51
|
Janssen WJ, Barthel L, Muldrow A, Oberley-Deegan RE, Kearns MT, Jakubzick C, Henson PM. Fas determines differential fates of resident and recruited macrophages during resolution of acute lung injury. Am J Respir Crit Care Med 2011; 184:547-60. [PMID: 21471090 DOI: 10.1164/rccm.201011-1891oc] [Citation(s) in RCA: 244] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
RATIONALE During acute lung injury (ALI) the macrophage pool expands markedly as inflammatory monocytes migrate from the circulation to the airspaces. As inflammation resolves, macrophage numbers return to preinjury levels and normal tissue structure and function are restored. OBJECTIVES To determine the fate of resident and recruited macrophages during the resolution of ALI in mice and to elucidate the mechanisms responsible for macrophage removal. METHODS ALI was induced in mice using influenza A (H1N1; PR8) infection and LPS instillation. Dye labeling techniques, bone marrow transplantation, and surface immunophenotyping were used to distinguish resident and recruited macrophages during inflammation and to study the role of Fas in determining macrophage fate during resolving ALI. MEASUREMENTS AND MAIN RESULTS During acute and resolving lung injury from influenza A and LPS, a high proportion of the original resident alveolar macrophages persisted. In contrast, recruited macrophages exhibited robust accumulation in early inflammation, followed by a progressive decline in their number. This decline was mediated by apoptosis with local phagocytic clearance. Recruited macrophages expressed high levels of the death receptor Fas and were rapidly depleted from the airspaces by Fas-activating antibodies. In contrast, macrophage depletion was inhibited in mice treated with Fas-blocking antibodies and in chimeras with Fas-deficient bone marrow. Caspase-8 inhibition prevented macrophage apoptosis and delayed the resolution of ALI. CONCLUSIONS These findings indicate that Fas-induced apoptosis of recruited macrophages is essential for complete resolution of ALI.
Collapse
Affiliation(s)
- William J Janssen
- Division of Pulmonary Medicine, Department of Medicine, National Jewish Health, Denver, Colorado 80206, USA.
| | | | | | | | | | | | | |
Collapse
|
52
|
Shirley S, Morizot A, Micheau O. Regulating TRAIL receptor-induced cell death at the membrane : a deadly discussion. Recent Pat Anticancer Drug Discov 2011; 6:311-23. [PMID: 21756247 PMCID: PMC3204462 DOI: 10.2174/157489211796957757] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 02/20/2011] [Accepted: 02/20/2011] [Indexed: 12/20/2022]
Abstract
The use of TRAIL/APO2L and monoclonal antibodies targeting TRAIL receptors for cancer therapy holds great promise, due to their ability to restore cancer cell sensitivity to apoptosis in association with conventional chemotherapeutic drugs in a large variety of tumors. TRAIL-induced cell death is tightly regulated right from the membrane and at the DISC (Death-Inducing Signaling Complex) level. The following patent and literature review aims to present and highlight recent findings of the deadly discussion that determines tumor cell fate upon TRAIL engagement.
Collapse
Affiliation(s)
- Sarah Shirley
- INSERM, U866, Dijon, F-21079 France; Faculty of Medicine and Pharmacy, University of Bourgogne, Dijon, F-21079 France.
| | | | | |
Collapse
|
53
|
Muntané J. Harnessing tumor necrosis factor receptors to enhance antitumor activities of drugs. Chem Res Toxicol 2011; 24:1610-6. [PMID: 21740002 DOI: 10.1021/tx2002349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cancer is the second-leading cause of death in the U.S. behind heart disease and over stroke. The hallmarks of cancer comprise six biological capabilities acquired during the multistep development of human tumors. The inhibition of cell death pathways is one of these tumor characteristics which also include sustained proliferative signaling, evading growth suppressor signaling, replicative immortality, angiogenesis, and promotion of invasion and metastasis. Cell death is mediated through death receptor (DR) stimulation initiated by specific ligands that transmit signaling to the cell death machinery or through the participation of mitochondria. Cell death involving DR is mediated by the superfamily of tumor necrosis factor receptor (TNF-R) which includes TNF-R type I, CD95, DR3, TNF-related apoptosis-inducing ligand (TRAIL) receptor-1 (TRAIL-R1) and -2 (TRAIL-R2), DR6, ectodysplasin A (EDA) receptor (EDAR), and the nerve growth factor (NGF) receptor (NGFR). The expression of these receptors in healthy and tumor cells induces treatment side effects that limit the systemic administration of cell death-inducing therapies. The present review is focused on the different therapeutic strategies such as targeted antibodies or small molecules addressed to selective stimulated DR-mediated apoptosis or reduce cell proliferation in cancer cells.
Collapse
Affiliation(s)
- Jordi Muntané
- Liver Research Unit, Instituto Maimónides para la Investigación Biomédica de Córdoba, Reina Sofia University Hospital , Córdoba, Spain.
| |
Collapse
|
54
|
The heme oxygenase-1 and c-FLIP in acute myeloid leukemias: two non-redundant but mutually exclusive cellular safeguards protecting cells against TNF-induced cell death? Oncotarget 2011; 1:317-9. [PMID: 21307398 DOI: 10.18632/oncotarget.100911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
55
|
Shirley S, Micheau O. Targeting c-FLIP in cancer. Cancer Lett 2010; 332:141-50. [PMID: 21071136 DOI: 10.1016/j.canlet.2010.10.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 09/29/2010] [Accepted: 10/11/2010] [Indexed: 12/15/2022]
Abstract
Cellular-FLICE inhibitory protein (c-FLIP) is a key anti-apoptotic regulator that inhibits cell death mediated by the death receptors Fas, DR4, DR5, and TNF-R1. Three splice variants of c-FLIP function at the DISC level by blocking the processing and activation of procaspase-8 and -10. Overexpression of c-FLIP has been identified in many different tumour types, and its downregulation in vitro has been shown to restore apoptosis mediated by CD95L and TRAIL. c-FLIP therefore represents a promising target for cancer therapy. This review focuses on the molecular mechanisms that control c-FLIP expression and current research into inhibitors of the protein. Increasing evidence supports the investigation of c-FLIP as a therapeutic target to restore an apoptotic response in cancer cells.
