地黄寡糖对谷氨酸诱导的海马神经元损伤及葡萄糖摄入的影响

目的观察地黄寡糖(ROS)对谷氨酸(Glu)诱导海马神经元损伤及葡萄糖摄入的影响。方法将培养7d的SD大鼠海马细胞随机分为对照组、活性ROS用药组(4,20及100mg.L-1)、Glu损伤组(Glu0.1mmol.L-1)及Glu损伤前ROS预处理组(ROS+Glu)。采用倒置显微镜观察细胞形态学变化,噻唑蓝(MTT)法测定细胞存活率,比色法测定培养液中的乳酸脱氢酶(LDH)活性,[3H]葡萄糖掺入法测定神经元葡萄糖的摄取。结果单纯ROS4,20及100mg.L-1组与对照组间各指标差异没有显著性(P>0.05)。ROS4,20及100mg.L-1预处理可使Glu损伤的细胞存活率由70.4%分别上升为77.8%,85.2%,92.6%,同时也改善了神经细胞形态并减少LDH的漏出;[3H]葡萄糖掺入量也由Glu损伤组的(1547±120)分别下降为(1384±181),(1303±123),(1134±123)cpm。结论ROS对Glu引起的神经元损伤具有保护作用,这种保护作用可能与其抑制神经细胞对葡萄糖的过度摄入有关。     

谷胱甘肽抗谷氨酸诱导海马神经元损伤钙超载机制研究

目的观察还原型谷胱甘肽(GSH)及氧化型谷胱甘肽(GSSG)对谷氨酸(G lu)诱导海马神经元死亡影响及其作用机制。方法选用新生Wistar大鼠原代培养海马神经元Glu细胞毒性损伤模型,采用台盼蓝活细胞拒染、培养液乳酸脱氢酶(LDH)测定及TUNEL细胞凋亡原位检测等方法比较GSH及GSSG预处理3d对Glu细胞毒性损伤的影响,同时利用激光扫描共聚焦显微镜观测细胞内Ca2 浓度的变化,并与MK-801比较。结果GSH及GSSG均可减少Glu诱导神经元死亡,轻度抑制Glu诱导的神经元Ca2 内流,但不及MK-801。结论谷胱甘肽对Glu细胞毒性神经损伤有保护作用,除与通常公认抗氧化作用有关外,抑制Glu诱导的神经元Ca2 内流亦为其保护机制之一。     

谷胱甘肽抗谷氨酸诱导海马神经元损伤钙超载机制研究

目的观察还原型谷胱甘肽(GSH)及氧化型谷胱甘肽(GSSG)对谷氨酸(G lu)诱导海马神经元死亡影响及其作用机制。方法选用新生Wistar大鼠原代培养海马神经元Glu细胞毒性损伤模型,采用台盼蓝活细胞拒染、培养液乳酸脱氢酶(LDH)测定及TUNEL细胞凋亡原位检测等方法比较GSH及GSSG预处理3d对Glu细胞毒性损伤的影响,同时利用激光扫描共聚焦显微镜观测细胞内Ca²⁺浓度的变化,并与MK-801比较。结果GSH及GSSG均可减少Glu诱导神经元死亡,轻度抑制Glu诱导的神经元Ca²⁺内流,但不及MK-801。结论谷胱甘肽对Glu细胞毒性神经损伤有保护作用,除与通常公认抗氧化作用有关外,抑制Glu诱导的神经元Ca²⁺内流亦为其保护机制之一。     

脱氢表雄酮及其衍生物对谷氨酸致海马神经细胞损伤的保护作用

目的　观察脱氢表雄酮 (DHEA)及其衍生物 7 羰基 脱氢表雄酮 (7 oxo DHEA)对谷氨酸诱导的海马神经损伤的保护作用。方法　原代培养的SD大鼠海马神经细胞 ,MTT比色法检测细胞存活率 ;激光扫描共聚焦显微镜检测细胞内Ca2 + 及自由基随时间变化曲线 ;比色法测定细胞内谷胱甘肽(GSH)水平。结果　DHEA(0 1μmol·L-1)及 7 oxo DHEA(0 1μmol·L-1)预保护后的谷氨酸损伤海马神经细胞胞内Ca2 + 及自由基变化曲线均明显低于无预保护组 ,GSH水平明显高于无预保护组 (P <0 0 1)。结论　DHEA及 7 oxo DHEA对谷氨酸诱导海马神经细胞损伤有保护作用。     

