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Amratia PS, Kerr-Jones LE, Chapman L, Marsden M, Clement M, Stanton RJ, Humphreys IR. Cytomegalovirus-induced peroxynitrite promotes virus entry and contributes to pathogenesis in a murine model of infection. mBio 2024:e0315223. [PMID: 38953361 DOI: 10.1128/mbio.03152-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 06/04/2024] [Indexed: 07/04/2024] Open
Abstract
There are no licensed vaccines for human cytomegalovirus (HCMV), and current antiviral drugs that target viral proteins are toxic and prone to resistance. Targeting host pathways essential for virus replication provides an alternate strategy that may reduce opportunities for drug resistance to occur. Oxidative stress is triggered by numerous viruses including HCMV. Peroxynitrite is a reactive nitrogen species that is formed during oxidative stress. Herein, we identified that HCMV rapidly induces the generation of intracellular peroxynitrite upon infection in a manner partially dependent upon xanthine oxidase generation. Peroxynitrite promoted HCMV infection in both cell-free and cell-associated infection systems in multiple cell types. Inhibiting peroxynitrite within the first 24 hours of infection prevented HCMV replication and peroxynitrite promoted cell entry and pp65 translocation into the host cell nuclei. Furthermore, using the murine cytomegalovirus model, we demonstrated that antagonizing peroxynitrite significantly reduces cytomegalovirus replication and pathogenesis in vivo. Overall, our study highlights a proviral role for peroxynitrite in CMV infection and implies that RNS and/or the mechanisms that induce their production could be targeted as a novel strategy to inhibit HCMV infection. IMPORTANCE Human cytomegalovirus (HCMV) causes significant disease in individuals with impaired or immature immune systems, such as transplant patients and after congenital infection. Antiviral drugs that target the virus directly are toxic and are susceptible to antiviral drug resistance due to virus mutations. An alternate strategy is to target processes within host cells that are required by the virus for replication. Herein, we show that HCMV infection triggers a highly reactive molecule, peroxynitrite, during the initial stages of infection. Peroxynitrite was required for the initial entry of the virus into the cell and promotes virus replication in multiple cell types, suggesting a broad pro-viral function. Importantly, targeting peroxynitrite dramatically inhibited cytomegalovirus replication in cells in the laboratory and in mice, suggesting that therapeutic targeting of this molecule and/or the cellular functions it regulates could represent a novel strategy to inhibit HCMV infection.
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Affiliation(s)
- Pragati S Amratia
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Lauren E Kerr-Jones
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Lucy Chapman
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Morgan Marsden
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Mathew Clement
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Richard J Stanton
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Ian R Humphreys
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff University, Cardiff, United Kingdom
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2
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de Jong IEM, Wells RG. In Utero Extrahepatic Bile Duct Damage and Repair: Implications for Biliary Atresia. Pediatr Dev Pathol 2024:10935266241247479. [PMID: 38762769 DOI: 10.1177/10935266241247479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/20/2024]
Abstract
Biliary atresia (BA) is a cholangiopathy affecting the extrahepatic bile duct (EHBD) of newborns. The etiology and pathophysiology of BA are not fully understood; however, multiple causes of damage and obstruction of the neonatal EHBD have been identified. Initial damage to the EHBD likely occurs before birth. We discuss how different developmental stages in utero and birth itself could influence the susceptibility of the fetal EHBD to damage and a damaging wound-healing response. We propose that a damage-repair response of the fetal and neonatal EHBD involving redox stress and a program of fetal wound healing could-regardless of the cause of the initial damage-lead to either obstruction and BA or repair of the duct and recovery. This overarching concept should guide future research targeted toward identification of factors that contribute to recovery as opposed to progression of injury and fibrosis. Viewing BA through the lens of an in utero damage-repair response could open up new avenues for research and suggests exciting new therapeutic targets.
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Affiliation(s)
- Iris E M de Jong
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Rebecca G Wells
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Engineering MechanoBiology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
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3
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Purandare N, Ghosalkar E, Grossman LI, Aras S. Mitochondrial Oxidative Phosphorylation in Viral Infections. Viruses 2023; 15:2380. [PMID: 38140621 PMCID: PMC10747082 DOI: 10.3390/v15122380] [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: 10/25/2023] [Revised: 11/26/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
Mitochondria have been identified as the "powerhouse" of the cell, generating the cellular energy, ATP, for almost seven decades. Research over time has uncovered a multifaceted role of the mitochondrion in processes such as cellular stress signaling, generating precursor molecules, immune response, and apoptosis to name a few. Dysfunctional mitochondria resulting from a departure in homeostasis results in cellular degeneration. Viruses hijack host cell machinery to facilitate their own replication in the absence of a bonafide replication machinery. Replication being an energy intensive process necessitates regulation of the host cell oxidative phosphorylation occurring at the electron transport chain in the mitochondria to generate energy. Mitochondria, therefore, can be an attractive therapeutic target by limiting energy for viral replication. In this review we focus on the physiology of oxidative phosphorylation and on the limited studies highlighting the regulatory effects viruses induce on the electron transport chain.
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Affiliation(s)
- Neeraja Purandare
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Esha Ghosalkar
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Lawrence I. Grossman
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
| | - Siddhesh Aras
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA; (N.P.); (E.G.); (L.I.G.)
- Department of Obstetrics and Gynecology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
- Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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4
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Carestia A, Godin LC, Jenne CN. Step up to the platelet: Role of platelets in inflammation and infection. Thromb Res 2023; 231:182-194. [PMID: 36307228 DOI: 10.1016/j.thromres.2022.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 11/18/2022]
Abstract
Platelets are anucleated cells derived from megakaryocytes that are primarily responsible for hemostasis. However, in recent years, these cytoplasts have become increasingly recognized as immune cells, able to detect, interact with, and kill pathogens. As platelets are involved in both immunity and coagulation, they have a central role in immunothrombosis, a physiological process in which immune cells induce the formation of microthrombi to both prevent the spread of pathogens, and to help facilitate clearance. In this review, we will highlight the role of platelets as key players in the inflammatory and innate immune response against bacterial and viral infection, including direct and indirect interactions with pathogens and other immune cells.
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Affiliation(s)
- Agostina Carestia
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada.
| | - Laura C Godin
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada.
| | - Craig N Jenne
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada.
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5
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Wu X, Zhou X, Wang S, Mao G. DNA damage response(DDR): a link between cellular senescence and human cytomegalovirus. Virol J 2023; 20:250. [PMID: 37915066 PMCID: PMC10621139 DOI: 10.1186/s12985-023-02203-y] [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: 05/22/2023] [Accepted: 10/04/2023] [Indexed: 11/03/2023] Open
Abstract
The DNA damage response (DDR) is a signaling cascade that is triggered by DNA damage, involving the halting of cell cycle progression and repair. It is a key event leading to senescence, which is characterized by irreversible cell cycle arrest and the senescence-associated secretory phenotype (SASP) that includes the expression of inflammatory cytokines. Human cytomegalovirus (HCMV) is a ubiquitous pathogen that plays an important role in the senescence process. It has been established that DDR is necessary for HCMV to replicate effectively. This paper reviews the relationship between DDR, cellular senescence, and HCMV, providing new sights for virus-induced senescence (VIS).
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Affiliation(s)
- Xinna Wu
- Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310030, China
| | - Xuqiang Zhou
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Sanying Wang
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, China.
| | - Genxiang Mao
- Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310030, China.
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, China.
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6
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Ghosh AK, Su YP, Forman M, Keyes RF, Smith BC, Hu X, Ferrer M, Arav-Boger R. Harnessing the Noncanonical Keap1-Nrf2 Pathway for Human Cytomegalovirus Control. J Virol 2023; 97:e0016023. [PMID: 36939350 PMCID: PMC10134830 DOI: 10.1128/jvi.00160-23] [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: 01/29/2023] [Accepted: 03/02/2023] [Indexed: 03/21/2023] Open
Abstract
Host-derived cellular pathways can provide an unfavorable environment for virus replication. These pathways have been a subject of interest for herpesviruses, including the betaherpesvirus human cytomegalovirus (HCMV). Here, we demonstrate that a compound, ARP101, induces the noncanonical sequestosome 1 (SQSTM1)/p62-Keap1-Nrf2 pathway for HCMV suppression. ARP101 increased the levels of both LC3 II and SQSTM1/p62 and induced phosphorylation of p62 at the C-terminal domain, resulting in its increased affinity for Keap1. ARP101 treatment resulted in Nrf2 stabilization and translocation into the nucleus, binding to specific promoter sites and transcription of antioxidant enzymes under the antioxidant response element (ARE), and HCMV suppression. Knockdown of Nrf2 recovered HCMV replication following ARP101 treatment, indicating the role of the Keap1-Nrf2 axis in HCMV inhibition by ARP101. SQSTM1/p62 phosphorylation was not modulated by the mTOR kinase or casein kinase 1 or 2, indicating ARP101 engages other kinases. Together, the data uncover a novel antiviral strategy for SQSTM1/p62 through the noncanonical Keap1-Nrf2 axis. This pathway could be further exploited, including the identification of the responsible kinases, to define the biological events during HCMV replication. IMPORTANCE Antiviral treatment for human cytomegalovirus (HCMV) is limited and suffers from the selection of drug-resistant viruses. Several cellular pathways have been shown to modulate HCMV replication. The autophagy receptor sequestosome 1 (SQSTM1)/p62 has been reported to interact with several HCMV proteins, particularly with components of HCMV capsid, suggesting it plays a role in viral replication. Here, we report on a new and unexpected role for SQSTM1/p62, in HCMV suppression. Using a small-molecule probe, ARP101, we show SQSTM1/p62 phosphorylation at its C terminus domain initiates the noncanonical Keap1-Nrf2 axis, leading to transcription of genes under the antioxidant response element, resulting in HCMV inhibition in vitro. Our study highlights the dynamic nature of SQSTM1/p62 during HCMV infection and how its phosphorylation activates a new pathway that can be exploited for antiviral intervention.
