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Rao M, Huang YK, Liu CC, Meadows C, Cheng HC, Zhou M, Chen YC, Xia X, Goldberg JL, Williams AM, Kuwajima T, Chang KC. Aldose reductase inhibition decelerates optic nerve degeneration by alleviating retinal microglia activation. Sci Rep 2023; 13:5592. [PMID: 37019993 PMCID: PMC10076364 DOI: 10.1038/s41598-023-32702-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/31/2023] [Indexed: 04/07/2023] Open
Abstract
As part of the central nervous system (CNS), retinal ganglion cells (RGCs) and their axons are the only neurons in the retina that transmit visual signals from the eye to the brain via the optic nerve (ON). Unfortunately, they do not regenerate upon injury in mammals. In ON trauma, retinal microglia (RMG) become activated, inducing inflammatory responses and resulting in axon degeneration and RGC loss. Since aldose reductase (AR) is an inflammatory response mediator highly expressed in RMG, we investigated if pharmacological inhibition of AR can attenuate ocular inflammation and thereby promote RGC survival and axon regeneration after ON crush (ONC). In vitro, we discovered that Sorbinil, an AR inhibitor, attenuates BV2 microglia activation and migration in the lipopolysaccharide (LPS) and monocyte chemoattractant protein-1 (MCP-1) treatments. In vivo, Sorbinil suppressed ONC-induced Iba1 + microglia/macrophage infiltration in the retina and ON and promoted RGC survival. Moreover, Sorbinil restored RGC function and delayed axon degeneration one week after ONC. RNA sequencing data revealed that Sorbinil protects the retina from ONC-induced degeneration by suppressing inflammatory signaling. In summary, we report the first study demonstrating that AR inhibition transiently protects RGC and axon from degeneration, providing a potential therapeutic strategy for optic neuropathies.
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Affiliation(s)
- Mishal Rao
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Yu-Kai Huang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, 80708, Taiwan
- Department of Surgery, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, 80145, Taiwan
| | - Chia-Chun Liu
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Chandler Meadows
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Hui-Chun Cheng
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Mengli Zhou
- Department of Computational and Systems Biology, Hillman Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Yu-Chih Chen
- Department of Computational and Systems Biology, Hillman Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Xin Xia
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, 94304, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, 94304, USA
| | - Andrew M Williams
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Takaaki Kuwajima
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA
| | - Kun-Che Chang
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, 203 Lothrop, Pittsburgh, PA, 15213, USA.
- Department of Neurobiology, Center of Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
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Stat3 role in the protective effect of FXR Agonist in parenteral nutrition-associated cholestasis. Hepatol Commun 2023; 7:e0056. [PMID: 36848082 PMCID: PMC9974070 DOI: 10.1097/hc9.0000000000000056] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/12/2022] [Indexed: 03/01/2023] Open
Abstract
BACKGROUND AND AIMS Parenteral nutrition (PN) in patients with intestinal failure can lead to cholestasis (PNAC). In a PNAC mouse model, farnesoid X receptor (FXR) agonist (GW4064) treatment alleviated IL-1β-dependent cholestatic liver injury. The objective of this study was to determine whether this hepatic protection of FXR activation is mediated through IL-6-STAT3 signaling. APPROACH AND RESULTS Hepatic apoptotic pathways [Fas-associated protein with death domain (Fas) mRNA, caspase 8 protein, and cleaved caspase 3] and IL-6-STAT3 signaling, and expression of its downstream effectors Socs1/3 were all upregulated in the mouse PNAC model (dextran sulfate sodium enterally × 4 d followed by total PN for 14 d). Il1r-/- mice were protected from PNAC in conjunction with suppression of the FAS pathway. GW4064 treatment in the PNAC mouse increased hepatic FXR binding to the Stat3 promoter, further increased STAT3 phosphorylation and upregulated Socs1 and Socs3 mRNA, and prevented cholestasis. In HepG2 cells and primary mouse hepatocytes, IL-1β induced IL-6 mRNA and protein, which were suppressed by GW4064. In IL-1β or phytosterols treated HepG2 and Huh7 cells, siRNA knockdown of STAT3 significantly reduced GW4064-upregulated transcription of hepatoprotective nuclear receptor subfamily 0, group B, member 2 (NR0B2) and ABCG8. CONCLUSIONS STAT3 signaling mediated in part the protective effects of GW4064 in the PNAC mouse, and in HepG2 cells and hepatocytes exposed to either IL-1β or phytosterols, 2 factors critical in PNAC pathogenesis. These data demonstrate that FXR agonists may mediate hepatoprotective effects in cholestasis by inducing STAT3 signaling.
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Nainu F, Ophinni Y, Shiratsuchi A, Nakanishi Y. Apoptosis and Phagocytosis as Antiviral Mechanisms. Subcell Biochem 2023; 106:77-112. [PMID: 38159224 DOI: 10.1007/978-3-031-40086-5_3] [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] [Indexed: 01/03/2024]
Abstract
Viruses are infectious entities that make use of the replication machinery of their hosts to produce more progenies, causing disease and sometimes death. To counter viral infection, metazoan hosts are equipped with various defense mechanisms, from the rapid-evoking innate immune responses to the most advanced adaptive immune responses. Previous research demonstrated that cells in fruit flies and mice infected with Drosophila C virus and influenza, respectively, undergo apoptosis, which triggers the engulfment of apoptotic virus-infected cells by phagocytes. This process involves the recognition of eat-me signals on the surface of virus-infected cells by receptors of specialized phagocytes, such as macrophages and neutrophils in mice and hemocytes in fruit flies, to facilitate the phagocytic elimination of virus-infected cells. Inhibition of phagocytosis led to severe pathologies and death in both species, indicating that apoptosis-dependent phagocytosis of virus-infected cells is a conserved antiviral mechanism in multicellular organisms. Indeed, our understanding of the mechanisms underlying apoptosis-dependent phagocytosis of virus-infected cells has shed a new perspective on how hosts defend themselves against viral infection. This chapter explores the mechanisms of this process and its potential for developing new treatments for viral diseases.
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Affiliation(s)
- Firzan Nainu
- Department of Pharmacy, Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia.
| | - Youdiil Ophinni
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan
- Laboratory of Host Defense, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Akiko Shiratsuchi
- Center for Medical Education, Sapporo Medical University, Sapporo, Japan
- Division of Biological Function and Regulation, Graduate School of Medicine, Sapporo Medical University, Sapporo, Japan
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Hartel JC, Merz N, Grösch S. How sphingolipids affect T cells in the resolution of inflammation. Front Pharmacol 2022; 13:1002915. [PMID: 36176439 PMCID: PMC9513432 DOI: 10.3389/fphar.2022.1002915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
The concept of proper resolution of inflammation rather than counteracting it, gained a lot of attention in the past few years. Re-assembly of tissue and cell homeostasis as well as establishment of adaptive immunity after inflammatory processes are the key events of resolution. Neutrophiles and macrophages are well described as promotors of resolution, but the role of T cells is poorly reviewed. It is also broadly known that sphingolipids and their imbalance influence membrane fluidity and cell signalling pathways resulting in inflammation associated diseases like inflammatory bowel disease (IBD), atherosclerosis or diabetes. In this review we highlight the role of sphingolipids in T cells in the context of resolution of inflammation to create an insight into new possible therapeutical approaches.
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Affiliation(s)
- Jennifer Christina Hartel
- Institute of Clinical Pharmacology, Goethe-University Frankfurt. Frankfurt am Main, Frankfurt, Germany
- Department of Life Sciences, Goethe-University Frankfurt, Frankfurt, Germany
| | - Nadine Merz
- Institute of Clinical Pharmacology, Goethe-University Frankfurt. Frankfurt am Main, Frankfurt, Germany
| | - Sabine Grösch
- Institute of Clinical Pharmacology, Goethe-University Frankfurt. Frankfurt am Main, Frankfurt, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt, Germany
- *Correspondence: Sabine Grösch,
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Mcl-1 levels critically impact the sensitivities of human colorectal cancer cells to APG-1252-M1, a novel Bcl-2/Bcl-XL dual inhibitor that induces Bax-dependent apoptosis. Neoplasia 2022; 29:100798. [PMID: 35462114 PMCID: PMC9046866 DOI: 10.1016/j.neo.2022.100798] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/08/2022] [Accepted: 04/08/2022] [Indexed: 11/23/2022]
Abstract
New treatment options, such as targeted therapies, are urgently needed for the treatment of colorectal cancer (CRC), the third leading cause of cancer-related deaths worldwide. The current study focuses on demonstrating the therapeutic efficacies of APG-1252-M1 (an active form of the prodrug, APG-1252 or pelcitoclax), a highly potent Bcl-2/Bcl-XL dual inhibitor in clinical trials, against CRC and understanding the underlying mechanisms. APG-1252-M1 effectively decreased the survival of CRC cell lines, particularly those expressing relatively low levels of Mcl-1, with the induction of apoptosis. High levels of Mcl-1 were significantly correlated with decreased sensitivity of CRC cell lines to APG-1252-M1. When combined with an Mcl-1 inhibitor, APG-1252-M1 synergistically decreased the survival and induced apoptosis of APG-1252-M1-insensitive cell lines with high levels of Mcl-1. This combination further decreased the survival and enhanced apoptosis even in sensitive cell lines with relatively low levels of Mcl-1, whereas enforced expression of ectopic Mcl-1 in these cells abrogated APG-1252-M1’s effects on decreasing cell survival and inducing apoptosis, which could be reversed by Mcl-1 inhibition. APG-1252-M1 rapidly induced cytochrome C and Smac release from mitochondria with caspase-3 and PARP cleavage. Deficiency of Bax in CRC cells abolished APG-1252-M1’s ability to induce apoptosis, indicating that APG-1252-M1 induces Bax-dependent apoptosis. The current study thus demonstrates the potential of APG-1252-M1 as a monotherapy in the treatment of CRC, particularly those with low Mcl-1 expression, or in combination with an Mcl-1 inhibitor, warranting further evaluation in vivo and in the clinic.
