钩藤碱对多巴胺诱导的NT2细胞凋亡的影响

目的:观察钩藤碱(rhnchophylline,Rhy)对多巴胺(dopamine,DA)诱导NT2细胞凋亡的防护作用.方法:以LDH的漏出率反映细胞的生存率;用TUNEL染色法和DNA琼脂糖凝胶电泳法观察NT2神经元凋亡情况;用Western blotting法测定Bcl-2蛋白表达.结果:Rhy在5和50μmol/L的浓度下能显著地抑制由DA所致的乳酸脱氢酶的漏出,以及明显地提高以PMS试剂转化为指标的生存率(P<0.05,P<0.01);在分化的NT2细胞神经元中,转染bcl-2基因的神经元凋亡率明显低于未经bcl-2基因转染的神经元,而Rhy使DA诱导的转染bcl-2基因神经元和未转染bcl-2基因神经元的凋亡率均明显减少;Rhy能抑制DA所致的DNA降解,但Phy对NT2细胞Bcl-2蛋白表达无明显影响.结论:Rhy能对抗DA诱导的NT2细胞的损伤.     

人参皂苷Rg1对抗多巴胺对PC12细胞凋亡的诱导作用

通过测定细胞的凋亡率 ,内源性NO的水平和iNOSmRNA的表达及半胱天冬酶 3的活性 ,探讨人参皂苷Rg1对抗多巴胺对PC12细胞凋亡诱导作用的可能机理 .结果表明多巴胺 (0 .15～ 0 .60mmol·L- 1)可诱导PC12细胞凋亡 ,预先经过 10 μmol·L- 1Rg 1处理后 ,PC12细胞的凋亡率显著下降 (P <0 .0 0 1) ,同时NO2- 水平和iNOSmRNA表达水平及半胱天冬酶 3活力较单纯多巴胺处理组明显降低(P <0 .0 0 1) .结果提示 ,Rg1减少细胞内源性NO的生成及抑制半胱天冬酶 3的活化可能是Rg1对抗多巴胺诱导PC12细胞凋亡的重要机理 .     

H_2O_2预处理对多巴胺损伤PC12细胞的适应性保护作用

目的探讨H2O2预处理对多巴胺(dopamine,DA)损伤PC12细胞的适应性保护作用。方法透射电镜、Hoechst染色和PI染色流式细胞仪(flowcytometry,FCM)观测细胞凋亡,MTT代谢率法观察细胞线粒体氧化磷酸化功能状态,Rh123染色FCM检测细胞线粒体膜电位(△Ψm)。结果50μmol·L-1DA作用PC12细胞24h后,电镜可观察到PC12细胞体积缩小,核染色质浓缩、边集,核碎裂等细胞凋亡征象。Hoechst33258染色显示,DA(50μmol·L-1)作用24h后,经H2O2预处理的PC12细胞的凋亡量较未预处理的明显减少。50、100和200μmol·L-1DA作用24h后,PC12细胞的凋亡率分别为(20.9±1.8)%、(40.5±6.4)%、(88.1±3.9)%,而经H2O2预处理的PC12细胞的凋亡率分别下降至(4.9±2.9)%、(12.0±1.4)%、(61.5±3.4)%(P<0.01)。20、40、80μmol·L-1DA作用细胞24h后,细胞MTT代谢率明显下降,而H2O2预处理抑制20、40、80μmol·L-1DA引起的PC12细胞MTT代谢率的下降(P<0.01)。50μmol·L-1DA作用24h后,PC12细胞的平均Rh123荧光强度由正常对照的(46.87±0.33)下降至(4.39±2.93),而经H2O2预处理的PC12细胞,其平均Rh123荧光强度仅下降到(10.50±0.28),下降程度明显减轻(P<0.01)。结论H2O2预处理对DA损伤PC12细胞具有适应性保护作用。     