Collapse
|
56
|
Shirley S, Micheau O. The heme oxygenase-1 and c-FLIP in acute myeloid leukemias: two non-redundant but mutually exclusive cellular safeguards protecting cells against TNF-induced cell death? Oncotarget 2010; 1:317-319. [PMID: 21307398 PMCID: PMC3157731 DOI: 10.18632/oncotarget.163] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 09/16/2010] [Indexed: 11/25/2022] Open
Affiliation(s)
- S. Shirley
- INSERM, U866, Dijon, F-21079 France; Faculty of Medicine and Pharmacy, Univ. Bourgogne, Dijon, F-21079, France
| | - O. Micheau
- INSERM, U866, Dijon, F-21079 France; Faculty of Medicine and Pharmacy, Univ. Bourgogne, Dijon, F-21079, France
- Centre Georges-François Leclerc, Dijon, F-21000, France
| |
Collapse
|
57
|
Gore A, Muralidhar M, Espey MG, Degenhardt K, Mantell LL. Hyperoxia sensing: from molecular mechanisms to significance in disease. J Immunotoxicol 2010; 7:239-54. [PMID: 20586583 DOI: 10.3109/1547691x.2010.492254] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Oxygen therapy using mechanical ventilation with hyperoxia is necessary to treat patients with respiratory failure and distress. However, prolonged exposure to hyperoxia leads to the generation of excessive reactive oxygen species (ROS), causing cellular damage and multiple organ dysfunctions. As the lungs are directly exposed, hyperoxia can cause both acute and chronic inflammatory lung injury and compromise innate immunity. ROS may contribute to pulmonary oxygen toxicity by overwhelming redox homeostasis, altering signaling cascades that affect cell fate, ultimately leading to hyperoxia-induced acute lung injury (HALI). HALI is characterized by pronounced inflammatory responses with leukocyte infiltration, injury, and death of pulmonary cells, including epithelia, endothelia, and macrophages. Under hyperoxic conditions, ROS mediate both direct and indirect modulation of signaling molecules such as protein kinases, transcription factors, receptors, and pro- and anti-apoptotic factors. The focus of this review is to elaborate on hyperoxia-activated key sensing molecules and current understanding of their signaling mechanisms in HALI. A better understanding of the signaling pathways leading to HALI may provide valuable insights on its pathogenesis and may help in designing more effective therapeutic approaches.
Collapse
Affiliation(s)
- Ashwini Gore
- Department of Pharmaceutical Sciences, St. John's University College of Pharmacy and Allied Health Professions, Queens, NY, USA
| | | | | | | | | |
Collapse
|
58
|
Gillissen B, Wendt J, Richter A, Richter A, Müer A, Overkamp T, Gebhardt N, Preissner R, Belka C, Dörken B, Daniel PT. Endogenous Bak inhibitors Mcl-1 and Bcl-xL: differential impact on TRAIL resistance in Bax-deficient carcinoma. ACTA ACUST UNITED AC 2010; 188:851-62. [PMID: 20308427 PMCID: PMC2845080 DOI: 10.1083/jcb.200912070] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Although both Mcl-1 and Bcl-xL keep proapoptotic Bak in check, it is the loss of Mcl-1 that sensitizes cells to death receptor–mediated apoptosis. Tumor necrosis factor (α)–related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent that preferentially kills tumor cells with limited cytotoxicity to nonmalignant cells. However, signaling from death receptors requires amplification via the mitochondrial apoptosis pathway (type II) in the majority of tumor cells. Thus, TRAIL-induced cell death entirely depends on the proapoptotic Bcl-2 family member Bax, which is often lost as a result of epigenetic inactivation or mutations. Consequently, Bax deficiency confers resistance against TRAIL-induced apoptosis. Despite expression of Bak, Bax-deficient cells are resistant to TRAIL-induced apoptosis. In this study, we show that the Bax dependency of TRAIL-induced apoptosis is determined by Mcl-1 but not Bcl-xL. Both are antiapoptotic Bcl-2 family proteins that keep Bak in check. Nevertheless, knockdown of Mcl-1 but not Bcl-xL overcame resistance to TRAIL, CD95/FasL and tumor necrosis factor (α) death receptor ligation in Bax-deficient cells, and enabled TRAIL to activate Bak, indicating that Mcl-1 rather than Bcl-xL is a major target for sensitization of Bax-deficient tumors for death receptor–induced apoptosis via the Bak pathway.
Collapse
Affiliation(s)
- Bernhard Gillissen
- Department of Hematology, Oncology, and Tumor Immunology, University Medical Center Charité, Humboldt University, 13125 Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
59
|
Cellular stress responses: cell survival and cell death. Int J Cell Biol 2010; 2010:214074. [PMID: 20182529 PMCID: PMC2825543 DOI: 10.1155/2010/214074] [Citation(s) in RCA: 819] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 11/20/2009] [Indexed: 12/13/2022] Open
Abstract
Cells can respond to stress in various ways ranging from the activation of survival pathways to the initiation of cell death that eventually eliminates damaged cells. Whether cells mount a protective or destructive stress response depends to a large extent on the nature and duration of the stress as well as the cell type. Also, there is often the interplay between these responses that ultimately determines the fate of the stressed cell. The mechanism by which a cell dies (i.e., apoptosis, necrosis, pyroptosis, or autophagic cell death) depends on various exogenous factors as well as the cell's ability to handle the stress to which it is exposed. The implications of cellular stress responses to human physiology and diseases are manifold and will be discussed in this review in the context of some major world health issues such as diabetes, Parkinson's disease, myocardial infarction, and cancer.
Collapse
|
60
|
Evasion of apoptosis as a cellular stress response in cancer. Int J Cell Biol 2010; 2010:370835. [PMID: 20182539 PMCID: PMC2825553 DOI: 10.1155/2010/370835] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 11/06/2009] [Indexed: 02/08/2023] Open
Abstract
One of the hallmarks of human cancers is the intrinsic or acquired resistance to apoptosis. Evasion of apoptosis can be part of a cellular stress response to ensure the cell's survival upon exposure to stressful stimuli. Apoptosis resistance may contribute to carcinogenesis, tumor progression, and also treatment resistance, since most current anticancer therapies including chemotherapy as well as radio- and immunotherapies primarily act by activating cell death pathways including apoptosis in cancer cells. Hence, a better understanding of the molecular mechanisms regarding how cellular stress stimuli trigger antiapoptotic mechanisms and how this contributes to tumor resistance to apoptotic cell death is expected to provide the basis for a rational approach to overcome apoptosis resistance mechanisms in cancers.