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Raman D, Tay P, Hirpara JL, Liu D, Pervaiz S. TRAIL sensitivity of nasopharyngeal cancer cells involves redox dependent upregulation of TMTC2 and its interaction with membrane caspase-3. Redox Biol 2021; 48:102193. [PMID: 34839142 PMCID: PMC8636823 DOI: 10.1016/j.redox.2021.102193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/12/2021] [Accepted: 11/19/2021] [Indexed: 12/09/2022] Open
Abstract
AIMS Preferential expression of receptors for TNF-family related apoptosis inducing ligand (TRAIL), DR4 and DR5 makes TRAIL an attractive anti-cancer therapeutic. However, the efficacy of targeting death receptors has not been extensively studied in nasopharyngeal cancer (NPC). Here we investigated TRAIL sensitivity and its underlying mechanism in NPC cell lines, and assessed the potential of TRAIL as a therapeutic option against NPC. RESULTS Using two established NPC cell lines, we report the expression of DR4 and DR5, which respond to TRAIL ligation by triggering efficient Type II apoptosis. Mechanistically, early activation of caspase-3 and its membrane recruitment is identified in NPC cell lines, which is associated with, hitherto unreported, interaction with transmembrane and tetratricopeptide repeat containing 2 (TMTC2) in the lipid raft domains. TMTC2 expression is induced upon exposure to TRAIL and involves intracellular increase in peroxynitrite (ONOO-) production. While ONOO- increase is downstream of caspase-8 activation, it is involved in the upregulation of TMTC2, gene knockdown of which abrogated TRAIL-induced apoptotic execution. Bioinformatics analyses also provide evidence for a strong correlation between TMTC2 and DR4 or caspase-3 as well as a significantly better disease-free survival in patients with high TMTC2 expression. INNOVATION AND CONCLUSION Collectively, redox-dependent execution of NPC cells upon ligation of TRAIL receptors reintroduces the possible therapeutic use of TRAIL in NPC as well as underscores the potential of using TMTC2 as a biomarker of TRAIL sensitivity.
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Affiliation(s)
- Deepika Raman
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Patricia Tay
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Dan Liu
- Integrated Science and Engineering Program (ISEP), NUS Graduate School, National University of Singapore, Singapore
| | - Shazib Pervaiz
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Cancer Science Institute, National University of Singapore, Singapore; NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore; National University Cancer Institute, National University Health System, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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7
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Combination of 5-aminosalicylic acid and hyperthermia synergistically enhances apoptotic cell death in HSC-3 cells due to intracellular nitric oxide/peroxynitrite generation. Cancer Lett 2019; 451:58-67. [DOI: 10.1016/j.canlet.2019.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/19/2019] [Accepted: 03/01/2019] [Indexed: 01/01/2023]
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8
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Li XM, Luo XG, He JF, Wang N, Zhou H, Yang PL, Zhang TC. Induction of apoptosis in human cervical carcinoma HeLa cells by active compounds from Hypericum ascyron L. Oncol Lett 2018; 15:3944-3950. [PMID: 29556280 DOI: 10.3892/ol.2018.7812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 11/21/2017] [Indexed: 12/16/2022] Open
Abstract
Hypericum ascyron L. (Great St. Johnswort), which belongs to the Hypericaceae family, has been used for the treatment of hematemesis, metrorrhagia, rheumatism, swelling, stomach ache, abscesses, dysentery and irregular menstruation for >2,000 years in China. The aim of the present study was to clarify the anticancer activity compounds from H. ascyron L. and the underlying molecular mechanism. Anticancer activity of H. ascyron L. extract was evaluated using an MTT assay. To confirm the anticancer mechanism of activity compounds, Hoechst 33258, Annexin V-fluorescein isothiocyanate/propidium iodide, 2',7'-dichlorodihydrofluorescein diacetate, rhodamine 123 staining and caspase-3 activity analysis were performed. The results demonstrated that the anti-proliferative action of the mixture of kaempferol 3-O-β-(2″-acetyl) galactopyranoside (K) and quercetin (Q) (molar ratio, 1:1) was significantly increased compared with either of these two compounds separately, and the active fraction of the H. ascyron L. extract |(HALE). HALE, indicating that the anti-proliferative function of H. ascyron L. may be a synergic effect of K and Q. Furthermore, the inhibitory effect of KQ on the growth of HeLa cells was mediated by the induction of apoptosis. To the best of our knowledge, the present study is the first to identify that KQ exhibits significant anti-proliferation activity on HeLa cells via the apoptotic pathway, and is also the first to evaluate the anticancer potential of H. ascyron L. The results of the present study may provide a rational base for the use of H. ascyron L. in the clinic, and shed light on the development of novel anticancer drugs.
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Affiliation(s)
- Xiu-Mei Li
- Key Laboratory for Feed Biotechnology of The Ministry of Agriculture, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Xue-Gang Luo
- Key Laboratory of Industrial Fermentation Microbiology of The Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, Hebei 300457, P.R. China
| | - Jun-Fang He
- Key Laboratory of Industrial Fermentation Microbiology of The Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, Hebei 300457, P.R. China
| | - Nan Wang
- Key Laboratory of Industrial Fermentation Microbiology of The Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, Hebei 300457, P.R. China
| | - Hao Zhou
- Key Laboratory of Industrial Fermentation Microbiology of The Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, Hebei 300457, P.R. China
| | - Pei-Long Yang
- Key Laboratory for Feed Biotechnology of The Ministry of Agriculture, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Tong-Cun Zhang
- Key Laboratory of Industrial Fermentation Microbiology of The Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, Hebei 300457, P.R. China.,Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, Hubei 430000, P.R. China
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9
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Katow H, Kanaya T, Ogawa T, Egawa R, Yawo H. Regulation of axon arborization pattern in the developing chick ciliary ganglion: Possible involvement of caspase 3. Dev Growth Differ 2017; 59:115-128. [PMID: 28430358 DOI: 10.1111/dgd.12346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 03/01/2017] [Accepted: 03/05/2017] [Indexed: 12/30/2022]
Abstract
During a certain critical period in the development of the central and peripheral nervous systems, axonal branches and synapses are massively reorganized to form mature connections. In this process, neurons search their appropriate targets, expanding and/or retracting their axons. Recent work suggested that the caspase superfamily regulates the axon morphology. Here, we tested the hypothesis that caspase 3, which is one of the major executioners in apoptotic cell death, is involved in regulating the axon arborization. The embryonic chicken ciliary ganglion was used as a model system of synapse reorganization. A dominant negative mutant of caspase-3 precursor (C3DN) was made and overexpressed in presynaptic neurons in the midbrain to interfere with the intrinsic caspase-3 activity using an in ovo electroporation method. The axon arborization pattern was 3-dimensionally and quantitatively analyzed in the ciliary ganglion. The overexpression of C3DN significantly reduced the number of branching points, the branch order and the complexity index, whereas it significantly elongated the terminal branches at E6. It also increased the internodal distance significantly at E8. But, these effects were negligible at E10 or later. During E6-8, there appeared to be a dynamic balance in the axon arborization pattern between the "targeting" mode, which is accompanied by elongation of terminal branches and the pruning of collateral branches, and the "pathfinding" mode, which is accompanied by the retraction of terminal branches and the sprouting of new collateral branches. The local and transient activation of caspase 3 could direct the balance towards the pathfinding mode.
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Affiliation(s)
- Hidetaka Katow
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Teppei Kanaya
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Tomohisa Ogawa
- Department of Biomolecular Sciences, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Ryo Egawa
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Hiromu Yawo
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan.,Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
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Stephan M, Edelmann B, Winoto-Morbach S, Janssen O, Bertsch U, Perrotta C, Schütze S, Fritsch J. Role of caspases in CD95-induced biphasic activation of acid sphingomyelinase. Oncotarget 2017; 8:20067-20085. [PMID: 28223543 PMCID: PMC5386744 DOI: 10.18632/oncotarget.15379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 01/24/2017] [Indexed: 12/04/2022] Open
Abstract
Acid sphingomyelinase (A-SMase) plays an important role in the initiation of CD95 signaling by forming ceramide-enriched membrane domains that enable clustering and activation of the death receptors. In TNF-R1 and TRAIL-R1/R2 signaling, A-SMase also contributes to the lysosomal apoptosis pathway triggered by receptor internalization. Here, we investigated the molecular mechanism of CD95-mediated A-SMase activation, demonstrating that A-SMase is located in internalized CD95-receptosomes and is activated by the CD95/CD95L complex in a biphasic manner.Since several caspases have been described to be involved in the activation of A-SMase, we evaluated expression levels of caspase-8, caspase-7 and caspase-3 in CD95-receptosomes. The occurrence of cleaved caspase-8 correlated with the first peak of A-SMase activity and translocation of the A-SMase to the cell surface which could be blocked by the caspase-8 inhibitor IETD.Inhibition of CD95-internalization selectively reduced the second phase of A-SMase activity, suggesting a fusion between internalized CD95-receptosomes and an intracellular vesicular pool of A-SMase. Further analysis demonstrated that caspase-7 activity correlates with the second phase of the A-SMase activity, whereas active caspase-3 is present at early and late internalization time points. Blocking caspases-7/ -3 by DEVD reduced the second phase of A-SMase activation in CD95-receptosomes suggesting the potential role of caspase-7 or -3 for late A-SMase activation.In summary, we describe a biphasic A-SMase activation in CD95-receptosomes indicating (I.) a caspase-8 dependent translocation of A-SMase to plasma membrane and (II.) a caspase-7 and/or -3 dependent fusion of internalized CD95-receptosomes with intracellular A-SMase-containing vesicles.
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Affiliation(s)
- Mario Stephan
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Bärbel Edelmann
- Department of Hematology and Oncology, University Hospital Magdeburg, Magdeburg, Germany
| | | | - Ottmar Janssen
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Uwe Bertsch
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Cristiana Perrotta
- Department of Biomedical and Clinical Sciences “Luigi Sacco” (DIBIC), Università degli Studi di Milano, Milano, Italy
| | - Stefan Schütze
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Jürgen Fritsch
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
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11
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Volpe E, Sambucci M, Battistini L, Borsellino G. Fas-Fas Ligand: Checkpoint of T Cell Functions in Multiple Sclerosis. Front Immunol 2016; 7:382. [PMID: 27729910 PMCID: PMC5037862 DOI: 10.3389/fimmu.2016.00382] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/13/2016] [Indexed: 12/30/2022] Open
Abstract
Fas and Fas Ligand (FasL) are two molecules involved in the regulation of cell death. Their interaction leads to apoptosis of thymocytes that fail to rearrange correctly their T cell receptor (TCR) genes and of those that recognize self-antigens, a process called negative selection; moreover, Fas–FasL interaction leads to activation-induced cell death, a form of apoptosis induced by repeated TCR stimulation, responsible for the peripheral deletion of activated T cells. Both control mechanisms are particularly relevant in the context of autoimmune diseases, such as multiple sclerosis (MS), where T cells exert an immune response against self-antigens. This concept is well demonstrated by the development of autoimmune diseases in mice and humans with defects in Fas or FasL. In recent years, several new aspects of T cell functions in MS have been elucidated, such as the pathogenic role of T helper (Th) 17 cells and the protective role of T regulatory (Treg) cells. Thus, in this review, we summarize the role of the Fas–FasL pathway, with particular focus on its involvement in MS. We then discuss recent advances concerning the role of Fas–FasL in regulating Th17 and Treg cells’ functions, in the context of MS.
