的重要原因.     

星形胶质细胞源性因子对神经干细胞分化的实验研究

目的探讨星形胶质细胞源性因子对神经干细胞分化的影响。方法分离和培养新生大鼠脑组织的神经干细胞;采用差速贴壁法和振荡法分离纯化星形胶质细胞,用免疫细胞化学染色法,胶质纤维酸性蛋白(GFAP)标记星形胶质细胞,进行细胞的纯度鉴定;将星形胶质细胞和神经干细胞在互不接触的情况下进行共培养,免疫荧光法观察神经干细胞分化后神经元特异性烯醇化酶(NSE)、GFAP和酪氨酸羟化酶(TH)的表达。结果纯化的星形胶质细胞GFAP抗体标记阳性,细胞纯度达98%;星形胶质细胞与神经干细胞共培养时,神经干细胞贴壁分化加快,NSE阳性细胞及TH阳性细胞明显多于对照组(P<0·05)。结论星形胶质细胞源性因子可快速诱导神经干细胞向神经元细胞、包括多巴胺神经元细胞分化,提示星形胶质细胞支持神经元发生。     

雌激素受体α免疫阳性星形胶质细胞在阿尔茨海默病病人海马中分布的改变

目的 :观察雌激素受体α(estrogenreceptorα,ERα)免疫阳性星形胶质细胞在阿尔茨海默病 (Alzheimerdisease,AD)病人组和老年对照组海马中的分布变化。 方法 :采用免疫荧光细胞化学双标方法和激光共聚焦扫描显微镜。结果 :ERα免疫阳性星形胶质细胞主要分布在齿状回的门和海马的分子层、放射层及始层。GFAP (glialfibrillaryacidicprotein)免疫阳性细胞、ERα胞核染色的和ERα胞质染色的星形胶质细胞 (number/mm2 )在AD组的CA1均显著增加 (P分别小于 0 .0 0 1,0 .0 5 ,0 .0 5 ) ,但其ERα核着色或质着色的星形胶质细胞占GFAP免疫阳性星形胶质细胞的百分数 ,在对照组 (2 .5 6 %,n =13;16 .6 8%,n =13)和AD病人组 (2 .15 %,n =13;2 6 .0 0 %,n=13)之间无显著差异 (P >0 .0 5 )。结论 :这些结果表明 ,在AD的发病过程中雌激素可能通过ERα介导对海马星形胶质细胞的作用。     

GABAA-receptor heterogeneity in the adult rat brain: Differential regional and cellular distribution of seven major subunits

GABA_A-receptors display an extensive structural heterogeneity based on the differential assembly of a family of at least 15 subunits (α1–6, β1–3, γ1–3, θ, ρl–2) into distinct heteromeric receptor complexes. The subunit composition of receptor subtypes is expected to determine their physiological properties andipharmacological profiles, thereby contributing to flexibility in signal transduction and allosteric modulation. In heterologous expression systems, functional receptors require a combination of α-, β-, and γ-subunit variants, the γ2-subunit being essential to convey a classical benzodiazepine site to the receptor. The subunit composition and stoichiometry of native GABA_A-receptor subtypes remain unknown. The aim of this study was to identify immunohistochemically the main subunit combinations expressed in the adult rat brain and to allocate them to identified neurons. The regional and cellular distribution of seven major subunits (α1, α2, α3, α5, β2,3, γ2, δ) was visualized by immunoperoxidase staining with subunit-specific antibodies (the β2- and β3-subunits were covisualized with the monoclonal antibody bd-17). Putative receptor subtypes were identified on the basis of colocalization of subunits within individual neurons, as analyzed by confocal laser microscopy in double- and triple-immunofluoreseence staining expeximents. The results reveal an extraordinary heterogeneity in the distribution of GABA_A-receptor subunits, as evidenced by abrupt changes in immunoreactivity along well-defined cytoarchitectonic boundaries and by pronounced differences in the cellular distribution of subunits among various types of neurons. Thus, functionally and morphologically diverse neurons were characterized by a distinct GABA_A-receptor subunit repertoire. The pultiple staining experiments identified 12 subunit combinations in defined neurons. The most prevalent combination was the triplet α1/β2,3/γ2, detected in numerous cell types throughout the brain. An additional subunit (α2, α3, or δ) sometimes was associated with this triplet, pointing to the existence of receptors containing four subunits. The triplets α2/β2,3/γ2, α3/β2,3/γ2, and α5/β2,3/γ2 were also identified in discrete cell populations. The prevalence of these seven combinations suggest that they represent major GABAA-receptor subtypes. Five combinations also apparently lacked the β2,3-subunits, including one devoid of γ2-subunit (α1/α2/γ2, α2/γ2, α3/γ2, α2/α3/γ2, α2/α5/δ). These combinations were selectively associated with small neuron populations, thereby representing minor GABA_A receptor subtypes. These results provide the basis for a functional analysis of GABA_A-receptor subtypes of known subunit composition and may open the way for unproved therapeutic approaches based on the development of subtype-selective drugs. © 1995 Wiley-Liss, Inc.     

