粪肠球菌脂磷壁酸通过 激活NF-κB活化NLRP3炎性体

目的检测粪肠球菌脂磷壁酸(LTA)对NLRP3炎性体的活化机制。方法粪肠球菌LTA及NF-κB抑制剂作用于小鼠巨噬细胞RAW264.7上,运用Western blot及ELISA法检测NLRP3炎性体相关因子mRNA及蛋白的表达,检验LTA对NLRP3的活化是否借助NF-κB信号通路,免疫荧光染色检测NF-κB的核转位。结果LTA可直接活化RAW264.7细胞的NLRP3炎性体。LTA作用于细胞后NLRP3、Caspase-1和IL-1β蛋白的表达明显高于对照组(P0.05)。NF-κB抑制剂可有效抑制NF-κB P65的核转位,而一旦NF-κB信号通路被抑制,NLRP3炎性体蛋白的表达均明显降低。结论 LTA能直接激活小鼠巨噬细胞系RAW264.7的NLRP3炎性体的表达,NF-κB信号通路参与此过程。     

百草枯对活性氧类物质的产生和中性粒细胞凋亡的影响

目的:探讨百草枯(PQ)对活性氧类物质(ROS)和中性粒细胞凋亡的影响及可能机制。方法:离体培养健康成人中性粒细胞,给予不同浓度百草枯刺激后培养6~24 h,流式细胞仪检测中性粒细胞凋亡率及ROS含量,Western blot检测信号蛋白核因子kappa B(NF-кB)、天冬氨酸特异性半胱氨酸蛋白酶3(Caspase 3);给予ROS、NF-κB拮抗剂后,再次检测中性粒细胞凋亡率及信号蛋白含量。结果:PQ可明显促进ROS产生及抑制中性粒细胞凋亡,这种效应可被ROS抑制剂二联苯碘(DPI)及NF-кB抑制剂四氢吡咯二硫代氨基甲酯(PDTC)逆转。同时,PQ能促进NF-κB表达增加,而Caspase 3表达则受到明显抑制。结论:百草枯是强力的ROS诱导剂,并能抑制中性粒细胞凋亡,其机制可能与NF-κB活化,进而抑制Caspase 3表达有关。     

无患子皂苷对人肝癌细胞HepG2增殖与凋亡的影响

为了探究无患子皂苷对人肝癌细胞Hep G2增殖和凋亡的影响。本研究采用不同浓度的无患子皂苷对Hep G2细胞进行处理,分别利用MTT法、流式细胞术、qPCR的方法检测细胞增殖、周期和凋亡情况以及NF-κB和Caspase3的表达情况。结果发现25μg/m L~100μg/m L的无患子皂苷分别作用12、24和36 h后,显微镜下发现细胞形态发生明显变化,MTT法检测发现细胞的增殖受到明显的抑制。无患子皂苷作用24 h后流式细胞术检测出现明显的凋亡峰,细胞周期阻滞在G0/G1期。qPCR检测发现随着皂苷浓度的提高,Caspase3的表达上调,而NF-κB的表达下调。以上结果说明无患子皂苷能够抑制人肝癌细胞HepG2的增殖并诱导其凋亡。     

抑制GSK-3β活性促进NF-κB诱导的儿童急性淋巴细胞白血病细胞凋亡

核转录因子-κB(NF-κB)是维持急性淋巴细胞白血病(ALL)细胞生存的关键因子.近年来发现,糖原合成酶激酶-3β(GSK-3β)可以正性调控NF-κB的活性.本研究通过抑制GSK-3β活性初步探讨ALL细胞中GSK-3β在NF-κB诱导细胞凋亡中的作用机制.收集ALL患儿骨髓单个核细胞,采用免疫荧光细胞化学方法检测到ALL细胞核内GSK-3β有明显聚集.体外培养ALL细胞后经GSK-3β抑制剂氯化锂(LiCl)和SB216763处理,采用Western印迹和EMSA检测发现,ALL细胞核内GSK-3β表达下降,而NF-κBP65蛋白无明显变化,但是其活性明显降低.同时RT-PCR结果显示,NF-κB下游抗凋亡基因存活素(survivin)的表达随之下降,AnnexinV-PE/7-AAD双染流式细胞仪检测结果证实,ALL细胞凋亡明显增加(P0.01).该结果表明,抑制GSK-3β活性可以下调NF-κB的转录活性,并通过下调抗凋亡基因存活素的表达而促进ALL细胞的凋亡.     

