吡格列酮对脂多糖诱导的星形胶质细胞炎性细胞因子释放的影响

目的研究吡格列酮对脂多糖(LPS)诱导的星形胶质细胞炎症介质释放的抑制作用及其信号传导通路。方法神经胶质酸性蛋白(glial fibrillary acid protein,GFAP)免疫荧光染色法鉴定星形胶质细胞纯度。ELISA方法检测IL-1β、IL-6和TNF-α蛋白表达量的变化。Griess法测定培养细胞上清液中一氧化氮(NO)含量。结果星形胶质细胞经GFAP免疫荧光鉴定,其阳性率可达95%以上。LPS组能明显增加星形胶质细胞分泌IL-1β、IL-6、TNF-α及NO。吡格列酮能明显抑制LPS引起的这些作用,并呈一定浓度依赖性。过氧化物酶体增殖物激活受体γ(PPARγ)的特异性阻断剂GW9662能明显对抗吡格列酮对LPS引起的IL-1β、IL-6、TNF-α及NO增加的抑制作用。与LPS组相比,JNK特异性阻断剂SP600125(5μmol·L-1)亦能有效对抗LPS诱导星形胶质细胞IL-1β、IL-6、TNF-α及NO分泌的增加;特异性iNOS抑制剂SMT可明显抑制LPS引起的NO分泌增加。结论吡格列酮能明显改善LPS诱导的大鼠皮层星形胶质细胞的损伤,这种作用可能与激活PPARγ、抑制JNK信号传导通路有关。     

知母皂苷通过调节NF-κB-iNOS-NO信号通路抑制LPS诱导的RAW264.7细胞功能

目的研究知母皂苷(SAaB)对脂多糖(LPS)诱导的RAW264.7细胞功能的影响,以及对NF-κB-诱导型一氧化氮合酶(iNOS)-NO信号通路的调节。方法以LPS刺激RAW264.7细胞构建体外炎症细胞模型,采用Griess法和ELISA法分别检测SAaB干预下,RAW264.7炎症细胞中的NO、iNOS、肿瘤坏死因子α(TNF-α)和白介素-6(IL-6)的含量;Western blot检测RAW264.7细胞NF-κB p65蛋白的表达水平。结果 RAW264.7细胞在LPS(10 mg·L~(-1))诱导下,NO、iNOS、TNF-α、IL-6的含量以及NF-κB p65蛋白表达水平与正常对照组比较均明显增高。SAaB(0.3、3、30 mg·L~(-1))可明显降低RAW264.7炎症细胞中NO、iNOS、TNF-α和IL-6的含量(P<0.01),且明显下调NF-κB p65的蛋白表达水平(P<0.01)。结论 SAaB可通过调节NF-κB-iNOS-NO信号通路,抑制LPS诱导的RAW264.7细胞功能。     

石菖蒲抑制脂多糖诱导的神经胶质细胞炎性反应及其机制

目的 观察石菖蒲对脂多糖(lipopolysaccharide,LPS)诱导的大鼠原代神经胶质细胞炎性反应的抑制作用并探讨其可能机制.方法 分离提取大鼠原代神经胶质细胞,用LPS刺激2h后分别加入不同浓度的石菖蒲含药血清,采用硝酸还原酶法检测石菖蒲对一氧化氮的影响,运用酶联免疫吸附法(ELISA)测定培养上清液中IL-1 β、IL-8、TNF-α水平,通过实时逆转录聚合酶链反应(RT-PCR)测定细胞中诱导型一氧化氮合酶(iNOS) mRNA表达.结果 LPS能够激活神经胶质细胞,不同浓度的石菖蒲含药大鼠血清在不影响细胞存活率的情况下,可以显著降低细胞培养上清液中NO、IL-1β、IL-8、TNF-α水平,抑制细胞内iNOS mRNA表达(P＜0.05).结论 石菖蒲的神经保护机制可能与抑制胶质细胞炎症反应有关.     

