硫辛酸抑制帕金森病模型细胞铁聚积的实验研究

目的观察硫辛酸(LA)对6-羟基多巴胺(6-OHDA)诱导的PC12细胞铁代谢的影响,并探讨其作用机制。方法 MTT法确定6-OHDA最适造模浓度,筛选LA低、高保护浓度。实验分为正常对照组、模型组(6-OHDA 50μmol/L)、LA低剂量(0.001μmol/L)组和LA高剂量(0.1μmol/L)组。比色法测定细胞内MDA、铁含量,Western blot检测铁代谢相关蛋白DMT1(+IRE)、IRP1、IRP2水平,实时荧光定量PCR分析DMT1(+IRE)、IRP1、IRP2的mRNA表达。结果 (1)与对照组相比,模型组细胞活力明显下降(P<0.01),MDA、铁含量显著增加(P<0.01),DMT1(+IRE)、IRP1、IRP2蛋白及mRNA水平明显上调(P<0.01)。(2)与模型组相比,LA低、高剂量组细胞活力均上升(P<0.05,P<0.01),MDA、铁含量均显著减少(P<0.01),DMT1(+IRE)、IRP1、IRP2蛋白及mRNA水平均下调(P<0.05,P<0.01)。(3)与LA低剂量组相比,LA高剂量组MDA、铁含量减少(P<0.05),DMT1(+IRE)、IRP1蛋白及mRNA水平降低(P<0.05,P<0.01);而LA低剂量组与LA高剂量组相比,两组的IRP2蛋白及mRNA表达差异不具有统计学意义(P>0.05)。结论 LA对6-OHDA诱导的PC12细胞损伤具有保护作用,其机制可能是通过抑制IRP/IRE途径下调6-OHDA诱导的DMT1(+IRE)上升,从而减少细胞对铁离子的吸收,减轻铁聚集引起的氧化应激对细胞的损伤。     

灵芝多糖对Aβ25-35诱导的PC12细胞损伤的保护性研究

目的观察灵芝多糖(GLP)对β-淀粉样蛋白(Aβ25-35)诱导的PC12细胞损伤的保护作用。方法将Aβ25-35或(和)不同浓度的GLP加入体外培养的PC12细胞中,用MTT检测PC12细胞活力的变化;以DCFH-DA来检测细胞内活性氧(ROS)水平的改变;通过Western Blotting来检测Bcl-2和Bax的表达水平。结果 Aβ25-35处理36h后的PC12细胞存活率仅为对照的60.7%,细胞内ROS水平上升到原来的222.7%,同时Bcl-2/Bax比值下降,为对照组的60.0%。经不同浓度的GLP预处理后,细胞存活率均显著提高,分别能达到69.7%,80.7%和88.3%(P<0.01);10g/ml GLP预处理PC12细胞24h后,细胞内ROS水平下降至正常组的160.6%,Bcl-2/Bax比值升高到93.6%,P值均<0.01。结论 GLP对Aβ25-35诱导的PC12细胞损伤有保护作用。     

