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Juilland M, Alouche N, Ubezzi I, Gonzalez M, Rashid HO, Scarpellino L, Erdmann T, Grau M, Lenz G, Luther SA, Thome M. Identification of Tensin-3 as a MALT1 substrate that controls B cell adhesion and lymphoma dissemination. Proc Natl Acad Sci U S A 2023; 120:e2301155120. [PMID: 38109544 PMCID: PMC10756297 DOI: 10.1073/pnas.2301155120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 10/24/2023] [Indexed: 12/20/2023] Open
Abstract
The protease MALT1 promotes lymphocyte activation and lymphomagenesis by cleaving a limited set of cellular substrates, most of which control gene expression. Here, we identified the integrin-binding scaffold protein Tensin-3 as a MALT1 substrate in activated human B cells. Activated B cells lacking Tensin-3 showed decreased integrin-dependent adhesion but exhibited comparable NF-κB1 and Jun N-terminal kinase transcriptional responses. Cells expressing a noncleavable form of Tensin-3, on the other hand, showed increased adhesion. To test the role of Tensin-3 cleavage in vivo, mice expressing a noncleavable version of Tensin-3 were generated, which showed a partial reduction in the T cell-dependent B cell response. Interestingly, human diffuse large B cell lymphomas and mantle cell lymphomas with constitutive MALT1 activity showed strong constitutive Tensin-3 cleavage and a decrease in uncleaved Tensin-3 levels. Moreover, silencing of Tensin-3 expression in MALT1-driven lymphoma promoted dissemination of xenografted lymphoma cells to the bone marrow and spleen. Thus, MALT1-dependent Tensin-3 cleavage reveals a unique aspect of the function of MALT1, which negatively regulates integrin-dependent B cell adhesion and facilitates metastatic spread of B cell lymphomas.
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Affiliation(s)
- Mélanie Juilland
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Nagham Alouche
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Ivana Ubezzi
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Montserrat Gonzalez
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Harun-Or Rashid
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Leonardo Scarpellino
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Tabea Erdmann
- Department of Medicine A for Hematology, Oncology and Pneumology, University Hospital Münster, MünsterD-48149, Germany
| | - Michael Grau
- Department of Medicine A for Hematology, Oncology and Pneumology, University Hospital Münster, MünsterD-48149, Germany
| | - Georg Lenz
- Department of Medicine A for Hematology, Oncology and Pneumology, University Hospital Münster, MünsterD-48149, Germany
| | - Sanjiv A. Luther
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
| | - Margot Thome
- Department of Immunobiology, University of Lausanne, EpalingesCH-1066, Switzerland
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2
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Ohta K, Ito M, Chida T, Nakashima K, Sakai S, Kanegae Y, Kawasaki H, Aoshima T, Takabayashi S, Takahashi H, Kawata K, Shoji I, Sawasaki T, Suda T, Suzuki T. Role of hepcidin upregulation and proteolytic cleavage of ferroportin 1 in hepatitis C virus-induced iron accumulation. PLoS Pathog 2023; 19:e1011591. [PMID: 37585449 PMCID: PMC10461841 DOI: 10.1371/journal.ppat.1011591] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/28/2023] [Accepted: 07/31/2023] [Indexed: 08/18/2023] Open
Abstract
Hepatitis C virus (HCV) is a pathogen characterized not only by its persistent infection leading to the development of cirrhosis and hepatocellular carcinoma (HCC), but also by metabolic disorders such as lipid and iron dysregulation. Elevated iron load is commonly observed in the livers of patients with chronic hepatitis C, and hepatic iron overload is a highly profibrogenic and carcinogenic factor that increases the risk of HCC. However, the underlying mechanisms of elevated iron accumulation in HCV-infected livers remain to be fully elucidated. Here, we observed iron accumulation in cells and liver tissues under HCV infection and in mice expressing viral proteins from recombinant adenoviruses. We established two molecular mechanisms that contribute to increased iron load in cells caused by HCV infection. One is the transcriptional induction of hepcidin, the key hormone for modulating iron homeostasis. The transcription factor cAMP-responsive element-binding protein hepatocyte specific (CREBH), which was activated by HCV infection, not only directly recognizes the hepcidin promoter but also induces bone morphogenetic protein 6 (BMP6) expression, resulting in an activated BMP-SMAD pathway that enhances hepcidin promoter activity. The other is post-translational regulation of the iron-exporting membrane protein ferroportin 1 (FPN1), which is cleaved between residues Cys284 and Ala285 in the intracytoplasmic loop region of the central portion mediated by HCV NS3-4A serine protease. We propose that host transcriptional activation triggered by endoplasmic reticulum stress and FPN1 cleavage by viral protease work in concert to impair iron efflux, leading to iron accumulation in HCV-infected cells.
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Affiliation(s)
- Kazuyoshi Ohta
- 2nd Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
- Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Masahiko Ito
- Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Takeshi Chida
- Department of Regional Medical Care Support, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Kenji Nakashima
- Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Satoshi Sakai
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Yumi Kanegae
- Core Research Facilities, Research Center for Medical Sciences, The Jikei University School of Medicine, Tokyo, Japan
| | - Hideya Kawasaki
- Institute for NanoSuit Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Takuya Aoshima
- Laboratory Animal Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Shuji Takabayashi
- Laboratory Animal Facilities & Services, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Hirotaka Takahashi
- Division of Cell-Free Science, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Kazuhito Kawata
- 2nd Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Ikuo Shoji
- Division of Infectious Disease Control, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Tatsuya Sawasaki
- Division of Cell-Free Science, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Takafumi Suda
- 2nd Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Tetsuro Suzuki
- Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
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3
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Mylonas R, Potts A, Waridel P, Barblan J, Conde Rubio MDC, Widmann C, Quadroni M. A Database of Accurate Electrophoretic Migration Patterns for Human Proteins. J Mol Biol 2023; 435:167933. [PMID: 36581244 DOI: 10.1016/j.jmb.2022.167933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/27/2022]
Abstract
Native molecular weight (MW) is one of the defining features of proteins. Denaturing gel electrophoresis (SDS-PAGE) is a very popular technique for separating proteins and determining their MW. Coupled with antibody-based detection, SDS-PAGE is widely applied for protein identification and quantitation. Yet, electrophoresis is poorly reproducible and the MWs obtained are often inaccurate. This hampers antibody validation and negatively impacts the reliability of western blot data, resulting worldwide in a considerable waste of reagents and labour. We argue that, to alleviate these problems there is a need to establish a database of reference MWs measured by SDS-PAGE. Using mass spectrometry as an orthogonal detection method, we acquired electrophoretic migration patterns for approximately 10'000 human proteins in five commonly used cell lines. We applied a robust internal calibration of migration to determine accurate and reproducible molecular weights. This in turn allows merging replicates to increase accuracy, but also enables comparing different cell lines. Mining of the data obtained highlights structural factors that affect migration of distinct classes of proteins. When combined with peptide coverage, the data produced recapitulates known post-translational modifications and differential splicing and can be used to formulate hypotheses on new or poorly known processing events. The full information is freely accessible as a web resource through a user friendly graphical interface (https://pumba.dcsr.unil.ch/). We anticipate that this database will be useful to investigators worldwide for troubleshooting western blot experiments, but could also contribute to the characterization of human proteoforms.
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Affiliation(s)
- Roman Mylonas
- Protein Analysis Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Alexandra Potts
- Protein Analysis Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Patrice Waridel
- Protein Analysis Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Jachen Barblan
- Protein Analysis Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Maria Del Carmen Conde Rubio
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Christian Widmann
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Manfredo Quadroni
- Protein Analysis Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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4
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ROS as Regulators of Cellular Processes in Melanoma. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:1208690. [PMID: 34725562 PMCID: PMC8557056 DOI: 10.1155/2021/1208690] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/28/2021] [Indexed: 12/16/2022]
Abstract
In this review, we examine the multiple roles of ROS in the pathogenesis of melanoma, focusing on signal transduction and regulation of gene expression. In recent years, different studies have analyzed the dual role of ROS in regulating the redox system, with both negative and positive consequences on human health, depending on cell concentration of these agents. High ROS levels can result from an altered balance between oxidant generation and intracellular antioxidant activity and can produce harmful effects. In contrast, low amounts of ROS are considered beneficial, since they trigger signaling pathways involved in physiological activities and programmed cell death, with protective effects against melanoma. Here, we examine these beneficial roles, which could have interesting implications in melanoma treatment.
