細胞凋亡-華子春

1、細胞凋亡與雙語教學華 子 春醫(yī)藥生物技術(shù)國家重點實驗室 1南京大學細胞生物學課程雙語課程介紹2細胞生物學： 專業(yè)必修課，2學時，本科生2年級細胞生物學實驗：專業(yè)必修課，3學時，本科生2年級 分子細胞生物學：研究生選修課，4學時，研究生1年級 授 課 對 象： 生命科學學院、醫(yī)學院、環(huán)境學院、強化部、 物理系、生物制藥（合辦）專業(yè) 課 程 情 況 3 課 程 定 位 細胞生物學：是研究細胞基本生命活動規(guī)律的科學，是介于分子生物學和生理學、 普通生物學之間的一門綜合性學科；是聯(lián)系分子生物學（即微觀生物學）和生物學或醫(yī)學的橋梁；是近10年來飛速發(fā)展的學科。夯實專業(yè)基礎知識 + 提高專業(yè)興趣和信心41

2、基礎知識與學科發(fā)展相結(jié)合；2細胞層次與其它微/宏觀層次相結(jié)合；3. 細胞的結(jié)構(gòu)與其功能相結(jié)合；4. 與普通生物學、生理學、分子生物學相結(jié)合、與生理和病理過程相結(jié)合；5本專業(yè)知識與其它學科相結(jié)合：教 學 要 點 整體及生理、病理過程中的細胞結(jié)構(gòu)與功能5將基礎理論知識與學科前沿發(fā)展相結(jié)合將分子細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 理 念寓學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思維于基本概念之中6中英文教學英文教學國內(nèi)教師主講外聘教師短期授課循序漸進、國際化和多元化的雙語教學7Molecular Biology of t

3、he CellBruce Alberts 細胞生物學王金發(fā)Molecular Cell BiologyHarvey Lodish 外籍教師教學錄像：共84盤教材及參考資料8 第1章： 細胞概述（2學時）； 第3章： 細胞質(zhì)膜與跨膜運輸（3學時）； 第4章： 細胞環(huán)境與互作（3學時）； 第5章： 細胞通訊（6學時）； 第6章： 核糖體與核酶（2學時）； 第7章： 線粒體與過氧化物酶體（4學時）； 第9章： 內(nèi)膜系統(tǒng)與蛋白質(zhì)分選和膜運輸（6學時）； 第10章：細胞骨架與細胞運動（4學時）； 第11章：細胞核與染色體（2學時）； 第12章：細胞周期與細胞分裂（4學時）； 第13和: 細胞死亡（2學時

4、）。課 時 安 排9第十三章細胞死亡 基礎概念與實際應用 10Apoptosis vs necrosisApoptosisNecrosisDeath by apoptosis is a neat, orderly process11Cell death Cells die by one of two mechanisms: necrosis or apoptosis Two physiologically different processes - Necrosis: death by injury - Apoptosis: death by suicide Apoptosis and nec

5、rosis have different characteristics12Necrosis Death by accident Associated with nonphysiological circumstances that disrupt cellular homeostasis (eg., ischemia, hypoxia and poisoning) Necrosis is caused by membrane dissolution (osmotic lysis, shear stress, pore-forming proteins, loss of ATP) Necros

6、is is bad because cellular material (including degradative 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 of the plasma membrane Cytoplasm is spil

7、led to the extracellular environment13Apoptosis Death by design genetically programmed cell death Induced by new gene synthesis, primarily in response to developmental cues Requires new RNA and protein synthesis Inhibitors of transcription or translation prevent apoptosis Important for development,

8、homeostasis and elimination of pathogens and tumor cells Causes deletion 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)14Morphologic changes during apoptosis Membranes beco

9、me irregular Chromatin becomes condensed and segregated Condensation of cytoplasm DNA is fragmented Cell is fragmented and phagocytosed15 Morphological and biochemical characteristics of apoptosis Morphological changes: Early : Chromosome condensation, cell body shrink Later : Blebbing and Nucleus a

10、nd cytoplasm fragment Apoptotic bodies At last: PhagocytosedA、Normal cell B、Apoptosis: Apoptotic bodies16 Biochemical characteristics of apoptosis:Apoptosis induced by Cyto CLane 10 h 21 h 32 h 43 h 54 h 6Control 7Marker 2.0kbp1.00.50.2180200bp DNA ladder, Accumulation of tTG, PS flip-flop17體內(nèi)細胞凋亡檢測

11、紫杉醇治療小鼠肺癌腫瘤18肺癌腫瘤組織的免疫組織化學分析19Apoptosis Does Not Damage Neighboring CellsMorphological features of apoptosis: Cytoskeleton collapses Nuclear envelope disassembles Nuclear DNA breaks up into fragments Cell surface changes so that the cell can be rapidly phagocytosedThe consequence is neat death-no da