黄芩苷通过上调lncRNAH19表达来减轻MPP+诱导的PC12细胞神经毒性

目的 探讨黄芩苷是否通过上调长链非编码RNA(Long noncoding RNA,lncRNA)H19表达来减轻1-甲基4-苯基吡啶离子(1-methyl-4-phenylpyridinium,MPP⁺)诱导的PC12细胞神经毒性。方法 分别采用0.5、0.75、1、2 mmol/L MPP⁺和10、20、50和70 μmol/L黄芩苷作用PC12细胞,后续试验使用水平分别选择0.75 mmol/L MPP⁺和50 μmol/L黄芩苷; 以0.75 mmol/L MPP⁺损伤PC12细胞,体外模拟帕金森病,并加入黄芩苷; 采用四甲基偶氮唑盐(Methyl thiazolyl tetrazolium,MTT)进行细胞活力测定,Annexin V-异硫氰酸荧光素(Fluorescein isothiocyanate isomer,FITC)/碘化丙啶(Propidium iodide,PI)双染法进行凋亡定量分析,蛋白质印迹分析(Western blot)检测Pro-天冬氨酸特异性半胱氨酸蛋白酶(Cysteinyl aspartate specific proteinase,Caspase)-3,Cleaved-caspase-3,B细胞淋巴瘤/白血病-2(B cell lymphoma/lewkmia-2,Bcl-2)蛋白和Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)的相对表达水平,实时定量聚合酶链式反应(Quantitative real-time polymerase chain reaction,qPCR)进行lncRNA H19的相对表达水平检测; 在PC12细胞中转染lncRNA H19小干扰RNA(lncRNA H19 siRNA,si-H19),并加入MPP⁺和黄芩苷,考察PC12细胞增殖、凋亡等变化。结果 与对照组比较,MPP⁺降低PC12细胞的存活率、Bcl-2蛋白、lncRNA H19相对表达水平,提高PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。与MPP⁺组比较,黄芩苷显著提高MPP⁺诱导的PC12细胞的存活率、Bcl-2蛋白、lncRNA H19相对表达水平,降低PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。转染si-H19后黄芩苷和MPP⁺诱导的PC12细胞的存活率、Bcl-2蛋白相对表达水平降低,PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平升高(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。结论 黄芩苷上调lncRNA H19表达,提高MPP⁺诱导的PC12细胞活力和降低其凋亡,减轻MPP⁺诱导的PC12细胞神经毒性。     

促红细胞生成素对体外帕金森病模型细胞凋亡及Bax蛋白表达的影响

目的 观察促红细胞生成素(EPO)对体外帕金森病模型细胞凋亡及Bax蛋白表达的影响.方法 体外培养多巴胺能神经元细胞加入6-OHDA建立帕金森病细胞模型,分为对照组、6OHDA组和EPO+ 6-OHDA组,采用TH免疫组织化学方法和TUNEL法观察体外培养7d时细胞凋亡情况,检测Bax蛋白表达.结果 与对照组比较,6-OHDA组存在明显的细胞凋亡和Bax蛋白高表达(P＜0.05)；与6-OHDA组比较,EPO+ 6-OHDA组细胞凋亡明显减少,Bax蛋白表达降低(P＜0.05).结论 促红细胞生成素能减少6-羟基多巴诱导的神经元细胞凋亡,降低Bax蛋白表达.     

蛇床子素对MPP~＋损伤PC12细胞的保护作用研究

目的观察蛇床子素（osthole）对1-甲基-4-苯基吡啶离子（MPP＋）诱导PC12细胞损伤的神经保护作用。方法将MPP＋加入培养的PC12细胞中,建立多巴胺能神经元损伤模型,加入不同浓度的蛇床子素预处理细胞（0.01、0.05、0.1mmol/L）。处理24h后用噻唑蓝（MTT）比色法检测细胞活性;以乳酸脱氢酶（LDH）活性测定反映细胞的损伤程度;采用Westernblot法检测Bax、Bcl-2蛋白的表达,分析Bax/Bcl-2比值变化,以及检测细胞色素C的改变。结果蛇床子素可以明显减少MPP＋诱导的PC12细胞活性的降低,LDH的释放,Bax/Bcl-2比值的增高以及细胞色素C的释放（P〈0.05）。结论蛇床子素对MPP＋诱导的PC12细胞损伤具有保护作用。     

槲皮苷对过氧化氢诱导PC12细胞损伤的保护作用

目的探讨槲皮苷对H2O2所致的PC12细胞凋亡的保护作用及机制。方法 PC12细胞培养后,MTT检测细胞存活率的方法进行H2O2损伤模型的摸索和槲皮苷药物浓度的筛选,将PC12细胞分为对照组、模型组和不同剂量槲皮苷组。用400μmol H2O2刺激PC12神经元细胞使其发生凋亡复制阿尔茨海默病(AD)模型,MTT法检测PC12细胞存活率、硫辛酰胺脱氢酶催化的INT显色反应检测乳酸脱氢酶(LDH)释放量和DAPI荧光核染色观察细胞凋亡形态学改变,Western blot方法检测Cytc和caspase-3表达的变化。结果 400μmol H2O2诱导PC12细胞损伤明显,与模型组比较,槲皮苷组PC12细胞存活率显著提高(P<0.01),凋亡率显著下降(P<0.01),LDH释放量和凋亡相关蛋白Cytc和caspase-3的表达显著减少(P<0.01)。结论槲皮苷可抑制H2O2诱导的PC12细胞凋亡,其机制可能与抑制细胞凋亡线粒体途径中凋亡相关蛋白Cytc和caspase-3的表达有关。     

