Segregation of RNA and separate packaging of DNA and RNA in apoptotic bodies during apoptosis
Segregation of RNA and separate packaging of DNA and RNA in apoptotic bodies during apoptosis
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DOI：
10.1006/excr.2000.5027
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发表时间：
2000-11-01
影响因子：
3.7
通讯作者：
Darzynkiewicz, Z
中科院分区：
文献类型：
--
作者：
Halicka, HD;Bedner, E;Darzynkiewicz, Z
细胞凋亡的特征在于由准备和执行步骤组成的事件的复杂和显著有序的编排，所有这些步骤都以处理细胞残余物而告终。这种处理以对组织破坏性最小的方式进行：核染色质和细胞质的残留物被包装在凋亡小体中，然后被邻近的活细胞吞噬，而不会引起炎症或自身免疫反应。在本研究中，我们描述了在凋亡过程中，细胞RNA与DNA分离并包装成颗粒，然后进入凋亡小体。这种分离似乎是由核仁分离引发的，在HL-60细胞中观察到，这些细胞在培养中经历自发凋亡，或用DNA损伤药物DNA拓扑异构酶I抑制剂喜树碱（CPT）或细胞死亡配体肿瘤坏死因子-α处理。CPT处理后，在凋亡MCF-7细胞中也观察到RNA分离。凋亡细胞中的RNA和DNA分别用派洛宁Y和Hoechst 33342荧光染料进行组织化学鉴别，用BrU标记RNA不同时间，用荧光标记的抗BrU mAb检测掺入的前体; DNA用7-氨基放线菌素D复染。超过90%的凋亡小体含有RNA，但没有可检测的DNA，反之亦然，含有DNA的凋亡小体没有可检测的RTA。将RNA和DNA包装成单独的凋亡小体表明，摄取这些颗粒的细胞的吞噬体是专门的：其中一些负责DNA降解，另一些负责RNA降解。这种特化可以促进细胞凋亡期间核酸的异噬降解。(C)北京大学出版社.
Apoptosis is characterized by a complex and remarkably ordered choreography of events consisting of the preparatory and execution steps that all culminate in disposal of the cell remnants. The disposal occurs in a manner that is the least destructive to the tissue: the remains of nuclear chromatin and cytoplasm are packaged in apoptotic bodies which are then phagocytized by neighboring live cells without invoking inflammatory or autoimmune response. In the present study we describe that in the course of apoptosis cellular RNA becomes sequestered and packaged into granules and then into apoptotic bodies, separately from DNA. This separation, which appears to be initiated by the nucleolar segregation, was observed in HL-60 cells that were undergoing spontaneous apoptosis in cultures or were treated with the DNA-damaging drug, DNA topoisomerase I inhibitor camptothecin (CPT), or with the cell death ligand, tumor necrosis factor-alpha. RNA separation was also observed in apoptotic MCF-7 cells following treatment with CPT. RNA and DNA in apoptotic cells were identified histochemically, by their differential stainability with pyronin Y and Hoechst 33342 fluorochromes, respectively, and immunocytochemically, by labeling the RNA with BrU for various periods of time and detection of the incorporated precursor with fluoresceinated anti-BrU mAb; DNA was counterstained with 7-aminoactinomycin D. Over 90% of apoptotic bodies that contained RNA had no detectable DNA and vice versa, the apoptotic bodies containing DNA had no detectable RTA. Packaging RNA and DNA into separate apoptotic bodies suggests that the phagosomes of the cells that ingest these particles are specialized: some of them are responsible for DNA degradation, others for degradation of RNA. Such specialization may facilitate heterophagic degradation of nucleic acids during apoptosis. (C) 2000 Academic Press.