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Kok CY, MacLean LM, Rao R, Tsurusaki S, Kizana E. Promoter Optimization Circumvents Bcl-2 Transgene-Mediated Suppression of Lentiviral Vector Production. Biomolecules 2023; 13:1397. [PMID: 37759797 PMCID: PMC10526134 DOI: 10.3390/biom13091397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Lentiviral vectors are a robust gene delivery tool for inducing transgene expression in a variety of cells. They are well suited to facilitate the testing of therapeutic candidate genes in vitro, due to relative ease of packaging and ability to transduce dividing and non-dividing cells. Our goal was to identify a gene that could be delivered to the heart to protect against cancer-therapy-induced cardiotoxicity. We sought to generate a lentivirus construct with a ubiquitous CMV promoter driving expression of B-cell lymphocyte/leukemia 2 gene (Bcl-2), a potent anti-apoptotic gene. Contrary to our aim, overexpression of Bcl-2 induced cell death in the producer HEK293T cells, resulting in failure to produce usable vector titre. This was circumvented by exchanging the CMV promoter to the cardiac-specific NCX1 promoter, leading to the successful production of a lentiviral vector which could induce cardioprotective expression of Bcl-2. In conclusion, reduced expression of Bcl-2 driven by a weaker promoter improved vector yield, and led to the production of functional cardioprotective Bcl-2 in primary cardiomyocytes.
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Affiliation(s)
- Cindy Y. Kok
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
| | - Lauren M. MacLean
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
| | - Renuka Rao
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
| | - Shinya Tsurusaki
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
| | - Eddy Kizana
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
- Department of Cardiology, Westmead Hospital, Westmead, NSW 2145, Australia
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Michot JM, Quivoron C, Sarkozy C, Danu A, Lazarovici J, Saleh K, El-Dakdouki Y, Goldschmidt V, Bigenwald C, Dragani M, Bahleda R, Baldini C, Arfi-Rouche J, Martin-Romano P, Tselikas L, Gazzah A, Hollebecque A, Lacroix L, Ghez D, Vergé V, Marzac C, Cotteret S, Rahali W, Soria JC, Massard C, Bernard OA, Dartigues P, Camara-Clayette V, Ribrag V. Sequence analyses of relapsed or refractory diffuse large B-cell lymphomas unravel three genetic subgroups of patients and the GNA13 mutant as poor prognostic biomarker, results of LNH-EP1 study. Am J Hematol 2023; 98:645-657. [PMID: 36606708 DOI: 10.1002/ajh.26835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 12/29/2022] [Accepted: 01/01/2023] [Indexed: 01/07/2023]
Abstract
Advances in molecular profiling of newly diagnosed diffuse large B-cell lymphoma (DLBCL) have recently refine genetic subgroups. Genetic subgroups remain undetermined at the time of relapse or refractory (RR) disease. This study aims to decipher genetic subgroups and search for prognostic molecular biomarkers in patients with RR-DLBCL. From 2015 to 2021, targeted next-generation sequencing analyses of germline-matched tumor samples and fresh tissue from RR-DLBCL patients were performed. Unsupervised clustering of somatic mutations was performed and correlations with patient outcome were sought. A number of 120 patients with RR-DLBCL were included in LNH-EP1 study and a molecular tumor landscape was successfully analyzed in 87% of patients (104/120 tumor samples). The median age was 67.5 years (range 27.4-87.4), median number of previous treatments was 2 (range 1-9). The most frequently mutated genes were TP53 (n = 53 mutations; 42% of samples), CREBBP (n = 39; 32%), BCL2 (n = 86; 31%), KMT2D (n = 39; 28%) and PIM1 (n = 54; 22%). Unsupervised clustering separated three genetic subgroups entitled BST (enriched in BCL2, SOCS1, and TNFRSF14 mutations); TKS (enriched in TP53, KMT2D, and STAT6 mutations); and PCM (enriched in PIM1, CD79B, and MYD88 mutations). Median overall survival (OS) was 11.0 (95% confidence interval [CI]: 8.1-12.6) months. OS was not significantly different between the three genetic subgroups. GNA13 mutant was significantly associated with an increased risk of death (hazard ratio: 6.6 [95% CI: 2.1-20.6]; p = .0011) and shorter OS (p = .0340). At the time of relapse or refractory disease, three genetic subgroups of DLBCL patients were delineated, which could help advance precision molecular medicine programs.
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Affiliation(s)
- Jean-Marie Michot
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
- INSERM U1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Cyril Quivoron
- Translational Research Hematological Laboratory, AMMICA, INSERM US23/CNRS UMS3655, Gustave Roussy Cancer Campus, Villejuif, France
- Hematology Department, Gustave Roussy, Villejuif, France
| | - Clémentine Sarkozy
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
- INSERM U1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Alina Danu
- Hematology Department, Gustave Roussy, Villejuif, France
| | | | - Khalil Saleh
- Hematology Department, Gustave Roussy, Villejuif, France
| | | | - Vincent Goldschmidt
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | | | - Matteo Dragani
- Hematology Department, Gustave Roussy, Villejuif, France
| | - Rastislav Bahleda
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | - Capucine Baldini
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | | | | | | | - Anas Gazzah
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | - Antoine Hollebecque
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | - Ludovic Lacroix
- Department of Medical Biology and Pathology, Gustave Roussy, Villejuif, France
| | - David Ghez
- Hematology Department, Gustave Roussy, Villejuif, France
| | - Veronique Vergé
- Department of Medical Biology and Pathology, Gustave Roussy, Villejuif, France
| | - Christophe Marzac
- Department of Medical Biology and Pathology, Gustave Roussy, Villejuif, France
| | - Sophie Cotteret
- Department of Medical Biology and Pathology, Gustave Roussy, Villejuif, France
| | - Wassila Rahali
- Hematology Department, Gustave Roussy, Villejuif, France
| | - Jean-Charles Soria
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | - Christophe Massard
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
| | - Olivier A Bernard
- INSERM U1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France
| | - Peggy Dartigues
- Department of Medical Biology and Pathology, Gustave Roussy, Villejuif, France
| | - Valérie Camara-Clayette
- Translational Research Hematological Laboratory, AMMICA, INSERM US23/CNRS UMS3655, Gustave Roussy Cancer Campus, Villejuif, France
- Biological Resource Center, AMMICA, INSERM US23/CNRS UMS3655, Gustave Roussy Cancer Campus, Villejuif, France
| | - Vincent Ribrag
- Département d'Innovation Thérapeutique et d'Essais Précoces, Villejuif, France
- INSERM U1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France
- Translational Research Hematological Laboratory, AMMICA, INSERM US23/CNRS UMS3655, Gustave Roussy Cancer Campus, Villejuif, France
- Hematology Department, Gustave Roussy, Villejuif, France
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Tang J, Yao C, Liu Y, Yuan J, Wu L, Hosoi K, Yu S, Huang C, Wei H, Chen G. Arsenic trioxide induces expression of BCL-2 expression via NF-κB and p38 MAPK signaling pathways in BEAS-2B cells during apoptosis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 222:112531. [PMID: 34303041 DOI: 10.1016/j.ecoenv.2021.112531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/04/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Inorganic arsenic compounds are environmental toxicants that are widely distributed in air, water, and food. B-cell lymphoma 2 (BCL-2) is an oncogene having anti-apoptotic function. In this study, we clarify that BCL-2, as a pro-apoptotic factor, participates in As2O3-induced apoptosis in BEAS-2B cells. Specifically, As2O3 stimulated the expression of BCL-2 mRNA and protein in a dose-dependent manner which was highly accumulated in the nucleus of BEAS-2B cell together with chromatin condensation and DNA fragmentation during apoptosis. Mechanistically, the process described above is mediated through the NF-κB and p38 MAPK signaling pathways, which can be abated by corresponding inhibitors, such as BAY11-7082 and SB203580, respectively. Additionally, BAY11-7082, actinomycin D, and cycloheximide have inhibitory effects on As2O3-induced expression of BCL-2 mRNA and protein, and restore the cell viability of BEAS-2B cells. Suppression of BCL-2 protein activation by ABT-199 also restored viability of BEAS-2B cell in As2O3-induced apoptosis. Furthermore, As2O3 increased the level of BCL-2 phosphorylation. These results suggest that in BEAS-2B cells, As2O3-induced apoptosis is mainly dominated by BCL-2 upregulation, nuclear localization and phosphorylation. The study presented here provides a novel insight into the molecular mechanism of BCL-2-induced apoptosis.
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Affiliation(s)
- Jing Tang
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China
| | - Chenjuan Yao
- Department of Molecular Oral Physiology, Institute of Health Biosciences, University of Tokushima Graduate School, Toku shima-Shi 770-8504, Tokushima, Japan
| | - Yingqi Liu
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China
| | - Jiaming Yuan
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China
| | - Li Wu
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China
| | - Kazuo Hosoi
- Department of Molecular Oral Physiology, Institute of Health Biosciences, University of Tokushima Graduate School, Toku shima-Shi 770-8504, Tokushima, Japan; Kosei Pharmaceutical Co. Ltd., Osaka-shi 540-0039, Osaka, Japan
| | - Shali Yu
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China
| | - Chunyan Huang
- Department of Chronic Disease Prevention and Control, Suzhou Center for Disease Control and Prevention, Suzhou 215004, China
| | - Haiyan Wei
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China.
| | - Gang Chen
- Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, Jiangsu, China.
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The La protein counteracts cisplatin-induced cell death by stimulating protein synthesis of anti-apoptotic factor Bcl2. Oncotarget 2018; 7:29664-76. [PMID: 27105491 PMCID: PMC5045424 DOI: 10.18632/oncotarget.8819] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/28/2016] [Indexed: 02/06/2023] Open
Abstract
Up-regulation of anti-apoptotic factors is a critical mechanism of cancer cell resistance and often counteracts the success of chemotherapeutic treatment. Herein, we identified the cancer-associated RNA-binding protein La as novel factor contributing to cisplatin resistance. Our data demonstrate that depletion of the RNA-binding protein La in head and neck squamous cell carcinoma cells (HNSCC) increases the sensitivity toward cisplatin-induced cell death paralleled by reduced expression of the anti-apoptotic factor Bcl2. Furthermore, it is shown that transient expression of Bcl2 in La-depleted cells protects against cisplatin-induced cell death. By dissecting the underlying mechanism we report herein, that the La protein is required for Bcl2 protein synthesis in cisplatin-treated cells. The RNA chaperone La binds in close proximity to the authentic translation start site and unwinds a secondary structure embedding the authentic AUG. Altogether, our data support a novel model, whereby cancer-associated La protein contributes to cisplatin resistance by stimulating the translation of anti-apoptotic factor Bcl2 in HNSCC cells.
