Smac/DIABLO对胰腺癌SW1990细胞凋亡及化疗敏感性的影响

目的研究Smac/DIABLO与胰腺癌对TRAIL和吉西他滨化疗敏感性的关系。方法构建Flagpc3.1-Smac外源表达质粒,在SW1990细胞中过表达SMAC,采用实时定量荧光PCR方法检测Smac mRNA水平;应用Western免疫印迹法检测caspase-3、caspase-9和Bcl-2蛋白水平;利用MTT法检测转染Flag-pc3.1-Smac和TRAIL、吉西他滨处理后SW1990细胞增殖能力的改变;利用流式细胞术检测转染Flag-pc3.1-Smac后SW1990细胞的凋亡情况。结果转染Flag-pc3.1-Smac后,SW1990细胞中Smac mRNA和蛋白质表达水平显著高于对照组;MTT试验显示,过表达Flag-pc3.1-Smac的SW1990细胞在1~5 d的培养期中490 nm处吸光值均低于对照组。结论 Smac/DIABLO促进胰腺癌SW1990细胞凋亡,并增加对TRAIL和吉西他滨的化疗敏感性。     

槲皮素通过Bim-Bak/Bax途径提高顺铂耐药膀胱癌细胞对顺铂敏感性的研究

目的 探讨槲皮素能否逆转膀胱癌细胞对顺铂的耐药性并研究其机制。方法 MTT法检测顺铂耐药T24膀胱癌细胞在顺铂和槲皮素处理下的细胞活力。流式细胞实验检测顺铂耐药T24膀胱癌细胞在顺铂和槲皮素处理下的细胞凋亡。Western blot试验检测顺铂耐药T24膀胱癌细胞在顺铂和槲皮素处理下Bim、活化caspase-9、活化caspase-3的表达水平以及细胞色素c、Smac/DIABLO的释放。免疫共沉淀实验检测顺铂耐药T24膀胱癌细胞在顺铂和槲皮素处理下Bim蛋白与Bak、Bax蛋白的相互作用。结果 相比于常规T24细胞,顺铂耐药T24细胞对顺铂的敏感性显著下降。MTT和流式细胞实验结果表明槲皮素能显著促进顺铂对耐药T24细胞的杀伤活性和凋亡诱导活性。免疫共沉淀和Western blot试验结果表明槲皮素能显著上调顺铂耐药T24细胞中Bim蛋白的表达,从而通过与Bak、Bax蛋白的相互作用促进顺铂对肿瘤细胞线粒体膜孔道的开放,诱导细胞色素c和Smac/DIABLO从线粒体中释放到细胞质中,最终引起caspase-9和caspase-3的活化。结论 槲皮素通过Bim-Bak/Bax途径提高顺铂耐药膀胱癌细胞对顺铂的敏感性。     

miR-489协同卡铂通过抑制XIAP的表达发挥抗乳腺癌作用

目的 研究miR-489对卡铂的协同抗乳腺癌效应及机制。方法 MTT细胞活力试验检测卡铂和miR-489对T-47D细胞的杀伤活性。生物信息学、western blot试验及荧光素酶报告基因试验验证X连锁凋亡抑制蛋白（X-linked inhibitor of apoptosis protein,XIAP）是否为miR-489的靶点。分离去除T-47D细胞中的线粒体,western blot试验检测miR-489、卡铂及XIAP质粒处理后T-47D细胞Smac/DIABLO的释放和caspase-9及caspase-3的活化。免疫共沉淀试验检测XIAP与Smac/DIABLO的相互作用。流式细胞术检测T-47D细胞的凋亡情况。结果 miR-489处理能显著增强卡铂对T-47D细胞的杀伤活性。XIAP是miR-489的靶点。miR-489不影响卡铂依赖的线粒体中Smac/DIABLO的释放,但能通过下调XIAP的表达减弱XIAP与Smac/DIABLO的相互作用。另外,转染XIAP质粒能显著抑制miR-489对卡铂的协同抗乳腺癌效应,XIAP质粒能显著抑制miR-489联合卡铂对T-47D细胞凋亡的诱导。XIAP质粒能显著抑制miR-489联合卡铂对T-47D细胞caspase-9及caspase-3的活化。结论 miR-489抑制XIAP的表达发挥对卡铂的协同抗乳腺癌作用。     

青蒿琥酯对人白血病K562，K562 /ADM细胞凋亡的作用及对NF-κB p65表达的影响

摘 要 目的:观察青蒿琥酯对人白血病K562、K562 /ADM细胞凋亡以及对p65表达的影响。方法: 采用流式细胞仪检测青蒿琥酯在不同浓度和不同时间段对K562、K562 /ADM细胞凋亡的影响,采用Western blot法检测15 μmol·L^-1青蒿琥酯在不同时间对K562细胞NF-κB p65表达的影响。结果 青蒿琥酯对K562细胞凋亡影响不明显,但对阿霉素耐药K562 /ADM细胞影响较大,青蒿琥浓度为7.5 μmol·L^-1和15 μmol·L^-1时,K562 /ADM细胞的调亡率明显高于K562细胞（P<0.01）,15 μmol·L^-1青蒿琥酯作用后4 h后,K562 /ADM细胞的调亡率明显增加（P<0.01）;经15 μmol·L^-1青蒿琥酯作用后, p65表达随时间的增加而明显降低（P<0.01）。结论 青蒿琥酯通过下调P65的表达而诱导白血病细胞凋亡。     

