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Vittori C, Jeansonne D, Yousefi H, Faia C, Lin Z, Reiss K, Peruzzi F. Mechanisms of miR-3189-3p-mediated inhibition of c-MYC translation in triple negative breast cancer. Cancer Cell Int 2022; 22:204. [PMID: 35642054 PMCID: PMC9158314 DOI: 10.1186/s12935-022-02620-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/20/2022] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the lack of estrogen receptor, progesterone receptor, and HER2. Our lab previously characterized miR-3189-3p as a microRNA with potent anti-cancer activity against glioblastoma. Here, we hypothesized a similar activity in TNBC cells. As miR-3189-3p is predicted to target a variety of RNA binding proteins, we further hypothesized an inhibitory effect of this miRNA on protein synthesis. METHODS MDA-MB-231 and MDA-MB-468 cells were used to investigate the effect of miR-3189-3p on cell proliferation, migration, and invasion. TGCA database was used to analyze the expression of miR-3189-3p, c-MYC, 4EPB1, and eIF4E in breast cancer. Western blotting and RT-qPCR assays were used to assess the expression of selected proteins and RNAs after transfections. RESULTS Although c-MYC is not a predicted gene target for miR-3189-3p, we discovered that c-MYC protein is downregulated in miRNA-treated TNBC cells. We found that the downregulation of c-MYC by miR-3189-3p occurs in both normal growth conditions and in the absence of serum. The mechanism involved the direct inhibition of eIF4EBP1 by miR-3189-3p. Additionally, we found that miR-3189-3p could negatively affect cap-independent translation mediated by internal ribosome entry sites (IRES) or by m6A. Finally, miR-3189-3p sensitized TNBC cells to doxorubicin. CONCLUSION Overall, results indicated that miR-3189-3p exerts its anti-tumor activity through targeting translational regulatory proteins leading to an impairment in c-MYC translation, and possibly other oncogenic factors, suggesting that miR-3189-3p, alone or in combination, could be a valuable therapeutic approach against a malignancy with few treatment options.
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Affiliation(s)
- Cecilia Vittori
- grid.279863.10000 0000 8954 1233Louisiana State University Health Sciences Center and Stanley S. Scott Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
| | - Duane Jeansonne
- grid.279863.10000 0000 8954 1233Louisiana State University Health Sciences Center and Stanley S. Scott Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
| | - Hassan Yousefi
- grid.279863.10000 0000 8954 1233Department of Biochemistry, Louisiana State University Health Sciences Center, 533 Bolivar St., New Orleans, LA USA
| | - Celeste Faia
- grid.279863.10000 0000 8954 1233Louisiana State University Health Sciences Center and Stanley S. Scott Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
| | - Zhen Lin
- grid.265219.b0000 0001 2217 8588Department of Pathology and Laboratory Medicine, Tulane University Health Sciences Center and Tulane Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
| | - Krzysztof Reiss
- grid.279863.10000 0000 8954 1233Louisiana State University Health Sciences Center and Stanley S. Scott Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
| | - Francesca Peruzzi
- grid.279863.10000 0000 8954 1233Louisiana State University Health Sciences Center and Stanley S. Scott Cancer Center, 1700 Tulane Ave, New Orleans, LA USA
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Ide Y, Kitab B, Ito N, Okamoto R, Tamura Y, Matsui T, Sakoda Y, Tsukiyama-Kohara K. Characterization of host factors associated with the internal ribosomal entry sites of foot-and-mouth disease and classical swine fever viruses. Sci Rep 2022; 12:6709. [PMID: 35468926 PMCID: PMC9039067 DOI: 10.1038/s41598-022-10437-z] [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: 11/15/2021] [Accepted: 04/01/2022] [Indexed: 11/18/2022] Open
Abstract
Foot-and-mouth disease virus (FMDV) and classical swine fever virus (CSFV) possess positive-sense single-stranded RNA genomes and an internal ribosomal entry site (IRES) element within their 5′-untranslated regions. To investigate the common host factors associated with these IRESs, we established cell lines expressing a bicistronic luciferase reporter plasmid containing an FMDV-IRES or CSFV-IRES element between the Renilla and firefly luciferase genes. First, we treated FMDV-IRES cells with the French maritime pine extract, Pycnogenol (PYC), and examined its suppressive effect on FMDV-IRES activity, as PYC has been reported to have antiviral properties. Next, we performed microarray analysis to identify the host factors that modified their expression upon treatment with PYC, and confirmed their function using specific siRNAs. We found that polycystic kidney disease 1-like 3 (PKD1L3) and ubiquitin-specific peptidase 31 (USP31) were associated with FMDV-IRES activity. Moreover, silencing of these factors significantly suppressed CSFV-IRES activity. Thus, PKD1L3 and USP31 are host factors associated with the functions of FMDV- and CSFV-IRES elements.
