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Hung JC, Mahoney DW, Huang DC, Wang A. The relationship between elution time and eluate volume using the Ultra-TechneKow DTE technetium-99m generator. J Nucl Med Technol 2000; 28:178-81. [PMID: 11001502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
OBJECTIVE The new Ultra-TechneKow Dry Ship Top Elute 99mTc generator (UTK-DTE generator; Mallinckrodt Medical, Inc., St. Louis, MO) was devised to facilitate fractionated elution with an ergonomically designed elution shield. Fractionation is accomplished traditionally by visually observing the eluted volume through 2 layers of leaded glass windows located in a lighted elution shield and generator auxiliary shield. The goal of our study was to use elution time to determine the endpoint for obtaining the required volume of 99mTc-eluate from a UTK-DTE generator. METHODS After triplicate elution at several predetermined elution times, the initial weight of the evacuated collecting vial was subtracted from the total weight after elution to determine the elution volume. RESULTS A quadratic relationship was established between the eluate volume (v, mL) and elution time (t, s) (v = 0.3594 + 0.1889 t - 0.0009 t2). This equation is suitable for use with the 10-mL elution vial. This formula may not be accurate for the first elution since the UTK-DTE generator is a dry-column generator when shipped. The following elution times were calculated for some commonly eluted volumes: 2 mL (9 s), 4 mL (22 s), 5 mL (28 s), 7 mL (45 s), and 10 mL (88 s). CONCLUSION Our calculated elution time method can be used to predict the eluate volume from a UTK-DTE generator.
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Villunger A, Huang DC, Holler N, Tschopp J, Strasser A. Fas ligand-induced c-Jun kinase activation in lymphoid cells requires extensive receptor aggregation but is independent of DAXX, and Fas-mediated cell death does not involve DAXX, RIP, or RAIDD. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:1337-43. [PMID: 10903735 DOI: 10.4049/jimmunol.165.3.1337] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Jun kinase signaling can be elicited by death receptor activation, but the mechanism and significance of this event are still unclear. It has been reported that cross-linking Abs to Fas trigger c-Jun N-terminal kinase (JNK) signaling via caspase-mediated activation of MEKK1 (JNK kinase kinase), elevation of ceramide levels or by recruitment of death domain associated protein (DAXX) to Fas. The effect of physiological ligand for Fas on JNK signaling was never investigated, although evidence is accumulating that Fas ligand is able to induce cellular responses distinct from those evoked by Ab-mediated cross-linking of Fas. Therefore, we investigated the effect of Fas ligand on JNK signaling. Like its ability to induce cell death, Fas ligand reliably activated JNK only upon extensive aggregation of the receptor. Although this was partially dependent on caspase activation, DAXX was not required. DAXX and other death receptor-associated proteins, which have been reported to bind directly or indirectly to Fas, such as receptor interacting protein (RIP) and RIP-associated ICH-1/CED-3-homologous protein with a death domain (RAIDD), were shown to be dispensable for Fas ligand-induced apoptosis.
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Huang DC, Tschopp J, Strasser A. Bcl-2 does not inhibit cell death induced by the physiological Fas ligand: implications for the existence of type I and type II cells. Cell Death Differ 2000; 7:754-5. [PMID: 11202986 DOI: 10.1038/sj.cdd.4400683] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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O'Reilly LA, Cullen L, Visvader J, Lindeman GJ, Print C, Bath ML, Huang DC, Strasser A. The proapoptotic BH3-only protein bim is expressed in hematopoietic, epithelial, neuronal, and germ cells. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 157:449-61. [PMID: 10934149 PMCID: PMC1850143 DOI: 10.1016/s0002-9440(10)64557-9] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Proapoptotic Bcl-2 family members activate cell death by neutralizing their anti-apoptotic relatives, which in turn maintain cell viability by regulating the activation of the cell death effectors, the caspases. Bim belongs to a distinct subgroup of proapoptotic proteins that only resemble other Bcl-2 family members within the short BH3 domain. Gene targeting experiments in mice have shown that Bim is essential for the execution of some but not all apoptotic stimuli, for hematopoietic cell homeostasis, and as a barrier against autoimmunity. There are three Bim isoforms, Bim(S), Bim(L), and Bim(EL), which have different proapoptotic potencies due at least in part to differences in interaction with the dynein motor complex. The expression pattern of Bim was investigated by immunohistochemical staining, immunoprecipitation followed by Western blotting, and in situ hybridization. Bim was found in hematopoietic, epithelial, neuronal, and germ cells. Bim(L) and Bim(EL) were coexpressed at similar levels in many cell types, but Bim(S) was not detected. Microscopic examination revealed a punctate pattern of Bim(L) and Bim(EL) immunostaining, indicating association with cytoplasmic structures. These results are discussed in the context of the phenotype of Bim-deficient mice and the post-translational regulation of Bim's pro-apoptotic activity.