肉苁蓉总苷对β淀粉样蛋白25-35诱导PC12细胞凋亡的保护作用

目的研究肉苁蓉总苷(GCs)对β淀粉样蛋白25-35(Aβ25-35)诱导大鼠嗜铬细胞瘤PC12细胞凋亡的保护作用。方法体外培养的大鼠PC12细胞分6组:正常对照组、模型组、银杏叶片组(40mg·L-1)、GCs低剂量组(25mg·L-1)、GCs中剂量组(50mg·L-1)和GCs高剂量组(100mg·L-1)。细胞培养至对数生长期时分别加入上述各组药物,每日1次。培养h96时,模型组、银杏叶片组和GCs各剂量组分别加入终浓度20μmol·L-1的Aβ25-35,正常对照组以等体积培养基替代。继续培养24h和48h时,光镜观察各组细胞的形态及生长情况,MTT比色法检测各组细胞的存活率,分光光度法检测细胞中乳酸脱氢酶(LDH)活性,流式细胞术AnnexinⅤ/PI法检测细胞凋亡率。结果与正常对照组比较,模型组细胞数目显著减少,部分细胞皱缩,变圆、脱落的细胞数目较多,其存活率显著降低、LDH活性明显提高、凋亡率显著增加(P<0.01)。与模型组相比,GCs各剂量组细胞数目显著增多,细胞形态学变化明显改善,细胞的存活率增高、LDH活性下降、凋亡率降低,有非常显著差异(P<0.01)。其中,GCs高剂量作用48h效果最显著。结论GCs对Aβ25-35引起的PC12凋亡细胞损伤具有明显的保护作用。     

Aβ25-35对原代培养大鼠皮质神经元的损伤作用

目的 考察Aβ25-35对原代培养大鼠皮质神经元的损伤作用.方法 将原代培养的大鼠皮质神经元分为对照组、谷氨酸(glutamate,Glu)组及3个浓度的Aβ25-35组,每组各6孔.观察神经元的形态改变,并测定细胞存活率及培养液中乳酸脱氢酶(LDH)的活力值.结果 与对照组比较,Glu组可造成大鼠皮质神经元明显损伤,形态发生显著改变,细胞存活率为(53.1±5.5)%(P<0.01),并且培养液中LDH漏出显著增多,LDH的活力值为(39.9 4±2.9)U/g Prot (P<0.01);Aβ25-35三个剂量组神经元存活率均显著降低,分别为(69.3±5.9)%(P<0.01)、(52.7±3.0)%(P<0.01)和(33.2±1.8)%(P<0.01),Aβ25-35低、中剂量组培养液中LDH漏出未见明显改变,LDH活力值分别为(23.5±1.4)U/g Prot和(24.7±1.3)U/g Prot(P>0.05),Aβ25-35高剂量组培养液中LDH漏出显著升高,LDH活力值为(38.8±2.0)U/g Prot(P<0.01),与Glu组相当(P>0.05).结论 Aβ25-35能剂量依赖性地损伤皮质神经元,1 μmol/L Aβ25-35剂量组处理24 h后细胞存活率可降低50%左右,可用于Aβ25-35体外诱导阿尔茨海默病细胞模型的建立.     