新型倍半萜Souliene A抑制小胶质细胞活化作用及机制

目的研究Souliene A对LPS与IFN-γ介导的小胶质细胞激活的抑制作用与机制及其对小胶质细胞激活引起的神经元损伤的保护作用。方法分别用LPS与IFN-γ刺激小鼠小胶质细胞BV2,Griess法测定NO。Western blotting和半定量RT-PCR法检测iNOS,COX-2,IL-6,IL-1β,TNF-α的表达及其相关信号通路。ELISA法检测PGE2和IL-6,IL-1β,TNF-α的表达。用流式细胞术检测小胶质细胞内ROS生成。用MTT法检测神经元细胞的存活率。结果 SoulieneA能明显抑制NO和PGE2的生成,减少炎症介质IL-6,IL-1β,TNF-α的表达,抑制小胶质细胞内ROS的产生。SoulieneA还能抑制NF-κB的活化与Akt的磷酸化并能有效的抑制小胶质细胞条件培养液引起的神经元损伤。     

丹参酮ⅡA体内外抗炎作用研究

目的采用体内外炎症模型研究丹参酮IIA抗炎活性作用及其作用机制。方法建立脂多糖(LPS)诱导巨噬细胞RAW264.7细胞体外炎症模型,检测不同浓度丹参酮IIA对炎症因子水平、诱导型一氧化氮合酶(iNOS)、环氧化酶2(COX-2)蛋白表达及其基因表达的影响。建立二甲苯致小鼠耳廓肿胀和角叉菜胶大鼠足跖肿胀炎症模型,探讨不同浓度丹参酮IIA的体内抗炎作用。结果丹参酮IIA对RAW264.7细胞无明显毒性。与LPS组比较,丹参酮IIA剂量在2.5～40 mg/L呈明显剂量相关性地抑制一氧化氮(NO)、白细胞介素-1?(IL-1?)和白细胞介素-6(IL-6)释放(P0.05、0.01)。与LPS组比较,丹参酮IIA呈现剂量相关性地抑制LPS诱导的RAW264.7细胞iNOS和COX-2蛋白的表达(P0.01)。与LPS组比较,丹参酮IIA呈剂量相关性地下调LPS诱导的RAW264.7细胞中的iNOS、COX-2、IL-1?和IL-6基因表达(P0.05、0.01)。丹参酮IIA在10～60 mg/kg对二甲苯所致小鼠耳廓肿胀有不同程度的抑制作用,对角叉菜胶所致大鼠足跖肿胀有不同程度的抑制作用,并呈剂量相关性(P0.05、0.01),且当丹参酮IIA给药剂量达到40 mg/kg时,其抗炎效果强于阿司匹林。结论丹参酮IIA具有抗炎作用,其作用机制可能与减少巨噬细胞炎症介质生成和释放、炎症基因iNOS、COX-2、IL-1?和IL-6的表达密切相关。     

青蒿素抑制星形胶质细胞炎症通路的分子机制研究

目的 分别以P2X7、外泌体以及瞬时受体电位香草酸亚型1(TRPV1)为作用靶点,研究青蒿素(ART)抑制星形胶质细胞炎症通路的分子机制。方法 培养小鼠原代星形胶质细胞,利用胶质纤维酸性蛋白(GFAP)免疫荧光鉴定原代星形胶质细胞的纯度;MTT法检测ART对细胞活性的影响;脂多糖(LPS)处理原代星形胶质细胞,构建细胞炎症模型;分为空白对照组,ART组,外泌体抑制剂组,P2X7受体抑制剂组,TRPV1受体抑制剂组,TRPV1受体激动剂组,通过ELISA法和吸光光度法检测细胞上清液中炎症因子的含量(TNF-α、IL-1β、IL-6及NO)。结果 GFAP阳性细胞数达95%表明成功分离培养小鼠原代星形胶质细胞;300 ng/mL的LPS处理12 h是刺激星形胶质细胞构建炎症模型的最佳浓度和时间;10μmol/mL的ART处理12 h可以达到最佳的抗炎效果,并且当浓度小于20μmol/mL时,对细胞活性基本无影响;抑制P2X7受体的表达和外泌体的释放均能降低细胞中炎症因子TNF-α的含量,但不能与ART产生协同降低的效果;抑制TRPV1受体增加了细胞中的TNF-α、IL-1β、IL-6以及N...     

鬼针草总黄酮对脂多糖诱导小鼠神经炎症的改善作用及机制

目的 探讨鬼针草总黄酮（TFB）对脂多糖（LPS）诱导小鼠神经炎症的改善作用及机制。方法 将50只C57BL/6小鼠随机分为正常对照组、LPS组和TFB低、中、高剂量组，每组10只。TFB低、中、高剂量组小鼠按60、120、240 mg/kg灌胃TFB溶液，正常对照组和LPS组小鼠灌胃等体积生理盐水，每日1次，连续给药21 d。从给药第15天起，除正常对照组外，其余组小鼠连续7 d腹腔注射LPS(400μg/kg)建立神经炎症模型。末次给药4 h后麻醉小鼠取脑组织。观察小鼠神经元形态变化，检测小鼠脑组织中一氧化氮（NO）和肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、IL-6、IL-10的含量，检测小鼠脑组织中炎症通路相关蛋白[诱导型NO合酶（iNOS）、环氧合酶2(COX-2)、髓样分化因子88(Myd88)及蛋白激酶C(PKC)]的表达。结果 与正常对照组相比，LPS组小鼠脑组织的海马区神经元排列稀疏紊乱，大量神经元固缩，核缩小；脑组织中TNF-α、IL-1β、IL-6、NO含量均显著增加，IL-10含量显著降低，iNOS、COX-2、Myd88、PKC蛋白相对表达量...     

