14-3-3蛋白过表达减轻MPP+对PC12细胞的毒性损伤

目的 探讨14-3-3蛋白过表达对1-甲基-4-苯基吡啶离子(MPP+)诱导PC12细胞损伤的保护作用和可能的机制.方法 构建pcDNA3.1(+)-14-3-3真核表达质粒,转染PC12细胞,建立稳定过表达14-3-3蛋白细胞株;通过四甲基偶氮唑盐法(MTT法)、流式细胞术和酶标仪分别检测14-3-3蛋白过表达对MPP+诱导的PC12细胞存活力、凋亡率和SOD及谷胱甘肽过氧化物酶(GSH-Px)活性的影响.结果 14-3-3蛋白过表达显著增加PC12细胞SOD活性[质粒转染组(9.13±0.41)U/mg,MPP+组(6.45±0.52)U/mg]和GSH-Px活性[质粒转染组(89.66±3.42)μmol/mg,MPP+组(82.73±4.15)μmol/mg]、增强细胞活力[吸光度(A570):质粒转染组0.78±0.06,MPP+组0.54±0.07]、抑制细胞的凋亡(质粒转染组11.87%±3.26%,MPP+组36.30%±2.39%).结论 14-3-3蛋白过表达对MPP+的毒性有保护作用,这是通过增加SOD和GSH-Px的活性,减少氧化应激实现的.     

1-甲基-4-苯基吡啶离子调控线粒体自噬对线粒体氧化应激损伤的影响

目的 探讨1-甲基-4-苯基吡啶离子(MPP+)诱导线粒体自噬在帕金森病(PD)发病机制中的作用.方法 将细胞分为MPP+(0 mmol/L)对照组、MPP+(1 mmol/L)处理组和MPP+ (2 mmol/L)处理组,共同转染EGFP-LC3和RFP-MI-TO后加入MPP+处理48 h.Western blot检测细胞自噬水平的变化,甲丹磺酸尸胺(MDC)检测自噬空泡聚集,免疫荧光法检测EGFP-LC3和RFP-MITO亚细胞共定位,流式技术检测线粒体膜电位及活性氧.结果 MPP+1 mmol/L及MPP+2 mmol/L组LAMP2A、Beclin1和LC3-Ⅱ/LC3-Ⅰ的灰度值与对照组相比均上调,差异有统计学意义(P＜0.05).与对照组相比,MPP+处理组自噬水平增加,自噬空泡增加,外源性LC3表达上调,EGFP-LC3和RFP-MITO存在亚细胞共定位.MPP+1 mmol/L及MPP+2 mmol/L组线粒体膜电位较对照组降低;MPP+1 mmol/L及MPP+2 mmol/L组线粒体活性氧较对照组增加,差异均有统计学意义(P＜0.05).结论 MPP+通过调控线粒体自噬水平致线粒体氧化应激损伤.     

促红细胞生成素对1-甲基-4-苯基吡啶损伤的PC12细胞的保护作用(英文)

目的探讨促红细胞生成素(erythropoietin,EPO)对1-甲基-4-苯基吡啶离子(MPP+)诱导的PC12细胞变性损伤的保护作用及机制。方法用MPP+处理PC12细胞制作帕金森病细胞模型,采用四甲基偶氮唑蓝法检测暴露于不同浓度EPO后细胞的活性;流式细胞术与DNA断端原位标记法(terminal deoxynucleotidyl transferase dUTPnick end labeling, TUNEL)检测各组的细胞凋亡率;免疫印迹法检测不同处理组PC12细胞Bcl-2和Bax的表达,并采用荧光法观察不同处理组PC12细胞活性氧(reactive oxygen species,ROS)与线粒体膜电位水平以及caspase-3活性的变化。结果 MPP+可以使PC12细胞存活率下降,凋亡率增高;同时PC12细胞内ROS增多,线粒体膜电位下降。MPP+还可以明显地提高Bax/Bcl-2比值并激活caspase-3。而EPO可以抑制这些由MPP+引发的改变,并在1 U/mL时发挥最大保护作用。结论 EPO可抑制MPP+诱导的PC12细胞死亡,其作用机制可能与其自身抗氧化和抗凋亡的特性有关。     

