JNK信号通路在游离胆固醇诱导巨噬细胞凋亡中的作用

目的 研究JNK信号通路在游离胆固醇诱导巨噬细胞凋亡中的作用.方法 收集兔腹腔巨噬细胞进行体外培养,使用100μg/ml乙酰低密度脂蛋白及10μg/ml胆固醇乙酰转移酶抑制剂-58035促进FC聚集,以JNK特异性抑制剂SP600125进行干预,Annexin-V和PI双染后用流式细胞仪检测细胞凋亡,用Western-bolt检测JNK蛋白表达.结果 普通培养基孵育的巨噬细胞无磷酸化JNK表达,只有少量细胞凋亡,普通培养基加上胆固醇乙酰转移酶抑制剂和乙酰低密度脂蛋白孵育的巨噬细胞磷酸化JNK表达明显,8h后凋亡细胞占总细胞的(19.8±0.6)%;使用JNK特异性抑制剂SP600125可以有效抑制JNK活性,减少细胞凋亡.结论 游离胆固醇聚集是诱导巨噬细胞凋亡的重要原因,JNK信号途径参与这一过程,JNK特异性抑制剂SP600125通过抑制JNK活性对游离胆固醇诱导的巨噬细胞凋亡具有保护作用.     

舒马普坦通过细胞外信号调节激酶1/2和c-Jun氨基末端激酶信号通路下调三叉神经节内降钙素基因相关肽的表达

目的 探讨舒马普坦对大鼠三叉神经节(TG)离体培养后降钙素基因相关肽(CGRP)表达水平的影响.方法 采用TG离体培养模型,按数字随机表法将54个TG随机分为新鲜组(6个)、对照组(6个)和实验组(7个亚组,每亚组6个,共42个).实验组TG培养液中分别加入4种不同浓度舒马普坦,细胞外信号调节激酶1/2 (ERK1/2)信号通路阻滞剂U0126和PD98059,c-Jun氨基末端激酶(JNK)信号通路阻滞剂SP600125,孵育24h后免疫组织化学染色检测CGRP免疫反应(CGRP-ir)阳性细胞表达,实时定量PCR检测CGRP-mRNA表达量,Western blot定量磷酸化ERK1/2( pERK1/2)和JNK (pJNK)蛋白水平.结果 离体培养24h后,TG内CGRP-ir(+)细胞表达明显增高,0.1和0.5 mg/ml舒马普坦组CGRP-ir(+)细胞百分比、阳性面积、累积吸光度、平均吸光度、CGRP-mRNA水平较对照组明显下降(tPCP=8.652、26.382,tares=6.220、13.917,tIA=5.606、15.904,tM14=2.661、21.748,tmRNA=8.032、15.675,均P＜0.05);而0.02和2.50 mg/ml舒马普坦与对照组CGRP表达差异无统计学意义.Western blot结果显示:0.50 mg/ml浓度舒马普坦显著降低TG内pERKl/2、pJNK水平,降低程度分别接近于10μmol/L的U0126、PD98059和SP600125.结论 一定浓度舒马普坦通过细胞内ERKl/2、JNK信号通路下调大鼠TG离体培养后CGRP的过度表达.     

溶血磷脂酸对人单核细胞株基质金属蛋白酶-9和Toll样受体4表达的影响以及核因子-κB抑制剂的干预作用

目的 探讨溶血磷脂酸(LPA)对人单核细胞株(THP-1)基质金属蛋白酶(MMP)-9和Toll样受体4(TLR-4)表达的影响以及核因子(NF)-κB抑制剂的干预作用.方法 分别以0、0.1、0.5、1、5、10 μmol/L的LPA加入人THP-1细胞4 h,以及将NF-κB抑制剂咖啡酸苯乙酯(CAPE)20 mg/L预处理THP-1细胞1 h后,再加入LPA 1μmol/L4 h.应用酶联免疫吸附法测定细胞上清液的MMP-9含量,RT-PCR法测定TLR-4mRNA表达,Western Blot检测NF-κBp65活性.结果 LPA 0、0.1、0.5、1、5、10 μmol/L组细胞上清液MMP-9水平分别为(256.63±20.51)ng/ml、(296.57±10.92)ng/ml、(330.73±9.05)ng/ml、(367.8±6.4)ng/ml、(316.4±4.87)ng/ml及(303.00±6.45)ng/ml,各组间差异有统计学意义(均P＜0.01);各组TLR-4 mRNA表达的差异有统计学意义(均P＜0.01).CAPE干预组细胞上清液MMP-9含量、TLR-4 mRNA表达及NF-κBp65活性显著低于LPA 1μmol/L组(均P＜0.01).结论 LPA能促进THP-1细胞MMP-9和TLR-4的表达,NF-κB抑制剂预处理可以降低其表达水平.     

LPA通过JNK磷酸化诱导PC12细胞焦亡

目的 探讨溶血磷脂酸(LPA)能否诱导PC12细胞焦亡及其机制。方法 浓度梯度实验:不同浓度的LPA(0、20、40、60 μM)处理PC12细胞24 h,用CCK-8检测细胞活力; Hochest33342/PI 染色检测细胞膜破裂及坏死; 蛋白免疫印迹检测焦亡相关指标(NLRP3,ASC,caspase-1,IL-1β)的表达水平以及p-JNK和JNK的表达水平; JNK抑制剂实验分为4组,即CTR组(0 μM LPA),LPA 组(20 μM LPA),SP600125组(5 μM SP600125),LPA+SP600125组(20 μM LPA+5 μM SP600125),用免疫印迹检测caspase-1及IL-1β的表达水平。结果 LPA呈水平依赖降低PC12细胞活力,诱导PC12细胞坏死使PI阳性细胞数增加,并使焦亡相关指标(NLRP3,ASC,caspase-1,IL-1β)的表达水平升高以及p-JNK和JNK的水平增高。JNK抑制剂SP600125(5 μM)可以极大地抑制LPA诱导的PC12细胞焦亡相关指标caspase-1及IL-1β的表达。结论 LPA通过JNK磷酸化诱导PC12细胞焦亡,SP600125可以挽救此过程     

