细胞周期依赖激酶抑制剂Olomoucine对活化星形胶质细胞神经蛋白聚糖、短蛋白聚糖表达的抑制作用

目的研究细胞周期依赖激酶抑制剂Olomoucine对星形胶质细胞活化后神经蛋白聚糖(Neurocan)、短蛋白聚糖(Brevican)表达的抑制作用。方法应用睫状神经营养因子(CNTF)刺激法建立体外培养星形胶质细胞的活化模型,实验分3组:对照组、活化组与抑制组。对照组:正常培养的星形胶质细胞;活化组:星形胶质细胞加入20 ng/ml睫状神经营养因子(CNTF)处理24 h;抑制组:星形胶质细胞用20 ng/ml睫状神经营养因子预处理24 h,加入100μmol/L Olomoucine。应用ELISA法检测不同时间点(12 h、24 h、48 h)各组细胞上清液中Neurocan、Brevican含量变化,半定量RT-PCR检测各组细胞GFAP mRNA及Neurocanm RNA、Brevican mRNA的表达变化。结果(1)活化组上清液中Neurocan、Brevican的含量在12 h、24 h、48 h随着时间的延长逐渐增加,与对照组比较差异有显著性(P0.01);抑制组上清液中Neurocan、Brevican含量随着时间的延长较活化组明显降低,与对照组、活化组比较差异有显著性(P0.01)。(2)活化组细胞GFAP mRNA、Neurocan mRNA、Brevican mRNA表达明显增加,与对照组比较差异有显著性(P0.01);抑制组细胞GFAP mRNA、Neurocan mRNA、Brevican mRNA表达均明显下调,与活化组比较差异有显著性(P0.01)。结论细胞周期依赖激酶抑制剂Olomoucine可抑制活化星形胶质细胞神经蛋白聚糖、短蛋白聚糖表达。     

大鼠脑出血后活化星形胶质细胞EGFR-JAK1/STAT3表达及Genistein的抑制作用

目的探讨EGFR-JAK1/STAT3信号通路在大鼠脑出血后星形胶质细胞活化中的作用。方法 SD大鼠60只,随机分为ICH组、DMSO组、GST组,每组20只,Ⅶ型胶原酶注入苍白球进行脑出血造模。GST组在造模后每天腹腔注射Genistein溶液(50 mg/kg),DMSO组腹腔注射相同剂量DMSO溶液,一次/d。取术后1 d、7 d、14 d、28 d共4个时间点进行神经功能评分,各时间点每组随机取5只大鼠处死取脑,免疫组化检测EGFR、GFAP在星形胶质细胞中的表达变化,Western blot检测每各组p-JAK1、p-STAT3蛋白水平的表达。结果神经功能评分:GST组优于ICH组与DMSO组、ICH组与DMSO组比较差异无统计学意义(P>0.05);免疫组化显示脑出血后EGFR、GFAP表达增高,给予GST干预后,GFAP、EGFR表达显著少于ICH组及DMSO组,差异有统计学意义(P<0.05);7 d时p-JAK1/p-STAT3蛋白表达显著上升,予GST干预后,p-JAK1/p-STAT3蛋白水平较ICH组明显降低,差异有统计学意义(P<0.05),DMSO组EGFR、GFAP及p-JAK1/p-STAT3蛋白表达水平,与ICH组比较,差异无统计学意义(P<0.05)。结论脑出血所致星形胶质细胞活化与EGFR表达上调有关,抑制EGFR表达,可使pJAK1/p-STAT3蛋白表达水平下调,提示EGFR-JAK1/STAT3信号通路可能与脑出血后星形胶质细胞活化相关。     

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.     

缺血缺氧对体外培养星形胶质细胞细胞周期和增殖的影响

目的 观察缺血缺氧损伤对星形胶质细胞细胞周期和增殖的影响。方法 用流式细胞仪检测缺血缺氧后不同时问点星形胶质细胞细胞周期变化，并用荧光免疫细胞化学技术测定胶质细胞纤维酸性蛋白(GFAP)和增殖细胞核抗原(PCNA)的表达水平。结果 体外缺血缺氧损伤后星形胶质细胞S期较正常组明显增高，6h达高峰，而随后则呈下降趋势。PCNA阳性反应损伤后表达均增加，6h表达最高；在缺血缺氧早期，GFAP阳性染色增强，6h最高；缺血缺氧12h后GFAP阳性染色变弱。结论 缺血缺氧损伤后星形胶质细胞活化进入增殖期；PCNA参与了损伤后星形胶质细胞的修复和增殖；细胞周期事件与星形胶质细胞的活化密切相关。     