H2O2预处理通过上调14-3-3蛋白表达减轻MPP+对PC12细胞的毒性作用

目的 探讨H2O2预处理(HPP)1-甲基4-苯基吡啶离子(MPP )诱导PC12细胞损伤的保护作用和可能的机制.方法 采用4甲基偶氮唑盐法(MTT法)、自动生化分析仪、4,6-二氨基-2-苯基吲哚(DAPI)染色法及免疫印迹(western blot)技术分别检测细胞活力、乳酸脱氢酶(LDH)活性、细胞凋亡及14-3-3蛋白的表达.结果 H2O2预处理能够上调14-3-3蛋白表达,增加PC12细胞活力(MPP 组52.46%±6.15%,HPP MPP 组83.78%±5.84%),抑制LDH的活性[MPP 组(37.31±3.99)U/L,HPP MPP 组(12.49±2.26)U/L];抑制细胞凋亡(MPP 48.72%±6.68%,HPP MPP 组17.56%±5.21%).结论 H202预处理能减轻MPP 对PCI2细胞的毒性损伤作用,这种保护作用是通过上调14-3-3蛋白的表达实现的.     

IFN-γ和热干预对U251胶质瘤细胞的MHC-I类分子和HSP70表达的影响

目的 观察重组人干扰素-γ(IFN-γ)和热干预对人多形胶质母细胞瘤(GBM)U251细胞胞膜主要组织相容性抗原复合体-I(MHC-I)类分子和热休克蛋白70(HSP70)分子表达的影响.方法 将U251细胞分为3个干预组:IFN干预组(IFN-γ500 U/ml诱导48h),热干预组(43℃热休克2h).联合干预组(IFN-γ500U/ml诱导48h+43℃热休克2h),分别行相应诱导干预.流式细胞仪(FCM)检测不同干预因素处理后的U251细胞胞膜MHC-I类分子和HSP70表达情况.结果 IFN干预组、热干预组、联合干预组U251细胞胞膜MHC-I及HSP70表达率分别为(89.92±3.45)%和(5.11±1.89)%、(78.89±2.02)%和(42.18±3.85)%、(96.00.4±2.63)%和(53.61±4.24)%.结论 双因素(IFN-γ500 U/ml诱导48 h+43℃热休克2 h)联合干预是U251细胞胞膜MHC-I类分子和HSP70双高表达的最佳体外诱导方案.     

1-甲基-4-苯基吡啶离子诱导嗜铬细胞瘤细胞自噬应激并导致α-突触核蛋白的自噬性清除障碍

目的 探讨1-甲基-4-苯基吡啶离子(MPP+)所诱导的自噬应激在嗜铬细胞瘤(PC12)细胞损伤中的作用以及MPP+导致α-突触核蛋白自噬性清除障碍及其异常聚集的可能机制.方法 在MPP+处理细胞24 h后,采用四甲基偶氮盐法检测细胞活力,Western blot检测α-突触核蛋白及微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)在蛋白水平表达的变化,并用MDC染色和免疫荧光标记观察自噬水平的变化及α-突触核蛋白、LC3-Ⅱ和溶酶体相关膜蛋白-1(LAMP-1)在细胞内的共定位情况.结果 MPP+处理后细胞的活力明显下降;与未处理组相比(PC12组:0.20±0.08;A30P组:0.76±0.09),PC12+MPP+组(0.66±0.07,t=5.7271,P=0.0023)和A30P+MPP+组(1.71 4±0.40,t=8.6100,P=0.0005)α-突触核蛋白表达增加;LC3-Ⅱ蛋白的表达水平及自噬泡的平均数目均增高.另外,MPP+处理后,α-突触核蛋白和LC3-Ⅱ的荧光信号及其共定位增加,尽管LAMP-1标记的溶酶体荧光信号增加,但与LC3-Ⅱ标记的自噬体共定位程度却减小.结论 MPP+导致自噬体与溶酶体的融合出现障碍,引起α-突触核蛋白的自噬性清除障碍与自噬应激的出现,最终导致细胞的损伤甚至死亡.     

