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Das GC, Hollinger FB. GSK-3β as a Potential Coordinator of Anabolic and Catabolic Pathways in Hepatitis C Virus Insulin Resistance. Intervirology 2023; 67:6-18. [PMID: 38104537 PMCID: PMC10794973 DOI: 10.1159/000535787] [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: 11/16/2022] [Accepted: 12/11/2023] [Indexed: 12/19/2023] Open
Abstract
INTRODUCTION Chronic hepatitis C infection can result in insulin resistance (IR). We have previously shown that it occurs through the interaction of pathways for glucose homeostasis, insulin signaling, and autophagy. But it is not known how soon the pathways are activated and how IR is related to the signals generated by catabolic and anabolic conditions occurring in infected cells. We have extended our studies to a cell culture system mimicking acute infection and to downstream pathways involving energy-sensor AMPK and nutrient-sensor mTOR that are active in catabolic and anabolic processes within the infected cells. METHODS Huh7 liver cells in culture were infected with hepatitis C virus (HCV). We performed proteomics analysis of key proteins in infected cells by Western blotting and IP experiments, with or without IFNα exposure as a component of conventional therapeutic strategy. RESULTS We present evidence that (a) IRS-1 Ser312, Beclin-1, protein conjugate Atg12-Atg5 or GS Ser641 are up-regulated early in infection presumably by activating the same pathways as utilized for persistent infection; (b) Bcl-XL, an inhibitor of both autophagy and apoptosis, is present in a core complex with IRS-1 Ser312 and Beclin-1 during progression of IR; (c) AMPK level remains about the same in infected cells where it is activated by phosphorylation at Thr172 concomitant with increased autophagy, a hallmark of catabolic conditions; (d) an mTOR level that promotes anabolism is increased rather than decreased under an expanded autophagy; (e) hypophosphorylation of translational repressor 4E-BP1 downstream of mTOR is suggestive of reduced protein synthesis; and (f) β-catenin, is up-regulated but not phosphorylated suggesting indirectly our previous contention that its kinase, GSK-3β, is mostly in an inactive state. CONCLUSION We report that in the development of IR following chronic infection, anabolic and catabolic pathways are activated early, and the metabolic interaction occurs possibly in a core complex with IRS-1 Ser312, Beclin-1, and autophagy inhibitor Bcl-XL. Induction of autophagy is usually controlled by a two-edged mechanism acting in opposition under anabolic and catabolic conditions by AMPK/mTOR/4E-BP1 pathway with GSK-3β-mediated feedback loops. However, we have observed an up-regulation of mTOR along with an up-regulation of AMPK caused by HCV infection is a deviation from the normal scenario described above which might be of therapeutic interest.
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Affiliation(s)
- Gokul C Das
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - F Blaine Hollinger
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
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Kouroumalis E, Voumvouraki A, Augoustaki A, Samonakis DN. Autophagy in liver diseases. World J Hepatol 2021; 13:6-65. [PMID: 33584986 PMCID: PMC7856864 DOI: 10.4254/wjh.v13.i1.6] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 12/10/2020] [Accepted: 12/26/2020] [Indexed: 02/06/2023] Open
Abstract
Autophagy is the liver cell energy recycling system regulating a variety of homeostatic mechanisms. Damaged organelles, lipids and proteins are degraded in the lysosomes and their elements are re-used by the cell. Investigations on autophagy have led to the award of two Nobel Prizes and a health of important reports. In this review we describe the fundamental functions of autophagy in the liver including new data on the regulation of autophagy. Moreover we emphasize the fact that autophagy acts like a two edge sword in many occasions with the most prominent paradigm being its involvement in the initiation and progress of hepatocellular carcinoma. We also focused to the implication of autophagy and its specialized forms of lipophagy and mitophagy in the pathogenesis of various liver diseases. We analyzed autophagy not only in well studied diseases, like alcoholic and nonalcoholic fatty liver and liver fibrosis but also in viral hepatitis, biliary diseases, autoimmune hepatitis and rare diseases including inherited metabolic diseases and also acetaminophene hepatotoxicity. We also stressed the different consequences that activation or impairment of autophagy may have in hepatocytes as opposed to Kupffer cells, sinusoidal endothelial cells or hepatic stellate cells. Finally, we analyzed the limited clinical data compared to the extensive experimental evidence and the possible future therapeutic interventions based on autophagy manipulation.
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Affiliation(s)
- Elias Kouroumalis
- Liver Research Laboratory, University of Crete Medical School, Heraklion 71110, Greece
| | - Argryro Voumvouraki
- 1 Department of Internal Medicine, AHEPA University Hospital, Thessaloniki 54636, Greece
| | - Aikaterini Augoustaki
- Department of Gastroenterology and Hepatology, University Hospital of Crete, Heraklion 71110, Greece
| | - Dimitrios N Samonakis
- Department of Gastroenterology and Hepatology, University Hospital of Crete, Heraklion 71110, Greece.
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3
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Chu JYK, Ou JHJ. Autophagy in HCV Replication and Protein Trafficking. Int J Mol Sci 2021; 22:ijms22031089. [PMID: 33499186 PMCID: PMC7865906 DOI: 10.3390/ijms22031089] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/11/2022] Open
Abstract
Autophagy is a catabolic process that is important for maintaining cellular homeostasis. It is also known to possess other functions including protein trafficking and anti-microbial activities. Hepatitis C virus (HCV) is known to co-opt cellular autophagy pathway to promote its own replication. HCV regulates autophagy through multiple mechanisms to control intracellular protein and membrane trafficking to enhance its replication and suppress host innate immune response. In this review, we discuss the current knowledge on the interplay between HCV and autophagy and the crosstalk between HCV-induced autophagy and host innate immune responses.
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Li C, Wang L, Liu J, Yu Y, Huang Y, Huang X, Wei J, Qin Q. Singapore Grouper Iridovirus (SGIV) Inhibited Autophagy for Efficient Viral Replication. Front Microbiol 2020; 11:1446. [PMID: 32676067 PMCID: PMC7333352 DOI: 10.3389/fmicb.2020.01446] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 06/04/2020] [Indexed: 01/10/2023] Open
Abstract
Autophagy is a conserved catabolic process that occurs at basal levels to maintain cellular homeostasis. Most virus infections can alter the autophagy level, which functions as either a pro-viral or antiviral pathway, depending on the virus and host cells. Singapore grouper iridovirus (SGIV) is a novel fish DNA virus that has caused great economic losses for the marine aquaculture industry. In this study, we found that SGIV inhibited autophagy in grouper spleen (GS) cells which was evidenced by the changes of LC3-II, Beclin1 and p-mTOR levels. Further study showed that SGIV developed at least two strategies to inhibit autophagy: (1) increasing the cytoplasmic p53 level; and (2) encoding viral proteins (VP48, VP122, VP132) that competitively bind autophagy related gene 5 and mediately affect LC3 conversion. Moreover, activation of autophagy by rapamycin or overexpressing LC3 decreased SGIV replication. These results provide an antiviral strategy from the perspective of autophagy.
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Affiliation(s)
- Chen Li
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Liqun Wang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jiaxin Liu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yepin Yu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Youhua Huang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Xiaohong Huang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jingguang Wei
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Qiwei Qin
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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5
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Lin H, Li B, Liu M, Zhou H, He K, Fan H. Nonstructural protein 6 of porcine epidemic diarrhea virus induces autophagy to promote viral replication via the PI3K/Akt/mTOR axis. Vet Microbiol 2020; 244:108684. [PMID: 32402351 PMCID: PMC7165116 DOI: 10.1016/j.vetmic.2020.108684] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 04/05/2020] [Accepted: 04/08/2020] [Indexed: 02/07/2023]
Abstract
Autophagy is beneficial to PEDV replication. PEDV nonstructural protein 6 (nsp6) is a key protein involved in PEDV-induced autophagy. Nsp6 of PEDV induced autophagy via the PI3K/Akt/mTOR signaling pathway.
Porcine epidemic diarrhea virus (PEDV) has caused, and continues to cause, severe economic losses to the swine industry worldwide. The pathogenic mechanism and immune regulatory interactions between PEDV and the host remain largely unknown. In this study, the interaction between autophagy and PEDV replication in intestinal porcine epithelial (IPEC-J2) cells was investigated. The effects of the structural and nonstructural proteins of PEDV on the autophagy process and the autophagy-related signaling pathways were also examined. The results shown that PEDV replication increased the autophagy flux in IPEC-J2 cells, and that autophagy was beneficial to PEDV replication, which may be one of the reasons for the rapid damage to intestinal epithelial cells and the enhanced virulence of PEDV in both newborn piglets and finishing pigs. When autophagy was pharmacologically induced by rapamycin, PEDV replication increased from 8.5 × 105 TCID50/mL to 8.8 × 106 TCID50/mL in IPEC-J2 cells. When autophagy was pharmacologically suppressed by hydroxychloroquine, PEDV replication decreased from 8.5 × 105 TCID50/mL to 7.9 × 104 TCID50/mL. To identify which PEDV proteins were the key inducers of autophagy, all 4 structural proteins and 17 nonstructural proteins of PEDV were eukaryotic expressed. It was found that the nonstructural protein 6 (nsp6) and ORF3 of PEDV were able to induce significant autophagy in IPEC-J2 cells, but the other proteins were unable to induce autophagy. It was indicated that nsp6-induced autophagy mainly occurred via the PI3K/Akt/mTOR signaling pathway. The results accelerate the understanding of the biology and pathogenesis of PEDV infection and provide new insights into the development of effective therapeutic strategies.