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Affiliation(s)
- Ayan K. Ghosh
- Department of Pediatrics, Division of Infectious Disease, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Yu-Pin Su
- Department of Pediatrics, Division of Infectious Disease, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Forman
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Robert F. Keyes
- Department of Biochemistry, Program in Chemical Biology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Brian C. Smith
- Department of Biochemistry, Program in Chemical Biology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Xin Hu
- National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, Rockville, Maryland, USA
| | - Marc Ferrer
- National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, Rockville, Maryland, USA
| | - Ravit Arav-Boger
- Department of Pediatrics, Division of Infectious Disease, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Pediatrics, Division of Infectious Disease, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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7
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Chen PH, Hsueh TC, Hong JR. Infectious spleen and kidney necrosis virus induces the reactive oxidative species/Nrf2-mediated oxidative stress response for the regulation of mitochondrion-mediated Bax/Bak cell death signals in GF-1 cells. Front Microbiol 2022; 13:958476. [PMID: 36304944 PMCID: PMC9593061 DOI: 10.3389/fmicb.2022.958476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) infections can trigger host cell death and are correlated with viral replication; however, they have rarely been considered in terms of the host organelle involvement. In the present study, we demonstrated that ISKNV triggered an oxidative stress signal in the Nrf2-mediated oxidative stress response and induced stress signals for Bax/Bak-mediated host cell death in fish GF-1 cells. The results showed that after ISKNV infection, the levels of reactive oxidative species (ROS) increased by 60–80% from day 3 to day 5, as assessed by an H2DCFDA assay for tracing hydrogen peroxide (H2O2), which was correlated with up to a one-fold change in the fish GF-1 cells. Furthermore, we found that ISKNV infection induced Nrf2-mediated ROS stress signals from D1 to D5, which were correlated with the upregulation of antioxidant enzymes, such as catalase, SOD1, and SOD2; these effects were blocked by the antioxidants GSH and NAC. By analyzing Nrf2-mediated ROS stress signals for cell death regulation via an apoptotic assay, we found that treatment with antioxidants reduced annexin-V-positive signals by 10% (GSH) to 15% (NAC); moreover, necrotic-positive signals were reduced by 6% (GSH) and 32% (NAC) at day 5 (D5) in GF-1 cells, as indicated by PI staining. Furthermore, we found that Nrf2-mediated ROS stress regulated mitochondrion-mediated Bax/Bak death signals at D3 and D5; this was effectively blocked by antioxidant treatment in the GF-1 cells, as demonstrated by a JC1 assay (ΔΨm) and western blot analysis. In addition, we found that downstream signals for caspase-9 and -3 activation were apparently blocked by antioxidant treatment at D3 and D5. Finally, we found that treatment with GSH and NAC reduced major capsid protein (MCP) expression and virus titer (TCID50%) by up to 15-fold at D5 in GF-1 cells. Thus, our data suggest that ISKNV can induce ROS production, which triggers Nrf2-mediated stress signals. Then, these stress signals can regulate mitochondrion-mediated Bax/Bak apoptotic signaling, which is connected to downstream caspase-9 and -3 activation. If ISKNV-induced Nrf2-mediated stress signaling is blocked, then the antioxidants GSH and NAC can also suppress apoptotic signals or reduce viral replication. These findings may provide insights into the control and treatment of double-stranded DNA viruses.
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Affiliation(s)
- Pin-Han Chen
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Tsai-Ching Hsueh
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Jiann-Ruey Hong
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- *Correspondence: Jiann-Ruey Hong,
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8
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Bidgood SR, Samolej J, Novy K, Collopy A, Albrecht D, Krause M, Burden JJ, Wollscheid B, Mercer J. Poxviruses package viral redox proteins in lateral bodies and modulate the host oxidative response. PLoS Pathog 2022; 18:e1010614. [PMID: 35834477 PMCID: PMC9282662 DOI: 10.1371/journal.ppat.1010614] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 05/24/2022] [Indexed: 01/23/2023] Open
Abstract
All poxviruses contain a set of proteinaceous structures termed lateral bodies (LB) that deliver viral effector proteins into the host cytosol during virus entry. To date, the spatial proteotype of LBs remains unknown. Using the prototypic poxvirus, vaccinia virus (VACV), we employed a quantitative comparative mass spectrometry strategy to determine the poxvirus LB proteome. We identified a large population of candidate cellular proteins, the majority being mitochondrial, and 15 candidate viral LB proteins. Strikingly, one-third of these are VACV redox proteins whose LB residency could be confirmed using super-resolution microscopy. We show that VACV infection exerts an anti-oxidative effect on host cells and that artificial induction of oxidative stress impacts early and late gene expression as well as virion production. Using targeted repression and/or deletion viruses we found that deletion of individual LB-redox proteins was insufficient for host redox modulation suggesting there may be functional redundancy. In addition to defining the spatial proteotype of VACV LBs, these findings implicate poxvirus redox proteins as potential modulators of host oxidative anti-viral responses and provide a solid starting point for future investigations into the role of LB resident proteins in host immunomodulation.
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Affiliation(s)
- Susanna R. Bidgood
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Jerzy Samolej
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Karel Novy
- Swiss Federal Institute of Technology (ETH Zürich), Department of Health Sciences and Technology (D-HEST), Institute of Translational Medicine (ITM), Zürich, Switzerland
| | - Abigail Collopy
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - David Albrecht
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Melanie Krause
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Jemima J. Burden
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Bernd Wollscheid
- Swiss Federal Institute of Technology (ETH Zürich), Department of Health Sciences and Technology (D-HEST), Institute of Translational Medicine (ITM), Zürich, Switzerland
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Jason Mercer
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
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9
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Kjar A, Wadsworth I, Vargis E, Britt DW. Poloxamer 188 - quercetin formulations amplify in vitro ganciclovir antiviral activity against cytomegalovirus. Antiviral Res 2022; 204:105362. [PMID: 35709898 DOI: 10.1016/j.antiviral.2022.105362] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/28/2022] [Accepted: 06/06/2022] [Indexed: 11/19/2022]
Abstract
Treatment of human cytomegalovirus (CMV) infection requires long-term administration of nucleoside analog antivirals such as ganciclovir (GCV), a therapy frequently limited by GCV-induced toxicity. Here, combining GCV treatment with two bioactive excipients, poloxamer 188 and quercetin, was investigated in vitro to reduce GCV dosage. Quercetin is a natural flavonoid exhibiting antiviral activity against CMV by a mechanism distinct from GCV, but is poorly soluble, limiting its use as a therapeutic. To overcome this challenge, quercetin was co-formulated with poloxamer 188 (P188, Pluronic ® F68). Quercetin-P188 (QP188) formulations yielded only modest CMV viral inhibition, with a selectivity index of 11.4, contrasted with a GCV selectivity index of 95. More significantly, when coadministered with GCV, QP188 exhibited an additive or synergistic interaction in subtherapeutic ranges of GCV. Fluorescence microscopy revealed QP188 accumulation in fibroblast mitochondria, suggesting that the excipient may modulate mitochondrial processes relevant to CMV infection. GCV antiviral therapy augmented with poloxamer-solubilized quercetin may be a viable approach to maintain CMV inhibition while lowering GCV doses, translating to reduced associated toxicity.
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Affiliation(s)
- Andrew Kjar
- Biological Engineering Department, Utah State University, Logan Utah, 84325, USA
| | - Ian Wadsworth
- Biological Engineering Department, Utah State University, Logan Utah, 84325, USA
| | - Elizabeth Vargis
- Biological Engineering Department, Utah State University, Logan Utah, 84325, USA.
| | - David W Britt
- Biological Engineering Department, Utah State University, Logan Utah, 84325, USA.
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10
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Mitochondria-mediated oxidative stress during viral infection. Trends Microbiol 2022; 30:679-692. [DOI: 10.1016/j.tim.2021.12.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/20/2022]
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11
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Virus-induced FoxO factor facilitates replication of human cytomegalovirus. Arch Virol 2021; 167:109-121. [PMID: 34751815 DOI: 10.1007/s00705-021-05279-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/06/2021] [Indexed: 10/19/2022]
Abstract
Recently, it was reported that the forkhead box O (FoxO) transcription factor promotes human cytomegalovirus (HCMV) replication via direct binding to the promoters of the major immediate-early (MIE) genes, but how the FoxO factor impacts HCMV replication remains unknown. Here, it is reported that FoxO1 expression is strongly induced by HCMV infection in cells of fibroblast origin. Suppression of the FoxO1 gene by specific RNA interference significantly inhibited HCMV growth and replication, but viral DNA synthesis was not affected considerably. Interestingly, depletion or overexpression of FoxO1 had a significant effect on the expression of viral early/late transcripts. FoxO1 was found to colocalize with the pUL44 protein subunit of viral replication compartments without direct association with DNA. This study highlights how FoxO enhances HCMV gene transcription and viral replication to promote infection.
