二苯乙烯苷对H2O2诱导血管内皮细胞ICAM-1及VCAM-1表达的影响

目的:通过研究二苯乙烯苷(TSG)对H2O2诱导的人脐静脉内皮细胞ICAM-1、VCAM-1表达的影响,探明二苯乙烯苷抗氧化保护内皮细胞的作用机制.方法:体外培养人脐静脉内皮细胞,实验分为空白对照组、H2O2组、辛伐他汀组、TSG组,运用逆转录聚合酶链式反应和酶联免疫吸附试验分别检测ICAM-1及VCAM-1 mRNA与其蛋白的表达.结果:200 μmol· L-1的H2O2作用内皮细胞24h后,ICAM-1和VCAM-1的mRNA和蛋白表达水平均明显上调,与空白对照组比较,差异有显著性(P＜0.01).而在200μmol· L-1的H2O2作用前用1μmol· L-1二苯乙烯苷预处理体外培养人脐静脉内皮细胞4h,结果显示二苯乙烯苷能抑制H2O2诱导的内皮细胞ICAM-1、VCAM-1的mRNA和VCAM-1的蛋白水平表达,与H2O2组比较差异有显著性(P＜0.01);而ICAM-1的蛋白表达水平与H2O2组比较差异有统计学意义(P＜0.05);辛伐他汀组ICAM-1和VCAM-1的mRNA及其蛋白水平表达降低,与H2O2组比较差异均有显著性(P＜0.01).实验结果表明二苯乙烯苷可抑制H2O2诱导的内皮细胞粘附分子ICAM-1、VCAM-1表达.结论:二苯乙烯苷可通过降低细胞粘附分子ICAM-1和VCAM-1的表达保护氧化应激引起的人脐静脉内皮细胞损伤.     

二苯乙烯苷对H202诱导血管内皮细胞ICAM-1及VCAM-1表达的影响

目的：通过研究二苯乙烯苷（TSG）对H20：诱导的人脐静脉内皮细胞ICAM-1、VCAM-1表达的影响,探明二苯乙烯苷抗氧化保护内皮细胞的作用机制。方法：体外培养人脐静脉内皮细胞,实验分为空白对照组、H20：组、辛伐他汀组、TSG组,运用逆转录聚合酶链式反应和酶联免疫吸附试验分别检测ICAM-1及VCAM-1mRNA与其蛋白的表达。结果：200μmol·L。的H202作用内皮细胞24h后。ICAM．1和VCAM-1的mRNA和蛋白表达水平均明显上调,与空白对照组比较,差异有显著性（P〈0．01）。而在200μmol·L。的H202作用前用1μmol·L^-1二苯乙烯苷预处理体外培养人脐静脉内皮细胞4h,结果显示二苯乙烯苷能抑制H2O2诱导的内皮细胞ICAM-1、VCAM-1的mRNA和VCAM-1的蛋白水平表达,与H2O2组比较差异有显著性（P〈0．01）;而ICAM-1的蛋白表达水平与H202组比较差异有统计学意义（P〈0．05）;辛伐他汀组ICAM-1和VCAM-1的mRNA及其蛋白水平表达降低,与H20：组比较差异均有显著性（P〈0．01）。实验结果表明二苯乙烯苷可抑制H2O2诱导的内皮细胞粘附分子ICAM-1、VCAM-1表达。结论：二苯乙烯苷可通过降低细胞粘附分子ICAM-1和VCAM-1的表达保护氧化应激引起的人脐静脉内皮细胞损伤。     

三七总皂苷及单体组合对ox-LDL诱导内皮细胞ICAM-1表达的影响

目的:研究三七总皂苷及其单体组合对ox-LDL诱导的人脐静脉内皮细胞(HUVECs)粘附分子ICAM-1表达的影响.方法:体外培养人脐静脉内皮细胞,加入100mg·L-lox-LDL刺激HUVECs,诱导单核-内皮细胞黏附,加入不同浓度的PNS及单体组合进行干预,蛋白染料法测定黏附值,RT-PCR检测HUVECs粘附分子ICAM-ImRNA的表达,Western-blotting检测HUVECs粘附分子ICAM-1蛋白的表达.结果:PNS各剂量组及单体组合组可有效降低单核-内皮细胞的黏附;ox-LDL可显著增加HUVECs的ICAM-1 mRNA及蛋白表达(P＜0.05);PNS各剂量组及单体组合组与ox-LDL组相比,均能显著降低ICAM-1的mRNA及蛋白表达(P＜0.05).结论:抑制ox-LDL诱导的内皮细胞ICAM-1mRNA及蛋白的表达,可能为PNS抗动脉粥样硬化作用机制之一.     

