二烯丙基二硫诱导人胃癌细胞G_2/M期阻滞中p-CDK1、cyclin B1和p21~(WAF1)蛋白的表达

二烯丙基二硫(diallyl disulfide, DADS)是大蒜中提取的一种低分子量的脂溶性成分,也是大蒜中的主要有效成分,对结肠癌、乳腺癌、肝癌、肺癌、膀胱癌、前列腺癌和白血病等多种肿瘤均有明显的抑制作用.本实验室以前研究表明[1],DADS对人类白血病细胞HL60有诱导分化作用,对体外[2]和体内[3]的人胃癌MGC803细胞均有生长抑制作用、G2/M期阻滞作用.对体内的人胃癌细胞有诱导分化作用[3],对体外的人胃癌细胞有诱导凋亡作用[4].     

二烯丙基二硫对人胃癌MGC803细胞G_2/M期检查点Chk1与Chk2的影响

目的研究二烯丙基二硫(diallyl disulfide,DADS)对人胃癌MGC803细胞G2/M期检查点Chk1与Chk2的影响。方法流式细胞术检测细胞周期改变;Northern blot、Westernblot与免疫细胞化学检测DADS处理MGC803细胞的Chk1与Chk2表达。结果流式细胞术分析显示,30 mg.L-1DADS呈时间依赖性阻滞MGC803细胞在G2/M期(P<0.05);Northern blot检测表明,DADS不同时间作用MGC803细胞后,Chk1与Chk2 mRNA表达与未处理组差异无显著性(P>0.05);免疫细胞化学发现Chk1与Chk2表达与未处理组无明显改变(P>0.05);Western blot DADS在不同时间对MGC803细胞Chk1与Chk2总蛋白表达无改变(P>0.05),而磷酸化的Chk1表达呈时间依赖性增加(P<0.05),但磷酸化的Chk2无明显改变(P>0.05)。结论 DADS阻滞MGC803细胞G2/M期与磷酸化Chk1有关。     

二烯丙基二硫对人胃癌MGC803细胞Rac1-Pak1/Rock1通路的影响

目的研究二烯丙基二硫(diallyl disulfide,DADS)对人胃癌MGC803细胞Rac1-Pak1/Rock1通路分子的影响。方法 30 mg·L-1DADS分别处理MGC803细胞不同时间后,采用RT-PCR、Western blot分别检测Rac1、Pak1、Rock1、cofilin1和destrin的mRNA和蛋白水平。结果 DADS可下调MGC803细胞Rac1、Pak1和Rock1 mRNA和蛋白水平(P<0.05),对cofilin1和destrin的表达无影响,但可抑制cofilin1磷酸化(P<0.01)。结论 DADS可下调Rac1、Pak1和Rock1表达和磷酸化cofilin1;DADS抑制Rac1-Pak1/Rock1通路可能与DADS抗人胃癌MGC803细胞迁移侵袭作用机制有关。     

DADS诱导人胃癌细胞周期阻滞相关基因的差异表达

目的研究二烯丙基二硫(diallyl disulfide,DADS)诱导人胃癌MGC803细胞G2/M周期阻滞相关基因表达的变化。方法MTT法、流式细胞术分别分析DADS对MGC803细胞的抑制作用与细胞周期分布的影响;功能基因芯片检测周期相关差异表达基因;Western blot、RT-PCR验证周期相关基因的表达。结果MTT法、流式细胞术证明DADS可明显抑制MGC803细胞增殖并诱导G2/M期阻滞。基因芯片结果显示,30 mg.L-1DADS作用MGC803细胞4 h后,表达上调的基因有CDC45L、CDK5R1、p21、CUL4A、GADD45α、RAD17、TP53,下调的基因是ANAPC5、ATR、BRCA1、CCNA2、CCNB2、CCNE1、CCNE2、CDC16、CDC6、CDK5RAP1、GTF2H1、MCM5、RAD9A、RGC32。RT-PCR显示30 mg.L-1DADS处理MGC803细胞4、8、12 h后,p21、GADD45α时间依赖性的表达增强(P<0.05),CyclinB1呈时间依赖性的表达降低(P<0.05)。TP53在4、8、12 h后与对照组比较表达明显增强(P<0.05)。Western blot结果表明,30 mg.L-1DADS作用MGC803细胞6、12、24 h后,p53、GADD45α、p21蛋白表达上调,CyclinB1蛋白表达下调(P<0.01)。结论DADS诱导人胃癌MGC803细胞G2/M周期阻滞是由多基因协同作用的结果,可能通过两种途径共同调节完成的。     