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IL-15 maintains T-cell survival via S-nitrosylation-mediated inhibition of caspase-3. Cell Death Differ 2014; 21:904-14. [PMID: 24510126 DOI: 10.1038/cdd.2014.10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 12/27/2013] [Accepted: 01/08/2014] [Indexed: 12/18/2022] Open
Abstract
Caspase activity is critical for both T-cell survival and death. However, little is known regarding what determines caspase activity in cycling T cells. Interleukin (IL)-2 and IL-15 confer very different susceptibilities to T-cell death. We therefore considered that IL-2 and IL-15 differentially regulate caspase activity to influence T-cell survival. We observed that IL-2-cultured primary murine effector T cells manifested elevated levels of caspase-3 activity compared with IL-15-cultured T cells. T cell receptor (TCR) restimulation further increased caspase activity and induced considerable cell death in IL-2-cultured T cells, but provoked only a minimal increase of caspase activity and cell death in IL-15-cultured T cells. IL-2 sensitization to cell death was caspase-3 mediated. Interestingly, increased active caspase-3 levels with IL-2 were independent of active initiator caspase-8 and caspase-9 that were similar with IL-2 and IL-15. Rather, caspase-3 activity was inhibited by posttranslational S-nitrosylation in IL-15-cultured T cells, but not in the presence of IL-2. This paralleled increased reactive nitrogen and oxygen species with IL-15 and reduced glycolysis. Taken together, these data suggest that the metabolic state conferred by IL-15 inhibits T-cell apoptosis in part by maintaining low levels of active caspase-3 via S-nitrosylation.
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13
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Wang AP, Li X, Zheng Y, Liu BL, Huang G, Yan X, Liu Z, Zhou Z. Thiazolidinediones protect mouse pancreatic β-cells directly from cytokine-induced cytotoxicity through PPARγ-dependent mechanisms. Acta Diabetol 2013; 50:163-73. [PMID: 21153483 DOI: 10.1007/s00592-010-0239-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 11/03/2010] [Indexed: 01/04/2023]
Abstract
Since most of the current studies of thiazolidinediones (TZDs) are only focused on improving glycemic control, increasing insulin sensitivity, and regulating inflammatory states in Type 2 Diabetes, it is still controversial whether TZDs have direct, protective effects on pancreatic β-cells in autoimmune diabetes. Here, we show the protective effects of TZDs on mouse pancreatic β-cell line cells (NIT-1) impaired by exposure to inflammatory cytokines (IL-1β and IFN-γ) and explore the potential mechanisms for this. The apoptosis rate and caspase-3 activity were remarkably increased, and insulin secretion response to glucose was impaired severely by exposure to IL-1β/IFN-γ for 48 h compared to control cells, whereas apoptosis rate and caspase-3 activity were significantly decreased in cells with treatment of rosiglitazone (RGZ) or pioglitazone (PIG), and the capacity for insulin secretion response to glucose was recovered. TZDs protect pancreatic β-cells from cytokine-induced cytotoxicity through PPARγ activation. The protective effects of the TZDs on NIT-1 cells disappeared when PPARγ was blocked with PPARγ-siRNA interference or treatment with GW9662, the PPARγ antagonist. Additionally, the enhancement of PPARγ expression by treatment with TZDs inhibited the expression of caspase 3 in IL-1β/IFN-γ-induced NIT-cells. Also, the inhibition of caspase 3 expression by TZDs was blocked by co-treatment with GW9662 or infection with PPARγ-siRNA. Taken together, our data suggest that TZDs might serve to protect pancreatic β-cells directly from cytokine-induced cytotoxicity through a PPARγ-dependent pathway, and caspase-3 may play an important role in the mechanisms involved.
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Affiliation(s)
- An-ping Wang
- Diabetes Center, Metabolic Syndrome Research Center, Institute of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
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14
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Thai PT, Collins CC, Fortner KA, Koenig A, Hayes SM, Budd RC. Increased caspase activity primes human Lyme arthritis synovial γδ T cells for proliferation and death. Hum Immunol 2011; 72:1168-75. [PMID: 21983117 DOI: 10.1016/j.humimm.2011.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 08/03/2011] [Accepted: 08/25/2011] [Indexed: 01/16/2023]
Abstract
γδ T cells function between the innate and adaptive immune responses, promoting antigen-presenting cell function and manifesting cytolytic activity. Their numbers often increase during infections, such as human immunodeficiency virus, and at sites of chronic inflammation. However, the turnover dynamics of human γδ T cells are poorly understood. Here we observed that despite more rapid proliferation in vitro by human Lyme arthritis synovial γδ T cells of the Vδ1 subset, they have reduced surviving cell numbers compared with αβ T cells because of increased cell death by the γδ T cells. Because caspases are involved in cell proliferation and death, and because signaling is more efficient through T cell receptor (TCR)-γδ than through TCR-αβ, we examined the levels of active caspases during cell cycling and following TCR restimulation. We observed higher overall caspase activity in Borrelia-reactive γδ T cells than in comparable αβ T cells. This was paralleled by greater spontaneous cell death and TCR restimulation-induced cell death of the γδ T cells, which was caspase dependent. Our current findings thus are consistent with a model in which human γδ T cells evolved to function quickly and transiently in an innate fashion.
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MESH Headings
- Caspases/immunology
- Caspases/metabolism
- Cell Communication/immunology
- Cell Death/immunology
- Cell Proliferation
- Cells, Cultured
- Humans
- Immunoprecipitation
- Lyme Disease/immunology
- Lyme Disease/metabolism
- Lyme Disease/pathology
- Lymphocyte Activation
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Signal Transduction/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
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Affiliation(s)
- Phan T Thai
- Vermont Center for Immunology and Infectious Diseases, University of Vermont College of Medicine, Burlington, VT 05405, USA
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15
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Apoptosis modulation as a promising target for treatment of systemic sclerosis. Int J Rheumatol 2011; 2011:495792. [PMID: 21912551 PMCID: PMC3170778 DOI: 10.1155/2011/495792] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 07/06/2011] [Accepted: 07/06/2011] [Indexed: 12/22/2022] Open
Abstract
Diffuse systemic sclerosis (SSc) is a fatal autoimmune disease characterized by an excessive ECM deposition inducing a loss of function of skin and internal organs. Apoptosis is a key mechanism involved in all the stages of the disease: vascular damage, immune dysfunction, and fibrosis. The purpose of this paper is to gather new findings in apoptosis related to SSc, to highlight relations between apoptosis and fibrosis, and to identify new therapeutic targets.
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16
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Kemp CM, Wheeler TL. Effects of manipulation of the caspase system on myofibrillar protein degradation in vitro. J Anim Sci 2011; 89:3262-71. [PMID: 21622882 DOI: 10.2527/jas.2010-3552] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Apoptosis via the intrinsic caspase 9 pathway can be induced by oxidative stressors hydrogen peroxide (H₂O₂) and N-(4 hydroxyphenol) rentinamide (fenretinide), a synthetic retinoid. Accelerated muscle atrophy and proteolysis in muscle-wasting conditions have been linked to oxidative stress and activated protease systems. Therefore, the hypothesis of this study was that proteolysis of myofibrillar proteins could be manipulated through the induction or inhibition of the caspase system. After slaughter, LM and supraspinatus muscles from callipyge (n = 5) and normal (n = 3) lambs were excised, finely diced, and incubated with treatment buffers containing oxidative stressors fenretinide or H₂O₂, recombinant caspase 3, caspase-specific inhibitor N-acetyl-Asp-Glu-Val-Asp-CHO (DEVD), or control solution. Muscle samples were incubated for 1, 2, 7, and 21 d at 4°C. Activation of the initiator caspase, caspase 9, and myofibrillar protein degradation was determined by SDS-PAGE and Western blotting. Results showed that fenretinide, H₂O₂, and recombinant caspase 3 increased (P < 0.05) proteolysis of myofibril proteins, whereas DEVD inhibited degradation (P < 0.05). Proteolysis of myofibrillar proteins increased with incubation time (P < 0.0001), and incubation time × treatment interactions (P < 0.05) indicated that the treatment effects did not all occur at the same rate. This study has shown that manipulation of the caspase system through induction or inhibition of activity can affect degradation of myofibrillar proteins, providing further evidence that the caspase system could be involved in postmortem proteolysis and tenderization. However, these stimulated changes were not sufficient to overcome the lack of proteolysis that is characteristic of muscle from callipyge lambs.
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Affiliation(s)
- C M Kemp
- Roman L. Hruska US Meat Animal Research Center, USDA, ARS, Clay Center, NE 68933-0166, USA
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17
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Caspase-8 and caspase-7 sequentially mediate proteolytic activation of acid sphingomyelinase in TNF-R1 receptosomes. EMBO J 2010; 30:379-94. [PMID: 21157428 DOI: 10.1038/emboj.2010.326] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 11/16/2010] [Indexed: 01/02/2023] Open
Abstract
We previously demonstrated that tumour necrosis factor (TNF)-induced ceramide production by endosomal acid sphingomyelinase (A-SMase) couples to apoptosis signalling via activation of cathepsin D and cleavage of Bid, resulting in caspase-9 and caspase-3 activation. The mechanism of TNF-mediated A-SMase activation within the endolysosomal compartment is poorly defined. Here, we show that TNF-induced A-SMase activation depends on functional caspase-8 and caspase-7 expression. The active forms of all three enzymes, caspase-8, caspase-7 and A-SMase, but not caspase-3, colocalize in internalized TNF receptosomes. While caspase-8 and caspase-3 are unable to induce activation of purified pro-A-SMase, we found that caspase-7 mediates A-SMase activation by direct interaction resulting in proteolytic cleavage of the 72-kDa pro-A-SMase zymogen at the non-canonical cleavage site after aspartate 253, generating an active 57 kDa A-SMase molecule. Caspase-7 down modulation revealed the functional link between caspase-7 and A-SMase, confirming proteolytic cleavage as one further mode of A-SMase activation. Our data suggest a signalling cascade within TNF receptosomes involving sequential activation of caspase-8 and caspase-7 for induction of A-SMase activation by proteolytic cleavage of pro-A-SMase.
