氧化低密度脂蛋白

1 .氧化低密度脂蛋白 (ＬＤＬ)的发现形成动脉粥样硬化过程中的泡沫细胞病变与巨噬细胞的脂化胆固醇积累相关 ,在巨噬细胞极少发现ＬＤＬ受体 ,特别是遗传性ＬＤＬ受体缺乏的同形合子患者的家族性高胆固醇血症及其动物模型中 ,极早出现动脉粥样硬化病变。以后用抗氧化药能阻止高ＬＤＬ血症的实验兔发生动脉粥样硬化。用特异性的氧化ＬＤＬ的单克隆抗体 ,采用免疫组织化学法 ,从高脂血症的患者及动物模型的动脉粥样硬化病变部位检出氧化ＬＤＬ。ＬＤＬ的氧化变性的实际部位在活体内 ,特别是在血管壁内发生 ,对动脉粥样硬化的形成起重要作用。…     

氧化低密度脂蛋白对THP-1巨噬细胞吞噬和分泌功能的影响

目的:探讨氧化低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)对巨噬细胞源性泡沫细胞吞噬功能和炎症相关因子分泌功能的影响。方法:利用佛波酯(phorbol ester,PMA)诱导THP-1细胞分化形成巨噬细胞,之后采用ox-LDL处理48小时后,诱导其形成泡沫细胞。利用中性红吞噬实验,分析泡沫细胞形成前后吞噬功能的变化;通过ELISA法,检测细胞培养上清中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)含量,观察ox-LDL对THP-1巨噬细胞功能的影响。结果:细胞形态学结果表明,我们成功利用ox-LDL诱导THP-1巨噬细胞形成泡沫细胞;进一步发现ox-LDL诱导THP-1巨噬细胞表面的清道夫受体CD36表达升高,并促进细胞吞噬功能增加,进一步促进细胞内胆固醇含量显著升高(P0.05);同时,ox-LDL能够刺激巨噬细胞大量分泌TNF-α(P0.05)。结论:ox-LDL通过增强清道夫受体CD36表达,提高巨噬细胞的吞噬功能,引起大量胆固醇聚集,产生细胞毒性损伤,并促进TNF-α炎性因子的大量分泌。     

β-榄香烯对RAW264.7巨噬细胞源性泡沫细胞作用的研究

目的:研究β-榄香烯抗巨噬细胞源性泡沫细胞的形成及抑制巨噬细胞炎症因子分泌的作用。为探讨β-榄香烯抗动脉粥样硬化(AS)的作用提供依据。方法:采用氧化低密度脂蛋白(ox-LDL)诱导小鼠单核/巨噬细胞(RAW264.7)建立巨噬细胞源性泡沫细胞模型,采用油红O染色鉴定泡沫细胞形成。给予不同浓度(0.5,5,50μM)β-榄香烯干预后,ELISA方法检测巨噬细胞源性泡沫细胞内胆固醇含量和肿瘤坏死因子-α(TNF-α),白介素-6(IL-6)分泌量的变化。结果:β-榄香烯可降低巨噬细胞源性泡沫细胞内总胆固醇(P0.05或P0.01),胆固醇酯含量(P0.01),减少炎症因子TNF-α,IL-6的分泌(P0.05或P0.01),并且呈现出一定的浓度依赖性。结论:β-榄香烯抑制巨噬细胞对ox-LDL的摄取,降低细胞内胆固醇的含量,抑制泡沫细胞的形成,同时改善巨噬细胞的炎症状态从而发挥抗动脉粥样硬化的作用。     