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Tseng SH, Chen SM, Lin SM, Huang DC. Increased immunoreactive labeling of the spinal N-methyl-D-aspartate R1 receptors after dorsal root ganglionectomy in the rats. Neurosci Lett 2000; 286:41-4. [PMID: 10822148 DOI: 10.1016/s0304-3940(00)01091-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The N-methyl-D-aspartate (NMDA) receptor plays an important role in the development of the autotomy after dorsal root ganglionectomy (DRGn). In this study, we further investigated the expression of the NMDAR1 in the spinal cord of the rats after right DRGn by immunohistochemical analyses. Computerized densitometric analysis of the NMDAR1 immunoreactivity was done and the integrated optical density (IOD) of the superficial laminae of the dorsal horn of the spinal cord was measured. The immunoreactive labeling of the NMDAR1 was increased in the cervical spinal cord ipsilateral to the DRGn from day 5 to 14 after DRGn. The ratio of the right/left IOD of the rats receiving DRGn was significantly higher than the rats in the sham-operated group and the control group (P<0.05). The expression of the NMDAR1 increased gradually to reach the peak at day 7 after DRGn (mean right/left IOD ratio=1.52), then decreased thereafter. The increased expression of the NMDAR1 at day 7 was suppressed by MK-801 (NMDA receptor antagonist) administered immediately after DRGn, but not by normal saline or 1,2,3,4-tetrahydro-6-nitro-2, 3-dioxo-benzo[f] quinoxaline-7-sulfonamide (NBQX, non-NMDA receptor antagonist). The results indicated that the expression of the NMDAR1 in the superficial laminae of the dorsal horn of the spinal cord was increased after DRGn and the time course was compatible with the onset and development of the autotomy induced by DRGn.
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Hausmann G, O'Reilly LA, van Driel R, Beaumont JG, Strasser A, Adams JM, Huang DC. Pro-apoptotic apoptosis protease-activating factor 1 (Apaf-1) has a cytoplasmic localization distinct from Bcl-2 or Bcl-x(L). J Cell Biol 2000; 149:623-34. [PMID: 10791976 PMCID: PMC2174854 DOI: 10.1083/jcb.149.3.623] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/1999] [Accepted: 03/23/2000] [Indexed: 12/26/2022] Open
Abstract
How Bcl-2 and its pro-survival relatives prevent activation of the caspases that mediate apoptosis is unknown, but they appear to act through the caspase activator apoptosis protease-activating factor 1 (Apaf-1). According to the apoptosome model, the Bcl-2-like proteins preclude Apaf-1 activity by sequestering the protein. To explore Apaf-1 function and to test this model, we generated monoclonal antibodies to Apaf-1 and used them to determine its localization within diverse cells by subcellular fractionation and confocal laser scanning microscopy. Whereas Bcl-2 and Bcl-x(L) were prominent on organelle membranes, endogenous Apaf-1 was cytosolic and did not colocalize with them, even when these pro-survival proteins were overexpressed or after apoptosis was induced. Immunogold electron microscopy confirmed that Apaf-1 was dispersed in the cytoplasm and not on mitochondria or other organelles. After the death stimuli, Bcl-2 and Bcl-x(L) precluded the release of the Apaf-1 cofactor cytochrome c from mitochondria and the formation of larger Apaf-1 complexes, which are steps that presage apoptosis. However, neither Bcl-2 nor Bcl-x(L) could prevent the in vitro activation of Apaf-1 induced by the addition of exogenous cytochrome c. Hence, rather than sequestering Apaf-1 as proposed by the apoptosome model, Bcl-2-like proteins probably regulate Apaf-1 indirectly by controlling upstream events critical for its activation.
