异莲心碱对HepG2细胞周期和凋亡的影响

摘要：目的:研究异莲心碱对人肝癌Hep G2细胞周期与凋亡的影响。方法:采取流式细胞术检测不同浓度异莲心碱诱导Hep G2细胞24 h后对周期的影响; Hoechst33258染色观察异莲心碱诱导Hep G2细胞凋亡后细胞核形态的变化; JC-1染色检测细胞线粒体膜电位变化;蛋白免疫印记法(Western blot)检测Bax、Bcl-2蛋白的表达量。结果:流式结果显示,G0/G1期和G2/M期比例明显升高,而S期比例明显下降,并呈现剂量依赖性; Hoechst33258结果表明,药物诱导Hep G2细胞后,细胞数量减少,形态皱缩或改变,蓝色荧光加深; Western bolt检测可知,异莲心碱上调Bax蛋白并下调Bcl-2蛋白的表达水平。结论:异莲心碱可使Hep G2细胞阻滞于G0/G1期、G2/M期,诱导Hep G2细胞发生早期凋亡,其作用可能与Bax、Bcl-2两种凋亡蛋白表达水平变化相关。     

北美海篷子三萜皂苷bigelovii E抑制mTOR信号通路诱导乳腺癌MCF-7细胞凋亡

目的探究北美海篷子的bigelovii E诱导乳腺癌MCF-7细胞凋亡的作用机制。方法使用MTT和集落克隆实验检测bigelovii E对肿瘤细胞增殖的抑制作用;Hoechst33258荧光染色观察bigelovii E作用后细胞形态的改变;流式细胞仪分析bigelovii E对细胞凋亡、细胞线粒体膜电位、细胞ROS水平的影响;Western blot分析线粒体凋亡通路及其调控蛋白表达量的变化。结果 Bigelovii E对乳腺癌细胞MCF-7最敏感;bigelovii E对正常细胞HLF-1毒性较低;bigelovii E抑制乳腺癌MCF-7的集落形成;Hoechst 33258荧光染色检测到bigelovii E诱导的细胞凋亡形态;流式细胞仪检测到bigelovii E引起细胞凋亡和细胞线粒体膜电位下降,并使细胞内ROS水平升高;Western blot表明bigelovii E可通过抑制m TOR磷酸化水平,下调其下游靶点p70S6K、4-EBP的磷酸化水平,进而上调Bax,下调Bcl-xl、Mcl-1蛋白表达,促进线粒体凋亡通路,降低线粒体膜电位,诱发ROS,导致线粒体功能损伤,最终诱导细胞凋亡。结论 Bigelovii E通过m TOR通路调控线粒体凋亡通路,诱导细胞凋亡,具有良好的抗肿瘤效果。     

Salinomycin对乳腺癌阿霉素耐药细胞株MCF-7/DOX的增殖抑制作用及机制

目的本研究旨在探讨Salinomycin对乳腺癌阿霉素耐药细胞株MCF-7/DOX增殖和凋亡的影响及可能作用机制。方法 MTS实验检测Salinomycin对MCF-7/DOX细胞增殖的影响;Annexin V-FITC/PI染色检测Salinomycin对MCF-7/DOX耐药细胞凋亡的影响;DCFH-DA染色检测Salinomycin对MCF-7/DOX耐药细胞活性氧(reactive oxygen species,ROS)产生的影响;JC-1法测定细胞线粒体膜电位;Western blot法检测细胞凋亡相关蛋白BAX、BCL-2、caspase-3和caspase-9的表达变化。结果 Salinomycin能明显抑制MCF-7/DOX耐药细胞增殖,且具有浓度依赖性;流式分析发现Salinomycin能够诱导MCF-7/DOX细胞凋亡,增加细胞内ROS水平,降低细胞线粒体膜电位;与对照组相比较,Salinomycin处理明显抑制BCL-2的表达,上调BAX、cleaved caspase-3和cleaved caspase-9的蛋白表达;抗氧化剂N-acetylcysteine(NAC)则逆转上述作用。结论 Salinomycin能够诱导MCF-7/DOX细胞凋亡,其机制可能与Salinomycin诱导ROS的产生,激活线粒体凋亡途径有关。     

瓜子金皂苷丙对MPP~+诱导PC12细胞凋亡的抑制作用

目的观察瓜子金皂苷丙对MPP+诱导的PC12细胞凋亡的影响,并且探讨其作用机制。方法采用MTT法检测细胞存活率,碘化丙啶染色流式细胞术(FCM)检测PC12细胞凋亡,Western blotting检测Bax和Bcl-2蛋白的表达,罗丹明123染色FCM检测细胞线粒体膜电位(ΔΨm),荧光酶标仪检测细胞内活性氧(R0S)的含量。结果不同浓度MPP+作用PC12细胞24 h后,细胞存活率显著下降(P<0.01),细胞凋亡明显,凋亡相关蛋白Bcl-2/Bax比之下降,线粒体膜电位降低,细胞内ROS显著增加。与MPP+处理组相比,瓜子金皂苷丙10μmol·L-1组,细胞存活率显著升高(P<0.01);细胞凋亡率下降(P<0.01);Bcl-2/Bax比率增加(P<0.01),线粒体膜电位上升(P<0.01),ROS含量减少。结论瓜子金皂苷丙可以抑制MPP+诱导的PC12细胞凋亡,其作用机理可能与上调Bcl-2和下调Bax蛋白的表达,维持线粒体正常膜电位,稳定线粒体功能,清除R0S有关。     