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Jiang XS, Backlund PS, Wassif CA, Yergey AL, Porter FD. Quantitative proteomics analysis of inborn errors of cholesterol synthesis: identification of altered metabolic pathways in DHCR7 and SC5D deficiency. Mol Cell Proteomics 2010; 9:1461-75. [PMID: 20305089 DOI: 10.1074/mcp.m900548-mcp200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) and lathosterolosis are malformation syndromes with cognitive deficits caused by mutations of 7-dehydrocholesterol reductase (DHCR7) and lathosterol 5-desaturase (SC5D), respectively. DHCR7 encodes the last enzyme in the Kandutsch-Russel cholesterol biosynthetic pathway, and impaired DHCR7 activity leads to a deficiency of cholesterol and an accumulation of 7-dehydrocholesterol. SC5D catalyzes the synthesis of 7-dehydrocholesterol from lathosterol. Impaired SC5D activity leads to a similar deficiency of cholesterol but an accumulation of lathosterol. Although the genetic and biochemical causes underlying both syndromes are known, the pathophysiological processes leading to the developmental defects remain unclear. To study the pathophysiological mechanisms underlying SLOS and lathosterolosis neurological symptoms, we performed quantitative proteomics analysis of SLOS and lathosterolosis mouse brain tissue and identified multiple biological pathways affected in Dhcr7(Delta3-5/Delta3-5) and Sc5d(-/-) E18.5 embryos. These include alterations in mevalonate metabolism, apoptosis, glycolysis, oxidative stress, protein biosynthesis, intracellular trafficking, and cytoskeleton. Comparison of proteome alterations in both Dhcr7(Delta3-5/Delta3-5) and Sc5d(-/-) brain tissues helps elucidate whether perturbed protein expression was due to decreased cholesterol or a toxic effect of sterol precursors. Validation of the proteomics results confirmed increased expression of isoprenoid and cholesterol synthetic enzymes. This alteration of isoprenoid synthesis may underlie the altered posttranslational modification of Rab7, a small GTPase that is functionally dependent on prenylation with geranylgeranyl, that we identified and validated in this study. These data suggested that although cholesterol synthesis is impaired in both Dhcr7(Delta3-5/Delta3-5) and Sc5d(-/-) embryonic brain tissues the synthesis of nonsterol isoprenoids may be increased and thus contribute to SLOS and lathosterolosis pathology. This proteomics study has provided insight into the pathophysiological mechanisms of SLOS and lathosterolosis, and understanding these pathophysiological changes will help guide clinical therapy for SLOS and lathosterolosis.
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Affiliation(s)
- Xiao-Sheng Jiang
- NICHD, National Institutes of Health, United States Department of Health and Human Services, Bethesda, Maryland 20892, USA.
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19
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Ontiveros SJ, Li Q, Jonsson CB. Modulation of apoptosis and immune signaling pathways by the Hantaan virus nucleocapsid protein. Virology 2010; 401:165-78. [PMID: 20227103 DOI: 10.1016/j.virol.2010.02.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 12/12/2009] [Accepted: 02/10/2010] [Indexed: 01/23/2023]
Abstract
Herein, we show a direct relationship between the Hantaan virus (HTNV) nucleocapsid (N) protein and the modulation of apoptosis. We observed an increase in caspase-7 and -8, but not -9 in cells expressing HTNV N protein mutants lacking amino acids 270-330. Similar results were observed for the New World hantavirus, Andes virus. Nuclear factor kappa B (NF-kappaB) was sequestered in the cytoplasm after tumor necrosis factor receptor (TNFR) stimulation in cells expressing HTNV N protein. Further, TNFR stimulated cells expressing HTNV N protein inhibited caspase activation. In contrast, cells expressing N protein truncations lacking the region from amino acids 270-330 were unable to inhibit nuclear import of NF-kappaB and the mutants also triggered caspase activity. These results suggest that the HTNV circumvents host antiviral signaling and apoptotic response mediated by the TNFR pathway through host interactions with the N protein.
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Affiliation(s)
- Steven J Ontiveros
- Graduate Program in Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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20
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The nonsteroidal anti-inflammatory drug indomethacin induces heterogeneity in lipid membranes: potential implication for its diverse biological action. PLoS One 2010; 5:e8811. [PMID: 20098676 PMCID: PMC2809093 DOI: 10.1371/journal.pone.0008811] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/15/2009] [Indexed: 11/19/2022] Open
Abstract
Background The nonsteroidal anti-inflammatory drug (NSAID), indomethacin (Indo), has a large number of divergent biological effects, the molecular mechanism(s) for which have yet to be fully elucidated. Interestingly, Indo is highly amphiphilic and associates strongly with lipid membranes, which influence localization, structure and function of membrane-associating proteins and actively regulate cell signaling events. Thus, it is possible that Indo regulates diverse cell functions by altering micro-environments within the membrane. Here we explored the effect of Indo on the nature of the segregated domains in a mixed model membrane composed of dipalmitoyl phosphatidyl-choline (di16∶0 PC, or DPPC) and dioleoyl phosphatidyl-choline (di18∶1 PC or DOPC) and cholesterol that mimics biomembranes. Methodology/Principal Findings Using a series of fluorescent probes in a fluorescence resonance energy transfer (FRET) study, we found that Indo induced separation between gel domains and fluid domains in the mixed model membrane, possibly by enhancing the formation of gel-phase domains. This effect originated from the ability of Indo to specifically target the ordered domains in the mixed membrane. These findings were further confirmed by measuring the ability of Indo to affect the fluidity-dependent fluorescence quenching and the level of detergent resistance of membranes. Conclusion/Significance Because the tested lipids are the main lipid constituents in cell membranes, the observed formation of gel phase domains induced by Indo potentially occurs in biomembranes. This marked Indo-induced change in phase behavior potentially alters membrane protein functions, which contribute to the wide variety of biological activities of Indo and other NSAIDs.
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21
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Luo P, Lin M, Lin M, Chen Y, Yang B, He Q. Function of retinoid acid receptor alpha and p21 in all-trans-retinoic acid-induced acute T-lymphoblastic leukemia apoptosis. Leuk Lymphoma 2009; 50:1183-9. [PMID: 19557639 DOI: 10.1080/10428190902934936] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
All-trans-retinoic acid (ATRA) is a morphogenetic signalling molecule derived from vitamin A and is used clinically to target acute promyelocytic leukemia by inducing differentiation of immature blood cells. Retinoid signals are mediated by retinoic acid (RA) receptors (RARs) and retinoid X receptors (RXRs). Retinoic acid receptors consist of RARalpha, RARbeta and RARgamma isotypes. Among these components, RARalpha is preferentially bound to ATRA, which is used to treat acute T-lymphoblastic leukemia, yet the conditions and mechanisms remain unknown. In this study, we have demonstrated that, in human acute T-lymphoblastic leukemia Molt3 cells, inhibition of RA-induced proliferation results from massive cell death characterised by apoptosis. The effect of ATRA:RARalpha binding on apoptosis in Molt3 cells has been investigated. Consequently, it has been shown that, in RA-treated Molt3 cells, upregulation of p21 due to RA accompanies caspase 3/PARP activation which precedes the occurrence of apoptosis.
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Affiliation(s)
- Peihua Luo
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People's Republic of China
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22
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Franco R, Sánchez-Olea R, Reyes-Reyes EM, Panayiotidis MI. Environmental toxicity, oxidative stress and apoptosis: ménage à trois. Mutat Res 2008; 674:3-22. [PMID: 19114126 DOI: 10.1016/j.mrgentox.2008.11.012] [Citation(s) in RCA: 350] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 11/27/2008] [Indexed: 12/21/2022]
Abstract
Apoptosis is an evolutionary conserved homeostatic process involved in distinct physiological processes including organ and tissue morphogenesis, development and senescence. Its deregulation is also known to participate in the etiology of several human diseases including cancer, neurodegenerative and autoimmune disorders. Environmental stressors (cytotoxic agents, pollutants or toxicants) are well known to induce apoptotic cell death and to contribute to a variety of pathological conditions. Oxidative stress seems to be the central element in the regulation of the apoptotic pathways triggered by environmental stressors. In this work, we review the established mechanisms by which oxidative stress and environmental stressors regulate the apoptotic machinery with the aim to underscore the relevance of apoptosis as a component in environmental toxicity and human disease progression.
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Affiliation(s)
- Rodrigo Franco
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, P. O. Box 12233, 111. T.W. Alexander Drive, Research Triangle Park, NC 27709, United States.
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23
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Targeting the apoptotic pathway with BCL-2 inhibitors sensitizes primary chronic lymphocytic leukemia cells to vesicular stomatitis virus-induced oncolysis. J Virol 2008; 82:8487-99. [PMID: 18579592 DOI: 10.1128/jvi.00851-08] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Chronic lymphocytic leukemia (CLL) is characterized by clonal accumulation of CD5(+) CD19(+) B lymphocytes that are arrested in the G(0)/G(1) phase of the cell cycle and fail to undergo apoptosis because of overexpression of the antiapoptotic B-cell CLL/lymphoma 2 (BCL-2) protein. Oncolytic viruses, such as vesicular stomatitis virus (VSV), have emerged as potential anticancer agents that selectively target and kill malignant cells via the intrinsic mitochondrial pathway. Although primary CLL cells are largely resistant to VSV oncolysis, we postulated that targeting the apoptotic pathway via inhibition of BCL-2 may sensitize CLL cells to VSV oncolysis. In the present study, we examined the capacity of EM20-25--a small-molecule antagonist of the BCL-2 protein--to overcome CLL resistance to VSV oncolysis. We demonstrate a synergistic effect of the two agents in primary ex vivo CLL cells (combination index of 0.5; P < 0.0001). In a direct comparison of peripheral blood mononuclear cells from healthy volunteers with primary CLL, the two agents combined showed a therapeutic index of 19-fold; furthermore, the combination of VSV and EM20-25 increased apoptotic cell death in Karpas-422 and Granta-519 B-lymphoma cell lines (P < 0.005) via the intrinsic mitochondrial pathway. Mechanistically, EM20-25 blocked the ability of the BCL-2 protein to dimerize with proapoptotic BAX protein, thus sensitizing CLL to VSV oncolytic stress. Together, these data indicate that the use of BCL-2 inhibitors may improve VSV oncolysis in treatment-resistant hematological malignancies, such as CLL, with characterized defects in the apoptotic response.