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Inhibition and conformational change of SERCA3b induced by Bcl-2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1865:121-131. [PMID: 27639965 DOI: 10.1016/j.bbapap.2016.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 09/10/2016] [Accepted: 09/13/2016] [Indexed: 02/04/2023]
Abstract
An interaction of Bcl-2 with SERCA had been documented in vitro using the SERCA1a isoform isolated from rat skeletal muscle [Dremina, E. S., Sharov, V. S., Kumar, K., Azidi, A., Michaelis, E. K., Schöneich, C. (2004) Biochem. J. 383 (361-370)]. Here, we demonstrate the interaction of Bcl-2 with the SERCA3b isoform both in vitro and in cell culture. In vitro, the interaction of Bcl-2 with SERCA3b was studied using Bcl-2∆21, a truncated form of human Bcl-2, and microsomes isolated from SERCA3b-overexpressing HEK-293 cells. For these experiments, SERCA3b was quantified by a combination of amino acid analysis and Western blotting. We observed that Bcl-2∆21 both inactivates SERCA3b and co-immunoprecipitates with SERCA3b. The incubation with Bcl-2∆21 changes the distribution of SERCA3b during sucrose density gradient centrifugation, likely as the result of Bcl-2∆21-induced conformational change of SERCA3b. When SERCA3b-overexpressing HEK-293 cells were co-transfected with Bcl-2, Bcl-2-dependent SERCA3b inactivation was observed. In these cells, Bcl-2 interaction with SERCA3b was demonstrated by co-immunoprecipitation. Furthermore, overexpression of Bcl-2 reduced fluorescein isothiocyanate (FITC) labeling of SERCA3b. Together, our data provide evidence for the interaction of Bcl-2 with SERCA3b in vitro and in cell culture, and for Bcl-2-dependent conformational and functional changes of SERCA3b.
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Zou H, Lai Y, Zhao X, Yan G, Ma D, Cardenes N, Shiva S, Liu Y, Bai X, Jiang Y, Jiang Y. Regulation of mammalian target of rapamycin complex 1 by Bcl-2 and Bcl-XL proteins. J Biol Chem 2013; 288:28824-30. [PMID: 23960074 DOI: 10.1074/jbc.m113.505370] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) is a key regulator of cell growth and metabolism. Its activity is controlled by various types of signals, including growth factors, nutrients, and stresses. In this study, we show that changes in expression levels of two antiapoptotic proteins, Bcl-2 and Bcl-XL, also affect mTORC1 signaling activity. In cells overexpressing Bcl-XL, mTORC1 activity is increased and becomes less sensitive to growth factor or nutrient conditions. In contrast, reduction in expression levels of the two antiapoptotic proteins inhibits mTORC1 signaling activity. Our results suggest that the effect of Bcl-2 and Bcl-XL on mTORC1 is mediated by FKBP38, an inhibitor of mTORC1. The two proteins compete with mTORC1 for FKBP38 binding and hence alter mTORC1 activity. This study reveals a novel cross-talk between Bcl-2/XL and mTORC1 signaling, which is likely to contribute to cancer development.
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Affiliation(s)
- Huafei Zou
- From the Department of Pharmacology and Chemical Biology and
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7
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Thomadaki H, Floros KV, Pavlovic S, Tosic N, Gourgiotis D, Colovic M, Scorilas A. Overexpression of the novel member of the BCL2 gene family, BCL2L12, is associated with the disease outcome in patients with acute myeloid leukemia. Clin Biochem 2012; 45:1362-7. [DOI: 10.1016/j.clinbiochem.2012.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 05/31/2012] [Accepted: 06/12/2012] [Indexed: 10/28/2022]
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Liman N, Alan E, Bayram GK, Gürbulak K. Expression of Survivin, Bcl-2 and Bax Proteins in the Domestic Cat (Felis catus) Endometrium During the Oestrus Cycle. Reprod Domest Anim 2012; 48:33-45. [DOI: 10.1111/j.1439-0531.2012.02021.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bcl-2 interaction with the inositol 1,4,5-trisphosphate receptor: role in Ca(2+) signaling and disease. Cell Calcium 2011; 50:234-41. [PMID: 21628070 DOI: 10.1016/j.ceca.2011.05.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 01/02/2023]
Abstract
The Bcl-2 protein, best known for its ability to inhibit apoptosis, interacts with the inositol 1,4,5-trisphosphate receptor (IP(3)R) Ca(2+) channel to regulate IP(3)-mediated Ca(2+) release from the endoplasmic reticulum. This review summarizes the current state of knowledge regarding the interaction of Bcl-2, and also its homologue Bcl-xl, with the IP(3)R and how these interactions regulate Ca(2+) signaling. The dual role of these interactions in promoting prosurvival Ca(2+) signals, while at the same time inhibiting proapoptotic Ca(2+) signals, is discussed. Moreover, this review will elucidate the recently recognized importance of the Bcl-2-IP(3)R interaction in human disease.
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Machado-Vieira R, Pivovarova NB, Stanika RI, Yuan P, Wang Y, Zhou R, Zarate CA, Drevets WC, Brantner CA, Baum A, Laje G, McMahon FJ, Chen G, Du J, Manji HK, Andrews SB. The Bcl-2 gene polymorphism rs956572AA increases inositol 1,4,5-trisphosphate receptor-mediated endoplasmic reticulum calcium release in subjects with bipolar disorder. Biol Psychiatry 2011; 69:344-52. [PMID: 21167476 PMCID: PMC3035040 DOI: 10.1016/j.biopsych.2010.10.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 10/11/2010] [Accepted: 10/12/2010] [Indexed: 12/16/2022]
Abstract
BACKGROUND Bipolar disorder (BPD) is characterized by altered intracellular calcium (Ca(2+)) homeostasis. Underlying mechanisms involve dysfunctions in endoplasmic reticulum (ER) and mitochondrial Ca(2+) handling, potentially mediated by B-cell lymphoma 2 (Bcl-2), a key protein that regulates Ca(2+) signaling by interacting directly with these organelles, and which has been implicated in the pathophysiology of BPD. Here, we examined the effects of the Bcl-2 gene single nucleotide polymorphism (SNP) rs956572 on intracellular Ca(2+) dynamics in patients with BPD. METHODS Live cell fluorescence imaging and electron probe microanalysis were used to measure intracellular and intra-organelle free and total calcium in lymphoblasts from 18 subjects with BPD carrying the AA, AG, or GG variants of the rs956572 SNP. Analyses were carried out under basal conditions and in the presence of agents that affect Ca(2+) dynamics. RESULTS Compared with GG homozygotes, variant AA-which expresses significantly reduced Bcl-2 messenger RNA and protein-exhibited elevated basal cytosolic Ca(2+) and larger increases in inositol 1,4,5-trisphosphate receptor-mediated cytosolic Ca(2+) elevations, the latter in parallel with enhanced depletion of the ER Ca(2+) pool. The aberrant behavior of AA cells was reversed by chronic lithium treatment and mimicked in variant GG by a Bcl-2 inhibitor. In contrast, no differences between SNP variants were found in ER or mitochondrial total Ca(2+) content or in basal store-operated Ca(2+) entry. CONCLUSIONS These results demonstrate that, in patients with BPD, abnormal Bcl-2 gene expression in the AA variant contributes to dysfunctional Ca(2+) homeostasis through a specific ER inositol 1,4,5-trisphosphate receptor-dependent mechanism.
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Affiliation(s)
- Rodrigo Machado-Vieira
- Laboratory of Molecular Pathophysiology and Experimental Therapeutics, Mood and Anxiety Disorders Program, National Institute of Mental Health, Bethesda, Maryland, USA
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Renton JP, Xu N, Clark JJ, Hansen MR. Interaction of neurotrophin signaling with Bcl-2 localized to the mitochondria and endoplasmic reticulum on spiral ganglion neuron survival and neurite growth. J Neurosci Res 2010; 88:2239-51. [PMID: 20209634 DOI: 10.1002/jnr.22381] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Enhanced spiral ganglion neuron (SGN) survival and regeneration of peripheral axons following deafness will likely enhance the efficacy of cochlear implants. Overexpression of Bcl-2 prevents SGN death but inhibits neurite growth. Here we assessed the consequences of Bcl-2 targeted to either the mitochondria (GFP-Bcl-2-Maob) or the endoplasmic reticulum (ER, GFP-Bcl-2-Cb5) on cultured SGN survival and neurite growth. Transfection of wild-type GFP-Bcl-2, GFP-Bcl-2-Cb5, or GFP-Bcl-2-Maob increased SGN survival, with GFP-Bcl-2-Cb5 providing the most robust response. Paradoxically, expression of GFP-Bcl-2-Maob results in SGN death in the presence of neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF), neurotrophins that independently promote SGN survival via Trk receptors. This loss of SGNs is associated with cleavage of caspase 3 and appears to be specific for neurotrophin signaling, insofar as coexpression of constitutively active mitogen-activated kinase kinase (MEKDeltaEE) or phosphatidyl inositol-3 kinase (P110), but not other prosurvival stimuli (e.g., membrane depolarization), also results in the loss of SGNs expressing GFP-Bcl-2-Maob. MEKDeltaEE and P110 promote SGN survival, whereas P110 promotes neurite growth to a greater extent than NT-3 or MEKDeltaEE. However, wild-type GFP-Bcl-2, GFP-Bcl-2-Cb5, and GFP-Bcl-2-Maob inhibit neurite growth even in the presence of neurotrophins, MEKDeltaEE, or P110. Historically, Bcl-2 has been thought to act primarily at the mitochondria to prevent neuronal apoptosis. Nevertheless, our data show that Bcl-2 targeted to the ER is more effective at rescuing SGNs in the absence of trophic factors. Additionally, Bcl-2 targeted to the mitochondria results in SGN death in the presence of neurotrophins. (c) 2010 Wiley-Liss, Inc.
