Role of TOR signaling in aging and related biological processes
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围区盟瘗堂苤查!!!!至!!旦笙!!鲞筮!!塑』!堕Q!!!!:Q塑!竺!!!!:!生!!!盟!:!!甘丙肽在肿瘤发生发展中的作用隋玉梅方彭华史明仪1、平【摘要】甘丙肽(GAL)作为一种神经肽,广泛分布于中枢和外周神经系统及内分泌系统。
目前已发现GAL及其受体存在于多种神经内分泌肿瘤组织和非神经内分泌肿瘤组织中,如嗜铬细胞瘤、鳞状细胞瘤、脑垂体腺瘤和胃肠癌等等。
GAL及其受体参与多种肿瘤的发生发展过程,研究其在肿瘤发生发展过程中的作用,对于有目的性地诊断和治疗肿瘤有积极作用。
【关键词】甘丙肽;肿瘤;甘丙肽受体RolesofgalaninpeptideintumorigenesisandtumorprogressionSU/Yu一.wi,FANGPeng—hua,SHl胁ng—yi,BU尸i愕.DepartmentofPhysiology,YangzhouUniversityMedicalAcademy,Yangzhou225001,ChinaCorrespondingauthor:SHIMing—yi.E—mail:shimingyi2000@yahoo.com.cn【Abstract】Galaninisapeptidewithwide—rangingeffects,especiallywithinthecentral,peripheralnervoussystemandendocrinesystem.Manytumorsofneuroendocrineorigin,andalsoanincreasingnurnl3erofnon—neuroendocrinecancers,havebeenshowntoexpressgalaninand/oritsreceptors.Expressionofgalaninpeptidehasbeendetectedinpheochromooytoma,squamouscellcarcinoma,pituitaryadenoma,gastrointestinalcancersandSOon.Galaninpeptideplaysanimportantroleintumori—genesisandprogressionofmanykindsoftumors.Therefore,studyingtherolesofgalaninanditsreeeplorsarehelpfultordiagnosisandtreatmentoftumors.。
衍射的应用英语作文Diffraction: A Fascinating Phenomenon in Our Lives.You know, diffraction is this cool thing in physicsthat happens when light or sound waves bend around obstacles. It's like magic, but science!Have you ever noticed those rainbow-colored spots on a CD when you shine a light on it? That's diffraction in action! The tiny grooves on the CD surface scatter thelight in all directions, creating those pretty patterns.In music, diffraction plays a role too. Have you ever noticed that sound seems to travel differently in different environments? That's because walls, floors, and ceilings can diffract sound waves, changing how they travel through a space.Astronomers use diffraction to their advantage too. Telescopes rely on diffraction to gather light from distantstars and galaxies, allowing us to peer into the depths of space. Without diffraction, we'd miss out on so much of the universe's wonders.But diffraction isn't just for scientists and astronomers. It's a part of our daily lives too. From the way light dances through a window's blinds to the way our voices echo in a large room, diffraction is constantly shaping our perception of the world.So, next time you see those rainbow spots on a CD or hear a distant voice echoing in a hallway, remember: it's all thanks to diffraction, that fascinating phenomenon that makes our world just a little bit more magical.。
cell s...so far away,so cl ose[J].R ev Neu rol(Paris),2008,164:1057-1062.[2]Nave KA,T rapp BD.Axon glial si gnali ng and t h e glial s upport ofaxon f uncti on.A nnu[J].Rev N eurosc,i2008,31:535-561. [3]Edgar J M,Garbern J.TheM yeli nated axon i s dep endent on t h em yeli n ati ng cell f or s upport and m a i ntenan ce m olecu l es i nvolved[J].Neu rosciRes,2004,76:593-598.[4]C ol ello R J,PottU.S i gnals that in i ti ate m yelinati on i n the develop i ng m a mm alian nervou s s yste m[J].M o lNeu rob i o,l1997,15:83 -100.[5]Chan J R.M yeli nati on:a ll abou tR ac n''rol[J].J C ell B i o,l2007,177:953-955.[6]Perli n J R,Ta l bot W S.Pu tti ng t he gl u e i n glia:Necls m ed i ateSchw ann cell axon adh es i on[J].J Cell B i o,l2007,178:721-723.[7]Parri nell o S,Noon LA,H arrisi ngh M C,e t al.NF1l oss d i sruptsSchw ann cell axon al i n teracti ons:a novel role f or se m aphori n4F [J].G enes Dev,2008,22:3335-3348.[8]FeltriM L,Su t erU,Relvas J B.The f un cti on ofRho GTPases in axonen s heathm ent and m yeli nati on[J].Gli a,2008,56:1508-1517. [9]C osgaya J M,Ch an J R,Shooter E M,e t al.The neu rotroph i n receptor p75NTR as a positive m odu l at or of m yelinati on[J].S ci en ce,2002,298:1245-1248.[10]E rb M,F l ueck B,K ern F,et al.U nraveling t h e d ifferenti al exp ress i on of the t w o isof or m s ofm yeli n associated gl ycop rotei n i n a mouse expressi ng GFP tagged S M AG s p ecifically regu lated and targetedi n t o t he d iff eren t myeli n co m part m ents[J].M ol Cell N eurosc,i2006,31:613-627.[11]Dong Z,Dean C,W alters J E,et al.Res ponse of Schw ann cell s tom itogens in vitro i s deter m i ned by pre expos u re to serum,ti m e i n vitro,and developm ental age[J].G li a,1997,20:219-230.[12]Plant G W,C urri er PF,Cu ervo EP,et a l.Purifi ed adult en s heath i ng glia fail to myeli nate axons under culture cond i ti on s that enab leSchw ann cell s to for m m yelin[J].Neu ros cience,2002,22:6083-6091.[13]Ro m ij n H J.Devel opm en t and advantage of serum free,c h e m icallydefi n ed nu tri entm ed i um for cu lt u ri ng ofn erve ti ss u e[J].B i olC el,l1988,63:263-268.[14]Bre w er G J.S erum freeB27/neurobasalm ed i um supports d ifferen ti ated gro w t h of neu ron s from the striatum,sub stanti an i gra,s ept um,cerebralcortex,cereb ell um,and den tategyrus[J].Neu rosci Res,1995,42:674-683.[15]E l dri dge CF,BungeM B,B unge RP,e t al.D ifferen ti ati on of axonrel ated S chw ann cells in vitro.I.Ascorb ic aci d regulat es bas al l a mi na asse mb l y and myeli n for m ation[J].J Cell B io,l1987,105:1023-1034.[16]E ldri dge CF,BungeM B,Bunge RP.D iff eren tiati on of axon rel atedSchw ann cells i n vitro:II.Con trol ofm yeli n for m ation by bas al l a m i na[J].Neuroscience,1989,9:625-638.(收稿日期:2009-05-10)et al.与etc.的用法与区别在英文论文中,常会出现e t a.l和e tc.的错误或混淆使用,本文试分析这两种表达的用法和区别。
山东医药2023 年第 63 卷第 35 期RET指样蛋白3在恶性肿瘤发生发展中的作用研究进展孙程妍,杭晓朦,程凯,陈政华,马维昌,李文杰滨州医学院烟台附属医院甲状腺乳腺外科,山东烟台264100摘要:RET指样蛋白(RFPL)作为一类RET指样蛋白类似物家族,在多种恶性肿瘤中广泛表达。
RET指样蛋白3(RFPL-3)是RFPL中的一员,在肿瘤的发生发展中发挥重要作用。
在乳腺癌中,RFPL-3主要通过促进人端粒逆转录酶基因(hTERT)转录和上调端粒酶活性,来介导乳腺癌的发生。
RFPL-3还可以通过MAPK通路和转化生长因子β(TGF-β)/Smad通路以及与p53重要的负调控因子双微体同源基因2(MDM2)竞争p53结合位点,从而促进肺癌的进展。
而在睾丸生殖细胞肿瘤中,RFPL-3表达下调促进了肿瘤细胞的转移和增殖相关通路激活,包括细胞外基质—受体相互作用、黏着斑信号通路、黏附连接信号通路以及PI3K/Akt信号通路、Wnt信号通路和Hippo信号通路。
在甲状腺癌的发生发展中,促进肿瘤细胞增殖的重要原因在于RFPL-3对Yes-associated蛋白的修饰,从而激活Hippo信号通路。
因此,RFPL-3与多种恶性肿瘤的发生发展密切相关,有望成为治疗恶性肿瘤的潜在靶点,为患者的治疗提供更多选择。
关键词:RET指样蛋白3;乳腺癌;肺癌;甲状腺癌;睾丸生殖细胞肿瘤;恶性肿瘤doi:10.3969/j.issn.1002-266X.2023.35.021中图分类号:R73 文献标志码:A 文章编号:1002-266X(2023)35-0085-03恶性肿瘤是威胁人类健康的主要疾病,其复发转移仍是困扰临床医生的主要难题[1]。
随着精准医学的发展,寻找恶性肿瘤新的分子标志物以及治疗靶点,避免肿瘤的复发、转移则显得尤为重要。
RET 指样蛋白3(RFPL-3)作为RET指样蛋白(RFPL)家族的主要成员,在调节细胞的生长和分化中具有重要作用。
自噬与足细胞病宋诩;卢宏柱【摘要】足细胞是一种高度分化细胞,对维持肾小球滤过屏障的完整性非常重要.自噬是溶酶体降解胞质成分来维持细胞内稳态的细胞生物学过程,其参与足细胞病的发生、发展.自噬在肾小球足细胞中起到的调控作用成为对抗足细胞损伤的研究热点,现就自噬与足细胞病的相关研究进行综述.【期刊名称】《广东医学》【年(卷),期】2018(039)023【总页数】4页(P3578-3581)【关键词】自噬;足细胞病;肾小球滤过屏障【作者】宋诩;卢宏柱【作者单位】长江大学附属第一医院儿科湖北荆州 434000;长江大学附属第一医院儿科湖北荆州 434000【正文语种】中文足细胞产生的各种裂孔膜蛋白和细胞骨架蛋白是维持肾小球通透性的关键结构,因此,足细胞结构和功能的正常对维持肾小球滤过屏障的完整性非常重要。
自噬是一种广泛存在于真核细胞中,用于降解和回收利用细胞长效生物大分子和受损细胞器的过程,它作为一种细胞保护机制,在多种肾脏疾病尤其是足细胞病的进程中发挥着重要作用。
本文就自噬与足细胞病的研究进展进行阐述。
1 足细胞自噬足细胞是一种终末分化细胞,其分裂和增殖能力较差,足细胞数量的减少,可作为预测肾脏疾病及肾脏老化进展的指标之一[1]。
与其他肾小球细胞相比,有丝分裂后分化足细胞具有更高水平的基础自噬和哺乳类雷帕霉素靶蛋白复合物1(mTORC1)活性。
这看起来似乎相互矛盾,通过独特的细胞区室进行合理的空间管理可以很好的解释这一现象,这一区室叫做TOR-自噬耦合空间舱(TOR-autophagy spatial coupling compartment,TASCC)。
TASCC紧邻反面高尔基网并提供大量的溶酶体、自噬溶酶体、雷帕霉素靶蛋白(mTOR)。
这种空间上的分离使得自噬小体得以形成,并且不受mTORC1依赖的自噬抑制的影响[2]。
在持续的能量供应下,足细胞能产生足量的分泌性蛋白质[3-4]。
足细胞较其他肾小球细胞有更高水平的基础自噬,并以此来阻止足细胞变性。
综 述162 *基金项目: 国家自然科学基金青年基金(81704054)“基于JAK/STAT及PI3K/Akt/mTOR信号通路研究贞术消积汤对肝癌细胞的干预作用及其机制”;国家自然科学基金面上项目(81873312)“基于皮肤微生物群与Th17/Treg失衡相关性探讨发汗祛风托毒方治疗白癜风机制及病因学研究”;中国博士后科学基金资助项目(2014M551288)“鳖甲煎丸对肝癌细胞的抑制作用及其机制研究”;黑龙江省博士后资助项目(LBH-Z13205)“鳖甲煎丸诱导肝癌细胞凋亡及对JAK-STAT信号通路的影响”;黑龙江省自然科学基金面上项目(H201462)“温阳发汗法对白癜风T细胞免疫异常的作用机制研究”;黑龙江中医药大学研究生创新科研项目(2020yjscx013)“基于STAT3信号通路研究IL-12诱导肝癌细胞自噬的分子机制”①黑龙江中医药大学基础医学院 黑龙江 哈尔滨 150040②黑龙江中医药大学中医药研究院 黑龙江 哈尔滨 150040③黑龙江中医药大学附属第一医院皮肤科 黑龙江 哈尔滨 150040作者简介:孙阳,女,(1979- ),博士,副教授,研究方向:中医药抗肿瘤分子机制的基础研究。
[文章编号] 1672-8270(2021)01-0162-05 [中图分类号] R394 [文献标识码] A孙 阳① 孙 悦① 顾媛媛② 陶雪莲① 王远红③*mTOR信号通路在细胞自噬和凋亡调节中的作用*中国医学装备2021年1月第18卷第1期 China Medical Equipment 2021 January V ol.18 No.1Role of mTOR signaling pathway in the regulation of autophagy and apoptosis/SUN Yang, SUN Yue, GU Yuan-yuan, et al//China Medical Equipment,2021,18(1):162-166.[Abstract] Autophagy and apoptosis widely exist in cells, which are the degradation and recycling process of biomolecules in cell and play an important role in cell growth and metabolism. Their interaction jointly promote and influence the programmed death of cells, and maintain the self-stability of body and stress response under external environmental stimulation. The mTOR signaling pathway is one of classical signaling pathway of regulating autophagy-apoptosis that plays an important role in cell metabolism. This paper combined with mTOR signaling pathway and related research progress. It mainly discussed the role and relevant research progress of autophagy and apoptosis in cell metabolism and organism growth-development, and reviewed the autophagy and apoptosis in cell growth, development, aging and tumor formation. This will provide a positive reference in the diagnosis and treatment of tumor and other diseases. [Key words] mTOR signaling pathway; Autophagy; Apoptosis[First-author’s address] College of Basic Medicine Heilongjiang University of Chinese Medicine, Harbin 150040,China.[摘要] 自噬及凋亡广泛存在于细胞中,是细胞内生物大分子的降解再循环过程,在细胞生长代谢中发挥着重要作用。