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Affiliation(s)
- Yutaro Ide
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Bouchra Kitab
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Nobumasa Ito
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Riai Okamoto
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yui Tamura
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Takafumi Matsui
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yoshihiro Sakoda
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, 060-0818, Japan
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan. .,Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima, 890-0065, Japan.
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3
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van den Akker GGH, Zacchini F, Housmans BAC, van der Vloet L, Caron MMJ, Montanaro L, Welting TJM. Current Practice in Bicistronic IRES Reporter Use: A Systematic Review. Int J Mol Sci 2021; 22:5193. [PMID: 34068921 PMCID: PMC8156625 DOI: 10.3390/ijms22105193] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/05/2021] [Accepted: 05/12/2021] [Indexed: 12/26/2022] Open
Abstract
Bicistronic reporter assays have been instrumental for transgene expression, understanding of internal ribosomal entry site (IRES) translation, and identification of novel cap-independent translational elements (CITE). We observed a large methodological variability in the use of bicistronic reporter assays and data presentation or normalization procedures. Therefore, we systematically searched the literature for bicistronic IRES reporter studies and analyzed methodological details, data visualization, and normalization procedures. Two hundred fifty-seven publications were identified using our search strategy (published 1994-2020). Experimental studies on eukaryotic adherent cell systems and the cell-free translation assay were included for further analysis. We evaluated the following methodological details for 176 full text articles: the bicistronic reporter design, the cell line or type, transfection methods, and time point of analyses post-transfection. For the cell-free translation assay, we focused on methods of in vitro transcription, type of translation lysate, and incubation times and assay temperature. Data can be presented in multiple ways: raw data from individual cistrons, a ratio of the two, or fold changes thereof. In addition, many different control experiments have been suggested when studying IRES-mediated translation. In addition, many different normalization and control experiments have been suggested when studying IRES-mediated translation. Therefore, we also categorized and summarized their use. Our unbiased analyses provide a representative overview of bicistronic IRES reporter use. We identified parameters that were reported inconsistently or incompletely, which could hamper data reproduction and interpretation. On the basis of our analyses, we encourage adhering to a number of practices that should improve transparency of bicistronic reporter data presentation and improve methodological descriptions to facilitate data replication.
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Affiliation(s)
- Guus Gijsbertus Hubert van den Akker
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Federico Zacchini
- Department of Experimental, Diagnostic and Specialty Medicine, Bologna University, I-40138 Bologna, Italy; (F.Z.); (L.M.)
- Centro di Ricerca Biomedica Applicata—CRBA, Bologna University, Policlinico di Sant’Orsola, I-40138 Bologna, Italy
| | - Bas Adrianus Catharina Housmans
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Laura van der Vloet
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Marjolein Maria Johanna Caron
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Lorenzo Montanaro
- Department of Experimental, Diagnostic and Specialty Medicine, Bologna University, I-40138 Bologna, Italy; (F.Z.); (L.M.)