抗氧化作用可能是人参皂甙Rg1抗细胞凋亡的机制

目的 :探讨人参皂甙Rg1对MPP+诱导SHSY5Y细胞凋亡的保护作用及其可能的机制。方法 :用吖啶橙溴化乙锭染色观察SHSY5Y细胞凋亡率 ,流式细胞仪检测线粒体跨膜电位及细胞内活性氧 (ROS)水平 ,WesternBlot法检测bcl 2、bax蛋白表达水平。结果 :经 10 μmol·L- 1Rg1预处理后 ,MPP+诱导的SHSY5Y细胞凋亡受到明显的抑制 ,虽然线粒体跨膜电位无明显改变 ,但细胞内ROS下降 ,而bcl 2蛋白表达水平增加 ,bax蛋白表达水平减少。结论 :Rg1可抑制MPP+诱导的SHSY5Y细胞凋亡 ,其作用机制可能是通过清除ROS、调节bcl 2、bax蛋白表达水平起作用。     

CAFs分泌的PDGFC通过PI3K-mTOR信号通路促进乳腺癌细胞对阿霉素耐药

目的 探讨肿瘤相关成纤维细胞(cancer-associated fibroblasts, CAFs)来源的血小板衍生生长因子C(platelet derived growth factor C,PDGFC)是否促进乳腺癌细胞对阿霉素(doxorubicin, DOX)耐药并探讨其机制。方法 原代提取CAFs和正常成纤维细胞(normal fibroblasts, NFs)并获取CAFs和NFs的条件培养基(conditional medium, CM),观察CAFs-CM是否影响乳腺癌细胞对DOX的敏感性;检测CAFs及其条件培养基中PDGFC的表达;Western blot检测乳腺癌细胞凋亡相关蛋白BAX/BCL2、耐药蛋白ABCG2、线粒体膜蛋白TOM20与COXⅣ及信号蛋白(p-)PI3K与(p-)mTOR的表达;DCFH-DA荧光染色、JC-1试剂盒分别检测乳腺癌细胞内ROS水平与线粒体膜电位。结果 CAFs-CM减少乳腺癌细胞中DOX的含量,诱导对DOX耐药,同时乳腺癌细胞中BAX减少,Bcl2增加,ROS减少,线粒体膜电位升高及线粒体膜蛋白TOM20与COXⅣ表达增加。进...     

6'-羟基爵床素A诱导人肝癌HepG2细胞凋亡及其机制

目的探讨6'-羟基爵床素A(JR6)对人肝癌Hep G2细胞凋亡的诱导作用及其机制。方法体外培养人肝癌Hep G2细胞,采用MTT法观察不同浓度的JR6和5-氟尿嘧啶(5-FU)对Hep G2细胞存活的作用,荧光显微镜观察Hoechst33258染色后细胞核形态改变,用流式细胞仪检测AnnexinⅤ-FITC/PI双染后Hep G2细胞的凋亡率,JC-1荧光染色观察药物对细胞线粒体膜电位的影响,Western蛋白质印迹法检测细胞凋亡相关蛋白细胞色素c、Bax和Bcl-2蛋白的表达。结果 JR6 6.1~196μmol·L-1和5-FU 3.4~192μmol·L-1分别作用Hep G2细胞48 h,对Hep G2细胞存活具有抑制作用,IC50分别为74.90和49.75μmol·L-1。JR6 12.3,49和196μmol·L-1作用Hep G2细胞48 h,细胞凋亡率明显增加,由正常对照组的(6.9±2.0)%增加至(13.8±2.0)%,(18.6±4.3)%和(32.4±3.2)%(P<0.05,P<0.01)。Hoechst33258染色结果显示,JR6 49和196μmol·L-1作用Hep G2细胞48 h,部分细胞出现细胞核固缩和染色质凝集等凋亡变化。线粒体膜电位检测结果发现,JR6 49和196μmol·L-1作用48 h能使Hep G2细胞线粒体膜电位水平明显降低(P<0.05,P<0.01)。线粒体凋亡相关蛋白的检测结果表明,JR6 12.3,49和196μmol·L-1作用Hep G2细胞48 h,胞浆细胞色素c表达增加,促凋亡蛋白Bax表达增加,抗凋亡蛋白Bcl-2表达降低,且Bax/Bcl-2比值增加(P<0.05,P<0.01)。JR6 49μmol·L-1和5-FU组上述蛋白表达无明显差异。结论 JR6可能通过促进细胞色素c释放、打破Bcl-2/Bax平衡诱导Hep G2细胞凋亡。     