Collapse
|
61
|
Park SJ, Sohn HY, Yoon J, Park SI. Down-regulation of FoxO-dependent c-FLIP expression mediates TRAIL-induced apoptosis in activated hepatic stellate cells. Cell Signal 2009; 21:1495-503. [PMID: 19470406 DOI: 10.1016/j.cellsig.2009.05.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/15/2009] [Accepted: 05/19/2009] [Indexed: 11/17/2022]
Abstract
Activated hepatic stellate cells which contribute to liver fibrosis have represented an important target for antifibrotic therapy. In this study, we found that TRAIL inhibited PI3K/Akt-dependent FoxO phosphorylation and relocated FoxO proteins into the nucleus from the cytosol in activated human hepatic stellate LX-2 cells. The accumulated FoxO proteins in the nucleus led to down-regulation of c-FLIP(L/S) expression, resulting in the activation of apoptosis-related signaling molecules including the activation of caspase-8, -3, and Bid, as well as mitochondrial cytochrome c release. These results were supported by showing that siRNA-mediated knockdown of FoxO led to restoration of c-FLIP(L/S) expression and resistance to TRAIL-induced apoptosis after treatment of LX-2 cells with TRAIL. Furthermore, c-FLIP(L/S)-transfected LX-2 cells showed the decreased sensitivity to TRAIL-induced apoptosis. Collectively, our data suggest that sequential activation of FoxO proteins under conditions of suppressed PI3K/Akt signaling by TRAIL can down-regulate c-FLIP(L/S), consequently promoting TRAIL-induced apoptosis in LX-2 cells. Therefore, the present study suggests TRAIL may be an effective strategy for antifibrotic therapy in liver fibrosis.
Collapse
Affiliation(s)
- Soo-Jung Park
- Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health, Seoul 122-701, South Korea
| | | | | | | |
Collapse
|
62
|
Yuan P, Salvadore G, Li X, Zhang L, Du J, Chen G, Manji HK. Valproate activates the Notch3/c-FLIP signaling cascade: a strategy to attenuate white matter hyperintensities in bipolar disorder in late life? Bipolar Disord 2009; 11:256-69. [PMID: 19419383 PMCID: PMC2788821 DOI: 10.1111/j.1399-5618.2009.00675.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVES Increased prevalence of deep white matter hyperintensities (DWMHs) has been consistently observed in patients with geriatric depression and bipolar disorder. DMWHs are associated with chronicity, disability, and poor quality of life. They are thought to be ischemic in their etiology and may be related to the underlying pathophysiology of mood disorders in the elderly. Notably, these lesions strikingly resemble radiological findings related to the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephelopathy (CADASIL) syndrome. CADASIL arises from mutations in Notch3, resulting in impaired signaling via cellular Fas-associated death domain-like interleukin-1-beta-converting enzyme-inhibitory protein (c-FLIP) through an extracellular signal-regulated kinase (ERK)-dependent pathway. These signaling abnormalities have been postulated to underlie the progressive degeneration of vascular smooth muscle cells (VSMC). This study investigates the possibility that the anticonvulsant valproate (VPA), which robustly activates the ERK mitogen-activated protein kinase (MAPK) cascade, may exert cytoprotective effects on VSMC through the Notch3/c-FLIP pathway. METHODS Human VSMC were treated with therapeutic concentrations of VPA subchronically. c-FLIP was knocked down via small interfering ribonucleic acid transfection. Cell survival, apoptosis, and protein levels were measured. RESULTS VPA increased c-FLIP levels dose- and time-dependently and promoted VSMC survival in response to Fas ligand-induced apoptosis in VSMC. The anti-apoptotic effect of VPA was abolished by c-FLIP knockdown. VPA also produced similar in vivo effects in rat brain. CONCLUSIONS These results raise the intriguing possibility that VPA may be a novel therapeutic agent for the treatment of CADASIL and related disorders. They also suggest that VPA might decrease the liability of patients with late-life mood disorders to develop DWMHs.
Collapse
Affiliation(s)
- Peixiong Yuan
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Giacomo Salvadore
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Xiaoxia Li
- Department of Psychiatry, Uniformed Service University of Health Sciences, Bethesda, MD, USA
| | - Lei Zhang
- Department of Psychiatry, Uniformed Service University of Health Sciences, Bethesda, MD, USA
| | - Jing Du
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Guang Chen
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Husseini K Manji
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
63
|
Wang X, Zhao J, Tang S, Lee S, Glazer RI, Hewlett I. c-FLIPL regulates PKC via AP-2 to inhibit Bax-mediated apoptosis induced by HIV-1 gp120 in Jurkat cells. Mol Cell Biochem 2009; 330:23-9. [PMID: 19363595 DOI: 10.1007/s11010-009-0096-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 03/30/2009] [Indexed: 01/10/2023]
Abstract
c-FLIPL, an inhibitor of caspase 8, is known to inhibit the Fas/caspase 8 apoptotic pathway; however, its involvement of Bax/mitochondrial apoptosis is not well understood. Using human cells, Jurkat cell line, induced with HIV-1 gp120, we studied the effects of c-FLIPL on Bax/mitochondrial apoptosis. We found that the induction of apoptosis by HIV-1 envelope protein, gp120, involved the activation of both Bax-dependent and death receptor-mediated pathways, and HIV-1 infection deceased c-FLIPL expression. Interestingly, c-FLIPL expression downregulated protein kinase C (PKC) expression at the transcript level involving activated protein-2 (AP-2). c-FLIPL expression reduced AP-2 protein levels required to promote PKC protein expression and PKC-associated inactive form of Bax, and inhibited Bax activation, suggesting that c-FLIPL inhibits Bax activation via modulating PKC expression at the transcriptional level involving AP-2 during gp120 treatment. Collectively, these findings further corroborate the concept that gp120 plays an important role, via involvement of molecules such as c-FLIPL, in apoptotic cell death due to HIV-1 infection.
Collapse
Affiliation(s)
- Xue Wang
- Laboratory of Molecular Virology, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29B, Rm 4NN16, 8800 Rockville Pike, Bethesda, MD, 20892, USA.
| | | | | | | | | | | |
Collapse
|
64
|
Abstract
One of the hallmarks of human cancers is the intrinsic or acquired resistance to apoptosis. Evasion of apoptosis may contribute to carcinogenesis, tumor progression and also to treatment resistance, since most current anticancer therapies including chemotherapy, radio- and immunotherapy primarily act by activating cell death pathways including apoptosis in cancer cells. Hence, a better understanding of the molecular mechanisms underlying tumor resistance to apoptotic cell death is expected to provide the basis for a rational approach to develop molecular targeted therapies.
Collapse
Affiliation(s)
- Simone Fulda
- Children's Hospital, Ulm University, Ulm 89075, Germany.
| |
Collapse
|
65
|
Fulda S. Betulinic Acid for cancer treatment and prevention. Int J Mol Sci 2008; 9:1096-1107. [PMID: 19325847 PMCID: PMC2658785 DOI: 10.3390/ijms9061096] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 06/03/2008] [Accepted: 06/04/2008] [Indexed: 01/06/2023] Open
Abstract
Betulinic acid is a natural product with a range of biological effects, for example potent antitumor activity. This anticancer property is linked to its ability to induce apoptotic cell death in cancer cells by triggering the mitochondrial pathway of apoptosis. In contrast to the cytotoxicity of betulinic acid against a variety of cancer types, normal cells and tissue are relatively resistant to betulinic acid, pointing to a therapeutic window. Compounds that exert a direct action on mitochondria present promising experimental cancer therapeutics, since they may trigger cell death under circumstances in which standard chemotherapeutics fail. Thus, mitochondrion-targeted agents such as betulinic acid hold great promise as a novel therapeutic strategy in the treatment of human cancers.
