細(xì)胞凋亡華子春

1、,,細(xì)胞凋亡與雙語教學(xué),華 子 春南京大學(xué)生命科學(xué)學(xué)院醫(yī)藥生物技術(shù)國家重點實驗室,,,南京大學(xué)《細(xì)胞生物學(xué)》課程雙語課程介紹,《細(xì)胞生物學(xué)》： 專業(yè)必修課，2學(xué)時，本科生2年級《細(xì)胞生物學(xué)實驗》：專業(yè)必修課，3學(xué)時，本科生2年級 《分子細(xì)胞生物學(xué)》：研究生選修課，4學(xué)時，研究生1年級 授 課 對 象： 生命科學(xué)學(xué)院、醫(yī)學(xué)院、環(huán)境學(xué)院、強(qiáng)化部、 物理系、生物制藥（合辦

2、）專業(yè),課 程 情 況,課 程 定 位,細(xì)胞生物學(xué)：是研究細(xì)胞基本生命活動規(guī)律的科學(xué)，是介于分子生物學(xué)和生理學(xué)、 普通生物學(xué)之間的一門綜合性學(xué)科；是聯(lián)系分子生物學(xué)（即微觀生物學(xué)）和生物學(xué)或醫(yī)學(xué)的橋梁；是近10年來飛速發(fā)展的學(xué)科。,夯實專業(yè)基礎(chǔ)知識 + 提高專業(yè)興趣和信心,1．基礎(chǔ)知識與學(xué)科發(fā)展相結(jié)合；2．細(xì)胞層次與其它微/宏觀層次相結(jié)合；3. 細(xì)胞的結(jié)構(gòu)與其功能相結(jié)合；4. 與普通生物學(xué)、生理學(xué)、分子生物學(xué)相結(jié)合、與

3、生理和病理過程相結(jié)合；5．本專業(yè)知識與其它學(xué)科相結(jié)合：,教 學(xué) 要 點,整體及生理、病理過程中的細(xì)胞結(jié)構(gòu)與功能,將基礎(chǔ)理論知識與學(xué)科前沿發(fā)展相結(jié)合將分子細(xì)胞層次與病理生理過程相結(jié)合將夯實基本概念與培養(yǎng)創(chuàng)新意識相結(jié)合將國內(nèi)教師主講與外聘教師授課相結(jié)合,教 學(xué) 理 念,寓學(xué)科前沿于基本理論之中寓實驗原理于基本概念之中寓科學(xué)思維于基本概念之中,中英文教學(xué)?英文教學(xué)國內(nèi)教師主講?外聘教師短期授課,循序漸進(jìn)、國際化和多元化的雙語教學(xué)

4、,《Molecular Biology of the Cell》Bruce Alberts 《細(xì)胞生物學(xué)》王金發(fā)《Molecular Cell Biology》Harvey Lodish 外籍教師教學(xué)錄像：共84盤,教材及參考資料,第1章： 細(xì)胞概述（2學(xué)時）； 第3章： 細(xì)胞質(zhì)膜與跨膜運輸（3學(xué)時）； 第4章： 細(xì)胞環(huán)境與互作（3學(xué)時）； 第5章： 細(xì)胞通訊（6學(xué)時）； 第6章： 核糖體與核酶

5、（2學(xué)時）； 第7章： 線粒體與過氧化物酶體（4學(xué)時）； 第9章： 內(nèi)膜系統(tǒng)與蛋白質(zhì)分選和膜運輸（6學(xué)時）； 第10章：細(xì)胞骨架與細(xì)胞運動（4學(xué)時）； 第11章：細(xì)胞核與染色體（2學(xué)時）； 第12章：細(xì)胞周期與細(xì)胞分裂（4學(xué)時）； 第13和: 細(xì)胞死亡（2學(xué)時）。,課 時 安 排,第十三章細(xì)胞死亡 —基礎(chǔ)概念與實際應(yīng)用,Apop

6、tosis vs necrosis,Apoptosis,Necrosis,Death by apoptosis is a neat, orderly process,Cell death,Cells die by one of two mechanisms: necrosis or apoptosis Two physiologically different processes -- Necrosis: death by

7、injury -- Apoptosis: death by suicide Apoptosis and necrosis have different characteristics,Necrosis,? Death by accident? Associated with nonphysiological circumstances that disrupt cellular homeostasis (eg