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Affiliation(s)
- Huixing Lin
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bin Li
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Mingxing Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hong Zhou
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Kongwang He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, China.
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Ríos-Ocampo WA, Navas MC, Buist-Homan M, Faber KN, Daemen T, Moshage H. Hepatitis C Virus Proteins Core and NS5A Are Highly Sensitive to Oxidative Stress-Induced Degradation after eIF2α/ATF4 Pathway Activation. Viruses 2020; 12:v12040425. [PMID: 32283772 PMCID: PMC7232227 DOI: 10.3390/v12040425] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/07/2020] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) infection is accompanied by increased oxidative stress and endoplasmic reticulum stress as a consequence of viral replication, production of viral proteins, and pro-inflammatory signals. To overcome the cellular stress, hepatocytes have developed several adaptive mechanisms like anti-oxidant response, activation of Unfolded Protein Response and autophagy to achieve cell survival. These adaptive mechanisms could both improve or inhibit viral replication, however, little is known in this regard. In this study, we investigate the mechanisms by which hepatocyte-like (Huh7) cells adapt to cellular stress in the context of HCV protein overexpression and oxidative stress. Huh7 cells stably expressing individual HCV (Core, NS3/4A and NS5A) proteins were treated with the superoxide anion donor menadione to induce oxidative stress. Production of reactive oxygen species and activation of caspase 3 were quantified. The activation of the eIF2α/ATF4 pathway and changes in the steady state levels of the autophagy-related proteins LC3 and p62 were determined either by quantitative polymerase chain reaction (qPCR) or Western blotting. Huh7 cells expressing Core or NS5A demonstrated reduced oxidative stress and apoptosis. In addition, phosphorylation of eIF2α and increased ATF4 and CHOP expression was observed with subsequent HCV Core and NS5A protein degradation. In line with these results, in liver biopsies from patients with hepatitis C, the expression of ATF4 and CHOP was confirmed. HCV Core and NS5A protein degradation was reversed by antioxidant treatment or silencing of the autophagy adaptor protein p62. We demonstrated that hepatocyte-like cells expressing HCV proteins and additionally exposed to oxidative stress adapt to cellular stress through eIF2a/ATF4 activation and selective degradation of HCV pro-oxidant proteins Core and NS5A. This selective degradation is dependent on p62 and results in increased resistance to apoptotic cell death induced by oxidative stress. This mechanism may provide a new key for the study of HCV pathology and lead to novel clinically applicable therapeutic interventions.
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Affiliation(s)
- W. Alfredo Ríos-Ocampo
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (M.B.-H.); (K.N.F.); (H.M.)
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
- Gastrohepatology Group, Medicine School, University of Antioquia, Medellin 050010, Colombia;
- Correspondence: ; Tel.: +31-50-361-2364 or +31-638-955-716
| | - María-Cristina Navas
- Gastrohepatology Group, Medicine School, University of Antioquia, Medellin 050010, Colombia;
| | - Manon Buist-Homan
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (M.B.-H.); (K.N.F.); (H.M.)
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (M.B.-H.); (K.N.F.); (H.M.)
| | - Toos Daemen
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
| | - Han Moshage
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (M.B.-H.); (K.N.F.); (H.M.)
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7
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The Role of Autophagy in Interferon/Ribavirin Responders and Non-Responders with Hepatitis C Virus Infection. Jundishapur J Microbiol 2020. [DOI: 10.5812/jjm.92560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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8
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Echavarria-Consuegra L, Smit JM, Reggiori F. Role of autophagy during the replication and pathogenesis of common mosquito-borne flavi- and alphaviruses. Open Biol 2020; 9:190009. [PMID: 30862253 PMCID: PMC6451359 DOI: 10.1098/rsob.190009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Arboviruses that are transmitted to humans by mosquitoes represent one of the most important causes of febrile illness worldwide. In recent decades, we have witnessed a dramatic re-emergence of several mosquito-borne arboviruses, including dengue virus (DENV), West Nile virus (WNV), chikungunya virus (CHIKV) and Zika virus (ZIKV). DENV is currently the most common mosquito-borne arbovirus, with an estimated 390 million infections worldwide annually. Despite a global effort, no specific therapeutic strategies are available to combat the diseases caused by these viruses. Multiple cellular pathways modulate the outcome of infection by either promoting or hampering viral replication and/or pathogenesis, and autophagy appears to be one of them. Autophagy is a degradative pathway generally induced to counteract viral infection. Viruses, however, have evolved strategies to subvert this pathway and to hijack autophagy components for their own benefit. In this review, we will focus on the role of autophagy in mosquito-borne arboviruses with emphasis on DENV, CHIKV, WNV and ZIKV, due to their epidemiological importance and high disease burden.
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Affiliation(s)
- Liliana Echavarria-Consuegra
- 1 Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen , Groningen , The Netherlands
| | - Jolanda M Smit
- 1 Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen , Groningen , The Netherlands
| | - Fulvio Reggiori
- 2 Department of Cell Biology, University of Groningen, University Medical Center Groningen , Groningen , The Netherlands
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Li C, Liu J, Zhang X, Yu Y, Huang X, Wei J, Qin Q. Red grouper nervous necrosis virus (RGNNV) induces autophagy to promote viral replication. FISH & SHELLFISH IMMUNOLOGY 2020; 98:908-916. [PMID: 31770643 DOI: 10.1016/j.fsi.2019.11.053] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Abstract
Autophagy is an evolutionarily conserved cellular degradation process that is essential for homeostasis. As a cell steward, autophagy is thought to be a process that may have evolved to combat intracellular pathogens. However, some virus can subvert or utilize autophagy-related membrane structures to increase viral replication. The red-spotted grouper nervous necrosis virus (RGNNV) is a fish pathogen which leads to disastrous viral nervous necrosis in larvae and juvenile groupers and other marine fishes. To better comprehend the pathogenesis and replication mechanism of RGNNV, we investigated the relationship between RGNNV and autophagy. Here, we demonstrated that RGNNV induced autophagy in grouper spleen (GS) cells, as the significant increase in ultrastructural autophagosome-like vesicles, fluorescent punctate pattern of microtubule-associated protein 1 light chain 3 (LC3), and the conversion of LC3-I to LC3-II. Additionally, ultraviolet-inactivated RGNNV and the capsid protein also triggered autophagy. Enhancement of autophagy contributed to RGNNV replication, whereas blocked autophagy decreased RGNNV replication. Moreover, impeded fusion of autophagosomes and lysosomes also reduced RGNNV replication, indicating that RGNNV utilized the different steps of autophagy pathway to facilitate viral replication. The further study showed that RGNNV induced autophagy through activating the phosphorylation of eIF2α and inhibiting the phosphorylation of mTOR. These results will assist the search for novel drugs targets and vaccine design against RGNNV from the perspective of downregulating autophagy.
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Affiliation(s)
- Chen Li
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Jiaxin Liu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Xin Zhang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yepin Yu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Xiaohong Huang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Jingguang Wei
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China.
| | - Qiwei Qin
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China.
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Oyarzún-Arrau A, Alonso-Palomares L, Valiente-Echeverría F, Osorio F, Soto-Rifo R. Crosstalk between RNA Metabolism and Cellular Stress Responses during Zika Virus Replication. Pathogens 2020; 9:E158. [PMID: 32106582 PMCID: PMC7157488 DOI: 10.3390/pathogens9030158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/21/2020] [Accepted: 02/23/2020] [Indexed: 12/16/2022] Open
Abstract
Zika virus (ZIKV) is a mosquito-borne virus associated with neurological disorders such as Guillain-Barré syndrome and microcephaly. In humans, ZIKV is able to replicate in cell types from different tissues including placental cells, neurons, and microglia. This intricate virus-cell interaction is accompanied by virally induced changes in the infected cell aimed to promote viral replication as well as cellular responses aimed to counteract or tolerate the virus. Early in the infection, the 11-kb positive-sense RNA genome recruit ribosomes in the cytoplasm and the complex is translocated to the endoplasmic reticulum (ER) for viral protein synthesis. In this process, ZIKV replication is known to induce cellular stress, which triggers both the expression of innate immune genes and the phosphorylation of eukaryotic translation initiation factor 2 (eIF2α), shutting-off host protein synthesis. Remodeling of the ER during ZIKV replication also triggers the unfolded protein response (UPR), which induces changes in the cellular transcriptional landscapes aimed to tolerate infection or trigger apoptosis. Alternatively, ZIKV replication induces changes in the adenosine methylation patterns of specific host mRNAs, which have different consequences in viral replication and cellular fate. In addition, the ZIKV RNA genome undergoes adenosine methylation by the host machinery, which results in the inhibition of viral replication. However, despite these relevant findings, the full scope of these processes to the outcome of infection remains poorly elucidated. This review summarizes relevant aspects of the complex crosstalk between RNA metabolism and cellular stress responses against ZIKV and discusses their possible impact on viral pathogenesis.
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Affiliation(s)
- Aarón Oyarzún-Arrau
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (A.O.-A.); (L.A.-P.); (F.V.-E.)
| | - Luis Alonso-Palomares
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (A.O.-A.); (L.A.-P.); (F.V.-E.)
- HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Fernando Valiente-Echeverría
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (A.O.-A.); (L.A.-P.); (F.V.-E.)
- HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Fabiola Osorio
- Laboratory of Immunology and Cellular Stress, Immunology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; (A.O.-A.); (L.A.-P.); (F.V.-E.)
- HIV/AIDS Workgroup, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
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11
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Li X, Ma R, Li Q, Li S, Zhang H, Xie J, Bai J, Idris A, Feng R. Transmembrane Protein 39A Promotes the Replication of Encephalomyocarditis Virus via Autophagy Pathway. Front Microbiol 2019; 10:2680. [PMID: 31849860 PMCID: PMC6901969 DOI: 10.3389/fmicb.2019.02680] [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: 08/25/2019] [Accepted: 11/05/2019] [Indexed: 12/31/2022] Open
Abstract
Encephalomyocarditis virus (EMCV) causes encephalitis, myocarditis, neuropathy, reproductive disorders, and diabetes in animals. EMCV is known to induce cell autophagy; however, the molecular mechanisms underlying this remain unclear. Here, we show that the type III-transmembrane protein, transmembrane protein 39A (TMEM39A), plays a critical role in EMCV replication. We showed that EMCV GS01 strain infection upregulated TMEM39A expression. Importantly, EMCV induced autophagy in a range of host cells. The autophagy chemical inhibitor, 3-MA, inhibited EMCV replication and reduced TMEM39A expression. This is the first study demonstrating TMEM39A promoting the replication of EMCV via autophagy. Overall, we show that TMEM39A plays a positive regulatory role in EMCV proliferation and that TMEM39A expression is dependent on the autophagy pathway.
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Affiliation(s)
- Xiangrong Li
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Gansu Tech Innovation Center of Animal Cell, Biomedical Research Center, Lanzhou, China
| | - Ruixian Ma
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Life Science and Engineering College, Northwest Minzu University, Lanzhou, China
| | - Qian Li
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Life Science and Engineering College, Northwest Minzu University, Lanzhou, China
| | - Shengjun Li
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Life Science and Engineering College, Northwest Minzu University, Lanzhou, China
| | - Haixia Zhang
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Gansu Tech Innovation Center of Animal Cell, Biomedical Research Center, Lanzhou, China
| | - Jingying Xie
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China
| | - Jialin Bai
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Gansu Tech Innovation Center of Animal Cell, Biomedical Research Center, Lanzhou, China
| | - Adi Idris
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia
| | - Ruofei Feng
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.,Gansu Tech Innovation Center of Animal Cell, Biomedical Research Center, Lanzhou, China
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12
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Ke PY. Diverse Functions of Autophagy in Liver Physiology and Liver Diseases. Int J Mol Sci 2019; 20:E300. [PMID: 30642133 PMCID: PMC6358975 DOI: 10.3390/ijms20020300] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/05/2019] [Accepted: 01/08/2019] [Indexed: 01/09/2023] Open
Abstract
Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for degradation, thus maintaining cellular homeostasis and the integrity of organelles. Autophagy has emerged as playing a critical role in the regulation of liver physiology and the balancing of liver metabolism. Conversely, numerous recent studies have indicated that autophagy may disease-dependently participate in the pathogenesis of liver diseases, such as liver hepatitis, steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma. This review summarizes the current knowledge on the functions of autophagy in hepatic metabolism and the contribution of autophagy to the pathophysiology of liver-related diseases. Moreover, the impacts of autophagy modulation on the amelioration of the development and progression of liver diseases are also discussed.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
- Division of Allergy, Immunology, and Rheumatology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
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13
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Boga JA, Caballero B, Potes Y, Perez-Martinez Z, Reiter RJ, Vega-Naredo I, Coto-Montes A. Therapeutic potential of melatonin related to its role as an autophagy regulator: A review. J Pineal Res 2019; 66:e12534. [PMID: 30329173 DOI: 10.1111/jpi.12534] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/01/2018] [Accepted: 10/08/2018] [Indexed: 12/16/2022]
Abstract
There are several pathologies, syndromes, and physiological processes in which autophagy is involved. This process of self-digestion that cells trigger as a survival mechanism is complex and tightly regulated, according to the homeostatic conditions of the organ. However, in all cases, its relationship with oxidative stress alterations is evident, following a pathway that suggests endoplasmic reticulum stress and/or mitochondrial changes. There is accumulating evidence of the beneficial role that melatonin has in the regulation and restoration of damaged autophagic processes. In this review, we focus on major physiological changes such as aging and essential pathologies including cancer, neurodegenerative diseases, viral infections and obesity, and document the essential role of melatonin in the regulation of autophagy in each of these different situations.
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Affiliation(s)
- Jose A Boga
- Service of Microbiology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Beatriz Caballero
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Department of Morphology and Cell Biology, University of Oviedo, Oviedo, Spain
| | - Yaiza Potes
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Department of Morphology and Cell Biology, University of Oviedo, Oviedo, Spain
| | - Zulema Perez-Martinez
- Service of Microbiology, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, Texas
| | - Ignacio Vega-Naredo
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Department of Morphology and Cell Biology, University of Oviedo, Oviedo, Spain
| | - Ana Coto-Montes
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Department of Morphology and Cell Biology, University of Oviedo, Oviedo, Spain
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14
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Ke PY. The Multifaceted Roles of Autophagy in Flavivirus-Host Interactions. Int J Mol Sci 2018; 19:ijms19123940. [PMID: 30544615 PMCID: PMC6321027 DOI: 10.3390/ijms19123940] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/05/2018] [Accepted: 12/05/2018] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an evolutionarily conserved cellular process in which intracellular components are eliminated via lysosomal degradation to supply nutrients for organelle biogenesis and metabolic homeostasis. Flavivirus infections underlie multiple human diseases and thus exert an immense burden on public health worldwide. Mounting evidence indicates that host autophagy is subverted to modulate the life cycles of flaviviruses, such as hepatitis C virus, dengue virus, Japanese encephalitis virus, West Nile virus and Zika virus. The diverse interplay between autophagy and flavivirus infection not only regulates viral growth in host cells but also counteracts host stress responses induced by viral infection. In this review, we summarize the current knowledge on the role of autophagy in the flavivirus life cycle. We also discuss the impacts of virus-induced autophagy on the pathogeneses of flavivirus-associated diseases and the potential use of autophagy as a therapeutic target for curing flavivirus infections and related human diseases.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
- Division of Allergy, Immunology and Rheumatology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
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15
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LC3B is not recruited along with the autophagy elongation complex (ATG5-12/16L1) at HCV replication site and is dispensable for viral replication. PLoS One 2018; 13:e0205189. [PMID: 30286180 PMCID: PMC6171931 DOI: 10.1371/journal.pone.0205189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/20/2018] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) infection is known to induce autophagosome accumulation as observed by the typical punctate cytoplasmic distribution of LC3B-II in infected cells. Previously, we showed that viral RNA-dependent RNA polymerase (NS5B) interacts with ATG5, a major component of the autophagy elongation complex that is involved in the formation of double-membrane vesicles (DMV), and demonstrated that the autophagy elongation complex (ATG5-12/16L1) but not LC3B is required for proper membranous web formation. In this study, the colocalization and in situ interaction of all HCV replicase components with the constituent of the autophagy elongation complex and LC3B were analyzed. The results clearly show the recruitment of the elongation complex to the site of viral replication. Using in situ proximity ligation assay, we show that ATG5, but not ATG16L1, interacts with several HCV replicase components suggesting that the recruitment is directed via the ATG5-12 conjugate. Interestingly, no E3-like conjugation activity of ATG5-12/16L1 can be detected at the at HCV replication site since LC3B-II is not found along with the elongation complex at the site of viral replication. In agreement with this result, no sign of in situ interaction of LC3B with the replicase components is observed. Finally, using dominant negative forms of ATG proteins, we demonstrate that ATG5-12 conjugate, but not LC3-II formation, is critical for viral replication. Altogether, these findings suggest that although HCV needs the elongation complex for its replication, it has developed a mechanism to avoid canonical LC3-II accumulation at viral replication site.
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16
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Khan M, Imam H, Siddiqui A. Subversion of cellular autophagy during virus infection: Insights from hepatitis B and hepatitis C viruses. LIVER RESEARCH 2018; 2:146-156. [PMID: 31803515 PMCID: PMC6892584 DOI: 10.1016/j.livres.2018.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Autophagy is a self-eating process, in which the damaged or excessed cell organelles and misfolded protein aggregates are removed from the cellular microenvironment. Autophagy is generally thought of as a pro-survival mechanism which is not only important for balancing energy supply at times of nutrient deprivation but also in the removal of various stress stimuli to ensure homeostasis. In addition to the target materials of "self" origin, autophagy can also eliminate intracellular pathogens and acts as a defense mechanism to curb infections. In addition, autophagy is linked to the host cell's innate immune response. However, viruses have evolved various strategies to manipulate and overtake host cell machinery to establish productive replication and maintain infectious process. In fact, replication of many viruses has been found to be autophagy-dependent and suppression of autophagy can potentially affect the viral replication. Thus, autophagy can either serve as an anti-viral defense mechanism or a pro-viral process that supports viral replication. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are known to co-opt cellular autophagy process as a pro-viral tool. Both viruses also induce mitophagy, which contributes to the establishment of chronic hepatitis. This review focuses on the roles of autophagy and mitophagy in the chronic liver disease pathogenesis associated with HBV and HCV infections.