小鼠骨髓源性树突状细胞体外诱导培养方法的比较研究

目的探讨最佳体外诱导培养小鼠成熟树突状细胞（dendritic cells,DC）的方法。方法分离、纯化6周龄C57BL／6小鼠骨髓单核细胞,以含10％胎牛血清、20ng／ml重组小鼠粒细胞-巨噬细胞集落刺激因子（GM—CSF）和10ng／ml重组小鼠白细胞介素-4（IL-4）的RPMI-1640培养基培养7d,然后将细胞分成对照未刺激组、肿瘤坏死因子-α（TNF-α）刺激组和TNF-α＋脂多糖（lipopolysaccharides,LPS）刺激组。继续培养48h后,观察各组细胞形态,检测IL-12、IL-6浓度及细胞表面标志CD11c、CD80、CD86和MHC II。结果培养9d后,两刺激组培养的细胞经相差显微镜观察有DC生长。TNF—α刺激组细胞培养上清液中IL-6、IL-12含量显著高于对照组（P〈0．01）,但显著低于TNF—α＋LPS刺激组（P〈0．05）。3组均高表达CD11c,各组间无显著差异;而CD80、CD86和MHC II表达阳性率TNF-α刺激组显著高于对照组（P〈0．01）,TNF-α＋LPS刺激组显著高于单纯TNF—α刺激组（P〈0．05）。结论联合使用TNF-α与LPS刺激可使DC成熟度提高,分泌IL-6、IL-12增加。     

人脐静脉血管平滑肌促内皮细胞组织因子表达的体外实验研究

目的研究血管平滑肌细胞对血管内皮细胞组织因子表达的影响并探讨其临床意义.方法用贴块法培养人脐静脉平滑肌细胞;酶消化法培养人脐静脉内皮细胞;用培养平滑肌细胞条件培养液(SMC-CM)刺激培养的内皮细胞,一步凝固法检测内皮细胞组织因子的活性;Northern blot检测内皮细胞组织因子的mRNA表达;并用酶联免疫吸附试验检测SMC-CM中IL-1α、IL-1β、TNF-α和VEGF的含量.结果 SMC-CM使内皮细胞组织因子活性呈剂量依赖性增强,作用6h增至最高,最高增强约38倍;SMC-CM使内皮细胞组织因子mRNA表达显著增强;SMC-CM中的组织因子诱导剂不耐热,且并非IL-1α、IL-1β、TNF-α和VEGF等已知的组织因子诱导剂.结论血管平滑肌细胞能促进血管内皮细胞组织因子的表达,提示体内增生的平滑肌细胞,如动脉再狭窄新内膜中的平滑肌细胞可能诱导局部血管内皮细胞活化及表达组织因子,在局部血栓形成中起一定作用.     

L-精氨酸对脂多糖诱导大鼠肺损伤的保护作用及其机制的研究

目的：观察一氧化氮供体L-精氨酸（L-Arg）对脂多糖诱导大鼠肺损伤炎症反应和核因子-κB（NF-κB）信号通路的影响,探讨L-Arg对肺损伤的保护作用及其机制。方法：健康雄性SD大鼠采用舌下静脉注射脂多糖（LPS）复制肺损伤模型,分别于给予LPS3h和6h后给予生理盐水（对照组及LPS组,ip）和L-Arg（500mg/kgip）（L-Arg治疗组）,治疗3h。每组8只动物。免疫组化染色分析肺组织中NF-κB的核移位;逆转录多聚酶链反应（RT-PCR）检测肺组织细胞间粘附分子-1（ICAM-1）基因表达;放射免疫法分别测定肺组织中肿瘤坏死因子α（TNF-α）和白介素6（IL-6）的含量;光镜观察肺组织病理变化。结果：与对照组比较,大鼠肺损伤后NF-κB活化,明显从细胞浆移位于细胞核,表达量也显著增加;ICAM-1基因表达上调;肺组织中TNF-α、IL-6含量明显升高。肺损伤3h用L-Arg治疗3h后,NF-κB从细胞浆向细胞核的移位被明显限制,NF-κB的表达量、肺组织中TNF-α、IL-6含量明显低于相应的LPS组,肺组织病理改变减轻;肺损伤6h用L-Arg治疗3h对LPS引起的以上变化没有明显影响。结论：LPS3h后给予L-Arg可减轻内毒素性肺损伤,抑制核因子的活化,在一定程度上阻断NF-κB相关信号通路的传导,减轻炎症反应是其机制之一。     