粉防己碱对喹啉酸致海马神经元损伤的保护作用

目的研究粉防己碱(Tet)对喹啉酸(QA)诱导原代培养乳鼠海马神经元兴奋毒损伤的保护作用。方法乳鼠海马神经元原代培养后用QA诱导损伤,MTT法测定细胞活力,同时测定培养上清中LDH活性,神经元病理染色后进行形态学观察。结果Tet(10-6mol·L-1和10-7mol·L-1)能明显提高QA损伤后原代培养乳鼠海马神经元的细胞活力,降低其上清液中LDH活性,与模型组相比,差异均有显著性(P<0.01),并明显改善神经元病理损伤。结论Tet(10-6mol·L-1和10-7mol·L-1)对QA所致的原代培养乳鼠海马神经元损伤有明显保护作用。     

红景天苷衍生物S01对谷氨酸及缺氧缺糖所致SH-SY5Y细胞损伤的保护作用

目的探讨红景天苷衍生物S01(3′,4′,5′-三甲氧基苄基-1-硫代-β-D-吡喃葡萄糖苷)对神经细胞的保护作用,并初步探讨其作用机制。方法用不同浓度S01(2,10和50mg.L-1)预处理SH-SY5Y细胞,12h后用谷氨酸或连二亚硫酸钠(Na2S2O4)诱导SH-SY5Y细胞损伤,用MTT法检测细胞存活率,比色法检测乳酸脱氢酶(LDH)释放、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,荧光探针负载法检测细胞内活性氧(ROS)水平和细胞内游离钙离子浓度([Ca2+]i),化学发光法检测细胞中腺苷三磷酸(ATP)水平。结果在谷氨酸所致SH-SY5Y细胞损伤模型中,与对照组比较,模型组细胞存活率、SOD活性和ATP水平降低,LDH释放、MDA含量和细胞内ROS水平增加。与模型组比较,S01(2,10和50mg.L-1)可提高细胞存活率,减少谷氨酸引起的LDH释放,拮抗谷氨酸引起的SOD活性和ATP水平降低,并拮抗MDA和ROS水平升高。在Na2S2O4所致SH-SY5Y细胞缺氧缺糖损伤模型中,与对照组比较,模型组细胞存活率下降,LDH释放增多,细胞[Ca2+]i升高。与模型组比较,S01(2,10和50mg.L-1)可提高细胞存活率,减少缺氧缺糖引起的LDH释放和细胞内钙超载。结论S01对谷氨酸和缺氧缺糖所致神经细胞损伤具有保护作用,提示S01可能对脑缺血具有治疗作用。     

苯环壬酯对N-甲基-D-天冬氨酸诱导的原代培养的大鼠海马神经细胞损伤的保护作用

目的　观察苯环壬酯对N 甲基 D 天冬氨酸(NMDA)诱导的原代培养大鼠海马神经细胞损伤的保护作用。方法　建立NMDA诱导的原代培养大鼠海马神经细胞损伤模型 ,采用乳酸脱氢酶 (LDH )法及噻唑蓝 (MTT)比色法 ,以特异性NMDA受体拮抗剂MK 80 1作为阳性对照药 ,观察抗胆碱药苯环壬酯、东莨菪碱对NMDA诱导的原代培养大鼠海马神经细胞损伤的保护作用。结果　NMDA (4 0 0μmol·L- 1)可明显降低海马神经细胞的存活率 ,表现为细胞LDH释放量明显增高 ,MTT比色后的吸光值明显降低。苯环壬酯 (1,2 .5 ,10 ,2 0和 5 0 μmol·L- 1)对NMDA所致的LDH升高有明显对抗作用 ,MTT比色后的吸光值明显增高 (P <0 .0 1) ,其作用类似于MK 80 1(1,10 μmol·L- 1) ;而另外一种抗胆碱药东莨菪碱 (1,10 ,10 0 0 μmol·L- 1)对损伤细胞的LDH释放及MTT比色后的吸光值无明显影响。结论　苯环壬酯对NMDA诱导的大鼠海马神经细胞损伤有明显保护作用 ,其作用机制可能与其对NMDA受体的拮抗作用有关     