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Colussi PA, Quinn LM, Huang DC, Coombe M, Read SH, Richardson H, Kumar S. Debcl, a proapoptotic Bcl-2 homologue, is a component of the Drosophila melanogaster cell death machinery. J Cell Biol 2000; 148:703-14. [PMID: 10684252 PMCID: PMC2169366 DOI: 10.1083/jcb.148.4.703] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bcl-2 family of proteins are key regulators of apoptosis. Both proapoptotic and antiapoptotic members of this family are found in mammalian cells, but no such proteins have been described in insects. Here, we report the identification and characterization of Debcl, the first Bcl-2 homologue in Drosophila melanogaster. Structurally, Debcl is similar to Bax-like proapoptotic Bcl-2 family members. Ectopic expression of Debcl in cultured cells and in transgenic flies causes apoptosis, which is inhibited by coexpression of the baculovirus caspase inhibitor P35, indicating that Debcl is a proapoptotic protein that functions in a caspase-dependent manner. debcl expression correlates with developmental cell death in specific Drosophila tissues. We also show that debcl genetically interacts with diap1 and dark, and that debcl-mediated apoptosis is not affected by gene dosage of rpr, hid, and grim. Biochemically, Debcl can interact with several mammalian and viral prosurvival Bcl-2 family members, but not with the proapoptotic members, suggesting that it may regulate apoptosis by antagonizing prosurvival Bcl-2 proteins. RNA interference studies indicate that Debcl is required for developmental apoptosis in Drosophila embryos. These results suggest that the main components of the mammalian apoptosis machinery are conserved in insects.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Apoptosis/drug effects
- Apoptosis/genetics
- Apoptosis/physiology
- Caspase Inhibitors
- Caspases/metabolism
- Cell Survival/drug effects
- Cells, Cultured
- Cloning, Molecular
- Drosophila Proteins
- Drosophila melanogaster/cytology
- Drosophila melanogaster/embryology
- Drosophila melanogaster/genetics
- Drosophila melanogaster/metabolism
- Epistasis, Genetic
- Gene Expression
- Genes, Insect/genetics
- Inhibitor of Apoptosis Proteins
- Insect Proteins/genetics
- Molecular Sequence Data
- Mutation/genetics
- Protein Binding
- Protein Structure, Tertiary
- Proteins/genetics
- Proto-Oncogene Proteins c-bcl-2/chemistry
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA, Double-Stranded/administration & dosage
- RNA, Double-Stranded/pharmacology
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Sequence Homology, Amino Acid
- Viral Proteins/genetics
- Viral Proteins/metabolism
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Allison J, Thomas H, Beck D, Brady JL, Lew AM, Elefanty A, Kosaka H, Kay TW, Huang DC, Strasser A. Transgenic overexpression of human Bcl-2 in islet beta cells inhibits apoptosis but does not prevent autoimmune destruction. Int Immunol 2000; 12:9-17. [PMID: 10607745 DOI: 10.1093/intimm/12.1.9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Insulin-dependent diabetes mellitus results when > 90% of the insulin-producing beta cells in the pancreatic islets are killed as a result of autoimmune attack by T cells. During the progression to diabetes, islet beta cells die as a result of different insults from the immune system. Agents such as perforin and granzymes, CD95 ligand and tumor necrosis factor-alpha, or cytokines and free-radicals have all been shown to cause beta cell apoptosis. The anti-apoptotic protein, Bcl-2, might protect against some of these stimuli. We have therefore generated transgenic mice expressing human Bcl-2 in their islet beta cells. Although Bcl-2 was able to prevent apoptosis induced by cytotoxic agents against beta cells in vitro, Bcl-2 alone could not prevent or ameliorate cytotoxic or autoimmune beta cell damage in vivo.
