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A Avelar R, Gupta R, Carvette G, da Veiga Leprevost F, Jasti M, Colina J, Teitel J, Nesvizhskii AI, O'Connor CM, Hatzoglou M, Shenolikar S, Arvan P, Narla G, DiFeo A. Integrated stress response plasticity governs normal cell adaptation to chronic stress via the PP2A-TFE3-ATF4 pathway. Cell Death Differ 2024; 31:1761-1775. [PMID: 39349971 PMCID: PMC11618521 DOI: 10.1038/s41418-024-01378-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 09/04/2024] [Accepted: 09/12/2024] [Indexed: 10/09/2024] Open
Abstract
The integrated stress response (ISR) regulates cell fate during conditions of stress by leveraging the cell's capacity to endure sustainable and efficient adaptive stress responses. Protein phosphatase 2A (PP2A) activity modulation has been shown to be successful in achieving both therapeutic efficacy and safety across various cancer models. However, the molecular mechanisms driving its selective antitumor effects remain unclear. Here, we show for the first time that ISR plasticity relies on PP2A activation to regulate drug response and dictate cellular survival under conditions of chronic stress. We demonstrate that genetic and chemical modulation of the PP2A leads to chronic proteolytic stress and triggers an ISR to dictate whether the cell lives or dies. More specifically, we uncovered that the PP2A-TFE3-ATF4 pathway governs ISR cell plasticity during endoplasmic reticular and cellular stress independent of the unfolded protein response. We further show that normal cells reprogram their genetic signatures to undergo ISR-mediated adaptation and homeostatic recovery thereby avoiding toxicity following PP2A-mediated stress. Conversely, oncogenic specific cytotoxicity induced by chemical modulation of PP2A is achieved by activating chronic and irreversible ISR in cancer cells. Our findings propose that a differential response to chemical modulation of PP2A is determined by intrinsic ISR plasticity, providing a novel biological vulnerability to selectively induce cancer cell death and improve targeted therapeutic efficacy.
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Affiliation(s)
- Rita A Avelar
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | - Riya Gupta
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | - Grace Carvette
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | | | - Medhasri Jasti
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | - Jose Colina
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | - Jessica Teitel
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
| | - Alexey I Nesvizhskii
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Caitlin M O'Connor
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
- Department of Internal Medicine, Division of Genetic Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Shirish Shenolikar
- Duke-NUS Medical School, Singapore, Singapore
- Duke University School of Medicine, Durham, NC, USA
| | - Peter Arvan
- Division of Metabolism Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Goutham Narla
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA
- Department of Internal Medicine, Division of Genetic Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Analisa DiFeo
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA.
- Rogel Cancer Center, The University of Michigan, Ann Arbor, MI, USA.
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
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Park JY, Senevirathne A, Lloren KKS, Lee JH. The Effect of Tryptophan-to-Tyrosine Mutation at Position 61 of the Nonstructural Protein of Severe Fever with Thrombocytopenia Syndrome Virus on Viral Replication through Autophagosome Modulation. Int J Mol Sci 2024; 25:6394. [PMID: 38928101 PMCID: PMC11203599 DOI: 10.3390/ijms25126394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/29/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
In our prior investigations, we elucidated the role of the tryptophan-to-tyrosine substitution at the 61st position in the nonstructural protein NSsW61Y in diminishing the interaction between nonstructural proteins (NSs) and nucleoprotein (NP), impeding viral replication. In this study, we focused on the involvement of NSs in replication via the modulation of autophagosomes. Initially, we examined the impact of NP expression levels, a marker for replication, upon the infection of HeLa cells with severe fever thrombocytopenia syndrome virus (SFTSV), with or without the inhibition of NP binding. Western blot analysis revealed a reduction in NP levels in NSsW61Y-expressing conditions. Furthermore, the expression levels of the canonical autophagosome markers p62 and LC3 decreased in HeLa cells expressing NSsW61Y, revealing the involvement of individual viral proteins on autophagy. Subsequent experiments confirmed that NSsW61Y perturbs autophagy flux, as evidenced by reduced levels of LC3B and p62 upon treatment with chloroquine, an inhibitor of autophagosome-lysosome fusion. LysoTracker staining demonstrated a decrease in lysosomes in cells expressing the NS mutant compared to those expressing wild-type NS. We further explored the mTOR-associated regulatory pathway, a key regulator affected by NS mutant expression. The observed inhibition of replication could be linked to conformational changes in the NSs, impairing their binding to NP and altering mTOR regulation, a crucial upstream signaling component in autophagy. These findings illuminate the intricate interplay between NSsW61Y and the suppression of host autophagy machinery, which is crucial for the generation of autophagosomes to facilitate viral replication.