beta- 榄香烯对RAW264.7 巨噬细胞源性泡沫细胞作用的研究

目的:研究β-榄香烯抗巨噬细胞源性泡沫细胞的形成及抑制巨噬细胞炎症因子分泌的作用。为探讨β-榄香烯抗动脉粥样硬化(AS)的作用提供依据。方法:采用氧化低密度脂蛋白(ox-LDL)诱导小鼠单核/巨噬细胞(RAW264.7)建立巨噬细胞源性泡沫细胞模型,采用油红O染色鉴定泡沫细胞形成。给予不同浓度(0.5,5,50μM)β-榄香烯干预后,ELISA方法检测巨噬细胞源性泡沫细胞内胆固醇含量和肿瘤坏死因子-α(TNF-α),白介素-6(IL-6)分泌量的变化。结果:β-榄香烯可降低巨噬细胞源性泡沫细胞内总胆固醇(P<0.05或P<0.01),胆固醇酯含量(P<0.01),减少炎症因子TNF-α,IL-6的分泌(P<0.05或P<0.01),并且呈现出一定的浓度依赖性。结论:β-榄香烯抑制巨噬细胞对ox-LDL的摄取,降低细胞内胆固醇的含量,抑制泡沫细胞的形成,同时改善巨噬细胞的炎症状态从而发挥抗动脉粥样硬化的作用。     

甲状腺激素对氧化型低密度脂蛋白诱导的巨噬细胞功能紊乱的影响

甲状腺功能减退症(甲减)患者的动脉粥样硬化(atherosclerosis,AS)及冠心病风险指数显著增加,但机制不清楚。巨噬细胞功能紊乱是促进AS斑块形成及发展的重要环节,本研究旨在探讨甲状腺激素对巨噬细胞功能的直接影响,为甲减相关AS的机制研究提供新思路。用氧化型低密度脂蛋白(oxidized low-density lipoprotein,oxLDL)诱导小鼠单核巨噬细胞系RAW264.7,建立体外巨噬泡沫细胞模型,并观察不同浓度甲状腺素(thyroxine,T4)对巨噬泡沫细胞功能的改善效应。分别采用MTT法、划痕实验、β-半乳糖苷酶染色实验检测巨噬细胞增殖、迁移功能及细胞衰老情况;ELISA法检测巨噬细胞分泌肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)及白细胞介素-1β(interleukin-1β,IL-1β)情况;Western blot检测参与巨噬细胞增殖、迁移等过程的粘着斑激酶(focal adhesion kinase,FAK)的磷酸化水平。结果显示:oxLDL可显著抑制巨噬细胞增殖和迁移、促进其衰老及分泌TNF-α、MCP-1和IL-1β,而T4可浓度依赖性逆转oxLDL对巨噬细胞上述功能的影响;oxLDL可使巨噬细胞磷酸化FAK蛋白表达上调,而T4可浓度依赖性降低FAK蛋白磷酸化水平。上述结果提示,T4可呈浓度依赖性地调控巨噬细胞增殖、迁移、衰老及炎性因子分泌等功能。     

氧化型胆固醇与动脉粥样硬化的关系

氧化型胆固醇是胆固醇氧化衍生物,多达上百种。氧化型胆固醇存在于胆固醇膳食,高胆固醇血症的血浆和动脉组织、人动脉粥样硬化斑块和斑块内的泡沫细胞,以及氧化型低密度脂蛋白中。大量实验表明氧化型胆固醇对与动脉粥样硬化形成有关的细胞（如血管内皮细胞,平滑肌细胞以及单核／巨噬细胞等）具有毒性作用,提示,氧化型胆固醇在动脉粥样硬化的发生和演变中具有不可忽视的作用。     

巨噬细胞移动抑制因子及其在动脉粥样硬化中的作用

巨噬细胞移动抑制因子（macrophage migration inhibitory factor,MIF）,其主要作用为抑制巨噬细胞的游走移动、促进巨噬细胞在炎症局部浸润、聚集、激活及分泌一些细胞因子,如IL-1、TNF—α、NO等,从而间接增强巨噬细胞的功能。巨噬细胞不仅是产生MIF的主要细胞,也是MIF作用的靶细胞,因此MIF在巨噬细胞参与调节的各种疾病尤其是动脉粥样硬化中发挥着重要作用。研究表明,血管发生动脉粥样硬化部位的MIF表达水平明显上调,且随着斑块的发展逐渐上升;相反,阻断MIF的表达则可以显著廷缓动脉粥样硬化的发撮并稳定斑块。因此,MIF在单核巨噬细胞的血管粘附、跨膜移动、内皮下聚集、泡沫细胞的形成及斑块稳定中的作用可能与动脉粥样硬化的发生和发展有密切关系。本文将主要就MIF的生理及病理生理学功能特别是其在动脉粥样硬化发病及治疗中的作用作一综述。     