SGT1正调控橡胶树白粉菌在拟南芥上激活的抗病性戎伟;梅双双【摘要】通过在拟南芥野生型Col-0和突变体sgt1b、eds1上接种橡胶树白粉菌Oidium heveae HN1106,分析了白粉菌细胞进入率、叶片发病症状、菌丝生长状态、细胞死亡和活性氧产生等表型.结果表明,与野生型Col-0相比,橡胶树白粉菌在拟南芥sgt1b上激发的早期抗病性、后期抗病性以及抗病反应部分降低,暗示着SGTI在稳定识别橡胶树白粉菌的抗性蛋白方面发挥着非常重要的作用.【期刊名称】《广东农业科学》【年(卷),期】2016(043)010【总页数】6页(P112-116,封3)【关键词】橡胶树白粉菌;拟南芥;SGT1;抗病性【作者】戎伟;梅双双【作者单位】海南大学农学院,海南海口570228;海南大学环境与植物保护学院,海南海口570228【正文语种】中文【中图分类】Q945.8SGT1 (Suppressor of G-Two Allele of Skp1)是与着丝粒装配和蛋白泛素化有关的基因,最早在酵母中被发现[4],在模式植物拟南芥和烟草以及大麦等许多植物中都有发现,且大多数植物包括SGT1a和 SGT1b两个基因。
通过在烟草或拟南芥中进行基因沉默、突变和过表达等试验表明,SGT1与植物抗性基因介导的抗病反应密切相关[5-11]。
SGT1基因沉默或突变会导致一些抗性基因表达下调以及介导的抗性反应消失[6]。
反之,SGT1基因超表达会增强植株的抗病能力[8]。
最近研究发现,SGT1、RAR1作为HSP90的分子伴侣蛋白,三者在植物体内相互作用,对R蛋白的积累与稳定性具有重要作用[12-13]。
作为HSP90的伴侣蛋白,RAR1参与了橡胶树白粉菌在拟南芥上激活的抗病性[3],但SGT1是否具有RAR1相同的功能目前仍然未知。
由于sgt1a和 sgt1b 双突变体拟南芥是致死的表型,因此本研究选择了sgt1b单突变体,通过在拟南芥野生型Col-0、突变体sgt1b和eds1上接种橡胶树白粉菌Oidium heveaeHN1106,进行了白粉菌细胞进入率、菌丝生长抗性、叶片发病症状、细胞死亡、活性氧产生及致病相关基因PR1 (Pathogenesis-related gene 1)表达等表型分析,发现SGT1b 参与了橡胶树白粉菌激活的抗病性。
Cancer Res,2004,10(10):3309.[15]L iu SS,Chan KY,Leung RC,et al.Enhance ment of the radi osen2 sitivity of cervical cancer cells by overexp ressing p73al pha.Mol Cancer T2 her,2006,5(5):1209.[16]L iu SS,Chan KY,Cheung AN,et al.Exp ressi on of delta Np73and T Ap73al pha independently ass ociated with radi osensitivities and p r ognoses in cervical squamous cell carcinoma.Clin Cancer Res,2006,12(13): 3922.[17]Hunt CR,D ix DJ,Shar ma GG,et al.Genom ic instability and en2 hanced radi osensitivity in H s p70.1-and H s p70.3-deficientm ice.Mol Cell B i ol,2004,24(2):899.[18]N iu P,L iu L,Gong L,et al.Overexp ressed heat shock p r otein70 p r otects cells against DNA da mage caused by ultravi olet C in a dose-de2 pendent manner.Cell Stress Chaper ones,2006,11(2):162.[19]W ano C,Kita K,Takahashi S,et al.Pr otective r ole of HSP27a2 gainst UVC-induced cell death in human cells.Exp Cell Res,2004, 298(2):584.[20]Tei m ourian S,Jalal R,Sohrabpour M,et al.Down-regulati on ofH s p27radi osensitizes human p r ostate cancer cells.I nt J U r ol,2006,13(9):1221.[21]Lee YS,Chang HW,Jeong JE,et al.Pr oteom ic analysis of t w o head and neck cancer cell lines p resenting different radiati on sensitivity. Acta O t olaryngol,2008,128(1):86.[22]Kassem H sh,Sangar V,Cowan R,et al.A potential r ole of heat shock p r oteins and nicotina m ide n-methyl transferase in p redicting re2 s ponse t o radiati on in bladder cancer.I nt J Cancer,2002,101(5):454.[23]Baek SH,M in JN,Park E M,et al.Role of s mall heat shock p r otein HSP25in radi oresistance and glutathi one-redox cycle.J Cell Physi ol, 2000,183(1):100.[24]A l oy MT,Hadchity E,B i onda C,et al.Pr otective r ole of H s p27 p r otein against gamma radiati on-induced apop t osis and radi osensitizati on effects of H s p27gene silencing in different human tumor cells.I nt J Radi2 at Dncol B i ol Phys,2008,70(2):543.(2008-07-03收稿)TLR4研究进展与肾脏疾病(文献综述)韩 凝1,2(综述) 张 彩1 罗南萍2(审阅) T oll样受体(T oll like recep t or,T LR)最早是从果蝇体内分离得到的,它主要决定果蝇腹背侧体轴发展方向和非特异性免疫反应。
G蛋白偶联受体激酶2在心血管疾病发生发展中的作用研究进展宋倩1,刘永铭21 兰州大学第一临床医学院,兰州730030;2 兰州大学第一医院老年心血管科甘肃省老年疾病临床医学研究中心摘要:心血管疾病是我国致死率及致残率较高的疾病之一,对患者造成严重的身心影响。
G蛋白偶联受体激酶2(GRK2)也称为β肾上腺素受体蛋白激酶1,主要作用是使G蛋白受体磷酸化,从而不能结合G蛋白,进一步调节多条由G蛋白参与的信号通路。
多项研究显示,GRK2的异常活化及表达改变参与调控多种心血管疾病的发生发展过程,包括心肌梗死、心肌肥厚、心力衰竭及其他心血管疾病等。
对GRK2在心血管疾病发生发展中的作用进行总结可为心血管疾病的治疗提供新思路。
关键词:G蛋白偶联受体激酶2;心肌梗死;心肌肥厚;心力衰竭;心血管疾病doi:10.3969/j.issn.1002-266X.2023.23.025中图分类号:R543.1 文献标志码:A 文章编号:1002-266X(2023)23-0097-03《中国心血管健康及疾病报告2020》显示,目前我国存在3.3亿例左右心血管疾病(CVD)患者,且CVD发病率呈现逐渐升高趋势,并在居民总死亡原因中位居首位[1]。
尽管CVD治疗药物不断在研发,但依旧多为单一神经内分泌抑制剂且治疗效果不理想,CVD患者再入院率及病死率仍然居高不下。
因此,寻找新靶点、开发新药以改善患者预后是非常必要的。
G蛋白偶联受体(GPCRs)是介导许多生理过程的关键细胞传感器,分布在心脏上,通过调节心肌细胞收缩及冠状血管血流灌注等重要过程参与调节心脏功能。
G蛋白偶联受体激酶(GRKs)主要使GPCRs磷酸化,从而使GPCRs的敏感性下降、表达下调[2]。
G蛋白偶联受体激酶2(GRK2)是研究较为广泛的GRKs分子,不仅参与炎症反应,还参与减弱心肌能量代谢弹性[3-4];此外,GRK2的不同功能区与不同蛋白之间的相互作用对心脏功能的调节具有两面性,这使得针对GRK2治疗CVD具有较高特异性[5]。
中药复方治疗急性胰腺炎作用机制的研究进展牛小龙1,2,姚广涛1,31 上海中医药大学研究生院,上海201203;2 上海中医健康服务协同创新中心;3 上海中医药大学创新中药研究院摘要:急性胰腺炎(AP)是临床常见的一种急腹症。
大多数AP患者为轻症,病程具有自限性,通常1~2周即可恢复。
但约20% AP患者会发展为重症急性胰腺炎(SAP),病死率为20%~40%。
西医治疗AP易引起继发性感染、腹膜炎、休克等并发症,整体治疗效果并不理想。
中医认为,AP起因于诸多病邪,包括热、湿、水、气、瘀等壅阻于胰、肝、胆、胃、脾、肠等脏腑,在治疗上应以“攻下通腑”“疏肝退热”“清热解毒”为突破点。
常用的中药复方包括大承气汤、大柴胡汤、大黄牡丹汤、柴芩承气汤、清胰汤等,其作用机制包括改善胃肠功能,修复肠黏膜屏障;抑制炎症反应,提高免疫功能;促进胰腺微循环;诱导胰腺腺泡细胞凋亡等。
这些中药复方以其多组分、多途径、多靶点相互作用,协同发挥治疗作用。
关键词:急性胰腺炎;中药复方;作用机制doi:10.3969/j.issn.1002-266X.2024.01.023中图分类号:R657.5+1 文献标志码:A 文章编号:1002-266X(2024)01-0093-05急性胰腺炎(AP)是临床常见的消化系统急症之一。
大多数AP患者为轻症,病程具有自限性,通常1~2周即可恢复。
但仍有约20% AP患者会发展为重症急性胰腺炎(SAP),病死率为20%~40%[1]。
西医治疗AP的主要方法包括立即禁食水、持续胃肠减压、静脉输液支持、抑制胃酸和胰液分泌等[2]。
但西医治疗易引起继发性感染、腹膜炎、休克等并发症,整体治疗效果并不理想。
中医药以其多组分、多途径、多靶点相互作用,协同发挥治疗作用,在治疗AP方面具有独特优势。
经典中药复方大承气汤、清胰汤能够减轻胰腺炎症,抑制病情加重[3]。
此外,大柴胡汤、大黄牡丹汤、柴芩承气汤等中药复方亦能通过改善胃肠功能、修复肠黏膜屏障、诱导细胞凋亡等基金项目:上海市科技计划项目资助(22S21901300)。
秀丽隐杆线虫在衰老与延缓衰老研究中的应用张宗敏【期刊名称】《贵州医药》【年(卷),期】2018(042)006【总页数】3页(P670-672)【关键词】秀丽隐杆线虫;衰老;延缓衰老【作者】张宗敏【作者单位】遵义医学院附属医院,贵州遵义 563000【正文语种】中文【中图分类】R383.1衰老是机体各种组织和器官功能随着时间的推移逐渐退行性变化的过程。
衰老可以降低机体面对环境胁迫维持自身稳态的能力,从而增加机体患病和死亡的可能性。
伴随衰老,许多疾病的发病率增加,而这些疾病已逐渐成为人类死亡的主要原因[1]。
秀丽隐杆线虫(C.elegans)由于具有寿命短、身体透明易于观察、饲养成本低、容易获取大量同期化样本、可长期保存、实验可操作性强等优点,已成为衰老研究中常用的模式生物。
在遗传学方面,C.elegans的基因与哺乳类动物在进化上都是保守的,且与人类基因的同源性达60%~80%,可通过基因操作技术获得变异株,构建与衰老及衰老相关疾病相似的模型,使得C.elegans广泛应用于衰老与延缓衰老的研究[2-3]。
1 C.elegans与衰老相关的实验1.1 寿命实验 C.elegans由于其具有寿命短、同期化后可减少个体差异、便于大规模筛选等优点,使其成为寿命实验的优选模型[2]。
在寿命实验中,C.elegans通常使用固体或液体培养基进行培养,其中固体培养基比较常用。
线虫用固体培养基进行培养时,同期化的L1线虫生长于涂布有OP50大肠杆菌的标准线虫生长培养基(NGM)中,待线虫生长到L4期,将线虫转移到添加有测试药物的NGM上。
存活的线虫每天被转移到新的NGM上,并准确记录下当天线虫存活和死亡数目,直至线虫全部死亡,然后计算存活率或死亡率[4]。
线虫液体培养基的寿命分析是在小容积的微孔板中进行的,同期化的L1期线虫在含有大肠杆菌的S培养基中进行培养至L4期,然后将L4期线虫平均分配到微孔板上,向微孔板中添加测试的药物,每天计算一次活体线虫的数量,直至所有的线虫死亡[5]。
Hippo通路在原发性肝癌发生发展中的作用洪莹晖,王 纯,叶明亮,罗 杰,刘佳良,任 超,蓝 瑜,赵 秋,常 莹武汉大学中南医院消化内科,湖北省肠病医学临床研究中心,肠病湖北省重点实验室,武汉430071摘要:原发性肝癌在全球范围内发病率持续上升,发病年龄趋于年轻化,并且总体预后不良。
Hippo通路作为最经典的感知细胞极性和密度、机械信号转导并促进细胞增殖、器官发育的调节器,能够促进包括原发性肝癌在内多种癌症的发生发展。
YAP作为Hippo通路的经典核效应器在原发性肝癌中显著上调,并且促进原发性肝癌耐药的发生。
原发性肝癌中Hippo信号通路的失调与肝癌的发生发展相联系,Hippo信号通路作为原发性肝癌发生的早期事件,影响原发性肝癌耐药的发生机制,这对于探索新的原发性肝癌临床治疗策略具有重要意义。
关键词:肝肿瘤;信号传导;Hippo通路中图分类号:R735.7 文献标志码:A 文章编号:1001-5256(2020)05-1171-04RoleoftheHipposignalingpathwayinthedevelopmentandprogressionofprimarylivercancerHONGYinghui,WANGChun,YEMingliang,etal.(HubeiKeyLaboratoryofIntestinalandColorectalDiseases,HubeiClinicalCenterofIn testinalandColorectalDiseases,DepartmentofGastroenterology,ZhongnanHospitalofWuhanUniversity,Wuhan430071,China)Abstract:Theincidencerateofprimarylivercancercontinuestoincreasearoundtheworld,withayoungerageofonsetandpoorerprognosis.Asthemostclassicregulatorofcellpolarityanddensity,mechanicalsignaltransduction,cellproliferation,andorgandevelopment,theHippopathwaycanpromotethedevelopmentandprogressionofvariouscancersincludingprimarylivercancer.YAP,aclassicnucleareffec toroftheHippopathway,issignificantlyupregulatedinprimarylivercancerandpromotesthedevelopmentofdrugresistance.ThisarticleaimstoinvestigatetheassociationofthedysregulationoftheHipposignalingpathwaywiththedevelopmentandprogressionofprimarylivercancerandanalyzesthemechanismofactionoftheHipposignalingpathwayinthedrugresistanceofprimarylivercancerasanearlyeventofthedevelopmentofprimarylivercancer,whichisofgreatsignificanceforexploringnewtreatmentstrategiesforprimarylivercancer.Keywords:liverneoplasms;signaltransduction;Hippopathwaydoi:10.3969/j.issn.1001-5256.2020.05.050收稿日期:2019-11-22;修回日期:2019-12-23。
碧云天生物技术/Beyotime Biotechnology订货热线:400-1683301或800-8283301订货e-mail:******************技术咨询:*****************碧云天网站微信公众号网址:BeyoECL Star (特超敏ECL化学发光试剂盒)产品编号产品名称包装P0018AS BeyoECL Star (特超敏ECL化学发光试剂盒) 100mlP0018AM BeyoECL Star (特超敏ECL化学发光试剂盒) 500ml产品简介:碧云天生产的Western萤光检测试剂BeyoECL Star是一种特超敏ECL化学发光试剂盒,发光效果显著优于BeyoECL Plus,可与二抗上偶联的辣根过氧化物酶(horseradish peroxidase, HRP)发生化学反应,发出萤光,从而可以通过用X光片压片或其它化学发光成像设备检测样品。
