氯喹抑制体外培养星形胶质细胞的激活

目的研究氯喹对体外培养大鼠海马星形胶质细胞激活的抑制作用,为癫痫的治疗提供实验依据。方法分离新生SD大鼠海马,体外培养星形胶质细胞,经纯化鉴定后分为:对照组、戊四氮(PTZ)组、氯喹干预组(25、50和75 mg/L),经相应处理后,分别用MTT法、免疫荧光、Western blot测定星形胶质细胞数量及活性、星形胶质纤维酸性蛋白(GFAP)及CyclinD1的表达量。结果与对照组比较,PTZ可激活星形胶质细胞的增殖,使GFAP、CyclinD1的表达量增加(P<0.05);与PTZ组比较,氯喹阻滞了PTZ激活的星形胶质细胞的增殖(P<0.05);氯喹可抑制PTZ激活星形胶质细胞异常增加的GFAP的表达;氯喹可抑制PTZ激活星形胶质细胞的CyclinD1的表达量(P<0.05);与对照组相比,3种结果均显示75 mg/L氯喹对体外培养星形胶质细胞激活的抑制作用较强,并可维持其在正常范围。结论氯喹具有抑制PTZ激活体外培养星形胶质细胞的作用,其可能通过抑制星形胶质细胞的增殖来发挥抗癫痫作用。     

活化小胶质细胞致星形胶质细胞激活

目的探讨活化小胶质细胞培养液对星形胶质细胞的影响。方法 LPS激活原代培养小胶质细胞,采用活化的小胶质细胞条件培养液刺激星形胶质细胞,观察星形胶质细胞GFAP及IL-1β和TNFα的表达。结果 LPS刺激后,小胶质细胞OX42表达量上升,IL-1β和TNFα的表达量增高;小胶质细胞条件培养液可致星形胶质细胞激活,GFAP表达量上升,IL-1β和TNFα的表达量增加。结论活化小胶质细胞的条件培养液可致星形胶质细胞激活,激活的小胶质细胞和星形胶质细胞表达前炎症介质IL-1β和TNFα。     

布洛芬对戊四氮点燃癫痫大鼠星形胶质细胞的影响

目的:探讨不同剂量布洛芬对戊四氮(PTZ)点燃癫痫大鼠的影响及其作用机制。方法:雄性SD大鼠60只,随机分为对照组、PTZ组和PTZ+布洛芬组(按布洛芬剂量分为4组),分别对其进行干预,观察记录各组大鼠行为学及脑电图变化,同时观测布洛芬的不良反应,采用免疫荧光染色及Western Blot检测GFAP的表达情况。结果:PTZ组与对照组相比,痫样发作和星形胶质细胞增生明显(P 0. 05); PTZ+布洛芬各组痫样发作和星形胶质细胞增生情况较PTZ组降低,且剂量越高抑制作用越明显(P 0. 05),但不良反应的发生也越多。结论:布洛芬可通过抑制星形胶质细胞增生影响癫痫发作,且剂量越高抑制作用越强,但其不良反应也随剂量的增加而增加。     

糖尿病模型大鼠海马区星形胶质细胞活化与凋亡的观察

目的:探讨糖尿病高血糖状态对于大鼠海马星形胶质细胞的影响。方法:应用链脲佐菌素(STZ)诱导Ⅰ型糖尿病SD大鼠模型,分为糖尿病模型1、2、3、4周和5周组(DM1,DM2,DM3,DM4,DM5),同周龄SD大鼠作为对照组。采用免疫荧光、免疫组化和Western Blot等技术,对比观察糖尿病大鼠海马区星形胶质细胞的形态、caspase-3和GFAP的表达情况。结果:免疫荧光和免疫组化检测结果显示:DM1和DM2大鼠海马区星形胶质细胞的胞体增大,突起增粗;DM3和DM4大鼠海马内星形胶质细胞的突起增粗、变长,其数量明显多于正常对照组(P0.05);而DM5大鼠海马内星形胶质细胞的突起僵硬,细胞数量有所减少,但仍高于正常对照组(P0.05)。Western Blot结果显示:DM3,DM4,DM5大鼠海马区GFAP含量明显高于对照组和DM1,DM2(P0.05)。caspase-3/GFAP免疫组化双标结果显示:DM1和DM2大鼠海马区偶见caspase-3阳性标记的星形胶质细胞;而DM3,DM4,DM5大鼠海马区caspase-3/GFAP双标细胞数明显多于正常对照组(P0.05);其中DM5双标阳性细胞数明显多于DM3和DM4(P0.05)。结论:糖尿病高血糖早期可激活星形胶质细胞,持续性糖尿病高血糖可诱导海马区星形胶质细胞活化的抑制,并引起星形胶质细胞凋亡。     