MYR通过NF-κκB信号通路改善LPS诱导小鼠纹状体炎症反应

目的研究MYR对LPS诱导小鼠纹状体内神经炎症的作用及机制。方法雄性BALB/c小鼠随机分为正常对照组、LPS模型组、MYR 20和50 mg·kg~(-1)给药组。连续给予MYR 7 d,于末次给药后,模型组和给药组小鼠采用腹腔注射LPS5 mg·kg~(-1)诱导小鼠急性神经炎症的发生,LPS注射6 h后,ELISA法检测小鼠纹状体中IL-1β,IL-6,TNF-α,MCP-1以及ICAM-1等炎症因子的变化;Western印迹法检测小鼠纹状体中NF-κB信号通路相关蛋白的表达变化。结果与正常对照组比较,LPS诱导组小鼠纹状体中炎症因子IL-1β,IL-6,TNF-α,MCP-1以及ICAM-1显著增加(所有P<0.01),NF-κB信号通路相关蛋白表达显著增加。而给予MYR 20和50 mg·kg~(-1)可显著抑制LPS诱导的小鼠纹状体炎症因子的释放,抑制NF-κB,IκB蛋白的磷酸化,抑制胞浆内NF-κB的核转位。结论 MYR可有效抑制LPS诱导的神经炎症,保护小鼠纹状体中多巴胺神经元,其抗炎保护作用与抑制NF-κB信号通路密切相关。     

姜黄素衍生物体外抗炎及防治小鼠脓毒症的研究

目的探讨姜黄素衍生物FM0901体外抗炎作用,及其对大肠埃希菌引起的细菌脓毒症小鼠的保护作用。方法①用脂多糖（LPS）刺激RAW264.7细胞,ELISA法测定FM0901对细胞分泌TNF-α、IL-6水平的变化硝酸还原酶法测定NO的变化;②小鼠尾静脉注射大肠杆菌建立脓毒血症模型,考察FM0901对小鼠血清中TNF-α、IL-6及NO的影响,观察小鼠的活动状态及生存率。结果①FM0901显著抑制LPS诱导RAW264.7细胞的TNF-α、IL-6和NO释放,并具有明显的量效关系;②FM0901降低脓毒血症小鼠血清中TNF-α、IL-6和NO的含量,改善小鼠的状态,低剂量组提高大肠埃希菌感染小鼠的生存率。结论FM0901抑制RAW264.7细胞炎症介质释放,减轻脓毒症小鼠的炎症反应,提高其生存率。     

银星养脑片对血管性痴呆模型大鼠的记忆改善作用及机制研究

目的 初步探讨银星养脑片治疗血管性痴呆的药效及可能机制。方法 构建双侧颈动脉结扎的血管性痴呆大鼠模型,术后14d分别给予银星养脑片0.07,0.135,0.27 g·kg^-1及吡拉西坦片0.4 g·kg^-1,持续灌胃14d后进行水迷宫行为学测试,随后收集血清及动物脑组织,检测血清中炎症因子TNF-α、IL-1β含量,对脑组织进行HE染色及尼氏染色观察海马区病理结构变化。使用BV2细胞构建LPS刺激模型,给予银星养脑片0.5,1,2 mg·kg^-1不同剂量后检测细胞上清炎症相关因子NO、IL-6、TNF-α的释放量,收集细胞蛋白检测iNOS、NF-κB p65、p-NF-κB p65、IκB-α、p-IκB-α、NLRP3、caspase-1炎症相关蛋白表达变化,免疫荧光检测细胞iNOS、NLRP3的表达情况。结果 水迷宫结果提示血管性痴呆大鼠出现明显的记忆损伤,而银星养脑片给药组能有效改善记忆损伤情况,且还能降低血管性痴呆大鼠血清炎症水平;在BV2细胞上给予银星养脑片的干预能减少LPS刺激后的炎症因子释放,抑制NF-κB...     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.