碧云天生产的Western萤光检测试剂目前共有三种,分别是P0018S/P0018M BeyoECL Plus、P0018AS/P0018AM BeyoECL Star 和P0018FS/P0018FM BeyoECL Moon。
常规的Western检测,优先推荐使用BeyoECL Star。
对于丰度比较高的目的蛋白的检测,例如内参蛋白等的检测,推荐使用性价比更高的BeyoECL Plus。
对于低丰度较难检测的目的蛋白,优先推荐使用检测灵敏度最高的BeyoECL Moon。
但对于丰度适中的目的蛋白的检测,不太推荐使用BeyoECL Moon,因为使用BeyoECL Moon时由于检测灵敏度特别高,容易产生过曝的现象。
BeyoECL Star灵敏度极高,比DAB显色的灵敏度至少高1000倍,比Amersham公司的ECL或碧云天以前生产的BeyoECL的灵敏度高100-500倍左右,比碧云天生产的BeyoECL Plus的灵敏度高约5-10倍(参考图1),比原Pierce公司(现Thermo公司)的SuperSignal West Pico Substrate的灵敏度高10倍以上,实际检测效果与原Pierce公司的SuperSignal West Dura和SuperSignal West Femto的检测灵敏度相近。
白念珠菌药物耐受机制研究进展黄宇颖1刘维达1,2李筱芳1,2(1.中国医学科学院北京协和医学院皮肤病研究所真菌科,南京210042;2.江苏省皮肤病与性病学分子生物学重点实验室,南京210042)ʌ摘要ɔ白念珠菌是侵袭性念珠菌病最常见的致病菌,念珠菌血症的高死亡率和不良预后造成了严重的临床问题㊂由于治疗药物有限,其耐药问题使临床治疗面临严峻挑战㊂此外,对于一部分持续性感染的患者,即使采用体外药敏试验提示敏感的药物进行治疗,也常常伴随迁延不愈和复发,临床疗效和低耐药率不一致的情况可能和药物耐受有关㊂而临床上常将耐受和耐药概念混淆,忽视白念珠菌耐受对治疗的影响㊂该文就白念珠菌耐受的概念㊁机制及其与耐药之间的联系进行综述㊂ʌ关键词ɔ白念珠菌;耐受;耐药;抗真菌药ʌ中图分类号ɔ R379.4ʌ文献标志码ɔ A ʌ文章编号ɔ1673-3827(2023)18-0546-04念珠菌引起的侵袭性感染严重威胁人类健康,全球侵袭性念珠菌感染病例每年有约70万例,是重症监护室患者血流感染的常见病因㊂而世界范围内大部分地区,白念珠菌仍为侵袭性念珠菌的主要病原体[1-2]㊂成年人念珠菌血症死亡率达40% ~70%,新生儿念珠菌血流感染后的死亡率达20%~34%[3]㊂目前治疗白念珠菌感染的药物种类有限,主要为唑类㊁多烯类和棘白菌素类,但随着临床上的广泛使用,耐药(d r u g r e s i s t a n c e)菌株的报道越来越多㊂此外,在持续性念珠菌血症中,即使采用体外药敏试验提示敏感的药物进行治疗,也常常伴随迁延不愈和复发,死亡率显著高于非持续性感染[4],这种临床疗效和低耐药率不一致的情况可能与其药物耐受性(d r u g t o l e r a n c e)有关[5-6]㊂白念珠菌的耐受问题使临床治疗面临严峻挑战,因此了解白念珠菌耐受的概念㊁机制及其与耐药之间的联系至关重要㊂1白念珠菌药物耐受的概念真菌的耐受是敏感菌株的一个特征,定义为敏感株在最小抑菌浓度(m i n i m a l i n h i b i t o r y c o n c e n-基金项目:国家自然科学基金(82273546)作者简介:黄宇颖,女(汉族),博士,住院医师.E-m a i l:s u p e r-h y y2019@163.c o m通信作者:李筱芳,E-m a i l:l x f3568@163.c o mt r a t i o n,M I C)以上的高浓度药物中缓慢生长的能力[9]㊂药敏试验中,琼脂扩散法抑菌圈内少量菌的生长或微量液基稀释法的拖尾现象都是真菌对药物耐受的体外表现[7]㊂在念珠菌中,氟康唑治疗的白念珠菌耐受的概念和量化研究最为广泛㊂有研究对分离自不同部位的66株白念珠菌进行氟康唑㊁伊曲康唑和伏立康唑的药敏实验,仅发现2株耐药菌,但大部分菌株均存在拖尾现象[6]㊂R o s e n-b e r g等[6]采用琼脂扩散法的生长分数(f r a c t i o n o f g r o w t h,F o G)和微量液基稀释法的超M I C生长指数(s u p r a-M I C g r o w t h,S MG)(见图1)更为精确地分析了219株不同感染来源的白念珠菌,发现均存在三唑类药物耐受现象,棘白菌素和多烯类相对少见;不同菌株的耐受程度不一样,体现在高于M I C 时生长的亚群规模和菌落出现的速度存在差异; 219株白念珠菌的F o G值变化范围为0.10~ 0.85,耐受程度越高,F o G越大,并与S MG值保持一致㊂2白念珠菌药物耐受机制的研究目前对白念珠菌耐受机制的研究主要包括以下四个方面㊂2.1压力应答调控目前认为耐受是一种应激策略,对药靶没有直接影响,压力应答调控被认为是耐受的重要方式之㊃645㊃中国真菌学杂志2023年12月第18卷第6期 C h i n J M y c o l,D e c e m b e r2023,V o l18,N o.6图1 F o G和S M G测量方法图解及公式.A.应用d i s k I m a g e R系统分析测量与细胞密度相对应的像素强度㊂R A D代表平均半径, F o G为R A D值对应曲线下面积(红色)除以最大面积;B.S MG的计算图示,即48h高于M I C50的孔中平均生长水平(O D600数值)除以不含药物孔中的生长水平(O D600数值)[6]F i g.1I l l u s t r a t i o n a n d f o r m u l a s f o r F oG a n d S M G.A.d i s k I m a g-e R a n a l y s i s m e a s u r e s p i x e l i n t e n s i t y c o r r e s p o n d i n g t o c e l l d e n s i t y. T h e f r a c t i o n o f g r o w t h(F o G)i n s i d e t h e z o n e o f i n h i b i t i o n w s t h e a r e a u n d e r t h e c u r v e(r e d)a t t h e a v e r a g e r a d i u s(R A D)t h r e s h o l d, d i v i d e d b y t h e m a x i m u m a r e a;B.I l l u s t r a t i o n o f s u p r a-M I C g r o w t h (S M G)c a l c u l a t i o n s.M I C50w a s c a l c u l a t e d a t24h a s t h e F L C c o n-c e n t r a t i o n a t w h i c h50%o f t h e g r o w t h w a s i n h i b i t e d,r e l a t i v e t o g r o w t h i n t h e a b s e n c e o f d r u g.S MG w a s c a l c u l a t e d a s t h e a v e r a g e g r o w t h p e r w e l l a b o v e t h e M I C50d i v i d e d b y t h e l e v e l o f g r o w t h w i t h o u t d r u g一[7]㊂压力应答调控的关键因子热休克蛋白90 (H s p90)㊁钙调磷酸酶㊁蛋白激酶C(p r o t e i n k i n a s e C,P K C)㊁R i m101和雷帕霉素靶蛋白(t a r g e t o f r a-p a m y c i n,T O R)通过C a2+-钙调磷酸酶㊁P K C-MA P K㊁R i m途径和HO G信号通路来调控白念珠菌的压力应答,以对唑类㊁多烯类和棘白菌素类药物产生适应性[9]㊂这些压力应答调控因子的抑制剂和突变体可以有效地消除白念珠菌耐受性,并提高氟康唑对一组不同耐受水平菌株的抑菌活性[10-13]㊂与此一致,H s p90㊁钙调磷酸酶㊁T O R㊁赖氨酸去乙酰化酶或R i m101基因功能破坏可增强氟康唑的作用[14]㊂值得注意的是,抑制这些压力应答途径并不影响菌株的M I C水平,因此推测白念珠菌的耐受性水平与这些途径相关[15]㊂除上述的核心压力应答途径外,还有许多其他途径和信号蛋白参与耐受现象的产生和维持,例如白念珠菌中的转录因子C a s5在细胞壁压力应答中发挥作用,并参与对棘白菌素的耐受[16]㊂参与翻译后修饰的酶也参与压力应答调控,其中研究较多的是调节白念珠菌对唑类敏感性的赖氨酸乙酰转移酶(l y s i n e a c e t y l-t r a n s f e r a s e,K A T)[17]㊂白念珠菌中S p t-A d a-G c n5-乙酰转移酶(S p t-A d a-G c n5-a c e t y l-t r a n s f e r a s e,S A G A)复合物的共激活因子A d a2功能破坏可导致药物外排泵表达上调,除了影响耐药性之外,还部分影响白念珠菌的耐受程度[18-19]㊂另有研究发现在同一M I C水平不同耐受程度的白念珠菌中,高耐受菌株细胞内氟康唑含量低于低耐受菌株[6],因此某些压力应答调控途径可能部分影响药物的摄取和外排,并间接地促进菌株对氟康唑的耐受㊂2.2 非整倍体形成及杂合性缺失(l o s s o f h e t-e r o z y g o s i t y,L O H)真菌病原体基因组具有显著的可塑性,能够通过基因组修饰来适应环境干预㊂基因组修饰不仅可以导致耐药,也可以使白念珠菌敏感株产生药物耐受㊂研究发现白念珠菌暴露于唑类药物中数小时后,其有丝分裂的细胞周期及纺锤体数目出现异常,产生四倍体和非整倍体细胞[20]㊂而非整倍体细胞可以改变白念珠菌对氟康唑的耐受性,例如3号染色体右臂形成的三倍体使白念珠菌敏感株对氟康唑存在的环境产生更高的适应性但不改变其M I C值,并观察到该节段上编码尿素转运蛋白的N P R2基因拷贝增加[21]㊂值得注意的是,由于非整倍体同时影响多个基因,因此它可能赋予同一细胞多种表型,例如2号染色体形成的三倍体可以对羟基脲及卡泊芬净产生交叉适应性,即预先暴露于羟基脲中的白念珠菌在卡泊芬净中的存活率也大大提高㊂此外,白念珠菌中5号染色体形成的单倍体可同时对氟康唑和卡泊芬净产生耐受[22]㊂最近一项研究表明,R染色体非整倍体形成是白念珠菌对唑类药物耐受相关性最大的非整倍体㊂遗传多样性往往是在适应压力的过程中产生的,F o r c h e 等[23]发现白念珠菌暴露于氟康唑㊁H2O2及高温等环境中,其L O H率显著升高,通常这类菌株对环境的适应性增加㊂2.3环境因素及生理代谢白念珠菌的耐受水平除了受遗传因素影响外,还受生长环境等物理因素的影响㊂p H值㊁温度以及培养基成分均可影响白念珠菌对氟康唑的耐受水平㊂已有研究表明在p H值为中性的培养基上白念珠菌的拖尾现象较p H值低的酸性培养基更明显[24]㊂最近的研究发现大部分白念珠菌在体温(37ħ)下生长的耐受水平高于实验室温度(30ħ),并且在Y P D培养基上耐受程度高于R P M I-1640培养基[25]㊂此外,在棘白菌素类药物存在的情况下,增加细胞壁几丁质成分促进细胞的存活[26],而添加钙调磷酸酶抑制剂则降低菌株对棘白菌素类药物的耐受性[27]㊂氟康唑联合多西环素可降低白念珠菌的耐受性并具有杀菌作用,此效应依赖于多西环素结合培养基中铁离子导致的铁离子耗竭,并可以通过添加铁离子逆转㊂因此,铁离子稳态与白念珠菌耐受性之间存在关联[28]㊂2.4液泡的发生发育在白念珠菌中,参与逆行转运的因子V P S21㊁㊃745㊃中国真菌学杂志2023年12月第18卷第6期 C h i n J M y c o l,D e c e m b e r2023,V o l18,N o.6V P S15㊁V P S51和R i m101可能通过调控液泡转运途径中关键因子的转录,对其耐受程度产生影响㊂该研究推测液泡的发生发育与甾醇稳态相关,也证明了白念珠菌的药物耐受性更多依赖于细胞内的生理过程[29-30]㊂3耐受与耐药的区别与联系目前白念珠菌的耐药是研究热点,而耐受在临床中常常被忽视㊂白念珠菌中耐受细胞与耐药细胞虽然都有在药物存在的环境中生长的能力,但前者的M I C值常在 临床折点 之前,被定义为敏感株;而后者的M I C值则在 临床折点 之后,被定义为耐药株㊂在氟康唑诱导白念珠菌敏感株产生耐受与耐药的实验中发现,耐药更容易在浓度与M I C值相近的药物环境中被诱导,而耐受则更容易出现在超M I C值(即为M I C值5~10倍以上)的高浓度药物环境中[25]㊂此外,在含氟康唑的培养基上,耐药株较耐受株出现的时间更早,菌落更大㊂耐药株在含药培养基上的生长量与其在空白培养基上生长量相当,而耐受株在含药培养基上的生长量少于其在空白培养基上生长量[6,31]㊂越来越多的研究提示耐药和耐受的机制不同,由不可逆转的基因突变导致的稳定性M I C值升高是耐药的主要机制和表现,而耐受机制目前认为主要以表观遗传修饰和生理代谢因素为主㊂另外,不同菌株之间耐受水平的差异是由于菌株之间的基因多样性;而在特定的分离株中,只有部分亚群可以在超M I C药物浓度中缓慢生长则是由于同一菌株不同细胞之间的生理或代谢变化差异[28]㊂有学者提出白念珠菌的耐受性在一定程度上可增加其耐药突变的频率,该观点基于以下观察结果:在氟康唑存在时,抑制H s p90不仅可以消除白念珠菌的耐受性,还能使氟康唑产生杀菌效应;高耐受水平的菌株分裂频率高于低耐受水平的菌株,因此其获得耐药基因突变的可能性也更高[6,32]㊂L e v i n-R e i s m a n等[33]也证实了耐药突变产生于病原菌的耐受亚群,耐受是耐药的重要前提和基础㊂图2典型药敏试验中抗真菌耐药和耐受性的行为图示F i g.2T h e o c c u r r e n c e o f a n t i f u n g a l r e s i s t a n c e a n d t o l e r a n c e i n t y p i c a l s u s c e p t i b i l i t y t e s t s4小结与展望白念珠菌的耐药问题目前研究已十分广泛,但其耐受性对疗效的影响在临床中常被忽略㊂近年来发现耐药并不是白念珠菌抵抗药物的唯一策略,临床疗效和低耐药率不一致的情况可能和药物耐受有关㊂本综述系统阐述了耐受的概念与机制,并指出其与耐药的区别与联系㊂阐明耐受产生的具体机制并发现其抑制剂将成为临床治疗念珠菌感染的潜在靶标,因为其不但可以增加药物疗效,并最终可能延缓耐药性的发展㊂参考文献[1]B O N G OM I N F,G A G O S,O L A D E L E R O,e t a l.G l o b a la n d m u l t i-n a t i o n a l p r e v a l e n c e o f f u n g a l d i s e a s e s-e s t i m a t ep r e c i s i o n[J].J F u n g i(B a s e l),2017,3(4):57.[2]L O G A N C,MA R T I N-L O E C H E S I,B I C A N I C T.I n v a s i v ec a nd i d i a s i s i n c r i t i c a l c a r e:c h a l le n g e s a n df u t u r e d i r e c t i o n s[J].I n t e n s i v e C a r e M e d,2020,46(11):2001-2014.[3]P A P P A S P G,L I O N A K I S M S,A R E N D R U P M C,e t a l.I n v a s i v e c a n d i d i a s i s[J].N a t R e v D i s P r i m e r s,2018,4:18026.D O I:10.1038/n r d p.2018.26.[4]HAMMO U D M S,A L-T A I A R A,F O U A D M,e t a l.P e r-s i s t e n t c a n d i d e m i a i n n e o n a t a l c a r e u n i t s:r i s k f a c t o r s a n d c l i n i c a l s i g n i f i c a n c e[J].I n t J I n f e c t D i s,2013,17(8):e624-628.[5]S A N G U I N E T T I M,P O S T E R A R O B,L A S S-F LÖR L C.A n t i f u n g a l d r u g r e s i s t a n c e a m o n g C a n d i d a s p e c i e s:m e c h a n i s m sa n d c l i n i c a l i m p a c t[J].M y c o s e s,2015,58(S u p p l2):2-13.[6]R O S E N B E R G A,E N E I V,B I B I M,e t a l.A n t i f u n g a l t o l-e r a n c e i s a s u b p o p u l a t i o n ef f e c t d i s t i n c t f r o m r e s i s t a n c e a n di s a s s o c i a t e d w i t h p e r s i s t e n t c a n d i d e m i a[J].N a t C o mm u n,2018,9(1):2470.[7]B E R MA N J,K R Y S A N D J.D r u g r e s i s t a n c e a n d t o l e r a n c ei n f u n g i[J].N a t R e v M i c r o b i o l,2020,18(6):319-331.[8]蔡晴,沈永年,胡素泉,等.白念珠菌对三唑类药物体外抗真菌敏感性及拖尾现象的研究[J].中国麻风皮肤病杂志2013,29(6):365-368.㊃845㊃中国真菌学杂志2023年12月第18卷第6期 C h i n J M y c o l,D e c e m b e r2023,V o l18,N o.6[9]I Y E R K R,R O B B I N S N,C OW E N L E.T h e r o l e o f C a n d i-d a a l b i c a n s s t re s s r e s p o n s e p a t h w a y s i n a n t if u ng a l t o l e r a n c ea n d r e s i s t a n c e[J].i S c i e n c e,2022,25(3):103953.