异丙酚对神经元缺氧损伤的保护及其作用机制

目的　研究异丙酚对离体大鼠海马神经元缺氧损伤的保护作用及其机制。方法　以原代培养的大鼠海马神经元作为研究对象 ,建立缺氧、H2 O2 和谷氨酸损伤模型 ,用MTT法测定神经元存活率。采用激光扫描共聚焦显微镜动态监测缺氧前后 ,单个海马神经元内Ca2 + 浓度和线粒体膜电位 (△Ψm)的变化。用电子自旋共振技术测定异丙酚对羟基自由基和超氧阴离子自由基的清除作用。结果　 6～ 4 8mg·L-1浓度的异丙酚可明显降低神经元缺氧损伤时的细胞死亡率 (P <0 0 1) ,作用程度均呈剂量相关 (r =0 89,P <0 0 5 ) ;2 4～ 4 8mg·L-1浓度的异丙酚可明显降低H2 O2 损伤时的细胞死亡率 (P <0 0 1) ;12～ 4 8mg·L-1浓度的异丙酚可明显降低谷氨酸损伤时的细胞死亡率 (P <0 0 1)。 3～ 4 8mg·L-1异丙酚对缺氧诱发的细胞内钙离子超载有抑制作用(P <0 0 5 ) ;12、4 8mg·L-1异丙酚能减缓缺氧引起的△Ψm降低 (P <0 0 1)。 12、4 8mg·L-1异丙酚对羟基自由基的清除率分别为 17 1%和 2 1 1% ,但对超氧阴离子自由基无清除作用。结论　异丙酚对离体培养的大鼠海马神经元缺氧性损伤具有保护作用 ,其作用机制部分与异丙酚抑制缺氧引起的 [Ca2 + ]i 异常升高、抑制线粒体膜电位的下降和清除羟基自由基有关     

二氢石蒜碱对过氧化氢损伤的PC12细胞的保护作用

目的:探讨二氢石蒜碱(DL)对H2O2诱导的PC12细胞氧化损伤的影响及其可能机制。方法:用H2O2(200μmol.L-1)处理PC12细胞建立氧化应激模型,并加入二氢石蒜碱预处理作为保护。噻唑蓝(MTT)法和乳酸脱氢酶(LDH)检测细胞存活率和细胞损伤程度,利用荧光探针DCFH-DA和JC-1分别检测细胞内活性氧(ROS)和线粒体膜电位。结果:H2O2作用于PC12细胞后,细胞存活率下降,LDH活性和ROS含量增高,线粒体膜电位降低,与正常对照组比较具有显著性差异(P<0.01);10-7～10-5mol.L-1DL预处理后,细胞存活率提高,LDH和ROS变低,线粒体膜电位回升,且在一定范围呈剂量依赖性。结论:DL对H2O2诱导PC12细胞氧化损伤具有保护作用,其作用机制可能与减少ROS产生和稳定线粒体膜电位有关。     

黄芪提取物对缺氧/复氧诱导神经元损伤的保护作用

目的探讨黄芪提取物在缺氧/复氧所致神经元损伤中的保护作用。方法原代培养大鼠海马神经元细胞,建立缺氧/复氧损伤的海马神经元凋亡模型。采用四唑盐(MTT)法和LDH释放法检测细胞活力;Hoechst染色、Annexin V/PI双染流式细胞术检测细胞凋亡;Western blot法检测AKT和磷酸化AKT蛋白的表达。结果经缺氧/复氧后细胞活力明显下降,出现凋亡典型的形态学特征,磷酸化AKT蛋白表达下降;黄芪提取物能明显提高损伤海马神经元细胞活力,降低细胞凋亡率,促进磷酸化AKT蛋白的表达。结论黄芪提取物对缺氧/复氧神经元具有保护作用,其机制可能与激活PI3K/AKT细胞信号通路有关。     