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24
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Ceramide-induced cell death in malignant cells. Cancer Lett 2008; 264:1-10. [DOI: 10.1016/j.canlet.2008.02.020] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/28/2008] [Accepted: 02/03/2008] [Indexed: 01/18/2023]
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25
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Tang W, Liu Q, Wang X, Wang P, Cao B, Mi N, Zhang J. Involvement of caspase 8 in apoptosis induced by ultrasound-activated hematoporphyrin in sarcoma 180 cells in vitro. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2008; 27:645-656. [PMID: 18359913 DOI: 10.7863/jum.2008.27.4.645] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE Sonodynamic therapy (SDT), a novel and promising cancer therapy that uses a combination of ultrasound and hematoporphyrin, can induce apoptosis in some cancer cells. However, the mechanism(s) of SDT-induced cell apoptosis is not well understood. This study investigated SDT-induced apoptosis in sarcoma 180 cells. METHODS Cell suspension were treated by 1.75-MHz continuous focused ultrasound in the presence of hematoporphyrin for 3 minutes, and apoptosis was assessed by flow cytometry, scanning electron microscopy, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling, confocal microscopy, and apoptosis-related protein analysis. RESULTS DNA breaks, apoptotic bodies, and cleaved poly (adenosine triphosphate-ribose) polymerase were observed 1 hour after SDT. By using laser-scanning confocal microscopy, we found that the Fas-associated death domain and caspase 8 translocated from the cytoplasm to the plasma membrane. Activities of caspase 8 and caspase 3 were detected by an immunohistochemical assay. The results suggested that SDT led to activation of caspase 8, which in turn activated downstream caspase 3. In addition, Z-Ile-Glu-Thr-Asp-fluoromethylketone, a specific inhibitor for caspase 8, was used to confirm the effect of caspase 8 in apoptosis. CONCLUSIONS Our data primarily show that SDT can induce apoptosis in sarcoma 180 cells in vitro, and caspase 8 may play an important role in SDT-induced apoptosis.
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Affiliation(s)
- Wei Tang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
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26
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Conversion of CD95 (Fas) Type II into Type I signaling by sub-lethal doses of cycloheximide. Exp Cell Res 2008; 314:554-63. [PMID: 18078929 DOI: 10.1016/j.yexcr.2007.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 10/11/2007] [Accepted: 11/08/2007] [Indexed: 12/24/2022]
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Mechanisms of enhancement of TRAIL tumoricidal activity against human cancer cells of different origin by dipyridamole. Oncogene 2008; 27:3435-45. [PMID: 18193086 DOI: 10.1038/sj.onc.1211008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has emerged as an attractive cytokine that selectively targets cancer cells, however its efficacy has been challenged by a number of resistance mechanisms. Therefore, the current study investigated the potential of dipyridamole to enhance TRAIL efficacy and the probable underlying mechanisms. Dipyridamole dramatically sensitized p53-mutant human cancer cell lines: SW480, MG63 and DU145, to the antitumor activity of TRAIL, as evidenced by enabling TRAIL to efficiently cleave initiator and executioner caspases. Although dipyridamole upregulated both DR4 and DR5 and increased their cell surface expression, RNA interference revealed a preferential dependence on DR5. Moreover, dipyridamole inhibited survivin expression and its important consequences were confirmed by small interfering RNA. Mechanistically, dipyridamole induced transcriptional shutdown of survivin expression accompanying G(1) arrest that was characterized by downregulation of D-type cyclins and cdk6. In addition, a transcriptional mechanism powered by CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) induction was responsible for DR5 upregulation by dipyridamole. Importantly, dipyridamole-induced enhancement of TRAIL efficacy and alterations of protein expression were independent of either protein kinase A or protein kinase G. In conclusion, findings of the present study described novel mechanisms of dipyridamole action and highlighted its promising use as a potential enhancer of TRAIL efficacy.
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Sharif-Askari E, Gaucher D, Halwani R, Ma J, Jao K, Abdallah A, Haddad EK, Sékaly RP. p56Lck tyrosine kinase enhances the assembly of death-inducing signaling complex during Fas-mediated apoptosis. J Biol Chem 2007; 282:36048-56. [PMID: 17932036 DOI: 10.1074/jbc.m706007200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although the death-inducing signaling complex (DISC) is rapidly assembled, several lines of evidence suggest that formation of this complex is not the first consequence of cell surface CD95 (Fas) stimulation but rather a later step in this process. Activation of Fas triggers a cascade of signaling events that culminate in cellular apoptosis. Tyrosine kinases are critical effectors in T cell activation. However, their functional involvement in death receptor-mediated apoptosis is unknown. Here, we used p56(Lck)-deficient cells to show that CD95-induced cell death is highly dependent on p56(Lck) activity and its localization within plasma membrane. We found that p56(Lck) acts upstream of the mitochondria; in the absence of p56(Lck), Bid cleavage and the release of cytochrome c were severely impaired. Moreover, p56(Lck)-deficient cells or cells expressing an inactive form of p56(Lck) displayed defective formation of the DISC post CD95 stimulation. In vivo reconstitution of thymocytes from p56(lck)-deficient mice, which are resistant to apoptosis, with p56(Lck) restored Fas-mediated cell death. Our results support a novel model whereby sensitivity to apoptosis is regulated through quantitative changes in the stoichiometry of DISC components triggered by p56(Lck) activation and localization.
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Affiliation(s)
- Ehssan Sharif-Askari
- Laboratoire d'Immunologie, Centre de Recherche CHUM Saint-Luc, Montréal H2X 1P1, Canada
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30
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Davis AR, Lotocki G, Marcillo AE, Dietrich WD, Keane RW. FasL, Fas, and death-inducing signaling complex (DISC) proteins are recruited to membrane rafts after spinal cord injury. J Neurotrauma 2007; 24:823-34. [PMID: 17518537 DOI: 10.1089/neu.2006.0227] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The Fas/CD95 receptor-ligand system plays an essential role in apoptosis that contributes to secondary damage after spinal cord injury (SCI), but the mechanism regulating the efficiency of FasL/Fas signaling in the central nervous system (CNS) is unknown. Here, FasL/Fas signaling complexes in membrane rafts were investigated in the spinal cord of adult female Fischer rats subjected to moderate cervical SCI and sham operation controls. In sham-operated animals, a portion of FasL, but not Fas was present in membrane rafts. SCI resulted in FasL and Fas translocation into membrane raft microdomains where Fas associates with the adaptor proteins Fas-associated death domain (FADD), caspase-8, cellular FLIP long form (cFLIPL ), and caspase-3, forming a death-inducing signaling complex (DISC). Moreover, SCI induced expression of Fas in clusters around the nucleus in both neurons and astrocytes. The formation of the DISC signaling platform leads to rapid activation of initiator caspase-8 and effector caspase-3, and the modification of signaling intermediates such as FADD and cFLIP(L) . Thus, FasL/Fas-mediated signaling after SCI is similar to Fas expressing Type I cell apoptosis.
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Affiliation(s)
- Angela R Davis
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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Fernández M, Segura MF, Solé C, Colino A, Comella JX, Ceña V. Lifeguard/neuronal membrane protein 35 regulates Fas ligand-mediated apoptosis in neurons via microdomain recruitment. J Neurochem 2007; 103:190-203. [PMID: 17635665 DOI: 10.1111/j.1471-4159.2007.04767.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fas ligand (FasL)-receptor system plays an essential role in regulating cell death in the developing nervous system, and it has been implicated in neurodegenerative and inflammatory responses in the CNS. Lifeguard (LFG) is a protein highly expressed in the hippocampus and the cerebellum, and it shows a particularly interesting regulation by being up-regulated during postnatal development and in the adult. We show that over-expression of LFG protected cortical neurons from FasL-induced apoptosis and decreased caspase-activation. Reduction of endogenous LFG expression by small interfering RNA sensitized cerebellar granular neurons to FasL-induced cell death and caspase-8 activation, and also increased sensitivity of cortical neurons. In differentiated cerebellar granular neurons, protection from FasL-induced cell death could be attributed exclusively to LFG and appears to be independent of FLICE inhibitor protein. Thus, LFG is an endogenous inhibitor of FasL-mediated neuronal death and it mediates the FasL resistance of CNS differentiated neurons. Finally, we also demonstrate that LFG is detected in lipid rafts microdomains, where it may interact with Fas receptor and regulate FasL-activated signaling pathways.
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Affiliation(s)
- Miriam Fernández
- Unidad Asociada Neurodeath, UCLM-CSIC, Departamento de Ciencias Médicas, Universidad de Castilla-La Mancha, Albacete, Spain
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Misra RS, Russell JQ, Koenig A, Hinshaw-Makepeace JA, Wen R, Wang D, Huo H, Littman DR, Ferch U, Ruland J, Thome M, Budd RC. Caspase-8 and c-FLIPL associate in lipid rafts with NF-kappaB adaptors during T cell activation. J Biol Chem 2007; 282:19365-74. [PMID: 17462996 PMCID: PMC4521413 DOI: 10.1074/jbc.m610610200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Humans and mice lacking functional caspase-8 in T cells manifest a profound immunodeficiency syndrome due to defective T cell antigen receptor (TCR)-induced NF-kappaB signaling and proliferation. It is unknown how caspase-8 is activated following T cell stimulation, and what is the caspase-8 substrate(s) that is necessary to initiate T cell cycling. We observe that following TCR ligation, a small portion of total cellular caspase-8 and c-FLIP(L) rapidly migrate to lipid rafts where they associate in an active caspase complex. Activation of caspase-8 in lipid rafts is followed by rapid cleavage of c-FLIP(L) at a known caspase-8 cleavage site. The active caspase.c-FLIP complex forms in the absence of Fas (CD95/APO1) and associates with the NF-kappaB signaling molecules RIP1, TRAF2, and TRAF6, as well as upstream NF-kappaB regulators PKC theta, CARMA1, Bcl-10, and MALT1, which connect to the TCR. The lack of caspase-8 results in the absence of MALT1 and Bcl-10 in the active caspase complex. Consistent with this observation, inhibition of caspase activity attenuates NF-kappaB activation. The current findings define a link among TCR, caspases, and the NF-kappaB pathway that occurs in a sequestered lipid raft environment in T cells.