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5
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Conde-Rubio MDC, Mylonas R, Widmann C. The proteolytic landscape of cells exposed to non-lethal stresses is shaped by executioner caspases. Cell Death Discov 2021; 7:164. [PMID: 34226511 PMCID: PMC8257705 DOI: 10.1038/s41420-021-00539-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/26/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
Cells are in constant adaptation to environmental changes to insure their proper functioning. When exposed to stresses, cells activate specific pathways to elicit adaptive modifications. Those changes can be mediated by selective modulation of gene and protein expression as well as by post-translational modifications, such as phosphorylation and proteolytic processing. Protein cleavage, as a controlled and limited post-translational modification, is involved in diverse physiological processes such as the maintenance of protein homeostasis, activation of repair pathways, apoptosis and the regulation of proliferation. Here we assessed by quantitative proteomics the proteolytic landscape in two cell lines subjected to low cisplatin concentrations used as a mild non-lethal stress paradigm. This landscape was compared to the one obtained in the same cells stimulated with cisplatin concentrations inducing apoptosis. These analyses were performed in wild-type cells and in cells lacking the two main executioner caspases: caspase-3 and caspase-7. Ninety-two proteins were found to be cleaved at one or a few sites (discrete cleavage) in low stress conditions compared to four hundred and fifty-three in apoptotic cells. Many of the cleaved proteins in stressed cells were also found to be cleaved in apoptotic conditions. As expected, ~90% of the cleavage events were dependent on caspase-3/caspase-7 in apoptotic cells. Strikingly, upon exposure to non-lethal stresses, no discrete cleavage was detected in cells lacking caspase-3 and caspase-7. This indicates that the proteolytic landscape in stressed viable cells fully depends on the activity of executioner caspases. These results suggest that the so-called executioner caspases fulfill important stress adaptive responses distinct from their role in apoptosis. Mass spectrometry data are available via ProteomeXchange with identifier PXD023488.
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Affiliation(s)
| | - Roman Mylonas
- Protein Analysis Facility, University of Lausanne, Génopode, Lausanne, Switzerland.,SIB Swiss Institute of Bioinformatics, Amphipole, Lausanne, Switzerland
| | - Christian Widmann
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, Lausanne, Switzerland.
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6
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Martiáñez-Vendrell X, Kikkert M. Proteomics approaches for the identification of protease substrates during virus infection. Adv Virus Res 2021; 109:135-161. [PMID: 33934826 DOI: 10.1016/bs.aivir.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Proteases precisely and irreversibly catalyze the hydrolysis of peptide bonds, regulating the fate, localization, and activity of many proteins. Consequently, proteolytic activity plays an important role in fundamental cellular processes such as differentiation and migration, immunological and inflammatory reactions, apoptosis and survival. During virus infection, host proteases are involved in several processes, from cell entry to initiation, progression and resolution of inflammation. On the other hand, many viruses encode their own highly specific proteases, responsible for the proteolytic processing of viral proteins, but, at the same time, to cleave host proteins to corrupt antiviral host responses and adjust protein activity to favor viral replication. Traditionally, protease substrate identification has been addressed by means of hypothesis-driven approaches, but recent advances in proteomics have made a toolkit available to uncover the extensive repertoire of host proteins cleaved during infection, either by viral or host proteases. Here, we review the currently available proteomics-based methods that can and have contributed to the systematic and unbiased identification of new protease substrates in the context of virus-host interactions. The role of specific proteases during the course of virus infections will also be highlighted.
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Affiliation(s)
- Xavier Martiáñez-Vendrell
- Molecular Virology Laboratory, Department of Medical Microbiology, LUMC Center for Infectious Diseases (LU-CID), Leiden University Medical Center, Leiden, The Netherlands
| | - Marjolein Kikkert
- Molecular Virology Laboratory, Department of Medical Microbiology, LUMC Center for Infectious Diseases (LU-CID), Leiden University Medical Center, Leiden, The Netherlands.
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7
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Buday K, Conrad M. Emerging roles for non-selenium containing ER-resident glutathione peroxidases in cell signaling and disease. Biol Chem 2020; 402:271-287. [PMID: 33055310 DOI: 10.1515/hsz-2020-0286] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022]
Abstract
Maintenance of cellular redox control is pivotal for normal cellular functions and cell fate decisions including cell death. Among the key cellular redox systems in mammals, the glutathione peroxidase (GPX) family of proteins is the largest conferring multifaceted functions and affecting virtually all cellular processes. The endoplasmic reticulum (ER)-resident GPXs, designated as GPX7 and GPX8, are the most recently added members of this family of enzymes. Recent studies have provided exciting insights how both enzymes support critical processes of the ER including oxidative protein folding, maintenance of ER redox control by eliminating H2O2, and preventing palmitic acid-induced lipotoxicity. Consequently, numerous pathological conditions, such as neurodegeneration, cancer and metabolic diseases have been linked with altered GPX7 and GPX8 expression. Studies in mice have demonstrated that loss of GPX7 leads to increased differentiation of preadipocytes, increased tumorigenesis and shortened lifespan. By contrast, GPX8 deficiency in mice results in enhanced caspase-4/11 activation and increased endotoxic shock in colitis model. With the increasing recognition that both types of enzymes are dysregulated in various tumor entities in man, we deem a review of the emerging roles played by GPX7 and GPX8 in health and disease development timely and appropriate.
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Affiliation(s)
- Katalin Buday
- Institute of Metabolism and Cell Death, Helmholtz Zentrum München, Ingolstädter Landstr. 1, D-85764Neuherberg, Germany
| | - Marcus Conrad
- Institute of Metabolism and Cell Death, Helmholtz Zentrum München, Ingolstädter Landstr. 1, D-85764Neuherberg, Germany.,National Research Medical University, Laboratory of Experimental Oncology, Ostrovityanova 1, 117997Moscow, Russia
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8
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Dultz G, Shimakami T, Schneider M, Murai K, Yamane D, Marion A, Zeitler TM, Stross C, Grimm C, Richter RM, Bäumer K, Yi M, Biondi RM, Zeuzem S, Tampé R, Antes I, Lange CM, Welsch C. Extended interaction networks with HCV protease NS3-4A substrates explain the lack of adaptive capability against protease inhibitors. J Biol Chem 2020; 295:13862-13874. [PMID: 32747444 PMCID: PMC7535904 DOI: 10.1074/jbc.ra120.013898] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/26/2020] [Indexed: 12/20/2022] Open
Abstract
Inhibitors against the NS3-4A protease of hepatitis C virus (HCV) have proven to be useful drugs in the treatment of HCV infection. Although variants have been identified with mutations that confer resistance to these inhibitors, the mutations do not restore replicative fitness and no secondary mutations that rescue fitness have been found. To gain insight into the molecular mechanisms underlying the lack of fitness compensation, we screened known resistance mutations in infectious HCV cell culture with different genomic backgrounds. We observed that the Q41R mutation of NS3-4A efficiently rescues the replicative fitness in cell culture for virus variants containing mutations at NS3-Asp168 To understand how the Q41R mutation rescues activity, we performed protease activity assays complemented by molecular dynamics simulations, which showed that protease-peptide interactions far outside the targeted peptide cleavage sites mediate substrate recognition by NS3-4A and support protease cleavage kinetics. These interactions shed new light on the mechanisms by which NS3-4A cleaves its substrates, viral polyproteins and a prime cellular antiviral adaptor protein, the mitochondrial antiviral signaling protein MAVS. Peptide binding is mediated by an extended hydrogen-bond network in NS3-4A that was effectively optimized for protease-MAVS binding in Asp168 variants with rescued replicative fitness from NS3-Q41R. In the protease harboring NS3-Q41R, the N-terminal cleavage products of MAVS retained high affinity to the active site, rendering the protease susceptible for potential product inhibition. Our findings reveal delicately balanced protease-peptide interactions in viral replication and immune escape that likely restrict the protease adaptive capability and narrow the virus evolutionary space.
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Affiliation(s)
- Georg Dultz
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Tetsuro Shimakami
- Department of Gastroenterology, Kanazawa University Hospital, Kanazawa, Japan
| | - Markus Schneider
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Life Sciences, Technical University Munich, Freising-Weihenstephan, Germany
| | - Kazuhisa Murai
- Department of Gastroenterology, Kanazawa University Hospital, Kanazawa, Japan
| | - Daisuke Yamane
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Antoine Marion
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Life Sciences, Technical University Munich, Freising-Weihenstephan, Germany
| | - Tobias M Zeitler
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Life Sciences, Technical University Munich, Freising-Weihenstephan, Germany
| | - Claudia Stross
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Christian Grimm
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Rebecca M Richter
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Katrin Bäumer
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - MinKyung Yi
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, USA
| | - Ricardo M Biondi
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany; Biomedicine Research Institute of Buenos Aires - CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Stefan Zeuzem
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany; University Center for Infectious Diseases, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter and Cluster of Excellence-Macromolecular Complexes, Goethe University Frankfurt, Frankfurt, Germany
| | - Iris Antes
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Life Sciences, Technical University Munich, Freising-Weihenstephan, Germany
| | - Christian M Lange
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany
| | - Christoph Welsch
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt, Germany; University Center for Infectious Diseases, Goethe University Hospital Frankfurt, Frankfurt, Germany.
