PIAS3α过表达对前列腺癌细胞增殖和凋亡的影响

目的 研究过表达PIAS3α蛋白对人前列腺癌细胞系DU145细胞增殖、细胞周期和凋亡的影响.方法 构建pcDNA3.1(+)-HA-PIAS3α真核表达载体,转染前列腺癌细胞系DU145,以蛋白免疫印迹实验检测外源PIAS3α的表达,通过MTT法检测细胞增殖,以流式细胞术分析细胞周期和细胞凋亡.结果 成功构建PIAS3α真核表达质粒,蛋白免疫印迹实验证实外源性PIAS3蛋白质DU145细胞中获得表达.分析目的 蛋白质过表达后的细胞生物学效应,结果显示在DU145细胞中过表达PIAS3α后,细胞增殖受到抑制;同时,细胞周期G0/G1期细胞显著增加,而S期细胞减少,细胞凋亡比率增加.结论 过表达PIAS3α抑制前列腺癌细胞的增殖并诱导其凋亡.     

ERK1/2在食管鳞状细胞癌中促进细胞增殖、抑制凋亡及其调控机制的研究

探讨ERK1/2在食管鳞状细胞癌(ESCC)中对肿瘤细胞增殖、凋亡的调控及其机制。平板克隆、细胞凋亡和细胞周期实验结果发现ERK1/2 MAPK通路抑制可减弱Eca109细胞克隆形成和增殖,促进细胞凋亡,减慢细胞周期;进一步发现ERK1/2 MAPK通路抑制可以反转由mi R-21过表达诱导的Eca109细胞增殖、凋亡和周期的变化;q RT-PCR和Western-blot免疫印迹结果发现ERK1/2 MAPK信号通路抑制可以下调内源性mi R-21表达和反转外源性mi R-21诱导的ERK1/2 MAPK信号通路活化。实验结果提示ERK1/2 MAPK通路抑制可能通过下调Eca109细胞中mi R-21表达阻碍Eca109细胞增殖、促进细胞凋亡和减慢细胞周期,最终导致ESCC细胞生长抑制。     

酸性鞘磷脂水解酶和MAPK信号通路在UVA诱导细胞凋亡中的作用

为了探讨酸性鞘磷脂水解酶 (ASM)和MAPK信号通路在UVA诱导的细胞凋亡中的作用 ,用DNA梯形条带 (DNAladder)和荧光显微镜鉴定细胞凋亡 ,Western印迹分析MAPK信号通路的激活情况 .结果显示 :①经UVA照射 ,正常的淋巴母细胞JY出现严重的细胞凋亡 ,而ASM遗传性缺陷的淋巴母细胞MS1 4 1 8出现轻微凋亡 ;给予ASM特异性抑制剂NB6 ,UVA诱导的JY细胞凋亡明显减轻 ,表明UVA诱导的细胞凋亡依赖于ASM .②UVA照射后 ,磷酸化ERK含量在MS1 4 1 8细胞中明显升高 ,在JY细胞中受到抑制 ;UVA照射前给予NB6 ,JY细胞中磷酸化ERK含量上升 ,表明ASM能抑制ERK的激活 .③UVA照射后 ,磷酸化JNK含量在MS1 4 1 8细胞中几乎没有变化 ,而在JY细胞中含量升高 ;UVA照射前给予NB6 ,JY细胞中磷酸化JNK含量没有明显升高 ,表明ASM激活JNK通路 .④NB6对UVA激活的p38MAPK信号通路没有影响 ,表明p38的激活与ASM关系不大 .研究表明 ,UVA诱导的细胞凋亡是通过激活ASM、激活JNK信号通路并抑制ERK信号通路来完成的     

六氯苯对PC-12 细胞凋亡的影响

目的:探讨环境内分泌干扰物六氯苯对PC-12细胞凋亡的影响及其可能机制。方法:采用体外细胞培养方法,5%CO2 37℃恒温条件下,将PC-12细胞培养于含10%灭活胎牛血清的高糖DMEM培养基中。0、1、10、20、100、200μmol.L-1六氯苯处理组,每组设3组复孔,培养24 h后应用Cell Counting Kit-8试剂盒进行六氯苯对PC-12细胞增殖和毒性分析;流式细胞术FITC-An-nexinV/PI双染检测细胞凋亡率;Hoechst33258染色及倒置荧光显微镜拍摄细胞平片,观察细胞形态学改变;免疫印记法(Western blot)检测相关蛋白PLCγ及ERK蛋白磷酸化表达变化。结果:随着六氯苯浓度增加,细胞凋亡率升高,呈剂量依赖关系;Hoechst33258染色可见细胞核膨大、染色质边集浓染等凋亡特征;与对照组相比p-PLCγ及p-ERK1/2表达均降低,呈剂量依赖效用。结论:六氯苯能够诱导PC-12细胞凋亡,p-PLCγ及p-ERK1/2信号通路可能在此过程中发挥作用。     