IL-10基因转染对大鼠脑缺血再灌注损伤半影区钠氢交换器-1基因表达的影响

目的 观察SA脂质体介导入白介素-10(hIL-10)基因转染对脑缺血再灌注损伤模型大鼠半影区钠氢交换器-1(NHE-1)基因表达的影响,探讨IL-10缺血脑保护的作用机制.方法 成年雄性SD大鼠78只按随机数字表法分为正常对照组(6只)、缺血对照组(24只)、hIL-10基因转染组(24只)、空质粒组(24只).采用Longa法建立大鼠局灶性脑缺血再灌注损伤模型.正常对照组不做任何操作;缺血对照组仅做大脑巾动脉阻塞(MCAO)模型和立体定向操作,不注射任何药物;hIL-10基因转染组和空质粒组在建立MCAO模型后,采用立体定向方式分别将SA脂质体/pcDNA3.1-hIL-10混合物或SA脂质体/pcDNA3.1混合物注射入大鼠侧脑室内.24、72、168 h分别用RT-PCR和ELISA检测其转染效果,TTC染色测定脑梗死体积,采用荧光实时定量PCR技术观察各组大鼠脑组织中NHE-1 mRNA和核转录因子NF-κB mRNA的表达水平.结果 (1)RT-PCR结果 :hIL-10基因转染组人鼠在缺血再灌注72 h时,其皮层和海马中均能检测到hIL-10mRNA的表达,而正常对照组、缺血对照组和空质粒组中则不能检测剑hIL-10 mRNA.ELISA结果 :基因转染后24 h(764.63±87.88)脑组织中hIL-10蛋白与正常对照组(81.23±8.61)比较明显升高,72h(1310.21±86.19)较24h更高,但到168 h(541.32±80.77)时已明显下降,但仍高于缺血对照组和空质粒组差异均有统计学意义(P＜0.05).同时hlL-10基因转染组大鼠脑梗死体积明显小于缺血对照组和空质粒组差异均有统计学意义(P＜0.05).(2)正常对照组、缺血对照组、空质粒组和hIL-10基因转染组NF-κBmRNA的表达量分别为1.00±0.33、4.76±0.41、4.58±0.62和2.77±0.43.与正常对照组相比,其它三组NF-κB mRNA的表达量均升高,差异有统计学意义(p＜0.01).但hIL-10基因转染组的升高水平低于缺血对照组和空质粒组,差异有统计学意义(p＜0.01).(3)正常对照组、缺血对照组、空质粒组和hIL-10基囚转染组NHE-1 mRNA的表达量分别为1.00±0.22、4.16±0.48、3.97±0.51和2.82±0.47.与正常对照组相比,后三组NHE-1 mRNA的表达量均升高,差异有统计学意义(P＜0.01),其中hIL-10基因转染组的升高水平低于其它两组差异有统计学意义(P＜0.01).结论 hIL-10基因转染可能通过抑制脑缺血再灌注引起的NHE-1基因表达的增加而发挥缺血脑保护作用.     

线粒体Miro1蛋白对无镁致痫海马神经元氧化应激损伤的保护作用

目的探讨线粒体Miro1蛋白在体外颞叶癫痫模型中氧化应激方面的保护作用及其机制。方法原代培养新生24h内的SD大鼠海马神经元,通过无镁细胞外液诱导体外癫痫模型。培养至14d的海马神经元随机分为对照组(CON)、无镁诱导组(AE)、无镁诱导+rAd转染组(AE+rAdv)、无镁诱导+rAd-Miro1转染组(AE+rAd-Miro1),CON组及AE组分别用正常细胞外液和无镁细胞外液作用3h后,更换为正常维持液,腺病毒转染组于无镁诱导48h前转染腺病毒,各组分别于造模后24h终止细胞培养,采用Western blot法检测细胞内Miro1、ND6的表达,免疫荧光法检测细胞内ND6表达,比色法测定MDA、GSH的表达。结果与CON组比较,AE组Miro1表达升高,ND6表达降低,MDA表达升高,GSH表达降低,差异均具有统计学意义(P0.05);与AE组比较,AE+rAdv组Miro1表达升高,ND6表达降低,MDA表达升高,GSH表达降低,差异均无统计学意义(P0.05);与AE组比较,AE+rAd-Miro1组Miro1、ND6表达升高,MDA表达降低,GSH表达升高,差异均具有统计学意义(P0.05)。结论线粒体蛋白Miro1对无镁致痫海马神经元有保护作用,其机制可能与降低线粒体氧化应激损伤,提高ND6、GSH蛋白表达,降低MDA蛋白表达有关。     