氯喹对体外培养星形胶质细胞激活的抑制作用

  目的 研究氯喹对体外培养大鼠海马星形胶质细胞激活的抑制作用,为癫痫的治疗提供实验依据。方法 分离新生SD大鼠海马,体外培养星形胶质细胞,经纯化鉴定后分组：a 对照组;b 戊四氮（PTZ）组;c 氯喹干预组（25mg、50mg、75mg/L）,经相应处理后,分别运用MTT法、免疫荧光、western-blot测定星形胶质细胞数量及活性、星形胶质纤维酸性蛋白(GFAP)及CyclinD1的表达量,并分析比较各组星形胶质细胞激活情况。结果 与b组比较,MTT法显示氯喹阻滞了PTZ激活的星形胶质细胞的增殖（P<0.05）;免疫荧光结果显示,氯喹可抑制PTZ激活星形胶质细胞异常增加的GFAP的表达;western-blot结果显示氯喹可抑制PTZ激活星形胶质细胞的CyclinD1的表达量（P<0.05）;与a组比较,3种结果均显示75mg/L氯喹对体外培养星形胶质细胞激活的抑制作用较强,并可维持其在正常范围。结论 氯喹具有抑制PTZ激活体外培养星形胶质细胞的作用,其可能通过抑制星形胶质细胞的增殖来发挥抗癫痫作用。     

马桑内酯所致慢性癫痫大鼠海马星形胶质细胞胶质纤维酸性蛋 …

用免疫组织化学方法研究了系统应用马桑内酯所致的慢性癫痫大鼠海马中星表胶质细胞伯胶质纤维酸性蛋白的表达。结果证明，整个海马的胶质纤维酸性蛋白免疫反应明显增强，并可见阳性细胞增生，胞体肥大，尤以齿状回门区和海分子腔隙层及始层为甚，此外，本实验还发现海胶质纤维酸性蛋白的阳性反应随发作后不同时间间隔（２ｈ～９ｄ）而不同，而直至发作后９ｄ胶质纤维酸性蛋白阳性反应程度仍高于对照组，此结果表明，马桑内酯所致癫痫     

雷帕霉素对小鼠星形胶质细胞体外诱导凋亡的影响

目的:探讨雷帕霉素(rapamycin,Rapa)对小鼠星形胶质细胞体外凋亡的影响。方法:无菌分离并体外培养C57BL/6J幼鼠脑组织星形胶质细胞。通过MTT比色法测定并分析Rapa浓度对幼鼠星形胶质细胞存活的影响;SYTOXGreen荧光染色联合荧光酶标仪检测并分析Rapa对H2O2、ionomycin、deferorxamine等诱导剂作用一定时间内细胞存活的影响;Di OC6(3)染色分析Rapa在H2O2氧化应激损伤条件下对星形胶质细胞线粒体膜电势的影响;分别采用H2DCFDA和Mito SOXTMRed荧光染色联合流式细胞术检测Rapa预适应对星形胶质细胞ROS生成以及线粒体内ROS含量的影响。结果:Rapa能促进H2O2以及ionomycin联合deferorxamine损伤作用下的星形胶质细胞的存活,对线粒体膜电势有保护作用,可降低H2O2损伤作用下星形胶质细胞ROS的产生并可以维持胞内线粒体ROS的含量在较低水平。结论:Rapa能够减少细胞内ROS的生成量并降低胞内线粒体内ROS水平;能够减轻H2O2对细胞线粒体膜的损伤破坏,维护线粒体膜电势的稳定性,进而对氧化应激损伤介导细胞凋亡有一定的抑制作用。     

三七总皂苷抑制星形胶质细胞活化改善脂多糖导致的小鼠抑郁样行为

目的 :观察三七总皂苷(PNS)对脂多糖(LPS)诱导的小鼠抑郁样行为以及海马星形胶质细胞(AST)活化的影响。方法 :将小鼠随机分为生理盐水(NS)组、LPS组、PNS+LPS组。利用喷糖实验、糖水偏好实验及强迫游泳实验检测小鼠抑郁样行为,免疫组织化学显色观察胶质原纤维酸性蛋白(GFAP)的表达变化,免疫印迹检测海马GFAP、乙醛脱氢酶1蛋白家族L1(ALDH1L1)的表达变化,荧光定量PCR检测海马GFAP和肿瘤坏死因子-α(TNF-α)mRNA的表达。结果 :与NS组相比,LPS组舔糖潜伏期延长、糖水偏好百分比下降、强迫游泳不动时间增加,PNS预处理可逆转上述抑郁样行为;与NS组相比,LPS组海马GFAP阳性细胞数目增加,GFAP及ALDH1L1蛋白表达上调,GFAP及TNF-αmRNA表达上调,PNS预处理均可减少GFAP、ALDH1L1及TNF-α的表达;结论 :三七总皂苷可能通过抑制星形胶质细胞活化,改善脂多糖导致的小鼠抑郁样行为。     

