Induction of apoptotic program in cell-free extracts : requirement for datp and cytochrome c
TL;DR: Cells undergoing apoptosis in vivo showed increased release of cy tochrome c to their cytosol, suggesting that mitochondria may function in apoptosis by releasing cytochrome c.
About: This article is published in Cell.The article was published on 1996-07-12 and is currently open access. It has received 5128 citations till now. The article focuses on the topics: Cytochrome c & Apoptosome.
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TL;DR: Mutation of the active site of caspase-9 attenuated the activation of cazase-3 and cellular apoptotic response in vivo, indicating that casp enzyme-9 is the most upstream member of the apoptotic protease cascade that is triggered by cytochrome c and dATP.
7,231 citations
TL;DR: This work has shown that understanding caspase regulation is intimately linked to the ability to rationally manipulate apoptosis for therapeutic gain.
Abstract: Apoptosis, an evolutionarily conserved form of cell suicide, requires specialized machinery. The central component of this machinery is a proteolytic system involving a family of proteases called caspases. These enzymes participate in a cascade that is triggered in response to proapoptotic signals and culminates in cleavage of a set of proteins, resulting in disassembly of the cell. Understanding caspase regulation is intimately linked to the ability to rationally manipulate apoptosis for therapeutic gain.
6,924 citations
TL;DR: In this article, the inflammasome is identified as a caspase-activating complex that comprises caspases-1, casp-5, Pycard/Asc, and NALP1, a Pyrin domain-containing protein sharing structural homology with NODs.
5,032 citations
TL;DR: One possible role of Bcl-2 in prevention of apoptosis is to block cytochrome c release from mitochondria, which is normally located in the mitochondrial intermembrane space.
Abstract: Bcl-2 is an integral membrane protein located mainly on the outer membrane of mitochondria. Overexpression of Bcl-2 prevents cells from undergoing apoptosis in response to a variety of stimuli. Cytosolic cytochrome c is necessary for the initiation of the apoptotic program, suggesting a possible connection between Bcl-2 and cytochrome c, which is normally located in the mitochondrial intermembrane space. Cells undergoing apoptosis were found to have an elevation of cytochrome c in the cytosol and a corresponding decrease in the mitochondria. Overexpression of Bcl-2 prevented the efflux of cytochrome c from the mitochondria and the initiation of apoptosis. Thus, one possible role of Bcl-2 in prevention of apoptosis is to block cytochrome c release from mitochondria.
4,961 citations
TL;DR: In a cell-free apoptosis system, mitochondria spontaneously released cytochrome c, which activated DEVD-specific caspases, leading to fodrin cleavage and apoptotic nuclear morphology, and Bcl-2 acts to inhibit cy tochrome c translocation, thereby blocking caspase activation and the apoptotic process.
Abstract: In a cell-free apoptosis system, mitochondria spontaneously released cytochrome c, which activated DEVD-specific caspases, leading to fodrin cleavage and apoptotic nuclear morphology. Bcl-2 acted in situ on mitochondria to prevent the release of cytochrome c and thus caspase activation. During apoptosis in intact cells, cytochrome c translocation was similarly blocked by Bcl-2 but not by a caspase inhibitor, zVAD-fmk. In vitro, exogenous cytochrome c bypassed the inhibitory effect of Bcl-2. Cytochrome c release was unaccompanied by changes in mitochondrial membrane potential. Thus, Bcl-2 acts to inhibit cytochrome c translocation, thereby blocking caspase activation and the apoptotic process.
4,754 citations
References
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TL;DR: It has proved feasible to categorize most if not all dying cells into one or the other of two discrete and distinctive patterns of morphological change, which have, generally, been found to occur under disparate but individually characteristic circumstances.
Abstract: Publisher Summary The classification of cell death can be based on morphological or biochemical criteria or on the circumstances of its occurrence. Currently, irreversible structural alteration provides the only unequivocal evidence of death; biochemical indicators of cell death that are universally applicable have to be precisely defined and studies of cell function or of reproductive capacity do not necessarily differentiate between death and dormant states from which recovery may be possible. It has also proved feasible to categorize most if not all dying cells into one or the other of two discrete and distinctive patterns of morphological change, which have, generally, been found to occur under disparate but individually characteristic circumstances. One of these patterns is the swelling proceeding to rupture of plasma and organelle membranes and dissolution of organized structure—termed “coagulative necrosis.” It results from injury by agents, such as toxins and ischemia, affects cells in groups rather than singly, and evokes exudative inflammation when it develops in vivo. The other morphological pattern is characterized by condensation of the cell with maintenance of organelle integrity and the formation of surface protuberances that separate as membrane-bounded globules; in tissues, these are phagocytosed and digested by resident cells, there being no associated inflammation.