人参皂甙Rg1对抗多巴胺诱导的PC12细胞凋亡

目的:探讨外源性多巴胺诱导PC12细胞凋亡以及人参皂甙Rg1保护作用的分子机制。方法:流式细胞仪定量测定PC12细胞的凋亡和Bcl-2、Bax蛋白的表达;电子显微镜观察PC12细胞的形态;凝胶电泳评价DNA的断裂;荧光分光光度计法测定caspase-3的活力;半定量RT-PCR分析bcl-2和bax mRNA的表达。结果:多巴胺(浓度为0.15、0.30、0.45和0.60mmol/L)诱导PC12细胞凋亡,各剂量组细胞凋亡率分别从对照组1.1％±0.4％增加到41％±3％,46.4％±2.7％,53％±3％和64.5％±2.7％;人参皂甙Rg1 10μmol/L预处理24h后,较多巴胺0.45mmol/L单独处理时,PC12细胞的凋亡率和caspase-3的活力分别从53％±3％和683±8(平均荧光强度)下降到1.9％±0.6％和325±5,Bcl-2蛋白阳性率从14.3％±1.1％增加到25.9％±1.6％,Bax蛋白阳性率从48％±3％下降到35％±3％。结论:人参皂甙Rg1通过抑制cas-pase-3的激活并调节Bcl-2和Bax两者间蛋白的比值对抗多巴胺对PC12细胞凋亡的诱导作用。     

芍药苷对6羟基多巴胺致PC12细胞损伤的保护作用

目的:探讨芍药苷对6羟基多巴胺(6-OHDA)致大鼠肾上腺嗜铬细胞瘤细胞(PC12)的细胞损伤保护作用及其可能机制.方法:体外培养PC12细胞,用6-OHDA建立细胞损伤模型.MTT和乳酸脱氢酶(LDH)活性测定存活率;RT-PCR检测Bcl-2、Bax的mRNA表达,Hochest33342/PI双染检测细胞凋亡率.结果:25、50、100 μmol·L-1芍药苷可显著减少6-OHDA诱导的PC12细胞凋亡,降低LDH漏出率,增加Bcl-2 mRNA和减少Bax mRNA表达.结论:芍药苷可显著减少6-OHDA诱导的PC12细胞凋亡,其作用机制可能与调节Bax、Bcl-2表达有关.     

尼古丁对6-羟多巴胺诱导PC12细胞凋亡的拮抗作用

目的　探讨尼古丁对 6 羟多巴胺 (6 OHDA)诱导PC1 2细胞凋亡的拮抗作用及其与烟碱受体的关系。方法　用 6 OHDA诱导大鼠肾上腺嗜铬细胞瘤细胞株PC1 2细胞凋亡的细胞模型 ;用MTT、二乙酸荧光素活细胞染色、流式细胞仪和DNA琼脂糖凝胶电泳等方法检测PC1 2细胞的凋亡 ;用尼古丁及N型和M型受体拮抗剂预处理 ,观察尼古丁的拮抗作用及其与受体的关系。结果　尼古丁可明显拮抗 6 OHDA(50 μmol·L-1 )诱导PC1 2细胞凋亡 ,呈钟型浓度效应关系 ,1 0 μmol·L-1 尼古丁的拮抗作用最强。用 1 0 μmol·L-1 尼古丁预处理PC1 2细胞 2h可明显降低 6 OHDA诱导的细胞凋亡。用 1 0 μmol·L-1 六甲溴胺阻断烟碱受体 ,可取消尼古丁对 6 OHDA诱导细胞凋亡的拮抗作用 ;但用阿托品阻断M型胆碱受体 ,对尼古丁的拮抗作用则无明显影响。结论　尼古丁对 6 OHDA诱导的PC1 2细胞凋亡有明显的拮抗作用 ,这种作用由烟碱受体所介导。     

色霉素对多巴胺能神经元的保护作用

目的研究色霉素对MPP+诱导凋亡的多巴胺能神经元的保护作用。方法体外培养的胎鼠腹侧中脑神经元,以MPP+引起多巴胺能神经元凋亡作为帕金森病的细胞模型,Hoechst 33258荧光核染色法检测神经元的凋亡情况,免疫细胞化学方法检测多巴胺能神经元内磷酸化Tau水平。结果10μmol·L-1 MPP+可以升高Tau磷酸化水平,诱导神经元发生典型的凋亡。而色霉素通过抑制Tau磷酸化,减少神经元凋亡,使TH-阳性细胞数目增加。结论色霉素可以通过抑制Tau磷酸化而对MPP+诱导凋亡的多巴胺能神经元发挥保护作用,色霉素可能用于临床防治帕金森病等神经退行性疾病。     