大蒜素对6-羟多巴胺所致PC12细胞损伤的保护作用及机制

目的研究大蒜素对6-羟多巴胺(6-hydroxydopamine,6-OHDA)引起的PC12细胞损害的保护作用和相关机制。方法使用6-OHDA在PC12细胞建立损伤模型,细胞活力、乳酸脱氢酶(lactate dehydrogenase,LDH)释放和细胞凋亡检测被用于观察大蒜素的保护作用,氧自由基(reactive oxygen species,ROS)和内源性抗氧化酶活性被用于检测其抗氧化活性,蛋白免疫印迹用于检测大电导、钙离子激活的钾离子通道(Large-conductance Ca2+-activated K+channels,BK)蛋白表达并研究可能的相关机制。结果 1大蒜素显著减轻6-OHDA所致的细胞活力下降和LDH释放,并抑制细胞凋亡。2大蒜素显著抑制6-OHDA所致的ROS产生和丙二醛(malondialdehyde,MDA)升高,并增加内源性抗氧化酶的活性。3大蒜素显著增加BK蛋白表达,使用BK阻滞剂paxilline可部分逆转大蒜素的保护作用。结论大蒜素通过激活BK和抗氧化机制对6-OHDA损伤的PC12细胞发挥保护作用。     

亲环素A对Aβ25-35诱导PC12细胞凋亡的影响及机制研究

目的 探讨亲环素A(CyPA)对Aβ25-35诱导的PC12细胞凋亡影响及可能的作用机制.方法 将PC12细胞分为正常对照组(0 μmol/L Aβ25-35)、Aβ25-35诱导组(10 μmol/L Aβ25-35)和药物保护组(0.1、1、10、100 nmol/L CyPA+10 μmoi/Lβ25-35),药物保护组采用相应浓度CyPA预处理PC12细胞30 min,再加入Aβ25-35继续培养.MTT法分析细胞存活率,Hoechst33258染色法检测细胞凋亡,RT-PCR检测Bcl-2和Bax mRNA表达,Western blotting检测Bcl-2和Bax蛋白表达.结果 1、10和100 nmol/L CyPA可提高细胞的存活率,减少Aβ25-35引起的细胞凋亡,增加Bcl-2mRNA表达以及Bcl-2蛋白表达,降低Bax mRNA表达以及Bax蛋白表达,与Aβ25-35诱导组比较差异有统计学意义(P<0.05),且CyPA剂量越高效果越明显.结论 CyPA可剂量依赖性对抗Aβ25-35对PC12细胞的毒性作用,减少细胞凋亡,其机制与上调抗凋亡基因Bcl-2表达和下调凋亡基因Bax表达有关.

Abstract：

Objective To explore the effect of cyclophilin A (CyPA) on apoptosis of PC 12 cells induced by Aβ25-35 and its potential mechanism. Methods PC 12 cells were divided into normal control group (0 μmol/L Aβ25-35), Aβ25-35 inducement group (10 μmol/L Aβ25-35) and drug protection groups (0.1, 1,10 and 100 nmol/L CyPA+10 μmol/L Aβ25-35). Cells in the drug protection groups were pretreated by CyPA of different concentrations for 30 min, and then co-cultured with Aβ25-35 We evaluated the survival rate of PC12 cells with MTT assay, analyzed the apoptosis of PC12 cells with Hoechst33258 staining, and detected the mRNA expressions of Bcl-2 and Bax with PT-PCR and the protein levels of Bcl-2 and Bax with Western blotting. Results Cells pretreated wth CyPA of 1, 10 and 100 nmol/L enjoyed an obvious elevation of survival rate of PC 12 cells, a significant reduction of apoptosis induced by Aβ25-35,an obvious increase of mRNA expression of Bcl-2 and protein level of Bcl-2, and a statistical decrease of mRNA expression of Bax and protein level of Bax as compared with those cells of the Aβ25-35 inducement group (P<0.05);and these effects were dose-dependent. Conclusion CyPA could resist the toxic role of Aβ25-35 on PC 12 cells and reduce the apoptosis in a dose-dependent manner by up-regulation of anti-apoptosis gene Bcl-2 and down-regulation of apoptosis gene Bax.     