青蒿琥酯对人结肠腺癌细胞的放射增敏作用

目的 研究青蒿琥酯对人结肠腺癌SW480细胞的放射增敏作用。方法 用MTT法测定青蒿琥酯的半数抑制浓度(IC₅₀)。将SW480细胞分为4组：对照组、药物组(给予20% IC₅₀的青蒿琥酯)、照射组(给予6 MV 4 Gy X射线照射)、联合组(经20% IC₅₀浓度的青蒿琥酯培养8 h后,给予6 MV 4 Gy X射线照射)。MTT法测定4组细胞增殖抑制率。再测定细胞集落形成情况,计算细胞集落形成率(PE),细胞存活分数(SF)。根据多靶单击公式,计算平均致死剂量、外推值、2 Gy时的细胞存活分数和放射增敏比。用流式细胞仪测定各组细胞的凋亡率。结果 青蒿琥酯的IC50为20.87 μg·mL^-1。与对照组相比,3个实验组的细胞增殖抑制率和凋亡率有显著差异(P<0.05),而与其他3组相比,联合组的细胞增殖抑制率和凋亡率有显著差异(P<0.05)。放射增敏比为1.38。结论 青蒿琥酯对人结肠癌腺癌SW480细胞有一定的放射增敏作用,机制可能与促进凋亡有关。     

YM-155协同顺铂杀伤非小细胞肺癌细胞的机制研究

目的 探讨survivin小分子抑制剂YM-155对非小细胞肺癌顺铂化疗的协同治疗作用并研究其机制。方法 MTT法检测YM-155和顺铂对非小细胞肺癌细胞系A549的杀伤活性。Western blot试验检测A549细胞中survivin、细胞色素C、凋亡诱导因子、caspase-9和caspase-3的表达水平。流式细胞术检测A549细胞的线粒体膜电位和凋亡率。结果 YM-155能增强顺铂的抗肺癌活性,显著降低顺铂对A549细胞的半抑制浓度（IC₅₀）。YM-155处理能显著抑制A549细胞中survivin的表达。顺铂+YM-155组A549细胞的线粒体膜电位明显低于顺铂单治疗组。顺铂+YM-155组A549细胞的凋亡率,细胞色素C、凋亡诱导因子释放水平以及caspase-9、caspase-3活化水平均明显高于顺铂单治疗组。顺铂+YM-155+survivin质粒组A549细胞的相对细胞活力和线粒体膜电位明显高于顺铂+YM-155组。顺铂+YM-155+survivin质粒组A549细胞的凋亡率、细胞色素C、凋亡诱导因子释放水平以及caspase-9、caspase-3活化水平均明显低于顺铂+YM-155组。结论 YM-155通过抑制survivin的表达能够增强顺铂对非小细胞肺癌细胞线粒体途径凋亡的诱导活性。     

基于caspase-3/bcl-2/bax信号通路的槐定碱诱导胰腺癌细胞株capan-1凋亡机制研究

目的 探讨槐定碱对人胰腺癌细胞株capan-1作用及机制。方法 MTT法检测细胞增殖;Hoechst33342染色法观察细胞凋亡;流式检测细胞凋亡和细胞周期百分率;Western blot法检测caspase-3/bcl-2/bax表达。结果 槐定碱可以成浓度依赖性诱导capan-1细胞增殖抑制和凋亡,增加S/G2期细胞比例,下调bcl-2和pro-caspase-3表达水平,上调bax蛋白的表达。结论 槐定碱能通过调节caspase-3/bcl-2/bax信号通路而诱导细胞凋亡。     

芍药苷对醋酸铅诱导海马神经元凋亡及Bcl-2/Bax蛋白表达的影响

目的 探讨芍药苷(paeoniflorin,PF)对醋酸铅诱导海马神经元凋亡及Bcl-2/Bax蛋白表达的影响。方法 分离培养胎鼠海马神经元细胞,细胞免疫荧光染色鉴定纯度。MTT测定海马神经元细胞活力以确定醋酸铅最适造模浓度及时间,同时筛选合适剂量PF干预海马神经元凋亡。依据MTT测定结果,分为空白组、模型组和20,40,80 μmol·L^-1 PF组干预海马神经元细胞,作用24 h后,加醋酸铅染毒,检测细胞色素C (cytochrome C,Cyt-C)含量、线粒体膜电位及细胞内Ca²⁺浓度。流式细胞仪检测细胞凋亡情况,Western blotting测定海马神经元细胞中caspase-3、cleaved-caspase-3、caspase-8、cleaved-caspase-8、caspase-9、cleaved-caspase-9、Bax、Bcl-2蛋白表达水平。结果 细胞免疫荧光染色鉴定结果显示分离培养的细胞为海马神经元细胞,且纯度较高。MTT测定结果显示醋酸铅最适造模浓度及时间为25 μmol·L^-1染毒24 h;PF剂量为20,40,80 μmol·L-1可显著改善海马神经元细胞活性,呈剂量依赖性。与空白组相比,模型组Cyt-C含量、凋亡率、细胞内Ca²⁺浓度显著升高(P<0.01),线粒体膜电位显著降低(P<0.01)。与模型组相比,40 μmol·L^-1 PF组和80 μmol·L^-1 PF组可降低Cyt-C含量、凋亡率、细胞内Ca²⁺浓度(P<0.05或P<0.01),升高线粒体膜电位(P<0.01),20 μmol·L^-1PF组可显著升高线粒体膜电位(P<0.05)。此外,一定剂量的PF可下调cleaved-caspase-3、cleaved-caspase-8、cleaved-caspase-9、Bax蛋白表达,上调Bcl-2蛋白表达。结论 PF可抑制醋酸铅诱导的海马神经元凋亡,可通过调控Bcl-2/Bax蛋白表达发挥神经保护作用。     