多巴胺β-羟化酶基因与药物滥用相关研究进展

多巴胺β-羟化酶（dopamine β-hydroxylase，DBH，EC1．14．17．1）为含C矿蛋白质，由578个氨基酸组成，分子量290KD，存在于神经细胞的囊泡内，催化多巴胺（dopamine，DA）生成去甲肾上腺素（norepinephrine，NE），是去甲肾上腺素能神经元的标志酶。NE在心血管功能调节、镇痛和情感调节中起到重要作用，DA可以调控心血管功能、锥体外系的运动功能和影响精神活动。DBH的活性可以影响DA和NE这两种神经递质的水平，从而在神经调节中起到重要作用。本文对DBH基因表达调控、基因多态性和药物滥用相关研究等方面的进展作一综述。     

多巴胺作用机制及代谢

帕金森病(Parkinsondisease,PD)是一种多发于中老年人,以肌肉震颤、肌肉强直、运动活动启动困难、姿势反射丧失为特征的中枢神经系统疾病。首次就诊时的平均年龄是55岁,此年龄组人口约1%患有此病,其症状特点首先由JamesParkinson于1817年描述。PD主要病理生理学特点是黑质致密部(SNc)色素沉着神经元进行性死亡导致多巴胺(Dopamine,DA)代谢障碍,此种神经元已被鉴定为黑质DA神经元。脑的其他区域亦可累及,如蓝斑核,Meynert'基底核,甚至下丘脑。SNc多巴胺能神经元的死亡导致帕金森综合征,这一重大发现为药物治疗PD、调控DA突触传递提…     

多巴胺代谢引起氧化应激导致鱼藤酮诱导的PC12细胞毒性作用

鱼藤酮是一种常见的杀虫剂,也是线粒体呼吸链复合体Ⅰ的特异性抑制剂,大鼠长期喂鱼藤酮可以引起类似帕金森病(PD)的生化和组织水平的改变,如黑质致密部多巴胺能神经元的选择性丧失等等.该文用PC12细胞系从氧化应激的角度论证多巴胺在此细胞毒性过程中的作用.实验结果表明,加鱼藤酮组的细胞成活率有明显降低而且胞内多巴胺浓度显著升高并与加药脸始亮恳览倒叵?鱼藤酮也影响PC12细胞中与多巴胺合成和转运相关的蛋白质和酶活性的改变.在这些细胞中,单胺转运蛋白2(VMAT2)活性显著下调,多巴胺转运蛋白(DAT)活性上调,单胺氧化酶(MAO)活性增强.     

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.     

Intracellular dopamine oxidation mediates rotenone-induced apoptosis in PC12 cells

Aim: To study the role of dopamine (DA) in rotenone-induced neurotoxicity in PC12 cells. Methods: Cell viability was assessed by detecting the leakage of lactate dehydrogenase (LDH) into the medium. Apoptosis rate was measured by flow cytometry. Caspase-3-1ike activity was measured by fluorescence assay using the probe Ac-DEVD-AMC. The level of intracellular hydrogen peroxide and other peroxides in PC12 cells were quantified by loading cells with 2‘-7‘-Dichlorodihydrofluorescein diacetate (DCFH-DA) in fluorescence assay. Lactic acid was measured spectrophotometrically. The DA levels in PC 12 cells weredetermined by HPLC-ECD. Results: A 48-h incubation of PC 12 cells with rotenone caused an apoptotic cell death and elevated intracellular reactive oxygen species (ROS) and lactic acid accumulation. Intracellular DA depletion with reserpine significantly attenuated rotenone-induced ROS accumulation and apoptotic cell death. No change was found in rotenone-induced ROS accumulation when cells were co-treated with deprenyl. Brief treatment with reserpine at the end of rotenone treatment had no effect on rotenone-induced neurotoxicity. However, when cells were first incubated with deprenyl, a monoamine oxidase-B inhibitor for 30 min then co-incubated with rotenone plus deprenyl, a brief treatment with reserpine enhanced cell injury. Conclusion: Rotenone-inducedapoptosisinPC12 cells was mediated by intracellular dopamine oxidation.     