硫化氢通过JAK2/STAT3通路抑制脂多糖诱导的小胶质细胞M1型极化

目的观察硫化氢(H_2S)对脂多糖(LPS)诱导的小胶质细胞极化的影响并探讨JAK2/STAT3信号通路是否介导其作用。方法将培养的N9小胶质细胞随机分为对照组、LPS组、硫氢化钠(NaHS)组、LPS+NaHS组、蛋白酪氨酸激酶(JAK2)/信号转导和转录激活因子(STAT3)抑制剂α-氰基-(3,4-羟基)N-苄苯乙烯胺(AG-490)组、LPS+NaHS+AG-490组共6组,每组设3个复孔。采用MTT法检测各组细胞活力,采用ELISA法检测各组胶质细胞及培养上清液中白细胞介素1β(IL-1β)、IL-6、IL-4 IL-10水平,采用Western-blot检测各组细胞精氨酸酶1(Arg1)、诱导型一氧化氮合酶(iNOS)、磷酸化JAK2(p-JAK2)和磷酸化STAT3(p-STAT3)蛋白表达。结果与对照组比较,LPS组细胞Arg1蛋白及IL-4和IL-10表达水平增加,而iNOS蛋白、IL-1β、IL-6、p-JAK2蛋白和p-STAT3蛋白表达降低,p-JAK2/t-JAK和p-STAT3/t-STAT3比值降低(均P0.05)。与LPS组比较,LPS+NaHS组细胞Arg1蛋白及IL-4和IL-10表达水平增加,而iNOS蛋白、IL-1β、IL-6、p-JAK2蛋白和p-STAT3蛋白表达降低,p-JAK2/t-JAK2和p-STAT3/t-STAT3比值降低(均P0.05)。JAK2/STAT3信号通路抑制剂AG-490可减弱NaHS的作用。结论 H_2S可抑制LPS诱导的小胶质细胞M1型极化,其机制可能是通过JAK2/STAT3信号通路实现。     

TLR4-P38MAPK信号通路在LPS诱导BV2细胞中的表达及意义

目的观察LPS诱导小胶质细胞后信号通路Toll样受体4(TLR4)-p38蛋白激酶(p38MAPK)的表达及意义。方法体外培养BV2小胶质细胞,分为对照组、LPS诱导组(LPS刺激12h及24h)及SB203580干预组(LPS+SB203580诱导12h及24h),应用ELISA法检测各组TNF-α、IL-6水平,RT-PCR法检测各组TLR4mRNA和p38MAPK mRNA的表达变化。结果 LPS诱导组细胞分泌TNF-α、IL-6水平显著提高,诱导24h后细胞上清液含量分别为(513.67±14.05)pg/mg和(396.84±15.41)pg/mg。给予SB203580抑制剂后TLR4mRNA和p38MAPK mRNA表达明显减弱,细胞分泌TNF-α、IL-6含量表达与感染组比较也明显降低。结论 LPS刺激小胶质细胞可引起TLR4-p38MAPK信号通路的活化并释放炎性细胞因子,而SB203580则对其有明显的抑制作用,证明TLR4-p38MAPK信号通路与小胶质细胞的炎性活化密切相关。     

二氢杨梅素抑制脂多糖诱导后BV2细胞HMGB1的核质转位和释放

目的 探索二氢杨梅素(Ampelopsin,AMP)对脂多糖(LPS)刺激的小胶质细胞BV2高迁移率族蛋白B1(HMGB1)核质转位和释放的影响。方法 不同浓度的二氢杨梅素(10μmol/L,30μmol/L,50μmol/L)联合LPS处理BV2细胞,用Elisa法检测HMGB1的分泌水平;细胞核质分离方法检测HMGB1核/质转位;免疫共沉淀检测HMGB1磷酸化的表达情况;免疫印迹检测JAK2、STAT3磷酸化水平。结果 不同浓度的二氢杨梅素显著抑制了LPS引起的BV2细胞HMGB1释放,减少了LPS诱导的HMGB1由细胞核到细胞质的转位。免疫共沉淀和免疫印迹结果表明:二氢杨梅素可减少HMGB1磷酸化水平,抑制LPS诱导的JAK2-STAT3信号通路激活。结论 二氢杨梅素可以抑制LPS介导的BV2细胞HMGB1的转位和释放,其主要机制可能是通过降低HMGB1的磷酸化以及抑制JAK2-STAT3信号途径。     

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.     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

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.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

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.     

Treatment Considerations in Anticonvulsant Monotherapy

Summary: The long-standing practice of polypharmacy in treating epilepsy is giving way to use of monotherapy. Monotherapy can improve seizure control as well as reduce the risk of serious idiosyncratic reactions, dose-related side effects, and complex drug interactions. Monotherapy also offers improved compliance and cost-effectiveness. The basis of monotherapy is accurate diagnosis and assessment of the patient's seizure type(s), followed by selection of a single appropriate anticonvulsant drug. Many patients currently treated with multiple anticonvulsants can be successfully converted to monotherapy with a carefully monitored program in which troublesome and redundant drugs are gradually withdrawn from the therapeutic regimen.