沉默Prohibitin基因对人结直肠癌细胞株HCT116增殖和凋亡的影响

目的 siRNA介导抗增殖蛋白Prohibitin (PHB)基因沉默对人结直肠癌细胞株HCT116增殖和凋亡的影响.方法 通过脂质体LipofectamineTM 2000在HCT116细胞中转染PHB-siRNA,以Western blot来筛选siRNA片段.设立阴性对照NC组和高效沉默PHB138,PHB539 siRNA片段为实验组,重新转染HCT116,通过平板克隆形成实验、CCK-8检测细胞增殖能力;Annexin Ⅴ-FITC细胞凋亡试剂流式细胞术、Caspase-3/ Caspase-9活性检测等方法检测细胞凋亡;Annexin Ⅴ-FITC和Hoechst染色荧光显微镜观察.结果 Western blot结果显示siRNA片段PHB138、PHB539能明显抑制PHB蛋白表达;转染后HCT 116平板克隆形成率分别PHB138 (31.1±4.0)％、PHB539 (12.4±1.2)％、NC (43.4±2.1)％,差异有统计学意义(P＜0.001);CCK8实验发现转染后1～5 d,实验组与对照组比较,细胞增殖未收到显著影响(P＞0.05).在转染第7天,PHB539 siRNA能显著抑制细胞增殖(P＜0.01);Caspase-3活性度为PHB138 (1.50±0.39)、PHB539 (1.81±0.41),Caspase-9活性度PHB138(2.02±0.43)、PHB539 (2.81±0.51),差异有统计学意义(P＜0.05);Annexin Ⅴ-FITC和Hoechst染色均在荧光显微镜下观测有明显的凋亡现象,且凋亡比例和强度比阴性对照强.结论 靶向PHB-siRNA干扰可以有效地沉默结直肠癌细胞HCT116 PHB基因,下调PHB蛋白水平,从而抑制结直肠癌细胞HCT116增殖、促进凋亡.     

上调NDRG1表达降低奥沙利铂耐药结肠癌细胞的存活率

目的观察上调NDRG1表达对结肠癌细胞及奥沙利铂耐药结肠癌细胞的毒性作用并探讨其机制。方法以重组真核表达质粒pEGFP-NDRG1-N3转染HCT 116及奥沙利铂耐药的OHP-HCT 116结肠癌细胞,以实时定量(qRT)-PCR法和Western blot法检测转染效率。MTT法检测奥沙利铂对不同结肠癌细胞的毒性及验证OHP-HCT 116细胞的耐药性。给予奥沙利铂干预转染pEGFP-NDRG1-N3的HCT 116细胞及OHP-HCT 116细胞,MTT法检测细胞存活率,流式细胞术检测细胞凋亡率,Western blot法检测凋亡蛋白Bcl-2及p53蛋白水平变化。结果不同浓度奥沙利铂干预下的3株结肠癌细胞中HCT 116细胞对奥沙利铂最敏感,OHP-HCT 116细胞对奥沙利铂耐药得到验证。以不同浓度梯度奥沙利铂干扰转染pEGFP-NDRG1-N3的HCT 116细胞及OHP-HCT 116细胞,与MOCK及siNC组比较,在HCT 116细胞及OHP-HCT 116细胞,转染pEGFP-NDRG1-N3细胞的存活率下降(P<0.05),凋亡率升高(P<0.05),Bcl-2表达降低(P<0.05),p53表达升高(P<0.05)。结论上调NDRG1表达通过调控p53表达改善结肠癌细胞奥沙利铂耐药,提高化疗敏感性。     

shRNA沉默STAT3基因对结肠癌细胞增殖及顺铂敏感性的影响

目的 构建携带信号转导与转录激活子3（STAT3）基因的短发夹RNA（shRNA）真核表达载体,观察pGPU6/GFP/Neo- STAT3重组质粒对HCT116细胞顺铂化疗敏感性的影响。方法 设计并构建稳定转录shRNA STAT3的质粒,采用脂质体法转染结肠癌HCT116细胞,Western blot法检测转染后STAT3蛋白表达变化,MTT法检测细胞增殖变化。重组质粒联合顺铂作用于HCT116细胞后,MTT法检测细胞存活率。结果 成功构建了pGPU6/GFP/Neo-STAT3重组质粒,测序证实重组质粒构建正确。重组质粒转染HCT116细胞后,细胞增殖明显受抑制,STAT3蛋白表达降低。重组质粒联合顺铂治疗后,细胞增殖活性显著降低。结论 shRNA STAT3重组质粒能明显降低HCT116细胞中STAT3蛋白的表达,抑制细胞增殖,提高结肠癌细胞对顺铂的敏感性。     