大鼠前脑缺血再灌注后GFAP、S-100表达的变化

目的 探讨胶质纤维酸性蛋白（GFAP）和S-100蛋白在大鼠前脑缺血再灌注后反应性星形胶质细胞的活化情况.方法 利用免疫组织化学方法检测前脑缺血再灌注模型的细胞活化情况.结果 脑缺血再灌注后第1d,顶叶皮层和海马可见少量GFAP阳性细胞表达 脑缺血再灌注第3d及第5d后GFAP阳性表达明显增加,并与对照组比较有统计学意义（P＜0.01）.S-100蛋白在脑缺血再灌注后第1d即有增加,并随着时间延长表达明显增强,各时间点与对照组有显著性差异（P＜0.01）.结论 脑缺血再灌注后GFAP、S-100蛋白表达增加,说明反应性星形胶质细胞的活化参与了脑缺血损伤后神经元的修复过程.     

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。     

伽玛刀照射后胶质细胞CX43和GFAP表达变化及意义

目的研究伽玛刀照射后胶质细胞缝隙连接蛋白43(Connexin43,Cx43)和胶质纤维酸蛋白(glial fibrillary acid protein,GFAP)表达的变化。方法体外培养原代星形胶质细胞(astrocytes,Ast)分为正常对照组和γ刀照射组,后者经γ刀照射(边缘剂量4～36Gy),培养72小时后检测GFAP,Cx43。结果4～12Gy组与正常对照组无显著差异,至16Gy组胶质细胞开始增生GFAP表达阳性细胞数大于正常对照组且呈剂量依赖性增高至32Gy组GFAP表达达最大值。Cx43表达在12Gy组即开始明显下降且Cx43表达呈计量依赖性减低,在24～32Gy降低尤为显著至32Gy组达最低值。结论原代培养Ast经伽玛刀照射后GFAP表达增高,同时Cx43表达减低。Cx43的异常低表达可能是胶质增生及放射损伤的重要原因。     

头孢曲松钠减轻水通道蛋白4抗体对星形胶质细胞的毒性作用

目的探讨头孢曲松钠在水通道蛋白4(AQP4)抗体诱导的星形胶质细胞损伤中的作用以及机制。方法常规体外培养新生SD大鼠大脑皮质细胞,将培养的细胞分为4组,分别加入健康人血清(对照组)、AQP4抗体阳性患者血清、头孢曲松钠+AQP4抗体阳性血清以及单纯头孢曲松钠。细胞培养24h后采用免疫组织化荧光染色观察不同组星形胶质细胞数目的变化,采用比色法测定上清液谷氨酸浓度以及免疫印迹分析谷氨酸转运体-1(GLT-1)蛋白表达水平。结果和对照组比较,AQP4抗体阳性血清组星形胶质细胞数目和谷氨酸转运体-1(GLT-1)蛋白表达明显减少,上清液谷氨酸浓度明显增高(均P0.01),而单纯头孢曲松钠组仅显著增加GLT-1蛋白表达(P0.01),并不影响星形胶质细胞数目和谷氨酸水平(P0.05);和AQP4抗体阳性组比较,头孢曲松钠+AQP4抗体阳性血清组星形胶质细胞数目和GLT-1蛋白表达增加,上清液谷氨酸浓度明显下降(P0.01)。结论头孢曲松钠可能通过上调星形胶质细胞GLT-1表达、减少细胞外液谷氨酸水平发挥减轻AQP4抗体对体外培养的大鼠脑皮质星形胶质细胞的毒性作用。     

糖基化终产物对大鼠海马组织小胶质细胞活化及COX-2、p-NF-κB表达的影响

目的 研究糖基化终产物(AGEs-BSA)对大鼠海马小胶质细胞活化及COX-2、p-NF-κB表达的影响.方法 30只Wistar大鼠随机分为正常对照组(NC组)、BSA-C组、AGEs-BSA组、RAGE-Ab组及RAGE-Ab-C组.通过向大鼠海马区注射AGEs-BSA,建立AD大鼠局部炎症病理模型.Morris水迷宫检测大鼠认知功能,免疫荧光观察海马组织小胶质细胞标记物(CD11b)、星形胶质细胞标记物胶质纤维酸性蛋白(GFAP)表达的变化;蛋白质免疫印迹法检测各组海马组织COX-2、p-NF-κB的表达.结果 与NC组比较,AGEs-BSA组大鼠认知功能下降,在海马区可见神经胶质细胞增生,以小胶质细胞为主;COX-2、p-NF-κB的表达明显增高(P<0.001);RAGE-Ab组海马区小胶质细胞增生减弱,COX-2、p-NF-κB表达显著下调(P<0.01),但仍高于NC组;NC组、BSA-C组、RAGE-Ab-C组COX-2、p-NF-κB表达差异不显著(P>0.05).结论 大鼠海马区注射AGEs-BSA可诱导小胶质细胞增殖、活化,促进COX-2、p-NF-κB的蛋白表达增强.     