碲化镉量子点对血管平滑肌细胞的损伤作用

目的观察碲化镉量子点(CdTe QD)在体外对大鼠血管平滑肌细胞(VSMC)的损伤作用。方法CdTe QD(0.01~100 mg·L~(-1))与原代培养的大鼠胸/腹主动脉平滑肌细胞共孵育24 h,MTT法检测CdTe QD对细胞存活的抑制;钙黄绿素乙酰甲酯(calcein-AM)荧光染色观察CdTe QD对VSMC细胞活性的影响;DCFH-DA和JC-1染色、流式细胞术检测CdTe QD作用后细胞内活性氧(ROS)含量和线粒体膜电位的变化;流式细胞术检测细胞凋亡;Western蛋白印迹法检测BCL-2和BAX蛋白表达变化。结果 MTT结果显示,CdTe QD 0.01~100 mg·L~(-1)作用VSMC细胞24 h,细胞存活率降低(P<0.01),24 h IC_(50)值为25.60 mg·L~(-1)。Calcein-AM荧光检测发现,CdTe QD 0.1~25 mg·L~(-1)作用后,VSMC细胞活性下降。DCFH-DA染色结果显示,CdTe QD 0.1~25 mg·L~(-1)使细胞内ROS逐渐增加(P<0.05,P<0.01);JC-1染色结果表明,VSMC线粒体膜电位呈浓度依赖性降低(r=0.903,P<0.01)。Western蛋白印迹结果表明,CdTe QD诱导抗凋亡蛋白BCL-2表达显著降低(P<0.01),促凋亡蛋白BAX表达显著上升(P<0.01);流式细胞术FITC-AnnexinⅤ染色结果显示,CdTe QD 0.1~25 mg·L~(-1)作用24 h能显著促进VSMC细胞凋亡(P<0.05,P<0.01)。结论CdTe QD可诱导VSMC细胞凋亡,其机制可能与胞内ROS含量上升和线粒体介导的凋亡通路激活相关。     

蛇床子素通过PINK1/Parkin通路诱导HeLa细胞自噬

目的 探讨蛇床子素促进宫颈癌HeLa细胞发生自噬的潜在作用机制。方法 不同浓度蛇床子素(0、10、20、40、80、160、240、320 mg·L^-1)作用于HeLa细胞,MTT法检测蛇床子素对HeLa细胞增殖的抑制作用;透射电镜观察经蛇床子素干预的HeLa细胞形态;单丹磺酰尸胺(monodansylcadaverine, MDC)染色检测自噬水平;流式细胞术检测活性氧(reactive oxygen species, ROS)水平;Western blot分析线粒体相关蛋白MFN1、DPR1表达水平;JC-1荧光探针检测线粒体膜电位变化;建立裸鼠宫颈癌体内移植瘤模型探讨蛇床子素对宫颈癌的抑制作用;Western blot检测PINK1、Parkin和LC3Ⅱ/Ⅰ蛋白表达水平。结果 蛇床子素能明显抑制HeLa细胞增殖;通过透射电镜观察,经蛇床子素干预的HeLa细胞有典型的自噬小体形成;MDC染色荧光强度增强,细胞发生自噬;线粒体融合蛋白MFN1表达下调,分裂蛋白DRP1表达上调;JC-1显示线粒体膜电位下降;流式细胞术检测结果显示细胞内ROS水平升高,且能被自噬...     

三萜皂苷Saxifragifolin D抑制人肝癌耐药细胞HepG2/ADM生长并诱导细胞凋亡作用研究

目的研究Saxifragifolin D(SD)对人肝癌耐药细胞HepG2/ADM的生长抑制及诱导凋亡作用。方法采用MTT法观察SD对HepG2/ADM细胞的增殖抑制作用,应用流式细胞仪分析SD对细胞周期的影响,AnnexinⅤ-FITC/PI双染检测凋亡细胞比率,JC-1染色观察SD对细胞内线粒体膜电位的影响,Western blot检测凋亡相关蛋白caspase-9,caspase-3和PARP的激活及c-Raf,MEK和ERK蛋白的表达和磷酸化水平。结果 SD可以明显抑制人肝癌耐药细胞HepG2/ADM的增殖。细胞周期检测发现SD诱导细胞产生亚二倍体凋亡峰,同时细胞凋亡率也由对照组的5.3%增加到34.8%和47.8%。线粒体膜电位检测结果显示SD导致细胞内线粒体膜电位的明显降低。Western blot检测结果表明caspase-9,caspase-3被激活,PARP被剪切活化,cytochrome C由线粒体释放至胞质,c-Raf、MEK和ERK蛋白的磷酸化水平降低。结论 SD可以抑制人肝癌耐药细胞HepG2/ADM增殖并诱导其凋亡,作用机制可能与线粒体功能障碍及抑制c-Raf/MEK/ERK通路的活化有关。     

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.     

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.     

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.