脂肪酸受体GPR84及其调节剂的研究进展

G蛋白偶联受体84(GPR84)属于脂肪酸受体,能被中链脂肪酸(C9-C14)激活。人体内GPR84主要表达在骨髓,其次表达在外周白细胞和肺,在生理状态下GPR84表达量较低,炎症刺激(如脂多糖)可诱导GPR84在单核/巨噬细胞中高表达,可知GPR84与炎症有很大关系。许多疾病的发生发展伴随着炎症反应,而GPR84小分子调节剂能调节炎症反应,从而干预相关疾病的进程。本文主要就GPR84与各类疾病的关系,以及GPR84小分子调节剂的研究展开综述。     

两个黄酮类化合物对GPR35受体激动活性的研究

GPR35受体是G蛋白偶联受体家族中的孤儿受体,它的很多生物学功能还不是很清楚.寻找发现GPR35受体的配体对于GPR35受体的生物学及药理学研究具有重要意义.本研究利用无标记细胞靶点药理学筛选技术,系统研究了天然黄酮类化合物对GPR35受体的激动活性,新发现了草质素和异补骨脂二氢黄酮具有GPR35受体激动活性,其中草质素EC50=(1.452±0.093)μmol/L,是最具药物开发潜力的一个GPR35受体激动剂.     

肿瘤内皮标志物8同型物Ⅰ基因真核表达载体的构建及其在HEK293F细胞中的表达

目的:构建肿瘤内皮标志物8(TEM8)基因真核表达载体,实现TEM8在HEK293F细胞中的外源表达。方法:用PCR技术扩增TEM8基因,经限制性酶切、连接、转化,插入pcDNA3.1(+)-EGFP真核表达载体,并通过脂质体将TEM8表达质粒转染至HEK293F细胞中,Western印迹检测TEM8的表达。结果:PCR扩增得到TEM8基因,构建了真核表达载体pcDNA3.1(+)-TEM8-EGFP并转染HEK293F细胞,经G418加压筛选及有限稀释法得到生长性状良好、表达效率高的单克隆细胞系TEM8-EGFP/HEK293F;Western印迹证明过表达细胞系TEM8-EGFP/HEK293F显著表达TEM8蛋白。结论:构建了表达TEM8的重组HEK293F工程细胞系TEM8-EGFP/HEK293F,为进一步研究TEM8的生理功能奠定了基础。     

家鸡GPR15基因的克隆、功能探究及组织表达分析

孤儿受体G蛋白偶联受体15(GPR15)在哺乳动物肠道稳态以及炎症反应中发挥重要生理效应,但在非哺乳动物中,针对GPR15的研究几属空白。本文以家鸡Gallus gallus domesticus为模型,首次克隆了GPR15基因,并对其功能与组织表达进行了探究。结果显示:家鸡GPR15编码区cDNA长度为1 107 bp,由1个外显子组成,可编码368个氨基酸的受体蛋白。序列分析表明家鸡GPR15是具有7次跨膜结构的G蛋白偶联受体,且家鸡GPR15与人Homo sapiens、北美绿蜥蜴Anolis carolinensis、小鼠Mus musculus的GPR15具有约56%的氨基酸序列一致性;虽然系统进化树分析表明GPR15与爱帕琳肽受体(APLNR)有较近的进化关系,但在表达家鸡GPR15的HEK293细胞中,APLNR的内源性配体Apelin和Apela不能激活家鸡GPR15;此外,实时定量PCR分析发现GPR15在家鸡脾脏中高表达,在盲肠、肺中有中等水平表达,而在其他组织中微弱表达。上述结果为探究GPR15在禽类中的生理功能奠定了基础。     

游离脂肪酸受体的结构、分布及功能

游离脂肪酸的生理功能及其与某些疾病的相关性长期以来受到人们的关注。由于特异性膜受体一直未被发现．关于其分子机制的认识无法深入。最近的研究表明,长链脂肪酸是孤儿型G蛋白偶联受体GPR40的配基．而短链脂肪酸则是孤儿型G蛋白偶联受体GPR4l和GPR43的配基。体外实验显示,长链脂肪酸通过GPR40增强胰岛B细胞的分泌功能;短链脂肪酸经GPR41刺激脂肪细胞中瘦蛋白(1eptin)的产生。GPR43在白细胞活化过程中发挥一定的作用。作为潜在的药物作用靶点,游离脂肪酸特异性受体为寻找治疗代谢性疾病的新手段指明了的方向。     

外源表达的人copine V诱导细胞死亡的研究

目的：copines蛋白家族是新近发现的一类分布广泛、进化保守的Ca2＋依赖性磷脂结合蛋白,copineV是其成员之一.为研究copineV基因的功能,构建了人copineV基因的真核表达质粒并转染HEK293细胞,以进一步研究其功能.方法：构建人copineV编码区序列的真核表达质粒pCDNA4/copineV,脂质体法转染HEK293细胞.通过RT-PCR、克隆形成实验和Hochesst33342染色等方法观察copineV基因对HEK293细胞生长的影响.结果：外源表达的人copine V可以诱导HEK293细胞死亡,无法筛选到稳定克隆.结论：人copineV可以诱导HEK293细胞死亡,为进一步研究copineV基因的生物功能提供了线索.     