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17
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Morozov VA, Lagaye S. Hepatitis C virus: Morphogenesis, infection and therapy. World J Hepatol 2018; 10:186-212. [PMID: 29527256 PMCID: PMC5838439 DOI: 10.4254/wjh.v10.i2.186] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/11/2018] [Accepted: 02/07/2018] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is a major cause of liver diseases including liver cirrhosis and hepatocellular carcinoma. Approximately 3% of the world population is infected with HCV. Thus, HCV infection is considered a public healthy challenge. It is worth mentioning, that the HCV prevalence is dependent on the countries with infection rates around 20% in high endemic countries. The review summarizes recent data on HCV molecular biology, the physiopathology of infection (immune-mediated liver damage, liver fibrosis and lipid metabolism), virus diagnostic and treatment. In addition, currently available in vitro, ex vivo and animal models to study the virus life cycle, virus pathogenesis and therapy are described. Understanding of both host and viral factors may in the future lead to creation of new approaches in generation of an efficient therapeutic vaccine.
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Affiliation(s)
- Vladimir Alexei Morozov
- Center for HIV and Retrovirology, Department of Infectious Diseases, Robert Koch Institute, Berlin 13353, Germany
| | - Sylvie Lagaye
- Department of Immunology, Institut Pasteur, INSERM U1223, Paris 75015, France
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18
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Lee YR, Kuo SH, Lin CY, Fu PJ, Lin YS, Yeh TM, Liu HS. Dengue virus-induced ER stress is required for autophagy activation, viral replication, and pathogenesis both in vitro and in vivo. Sci Rep 2018; 8:489. [PMID: 29323257 PMCID: PMC5765116 DOI: 10.1038/s41598-017-18909-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/14/2017] [Indexed: 12/21/2022] Open
Abstract
Dengue virus (DENV) utilizes the endoplasmic reticulum (ER) for replication and assembling. Accumulation of unfolded proteins in the ER lumen leads to ER stress and unfolded protein response (UPR). Three branches of UPRs temporally modulated DENV infection. Moreover, ER stress can also induce autophagy. DENV infection induces autophagy which plays a promotive role in viral replication has been reported. However, the role of ER stress in DENV-induced autophagy, viral titer, and pathogenesis remain unclear. Here, we reveal that ER stress and its downstream UPRs are indispensable for DENV-induced autophagy in various human cells. We demonstrate that PERK-eIF2α and IRE1α-JNK signaling pathways increased autophagy and viral load after DENV infection. However, ATF6-related pathway showed no effect on autophagy and viral replication. IRE1α-JNK downstream molecule Bcl-2 was phosphorylated by activated JNK and dissociated from Beclin 1, which playing a critical role in autophagy activation. These findings were confirmed as decreased viral titer, attenuated disease symptoms, and prolonged survival rate in the presence of JNK inhibitor in vivo. In summary, we are the first to reveal that DENV2-induced ER stress increases autophagy activity, DENV replication, and pathogenesis through two UPR signaling pathways both in vitro and in vivo.
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Affiliation(s)
- Ying-Ray Lee
- Department of Medical Research, Chiayi Christian Hospital, 600, Chiayi, Taiwan
| | - Szu-Han Kuo
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 701, Tainan, Taiwan
| | - Ching-Yen Lin
- Department of Medical Research, Chiayi Christian Hospital, 600, Chiayi, Taiwan
| | - Po-Jung Fu
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 701, Tainan, Taiwan
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 701, Tainan, Taiwan
| | - Trai-Ming Yeh
- Department of Medical Laboratory, Science and Biotechnology, College of Medicine, National Cheng Kung University, 701, Tainan, Taiwan
| | - Hsiao-Sheng Liu
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 701, Tainan, Taiwan.
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19
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Denolly S, Mialon C, Bourlet T, Amirache F, Penin F, Lindenbach B, Boson B, Cosset FL. The amino-terminus of the hepatitis C virus (HCV) p7 viroporin and its cleavage from glycoprotein E2-p7 precursor determine specific infectivity and secretion levels of HCV particle types. PLoS Pathog 2017; 13:e1006774. [PMID: 29253880 PMCID: PMC5749900 DOI: 10.1371/journal.ppat.1006774] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 01/02/2018] [Accepted: 11/27/2017] [Indexed: 12/18/2022] Open
Abstract
Viroporins are small transmembrane proteins with ion channel activities modulating properties of intracellular membranes that have diverse proviral functions. Hepatitis C virus (HCV) encodes a viroporin, p7, acting during assembly, envelopment and secretion of viral particles (VP). HCV p7 is released from the viral polyprotein through cleavage at E2-p7 and p7-NS2 junctions by signal peptidase, but also exists as an E2p7 precursor, of poorly defined properties. Here, we found that ectopic p7 expression in HCVcc-infected cells reduced secretion of particle-associated E2 glycoproteins. Using biochemical assays, we show that p7 dose-dependently slows down the ER-to-Golgi traffic, leading to intracellular retention of E2, which suggested that timely E2p7 cleavage and p7 liberation are critical events to control E2 levels. By studying HCV mutants with accelerated E2p7 processing, we demonstrate that E2p7 cleavage controls E2 intracellular expression and secretion levels of nucleocapsid-free subviral particles and infectious virions. In addition, our imaging data reveal that, following p7 liberation, the amino-terminus of p7 is exposed towards the cytosol and coordinates the encounter between NS5A and NS2-based assembly sites loaded with E1E2 glycoproteins, which subsequently leads to nucleocapsid envelopment. We identify punctual mutants at p7 membrane interface that, by abrogating NS2/NS5A interaction, are defective for transmission of infectivity owing to decreased secretion of core and RNA and to increased secretion of non/partially-enveloped particles. Altogether, our results indicate that the retarded E2p7 precursor cleavage is essential to regulate the intracellular and secreted levels of E2 through p7-mediated modulation of the cell secretory pathway and to unmask critical novel assembly functions located at p7 amino-terminus.
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Affiliation(s)
- Solène Denolly
- CIRI–International Center for Infectiology Research, Team EVIR, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - Chloé Mialon
- CIRI–International Center for Infectiology Research, Team EVIR, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - Thomas Bourlet
- GIMAP, EA 3064, Faculté de Médecine, Université de Saint-Etienne, Univ Lyon, Saint Etienne, France
| | - Fouzia Amirache
- CIRI–International Center for Infectiology Research, Team EVIR, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - François Penin
- IBCP—Institut de Biologie et Chimie des Protéines, MMSB, UMR 5086, CNRS, Univ Lyon, Lyon, France
| | - Brett Lindenbach
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT, United States of America
| | - Bertrand Boson
- CIRI–International Center for Infectiology Research, Team EVIR, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - François-Loïc Cosset
- CIRI–International Center for Infectiology Research, Team EVIR, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
- * E-mail:
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20
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Dionicio CL, Peña F, Constantino-Jonapa LA, Vazquez C, Yocupicio-Monroy M, Rosales R, Zambrano JL, Ruiz MC, Del Angel RM, Ludert JE. Dengue virus induced changes in Ca 2+ homeostasis in human hepatic cells that favor the viral replicative cycle. Virus Res 2017; 245:17-28. [PMID: 29269104 DOI: 10.1016/j.virusres.2017.11.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/09/2017] [Accepted: 11/28/2017] [Indexed: 02/07/2023]
Abstract
The role of Ca2+ during dengue virus (DENV) replication is unknown; thus, changes in Ca2+ homeostasis in DENV infected human hepatic HepG2 and Huh-7 cells were analyzed. Infected HepG2 cells, but not Huh-7 cells, showed a significant increase in plasma membrane permeability to Ca2+, while both cell lines showed marked reduced levels of Ca2+ stored in the endoplasmic reticulum. While the expression levels of STIM1 and ORAI1 showed no changes, STIM1 and ORAI1 were shown to co-localized in infected cells, indicating activation of the store-operated Ca2+ entry (SOCE) pathway. Finally, manipulation in the infected cells of the intra and extracellular Ca2+ levels by chelators (BAPTA-AM and EGTA), SOC inhibitor (SKF96365), IP3 Receptor antagonist (2APB) or increase of extracellular [Ca2+], significantly reduced DENV yield, but not vesicular stomatitis virus yield, used as a control. These results show that DENV infection alters cell Ca2+ homeostasis and that such changes favor viral replication.
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Affiliation(s)
- Cinthia L Dionicio
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Franshelle Peña
- Center for Biochemistry and Biophysics, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Luis A Constantino-Jonapa
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Carlos Vazquez
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Martha Yocupicio-Monroy
- Genomic Sciences Graduate School, Autonomous University of the City of Mexico (UACM), Mexico
| | - Romel Rosales
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - José Luis Zambrano
- Center for Microbiology and Cell Biology, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Marie Christine Ruiz
- Center for Biochemistry and Biophysics, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Rosa M Del Angel
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Juan E Ludert
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico.