Collapse
Key Words
- AIF, apoptosis inducing factor
- Apaf-1, Apoptotic protease activating factor-1
- BA, betulinic acid
- DIABLO, direct IAP Binding protein with Low PI
- HtrA2, high temperature requirement protein A
- IAPs, Inhibitor of Apoptosis Proteins
- MOMP, mitochondrial outer membrane permeabilization
- PARP, Poly (ADP-ribose) Polymerase
- ROS, reactive oxygen species
- Smac, second mitochondria-derived activator of caspase
- TNF, tumor necrosis factor
- TRAIL, tumor necrosis factor-related apoptosis-inducing ligand
- apoptosis
- betulinic acid
- cancer
- mitochondria
- zVAD.fmk, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone
Collapse
Affiliation(s)
- Simone Fulda
- University Children's Hospital, Eythstr. 24, 89075 Ulm, Germany
| |
Collapse
|
66
|
Mérino D, Lalaoui N, Morizot A, Solary E, Micheau O. TRAIL in cancer therapy: present and future challenges. Expert Opin Ther Targets 2007; 11:1299-314. [PMID: 17907960 PMCID: PMC2976473 DOI: 10.1517/14728222.11.10.1299] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Since its identification in 1995, TNF-related apoptosis-inducing ligand (TRAIL) has sparked growing interest in oncology due to its reported ability to selectively trigger cancer cell death. In contrast to other members of the TNF superfamily, TRAIL administration in vivo is safe. The relative absence of toxic side effects of this naturally occurring cytokine, in addition to its antitumoural properties, has led to its preclinical evaluation. However, despite intensive investigations, little is known in regards to the mechanisms underlying TRAIL selectivity or efficiency. An appropriate understanding of its physiological relevance, and of the mechanisms controlling cancer cells escape from TRAIL-induced cell death, will be required to optimally use the cytokine in clinics. The present review focuses on recent advances in the understanding of TRAIL signal transduction and discusses the existing and future challenges of TRAIL-based cancer therapy development.
Collapse
|
67
|
Materi W, Wishart DS. Computational systems biology in cancer: modeling methods and applications. GENE REGULATION AND SYSTEMS BIOLOGY 2007; 1:91-110. [PMID: 19936081 PMCID: PMC2759135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In recent years it has become clear that carcinogenesis is a complex process, both at the molecular and cellular levels. Understanding the origins, growth and spread of cancer, therefore requires an integrated or system-wide approach. Computational systems biology is an emerging sub-discipline in systems biology that utilizes the wealth of data from genomic, proteomic and metabolomic studies to build computer simulations of intra and intercellular processes. Several useful descriptive and predictive models of the origin, growth and spread of cancers have been developed in an effort to better understand the disease and potential therapeutic approaches. In this review we describe and assess the practical and theoretical underpinnings of commonly-used modeling approaches, including ordinary and partial differential equations, petri nets, cellular automata, agent based models and hybrid systems. A number of computer-based formalisms have been implemented to improve the accessibility of the various approaches to researchers whose primary interest lies outside of model development. We discuss several of these and describe how they have led to novel insights into tumor genesis, growth, apoptosis, vascularization and therapy.
Collapse
Affiliation(s)
- Wayne Materi
- National Research Council, National Institute for Nanotechnology (NINT) Edmonton, Alberta, Canada
| | - David S. Wishart
- Departments of Biological Sciences and Computing Science, University of Alberta, National Research Council, National Institute for Nanotechnology (NINT) Edmonton, Alberta, Canada,Correspondence: David S Wishart, 2-21 Athabasca Hall, University of Alberta, Edmonton, AB, Canada T6G 2E8. Tel: 780-492-0383; Fax: 780-492-1071;
| |
Collapse
|
68
|
Rae C, Langa S, Tucker SJ, MacEwan DJ. Elevated NF-kappaB responses and FLIP levels in leukemic but not normal lymphocytes: reduction by salicylate allows TNF-induced apoptosis. Proc Natl Acad Sci U S A 2007; 104:12790-5. [PMID: 17646662 PMCID: PMC1937545 DOI: 10.1073/pnas.0701437104] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Indexed: 01/04/2023] Open
Abstract
As its name suggests, tumor necrosis factor (TNF) is known to induce cytotoxicity in a wide variety of tumor cells and cell lines. However, its use as a chemotherapeutic drug has been limited by its deleterious side effects of systemic shock and widespread inflammatory responses. Some nonsteroidal antiinflammatory drugs, such as sodium salicylate, have been shown to have a chemopreventive role in certain forms of cancer. Here, we reveal that sodium salicylate selectively enhances the apoptotic effects of TNF in human erythroleukemia cells but does not affect primary human lymphocytes or monocytes. Sodium salicylate did not affect the intracellular distribution of TNF receptors (TNFRs) but stimulated cell surface TNFR2 shedding. Erythroleukemia cells were shown to possess markedly greater basal NF-kappaB responses and elevated Fas-associated protein with death domain-like IL-1 converting enzyme (FLIP) levels. Sodium salicylate achieved its effects by reducing the elevated NF-kappaB responsiveness and FLIP levels and restoring the apoptotic response of TNF rather than the proliferative/proinflammatory effects of the cytokine in these cancer cells. Inhibition of NF-kappaB or FLIP levels in human erythroleukemia cells by pharmacological or molecular-biological means also resulted in switching the character of these cells from a TNF-responsive proliferative phenotype into an apoptotic one. These findings expose that the enhanced proliferative nature of human leukemia cells is caused by elevated NF-kappaB and FLIP responses and basal levels, reversible by sodium salicylate to allow greater apoptotic responsiveness of cytotoxic stimuli such as TNF. Such findings provide insight into the molecular mechanisms by which human leukemia cells can switch from a proliferative into an apoptotic phenotype.