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12
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Non-Coding RNAs and Reactive Oxygen Species–Symmetric Players of the Pathogenesis Associated with Bacterial and Viral Infections. Symmetry (Basel) 2021. [DOI: 10.3390/sym13071307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Infections can be triggered by a wide range of pathogens. However, there are few strains of bacteria that cause illness, but some are quite life-threatening. Likewise, viral infections are responsible for many human diseases, usually characterized by high contagiousness. Hence, as bacterial and viral infections can both cause similar symptoms, it can be difficult to determine the exact cause of a specific infection, and this limitation is critical. However, recent scientific advances have geared us up with the proper tools required for better diagnoses. Recent discoveries have confirmed the involvement of non-coding RNAs (ncRNAs) in regulating the pathogenesis of certain bacterial or viral infections. Moreover, the presence of reactive oxygen species (ROS) is also known as a common infection trait that can be used to achieve a more complete description of such pathogen-driven conditions. Thus, this opens further research opportunities, allowing scientists to explore infection-associated genetic patterns and develop better diagnosis and treatment methods. Therefore, the aim of this review is to summarize the current knowledge of the implication of ncRNAs and ROS in bacterial and viral infections, with great emphasis on their symmetry but, also, on their main differences.
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13
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Fontoura MA, Rocha RF, Marques RE. Neutrophil Recruitment and Participation in Severe Diseases Caused by Flavivirus Infection. Life (Basel) 2021; 11:717. [PMID: 34357089 PMCID: PMC8304117 DOI: 10.3390/life11070717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 12/21/2022] Open
Abstract
Neutrophils are first-line responders to infections and are recruited to target tissues through the action of chemoattractant molecules, such as chemokines. Neutrophils are crucial for the control of bacterial and fungal infections, but their role in the context of viral infections has been understudied. Flaviviruses are important human viral pathogens transmitted by arthropods. Infection with a flavivirus may result in a variety of complex disease manifestations, including hemorrhagic fever, encephalitis or congenital malformations. Our understanding of flaviviral diseases is incomplete, and so is the role of neutrophils in such diseases. Here we present a comprehensive overview on the participation of neutrophils in severe disease forms evolving from flavivirus infection, focusing on the role of chemokines and their receptors as main drivers of neutrophil function. Neutrophil activation during viral infection was shown to interfere in viral replication through effector functions, but the resulting inflammation is significant and may be detrimental to the host. For congenital infections in humans, neutrophil recruitment mediated by CXCL8 would be catastrophic. Evidence suggests that control of neutrophil recruitment to flavivirus-infected tissues may reduce immunopathology in experimental models and patients, with minimal loss to viral clearance. Further investigation on the roles of neutrophils in flaviviral infections may reveal unappreciated functions of this leukocyte population while increasing our understanding of flaviviral disease pathogenesis in its multiple forms.
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Affiliation(s)
- Marina Alves Fontoura
- Brazilian Biosciences National Laboratory—LNBio, Brazilian Center for Research in Energy and Materials—CNPEM, Campinas 13083-100, Brazil; (M.A.F.); (R.F.R.)
- Cellular and Structural Biology Graduate Program, Institute of Biology, University of Campinas (UNICAMP), Campinas 13083-865, Brazil
| | - Rebeca Fróes Rocha
- Brazilian Biosciences National Laboratory—LNBio, Brazilian Center for Research in Energy and Materials—CNPEM, Campinas 13083-100, Brazil; (M.A.F.); (R.F.R.)
- Genetics and Molecular Biology Graduate Program, Institute of Biology, University of Campinas (UNICAMP), Campinas 13083-970, Brazil
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rafael Elias Marques
- Brazilian Biosciences National Laboratory—LNBio, Brazilian Center for Research in Energy and Materials—CNPEM, Campinas 13083-100, Brazil; (M.A.F.); (R.F.R.)
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Boeckmans J, Rombaut M, Demuyser T, Declerck B, Piérard D, Rogiers V, De Kock J, Waumans L, Magerman K, Cartuyvels R, Rummens JL, Rodrigues RM, Vanhaecke T. Infections at the nexus of metabolic-associated fatty liver disease. Arch Toxicol 2021; 95:2235-2253. [PMID: 34027561 PMCID: PMC8141380 DOI: 10.1007/s00204-021-03069-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/29/2021] [Indexed: 02/07/2023]
Abstract
Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease that affects about a quarter of the world population. MAFLD encompasses different disease stadia ranging from isolated liver steatosis to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis and hepatocellular carcinoma. Although MAFLD is considered as the hepatic manifestation of the metabolic syndrome, multiple concomitant disease-potentiating factors can accelerate disease progression. Among these risk factors are diet, lifestyle, genetic traits, intake of steatogenic drugs, male gender and particular infections. Although infections often outweigh the development of fatty liver disease, pre-existing MAFLD could be triggered to progress towards more severe disease stadia. These combined disease cases might be underreported because of the high prevalence of both MAFLD and infectious diseases that can promote or exacerbate fatty liver disease development. In this review, we portray the molecular and cellular mechanisms by which the most relevant viral, bacterial and parasitic infections influence the progression of fatty liver disease and steatohepatitis. We focus in particular on how infectious diseases, including coronavirus disease-19, hepatitis C, acquired immunodeficiency syndrome, peptic ulcer and periodontitis, exacerbate MAFLD. We specifically underscore the synergistic effects of these infections with other MAFLD-promoting factors.
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Affiliation(s)
- Joost Boeckmans
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
- Clinical Laboratory, Jessa Hospital, Stadsomvaart 11, 3500, Hasselt, Belgium.
| | - Matthias Rombaut
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Thomas Demuyser
- Department of Microbiology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090, Brussels, Belgium
- Center for Neurosciences, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Baptist Declerck
- Department of Microbiology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Denis Piérard
- Department of Microbiology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Vera Rogiers
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Joery De Kock
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Luc Waumans
- Clinical Laboratory, Jessa Hospital, Stadsomvaart 11, 3500, Hasselt, Belgium
| | - Koen Magerman
- Clinical Laboratory, Jessa Hospital, Stadsomvaart 11, 3500, Hasselt, Belgium
- Department of Immunology and Infection, Hasselt University, Martelarenlaan 42, 3500, Hasselt, Belgium
| | - Reinoud Cartuyvels
- Clinical Laboratory, Jessa Hospital, Stadsomvaart 11, 3500, Hasselt, Belgium
| | - Jean-Luc Rummens
- Clinical Laboratory, Jessa Hospital, Stadsomvaart 11, 3500, Hasselt, Belgium
| | - Robim M Rodrigues
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
| | - Tamara Vanhaecke
- Department of In Vitro Toxicology and Dermato-Cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
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15
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Effect of Reactive Oxygen Species on the Endoplasmic Reticulum and Mitochondria during Intracellular Pathogen Infection of Mammalian Cells. Antioxidants (Basel) 2021; 10:antiox10060872. [PMID: 34071633 PMCID: PMC8229183 DOI: 10.3390/antiox10060872] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/24/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress, particularly reactive oxygen species (ROS), are important for innate immunity against pathogens. ROS directly attack pathogens, regulate and amplify immune signals, induce autophagy and activate inflammation. In addition, production of ROS by pathogens affects the endoplasmic reticulum (ER) and mitochondria, leading to cell death. However, it is unclear how ROS regulate host defense mechanisms. This review outlines the role of ROS during intracellular pathogen infection, mechanisms of ROS production and regulation of host defense mechanisms by ROS. Finally, the interaction between microbial pathogen-induced ROS and the ER and mitochondria is described.