GABA对体外培养大鼠神经元GABA_A受体亚单位mRNA表达的影响

目的观察γ-氨基丁酸(GABA)对体外大鼠培养神经元GABAA受体亚单位mRNA表达的影响,探讨肝性脑病(HE)发病机制。方法采用原位杂交技术,观察GABA对体外培养新生大鼠神经元GABAA受体亚单位α1β1γ2mRNA表达的改变。结果与对照组相比,GABA组神经元GABAA受体亚单位α1及γ2(增幅14%,P<0.01)的mRNA表达显著上升,亚单位β1的mRNA表达显著减少(降幅11%,P<0.05)。结论GABA可通过影响GABAA受体亚单位的表达发挥其对肝性脑病的致病作用。     

β-Amyloid peptide induced cytoskeletal reorganization in cultured astrocytes

The effects of β-amyloid (25–35) (βA) on cultured astrocytes from rat cortex were studied and compared with those of a scrambled peptide and with untreated cultures. Single addition (from 5 to 200 μg/ml) of βA peptide induced a marked morphological change in astrocytes, changing their flat polygonal shape into stellate process-bearing morphology. The changes induced by βA were concentration and time-dependent. The addition of the scrambled peptide did not alter cell viability in comparison with untreated astrocyte cultures. However, cell viability was dose-dependently decreased by βA. A subpopulation of βA-treated astrocytes showed an increase in glial fibrillary acidic protein (GFAP) and Vimentin (Vim) immunostaining while other reactive astrocyte markers such as S100β, MAP2, and ApoE remained unaltered or undetectable. The morphological changes in βA-treated astrocytes appeared to be mainly due to a cytoskeletal reorganization, since the total amounts of GFAP and Vim proteins were not essentially modified. These results strongly suggest that astrocytes are another cellular target of the effects of βA and this may be relevant to understanding the neuropathology of Alzheimer's disease. J. Neurosci. Res. 47:216–223, 1997. © 1997 Wiley-Liss, Inc.     

氨中毒对体外培养大鼠神经元GABA_A受体亚单位mRNA表达的影响

目的观察氨中毒对体外大鼠培养神经元GABAA受体亚单位mRNA表达的影响,探讨肝性脑病(HE)发病机制。方法采用原位杂交技术,观察氨对体外培养新生大鼠神经元GABAA受体亚单位α1、β1及γ2mRNA表达的改变。结果与对照组相比,氨中毒神经元GABAA受体亚单位α1(增幅18%,P<0.05)、γ2(增幅23%,P<0.01)的mRNA表达显著上升,亚单位β1的mRNA表达无明显改变。结论氨可通过影响GABAA受体亚单位的表达发挥其对肝性脑病的致病作用。     

Type IV collagen induces expression of thrombospondin‐1 that is mediated by integrin α1β1 in astrocytes