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21
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Takahashi S, Sato N, Kikuchi J, Kakinuma H, Okawa J, Masuyama Y, Iwasa S, Irokawa H, Hwang GW, Naganuma A, Kohara M, Kuge S. Immature Core protein of hepatitis C virus induces an unfolded protein response through inhibition of ERAD-L in a yeast model system. Genes Cells 2017; 22:160-173. [PMID: 28097745 DOI: 10.1111/gtc.12464] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 11/29/2016] [Indexed: 01/18/2023]
Abstract
The structural protein Core of hepatitis C virus (HCV), a cytosolic protein, induces endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in hepatocytes, and is responsible for the pathogenesis of persistent HCV infection. Using yeast as a model system, we evaluated mechanisms underlying Core-induced interference of ER homeostasis and UPR, and found that UPR is induced by the immature Core (aa 1-191, Core191) but not by the mature Core (aa 1-177, Core177). Interestingly, Core191 inhibits both ERAD-L, a degradation system responsible for misfolded/unfolded proteins in the ER lumen, and ERAD-M, a degradation system responsible for proteins carrying a misfolded/unfolded region in the ER membrane. In contrast, Core177 inhibits ERAD-M but not ERAD-L. In addition, requirement of an unfolded protein sensor in the ER lumen suggested that inhibition of ERAD-L is probably responsible for Core191-dependent UPR activation. These results implicate inadequate maturation of Core as a trigger for induction of ER stress and UPR.
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Affiliation(s)
- Shota Takahashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan
| | - Naoko Sato
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan.,Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Junichi Kikuchi
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Hideaki Kakinuma
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Jun Okawa
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Yukiko Masuyama
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Singo Iwasa
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan
| | - Hayato Irokawa
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan
| | - Gi-Wook Hwang
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Akira Naganuma
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Michinori Kohara
- Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Shusuke Kuge
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan.,Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
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22
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The autophagy elongation complex (ATG5-12/16L1) positively regulates HCV replication and is required for wild-type membranous web formation. Sci Rep 2017; 7:40351. [PMID: 28067309 PMCID: PMC5220323 DOI: 10.1038/srep40351] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/05/2016] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) infection induces intracellular membrane rearrangements, thus forming a membranous web (MW) in which HCV replication and assembly occur. The HCV-induced MW is primarily composed of double membrane vesicles (DMVs) transfused by multi-membrane vesicles. The autophagy machinery has been proposed to participate in the formation of such vesicles. However, no clear evidence has been found linking autophagy to the formation of these DMVs. In this study, we evaluated the role of the autophagy elongation complex (ATG5-12/16L1) in HCV replication and MW formation. Using a dominant negative form of ATG12 and an siRNA approach, we demonstrated that the ATG5-12 conjugate, but not LC3-II formation, is crucial for efficient viral replication. Furthermore, purification of HCV MW revealed the presence of ATG5-12 and ATG16L1 along with HCV nonstructural proteins. Interestingly, LC3 was not recruited along with the elongation complex to the site of viral replication. Finally, inhibition of the elongation complex, but not LC3, greatly impaired the formation of the wild-type MW phenotype. To our knowledge, this study provides the first evidence of the involvement of autophagy proteins in the formation of wild-type MWs.
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23
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Abstract
Autophagy is a catabolic process by which cells remove protein aggregates and damaged organelles for recycling. It can also be used by cells to remove intracellular microbial pathogens, including viruses, in a process known as xenophagy. However, many viruses have developed mechanisms to subvert this intracellular antiviral response and even use this pathway to support their own replications. Hepatitis C virus (HCV) is one such virus and is an important human pathogen that can cause severe liver diseases. Recent studies indicated that HCV could activate the autophagic pathway to support its replication. This review summarizes the current knowledge on the interplay between HCV and autophagy and how this interplay affects HCV replication and host innate immune responses.
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24
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Lagaye S, Brun S, Gaston J, Shen H, Stranska R, Camus C, Dubray C, Rousseau G, Massault PP, Courcambeck J, Bassisi F, Halfon P, Pol S. Anti-hepatitis C virus potency of a new autophagy inhibitor using human liver slices model. World J Hepatol 2016; 8:902-14. [PMID: 27478540 PMCID: PMC4958700 DOI: 10.4254/wjh.v8.i21.902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/01/2016] [Accepted: 06/27/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the antiviral potency of a new anti-hepatitis C virus (HCV) antiviral agent targeting the cellular autophagy machinery. METHODS Non-infected liver slices, obtained from human liver resection and cut in 350 μm-thick slices (2.7 × 10(6) cells per slice) were infected with cell culture-grown HCV Con1b/C3 supernatant (multiplicity of infection = 0.1) cultivated for up to ten days. HCV infected slices were treated at day 4 post-infection with GNS-396 for 6 d at different concentrations. HCV replication was evaluated by strand-specific real-time quantitative reverse transcription - polymerase chain reaction. The infectivity titers of supernatants were evaluated by foci formation upon inoculation into naive Huh-7.5.1 cells. The cytotoxic effect of the drugs was evaluated by lactate dehydrogenase leakage assays. RESULTS The antiviral efficacy of a new antiviral drug, GNS-396, an autophagy inhibitor, on HCV infection of adult human liver slices was evidenced in a dose-dependent manner. At day 6 post-treatment, GNS-396 EC50 was 158 nmol/L without cytotoxic effect (compared to hydroxychloroquine EC50 = 1.17 μmol/L). CONCLUSION Our results demonstrated that our ex vivo model is efficient for evaluation the potency of autophagy inhibitors, in particular a new quinoline derivative GNS-396 as antiviral could inhibit HCV infection in a dose-dependent manner without cytotoxic effect.
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Affiliation(s)
- Sylvie Lagaye
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Sonia Brun
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Jesintha Gaston
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Hong Shen
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Ruzena Stranska
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Claire Camus
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Clarisse Dubray
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Géraldine Rousseau
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Pierre-Philippe Massault
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Jerôme Courcambeck
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Firas Bassisi
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Philippe Halfon
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
| | - Stanislas Pol
- Sylvie Lagaye, Jesintha Gaston, Stanislas Pol, Institut Pasteur, INSERM U1223, 75015 Paris, France
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Wang A, Zhou X. ER Stress, UPR and Virus Infections in Plants. CURRENT RESEARCH TOPICS IN PLANT VIROLOGY 2016. [PMCID: PMC7123154 DOI: 10.1007/978-3-319-32919-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
The endoplasmic reticulum (ER) endomembrane is a central site for protein synthesis. Perturbation of ER homeostasis can result in an accumulation of unfolded proteins within the ER lumen, causing ER stress and the unfolded protein response (UPR). In humans, ER stress and UPR are closely associated with a vast number of diseases, including viral diseases. In plants, two arms that govern the UPR signaling network have been described: one that contains two ER membrane–associated transcription factors (bZIP17 and bZIP28) and the other that encompasses a dual protein kinase (RNA-splicing factor IRE1) and its target RNA (bZIP60). Although early studies mainly focus on the essential roles of the UPR in abiotic stresses, the significance of UPR in plant diseases caused by virus infections has recently drawn much attention. This chapter summarizes the latest scenario of ER stress and UPR in virus-infected plant cells, highlights the emerging roles of the IRE1 pathway in virus infections, and outlines exciting future directions to spark more research interest in the UPR field in plants.
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Affiliation(s)
- Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario Canada
| | - Xueping Zhou
- State Key Laboratory for Biology of Plan, Chinese Academy of Agricultural Sciences, Beijing, China
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Hepatitis C Virus Infection Induces Autophagy as a Prosurvival Mechanism to Alleviate Hepatic ER-Stress Response. Viruses 2016; 8:v8050150. [PMID: 27223299 PMCID: PMC4885105 DOI: 10.3390/v8050150] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/04/2016] [Accepted: 05/18/2016] [Indexed: 12/17/2022] Open
Abstract
Hepatitis C virus (HCV) infection frequently leads to chronic liver disease, liver cirrhosis and hepatocellular carcinoma (HCC). The molecular mechanisms by which HCV infection leads to chronic liver disease and HCC are not well understood. The infection cycle of HCV is initiated by the attachment and entry of virus particles into a hepatocyte. Replication of the HCV genome inside hepatocytes leads to accumulation of large amounts of viral proteins and RNA replication intermediates in the endoplasmic reticulum (ER), resulting in production of thousands of new virus particles. HCV-infected hepatocytes mount a substantial stress response. How the infected hepatocyte integrates the viral-induced stress response with chronic infection is unknown. The unfolded protein response (UPR), an ER-associated cellular transcriptional response, is activated in HCV infected hepatocytes. Over the past several years, research performed by a number of laboratories, including ours, has shown that HCV induced UPR robustly activates autophagy to sustain viral replication in the infected hepatocyte. Induction of the cellular autophagy response is required to improve survival of infected cells by inhibition of cellular apoptosis. The autophagy response also inhibits the cellular innate antiviral program that usually inhibits HCV replication. In this review, we discuss the physiological implications of the HCV-induced chronic ER-stress response in the liver disease progression.