12、mage to the neighboring cellsDeath by cell necrosis; cell contents spilled all over the neighborsCell apoptosis, in culture dish Cell apoptosis, in tissue. Showing phagocytosis 20Forms of cell deathNecrosis ApoptosisPassive ActivePathological Physiological or pathologicalSwelling, lysis Condensation

13、, cross-linking Dissipates PhagocytosedInflammation No inflammationExternally induced Internally or externally induced 21APOPTOSISProgrammed cell deathOrderly cellular self destructionProcess: as crucial for survival of multi-cellularorganisms as cell divisionMULTIPLE FORMS?22Apoptosis Is Important

14、to the Development and Survival of the OrganismIn 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 embryo showing apoptosisOne day later, As tadpole changes into frog, the tail i

15、s lost due to apoptosis23Apoptosis pathways24APOPTOSIS: important in embryogenesis25APOPTOSISEvolutionarily conservedOccurs in all multicellular animals studies (plants too!)Stages and genes conserved from nematodes (worms)and flies to mice and humans26Apoptosis pathways27 Intrinsic/ Mitochondrial A

16、poptosis Regulated by Mitochondria Cytochrome c release Extrinsic/ Death Receptor Apoptosis Activated by ligation of Death Receptors Fas, TNF alpha These pathways intersect at the effector caspasesTwo Pathways that Initiate Apoptosis28APOPTOSIS: control Receptor pathway (physiological):Death recepto

17、rs:(FAS, TNF-R, etc)FAS ligandTNFDeathdomainsAdaptor proteinsPro-caspase 8 (inactive)Caspase 8 (active)Pro-execution caspase (inactive)Execution caspase (active)DeathMITOCHONDRIA29APOPTOSIS: control Physiological Intrinsicreceptor pathway damage pathway MITOCHONDRIAL SIGNALSCaspase cleavage cascadeO

18、rderly cleavage of proteins and DNACROSSLINKING OF CELL CORPSES; ENGULFMENT(no inflammation)30Apoptosis Is Mediated by a CaspasesApoptosis depends on a group of proteases - Caspases (胱冬蛋白酶) Have a cysteine (半胱氨酸) in the active site Cleave the target proteins at specific aspartic acid (天冬氨酸) residues

19、Caspases are synthesized as inactive procursor, “procaspase”. Other caspases activate it by cleaving it:31 A apoptotic proteolytic system caspase Why called caspase?Active site: CysteineCleavage site: Asparatic acid Cysteine Asparatic acid specific proteaseAps-Xxx天冬氨酸特異性的半胱氨酸蛋白水解酶32Caspases Trigger

20、a Proteolysis CascadeCleaves inhibitors of DNase DNA fragmentation33APOPTOSIS: Role in DiseaseCancerApoptosis eliminates damaged cells(damage = mutations = cancer )Tumor suppressor p53 controls senescenceand apoptosis responses to damageMost cancer cells are defective in apoptotic response(damaged,

21、mutant cells survive)High levels of anti-apoptotic proteinsor Low levels of pro-apoptotic proteins= CANCER34TRAIL: 一種細胞凋亡誘導蛋白質(zhì)TRAIL: 腫瘤壞死因子相關的凋亡誘導配體35TRAIL腫瘤選擇性: 不同TRAIL受體表達的結(jié)果死亡受體(DR4，DR5): 介導細胞凋亡信號 誘騙受體 (DcR1，DcR2) :不傳導細胞凋亡信號DcRs 與 DRs 競爭結(jié)合TRAIL，賦予正常組織TRAIL抗性36TRAIL變體具有更好的細胞凋亡活性37 Adaptor proteins

22、 bring many copies of initiator procaspase together Initiator caspase has low activity, but when they form aggregates, they can cross-activate each other. Aggregation causes conformational changesApoptosis Is Activated by Binding to Adaptor Proteins to Form AggregatesFasFasLFADDCaspase8APOPTOSIS38Ac

23、tivation of Apoptosis from Outside the CellDeath receptors Killer lymphocytes produce Fas ligand to bind to Fas protein (death receptor) on target cells Adaptor proteins aggregate caspase 8, which cross-activateSome damaged cells produce both Fas ligand and Fas protein for self-destructionExtrinsic

24、pathway39APOPTOSIS: control Intrinsic pathway (damage):MitochondriaCytochrome c releasePro-caspase 9 cleavagePro-execution caspase (3) cleavageCaspase (3) cleavage of cellular proteins,nuclease activation, etc. DeathBAXBAKBOKBCL-XsBADBIDB IKBIMNIP3BNIP3BCL-2BCL-XLBCL-WMCL1BFL1DIVANR-13Several viral proteins40Activation of Apoptosis from Inside the CellInt