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16
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Mokry RL, Schumacher ML, Hogg N, Terhune SS. Nitric Oxide Circumvents Virus-Mediated Metabolic Regulation during Human Cytomegalovirus Infection. mBio 2020; 11:e02630-20. [PMID: 33323506 PMCID: PMC7773989 DOI: 10.1128/mbio.02630-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/30/2020] [Indexed: 12/25/2022] Open
Abstract
Nitric oxide is a versatile and critical effector molecule that can modulate many cellular functions. Although recognized as a regulator of infections, the inhibitory mechanism of nitric oxide against human cytomegalovirus (HCMV) replication remains elusive. We demonstrate that nitric oxide attenuates viral replication by interfering with HCMV-mediated modulation of several cellular processes. Nitric oxide exposure reduced HCMV genome synthesis and infectious viral progeny with cell-type-dependent differences observed. Mitochondrial respiration was severely reduced in both uninfected and HCMV-infected cells during exposure with little impact on ATP levels indicating changes in cellular metabolism. Metabolomics identified significantly altered small molecules in multiple pathways during nitric oxide exposure including nucleotide biosynthesis, tricarboxylic acid (TCA) cycle, and glutamine metabolism. Glutathione metabolites were increased coinciding with a reduction in the glutathione precursor glutamine. This shift was accompanied by increased antioxidant enzymes. Glutamine deprivation mimicked defects in HCMV replication and mitochondrial respiration observed during nitric oxide exposure. These data suggest that nitric oxide limits glutaminolysis by shuttling glutamine to glutathione synthesis. In addition, lipid intermediates were severely altered, which likely contributes to the observed increase in defective viral particles. Nitric oxide disrupts multiple cellular processes, and we had limited success in rescuing replication defects by supplementing with metabolic intermediates. Our studies indicate that nitric oxide attenuation of HCMV is multifactorial with interference in viral manipulation of cellular metabolism playing a central role.IMPORTANCE Human cytomegalovirus is a prevalent pathogen that can cause serious disease in patients with compromised immune systems, including transplant patients and during congenital infection. HCMV lytic replication likely occurs in localized sites of infection with immune cells infiltrating and releasing nitric oxide with other effector molecules. This nonspecific immune response results in both uninfected and infected cells exposed to high levels of nitric oxide. The absence of nitric oxide synthase has been associated with lethal HCMV infection. We demonstrate that nitric oxide inhibition of HCMV replication is multifactorial and cell type dependent. Our results indicate that nitric oxide controls replication by interfering with viral modulation of cellular metabolism while also affecting proliferation and mitochondrial respiration of neighboring uninfected cells. These studies identify the mechanism and contribution of nitric oxide during immune control of HCMV infection and provide insight into its role in other viral infections.
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Affiliation(s)
- Rebekah L Mokry
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Megan L Schumacher
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Neil Hogg
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Scott S Terhune
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Marquette University and Medical College of Wisconsin Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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17
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Monk CH, Zwezdaryk KJ. Host Mitochondrial Requirements of Cytomegalovirus Replication. CURRENT CLINICAL MICROBIOLOGY REPORTS 2020; 7:115-123. [PMID: 33816061 PMCID: PMC8015347 DOI: 10.1007/s40588-020-00153-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Purpose of Review Metabolic rewiring of the host cell is required for optimal viral replication. Human cytomegalovirus (HCMV) has been observed to manipulate numerous mitochondrial functions. In this review, we describe the strategies and targets HCMV uses to control different aspects of mitochondrial function. Recent Findings The mitochondria are instrumental in meeting the biosynthetic and bioenergetic needs of HCMV replication. This is achieved through altered metabolism and signaling pathways. Morphological changes mediated through biogenesis and fission/fusion dynamics contribute to strategies to avoid cell death, overcome oxidative stress, and maximize the biosynthetic and bioenergetic outputs of mitochondria. Summary Emerging data suggests that cytomegalovirus relies on intact, functional host mitochondria for optimal replication. HCMV large size and slow replication kinetics create a dependency on mitochondria during replication. Targeting the host mitochondria is an attractive antiviral target.
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Affiliation(s)
- Chandler H Monk
- Department of Microbiology & Immunology, Tulane University Health Sciences Center, 1430 Tulane Ave #8638, New Orleans, LA 70112, USA
| | - Kevin J Zwezdaryk
- Department of Microbiology & Immunology, Tulane University Health Sciences Center, 1430 Tulane Ave #8638, New Orleans, LA 70112, USA
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18
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Wang SY, Zhang J, Xu XG, Su HL, Xing WM, Zhang ZS, Jin WH, Dai JH, Wang YZ, He XY, Sun C, Yan J, Mao GX. Inhibitory effects of piceatannol on human cytomegalovirus (hCMV) in vitro. J Microbiol 2020; 58:716-723. [PMID: 32524342 DOI: 10.1007/s12275-020-9528-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/20/2020] [Accepted: 05/06/2020] [Indexed: 12/31/2022]
Abstract
Human cytomegalovirus (hCMV) is a ubiquitous herpesvirus, which results in the establishment of a latent infection that persists throughout the life of the host and can be reactivated when the immunity is low. Currently, there is no vaccine for hCMV infection, and the licensed antiviral drugs mainly target the viral enzymes and have obvious adverse reactions. Thus, it is important to search for compounds with anti-hCMV properties. The present study aimed to investigate the suppressive effects of piceatannol on hCMV Towne strain infection and the putative underlying mechanisms using human diploid fibroblast WI-38 cells. Piceatannol supplementation prevented the lytic changes induced by hCMV infection in WI-38 cells. Furthermore, piceatannol suppressed the expression of hCMV immediate-early (IE) and early (E) proteins as well as the replication of hCMV DNA in a dose-dependent manner. Moreover, hCMV-induced cellular senescence was suppressed by piceatannol, as shown by a decline in the senescence-associated β-galactosidase (SA-β-Gal) activity and decreased production of intracellular reactive oxygen species (ROS). p16INK4a, a major senescence-associated molecule, was dramatically elevated by current hCMV infection that was attenuated by pre-incubation with piceatannol in a dose-dependent manner. These results demonstrated that piceatannol suppressed the hCMV infection via inhibition of the activation of p16INK4a and cellular senescence induced by hCMV. Together, these findings indicate piceatannol as a novel and potent anti-hCMV agent with the potential to be developed as an effective treatment for chronic hCMV infection.
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Affiliation(s)
- San-Ying Wang
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Jing Zhang
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Xiao-Gang Xu
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Hui-Li Su
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Wen-Min Xing
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Zhong-Shan Zhang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, 313000, P. R. China
- Huzhou Central Hospital, Huzhou University, Huzhou, 313000, P. R. China
| | - Wei-Hua Jin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
| | - Ji-Huan Dai
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Ya-Zhen Wang
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Xin-Yue He
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
| | - Chuan Sun
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China
| | - Jing Yan
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China.
| | - Gen-Xiang Mao
- Zhejiang Provincial Key Lab of Geriatrics & Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, 310030, P. R. China.
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19
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Therapeutic Modulation of Virus-Induced Oxidative Stress via the Nrf2-Dependent Antioxidative Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6208067. [PMID: 30515256 PMCID: PMC6234444 DOI: 10.1155/2018/6208067] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/24/2018] [Indexed: 12/17/2022]
Abstract
Virus-induced oxidative stress plays a critical role in the viral life cycle as well as the pathogenesis of viral diseases. In response to reactive oxygen species (ROS) generation by a virus, a host cell activates an antioxidative defense system for its own protection. Particularly, a nuclear factor erythroid 2p45-related factor 2 (Nrf2) pathway works in a front-line for cytoprotection and detoxification. Recently, a series of studies suggested that a group of clinically relevant viruses have the capacity for positive and negative regulations of the Nrf2 pathway. This virus-induced modulation of the host antioxidative response turned out to be a crucial determinant for the progression of several viral diseases. In this review, virus-specific examples of positive and negative modulations of the Nrf2 pathway will be summarized first. Then a number of successful genetic and pharmacological manipulations of the Nrf2 pathway for suppression of the viral replication and the pathogenesis-associated oxidative damage will be discussed later. Understanding of the interplay between virus-induced oxidative stress and antioxidative host response will aid in the discovery of potential antiviral supplements for better management of viral diseases.
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20
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Jean Beltran PM, Cook KC, Hashimoto Y, Galitzine C, Murray LA, Vitek O, Cristea IM. Infection-Induced Peroxisome Biogenesis Is a Metabolic Strategy for Herpesvirus Replication. Cell Host Microbe 2018; 24:526-541.e7. [PMID: 30269970 PMCID: PMC6195127 DOI: 10.1016/j.chom.2018.09.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/12/2018] [Accepted: 08/20/2018] [Indexed: 12/28/2022]
Abstract
Viral proteins have evolved to target cellular organelles and usurp their functions for virus replication. Despite the knowledge of these critical functions for several organelles, little is known about peroxisomes during infection. Peroxisomes are primarily metabolic organelles with important functions in lipid metabolism. Here, we discovered that the enveloped viruses human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) induce the biogenesis of and unique morphological changes to peroxisomes to support their replication. Targeted proteomic quantification revealed a global virus-induced upregulation of peroxisomal proteins. Mathematical modeling and microscopy structural analysis show that infection triggers peroxisome growth and fission, leading to increased peroxisome numbers and irregular disc-like structures. HCMV-induced peroxisome biogenesis increased the phospholipid plasmalogen, thereby enhancing virus production. Peroxisome regulation and dependence were not observed for the non-enveloped adenovirus. Our findings uncover a role of peroxisomes in viral pathogenesis, with likely implications for multiple enveloped viruses.
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Affiliation(s)
- Pierre M Jean Beltran
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Katelyn C Cook
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Yutaka Hashimoto
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Cyril Galitzine
- College of Science, College of Computer and Information Science, Northeastern University, Boston, MA 02115, USA
| | - Laura A Murray
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA
| | - Olga Vitek
- College of Science, College of Computer and Information Science, Northeastern University, Boston, MA 02115, USA
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA.
