USP9X低表达通过下调Mcl-1促进肝癌细胞凋亡

研究抑制泛素特异性蛋白酶9X（ubiquitin-specific protease 9X,USP9X）对人肝癌（primary hepatocellular carcinoma,HCC）细胞SMMC7721和HepG2中髓细胞白血病-1（myeloid cell leukemia-1,Mcl-1）蛋白的表达调控及对细胞凋亡和生长活力的影响。实验分为USP9X-siRNA组和阴性对照NC组两组进行分析。通过Western blot技术分别检测USP9X在肝癌细胞SMMC7721、HepG2和正常人肝细胞株L02中的蛋白表达情况;应用化学合成USP9X-siRNA转染肝癌细胞SMMC7721和HepG2,通过Western blot、流式细胞仪和MTT检测转染前后Mcl-1的蛋白表达差异以及细胞凋亡和生长活力变化。结果表明,USP9X在肝癌细胞SMMC7721和HepG2中的蛋白表达水平均高于正常肝细胞L02（t=15.155,P=0.000;t=9.171,P=0.001）;SMMC7721和HepG2细胞中抑制USP9X能明显下调Mcl-1的蛋白表达,并导致细胞凋亡增加和生长活力降低。提示,肝癌细胞SMMC7721和HepG2中USP9X表达上调;USP9X表达降低可能通过下调Mcl-1的蛋白表达进而诱导人肝癌细胞SMMC7721和HepG2的凋亡。     

VEGF siRNA降低人肝癌细胞株SMMC7721的致瘤性

本研究应用RNA干扰（RNAi）技术高效抑制VEGF的表达,明显降低了人肝癌细胞株SMMC7721的致瘤性。化学合成针对人VEGF基因的siRNA,体外瞬时转染人肝癌细胞株SMMC7721,RT-PCR和Elisa法检测表明VEGFsiRNA实验组与对照组相比,细胞内VEGFmRNA表达下降了76．16％,VEGF分泌蛋白表达则下降了96．28％,而MTT法结果显示VEGFsiRNA对SMMC7721细胞增殖没有明显作用。体内实验中,不同时间对荷SMMC7721细胞瘤裸小鼠进行siRNA直接瘤内注射,同时测量瘤体积,最后取瘤块进行组织切片观察并进行分子生物学分析,结果显示,与对照组相比,VEGFsiRNA实验组肿瘤体积明显缩小,瘤内出现细胞坏死,同时肿瘤组织中VEGFmRNA和蛋白表达水平均明显降低。     

冬凌草甲素缓解脂多糖诱导的Caco-2肠上皮细胞屏障损伤和SIRT1/eIF2α信号通路活性的抑制

目的 探索冬凌草甲素对脂多糖（lipopolysaccharide, LPS）诱导的肠上皮屏障障碍的影响及其生物学机制。方法将Caco-2细胞进行单层培养21 d使其分化后，分为对照组、LPS组（2μg/mL LPS处理24 h）、LPS+低剂量冬凌草甲素组（10μg/mL冬凌草甲素预处理30 min,2μg/mL LPS处理24 h）和LPS+高剂量冬凌草甲素组（40μg/mL冬凌草甲素预处理30 min,2μg/mL LPS处理24 h）。采用跨上皮电阻法和FITC-dextran 4通量法评估细胞单层屏障功能；CCK-8法检测细胞活力；乳酸脱氢酶（LDH）法检测LDH释放活性；DCFH-DA探针法检测细胞内活性氧水平；ELISA法检测炎症因子IL-1β和TNF-α分泌水平；免疫荧光法检测细胞的屏障功能相关蛋白闭合蛋白（occludin）和闭锁小带蛋白1(zonula occludens protein 1, ZO-1)的表达分布情况；Western blot法检测SIRT1和p-eIF2α的相对表达水平。结果 与LPS组比较，冬凌草甲素能改善LPS诱导的肠上皮细胞单层屏障障碍，增...     