六氯苯对PC-12细胞凋亡的影响

目的：探讨环境内分泌干扰物六氯苯对PC-12细胞凋亡的影响及其可能机制。方法：采用体外细胞培养方法,5%CO2 37℃恒温条件下,将PC-12细胞培养于含10%灭活胎牛血清的高糖DMEM培养基中。0、1、10、20、100、200μmol.L-1六氯苯处理组,每组设3组复孔,培养24 h后应用Cell Counting Kit-8试剂盒进行六氯苯对PC-12细胞增殖和毒性分析;流式细胞术FITC-An-nexinV/PI双染检测细胞凋亡率;Hoechst33258染色及倒置荧光显微镜拍摄细胞平片,观察细胞形态学改变;免疫印记法（Western blot）检测相关蛋白PLCγ及ERK蛋白磷酸化表达变化。结果：随着六氯苯浓度增加,细胞凋亡率升高,呈剂量依赖关系;Hoechst33258染色可见细胞核膨大、染色质边集浓染等凋亡特征;与对照组相比p-PLCγ及p-ERK1/2表达均降低,呈剂量依赖效用。结论：六氯苯能够诱导PC-12细胞凋亡,p-PLCγ及p-ERK1/2信号通路可能在此过程中发挥作用。     

姜黄素通过MAPK信号通路诱导人肝癌SMMC-7721细胞凋亡

本文阐述了姜黄素(Curcumin)对体外培养的人肝癌SMMC-7721细胞增殖和凋亡的影响,并探讨了其诱导凋亡的信号转导机制。采用MTT法和细胞计数法检测不同浓度姜黄素对人肝癌细胞株SMMC-7721增殖的影响,利用流式细胞术检测姜黄素对人肝癌SMMC-7721细胞凋亡的影响,通过RT-PCR及Western blot检测姜黄素对人肝癌SMMC-7721细胞中凋亡相关蛋白Caspase-3、Survivin、Bcl-2和Bax表达的影响,最后通过检测MAPK的磷酸化水平分析姜黄素诱导SMMC-7721细胞凋亡的信号转导机制,通过MAPK抑制剂实验进一步证实诱导凋亡的分子机制。研究结果显示,姜黄素呈时间和剂量依赖性抑制人肝癌SMMC-7721细胞的增殖,其中40μmol/L姜黄素可明显诱导SMMC-7721细胞的凋亡,并呈时间依赖性上调促凋亡蛋白Caspase-3和Bax的表达、下调抗凋亡蛋白Survivin和Bcl-2的表达,姜黄素对凋亡相关蛋白表达的调节及诱导凋亡可以通过激活JNK、抑制ERK和p38 MAPK信号通路实现。表明姜黄素可诱导人肝癌SMMC-7721细胞凋亡,其机制与姜黄素激活JNK、抑制ERK和p38 MAPK信号通路从而上调Caspase-3和Bax的表达,下调Survivin和Bcl-2的表达有关。     

沙蟾毒精诱导肺癌PC-9细胞的凋亡效应及其作用机制初探

本文主要研究沙蟾毒精(Arenobufagin,ArBu)对非小细胞肺癌PC-9细胞的凋亡作用及其作用机制。以非小细胞肺癌PC-9细胞为研究对象,采用MTT法检测ArBu对肺癌PC-9细胞的生长抑制作用,结果发现ArBu各浓度组在不同时间点均对PC-9细胞具有显著的抑制作用。荧光显微镜观察经Hoechst 33258染色的细胞形态,结果显示ArBu给药组细胞减少且出现了染色质固缩、核碎裂、凋亡小体形成,说明ArBu诱导了细胞凋亡。进一步,流式细胞检测仪结果显示细胞凋亡呈明显的量效关系。此外,Western blot结果显示ArBu抑制EGFR/RAF/MEK/ERK信号通路蛋白的磷酸化,下调抗凋亡蛋白Bcl-2的表达,上调促凋亡蛋白Bax的表达。上述实验结果表明,ArBu对非小细胞肺癌细胞系PC-9具有明显的生长抑制和促凋亡作用,可作为抗非小细胞肺癌的先导化合物进一步研究。     