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21
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Seyoum M, Enawgaw B, Melku M. Human blood platelets and viruses: defense mechanism and role in the removal of viral pathogens. Thromb J 2018; 16:16. [PMID: 30026673 PMCID: PMC6048695 DOI: 10.1186/s12959-018-0170-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/18/2018] [Indexed: 12/19/2022] Open
Abstract
Platelets are small non-nucleated cell fragments and the second most abundant cell that play crucial role in managing vascular integrity and regulating hemostasis. Recent finding shows, beyond its hemostatic function platelets also play a main role in fighting against pathogen including viruses. With their receptors, platelet interacts with viral pathogen and this interaction between platelets and viral pathogens result in activation of platelets. Activated platelet releases different molecules that have antiviral activity including kinocidins and other platelet microbicidal peptides. In addition, activated platelet has antiviral role by different mechanism including; phagocytosis of viral pathogen, produce reactive oxygen species and interact with and activate other immune cells. In other side, antiplatelet treatments are one of defending mechanism of viral pathogen. This narrative review summarizes what is known regarding the role of human platelets in fighting viral pathogen.
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Affiliation(s)
- Masresha Seyoum
- University of Gondar hospital, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
- Department of Hematology & Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Bamlaku Enawgaw
- Department of Hematology & Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Mulugeta Melku
- Department of Hematology & Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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22
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Vincent HA, Moorman NJ. Human cytomegalovirus regulation of eIF2α kinases. Future Virol 2017. [DOI: 10.2217/fvl-2017-0068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Heather A Vincent
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Nathaniel J Moorman
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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23
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Assessing the risk of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients by monitoring oxidative-stress markers in plasma. J Gen Virol 2017; 98:1855-1863. [DOI: 10.1099/jgv.0.000838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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24
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ACSS2-mediated acetyl-CoA synthesis from acetate is necessary for human cytomegalovirus infection. Proc Natl Acad Sci U S A 2017; 114:E1528-E1535. [PMID: 28167750 DOI: 10.1073/pnas.1614268114] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Recent studies have shown that human cytomegalovirus (HCMV) can induce a robust increase in lipid synthesis which is critical for the success of infection. In mammalian cells the central precursor for lipid biosynthesis, cytosolic acetyl CoA (Ac-CoA), is produced by ATP-citrate lyase (ACLY) from mitochondria-derived citrate or by acetyl-CoA synthetase short-chain family member 2 (ACSS2) from acetate. It has been reported that ACLY is the primary enzyme involved in making cytosolic Ac-CoA in cells with abundant nutrients. However, using CRISPR/Cas9 technology, we have shown that ACLY is not essential for HCMV growth and virally induced lipogenesis. Instead, we found that in HCMV-infected cells glucose carbon can be used for lipid synthesis by both ACLY and ACSS2 reactions. Further, the ACSS2 reaction can compensate for the loss of ACLY. However, in ACSS2-KO human fibroblasts both HCMV-induced lipogenesis from glucose and viral growth were sharply reduced. This reduction suggests that glucose-derived acetate is being used to synthesize cytosolic Ac-CoA by ACSS2. Previous studies have not established a mechanism for the production of acetate directly from glucose metabolism. Here we show that HCMV-infected cells produce more glucose-derived pyruvate, which can be converted to acetate through a nonenzymatic mechanism.
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25
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Rieder FJJ, Gröschel C, Kastner MT, Kosulin K, Laengle J, Zadnikar R, Marculescu R, Schneider M, Lion T, Bergmann M, Kallay E, Steininger C. Human cytomegalovirus infection downregulates vitamin-D receptor in mammalian cells. J Steroid Biochem Mol Biol 2017; 165:356-362. [PMID: 27520300 PMCID: PMC5705058 DOI: 10.1016/j.jsbmb.2016.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/31/2022]
Abstract
Vitamin D (VD) is essential for the human body and involved in a wide variety of critical physiological processes including bone, muscle, and cardiovascular health, as well as innate immunity and antimicrobial responses. Here, we elucidated the significance of the VD system in cytomegalovirus (CMV) infection, which is one of the most common opportunistic infections in immunocompromised or -suppressed patients. We found that expression of vitamin D receptor (VDR) was downregulated in CMV-infected cells within 12h [hrs] post infection [p.i.] to 12% relative to VDR expression in mock-infected fibroblasts and did not recover during the CMV replication cycle of 96h. None of the biologically active metabolites of VD, cholecalciferol, calcidiol, or calcitriol, inhibit CMV replication significantly in human fibroblasts. In a feedback loop, expression of CYP24A1 dropped to 3% by 12h p.i. and expression of CYP27B1 increased gradually during the replication cycle of CMV to 970% probably as a consequence of VDR inhibition. VDR expression was not downregulated during influenza virus or adenovirus replication. The potent synthetic vitamin D analog EB-1089 was not able to inhibit CMV replication or antagonize its effect on VDR expression. Only CMV replication, and none of the other viral pathogens evaluated, inhibited the vitamin D system in vitro. In view of the pleiotropism of VDR, CMV-mediated downregulation may have far-reaching virological, immunological, and clinical implications and thus warrant further evaluations in vitro and in vivo.
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Affiliation(s)
- Franz J J Rieder
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Charlotte Gröschel
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Marie-Theres Kastner
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Karin Kosulin
- Children's Cancer Research Institute, Vienna, Austria
| | - Johannes Laengle
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Rene Zadnikar
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Rodrig Marculescu
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Martina Schneider
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas Lion
- Children's Cancer Research Institute, Vienna, Austria; Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Michael Bergmann
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Enikö Kallay
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Christoph Steininger
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
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26
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Xiao J, Song X, Deng J, Lv L, Ma P, Gao B, Zhou X, Zhang Y, Xu J. Inhibition of cyclophilin A suppresses H2O2-enhanced replication of HCMV through the p38 MAPK signaling pathway. FEBS Open Bio 2016; 6:961-71. [PMID: 27642560 PMCID: PMC5011495 DOI: 10.1002/2211-5463.12105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/24/2016] [Accepted: 07/25/2016] [Indexed: 01/18/2023] Open
Abstract
Human cytomegalovirus (HCMV) infection can be accelerated by intracellular and extracellular hydrogen peroxide (H2O2) stimulation, mediated by the activation of the p38 mitogen‐activated protein kinase (MAPK) pathway. However, it remains unknown whether host gene expression is involved in H2O2‐upregulated HCMV replication. Here, we show that the expression of the host gene, cyclophilin A (CyPA), could be facilitated by treatment with H2O2 in a dose‐dependent manner. Experiments with CyPA‐specific siRNA, or with cyclosporine A, an inhibitor of CyPA, confirmed that H2O2‐mediated upregulation of HCMV replication is specifically mediated by upregulation of CyPA expression. Furthermore, depletion or inhibition of CyPA reduced H2O2‐induced p38 activation, consistent with that of H2O2‐upregulated HCMV lytic replication. These results show that H2O2 is capable of activating ROS‐CyPA–p38 MAPK interactions to enhance HCMV replication.
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Affiliation(s)
- Jun Xiao
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Xin Song
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Jiang Deng
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Liping Lv
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Ping Ma
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Bo Gao
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Xipeng Zhou
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Yanyu Zhang
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
| | - Jinbo Xu
- Beijing Institute of Transfusion MedicineChina
- Beijing Key Laboratory of Blood Safety and Supply TechnologiesChina
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Six Hours after Infection, the Metabolic Changes Induced by WSSV Neutralize the Host's Oxidative Stress Defenses. Sci Rep 2016; 6:27732. [PMID: 27279169 PMCID: PMC4899751 DOI: 10.1038/srep27732] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/24/2016] [Indexed: 02/06/2023] Open
Abstract
Levels of intracellular ROS (reactive oxygen species) were significantly increased in hemocytes collected from WSSV-infected shrimp within the first 30–120 min after infection. Measurement of the NADPH/NADP+ and GSH/GSSG ratios revealed that after a significant imbalance toward the oxidized forms at 2 hpi, redox equilibrium was subsequently restored. Meanwhile, high levels of lactic acid production, elevated NADH/NAD+ ratios, and metabolic changes in the glycolysis pathway show that the Warburg effect was triggered by the virus. The timing of these changes suggests that WSSV uses this metabolic shift into aerobic glycolysis to counteract the high levels of ROS produced in response to viral infection. We further show that if the Warburg effect is inhibited by chemical inhibition of the PI3K-Akt-mTOR signaling pathway, or if the pentose phosphate pathway is chemically inhibited, then in both cases, the production of intracellular ROS is sustained. We conclude that WSSV uses the PI3K-Akt-mTOR-regulated Warburg effect to restore host redox balance and to counter the ROS produced by the host in response to WSSV infection. We also found that pyruvate kinase activity was inhibited by WSSV. This inhibition is likely to increase the availability of the raw materials essential for WSSV gene expression and replication.
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Le Sage V, Cinti A, Amorim R, Mouland AJ. Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway. Viruses 2016; 8:v8060152. [PMID: 27231932 PMCID: PMC4926172 DOI: 10.3390/v8060152] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 02/06/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors) and intracellular (energy status) molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs.