mTOR inhibition by rapamycin protects against deltamethrin‐induced apoptosis in PC12 Cells

The autophagy pathway can be induced and upregulated in response to intracellular reactive oxygen species (ROS). In this study, we explored a novel pharmacotherapeutic approach involving the regulation of autophagy to prevent deltamethrin (DLM) neurotoxicity. We found that DLM‐induced apoptosis in PC12 cells, as demonstrated by the activation of caspase‐3 and ‐9 and by nuclear condensation. DLM treatment significantly decreased dopamine (DA) levels in PC12 cells. In addition, we observed that cells treated with DLM underwent autophagic cell death, by monitoring the expression of LC3‐II, p62, and Beclin‐1. Exposure of PC12 cells to DLM led to the production of ROS. Treatment with N‐acetyl cysteine (NAC) effectively blocked both apoptosis and autophagy. In addition, mitogen‐activated protein kinase (MAPK) inhibitors attenuated apoptosis as well as autophagic cell death. We also investigated the modulation of DLM‐induced apoptosis in response to autophagy regulation. Pretreatment with the autophagy inducer, rapamycin, significantly enhanced the viability of DLM‐exposed cells, and this enhancement of cell viability was partially due to alleviation of DLM‐induced apoptosis via a decrease in levels of cleaved caspase‐3. However, pretreatment of cells with the autophagy inhibitor, 3‐methyladenine (3MA), significantly increased DLM toxicity in these cells. Our results suggest that DLM‐induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against DLM‐induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 109–121, 2017.     

银杏叶提取物对1—甲基—4—苯基—1，2，3，6—四氢吡啶所致帕金森症的保护作用及机制

目的:观察银杏叶提取物(EGb)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)及其离子1-甲基-4-苯基吡啶(MPP~ )诱导的帕金森症(PD)模型的保护作用。方法:用脑立体定位仪向黑质(AP-5.4mm,-2.2mm,H8.3mm)内注射MPTP诱导大鼠旋转。在注射MPTP 24h后将大鼠处死,硫代巴比妥法测定黑质中丙二醛(MDA),羟胺法(即改进的黄嘌呤氧化酶法)测定黑质中超氧化物歧化酶(SOD),荧光分光光度法(激发波长310nm,发射波长390nm)测定纹状体中多巴胺(DA)的含量。MPP~ 诱导PC12细胞凋亡,HE染色,光镜下观察凋亡细胞;吖啶橙/溴乙锭(AO/EB)染色,荧光显微镜记数凋亡细胞,观察不同浓度EGb(25,50,100mg/L)在6h,12h,24h对细胞凋亡率的影响。结果:EGb 100mg/kg组可减少模型鼠的旋转次数及旋转持续时间(n=10,P<0.05);与MPTP组比较,EGb 50mg/kg和100mg/kg组MDA相对降低,SOD及DA相对增高(n=10,P<0.05和P<0.01)。MPP~ 10μmol/L可诱导PC12细胞凋亡,EGb 50和100mg/L组在6h,12h,24h可降低细胞凋亡率(P<0.05和P<0.01,n=3)。结论:EGb对MPTP诱导的PD动物模型及其离子MPP~ 诱导的PD细胞模型均有保护作用,其保护机制与清除自由基及抑制神经元凋亡有关。     

Inhibition of serum deprivation-induced PC12 cell apoptosis by tanshinone II A.