人清道夫受体AII胞外部分在毕赤酵母(Pichia pastoris)中的分泌表达

清道夫受体A(SR-A)介导巨噬细胞无限制摄取修饰的低密度脂蛋白(mLDL)形成泡沫细胞,继而形成动脉粥样硬化病灶,在动脉粥样硬化的发生、发展过程中具有重要作用,被认为是治疗动脉粥样硬化的潜在靶点。本文应用RT-PCR方法扩增得到编码人Ⅱ型SR-A胞外部分(shSR-AII)的cDNA,将其克隆至毕赤酵母(Pichia pastoris)分泌表达载体pPIC9K构建重组表达质粒p9K-shSR-AII。将重组表达质粒线性化后,电转化毕赤酵母GS115,用原位双膜法筛选获得高表达shSR-AII的重组菌株GS115／p9K-shSR-AII。重组菌株经1％甲醇诱导,SDS-PAGE、Western blot分析表明shSR-AII获得了分泌表达。Ligand binding blot结果表明表达的shSR-AII具有与配基oxLDL结合的生物活性。U937泡沫细胞模型进一步表明shSR-AII可通过竞争性结合oxLDL来抑制泡沫细胞的形成,为以shSR-AII为靶点建立抗动脉粥样硬化药物筛选模型奠定了基础。     

治疗动脉粥样硬化的靶位:A类清道夫受体

动脉粥样硬化性心血管疾病是危害人类健康的常见疾病之一。A类清道夫受体是动脉粥样硬化发生和发展过程中的主要参与者之一,介导巨噬细胞内吞修饰的低密度脂蛋白,形成泡沫细胞,有明显的致动脉粥样硬化作用,是治疗动脉粥样硬化的潜在靶点。另外A类清道夫受体还参与机体的防御过程。重点综述了A类清道夫受体各成员结构及其在动脉粥样硬化中的生理作用和在新药研发方面的应用与展望。     

Adipophilin在动脉粥样硬化病变和脂质负荷细胞中的作用研究(英文)

Adipophilin是细胞内脂质聚集和与脂质聚集有关疾病的标志物 ,巨噬细胞源性泡沫细胞的形成是动脉粥样硬化性疾病发生的重要环节 .为了探讨adipophilin在动脉粥样硬化性疾病的作用 ,通过高胆固醇饲料喂养新西兰白兔 12周 ,复制动脉粥样硬化疾病模型 ,同时测定血脂的变化和动脉壁胆固醇 ,使用HE染色、苏丹Ⅳ染色观察动脉粥样硬化病变的形成 ,使用免疫组织化学的方法观察动脉粥样硬化病变处和动物肝脏中adipophilin的表达 .结果发现 ,高胆固醇饲料喂养组血清总胆固醇、低密度脂蛋白胆固醇和动脉壁胆固醇明显增高 ,动脉粥样硬化病变面积增加到 (40 0 6± 7 2 9) % ,动脉粥样硬化病变处adipophilin表达呈阳性 ;而adipophilin在肝脏中的表达无论是高胆固醇饲料喂养组或对照组均为阴性 .使用80mg/L OxLDL与小鼠腹膜巨噬细胞共孵育 ,复制脂质负荷细胞 ,然后把构建的 1mmol/Ladipophilin反义寡核苷酸与该细胞共孵育 .结果发现 ,使用油红O染色观察的细胞内脂滴明显减少 ,生化测定细胞内胆固醇酯显著降低 ,与对照组相比 ,差别有显著性 .说明adipophilin与动脉粥样硬化病变有密切的关系 ,控制adipophilin的表达能够减少巨噬细胞细胞内胆固醇酯的聚集     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.