8、., ischemia, hypoxia and poisoning)? Necrosis is caused by membrane dissolution (osmotic lysis, shear stress, pore-forming proteins, loss of ATP)? Necrosis is bad because cellular material (including degradative

9、 enzymes) is released into surrounding tissue? Affects contiguous groups of cell? Necrosis usually causes inflammatory reactionCytological characteristics of necrosis? Initial swelling of the cell? Rupture

10、 of the plasma membrane? Cytoplasm is spilled to the extracellular environment,Apoptosis,? Death by design – genetically programmed cell death? Induced by new gene synthesis, primarily in response to developmental c

11、ues? Requires new RNA and protein synthesis – Inhibitors of transcription or translation prevent apoptosis? Important for development, homeostasis and elimination of pathogens and tumor cells? Causes deletion

12、of individual cells in the midst of others – But it can be involved in deletion of entire structures? Apoptosis is followed by fast phagocytosis – Anti-inflammatory (housekeeping),Morphologic changes during a

13、poptosis,? Membranes become irregular ? Chromatin becomes condensed and segregated ? Condensation of cytoplasm ? DNA is fragmented ? Cell is fragmented and phagocytosed,,Morphological and biochemical cha

14、racteristics of apoptosis,? Morphological changes: Early : Chromosome condensation, cell body shrink Later : Blebbing and Nucleus and cytoplasm fragment— Apoptotic bodies At last: Phagocytosed,A、Nor

15、mal cell,B、Apoptosis: Apoptotic bodies,? Biochemical characteristics of apoptosis:,Apoptosis induced by Cyto CLane 1．0 h 2．1 h 3．2 h 4．3 h 5．4 h 6．Control 7．M

16、arker,180~200bp DNA ladder, Accumulation of tTG, PS flip-flop,體內(nèi)細(xì)胞凋亡檢測紫杉醇治療小鼠肺癌腫瘤,肺癌腫瘤組織的免疫組織化學(xué)分析,Apoptosis Does Not Damage Neighboring Cells,Morphological features of apoptosis: Cytoskeleton collapses Nuclear env

17、elope disassembles Nuclear DNA breaks up into fragments Cell surface changes so that the cell can be rapidly phagocytosedThe consequence is neat death---no damage to the neighboring cells,Death by cell necrosis;

18、 cell contents spilled all over the neighbors,,Cell apoptosis, in culture dish,Cell apoptosis, in tissue. Showing phagocytosis,Forms of cell death,Necrosis ApoptosisPassive

19、 ActivePathological Physiological or pathologicalSwelling, lysis Condensation,

20、 cross-linking Dissipates PhagocytosedInflammation No inflammationExternally induced Internally or externally

21、induced,APOPTOSIS,Programmed cell deathOrderly cellular self destructionProcess: as crucial for survival of multi-cellularorganisms as cell divisionMULTIPLE FORMS???,Apoptosis Is Important to the Development and S

22、urvival of the Organism,In human, billions of cells die in bone marrow and intestine every dayWhy such a “waste”? Normal development Balancing cell division Removing abnormal cells,The paw in mouse emb

23、ryo showing apoptosis,One day later,,,,,,,As tadpole changes into frog, the tail is lost due to apoptosis,Apoptosis pathways,,,,APOPTOSIS: important in embryogenesis,APOPTOSIS,Evolutionarily conservedOccurs in all mult

24、icellular animals studies (plants too!)Stages and genes conserved from nematodes (worms)and flies to mice and humans,Apoptosis pathways,,,,? Intrinsic/ Mitochondrial Apoptosis– Regulated by Mitochondria– Cytochrome

25、c release? Extrinsic/ Death Receptor Apoptosis– Activated by ligation of Death Receptors– Fas, TNF alpha? These pathways intersect at the effector caspases,Two Pathways that Initiate Apoptosis,APOPTOSIS: control,Re

26、ceptor pathway (physiological):,Death receptors:(FAS, TNF-R, etc),,,,,,,,,,FAS ligand,TNF,Deathdomains,,Adaptor proteins,,,,,,,Pro-caspase 8 (inactive),Caspase 8 (active),,,,,Pro-execution caspase (inactive),,,Executio