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9
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GPx8 Expression in Rat Oocytes, Embryos, and Female Genital Organs During Preimplantation Period of Pregnancy. Int J Mol Sci 2020; 21:ijms21176313. [PMID: 32878231 PMCID: PMC7503774 DOI: 10.3390/ijms21176313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/20/2022] Open
Abstract
This study aimed to detect the presence of glutathione peroxidase 8 (GPx8) in rat during preimplantation period of pregnancy. Females were killed on first (D1), third (D3), and fifth (D5) day of pregnancy. The presence of GPx8 in embryos was detected under the confocal microscope, the presence of GPx8 in genital organs was confirmed immunohistochemically, and the amount of GPx8 was determined using densitometry. We found that GPx8 is dispersed in the cytoplasm of oocytes, while after fertilization, it is concentrated in granules. From 4-cell stage till blastocyst, GPx8 reaction was found in the perinuclear region. In the ovary, GPx8 was seen in granulosa-lutein cells, in plasma of blood vessels, and inside Graafian follicles. In oviduct, GPx8 was detected in the plasma and in the extracellular matrix (ECM). Moreover, epithelial cells of isthmus were positive. In uterus, GPx8 was observed in the uterine glands, in the plasma, and in ECM. On D5, the enzyme disappeared from the uterine glands and appeared in fibroblasts. Densitometry revealed that the highest amount of GPx8 was on D1 and subsequently declined. To our knowledge, this is the first paper describing GPx8 presence in the oocytes, preimplantation embryos, and female genital organs in mammals. Our results improve the understanding of antioxidant enzymes presence during pregnancy in defense against oxidative stress, which is considered to be one of the main causes of infertility.
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10
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The glutathione peroxidase 8 (GPX8)/IL-6/STAT3 axis is essential in maintaining an aggressive breast cancer phenotype. Proc Natl Acad Sci U S A 2020; 117:21420-21431. [PMID: 32817494 DOI: 10.1073/pnas.2010275117] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
One of the emerging hallmarks of cancer illustrates the importance of metabolic reprogramming, necessary to synthesize the building blocks required to fulfill the high demands of rapidly proliferating cells. However, the proliferation-independent instructive role of metabolic enzymes in tumor plasticity is still unclear. Here, we provide evidence that glutathione peroxidase 8 (GPX8), a poorly characterized enzyme that resides in the endoplasmic reticulum, is an essential regulator of tumor aggressiveness. We found that GPX8 expression was induced by the epithelial-mesenchymal transition (EMT) program. Moreover, in breast cancer patients, GPX8 expression significantly correlated with known mesenchymal markers and poor prognosis. Strikingly, GPX8 knockout in mesenchymal-like cells (MDA-MB-231) resulted in an epithelial-like morphology, down-regulation of EMT characteristics, and loss of cancer stemness features. In addition, GPX8 knockout significantly delayed tumor initiation and decreased its growth rate in mice. We found that these GPX8 loss-dependent phenotypes were accompanied by the repression of crucial autocrine factors, in particular, interleukin-6 (IL-6). In these cells, IL-6 bound to the soluble receptor (sIL6R), stimulating the JAK/STAT3 signaling pathway by IL-6 trans-signaling mechanisms, so promoting cancer aggressiveness. We observed that in GPX8 knockout cells, this signaling mechanism was impaired as sIL6R failed to activate the JAK/STAT3 signaling pathway. Altogether, we present the GPX8/IL-6/STAT3 axis as a metabolic-inflammatory pathway that acts as a robust regulator of cancer cell aggressiveness.
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11
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OCIAD1 is a host mitochondrial substrate of the hepatitis C virus NS3-4A protease. PLoS One 2020; 15:e0236447. [PMID: 32697788 PMCID: PMC7375614 DOI: 10.1371/journal.pone.0236447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/06/2020] [Indexed: 12/15/2022] Open
Abstract
The hepatitis C virus (HCV) nonstructural protein 3-4A (NS3-4A) protease is a key component of the viral replication complex and the target of protease inhibitors used in current clinical practice. By cleaving and thereby inactivating selected host factors it also plays a role in the persistence and pathogenesis of hepatitis C. Here, we describe ovarian cancer immunoreactive antigen domain containing protein 1 (OCIAD1) as a novel cellular substrate of the HCV NS3-4A protease. OCIAD1 was identified by quantitative proteomics involving stable isotopic labeling using amino acids in cell culture coupled with mass spectrometry. It is a poorly characterized membrane protein believed to be involved in cancer development. OCIAD1 is cleaved by the NS3-4A protease at Cys 38, close to a predicted transmembrane segment. Cleavage was observed in heterologous expression systems, the replicon and cell culture-derived HCV systems, as well as in liver biopsies from patients with chronic hepatitis C. NS3-4A proteases from diverse hepacivirus species efficiently cleaved OCIAD1. The subcellular localization of OCIAD1 on mitochondria was not altered by NS3-4A-mediated cleavage. Interestingly, OCIAD2, a homolog of OCIAD1 with a cysteine residue in a similar position and identical subcellular localization, was not cleaved by NS3-4A. Domain swapping experiments revealed that the sequence surrounding the cleavage site as well as the predicted transmembrane segment contribute to substrate selectivity. Overexpression as well as knock down and rescue experiments did not affect the HCV life cycle in vitro, raising the possibility that OCIAD1 may be involved in the pathogenesis of hepatitis C in vivo.
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12
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Bosello Travain V, Miotto G, Vučković AM, Cozza G, Roveri A, Toppo S, Ursini F, Venerando R, Zaccarin M, Maiorino M. Lack of glutathione peroxidase-8 in the ER impacts on lipid composition of HeLa cells microsomal membranes. Free Radic Biol Med 2020; 147:80-89. [PMID: 31857233 DOI: 10.1016/j.freeradbiomed.2019.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 01/04/2023]
Abstract
GPx8 is a glutathione peroxidase homolog inserted in the membranes of endoplasmic reticulum (ER), where it seemingly plays a role in controlling redox status by preventing the spill of H2O2. We addressed the impact of GPx8 silencing on the lipidome of microsomal membranes, using stably GPx8-silenced HeLa cells. The two cell lines were clearly separated by Principal Component Analysis (PCA) and Partial Least Square Discriminant analysis (PLS-DA) of lipidome. Considering in detail the individual lipid classes, we observed that unsaturated glycerophospholipids (GPL) decreased, while only in phosphatidylinositols (PI) a substitution of monounsaturated fatty acids (MUFA) for polyunsaturated fatty acids (PUFA) was observed. Among sphingolipids (SL), ceramides (CER) decreased while sphingomyelins (SM) and neutral glycophingolipids (nGSL) increased. Here, in addition, longer chains than in controls in the amide fatty acid were present. The increase up to four folds of the CER (d18:1; c24:0) containing three hexose units, was the most remarkable species increasing in the differential lipidome of siGPx8 cells. Quantitative RT-PCR complied with lipidomic analysis specifically showing an increased expression of: i) acyl-CoA synthetase 5 (ACSL5); ii) CER synthase 2 and 4; iii) CER transporter (CERT); iv) UDP-glucosyl transferase (UDP-GlcT), associated to a decreased expression of UDP-galactosyl transferase (UDP-GalT). A role of the unfolded protein response (UPR) and the spliced form of the transcription factor XBP1 on the transcriptional changes of GPx8 silenced cells was ruled-out. Similarly, also the involvement of Nrf2 and NF-κB. Altogether our results indicate that GPx8-silencing of HeLa yields a membrane depleted by about 24% of polyunsaturated GPL and a corresponding increase of saturated or monounsaturated SM and specific nGSL. This is tentatively interpreted as an adaptive mechanism leading to an increased resistance to radical oxidations. Moreover, the marked shift of fatty acid composition of PI emerges as a possibly relevant issue in respect to the impact of GPx8 on signaling pathways.
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Affiliation(s)
- Valentina Bosello Travain
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Giovanni Miotto
- CRIBI Biotechnology Center, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Ana-Marija Vučković
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Giorgio Cozza
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Antonella Roveri
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Stefano Toppo
- CRIBI Biotechnology Center, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Rina Venerando
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Mattia Zaccarin
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
| | - Matilde Maiorino
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35131, Padova, Italy.
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13
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Abstract
Proteases are key regulators of vital biological processes, such as apoptosis, cell differentiation, viral infection and neurodegeneration. Proteases are tightly regulated, largely because proteolysis is a unique post-translational modification (PTM) that is essentially irreversible. In order to understand the role of proteases in health and disease, the identification of protease substrates is an important step toward our understanding of their biological functions. Classic approaches for the study of proteolysis in complex mixtures employ gel electrophoresis and mass spectrometry. Such approaches typically identify a few protein substrates at a time but often fail to identify specific cleavage site locations. In contrast, modern proteomic methods using enrichment of proteolytic protein fragments can lead to the identification of hundreds of modified peptides with precise cleavage site determination in a single experiment. In this manuscript, we will review recent advances in N-terminomics methods and highlight key studies that have taken advantage of these technologies to advance our understanding of the role of proteases in cellular physiology.