Following brain injury, thrombospondin‐1 (TSP‐1) is involved in angiogenesis and synaptic recovery. In this study, we used a cold injury‐model and found that TSP‐1 mRNA was markedly upregulated after brain injury. Immunohistochemistry showed that TSP‐1 was upregulated in both the core of the lesion and in the perilesional area of injured brain tissue. Numerous astrocytes immunopositive for glial fibrillary acidic protein (GFAP) were found in the perilesional area, and TSP‐1 was also expressed in almost all astrocytes surrounding blood vessels at 4 days after injury. Next, we examined the influence of vascular basement membrane components on TSP‐1 expression. When astrocytes were cultured on type IV collagen, TSP‐1 was significantly upregulated compared with the expression when cells were grown on laminin, fibronectin, or poly‐L ‐lysine. This increase occurred exclusively when astrocytes were grown on the native form of type IV collagen but not on the heat‐denatured form or the non‐collagenous 1 domain. Further, integrin α1 and β1 mRNAs were upregulated concomitantly with GFAP mRNA, and integrin α1 protein was localized to the endfeet of astrocytes that surrounded blood vessels in the injured brain. Using function‐blocking antibodies, we found that the effectof type IV collagen was attributed to integrin α1β1 in primary astrocytes. Collectively, our results suggest that vascular basement membrane components substantially impact gene expression in astrocytes during brain tissue repair. © 2010 Wiley‐Liss, Inc.     

Immunohistochemical distribution of 10 GABAA receptor subunits in the forebrain of the rhesus monkey Macaca mulatta

GABA_A receptors are composed of five subunits arranged around a central chloride channel. Their subunits originate from different genes or gene families. The majority of GABA_A receptors in the mammalian brain consist of two α-, two β- and one γ- or δ-subunit. This subunit organization crucially determines the physiological and pharmacological properties of the GABA_A receptors. Using immunohistochemistry, we investigated the distribution of 10 GABA_A receptor subunits (α1, α2, α3, α4, α5, β1, β2, β3, γ2, and δ) in the fore brain of three female rhesus monkeys (Macaca mulatta). Within the cerebral cortex, subunits α1, α5, β2, β3, and γ2 were found in all layers, α2, α3, and β1 were more concentrated in the inner and outer layers. The caudate/putamen was rich in α1, α2, α5, all three β-subunits, γ2, and δ. Subunits α3 and α5 were more concentrated in the caudate than in the putamen. In contrast, α1, α2, β1, β2, γ2, and δ were highest in the pallidum. Most dorsal thalamic nuclei contained subunits α1, α2, α4, β2, β3, and γ2, whereas α1, α3, β1, and γ2 were most abundant in the reticular nucleus. Within the amygdala, subunits α1, α2, α5, β1, β3, γ2, and δ were concentrated in the cortical nucleus, whereas in the lateral and basolateral amygdala α1, α2, α5, β1, β3, and δ, and in the central amygdala α1, α2, β3, and γ2 were most abundant. Interestingly, subunit α3-IR outlined the intercalated nuclei of the amygdala. In the hippocampus, subunits α1, α2, α5, β2, β3, γ2, and δ were highly expressed in the dentate molecular layer, whereas α1, α2, α3, α5, β1, β2, β3, and γ2 were concentrated in sector CA1 and the subiculum. The distribution of GABA_A receptor subunits in the rhesus monkey was highly heterogeneous indicating a high number of differently assembled receptors. In most areas investigated, notably in the striatum/pallidum, amygdaloid nuclei and in the hippocampus it was more diverse than in the rat and mouse indicating a more heterogeneous and less defined receptor assembly in the monkey than in rodent brain.     