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Huang DC, Hahne M, Schroeter M, Frei K, Fontana A, Villunger A, Newton K, Tschopp J, Strasser A. Activation of Fas by FasL induces apoptosis by a mechanism that cannot be blocked by Bcl-2 or Bcl-x(L). Proc Natl Acad Sci U S A 1999; 96:14871-6. [PMID: 10611305 PMCID: PMC24740 DOI: 10.1073/pnas.96.26.14871] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Fas activation triggers apoptosis in many cell types. Studies with anti-Fas antibodies have produced conflicting results on Fas signaling, particularly the role of the Bcl-2 family in this process. Comparison between physiological ligand and anti-Fas antibodies revealed that only extensive Fas aggregation, by membrane bound FasL or aggregated soluble FasL consistently triggered apoptosis, whereas antibodies could act as death agonists or antagonists. Studies on Fas signaling in cell lines and primary cells from transgenic mice revealed that FADD/MORT1 and caspase-8 were required for apoptosis. In contrast, Bcl-2 or Bcl-x(L) did not block FasL-induced apoptosis in lymphocytes or hepatocytes, demonstrating that signaling for cell death induced by Fas and the pathways to apoptosis regulated by the Bcl-2 family are distinct.
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36
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Bouillet P, Metcalf D, Huang DC, Tarlinton DM, Kay TW, Köntgen F, Adams JM, Strasser A. Proapoptotic Bcl-2 relative Bim required for certain apoptotic responses, leukocyte homeostasis, and to preclude autoimmunity. Science 1999; 286:1735-8. [PMID: 10576740 DOI: 10.1126/science.286.5445.1735] [Citation(s) in RCA: 1180] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Apoptosis can be triggered by members of the Bcl-2 protein family, such as Bim, that share only the BH3 domain with this family. Gene targeting in mice revealed important physiological roles for Bim. Lymphoid and myeloid cells accumulated, T cell development was perturbed, and most older mice accumulated plasma cells and succumbed to autoimmune kidney disease. Lymphocytes were refractory to apoptotic stimuli such as cytokine deprivation, calcium ion flux, and microtubule perturbation but not to others. Thus, Bim is required for hematopoietic homeostasis and as a barrier to autoimmunity. Moreover, particular death stimuli appear to activate apoptosis through distinct BH3-only proteins.
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37
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McGough CG, Huang DC, Hung JC. Comparison of four 1-mL syringes for administering first-pass radionuclide angiography doses. J Nucl Med Technol 1999; 27:227-9. [PMID: 10512480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
OBJECTIVE For optimal imaging in first-pass radionuclide angiography (FPRNA) studies, 1.11 GBq (30 mCi) 99mTc-sestamibi doses are drawn up in volumes of 0.1-0.3 mL. A single bolus injection of this small volume is important to obtain accurate time-activity curves. Because of the small volume and concentrated radioactivity, it is undesirable for study effectiveness and image quality to have a significant amount of residual activity remaining in the syringe after injection. The purpose of this study was to compare the amount of residual activity in 4 different 1-mL syringes. METHODS Each test syringe (n = 20) was filled with a volume (0.2 mL) of approximately 1.11 GBq (approximately 30 mCi) 99mTc-sestamibi. Initial activity was measured, and the dose was injected back into a vial only once, simulating bolus injection into a patient. The remaining activity was measured, followed by the calculation of percent residual activity. RESULTS The two 25-G x 5/8-in. permanent needles had a low percent of residual activity, as well as a much sturdier needle for injection. However, one of these syringes is more expensive. CONCLUSION The results of our comparison studies showed that the syringe with a 25-G x 5/8-in. permanent needle is ideal for FPRNA doses because of its sturdiness, low residual activity, and the quality of the bolus and resulting images.
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Moriishi K, Huang DC, Cory S, Adams JM. Bcl-2 family members do not inhibit apoptosis by binding the caspase activator Apaf-1. Proc Natl Acad Sci U S A 1999; 96:9683-8. [PMID: 10449754 PMCID: PMC22270 DOI: 10.1073/pnas.96.17.9683] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Bcl-2 family of proteins regulates apoptosis, the cell death program triggered by activation of certain proteases (caspases). An attractive model for how Bcl-2 and its closest relatives prevent caspase activation is that they bind to and inactivate an adaptor protein required for procaspase processing. That model has been supported by reports that mammalian prosurvival Bcl-2 relatives bind the adaptor Apaf-1, which activates procaspase-9. However, the in vivo association studies reported here with both overexpressed and endogenous Apaf-1 challenge this notion. Apaf-1 could be immunoprecipitated together with procaspase-9, and the Apaf-1 caspase-recruitment domain was necessary and sufficient for their interaction. Apaf-1 did not bind, however, to any of the six known mammalian prosurvival family members (Bcl-2, Bcl-x(L), Bcl-w, A1, Mcl-1, or Boo), or their viral homologs adenovirus E1B 19K and Epstein-Barr virus BHRF-1. Endogenous Apaf-1 also failed to coimmunoprecipitate with endogenous Bcl-2 or Bcl-x(L), or with two proapoptotic relatives (Bax and Bim). Moreover, apoptotic stimuli did not induce Apaf-1 to bind to these family members. Thus, the prosurvival Bcl-2 homologs do not appear to act by sequestering Apaf-1 and probably instead constrain its activity indirectly.