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Affiliation(s)
| | | | | | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea
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Ke PY. Crosstalk between Autophagy and RLR Signaling. Cells 2023; 12:cells12060956. [PMID: 36980296 PMCID: PMC10047499 DOI: 10.3390/cells12060956] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Autophagy plays a homeostatic role in regulating cellular metabolism by degrading unwanted intracellular materials and acts as a host defense mechanism by eliminating infecting pathogens, such as viruses. Upon viral infection, host cells often activate retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling to induce the transcription of type I interferons, thus establishing the first line of the innate antiviral response. In recent years, numerous studies have shown that virus-mediated autophagy activation may benefit viral replication through different actions on host cellular processes, including the modulation of RLR-mediated innate immunity. Here, an overview of the functional molecules and regulatory mechanism of the RLR antiviral immune response as well as autophagy is presented. Moreover, a summary of the current knowledge on the biological role of autophagy in regulating RLR antiviral signaling is provided. The molecular mechanisms underlying the crosstalk between autophagy and RLR innate immunity are also discussed.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
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Berbamine hydrochloride inhibits bovine viral diarrhea virus replication via interfering in late-stage autophagy. Virus Res 2022; 321:198905. [PMID: 36064041 DOI: 10.1016/j.virusres.2022.198905] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/22/2022] [Accepted: 08/27/2022] [Indexed: 12/24/2022]
Abstract
Bovine viral diarrhea virus (BVDV) is a harmful pathogen that easily causes large-scale infections and huge economic losses to the cattle industry. Berbamine hydrochloride (BBH) is a natural product extracted from berberis and has a wide range of pharmacological effects. However, the antiviral effect of BBH against BVDV needs to be further elucidated. This study aimed to evaluate the antiviral activities of BBH against BVDV infection. We mainly used RT-qPCR, Western blotting, immunofluorescence, and TEM assays to assess the inhibitory activity of BBH against BVDV. The results showed that BBH had an inhibitory effect on BVDV and higher inhibitory activity in the viral attachment and release in MDBK cells. This study found that BVDV could induce and use autophagy to replicate itself. Further results showed that BBH inhibited BVDV infection by inhibiting autophagy integrity in BVDV-infected cells, which was proven by the detection of autophagy-related proteins. Our data show that in BBH-treated BVDV-infected cells, the expression of p62 and LC3 increased over time. After the addition of an autophagy inhibitor, chloroquine (CQ), and an autophagy promoter, rapamycin (Rapa), we found that promoting autophagy was beneficial to the replication of BVDV, while inhibiting autophagy could reduce the number of infections by BVDV, which was evidenced by the expression of the BVDV E2 protein. Furthermore, BBH blocked the normal binding of LC3 and LAMP1 in BVDV-infected cells. In conclusion, BBH inhibited BVDV infection by inhibiting BVDV-induced autophagy in cells, and its inhibitory effect was obvious in the viral attachment and release stages. Therefore, our study provides a new idea for exploring novel anti-BVDV drugs.