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Affiliation(s)
- Valerie Le Sage
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
| | - Alessandro Cinti
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Raquel Amorim
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
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Monleón D, Giménez E, Muñoz-Cobo B, Morales JM, Solano C, Amat P, Navarro D. Plasma metabolomics profiling for the prediction of cytomegalovirus DNAemia and analysis of virus–host interaction in allogeneic stem cell transplant recipients. J Gen Virol 2016; 96:3373-3381. [PMID: 26341195 DOI: 10.1099/jgv.0.000275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Metabolomics analysis of biofluids is increasingly being recognized as a useful tool for the diagnosis and management of a number of infectious diseases. Here we showed that plasma metabolomics profiling by untargeted 1H nuclear magnetic resonance may allow the anticipation of the occurrence of cytomegalovirus (CMV) DNAemia in allogeneic stem cell transplant. For this purpose, key discriminatory metabolites were total glutathione, taurine, methylamine, trimethylamine N-oxide and lactate, all of which were upregulated in patients eventually developing CMV DNAemia. The overall classification accuracy (predictability) of the projection to latent structure discriminant analysis (PLS-DA) model in cross-validation technical replicates was 73 %. Increased levels of alanine, lactate and total fatty acids, and a shift in the fatty acid profile towards unsaturated species, were observed in patients with detectable CMV DNA in plasma. The classification accuracy of this PLS-DA model in cross-validation technical replicates was 81 %. Plasma metabolomics profiling may prove useful for identifying patients at highest risk for CMV DNAemia thus allowing early inception of antiviral therapy.
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Affiliation(s)
- Daniel Monleón
- Metabolomic and Molecular Image Laboratory, Fundación de Investigación INCLIVA, Valencia, Spain
| | - Estela Giménez
- Microbiology Service, Hospital Clínico Universitario, Fundación de Investigación INCLIVA, Valencia, Spain
| | - Beatriz Muñoz-Cobo
- Microbiology Service, Hospital Clínico Universitario, Fundación de Investigación INCLIVA, Valencia, Spain
| | - José Manuel Morales
- Metabolomic and Molecular Image Laboratory, Fundación de Investigación INCLIVA, Valencia, Spain
| | - Carlos Solano
- Hematalogy and Medical Oncology Service, Hospital Clínico Universitario, Fundación de Investigación INCLIVA, Valencia, Spain
- Department of Medicine, School of Medicine, University of Valencia, Valencia, Spain
| | - Paula Amat
- Hematalogy and Medical Oncology Service, Hospital Clínico Universitario, Fundación de Investigación INCLIVA, Valencia, Spain
| | - David Navarro
- Microbiology Service, Hospital Clínico Universitario, Fundación de Investigación INCLIVA, Valencia, Spain
- Department of Microbiology, School of Medicine, University of Valencia, Valencia, Spain
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Vincent HA, Ziehr B, Moorman NJ. Human Cytomegalovirus Strategies to Maintain and Promote mRNA Translation. Viruses 2016; 8:97. [PMID: 27089357 PMCID: PMC4848592 DOI: 10.3390/v8040097] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 03/25/2016] [Accepted: 03/31/2016] [Indexed: 02/02/2023] Open
Abstract
mRNA translation requires the ordered assembly of translation initiation factors and ribosomal subunits on a transcript. Host signaling pathways regulate each step in this process to match levels of protein synthesis to environmental cues. In response to infection, cells activate multiple defenses that limit viral protein synthesis, which viruses must counteract to successfully replicate. Human cytomegalovirus (HCMV) inhibits host defenses that limit viral protein expression and manipulates host signaling pathways to promote the expression of both host and viral proteins necessary for virus replication. Here we review key regulatory steps in mRNA translation, and the strategies used by HCMV to maintain protein synthesis in infected cells.
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Affiliation(s)
- Heather A Vincent
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Benjamin Ziehr
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Nathaniel J Moorman
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Shenk T, Alwine JC. Human Cytomegalovirus: Coordinating Cellular Stress, Signaling, and Metabolic Pathways. Annu Rev Virol 2016; 1:355-74. [PMID: 26958726 DOI: 10.1146/annurev-virology-031413-085425] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viruses face a multitude of challenges when they infect a host cell. Cells have evolved innate defenses to protect against pathogens, and an infecting virus may induce a stress response that antagonizes viral replication. Further, the metabolic, oxidative, and cell cycle state may not be conducive to the viral infection. But viruses are fabulous manipulators, inducing host cells to use their own characteristic mechanisms and pathways to provide what the virus needs. This article centers on the manipulation of host cell metabolism by human cytomegalovirus (HCMV). We review the features of the metabolic program instituted by the virus, discuss the mechanisms underlying these dramatic metabolic changes, and consider how the altered program creates a synthetic milieu that favors efficient HCMV replication and spread.
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Affiliation(s)
- Thomas Shenk
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | - James C Alwine
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104;
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Morris G, Berk M, Walder K, Maes M. The Putative Role of Viruses, Bacteria, and Chronic Fungal Biotoxin Exposure in the Genesis of Intractable Fatigue Accompanied by Cognitive and Physical Disability. Mol Neurobiol 2015; 53:2550-71. [PMID: 26081141 DOI: 10.1007/s12035-015-9262-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 05/28/2015] [Indexed: 01/08/2023]
Abstract
Patients who present with severe intractable apparently idiopathic fatigue accompanied by profound physical and or cognitive disability present a significant therapeutic challenge. The effect of psychological counseling is limited, with significant but very slight improvements in psychometric measures of fatigue and disability but no improvement on scientific measures of physical impairment compared to controls. Similarly, exercise regimes either produce significant, but practically unimportant, benefit or provoke symptom exacerbation. Many such patients are afforded the exclusionary, non-specific diagnosis of chronic fatigue syndrome if rudimentary testing fails to discover the cause of their symptoms. More sophisticated investigations often reveal the presence of a range of pathogens capable of establishing life-long infections with sophisticated immune evasion strategies, including Parvoviruses, HHV6, variants of Epstein-Barr, Cytomegalovirus, Mycoplasma, and Borrelia burgdorferi. Other patients have a history of chronic fungal or other biotoxin exposure. Herein, we explain the epigenetic factors that may render such individuals susceptible to the chronic pathology induced by such agents, how such agents induce pathology, and, indeed, how such pathology can persist and even amplify even when infections have cleared or when biotoxin exposure has ceased. The presence of active, reactivated, or even latent Herpes virus could be a potential source of intractable fatigue accompanied by profound physical and or cognitive disability in some patients, and the same may be true of persistent Parvovirus B12 and mycoplasma infection. A history of chronic mold exposure is a feasible explanation for such symptoms, as is the presence of B. burgdorferi. The complex tropism, life cycles, genetic variability, and low titer of many of these pathogens makes their detection in blood a challenge. Examination of lymphoid tissue or CSF in such circumstances may be warranted.
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Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Bryn Road seaside 87, Llanelli, SA15 2LW, Wales, UK
| | - Michael Berk
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Orygen, The National Centre of Excellence in Youth Mental Health, Department of Psychiatry and The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Ken Walder
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Geelong, Australia
| | - Michael Maes
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia. .,Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
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Xiao J, Deng J, Lv L, Kang Q, Ma P, Yan F, Song X, Gao B, Zhang Y, Xu J. Hydrogen Peroxide Induce Human Cytomegalovirus Replication through the Activation of p38-MAPK Signaling Pathway. Viruses 2015; 7:2816-33. [PMID: 26053925 PMCID: PMC4488715 DOI: 10.3390/v7062748] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/26/2015] [Indexed: 01/19/2023] Open
Abstract
Human cytomegalovirus (HCMV) is a major risk factor in transplantation and AIDS patients, which induces high morbidity and mortality. These patients infected with HCMV experience an imbalance of redox homeostasis that cause accumulation of reactive oxygen species (ROS) at the cellular level. H2O2, the most common reactive oxygen species, is the main byproduct of oxidative metabolism. However, the function of H2O2 on HCMV infection is not yet fully understood and the effect and mechanism of N-acetylcysteine (NAC) on H2O2-stimulated HCMV replication is unclear. We, therefore, examined the effect of NAC on H2O2-induced HCMV production in human foreskin fibroblast cells. In the present study, we found that H2O2 enhanced HCMV lytic replication through promoting major immediate early (MIE) promoter activity and immediate early (IE) gene transcription. Conversely, NAC inhibited H2O2-upregulated viral IE gene expression and viral replication. The suppressive effect of NAC on CMV in an acute CMV-infected mouse model also showed a relationship between antioxidants and viral lytic replication. Intriguingly, the enhancement of HCMV replication via supplementation with H2O2 was accompanied with the activation of the p38 mitogen-activated protein kinase pathway. Similar to NAC, the p38 inhibitor SB203580 inhibited H2O2-induced p38 phosphorylation and HCMV upregulation, while upregulation of inducible ROS was unaffected. These results directly relate HCMV replication to H2O2, suggesting that treatment with antioxidants may be an attractive preventive and therapeutic strategy for HCMV.
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Affiliation(s)
- Jun Xiao
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Jiang Deng
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Liping Lv
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Qiong Kang
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Ping Ma
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Fan Yan
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Xin Song
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Bo Gao
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Yanyu Zhang
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
| | - Jinbo Xu
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Beijing 100850, China.
- Beijing Institute of Transfusion Medicine, 27 (9) Taiping Road, Beijing 100850, China.