新型小分子激酶抑制剂Ibr-7对人胰腺癌Capan-2细胞的抑制作用及机制研究

目的:观察新型小分子激酶抑制剂Ibr-7[依鲁替尼(Ibr)衍生物]对人胰腺癌Capan-2细胞的抑制作用及其可能机制。方法:以Capan-2细胞为对象,采用CCK-8法检测1、2、4、8μmol/L Ibr、Ibr-7作用48 h后的细胞增殖情况,计算细胞存活率;同法检测1μmol/L Ibr、Ibr-7对不同剂量吉西他滨/紫杉醇(均分别为0.062 5、0.125、0.25、0.5、1μmol/L)的增敏作用。采用克隆形成试验检测1、2、4μmol/L Ibr、Ibr-7作用48 h后的细胞克隆形成情况,并记录细胞集落形成数量。采用流式细胞术或JC-1法检测2、4、8μmol/L Ibr-7作用24或16 h后细胞凋亡情况和线粒体膜电位变化情况,并计算总凋亡率及细胞线粒体膜电位下降比例。采用Westernblotting法检测细胞中相关凋亡蛋白[多聚二磷酸腺苷核糖聚合酶(PARP)、Noxa、Bcl-2、Bax、髓样细胞白血病1(Mcl-1)、B淋巴细胞瘤x L(Bcl-xL)]的表达情况。结果:1、2、4、8μmol/L Ibr、Ibr-7作用48 h后,细胞的存活率均显著下降,各剂量Ibr-7组均显著低于同剂量Ibr组,且Ibr-7的半数抑制浓度显著低于Ibr(P<0.05或P<0.01)。联用Ibr、Ibr-7后,细胞的存活率均显著低于同剂量吉西他滨/紫杉醇单用组,且Ibr-7联用组显著低于同剂量Ibr联用组(P<0.05或P<0.01)。经2、4μmol/L Ibr以及1、2、4μmol/L Ibr-7作用48 h后,细胞集落形成数量均显著减少,且各剂量Ibr-7组均显著低于同剂量Ibr组(P<0.01)。经不同剂量Ibr-7作用24或16h后,Capan-2细胞的总凋亡率(2、4、8μmol/L组)、细胞线粒体膜电位下降比例(8μmol/L组)以及Noxa(2、4、8μmol/L组)、Bax(8μmol/L组)蛋白的相对表达量均显著上升,PARP(8μmol/L组)、Bcl-2(4μmol/L组)、Mcl-1(2、4、8μmol/L组)蛋白的相对表达量均显著下降,且8μmol/L Ibr-7组上述指标(PARP、Bcl-2相对表达量除外)均显著优于同剂量Ibr组(P<0.05或P<0.01)。而各组细胞Bcl-xL蛋白的相对表达量差异均无统计学意义(P>0.05)。结论:与Ibr相比,Ibr-7对人胰腺癌Capan-2细胞具有更强的体外增殖抑制作用和促凋亡作用,且具有更强的化疗药物增敏活性;其作用机制可能与降低细胞线粒体膜电位,下调细胞中PARP、Bcl-2、Mcl-1蛋白的表达,上调Noxa、Bax蛋白的表达有关。     

青蒿琥酯和熊果酸降血脂作用的最佳配比筛选

目的 观察青蒿琥酯和熊果酸不同剂量和配伍对大鼠脂质代谢紊乱模型的影响,寻找青蒿琥酯和熊果酸配伍应用的最佳配比。方法 利用喂养高脂饲料诱导大鼠形成脂质代谢紊乱模型,通过比较各给药组大鼠的血脂水平筛选最佳配比。结果 实验结果显示,青蒿琥酯(高剂量)+熊果酸(高剂量)均有显著降低TG、CHO、LDL-C作用,可明显升高HDL-C,对H/L值也有一定的升高作用。综合降脂效果优于阳性药非诺贝特,也优于单用同等剂量的青蒿琥酯或熊果酸。各受试样品对大鼠肝功能没有显著影响(P>0.05,与正常组比较)。结论 青蒿琥酯和熊果酸1:1配比降脂效果最佳,建议剂量为(50+50) mg/kg。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.     

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.