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Zeng S, Zhao Y, Peng O, Xia Y, Xu Q, Li H, Xue C, Cao Y, Zhang H. Swine Acute Diarrhea Syndrome Coronavirus Induces Autophagy to Promote Its Replication via the Akt/mTOR Pathway. iScience 2022; 25:105394. [PMID: 36281226 PMCID: PMC9581643 DOI: 10.1016/j.isci.2022.105394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 08/06/2022] [Accepted: 10/14/2022] [Indexed: 11/28/2022] Open
Abstract
Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an enveloped, single-stranded, positive-sense RNA virus belonging to the Coronaviridae family. Increasingly studies have demonstrated that viruses could utilize autophagy to promote their own replication. However, the relationship between SADS-CoV and autophagy remains unknown. Here, we reported that SADS-CoV infection-induced autophagy and pharmacologically increased autophagy were conducive to viral proliferation. Conversely, suppression of autophagy by pharmacological inhibitors or knockdown of autophagy-related protein impeded viral replication. Furthermore, we demonstrated the underlying mechanism by which SADS-CoV triggered autophagy through the inactivation of the Akt/mTOR pathway. Importantly, we identified integrin α3 (ITGA3) as a potential antiviral target upstream of Akt/mTOR and autophagy pathways. Knockdown of ITGA3 enhanced autophagy and consequently increased the replication of SADS-CoV. Collectively, our studies revealed a novel mechanism that SADS-CoV-induced autophagy to facilitate its proliferation via Akt/mTOR pathway and found that ITGA3 was an effective antiviral factor for suppressing viral infection.
SADS-CoV triggers autophagy pathway to facilitate its proliferation Inhibition of autophagy flux impairs SADS-CoV replication SADS-CoV negatively regulates Akt/mTOR pathway to induce autophagy ITGA3 prevents SADS-CoV production through autophagy inhibition
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Affiliation(s)
- Siying Zeng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yan Zhao
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ouyang Peng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yu Xia
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Qiuping Xu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China,Medical Research Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
| | - Hongmei Li
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Chunyi Xue
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yongchang Cao
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Hao Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China,Corresponding author
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Ke PY. Autophagy and antiviral defense. IUBMB Life 2022; 74:317-338. [PMID: 34859938 DOI: 10.1002/iub.2582] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/04/2021] [Accepted: 11/15/2021] [Indexed: 12/14/2022]
Abstract
Targeting intracellular components for lysosomal degradation by autophagy not only maintains cellular homeostasis but also counteracts the effects of external stimuli, including invading pathogens. Among various kinds of pathogens, viruses have been extensively shown to induce autophagy to benefit viral growth in infected cells and to modulate host defense responses, such as innate antiviral immunity. Recently, numerous lines of evidence have implied that virus-induced autophagy triggers multilayer mechanisms to regulate the innate antiviral response of host cells, thus promoting a balance in virus-host cell interactions. In this review, the detailed mechanisms underlying autophagy and the innate antiviral immune response are first described. Then, I summarize the current information regarding the diverse functional role(s) of autophagy in the control of antiviral defenses against different types of viral infections. Moreover, the physiological significance of autophagy-regulated antiviral responses on the viral life cycle and the potential autophagy alterations induced by virus-associated antiviral signaling is further 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, Taiwan, ROC
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan, ROC
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Kung MH, Lin YS, Chang TH. Aichi virus 3C protease modulates LC3- and SQSTM1/p62-involved antiviral response. Theranostics 2020; 10:9200-9213. [PMID: 32802187 PMCID: PMC7415801 DOI: 10.7150/thno.47077] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/05/2020] [Indexed: 12/18/2022] Open
Abstract
Rationale: Autophagy is an essential, homeostatic process by which cells break down their own components, it also contributes to restricting bacterial infection in host defense systems; yet, how autophagy regulates viral infection remains inconclusive. Aichi virus (AiV), belonging to the genus Kobuvirus in the Picornaviridae family, causes acute gastroenteritis in human. The role of autophagy-mediated anti-viral activity on AiV infection was investigated in this study. Methods: The effect of autophagy-associated molecules in retinoic acid-inducible gene-I (RIG-I)-like receptor (RLR) antiviral signal axis was analyzed in AiV infected cells by using biochemistry and pharmacologic approaches. In addition, the AiV viral protein regulating autophagy-associated RLR activity was also evaluated. Results: In AiV-infected cells, autophagic flux including the formation of autophagic vacuoles, as well as degradation of microtubule-associated protein light chain 3 (LC3) and sequestosome-1 (SQSTM1/p62) were observed. Ectopic overexpression of LC3 and p62, but not Atg proteins, contributed to RLR antiviral signal axis, shRNA knockdown of LC3 and p62 led to a downregulation of antiviral inflammation. Moreover, AiV infection inhibited double-stranded RNA (dsRNA)-activated RLR activity by the viral protein 3C protease but not H42D, C143S protease dead mutants. AiV 3C protease caused the degradation of LC3 and p62, and also RLR signal proteins. Conclusion: This study reveals a possible mechanism of autophagy-associated proteins regulating virus replication. Maintaining a cellular level of LC3 and p62 during the viral infection period might help restrict virus replication. Although, AiV 3C protease dampens the LC3 and p62-mediated host antiviral machinery for AiV replication. Results obtained provide a better understanding of the molecular pathogenesis of AiV for developing methods of prevention and treatment.