骨髓间充质干细胞向角膜上皮细胞分化及其免疫调节作用

目的：探讨大鼠骨髓间充质干细胞（rBMMSCs）转分化为角膜上皮的潜能,并在体外共培养体系中研究rBMMSCs对促炎细胞因子干扰素-γ（IFN-γ）和肿瘤坏死因子-α（TNF-α）刺激下的人角膜上皮细胞（hCECs）的免疫调节作用。方法采用聚蔗糖梯密度离心法获得rBMMSCs,并通过上皮细胞培养微环境来诱导rBMMSCs分化为上皮样细胞。通过免疫组织化学方法鉴定CD29、CD34、CK5＆8和ZO-1等标记物在rBMMSCs及诱导的上皮样细胞中的表达。流式细胞术用来分析CD29/CD34的表达及细胞分化过程中表达量的变化。hCECs单独培养或与rBMMSCs共培养,并采用IFN-γ/TNF-α刺激24或48 h。通过流式细胞术来分析细胞间黏附分子-1（ICAM-1）于IFN-γ/TNF-α刺激前后在hCECs上的表达,并通过黏附分析实验验证rBMMSC条件培养基对单核细胞黏附于IFN-γ/TNF-α刺激后的hCECs的作用。多组间比较采用单因素方差分析（ANOVA）,两组间比较采用双侧t检验。结果成功分离rBMMSCs,细胞表达CD29,但不表达CD34。在上皮细胞培养条件中培养5 d,大约4﹪的rBMMSCs可分化为上皮样细胞。此类细胞失去了CD29的标志,转为表达CK5＆8和ZO-1。IFN-γ/TNF-α能显著上调hCECs中ICAM-1的表达,在IFN-γ/TNF-α处理24 h和48 h后,ICAM-1分别呈现10倍和8倍的升高,分别达到4524±554.2和3107±329.6（P=0.0025,0.0014）。但与MSC共同培养时,上调作用被显著抑制,ICAM-1平均值为1356±325.6（24 h）与1323±106.6（48 h）（P=0.0079,0.0024）。MSC条件培养基可显著抑制单核细胞对hCECs的黏附作用,黏附细胞数从（10.01±3.01）×10^3/ml细胞降至（2.21±0.19）×10^3/ml细胞（P=0.0271）。结论rBMMSCs可转分化为角膜上皮样细胞,并抑制由促炎细胞因子诱导的ICAM-1在hCECs上的表达,同时对促炎细胞因子诱导的单核细胞的黏附性具有抑制作用,提示BMMSCs具有在角膜炎症疾病和损伤修复中的治疗潜能。     

三氧化二砷对人脐静脉内皮细胞凋亡及VCAM-1/ICAM-1 表达的影响

目的:观察三氧化二砷(As2O3)对血管内皮细胞增殖、凋亡及VCAM-1/ICAM-1表达的影响,探讨As2O3对血管内皮细胞增殖生长以及炎症反应的影响。方法:人脐静脉内皮细胞(HUVEC)体外培养,以不同As2O3浓度及时间对其进行干预。采用CCK-8测定细胞增殖活性,流式细胞仪AnnexinⅤ/PI双染法检测细胞的凋亡率,实时荧光定量PCR检测VCAM-1mRNA表达,酶联免疫吸附试验(ELISA)检测细胞间黏附分子(VCAM-1)及血管细胞黏附分子(ICAM-1)的表达情况。结果:当As2O3浓度在3μmol.L-1时HUVEC培养24 h的的凋亡率为(0.134±0.03)%,48 h为(3.305±0.53)%,72 h为(3.748±0.84)%(P<0.05),凋亡率均在一较低水平。当As2O3浓度>3μmol.L-1时HUVEC凋亡率明显增加(P<0.01)。不同浓度As2O3作用HUVEC48 h后检测上清液中ICAM-1与VCAM-1浓度时发现1μmol.L-1时VCAM-1表达即开始增加(123.32±3.78 mmol.L-1,P<0.01),而HUVEC表达ICAM-1含量与对照组相比差异并不明显(38.94±2.59 mmol.L-1,P>0.05),随着As2O3浓度的增加,HUVEC表达ICAM-1/VCAM-1的量均增加但敏感性不同。对照组及(1.0、2.0、3.0、4.0、5.0)μmol.L-1As2O3作用于HUVEC 48 h实时荧光定量PCR法检测VCAM-1mRNA表达量明显增加,与对照组相比实验组的表达量分别为(1.657±0.287,1.858±0.241,2.321±0.280,3.012±0.235,3.508±0.342)(P<0.01)。结论:As2O3可直接降低细胞活性,诱导细胞凋亡,并且呈一定的时间-浓度依赖性。在较低浓度时VCAM-1/ICAM-1的表达在一个相对较低的水平,随着As2O3浓度的逐渐升高,内皮细胞凋亡率增高,VCAM-1/ICAM-1表达增加,并且VCAM-1/ICAM-1对As2O3的敏感性呈现一定的差异性。     

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.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).