咖啡酸对大鼠海马神经元铝盐损伤的保护作用

目的建立氯化铝致原代培养大鼠海马神经元损伤模型,观察咖啡酸对神经元铝盐损伤的保护作用。方法新生24h内SD大鼠海马神经元原代培养,7d后用免疫组化鉴定纯度;并分成空白对照组(NaCl200μmol.L-1)、铝负荷模型组(AlCl3200μmol.L-1)、铝和不同浓度的5-LO抑制剂咖啡酸(10-6、10-7、10-8mol.L-1)混合处理组。以HE染色,MTT测定,LDH漏出率,SOD活性和MDA含量为观测指标。结果神经元纯度超过95%。铝负荷致神经细胞数目明显减少,神经元突起减少变短,原代培养海马神经元活力降低,LDH漏出明显增多,SOD活性降低,MDA含量升高。咖啡酸能剂量依赖性地减轻铝盐所致的原代培养的海马神经元损伤,提高神经细胞的活力,减少LDH漏出,明显阻遏铝负荷所致的神经元SOD活性的降低和MDA含量的升高。结论咖啡酸对铝负荷所致的原代培养大鼠海马神经元损伤有一定的保护作用,其机制可能与其抑制5-LO活性,进而抑制炎症反应和氧化应激有关。     

Cadmium induces actin cytoskeleton alterations and dysfunction in Neuro‐2a cells

Cadmium (Cd) is considered a possible etiological factor in neurodegenerative diseases. However, the exact mechanism by which Cd induces neurotoxicity is not well elucidated. In this study, Neuro‐2a cells were treated with 0, 10, 20, and 40 μM cadmium chloride for 24 hours to investigate the effects of Cd on the cytoskeleton of nerve cells. MTT assay and ELISA assay were used to examine cell viability and release of lactate dehydrogenase (LDH) from cells, respectively. Results showed that Cd reduced cell viability and increased the release of LDH in a dose‐dependent manner (P < 0.05). The morphology of treated cell was damaged as indicated by cell collapse and dimensionality reduction. Moreover, the axonal spines and normal features of Cd‐treated neurons disappeared. We checked the ultrastructure of Neuro‐2a cells and found that Cd‐induced swelling, membrane damage, overflow of cytoplasm contents, and cell fragmentation. Damaged mitochondria, expanded endoplasmic reticulum, and abnormal microfilaments were found in Cd‐treated cells rather than in untreated cells. Compared with the control group, the relative release of glutamate in the supernatant after Cd treatment was reduced, indicating that Cd exposure could reduce the release of glutamate by inhibiting the function of nerve‐2a cells. Cd decreased the mRNA and protein expression levels of cytoskeletal proteins including DBN, SYP, and TAU, which might promote cytoskeleton alterations in Cd‐treated cells. In conclusion, Cd‐induced actin cytoskeleton alterations and dysfunction of cultured neurons. The results of the present study provide new insights for the investigation of Cd‐induced neurotoxicity.     

Inhibition of ethanol-induced toxicity by tanshinone IIA in PC12 cells

AIM: To observe the effects of tanshinone IIA (Tan IIA) on the neurotoxicity induced by ethanol in PC12 cells and to explore its protective role. METHODS: PC12 cell survival was measured by MTT assay. The formation of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) release were detected by 2',7'-dichlorofluorescin (DCF) fluorescence and calorimetric method, respectively. The percentage of cell apoptosis was monitored by flow cytometry. The expression of p53 was detected by immuno-fluorescence and flow cytometry. RESULTS: Ethanol significantly impaired the survival of PC12 cells as demonstrated by MTT assay. Ethanol also induced significant ROS formation and increased LDH release. Pre-incubation with Tan IIA in the culture medium significantly reversed these changes. Ethanol caused cell apoptosis and the upregulation of p53 protein. The anti-apoptosis effects of Tan IIA on ethanol-induced toxicity were accompanied by the downregulation of pro-apoptotic p53 protein expression. CONCLUSION: Tan IIA can protect neurons from apoptosis and might serve as a potential therapeutic drug for neurological disorders induced by ethanol.     

