汉坦病毒感染诱导乳鼠脑神经细胞表达热休克蛋白70

生后2～3天的昆明乳鼠,每只腹腔接种0.05mL100个半数致死量的陈株汉坦病毒,于接种后不同时间点处死动物,取其脑组织常规固定,石蜡包埋制备5μm连续组织切片,用免疫组化法检测组织中的病毒抗原及热休克蛋白70的表达,用共聚焦显微镜观察二者之间的关系。结果发现,感染了病毒的组织能够稳定地检测到热休克蛋白70的表达,而病毒阴性的组织则检测不到热休克蛋白70的表达,且二者有共定位关系,其分布与组织病变一致。这与在病毒感染的VeroE6细胞及EHF病人尸检组织中得到的结果一致,说明病毒感染可诱导热休克蛋白70的表达,后者可能具有保护组织避免或减轻损伤的作用。     

汉滩病毒核蛋白与热休克蛋白GRP94、HSP27的相互作用

为研究汉滩病毒(Hantaan virus,HTNV)感染诱导乳鼠脑组织热休克蛋白GRP94、HSP27与病毒蛋白的相互关系,选出生2—3d的昆明乳鼠实验性感染汉滩病毒,取8d后发病乳鼠脑组织部分制石蜡切片,用免疫组化结合共聚焦显微镜检测组织中病毒抗原及GRP94、HSP27的表达,部分制匀浆液,用ELISA、免疫共沉淀方法分析病毒抗原和GRP94、HSP27的关系。结果示汉滩病毒感染诱导乳鼠脑组织神经细胞高表达GRP94且与细胞内病毒抗原有共定位关系,但未见HSP27诱导高表达;免疫共沉淀显示汉滩病毒核心抗原(HINV—NP)与GRP94、HSP27呈非共价复合物形式存在。该结果为进一步探讨HSPs在病毒感染复制中的作用以及抗病毒感染方面提供了有意义的实验资料。     

汉滩病毒核蛋白与热休克蛋白GRP94、HSP27的相互作用

为研究汉滩病毒(Hantaan virus, HTNV)感染诱导乳鼠脑组织热休克蛋白GRP94、HSP27与病毒蛋白的相互关系,选出生2～3d的昆明乳鼠实验性感染汉滩病毒,取8d后发病乳鼠脑组织部分制石蜡切片,用免疫组化结合共聚焦显微镜检测组织中病毒抗原及GRP94、HSP27的表达,部分制匀浆液,用ELISA、免疫共沉淀方法分析病毒抗原和GRP94、HSP27的关系.结果示汉滩病毒感染诱导乳鼠脑组织神经细胞高表达GRP94且与细胞内病毒抗原有共定位关系,但未见HSP27诱导高表达;免疫共沉淀显示汉滩病毒核心抗原(HINV-NP)与GRP94、HSP27呈非共价复合物形式存在.该结果为进一步探讨HSPs在病毒感染复制中的作用以及抗病毒感染方面提供了有意义的实验资料.     

流行性出血热尸检组织中热休克蛋白70mRNA的定位及分布

应用核酸原位分子杂交技术研究了国内不同地区３０例流行性出血热患者尸检组织中病毒ＲＮＡ及ＨＳＰ７０ｍＲＮＡ细胞内定位,同时观察了汉坦病毒感染的ＶｅｒｏＥ６细胞中ＨＳＰ７０的表达情况。结果表明,热休克蛋白７０ｍＲＮＡ在多数组织中均可检测到,分布与病毒ＲＮＡ一致,并且与组织的病理损害有关;体外实验的结果也表明在出血热病毒感染的细胞中有ＨＳＰ７０的高表达。提示热休克蛋白与汉坦病毒的致病以及流行性出血热的发病机理有关。     

汉滩病毒感染诱导热休克蛋白70表达

为了解汉滩病毒感染后细胞的应激反应及HSP70的表达与病毒复制的关系,在汉滩病毒A9株感染Vero-E6细胞后,用免疫组织化学及核酸分子原位杂交法,对细胞HSP70基因的表达进行了检测.结果表明,汉滩病毒感染细胞4h后即可诱导Vero-E6细胞表达HSP70,表达可持续至感染后5d,且HSP70在细胞内的分布也有改变.提示汉滩病毒可直接诱导HSP70的高表达.     

人热休克蛋白70和热休克固有蛋白70的基因克隆和表达

目的:克隆人热休克蛋白70(HSP70)和热休克固有蛋白70(HSC70)基因,并在大肠杆茵中表达,获得重组蛋白.方法:用RT-PCR法从HepG2细胞中扩增HSP70及HSC70cDNA序列.测序后,将相应的cDNA插入pRSET-A表达载体,在大肠杆菌中表达,重组蛋白纯化后用SDS-PAGE及Western Blotting分析.结果:DNA序列结果显示.本研究所获得的HSP70及HSC70 cDNA序列与参考序列一致.将全长cDNA分别插入表达质粒后,转化BL21(DE3)细菌,在IPTG的诱导下,表达产物SDS-PAGE显示相应的分子量(70kDa)位置有明显的蛋白条带.Western Blotting结果证实了其为目的蛋白,经镍树脂柱纯化,获得了相应的重组多肽.结论:成功构建了原核表达重组质粒HSP70-pRSET-A和HSC70-pRSET-A,并获得了纯化的重组人HSP70和HSC70蛋白,为进一步研究这两种蛋白的结构、功能及临床应用奠定了基础.     