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27
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de Armas-Rillo L, Valera MS, Marrero-Hernández S, Valenzuela-Fernández A. Membrane dynamics associated with viral infection. Rev Med Virol 2016; 26:146-60. [PMID: 26817660 PMCID: PMC5066672 DOI: 10.1002/rmv.1872] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 12/15/2022]
Abstract
Viral replication and spreading are fundamental events in the viral life cycle, accounting for the assembly and egression of nascent virions, events that are directly associated with viral pathogenesis in target hosts. These processes occur in cellular compartments that are modified by specialized viral proteins, causing a rearrangement of different cell membranes in infected cells and affecting the ER, mitochondria, Golgi apparatus, vesicles and endosomes, as well as processes such as autophagic membrane flux. In fact, the activation or inhibition of membrane trafficking and other related activities are fundamental to ensure the adequate replication and spreading of certain viruses. In this review, data will be presented that support the key role of membrane dynamics in the viral cycle, especially in terms of the assembly, egression and infection processes. By defining how viruses orchestrate these events it will be possible to understand how they successfully complete their route of infection, establishing viral pathogenesis and provoking disease. © 2015 The Authors Reviews in Medical Virology Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Laura de Armas-Rillo
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - María-Soledad Valera
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Sara Marrero-Hernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
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28
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Khachatoorian R, French SW. Chaperones in hepatitis C virus infection. World J Hepatol 2016; 8:9-35. [PMID: 26783419 PMCID: PMC4705456 DOI: 10.4254/wjh.v8.i1.9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 10/01/2015] [Accepted: 12/18/2015] [Indexed: 02/06/2023] Open
Abstract
The hepatitis C virus (HCV) infects approximately 3% of the world population or more than 185 million people worldwide. Each year, an estimated 350000-500000 deaths occur worldwide due to HCV-associated diseases including cirrhosis and hepatocellular carcinoma. HCV is the most common indication for liver transplantation in patients with cirrhosis worldwide. HCV is an enveloped RNA virus classified in the genus Hepacivirus in the Flaviviridae family. The HCV viral life cycle in a cell can be divided into six phases: (1) binding and internalization; (2) cytoplasmic release and uncoating; (3) viral polyprotein translation and processing; (4) RNA genome replication; (5) encapsidation (packaging) and assembly; and (6) virus morphogenesis (maturation) and secretion. Many host factors are involved in the HCV life cycle. Chaperones are an important group of host cytoprotective molecules that coordinate numerous cellular processes including protein folding, multimeric protein assembly, protein trafficking, and protein degradation. All phases of the viral life cycle require chaperone activity and the interaction of viral proteins with chaperones. This review will present our current knowledge and understanding of the role of chaperones in the HCV life cycle. Analysis of chaperones in HCV infection will provide further insights into viral/host interactions and potential therapeutic targets for both HCV and other viruses.
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Mohl BP, Bartlett C, Mankouri J, Harris M. Early events in the generation of autophagosomes are required for the formation of membrane structures involved in hepatitis C virus genome replication. J Gen Virol 2016; 97:680-693. [PMID: 26727924 DOI: 10.1099/jgv.0.000387] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) infection has been shown to induce autophagy but the mechanisms underpinning this process remain to be elucidated. Induction of autophagy requires the class III phosphatidylinositol 3-kinase, Vps34, which produces phosphatidylinositol 3-phosphate (PI3P) within the endoplasmic reticulum (ER) membrane. This recruits proteins with PI3P binding domains such as the double-FYVE-containing protein 1 (DFCP1). DFCP1 generates cup-shaped protrusions from the ER membrane, termed omegasomes, which provide a platform for the production of autophagosomes. Here we present data demonstrating that both Vps34 and DFCP1 are required for HCV genome replication, in the context of both a subgenomic replicon and virus infection, but did not affect virus entry or initial translation. Using live cell fluorescence microscopy we demonstrated that early during HCV infection the nascent viral genome replication complexes (identified by using non-structural protein NS5A as a marker) transiently colocalize with DFCP1-positive punctae (omegasomes), before the two structures move apart from each other. This observation is reminiscent of the transient association of LC3 and DFCP1 during omegasome formation, and therefore we propose that omegasomes are utilized by HCV to generate the double-membrane vesicles which are the hallmark of HCV replication complexes.
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Affiliation(s)
- Bjorn-Patrick Mohl
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Christopher Bartlett
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Jamel Mankouri
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
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30
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Liu C, Qu A, Han X, Wang Y. HCV core protein represses the apoptosis and improves the autophagy of human hepatocytes. Int J Clin Exp Med 2015; 8:15787-15793. [PMID: 26629077 PMCID: PMC4658966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVES This study aims to investigate the influence on human hepatocytes apoptosis and autophagy by the hepatitis C virus (HCV) core protein. METHODS QSG-7701, a human-derived non-neoplastic liver cell line, was transfected with PIRES-core vector that was a eukaryotic vector to express HCV core protein. Fluorescence microscope was used to observe the changes of nuclei in apoptosis cells by Annex in V-FITC/PI double staining. Flow cytometry was applied to detect the rate of cell apoptosis. Western blotting was used to detect the expression of HCV core protein, transcription factor nuclear factor-kappa B (NF-κB), autophagic biomarker microtubule associated protein 1 light chain 3 (LC3), and Beclin-1. RESULTS The apoptosis rate was significantly lower (P < 0.05) in QSG7701/core group (transfected with PIRES-core vector, (1.34±0.07)%) than in QSG7701 group (no transfection, (2.35±0.11)%) and in QSG7701 QSG7701/pcDNA3.1 group (transfected with pcDNA3.1 vector, (2.58±0.1)%). NF-κB expression was up-expressed in QSG7701/core group than in QSG7701/pcDNA3.1 group and QSG7701 group (P < 0.05). LC3-II expression and Beclin-1 expression was significant higher in QSG7701/core group than in the QSG7701/pcDNA3.1 group and QSG7701 group (P < 0.05). CONCLUSION HCV core protein can repress the apoptosis and improve the autophagy of QSG7701 through up-regulating NF-κB and Beclin-1 expression.
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Affiliation(s)
- Changhong Liu
- School of Medicine, Shandong UniversityJinan 250012, China
- Department of Gastroenterology, Shandong Provincial Qianfoshan HospitalJinan 250014, China
| | - Aihua Qu
- Zouping Affiliated Hospital of Taishan Medical CollegeZouping 256200, China
| | - Xiaochun Han
- College of Traditional Chinese Medicine (College of Basic Medical Sciences), Shandong University of Traditional Chinese MedicineJinan 250355, China
| | - Yiguo Wang
- Department of Gastroenterology, Shandong Provincial Qianfoshan HospitalJinan 250014, China
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31
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Steele S, Brunton J, Kawula T. The role of autophagy in intracellular pathogen nutrient acquisition. Front Cell Infect Microbiol 2015; 5:51. [PMID: 26106587 PMCID: PMC4460576 DOI: 10.3389/fcimb.2015.00051] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/26/2015] [Indexed: 01/01/2023] Open
Abstract
Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates, and amino acids). It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral, and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells.
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Affiliation(s)
- Shaun Steele
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Jason Brunton
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
| | - Thomas Kawula
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina Chapel Hill, NC, USA
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32
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Cellular stress responses in hepatitis C virus infection: Mastering a two-edged sword. Virus Res 2015; 209:100-17. [PMID: 25836277 DOI: 10.1016/j.virusres.2015.03.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 03/21/2015] [Accepted: 03/23/2015] [Indexed: 12/11/2022]
Abstract
Hepatitis C virus (HCV) infection affects chronically more than 150 million humans worldwide. Chronic HCV infection causes severe liver disease and hepatocellular carcinoma. While immune response-mediated events are major players in HCV pathogenesis, the impact that viral replication has on cellular homeostasis is increasingly recognized as a necessary contributor to pathological manifestations of HCV infection such as steatosis, insulin-resistance or liver cancer. In this review, we will briefly overview the different cellular stress pathways that are induced by hepatitis C virus infection, the response that the cell promotes to attempt regaining homeostasis or to induce dysfunctional cell death, and how the virus co-opts these response mechanisms to promote both viral replication and survival of the infected cell. We will review the role of unfolded protein and oxidative stress responses as well as the role of auto- and mitophagy in HCV infection. Finally, we will discuss the recent discovery of a cellular chaperone involved in stress responses, the sigma-1 receptor, as a cellular factor required at the onset of HCV infection and the potential molecular events underlying the proviral role of this cellular factor in HCV infection.
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33
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Wang L, Tian Y, Ou JHJ. HCV induces the expression of Rubicon and UVRAG to temporally regulate the maturation of autophagosomes and viral replication. PLoS Pathog 2015; 11:e1004764. [PMID: 25807108 PMCID: PMC4373777 DOI: 10.1371/journal.ppat.1004764] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 02/25/2015] [Indexed: 01/01/2023] Open
Abstract
Hepatitis C virus (HCV) induces autophagy to enhance its replication. However, how HCV regulates the autophagic pathway remains largely unclear. In this report, we demonstrated that HCV infection could induce the expression of Rubicon and UVRAG, which inhibited and stimulated the maturation of autophagosomes, respectively. The induction of Rubicon by HCV was prompt whereas the induction of UVRAG was delayed, resulting in the accumulation of autophagosomes in the early time points of viral infection. The role of Rubicon in inhibiting the maturation of autophagosomes in HCV-infected cells was confirmed by siRNA knockdown and the over-expression of Rubicon, which enhanced and suppressed the maturation of autophagosomes, respectively. Rubicon played a positive role in HCV replication, as the suppression of its expression reduced HCV replication and its over-expression enhanced HCV replication. In contrast, the over-expression of UVRAG facilitated the maturation of autophagosomes and suppressed HCV replication. The HCV subgenomic RNA replicon, which expressed only the nonstructural proteins, could also induce the expression of Rubicon and the accumulation of autophagosomes. Further analysis indicated that the HCV NS4B protein was sufficient to induce Rubicon and autophagosomes. Our results thus indicated that HCV, by differentially inducing the expression of Rubicon and UVRAG, temporally regulated the autophagic flux to enhance its replication.