Collapse
Affiliation(s)
- Colin Rae
- School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Susana Langa
- School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Steven J. Tucker
- School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - David J. MacEwan
- School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| |
Collapse
|
69
|
Wang X, Wang Y, Kim HP, Choi AMK, Ryter SW. FLIP inhibits endothelial cell apoptosis during hyperoxia by suppressing Bax. Free Radic Biol Med 2007; 42:1599-609. [PMID: 17448907 DOI: 10.1016/j.freeradbiomed.2007.02.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 02/16/2007] [Accepted: 02/20/2007] [Indexed: 02/08/2023]
Abstract
High oxygen tension (hyperoxia) causes pulmonary cell death, involving apoptosis, necrosis, or mixed death phenotypes, though the underlying mechanisms remain unclear. In mouse lung endothelial cells (MLEC) hyperoxia activates both extrinsic (Fas-dependent) and intrinsic (mitochondria-dependent) apoptotic pathways. We examined the hypothesis that FLIP, an inhibitor of caspase-8, can protect endothelial cells against the lethal effects of hyperoxia. Hyperoxia caused the time-dependent downregulation of FLIP in MLEC. Overexpression of FLIP attenuated intracellular reactive oxygen species generation during hyperoxia exposure, by downregulating extracellular-regulated kinase-1/2 activation and p47(phox) expression. FLIP prevented hyperoxia-induced trafficking of the death-inducing signal complex from the Golgi apparatus to the plasma membrane. Furthermore, FLIP blocked the activations of caspase-8/Bid, caspases -3/-9, and inhibited the mitochondrial translocation and activation of Bax, resulting in protection against hyperoxia-induced cell death. Under normoxic conditions, FLIP expression increased the phosphorylation of p38 mitogen-activated protein kinase leading to increased phosphorylation of Bax during hyperoxic stress. Furthermore, FLIP expression markedly inhibited protein kinase C activation and expression of distinct protein kinase C isoforms (alpha, eta, and zeta), and stabilized an interaction of PKC with Bax. In conclusion, FLIP exerted novel inhibitory effects on extrinsic and intrinsic apoptotic pathways, which significantly protected endothelial cells from the lethal effects of hyperoxia.
Collapse
Affiliation(s)
- Xue Wang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, 3459 Fifth Avenue, MUH 628NW, Pittsburgh, PA 15213, USA
| | | | | | | | | |
Collapse
|
70
|
Guicciardi ME, Bronk SF, Werneburg NW, Gores GJ. cFLIPL prevents TRAIL-induced apoptosis of hepatocellular carcinoma cells by inhibiting the lysosomal pathway of apoptosis. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1337-46. [PMID: 17272514 DOI: 10.1152/ajpgi.00497.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Sensitivity to TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis and the lysosomal pathway of cell death are features of cancer cells. However, it is unknown if TRAIL cytotoxic signaling engages the lysosomal pathway of cell death. Our aim, therefore, was to ascertain if TRAIL killing involves lysosomal permeabilization. TRAIL-induced apoptosis of hepatocellular carcinoma cells (HuH-7, Hep3B) was associated with lysosomal permeabilization, as demonstrated by redistribution of the lysosomal protease cathepsin B into the cytosol. Pharmacological and short hairpin RNA-targeted inhibition of cathepsin B reduced apoptosis. Because cellular FLICE-inhibitory protein (cFLIP) inhibits TRAIL-induced cell death and is frequently overexpressed by human cancers, the ability of cFLIP to prevent lysosomal permeabilization during TRAIL treatment was examined. Enforced long-form cFLIP (cFLIP(L)) expression reduced release of cathepsin B from lysosomes and attenuated apoptosis. cFLIP(L) overexpression was also associated with robust p42/44 MAPK activation following exposure to TRAIL. In contrast, cFLIP(L) overexpression attenuated p38 MAPK activation and had no significant effect on JNK and NF-kappaB activation. Inhibition of p42/44 MAPK by PD98059 restored TRAIL-mediated lysosomal permeabilization and apoptosis in cFLIP-overexpressing cells. In conclusion, these results demonstrate that lysosomal permeabilization contributes to TRAIL-induced apoptosis of hepatocellular carcinoma cells and suggest that cFLIP(L) cytoprotection is, in part, due to p42/44 MAPK-dependent inhibition of lysosomal breakdown.
Collapse
Affiliation(s)
- Maria Eugenia Guicciardi
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905, USA
| | | | | | | |
Collapse
|
71
|
Charo J, Robbins PF. Contrasting effects of FLIPL
overexpression in human T cells on activation-induced cell death and cytokine production. J Leukoc Biol 2007; 81:1297-302. [PMID: 17311934 DOI: 10.1189/jlb.0306218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
There have been disparate findings about the role of FLIP in the survival of mouse T cells and human tumor cell lines. The role of cellular FLIP in human T cell activation and function needs to be clarified further. To study this role, we have overexpressed long transcript FLIP (FLIPL) in primary T cells, including self-antigen-reactive, melanoma-specific T cells. We found that FLIPL overexpression protects human T cells from activation-induced cell death and enhances their proliferative capacity but suppresses the ability of these cells to produce the proinflammatory cytokines IL-2 and IFN-gamma in response to CD3 or antigen-specific stimulation. The multiple effects of FLIPL indicate that this protein may influence T cell responses to antigenic stimulation.
Collapse
Affiliation(s)
- Jehad Charo
- Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
| | | |
Collapse
|
72
|
Ryter SW, Kim HP, Hoetzel A, Park JW, Nakahira K, Wang X, Choi AMK. Mechanisms of cell death in oxidative stress. Antioxid Redox Signal 2007; 9:49-89. [PMID: 17115887 DOI: 10.1089/ars.2007.9.49] [Citation(s) in RCA: 876] [Impact Index Per Article: 51.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reactive oxygen or nitrogen species (ROS/RNS) generated endogenously or in response to environmental stress have long been implicated in tissue injury in the context of a variety of disease states. ROS/RNS can cause cell death by nonphysiological (necrotic) or regulated pathways (apoptotic). The mechanisms by which ROS/RNS cause or regulate apoptosis typically include receptor activation, caspase activation, Bcl-2 family proteins, and mitochondrial dysfunction. Various protein kinase activities, including mitogen-activated protein kinases, protein kinases-B/C, inhibitor-of-I-kappaB kinases, and their corresponding phosphatases modulate the apoptotic program depending on cellular context. Recently, lipid-derived mediators have emerged as potential intermediates in the apoptosis pathway triggered by oxidants. Cell death mechanisms have been studied across a broad spectrum of models of oxidative stress, including H2O2, nitric oxide and derivatives, endotoxin-induced inflammation, photodynamic therapy, ultraviolet-A and ionizing radiations, and cigarette smoke. Additionally ROS generated in the lung and other organs as the result of high oxygen therapy or ischemia/reperfusion can stimulate cell death pathways associated with tissue damage. Cells have evolved numerous survival pathways to counter proapoptotic stimuli, which include activation of stress-related protein responses. Among these, the heme oxygenase-1/carbon monoxide system has emerged as a major intracellular antiapoptotic mechanism.