双歧杆菌脂磷壁酸对NF-κB在结肠癌细胞中表达的影响

目的探讨双歧杆菌脂磷壁酸（LTA）对NF-κB在结肠癌细胞HCT-116中表达的影响。方法采用免疫细胞化学染色、PAGE及Western blot等,分析经双歧杆菌LTA处理前后,NF-κB蛋白在结肠癌细胞HCT-116中表达的差异。结果经LTA处理后,NF-κB在HCT-116细胞中的表达明显降低,且呈剂量依赖性。结论双歧杆菌LTA可下调NF-κB的表达,对了解LTA诱导HCT-116细胞凋亡的机制提供了一定的实验依据。     

槐果碱抑制糖尿病大鼠肾损伤、NLRP3炎性小体和NF-κB通路活化

目的 观察槐果碱（sophocarpine, SC）对糖尿病大鼠肾损伤的影响,并探讨其相关机制。方法 选用SD大鼠,以高脂饮食12周和链脲佐菌素处理制作糖尿病模型,灌胃给予槐果碱治疗12周。PAS染色以及纤连蛋白（fibronectin, FN）和Cleaved Caspase-3免疫组织化学染色评估肾组织损伤,ELISA检测肾组织中IL-1β及IL-6水平,Western blot检测肾组织中NLRP3、凋亡相关斑点样蛋白（apoptosis-associated speck-like protein containing CARD, ASC）、Cleaved Caspase-1和NF-κB p65蛋白表达水平。结果 糖尿病大鼠肾重指数、尿蛋白排泄水平、血清尿酸水平、肾小球系膜基质扩张系数均较对照大鼠明显升高,肾组织中FN、Cleaved Caspase-3、IL-1β、IL-6、NLRP3、ASC、Cleaved Caspase-1和NF-κB p65蛋白水平均较对照大鼠明显上调,槐果碱干预能明显抑制糖尿病大鼠上述指标变化。结论 槐果碱可能通过抑制NLRP3炎性小体和NF-κB通路...     

PHD1通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖

目的:探讨PHD1在肺癌中的功能,并进一步研究其分子机制,为肺癌的治疗寻找新的靶点。方法:选取人肺癌细胞A549,以脂质体为载体一方面过表达PHD1,另一方面合成设计靶向PHD1的siRNA沉默PHD1,利用荧光素酶检测NF-κB的活性,分别用western blot和real-time PCR检测cyclinD1的表达水平。在A549细胞中过量稳定表达带GFP标记的PHD1,流式细胞仪检测细胞周期变化,测量细胞的生长曲线,并将细胞注射到裸鼠皮下观察其成瘤情况。结果:过表达PHD1可明显抑制NF-κB的活性和IκBα的降解,降低cyclin D1的mRNA和蛋白表达水平;而干扰PHD1的表达可显著增加NF-κB的活性,并上调cyclin D1的mRNA和蛋白表达水平,而不影响cyclinE1。过表达IκBαSR可以阻止干扰PHD1引起的cyclinD1 mRNA水平的上调。过表达PHD1可引起细胞周期的停滞,显著抑制细胞的增殖和移植瘤的生长。结论:PHD1可能通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖。     