BNIP3表达变化与脑缺血损伤关系的研究

目的观察大鼠永久性大脑中动脉闭塞(permanent middle cerebral artery occlusion,pMCAO)不同时间点脑损伤情况、Bcl-2/腺病毒E1B19kD相互作用蛋白3(Bcl-2/adenovirus E1B-19kDa-interacting protein 3,BNIP3)及线粒体自噬相关蛋白的表达,探讨BNIP3与脑缺血损伤程度的关系。方法将健康雄性SD大鼠随机分为假手术组(sham组,即pMCAO 0h组)、pMCAO 3h组、9h组和24h组,每组12只。分别采用TTC染色检测大鼠脑梗死体积、透射电镜观察线粒体形态变化、Western blot检测BNIP3及相关蛋白表达。结果 (1)各组大鼠脑梗死体积变化:sham组TTC染色显示无梗死发生,其余3组均存在脑梗死区。pMCAO 3h、9h、24h组矫正脑梗死体积〔分别为(12.12±2.15)%、(37.00±4.24)%和(51.82±4.39)%〕均明显高于sham组(均P0.01),且随缺血时间延长而矫正脑梗死体积增加(四组间两两比较,均P0.01)。(2)各组大鼠脑组织中线粒体形态变化:sham组透射电镜可以观察到完整的双层线粒体膜结构;pMCAO 3h和9h组观察到典型的线粒体自噬现象:具有双层膜结构的线粒体自噬溶酶体;pMCAO 24h组线粒体受损严重,嵴消失,膜破损,线粒体肿胀加剧,未观察到线粒体自噬现象。(3)各组BNIP3和线粒体自噬相关蛋白表达:与sham组比较,pMCAO 3h和9h组BNIP3和自噬诱导分子Beclin-1表达增加,自噬标记分子LC3-Ⅱ/Ⅰ比值升高,接头蛋白P62和线粒体标记分子热休克蛋白60(heat shockprotein-60,HSP60)、线粒体外膜易位酶(translocase of outer mitochondrial membrane 20,TOM20)表达下降(均P0.01);与pMCAO 9h组比较,pMCAO 24h组BNIP3和Beclin-1表达下降,LC3-Ⅱ/Ⅰ比值降低,P62和TOM20、HSP60表达增加(均P0.01)。结论 BNIP3很可能在脑缺血早期通过促进线粒体自噬来发挥对脑缺血损伤的保护作用。     

1-甲基-4-苯基吡啶时程依赖性改变PC12细胞内氧基-鸟嘌呤DNA糖苷酶和着色性干皮病蛋白F的表达(英文)

目的探讨离体条件下DNA剪切修复相关蛋白酶氧基-鸟嘌呤DNA糖苷酶 (OGG1) 和着色性干皮病蛋白F(XPF) 是否参与帕金森病 (PD) 的病理过程。方法用1 mmol/L 1-甲基-4-苯基吡啶 (MPP+) 处理PC12细胞不同时间,诱导细胞产生DNA氧化损伤,建立PD细胞模型。在此模型上,采用MTT法检测细胞活力;采用8-氧基-7,8- 双氢脱氧鸟嘌呤 (8-oxodG) 免疫细胞化学技术检测细胞DNA氧化损伤;用Western blot技术检测细胞内OGG1和XPF的蛋白表达水平。结果MPP+ 时程依赖性地降低细胞活力,18 h 和24 h 后细胞活力分别降至对照组的78.6% 和70.3%。MPP+ 显著增加了 8-oxodG 免疫阳性反应,在 3 h 时 8-oxodG 主要分布于细胞质,在 24 h 时其主要位于细胞核内。此外,MPP+ 显著改变了 OGG1 和 XPF 的蛋白表达水平。在 MPP+ 处理 1 h 后,OGG1 和 XPF 蛋白表达水平均显著上调,分别于3 h和18 h达到顶峰,随后依次下降,且OGG1的峰值几乎是XPF的两倍。结论MPP+时程依赖性地增加了PC12细胞内XP...     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.