紫杉醇对人肝癌SMMC7721细胞NDRG1表达及增值的影响

旨在探索紫杉醇对人肝癌SMMC7721细胞NDRG1表达的影响,及紫杉醇对肝癌SMMC7721细胞系增殖的抑制作用。分别提取紫杉醇处理前后SMMC7721细胞的RNA,进行逆转录-聚合酶链反应(RT-PCR),判断紫杉醇处理前后肝癌细胞中NDRG1表达的情况;采用蛋白印迹技术(Western blotting)分析紫杉醇处理前后肝癌细胞中NDRG1蛋白表达的情况;应用不同浓度紫杉醇处理肝癌细胞,以MTT法检测处理前后肝癌细胞的抑制率,流式细胞术(FCM)观察细胞周期变化的况。结果表明紫杉醇处理后的肝癌SMMC7721细胞中NDRG1表达下降,紫杉醇浓度越高,NDRG1表达水平越低,具有浓度依赖性。以MTT法观察紫杉醇对肝癌细胞的抑制作用,试验结果表明不同浓度的紫杉醇处理肝癌SMMC7721细胞后,癌细胞被明显抑制;以流式细胞术观察紫杉醇作用后肝癌SMMC7721细胞周期的变化,结果显示G2-M期细胞比例升高的程度随浓度增高而升高,细胞越来越多地被阻滞在G2-M期,不能继续分裂增殖。分化相关基因NDRG1的表达可能是肝癌的发病机制之一,紫杉醇可抑制肝癌SMMC 7721细胞中NDRG1的表达;同时紫杉醇能使肝癌SMMC7721细胞的生长阻滞在G2-M期,从而显著抑制SMMC7721细胞的增殖,并且具有剂量、时间依赖效应。     

三氧化二砷对肝癌细胞系SMMC-7721凋亡及 Smac caspase-9、caspase-3 蛋白表达的影响

目的：研究三氧化二砷（As203）对人肝癌细胞SMMC-7721的促凋亡作用及对Smac、caspase-9、caspase-3表达的影响。方法：人肝癌细胞SMMC-7721经As20,处理,共分为四组,分别为空白对照组、低剂量组、中等剂量组、高剂量组。分别采用MTT、Hoechst33258染色法、Annexin V-FITC／PI双染法观察其对SMMC．7721细胞增殖的抑制,凋亡细胞核的形态学变化,以及诱导凋亡作用;采用Westemblot法检测凋亡相关蛋白Smac、caspase-9、caspase-3表达的变化。结果：MTT显示：As203在体外能明显抑制SMMC-7721的生长,具有时间剂量依赖关系,与空白对照组相比,其余三组细胞生存率明显下降,差异均有统计学意义（P〈0．05）;Hoechst33258显示细胞呈明显的凋亡细胞形态学特征,具有剂量依赖性;AnnexinV-FITC／PI双染法显示：As203作用24小时可诱导SMMC-7721细胞凋亡,且呈剂量依赖性,与空白对照组相比（2．69±0．58）,其余三组（4．01±0．58）、（5．99±1．69）、（9．26±2．34）差异均有统计学意义（P〈0．05）;Westernblot显示：As2O3作用SMMC-7721细胞24小时,Smac、caspase-9、caspase-3表达上升,呈剂量依赖性,与空白对照组相比,其余三组蛋白表达量明显增加,差异均有统计学意义（P〈0．05）。结论：-定量的As203能抑制SMMC-7721细胞增殖,促进其凋亡,其机制可能与调控Smac、caspase-9、caspase-3表达有关。     

温度对虎斑颈槽蛇3种组织SDH和LDH活性的影响

研究了虎斑颈槽蛇骨骼肌、肝脏、心肌组织中琥珀酸脱氢酶（SDH）、乳酸脱氢酶（LDH）活性对温度的依赖关系。结果表明：虎斑颈槽蛇骨骼肌、肝脏、心肌SDH在5-15℃范围内表现出较低活性,在25℃左右表现出较高活性,该温度可能为SDH的最适温度;除心肌KLDH活性在35℃以上开始下降,其余两种组织的LDH活性随温度的上升而升高。SDH、LDH活性呈现组织问的特异性,3种组织中,SDH活性心肌中最高,LDH活性骨骼肌中最高。     

蝎毒对人肝癌细胞（SMMC7721）和宫颈癌（Hela）细胞抑制作用的研究

目的：探讨蝎毒粗粉及经初步纯化的蝎毒对人肝癌细胞（SMMC7721）和Hela细胞株的抑制作用。方法：以四甲基偶氮唑盐法（MTT）,Western Blotting,免疫细胞化学以及荧光标记的方法,对人肝癌细胞（SMMC7721）和Hela细胞株的凋亡相关蛋白进行检测。结果：蝎毒粗毒及经初步纯化的蝎毒具有诱导SMMC7721和Hela凋亡的作用。结论：蝎毒粗毒及经初步纯化的蝎毒对人肝癌细胞（SMMC7721）及Hela细胞的生长具有明显的抑制作用。     

SMMC 7721肝癌细胞蛋白激酶B活性增高可驱动有功能的上皮钙粘着蛋白到细胞表面(英)