cyclin G2荧光蛋白重组质粒的构建及其对宫颈癌HeLa细胞的作用

目的 构建包含人cyclin G2基因的荧光蛋白重组质粒,探讨cyclin G2对宫颈癌HeLa细胞凋亡的影响.方法 运用RT-PCR和基因克隆技术构建pDsRed2-Cyclin G2重组质拉;脂质体法转染重组质粒至HeLa细胞中,荧光显微镜下观察其蛋白的表达和定位;流式细胞术检测HeLa细胞的凋亡率.结果 成功地构...     

和厚朴酚抑制结肠癌细胞增殖与骨形态发生蛋白7关系的研究北大核心CSCD

目的研究和厚朴酚(honokial,HNK)对人源结肠癌细胞HCT116增殖的影响及其可能分子机制。方法采用结晶紫染色、流式细胞术检测和厚朴酚对HCT116细胞增殖和细胞周期的影响;Western blot分析和厚朴酚对增殖细胞核抗原(PCNA)及细胞凋亡指标Bcl-2的影响;Western blot及半定量PCR分析和厚朴酚对HCT116细胞中内源性骨形态蛋白7(BMP7)表达的影响;利用BMP7过表达腺病毒及抗体,通过结晶紫定量和Western blot,分析和厚朴酚联合应用BMP7腺病毒与抗体对HCT116细胞增殖的影响。结果和厚朴酚呈浓度和时间依赖性地抑制HCT116细胞增殖、诱导细胞凋亡、使细胞阻滞于G_2期,并上调PCNA的蛋白表达水平,下调Bcl-2的蛋白表达水平;和厚朴酚可上调HCT116细胞中BMP7的mRNA及蛋白表达水平;外源性BMP7过表达腺病毒可促进和厚朴酚的增殖抑制和促凋亡作用,而BMP7抗体可抑制此作用。结论和厚朴酚能够抑制HCT116的增殖并促进凋亡,其机制可能与上调BMP7的表达有关。     

白藜芦醇抑制HCT116结肠癌细胞增殖与Wnt/β-catenin的关系研究

目的研究白藜芦醇(resveratrol,Res)对人结肠癌细胞增殖的抑制作用及可能的分子机制。方法采用结晶紫染色和Western blot分析Res对HCT116细胞增殖的抑制作用;应用流式细胞术和Western blot分析Res对HCT116细胞凋亡的促进作用;利用TCF4/LEF萤光素酶报告质粒检测Res对Wnt/β-catenin信号转导的影响。采用Western blot和PCR分析Res对HCT116细胞内β-catenin表达水平的影响。结果与对照组相比,Res能抑制HCT116细胞增殖,下调PCNA蛋白水平;流式细胞术和Western blot检测结果均显示,Res能明显促进HCT116细胞凋亡;报告质粒分析结果显示,Res呈浓度依赖性降低TCF4/LEF报告质粒萤光素酶活性(Res为20μmol·L-1时,P<0.05;Res为40或80μmol·L-1时,P<0.01);Western blot和PCR分析结果显示,Res不仅明显降低HCT116细胞中β-catenin的蛋白水平,同时也下调β-catenin mRNA的表达水平。结论Res能抑制HCT116细胞增殖并促进凋亡,其机制可能至少与Res下调β-catenin mRNA表达,抑制Wnt/β-catenin信号转导有关。     

小檗碱抑制HCT116细胞生长与Wnt/β-catenin信号的关系研究

目的研究小檗碱对结肠癌细胞的增殖抑制作用与Wnt/β-catenin信号的关系。方法结晶紫染色法检测小檗碱对HCT116细胞增殖的抑制作用,采用流式分析及West-ern blot研究小檗碱诱导HCT116细胞凋亡;Western blot检测β-catenin蛋白表达、RT-PCR法检测β-catenin mRNA表达,确定小檗碱对其表达的影响;采用外源性过表达β-cate-nin研究小檗碱抑制HCT116细胞增殖与β-catenin的关系。结果小檗碱处理组细胞较对照组细胞增殖明显受到抑制,并诱导HCT116细胞凋亡。小檗碱处理组全细胞、胞质及核内β-catenin蛋白水平均明显较对照组低。外源性过表达β-catenin能减弱小檗碱对HCT116细胞增殖的抑制作用。小檗碱处理组β-catenin mRNA表达明显受到抑制。结论小檗碱能抑制HCT116细胞增殖并抑制Wnt/β-catenin信号转导,其机制可能与下调β-catenin mRNA表达有关。     