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34
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Tuberous Sclerosis Complex Protein 2-Independent Activation of mTORC1 by Human Cytomegalovirus pUL38. J Virol 2015; 89:7625-35. [PMID: 25972538 DOI: 10.1128/jvi.01027-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/05/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED The mammalian target of rapamycin complex 1 (mTORC1) controls cell growth and anabolic metabolism and is a critical host factor activated by human cytomegalovirus (HCMV) for successful infection. The multifunctional HCMV protein pUL38 previously has been reported to activate mTORC1 by binding to and antagonizing tuberous sclerosis complex protein 2 (TSC2) (J. N. Moorman et al., Cell Host Microbe 3:253-262, 2008, http://dx.doi.org/10.1016/j.chom.2008.03.002). pUL38 also plays a role in blocking endoplasmic reticulum stress-induced cell death during HCMV infection. In this study, we showed that a mutant pUL38 lacking the N-terminal 24 amino acids (pHA-UL3825-331) was fully functional in suppressing cell death during infection. Interestingly, pHA-UL3825-331 lost the ability to interact with TSC2 but retained the ability to activate mTORC1, although to a lesser extent than full-length pHA-UL38. Recombinant virus expressing pHA-UL3825-331 replicated with ∼10-fold less efficiency than the wild-type virus at a low multiplicity of infection (MOI), but it grew similarly well at a high MOI, suggesting an MOI-dependent importance of pUL38-TSC2 interaction in supporting virus propagation. Site-directed mutational analysis identified a TQ motif at amino acid residues 23 and 24 as critical for pUL38 interaction with TSC2. Importantly, when expressed in isolation, the TQ/AA substitution mutant pHA-UL38 TQ/AA was capable of activating mTORC1 just like pHA-UL3825-331. We also created TSC2-null U373-MG cell lines by CRISPR genome editing and showed that pUL38 was capable of further increasing mTORC1 activity in TSC2-null cells. Therefore, this study identified the residues important for pUL38-TSC2 interaction and demonstrated that pUL38 can activate mTORC1 in both TSC2-dependent and -independent manners. IMPORTANCE HCMV, like other viruses, depends exclusively on its host cell to propagate. Therefore, it has developed methods to protect against host stress responses and to usurp cellular processes to complete its life cycle. mTORC1 is believed to be important for virus replication, and HCMV maintains high mTORC1 activity despite the stressful cellular environment associated with infection. mTORC1 inhibitors suppressed HCMV replication in vitro and reduced the incidence of HCMV reactivation in transplant recipients. We demonstrated that mTORC1 was activated by HCMV protein pUL38 in both TSC2-dependent and TSC2-independent manners. The pUL38-independent mode of mTORC1 activation also has been reported. These novel findings suggest the evolution of sophisticated approaches whereby HCMV activates mTORC1, indicating its importance in the biology and pathogenesis of HCMV.
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Rodrigues AF, Carrondo MJT, Alves PM, Coroadinha AS. Cellular targets for improved manufacturing of virus-based biopharmaceuticals in animal cells. Trends Biotechnol 2014; 32:602-7. [PMID: 25450042 DOI: 10.1016/j.tibtech.2014.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 09/18/2014] [Accepted: 09/26/2014] [Indexed: 12/24/2022]
Abstract
The past decade witnessed the entry into the market of new virus-based biopharmaceuticals produced in animal cells such as oncolytic vectors, virus-like particle vaccines, and gene transfer vectors. Therefore, increased attention and investment to optimize cell culture processes towards enhanced manufacturing of these bioproducts is anticipated. Herein, we review key findings on virus-host interactions that have been explored in cell culture optimization. Approaches supporting improved productivity or quality of vector preparations are discussed, mainly focusing on medium design and genetic manipulation. This review provides an integrated outline for current and future efforts in exploring cellular targets for the optimization of cell culture manufacturing of virus-based biopharmaceuticals.
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Affiliation(s)
- Ana F Rodrigues
- iBET - Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Manuel J T Carrondo
- iBET - Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; FCT-UNL, P-2829-516 Caparica, Portugal
| | - Paula M Alves
- iBET - Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Ana S Coroadinha
- iBET - Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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36
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Xiaofei E, Kowalik TF. The DNA damage response induced by infection with human cytomegalovirus and other viruses. Viruses 2014; 6:2155-85. [PMID: 24859341 PMCID: PMC4036536 DOI: 10.3390/v6052155] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/02/2014] [Accepted: 05/08/2014] [Indexed: 12/12/2022] Open
Abstract
Viruses use different strategies to overcome the host defense system. Recent studies have shown that viruses can induce DNA damage response (DDR). Many of these viruses use DDR signaling to benefit their replication, while other viruses block or inactivate DDR signaling. This review focuses on the effects of DDR and DNA repair on human cytomegalovirus (HCMV) replication. Here, we review the DDR induced by HCMV infection and its similarities and differences to DDR induced by other viruses. As DDR signaling pathways are critical for the replication of many viruses, blocking these pathways may represent novel therapeutic opportunities for the treatment of certain infectious diseases. Lastly, future perspectives in the field are discussed.
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Affiliation(s)
- E Xiaofei
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation St, Worcester, MA 01605, USA.
| | - Timothy F Kowalik
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation St, Worcester, MA 01605, USA.
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Lv Y, Lei N, Wang D, An Z, Li G, Han F, Liu H, Liu L. Protective effect of curcumin against cytomegalovirus infection in Balb/c mice. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:1140-1147. [PMID: 24802527 DOI: 10.1016/j.etap.2014.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 04/04/2014] [Accepted: 04/11/2014] [Indexed: 06/03/2023]
Abstract
Curcumin has been found to suppress the activity of human cytomegalovirus (HCMV) in vitro, whereas its protective effects against HCMV infection in vivo remain unclear. In this study, we aimed to investigate the protective effects of curcumin against HCMV infection in Balb/c mice. Mice were randomly divided into the control, model, model+ganciclovir (positive control), and model+high-dose, model+middle-dose, and model+low-dose curcumin groups. In the model groups, each mouse was given HCMV by tail injection intravenously. Positive control animals were given ganciclovir. Animals in the curcumin treatment groups were given different concentrations of curcumin. The anti-HCMV activities of ganciclovir and curcumin were assessed by serological examination and pathology. Ganciclovir and curcumin treatment reduced the HCMV IgM level and HCMV DNA load; decreased the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and lactate dehydrogenase (LDH) as well as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) generation in infected mice. These treatments also suppressed malondialdehyde (MDA) content and upregulated superoxide dismutase (SOD) and glutathione (GSH) levels. In addition, both treatments prevented pathological changes of the lung, kidney, liver, and heart tissues in infected mice. Our findings indicate that curcumin protected Balb/c mice against HCMV infection possibly by its anti-inflammatory and antioxidant effects.
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Affiliation(s)
- Yali Lv
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China
| | - Ning Lei
- General Hospital of the Second Artillery, Beijing 100088, PR China
| | - Dan Wang
- General Hospital of the Second Artillery, Beijing 100088, PR China
| | - Zhuoling An
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China
| | - Guangrun Li
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China
| | - Feifei Han
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China
| | - He Liu
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China
| | - Lihong Liu
- Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, PR China.
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38
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Abstract
Reactive oxygen species (ROS) are deadly weapons used by phagocytes and other cell types, such as lung epithelial cells, against pathogens. ROS can kill pathogens directly by causing oxidative damage to biocompounds or indirectly by stimulating pathogen elimination by various nonoxidative mechanisms, including pattern recognition receptors signaling, autophagy, neutrophil extracellular trap formation, and T-lymphocyte responses. Thus, one should expect that the inhibition of ROS production promote infection. Increasing evidences support that in certain particular infections, antioxidants decrease and prooxidants increase pathogen burden. In this study, we review the classic infections that are controlled by ROS and the cases in which ROS appear as promoters of infection, challenging the paradigm. We discuss the possible mechanisms by which ROS could promote particular infections. These mechanisms are still not completely clear but include the metabolic effects of ROS on pathogen physiology, ROS-induced damage to the immune system, and ROS-induced activation of immune defense mechanisms that are subsequently hijacked by particular pathogens to act against more effective microbicidal mechanisms of the immune system. The effective use of antioxidants as therapeutic agents against certain infections is a realistic possibility that is beginning to be applied against viruses.
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Affiliation(s)
- Claudia N Paiva
- Departamento de Imunologia, Instituto de Microbiologia , CCS Bloco D, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Pyo CW, Choi JH, Oh SM, Choi SY. Oxidative stress-induced cyclin D1 depletion and its role in cell cycle processing. Biochim Biophys Acta Gen Subj 2013; 1830:5316-25. [PMID: 23920145 DOI: 10.1016/j.bbagen.2013.07.030] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 07/01/2013] [Accepted: 07/27/2013] [Indexed: 12/19/2022]
Abstract
BACKGROUND Cyclin D1 is immediately down-regulated in response to reactive oxygen species (ROS) and implicated in the induction of cell cycle arrest in G2 phase by an unknown mechanism. Either treatment with a protease inhibitor alone or expression of protease-resistant cyclin D1 T286A resulted in only a partial relief from the ROS-induced cell cycle arrest, indicating the presence of an additional control mechanism. METHODS Cells were exposed to hydrogen peroxide (H2O2), and analyzed to assess the changes in cyclin D1 level and its effects on cell cycle processing by kinase assay, de novo synthesis, gene silencing, and polysomal analysis, etc. RESULTS Exposure of cells to excessive H2O2 induced ubiquitin-dependent proteasomal degradation of cyclin D1, which was subsequently followed by translational repression. This dual control mechanism was found to contribute to the induction of cell cycle arrest in G2 phase under oxidative stress. Silencing of an eIF2α kinase PERK significantly retarded cyclin D1 depletion, and contributed largely to rescuing cells from G2 arrest. Also the cyclin D1 level was found to be correlated with Chk1 activity. CONCLUSIONS In addition to an immediate removal of the pre-existing cyclin D1 under oxidative stress, the following translational repression appear to be required for ensuring full depletion of cyclin D1 and cell cycle arrest. Oxidative stress-induced cyclin D1 depletion is linked to the regulation of G2/M transit via the Chk1-Cdc2 DNA damage checkpoint pathway. GENERAL SIGNIFICANCE The control of cyclin D1 is a gate keeping program to protect cells from severe oxidative damages.