生殖支原体脂质相关膜蛋白激活核因子κB诱导人单核细胞表达前炎症细胞因子及凋亡

为了解生殖支原体(Mg)潜在的致病性及其脂质相关膜蛋白(LAMPs)诱导人单核细胞(THP-1)凋亡及表达前炎症细胞因子(CKs)的分子机制,用Mg提取的LAMPs刺激THP-1细胞,以ELISA法和RT-PCR方法分析CKs产生和其mRNA的表达。不同试实验组的细胞经AnnexinV联合PI染色后通过流式细胞仪检测细胞凋亡。采用EMSA方法检测LAMPs处理的THP-1细胞中核转录因子kappaB(NF-κB)的激活,并分析NF-κB抑制剂二硫代氨基甲酸吡咯烷(pyrrolidine dithiocoarbamate,PDTC)对LAMPs处理的THP-1细胞产生CKs的量和其mRNA表达及细胞凋亡的影响。LAMPs能以时间和剂量依赖方式刺激THP-1细胞产生TNF-α、IL-1β和IL-6,且能激活NF-κB诱导THP-1细胞表达CKs的mRNA及发生凋亡,PDTC能显著抑制CKs的mRNA表达水平和细胞凋亡。由于LAMPs能激活NF-κB诱导THP-1细胞表达CKs及产生细胞凋亡,因而可能是一个重要的致病因素。     

B族维生素抑制NLRP3炎性小体活化减轻PM2.5致孕鼠脑损伤

目的 探讨NOD样受体热蛋白结构区域3(NOD-like receptor pyrin domain containing 3, NLRP3)炎性小体通路在B族维生素干预孕期PM2.5致脑损伤中的表达变化,明确B族维生素改善PM2.5污染所致危害的作用机制。方法 建立孕期PM2.5损伤动物模型,并给予B族维生素干预。将孕鼠随机分为PBS对照组,PM2.5模型组和VB干预组。分离孕鼠大脑皮层,采用RT-qPCR技术、Western blot技术、ELISA及免疫荧光染色方法检测孕鼠大脑皮层炎性小体通路NLRP3、cleaved caspase-1和IL-1β的表达变化。结果 RT-qPCR结果显示,模型组孕鼠大脑皮层NLRP3、IL-1βmRNA表达水平明显高于对照组;而干预组明显低于模型组,但与对照组无明显差异。Western blot和ELISA检测结果显示,模型组孕鼠大脑皮层NLRP3、cleaved caspase-1和IL-1β的蛋白表达较对照组明显增加,而干预组则明显低于模型组。免疫荧光染色方法显示,干预组孕鼠大脑皮层中NLRP3、cleaved caspase-1免疫反应阳性细胞数较模型组明显减少,与对照组无明显差异。结论 孕期给予B族维生素干预可以抑制孕鼠大脑皮层NLRP3炎性小体通路激活,对PM2.5暴露所致孕鼠大脑皮层损伤可能有一定的保护作用。     

人参皂苷Rg1对游离脂肪酸诱导非酒精性脂肪肝细胞炎症的改善作用及机制研究

该研究探讨人参皂苷Rg1对非酒精性脂肪性肝细胞炎症反应的作用及其分子机制。用1 mmol/L游离脂肪酸处理HepG2和L02细胞24 h,再用20μg/mL或40μg/mL人参皂苷Rg1处理6 h;设置对照组、模型组、低剂量Rg1组、高剂量Rg1组。全自动生化仪检测各组细胞上清谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)的含量;酶联免疫吸附法测定细胞上清IL-1β、IL-6、TNF-α。RT-qPCR及Western blot检测NF-κB通路相关基因及蛋白的改变。免疫荧光染色观察NF-κB核转移;Western blot检测各组胞质与胞核内的NF-κB P65蛋白的表达。与对照组相比,模型组培养上清炎症指标明显增加(P<0.05);Rg1能降低炎症指标的表达(P<0.05)。Rg1能减少游离脂肪酸诱导的NF-κB磷酸化及其下游IL-1β、IL-6、TNF-α的表达,减少NF-κB P65从胞质向胞核的转移(P<0.05)。Rg1可通过抑制NF-κB活化减少NASH细胞模型炎症反应,为非酒精性脂肪性肝炎的治疗提供了可能的靶点。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.