- Centro di Ricerca Biomedica Applicata—CRBA, Bologna University, Policlinico di Sant’Orsola, I-40138 Bologna, Italy
- Programma Dipartimentale in Medicina di Laboratorio, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, I-40138 Bologna, Italy
| | - Tim Johannes Maria Welting
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
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Lattimer J, Stewart H, Locker N, Tuplin A, Stonehouse NJ, Harris M. Structure-function analysis of the equine hepacivirus 5' untranslated region highlights the conservation of translational mechanisms across the hepaciviruses. J Gen Virol 2019; 100:1501-1514. [PMID: 31490115 PMCID: PMC7615701 DOI: 10.1099/jgv.0.001316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Equine hepacivirus (EHcV) (now also classified as hepacivirus A) is the closest genetic relative to hepatitis C virus (HCV) and is proposed to have diverged from HCV within the last 1000 years. The 5' untranslated regions (UTRs) of both HCV and EHcV exhibit internal ribosome entry site (IRES) activity, allowing cap-independent translational initiation, yet only the HCV 5'UTR has been systematically analysed. Here, we report a detailed structural and functional analysis of the EHcV 5'UTR. The secondary structure was determined using selective 2' hydroxyl acylation analysed by primer extension (SHAPE), revealing four stem-loops, termed SLI, SLIA, SLII and SLIII, by analogy to HCV. This guided a mutational analysis of the EHcV 5'UTR, allowing us to investigate the roles of the stem-loops in IRES function. This approach revealed that SLI was not required for EHcV IRES-mediated translation. Conversely, SLIII was essential, specifically SLIIIb, SLIIId and a GGG motif that is conserved across the Hepaciviridae. Further SHAPE analysis provided evidence that this GGG motif mediated interaction with the 40S ribosomal subunit, whilst a CUU sequence in the apical loop of SLIIIb mediated an interaction with eIF3. In addition, we showed that a microRNA122 target sequence located between SLIA and SLII mediated an enhancement of translation in the context of a subgenomic replicon. Taken together, these results highlight the conservation of hepaciviral translation mechanisms, despite divergent primary sequences.
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Affiliation(s)
- Joseph Lattimer
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Hazel Stewart
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, GU2 7XH, UK
| | - Andrew Tuplin
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Nicola J. Stonehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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5
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Matsui T, Handa Y, Kanda T, Tsukiyama-Kohara K. Silencing of the foot-and-mouth disease virus internal ribosomal entry site by targeting relatively conserved region among serotypes. Virus Genes 2019; 55:786-794. [PMID: 31367998 PMCID: PMC6831537 DOI: 10.1007/s11262-019-01696-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/24/2019] [Indexed: 02/05/2023]
Abstract
Foot-and-mouth disease (FMD) is a host-restricted disease of cloven-hoofed animals, such as cattle and pigs. There are seven major serotypes of FMD virus that exhibit high antigenic variation, making vaccine strain selection difficult. However, there is an internal ribosomal entry site (IRES) element within the 5′ untranslated region of the FMD virus (FMDV) RNA genome that is relatively conserved among FMDV serotypes and could be used as a pan-serotype target for disease interventions. To determine the potential for targeting the IRES as promising drug target, we designed a short interfering RNA (siRNA) targeting a relatively conserved region in the FMDV-IRES. The siRNA affected FMDV-IRES expression but not the expression of the encephalomyocarditis virus or hepatitis C virus IRES. To evaluate the effects of siRNA-mediated silencing, we established cell lines expressing a bicistronic luciferase reporter plasmid, which contained an FMDV-IRES element between the Renilla and firefly luciferase genes. The designed siRNA inhibited FMDV-IRES-mediated translation in a concentration-dependent manner. In order to sustain this inhibitory effect, we designed a short hairpin RNA (shRNA)-expressing lentiviral vector. The results showed that the lenti-shRNA vector significantly suppressed FMDV-IRES activity for up to 2 weeks in cell culture. Thus, our findings in this study provided a basis for the development of effective pan-serotype FMDV inhibitors.
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Affiliation(s)
- Takafumi Matsui
- Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan
| | - Yoshio Handa
- Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan
| | - Takehiro Kanda
- Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan.,Department of Molecular Virology, Graduate School of Medicine, Kyoto University, 53 Shogoin-kawahara-cho Sakyo-ku, Kyoto, Kyoto, 606-8507, Japan
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan. .,Department of Animal Hygiene, Joint Facility of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima, 890-0065, Japan.