环阿尔廷烷型四环三萜化合物对HCT116细胞增殖、细胞周期和凋亡的影响

目的探讨升麻中分离的环阿尔廷烷型四环三萜化合物(KY17)对人结肠癌HCT116(p53WT)细胞增殖、凋亡、细胞周期的影响。方法MTT法测定KY17对小鼠胚胎成纤维细胞(MEF)和HCT116细胞株增殖的影响;检测KY17对HCT116细胞周期的影响;荧光显微镜、流式细胞仪分析细胞凋亡情况;Western blot法检测KY17对细胞凋亡蛋白PARP表达的影响;q PCR法检测miRNA-34a的表达情况。结果KY17处理MEF细胞的IC₅₀值为27.28μmol·L^-1。KY17处理HCT116细胞的IC₅₀值为9.31μmol·L^-1,细胞周期阻滞在G_2/M期,且凋亡蛋白PARP有切割;同时,miRNA-34a上调,p53蛋白表达量增加。结论KY17对HCT116细胞的增殖具有抑制作用,使细胞周期停滞于G_2/M期,最终诱导肿瘤细胞的凋亡,其作用机制与miRNA-34a上调、p53基因激活有关。     

TGF-β3与熊果酸抑制人结肠癌细胞增殖作用的研究

目的研究TGF-β3与熊果酸(ursolic acid,UA)抑制结肠癌细胞增殖作用的关系及可能的分子机制。方法采用结晶紫染色法和流式细胞术分析不同浓度UA对HCT116细胞增殖的作用。利用Western blot和流式细胞术等方法分析UA对HCT116细胞凋亡的影响。通过RT-PCR和(或)Western blot实验分析UA在HCT116细胞中对TGF-β3、Smad2/3和β-catenin表达及磷酸化水平的影响。采用TGF-β3重组腺病毒和特异性抑制剂以及萤光素酶报告质粒分析TGF-β3介导UA抑制结肠癌细胞增殖的可能分子机制。结果UA能明显抑制HCT116细胞增殖,诱导G1期阻滞,并促进其凋亡。UA能明显降低TGF-β3的mRNA和蛋白表达水平;UA对Smad2/3的总蛋白水平无明显影响,但能明显降低Smad2/3的磷酸化水平;外源性过表达TGF-β3可部分逆转UA对HCT116细胞增殖的抑制作用,TGF-β3特异性抑制剂则增强UA对HCT116细胞增殖的抑制作用;UA降低β-catenin蛋白水平,并明显抑制Wnt/β-catenin信号转导;外源性过表达TGF-β3促进β-catenin蛋白表达,并部分逆转UA对β-catenin蛋白表达的抑制效应;TGF-β3特异性抑制剂增强UA对β-catenin蛋白表达的抑制作用。结论 UA能抑制结肠癌细胞HCT116增殖并诱导凋亡,其作用可能是通过下调TGF-β3表达,进而抑制Wnt/β-catenin信号转导。     

靶向FAK基因RNAi联合吉西他滨抗非小细胞肺癌的作用

目的探讨通过RNAi下调非小细胞肺癌局部粘着斑激酶(FAK)的活性后对吉西他滨药理的影响。方法靶向FAK的shRNA重组质粒转染并下调细胞FAK蛋白表达,用Western Blot检测转染细胞中FAK的下调;利用MTT检测吉西他滨在不同浓度下对转染细胞增殖的影响;用流式细胞术、PI荧光染色检测吉西他滨作用下转染细胞的凋亡;Caspase与Akt活性分别用Apo-ONETM均质Caspase-3/7检测系统、Western blot检测。结果在吉西他滨不参与的情况下,FAK RNAi不能影响细胞的增殖和凋亡,但FAK RNAi明显增加了吉西他滨对肿瘤细胞的灵敏度,Akt活性的下调与这一现象有关。结论靶向FAK的shRNA重组质粒下调细胞FAK蛋白表达能够增加吉西他滨对非小细胞肺癌的细胞毒性。     

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.     

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.