[10] C OW E N L E,L I N D Q U I S T S.H s p90p o t e n t i a t e s t h e r a p i de v o l u t i o n of n e w t r a i t s:d r ug r e s i s t a n c e i n d i v e r s e f u n g i[J].S c i e n c e,2005,309(5744):2185-2189.[11] K HA N D E L WA L N K,C H A UH A N N,S A R K A R P,e ta l.A z o l e r e s i s t a n c e i n a C a n d i d a a lb ic a n s m u t a n t l a c k i n gt h e A B C t r a n s p o r t e r C D R6/R O A1d e p e n d s o n T O R s i g n a-l i n g[J].J B i o l C h e m,2018,293(2):412-432. [12] G A R N A U D C,G A R CÍA-O L I V E R E,WA N G Y,e t a l.T h e r i m p a t h w a y m e d i a t e s a n t i f u n g a l t o l e r a n c e i n C a n d i d aa lb ic a n s t h r o u g h n e w l y ide n t if i e d R i m101t r a n s c r i p t i o n a l t a r-g e t s,i n c l u d i n g H s p90a n d I p t1[J].A n t i m i c r o b A g e n t s C h e-m o t h e r,2018,62(3):e01785-01717.[13] O'M E A R A T R,R O B B I N S N,C OW E N L E.T h e H s p90c h a p e r o n e n e t w o r k m od u l a te s C a n d i d a v i r u l e n c e t r a i t s[J].T r e n d s M i c r o b i o l,2017,25(10):809-819. [14] R O B B I N S N,C A P L A N T,C OW E N L E.M o l e c u l a r e v o l u-t i o n o f a n t i f u n g a l d r u g r e s i s t a n c e[J].A n n u R e v M i c r o b i o l, 2017,71:753-775.D O I:10.1146/a n n u r e v-m i c r o-030117-020345.[15]MA R C H E T T I O,MO R E I L L O N P,G L A U S E R M P,e ta l.P o t e n t s y n e r g i s m o f t h e c o mb i n a t i o n o f f l uc o n a z o l e a n dc y c l o s p o r i n e i n C a nd i d a a l b i c a n s[J].A n t i m i c r o b A ge n t sC h e m o t h e r,2000,44(9):2373-2381.[16] B R U N O V M,K A L A C H I K O V S,S U B A R A N R,e t a l.C o n t r o l o f t h e C.a l b i c a n s c e l l w a l l d a m a g e r e s p o n s e b yt r a n s c r i p t i o n a l r e g u l a t o r C a s5[J].P L o S P a t h o g,2006,2(3):e21.[17] L E E Y,P U UMA L A E,R O B B I N S N,e t a l.A n t i f u n g a ld r u g re s i s t a n c e:m o l e c u l a r m e c h a n i s m s i n C a n d i d a a l b i c a n sa n db e y o n d[J].C h e m R e v,2021,121(6):3390-3411.[18]S E L L AM A,A S K E W C,E P P E,e t a l.G e n o m e-w i d e m a p-p i n g o f t h e c o a c t i v a t o r A d a2p y i e l d s i n s i g h t i n t o t h e f u n c-t i o n a l r o l e s o f S A G A/A D A c o m p l e x i n C a n d i d a a l b i c a n s[J].M o l B i o l C e l l,2009,20(9):2389-2400.[19] B E N HAMO U R I,B I B I M,B E R MA N J,e t a l.L o c a l i z i n ga n t i f u n g a l d r u g s t o t h e c o r r e c t o r g a n e l l e c a n m a r k e d l y e n-h a n c e t h e i r e f f i c a c y[J].A n g e w C h e m I n t E d E n g l,2018,57(21):6230-6235.[20] H A R R I S O N B D,H A S H E M I J,B I B I M,e t a l.A t e t r a-p l o i d i n t e r m e d i a t e p r e c e d e s a n e u p l o i d f o r m a t i o n i n y e a s t s e x-p o s e d t o f l u c o n a z o l e[J].P L o S B i o l,2014,12(3):e1001815.[21] MO U N T H O,R E V I E N M,T O D D R T,e t a l.G l o b a l a-n a l y s i s o f g e n e t i c c i r c u i t r y a n d a d a p t i v e m e c h a n i s m s e n a b l i n g r e s i s t a n c e t o t h e a z o l e a n t i f u n g a l d r u g s[J].P L o S G e n e t, 2018,14(4):e1007319.[22] Y A N G F,T E O H F,T A N A S M,e t a l.A n e u p l o i d y e n a-b l e sc r o s s-ad a p t a t i o n t o u n re l a t e d d r u g s[J].M o l B i o l E v o l,2019,36(8):1768-1782.[23] F O R C H E A,A B B E Y D,P I S I T H K U L T,e t a l.S t r e s s a l-t e r s r a t e s a n d t y p e s o f l o s s o f h e t e r o z y g o s i t y i n C a n d i d a a l-b ic a n s[J].m B i o,2011,2(4):e00129-00111.[24] MA R R K A,R U S T A D T R,R E X J H,e t a l.T h e t r a i l i n ge n d p o i n t p h e n o t y p e i n a n t if u ng a l s u s c e p t i b i l i t y t e s t i n g i s p Hd e p e n d e n t[J].A n t i m i c r o b A g e n t s C h e m o t h e r,1999,43(6):1383-1386.[25] Y A N G F,S C O P E L E F C,L I H,e t a l.A n t i f u n g a l t o l e r-a n c e a n d r e s i s t a n c e e m e r g e a t d i s t i n c t d r u g c o n c e n t r a t i o n sa n d r e l y u p o n d i f f e r e n t a n e u p l o i d c h r o m o s o m e s[J].m B i o,2023,14(2):e0022723.[26] WA L K E R L A,G OW N A,MU N R O C A.E l e v a t e d c h i t i nc o n t e n t r ed u ce s t h e s u s c e p t i b i l i t y of C a n d i d a s p e c i e s t oc a s p o f u n g i n[J].A n t i m i c r o b A g e n t s C h e m o t h e r,2013,57(1):146-154.[27] L E E K K,MA C C A L L UM D M,J A C O B S E N M D,e t a l.E l e v a t e d c e l l w a l l c h i t i n i n C a n d i d a a l b i c a n s c o n f e r s e c h i n o-c a nd i n re s i s t a n c e i n v i v o[J].A n t i m i c r o b A g e n t s C h e m o t h-e r,2012,56(1):208-217.[28] D E L A R Z E E,S A N G L A R D D.D e f i n i n g t h e f r o n t i e r s b e-t w e e n a n t i f u n g a l r e s i s t a n c e,t o l e r a n c e a n d t h e c o n c e p t o f p e r s i s t e n c e[J].D r u g R e s i s t U p d a t,2015,23:12-19.D O I:10.1016/j.d r u p.2015.10.001.[29] L U N A-T A P I A A,K E R N S M E,E B E R L E K E,e t a l.T r a f f i c k i n g t h r o u g h t h e l a t e e n d o s o m e s i g n i f i c a n t l y i m p a c t sC a n d i d a a l b i c a n s t o l e r a n c e o f t h e a z o l e a n t i f u n g a l s[J].A n-t i m i c r o b A g e n t s C h e m o t h e r,2015,59(4):2410-2420.[30] C O R N E T M,B I D A R D F,S C HWA R Z P,e t a l.D e l e t i o n so f e n d o c y t i c c o m p o n e n t s V P S28a n d V P S32a f f e c t g r o w t h a ta l k a l i n e p H a n d v i r u l e n c e t h r o u g hb o t h R I M101-d e p e n d e n ta n d R I M101-i n d e p e n d e n t p a t h w a y s i n C a n d i d a a lb ic a n s[J].I n f e c t I mm u n,2005,73(12):7977-7987.[31]S T O N E N R,R HO D E S J,F I S H E R M C,e t a l.D y n a m i cp l o i d y c h a n g e s d r i v e f l u c o n a z o l e r e s i s t a n c e i n h u m a n c r y p t o-c o c c a l m e n i n g i t i s[J].J C l i n I n v e s t,2019,129(3):999-1014.[32] C OW E N L E,S I N G H S D,KÖH L E R J R,e t a l.H a r n e s s-i n g H s p90f u n c t i o n a s a p o w e r f u l,b r o a d l y e f f e c t i v e t h e r a-p e u t i c s t r a t e g y f o r f u n g a l i n f e c t i o u s d i s e a s e[J].P r o c N a t lA c a d S c i U S A,2009,106(8):2818-2823.[33] L E V I N-R E I S MA N I,R O N I N I,G E F E N O,e t a l.A n t i b i-o t i c t o l e r a n c e f a c i l i t a t e s t h e e v o l u t i o n o f r e s i s t a n c e[J].S c i-e n c e,2017,355(6327):826-830.[收稿日期]2023-07-03[本文编辑]卫凤莲㊃综述㊃㊃945㊃中国真菌学杂志2023年12月第18卷第6期 C h i n J M y c o l,D e c e m b e r2023,V o l18,N o.6。
2-D-脱氧葡萄糖对二甲双胍抑制人结肠癌细胞作用的影响及机制谢敏;李红霞;顾馨仪;郝舒捷;王仁军;刘庆平;秦建中;张帆【摘要】目的观察己糖激酶抑制剂2-D-脱氧葡萄糖 (2-DG) 对降糖药二甲双胍抑制人结肠癌细胞作用的影响, 并探讨其机制.方法将不同浓度的2-DG、二甲双胍单药或联合作用于人结肠癌HT-29细胞, 采用台盼蓝染色法测算细胞死亡率观察细胞活力, MTT掺入法测算细胞存活率观察细胞增殖能力, 流式细胞术以Annexin V/PI 双染色法测算细胞凋亡率, 免疫印迹法检测细胞中的蛋白激酶B (AKT) /雷帕霉素靶蛋白 (TOR) 信号通路相关蛋白[AKT、磷酸化AKT (p-AKT) 、核糖体p70S6激酶 (p70S6K) 、磷酸化核糖体p70S6激酶 (p-p70S6K) ]、自噬相关蛋白p62.结果不同浓度2-DG (1、5、10 mmol/L) 和二甲双胍 (5、10 mmol/L) 联合处理24 h 后, HT-29细胞死亡率均高于单药处理细胞 (P均<0. 05) ;在2-DG、二甲双胍均为10 mmol/L时, HT-29细胞死亡率最高 (P均<0. 01) .以10mmol/L 2-DG与不同浓度的二甲双胍 (0、1、5、10、15、20 mmol/L) 联合处理48 h, 在二甲双胍浓度≥5 mmol/L后HT-29细胞存活率低于单药处理的细胞 (P均<0. 05) , 10 mmol/L时HT-29细胞存活率最低 (P均<0. 01) , 20 mmmol/L时HT-29细胞存活率未继续明显降低.不同浓度2-DG (5、10 mmol/L) 和10 mmol/L二甲双胍联合处理24 h, 仅10 mmol/L 2-DG与二甲双胍处理时HT-29细胞凋亡率高于单药处理细胞 (P均<0. 05) , 且细胞中p-AKT、pp70S6K、p62蛋白相对表达量低于单药处理细胞 (P均<0. 05) .结论 2-DG能增强二甲双胍抑制人结肠癌HT-29细胞活力、增殖和诱导细胞凋亡的作用, 以10 mmol/L 2-DG时增强作用最明显;其作用机制可能与两者协同抑制AKT/mTOR信号通路及细胞自噬有关.%Objective To investigate the role of hexokinase inhibitor 2-deoxy-D-glucose ( 2-DG) inenhancing antitumor effect of metformin on human colon cancer cells and its mechanism. Methods HT-29 human colon cancer cells were treated with different dosages of 2-DG and metformin alone or jointly. The cell viability and proliferation rate were determined by trypan blue staining and MTT assay, respectively. The apoptotic rate was recorded by a double staining with Annexin V/PI followed by FACS analysis. Western blotting was used to detect the protein levels of several key components involved in AKT/mTOR signaling pathway and autophagy, including AKT, phosphorylated AKT ( p-AKT) , ribosomal p70S6 kinase ( p70S6K) , phosphorylated ribosomalp70S6 kinase ( p-p70S6K) , and p62. Results After combined treatment of 2-DG ( 1, 5, and 10 mmol/L) and metformin ( 5 and 10 mmol/L) for 24 h, the cell mortality rates of HT-29 cells were much higher than those of cells receiving single drug treatment ( all P < 0. 