二烯丙基二硫上调miR-22通过Wnt-1通路抑制人胃癌细胞增殖与迁移侵袭

目的探讨二烯丙基二硫(diallyl disulfide,DADS)上调miR-22是否通过Wnt-1通路抑制人胃癌MGC803细胞增殖与迁移侵袭。方法 MTT、细胞划痕实验、侵袭实验分别检测DADS与miR-22对MGC803细胞增殖与迁移侵袭的影响。在线预测软件寻找miR-22调控的靶基因,荧光素酶报告基因检测miR-22对Wnt-1 3'UTR荧光酶活性的影响。qRT-PCR检测Wnt-1mRNA表达变化。Western blot检测Wnt-1、β-catenin与TCF-4蛋白表达。结果MTT显示,DADS与miR-22可明显抑制MGC803细胞增殖(P<0.05)。划痕实验显示,DADS与miR-22可明显抑制MGC803细胞迁移,而miR-22+DADS更为明显(P<0.05)。侵袭实验显示,miR-22可抑制人胃癌MGC803细胞侵袭,而miR-22+DADS更为明显(P<0.05)。在线预测软件寻找miR-22调控的靶基因显示,Wnt-1可能是miR-22的靶基因,荧光素报告基因检测证实Wnt-1是miR-22直接调控的靶基因;qRT-PCR显示,DADS与miR-22能下调Wnt-1 mRNA表达,而miR-22+DADS更为明显(P<0.05)。Western blot显示,DADS与miR-22能下调Wnt-1、β-catenin与TCF-4蛋白表达,而miR-22+DADS尤为明显(P<0.05)。结论 DADS可上调miR-22通过Wnt-1通路明显抑制MGC803细胞增殖与迁移侵袭。     

二烯丙基二硫下调LIMK1抑制人胃癌MGC803细胞迁移与侵袭

目的研究二烯丙基二硫(diallyl disulfide,DADS)对人胃癌MGC803细胞迁移侵袭及LIMK1表达的影响。方法MTT、划痕愈合和侵袭实验分别检测DADS对MGC803细胞增殖、迁移与侵袭能力的作用;RT-PCR、Western blot与免疫细胞化学检测LIMK1表达。结果 MTT显示,30 mg.L-1DADS作用MGC803细胞24、48、72、96 h后,增殖抑制率分别为31.8%、66.1%、83.6%、89.2%,呈明显的时间依赖关系(P<0.05)。划痕实验显示,10、20、30、40、50 mg.L-1DADS分别作用MGC803细胞,划痕愈合明显慢于对照组,呈剂量依赖关系(P<0.05)。侵袭实验显示,10、20、30、40、50 mg.L-1DADS作用MGC803细胞24 h后,穿过基质胶的细胞数分别为(35.8±3.74)、(34.1±2.02)、(31.7±4.81)、(17.2±3.08)、(13.2±3.36)个,较对照组(39.5±2.99)个数明显减少,呈剂量依赖性(P<0.05)。RT-PCR显示,30 mg.L-1DADS与MGC803细胞作用48 h后,LIMIK1mRNA明显下调(P<0.05)。Western blot与免疫细胞化学检测显示,30 mg.L-1DADS作用MGC803细胞6、12、24、48h后,LIMK1蛋白的表达水平呈时间依赖性下降(P<0.05)。结论 DADS可抑制人胃癌MGC803细胞迁移与侵袭能力,其机制可能与下调LIMK1有关。     

二烯丙基二硫诱导人胃癌MGC803细胞的差异microRNA表达

目的研究二烯丙基二硫(diallyl disulfide,DADS)诱导人胃癌MGC803细胞的差异miRNAs表达。方法采用miRNAs芯片与qRT-PCR检测DADS诱导人胃癌MGC803细胞的差异miRNAs表达。结果 microRNA芯片检测显示,30 mg·L~(-1)DADS处理24 h后,MGC803细胞的差异miRNAs表达中,miR-200b、miR-22、miR-7、miR-143、miR-138、miR-34a、miR-150等7个miRNA表达明显上调,miR-222、miR-21、miR-15b、miR-182、miR-18a等5个miRNA下调。q PCR证实,30 mg·L~(-1)DADS处理MGC803细胞后,miR-200b、miR-22、miR-7、miR-143、miR-138、miR-34a、miR-150等表达较未处理组明显上调(P <0. 05)。且q PCR检测显示,miR-200b与miR-22在MGC-803、BGC-823、MKN-28、SGC-7901、HGC-27等各种人胃癌细胞表达较正常人胃癌GES-1细胞明显下调(P <0. 05)。miR-200b与miR-22在胃癌组织中表达较正常胃组织明显下调(P <0. 05)。结论DADS诱导人胃癌MGC803细胞的差异miRNAs表达有7个miRNA明显上调,5个miRNA下调。miR-200b与miR-22在胃癌组织与细胞中表达下调。DADS可上调MGC803细胞miR-200b与miR-22表达。     