柴胡皂苷A减轻脑缺血再灌注大鼠海马神经元损伤

目的 探讨柴胡皂苷A（Saikosaponin A,SA）通过上调SIRT1水平减轻脑缺血再灌注（ischemia reperfusion,I/R）大鼠海马神经元损伤的作用。 方法 大鼠随机分为6组,每组9只,分别为假手术组（Sham）、模型组（I/R）、柴胡皂苷A 1 mg/kg组（I/R + SA 1 mg/kg）、柴胡皂苷A 5 mg/kg组（I/R + SA 5 mg/kg）、柴胡皂苷A 10 mg/kg（I/R + SA 10 mg/kg）和尼莫地平1 mg/kg组（I/R + NMDP 1 mg/kg）。双侧颈总动脉用微动脉夹夹闭法构建脑缺血再灌注模型,灌胃给药7 d。记录各组大鼠跳台实验犯错次数和Y迷宫实验检测新异臂进入次数,HE染色观察脑组织病理损伤,采用2,3,5-三苯基氯化四氮唑法计算各组大鼠脑梗死率、脑组织含水量及脑指数,尼氏小体染色检测神经元凋亡,免疫印迹法检测Caspase3,Caspase9,Bax／Bcl-2和SIRT1的表达,试剂盒检测SOD、MDA、LDH的含量,RT-PCR检测SIRT1的表达。 结果 柴胡皂苷A能减少大鼠跳台实验犯错次数,增加新异臂进入次数,减少脑梗死率、脑组织含水量及脑指数,降低Bax/Bcl-2和Cleaved caspase3/caspase3、Cleaved caspase9/caspase9的比值,降低MDA和LDH的含量,升高SOD活性,上调SIRT1表达水平（P<0.05）。 结论 胡皂苷A能缓解缺血再灌注大鼠海马神经元损伤和氧化应激,这与SIRT1上调有关。     

柴胡皂苷D通过下调miR-517a调节胶质瘤细胞体外和体内移植瘤生长

目的探究柴胡皂苷D通过调控miR-517a对胶质瘤细胞体外和体内移植瘤生长的影响.方法采用MTT试剂盒检测U-87细胞和正常星形细胞的存活率;Q-PCR检测miR-517a表达;流式细胞仪检测细胞凋亡;Transwell实验检测细胞迁移和侵袭;CCK-8试剂盒检测细胞增殖;蛋白免疫印迹试剂盒检测cleaved caspase-3、Ki67、MMP-2、Cyclin D1蛋白水平.建立裸鼠移植瘤模型,检测各组肿瘤重量;免疫组化检测Ki67、VEGF表达.结果柴胡皂苷D对正常星形细胞存活率无影响,降低U-87细胞存活率,下调miR-517a表达,促进细胞凋亡,上调cleaved caspase-3蛋白表达,抑制细胞迁移、侵袭、增殖,下调MMP-2、Cyclin D1、Ki67蛋白表达;抑制体内移植瘤生长,降低Ki67、VEGF阳性表达率.结论柴胡皂苷D具有下调miR-517a调节胶质瘤细胞体外和体内移植瘤生长的作用.     

On the role of astrocytes in epilepsy: a functional modeling approach

In the present research, we extend a biologically plausible cortical neural population model (CPM), which was developed previously in the literature, by integrating the functional role of astrocytes in the synaptic transmission in the model. In other words, the original CPM is modified to consider neuron-astrocyte interaction. Then, two modified CPMs (MCPMs) are coupled via excitatory synapses; the astrocytes are also coupled through gap junctions. Using the coupled MCPMs (CMCPMs), it is demonstrated that the healthy astrocytes provide appropriate feedback control in regulating neural activity. As a result, the astrocytes compensate the coupling variations between CPMs in order to maintain the normal level of synchronized behavior. Next, malfunction of astrocytes in the regulatory feedback loop as one of the plausible causes of seizures is investigated. In this way, dysfunctional astrocytes are not any more able to regulate the excessive increase of the inter-population coupling strength. Consequently, disruption of the homeostatic function of astrocytes may initiate the hypersynchronous firing of neurons. This suggests that the neuron-astrocyte interaction may represent a novel target to develop effective therapeutic strategies for epilepsy.     