05) , with the highest mortality rate at 10mmol/L of both drugs ( P < 0. 01) . The combined treatment of 10 mmol/L 2-DG and various amount of metformin ( 0, 1, 5, 10, 15, and 20 mmol/L) for 48 h inhibited the cell proliferation as compared with the corresponding single drug treatment when the metformin was ≥ 5 mmol/L ( all P < 0. 05) and the cell viability was the lowest at 10 mmol/L metformin ( P < 0. 01) , however, when the concentration was 20 mmmol/L, the survival rate of HT-29 cells did not continue to decrease significantly. HT-29 cells were treated with different dosages of 2-DG ( 5 and 10 mmol/L) and 10 mmol/L of metformin for 24 h, but only under the combined treatment of 10 mmol/L 2-DG and metformin, the apoptosis rate of HT-29 cells was higher than that under the single drug treatment ( all P < 0. 05) ,as well as the expression of p-AKT, p-p70S6 K and p62 proteins. Conclusion 2-DG enhances the efficacy of metformin in inhibiting the viability and proliferation of HT-29 cells and induces the apoptosis, with maximum effect at the dosage of 10 mmol/L, and the mechanism may be related to their synergistic inhibition of AKT/mTOR pathway and autophagy in tumor cells.【期刊名称】《山东医药》【年(卷),期】2019(059)002【总页数】5页(P1-5)【关键词】结直肠癌;2-D-脱氧葡萄糖;二甲双胍;AKT/mTOR信号通路;细胞自噬;p62蛋白【作者】谢敏;李红霞;顾馨仪;郝舒捷;王仁军;刘庆平;秦建中;张帆【作者单位】大连大学附属中山医院,辽宁大连 116001;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;内蒙古大学生命科学学院;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室;大连大学生命科学与技术学院辽宁省糖脂代谢研究重点实验室【正文语种】中文【中图分类】R735.4结肠癌是常见的消化道恶性肿瘤,发病率高,容易发生肝转移,严重威胁人类健康[1]。
蛋白质乳酸化修饰调控疾病发生的研究进展*关铭悦, 刘爽, 张雪△(佳木斯大学,黑龙江 佳木斯 154000)Advances in regulation of disease development by protein lactylationmodificationsGUAN Mingyue , LIU Shuang , ZHANG Xue △(Jiamusi University , Jiamusi 154000, China )[ABSTRACT ] Known as a classic product of glucose metabolism , lactic acid has been regarded as a metabolic waste. However , it wasn't until the discovery of Warburg effect in tumors that researchers refocused on the role of lactic acid in cells. Being a kind of signaling molecule with multiple functions , lactic acid is a key metabolic product connecting gly⁃colysis and oxidative phosphorylation , and it also has non -metabolic activity. Recent studies have shown that lactic acid can be used as a substrate to participate in a novel post -translational modification of proteins , known as protein lactylation.It can be involved in many kinds of diseases , and plays an important role in immune regulation and homeostasis mainte⁃nance. This paper briefly describes and summarizes the important role of lactylation modification in the developmental mecha⁃nisms of diseases such as tumors , inflammation , neuropsychiatric diseases , cardiocerebrovascular diseases , and so on.[关键词] 乳酸;乳酸化;肿瘤;炎症[KEY WORDS ] lactic acid ; lactylation ; tumor ; inflammation [中图分类号] R73; R541; R363.2 [文献标志码] Adoi : 10.3969/j.issn.1000-4718.2024.04.021细胞内的乳酸主要来源于糖酵解过程,作为葡萄糖代谢的经典副产物,很长一段时间被误认为是代谢废物[1]。
《物理化学》alinks的中文译本《物理化学》迈克尔·阿特金斯的中文译本是由alinks出版社出版的。
1. Physics and chemistry are closely related scientific disciplines.物理学和化学是密切相关的科学学科。
2. The study of thermodynamics provides a fundamental understanding of energy and its transformations.热力学的研究为能量及其转化提供了基本的理解。
3. Quantum mechanics describes the behavior of particles at the atomic and subatomic level.量子力学描述了粒子在原子和亚原子水平上的行为。
4. The study of chemical kinetics focuses on the rates of reactions and the factors that influence them.化学动力学的研究重点是反应速率及其影响因素。
5. Physical chemistry plays a crucial role in understanding the properties and behavior of materials.物理化学在理解材料的性质和行为方面起着关键作用。
6. The laws of thermodynamics govern energy transfer and the direction of chemical reactions.热力学定律统治着能量转移和化学反应的方向。
7. Spectroscopy is a powerful tool for studying the interaction of light with matter.光谱学是研究光与物质相互作用的有力工具。
CD38是一个定位于膜上的糖蛋白,催化环腺苷二磷酸核糖(cADPR, cyclic ADP-ribose)的合成和降解。
cADPR 是核苷酸的代谢产物,通过作用于ryanodine受体(RyRs)参与细胞内钙库的钙动员。
许多研究发现CD38/cADPR介导的Ca2+信号传递和通过RyRs通道的Ca2+释放在Ca2+内平衡的调控中发挥了重要的作用。
CD38/cADPR/ RyRs介导的Ca2+信号传递也参与了许多病理和生理过程。
本文就CD38基因的结构、表达、调控及在心血管系统的功能做一综述。
结构:cd38基因包括了8个外显子,5′UTR无TATA盒或CAAT盒(Nata K, Takamura T, Karasawa T, Kumagai T, Hashioka W, Tohgo A, Yonekura H, Takasawa S, Nakamura S, and Okamoto H. Human gene encoding CD38 (ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase): organization, nucleotide sequence and alternative splicing. Gene 186: 285–292, 1997.)。
一段高GC含量区可能是cd38的启动子区,调节CD38的表达。
CD38 是一个45kDa的单链跨膜糖蛋白,整体结构分为N末端短的胞质尾,单次跨膜域和C端长的胞外区(图1)。
其开放阅读框含有300个氨基酸残基,5′UTR比较短小,69bp;3′UTR含有260bp,不包括PolyA尾。
其编码的多肽链分子量为34,288道尔顿。
天然的CD38抗原的分子量为46,000道尔顿。
预测的氨基酸序列没有N-末端的引导肽序列,但在从翻译起始位点起21个氨基酸残基处含有一段长23个氨基酸残基的内部疏水序列。
CD38原始序列的亲水性图提示CD38分子仅跨膜一次,也就是说多肽链(pDavid G. Jackson, John I. Bell, Isolation of a cDNA encoding 的长C-末端指向胞外,N-末端有19aa的短胞质尾。
cells and also act as an immunosuppressant. Rapamycin binds to FPR1, a peptidyl-prolyl cis-trans isomerase, which binds and regulate activities of two proteins identified as TOR1and TOR2 in S. cerevisae (Heitman et al., 1991). These TOR proteins, encoded by two different genes, belong to the phosphatidylinositol kinase-related kinase (PIKK) family of kinases and exists in two complexes with different functions in yeast (Martin and Hall,2005). However, in mammals there is only one gene encoding mammalian TOR (mTOR)which exists in two complexes that consist of distinct sets of protein binding partners (Dann et al., 2007; Sabatini, 2006). TOR complex I (TORC1 in yeast and mTORC1 in mammals),is rapamycin sensitive and controls temporal aspects of cellular growth mediated mostly through S6 kinase 1 (S6K1) and initiation factor 4E-binding protein 1 (4E-BP1) (Um et al.,2006; Wullschleger et al., 2006). On the other hand, TORC2 is rapamycin-insensitive and controls spatial aspects of growth within the cell and the effects are mostly mediated through protein kinase B (PKB/Akt) (Jacinto et al., 2004).Following its initial discovery in S. cerevisae, TORs have been observed in all eukaryotes examined (Wullschleger et al., 2006). The conserved nature of the function of TOR as a nutrient sensor is reflected in the loss of function phenotypes of TOR in multiple species. In nematode, C. elegans , deletion of CeTOR leads to developmental arrest at the L3 larval stage and intestinal atrophy (Long et al., 2002). A similar phenotype was observed for mutants in daf-15, the worm ortholog of the mammalian protein Raptor, one of the TORC1interacting partners (Jia et al., 2004). Loss of function of mTOR in mice also leads to early embryonic lethality (Hentges et al., 2001; Murakami et al., 2004). The tissue-specific removal of Raptor in skeletal muscle induces progressive muscle dystrophy, which is likely due to impaired protein synthesis (Bentzinger et al., 2008). The loss of function phenotypes of TOR pathway genes in Drosophila also show defects in growth or development and are described below. Thus, mutations in TOR show developmental or growth arrest phenotypes in different species, comparable to those observed upon nutrient deprivation, supporting the notion that it has a conserved role in coupling of availability of nutrients to growth inmultiple species.One of the exciting developments in the field has been the realization that TORC1 isinvolved in a large number of human diseases, including diabetes, obesity, heart disease, andcancer (Inoki and Guan, 2006). Interestingly, a common risk factor for these diseases isaging, and it has been suggested that the mechanism of the link between cellular senescence,diseases and organismal aging is via TOR (Blagosklonny, 2006; Kapahi and Zid, 2004). Itwas recently demonstrated that cellular aging requires mTOR and that it can be suppressedby rapamycin (Demidenko et al., 2009). Growth stimulation, on the other hand, leads tocellular senescence when the cell cycle is blocked (Demidenko and Blagosklonny, 2008).Growing evidence has directly implicated the TORC1 pathway in determining lifespan inmultiple model systems. Specifically, inhibition of TORC1 (hereafter referred to as TOR),extends lifespan in yeast, worms, flies and mice (Kapahi et al., 2010). In further support ofthis longevity role, TOR is emerging as a robust mediator of the beneficial effects of DR, themost robust method known to increase lifespan and protect against age-related diseases byreducing nutrient intake without malnutrition in many species (Kapahi et al., 2010; Rogersand Kapahi, 2006). TOR integrates a variety of upstream signals, which aside from nutrientslike amino acids also include growth factors, energy status, and various stressors (Figure 1)(Kapahi et al., 2010). According to the type of input, TOR responds by regulating a numberof outputs, including protein translation, autophagy, metabolism, and stress responses(Figure1). Here, we discuss the contribution of Drosophila in understanding TOR signalingand how it impacts various biological processes with a view to discuss its relevance to agingand age-related diseases.