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Affiliation(s)
- Linya Wang
- Department of Molecular Microbiology and Immunology, University of Southern California, Keck School of Medicine, Los Angeles, California, United States of America
| | - Yongjun Tian
- Department of Molecular Microbiology and Immunology, University of Southern California, Keck School of Medicine, Los Angeles, California, United States of America
| | - Jing-hsiung James Ou
- Department of Molecular Microbiology and Immunology, University of Southern California, Keck School of Medicine, Los Angeles, California, United States of America
- * E-mail:
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34
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Blázquez AB, Martín-Acebes MA, Saiz JC. Amino acid substitutions in the non-structural proteins 4A or 4B modulate the induction of autophagy in West Nile virus infected cells independently of the activation of the unfolded protein response. Front Microbiol 2015; 5:797. [PMID: 25642225 PMCID: PMC4295549 DOI: 10.3389/fmicb.2014.00797] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/26/2014] [Indexed: 01/19/2023] Open
Abstract
West Nile virus (WNV) is a neurotropic mosquito-borne flavivirus responsible for outbreaks of meningitis and encephalitis. Whereas the activation of autophagy in cells infected with other flaviviruses is well known, the interaction of WNV with the autophagic pathway still remains unclear and there are reports describing opposite findings obtained even analyzing the same viral strain. To clarify this controversy, we first analyzed the induction of autophagic features in cells infected with a panel of WNV strains. WNV was determined to induce autophagy in a strain dependent manner. We observed that all WNV strains or isolates analyzed, except for the WNV NY99 used, upregulated the autophagic pathway in infected cells. Interestingly, a variant derived from this WNV NY99 isolated from a persistently infected mouse increased LC3 modification and aggregation. Genome sequencing of this variant revealed only two non-synonymous nucleotide substitutions when compared to parental NY99 strain. These nucleotide substitutions introduced one amino acid replacement in NS4A and other in NS4B. Using genetically engineered viruses we showed that introduction of only one of these replacements was sufficient to upregulate the autophagic pathway. Thus, in this work we have shown that naturally occurring point mutations in the viral non-structural proteins NS4A and NS4B confer WNV with the ability to induce the hallmarks of autophagy such as LC3 modification and aggregation. Even more, the differences on the induction of an autophagic response observed among WNV variants in infected cells did not correlate with alterations on the activation of the unfolded protein response (UPR), suggesting an uncoupling of UPR and autophagy during flavivirus infection. The findings here reported could help to improve the knowledge of the cellular processes involved on flavivirus–host cell interactions and contribute to the design of effective strategies to combat these pathogens.
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Affiliation(s)
- Ana-Belén Blázquez
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
| | - Miguel A Martín-Acebes
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain ; Department of Virology and Microbiology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid Spain
| | - Juan-Carlos Saiz
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
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35
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Batista MN, Carneiro BM, Braga ACS, Rahal P. Caffeine inhibits hepatitis C virus replication in vitro. Arch Virol 2014; 160:399-407. [PMID: 25491197 DOI: 10.1007/s00705-014-2302-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 11/28/2014] [Indexed: 12/27/2022]
Abstract
Hepatitis C is considered the major cause of cirrhosis and hepatocellular carcinoma. Conventional treatment is not effective against some hepatitis C virus (HCV) genotypes; therefore, new treatments are needed. Coffee and, more recently, caffeine, have been found to have a beneficial effect in several disorders of the liver, including those manifesting abnormal liver biochemistry, cirrhosis and hepatocellular carcinoma. Caffeine acts directly by delaying fibrosis, thereby improving the function of liver cellular pathways and interfering with pathways used by the HCV replication cycle. In the current study, the direct relationship between caffeine and viral replication was evaluated. The Huh-7.5 cell line was used for transient infections with FL-J6/JFH-5'C19Rluc2AUbi and to establish a cell line stably expressing SGR-Feo JFH-1. Caffeine efficiently inhibited HCV replication in a dose-dependent manner at non-cytotoxic concentrations and demonstrated an IC50 value of 0.7263 mM after 48 h of incubation. These data demonstrate that caffeine may be an important new agent for anti-HCV therapies due to its efficient inhibition of HCV replication at non-toxic concentrations.
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Affiliation(s)
- Mariana N Batista
- Department of Biology, Institute of Bioscience, Language and Literature and Exact Science, São Paulo State University, IBILCE, UNESP, Rua Cristóvão Colombo 2265, São José do Rio Preto, SP, 15054-000, Brazil
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36
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Autophagy in HCV infection: keeping fat and inflammation at bay. BIOMED RESEARCH INTERNATIONAL 2014; 2014:265353. [PMID: 25162004 PMCID: PMC4138948 DOI: 10.1155/2014/265353] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/11/2014] [Indexed: 12/14/2022]
Abstract
Hepatitis C virus (HCV) infection is one of the main causes of chronic liver disease. Viral persistence and pathogenesis rely mainly on the ability of HCV to deregulate specific host processes, including lipid metabolism and innate immunity. Recently, autophagy has emerged as a cellular pathway, playing a role in several aspects of HCV infection. This review summarizes current knowledge on the molecular mechanisms that link the HCV life cycle with autophagy machinery. In particular, we discuss the role of HCV/autophagy interaction in dysregulating inflammation and lipid homeostasis and its potential for translational applications in the treatment of HCV-infected patients.
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37
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Blázquez AB, Escribano-Romero E, Merino-Ramos T, Saiz JC, Martín-Acebes MA. Stress responses in flavivirus-infected cells: activation of unfolded protein response and autophagy. Front Microbiol 2014; 5:266. [PMID: 24917859 PMCID: PMC4042264 DOI: 10.3389/fmicb.2014.00266] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/15/2014] [Indexed: 12/11/2022] Open
Abstract
The Flavivirus is a genus of RNA viruses that includes multiple long known human, animal, and zoonotic pathogens such as Dengue virus, yellow fever virus, West Nile virus, or Japanese encephalitis virus, as well as other less known viruses that represent potential threats for human and animal health such as Usutu or Zika viruses. Flavivirus replication is based on endoplasmic reticulum-derived structures. Membrane remodeling and accumulation of viral factors induce endoplasmic reticulum stress that results in activation of a cellular signaling response termed unfolded protein response (UPR), which can be modulated by the viruses for their own benefit. Concomitant with the activation of the UPR, an upregulation of the autophagic pathway in cells infected with different flaviviruses has also been described. This review addresses the current knowledge of the relationship between endoplasmic reticulum stress, UPR, and autophagy in flavivirus-infected cells and the growing evidences for an involvement of these cellular pathways in the replication and pathogenesis of these viruses.
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Affiliation(s)
- Ana-Belén Blázquez
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
| | - Estela Escribano-Romero
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
| | - Teresa Merino-Ramos
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
| | - Juan-Carlos Saiz
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain
| | - Miguel A Martín-Acebes
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Madrid, Spain ; Departamento de Virología y Microbiología, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid Madrid, Spain
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38
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Chan SW. Unfolded protein response in hepatitis C virus infection. Front Microbiol 2014; 5:233. [PMID: 24904547 PMCID: PMC4033015 DOI: 10.3389/fmicb.2014.00233] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 04/30/2014] [Indexed: 12/14/2022] Open
Abstract
Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus of clinical importance. The virus establishes a chronic infection and can progress from chronic hepatitis, steatosis to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The mechanisms of viral persistence and pathogenesis are poorly understood. Recently the unfolded protein response (UPR), a cellular homeostatic response to endoplasmic reticulum (ER) stress, has emerged to be a major contributing factor in many human diseases. It is also evident that viruses interact with the host UPR in many different ways and the outcome could be pro-viral, anti-viral or pathogenic, depending on the particular type of infection. Here we present evidence for the elicitation of chronic ER stress in HCV infection. We analyze the UPR signaling pathways involved in HCV infection, the various levels of UPR regulation by different viral proteins and finally, we propose several mechanisms by which the virus provokes the UPR.