染料木黄酮对氨诱导的星形胶质细胞NF-κB活化的影响

目的:探讨染料木黄酮对氨所致星形胶质细胞NF-κB活化的影响及其机制。方法:以氯化铵刺激原代培养的星形胶质细胞,建立高血氨模型,Western blot检测星形胶质细胞中ERK、Akt及核因子κB(NF-κB)的活化。结果:AG1478及染料木黄酮可显著抑制氨诱导的星形胶质细胞ERK及Akt的活化。LY294002、染料木黄酮及AG1478可显著抑制氨诱导的星形胶质细胞NF-κB核转位。结论:染料木黄酮可显著抑制氨诱导的星形胶质细胞ERK活化和Akt介导的NF-κB活化,这可能是该天然物质抑制星形胶质细胞水肿的重要机制。     

GRK5对大鼠星形胶质细胞活化的作用及其机制研究

目的:探讨培养新生大鼠皮层星形胶质细胞G蛋白偶联受体激酶5(GRK5)基因沉默后核因子κB(NF-κB)表达的变化及其与胶质细胞活化、炎症反应和氧化应激的关系。方法:采用分别或联合RNA干扰沉默GRK5基因表达与NF-κB抑制剂N-乙酰半胱氨酸干预进行实验分组。利用免疫荧光、实时定量PCR和Western blotting观察GFAP与活性caspase-3表达,细胞分泌TNF-α与NO的浓度,p65、TNF-α、IL-1β和iNOS的表达情况等。结果:GRK5 siRNA刺激星形胶质细胞活化,并检测到NF-κB表达增多(P0.01),TNF-α、IL-1β和iNOS mRNA表达水平增高(P0.01),细胞分泌TNF-α和NO增多(P0.01),活性caspase-3表达增多(P0.01)。采用GRK5 siRNA+NF-κB抑制剂联合干预可部分逆转GRK5 siRNA引起的上述变化(P0.05)。结论:GRK5基因沉默可能通过刺激NF-κB表达增多引起星形胶质细胞活化。GRK5的正常表达可能具有抑制星形胶质细胞活化相关炎症反应及氧化应激的作用。     

Induction of P-glycoprotein expression in astrocytes following intracerebroventricular kainate injections

 The expression of P-glycoprotein (PGP) was studied by immunocytochemistry and light and electron microscopy, in normal rats and after intracerebroventricular kainate injections. Two antibodies to PGP, mdr (Ab-1) and c-219, were used. As in previous studies (Thiebault et al. and Jetté et al.), labelled capillaries were observed in normal rats. Kainate injections resulted in death of pyramidal neurons in the hippocampus, and a proliferation of glial cells in the affected cornu ammonis fields. An increase in PGP expression was observed in reactive astrocytes as early as 1 day postinjection. Immunoreactivity peaked at 2 weeks postinjection, but was still visible as late as 10 weeks postinjection. Similar results were observed using the two antibodies. Double immunolabelling and confocal microscopy also showed that PGP was colocalised with GFAP, a marker for astrocytes. The expression of PGP in astrocytes was confirmed by electron microscopy, which showed immunoreaction product in cells containing dense bundles of glial filaments and features of reactive astrocytes. The increased PGP expression in reactive astrocytes could be part of a cellular stress response program in these cells. Received: 17 August 1998 / Accepted: 26 January 1999     

孕酮对小鼠认知能力及星形胶质细胞表达的影响

目的研究孕酮对成年雌性去卵巢小鼠认知能力的影响,及其与星形胶质细胞GFAP免疫阳性细胞表达是否存在关联性。方法 60只雌性昆明小鼠随机分为5组,除假手术对照组(SHAM组)外,其余各组小鼠行双侧卵巢切除术。术后对各组小鼠分别腹腔注射不同剂量孕酮或生理盐水。用Y-型电迷宫测试系统测定小鼠的认知功能变化,免疫组化法测定星形胶质细胞(astrocytes,AC)标志物胶质纤维酸性蛋白(GFAP)免疫阳性细胞的表达和变化。结果小鼠认知功能测定中,去卵巢对照组(OVX组)小鼠与SHAM组小鼠相比,在第2、3时段正确反应次数显著降低(P<0.05),高孕酮剂量组(HP组)小鼠与OVX组相比,在第3时段正确反应次数显著增高(P<0.05);GFAP表达测定中,OVX组与SHAM组小鼠相比,GFAP阳性细胞AOD和阳性细胞面积表达水平增加(P<0.05),孕酮中剂量组(MP组)和HP组与OVX组小鼠相比,GFAP阳性细胞AOD和阳性细胞面积表达水平降低(P<0.05)。结论雌、孕激素的缺乏会引起成年雌性小鼠认知障碍,孕酮的长期补充治疗可以改善小鼠认知能力,其作用机制与星形胶质细胞的变化相关。     