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Holmgreen SP, Huang DC, Adams JM, Cory S. Survival activity of Bcl-2 homologs Bcl-w and A1 only partially correlates with their ability to bind pro-apoptotic family members. Cell Death Differ 1999; 6:525-32. [PMID: 10381646 DOI: 10.1038/sj.cdd.4400519] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Certain Bcl-2 family members promote cell survival, whereas others promote apoptosis. To explore further how heterodimerization of opposing members affects survival activity, we have compared the abilities of the anti-apoptotic Bcl-w and A1 to bind to the pro-apoptotic Bax, Bak, Bad and Bik and to protect cells from their cytotoxic action. Bcl-w co-immunoprecipitated from cell lysates with Bax, Bak, Bad and Bik, but A1 bound only Bak and Bik. Mutation of A1 at a highly conserved glycine within the BH1 domain prevented binding, but the comparable Bcl-w mutant still bound Bak, Bad and Bik, indicating that the glycine is not essential for all heterodimerization. Bcl-w and A1 protected against apoptosis induced by over-expression of Bax or Bad but not that induced by Bak or Bik. With several gene pairs, binding and protection were discordant. The results may reflect critical threshold affinities but also suggest that certain pro-apoptotic proteins may also contribute to apoptosis by a mechanism independent of binding pro-survival proteins.
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Grell M, Zimmermann G, Gottfried E, Chen CM, Grünwald U, Huang DC, Wu Lee YH, Dürkop H, Engelmann H, Scheurich P, Wajant H, Strasser A. Induction of cell death by tumour necrosis factor (TNF) receptor 2, CD40 and CD30: a role for TNF-R1 activation by endogenous membrane-anchored TNF. EMBO J 1999; 18:3034-43. [PMID: 10357816 PMCID: PMC1171385 DOI: 10.1093/emboj/18.11.3034] [Citation(s) in RCA: 225] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Several members of the tumour necrosis factor receptor (TNF-R) superfamily can induce cell death. For TNF-R1, Fas/APO-1, DR3, DR6, TRAIL-R1 and TRAIL-R2, a conserved 'death domain' in the intracellular region couples these receptors to activation of caspases. However, it is not yet known how TNF receptor family members lacking a death domain, such as TNF-R2, CD40, LT-betaR, CD27 or CD30, execute their death-inducing capability. Here we demonstrate in different cellular systems that cytotoxic effects induced by TNF-R2, CD40 and CD30 are mediated by endogenous production of TNF and autotropic or paratropic activation of TNF-R1. In addition, stimulation of TNF-R2 and CD40 synergistically enhances TNF-R1-induced cytotoxicity. These findings describe a novel pro-apoptotic mechanism induced by some members of the TNF-R family.
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MESH Headings
- Animals
- Antibodies/pharmacology
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/physiology
- Apoptosis/drug effects
- CD40 Antigens/genetics
- CD40 Antigens/physiology
- Caspase Inhibitors
- Caspases/metabolism
- Fas Ligand Protein
- Humans
- Interferon-gamma/antagonists & inhibitors
- Interferon-gamma/pharmacology
- Ki-1 Antigen/physiology
- Membrane Glycoproteins/physiology
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mutation
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/physiology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Interferon/genetics
- Receptors, Interferon/physiology
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Receptors, Tumor Necrosis Factor, Type I
- Receptors, Tumor Necrosis Factor, Type II
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/physiology
- Signal Transduction
- Transfection
- Tumor Cells, Cultured
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- Up-Regulation
- bcl-X Protein
- Interferon gamma Receptor
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Puthalakath H, Huang DC, O'Reilly LA, King SM, Strasser A. The proapoptotic activity of the Bcl-2 family member Bim is regulated by interaction with the dynein motor complex. Mol Cell 1999; 3:287-96. [PMID: 10198631 DOI: 10.1016/s1097-2765(00)80456-6] [Citation(s) in RCA: 806] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Bcl-2 family members that have only a single Bcl-2 homology domain, BH3, are potent inducers of apoptosis, and some appear to play a critical role in developmentally programmed cell death. We examined the regulation of the proapoptotic activity of the BH3-only protein Bim. In healthy cells, most Bim molecules were bound to LC8 cytoplasmic dynein light chain and thereby sequestered to the microtubule-associated dynein motor complex. Certain apoptotic stimuli disrupted the interaction between LC8 and the dynein motor complex. This freed Bim to translocate together with LC8 to Bcl-2 and to neutralize its antiapoptotic activity. This process did not require caspase activity and therefore constitutes an initiating event in apoptosis signaling.