新生儿缺氧缺血性脑病临床与神经病理的相关性研究

目的观察新生儿缺氧缺血性脑病临床与神经病理之间的相关性。方法纳入2014-05—2015-04缺氧缺血性脑病患儿90例,进行免疫组化法观察不同生存时间的原纤维性酸性蛋白(GFAP)标记的星形胶质细胞的变化;比较宫内窘迫组(慢性缺氧缺血)、出生窒息组(急性缺氧缺血)、混合性缺氧缺血组(同时存在出生窒息及宫内窘迫)的原纤维酸性蛋白(GFAP)标记的星形胶质细胞的变化。结果生后24h内死亡组GFAP标记的星形胶质细胞的增生程度显著高于生后24~72h内死亡组、生后72h~6d死亡组,差异有统计学意义(P0.05);宫内窘迫组(慢性缺氧缺血)、出生窒息组(急性缺氧缺血)、混合性缺氧缺血组(同时存在出生窒息及宫内窘迫)的原纤维酸性蛋白(GFAP)标记的星形胶质细胞的变化比较,差异有统计学意义(P0.05)。结论缺氧缺血性脑病患儿的神经病理改变与HIE的病程、病情严重程度密切相关。     

睫状神经营养因子对体外培养星形胶质细胞的激活作用(英文)

目的观察睫状神经营养因子(ciliary neurotrophic factor, CNTF)对体外培养星形胶质细胞的细胞激活作用。方法分别给予不同浓度(0、2、20、200 ng/ml)的CNTF孵育有血清培养和无血清培养的星形胶质细胞,采用免疫细胞化学技术及流式细胞术,观察星形胶质细胞形态及细胞周期的变化。结果有血清培养和无血清培养时CNTF均使星形胶质细胞GFAP表达增强,胞核增大。有血清培养时CNTF还可以促进星形胶质细胞进入细胞周期进行增殖;无血清培养时CNTF无此效应。结论无血清培养时CNTF可以刺激星形胶质细胞进入活化状态,但不刺激其增殖;有血清培养时CNTF可以协助血清中的丝裂原引起星形胶质细胞增殖。     

睫状神经营养因子对体外培养星形胶质细胞的激活作用

目的观察睫状神经营养因子（ciliary neurotrophic factor,CNTF）对体外培养星形胶质细胞的细胞激活作用。方法分别给予不同浓度（0、2、20、200ng／ml）的CNTF孵育有血清培养和无血清培养的星形胶质细胞,采用免疫细胞化学技术及流式细胞术,观察星形胶质细胞形态及细胞周期的变化。结果有血清培养和无血清培养时CNTF均使星形胶质细胞GFAP表达增强,胞核增大。有血清培养时CNTF还可以促进星形胶质细胞进入细胞周期进行增殖：无血清培养时CNTF无此效应。结论无血清培养时CNTF可以刺激星形胶质细胞进入活化状态,但不刺激其增殖：有血清培养时CNTF可以协助血清中的丝裂原引起星形胶质细胞增殖。     

Expression of Ciliary Neurotrophic Factor and the Neurotrophins-Nerve Growth Factor,Brain-Derived Neurotrophic Factor and Neurotrophin 3-in Cultured Rat Hippocampal Astrocytes