7,417 citations
"Induction of apoptotic program in c..." refers background in this paper
...…acid residues, a hallmark of ICE-like protebranes, and fragmentation of the cell into apoptotic ases (Thornberry et al., 1992), a cascade of ICE-like bodies that are rapidly phagocytosed by neighboring proteolytic cleavages leading to apoptosis has been cells (Kerr, 1971; Wyllie et al., 1980)....
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..., 1992), a cascade of ICE-like bodies that are rapidly phagocytosed by neighboring proteolytic cleavages leading to apoptosis has been cells (Kerr, 1971; Wyllie et al., 1980)....
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TL;DR: It is shown here that this morphological change is closely associated with excision of nucleosome chains from nuclear chromatin, apparently through activation of an intracellular, but non-lysosomal, endonuclease.
Abstract: In near-physiological concentrations, glucocorticoid hormones cause the death of several types of normal and neoplastic lymphoid cell, but the mechanisms involved are unknown. One of the earliest structural changes in the dying cell is widespread chromatin condensation, of the type characteristic of apoptosis, the mode of death frequently observed where cell deletion seems to be 'programmed'. It is shown here that this morphological change is closely associated with excision of nucleosome chains from nuclear chromatin, apparently through activation of an intracellular, but non-lysosomal, endonuclease.
4,605 citations
"Induction of apoptotic program in c..." refers background in this paper
...Actimarkers of apoptosis include DNA fragmentation into vated CPP32 from HeLa cell extracts was able to cleave nucleosomal fragments (Wyllie, 1980), activation of the the CPP32 precursor (Wang et al., 1996), indicating that interleukin-1b-converting enzyme (ICE) family of prote- CPP32 can be…...
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...Actimarkers of apoptosis include DNA fragmentation into vated CPP32 from HeLa cell extracts was able to cleave nucleosomal fragments (Wyllie, 1980), activation of the the CPP32 precursor (Wang et al....
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TL;DR: A potent peptide aldehyde inhibitor has been developed and shown to prevent apoptotic events in vitro, suggesting that apopain/CPP32 is important for the initiation of apoptotic cell death.
Abstract: The protease responsible for the cleavage of poly(ADP-ribose) polymerase and necessary for apoptosis has been purified and characterized. This enzyme, named apopain, is composed of two subunits of relative molecular mass (M(r)) 17K and 12K that are derived from a common proenzyme identified as CPP32. This proenzyme is related to interleukin-1 beta-converting enzyme (ICE) and CED-3, the product of a gene required for programmed cell death in Caenorhabditis elegans. A potent peptide aldehyde inhibitor has been developed and shown to prevent apoptotic events in vitro, suggesting that apopain/CPP32 is important for the initiation of apoptotic cell death.
4,096 citations
TL;DR: A model in which Bcl-2 regulates an antioxidant pathway at sites of free radical generation is proposed in which it protected cells from H2O2- and menadione-induced oxidative deaths and suppressed lipid peroxidation completely.
3,452 citations
"Induction of apoptotic program in c..." refers methods in this paper
...…105/ml) were harvested by centrifugation at 1800 3count for its involvement in apoptosis (Jacobson et al., g for 10 min at 48C.After being washed once with ice-cold phosphate1993; Hockenbery et al., 1993; Newmeyer et al., 1994). buffered saline (PBS), the cell pellet was suspended in 5 vol of ice-...
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...The cells (5 3 10(5)/ml) were harvested by centrifugation at 1800 3 count for its involvement in apoptosis (Jacobson et al., g for 10 min at 48C.After being washed once with ice-cold phosphate 1993; Hockenbery et al., 1993; Newmeyer et al., 1994)....
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TL;DR: Genetic studies in the nematode Caenorhabditis elegans and in the fruit fly Drosophila melanogaster have led to the isolation of genes that are specifically required for the induction of programmed cell death.
Abstract: Apoptosis is a morphologically distinct form of programmed cell death that plays a major role during development, homeostasis, and in many diseases including cancer, acquired immunodeficiency syndrome, and neurodegenerative disorders. Apoptosis occurs through the activation of a cell-intrinsic suicide program. The basic machinery to carry out apoptosis appears to be present in essentially all mammalian cells at all times, but the activation of the suicide program is regulated by many different signals that originate from both the intracellular and the extracellular milieu. Genetic studies in the nematode Caenorhabditis elegans and in the fruit fly Drosophila melanogaster have led to the isolation of genes that are specifically required for the induction of programmed cell death. At least some components of the apoptotic program have been conserved among worms, insects, and vertebrates.
2,616 citations