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Affiliation(s)
- John P Renton
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa
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Teijido O, Dejean L. Upregulation of Bcl2 inhibits apoptosis-driven BAX insertion but favors BAX relocalization in mitochondria. FEBS Lett 2010; 584:3305-10. [PMID: 20621101 DOI: 10.1016/j.febslet.2010.07.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 06/16/2010] [Accepted: 07/01/2010] [Indexed: 12/29/2022]
Abstract
Protein-protein interactions between the Bcl2 family proteins regulate apoptosis. An imbalance of this interaction network due to the upregulation of the proto-oncogene Bcl2 leads to a resistance to apoptosis associated with tumor formation. Bcl2 overexpression inhibits BAX oligomerization and mitochondrial outer membrane (MOM) permeabilization. However, Bcl2 effects on earlier steps of BAX-mediated apoptosis are not fully understood. Bcl2 overexpression inhibits BAX insertion into the MOM but spontaneously increases BAX relocalization to the mitochondria. Also, a physical interaction between BAX and Bcl2 is necessary for these two effects to occur. Taken together, these results suggest upregulated Bcl2 stabilizes BAX loose binding to mitochondrial membranes, inhibiting its insertion into the MOM and consequently cytochrome c release.
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Affiliation(s)
- O Teijido
- Department of Basic Science, College of Dentistry, New York University, New York, NY 10010, USA
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The hepatitis C virus core protein contains a BH3 domain that regulates apoptosis through specific interaction with human Mcl-1. J Virol 2009; 83:9993-10006. [PMID: 19605477 DOI: 10.1128/jvi.00509-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The hepatitis C virus (HCV) core protein is known to modulate apoptosis and contribute to viral replication and pathogenesis. In this study, we have identified a Bcl-2 homology 3 (BH3) domain in the core protein that is essential for its proapoptotic property. Coimmunoprecipitation experiments showed that the core protein interacts specifically with the human myeloid cell factor 1 (Mcl-1), a prosurvival member of the Bcl-2 family, but not with other prosurvival members (Bcl-X(L) and Bcl-w). Moreover, the overexpression of Mcl-1 protects against core-induced apoptosis. By using peptide mimetics, core was found to release cytochrome c from isolated mitochondria when complemented with Bad. Thus, core is a bona fide BH3-only protein having properties similar to those of Noxa, a BH3-only member of the Bcl-2 family that binds preferentially to Mcl-1. There are three critical hydrophobic residues in the BH3 domain of the core protein, and they are essential for the proapoptotic property of the core protein. Furthermore, the genotype 1b core protein is more effective than the genotype 2a core protein in inducing apoptosis due to a single-amino-acid difference at one of these hydrophobic residues (residue 119). Replacing this residue in the J6/JFH-1 infectious clone (genotype 2a) with the corresponding amino acid in the genotype 1b core protein produced a mutant virus, J6/JFH-1(V119L), which induced significantly higher levels of apoptosis in the infected cells than the parental J6/JFH-1 virus. Furthermore, the core protein of J6/JFH-1(V119L), but not that of J6/JFH-1, interacted with Mcl-1 in virus-infected cells. Taken together, the core protein is a novel BH3-only viral homologue that contributes to the induction of apoptosis during HCV infection.
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14
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Hong Y, Yang J, Wu W, Wang W, Kong X, Wang Y, Yun X, Zong H, Wei Y, Zhang S, Gu J. Knockdown of BCL2L12 leads to cisplatin resistance in MDA-MB-231 breast cancer cells. Biochim Biophys Acta Mol Basis Dis 2008; 1782:649-57. [PMID: 18930135 DOI: 10.1016/j.bbadis.2008.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Revised: 09/07/2008] [Accepted: 09/08/2008] [Indexed: 11/18/2022]
Abstract
BCL2L12, a newly identified member of Bcl-2 family, contains a BH2 domain and a putative BH3 domain. It was found to be highly expressed in normal breast tissues, and was associated with favorable prognosis in breast cancer patients. Here, we reported that the mRNA levels of BCL2L12 and its transcript variant BCL2L12A could be upregulated upon cisplatin treatment in MDA-MB-231 breast cancer cells. Knockdown of BCL2L12 and BCL2L12A dramatically inhibited cisplatin-induced apoptosis. In contrast, ectopic expressions of each of the proteins promoted cisplatin-induced apoptosis. These results indicated that decreased expressions or loss of BCL2L12 and BCL2L12A may contribute to the cisplatin resistance in breast cancer patients. Furthermore, we found that cisplatin-induced downregulation of beta-catenin was partially suppressed in BCL2L12- and BCL2L12A-knocked down MDA-MB-231 cells, which indicated that knockdown of these two proteins may stabilize beta-catenin in cisplatin-induced apoptosis. In short, we proposed that BCL2L12 and BCL2L12A may play an important role in cisplatin-induced apoptosis in MDA-MB-231 breast cancer cells.
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Affiliation(s)
- Yi Hong
- Gene Research Center, Institutes of Biomedical Science, Shanghai Medical College of Fudan University, Box 103, No. 138 Yi Xue Yuan Road, Shanghai, 200032, People's Republic of China
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15
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Abstract
Accumulating evidence indicates that deregulation of cyclin-dependent kinase 5 (Cdk5) activity is associated with apoptosis in various neurodegenerative disease models. Interestingly, recent studies suggest that Cdk5 may also favor neuronal survival. Nonetheless, whether Cdk5 is directly required for neuronal survival during development remains enigmatic. In the current study, we established the pivotal role of Cdk5 in neuronal survival during development by demonstrating that reduction or absence of Cdk5 activity markedly exacerbated neuronal death in cultures and in vivo. Interestingly, the antiapoptotic protein Bcl-2 (B-cell lymphoma protein 2) was identified as a novel substrate of Cdk5. We found that Cdk5-mediated phosphorylation of Bcl-2 at Ser70 was required for the neuroprotective effect of Bcl-2. Intriguingly, inhibition of this phosphorylation conferred proapoptotic property to Bcl-2. Furthermore, overexpression of a Bcl-2 mutant lacking the Cdk5 phosphorylation site abolished the protective effect of Cdk5 re-expression in Cdk5(-/-) neurons, suggesting that Ser70 phosphorylation of Bcl-2 contributed to Cdk5-mediated neuronal survival. Our observations revealed that Cdk5-mediated Bcl-2 phosphorylation is pivotal for the antiapoptotic effect of Bcl-2 and contributes to the maintenance of neuronal survival by Cdk5. Our study has also identified Cdk5 as a regulator of Bcl-2 function in neuronal apoptosis.
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16
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The cellular concentration of Bcl-2 determines its pro- or anti-apoptotic effect. Cell Calcium 2008; 44:243-58. [PMID: 18215418 DOI: 10.1016/j.ceca.2007.11.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 10/01/2007] [Accepted: 11/17/2007] [Indexed: 11/22/2022]
Abstract
Bcl-2 is an oncoprotein that is widely known to promote cell survival by inhibiting apoptosis. We explored the consequences of different expression paradigms on the cellular action of Bcl-2. Using either transient or stable transfection combined with doxycycline-inducible expression, we titrated the cellular concentration of Bcl-2. With each expression paradigm Bcl-2 was correctly targeted to the endoplasmic reticulum and mitochondria. However, with protocols that generated the greatest cellular concentrations of Bcl-2 the structure of these organelles was dramatically altered. The endoplasmic reticulum appeared to be substantially fragmented, whilst mitochondria coalesced into dense perinuclear structures. Under these conditions of high Bcl-2 expression, cells were not protected from pro-apoptotic stimuli. Rather Bcl-2 itself caused a significant amount of spontaneous cell death, and sensitised the cells to apoptotic agents such as staurosporine or ceramide. We observed a direct correlation between Bcl-2 concentration and spontaneous apoptosis. Expression of calbindin, a calcium buffering protein, or an enzyme that inhibited inositol 1,4,5-trisphosphate-mediated calcium release, significantly reduced cell death caused by Bcl-2 expression. We further observed that high levels of Bcl-2 expression caused lipid peroxidation and that the deleterious effects of Bcl-2 could be abrogated by the reactive oxygen species (ROS) scavenger Trolox. When stably expressed at low levels, Bcl-2 did not corrupt organelle structure or trigger spontaneous apoptosis. Rather, it protected cells from pro-apoptotic stimuli. These data reveal that high cellular concentrations of Bcl-2 lead to a calcium- and ROS-dependent induction of death. Selection of the appropriate expression paradigm is therefore crucial when investigating the biological role of Bcl-2.
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17
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Abstract
The ultimate growth of a tumour depends on not only the rate of tumour cell proliferation, but also the rate of tumour cell death (apoptosis). Nur77 (also known as TR3 or NGFI-B), an orphan member of the nuclear receptor superfamily, controls both survival and death of cancer cells. A wealth of recent experimental data demonstrates that the Nur77 activities are regulated through its subcellular localisation. In the nucleus, Nur77 functions as an oncogenic survival factor, promoting cancer cell growth. In contrast, it is a potent killer when migrating to mitochondria, where it binds to Bcl-2 and converts its survival phenotype, triggering cytochrome c release and apoptosis. Agents, such as 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (AHPN/CD437), which induce Nur77 migration from the nucleus to mitochondria, effectively induce apoptosis of cancer cells. Moreover, Nur77 translocation is highly controlled by retinoid X receptor (RXR), suggesting a role of RXR ligands in regulating the process. Thus, translocation of Nur77 from the nucleus to mitochondria represents a new paradigm in cancer cell apoptosis, and targeting the Nur77 translocation by AHPN/CD437 or RXR ligands promises to effectively restrict cancer cell growth by simultaneously promoting cancer cell death and suppressing cancer cell proliferation.
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Affiliation(s)
- Xiao-kun Zhang
- Burnham Institute for Medical Research, Cancer Center, 10901 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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18
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Luciano F, Krajewska M, Ortiz-Rubio P, Krajewski S, Zhai D, Faustin B, Bruey JM, Bailly-Maitre B, Lichtenstein A, Kolluri SK, Satterthwait AC, Zhang XK, Reed JC. Nur77 converts phenotype of Bcl-B, an antiapoptotic protein expressed in plasma cells and myeloma. Blood 2007; 109:3849-55. [PMID: 17227826 PMCID: PMC1874560 DOI: 10.1182/blood-2006-11-056879] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Defects in apoptosis mechanisms play important roles in malignancy and autoimmunity. Orphan nuclear receptor Nur77/TR3 has been demonstrated to bind antiapoptotic protein Bcl-2 and convert it from a cytoprotective to a cytodestructive protein, representing a phenotypic conversion mechanism. Of the 6 antiapoptotic human Bcl-2 family members, we found that Nur77/TR3 binds strongest to Bcl-B, showing selective reactivity with Bcl-B, Bcl-2, and Bfl-1 but not Bcl-X(L), Mcl-1, or Bcl-W. Nur77 converts the phenotype of Bcl-B from antiapoptotic to proapoptotic. Bcl-B is prominently expressed in plasma cells and multiple myeloma. Endogenous Bcl-B associates with endogenous Nur77 in RPMI 8226 myeloma cells, where RNA interference experiments demonstrated dependence on Bcl-B for Nur77-induced apoptosis. Furthermore, a Nur77-mimicking peptide killed RPMI 8226 myeloma cells through a Bcl-B-dependent mechanism. Because Bcl-B is abundantly expressed in plasma cells and some myelomas, these findings raise the possibility of exploiting the Nur77/Bcl-B mechanism for apoptosis for eradication of autoimmune plasma cells or myeloma.