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptTOR signaling pathway components in DrosophiladS6KThe first component of the TOR pathway to be identified in Drosophila was dS6K. Two independent studies showed the existence of a single homologue for mammalian S6K and showed its sensitivity to rapamycin (Stewart et al., 1996; Watson et al., 1996). Drosophila S6K expressed in COS or NIH 3T3 cells was shown to phosphorylate mammalian 40S ribosomal protein 6 (RPS6) in a mitogen-dependent and wortmannin and rapamycin-sensitive manner, suggesting that its regulation is similar to mammalian p70S6k (Watson et al., 1996). Similarly, dS6K from S2 cells was also shown to phosphorylate mammalian 40S ribosome in a rapamycin-sensitive manner (Stewart et al., 1996).Although most flies that are null for dS6K die during development, the surviving flies are normally proportioned but smaller than their heterozygous siblings or wild-type flies (Montagne et al., 1999). Examining cells of adult wings showed that the dS6K loss causes a reduction in cell size (by about 30%) without affecting the number of cells in the wing indicating that loss of S6K function reduces growth and body size to a lesser extent than loss of other positive components acting further upstream in the insulin cascade (Montagne et al.,1999). Using different variants of dS6K in which the conserved potential dS6K phosphorylation sites were substituted with acidic amino acids, it was shown that the kinase activity of dS6K is required for the growth phenotype (Barcelo and Stewart, 2002).dTOR Independent studies from two different groups identified dTOR in Drosophila and demonstrated its role in growth and development (Oldham et al., 2000; Zhang et al., 2000).In the first study, dTOR was identified in a genetic screen for recessive mutations affecting cell growth and proliferation in Drosophila compound eye. dTOR protein sequence showed about 56% identity with mTOR, with higher conservation in the kinase and FRB domains.dTOR mutants rescued the increased growth phenotype caused by loss of PTEN function.Drosophila Pten negatively regulates the growth-promoting effects of insulin signaling (Goberdhan et al., 1999). Similar to the amino acid starvation animals but not chico mutants,loss of dTOR function resulted in severe reduction of dS6 phosphorylation suggesting that insulin signaling and TOR signaling act in parallel pathways. The second study identified dTOR as one of the four members of the PIK-related family proteins. The dTOR mutants,generated by p element insertion, showed extended larval period with little or no growth suggesting that dTOR is required for normal growth of the larvae. The heterozygous mutant larvae showed increased sensitivity to rapamycin. The growth phenotype and rapamycin sensitivity of the dTOR mutant larvae was further rescued by overexpression of a constitutively active dS6K. Cells lacking dTOR exhibit reduced size proliferation in multiple tissues in the fly. The loss of dTOR function also caused a reduction in nucleolar size,aggregation of lipid vesicles and a cell type specific growth arrest. These phenotype were similar to that of the amino acid starved animals (Britton and Edgar, 1998). Interestingly, the cell cycle arrest of the dTOR mutant endoreplicative cells was rescued by overexpression of Cyclin E. In the fly, Cyclin E is required for induction of S-phase and is a G1-S phase cyclin - dimerization partner of cdc2c kinase. (Zhang et al., 2000).dTsc1-Tsc2Tuberous sclerosis 1 (Tsc1) and Tsc2 form a complex and was first shown to act parallel tothe insulin signaling pathway to inhibit TOR signaling. The fly mutants of dTsc1 and dTsc2were shown to modulate cell size and cell number. (Gao and Pan, 2001; Tapon et al., 2001).These mutants also antagonize the TOR-mediated response to amino acid availability (Gaoet al., 2002). Loss of Tsc1 and Tsc2 resulted in a TOR-dependent increase of S6KNIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author Manuscriptactivity(Gao et al., 2002; Radimerski et al., 2002). Although S6K is normally inactivated inanimal cells in response to amino acid starvation, loss of Tsc1–Tsc2 renders cells resistant toamino acid starvation (Gao et al., 2002).RhebThe small GTPase RHEB (Ras homologue enriched in brain) has been shown to be a directtarget of Tsc2. By using both in vivo and in vitro assays it was shown that the Tsc proteinsnegatively regulate Rheb through the GAP activity of Tsc2 (Zhang et al., 2003). Removal ofone of the two copies of Rheb gene was sufficient to partially rescue the the lethality of Tsc1null animals. (Zhang et al., 2003). Mutations in the Drosophila Rheb gene were also isolatedas growth-inhibitors, whereas overexpression of Rheb promoted cell growth (Stocker et al.,2003). In mitotic tissues, overexpression of Rheb accelerates passage through G1–S phasewithout affecting rates of cell division, whereas in endoreplicating tissues, Rheb increasesDNA ploidy (Saucedo et al., 2003). Mutation of Rheb suspends larval growth and preventsprogression from first to second instar. Genetic and biochemical tests indicate that Rhebfunctions in the insulin signaling pathway downstream of Tsc1–Tsc2 and upstream of TOR(Saucedo et al., 2003; Stocker et al., 2003). Levels of Rheb mRNA are rapidly induced inresponse to protein starvation, and overexpression of Rheb can drive cell growth in starvedanimals, suggesting a role for Rheb in the nutritional control of cell growth (Saucedo et al.,2003). Furthermore, S6K was shown to be a major effector of Rheb function (Stocker et al.,2003).d4E-BPDrosophila contains a single 4E-BP homolog, THOR/d4E-BP, which was first described tobe involved in host immune defense in Drosophila (Bernal and Kimbrell, 2000). The 4E-BPs constitute a family of low-molecular weight proteins that interact with eIF4E. Uponbinding to eIF4E they prevent its interaction with the scaffold protein eIF4G and inhibit cap-dependent translation initiation (Raught et al., 2000). Translational repression by 4E-BP isrelieved by the phosphorylation of a set of serine and threonine residues that causes 4E-BPdissociation from eIF4E. In flies, d4E-BP binds to deIF4E and this binding is modulated byinsulin and is sensitive to both LY294002 and rapamycin. Ectopic overexpression of astrongly active form of d4E-BP causes reduction in cell size (Miron et al., 2001). Although,d4E-BP null flies are viable and showed no difference in growth and development comparedto control flies, co-expression of d4E-BP with growth promoting genes (e.g. Dp110/dAkt )antagonizes their effect on growth (Miron et al., 2001). These results are consistent withd4E-BP being a downstream effector of both TOR and insulin signaling.Other modulators of the TOR pathwayRag GTPases (dRagA and dRagC ) were recently identified as novel activators of TORpathway in response to amino acids. Knockdown of dRagA or dRagC mRNA decreaseddS6K phosphorylation upon amino acid stimulation. The Rag proteins were further shown toregulate cell size in a nutrient dependent manner. Overexpression of constitutively activedRagA Q61L increased cell size, especially upon starvation, whereas expression of dominantnegative dRagA T16N decreased cell size and this effect was stronger when flies were fed.Constitutively active dRagA Q61L expression was shown to suppress starvation-inducedautophagy (Kim et al., 2008).A recent study indicates Rab1 and Arf1, two small GTPases, involved in intracellular vesicletransport to play a role in TOR activation in Drosophila S2 cells. Knockdown of both Rab1and Arf1 mRNA caused a significant decrease of dS6K phosphorylation and the effects