Up-regulation of reactivity and survival genes in astrocytes after exposure to short duration overpressure

Gurdjian et al. proposed decades ago that pressure gradients played a major factor in neuronal injury due to impact. In the late 1950s, their experiments on concussion demonstrated that the principal factor in the production of concussion in animals was the sudden increase of intracranial pressure accompanying head injury. They reported the increase in pressure severity correlated with an increase in 'altered cells' resulting in animal death. More recently, Hardy et al. (2006) demonstrated the presence of transient pressure pulses with impact conditions. These studies indicate that short duration overpressure should be further examined as a mechanism of traumatic brain injury (TBI). In the present study, we designed and fabricated a barochamber that simulated overpressure noted in various head injury studies. We tested the effect of overpressure on astrocytes. Expressions of apoptotic, reactivity and survival genes were examined at 24, 48 and 72 h post-overpressure exposure. At 24 h, we found elevated levels of reactivity and survival gene expression. By 48 h, a decreased expression of apoptotic genes was demonstrated. This study reinforces the hypothesis that transient pressure acts to instigate the cellular response displayed following TBI.     

Interferon-gamma-dependent cytotoxic activation of human astrocytes and astrocytoma cells

Astrocytes and microglia become activated in a broad spectrum of inflammatory neurodegenerative diseases. Activated microglia are widely believed to be the principal source of inflammation-induced neuronal degeneration in these disorders. To investigate the neurotoxic potential of human astrocytes, we exposed them and human astrocytic U-373 MG cells to a variety of inflammatory stimulants. We then assessed the effects of their supernatants on human SH-SY5 cells. When astrocytes and U-373 MG cells were stimulated with interferon (IFN)-γ (150 U/ml), their supernatants significantly reduced SH-SY5Y cell viability. Other powerful inflammatory stimulants such as lipopolysaccharide (0.5 μg/ml), tumor necrosis factor-α (10 ng/ml) and interleukin-1β (10 ng/ml), alone or in combination, were without effect. These combinations were also unable to enhance the IFN-γ effect. The induced cytotoxicities were reversed by JAK inhibitor I, a potent and specific inhibitor of JAKs. This result indicates that the neurotoxic effect was proceeding through the IFN-γ receptor (IFNGR)-JAK-STAT intracellular pathway. To establish that the IFNGR is expressed on both cultured astrocytes and U-373 MG cells, we performed RT-PCR on total RNA extracts to identify a specific IFNGR product. We showed the protein product on these cultured cells by immunocytochemistry using an antibody to IFNGR. Finally, using human postmortem material, we showed sharp upregulation of the IFNGR on activated astrocytes in affected areas in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. These findings suggest that activated astrocytes may become neurotoxic when stimulated by IFN-γ and may therefore exacerbate the pathology in a spectrum of neurodegenerative diseases.     

电针耳甲对癫痫大鼠行为学和脑电图的影响

目的: 探讨电针耳甲对癫痫大鼠的抑制效应及机制。方法: 健康成年雄性SD大鼠48只。行为学实验分为模型组、大椎组和耳甲组,每组8只。模型组大鼠腹腔注射戊四唑(PTZ)60 mg/kg造成急性癫痫模型。大椎组和耳甲组分别电针"大椎"和耳甲后腹腔注射PTZ。比较3组大鼠行为学的变化。电生理实验分为大椎组、颈迷走神经刺激组(VNS)组和耳甲组,每组8只,比较电针"大椎"、VNS和电针耳甲对癫痫大鼠脑电图的影响。结果: 与模型组和大椎组相比,耳甲组大鼠第1次大发作潜伏期延长,第1次大发作持续时间缩短,行为学积分减少。电针耳甲抑制脑电图癫痫波的时间与电针"大椎"相比增加;与VNS相比差异无显著。结论: 电针耳甲抑制癫痫发作的效应优于电针"大椎",与VNS相比无明显差异。由于电针耳甲创伤小,费用低,而且无明显副作用,可以作为治疗癫痫的替代疗法之一。