热休克蛋白27增强A型流感病毒NS1对β干扰素的抑制作用

热休克蛋白27(Heat shock protein 27,HSP27)是一种具有多重功能的小热休克蛋白,它在一些病毒的生命周期中也发挥着重要作用。为研究HSP27对流感病毒感染的调节作用,首先在原核及真核细胞中克隆并表达了人源的HSP27蛋白,并验证了HSP27和A型流感病毒NS1蛋白能够相互结合。通过荧光素酶检测试验发现,HSP27可以抑制病毒感染细胞中β干扰素(IFN-β)的表达,但不依赖于其自身的磷酸化状态,而且HSP27与NS1共同对于IFN-β的表达具有叠加抑制效果。进一步的结果表明HSP27可能通过RIG-I样RNA解旋酶(RLH)途径中MDA5因子抑制IFN-β的表达。研究表明,HSP27在被感染细胞的天然免疫中发挥一定作用,有助于进一步阐明宿主因子对于流感病毒感染的调节机理。     

热休克反应与哺乳动物高海拔(缺氧)适应

利用免疫学和分子生物学手段研究哺乳动物的高海拔(缺氧)适应, 通过哺乳动物热休克反应, 了解热休克蛋白在生物体高海拔(缺氧)适应中的意义. 用Western blot和常规RT-PCR及实时荧光定量PCR(real-time PCR detection)测定不同海拔哺乳动物(牦牛)心肌组织热休克蛋白70(Hsp70)的表达差异和脑组织中Hsp70基因的自然表达. 将低海拔哺乳动物(家兔)直接送达不同高海拔地区(海拔2300, 3300, 5000 m)喂养3周后宰杀, 再用RT-PCR测定其脑组织中Hsp70基因的诱导表达. 结果显示: 不同海拔哺乳动物都具有热休克反应基因, 应激时高海拔哺乳动物Hsp70表达快速升高; Hsp70可被高海拔(缺氧)诱导产生. 热休克反应中Hsp70的快速合成有利于维持应激时细胞的正常生理功能, Hsp70的表达存在着阈值, 海拔5000 m是热休克反应最佳的条件, 超过海拔6000 m时热休克反应减弱; Hsp70生成量与细胞的耐缺氧能力成正比.     

麻醉对大鼠应激反应的影响

用40、42、44℃分别处理清醒状态和麻醉状态大鼠30min,于正常饲养条件下恢复24h后,检测其肝脏热休克蛋白70（HSP70）的表达差异及酸性和中性蛋白水解酶活性变化。结果表明,当热休克温度为40-44℃时,清醒状态大鼠肝脏的HSP70合成能力逐渐下降,而麻醉大鼠肝脏HSP70合成能力逐渐增加,在42℃热休克条件下,麻醉状态大鼠肝脏的酸性蛋白水解酶活性最强,在44℃热休克条件下,清醒状态大鼠肝脏的酸性蛋白水解酶活性最强,在40-44℃热休克条件下,麻醉状态和清醒状态大鼠肝脏的45kD中性蛋白水解酶活性与对照相似,但40kD的中性蛋白水解酶活性随热休克温度升高而降低,另外,40℃热休克诱导麻醉状态大鼠肝脏出现一个高活性的35kD中性蛋白水解酶,根据实验结果推测,麻醉状态大鼠肝脏的热耐受性大于清醒大鼠,大鼠的热休克反应受整体水平和细胞水平的双重调控,并涉及除HSP70合成以外的其他生化活动。     

热休克蛋白HSP70在LPS诱导急性肺损伤中的表达

目的检测内毒素诱导急性肺损伤中热休克蛋白70的表达状况,探讨HSP70在急性肺损伤中的作用机制。方法在LPS致Wistar大鼠急性肺损伤动物模型上,采用免疫组织化学(SABC法)和蛋白印迹实验研究各组动物肺组织中HSP70的表达情况。结果LPS处理后1h,大鼠的支气管粘膜上皮及肺泡上皮细胞HSP70的表达与正常对照组相比明显增多,2h的表达达到高峰,6h后与对照组水平一致。Western blot结果显示,LPS处理2h、4h时,HSP70的表达较对照组明显增强。结论LPS诱导的急性肺损伤中可引起支气管、细支气管和肺泡上皮细胞HSP70应激性表达,提示HSP70对肺损伤起保护作用。     

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.