ondS6K phosphorylation were similar to that caused by RagA mRNA knockdown (Li et al.,2010). A protein tyrosine phosphatase 61F (Ptp61F) was also recently identified as a novelNIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscriptmodulator of TOR activity under hypoxic conditions and suggest that its function duringhypoxia contributes to the down-regulation of translation. The Ptp61F inhibited cellsexhibited increased cell survival and increased TOR signaling. It was also shown thatinhibition of Akt prevents both the cell survival and the increased TOR signaling seen underhypoxia and Ptp61F knockdown (Lee et al., 2008a). Recently, the B' regulatory subunit ofdPP2A (dPP2A-B') was identified as a conserved component that specifically targets thePP2A complex to dephosphorylate dS6K in Drosophila (Hahn et al., 2010).TOR is part of a complex network of signaling components. This is to be expected for aprotein like TOR which is versatile and has to integrate various inputs to decide cellular fate.A key role for TOR is to match the growth rate to the availability of the resources in bothintra- and extracellular environments. TOR achieves this by acting as a major hub for acomplex network of signals. The various inputs and outputs from the TOR pathway havepreviously been described elsewhere (Kapahi et al., 2010; Polak and Hall, 2009;Wullschleger et al., 2006).We discuss below a number of biological processes which are impacted by TOR signaling inDrosophila some of which are likely to help in improving our mechanistic understanding ofhow TOR signaling modulates lifespan.Role of TOR signaling in various biological processes in Drosophila TOR and aging As discussed in other reviews in this issue the fruit fly Drosophila has served as an excellent model organism to study the mechanisms of organismal aging. Some of the reasons for favoring Drosophila as a model organism include the ease of manipulation, speed of discovery, availability of powerful genetic tools in an organism that has a complex body plan and exhibits diverse behaviors. The role of various genes in the TOR pathway was firstidentified in Drosophila demonstrating the importance of this model for aging research.Inactivation of dTOR or activation of the upstream negative regulators dTSC1 and dTSC2has been found to extend the mean lifespan of flies by ~30% (Kapahi et al., 2004).Consistent with these observations, rapamycin can also leads to ~10% increase in meanlifespan in Drosophila (Bjedov et al., 2010). Interestingly, upregulation of dTsc2 specificallyin the fat body and muscle tissues was shown to be critical for the lifespan extension effectsin Drosophila (Kapahi et al., 2004; Luong et al., 2006). A key role for fat-storing tissues inmodulating lifespan was also observed in long-lived flies overexpressing dFOXO(Giannakou et al., 2004; Hwangbo et al., 2004), and in long-lived FIRKO (fat-specificinsulin receptor knockout) mice (Bluher et al., 2003). While large amounts of data show thatsignaling through the TOR pathway can act both in parallel to but also interact with theinsulin/IGF-1 pathway in flies (Kapahi and Zid, 2004; Oldham and Hafen, 2003), only fewexperiments have directly explored the interactions between these pathways in terms oflifespan. Rapamycin can extend lifespan of insulin/IGF-1 pathway mutants, suggesting thatthe two pathways may act in parallel for slowing aging (Bjedov et al., 2010). Clearly, moreexperiments, including genetic epistasis analysis, are needed to further clarify the interactionbetween the dTOR and the insulin/IGF-1 signaling pathways with regards to aging.DR in flies, either by restriction of total food (Clancy et al., 2002; Mair et al., 2003; Roginaet al., 2002), or by reducing the amount of yeast in the food (Kapahi et al., 2004; Mair et al.,2005), robustly extends lifespan. Inhibition of TOR signaling was first proposed to extendlifespan by overlapping mechanism to DR in Drosophila . Studies in yeast and worms alsosupport this conclusion (Kapahi et al., 2010; Katewa and Kapahi, 2010). The long lifespanof mutants overexpressing dTSC2 cannot be further extended by DR (Kapahi and Zid, 2004;NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptKapahi et al., 2004). Further studies have implicated a key role for d4E-BP in mediating the lifespan extension effects of DR as discussed below. However, a combination of rapamycin and caloric restriction, maximized for lifespan extension, can cause some additional longevity effects when compared to each single treatment (Bjedov et al., 2010). These experiments indicate that the effects of rapamycin, may not be identical to the mechanisms by which caloric restriction extends lifespan. However, the methods of DR utilized in the two studies were distinct suggesting that may play an important role in some forms of DR.Alternatively, it is possible that rapamycin has additional TOR-independent targets that are yet to be identified.Role of TOR in coordination of growth regulation TOR is a major nutrient sensing pathway which is found in both unicellular and multicellular eukaryotes (Wullschleger et al., 2006). The evolution of multi-cellularity necessitated the use of diffusible factors to co-ordinate growth (Bradley and Leevers, 2003;Neufeld, 2004; Wullschleger et al., 2006). It has been suggested that TOR is a more ancient signaling pathway that acts cell autonomously while the insulin signaling pathway evolved later to co-ordinate growth in certain multicellular organisms (Kapahi and Zid, 2004;Marygold and Leevers, 2002; Polak and Hall, 2009; Wullschleger et al., 2006). The parallel and interactive signaling of insulin/IGF and TOR signaling pathways, allows a much more robust biological sensor to assess the nutritional status of the growing organism both cell autonomously and non-autonomously and then relay this information to outputs which appropriately adjust the growth and somatic maintenance of the organism (Neufeld, 2004;Oldham and Hafen, 2003).The co-ordination of TOR and insulin signaling pathways occurs at many levels (Shamji et al., 2003). Consistent with an interplay between the insulin and TOR/S6K pathways,lethality of loss of function of InR is was suppressed by heterozygosity of Tsc1 or Tsc2 (Gao and Pan, 2001). Furthermore, overexpressed Akt phosphorylates and inactivates Tsc2 andthereby activates S6K (Inoki et al., 2003; Manning and Cantley, 2003). Another studyidentified slimfast as an amino acid transporter that activates TOR signaling in fat body(Colombani et al., 2003). Animals lacking slimfast in fat body behaved as amino aciddeprived animals and were smaller in size and had reduced S6 phosphorylation.Interestingly, this lack of nutrients and TOR inhibition is also communicated to other tissuesby modulation of insulin signaling. The mutants showed a significant decrease in insulinsignaling in other tissues. Reduced TOR signaling in fat body through a still unknown butsecreted molecule, results in a retention and accumulation of dilps in the median neuro-secretory cells (mNSC). The secretion of dilps from mNSC was restored by activation ofTOR in fat body or incubating the mNSC in presence of hemolymph from a fed animalsuggesting a presence of a humoral factor (Geminard et al., 2009). Recent findings suggestthat interaction of these two pathways is critical for cellular homeostasis. Tor/raptorsignaling was shown to slow down the cell division in response to increased insulinsignalling (Wu et al., 2007). Similarly, FOXO, which is a well established downstreameffector of insulin signaling was shown to be critical for restricting overgrowth of eyephenotype in a Tsc1 mutant (Harvey et al., 2008).Wnt signaling has also been demonstrated to regulate TOR activity (Inoki and Guan, 2006).Stimulation of the Wnt receptors culminates in the inhibition of glycogen synthase kinase 3(Gsk3). When active, Gsk3 has been shown to directly phosphorylate and activate Tsc2when primed by AMPK-dependent phosphorylation (Inoki and Guan, 2006). Therefore, Wntmediated inactivation of Gsk3 alleviates Tsc2-driven inhibition of Rheb and results in TORactivation. Inputs from various other growth factors, like that from transforming growthfactor (TGF) beta (Lamouille and Derynck, 2007), further supports the role of TOR insensing extracellular environment to keep cellular growth in tune with it.NIH-PA Author