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6
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Ye X, Pan T, Wang D, Fang L, Ma J, Zhu X, Shi Y, Zhang K, Zheng H, Chen H, Li K, Xiao S. Foot-and-Mouth Disease Virus Counteracts on Internal Ribosome Entry Site Suppression by G3BP1 and Inhibits G3BP1-Mediated Stress Granule Assembly via Post-Translational Mechanisms. Front Immunol 2018; 9:1142. [PMID: 29887867 PMCID: PMC5980976 DOI: 10.3389/fimmu.2018.01142] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 05/07/2018] [Indexed: 11/13/2022] Open
Abstract
Foot-and-mouth disease (FMD) is a highly contagious, severe viral illness notifiable to the World Organization for Animal Health. The causative agent, FMD virus (FMDV), replicates rapidly and efficiently inhibits host translation and the innate immune response for it has developed multiple tactics to evade host defenses and takes over gene expression machinery in the host cell. Here, we report a systemic analysis of the proteome and phosphoproteome of FMDV-infected cells. Bioinformatics analysis suggested that FMDV infection shuts off host cap-dependent translation, but leaves intact internal ribosome entry site (IRES)-mediated translation for viral proteins. Interestingly, several FMDV IRES-transacting factors, including G3BP stress granule assembly factor 1 (G3BP1), were dephosphorylated during FMDV infection. Ectopic expression of G3BP1 inhibited FMDV IRES activity, promoted assembly of stress granules, and activated innate immune responses, collectively suppressing FMDV replication. To counteract these host protective responses, FMDV-induced dephosphorylation of G3BP1, compromising its inhibitory effect on viral IRES. In addition, FMDV also proteolytically cleaved G3BP1 by its 3C protease (3Cpro). G3BP1 was cleaved at glutamic acid-284 (E284) by FMDV 3Cpro, and this cleavage completely lost the abilities of G3BP1 to activate innate immunity and to inhibit FMDV replication. Together, these data provide new insights into the post-translational mechanisms by which FMDV limits host stress and antiviral responses and indicate that G3BP1 dephosphorylation and its proteolysis by viral protease are important factors in the failure of host defense against FMDV infection.
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Affiliation(s)
- Xu Ye
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Ting Pan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Jun Ma
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Xinyu Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Yanling Shi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Keshan Zhang
- National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Haixue Zheng
- National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Kui Li
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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Kim JH, Sung PS, Lee EB, Hur W, Park DJ, Shin EC, Windisch MP, Yoon SK. GRIM-19 Restricts HCV Replication by Attenuating Intracellular Lipid Accumulation. Front Microbiol 2017; 8:576. [PMID: 28443075 PMCID: PMC5387058 DOI: 10.3389/fmicb.2017.00576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/20/2017] [Indexed: 12/15/2022] Open
Abstract
Gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) targets multiple signaling pathways involved in cell death and growth. However, the role of GRIM-19 in the pathogenesis of hepatitis virus infections remains unexplored. Here, we investigated the restrictive effects of GRIM-19 on the replication of hepatitis C virus (HCV). We found that GRIM-19 protein levels were reduced in HCV-infected Huh7 cells and Huh7 cells harboring HCV replicons. Moreover, ectopically expressed GRIM-19 caused a reduction in both intracellular viral RNA levels and secreted viruses in HCVcc-infected cell cultures. The restrictive effect on HCV replication was restored by treatment with siRNA against GRIM-19. Interestingly, GRIM-19 overexpression did not alter the level of phosphorylated STAT3 or its subcellular distribution. Strikingly, forced expression of GRIM-19 attenuated an increase in intracellular lipid droplets after oleic acid (OA) treatment or HCVcc infection. GRIM-19 overexpression abrogated fatty acid-induced upregulation of sterol regulatory element-binding transcription factor-1 (SREBP-1c), resulting in attenuated expression of its target genes such as fatty acid synthase (FAS) and acetyl CoA carboxylase (ACC). Treatment with OA or overexpression of SREBP-1c in GRIM-19-expressing, HCVcc-infected cells restored HCV replication. Our results suggest that GRIM-19 interferes with HCV replication by attenuating intracellular lipid accumulation and therefore is an anti-viral host factor that could be a promising target for HCV treatment.
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Affiliation(s)
- Jung-Hee Kim
- The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University of KoreaSeoul, South Korea
| | - Pil S Sung
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Eun B Lee
- The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University of KoreaSeoul, South Korea
| | - Wonhee Hur
- The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University of KoreaSeoul, South Korea
| | - Dong J Park
- The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University of KoreaSeoul, South Korea
| | - Eui-Cheol Shin
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Marc P Windisch
- Hepatitis Research Laboratory, Discovery Biology Department, Institut Pasteur Korea, Seongnam-siGyeonggi-do, South Korea
| | - Seung K Yoon
- The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University of KoreaSeoul, South Korea
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8
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Kanda T, Ozawa M, Tsukiyama-Kohara K. IRES-mediated translation of foot-and-mouth disease virus (FMDV) in cultured cells derived from FMDV-susceptible and -insusceptible animals. BMC Vet Res 2016; 12:66. [PMID: 27036295 PMCID: PMC4815274 DOI: 10.1186/s12917-016-0694-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 03/23/2016] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Foot-and-mouth disease virus (FMDV) possess a positive sense, single stranded RNA genome. Internal ribosomal entry site (IRES) element exists within its 5' untranslated region (5'UTR) of the viral RNA. Translation of the viral RNA is initiated by internal entry of the 40S ribosome within the IRES element. This process is facilitated by cellular factors known as IRES trans-acting factors (ITAFs). Foot-and-mouth disease (FMD) is host-restricted disease for cloven-hoofed animals such as cattle and pigs, but the factors determining the host range have not been identified yet. Although, ITAFs are known to promote IRES-mediated translation, these findings were confirmed only in cells derived from FMDV-insusceptible animals so far. We evaluated and compared the IRES-mediated translation activities among cell lines derived from four different animal species using bicistronic luciferase reporter plasmid, which possesses an FMDV-IRES element between Renilla and Firefly luciferase genes. Furthermore, we analyzed the effect of the cellular factors on IRES-mediated translation by silencing the cellular factors using siRNA in both FMDV-susceptible and -insusceptible animal cells. RESULTS Our data indicated that IRES-mediated translational activity was not linked to FMDV host range. ITAF45 promoted IRES-mediated translation in all cell lines, and the effects of poly-pyrimidine tract binding protein (PTB) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) were observed only in FMDV-susceptible cells. Thus, PTB and 4E-BP1 may influence the host range of FMDV. CONCLUSIONS IRES-mediated translation activity of FMDV was not predictive of its host range. ITAF45 promoted IRES-mediated translation in all cells, and the effects of PTB and 4E-BP1 were observed only in FMDV-susceptible cells.
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Affiliation(s)
- Takehiro Kanda
- Department of Animal Hygiene, Joint Facility of Veterinary Medicine, Kagoshima University, Kagoshima, Kagoshima, Japan
| | - Makoto Ozawa
- Department of Animal Hygiene, Joint Facility of Veterinary Medicine, Kagoshima University, Kagoshima, Kagoshima, Japan.,Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, Kagoshima, Kagoshima, Japan
| | - Kyoko Tsukiyama-Kohara
- Department of Animal Hygiene, Joint Facility of Veterinary Medicine, Kagoshima University, Kagoshima, Kagoshima, Japan. .,Transboundary Animal Disease Center, Joint Facility of Veterinary Medicine, Kagoshima University, Kagoshima, Kagoshima, Japan.
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9
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The second-generation mTOR kinase inhibitor INK128 exhibits anti-inflammatory activity in lipopolysaccharide-activated RAW 264.7 cells. Inflammation 2015; 37:756-65. [PMID: 24385238 DOI: 10.1007/s10753-013-9794-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cross-talk between the mTOR (mechanistic target of rapamycin) and NF-κB (nuclear factor kappa-B) pathways has been reported to regulate macrophage responses to lipopolysaccharide (LPS). In this study, we aimed to explore the effect of INK128, a second-generation inhibitor of mTOR, on the inflammatory cytokine production in LPS-stimulated RAW 264.7 cells. Our data showed that INK128 strikingly inhibited the phosphorylation of p70S6K, 4E-BP1 and AKTSer473 in both unstimulated and LPS-stimulated cells. Although it increased the phosphorylation levels of inhibitor kappa-B (IκB) in LPS-stimulated cells, INK128 did not significantly change the levels of NF-κB phosphorylation. In addition, LPS-induced expression of IL-1β and IL-6 was markedly suppressed by INK128 at both mRNA and protein levels. However, the expression of Tumor necrosis factor-alpha (TNF-α protein), but not its mRNA level, was suppressed by this reagent. Our results suggest that the mTOR inhibitor INK128 not only regulates the NF-κB signaling but also influences the inflammatory cytokine expression at both transcriptional and translational levels.
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10
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Promotion of Viral IRES-Mediated Translation Initiation under Mild Hypothermia. PLoS One 2015; 10:e0126174. [PMID: 25951166 PMCID: PMC4423848 DOI: 10.1371/journal.pone.0126174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/30/2015] [Indexed: 12/21/2022] Open
Abstract
Internal ribosome entry site (IRES)-mediated translation is an essential replication step for certain viruses. As IRES-mediated translation is regulated differently from cap-dependent translation under various cellular conditions, we sought to investigate whether temperature influences efficiency of viral IRES-mediated translation initiation by using bicistronic reporter constructs containing an IRES element of encephalomyocarditis virus (EMCV), foot-and-mouth disease virus (FMDV), hepatitis C virus (HCV), human rhinovirus (HRV) or poliovirus (PV). Under mild hypothermic conditions (30 and 35°C), we observed increases in the efficiency of translation initiation by HCV and HRV IRES elements compared to translation initiation at 37°C. The promotion of HRV IRES activity was observed as early as 2 hours after exposure to mild hypothermia. We also confirmed the promotion of translation initiation by HRV IRES under mild hypothermia in multiple cell lines. The expression levels and locations of polypyrimidine tract-binding protein (PTB) and upstream of N-Ras (unr), the IRES trans-acting factors (ITAFs) of HCV and HRV IRES elements, were not modulated by the temperature shift from 37°C to 30°C. Taken together, this study demonstrates that efficiency of translation initiation by some viral IRES elements is temperature dependent.
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Rapamycin and everolimus facilitate hepatitis E virus replication: revealing a basal defense mechanism of PI3K-PKB-mTOR pathway. J Hepatol 2014; 61:746-54. [PMID: 24859454 DOI: 10.1016/j.jhep.2014.05.026] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 05/08/2014] [Accepted: 05/09/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Humans are frequently exposed to hepatitis E virus (HEV). Nevertheless, the disease mainly affects pregnant women and immunocompromised individuals. Organ recipients receiving immunosuppressants, such as rapalogs, to prevent rejection have a high risk for developing chronic hepatitis following HEV infection. Rapalogs constitute potent inhibitors of mTOR including rapamycin and everolimus. As a master kinase, the mechanism-of-action of mTOR is not only associated with the immunosuppressive capacity of rapalogs but is also tightly regulated during pregnancy because of increased nutritional demands. METHODS We thus investigated the role of mTOR in HEV infection by using two state-of-the-art cell culture models: a subgenomic HEV containing luciferase reporter and a full-length HEV infectious cell culture system. RESULTS In both subgenomic and full-length HEV models, HEV infection was aggressively escalated by treatment of rapamycin or everolimus. Inhibition of mTOR was confirmed by Western blot showing the inhibition of its downstream target, S6 phosphorylation. Consistently, stable silencing of mTOR by lentiviral RNAi resulted in a significant increase in intracellular HEV RNA, suggesting an antiviral function of mTOR in HEV infection. By targeting a series of other up- and downstream elements of mTOR signaling, we further revealed an effective basal defense mechanism of the PI3K-PKB-mTOR pathway against HEV, which is through the phosphorylated eIF4E-binding protein 1 (4E-BP1), however independent of autophagy formation. CONCLUSIONS The discovery that PI3K-PKB-mTOR pathway limits HEV infection through 4E-BP1 and acts as a gate-keeper in human HEV target cells bears significant implications in managing immunosuppression in HEV-infected organ transplantation recipients.