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O'Reilly LA, Cullen L, Moriishi K, O'Connor L, Huang DC, Strasser A. Rapid hybridoma screening method for the identification of monoclonal antibodies to low-abundance cytoplasmic proteins. Biotechniques 1998; 25:824-30. [PMID: 9821584 DOI: 10.2144/98255st03] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Screening assays are the most time-consuming and labor-intensive part of generating monoclonal antibodies (MAbs). Antibodies identified by enzyme-linked immunosorbent assay (ELISA) screening often are not suitable for their intended application such as immunofluorescence staining. We describe here a rapid and efficient flow cytometric screening procedure for the identification of MAbs directed against low-abundance cytoplasmic proteins, in our case, the pro-apoptotic molecule Bim. Cells from an equal mixture of a parental cell line and a subline expressing Bim were fixed, permeabilized and incubated with hybridoma supernatants. The supernatants were derived from a fusion of Sp2/0 plasmacytoma cells and spleen cells from a rat immunized with recombinant glutathione-S-transferase (GST)-BimL fusion protein. Secondary staining with fluorochrome-labeled anti-rat Ig antibodies allowed detection of clones expressing Bim-specific antibodies. The screening procedure was rapid and efficient, and most monoclonal antibodies identified were proven to be useful for immunofluorescence staining and other applications.
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Huang DC, Adams JM, Cory S. The conserved N-terminal BH4 domain of Bcl-2 homologues is essential for inhibition of apoptosis and interaction with CED-4. EMBO J 1998; 17:1029-39. [PMID: 9463381 PMCID: PMC1170452 DOI: 10.1093/emboj/17.4.1029] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bcl-2 and close homologues such as Bcl-xL promote cell survival, while other relatives such as Bax antagonize this function. Since only the pro-survival family members possess a conserved N-terminal region denoted BH4, we have explored the role of this amphipathic helix for their survival function and for interactions with several agonists of apoptosis, including Bax and CED-4, an essential regulator in the nematode Caenorhabditis elegans. BH4 of Bcl-2 could be replaced by that of Bcl-x without perturbing function but not by a somewhat similar region near the N-terminus of Bax. Bcl-2 cell survival activity was reduced by substitutions in two of ten conserved BH4 residues. Deletion of BH4 rendered Bcl-2 (and Bcl-xL) inactive but did not impair either Bcl-2 homodimerization or ability to bind to Bax or five other pro-apoptotic relatives (Bak, Bad, Bik, Bid or Bim). Hence, association with these death agonists is not sufficient to promote cell survival. Significantly, however, Bcl-xL lacking BH4 lost the ability both to bind CED-4 and antagonize its pro-apoptotic activity. These results favour the hypothesis that the BH4 domain of pro-survival Bcl-2 family members allows them to sequester CED-4 relatives and thereby prevent apoptosis.