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Affiliation(s)
- Chul-Woong Pyo
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
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Lee J, Koh K, Kim YE, Ahn JH, Kim S. Upregulation of Nrf2 expression by human cytomegalovirus infection protects host cells from oxidative stress. J Gen Virol 2013; 94:1658-1668. [PMID: 23580430 DOI: 10.1099/vir.0.052142-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
NF-E2 related factor 2 (Nrf2) is a transcription factor that plays a key role(s) in cellular defence against oxidative stress. In this study, we showed that the expression of Nrf2 was upregulated in primary human foreskin fibroblasts (HFFs), following human cytomegalovirus (HCMV/HHV-5) infection. The expression of haem oxygenase-1, a downstream target of Nrf2, was also increased by HCMV infection, and this induction was suppressed in HFFs expressing a small hairpin RNA (shRNA) against Nrf2. The HCMV-mediated increase in Nrf2 expression was abolished when UV-irradiated virus was used or when the activity of casein kinase 2 was inhibited. Host cells infected by HCMV had higher survival rates following oxidative stress induced by buthionine sulfoximine compared with uninfected control cells, but this cell-protective effect was abolished by the use of Nrf2 shRNA. Our results suggest that HCMV-mediated activation of Nrf2 might be beneficial to the virus by increasing the host cell's ability to cope with oxidative stress resulting from viral infection and/or inflammation.
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Affiliation(s)
- Junsub Lee
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Kyungmi Koh
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Young-Eui Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Kyonggido 440-746, Korea
| | - Jin-Hyun Ahn
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Kyonggido 440-746, Korea
| | - Sunyoung Kim
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
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PKR-like endoplasmic reticulum kinase is necessary for lipogenic activation during HCMV infection. PLoS Pathog 2013; 9:e1003266. [PMID: 23592989 PMCID: PMC3617203 DOI: 10.1371/journal.ppat.1003266] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 02/06/2013] [Indexed: 12/21/2022] Open
Abstract
PKR-like endoplasmic reticulum (ER) kinase (PERK) is an ER-associated stress sensor protein which phosphorylates eukaryotic initiation factor 2α (eIF2α) to induce translation attenuation in response to ER stress. PERK is also a regulator of lipogenesis during adipocyte differentiation through activation of the cleavage of sterol regulatory element binding protein 1 (SREBP1), resulting in the upregulation of lipogenic enzymes. Our recent studies have shown that human cytomegalovirus (HCMV) infection in human fibroblasts (HF) induces adipocyte-like lipogenesis through the activation of SREBP1. Here, we report that PERK expression is highly increased in HCMV-infected cells and is necessary for HCMV growth. Depletion of PERK, using short hairpin RNA (shRNA), resulted in attenuation of HCMV growth, inhibition of lipid synthesis and reduction of lipogenic gene expression. Examination of the cleavage of SREBP proteins showed PERK depletion inhibited the cleavage of SREBP1, but not SREBP2, in HCMV-infected cells, suggesting different cleavage regulatory mechanisms for SREBP1 and 2. Further studies showed that the depletion of SREBP1, but not SREBP2, reduced lipid synthesis in HCMV infection, suggesting that activation of SREBP1 is sufficient to induce lipogenesis in HCMV infection. The reduction of lipid synthesis by PERK depletion can be partially restored by expressing a Flag-tagged nuclear form of SREBP1a. Our studies also suggest that the induction of PERK in HCMV-infected cells stimulates SREBP1 cleavage by reducing levels of Insig1 (Insulin inducible gene 1) protein; this occurs independent of the phosphorylation of eIF2α. Introduction of an exogenous Insig1-Myc into HCMV infected cells significantly reduced HCMV growth and lipid synthesis. Our data demonstrate that the induction of PERK during HCMV infection is necessary for full activation of lipogenesis; this effect appears to be mediated by limiting the levels of Insig1 thus freeing SREBP1-SCAP complexes for SREBP1 processing.
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Dynein mediates the localization and activation of mTOR in normal and human cytomegalovirus-infected cells. Genes Dev 2012; 26:2015-26. [PMID: 22987636 DOI: 10.1101/gad.196147.112] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Activation of stress signaling pathways normally leads to inhibition of the mammalian target of rapamycin complex 1 (mTORC1); however, human cytomegalovirus (HCMV) infection maintains mTORC1 activity in the presence of numerous types of stress. We previously demonstrated that HCMV infection maintains mTORC1 activity during amino acid deprivation through a Ras-related GTP-binding (Rag) protein-independent mechanism. This depends on the colocalization of mTOR and its activator, Rheb (Ras homology enriched in brain)-GTP, to a perinuclear position that corresponds to the viral cytoplasmic assembly compartment (AC). The data presented here show that the HCMV-induced, amino acid depletion-resistant perinuclear localization and activation of mTORC1 occurs as early as 8 h post-infection, prior to AC formation. We show that the molecular motor dynein is required for perinuclear localization of mTORC1 in both uninfected and HCMV-infected cells. Association between dynein and mTOR is shown by coimmunoprecipitation, and inhibition of dynein function using RNAi or the small molecule inhibitor ciliobrevin A inhibits mTORC1 activity in both uninfected and HCMV-infected cells. The data suggest that mTORC1 activation requires dynein-dependent transport to a position in the cell where it can be activated. Thus, the HCMV commandeers a cellular dynein-dependent mTORC1 activation mechanism to maintain stress-resistant mTORC1 activity during infection and to form the AC.
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McCormick AL, Roback L, Wynn G, Mocarski ES. Multiplicity-dependent activation of a serine protease-dependent cytomegalovirus-associated programmed cell death pathway. Virology 2012; 435:250-7. [PMID: 23159167 DOI: 10.1016/j.virol.2012.08.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/11/2012] [Accepted: 08/26/2012] [Indexed: 01/25/2023]
Abstract
At a low MOI (≤0.01), cytomegalovirus-associated programmed cell death terminates productive infection via a pathway triggered by the mitochondrial serine protease HtrA2/Omi. This infected cell death is associated with late phase replication events naturally suppressed by the viral mitochondrial inhibitor of apoptosis (vMIA). Here, higher MOI (ranging from 0.1-3.0) triggers cell death earlier during infection independent of viral DNA synthesis. Thus, MOI-dependent activating signals early, at high MOI, or late, at low MOI, during replication promote serine protease-dependent death that is suppressed by vMIA. Treatment with an antioxidant targeting reactive oxygen species (ROS) or the serine protease inhibitor N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) delays cell death, and the combination has an additive impact. These studies identify serine proteases and ROS as important factors triggering programmed cell death induced by vMIA-deficient virus, and show that this death pathway occurs earlier and reduces viral yields as the MOI is increased.
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Affiliation(s)
- A Louise McCormick
- Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, 1462 Clifton Rd NE, Atlanta, GA 30322, USA.
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Infection of vascular endothelial cells with human cytomegalovirus under fluid shear stress reveals preferential entry and spread of virus in flow conditions simulating atheroprone regions of the artery. J Virol 2012; 86:13745-55. [PMID: 23055562 DOI: 10.1128/jvi.02244-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Atherosclerosis is a major pathogenic factor in cardiovascular diseases, which are the leading cause of mortality in developed countries. While risk factors for atherosclerosis tend to be systemic, the distribution of atherosclerotic plaques within the vasculature is preferentially located at branch points and curves where blood flow is disturbed and shear stress is low. It is now widely accepted that hemodynamic factors can modulate endothelial gene expression and function and influence the pathophysiological changes associated with atherosclerosis. Human cytomegalovirus (HCMV), a ubiquitous pathogen, has long been proposed as a risk factor for atherosclerosis. To date, the role of HCMV in atherogenesis has been explored only in static conditions, and it is not known how HCMV infection is influenced by the physiological context of flow. In this study, we utilized a parallel-plate flow system to simulate the effects of shear stresses in different regions of the vasculature in vitro. We found that endothelial cells cultured under low shear stress, which simulates the flow condition of atheroprone regions in vivo, are more permissive to HCMV infection than cells experiencing high shear stress or static conditions. Cells exposed to low shear stress show increased entry of HCMV compared to cells exposed to high shear stress or static conditions. Viral structural gene expression, viral titers, and viral spread are also enhanced in endothelial cells exposed to low shear stress. These results suggest that hemodynamic factors modulate HCMV infection of endothelial cells, thus providing new insights into the induction/acceleration of atherosclerosis by HCMV.
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