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Affiliation(s)
- Ravi S. Misra
- Immunobiology Program, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405-0068
| | - Jennifer Q. Russell
- Immunobiology Program, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405-0068
| | - Andreas Koenig
- Immunobiology Program, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405-0068
| | - Jennifer A. Hinshaw-Makepeace
- Immunobiology Program, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405-0068
| | - Renren Wen
- Blood Research Institute, Department of Microbiology and Molecular Genetics, Blood Center of Wisconsin, Milwaukee, Wisconsin 53201-2178
| | - Demin Wang
- Blood Research Institute, Department of Microbiology and Molecular Genetics, Blood Center of Wisconsin, Milwaukee, Wisconsin 53201-2178
| | - Hairong Huo
- Howard Hughes Medical Institute, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York 10016
| | - Dan R. Littman
- Howard Hughes Medical Institute, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York 10016
| | - Uta Ferch
- Department of Medicine (Hematology/Oncology), Technical University of Munich, Munich, Germany
| | - Jurgen Ruland
- Department of Medicine (Hematology/Oncology), Technical University of Munich, Munich, Germany
| | - Margot Thome
- Institute of Biochemistry, University of Lausanne, BIL Biomedical Research Center, 1066 Epalinges, Switzerland
| | - Ralph C. Budd
- Immunobiology Program, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405-0068
- To whom correspondence should be addressed: Given Medical Bldg., Burlington, VT 05405-0068. Tel.: 802-656-2286; Fax: 802-656-3854;
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Garg H, Joshi A, Freed EO, Blumenthal R. Site-specific mutations in HIV-1 gp41 reveal a correlation between HIV-1-mediated bystander apoptosis and fusion/hemifusion. J Biol Chem 2007; 282:16899-906. [PMID: 17416587 DOI: 10.1074/jbc.m701701200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The loss of CD4(+) T cells in HIV-1 infections is hypothesized to be caused by apoptosis of bystander cells mediated by cell surface-expressed HIV-1 Env glycoprotein. However, the mechanism by which Env mediates this process remains controversial. Specifically, the role of HIV-1 gp120 binding to CD4 and CXCR4 versus the fusion process mediated by gp41 remains unresolved. Env-induced apoptosis in bystander cells has been shown to be gp41-dependent and correlates with the redistribution of membrane lipids between Env-expressing cells and target cells (hemifusion). Using a rational mutagenesis approach aimed at targeting Env function via the gp41 subunit, we examined the role of HIV gp41 in bystander apoptosis. A mutation in the fusion domain of gp41 (V513E) resulted in a fusion-defective Env that failed to induce apoptosis. A mutation in the gp41 N-terminal helix (G547D) reduced cell fusion capacity and apoptosis; conversely, an Env mutant with a deletion of the gp41 cytoplasmic tail (Ct Del) enhanced both cell-to-cell fusion and apoptosis. Most significantly, an Env mutant containing a substitution in the loop region of gp41 (D589L) mediated transfer of lipids (hemifusion) to bystander cells but was defective in cell-to-cell and to a lesser degree virus-to-cell fusion. This mutant was still able to induce apoptosis in bystander cells. Hence, we have provided the first direct evidence that gp41-mediated hemifusion is both required and sufficient for induction of apoptosis in bystander cells. These results may help to explain the mechanism of HIV-1 Env-induced T cell depletion.
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Affiliation(s)
- Himanshu Garg
- Membrane Structure and Function Section, Center for Cancer Research Nanobiology Program, NCI, National Institutes of Health, Frederick, Maryland 21702, USA
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DeMorrow S, Glaser S, Francis H, Venter J, Vaculin B, Vaculin S, Alpini G. Opposing actions of endocannabinoids on cholangiocarcinoma growth: recruitment of Fas and Fas ligand to lipid rafts. J Biol Chem 2007; 282:13098-113. [PMID: 17329257 DOI: 10.1074/jbc.m608238200] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cholangiocarcinomas are devastating cancers of biliary origin with limited treatment options. Modulation of the endocannabinoid system is being targeted to develop possible therapeutic strategies for a number of cancers; therefore, we evaluated the effects of the two major endocannabinoids, anandamide and 2-arachidonylglycerol, on numerous cholangiocarcinoma cell lines. Although anandamide was antiproliferative and proapoptotic, 2-arachidonylglycerol stimulated cholangiocarcinoma cell growth. Specific inhibitors for each of the cannabinoid receptors did not prevent either of these effects nor did pretreatment with pertussis toxin, a G(i/o) protein inhibitor, suggesting that anandamide and 2-arachidonylglycerol did not exert their diametric effects through any known cannabinoid receptor or through any other G(i/o) protein-coupled receptor. Using the lipid raft disruptors methyl-beta-cyclodextrin and filipin, we demonstrated that anandamide, but not 2-arachidonylglycerol, requires lipid raft-mediated events to inhibit cellular proliferation. Closer inspection of the lipid raft structures within the cell membrane revealed that although anandamide treatment had no observable effect 2-arachidonylglycerol treatment effectively dissipated the lipid raft structures and caused the lipid raft-associated proteins lyn and flotillin-1 to disperse into the surrounding membrane. In addition, anandamide, but not 2-arachidonylglycerol, induced an accumulation of ceramide, which was required for anandamide-induced suppression of cell growth. Finally we demonstrated that anandamide and ceramide treatment of cholangiocarcinoma cells recruited Fas and Fas ligand into the lipid rafts, subsequently activating death receptor pathways. These findings suggest that modulation of the endocannabinoid system may be a target for the development of possible therapeutic strategies for the treatment of this devastating cancer.
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Affiliation(s)
- Sharon DeMorrow
- Division of Research and Education, Scott and White Hospital and Texas A&M University System Health Science Center College of Medicine, Temple, Texas 76504, USA
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35
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Szymczyk KH, Freeman TA, Adams CS, Srinivas V, Steinbeck MJ. Active caspase-3 is required for osteoclast differentiation. J Cell Physiol 2007; 209:836-44. [PMID: 16972256 DOI: 10.1002/jcp.20770] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Based on our earlier observation that caspase-3 is present in osteoclasts that are not undergoing apoptosis, we investigated the role of this protein in the differentiation of primary osteoclasts and RAW264.7 cells (Szymczyk KH, et al., 2005, Caspase-3 activity is necessary for RANKL-induced osteoclast differentiation. The Proceedings of the 8th ICCBMT). We noted that osteoclast numbers are decreased in long bones of procaspase-3 knockout mice and that receptor activator of NF-kappaB ligand (RANKL) does not promote differentiation of isolated preosteoclasts. In addition, after treatment with inhibitors of caspase-3 activity, neither the wild-type primary nor the RAW264.7 cells express TRAP or became multinucleated. We found that immediately following RANKL treatment, procaspase-3 is cleaved and the activated protein is localized to lipid regions of the plasma membrane and the cytosol. We developed RAW264.7 procaspase-3 knockdown clonal cell lines using RNAi technology. Again, treatment with RANKL fails to induce TRAP activity or multinucleation. Finally, we evaluated NF-kappaB in procaspase-3 silenced cells. We found that RANKL treatment prevented activation and nuclear translocation of NF-kappaB. Together these findings provide direct support for the hypothesis that caspase-3 activity is required for osteoclast differentiation.
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Affiliation(s)
- K H Szymczyk
- Department of Orthopaedic Surgery, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107, USA
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36
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Stel AJ, Ten Cate B, Jacobs S, Kok JW, Spierings DCJ, Dondorff M, Helfrich W, Kluin-Nelemans HC, de Leij LFMH, Withoff S, Kroesen BJ. Fas Receptor Clustering and Involvement of the Death Receptor Pathway in Rituximab-Mediated Apoptosis with Concomitant Sensitization of Lymphoma B Cells to Fas-Induced Apoptosis. THE JOURNAL OF IMMUNOLOGY 2007; 178:2287-95. [PMID: 17277134 DOI: 10.4049/jimmunol.178.4.2287] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ab binding to CD20 has been shown to induce apoptosis in B cells. In this study, we demonstrate that rituximab sensitizes lymphoma B cells to Fas-induced apoptosis in a caspase-8-dependent manner. To elucidate the mechanism by which Rituximab affects Fas-mediated cell death, we investigated rituximab-induced signaling and apoptosis pathways. Rituximab-induced apoptosis involved the death receptor pathway and proceeded in a caspase-8-dependent manner. Ectopic overexpression of FLIP (the physiological inhibitor of the death receptor pathway) or application of zIETD-fmk (specific inhibitor of caspase-8, the initiator-caspase of the death receptor pathway) both specifically reduced rituximab-induced apoptosis in Ramos B cells. Blocking the death receptor ligands Fas ligand or TRAIL, using neutralizing Abs, did not inhibit apoptosis, implying that a direct death receptor/ligand interaction is not involved in CD20-mediated cell death. Instead, we hypothesized that rituximab-induced apoptosis involves membrane clustering of Fas molecules that leads to formation of the death-inducing signaling complex (DISC) and downstream activation of the death receptor pathway. Indeed, Fas coimmune precipitation experiments showed that, upon CD20-cross-linking, Fas-associated death domain protein (FADD) and caspase-8 were recruited into the DISC. Additionally, rituximab induced CD20 and Fas translocation to raft-like domains on the cell surface. Further analysis revealed that, upon stimulation with rituximab, Fas, caspase-8, and FADD were found in sucrose-gradient raft fractions together with CD20. In conclusion, in this study, we present evidence for the involvement of the death receptor pathway in rituximab-induced apoptosis of Ramos B cells with concomitant sensitization of these cells to Fas-mediated apoptosis via Fas multimerization and recruitment of caspase-8 and FADD to the DISC.
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Affiliation(s)
- Alja J Stel
- University Medical Center Groningen, Department of Pathology and Laboratory Medicine, Section Medical Biology-Laboratory Tumor Immunology, Groningen, The Netherlands
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37
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Larbi A, Muti E, Giacconi R, Mocchegiani E, Fülöp T. Role of lipid rafts in activation-induced cell death: the fas pathway in aging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 584:137-55. [PMID: 16802605 DOI: 10.1007/0-387-34132-3_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Anis Larbi
- Research Center on Aging, Immunological Graduate Programme, Department of Medicine, University of Sherbrooke, Sherbrooke, J1H 4C4, Québec, Canada
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38
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Chakrabandhu K, Hérincs Z, Huault S, Dost B, Peng L, Conchonaud F, Marguet D, He HT, Hueber AO. Palmitoylation is required for efficient Fas cell death signaling. EMBO J 2006; 26:209-20. [PMID: 17159908 PMCID: PMC1782379 DOI: 10.1038/sj.emboj.7601456] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 09/29/2006] [Indexed: 01/28/2023] Open
Abstract
Localization of the death receptor Fas to specialized membrane microdomains is crucial to Fas-mediated cell death signaling. Here, we report that the post-translational modification of Fas by palmitoylation at the membrane proximal cysteine residue in the cytoplasmic region is the targeting signal for Fas localization to lipid rafts, as demonstrated in both cell-free and living cell systems. Palmitoylation is required for the redistribution of Fas to actin cytoskeleton-linked rafts upon Fas stimulation and for the raft-dependent, ezrin-mediated cytoskeleton association, which is necessary for the efficient Fas receptor internalization, death-inducing signaling complex assembly and subsequent caspase cascade leading to cell death.