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Affiliation(s)
- Shu Yue Luo
- Department of Biochemistry, University of Alberta, Edmonton, Alberta Canada
| | - Luam Ellen Araya
- Department of Biochemistry, University of Alberta, Edmonton, Alberta Canada
| | - Olivier Julien
- Department of Biochemistry, University of Alberta, Edmonton, Alberta Canada
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14
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Perez S, Gevor M, Davidovich A, Kaspi A, Yamin K, Domovich T, Meirson T, Matityahu A, Brody Y, Stemmer SM, El-Osta A, Haviv I, Onn I, Gal-Tanamy M. Dysregulation of the cohesin subunit RAD21 by Hepatitis C virus mediates host-virus interactions. Nucleic Acids Res 2019; 47:2455-2471. [PMID: 30698808 PMCID: PMC6412124 DOI: 10.1093/nar/gkz052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 12/30/2018] [Accepted: 01/24/2019] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) infection is the leading cause of chronic hepatitis, which often results in liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC). HCV possesses an RNA genome and its replication is confined to the cytoplasm. Yet, infection with HCV leads to global changes in gene expression, and chromosomal instability (CIN) in the host cell. The mechanisms by which the cytoplasmic virus affects these nuclear processes are elusive. Here, we show that HCV modulates the function of the Structural Maintenance of Chromosome (SMC) protein complex, cohesin, which tethers remote regions of chromatin. We demonstrate that infection of hepatoma cells with HCV leads to up regulation of the expression of the RAD21 cohesin subunit and changes cohesin residency on the chromatin. These changes regulate the expression of genes associated with virus-induced pathways. Furthermore, siRNA downregulation of viral-induced RAD21 reduces HCV infection. During mitosis, HCV infection induces hypercondensation of chromosomes and the appearance of multi-centrosomes. We provide evidence that the underlying mechanism involves the viral NS3/4 protease and the cohesin regulator, WAPL. Altogether, our results provide the first evidence that HCV induces changes in gene expression and chromosome structure of infected cells by modulating cohesin.
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Affiliation(s)
- Shira Perez
- Molecular Virology Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- Cancer Personalized Medicine and Diagnostic Genomics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Michael Gevor
- Molecular Virology Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- Chromosome Instability and Dynamics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ateret Davidovich
- Molecular Virology Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Antony Kaspi
- Epigenetics in Human Health and Disease Laboratory, Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
| | - Katreena Yamin
- Chromosome Instability and Dynamics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Tom Domovich
- Molecular Virology Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Tomer Meirson
- Cell Migration and Invasion Laboratory, Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Avi Matityahu
- Chromosome Instability and Dynamics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Yehuda Brody
- The Broad institute of Harvard and MIT, Cambridge, MA, USA
| | - Salomon M Stemmer
- Davidoff Center, Rabin Medical Center, Beilinson Campus, Petach Tikva, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Assam El-Osta
- Epigenetics in Human Health and Disease Laboratory, Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
- Hong Kong Institute of Diabetes and Obesity, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR
| | - Izhak Haviv
- Cancer Personalized Medicine and Diagnostic Genomics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Itay Onn
- Chromosome Instability and Dynamics Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Meital Gal-Tanamy
- Molecular Virology Lab, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
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Morikawa K, Nakamura A, Shimazaki T, Sakamoto N. Safety and efficacy of elbasvir/grazoprevir for the treatment of chronic hepatitis C: current evidence. DRUG DESIGN DEVELOPMENT AND THERAPY 2018; 12:2749-2756. [PMID: 30233138 PMCID: PMC6132225 DOI: 10.2147/dddt.s133697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Treatments for hepatitis C virus (HCV) have advanced greatly, becoming more efficacious with fewer adverse events, due to the availability of direct-acting antiviral agents, which target specific steps in the HCV life cycle. Recently, a combination regimen consisting of the HCV nonstructural protein 5A inhibitor elbasvir (EBR) and the HCV NS3/4A protease inhibitor grazoprevir (GZR) was approved for the treatment of patients with chronic HCV and genotypes (Gts) 1 and 4 in various countries. In Phase III trials, the combination of EBR/GZR (fixed-dose combination table or single agent) for 12 or 16 weeks of treatment with or without ribavirin resulted in a high sustained virological response at 12 weeks in treatment-naïve and treatment-experienced patients with HCV Gt 1a, 1b, 4, or 6, including special populations, such as individuals with advanced chronic kidney disease, HCV-HIV coinfection, and compensated cirrhosis. In this review, we focus on the mode of action, pharmacokinetics, clinical applications, efficacy, and safety profile of EBR/GZR, including special populations who have been considered refractory from the extensive evidence of clinical trials.
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Affiliation(s)
- Kenichi Morikawa
- Department of Gastroenterology and Hepatology, Hokkaido University Faculty of Medicine and Graduate School of Medicine, Sapporo, Japan,
| | - Akihisa Nakamura
- Department of Gastroenterology and Hepatology, Hokkaido University Faculty of Medicine and Graduate School of Medicine, Sapporo, Japan,
| | - Tomoe Shimazaki
- Department of Gastroenterology and Hepatology, Hokkaido University Faculty of Medicine and Graduate School of Medicine, Sapporo, Japan,
| | - Naoya Sakamoto
- Department of Gastroenterology and Hepatology, Hokkaido University Faculty of Medicine and Graduate School of Medicine, Sapporo, Japan,
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16
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Matoušková P, Hanousková B, Skálová L. MicroRNAs as Potential Regulators of Glutathione Peroxidases Expression and Their Role in Obesity and Related Pathologies. Int J Mol Sci 2018; 19:ijms19041199. [PMID: 29662007 PMCID: PMC5979329 DOI: 10.3390/ijms19041199] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 12/19/2022] Open
Abstract
Glutathione peroxidases (GPxs) belong to the eight-member family of phylogenetically related enzymes with different cellular localization, but distinct antioxidant function. Several GPxs are important selenoproteins. Dysregulated GPx expression is connected with severe pathologies, including obesity and diabetes. We performed a comprehensive bioinformatic analysis using the programs miRDB, miRanda, TargetScan, and Diana in the search for hypothetical microRNAs targeting 3′untranslated regions (3´UTR) of GPxs. We cross-referenced the literature for possible intersections between our results and available reports on identified microRNAs, with a special focus on the microRNAs related to oxidative stress, obesity, and related pathologies. We identified many microRNAs with an association with oxidative stress and obesity as putative regulators of GPxs. In particular, miR-185-5p was predicted by a larger number of programs to target six GPxs and thus could play the role as their master regulator. This microRNA was altered by selenium deficiency and can play a role as a feedback control of selenoproteins’ expression. Through the bioinformatics analysis we revealed the potential connection of microRNAs, GPxs, obesity, and other redox imbalance related diseases.
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Affiliation(s)
- Petra Matoušková
- Faculty of Pharmacy, Department of Biochemical Sciences, Charles University, 500 05, Hradec Králové, Czech Republic.
| | - Barbora Hanousková
- Faculty of Pharmacy, Department of Biochemical Sciences, Charles University, 500 05, Hradec Králové, Czech Republic.
| | - Lenka Skálová
- Faculty of Pharmacy, Department of Biochemical Sciences, Charles University, 500 05, Hradec Králové, Czech Republic.
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17
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Oxidative stress, a trigger of hepatitis C and B virus-induced liver carcinogenesis. Oncotarget 2018; 8:3895-3932. [PMID: 27965466 PMCID: PMC5354803 DOI: 10.18632/oncotarget.13904] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022] Open
Abstract
Virally induced liver cancer usually evolves over long periods of time in the context of a strongly oxidative microenvironment, characterized by chronic liver inflammation and regeneration processes. They ultimately lead to oncogenic mutations in many cellular signaling cascades that drive cell growth and proliferation. Oxidative stress, induced by hepatitis viruses, therefore is one of the factors that drives the neoplastic transformation process in the liver. This review summarizes current knowledge on oxidative stress and oxidative stress responses induced by human hepatitis B and C viruses. It focuses on the molecular mechanisms by which these viruses activate cellular enzymes/systems that generate or scavenge reactive oxygen species (ROS) and control cellular redox homeostasis. The impact of an altered cellular redox homeostasis on the initiation and establishment of chronic viral infection, as well as on the course and outcome of liver fibrosis and hepatocarcinogenesis will be discussed The review neither discusses reactive nitrogen species, although their metabolism is interferes with that of ROS, nor antioxidants as potential therapeutic remedies against viral infections, both subjects meriting an independent review.