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Affiliation(s)
- Shiu-Wan Chan
- Faculty of Life Sciences, The University of Manchester Manchester, UK
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Gracia-Sancho J, Guixé-Muntet S, Hide D, Bosch J. Modulation of autophagy for the treatment of liver diseases. Expert Opin Investig Drugs 2014; 23:965-77. [DOI: 10.1517/13543784.2014.912274] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jordi Gracia-Sancho
- Barcelona Hepatic Hemodynamic Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) – Hospital Clínic de Barcelona – CIBEREHD,
Barcelona, Spain ;
| | - Sergi Guixé-Muntet
- Barcelona Hepatic Hemodynamic Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) – Hospital Clínic de Barcelona – CIBEREHD,
Barcelona, Spain ;
| | - Diana Hide
- Barcelona Hepatic Hemodynamic Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) – Hospital Clínic de Barcelona – CIBEREHD,
Barcelona, Spain ;
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Atkins E, Tatineni R, Li H, Gretch D, Harris M, Griffin S. The stability of secreted, acid-labile H77/JFH-1 hepatitis C virus (HCV) particles is altered by patient isolate genotype 1a p7 sequences. Virology 2014; 448:117-24. [PMID: 24314642 PMCID: PMC7615703 DOI: 10.1016/j.virol.2013.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/05/2013] [Accepted: 10/03/2013] [Indexed: 12/17/2022]
Abstract
Secreted infectious particles generated by the genotype 2a JFH-1 hepatitis C virus infectious clone are resistant to acidic pH, whereas intracellular virions remain acid-labile. Thus, JFH-1 particles are thought to undergo pH maturation as they are secreted from the cell. Here, we demonstrate that both infectious intracellular and secreted genotype 1a (H77)/JFH-1 chimaeric particles display enhanced acid sensitivity compared with JFH-1, although pH maturation still occurs upon release. Introduction of p7 sequences from genotype 1a infected HCV patients into the H77/JFH-1 background yielded variable effects on infectious particle production and sensitivity to small molecule inhibitors. However, two selected patient p7 sequences increased the acid stability of secreted, but not intracellular H77/JFH-1 particles, suggesting that p7 directly influences particle pH maturation via an as yet undefined mechanism. We propose that HCV particles vary in acid stability, and that this may be dictated by variations in both canonical structural proteins and p7.
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Affiliation(s)
- Elizabeth Atkins
- School of Molecular & Cellular Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - Ranjitha Tatineni
- Leeds Institute of Cancer & Pathology (LICAP) and Leeds Cancer Research UK Clinical Centre, Faculty of Medicine and Health, St James’ University Hospital, University of Leeds, Beckett St., Leeds, West Yorkshire LS9 7TF, United Kingdom
| | - Hui Li
- Department of Laboratory Medicine, University of Washington School of Medicine, Harborview Medical Centre, Ninth & Jefferson Building, 908 Jefferson Street, Seattle, WA 98104, USA
| | - David Gretch
- Department of Laboratory Medicine, University of Washington School of Medicine, Harborview Medical Centre, Ninth & Jefferson Building, 908 Jefferson Street, Seattle, WA 98104, USA
| | - Mark Harris
- School of Molecular & Cellular Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - Stephen Griffin
- School of Molecular & Cellular Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
- Leeds Institute of Cancer & Pathology (LICAP) and Leeds Cancer Research UK Clinical Centre, Faculty of Medicine and Health, St James’ University Hospital, University of Leeds, Beckett St., Leeds, West Yorkshire LS9 7TF, United Kingdom
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Hepatitis C virus induces the mitochondrial translocation of Parkin and subsequent mitophagy. PLoS Pathog 2013; 9:e1003285. [PMID: 23555273 PMCID: PMC3610669 DOI: 10.1371/journal.ppat.1003285] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 02/19/2013] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C Virus (HCV) induces intracellular events that trigger mitochondrial dysfunction and promote host metabolic alterations. Here, we investigated selective autophagic degradation of mitochondria (mitophagy) in HCV-infected cells. HCV infection stimulated Parkin and PINK1 gene expression, induced perinuclear clustering of mitochondria, and promoted mitochondrial translocation of Parkin, an initial event in mitophagy. Liver tissues from chronic HCV patients also exhibited notable levels of Parkin induction. Using multiple strategies involving confocal and electron microscopy, we demonstrated that HCV-infected cells display greater number of mitophagosomes and mitophagolysosomes compared to uninfected cells. HCV-induced mitophagy was evidenced by the colocalization of LC3 puncta with Parkin-associated mitochondria and lysosomes. Ultrastructural analysis by electron microscopy and immunoelectron microscopy also displayed engulfment of damaged mitochondria in double membrane vesicles in HCV-infected cells. The HCV-induced mitophagy occurred irrespective of genotypic differences. Silencing Parkin and PINK1 hindered HCV replication suggesting the functional relevance of mitophagy in HCV propagation. HCV-mediated decline of mitochondrial complex I enzyme activity was rescued by chemical inhibition of mitophagy or by Parkin silencing. Overall our results suggest that HCV induces Parkin-dependent mitophagy, which may have significant contribution in mitochondrial liver injury associated with chronic hepatitis C. Hepatitis C virus (HCV) infection alters host lipid metabolism. HCV-induced mitochondrial dysfunction may promote the metabolic alterations by affecting mitochondrial β-oxidation and oxidative phosphorylation. Dysfunctional mitochondria are detrimental to cell survival and require rapid clearance to sustain cell viability. Here, we investigated the effect of HCV gene expression in promoting selective autophagy of dysfunctional mitochondria, also termed mitophagy. HCV infection stimulated the gene expression of Parkin and PINK1, the two key mediators of mitophagy. Parkin stimulation was also observed in liver biopsies of chronic hepatitis C patients. HCV infection induced the perinuclear clustering of mitochondria and triggered Parkin translocation to mitochondria, a hallmark of mitophagy. Concomitant with the mitochondrial translocation of Parkin, we observed ubiquitination of Parkin and its substrates in HCV-infected cells. We also demonstrate the formation of mitophagosomes and their subsequent delivery to lysosomes in HCV-infected cells. Silencing both Parkin and PINK1 hindered HCV replication, suggesting the functional significance of mitophagy in HCV life cycle. Furthermore, we demonstrate that Parkin-dependent mitophagy is directly associated with HCV-mediated decline in oxidative phosphorylation. Our results implicate the functional significance of Parkin and mitophagy in the persistence of HCV infection and mitochondrial injury commonly seen in patients with chronic hepatitis C.
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Divergent roles of autophagy in virus infection. Cells 2013; 2:83-104. [PMID: 24709646 PMCID: PMC3972664 DOI: 10.3390/cells2010083] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/31/2012] [Accepted: 11/07/2012] [Indexed: 12/16/2022] Open
Abstract
Viruses have played an important role in human evolution and have evolved diverse strategies to co-exist with their hosts. As obligate intracellular pathogens, viruses exploit and manipulate different host cell processes, including cellular trafficking, metabolism and immunity-related functions, for their own survival. In this article, we review evidence for how autophagy, a highly conserved cellular degradative pathway, serves either as an antiviral defense mechanism or, alternatively, as a pro-viral process during virus infection. Furthermore, we highlight recent reports concerning the role of selective autophagy in virus infection and how viruses manipulate autophagy to evade lysosomal capture and degradation.
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Petkova DS, Viret C, Faure M. IRGM in autophagy and viral infections. Front Immunol 2013; 3:426. [PMID: 23335927 PMCID: PMC3547297 DOI: 10.3389/fimmu.2012.00426] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/23/2012] [Indexed: 12/22/2022] Open
Abstract
Autophagy is a cell autonomous process allowing each individual cell to fight intracellular pathogens. Autophagy can destroy pathogens within the cytosol, and can elicit innate and adaptive immune responses against microorganisms. Nevertheless, numerous pathogens have developed molecular strategies enabling them to avoid or even exploit autophagy for their own benefit. IRGM (immunity-related GTPase family M) is a human protein recently highlighted for its contribution to autophagy upon infections. The physical association of IRGM with mitochondria and different autophagy-regulating proteins, ATG5, ATG10, SH3GLB1, and LC3, contribute to explain how IRGM could regulate autophagy. Whereas IRGM is involved in autophagy-mediated immunity against bacteria, certain viruses seem to have developed strategies to manipulate autophagy through the selective targeting of this protein. Furthermore, irgm variants are linked to infection-associated human pathologies such as the inflammatory Crohn’s disease. Here, we discuss how IRGM might contribute to human autophagy upon viral infection, and why its targeting might be beneficial to virus replication.
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Affiliation(s)
- Denitsa S Petkova
- Laboratory of Autophagy, Infections and Immunity, INSERM, U1111, CIRI, Université Lyon 1 Lyon, France
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Ke PY, Chen SSL. Hepatitis C virus and cellular stress response: implications to molecular pathogenesis of liver diseases. Viruses 2012. [PMID: 23202463 PMCID: PMC3497051 DOI: 10.3390/v4102251] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Infection with hepatitis C virus (HCV) is a leading risk factor for chronic liver disease progression, including steatosis, cirrhosis, and hepatocellular carcinoma. With approximately 3% of the human population infected worldwide, HCV infection remains a global public health challenge. The efficacy of current therapy is still limited in many patients infected with HCV, thus a greater understanding of pathogenesis in HCV infection is desperately needed. Emerging lines of evidence indicate that HCV triggers a wide range of cellular stress responses, including cell cycle arrest, apoptosis, endoplasmic reticulum (ER) stress/unfolded protein response (UPR), and autophagy. Also, recent studies suggest that these HCV-induced cellular responses may contribute to chronic liver diseases by modulating cell proliferation, altering lipid metabolism, and potentiating oncogenic pathways. However, the molecular mechanism underlying HCV infection in the pathogenesis of chronic liver diseases still remains to be determined. Here, we review the known stress response activation in HCV infection in vitro and in vivo, and also explore the possible relationship of a variety of cellular responses with the pathogenicity of HCV-associated diseases. Comprehensive knowledge of HCV-mediated disease progression shall shed new insights into the discovery of novel therapeutic targets and the development of new intervention strategy.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan 33371, Taiwan, Republic of China; (P.-Y.K.)
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, Republic of China
| | - Steve S.-L. Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, Republic of China
- Author to whom correspondence should be addressed; (S.-L.C.); Tel.: +886-2-2652-3933, Fax: +886-2-2652-3073
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