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Affiliation(s)
- Frederic Luciano
- Burnham Institute for Medical Research, 10901 Torrey Pines Road, La Jolla, CA 92037, USA
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19
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Portier BP, Taglialatela G. Bcl-2 localized at the nuclear compartment induces apoptosis after transient overexpression. J Biol Chem 2006; 281:40493-502. [PMID: 17090549 DOI: 10.1074/jbc.m606181200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Bcl-2 is the best characterized member of a large family of proteins that regulate apoptosis. Although it is established that Bcl-2 localized at the mitochondria functions as an anti-apoptotic protein, the function of Bcl-2 at the nucleus remains unclear. Recently we showed that nuclear compartment-associated Bcl-2 inhibits transcription factor activation. Based on this observation, we hypothesized that presence of Bcl-2 at the nucleus may induce rather than protect cells from apoptosis. Here we investigated the putative apoptotic role of nuclear compartment-associated Bcl-2. Additionally, we examined the role of the Bcl-2 BH4 domain in mediating binding to FKBP38, the Bcl-2 mitochondrial chaperone. Our results demonstrate a novel, pro-apoptotic function for nuclear Bcl-2 and identify the Bcl-2 BH4 domain as a key regulator in mediating Bcl-2/FKBP38 binding. These results indicate that Bcl-2 has a dual role as both a protector and a killer and that the ability to switch roles depends on Bcl-2 subcellular localization.
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Affiliation(s)
- Bryce Patrick Portier
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1043, USA
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20
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Moll UM, Marchenko N, Zhang XK. p53 and Nur77/TR3 - transcription factors that directly target mitochondria for cell death induction. Oncogene 2006; 25:4725-43. [PMID: 16892086 DOI: 10.1038/sj.onc.1209601] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The complex apoptotic functions of the p53 tumor suppressor are central to its antineoplastic activity in vivo. Conversely, p53 function is altered or attenuated in one way or another in the majority of human cancers. Besides its well-understood action as a transcriptional regulator of multiple apoptotic genes, p53 also exerts a direct pro-apoptotic role at the mitochondria by engaging in protein-protein interactions with anti- and pro-apoptotic Bcl2 family members, thereby executing the shortest known circuitry of p53 death signaling. Nur77, also known as TR3 or NGFI-B, is a unique transcription factor belonging to the orphan nuclear receptor superfamily. Even more extreme than p53, Nur77 can exert opposing biological activities of survival and death. Its activities are regulated by subcellular distribution, expression levels, protein modification and heterodimerization with retinoid X receptor. In cancer cells, Nur77 functions in the nucleus as an oncogenic survival factor, but becomes a potent killer when certain death stimuli induce its migration to mitochondria, where it binds to Bcl2 and conformationally converts it to a killer that triggers cytochrome c release and apoptosis. This review focuses on their unexpected transcription-independent pro-death programs at mitochondria and highlights the remarkable mechanistic similarities between them. Moreover, an accumulating body of evidence provides ample rationale to further investigate how these mitochondrial p53 and Nur77 pathways could become exploitable targets for new cancer therapeutics.
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Affiliation(s)
- U M Moll
- Department of Pathology Stony Brook University, Stony Brook, New York 11794-8691, USA.
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21
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Matsuzaki Y, Xu Y, Ikegami M, Besnard V, Park KS, Hull WM, Wert SE, Whitsett JA. Stat3 is required for cytoprotection of the respiratory epithelium during adenoviral infection. THE JOURNAL OF IMMUNOLOGY 2006; 177:527-37. [PMID: 16785550 DOI: 10.4049/jimmunol.177.1.527] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The role of Stat3 in the maintenance of pulmonary homeostasis following adenoviral-mediated lung injury was assessed in vivo. Stat3 was selectively deleted from bronchiolar and alveolar epithelial cells in Stat3(DeltaDelta) mice. Although lung histology and function were unaltered by deletion of Stat3 in vivo, Stat3(DeltaDelta) mice were highly susceptible to lung injury caused by intratracheal administration of AV1-GFP, an early (E) region 1- and E3-deleted, nonproliferative adenovirus. Severe airspace enlargement, loss of alveolar septae, and sloughing of the bronchiolar epithelium were observed in Stat3(DeltaDelta) mice as early as 1 day after exposure to the virus. Although surfactant protein A, B, and C content and surfactant protein-B mRNA expression in Stat3(DeltaDelta) mice were similar, TUNEL staining and caspase-3 were increased in alveolar type II epithelial cells of Stat3(DeltaDelta) mice after exposure to virus. RNA microarray analysis of type II epithelial cells isolated from Stat3(DeltaDelta) mice demonstrated significant changes in expression of numerous genes, including those genes regulating apoptosis, supporting the concept that the susceptibility of Stat3-deficient mice to adenovirus was related to the role of Stat3 in the regulation of cell survival. AV1-Bcl-x(L), an E1- and E3-deleted, nonproliferative adenovirus expressing the antiapoptotic protein Bcl-x(L), protected Stat3(DeltaDelta) mice from adenoviral-induced lung injury. Adenoviral infection of the lungs of Stat3-deficient mice was associated with severe injury of the alveolar and bronchiolar epithelium. Thus, Stat3 plays a critical cytoprotective role that is required for epithelial cell survival and maintenance of alveolar structures during the early phases of pulmonary adenoviral infection.
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Affiliation(s)
- Yohei Matsuzaki
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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22
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Bivona TG, Quatela SE, Bodemann BO, Ahearn IM, Soskis MJ, Mor A, Miura J, Wiener HH, Wright L, Saba SG, Yim D, Fein A, Pérez de Castro I, Li C, Thompson CB, Cox AD, Philips MR. PKC regulates a farnesyl-electrostatic switch on K-Ras that promotes its association with Bcl-XL on mitochondria and induces apoptosis. Mol Cell 2006; 21:481-93. [PMID: 16483930 DOI: 10.1016/j.molcel.2006.01.012] [Citation(s) in RCA: 366] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Revised: 12/12/2005] [Accepted: 01/05/2006] [Indexed: 01/07/2023]
Abstract
K-Ras associates with the plasma membrane (PM) through farnesylation that functions in conjunction with an adjacent polybasic sequence. We show that phosphorylation by protein kinase C (PKC) of S181 within the polybasic region promotes rapid dissociation of K-Ras from the PM and association with intracellular membranes, including the outer membrane of mitochondria where phospho-K-Ras interacts with Bcl-XL. PKC agonists promote apoptosis of cells transformed with oncogenic K-Ras in a S181-dependent manner. K-Ras with a phosphomimetic residue at position 181 induces apoptosis via a pathway that requires Bcl-XL. The PKC agonist bryostatin-1 inhibited the growth in vitro and in vivo of cells transformed with oncogenic K-Ras in a S181-dependent fashion. These data demonstrate that the location and function of K-Ras are regulated directly by PKC and suggest an approach to therapy of K-Ras-dependent tumors with agents that stimulate phosphorylation of S181.
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Affiliation(s)
- Trever G Bivona
- Department of Cell Biology, New York University School of Medicine, 550 First Avenue, New York, New York 10016, USA
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23
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Rentsch M, Kienle K, Mueller T, Vogel M, Jauch KW, Püllmann K, Obed A, Schlitt HJ, Beham A. Adenoviral bcl-2 transfer improves survival and early graft function after ischemia and reperfusion in rat liver transplantation. Transplantation 2006; 80:1461-7. [PMID: 16340792 DOI: 10.1097/01.tp.0000178293.65311.8b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Primary graft dysfunction due to ischemia and reperfusion injury represents a major problem in liver transplantation. The related cell stress may induce apoptosis, which can be suppressed by bcl-2. The purpose of the study was to investigate the effect of adenoviral bcl-2 gene transfer on early graft function and survival in rat liver transplantation. METHODS An adenoviral construct that transfers bcl-2 under the control of a tetracycline inducible promoter was generated (advTetOn bcl-2) and used with a second adenovirus that transfers the repressor protein (advCMV Rep). Forty-eight hours before explantation, donor rats were treated with advTetOn bcl-2/ advCMV Rep (n=7) and doxycyclin, with the control adenoviral construct advCMV GFP (n=8) or with doxycyclin alone (n=8). Liver transplantation was performed following 16 hours of cold storage (UW). Bcl-2 expression and intrahepatic apoptosis was assessed. Bile flow was monitored 90 min posttransplantation. The endpoint for survival was 7 days. RESULTS Bcl-2 was expressed in hepatocytes and sinusoidal lining cells. This was associated with a significant reduction of apoptotic sinusoidal lining cells and hepatocytes after 24 hours and 7 days. Bile production was significantly higher following bcl-2 pretreatment. Furthermore, bcl-2 transfer resulted in significantly improved survival (100% vs. 50% both control groups). CONCLUSIONS Adenoviral bcl-2 transfer results in protein expression in hepatocytes and sinusoidal lining cells resulting in early graft function and survival enhancement after prolonged ischemia and reperfusion injury. The inhibition of apoptosis in the context of liver transplantation might be a reasonable approach in the treatment of graft dysfunction.