DADS对Chk1/2基因高表达人胃癌MGC803细胞G_2/M期的影响

目的在建立Chk1/2基因高表达人胃癌MGC803细胞基础上,探讨DADS对Chk1/2高表达MGC803细胞G_2/M期的作用。方法分别采用集落形成实验、流式细胞术、RTPCR、Western blot等方法,检测DADS对Chk1/2高表达MGC803细胞增殖、细胞周期分布、Chk1与Chk2 mRNA与蛋白、p-Chk1与p-Chk2及CDC25C与cyclinB1的表达。结果软琼脂集落形成实验显示,30 mg·L~(-1)DADS作用Chk1与Chk2高表达MGC803细胞组集落形成率均明显低于对照组与空载体组(P<0.05)。流式细胞术显示,30 mg·L~(-1)DADS作用12、24、36、48 h后,Chk1/MGC803细胞G_2/M期分别为41.3%、57.4%、68.9%、42.9%,较MGC803细胞与Chk2/MGC803细胞明显增加(P<0.05)。而Chk2/MGC803细胞与MGC803细胞差异没有显著性(P>0.05)。RT-PCR显示,Chk1/MGC803与Chk2/MGC803细胞Chk1与Chk2mRNA水平较对照组无明显变化;并且,Western blot显示,Chk1与Chk2总蛋白及p-Chk2的表达无明显改变,但pChk1呈时间依赖性上调,CDC25C与cyclinB1呈时间依赖性下调(P<0.05)。结论 DADS可阻滞Chk1/MGC803细胞于G_2/M期,与上调磷酸化Chk1和下调CDC25C与cyclinB1有关。     

二烯丙基二硫诱导人胃癌MGC803细胞凋亡及细胞周期阻滞的研究

目的　研究二烯丙基二硫 (diallyldisulfide ,DADS)诱导人胃癌MGC80 3细胞凋亡和对细胞周期的影响。方法　采用MTT法、丫啶橙染色、流式细胞仪等方法检测DADS对MGC80 3的增殖抑制 ,诱导凋亡以及细胞周期分布的影响。结果　MTT法显示 ,DADS对MGC80 3细胞有明显的抑制增殖作用 ,2 0、3 0、40mg·L- 1DADS作用MGC80 3细胞72h后 ,生长抑制率分别达 2 5 7%、58 6%、69% ;经 3 0mg·L- 1DADS作用MGC80 3细胞 48h后 ,用丫啶橙染色法观察到不同阶段的凋亡细胞形态学改变 ;流式细胞仪分析结果显示 ,DADS对MGC80 3细胞有明显的G2 /M期阻滞作用 ,3 0mg·L- 1DADS作用MGC80 3细胞 2 4h ,与对照组相比 ,可使G2 /M期细胞增加到 4倍多 ,且DADS呈时间依赖性诱导MGC80 3细胞凋亡 ,3 0mg·L- 1DADS作用MGC80 3细胞48h ,凋亡率从对照组的 3 5%升高到 3 9 5%。结论　DADS引起MGC80 3细胞G2 /M期阻滞并诱导凋亡可能是其抗肿瘤的机制之一     

DADS体内诱导人胃癌细胞分化作用中组蛋白乙酰化的变化

目的观察二烯丙基二硫(DADS)在体内诱导胃癌细胞分化的作用及对人胃癌细胞移植瘤组蛋白乙酰化的影响。方法裸鼠皮下注入人胃癌细胞MGC803建立人胃癌异种移植模型,采用光学显微镜观察移植瘤细胞形态变化,流式细胞光度术和W estern b lot分析DADS对MGC803细胞移植瘤细胞周期分布的影响及瘤组织中p21WAF1蛋白、组蛋白H3、H4乙酰化的表达情况。结果腹腔注射DADS剂量为100、200 mg.kg-1时对移植瘤有明显生长抑制作用;光学显微镜显示经DADS处理后瘤细胞密度及异型性明显减小。流式细胞仪分析结果显示DADS呈浓度依赖性将移植瘤细胞阻滞在G2/M期。DADS浓度为100 mg.kg-1和200 mg.kg-1作用瘤细胞后,与对照组相比分别可使G2/M期细胞增加2.22和3.37倍。W estern b lot分析表明在G2/M期阻滞同时有组蛋白H3乙酰化表达增加,但组蛋白H4乙酰化表达水平不受DADS作用的影响;瘤组织中的p21WAF1蛋白表达量也随DADS浓度升高而上升。结论DADS对胃癌细胞裸鼠移植瘤的生长有明显抑制和诱导分化作用,这种抑制可能与其阻滞移植瘤细胞周期、上调瘤细胞组蛋白乙酰化及p21WAF1蛋白水平有关。     

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.