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O'Connor L, Strasser A, O'Reilly LA, Hausmann G, Adams JM, Cory S, Huang DC. Bim: a novel member of the Bcl-2 family that promotes apoptosis. EMBO J 1998; 17:384-95. [PMID: 9430630 PMCID: PMC1170389 DOI: 10.1093/emboj/17.2.384] [Citation(s) in RCA: 883] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Certain members of the Bcl-2 family inhibit apoptosis while others facilitate this physiological process of cell death. An expression screen for proteins that bind to Bcl-2 yielded a small novel protein, denoted Bim, whose only similarity to any known protein is the short (nine amino acid) BH3 motif shared by most Bcl-2 homologues. Bim provokes apoptosis, and the BH3 region is required for Bcl-2 binding and for most of its cytotoxicity. Like Bcl-2, Bim possesses a hydrophobic C-terminus and localizes to intracytoplasmic membranes. Three Bim isoforms, probably generated by alternative splicing, all induce apoptosis, the shortest being the most potent. Wild-type Bcl-2 associates with Bim in vivo and modulates its death function, whereas Bcl-2 mutants that lack survival function do neither. Significantly, Bcl-xL and Bcl-w, the two closest homologues of Bcl-2, also bind to Bim and inhibit its activity, but more distant viral homologues, adenovirus E1B19K and Epstein-Barr virus BHRF-1, can do neither. Hence, Bim appears to act as a 'death ligand' which can only neutralize certain members of the pro-survival Bcl-2 sub-family.
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Weng KP, Hsieh KS, Huang SH, Lin CC, Huang DC. Serum HDL level at acute stage of Kawasaki disease. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1998; 39:28-32. [PMID: 9553289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Kawasaki disease is a disease of acute vascular inflammation of unknown etiology and HDL is a known risk factor of vascular damage. So far, there is no specific serum marker for KD. The previous study has shown a remarkable change of serum HDL in the patients with KD. To find whether changes in serum HDL level is a specific serum marker for early diagnosis of KD, we measured the concentration of HDL, LDL, TC, TG and CRP immediately after admission and one week later in three groups of patients (56 patients with KD, 38 patients with clinical viral infection, and 42 patients with bacterial infection). There was a significant decrease of HDL and increase of TG immediately after admission in three groups of patients. HDL and TG did not return to normal one week later. HDL level is more adversely affected in severe diseases than in mild diseases. Our results indicated that low HDL level is noted in various acute infection and is not a specific serum marker in the early stage of Kawasaki disease. It is interesting that low HDL is a universal phenomenon in this series. Further research is needed to explain the mechanism of lipid alterations and its consequences.
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Strasser A, Huang DC, Vaux DL. The role of the bcl-2/ced-9 gene family in cancer and general implications of defects in cell death control for tumourigenesis and resistance to chemotherapy. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1333:F151-78. [PMID: 9395285 DOI: 10.1016/s0304-419x(97)00019-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cell production within an organ is determined by the rate of immigration, proliferation, differentiation, emigration and death of cells. Abnormalities in any one of these processes will disturb normal control of cell production, thereby eliciting hyperplasia can be an early event in neoplasia. Cell death, apoptosis, is a physiological process responsible for removing unwanted cells. It is used in multi-cellular organisms for tissue remodelling during embryogenesis, regulation of cell turnover and as a defence strategy against invading pathogens. In this review article we describe the role of the bcl-2/ced-9 gene family in cancer and discuss the general implications of defects in the apoptosis program for tumourigenesis and resistance of cancer cells to chemotherapy in light of current knowledge of the molecular mechanisms of cell death.
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Huang DC, O'Reilly LA, Strasser A, Cory S. The anti-apoptosis function of Bcl-2 can be genetically separated from its inhibitory effect on cell cycle entry. EMBO J 1997; 16:4628-38. [PMID: 9303307 PMCID: PMC1170089 DOI: 10.1093/emboj/16.15.4628] [Citation(s) in RCA: 261] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Bcl-2 family of proteins regulate apoptosis, some antagonizing cell death and others facilitating it. It has recently been demonstrated that Bcl-2 not only inhibits apoptosis but also restrains cell cycle entry. We show here that these two functions can be genetically dissociated. Mutation of a tyrosine residue within the conserved N-terminal BH4 region had no effect on the ability of Bcl-2 or its closest homologs to enhance cell survival and did not prevent heterodimerization with death-enhancing family members Bax, Bak, Bad and Bik. Neither did this mutation override the growth-inhibitory effect of p53. However, on stimulation with cytokine or serum, starved quiescent cells expressing the mutant proteins re-entered the cell cycle much faster than those expressing comparable levels of wild-type proteins. When wild-type and Y28 mutant Bcl-2 were co-expressed, the mutant was dominant. Although R-Ras p23 has been reported to bind to Bcl-2, no interaction was detectable in transfected cells and R-Ras p23 did not interfere with the ability of Bcl-2 to inhibit apoptosis or cell cycle entry. These observations provide evidence that the anti-apoptotic function of Bcl-2 is mechanistically distinct from its inhibitory influence on cell cycle entry.