Anthocyanins extracted from black soybean seed coat protect primary cortical neurons against in vitro ischemia

The present study investigated the neuroprotective effects of anthocyanins extracted from black soybean (cv. Cheongja 3, Glycine max (L.) MERR.) seed coat against oxygen-glucose deprivation (OGD) and glutamate-induced cell death in rat primary cortical neurons. Lactate dehydrogenase (LDH) release and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assays were employed to assess cell membrane damage and viability of primary neurons, respectively. OGD-induced cell death in 7?d in vitro primary cortical neurons was found to be OGD duration-dependent, and approximately 3.5?h of OGD resulted in ≈60% cell death. Treatment with black soybean anthocyanins dose-dependently prevented membrane damage and increased the viability of primary neurons that were exposed to OGD. Glutamate-induced neuronal cell death was dependent on the glutamate concentration at relatively low concentrations and the number of days the cells remained in culture. Interestingly, black soybean anthocyanins did not protect against glutamate-induced neuronal cell death. They did, however, inhibit the excessive generation of reactive oxygen species (ROS) and preserve mitochondrial membrane potential (MMP) in primary neurons exposed to OGD. In agreement with the neuroprotective effect of crude black soybean anthocyanins, purified cyanidin-3-glucoside (C3G), the major component of anthocyanins, also offered dose-dependent neuroprotection against OGD-induced neuronal cell death. Moreover, black soybean C3G markedly prevented excessive generation of ROS and preserved MMP in primary neurons that were exposed to OGD. Collectively, these results suggest that the neuroprotection of primary rat cortical neurons by anthocyanins that were extracted from black soybean seed coat might be mediated through oxidative stress inhibition and MMP preservation but not through glutamate-induced excitotoxicity attenuation.     

白藜芦醇对MPP+所致MES23.5细胞损伤的保护作用

目的 探讨植物雌激素白藜芦醇对MPP<'+>所致MES 23.5细胞损伤的保护作用及其机制.方法 培养大鼠黑质多巴胺能神经细胞(MES23.5),分为3组:空白对照组、MPP<'+>处理组、白藜芦醇预处理组,分别采用甲基噻唑基四唑(MTT)法、细胞内乳酸脱氩酶(LDH)测定法、Hoechst染色等综合实验手段测定细胞损伤和凋亡情况.结果 MES 23.5细胞经MPP<'+>处理后,细胞存活率下降、LDH释放量增加、细胞核出现浓缩深染,与空白对照组差别具有统计学意义(P<0.05);白藜芦醇预处理后再经MPP<'+>处理,细胞存活率增加、LDH释放量减少、细胞核变化减轻,与MPP<'+>处理组差别具有统计学意义(P<0.05).结论 白藜芦醇对MPP<'+>所致MES 23.5细胞损伤具有保护作用,机制与抗凋亡有关.     

Nitric oxide-mediated effect of nipradilol, an alpha- and beta-adrenergic blocker, on glutamate neurotoxicity in rat cortical cultures

Nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-nitroxy-2H-1-benzopyran) is used clinically as an anti-glaucoma ophthalmic solution in Japan, and was recently reported to suppress N-methyl-d-aspartate-induced retinal damage in rats. Here we investigated cytotoxic and cytoprotective actions of nipradilol on primary cultures of rat cortical neurons. Treatment of cortical cultures with a high concentration (500 microM) of nipradilol significantly reduced cell viability, increased lactate dehydrogenase (LDH) release and nitrite concentration in culture medium, whereas desnitro-nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-hydroxy-2H-1-benzopyran) had no significant effects. Nipradilol-induced neuronal damage was inhibited by S-hexylglutathione, a glutathione S-transferase inhibitor, and FeTPPS (5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III) chloride), a peroxynitrite decomposition catalyst. On the other hand, relatively low concentrations (10-100 microM) of nipradilol but not desnitro-nipradilol prevented neuronal cell death induced by 24 h application of 100 microM glutamate. Importantly, neuroprotective concentration (100 microM) of nipradilol suppressed glutamate-induced elevation of intracellular Ca2+ concentrations, but had no effect on intracellular cyclic GMP levels. Hence, nipradilol can protect cultured cortical neurons against glutamate neurotoxicity via cyclic GMP-independent mechanisms, and nitric oxide (NO) released from the nitoroxy moiety of nipradilol may mediate neuroprotective effect through the modulation of NMDA receptor function.