Collapse
Affiliation(s)
- Stefan W Ryter
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
| | | | | | | | | | | | | |
Collapse
|
73
|
Mérino D, Lalaoui N, Morizot A, Schneider P, Solary E, Micheau O. Differential inhibition of TRAIL-mediated DR5-DISC formation by decoy receptors 1 and 2. Mol Cell Biol 2006; 26:7046-55. [PMID: 16980609 PMCID: PMC1592888 DOI: 10.1128/mcb.00520-06] [Citation(s) in RCA: 225] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family that induces cancer cell death by apoptosis with some selectivity. TRAIL-induced apoptosis is mediated by the transmembrane receptors death receptor 4 (DR4) (also known as TRAIL-R1) and DR5 (TRAIL-R2). TRAIL can also bind decoy receptor 1 (DcR1) (TRAIL-R3) and DcR2 (TRAIL-R4) that fail to induce apoptosis since they lack and have a truncated cytoplasmic death domain, respectively. In addition, DcR1 and DcR2 inhibit DR4- and DR5-mediated, TRAIL-induced apoptosis and we demonstrate here that this occurs through distinct mechanisms. While DcR1 prevents the assembly of the death-inducing signaling complex (DISC) by titrating TRAIL within lipid rafts, DcR2 is corecruited with DR5 within the DISC, where it inhibits initiator caspase activation. In addition, DcR2 prevents DR4 recruitment within the DR5 DISC. The specificity of DcR1- and DcR2-mediated TRAIL inhibition reveals an additional level of complexity for the regulation of TRAIL signaling.
Collapse
|
74
|
Abstract
Apoptosis mediated via extrinsic or intrinsic pathways is essential for maintaining cellular homeostasis in the liver. The extrinsic pathway is triggered from the cell surface by engagement of death receptors as CD95, TRAIL (TNF-related apoptosis inducing ligand) and TNF (tumour necrosis factor) or TGF-beta (transforming growth factor beta) receptors. The intrinsic pathway is initiated from the mitochondria and can be influenced by Bcl-2 family members. Both pathways are intertwined and play a physiological role in the liver. Dysregulation of apoptosis pathways contributes to diseases as hepatocellular carcinoma, viral hepatitis, autoimmune hepatitis, ischaemia-reperfusion injury, iron or copper deposition disorders, toxic liver damage and acute liver failure. The apoptosis defects are often central pathogenetic events; hence molecular mechanisms of apoptosis give not only insight into disease mechanisms but also provide potential corresponding therapeutic candidates in liver disease. The focus of this review is the identification of apoptotic signalling components in the liver as therapeutic targets.
Collapse
Affiliation(s)
- Sören T Eichhorst
- Ludwig-Maximilians-University, University Hospital Grosshadern, Department of Internal Medicine II, Research Lab B 5 E01 308, Marchioninistrasse 15, D-81377 Munich, Germany.
| |
Collapse
|
75
|
Boehrer S, Nowak D, Puccetti E, Ruthardt M, Sattler N, Trepohl B, Schneider B, Hoelzer D, Mitrou PS, Chow KU. Prostate-apoptosis-response-gene-4 increases sensitivity to TRAIL-induced apoptosis. Leuk Res 2006; 30:597-605. [PMID: 16513168 DOI: 10.1016/j.leukres.2005.09.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Accepted: 09/12/2005] [Indexed: 12/17/2022]
Abstract
The capacity of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) to preferentially induce apoptosis in malignant cells while sparing normal tissues renders it an attractive therapeutic agent. Nevertheless, the molecular determinants governing sensitivity towards TRAIL remain to be defined. Acknowledging the previously demonstrated deregulation of prostate-apoptosis-response-gene-4 (par-4) in ex vivo cells of patients suffering from acute and chronic lymphatic leukemia, we here tested the hypothesis that expression of par-4 influences sensitivity to TRAIL. Evaluating this hypothesis we show, that par-4-transfected T-lymphoblastic Jurkat cells exhibit a considerably increased rate of apoptosis upon incubation with an agonistic TRAIL-antibody as compared to their mock-transfected counterparts. Defining the underlying molecular mechanisms we provide evidence, that par-4 enhances sensitivity towards TRAIL by employing crucial members of the extrinsic pathway. Thus, par-4-overexpressing Jurkat clones show an enforced cleavage of c-Flip(L) together with an increased activation of the initiator caspases-8 and -10. In addition, expression of par-4 enables cells to down-regulate the inhibitor-of-apoptosis proteins cIAP-1, cIAP-2, XIAP and survivin with a concomitantly enhanced activation of the executioner caspases-6 and -7. Supporting the crucial role of caspase-8 in par-4-promoted apoptosis we demonstrate that inhibition of caspase-8 considerably reduces TRAIL-induced apoptosis in par-4 and mock-transfected Jurkat clones and reverses the described molecular changes. In conclusion, we here provide first evidence that expression of par-4 in neoplastic lymphocytes augments sensitivity to TRAIL-induced cell death and outline the responsible molecular mechanisms, in particular the crucial role of caspase-8 activation.
Collapse
Affiliation(s)
- Simone Boehrer
- Department of Medicine II, Johann Wolfgang Goethe-University Hospital, Theodor-Stern-Kai-7, 60590 Frankfurt, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
76
|
Georgakis GV, Li Y, Rassidakis GZ, Martinez-Valdez H, Medeiros LJ, Younes A. Inhibition of heat shock protein 90 function by 17-allylamino-17-demethoxy-geldanamycin in Hodgkin's lymphoma cells down-regulates Akt kinase, dephosphorylates extracellular signal-regulated kinase, and induces cell cycle arrest and cell death. Clin Cancer Res 2006; 12:584-90. [PMID: 16428504 DOI: 10.1158/1078-0432.ccr-05-1194] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Heat shock protein 90 (HSP90) is a chaperone for several client proteins involved in transcriptional regulation, signal transduction, and cell cycle control. HSP90 is abundantly expressed by a variety of tumor types and has been recently targeted for cancer therapy. The objective of this study was to determine the role of HSP90 in promoting growth and survival of Hodgkin's lymphoma and to determine the molecular consequences of inhibiting HSP90 function by the small-molecule 17-allylamino-17-demethoxy-geldanamycin (17-AAG) in Hodgkin's lymphoma. EXPERIMENTAL DESIGN HSP90 expression in Hodgkin's lymphoma cell lines was determined by Western blot and in primary lymph node sections from patients with Hodgkin's lymphoma by immunohistochemistry. Cell viability was determined by the 3-(4,5-dimethyl-thiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Apoptosis and cell cycle fractions were determined by flow cytometry. Expression of intracellular proteins was determined by Western blot. RESULTS HSP90 is overexpressed in primary and cultured Hodgkin's lymphoma cells. Inhibition of HSP90 function by 17-AAG showed a time- and dose-dependent growth inhibition of Hodgkin's lymphoma cell lines. 17-AAG induced cell cycle arrest and apoptosis, which were associated with a decrease in cyclin-dependent kinase (CDK) 4, CDK 6, and polo-like kinase 1 (PLK1), and induced apoptosis by caspase-dependent and caspase-independent mechanisms. Furthermore, 17-AAG depleted cellular contents of Akt, decreased extracellular signal-regulated kinase (ERK) phosphorylation, and reduced cellular FLICE-like inhibitory protein levels (FLIP), and thus enhanced the cytotoxic effect of doxorubicin and agonistic anti-tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor antibodies. CONCLUSION Inhibition of HSP90 function induces cell death and enhances the activity of chemotherapy and anti-tumor necrosis factor-related apoptosis-inducing ligand death receptor antibodies, suggesting that targeting HSP90 function might be of therapeutic value in Hodgkin's lymphoma.