ManuscriptNIH-PA Author ManuscriptNIH-PA Author ManuscriptIn a genetic screen for TOR interactors in Drosophila , clathrin-uncoating ATPase Hsc70-4,was identified as a key regulator of TOR mediated endocytosis..TOR signaling not onlystimulates bulk endocytic uptake but also inhibits the targeted endocytic degradation of theamino acid importer Slimfast (Hennig et al., 2006). Drosophila Hsc70-4 (Hsc4) mutantswere first shown to have an impairment in nerve-evoked neurotransmitter release in a Ca2+dependent manner (Bronk et al., 2001).Ecdysone is an insect hormone and is critical for pupariation and thus plays a major role infly development. Low protein in the diet causes a delay in development by increasing thelength of time taken by larvae to reach the wandering stage. Recently, it was shown that thenutrient dependent delay in development correlates negatively with the levels of dTORmRNA. Reduce TOR signaling in prothoracic gland silences the response toprothoracicotropic hormone and reduces the activation of ecdysone production (Layalle etal., 2008). Further experiments are needed to understand the role of various growth signalingpathways including those related to ecdysone in lifespan extension by inhibition of TOR.TOR and stress response regulationIn addition to nutrients and growth factors, appropriate control of cell growth also requiresintegration of information on environmental stresses. The modulation of stress pathways hasbeen well established to contribute to lifespan extension in multiple species (Martin et al.,1996). TOR is rendered less active by high temperature, hydrogen peroxide and high saltstress in S. cerevisiae (Urban et al., 2007). This poses the question whether reduced TORactivity triggers a stress resistance response. Inhibition of the TOR signaling network andalso a number of translation factor genes enhances resistance to various environmentalstresses (Hansen et al., 2007; Kaeberlein et al., 2005; Pan et al., 2007; Powers et al., 2006).Evidence from both C. elegans and S. cerevisae suggest that transcription factors such asPHA-4, HIF-1, Gis1 and Msn2/4, which are all involved in mediating stress responses, areregulated by TOR signaling and mediate its effects on lifespan extension (Chen et al., 2009;Medvedik et al., 2007; Sheaffer et al., 2008).In flies increasing Rheb-TOR-S6K signaling by overexpression of Rheb, TOR or aconstitutive active form of S6K sensitize flies to oxidative stress, while expression of theTsc2 or dominant-negative forms of TOR and S6K provides flies with resistance tooxidative stress (Patel and Tamanoi, 2006). Tissue specific analysis of stress resistanceindicated that overexpression of Rheb in muscle sensitizes flies to oxidative stress andinduced an age dependent loss of negative geotaxis (Patel and Tamanoi, 2006). Sestrin1 andSestrin2, both transcriptional targets of the DNA damage sensor p53, activate AMPK,thereby inhibiting TOR pathway activity (Budanov and Karin, 2008). TOR inhibition inadult flies by rapamycin increases stress resistance to both starvation and oxidative stress(Bjedov et al., 2010). d4E-BP has been shown to play an important role in mediating thestarvation and oxidative stress resistance in Drosophila (Tettweiler et al., 2005).Furthermore, starvation and oxidative stress increases the level of d4E-BP which isdependent on dFOXO (Teleman et al., 2005; Tettweiler et al., 2005). However, partialreduction of TOR, despite resulting in lifespan extension, was reported not to be sufficient toobtain significant stress resistance phenotypes (Kapahi et al., 2004; Luong et al., 2006).These results suggest that perhaps the increased stress phenotypes are not necessary for thelifespan extension effects though TOR influences both stress resistance and lifespan.Another link of TOR with stress signaling was demonstrated in Drosophila through itsinteraction with sestrins. Sestrins, which are conserved proteins accumulate in cells exposedto stress. The authors propose a model whereby enhanced TOR signaling leads to increasedoxidative stress and leads to increase in sestrin level. Sestrin act as feedback inhibitors ofTOR by potentiating the activity of AMPK which inhibits TOR. Loss of sestrin leads to ageNIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscriptrelated muscle degeneration, decline in heart function and enhanced lipid accumulation inDrosophila (Lee et al., 2010). Sestrins have been proposed to be protective through theireffects on enhancing autophagy. These data provide compelling evidence for the link ofROS in age-related decline of muscle function through increased TOR activity. However, itremains to be investigated if over-expression of sestrin is sufficient to alleviate age-linkedpathologies and whether it affects lifespan. In addition to the link through sestrin there areother examples in the fly where cellular stresses have been shown to modulate TOR activity.Scylla and charybdis , two homologous genes, first identified as growth suppressors in an EP(enhancer/promoter) overexpression screen, act as negative regulators of growth. Thesimultaneous loss of both genes generates flies that are more susceptible to hypoxia and alsoshow mild overgrowth phenotypes. Overactivation of either on the other hand reducesgrowth, which was associated with a reduction in S6K but not PKB/Akt activity.Furthermore, it was shown that scylla and charybdis are induced under hypoxic conditionsand that scylla is a target of dHIF-1 (hypoxia-inducible factor-1)(Reiling and Hafen, 2004).In flies, p38 stress-activated kinase cascade has shown to be critical for activation of TORsignaling pathway in response of amino acids, insulin/IGF and certain stresses such ashydrogen peroxide and anisomycin. This stress-induced TORC1 activation could be blockedby RNAi against mitogen-activated protein kinase kinase 3 and 6 (MKK3/6) or by theoverexpression of dominant negative dRags (Cully et al., 2010). Hence, TOR not onlymodulates stress responses but also responds to stressful situations by appropriatelymodifying its activity. It is likely that these responses play an important role in modulatinglifespan but further experiments are required to tease apart this link between stress resistanceand lifespan.TOR and regulation of protein synthesisThe regulation of protein synthesis by TOR is one of its critical functions to keep organismalgrowth and development in tune with environmental conditions (Sonenberg, 2000). Thisregulation of protein synthesis by TOR takes place at multiple levels including modulationof S6 kinase (S6K), mRNA translation initiation and ribosomal biogenesis (Ma and Blenis,2009; Shamji et al., 2003). S6K modulates protein synthesis by a number of mechanismswhich have been previously reviewed (Kapahi et al., 2010; Ma and Blenis, 2009).Interestingly, in addition to the important role of protein synthesis in growth anddevelopment, a number of pieces of evidence from multiple species point to its importancein determining lifespan as well. Hence TOR mediated changes in protein synthesis are likelyto have a major influence on its aging related phenotypes.Drosophila was the first organism where the role of S6K in lifespan was determined.Overexpression of the dominant-negative S6K fly mutants showed extended lifespan whileconversely the constitutively active form of S6K was found to exhibit significantly reducedlifespan (Kapahi and Zid, 2004). These studies prompted experiments examining the role ofS6K and mRNA translation in aging in other species. Inhibition of S6K also extendedlifespan in C. elegans (Hansen et al., 2007; Pan et al., 2007) and S. cerevisiae (Kaeberlein etal., 2005). In mice, female but not male animals lacking S6K1 (the mouse genome encodes 2paralogs, S6K1 and S6K2) have been shown to display increased lifespan and slowedprogression of age-related pathologies (Selman et al., 2009). These studies along with thefindings that feeding rapamycin can extend lifespan in mice (Harrison et al., 2009)demonstrate a conserved role for S6K in mediating lifespan extension in vertebrate andinvertebrate species which has generated much interest in targeting drugs for this pathwaywith the eventual goal of extending human healthspan (Kaeberlein and Kapahi, 2009;Kapahi et al., 2010; Kapahi and Vijg, 2009; Katewa and Kapahi, 2010)NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript。