【正文】
,引發(fā)彌散性血管內(nèi)凝血。 ?心肌梗塞,腦梗塞等疾病也是由于血管內(nèi)皮的破損、脫落而引發(fā)血栓。這些情況都與血管內(nèi)皮細(xì)胞抗血栓作用下降有關(guān)。 APOPTOSIS What is it? Why is it important? How is it controlled? What is its role in diseases? APOPTOSIS Programmed cell death Orderly cellular self destruction Process: as crucial for survival of multicellular anisms as cell division 基本概念 凋亡 是一種受基因調(diào)節(jié)的自主控制過(guò)程,在生物個(gè)體發(fā)育和生存中起著非常重要的作用;而 壞死則是細(xì)胞處于劇烈傷害性條件下發(fā)生的細(xì)胞死亡。在體內(nèi),兩者最大的區(qū)別是前者不引起機(jī)體炎癥反應(yīng),而后者則可引起炎癥反應(yīng)。因此在生理和絕大多數(shù)病理?xiàng)l件下的細(xì)胞死亡都呈現(xiàn)凋亡或程序性細(xì)胞死亡的典型特征。 Morphological Features of Apoptosis DNA Fragmentation Agarose gel electrophoresis Cells are balanced between life and death DAMAGE Physiological death signals DEATH SIGNAL PROAPOPTOTIC PROTEINS ANTIAPOPTOTIC PROTEINS APOPTOSIS: important in embryogenesis Morphogenesis (eliminates excess cells): Selection (eliminates nonfunctional cells): Apoptosis in the developing mouse paw the elimination of the tail during the metamorphosis of a tadpole into a frog STAGES OF APOPTOSIS Healthy cell DEATH SIGNAL Commitment to die (reversible) EXECUTION (irreversible) Dead cell (condensed, crosslinked) ENGULFMENT DEGRADATION 誘導(dǎo)凋亡的機(jī)理 誘導(dǎo)產(chǎn)生凋亡的因素很多,大體上分為以下幾大類(lèi) 內(nèi)部信號(hào)、外源性信號(hào)、凋亡誘導(dǎo)因子 ,但是它們之間并沒(méi)有嚴(yán)格的劃分,而是相互協(xié)調(diào)發(fā)揮作用。 內(nèi)部信號(hào) ? 線粒體 的功能變化可導(dǎo)致細(xì)胞凋亡 線粒體參與了細(xì)胞死亡的實(shí)時(shí)進(jìn)程 (active process),包括介導(dǎo)和調(diào)節(jié)細(xì)胞凋亡的發(fā)生,是一種調(diào)節(jié)細(xì)胞凋亡的細(xì)胞器。它可以通過(guò)三種方式影響細(xì)胞的生存與死亡: ? 線粒體 電子傳遞鏈的中斷和能量生成障礙可以直接導(dǎo)致細(xì)胞的死亡, ? 線粒體 可釋放或激活介導(dǎo)細(xì)胞凋亡的蛋白質(zhì), ? 還可