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18
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Boukadida C, Fritz M, Blumen B, Fogeron ML, Penin F, Martin A. NS2 proteases from hepatitis C virus and related hepaciviruses share composite active sites and previously unrecognized intrinsic proteolytic activities. PLoS Pathog 2018; 14:e1006863. [PMID: 29415072 PMCID: PMC5819835 DOI: 10.1371/journal.ppat.1006863] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 02/20/2018] [Accepted: 01/08/2018] [Indexed: 12/17/2022] Open
Abstract
Over the recent years, several homologues with varying degrees of genetic relatedness to hepatitis C virus (HCV) have been identified in a wide range of mammalian species. HCV infectious life cycle relies on a first critical proteolytic event of its single polyprotein, which is carried out by nonstructural protein 2 (NS2) and allows replicase assembly and genome replication. In this study, we characterized and evaluated the conservation of the proteolytic mode of action and regulatory mechanisms of NS2 across HCV and animal hepaciviruses. We first demonstrated that NS2 from equine, bat, rodent, New and Old World primate hepaciviruses also are cysteine proteases. Using tagged viral protein precursors and catalytic triad mutants, NS2 of equine NPHV and simian GBV-B, which are the most closely and distantly related viruses to HCV, respectively, were shown to function, like HCV NS2 as dimeric proteases with two composite active sites. Consistent with the reported essential role for NS3 N-terminal domain (NS3N) as HCV NS2 protease cofactor via NS3N key hydrophobic surface patch, we showed by gain/loss of function mutagenesis studies that some heterologous hepacivirus NS3N may act as cofactors for HCV NS2 provided that HCV-like hydrophobic residues are conserved. Unprecedently, however, we also observed efficient intrinsic proteolytic activity of NS2 protease in the absence of NS3 moiety in the context of C-terminal tag fusions via flexible linkers both in transiently transfected cells for all hepaciviruses studied and in the context of HCV dicistronic full-length genomes. These findings suggest that NS3N acts as a regulatory rather than essential cofactor for hepacivirus NS2 protease. Overall, unique features of NS2 including enzymatic function as dimers with two composite active sites and additional NS3-independent proteolytic activity are conserved across hepaciviruses regardless of their genetic distances, highlighting their functional significance in hepacivirus life cycle. Despite remarkable progress in the development of therapeutic options, more than 70 million individuals are chronically infected by hepatitis C virus (HCV) worldwide and major challenges in basic and translational research remain. Phylogenetically-related HCV homologues have recently been identified in the wild in several mammalian species, whose host restriction and potential for zoonosis remain largely unknown. We comparatively characterized the functions and properties of nonstructural proteins 2 (NS2) from several animal hepaciviruses and HCV. We demonstrated that NS2 from animal hepaciviruses, like HCV NS2, are cysteine proteases, which function as dimers with two composite active sites to ensure a key proteolytic event of the single viral polyprotein at the NS2/NS3 junction. In addition to the activation of HCV NS2 protease by NS3 N-terminal domain, our data revealed a novel NS3-independent substrate specificity and efficient intrinsic proteolytic activity of NS2. The conservation of its properties and peculiar mode of action among distantly related hepaciviruses supports an important regulatory role for NS2 protein in the life cycle of these viruses. It also strengthens the value of animal, notably rodent hepaciviruses for the development of surrogate, immunocompetent models of HCV infection to address HCV-associated pathogenesis and vaccine strategies.
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Affiliation(s)
- Célia Boukadida
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Matthieu Fritz
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Brigitte Blumen
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Marie-Laure Fogeron
- Institut de Biologie et Chimie des Protéines, Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, Lyon, France
| | - François Penin
- Institut de Biologie et Chimie des Protéines, Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, Lyon, France
| | - Annette Martin
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
- * E-mail:
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19
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Mehmeti I, Lortz S, Avezov E, Jörns A, Lenzen S. ER-resident antioxidative GPx7 and GPx8 enzyme isoforms protect insulin-secreting INS-1E β-cells against lipotoxicity by improving the ER antioxidative capacity. Free Radic Biol Med 2017; 112:121-130. [PMID: 28751022 DOI: 10.1016/j.freeradbiomed.2017.07.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/20/2017] [Accepted: 07/22/2017] [Indexed: 12/16/2022]
Abstract
Increased circulating levels of saturated fatty acids (FFAs) and glucose are considered to be major mediators of β-cell dysfunction and death in T2DM. Although it has been proposed that endoplasmic reticulum (ER) and oxidative stress play a crucial role in gluco/lipotoxicity, their interplay and relative contribution to β-cell dysfunction and apoptosis has not been fully elucidated. In addition it is still unclear how palmitate - the physiologically most abundant long-chain saturated FFA - elicits ER stress and which immediate signals commit β-cells to apoptosis. To study the underlying mechanisms of palmitate-mediated ER stress and β-cell toxicity, we exploited the observation that the recently described ER-resident GPx7 and GPx8 are not expressed in rat β-cells. Expression of GPx7 or GPx8 attenuated FFAs-mediated H2O2 generation, ER stress, and apoptosis induction. These results could be confirmed by a H2O2-specific inactivating ER catalase, indicating that accumulation of H2O2 in the ER lumen is critical in FFA-induced ER stress. Furthermore, neither the expression of GPx7 nor of GPx8 increased insulin content or facilitated disulfide bond formation in insulin-secreting INS-1E cells. Hence, reduction of H2O2 by ER-GPx isoforms is not rate-limiting in oxidative protein folding in rat β-cells. These data suggest that FFA-mediated ER stress is partially dependent on oxidative stress and selective expression of GPx7 or GPx8 improves the ER antioxidative capacity of rat β-cells without compromising insulin production and the oxidative protein folding machinery.
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Affiliation(s)
- Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Stephan Lortz
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Edward Avezov
- University of Cambridge, Cambridge Institute for Medical Research, the Wellcome Trust MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0XY, United Kingdom
| | - Anne Jörns
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Sigurd Lenzen
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany; Institute of Experimental Diabetes Research, Hannover Medical School, Hannover, Germany.
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20
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Yoboue ED, Rimessi A, Anelli T, Pinton P, Sitia R. Regulation of Calcium Fluxes by GPX8, a Type-II Transmembrane Peroxidase Enriched at the Mitochondria-Associated Endoplasmic Reticulum Membrane. Antioxid Redox Signal 2017; 27:583-595. [PMID: 28129698 DOI: 10.1089/ars.2016.6866] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
UNLABELLED Glutathione peroxidases (GPXs) are enzymes that are present in almost all organisms with the primary function of limiting peroxide accumulation. In mammals, two of the eight members (GPX7 and GPX8) reside in the endoplasmic reticulum (ER). A peculiar feature of GPX8 is the concomitant presence of a conserved N-terminal transmembrane domain (TMD) and a C-terminal KDEL-like motif for ER localization. AIMS Investigating whether and how GPX8 impacts Ca2+ homeostasis and signaling. RESULTS We show that GPX8 is enriched in mitochondria-associated membranes and regulates Ca2+ storage and fluxes. Its levels correlate with [Ca2+]ER, and cytosolic and mitochondrial Ca2+ fluxes. GPX7, which lacks a TMD, does not share these properties. Deleting or replacing the GPX8 TMD with an unrelated N-terminal membrane integration sequence abolishes all effects on Ca2+ fluxes, whereas appending the GPX8 TMD to GPX7 transfers the Ca2+-regulating properties. Innovation and Conclusion: The notion that the TMD of GPX8, in addition to its enzymatic activity, is essential for regulating Ca2+ dynamics reveals a novel level of integration between redox-related proteins and Ca2+ signaling/homeostasis. Antioxid. Redox Signal. 27, 583-595.
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Affiliation(s)
- Edgar Djaha Yoboue
- 1 Protein Transport and Secretion Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele , Milan, Italy
| | - Alessandro Rimessi
- 2 Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara, Italy
| | - Tiziana Anelli
- 1 Protein Transport and Secretion Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele , Milan, Italy .,3 Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
| | - Paolo Pinton
- 2 Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara, Italy
| | - Roberto Sitia
- 1 Protein Transport and Secretion Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele , Milan, Italy .,3 Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
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21
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Hepacivirus NS3/4A Proteases Interfere with MAVS Signaling in both Their Cognate Animal Hosts and Humans: Implications for Zoonotic Transmission. J Virol 2016; 90:10670-10681. [PMID: 27654291 DOI: 10.1128/jvi.01634-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022] Open
Abstract
Multiple novel members of the genus Hepacivirus have recently been discovered in diverse mammalian species. However, to date, their replication mechanisms and zoonotic potential have not been explored in detail. The NS3/4A serine protease of hepatitis C virus (HCV) is critical for cleavage of the viral polyprotein. It also cleaves the cellular innate immune adaptor MAVS, thus decreasing interferon (IFN) production and contributing to HCV persistence in the human host. To investigate the conservation of fundamental aspects of the hepaciviral life cycle, we explored if MAVS cleavage and suppression of innate immune signaling represent a common mechanism employed across different clades of the genus Hepacivirus to enhance viral replication. To estimate the zoonotic potential of these nonhuman hepaciviruses, we assessed if their NS3/4A proteases were capable of cleaving human MAVS. NS3/4A proteases of viruses infecting colobus monkeys, rodents, horses, and cows cleaved the MAVS proteins of their cognate hosts and interfered with the ability of MAVS to induce the IFN-β promoter. All NS3/4A proteases from nonhuman viruses readily cleaved human MAVS. Thus, NS3/4A-dependent cleavage of MAVS is a conserved replication strategy across multiple clades within the genus Hepacivirus Human MAVS is susceptible to cleavage by these nonhuman viral proteases, indicating that it does not pose a barrier for zoonotic transmission of these viruses to humans. IMPORTANCE Virus infection is recognized by cellular sensor proteins triggering innate immune signaling and antiviral defenses. While viruses have evolved strategies to thwart these antiviral programs in their cognate host species, these evasion mechanisms are often ineffective in a novel host, thus limiting viral transmission across species. HCV, the best-characterized member of the genus Hepacivirus within the family Flaviviridae, uses its NS3/4A protease to disrupt innate immune signaling by cleaving the cellular adaptor protein MAVS. Recently, a large number of HCV-related viruses have been discovered in various animal species, including wild, livestock, and companion animals. We show that the NS3/4A proteases of these hepaciviruses from different animals and representing various clades of the genus cleave their cognate host MAVS proteins in addition to human MAVS. Therefore, cleavage of MAVS is a common strategy of hepaciviruses, and human MAVS is likely unable to limit replication of these nonhuman viruses upon zoonotic exposure.