AIM: To study the effect of tanshinone II A (Tan II A) on PC12 cell apoptosis induced by serum deprivation. METHODS: PC12 cell survival was measured by MTT assay. The DNA content and percentage of apoptosis were monitored by flow cytometry and DNA fragmentation was analyzed by agarose gel electrophoresis. RESULTS: Serum-free (12 h) medium induced apoptosis in PC12 cells. When the cells had been treated with Tan II A (0.1 and 1 micromol . L-1) for 12 h, the percentage of PC12 cell apoptosis was greatly decreased to 25.71 % and 4.89 % from 96.07 % in serum deprivation alone group, and DNA fragmentation was prevented. Tan II A (0.01 - 10 micromol . L-1) attenuated the cytotoxic effect of sodium cyanide (20 mmol . L-1), glutamate (0.5 mmol . L-1), and sodium nitroprusside (0.5 mmol . L-1). CONCLUSION: Tan II A prevented PC12 cells from apoptosis induced by serum-free medium.     

反义ClC-3寡核苷酸促进thapsigargin诱导的PC12细胞凋亡

目的　研究反义ClC 3寡核苷酸对thapsigargin诱导的细胞凋亡的影响。方法　蛋白免疫印迹法检测ClC 3蛋白的表达 ;MTT法检测反义ClC 3寡核苷酸对TG诱导的细胞生长的影响 ;形态学方法、流式细胞仪和DNA琼脂糖凝胶电泳观察和分析PC12细胞在转染ClC 3反义寡核苷酸后 ,TG诱导的细胞形态、DNA含量的变化和DNA断裂的情况。结果　与对照组相比 ,反义ClC 3寡核苷酸呈浓度和时间依赖性地抑制ClC 3蛋白的表达 ;使TG诱导的PC12细胞存活率降低 ,凋亡程度加强 ,差异有显著性 ,而正义及随义ClC 3寡核苷酸对此没有影响。结论　反义ClC 3寡核苷酸对TG诱导的PC12细胞凋亡有促进作用。     

瓜子金皂苷己对MPP~+诱导PC12细胞凋亡的保护作用

目的观察瓜子金皂苷己(polygalasaponin F,PS-F)对1-甲基-4-苯基-吡啶离子(1-methyl-4-phenylpyridinium,MPP+)诱导的PC12细胞损伤的影响,并且探讨其作用机制。方法 MTT法检测细胞存活率,Annexin V/PI染色流式细胞术检测PC12细胞凋亡,JC-1染色倒置显微镜检测细胞线粒体膜电位(mitochondrial membrane potential,MMP),Western blot检测Caspase-3蛋白的水平。结果 500μmol.L-1MPP+作用PC12细胞48 h,能明显抑制细胞生长(P<0.01),诱导细胞发生凋亡,同时降低MMP,增加活性Caspase-3的蛋白水平。同时给予不同浓度PS-F处理,PC12细胞存活率增加(P<0.01);凋亡细胞量减少;MMP增高;活性Caspase-3蛋白水平降低(P<0.01)。结论 PS-F能抑制MPP+诱导的PC12细胞的凋亡,其作用机制可能与维持线粒体正常膜电位,稳定线粒体功能,降低活性Caspase-3蛋白水平有关。     

原花青素对Aβ_(25-35)诱导PC12细胞凋亡的影响及其机制的研究

目的　探讨原花青素(Procyanidins,PC)对β淀粉样肽25~35(βamyloidpeptide25 -35, Aβ25-35 )诱导PC12细胞凋亡的影响及其机制。方法　采用MTT比色法分析细胞存活率, Hoechst33258 PI荧光染色法检测凋亡, RT PCR检测P53和bcl 2基因mRNA表达,Westernblot检测P53和Bcl 2蛋白表达。结果　不同剂量PC预处理PC12细胞 1h可剂量依赖性对抗Aβ25-35引起的凋亡,提高细胞的存活率,减少Aβ25-35引起的核固缩,凝聚和碎裂,降低P53mRNA表达以及P53蛋白表达,增加bcl 2mRNA表达以及Bcl 2蛋白表达。结论　PC可剂量依赖性对抗Aβ25-35对PC12细胞的毒性作用,其机制可能与下调凋亡基因P53和上调抗凋亡基因bcl 2表达有关。