Cultured astrocytes are known to possess a range of neurotrophic activities in culture. In order to examine which factors may be responsible for these activities, we have examined the expression of the genes for four known neurotrophic factors – ciliary neurotrophic factor (CNTF), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) – in purified astrocyte cultures derived from neonatal rat hippocampus. Hippocampal astrocytes were found to express mRNA for three neurotrophic factors – CNTF, NGF and NT3 – at significantly higher levels than other cultured cell types or cell lines examined. BDNF messenger RNA (mRNA), however, was undetectable in these astrocytes. The levels of CNTF, NGF and NT3 mRNA in astrocytes were largely unaffected by their degree of confluency, while serum removal caused only a transient decrease in mRNA levels, which returned to basal levels within 48 h. Astrocyte-derived CNTF was found to comigrate with recombinant rat CNTF at 23 kD on a Western blot. Immunocytochemical analysis revealed strong CNTF immunoreactivity in the cytoplasm of astrocytes, weak staining in the nucleus, but no CNTF at the cell surface. NGF and NT3 were undetectable immunocytochemically. CNTF-like activity, as assessed by bioassay on ciliary ganglion neurons, was found in the extract of cultured astrocytes but not in conditioned medium, whereas astrocyte-conditioned medium supported survival of dorsal root ganglion neurons but not ciliary or nodose ganglion neurons. This conditioned medium activity was neutralized with antibodies to NGF. Astrocyte extract also supported survival of dorsal root ganglion and nodose ganglion neurons, but these activities were not blocked by anti-NGF. Part, but not all, of the activity in astrocyte extracts which sustained nodose ganglion neurons could be attributed to CNTF.     

Ciliary neurotrophic factor stimulates nuclear hypertrophy and increases the GFAP content of cultured astrocytes

Studies using transgenic mice that overexpress ciliary neurotrophic factor (CNTF), direct injection of CNTF into brain parenchyma, and ectopic expression of CNTF by an adenoviral vector have demonstrated that CNTF activates astrocytes. Paradoxically, studies to date have failed to show an effect of CNTF on the expression of GFAP by cultured astrocytes. Therefore, the goal of this study was to use nuclear hypertrophy and GFAP expression as indices of glial activation to compare the responsiveness of forebrain type 1 and type 2 astrocytes to CNTF. As reported by others, CNTF did not increase GFAP in type 1 astrocytes; however, it rapidly increased their nuclear size by 20%. Nuclear hypertrophy was apparent within 4 h after CNTF exposure and persisted for at least 48 h. In contrast, type 2 astrocyte GFAP increased 2-fold over the course of 48 h of CNTF treatment. During this same treatment period type 2 astroglial nuclei enlarged by 25%. We conclude that CNTF stimulates both type 1 and type 2 astrocytes directly. Together with our in vivo studies (Levison et al., 1996: Exp. Neurol. 141: 256), these data support the concept that CNTF is responsible for many of the progressive astroglial changes that appear after CNS injury and disease.     

Time course of ciliary neurotrophic factor mRNA expression is coincident with the presence of protoplasmic astrocytes in traumatized rat striatum

Adrenal grafting for Parkinson's disease has led to modest functional improvement despite poor graft survival. One explanation is a neurotrophic response within the traumatized striatum. This study was undertaken to investigate the time course of the astrocytic response in vivo and in vitro, and the expression of ciliary neurotrophic factor (CNTF) mRNA following striatal injury. Unilateral stereotaxic biopsy of the rat striatum was performed and gelatin sponge (gelfoam) was immediately placed into the biopsy cavity. Rats were sacrificed on days 1,3,5,7,14, and 28 post biopsy. Immunohistochemical staining of the traumatized striatum with antibodies to glial fibrillary acidic protein (GFAP) was carried out. The reactive astrocytes which appeared within 7 days after trauma were mostly protoplasmic on the basis of morphology, and maximal on day 7, being 30 times the level in the normal striatum. After day 7, fibrous astrocytes appeared and increased up to day 28, while protoplasmic astrocytes decreased. In addition, immunocytochemical double staining of short term cultured astrocytes from the traumatized striatum with anti-A2B5 and anti-GFAP antibodies revealed that 84% and 90% of astrocytes were type 1 astrocytes on days 3 and 7, respectively; however, by day 28 47% of astrocytes were type 2. Northern blot analysis revealed that CNTF mRNA expression was up-regulated and peaked on day 7, coincident with a predominance of protoplasmic astrocytes in vivo and type 1 astrocytes in vitro, respectively. These finding suggest that the expression of CNTF mRNA is part of the early astrocytic response to trauma, particularly associated with protoplasmic astrocytes in vivo and type 1 astrocytes in vitro. We conclude that reactive astrocytes are likely candidates to produce the neurite promoting activity seen in previous studies after trauma in the striatum. CNTF may represent an early signal in the astrocyte-mediated neurotrophic and neurite promoting responses. © 1995 Wiley-Liss, Inc.     

Ciliary neurotrophic factor activates spinal cord astrocytes, stimulating their production and release of fibroblast growth factor-2, to increase motor neuron survival.