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22
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Tsukuda Y, Suda G, Tsunematsu S, Ito J, Sato F, Terashita K, Nakai M, Sho T, Maehara O, Shimazaki T, Kimura M, Morikawa K, Natsuizaka M, Ogawa K, Ohnishi S, Chuma M, Sakamoto N. Anti-adipogenic and antiviral effects of l-carnitine on hepatitis C virus infection. J Med Virol 2016; 89:857-866. [PMID: 27664407 DOI: 10.1002/jmv.24692] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2016] [Indexed: 12/11/2022]
Abstract
Hepatitis C virus (HCV) has been reported to hijack fatty acid metabolism in infected hepatocytes, taking advantage of lipid droplets for virus assembly. In this study, we analyzed the anti-HCV activity of l-carnitine, a substance involved in the transport of fatty acids into mitochondria. JFH-1 or HCV replicon-transfected Huh7.5.1 cells were treated with or without l-carnitine to examine its anti-HCV effects. The effects of l-carnitine on HCV entry, HCV-induced adipogenesis and lipid droplet formation, and HCV-induced oxidative stress were examined. Treatment of JFH-1-infected cells with l-carnitine inhibited HCV propagation in a concentration-dependent manner. In contrast, l-carnitine had no anti-HCV activity in the HCV replicon system, which is lacking viral assembly. In addition, l-carnitine did not affect HCV entry. However, l-carnitine treatment decreased intracellular lipid droplets, which are crucial for HCV assembly in JFH-1-infected cells. The expression level of CPT-1 was decreased in JFH-1-infected cells, and l-carnitine treatment restored this expression. HCV-infected cells exhibited increased production of reactive oxygen species and glutathione oxidation. l-carnitine decreased oxidative stress induced by JFH-1-infection, as shown by glutathione/glutathione disulfide assays and MitoSOX staining. l-carnitine exhibited anti-HCV activity, possibly by inhibiting HCV assembly and through its anti-adipogenic activity in HCV-infected cells. Moreover, l-carnitine has antioxidant properties in HCV-infected hepatocytes. Overall, these results indicated that l-carnitine may be an effective adjunctive agent in antiviral therapies to treat chronic hepatitis C. J. Med. Virol. 89:857-866, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yoko Tsukuda
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Goki Suda
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | | | - Jun Ito
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Fumiyuki Sato
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Katsumi Terashita
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Masato Nakai
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Takuya Sho
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Osamu Maehara
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Tomoe Shimazaki
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Megumi Kimura
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Kenichi Morikawa
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Mitsuteru Natsuizaka
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Koji Ogawa
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Shunsuke Ohnishi
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Makoto Chuma
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Naoya Sakamoto
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
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AIM2 inflammasome is activated by pharmacological disruption of nuclear envelope integrity. Proc Natl Acad Sci U S A 2016; 113:E4671-80. [PMID: 27462105 DOI: 10.1073/pnas.1602419113] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inflammasomes are critical sensors that convey cellular stress and pathogen presence to the immune system by activating inflammatory caspases and cytokines such as IL-1β. The nature of endogenous stress signals that activate inflammasomes remains unclear. Here we show that an inhibitor of the HIV aspartyl protease, Nelfinavir, triggers inflammasome formation and elicits an IL-1R-dependent inflammation in mice. We found that Nelfinavir impaired the maturation of lamin A, a structural component of the nuclear envelope, thereby promoting the release of DNA in the cytosol. Moreover, deficiency of the cytosolic DNA-sensor AIM2 impaired Nelfinavir-mediated inflammasome activation. These findings identify a pharmacologic activator of inflammasome and demonstrate the role of AIM2 in detecting endogenous DNA release upon perturbation of nuclear envelope integrity.
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24
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Wang XY, Yu HZ, Geng L, Xu JP, Yu D, Zhang SZ, Ma Y, Fei DQ. Comparative Transcriptome Analysis of Bombyx mori (Lepidoptera) Larval Midgut Response to BmNPV in Susceptible and Near-Isogenic Resistant Strains. PLoS One 2016; 11:e0155341. [PMID: 27168061 PMCID: PMC4864234 DOI: 10.1371/journal.pone.0155341] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 04/27/2016] [Indexed: 01/04/2023] Open
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the primary pathogens causing severe economic losses in sericulture. However, the molecular mechanism of silkworm resistance to BmNPV remains largely unknown. Here, the recurrent parent P50 (susceptible strain) and the near-isogenic line BC9 (resistance strain) were used in a comparative transcriptome study examining the response to infection with BmNPV. A total of 14,300 unigenes were obtained from two different resistant strains; of these, 869 differentially expressed genes (DEGs) were identified after comparing the four transcriptomes. Many DEGs associated with protein metabolism, cytoskeleton, and apoptosis may be involved in the host response to BmNPV infection. Moreover, some immunity related genes were also altered following BmNPV infection. Specifically, after removing genetic background and individual immune stress response genes, 22 genes were found to be potentially involved in repressing BmNPV infection. These genes were related to transport, virus replication, intracellular innate immune, and apoptosis. Our study provided an overview of the molecular mechanism of silkworm resistance to BmNPV infection and laid a foundation for controlling BmNPV in the future.
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Affiliation(s)
- Xue-Yang Wang
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Hai-Zhong Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Lei Geng
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Jia-Ping Xu
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
- * E-mail:
| | - Dong Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Shang-Zhi Zhang
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Yan Ma
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
| | - Dong-Qiong Fei
- School of Life Sciences, Anhui Agricultural University, Hefei, People’s Republic of China
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25
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Natural HCV variants with increased replicative fitness due to NS3 helicase mutations in the C-terminal helix α18. Sci Rep 2016; 6:19526. [PMID: 26787124 PMCID: PMC4726148 DOI: 10.1038/srep19526] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 12/14/2015] [Indexed: 12/12/2022] Open
Abstract
High replicative fitness is a general determinant of a multidrug resistance phenotype and may explain lower sensitivity to direct-acting antiviral agents (DAAs) in some hepatitis C virus genotypes. Genetic diversity in the molecular target site of peptidomimetic NS3 protease inhibitors could impact variant replicative fitness and potentially add to virologic treatment failure. We selected NS3 helicase residues near the protease natural substrate in the NS3 domain interface and identified natural variants from a public database. Sequence diversity among different genotypes was identified and subsequently analyzed for potential effects of helicase variants on protein structure and function, and phenotypic effects on RNA replication and DAA resistance. We found increased replicative fitness in particular for amino acid substitutions at the NS3 helicase C-terminal helix α18. A network of strongly coupled residue pairs is identified. Helix α18 is part of this regulatory network and connects several NS3 functional elements involved in RNA replication. Among all genotypes we found distinct sequence diversity at helix α18 in particular for the most difficult-to-treat genotype 3. Our data suggest sequence diversity with implications for virus replicative fitness due to natural variants in helicase helix α18.