Collapse
Affiliation(s)
- Georgios V Georgakis
- Department of Lymphoma and Myeloma, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
77
|
Hainsworth AH, Bermpohl D, Webb TE, Darwish R, Fiskum G, Qiu J, McCarthy D, Moskowitz MA, Whalen MJ. Expression of cellular FLICE inhibitory proteins (cFLIP) in normal and traumatic murine and human cerebral cortex. J Cereb Blood Flow Metab 2005; 25:1030-40. [PMID: 15815586 PMCID: PMC1266275 DOI: 10.1038/sj.jcbfm.9600104] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cellular Fas-associated death domain-like interleukin-1-beta converting enzyme (FLICE) inhibitory proteins (cFLIPs) are endogenous caspase homologues that inhibit programmed cell death. We hypothesized that cFLIPs are differentially expressed in response to traumatic brain injury (TBI). cFLIP-alpha and cFLIP-delta mRNA were expressed in normal mouse brain-specifically cFLIP-delta (but not cFLIP-alpha) protein was robustly expressed. After controlled cortical impact (CCI), cFLIP-alpha expression increased initially then decreased to control levels at 12 h, increasing again at 24-72 h (P<0.05). cFLIP-delta expression was decreased in brain homogenates by 12 h after CCI, then increased again at 24 to 72 h (P<0.05). cFLIP-delta immunostaining was markedly reduced in injured cortex, but not hippocampus, at 3 to 72 h after CCI. In cortex, reduced cFLIP-delta staining was found in TUNEL-positive cells, but in hippocampus TUNEL-positive cells expressed cFLIP-delta immunoreactivity. cFLIP-delta was increased in a subset of reactive astrocytes in pericontusional cortex and hippocampus at 48 to 72 h. Low levels of both cFLIP isoforms were detected in human cortical tissue with no TBI, from four patients undergoing brain surgery for epilepsy and <24 h post mortem from three patients without CNS pathologic assessment. In cortical tissue surgically removed <18 h after severe TBI (n=3), cFLIP-alpha expression was increased relative to epilepsy controls (P<0.05) but not relative to post-mortem controls. The data suggest differential spatial and temporal regulation of cFLIP-alpha and cFLIP-delta expression that may influence the magnitude of cell death and further implicate programmed mechanisms of cell death after TBI.
Collapse
Affiliation(s)
- Atticus H Hainsworth
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
- Pharmacology Research Group, Leicester School of Pharmacy, De Montfort University, Leicester, UK
| | - Daniela Bermpohl
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Tania E Webb
- Pharmacology Research Group, Leicester School of Pharmacy, De Montfort University, Leicester, UK
| | - Ribal Darwish
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gary Fiskum
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jianhua Qiu
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Deirdre McCarthy
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Michael A Moskowitz
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michael J Whalen
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts, USA
- Correspondence: Dr MJ Whalen, Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. E-mail:
| |
Collapse
|
78
|
Gilot D, Serandour AL, Ilyin GP, Lagadic-Gossmann D, Loyer P, Corlu A, Coutant A, Baffet G, Peter ME, Fardel O, Guguen-Guillouzo C. A role for caspase-8 and c-FLIPL in proliferation and cell-cycle progression of primary hepatocytes. Carcinogenesis 2005; 26:2086-94. [PMID: 16033771 DOI: 10.1093/carcin/bgi187] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Growth factors are known to favor both proliferation and survival of hepatocytes. In the present study, we investigated if c-FLIP(L) (cellular FLICE-inhibitory protein, long isoform) could be involved in epidermal growth factor (EGF)-stimulated proliferation of rat hepatocytes since c-FLIP(L) regulates both cell proliferation and procaspase-8 maturation. Treatment with MEK inhibitors prevented induction of c-FLIP(L) by EGF along with total inhibition of DNA replication. However, EGF failed to inhibit processing of procaspase-8 in the presence of EGF suggesting that c-FLIP(L) does not play its canonical anti-apoptotic role in this model. Downregulation of c-FLIP expression using siRNA oligonucleotides strongly reduced DNA replication but did not result in enhanced apoptosis. Moreover, intermediate cleavage products of c-FLIP(L) and caspase-8 were found in EGF-treated hepatocytes in the absence of caspase-3 maturation and cell death. To determine whether the Fas/FADD/caspase-8/c-FLIP(L) complex was required for this activity, Fas, procaspase-8 and Fas-associated death domain protein (FADD) expression or function was inhibited using siRNA or constructs encoding dominant negative mutant proteins. Inhibition of any of these components of the Fas/FADD/caspase-8 pathway decreased DNA replication suggesting a function of these proteins in cell-cycle arrest. Similar results were obtained when the IETD-like caspase activity detectable in EGF-treated hepatocytes was inhibited by the pan-caspase inhibitor, z-ASP. Finally, we demonstrated co-immunoprecipitation between EGFR and Fas within 15 min following EGF stimulation. In conclusion, our results indicate that the Fas/FADD/c-FLIP(L)/caspase-8 pathway positively controls the G(1)/S transition in EGF-stimulated hepatocytes. Our data provide new insights into the mechanisms by which apoptotic proteins participate to mitogenic signals during the G(1) phase.