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Affiliation(s)
- Krittalak Chakrabandhu
- Equipe labelisée La Ligue, Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France
| | - Zoltán Hérincs
- Equipe labelisée La Ligue, Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France
| | - Sébastien Huault
- Equipe labelisée La Ligue, Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France
| | - Britta Dost
- Equipe labelisée La Ligue, Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France
| | - Ling Peng
- CNRS UMR 6114, Département de Chimie, Marseille, France
| | - Fabien Conchonaud
- Centre d'Immunologie de Marseille Luminy, Université de la Méditerranée, Marseille, France
- INSERM, UMR 631, Marseille, France
- CNRS, UMR 6102, Marseille, France
| | - Didier Marguet
- Centre d'Immunologie de Marseille Luminy, Université de la Méditerranée, Marseille, France
- INSERM, UMR 631, Marseille, France
- CNRS, UMR 6102, Marseille, France
| | - Hai-Tao He
- Centre d'Immunologie de Marseille Luminy, Université de la Méditerranée, Marseille, France
- INSERM, UMR 631, Marseille, France
- CNRS, UMR 6102, Marseille, France
| | - Anne-Odile Hueber
- Equipe labelisée La Ligue, Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France
- Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Centre A Lacassagne, 33, Avenue de Valombrose, 06189 Nice, France. Tel.: +33 492 031241; Fax: +33 492 031245; E-mail:
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Bermpohl D, You Z, Korsmeyer SJ, Moskowitz MA, Whalen MJ. Traumatic brain injury in mice deficient in Bid: effects on histopathology and functional outcome. J Cereb Blood Flow Metab 2006; 26:625-33. [PMID: 16395279 DOI: 10.1038/sj.jcbfm.9600258] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bid is a proapoptotic member of the Bcl-2 family that mediates cell death by caspase-dependent and -independent pathways. We tested mice genetically deficient in Bid in a controlled cortical impact (CCI) model to examine the hypothesis that Bid contributes to cell death and functional outcome after traumatic brain injury. After CCI, truncated Bid (15 kDa) was robustly detected in cortical brain homogenates of wild-type mice. Bid-/- mice had decreased numbers of cortical cells with acute plasmalemma injury at 6 h (wild type (WT), 1721+/-124; Bid-/-, 1173+/-129 cells/ x 200 field; P<0.01), decreased numbers of cells expressing cleaved caspase-3 in the dentate gyrus at 48 h (WT, 113+/-15; Bid-/-, 65+/-9 cells/ x 200 field; P<0.05), and reduced lesion volume at 12 days (Bid-/-, 5.9+/-0.4 mm(3); WT, 8.4+/-0.4 mm(3); P<0.001), but did not differ from WT mice at later times after injury regarding lesion size (30 days) or brain tissue atrophy (40 days). Compared with naïve mice, injured mice in both groups performed significantly worse on motor and Morris water maze (MWM) tests; however, mice deficient in Bid did not differ from WT in postinjury motor and MWM performance. The data show that Bid deficiency decreases early posttraumatic brain cell death and tissue damage, but does not reduce functional outcome deficits after CCI in mice.
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Affiliation(s)
- Daniela Bermpohl
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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Dumitru CA, Gulbins E. TRAIL activates acid sphingomyelinase via a redox mechanism and releases ceramide to trigger apoptosis. Oncogene 2006; 25:5612-25. [PMID: 16636669 DOI: 10.1038/sj.onc.1209568] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have previously shown that activation of the acid sphingomyelinase (ASM), the release of ceramide and the formation of ceramide-enriched membrane domains are central for the induction of apoptosis by CD95. Here, we demonstrate that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and CD95 activate the ASM via a redox mechanism resulting in release of ceramide and formation of ceramide-enriched membrane platforms. Ceramide-enriched membrane platforms serve to cluster DR5 upon stimulation. Antioxidants prevent TRAIL-mediated stimulation of ASM, the release of ceramide, the formation of ceramide-enriched membrane platforms and the induction of apoptosis by TRAIL. Further, ASM-deficient splenocytes fail to cluster DR5 in ceramide-enriched membrane domains upon TRAIL stimulation and resist TRAIL-induced apoptosis, events that were restored by addition of natural C(16)-ceramide. A dose-response analysis indicates that ceramide-enriched membrane platforms greatly sensitized tumor cells to TRAIL-induced apoptosis. Our data indicate that ceramide-enriched membrane platforms are required for the signaling of TRAIL-DR5 complexes under physiological conditions.
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Affiliation(s)
- C A Dumitru
- Department of Molecular Biology, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany
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41
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Nachbur U, Kassahn D, Yousefi S, Legler DF, Brunner T. Posttranscriptional regulation of Fas (CD95) ligand killing activity by lipid rafts. Blood 2006; 107:2790-6. [PMID: 16332972 DOI: 10.1182/blood-2005-07-2744] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AbstractFas (CD95/Apo-1) ligand-mediated apoptosis induction of target cells is one of the major effector mechanisms by which cytotoxic lymphocytes (T cells and natural killer cells) kill their target cells. In T cells, Fas ligand expression is tightly regulated at a transcriptional level through the activation of a distinct set of transcription factors. Increasing evidence, however, supports an important role for posttranscriptional regulation of Fas ligand expression and activity. Lipid rafts are cholesterol- and sphingolipid-rich membrane microdomains, critically involved in the regulation of membrane receptor signaling complexes through the clustering and concentration of signaling molecules. Here, we now provide evidence that Fas ligand is constitutively localized in lipid rafts of FasL transfectants and primary T cells. Importantly, disruption of lipid rafts strongly reduces the apoptosis-inducing activity of Fas ligand. Localization to lipid rafts appears to be predominantly mediated by the characteristic cytoplasmic proline-rich domain of Fas ligand because mutations of this domain result in reduced recruitment to lipid rafts and attenuated Fas ligand killing activity. We conclude that Fas ligand clustering in lipid rafts represents an important control mechanism in the regulation of T cell–mediated cytotoxicity.
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Affiliation(s)
- Ueli Nachbur
- Division of Immunopathology, Institute of Pathology, University of Bern, Murtenstr 31, 3010 Bern, Switzerland
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42
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Abstract
Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) induces apoptosis in U-1242 MG cells. To investigate the molecular events involved in this process, we studied the effects of TRAIL on the localization within membrane fractions of molecules critical to the extrinsic apoptotic pathway. We report here that death receptor-5 (DR5), tumor necrosis factor receptor-1 (TNF-R1), and Fas receptor (FasR) are all located in the caveolin-1-enriched membrane fractions, and TRAIL caused the translocation of DR5, FasR, and TNF-R1 to the caveolar fractions. Caspase-8 is mainly located outside of caveolae, but TRAIL caused it to redistribute to the caveolin-1-enriched fractions where it was cleaved. Within 6 hours, the cleaved caspase-8 appeared in the high-density, noncaveolin fractions. Using confocal microscopy, we found that DR5, caspase-8, and caveolin-1 became progressively concentrated in blebs of plasmalemma as they formed in response to TRAIL. Our results provide the first evidence for the caveolar localization of TNF-R1 and DR5 and the coordinated redistribution among membrane fractions of several death receptors in response to TRAIL. We propose that the coordinated movement of these molecules among membrane compartments is probably an important component of the mechanisms regulating and initiating the extrinsic apoptotic pathway in human glioma cells.
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Affiliation(s)
- H E Saqr
- Department of Pathology, The Ohio State University, 4166 Graves Hall, 333 W. 10th Avenue, Columbus, OH 43210, USA
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Gulbins E, Li PL. Physiological and pathophysiological aspects of ceramide. Am J Physiol Regul Integr Comp Physiol 2006; 290:R11-26. [PMID: 16352856 DOI: 10.1152/ajpregu.00416.2005] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Activation of cells by receptor- and nonreceptor-mediated stimuli not only requires a change in the activity of signaling proteins but also requires a reorganization of the topology of the signalosom in the cell. The cell membrane contains distinct domains, rafts that serve the spatial organization of signaling molecules in the cell. Many receptors or stress stimuli transform rafts by the generation of ceramide. These stimuli activate the acid sphingomyelinase and induce a translocation of this enzyme onto the extracellular leaflet of the cell membrane. Surface acid sphingomyelinase generates ceramide that serves to fuse small rafts and to form large ceramide-enriched membrane platforms. These platforms cluster receptor molecules, recruit intracellular signaling molecules to aggregated receptors, and seem to exclude inhibitory signaling factors. Thus ceramide-enriched membrane platforms do not seem to be part of a specific signaling pathway but may facilitate and amplify the specific signaling elicited by the cognate stimulus. This general function may enable these membrane domains to be critically involved in the induction of apoptosis by death receptors and stress stimuli, bacterial and viral infections of mammalian cells, and the regulation of cardiovascular functions.
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Affiliation(s)
- Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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44
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Garg H, Blumenthal R. HIV gp41-induced apoptosis is mediated by caspase-3-dependent mitochondrial depolarization, which is inhibited by HIV protease inhibitor nelfinavir. J Leukoc Biol 2005; 79:351-62. [PMID: 16330530 DOI: 10.1189/jlb.0805430] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Apoptotic loss of CD4+ T cells has been proposed as a mechanism of T cell depletion in human immunodeficiency virus (HIV) infections resulting in immunodeficiency. The Env glycoprotein has been implicated in apoptosis of uninfected bystander cells via gp120 binding to CD4/CXC chemokine receptor 4 as well as the fusion/hemifusion process mediated by gp41. Using an in vitro model of coculture of Env-expressing cells as effectors and CD4+ T cells as targets, we find that apoptosis mediated by Env glycoprotein in bystander cells in fact correlates with gp41-induced hemifusion. Further, the apoptotic pathway initiated by this interaction involves caspase-3-dependent mitochondrial depolarization and reactive oxygen species production. HIV gp41-induced mitochondrial depolarization is inhibited by protease inhibitor nelfinavir but not by other HIV protease inhibitors or inhibitors of calpain and cathepsin. This "kiss of death" (hemifusion) signaling pathway is independent of p38 mitogen-activated protein kinase and p53, making it distinct from the apoptosis seen in syncytia. We also show that virion-induced apoptosis is gp41-dependent. Our findings provide new insights into the mechanism via which HIV gp41 mediates apoptosis in bystander cells.
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Affiliation(s)
- Himanshu Garg
- NCI-Frederick, P.O. Box B, Building 469, Room 152, Miller Drive, Frederick, MD 21702-1201, USA
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Zhang R, Gong J, Wang H, Wang L. Bile salts inhibit growth and induce apoptosis of culture human normal esophageal mucosal epithelial cells. World J Gastroenterol 2005; 11:6466-71. [PMID: 16425417 PMCID: PMC4355787 DOI: 10.3748/wjg.v11.i41.6466] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of six bile salts: glycocholate (GC), glycochenodeoxycholate (GCDC), glycodeoxycholate (GDC), taurocholate (TC), taurochenodeoxycholate (TCDC), taurodeoxycholate (TDC), and their mixture on cultured human normal esophageal mucosal epithelial cells.
METHODS: Human normal esophageal mucosal epithelial cells were cultured with serum-free keratinocyte medium. 3-[4,5-Dimethylthiaolyl]-2,5-diphenyl-tetrazolium bromide assay was applied to the detection of cell proliferation. Apoptotic morphology was observed by phase-contrast video microscopy and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Sub-G1 DNA fragmentations and early apoptotic cells were assayed by flow cytometry (FCM) with propidium iodide (PI) staining and annexin V-FITC conjugated with PI staining. Apoptotic DNA ladders on agarose gel electrophoresis were observed.