为了研究蛋白激酶B（PKB）对上皮钙粘着蛋白（E-cadherin）的调节,使用了用胰岛素处理的野生型SMMC 7721细胞及稳定表达持续激活PKB的SMMC 7721细胞株(Gag-PKB/SMMC 7721).用RNA印迹法和蛋白质印迹法检测细胞E-cadherin 表达,发现通过胰岛素刺激或在细胞中表达持续激活PKB从而增加PKB活性,不影响E-cadherin的转录和蛋白质合成,但用流式细胞术和免疫荧光定位E-cadherin,则发现PKB活性增加能明显驱动E-cadherin到细胞表面,从而导致部分通过E-cadherin途径的细胞粘聚增加和细胞调亡的抑制.因此,我们提供新的证据表明,增加PKB活性可驱动有功能的E-cadherin分子到细胞表面.     

p14.5过表达抑制肝癌细胞株SMMC7721迁移

本课题组前期研究发现14.5 kD蛋白(以下简称p14.5)是肝癌相关抗原,目前研究发现p14.5在人体大部分正常器官组织内几乎不表达,仅在肝、肾组织内高表达;在多种肝癌细胞株和肝癌组织内p14.5mRNA和蛋白呈低表达,并与肝癌分化状态呈负相关。但是p14.5是否在肝癌发生发展中发挥作用还未明确。本研究采用Western blotting检测多种肝癌细胞株SK-Hep-1、Huh-7、HepG2、SMMC7721和BEl-7704内p14.5蛋白表达;采用lipo3000脂质体介导构建p14.5稳定过表达肝癌细胞株p14.5-SMMC7721和空载对照细胞株NC-SMMC7721,并用Real-time QRT-PCR和Western blotting检测转染细胞株及野生型细胞株内p14.5的表达;通过CCK-8实验方法,检测p14.5过表达对肝癌细胞增殖的影响;通过体外划痕和Transwell细胞迁移实验检测p14.5过表达对肝癌细胞迁移的影响。结果显示,Real-time QRT-PCR及Western blotting检测结果表明p14.5在p14.5-SMMC7721细胞内表达明显高于其他两组,已成功构建p14.5稳定表达的肝癌细胞系p14.5-SMMC7721;CCK-8法测定细胞生长曲线结果表明p14.5稳定表达的肝癌细胞株与其他两组生长速度并无明显差异;24 h、48 h后观察划痕愈合情况,p14.5-SMMC7721愈合率为(6.97±1.55)%、(11.16±1.49)%,低于NC-SMMC7721愈合率(28.28±3.71)%、(46.89±6.76)%及野生型SMMC7721愈合率(30.50±3.66)%、(43.00±2.43)%,且差异有统计学意义(p0.05)。Transwell细胞迁移实验表明,p14.5-SMMC7721中发生迁移的平均细胞数目为12.70±4.92,而NC-SMMC7721及野生型SMMC7721中发生迁移的细胞数目为41.20±11.55和40.20±8.04,p14.5-SMMC7721中发生迁移细胞数目显著低于对照系NC-SMMC7721及野生型SMMC7721中发生迁移的细胞数目,且差异有统计学意义(p0.05)。本研究证实过表达p14.5,不影响肝癌细胞SMMC7721细胞生长,但是抑制其体外迁移。提示p14.5在肝癌细胞SMMC7721迁移中有重要作用。     

牡砺糖胺聚糖对血管内皮细胞损伤的保护作用研究

目的：探讨牡蛎糖胺聚糖（O—GAG）对血管内皮细胞损伤的保护作用,观察它对损伤的血管内皮细胞内一氧化氮（NO）、丙二醛（iDA）含量及乳酸脱氢酶（LDH）活性的影响。方法：采用人脐静脉内皮细胞株ECV304体外培养的方法,建立过氧化氢（H2O2）诱导的内皮细胞损伤模型,噻唑蓝（MTT）比色法观察牡蛎糖胺聚糖对血管内皮细胞增殖活性的影响,硝酸还原酶法、硫代巴比妥酸法和硝基苯肼法分别检测细胞内NO的含量、细胞培养液内MDA的含量和LDH的活性。结果：模型组较正常对照组细胞增殖活性明显降低（P〈0．01）。与模型组相比,经牡蛎糖胺聚糖预处理的各保护组（除10μg／ml）细胞增殖活性明显增加（P〈0．05,P〈0．01）,NO的含量增加,MDA的含量和LDH的活性降低（P〈0．01）。牡蛎糖胺聚糖（100、200μg／ml）对于正常的内皮细胞有促增殖作用（P〈0．05）。结论：牡蛎糖胺聚糖对氧化损伤的血管内皮细胞具有保护作用,其作用机制可能与增加细胞NO含量、减少MDA生成和LDH释放有关。牡蛎糖胺聚糖对正常血管内皮细胞在一定剂量范围内有促增殖作用．     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.