Collapse
|
79
|
Wang X, Wang Y, Zhang J, Kim HP, Ryter SW, Choi AMK. FLIP protects against hypoxia/reoxygenation-induced endothelial cell apoptosis by inhibiting Bax activation. Mol Cell Biol 2005; 25:4742-51. [PMID: 15899875 PMCID: PMC1140634 DOI: 10.1128/mcb.25.11.4742-4751.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2004] [Revised: 12/13/2004] [Accepted: 02/28/2005] [Indexed: 02/08/2023] Open
Abstract
Hypoxia/reoxygenation causes cell death, yet the underlying regulatory mechanisms remain partially understood. Recent studies demonstrate that hypoxia/reoxygenation can activate death receptor and mitochondria-dependent apoptotic pathways, involving Bid and Bax mitochondrial translocation and cytochrome c release. Using mouse lung endothelial cells (MLEC), we examined the role of FLIP, an inhibitor of caspase 8, in hypoxia/reoxygenation-induced cell death. FLIP protected MLEC against hypoxia/reoxygenation by blocking both caspase 8/Bid and Bax/mitochondrial apoptotic pathways. FLIP inhibited Bax activation in wild-type and Bid(-/-) MLEC, indicating independence from the caspase 8/Bid pathway. FLIP also inhibited the expression and activation of protein kinase C (PKC) (alpha, zeta) during hypoxia/reoxygenation and promoted an association of inactive forms of PKC with Bax. Surprisingly, FLIP expression also inhibited death-inducing signal complex (DISC) formation in the plasma membrane and promoted the accumulation of the DISC in the Golgi apparatus. FLIP expression also upregulated Bcl-X(L), an antiapoptotic protein. In conclusion, FLIP decreased DISC formation in the plasma membrane by blocking its translocation from the Golgi apparatus and inhibited Bax activation through a novel PKC-dependent mechanism. The inhibitory effects of FLIP on Bax activation and plasma membrane DISC formation may play significant roles in protecting endothelial cells from the lethal effects of hypoxia/reoxygenation.
Collapse
Affiliation(s)
- Xue Wang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, 3459 Fifth Ave., MUH NW 628, Pittsburgh, PA 15213, USA
| | | | | | | | | | | |
Collapse
|
80
|
Jin TG, Kurakin A, Benhaga N, Abe K, Mohseni M, Sandra F, Song K, Kay BK, Khosravi-Far R. Fas-associated protein with death domain (FADD)-independent recruitment of c-FLIPL to death receptor 5. J Biol Chem 2004; 279:55594-601. [PMID: 15485835 PMCID: PMC2981793 DOI: 10.1074/jbc.m401056200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Here we show a novel mechanism by which FLICE-like inhibitory protein (c-FLIP) regulates apoptosis induced by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and one of its receptors, DR5. c-FLIP is a critical regulator of the TNF family of cytokine receptor signaling. c-FLIP has been postulated to prevent formation of the competent death-inducing signaling complex (DISC) in a ligand-dependent manner, through its interaction with FADD and/or caspase-8. In order to identify regulators of TRAIL function, we used the intracellular death domain (DD) of DR5 as a target to screen a phage-displayed combinatorial peptide library. The DD of DR5 selected from the library a peptide that showed sequence similarity to a stretch of amino acids in the C terminus of c-FLIP(L). The phage-displayed peptide selectively interacted with the DD of DR5 in in vitro binding assays. Similarly, full-length c-FLIP (c-FLIP(L)) and the C-terminal p12 domain of c-FLIP interacted with DR5 both in in vitro pull-down assays and in mammalian cells. This interaction was independent of TRAIL. To the contrary, TRAIL treatment released c-FLIP(L) from DR5, permitting the recruitment of FADD to the active DR5 signaling complex. By employing FADD-deficient Jurkat cells, we demonstrate that DR5 and c-FLIP(L) interact in a FADD-independent manner. Moreover, we show that a cellular membrane permeable version of the peptide corresponding to the DR5 binding domain of c-FLIP induces apoptosis in mammalian cells. Taken together, these findings indicate that c-FLIP interacts with the DD of DR5, thus preventing death (L)signaling by DR5 prior to the formation of an active DISC. Because TRAIL and DR5 are ubiquitously expressed, the interaction of c-FLIP(L) and DR5 indicates a mechanism by which tumor selective apoptosis can be achieved through protecting normal cells from undergoing death receptor-induced apoptosis.
Collapse
Affiliation(s)
- Tai-Guang Jin
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Alexei Kurakin
- Buck Institute for Age Research, Novato, California 94945
| | - Nordine Benhaga
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Karon Abe
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Mehrdad Mohseni
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Ferry Sandra
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Keli Song
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Brian K. Kay
- Argonne National Laboratory, Argonne, Illinois 60439
| | - Roya Khosravi-Far
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
- To whom correspondence should be addressed: Dept. of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Ave, RN 270F, Boston, MA 02215. Tel.: 617-667-8526; Fax: 617-667-3524;
| |
Collapse
|
81
|
Bentele M, Lavrik I, Ulrich M, Stösser S, Heermann DW, Kalthoff H, Krammer PH, Eils R. Mathematical modeling reveals threshold mechanism in CD95-induced apoptosis. J Cell Biol 2004; 166:839-51. [PMID: 15364960 PMCID: PMC2172102 DOI: 10.1083/jcb.200404158] [Citation(s) in RCA: 247] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mathematical modeling is required for understanding the complex behavior of large signal transduction networks. Previous attempts to model signal transduction pathways were often limited to small systems or based on qualitative data only. Here, we developed a mathematical modeling framework for understanding the complex signaling behavior of CD95(APO-1/Fas)-mediated apoptosis. Defects in the regulation of apoptosis result in serious diseases such as cancer, autoimmunity, and neurodegeneration. During the last decade many of the molecular mechanisms of apoptosis signaling have been examined and elucidated. A systemic understanding of apoptosis is, however, still missing. To address the complexity of apoptotic signaling we subdivided this system into subsystems of different information qualities. A new approach for sensitivity analysis within the mathematical model was key for the identification of critical system parameters and two essential system properties: modularity and robustness. Our model describes the regulation of apoptosis on a systems level and resolves the important question of a threshold mechanism for the regulation of apoptosis.
Collapse
Affiliation(s)
- M Bentele
- Division Theoretical Bioinformatics,German Caner Research Center DKFZ, Heidelberg 69120, Germany
| | | | | | | | | | | | | | | |
Collapse
|
82
|
Abstract
Developing neurons are programmed to die by an apoptotic pathway unless they are rescued by extrinsic growth factors that generate an anti-apoptotic response. By contrast, adult neurons need to survive for the lifetime of the organism, and their premature death can cause irreversible functional deficits. The default apoptotic pathway is shut down when development is complete, and consequently growth factors are no longer required to prevent death. To protect against accidental apoptotic cell death, anti-apoptotic mechanisms are activated in mature neurons in response to stress. Loss or reduced activity of these intrinsic anti-apoptotic 'brakes' might contribute to or accelerate neurodegeneration, whereas their activation might rescue neurons from injury or genetic abnormalities.
Collapse
Affiliation(s)
- Susanna C Benn
- Day Neuromuscular Research Lab, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02129, USA
| | | |
Collapse
|