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Huang DC, Cory S, Strasser A. Bcl-2, Bcl-XL and adenovirus protein E1B19kD are functionally equivalent in their ability to inhibit cell death. Oncogene 1997; 14:405-14. [PMID: 9053837 DOI: 10.1038/sj.onc.1200848] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Apoptosis is the physiological process by which unwanted cells in an organism are killed. Bcl-2, a membrane-bound cytoplasmic protein, is an effective inhibitor of apoptotic cell death induced by many cytotoxic agents. Survival-promoting homologues of Bcl-2 include its close relative, Bcl-xL and the 19 kD protein encoded by the E1B gene of adenoviruses. Whether these proteins are functionally equivalent and whether they can antagonise all or only some pathways to apoptosis is unresolved. We have carried out a systematic comparison of Bcl-2, Bcl-xL and adenovirus E1B19kD activity, using several cell lines and a range of cytotoxic conditions. High levels of expression of each of these proteins inhibited apoptosis induced by growth factor deprivation or treatment with gamma-radiation, glucocorticoid and various cytotoxic drugs. In contrast, none of them could effectively counter apoptosis induced via the TNF receptor or Fas/APO-1 (CD95). Biochemical analysis revealed that all three proteins can associate with Bax and Bak, members of the Bcl-2 protein subfamily that can facilitate apoptosis. The results provide evidence that Bcl-2, Bcl-xL and adenovirus protein E1B19kD are indistinguishable in their ability to regulate the cell death effector machinery.
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O'Reilly LA, Huang DC, Strasser A. The cell death inhibitor Bcl-2 and its homologues influence control of cell cycle entry. EMBO J 1996; 15:6979-90. [PMID: 9003774 PMCID: PMC452524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The effect of the cell death inhibitor Bcl-2 and its homologues on cell cycle regulation was explored in lymphocytes and cell lines. Expression of a bcl-2 transgene reduced proliferation of thymocytes and delayed cell cycle entry of mitogen-stimulated B and T lymphocytes. Overexpression of Bcl-2, Bcl-xL or adenovirus E1B19kD substantially delayed serum stimulation-induced S phase entry of quiescent NIH 3T3 fibroblasts. Bcl-2-mediated cell survival and growth inhibition are both antagonized by Bax. Bcl-2, Bcl-xL and E1B19kD, but not Bcl-2 mutants that are defective in blocking apoptosis, suppress growth of colon carcinoma cells. This evidence that regulation of cell survival is coupled to control of cell growth has implications for normal cell turnover and tumorigenesis.
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Strasser A, O'Connor L, Huang DC, O'Reilly LA, Stanley ML, Bath ML, Adams JM, Cory S, Harris AW. Lessons from bcl-2 transgenic mice for immunology, cancer biology and cell death research. BEHRING INSTITUTE MITTEILUNGEN 1996:101-17. [PMID: 8950469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The protein product of the proto-oncogene bcl-2, originally discovered by virtue of its chromosomal translocation in human follicular centre B cell lymphoma, is a physiological inhibitor of programmed cell death, apoptosis. Initial studies in transgenic mice overexpressing Bcl-2 in B or T lymphocytes demonstrated that Bcl-2 can potently antagonise cell death induced by multiple independent signal transduction routes and can contribute to oncogenesis, particularly in combination with other oncogenes, like c-myc, that promote cell proliferation. Further investigations using crosses between bcl-2 transgenic mice and T cell receptor or immunoglobulin transgenic mice or mutant mice deficient in proper antigen receptor gene rearrangement demonstrated that Bcl-2 can only block death of cells that failed to receive a positive stimulus, "death by neglect', but not activation induced apoptosis. Collectively, these results provide evidence that distinct signalling pathways for apoptosis converge upon a common effector machinery where Bcl-2 acts as an antagonist, but that there also exists a mechanism that can either bypass the Bcl-2 checkpoint or override its protective function. These experimental data are reviewed here and discussed in context of current knowledge of lymphocyte differentiation, tumorigenesis and cell death regulation.
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