At focal CNS injury sites, several cytokines accumulate, including ciliary neurotrophic factor (CNTF) and interleukin-1beta (IL-1beta). Additionally, the CNTF alpha receptor is induced on astrocytes, establishing an autocrine/paracrine loop. How astrocyte function is altered as a result of CNTF stimulation remains incompletely characterized. Here, we demonstrate that direct injection of CNTF into the spinal cord increases GFAP expression and astroglial size and that primary cultures of spinal cord astrocytes treated with CNTF, IL-1beta, or leukemia inhibitory factor exhibit nuclear hypertrophy comparable to that observed in vivo. Using a coculture bioassay, we further demonstrate that CNTF treatment of astrocytes increases their ability to support ChAT(+) ventral spinal cord neurons (presumably motor neurons) more than twofold compared with untreated astrocytes. Also, the complexity of neurites was significantly increased in neurons cultured with CNTF-treated astrocytes compared with untreated astrocytes. RT-PCR analysis demonstrated that CNTF increased levels of FGF-2 and nerve growth factor (NGF) mRNA and that IL-1beta increased NGF and hepatocyte growth factor mRNA levels. Furthermore, both CNTF and IL-1beta stimulated the release of FGF-2 from cultured spinal cord astrocytes. These findings demonstrate that cytokine-activated astrocytes better support CNS neuron survival via the production of neurotrophic molecules. We also show that CNTF synergizes with FGF-2, but not epidermal growth factor, to promote DNA synthesis in spinal cord astrocyte cultures. The significance of these findings is discussed by presenting a new model depicting the sequential activation of astrocytes by cytokines and growth factors in the context of CNS injury and repair.     

Regulation of Ciliary Neurotrophic Factor in Cultured Rat Hippocampal Astrocytes

Ciliary neurotrophic factor (CNTF) is a pleiotrophic cytokine which is detectable only at very low levels in the intact adult rat CNS, but following an aspirative lesion to the dorsal hippocampus and overlying cortex, CNTF mRNA levels are dramatically up-regulated in reactive astrocytes. In cultured rat hippocampal astrocytes, CNTF mRNA levels are high, similar to the levels in reactive astrocytes in vivo , but are strongly suppressed after administration of isoproterenol and forskolin, which stimulate the production of intracellular cyclic AMP, induce marked morphological change in the astrocytes and up-regulate glial fibrillary acidic protein mRNA and nerve growth factor mRNA in these cells. Following a single administration of forskolin to cultured astrocytes, suppression of CNTF mRNA was sustained for up to 7 days. A similar down-regulation was observed with the endogenous adrenergic agonists noradrenaline and adrenaline as well as, to a lesser extent, dopamine and adenosine. Down-regulation of CNTF mRNA resulted in a gradual reduction in the level of CNTF protein within the astrocytes. A single addition of forskolin or isoproterenol resulted in a drop in CNTF protein levels to 29 and 52% of control levels respectively after 9 days in vitro , although the rate of turnover of CNTF remained the same. Down-regulation of CNTF mRNA in cultured hippocampal astrocytes by adenylyl cyclase activation was quite specific, as a wide range of growth factors, cytokines and neurotransmitters had little or no effect upon CNTF mRNA levels.     

CNTF and CNTF receptor alpha are constitutively expressed by astrocytes in the mouse brain

Ciliary neurotrophic factor (CNTF) is regarded as one of the signals that lead to astrocyte activation following central nervous system lesion. However, it is not clear if CNTF can directly initiate astrocytic responses to injury because CNTF levels are very low in most areas of the unlesioned brain and CNTF receptor (CNTFRalpha) expression by astrocytes has not yet been demonstrated in the intact brain. In the present study, the expression patterns of CNTF protein and CNTFRalpha mRNA were studied in the intact mouse brain using immunocytochemistry and in situ hybridization, respectively. These procedures were combined with immunocytochemistry for glial fibrillary acidic protein in order to identify CNTF- and CNTFRalpha-expressing astrocytes. CNTF-immunoreactive astrocytes were exclusively found in white matter structures such as the optical tract, the corticospinal tract, and the fimbria-fornix. Gray matter astrocytes did not exhibit CNTF immunoreactivity. In contrast, CNTFRalpha mRNA-expressing astrocytes were found in gray matter areas, preferentially in the molecular layers of the cortex and hippocampus. White matter astrocytes did not show a detectable CNTFRalpha mRNA signal. These data demonstrate that both CNTF and its receptor are constitutively expressed by astrocytes in mouse brain. The nonoverlapping locations of astrocytes expressing detectable levels of CNTF and CNTFRalpha, respectively, may be related to distinct postlesional functions of these two glial cell populations.