布拉酵母菌对胃黏膜上皮细胞损伤的保护作用及机制

目的研究布拉酵母菌对胃黏膜上皮细胞损伤的保护作用。方法建立人胃黏膜上皮细胞GES-1单层细胞模型,并将其分为对照组,布拉酵母菌上清培养组,阿司匹林处理组(18.32mmol/L),阿司匹林+布拉酵母菌上清液组。采用流式细胞术检测各组细胞凋亡率;采用免疫荧光、Western blot方法检测胃黏膜上皮细胞中Occludin和ZO-1蛋白、JNK蛋白、ERK蛋白、磷酸化JNK(p-JNK)蛋白、磷酸化ERK(p-ERK)蛋白表达水平。结果流式细胞术显示阿司匹林+布拉酵母菌上清液组凋亡率低于阿司匹林处理组,差异有统计学意义(P0.05);免疫荧光结果显示,阿司匹林+布拉酵母菌上清液组Occludin蛋白、ZO-1蛋白表达较阿司匹林处理组增加,Western blot结果显示,阿司匹林+布拉酵母菌上清液组的该两种蛋白表达量较阿司匹林处理组增加,阿司匹林+布拉酵母菌上清液组p-ERK、p-JNK蛋白表达较阿司匹林处理组减少。结论布拉酵母菌对阿司匹林造成的胃黏膜上皮细胞损伤有保护作用,其机制可能通过抑制MAPK信号通路中ERK、JNK的激活而上调Occludin和ZO-1蛋白的表达。     

JNK、ERK信号通路在NaAsO_2诱导骨髓间充质干细胞增殖中的作用

目的：研究c-jnk氨基末端激酶（JNK）、细胞外信号调节激酶（ERK）在亚砷酸钠（NaAs02）诱导骨髓间充质干细胞（BMSC）增殖中的作用。方法：体外培养骨髓间充质干细胞,四甲基偶氮唑盐比色法（MTT法）检测细胞增殖,Western-blot检测磷酸化JNK、ERK表达水平。结果：低浓度1、2μmol/LNaAs02对BMSC有明显的促进增殖作用;高浓度16、32μmol/LNaAs02则对细胞生长产生抑制作用,具有一定剂量-效应关系;2、4、8μmol/LNaAs02处理BMSC24h后,JNK磷酸化表达水平明显增加,ERK磷酸化表达水平明显降低;JNK抑制剂SP600125可明显降低高浓度16、32μmol/LNaAs02的生长抑制作用;ERK抑制剂PD98059可抑制低浓度1、2μmol/LNaAs02对BMSC的促增殖作用。结论：低浓度NaAs02激活ERK信号通路,提高细胞增殖率,可被抑制剂PD98059阻断;高浓度NaAs02激活JNK信号通路,提高细胞凋亡率,可被抑制剂SP600125阻断。NaAs02致癌机制可能与JNK、ERK信号通路作用相关。     

JNK、ERK信号通路在NaAsO2诱导骨髓间充质干细胞增殖中的作用

目的:研究c-ink氨基末端激酶(JNK)、细胞外信号调节激酶(ERK)在亚砷酸钠(NaAsO2)诱导骨髓间充质干细胞(BMSC)增殖中的作用.方法:体外培养骨髓间充质干细胞,四甲基偶氮唑盐比色法(MTT法)检测细胞增殖,Western-blot检测磷酸化JNK、ERK表达水平.结果:低浓度1、2μ mol/L NaAsO2对BMSC有明显的促进增殖作用;高浓度16、32μ mol/LNaAsO2则对细胞生长产生抑制作用,具有一定剂量-效应关系;2、4、8μ mol/LNaAsO2处理BMSC 24h后,JNK磷酸化表达水平明显增加,ERK磷酸化表达水平明显降低;JNK抑制剂SP600125可明显降低高浓度16、32μmol/LNaAsO2的生长抑制作用;ERK抑制剂PD98059可抑制低浓度1、2μ mol/LNaAsO2对BMSC的促增殖作用.结论:低浓度NaAsO2激活ERK信号通路,提高细胞增殖率,可被抑制剂PD98059阻断;高浓度NaAsO2激活JNK信号通路,提高细胞凋亡率,可被抑制剂SP600125阻断.NaAsO2致癌机制可能与JNK、ERK信号通路作用相关.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.