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Affiliation(s)
- Markus Rentsch
- Department of Surgery, Klinikum Grosshadern, Ludwig-Maximilians-University, Munich, Germany
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24
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Kienle K, Rentsch M, Müller T, Engelhard N, Vogel M, Jauch KW, Beham A. Expression of BCL-2 in liver grafts after adenoviral transfer improves survival following prolonged ischemia and reperfusion in rat liver transplantation. Transplant Proc 2005; 37:439-41. [PMID: 15808669 DOI: 10.1016/j.transproceed.2004.12.268] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
UNLABELLED Apoptosis represents a crucial mechanism of ischemia-reperfusion injury after liver transplantation. Bcl-2 may inhibit apoptosis. This study investigates the effect on ischemia/reperfusion injury and survival after rat liver transplantation of adenoviral bcl-2 transfer into donor livers. METHODS A nonreplicative adenovirus, expressing bcl-2 under control of a tetracyclin-inducible promoter (adv TetOn bcl-2) was used to treat male Lewis rats in combination with a second adenovirus transferring the TetOn repressor protein under control of a cytomegalovirus promoter (advCMVRep). Virus induction was achieved by addition of doxycyclin to the drinking water. Controls were pretreated with a control adenovirus (advCMV GFP) or with doxycycline. Liver transplantations were performed after 16-hour graft storage. Bcl-2 expression was evaluated by Western blot and immunohistology. Survival was monitored for 7 days, and tissue specimens were collected at 24 hours and 7 days post reperfusion. RESULTS After pretreatment with advTetOn bcl-2/adv CMVRep, intrahepatic bcl-2 expression was evident at 24 hours and 7 days but was absent among controls. Bcl-2 expression was detected in hepatocytes and, to a high degree, in sinusoidal lining cells. TUNEL-positive sinusoidal lining cells were strikingly reduced after bcl-2 transfer (0.1 +/- 0.3 cells/hpf, mean +/- SD) compared to control virus (4.8 +/- 2.3) or doxycyclin-treated grafts (1.3 +/- 0.2); P < .05. After bcl-2 treatment, survival after transplantation was 100%, whereas it was 50% in both control groups (P = .035). CONCLUSION The study shows the feasibility of transient, doxycyclin-controlled adenoviral gene transfer in a transplantation model. Bcl-2 expression increased survival after ischemia/reperfusion in rat liver transplantation, potentially through protection of sinusoidal lining cells.
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Affiliation(s)
- K Kienle
- Department of Surgery, University of Regensburg, Munich, Germany
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25
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Yang WS, Ko JK, Park SO, Choi HY, Kim YN, Kim CW. C-terminal region of Bfl-1 induces cell death that accompanies caspase activation when fused with GFP. J Cell Biochem 2005; 94:1234-47. [PMID: 15696550 DOI: 10.1002/jcb.20381] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previously, we reported that anti-apoptotic Bfl-1 is converted to a pro-apoptotic protein following fusion at its N-terminus with green fluorescent protein (GFP) (GFP-Bfl-1). In this study, we performed a Bfl-1 deletion study in order to elucidate the underlying mechanism of GFP-Bfl-1-induced cell death. We found that the Bcl-2 homology (BH) domains in Bfl-1 are dispensable with respect to cell death and that GFP fusion with the 29 amino acids of the C-terminal region of Bfl-1 (GFP-BC) is sufficient to induce cell death. Moreover, when BC was fused with other tagging partners like GST or MBP, little cell death was observed, implying that the GFP region is as important as the BC region for GFP-BC-induced cell death. Further deletion analysis defined a region of GFP as a determinant of GFP-BC-induced cell death. Confocal microscopic analysis showed that GFP-chimeras containing the BC region of Bfl-1 are located mainly in mitochondria. The GFP-BC-induced cell death accompanied cellular caspase activation, and treatment with the pan-caspase inhibitor, Boc-D-FMK, partially inhibited GFP-BC-induced cell death. However, the over-expression of anti-apoptotic molecules, such as Bcl-x(L) and CrmA, did not block GFP-BC-induced cell death. In summary, GFP-BC induces cell death with caspase activation through mitochondria dependent process.
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Affiliation(s)
- Wan Seok Yang
- Department of Pathology, Tumor Immunity Medical Research Center and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
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26
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Kim R. Unknotting the roles of Bcl-2 and Bcl-xL in cell death. Biochem Biophys Res Commun 2005; 333:336-43. [PMID: 15922292 DOI: 10.1016/j.bbrc.2005.04.161] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 04/26/2005] [Indexed: 01/12/2023]
Abstract
The antiapoptotic Bcl-2 family proteins Bcl-2 and Bcl-xL play important roles in inhibiting mitochondria-dependent extrinsic and intrinsic cell death pathways. It seems that these two proteins have distinct functions for inhibiting extrinsic and intrinsic cell death pathways. The overexpression of Bcl-2 is able to inhibit not only apoptotic cell death but also in part nonapoptotic cell death, which has the role of cell cycle arrest in the G1 phase, which may promote cellular senescence. The overexpression of Bcl-2 may also have the ability to enhance cell death in the interaction of Bcl-xL with other factors. The overexpression of Bcl-xL enhances autophagic cell death when apoptotic cell death is inhibited in Bax(-/-)/Bak(-/-) double knockout cells. This review discusses the previously unexplained aspects of Bcl-2 and Bcl-xL functions associated with cell death, for better understanding of their functions in the regulation.
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Affiliation(s)
- Ryungsa Kim
- International Radiation Information Center, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
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27
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Shen Y, Iqbal J, Huang JZ, Zhou G, Chan WC. BCL2 protein expression parallels its mRNA level in normal and malignant B cells. Blood 2004; 104:2936-9. [PMID: 15242877 DOI: 10.1182/blood-2004-01-0243] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The regulation of B-cell lymphoma 2 (BCL2) protein expression in germinal center (GC) B cells has been controversial. Previous reports have indicated posttranscriptional regulation plays a dominant role. However, a number of recent studies contradicted these reports. Using real-time polymerase chain reaction (PCR) and Standardized Reverse Transcriptase-PCR (StaRT-PCR), we measured the level of mRNA expression in GC, mantle zone (MNZ), and marginal zone (MGZ) cells from laser capture microdissection. Both quantitative RT-PCR measurements of microdissected GC cells from tonsils showed that GC cells had low expression of BCL2 transcripts commensurate with the low protein expression level. These results are in agreement with microarray studies on fluorescence-activated cell sorter (FACS)-sorted cells and microdissected GC cells. We also examined BCL2 mRNA and protein expression on a series of 30 cases of diffuse large B-cell lymphoma (DLBCL) and found, in general, a good correlation. The results suggested that BCL2 protein expression is regulated at the transcriptional level in normal B cells and in the neoplastic cells in most B-cell lymphoproliferative disorders.
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Affiliation(s)
- Yulei Shen
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, USA
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28
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Abstract
The function of Bcl-2 family members on the endoplasmic reticulum has received increasing attention in recent years. The endoplasmic reticulum is the major organelle involved in intracellular calcium homeostasis and calcium signaling, including calcium signals that mediate apoptosis induction by anticancer drugs. But currently a controversy exists regarding reported effects of Bcl-2 on the calcium concentration within the lumen of the endoplasmic reticulum. Although several prominent reports indicate that Bcl-2 overexpression is associated with a decrease in luminal calcium, there are a large number of reports indicating that Bcl-2 either does not decrease luminal calcium or actually increases luminal calcium. This review summarizes this vast array of conflicting findings, and analyses potential reasons why different conclusions have been reached by different laboratories. Future directions are emphasized that might bring clarity to this important area of apoptosis biology.
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Affiliation(s)
- Clark W Distelhorst
- Division of Hematology/Oncology, Comprehensive Cancer Center, University Hospitals of Cleveland and Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106-4937, USA.
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Lin B, Kolluri SK, Lin F, Liu W, Han YH, Cao X, Dawson MI, Reed JC, Zhang XK. Conversion of Bcl-2 from protector to killer by interaction with nuclear orphan receptor Nur77/TR3. Cell 2004; 116:527-40. [PMID: 14980220 DOI: 10.1016/s0092-8674(04)00162-x] [Citation(s) in RCA: 514] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2003] [Revised: 12/22/2003] [Accepted: 01/08/2004] [Indexed: 10/26/2022]
Abstract
The Bcl-2 family proteins are key regulators of apoptosis in human diseases and cancers. Though known to block apoptosis, Bcl-2 promotes cell death through an undefined mechanism. Here, we show that Bcl-2 interacts with orphan nuclear receptor Nur77 (also known as TR3), which is required for cancer cell apoptosis induced by many antineoplastic agents. The interaction is mediated by the N-terminal loop region of Bcl-2 and is required for Nur77 mitochondrial localization and apoptosis. Nur77 binding induces a Bcl-2 conformational change that exposes its BH3 domain, resulting in conversion of Bcl-2 from a protector to a killer. These findings establish the coupling of Nur77 nuclear receptor with the Bcl-2 apoptotic machinery and demonstrate that Bcl-2 can manifest opposing phenotypes, induced by interactions with proteins such as Nur77, suggesting novel strategies for regulating apoptosis in cancer and other diseases.
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Affiliation(s)
- Bingzhen Lin
- The Burnham Institute, Cancer Center, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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Kaufmann JA, Perez M, Zhang W, Bickford PC, Holmes DB, Taglialatela G. Free radical-dependent nuclear localization of Bcl-2 in the central nervous system of aged rats is not associated with Bcl-2-mediated protection from apoptosis. J Neurochem 2004; 87:981-94. [PMID: 14622128 DOI: 10.1046/j.1471-4159.2003.02092.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously reported that Bcl-2 is up-regulated in the CNS of aged F344 rats as a consequence of oxidative stress. In addition to increased levels of expression, we now report that there is a subcellular redistribution of Bcl-2 in the CNS of aged F344 rats. Using western blotting, we found Bcl-2 predominantly located in the cytosol of young rats. However, in aged rats Bcl-2 was found primarily in the nucleus. This distribution, in the hippocampus and cerebellum, was reversed by treatment with the nitrone spin trap N-tert-butyl-alpha-phenylnitrone (PBN). Paradoxically, PBN treatment in young rats had the opposite effect, changing Bcl-2 from predominantly cytosolic to nuclear. We also detected an increase in Bax in aged hippocampal samples (both nuclear and cytosolic), which was reversed by treatment with PBN. The distribution of Bcl-2 and Bax in the cytosol of aged rats dramatically decreased the Bcl-2/Bax ratio, a probable indicator of neuronal vulnerability, which was restored upon treatment with PBN. In order to assess the effect of nuclear association of Bcl-2 we used PC12 cells stably transfected with a Bcl-2 construct to which we added the nuclear localization sequence of the SV40 large T antigen to the N-terminus which resulted in nuclear targeting of Bcl-2. Measurement of cell death using lactate dehydrogenase assays showed that, contrary to wild-type Bcl-2, Bcl-2 localized to the nucleus was not effective in protecting cells from treatment with 250 microm H2O2. These results suggest that nuclear localization of Bcl-2 observed in the aged CNS may not reflect a protective mechanism against oxidative stress, a major component of age-associated CNS impairments.