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Stewart H, Walter C, Jones D, Lyons S, Simmonds P, Harris M. The non-primate hepacivirus 5' untranslated region possesses internal ribosomal entry site activity. J Gen Virol 2013; 94:2657-2663. [PMID: 24026670 PMCID: PMC3836496 DOI: 10.1099/vir.0.055764-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The 5′ untranslated region (5′UTR) of the recently described non-primate hepacivirus (NPHV) contains a region with sequence homology to the internal ribosomal entry site (IRES) of hepatitis C virus (HCV) and GB virus B (GBV-B). Here, we demonstrated internal translation initiation by the NPHV 5′UTR in a bicistronic vector. An RNA stem–loop upstream of the NPHV IRES was structurally distinct from corresponding regions in HCV and GBV-B, and was not required for IRES function. Insertion of the NPHV stem–loop into the corresponding region of the HCV 5′UTR within the HCV subgenomic replicon significantly impaired RNA replication, indicating that long-range interactions between the 5′UTR and cis-acting downstream elements within the NPHV genome are not interchangeable with those of HCV. Despite similarities in IRES structure and function between hepaciviruses, replication elements in the NPHV 5′UTR appear functionally distinct from those of HCV.
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Affiliation(s)
- Hazel Stewart
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Cheryl Walter
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Dale Jones
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Sinead Lyons
- Infection and Immunity Division, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK
| | - Peter Simmonds
- Infection and Immunity Division, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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Dennis MD, Shenberger JS, Stanley BA, Kimball SR, Jefferson LS. Hyperglycemia mediates a shift from cap-dependent to cap-independent translation via a 4E-BP1-dependent mechanism. Diabetes 2013; 62:2204-14. [PMID: 23434932 PMCID: PMC3712054 DOI: 10.2337/db12-1453] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Diabetes and its associated hyperglycemia induce multiple changes in liver function, yet we know little about the role played by translational control of gene expression in mediating the responses to these conditions. Here, we evaluate the hypothesis that hyperglycemia-induced O-GlcNAcylation of the translational regulatory protein 4E-BP1 alters hepatic gene expression through a process involving the selection of mRNA for translation. In both streptozotocin (STZ)-treated mice and cells in culture exposed to hyperglycemic conditions, expression of 4E-BP1 and its interaction with the mRNA cap-binding protein eIF4E were enhanced in conjunction with downregulation of cap-dependent and concomitant upregulation of cap-independent mRNA translation, as assessed by a bicistronic luciferase reporter assay. Phlorizin treatment of STZ-treated mice lowered blood glucose concentrations and reduced activity of the cap-independent reporter. Notably, the glucose-induced shift from cap-dependent to cap-independent mRNA translation did not occur in cells lacking 4E-BP1. The extensive nature of this shift in translational control of gene expression was revealed using pulsed stable isotope labeling by amino acids in cell culture to identify proteins that undergo altered rates of synthesis in response to hyperglycemia. Taken together, these data provide evidence for a novel mechanism whereby O-GlcNAcylation of 4E-BP1 mediates translational control of hepatic gene expression.
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Affiliation(s)
- Michael D. Dennis
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; the
| | - Jeffrey S. Shenberger
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and the
| | - Bruce A. Stanley
- Department of Microbiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Scot R. Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; the
- Corresponding author: Scot R. Kimball,
| | - Leonard S. Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; the
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Cosnefroy O, Jaspart A, Calmels C, Parissi V, Fleury H, Ventura M, Reigadas S, Andréola ML. Activation of GCN2 upon HIV-1 infection and inhibition of translation. Cell Mol Life Sci 2013; 70:2411-21. [PMID: 23417324 PMCID: PMC11113181 DOI: 10.1007/s00018-013-1272-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/23/2012] [Accepted: 01/21/2013] [Indexed: 12/19/2022]
Abstract
Higher eukaryotic organisms have a variety of specific and nonspecific defense mechanisms against viral invaders. In animal cells, viral replication may be limited through the decrease in translation. Some viruses, however, have evolved mechanisms that counteract the response of the host. We report that infection by HIV-1 triggers acute decrease in translation. The human protein kinase GCN2 (eIF2AK4) is activated by phosphorylation upon HIV-1 infection in the hours following infection. Thus, infection by HIV-1 constitutes a stress that leads to the activation of GCN2 with a resulting decrease in protein synthesis. We have shown that GCN2 interacts with HIV-1 integrase (IN). Transfection of IN in amino acid-starved cells, where GCN2 is activated, increases the protein synthesis level. These results point to an as yet unknown role of GCN2 as an early mediator in the cellular response to HIV-1 infection, and suggest that the virus is able to overcome the involvement of GCN2 in the cellular response by eliciting methods to maintain protein synthesis.