G蛋白偶联受体40研究进展

G蛋白偶联受体40(G protein-coupled receptor 40, GPR40)是一种具有7个跨膜α螺旋结构的G蛋白偶联受体, 主要分布于胰腺细胞和神经系统细胞。它能与机体内游离的中长链脂肪酸结合, 激活细胞内信号通路, 从而调节其生理功能。在胰岛细胞中, GPR40可被游离脂肪酸激活, 促使细胞内钙离子浓度升高, 进而促进胰岛素释放。根据这一机理, 以GPR40为靶点的激动剂类药物相继被开发, 用于糖尿病治疗。GPR40也参与神经发生过程, 但到目前为止其相关机制尚不清楚。文章从基因结构、表达调控、蛋白配体及应用、生理功能等方面详细介绍了GPR40的研究现状, 总结了目前研究中所遇到的问题, 并对未来的研究热点进行展望。     

果蝇来源的GPCR Methuselah G蛋白偶联信号转导通路研究

Methuselah(MTH)是果蝇来源的GPCR中的一员,它的突变可延长果蝇平均寿命并提高果蝇对外界胁迫因素的耐受性。但目前对MTH在细胞水平的信号转导研究鲜有报道。该研究用稳定表达MTH的HEK293细胞株,对与该受体偶联的G蛋白选择性做了研究。首先,用免疫荧光染色、Western blot及钙流实验验证了MTH在HEK293/Myc-MTH细胞表面能稳定表达,且具有正常生物学活性;MTH受体被其配体N-stunted活化后所引起细胞内钙的上升不能被PTX预处理抑制,提示活化的MTH可能通过与Gq/11而非Gi/o蛋白相偶联;进一步研究发现,MTH激活后不显著改变细胞中的cAMP水平,表明MTH不与Gs和Gi/o相偶联;MTH被激活后可引起ERK磷酸化。这些结果提示:MTH可能是Gq/11蛋白的偶联受体,为进一步研究MTH的下游信号转导和生物学功能奠定了基础。     

shRNA随机文库结合TK自杀基因筛选靶向HIV-1LTR相关宿主因子

构建shRNA随机文库与HIV-1 LTR启动胸苷激酶基因(TK基因)稳定表达的稳定细胞系HEK293/TK,将两者结合起来,筛选靶向HIV-1 LTR相关宿主因子.方法:通过化学合成含有19个随机脱氧核苷酸的发夹结构,将其退火补平后与合成的接头Linker连接进行PCR反应,将PCR产物酶切后置于慢病毒载体pLenti-U6启动子下游由此构建shRNA随机文库;利用重叠PCR将HIV-1 LTR片段和TK基因连接起来,连接产物经酶切后与pcDNA3.1载体连接;将连接正确的质粒转染HEK293细胞同时用G418加压筛选获得稳定细胞系HEK293/TK;将所获得的文库质粒包装成慢病毒后侵染所构建的HEK293/TK细胞系,通过加入药物GCV进行加压筛选获得存活细胞.结果:成功筛选到加药后存活下来的细胞,抽提细胞基因组,采用巢式PCR扩增目的干扰序列并用Western blot对干扰序列进行验证,鉴定获得一个克隆所表达的shRNA能对TK基因的表达起到抑制作用,通过测序分析获得其干扰序列,该序列很有可能针对HIV-1 LTR某宿主相关因子.结论:成功构建了一种筛选HIV-1 LTR相关宿主因子的方法,筛选所得序列可以定位到具体相关宿主因子,为靶向筛选抗HIV-1药物提供了重要手段.     

磷脂酰肌醇蛋白聚糖3真核表达载体的构建及在细胞中的表达

构建载体表达人磷脂酰肌醇蛋白聚糖3(Glypican-3,GPC3)蛋白,用以获得抗GPC3单克隆抗体。用PCR技术扩增GPC3基因,利用酶切位点将该序列插入p3XFLAG-CMV-14载体,构建p CMV-gpc3表达载体。通过脂质体将该载体转染至HEK293细胞中,利用Western blot技术检测最终结果。收集稳定表达的细胞,破碎,通过亲和层析柱,获得纯度较高的GPC3蛋白。成功构建p CMV-gpc3真核表达载体,转染至HEK293细胞后,经G418筛选获得稳定表达的单克隆细胞系;Western blot分析结果表明目的蛋白高效表达。     

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.