简介:核受体是一类高度保守的配体依赖性转录因子家族,在哺乳动物发育、繁殖、免疫应答、心血管功能、组织生长、肿瘤形成、外源物清除及糖类和脂质代谢等生理过程中发挥重要作用。机体对外源物质的清除主要是由孕烷X受体等核受雄介导的。孕烷X受体最早是作为外源物感受器而被研究的,可以被大多数亲脂性药物等外源性化合物及一些内源性化合物如胆汁酸等结构差异很大的配体激活,进而与视黄醇类X受体等形成异源二聚体,结合在ER6、XREM等DNA元件上,调控下游靶基因(包括一相代谢酶、二相结合酶及药物转运体等基因)的表达。此外,孕烷X受体在能量代谢和免疫反应中也有重要作用,参与某些代谢疾病的发生发展,且已在动物模型中被证明是Ⅱ型糖尿病、血脂异常、肥胖症和动脉粥样硬化等代谢疾病治疗的有效靶标。我们主要就其发现、结构、组织分布、作用方式、自身表达的调节等方面的最新研究进行综述。
简介:AktandBcl-xLbothpromoteresistancetoapoptosis.AcomparisonofAkt-andBcl-xL-dependentcellsurvivalwasundertaken.ExpressionofconstitutivelyactiveAktallowscellstosurviveforprolongedperiodsintheabsenceofgrowthfactors.ThissurvivalcorrelateswiththeexpressionlevelofactivatedAktandiscomparableinmagnitudetotheprotectionprovidedbytheanti-apoptoticgeneBcl-xL.Althoughbothgenespreventcelldeath,Akt-protectedcellscanbedistinguishedfromBcl-xL-protectedcellsonthebasisofincreasedglucosetransporterexpression,glycolyticactivity,mitochondrialpotential,andcellsize.Inaddition,Akt-expressingcellsrequirehighlevelsofextracellularnutrientstosupportcellsurvival.In
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简介:ThesplicingofmanyalternativeexonsintheprecursormessengerRNA(pre-mRNA)isregulatedbyextracellularfactorsbuttheunderlyingmolecularbasesremainunclear.HerewereportthedifferentialregulationofBcl-xpre-mRNAsplicingbyextracellularfactorsandtheirdistinctrequirementsforpre-mRNAelements.InK562leukemiacells,treatmentwithinterleukin-6(IL-6)orgranulocyte-macrophagecolonystimulatingfactor(GM-CSF)reducedtheproportionoftheBcl-xLvariantmRNAwhiletreatmentwith12-O-tetradecanoylphorbol13-acetate(TPA)hadnoeffect.InU251gliomacells,however,TPAefficientlyincreasedtheBcl-xLlevel.Theseregulationswerealsoseenforatransfectedsplicingreportermini-gene.Furtheranalysesofdeletionmutantsindicatethatnucleotides1-176ofthedownstreamintronarerequiredfortheIL-6effect,whereasadditionalnucleotides177-284areessentialfortheGM-CSFeffect.AsfortheTPAeffect,onlynucleotides1-76arerequiredinthedownstreamintron.Thus,IL-6,GM-CSFandTPAdifferentiallyregulateBcl-xsplicingandrequirespecificintronicpre-mRNAsequencesfortheirrespectiveeffects.
简介:Nineshorttandemrepeat(STR)markersontheXchromosome(DXS101,DXS6789,DXS6799,DXS6804,DXS7132,DXS7133,DXS7423,DXS8378,andHPRTB)wereanalyzedinfourpopulationgroups(Mongol,Ewenki,Oroqen,andDaur)fromInnerMongolia,China,inordertolearnaboutthegeneticdiversity,forensicsuitability,andpossiblegeneticaffinitiesofthepopulations.Frequencyestimates,Hardy-Weinbergequilibrium,andotherparametersofforensicinterestwerecomputed.Theresultsrevealedthattheninemarkershaveamoderatede-greeofvariabilityinthepopulationgroups.Mostheterozygosityvaluesfortheninelocirangefrom0.480to0.891,andthereareevidentdifferencesofgeneticvariabilityamongthepopulations.AUPGMAtreeconstructedonthebasisofthegenerateddatashowsverylowgeneticdistancebetweentMongolandHan(Xi’an)populations.Ourresultsbasedongeneticdistanceanalysisareconsistentwiththeresultsofearlierstudiesbasedonlinguisticsandtheimmigrationhistoryandoriginofthesepopulations.TheminisatellitelociontheXchromosomestudiedherearenotonlyusefulinshowingsignificantgeneticvariationbetweenthepop-ulations,butalsoaresuitableforhumanidentitytestingamongInnerMongolianpopulations.
简介:南京美易科技有限公司属南京江宁国家级高新技术开发区内的高新技术企业,企业拥有企业标准并已通过ISO9001:2000国际质量管理体系认证。13年来,我们一直致力于生理科学实验仪器的研制与开发。公司成员大多是高校教师,技术力量雄厚,多学科的交叉和结合,使拥有自主知识产权的MedLab(登记号:3128284)系列产品在生物信号采集处理领域处于领先地位,多项功能超过国际同类产品,并不断开发出各类实验新产品。MedLab生物信号采集处理系统已获得国家专利(专利号ZL02220911.5)并获得香港专利博览会金奖。MedLab能替代传统的多道生理记录仪、示波器、X—Y记录仪和刺激器等仪器,一机多用,功能强大,可应用于医学院、药学院、生命学院、体育学院、师范学院、农学院等生命学科的生理学、药理学、病理生理学、运动生理学和心理学等实验。