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26
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Brault C, Lévy P, Duponchel S, Michelet M, Sallé A, Pécheur EI, Plissonnier ML, Parent R, Véricel E, Ivanov AV, Demir M, Steffen HM, Odenthal M, Zoulim F, Bartosch B. Glutathione peroxidase 4 is reversibly induced by HCV to control lipid peroxidation and to increase virion infectivity. Gut 2016; 65:144-54. [PMID: 25516417 DOI: 10.1136/gutjnl-2014-307904] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/19/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Inflammation and oxidative stress drive disease progression in chronic hepatitis C (CHC) towards hepatocellular carcinoma. HCV is known to increase intracellular levels of reactive oxygen species (ROS), but how it eliminates ROS is less well known. The role of the ROS scavenger glutathione peroxidase 4 (GPx4), induced by HCV, in the viral life cycle was analysed. DESIGN The study was performed using a replicative in vitro HCV infection model and liver biopsies derived from two different CHC patient cohorts. RESULTS A screen for HCV-induced peroxide scavengers identified GPx4 as a host factor required for HCV infection. The physiological role of GPx4 is the elimination of lipid peroxides from membranes or lipoproteins. GPx4-silencing reduced the specific infectivity of HCV by up to 10-fold. Loss of infectivity correlated with 70% reduced fusogenic activity of virions in liposome fusion assays. NS5A was identified as the protein that mediates GPx4 induction in a phosphatidylinositol-3-kinase-dependent manner. Levels of GPx4 mRNA were found increased in vitro and in CHC compared with control liver biopsies. Upon successful viral eradication, GPx4 transcript levels returned to baseline in vitro and also in the liver of patients. CONCLUSIONS HCV induces oxidative stress but controls it tightly by inducing ROS scavengers. Among these, GPx4 plays an essential role in the HCV life cycle. Modulating oxidative stress in CHC by specifically targeting GPx4 may lower specific infectivity of virions and prevent hepatocarcinogenesis, especially in patients who remain difficult to be treated in the new era of interferon-free regimens.
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Affiliation(s)
- Charlène Brault
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France
| | - Pierre Lévy
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France
| | - Sarah Duponchel
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France
| | - Maud Michelet
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France
| | - Aurèlie Sallé
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France
| | | | | | - Romain Parent
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France DevWeCan Laboratories of Excellence Network (Labex), France
| | - Evelyne Véricel
- Université de Lyon, UMR 1060 INSERM CarMeN, IMBL, INSA-Lyon, Lyon, France
| | - Alexander V Ivanov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Münevver Demir
- Clinic for Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | - Hans-Michael Steffen
- Clinic for Gastroenterology and Hepatology, University Hospital of Cologne, Cologne, Germany
| | | | - Fabien Zoulim
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France DevWeCan Laboratories of Excellence Network (Labex), France Hospices civils de Lyon, Lyon, France
| | - Birke Bartosch
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, Lyon, France DevWeCan Laboratories of Excellence Network (Labex), France
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27
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Decoding protein networks during virus entry by quantitative proteomics. Virus Res 2015; 218:25-39. [PMID: 26365680 PMCID: PMC4914609 DOI: 10.1016/j.virusres.2015.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/31/2015] [Accepted: 09/08/2015] [Indexed: 01/05/2023]
Abstract
Virus entry into host cells relies on interactions between viral and host structures including lipids, carbohydrates and proteins. Particularly, protein–protein interactions between viral surface proteins and host proteins as well as secondary host protein–protein interactions play a pivotal role in coordinating virus binding and uptake. These interactions are dynamic and frequently involve multiprotein complexes. In the past decade mass spectrometry based proteomics methods have reached sensitivities and high throughput compatibilities of genomics methods and now allow the reliable quantitation of proteins in complex samples from limited material. As proteomics provides essential information on the biologically active entity namely the protein, including its posttranslational modifications and its interactions with other proteins, it is an indispensable method in the virologist's toolbox. Here we review protein interactions during virus entry and compare classical biochemical methods to study entry with novel technically advanced quantitative proteomics techniques. We highlight the value of quantitative proteomics in mapping functional virus entry networks, discuss the benefits and limitations and illustrate how the methodology will help resolve unsettled questions in virus entry research in the future.
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28
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Douam F, Ploss A. Proteomic approaches to analyzing hepatitis C virus biology. Proteomics 2015; 15:2051-65. [PMID: 25809442 PMCID: PMC4559851 DOI: 10.1002/pmic.201500009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/25/2015] [Accepted: 03/19/2015] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV) is a major cause of liver disease worldwide. Acute infection often progresses to chronicity resulting frequently in fibrosis, cirrhosis, and in rare cases, in the development of hepatocellular carcinoma. Although HCV has proven to be an arduous object of research and has raised important technical challenges, several experimental models have been developed all over the last two decades in order to improve our understanding of the virus life cycle, pathogenesis and virus-host interactions. The recent development of direct acting-agents, leading to considerable progress in treatment of patients, represents the direct outcomes of these achievements. Proteomic approaches have been of critical help to shed light on several aspect of the HCV biology such as virion composition, viral replication, and virus assembly and to unveil diagnostic or prognostic markers of HCV-induced liver disease. Here, we review how proteomic approaches have led to improve our understanding of HCV life cycle and liver disease, thus highlighting the relevance of these approaches for studying the complex interactions between other challenging human viral pathogens and their host.
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Affiliation(s)
- Florian Douam
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544
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29
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Maiorino M, Bosello-Travain V, Cozza G, Miotto G, Roveri A, Toppo S, Zaccarin M, Ursini F. Understanding mammalian glutathione peroxidase 7 in the light of its homologs. Free Radic Biol Med 2015; 83:352-60. [PMID: 25724691 DOI: 10.1016/j.freeradbiomed.2015.02.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/09/2015] [Accepted: 02/14/2015] [Indexed: 01/24/2023]
Abstract
The glutathione peroxidase homologs (GPxs) efficiently reduce hydroperoxides using electrons from glutathione (GSH), thioredoxin (Trx), or protein disulfide isomerase (PDI). Trx is preferentially used by the GPxs of the majority of bacteria, invertebrates, plants, and fungi. GSH or PDI, instead, is preferentially used by vertebrate GPxs that operate by Sec or Cys catalysis, respectively. Mammalian GPx7 and GPx8 are unique homologs that contain a peroxidatic Cys (CP). Being reduced by PDI and located within the endoplasmic reticulum (ER), these enzymes have been involved in oxidative protein folding. Kinetic analysis indicates that oxidation of PDI by recombinant GPx7 occurs at a much faster rate than that of GSH. Nonetheless, activity measurement suggests that, at physiological concentrations, a competition between these two substrates takes place, with the rate of PDI oxidation by GPx7 controlled by the concentration of GSH, whereas the GSSG produced in the competing reaction contributes to the ER redox buffer. A mechanism has been proposed for GPx7 involving two Cys residues, in which an intramolecular disulfide of the CP is formed with an alleged resolving Cys (CR) located in the strongly conserved FPCNQ motif (C86 in humans), a noncanonical position in GPxs. Kinetic measurements and comparison with the other thiol peroxidases containing a functional CR suggest that a resolving function of C86 in the catalytic cycle is very unlikely. We propose that GPx7 is catalytically active as a 1-Cys-GPx, in which CP both reduces H2O2 and oxidizes PDI, and that the CP-C86 disulfide has instead the role of stabilizing the oxidized peroxidase in the absence of the reducing substrate.
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Affiliation(s)
- Matilde Maiorino
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy.
| | | | - Giorgio Cozza
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Giovanni Miotto
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Antonella Roveri
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Stefano Toppo
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Mattia Zaccarin
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Fulvio Ursini
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
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30
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Kazakov T, Yang F, Ramanathan HN, Kohlway A, Diamond MS, Lindenbach BD. Hepatitis C virus RNA replication depends on specific cis- and trans-acting activities of viral nonstructural proteins. PLoS Pathog 2015; 11:e1004817. [PMID: 25875808 PMCID: PMC4395149 DOI: 10.1371/journal.ppat.1004817] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/18/2015] [Indexed: 02/07/2023] Open
Abstract
Many positive-strand RNA viruses encode genes that can function in trans, whereas other genes are required in cis for genome replication. The mechanisms underlying trans- and cis-preferences are not fully understood. Here, we evaluate this concept for hepatitis C virus (HCV), an important cause of chronic liver disease and member of the Flaviviridae family. HCV encodes five nonstructural (NS) genes that are required for RNA replication. To date, only two of these genes, NS4B and NS5A, have been trans-complemented, leading to suggestions that other replicase genes work only in cis. We describe a new quantitative system to measure the cis- and trans-requirements for HCV NS gene function in RNA replication and identify several lethal mutations in the NS3, NS4A, NS4B, NS5A, and NS5B genes that can be complemented in trans, alone or in combination, by expressing the NS3-5B polyprotein from a synthetic mRNA. Although NS5B RNA binding and polymerase activities can be supplied in trans, NS5B protein expression was required in cis, indicating that NS5B has a cis-acting role in replicase assembly distinct from its known enzymatic activity. Furthermore, the RNA binding and NTPase activities of the NS3 helicase domain were required in cis, suggesting that these activities play an essential role in RNA template selection. A comprehensive complementation group analysis revealed functional linkages between NS3-4A and NS4B and between NS5B and the upstream NS3-5A genes. Finally, NS5B polymerase activity segregated with a daclatasvir-sensitive NS5A activity, which could explain the synergy of this antiviral compound with nucleoside analogs in patients. Together, these studies define several new aspects of HCV replicase structure-function, help to explain the potency of HCV-specific combination therapies, and provide an experimental framework for the study of cis- and trans-acting activities in positive-strand RNA virus replication more generally.