神经酸对紫杉醇诱导的神经细胞PC-12损伤的保护机制

目的观察神经酸(NA)对紫杉醇(PTX)损伤的神经细胞活力、脂肪型脂肪酸结合蛋白(A-FABP)、神经丝蛋白(NF200)、p38及凋亡蛋白Bcl-2、Bax、Cyt C、活化的Caspase-3(cl-Caspase-3)和Bcl-2/Bax表达的影响。方法采用PTX处理PC-12细胞,检测PTX IC50浓度。MTS法检测不同浓度NA(5μmol·L~(-1)、10μmol·L~(-1)、20μmol·L~(-1))对PTX(IC50浓度)干预后的PC-12细胞的相对增殖率。原位缺口末端检测法(TUNEL法)检测DNA断裂情况。蛋白印迹法检测相关蛋白表达。结果 PTX促进正常PC-12细胞凋亡。NA对维持细胞形态,保持细胞活力有一定作用。TUNEL法显示,神经酸组绿色荧光明显少于紫杉醇组。与紫杉醇组相比,神经酸组a-FABP、p-p38、Cyt C、cl-Caspase3表达下调(P0.01),NF200、Bcl-2表达上调(P0.01),Bcl-2/Bax比值升高(P0.01),p38、Bax无明显变化(P0.05)。结论NA可减轻PTX诱导的神经细胞的凋亡损伤,其作用机制可能与上调NF200、Bcl-2、Bcl-2/Bax表达,下调a-FABP、p-p38、Cyt C、cl-Caspase3表达有关。     

17β雌二醇对氯胺酮诱导发育期大鼠皮质神经细胞凋亡的影响

目的探讨17β雌二醇对氯胺酮诱导发育期大鼠额叶皮质区神经细胞凋亡的影响以及机制。方法30只7日龄雄性SD幼鼠,随机分为对照组(C组)、氯胺酮组(K组)、氯胺酮+17β雌二醇组(K+E组),每组10只。C组连续3 d腹腔注射等容量生理盐水;K组连续3 d腹腔注射75 mg/kg氯胺酮;K+E组连续3 d腹腔注射75mg/kg氯胺酮同时皮下注射600μg/kg 17β雌二醇。末次注药后24 h,取额叶皮质应用TUNEL法检测神经细胞凋亡,同时应用Western-blot法检测bcl-2,Bax以及cleaved-caspase-3蛋白的水平。结果与对照组比较,氯胺酮组皮质区凋亡细胞显著性增加(P<0.01),Bcl-2蛋白水平显著性下降(P<0.01),Bax蛋白水平显著性增加(P<0.01),Bcl-2/Bax显著性降低(P<0.01),cleaved-caspase-3蛋白水平显著性增加(P<0.01)。与氯胺酮组比较,氯胺酮+17β雌二醇组皮质区凋亡细胞显著性下降(P<0.01),Bcl-2蛋白水平显著性增加(P<0.01),Bax蛋白水平显著下降(P<0.01),Bcl-2/Bax显著性增加(P<0.01),cleaved-caspase-3蛋白水平显著性下降(P<0.01)。结论 17β雌二醇可对氯胺酮诱导的发育期大鼠大脑皮质区神经细胞凋亡产生保护作用,其机制可能与影响bc1-2和Bax蛋白表达有关。     

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.     

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.     

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.     

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.     

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.     

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.