27、n caspase (active),,Death,MITOCHONDRIA,,,,APOPTOSIS: control,Physiological Intrinsicreceptor pathway damage pathway,,,MITOCHONDRIAL SIGNALS,,Caspase cleavage cascade,,O

28、rderly cleavage of proteins and DNA,,CROSSLINKING OF CELL CORPSES; ENGULFMENT(no inflammation),,Apoptosis Is Mediated by a Caspases,Apoptosis depends on a group of proteases --- Caspases (胱冬蛋白酶) Have a cysteine (半胱氨酸

29、) in the active site Cleave the target proteins at specific aspartic acid (天冬氨酸) residuesCaspases are synthesized as inactive procursor, “procaspase”. Other caspases activate it by cleaving it:,A apoptotic proteolyt

30、ic system — caspase,Why called caspase?,Active site: CysteineCleavage site: Asparatic acid,,Cysteine Asparatic acid specific protease,Aps-Xxx,,天冬氨酸特異性的半胱氨酸蛋白水解酶,Caspases Trigger a Proteolysis Cascade,,Cleaves inhib

31、itors of DNase,,DNA fragmentation,APOPTOSIS: Role in DiseaseCancer,Apoptosis eliminates damaged cells(damage => mutations => cancer )Tumor suppressor p53 controls senescenceand apoptosis responses to damageM

32、ost cancer cells are defective in apoptotic response(damaged, mutant cells survive)High levels of anti-apoptotic proteinsor Low levels of pro-apoptotic proteins===> CANCER,TRAIL: 一種細(xì)胞凋亡誘導(dǎo)蛋白質(zhì),TRAIL: 腫瘤壞死因子相關(guān)的凋亡

33、誘導(dǎo)配體,TRAIL腫瘤選擇性: 不同TRAIL受體表達(dá)的結(jié)果,死亡受體(DR4，DR5): 介導(dǎo)細(xì)胞凋亡信號,誘騙受體 (DcR1，DcR2) :不傳導(dǎo)細(xì)胞凋亡信號,DcRs 與 DRs 競爭結(jié)合TRAIL，賦予正常組織TRAIL抗性,TRAIL變體具有更好的細(xì)胞凋亡活性,,,Adaptor proteins bring many copies of initiator procaspase together I

34、nitiator caspase has low activity, but when they form aggregates, they can cross-activate each other. Aggregation causes conformational changes,Apoptosis Is Activated by Binding to Adaptor Proteins to Form Aggr

35、egates,Activation of Apoptosis from Outside the Cell,Death receptors Killer lymphocytes produce Fas ligand to bind to Fas protein (death receptor) on target cells Adaptor proteins aggregate caspase

36、 8, which cross-activate,Some damaged cells produce both Fas ligand and Fas protein for self-destruction,,Extrinsic pathway,,APOPTOSIS: control,Intrinsic pathway (damage):,Mitochondria,,,Cytochrome c release,,Pro-caspase

37、 9 cleavage,,Pro-execution caspase (3) cleavage,,Caspase (3) cleavage of cellular proteins,nuclease activation, etc.,,,,,,,,,Death,,,,BAXBAKBOKBCL-XsBADBIDB IKBIMNIP3BNIP3,,,BCL-2BCL-XLBCL-WMCL1BFL1DIVAN

38、R-13Several viral proteins,Activation of Apoptosis from Inside the Cell,Intrinsic pathway,When cells are damaged: Mitochondria release cytochrome c In cytosol, cytochrome c binds to Apaf-1 (adaptor prot

39、ein) Apaf-1 aggregates of procaspase 9 p53 activates transcription of Bcl-2 family,Bcl-2 Family Proteins and IAP proteins Regulates Apoptosis,Members of the Bcl-2 family have different roles: Bcl-2, Bcl-X, etc:

40、Inhibit apoptosis by blocking cytochrome c release Bad:Promotes apoptosis by binding to and inactivating Bcl-2, Bcl-X, etc, Bax, Bak, etc:Stimulate the release of cytochrome c,The IAP (inhibitor of apop

41、tosis) family inhibit apoptosis: Bind to procaspases to prevent their activations Bind to caspases to prevent their activityMitochrondria release cytochrome c AND inhibitors of IAP to fully start the apoptosis,