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Affiliation(s)
- Teymur Kazakov
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Feng Yang
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Harish N. Ramanathan
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Andrew Kohlway
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Michael S. Diamond
- Departments of Medicine, Molecular Microbiology, and Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Brett D. Lindenbach
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
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31
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Bosello-Travain V, Forman HJ, Roveri A, Toppo S, Ursini F, Venerando R, Warnecke C, Zaccarin M, Maiorino M. Glutathione peroxidase 8 is transcriptionally regulated by HIFα and modulates growth factor signaling in HeLa cells. Free Radic Biol Med 2015; 81:58-68. [PMID: 25557012 DOI: 10.1016/j.freeradbiomed.2014.12.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 11/25/2014] [Accepted: 12/21/2014] [Indexed: 01/06/2023]
Abstract
GPx8 is a mammalian Cys-glutathione peroxidase of the endoplasmic reticulum membrane, involved in protein folding. Its regulation is mostly unknown. We addressed both the functionality of two hypoxia-response elements (HREs) within the promoter, GPx8 HRE1 and GPx8 HRE2, and the GPx8 physiological role. In HeLa cells, treatment with HIFα stabilizers, such as diethyl succinate (DES) or 2-2'-bipyridyl (BP), induces GPx8 expression at both mRNA and protein level. Luciferase activity of pGL3(GPx8wt), containing a fragment of the GPx8 promoter including the two HREs, is also induced by DES/BP or by overexpressing either individual HIFα subunit. Mutating GPx8 HRE1 within pGL3(GPx8wt) resulted in a significantly higher inhibition of luciferase activity than mutating GPx8 HRE2. Electrophoretic mobility-shift assay showed that both HREs exhibit enhanced binding to a nuclear extract from DES/BP-treated cells, with stronger binding by GPx8 HRE1. In DES-treated cells transfected with pGL3(GPx8wt) or mutants thereof, silencing of HIF2α, but not HIF1α, abolishes luciferase activity. Thus GPx8 is a novel HIF target preferentially responding to HIF2α binding at its two novel functional GPx8 HREs, with GPx8 HRE1 playing the major role. Fibroblast growth factor (FGF) treatment increases GPx8 mRNA expression, and reporter gene experiments indicate that induction occurs via HIF. Comparing the effects of depleting GPx8 on the downstream effectors of FGF or insulin signaling revealed that absence of GPx8 results in a 16- or 12-fold increase in phosphorylated ERK1/2 by FGF or insulin treatment, respectively. Furthermore, in GPx8-depleted cells, phosphorylation of AKT by insulin treatment increases 2.5-fold. We suggest that induction of GPx8 expression by HIF slows down proliferative signaling during hypoxia and/or growth stimulation through receptor tyrosine kinases.
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Affiliation(s)
| | - Henry J Forman
- Life and Environmental Sciences, University of California at Merced, Merced, CA 95344, USA
| | - Antonella Roveri
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy
| | - Stefano Toppo
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy
| | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy
| | - Rina Venerando
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy
| | - Christina Warnecke
- Department of Nephrology and Hypertension, Translational Research Center, University Hospital Erlangen-Nürnberg, Erlangen, Germany
| | - Mattia Zaccarin
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy
| | - Matilde Maiorino
- Department of Molecular Medicine, University of Padova, I-35121 Padova, Italy.
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32
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Welsch C, Haselow K, Gouttenoire J, Schneider M, Morikawa K, Martinez Y, Susser S, Sarrazin C, Zeuzem S, Antes I, Moradpour D, Lange CM. Hepatitis C virus variants resistant to macrocyclic NS3-4A inhibitors subvert IFN-β induction by efficient MAVS cleavage. J Hepatol 2015; 62:779-84. [PMID: 25463536 DOI: 10.1016/j.jhep.2014.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/12/2014] [Accepted: 11/13/2014] [Indexed: 01/02/2023]
Abstract
BACKGROUND & AIMS The hepatitis C virus (HCV) NS3-4A protease is essential for the HCV life cycle and a prime target of antiviral treatment strategies. Protease inhibitors, however, are limited by emergence of resistance-associated amino acid variants (RAVs). The capacity to cleave and inactivate mitochondrial antiviral-signaling protein (MAVS) in the RIG-I-signaling pathway is a cardinal feature of NS3-4A, by which HCV blocks induction of interferon-(IFN)-β, thereby promoting viral persistence. Here, we aimed to investigate the impact of NS3-4A RAVs on MAVS cleavage. METHODS The impact of NS3-4A RAVs on MAVS cleavage was assessed using immunoblot analyses, luciferase reporter assays and molecular dynamics simulations to study the underlying molecular principles. IFN-β was quantified in serum from patients with different NS3-4A RAVs. RESULTS We show that macrocyclic NS3-4A RAVS with substitutions at residue D168 of the protease result in an increased capacity of NS3-4A to cleave MAVS and suppress IFN-β induction compared with a comprehensive panel of RAVs and wild type HCV. Mechanistically, we show the reconstitution of a tight network of electrostatic interactions between protease and the peptide substrate that allows much stronger binding of MAVS to D168 RAVs than to the wild-type protease. Accordingly, we could show IFN-β serum levels to be lower in patients with treatment failure due to the selection of D168 variants compared to R155 RAVs. CONCLUSIONS Our data constitutes a proof of concept that the selection of RAVs against specific classes of direct antivirals can lead to the predominance of viral variants with possibly adverse pathogenic characteristics.
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Affiliation(s)
- Christoph Welsch
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany; Max-Planck-Institute for Informatics, Computational Biology & Applied Algorithmics, D-66123 Saarbrücken, Germany
| | - Katrin Haselow
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany
| | - Jérôme Gouttenoire
- Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Markus Schneider
- Technical University Munich, Center for Integrated Protein Science Munich (CIPS(M)) and Department of Life Science, D-85354 Freising-Weihenstephan, Germany
| | - Kenichi Morikawa
- Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Yolanda Martinez
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany
| | - Simone Susser
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany
| | - Christoph Sarrazin
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany
| | - Stefan Zeuzem
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany
| | - Iris Antes
- Technical University Munich, Center for Integrated Protein Science Munich (CIPS(M)) and Department of Life Science, D-85354 Freising-Weihenstephan, Germany
| | - Darius Moradpour
- Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Christian M Lange
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, D-60590 Frankfurt a.M., Germany.
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Lange CM, Gouttenoire J, Duong FHT, Morikawa K, Heim MH, Moradpour D. Vitamin D receptor and Jak-STAT signaling crosstalk results in calcitriol-mediated increase of hepatocellular response to IFN-α. THE JOURNAL OF IMMUNOLOGY 2014; 192:6037-44. [PMID: 24821973 DOI: 10.4049/jimmunol.1302296] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent clinical research suggests a role for vitamin D in the response to IFN-α-based therapy of chronic hepatitis C. Therefore, we aimed to explore the underlying mechanisms in vitro. Huh-7.5 cells harboring subgenomic hepatitis C virus (HCV) replicons or infected with cell culture-derived HCV were exposed to bioactive 1,25-dihydroxyvitamin D3 (calcitriol) with or without IFN-α. In these experiments, calcitriol alone had no effect on the HCV life cycle. However, calcitriol enhanced the inhibitory effect of IFN-α on HCV replication. This effect was based on a calcitriol-mediated increase of IFN-α-induced gene expression. Further mechanistic studies revealed a constitutive inhibitory interaction between the inactive vitamin D receptor (VDR) and Stat1, which was released upon stimulation with calcitriol and IFN-α. As a consequence, IFN-α-induced binding of phosphorylated Stat1 to its DNA target sequences was enhanced by calcitriol. Importantly, and in line with these observations, silencing of the VDR resulted in an enhanced hepatocellular response to IFN-α. Our findings identify the VDR as a novel suppressor of IFN-α-induced signaling through the Jak-STAT pathway.
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Affiliation(s)
- Christian M Lange
- Division of Gastroenterology and Hepatology, Vaud University Hospital Center, University of Lausanne, CH-1011 Lausanne, Switzerland; Department of Medicine 1, J.W. Goethe University Hospital, D-60590 Frankfurt, Germany; and
| | - Jérôme Gouttenoire
- Division of Gastroenterology and Hepatology, Vaud University Hospital Center, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - François H T Duong
- Department of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland
| | - Kenichi Morikawa
- Division of Gastroenterology and Hepatology, Vaud University Hospital Center, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Markus H Heim
- Department of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland
| | - Darius Moradpour
- Division of Gastroenterology and Hepatology, Vaud University Hospital Center, University of Lausanne, CH-1011 Lausanne, Switzerland;
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