RESULTS: Except for GC, GCDC, GDC, TC, TCDC, TDC and their mixture could initiate growth inhibition of esophageal mucosal epithelial cells in a dose- and time-dependent manner. TUNEL and FCM assays demonstrated that the bile salts at 500 μmol/L and their mixture at 1 500 μmol/L induced apoptosis except for GC. The percentage of sub-G1 detected by FCM with PI staining was 83.5% in cells treated with 500 μmol/L TC for 2 h, and 19.8%, 20.4%, 25.6%, 13.5%, and 75.8% in cells treated with 500 μmol/L GCDC, TCDC, GDC, TDC, and 1 500 μmol/L mixture for 24 h, respectively, which were higher than that of the control (1.5%). The percentage was 1.4% in cells with 500 μmol/L GC for 24 h. DNA ladders on agarose gel electrophoresis were seen in cells treated with 500 μmol/L TC for 2 h and 1 500 μmol/L mixture for 24 h.
CONCLUSION: All GCDC, GDC, TC, TCDC, TDC and their mixture can inhibit growth and induce apoptosis of cultured human normal esophageal mucosal epithelial cells, but GC is well tolerated by the cells.
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Affiliation(s)
- Ru Zhang
- Digestive Department of the Second Hospital, Xioan Jiaotong University, Xioan 710004, Shaanxi Province, China
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Bollinger CR, Teichgräber V, Gulbins E. Ceramide-enriched membrane domains. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1746:284-94. [PMID: 16226325 DOI: 10.1016/j.bbamcr.2005.09.001] [Citation(s) in RCA: 256] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 09/05/2005] [Accepted: 09/06/2005] [Indexed: 01/05/2023]
Abstract
Cellular activation involves the re-organization of receptor molecules and the intracellular signalosom in the cell membrane. Recent studies indicate that specialized domains of the cell membrane, termed rafts, are central for the spatial organization of receptors and signaling molecules. Rafts are converted into larger membrane platforms by activity of the acid sphingomyelinase, which hydrolyses raft-sphingomyelin to ceramide. Ceramide molecules spontaneously associate to form ceramide-enriched microdomains, which fuse to large ceramide-enriched membrane platforms. The acid sphingomyelinase is activated by multiple stimuli including CD95, CD40, DR5/TRAIL, CD20, FcgammaRII, CD5, LFA-1, CD28, TNF, the Interleukin-1 receptor, the PAF-receptor, CD14, infection with P. aeruginosa, S. aureus, N. gonorrhoeae, Sindbis-Virus, Rhinovirus, treatment with gamma-irradiation, UV-light, doxorubicin, cisplatin, disruption of integrin-signaling and under some conditions of developmental death. Ceramide-enriched membrane platforms serve the clustering of receptors, the recruitment of intracellular signaling molecules and the exclusion of inhibitory signaling factors and, thus, facilitate signal transduction initiated by the specific stimulus.
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Affiliation(s)
- Claudia R Bollinger
- Department of Molecular Biology, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany
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Zhu J, Xiong L, Yu B, Wu J. Apoptosis Induced by a New Member of Saponin Family Is Mediated through Caspase-8-Dependent Cleavage of Bcl-2. Mol Pharmacol 2005; 68:1831-8. [PMID: 16183855 DOI: 10.1124/mol.105.015826] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OSW-1 is a new member of cholestane saponin family, which is cytotoxic against several types of malignant cells. We reported herein that OSW-1 induced apoptosis of mammalian cells in a concentration- and time-dependent manner. The drug-induced apoptosis was mediated through the mitochondrial pathway, involving the cleavage of Bcl-2. This drug-induced Bcl-2 cleavage in Chinese hamster ovary (CHO) cells could be suppressed either by dominant-negative caspase-8 or by a caspase-8 inhibitor, suggesting that the Bcl-2 cleavage is dependent on caspase-8. In contrast, the Bcl-2 cleavage was independent of caspase-3 activity. The inhibition of caspase-8 activity also resulted in the reduction of apoptotic cells, indicating that Bcl-2 cleavage induced by caspase-8 promotes the progression of apoptosis. The involvement of the caspase-8 activity in the processes of the OSW-1-induced apoptosis was further examined by using caspase-8-deficient Jurkat T cells. It was found that the caspase-8-deficient cells were resistant to OSW-1-induced Bcl-2 cleavage or apoptosis. Furthermore, the small subunit of caspase-8 was found to interact with Bcl-2 as determined by yeast two-hybrid and coimmunoprecipitation assays. Overexpression of caspase-8 small subunit reduced the cleavage of Bcl-2 and inhibited the apoptosis induced by OSW-1. Taken together, these results demonstrate that OSW-1 is capable of inducing apoptosis in mammalian cells, in which the caspase-8-dependent cleavage of Bcl-2 plays an important role.
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Affiliation(s)
- Jianbei Zhu
- Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road., Shanghai 200031, China
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Zhang R, Gong J, Wang H, Wang L. Bile salts inhibit growth and induce apoptosis of human esophageal cancer cell line. World J Gastroenterol 2005; 11:5109-16. [PMID: 16127738 PMCID: PMC4320381 DOI: 10.3748/wjg.v11.i33.5109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the effect of six bile salts, including glycoc-holate (GC), glycochenodeoxycholate (GCDC), glycodeoxy-cholate (GDC), taurocholate (TC), taurochenodeoxycholate (TCDC), taurodeoxycholate (TDC), and two bile acids including cholic acid (CA) and deoxycholic acid (DCA) on esophageal cancer Eca109 cell line.
METHODS: Eca109 cells were exposed to six bile salts, two bile acids and the mixed bile salts at different concentrations for 24-72 h. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Apoptotic morphology was observed by phase-contrast video microscopy and deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Sub-G1 DNA fragmentations and early apoptosis cells were assayed by flow cytometry (FCM) with propidium iodide (PI) staining and annexin V-FITC conjugated with PI staining. Apoptosis DNA ladders on agarose were observed. Activation of caspase-3 was assayed by FCM with FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody and expressions of Bcl-2 and Bax proteins were examined immunocytochemically in 500 μmol/L-TC-induced apoptosis cells.
RESULTS: Five bile salts except for GC, and two bile acids and the mixed bile salts could initiate growth inhibition of Eca109 cells in a dose- and time-dependent manner. TUNEL, FCM, and DNA ladder assays all demonstrated apoptosis induced by bile salts and bile acids at 500 μmol/L, except for GC. Early apoptosis cell percentages in Eca109 cells treated with GCDC, GDC, TC, TCDC, TDC, CA at 500 μmol/L for 12 h, DCA at 500 μmol/L for 6 h, and mixed bile salts at 1 000 μmol/L for 12 h were 7.5%, 8.7%, 14.8%, 8.9%, 7.8%, 9.3%, 22.6% and 12.5%, respectively, all were significantly higher than that in control (1.9%). About 22% of the cell population treated with TC at 500 μmol/L for 24 h had detectable active caspase-3, and were higher than that in the control (1%). Immunocytochemical assay suggested that TC down-regulated Bcl-2 protein level and up-regulated Bax protein level.
CONCLUSION: GCDC, GDC, TC, TCDC, TDC, CA and DCA, except for GC, can inhibit growth and induce apoptosis of esophageal cancer Eca109 cells. Activation of caspase-3, decreased Bcl-2 protein and increased Bax protein are involved in TC-induced apoptosis of Eca109 cells.
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Affiliation(s)
- Ru Zhang
- Digestive Department of the Second Hospital, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
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49
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Cohen LY, Bourbonnière M, Sabbagh L, Bouchard A, Chew T, Jeannequin P, Lazure C, Sékaly RP. Notch1 antiapoptotic activity is abrogated by caspase cleavage in dying T lymphocytes. Cell Death Differ 2005; 12:243-54. [PMID: 15650752 DOI: 10.1038/sj.cdd.4401568] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Excessive signaling via the Notch1 receptor inhibits apoptosis in T lymphocytes. Since several antiapoptotic proteins are cleaved by caspases during cell death, we investigated whether Notch1 was a caspase substrate. Results demonstrate that the intracellular domain of Notch1 (NICD) is cleaved into six fragments during apoptosis in Jurkat cells or peripheral T lymphocytes. Notch1 cleavage is prevented by the caspase inhibitors DEVD-fmk and VEID-fmk or by Bcl-2 expression. Caspase-3 and caspase-6 cleave the NICD into six fragments using sites located within the NF-kappaB binding domain, the ankyrin repeats and the transactivation domain. Notch1 cleavage correlates with the loss of HES-1 expression in apoptotic T cells. Notch1 fragments cannot inhibit activation-induced cell death in a T-cell hybridoma, confirming the abrogation of Notch1 antiapoptotic activity by caspases. The ability of the NICD but not the fragments to antagonize Nur77 activity supports a role for this factor in Notch1 antiapoptotic function.
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Affiliation(s)
- L Y Cohen
- Laboratoire d'Immunologie, CR-CHUM, campus St-Luc, Pavillon Edouard-Asselin, 264 Bd. René Lévesque E., Montréal, Québec, Canada H2X 1P1.
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50
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Henkler F, Behrle E, Dennehy KM, Wicovsky A, Peters N, Warnke C, Pfizenmaier K, Wajant H. The extracellular domains of FasL and Fas are sufficient for the formation of supramolecular FasL-Fas clusters of high stability. ACTA ACUST UNITED AC 2005; 168:1087-98. [PMID: 15795317 PMCID: PMC2171833 DOI: 10.1083/jcb.200501048] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using fluorescent variants of Fas and FasL, we show that membrane FasL and Fas form supramolecular clusters that are of flexible shape, but nevertheless stable and persistent. Membrane FasL-induced Fas clusters were formed in caspase-8- or FADD-deficient cells or when a cytoplasmic deletion mutant of Fas was used suggesting that cluster formation is independent of the assembly of the cytoplasmic Fas signaling complex and downstream activated signaling pathways. In contrast, cross-linked soluble FasL failed to aggregate the cytoplasmic deletion mutant of Fas, but still induced aggregation of signaling competent full-length Fas. Moreover, membrane FasL-induced Fas cluster formation occurred in the presence of the lipid raft destabilizing component methyl-beta-cyclodextrin, whereas Fas aggregation by soluble FasL was blocked. Together, these data suggest that the extracellular domains of Fas and FasL alone are sufficient to drive membrane FasL-induced formation of supramolecular Fas-FasL complexes, whereas soluble FasL-induced Fas aggregation is dependent on lipid rafts and mechanisms associated with the intracellular domain of Fas.
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Affiliation(s)
- Frank Henkler
- Department of Molecular Internal Medicine, Medical Polyclinic, University of Wuerzburg, 97070 Wuerzburg, Germany
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