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Affiliation(s)
- Ophélie Cosnefroy
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Present Address: MRC National Institute for Medical Research, The Ridgeway Mill Hill, London, UK
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
| | - Anaïs Jaspart
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
| | - Christina Calmels
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
| | - Vincent Parissi
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
| | - Hervé Fleury
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
- Laboratoire de Virologie. CHU de Bordeaux, Bordeaux, France
| | - Michel Ventura
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
| | - Sandrine Reigadas
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
- Laboratoire de Virologie. CHU de Bordeaux, Bordeaux, France
| | - Marie-Line Andréola
- UMR 5234 CNRS; Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France
- Structure Fédérative de Recherche “TransbioMed”, Bordeaux, France
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Chan CP, Kok KH, Tang HMV, Wong CM, Jin DY. Internal ribosome entry site-mediated translational regulation of ATF4 splice variant in mammalian unfolded protein response. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2165-75. [PMID: 23665047 DOI: 10.1016/j.bbamcr.2013.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 04/30/2013] [Accepted: 05/02/2013] [Indexed: 02/04/2023]
Abstract
Activating transcription factor 4 (ATF4) is a master regulator of genes involved in unfolded protein response (UPR) and its translation is regulated through reinitiation at upstream open reading frames. Here, we demonstrate internal ribosome entry site (IRES)-mediated translation of an alternatively spliced variant of human ATF4. This variant that contains four upstream open reading frames in the 5' leader region was expressed in leukocytes and other tissues. mRNA and protein expression of this variant was activated in the UPR. Its translation was neither inhibited by steric hindrance nor affected by eIF4G1 inactivation, indicating a cap-independent and IRES-dependent mechanism not mediated by ribosome scanning-reinitiation. The IRES activity mapped to a highly structured region that partially overlaps with the third and fourth open reading frames was unlikely attributed to cryptic promoter or splicing, but was activated by PERK-induced eIF2α phosphorylation. Taken together, our findings reveal a new mechanism for translational regulation of ATF4 in mammalian UPR.
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Affiliation(s)
- Ching-Ping Chan
- Department of Biochemistry, The University of Hong Kong, Pokfulam, Hong Kong
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Kanda T, Wu S, Kiyohara T, Nakamoto S, Jiang X, Miyamura T, Imazeki F, Ishii K, Wakita T, Yokosuka O. Interleukin-29 suppresses hepatitis A and C viral internal ribosomal entry site-mediated translation. Viral Immunol 2012; 25:379-86. [PMID: 23035851 DOI: 10.1089/vim.2012.0021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Our aim was to investigate the effects of interferons (IFNs)-λ (interleukin-29 [IL-29], IL-28A, and IL-28B) on hepatitis C virus (HCV) and hepatitis A virus (HAV) internal ribosomal entry site (IRES)-mediated translation. The effects of these IFNs on HCV/HAV translation from HAV/HCV IRES were investigated using bicistronic reporter constructs. We transfected HCV/HAV IRES constructs into these IFN-expressing cell lines. IL-29 showed stronger inhibition of their IRES-mediated translation. Combining IL-29 with IFN-α or amantadine resulted in stronger inhibition of HAV IRES activity. Our findings demonstrated a novel antiviral effect of IFNs-λ against HAV and HCV through the suppression of IRES-mediated translation.
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Affiliation(s)
- Tatsuo Kanda
- Department of Medicine and Clinical Oncology, Chiba University Graduate School of Medicine, Chiba, Japan.
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