Extracellular matrix proteins expressed by human adult astrocytes in vivo and in vitro: An astrocyte surface protein containing the CS1 domain contributes to binding of lymphoblasts

Primary cultures of human astrocytes, expressing glial fibrillary acidic protein (GFAP), were obtained from postmortem brain tissue samples. These cultured astrocytes produced an extracellular matrix (ECM), containing laminin (Ln) and fibronectin (Fn), as shown with specific antibodies. The perinuclear staining observed in these cells indicated that these proteins were de novo synthesized. Monoclonal antibody (mAb) 90.45, which recognizes the CS1 sequence found in an alternatively spliced form of Fn, also stained cultured astrocytes. Immunohistochemical analysis of normal human brain tissue showed positive staining for the CS1 domain, both on protoplasmic and fibrous astrocytes located in the gray and white matter. In contrast to cultured astrocytes, no immunoreactivity for Ln or Fn was found on astrocytes in normal human brain tissue. These in situ data indicate that the CS1 domain expressed by astrocytes is not part of a splicing variant of Fn. Western blot analysis confirmed that the CS1 domain expressed by cultured human astrocytes is part of an astrocyte protein which is different from human Fn. The CS1 domain is a known ligand for the adhesion receptor α4β1 (VLA-4). We found that the human lymphoma cell lines Jurkat and Ramos, which express α4β1, bound to cultured human astrocytes, and that this interaction could be partly blocked by mAb 90.45 or a synthetic CS1 peptide. Thus, the novel CS1-containing surface protein expressed by astrocytes in vitro and in vivo, contributes to binding of lymphoblasts, and therefore may be a relevant adhesion molecule for the recruitment of α4-integrin expressing leukocytes into the central nervous system (CNS). J. Neurosci. Res. 50:539–548, 1997. © 1997 Wiley-Liss, Inc.     

SC1/hevin and reactive gliosis after transient ischemic stroke in young and aged rats

SC1 is a member of the SPARC family of glycoproteins that regulate cell-matrix interactions in the developing brain. SC1 is expressed in astrocytes, but nothing is known about the expression in the aged or after stroke. We found that after focal striatal ischemic infarction in adult rats, SC1 increased in astrocytes surrounding the infarct and in the glial scar, but in aged rats, SC1 was lower at the lesion edge. Glial fibrillary acidic protein (GFAP) also increased, but it was less prominent in reactive astrocytes further from the lesion in the aged rats. On the basis of their differential expression of several molecules, 2 types of reactive astrocytes with differing spatiotemporal distributions were identified. On Days 3 and 7, SC1 was prevalent in cells expressing markers of classic reactive astrocytes (GFAP, vimentin, nestin, S100β), as well as apoliprotein E (ApoE), interleukin 1β, aggrecanase 1 (ADAMTS4), and heat shock protein 25 (Hsp25). Adjacent to the lesion on Days 1 and 3, astrocytes with low GFAP levels and a "starburst" SC1 pattern expressed S100β, ApoE, and Hsp32 but not vimentin, nestin, interleukin 1β, ADAMTS4, or Hsp25. Neither cell type was immunoreactive for NG2,CC-1, CD11b, or ionized calcium-binding adapter-1. Their differing expression of inflammation-related and putatively protective molecules suggests different roles for starburst and classic reactive astrocytes in the early glial responses to ischemia.     

人脑胶质瘤干细胞TGF-32mRNA的表达及意义

目的 检测人脑胶质瘤干细胞(BGSCs)中转化生长因子-β2(TGF-β2) mRNA的表达水平,推断其在胶质瘤免疫治疗中的作用. 方法 选取中国医科大学第一医院神经外科自2008年10月至2009年1月间手术切除的脑胶质瘤标本8例,培养出BGSCs,免疫荧光染色检测肿瘤细胞球CD133、GFAP和TU-20的表达;RT-PCR检测BGSCs中TGF-β2 mRNA的表达,并与对应的原代分化脑胶质瘤细胞进行比较. 结果 肿瘤细胞球CD133呈阳性表达;分化于肿瘤球的细胞可表达GFAP和TU-20; RT-PCR检测发现TGF-β2 mRNA在BGSCs中的表达水平远高于原代分化胶质瘤细胞,差异有统计学意义(t=3.619,P=0.009). 结论 BGSCs中TGF-β2 mRNA呈高表达,这可能是胶质瘤TGF-β2高分泌、产生免疫逃逸并耐受各种常规治疗的决定性因素.