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Affiliation(s)
- Joel A Kaufmann
- Department of Anatomy and Neurosciences, University of Texas Medical Branch at Galveston, Galveston, Texas 77555-1043, USA
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Thomenius MJ, Distelhorst CW. Bcl-2 on the endoplasmic reticulum: protecting the mitochondria from a distance. J Cell Sci 2003; 116:4493-9. [PMID: 14576343 DOI: 10.1242/jcs.00829] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Bcl-2 has been described both as an inhibitor of programmed cell death and as an inhibitor of mitochondrial dysfunction during apoptosis. It is still not clear what biochemical activity of Bcl-2 is responsible for its function, but increasing evidence indicates that a functional activity of Bcl-2 on the endoplasmic reticulum (ER) protects mitochondria under diverse circumstances. Indeed, an emerging hypothesis is that, during apoptosis, the Bcl-2 family regulates ER-to-mitochondrion communication by BH3-only proteins and calcium ions and thereby triggers mitochondrial dysfunction and cell death.
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Affiliation(s)
- Michael J Thomenius
- Departments of Medicine and Pharmacology, Comprehensive Cancer Center, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Cleveland, OH 44106, USA
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32
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Subramanian T, Chinnadurai G. Pro-apoptotic activity of transiently expressed BCL-2 occurs independent of BAX and BAK. J Cell Biochem 2003; 89:1102-14. [PMID: 12898509 DOI: 10.1002/jcb.10573] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BCL-2 suppresses apoptosis induced by a wide variety of stimuli in multiple cell types. Most of the in vitro studies that have examined the activity of BCL-2 have employed stable cell lines that ectopically express BCL-2. We have reported that BCL-2 is expressed at high levels in the absence of the 5'- and 3'-UTRs of the Bcl-2 gene and transient high level of expression results in potent cell death (Uhlmann et al., [1998]: JBC 278:17926-17932). Expression of BCL-2 under the transcriptional control of the cognate 5'- and 3'-UTRs express lower levels of BCL-2 and does not cause cell death. Our present results suggest that in contrast to BCL-2, transient expression of BCL-xL does not induce cell death and coexpression of BCL-xL with the pro-apoptotic BCL-2 does not suppress cell death. The pro-apoptotic activity of BCL-2 appears to involve activation of the cytochrome c/caspase 9/caspase 3 pathway. Elevated levels of BCL-2 expression results in N-terminal cleavage of BCL-2 at a novel site different from a previously identified caspase cleavage site at Asp 34 by a non-caspase protease. Transient expression of a BCL-2 mutant lacking aa 51-85 within the loop region induces efficient cell death and N-terminal cleavage of BCL-2 while a different deletion mutant lacking aa 30-91 induces reduced levels of cell death in the absence of BCL-2 cleavage suggesting that N-terminal processing of BCL-2 may be an amplification event in BCL-2-mediated cell death. Overexpression of BCL-2 in a Bax-null human colon cancer cell line (HCT116Bax-/-) induces efficient cell death. The pro-apoptotic activity of BCL-2 is also observed in a Bax-null cells in which BAK expression is inhibited by stable RNAi expression. Our results suggest that BCL-2 contains an intrinsic pro-apoptotic activity and can induce apoptosis independent of BAX and BAK under specific conditions.
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Affiliation(s)
- T Subramanian
- Institute for Molecular Virology, Saint Louis University School of Medicine, 3681 Park Ave., St. Louis, Missouri 63110, USA
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Seyfried J, Evert BO, Schwarz CS, Schaupp M, Schulz JB, Klockgether T, Wüllner U. Gene dosage-dependent effects of bcl-2 expression on cellular survival and redox status. Free Radic Biol Med 2003; 34:1517-30. [PMID: 12788472 DOI: 10.1016/s0891-5849(03)00103-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human oncogene bcl-2 exerts protective functions in numerous models of apoptotic cell death and increased oxidative stress. We investigated the effects of inducible bcl-2 overexpression on cellular survival and redox status in dopaminergic rat pheochromocytoma PC 12 cells. Induction of high-level expression of bcl-2 in PC 12 cells resulted in generation of oxidative stress and cessation of growth by cell cycle arrest. Cell cycle arrest in bcl-2-overexpressing PC 12 cells was prevented by an inhibitor of extracellular signal-related kinase (ERK 1/2) activation. Protective effects of bcl-2 expression against L-DOPA neurotoxicity decreased with increasing amounts of bcl-2. Furthermore, high-level bcl-2 overexpression sensitized cells towards oxidative stress and glutathione depletion. Our data suggest that bcl-2 expression is beneficial only in a limited gene dosage range and that high-level expression of bcl-2 exerts potential deleterious effects.
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Affiliation(s)
- Jan Seyfried
- Department of Neurology, University of Bonn, Bonn, Germany.
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Kumazaki T, Sasaki M, Nishiyama M, Teranishi Y, Sumida H, Eboshida A, Mitsui Y. Life span shortening of normal fibroblasts by overexpression of BCL-2: a result of potent increase in cell death. Exp Cell Res 2003; 285:299-308. [PMID: 12706124 DOI: 10.1016/s0014-4827(03)00064-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It is well known that BCL-2 protects against cell death by both apoptosis and necrosis. The culture of bcl-2-transfected normal fibroblasts showed a shorter life span by about 12 population doubling levels compared to that of vector transfectants (64 vs 76 population doubling levels, respectively). An MTT assay revealed that BCL-2-overexpressing cells (HCA2/bcl-2) showed more severe growth suppression due to hydrogen peroxide or doxorubicin treatment than vector control cells (HCA2/vector). We observed a significant number of dead cells in the HCA2/bcl-2 culture, but not in the HCA2/vector culture. Other BCL-2 family proteins with both antiapoptotic and proapoptotic activity and other apoptosis-related factors were maintained at similar levels, indicating that overexpression of BCL-2 is the major reason that normal fibroblasts are sensitized to cell death. A broad caspase inhibitor (z-Val-Ala-Asp-fmk) and inhibitors of specific caspases (acetyl-Asp-Glu-Val-Asp-CHO, acetyl-Ile-Glu-Thr-Asp-CHO, and acetyl-Leu-Glu-His-Asp-CHO) suppressed cell death of HCA2/bcl-2 effectively, suggesting involvement of caspase 3-, 8-, and 9-dependent pathways in cell death and that the form of death is apoptosis. Unexpectedly, involvement of active MEK in cell death was shown by the use of its inhibitor, suggesting that crosstalk between BCL-2 and the MAP kinase cascade regulates death as well as life span.
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Affiliation(s)
- Tsutomu Kumazaki
- Department of Translational Cancer Research, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, 734-8553, Japan.
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Subramanian T, Chinnadurai G. Association of class I histone deacetylases with transcriptional corepressor CtBP. FEBS Lett 2003; 540:255-8. [PMID: 12681518 DOI: 10.1016/s0014-5793(03)00275-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The C-terminal binding protein (CtBP) family proteins are transcriptional regulators that are conserved from worm to human. They function as corepressors of a wide array of DNA-binding transcriptional repressors. The mammalian CtBPs appear to mediate transcriptional repression in a histone deacetylase (HDAC)-dependent or -independent manner, depending on the context of the promoter. To identify the components of the CtBP corepressor complex, we isolated CtBP-containing protein complexes from the nuclear extracts prepared from HeLa cells infected with adenovirus vectors that expresses hCtBP1. Western blot analysis of these complexes suggests that hCtBP1 associates with class I HDACs, HDAC-1, HDAC-2 and HDAC-3. Some of these HDACs also interact with the Drosophila CtBP homolog, dCtBP. The CtBP protein complex exhibits significant HDAC activity in vitro suggesting that association of CtBP with HDACs may be functionally relevant.
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Affiliation(s)
- T Subramanian
- Institute for Molecular Virology, Saint Louis University Health Sciences Center, 3681 Park Avenue, St Louis, MO 63110, USA
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36
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Lai D, Fu L, Weng S, Qi L, Yu C, Yu T, Wang H, Chen W. Blocking caspase-3 activity with a U6 SnRNA promoter-driven ribozyme enhances survivability of CHO Cells Cultured in Low Serum Medium and Production of Interferon-? Biotechnol Bioeng 2003; 85:20-8. [PMID: 14705008 DOI: 10.1002/bit.10769] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Apoptosis responding to various insults in bioreactors was observed to reduce cell viability and prevent cells from growing to high density. Inhibition of apoptosis in different ways has proved to be effective in keeping cells viable in high density and result in higher recombinant protein production. In apoptosis, death signals activate a family of proteinases, namely caspases, in a cascade and ultimately activate the final effector proteinase, caspase-3, which cleaves various substrates and drives the cells irreversibly to death. Caspase-3 is the executioner of an apoptotic cell and thus plays a central role in apoptosis. Therefore inhibition of caspase-3 may provide an effective way for apoptosis prevention. In this study, we designed a ribozyme targeted at the 451 nt of hamster caspase-3's open reading frame (ORF) and the ribozyme was proved to be effective in cleaving caspase-3 mRNA in vitro. Then, the ribozyme was cloned into a vector under the control of U6 snRNA promoter, an RNA polymerase III promoter, for high rate of transcription in vivo. The vector was transfected into an interferon-beta producing recombinant CHO cell line, and some clones were screened out that exhibited low caspase-3 production by Western blot analysis. One such clone was then further analyzed and it showed good anti-apoptosis property with respect to cell viability, cell density, and interferon-beta production.
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Affiliation(s)
- Dazhi Lai
- Department of Applied Molecular Biology, Beijing Institute of Microbiology and Epidemiology, 20 Dongdajie, Fengtai, Beijing 100071, China
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Oshiro T, Shiraishi M, Muto Y. Adenovirus mediated gene transfer of antiapoptotic protein in hepatic ischemia-reperfusion injury: the paradoxical effect of Bcl-2 expression in the reperfused liver. J Surg Res 2002; 103:30-6. [PMID: 11855914 DOI: 10.1006/jsre.2001.6313] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Although Bcl-2 is well known to have antiapoptotic activities in vitro and in vivo, the role of Bcl-2 remains controversial. In the present study, we evaluated whether the adenovirus mediated gene transfer of hBcl-2 could exert an antiapoptotic effect in a rat model of hepatic ischemia-reperfusion (I/R) injury. MATERIALS AND METHODS Each 6 x 10(9) plaque forming unit adenovirus vector encoding LacZ (AxCAilacZ) or hBcl-2 (AxCAhbcl2) was intravenously administered 48 h before I/R injury, in groups 1 and 2, respectively. In group 3, 1 ml of normal saline was injected instead of the virus vectors. Hepatic I/R injury was induced by the temporal occlusion of all hepatic influent vessels for 30 min under a portosystemic shunt. The animals were sacrificed at 6 h, 1, 3, and 14 days after reperfusion (each n = 12 in groups 1 and 2, and n = 8 in group 3). The expressions of hBcl-2 and Bax were evaluated at both the mRNA level by reverse transcription polymerase chain reaction and the protein level by immunohistochemistry. To assess the hepatocyte and sinusoidal endothelial cell damage after I/R injury, the serum asparate aminotransferase (AST), alanine aminotransferase, and hyaluronic acid were all evaluated. The number of apoptotic cells was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling (TUNEL). RESULTS To evaluate the antiapoptotic activities of the hBcl-2 sequence encoded into AxCAhbcl2, rat hepatocarcinoma cells were transfected with AxCAhbcl2 (10(3) moi) or AxCAilacZ (10(3) moi) and then challenged with TGF-beta1 protein (5 ng/ml) to induce apoptosis. Apoptotic cells were counted by TUNEL staining in about 2500 cells, and it was found that adenovirus mediated gene transfer of hBcl-2 significantly protected rat hepatocarcinoma cells from TGF-beta1 induced apoptosis (14.2 +/- 1.2%) in comparison to those of LacZ (21.9 +/- 1.4%). In the reperfused liver in vivo, the mRNA expression of hBcl-2 was detected only in the hBcl-2 transfected group 2. In group 2, a strong degree of Bcl-2 immunoreactivity was recognized as early as 6 h after reperfusion, while it was not recognized in groups 1 and 3 at 6 h after reperfusion. The AST levels were significantly higher in group 2 (AST: 356 +/- 100.1 IU/L) than those in group 1 (AST: 102.7 +/- 15 IU/L) at 1 day after reperfusion (P < 0.05). The number of TUNEL positive cells was significantly higher in group 2 than in groups 1 and 3 at 1 day after reperfusion. CONCLUSIONS These results indicated that an overexpression of antiapoptotic protein Bcl-2 paradoxically exerted a proapoptotic effect in the reperfused liver. The in vivo role of Bcl-2 should thus be carefully evaluated, depending on the levels of expression and the target organ.
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Affiliation(s)
- Takashi Oshiro
- First Department of Surgery, University of the Ryukyus, Okinawa, 903-0125, Japan.
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38
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Wilkinson BL, Sadler KA, Hyson RL. Rapid deafferentation-induced upregulation of bcl-2 mRNA in the chick cochlear nucleus. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2002; 99:67-74. [PMID: 11869810 DOI: 10.1016/s0169-328x(02)00113-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Neuronal survival in developing animals is often dependent on afferent activity. In the posthatch chick, approximately 30% of the neurons in the avian cochlear nucleus, nucleus magnocellularis (NM) die following elimination of VIIIth nerve activity. The factors that influence death or survival of an individual NM neuron are largely unknown. Previous studies indicate that both cell death and cell survival mechanisms compete to determine cell fate. One factor that has been shown to suppress cell death cascades in a variety of systems is bcl-2. If this gene product plays a role in regulating cell survival following deafferentation, then one might expect the expression of this gene to be influenced by removal of afferent input. In the present study, in situ hybridization revealed a rapid and transient increase in bcl-2 mRNA in NM neurons following deafferentation. Enhanced bcl-2 mRNA expression was observed at 6 and 12 h following deafferentation, but not at 3 or 24 h. Surprisingly, the upregulation of bcl-2 mRNA was limited to a subpopulation (20-30%) of deafferented neurons corresponding to the number of NM neurons that eventually die following cochlea removal. The robust and rapid upregulation of this gene suggests that cell death cascades regulated by bcl-2 may be initiated following deafferentation.
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Affiliation(s)
- Brandy L Wilkinson
- Department of Psychology, Program in Neuroscience, The Florida State University, Tallahassee, FL 32306-1270, USA
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Wang NS, Unkila MT, Reineks EZ, Distelhorst CW. Transient expression of wild-type or mitochondrially targeted Bcl-2 induces apoptosis, whereas transient expression of endoplasmic reticulum-targeted Bcl-2 is protective against Bax-induced cell death. J Biol Chem 2001; 276:44117-28. [PMID: 11546793 DOI: 10.1074/jbc.m101958200] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Bcl-2 protein family members function either to promote or inhibit programmed cell death. Bcl-2, typically an inhibitor of apoptosis, has also been demonstrated to have pro-apoptotic activity (Cheng, E. H., Kirsch, D. G., Clem, R. J., et al. (1997) Science 278, 1966-1968). The pro-apoptotic activity has been attributed to the cleavage of Bcl-2 by caspase-3, which converts Bcl-2 to a pro-apoptotic molecule. Bcl-2 is a membrane protein that is localized in the endoplasmic reticulum (ER) membrane, the outer mitochondrial membrane, and the nuclear envelope. Here, we demonstrate that transient expression of Bcl-2 at levels comparable to those found in stably transfected cells induces apoptosis in human embryonic kidney 293 cells and in the human breast cell line MDA-MB-468 cells. Furthermore, we have targeted Bcl-2 specifically to either the ER or the outer mitochondrial membrane to test whether induction of apoptosis by Bcl-2 is dependent upon its localization within either of these membranes. Our findings indicate that Bcl-2 specifically targeted to the mitochondria induces cell death, whereas Bcl-2 that is targeted to the ER does not. The expression of Bcl-2 does result in its cleavage to a 20-kDa protein; however, mutation of the caspase-3 cleavage site (D34A) does not inhibit its ability to induce cell death. Additionally, we find that transiently expressed ER-targeted Bcl-2 inhibits cell death induced by Bax overexpression. In conclusion, the ability of Bcl-2 to promote apoptosis is associated with its localization at the mitochondria. Furthermore, the ability of ER-targeted Bcl-2 to protect against Bax-induced apoptosis suggests that the ER localization of Bcl-2 may play an important role in its protective function.
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Affiliation(s)
- N S Wang
- Department of Medicine, Comprehensive Cancer Center, Case Western Reserve University and University Hospital of Cleveland, Cleveland, Ohio 44106, USA
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40
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Shen C, Buck A, Mehrke G, Polat B, Gross H, Bachem M, Reske S. Triplex forming oligonucleotide targeted to 3'UTR downregulates the expression of the bcl-2 proto-oncogene in HeLa cells. Nucleic Acids Res 2001; 29:622-8. [PMID: 11160882 PMCID: PMC30398 DOI: 10.1093/nar/29.3.622] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The bcl-2 proto-oncogene is overexpressed in a variety of human cancers and plays an important role in programmed cell death. Recent reports implied that the 3'-untranslated region (3'UTR) functions effectively in the regulation of gene expression. Here, we attempt to assay the ability of triplex forming oligonucleotides (TFOs) to inhibit expression of a target gene in vivo and to examine the potential of the 3'UTR of the bcl-2 proto-oncogene in the regulation of bcl-2 gene expression. To do this, we have developed a novel cellular system that involves transfection of a Doxycyclin inducible expression plasmid containing the bcl-2 ORF and the 3'UTR together with a TFO targeted to the 3'UTR of the bcl-2 proto-oncogene. Phosphorothioate-modified TFO targeted to the 3'UTR of the bcl-2 gene significantly downregulated the expression of the bcl-2 gene in HeLa cells as demonstrated by western blotting. Our results indicate that blocking the functions of the 3'UTR using the TFO can downregulate the expression of the targeted gene, and suggest that triplex strategy is a promising approach for oligonucleotide-based gene therapy. In addition, triplex-based sequence targeting may provide a useful tool for studying the regulation of gene expression.
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Affiliation(s)
- C Shen
- Department of Nuclear Medicine and Department of Clinical Chemistry, University of Ulm, Germany
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Biroccio A, Candiloro A, Mottolese M, Sapora O, Albini A, Zupi G, Del Bufalo D. Bcl-2 overexpression and hypoxia synergistically act to modulate vascular endothelial growth factor expression and in vivo angiogenesis in a breast carcinoma line. FASEB J 2000; 14:652-60. [PMID: 10744622 DOI: 10.1096/fasebj.14.5.652] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have previously demonstrated that bcl-2 overexpression enhances the metastatic potential of the MCF7 ADR human breast cancer cell line resistant to adriamycin by inducing metastasis-associated properties. To further elucidate the relationship between bcl-2 expression and the metastatic potential of the MCF7 ADR line, we evaluated whether bcl-2 could be also involved in the modulation of the angiogenic phenotype. Four bcl-2-overexpressing clones, a control transfectant clone, and the MCF7 ADR parental line were used for in vitro and in vivo experiments. Bcl-2 overexpression enhanced the synthesis of the hypoxia-stimulated VEGF protein and mRNA. Northern blot analysis demonstrated an increased VEGF mRNA expression in bcl-2-overexpressing clones, and reverse transcription-polymerase chain reaction showed higher levels of the VEGF(121) and VEGF(165) mRNA isoforms, which are the most active in eliciting angiogenesis. When incorporated into matrigel, supernatants of bcl-2-transfected cells cultured under hypoxic conditions induced an increased angiogenic response in C57BL/6 mice compared with that of control clone. Tumors from bcl-2 transfectants demonstrated increased VEGF expression and neovascularization as compared to the parental line, whereas the apoptosis in in vivo xenografts was similar in control and bcl-2 transfectants. The effect of bcl-2 on angiogenesis was not mediated by p53 protein. These results demonstrate that bcl-2 and hypoxia can act synergistically to modulate VEGF expression and the in vivo angiogenic response in the MCF7 ADR line.
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Affiliation(s)
- A Biroccio
- Experimental Chemotherapy Laboratory, Regina Elena Cancer Institute, Rome, Italy
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Abstract
It is now established that endothelial cells acquire several functional properties in response to a diverse array of extracellular stimuli. This expression of an altered phenotype is referred to as endothelial cell activation, and it includes several activities that promote inflammation and coagulation. While it is recognized that endothelial cell activation has a principal role in host defense, recent studies also demonstrate that endothelial cells are capable of complex molecular responses that protect the endothelium against various forms of stress including heat shock, hypoxia, oxidative stress, shock, ischemia-reperfusion injury, toxins, wounds, and mechanical stress. In this review, we examine endothelial cell genotypic and phenotypic responses to stress. Also, we highlight important cellular stress responses that, although not yet demonstrated directly in endothelial cells, likely exist as part of the repertoire of stress responses in endothelium. A detailed understanding of the molecular mechanisms mediating the adaptive responses of endothelial cells to stress should facilitate the development of novel therapeutics to aid in the management of diverse surgical diseases and their complications.
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Affiliation(s)
- T H Pohlman
- Department of Surgery, University of Washington, Seattle, Washington 98104, USA
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Dubois-Dauphin M, Poitry-Yamate C, de Bilbao F, Julliard AK, Jourdan F, Donati G. Early postnatal Müller cell death leads to retinal but not optic nerve degeneration in NSE-Hu-Bcl-2 transgenic mice. Neuroscience 2000; 95:9-21. [PMID: 10619458 DOI: 10.1016/s0306-4522(99)00313-9] [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: 12/01/2022]
Abstract
Topographically localized over-expression of the human Bcl-2 protein in retinal glial Müller cells of a transgenic mice (line 71) leads to early postnatal apoptotic Müller cell death and retinal degeneration. Morphological, immunohistological and confocal laser microscopic examination of transgenic and wild-type retinas were achieved on paraffin retinal sections, postnatally. Apoptosis occurs two to three days earlier in the internal nuclear layer of transgenic retinae, than in wild-type littermates. In parallel there was a progressive disappearance of transgenic Hu-Bcl-2 over-expression, as well as of the Müller cell markers, cellular retinaldehyde-binding protein and glutamine synthetase. This phenomenon led to retinal dysplasia, photoreceptor apoptosis and then retinal degeneration and proliferation of the retinal pigment epithelium. The optic nerve, however, remains intact. Two complementary observations confirm the pro-apoptotic action of Bcl-2 over-expression in Müller cells: (i) in the peri-papillary and peripheral regions where the transgene Bcl-2 is not expressed, cellular retinaldehyde-binding protein or glutamine synthetase immunostaining persist and Müller glia do not die; and (ii) the retina conserves a normal organisation in these two regions in spite of total retinal degeneration elsewhere. We conclude that retinal dysplasia and degeneration are linked to primary Müller cell disruption. Besides its generally accepted anti-apoptotic function, over-expression of Bcl-2 also exerts a pro-apoptotic action, at least in immature Müller glia. One may suppose that Bcl-2 translocation resulting in its over-expression in retinal Müller cells could be a putative mechanism for early retinal degeneration.
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Affiliation(s)
- M Dubois-Dauphin
- Division of Neuroscience, Geneva University Hospital, Belle Idée 2, Chemin du Petit Bel-Air, Geneva, Switzerland
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Zhu L, Ling S, Yu XD, Venkatesh LK, Subramanian T, Chinnadurai G, Kuo TH. Modulation of mitochondrial Ca(2+) homeostasis by Bcl-2. J Biol Chem 1999; 274:33267-73. [PMID: 10559201 DOI: 10.1074/jbc.274.47.33267] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have investigated the role of mitochondrial Ca(2+) (Ca(m)) homeostasis in cell survival. Disruption of Ca(m) homeostasis via depletion of the mitochondrial Ca(2+) store was the earliest event that occurred during staurosporine-induced apoptosis in neuroblastoma cells (SH-SY5Y). The decrease of Ca(m) preceded activation of the caspase cascade and DNA fragmentation. Overexpression of the anti-apoptosis protein Bcl-2 led to increased Ca(m) load, increased mitochondrial membrane potential (DeltaPsi(m)), and inhibition of staurosporine-induced apoptosis. On the other hand, ectopic expression of the pro-apoptotic protein Bik led to decreased Ca(m) load and decreased DeltaPsi(m). Inhibition of calcium uptake into mitochondria by ruthenium red induced a dose-dependent apoptosis as determined by nuclear staining and DNA ladder assay. Similarly, reducing the Ca(m) load by lowering the extracellular calcium concentration also led to apoptosis. We suggest that the anti-apoptotic effect of Bcl-2 is related to its ability to maintain a threshold level of Ca(m) and DeltaPsi(m) while the pro-apoptotic protein Bik has the opposite effect. Furthermore, both ER and mitochondrial Ca(2+) stores are important, and the depletion of either one will result in apoptosis. Thus, our results, for the first time, provide evidence that the maintenance of Ca(m) homeostasis is essential for cell survival.
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Affiliation(s)
- L Zhu
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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45
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Esposti MD, Hatzinisiriou I, McLennan H, Ralph S. Bcl-2 and mitochondrial oxygen radicals. New approaches with reactive oxygen species-sensitive probes. J Biol Chem 1999; 274:29831-7. [PMID: 10514462 DOI: 10.1074/jbc.274.42.29831] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Investigations into the capacity of the Bcl-2 protein to prevent apoptosis have targeted mitochondria as key sites of the preventative action accorded by Bcl-2 to cells. Using novel approaches with fluorescence probes and autofluorescence detection of endogenous NAD(P)H, we have examined the effects of expressing Bcl-2 in the Bcl-2 negative Burkitt's lymphoma cell line Daudi. We evaluated for the first time the effect of Bcl-2 expression on the intracellular distribution and production of hydrogen peroxide, under basal conditions and after treatment with apoptosis inducing agents, ceramide analogs and tumor necrosis factor (TNF)-alpha. Increased availability of mitochondrial NAD(P)H was detected in Bcl-2-expressing cells and was correlated with an increased constitutive mitochondrial production of hydrogen peroxide. Although production of hydrogen peroxide was increased by either C(6)-ceramide or TNF-alpha in Bcl-2 negative Daudi cells commensurate with the early phases of apoptosis, this increase did not occur in Bcl-2-expressing cells. Thus, Bcl-2 appears to allow cells to adapt to an increased state of oxidative stress, fortifying the cellular anti-oxidant defenses and counteracting the radical overproduction imposed by different cell death stimuli. Furthermore, we report altered cytological features of mitochondria during the early phases of apoptosis induced by C(6)-ceramide and TNF-alpha. In particular, mitochondria changed in appearance, clustering in the perinuclear region and Bcl-2 expression prevented these changes from occurring.
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Affiliation(s)
- M D Esposti
- Department of Biochemistry, Monash University, Clayton 3168 Victoria, Australia.
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Coulson EJ, Reid K, Bartlett PF. Signaling of neuronal cell death by the p75NTR neurotrophin receptor. Mol Neurobiol 1999; 20:29-44. [PMID: 10595871 DOI: 10.1007/bf02741363] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The neurotrophin receptor (p75NTR) is best known for mediating tropic support by participating in the formation of high-affinity nerve growth factor (NGF) receptor complexes with trkA, however, p75NTR more recently has been shown to act as a bona fide death-signaling receptor, which can signal independently of trkA. This article discusses the evidence for an active role of p75NTR in neuronal cell death and the mechanisms controlling this process, including roles for Bcl-2 family members, the c-jun stress kinase JNK, the transcription factor nuclear factor kappa B (NFkappaB), and caspases.
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Affiliation(s)
- E J Coulson
- Development and Neurobiology Group, The Walter and Eliza Hall Institute of Medical Research, PO The Royal Melbourne Hospital, Parkville, Australia
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Coulson EJ, Reid K, Barrett GL, Bartlett PF. p75 neurotrophin receptor-mediated neuronal death is promoted by Bcl-2 and prevented by Bcl-xL. J Biol Chem 1999; 274:16387-91. [PMID: 10347198 DOI: 10.1074/jbc.274.23.16387] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The p75 neurotrophin receptor (p75NTR) has been shown to mediate neuronal death through an unknown pathway. We microinjected p75NTR expression plasmids into sensory neurons in the presence of growth factors and assessed the effect of the expressed proteins on cell survival. We show that, unlike other members of the TNFR family, p75NTR signals death through a unique caspase-dependent death pathway that does not involve the "death domain" and is differentially regulated by Bcl-2 family members: the anti-apoptotic molecule Bcl-2 both promoted, and was required for, p75NTR killing, whereas killing was inhibited by its homologue Bcl-xL. These results demonstrate that Bcl-2, through distinct molecular mechanisms, either promotes or inhibits neuronal death depending on the nature of the death stimulus.
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Affiliation(s)
- E J Coulson
- Walter and Eliza Hall Institute for Medical Research, Post Office, The Royal Melbourne Hospital, Parkville, Victoria, 3050, Australia
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Arriola EL, Rodriguez-Lopez AM, Hickman JA, Chresta CM. Bcl-2 overexpression results in reciprocal downregulation of Bcl-X(L) and sensitizes human testicular germ cell tumours to chemotherapy-induced apoptosis. Oncogene 1999; 18:1457-64. [PMID: 10050882 DOI: 10.1038/sj.onc.1202420] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Testicular germ cell tumours are hypersentive to chemotherapy and cell lines derived from these tumours are chemosensitive in vitro. We have previously shown that these cell lines express undetectable levels of the suppressor of apoptosis Bcl-2 and relatively high levels of the apoptosis inducer Bax (Chresta et al., 1996). To determine whether the absence of Bcl-2 in these cell lines makes them highly susceptible to drug-induced apoptosis, Bcl-2 was expressed ectopically in the 833K testicular germ cell tumour cell line. Stable overexpressing clones were isolated and three clones were studied further. Surprisingly, Bcl-2 overexpressing cells were sensitized to chemotherapy-induced apoptosis compared to the parental and vector control cells. Analysis of potential mechanisms of sensitization revealed there was a reciprocal downregulation of the endogenously expressed Bcl-X(L) in the Bcl-2 overexpressing clones. Downregulation of Bcl-X(L) to the same extent using antisense oligonucleotides enhanced etoposide-induced apoptosis by twofold. Our results indicate that Bcl-2 and Bcl-X(L) have different abilities to protect against chemotherapy-induced apoptosis in testicular germ cell tumours. In contrast to findings in some tumour cell types, Bcl-2 did not act as a gatekeeper to prevent entry of p53 to the nucleus.
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Affiliation(s)
- E L Arriola
- CRC Molecular and Cellular Pharmacology Research Group, School of Biological Sciences, The University of Manchester, UK
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