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Affiliation(s)
- Ming-Hsiang Kung
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan
| | - You-Sheng Lin
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan
| | - Tsung-Hsien Chang
- Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei 11490, Taiwan
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Li C, Yu Y, Zhang X, Wei J, Qin Q. Grouper Atg12 negatively regulates the antiviral immune response against Singapore grouper iridovirus (SGIV) infection. FISH & SHELLFISH IMMUNOLOGY 2019; 93:702-710. [PMID: 31421242 DOI: 10.1016/j.fsi.2019.08.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Autophagy is an evolutionarily conserved, multi-step lysosomal degradation process used to maintain cell survival and homeostasis. A series of autophagy-related genes (Atgs) are involved in the autophagic pathway. In mammals, a growing number of studies have attributed functions to some Atgs that are distinct from their classical role in autophagosome biogenesis, such as resistance to pathogens. However, little is known about the functions of fish Atgs. In this study, we cloned and characterized an atg12 homolog from orange spotted grouper (Epinephelus coioides) (Ecatg12). Ecatg12 encodes a 117 amino acid protein that shares 94.0% and 76.8% identity with gourami (Anabas_testudineus) and humans (Homo sapiens), respectively. The transcription level of Ecatg12 was lower in cells infected with Singapore grouper iridovirus (SGIV) than in non-infected cells. Fluorescence microscopy revealed that EcAtg12 localized in the cytoplasm and nucleus in grouper spleen cells. Overexpression of EcAtg12 significantly increased the replication of SGIV, as evidenced by increased severity of the cytopathic effect, transcription levels of viral genes, levels of viral proteins, and progeny virus yield. Further studies showed that EcAtg12 overexpression decreased the expression levels of interferon (IFN) related molecules and pro-inflammatory factors and inhibited the promoter activity of IFN-3, interferon-stimulated response element, and nuclear factor-κB. Together, these results demonstrate that EcAtg12 plays crucial roles in SGIV replication by downregulating antiviral immune responses.
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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
| | - 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
| | - 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
| | - 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; Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-sen 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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Junín Virus Promotes Autophagy To Facilitate the Virus Life Cycle. J Virol 2019; 93:JVI.02307-18. [PMID: 31118257 DOI: 10.1128/jvi.02307-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 05/05/2019] [Indexed: 01/19/2023] Open
Abstract
Junín virus (JUNV), a member of the family Arenaviridae, is the etiological agent of Argentine hemorrhagic fever (AHF), a potentially deadly endemic-epidemic disease affecting the population of the most fertile farming land of Argentina. Autophagy is a degradative process with a crucial antiviral role; however, several viruses subvert the pathway to their benefit. We determined the role of autophagy in JUNV-infected cells by analyzing LC3, a cytoplasmic protein (LC3-I) that becomes vesicle membrane associated (LC3-II) upon induction of autophagy. Cells overexpressing enhanced green fluorescent protein (EGFP)-LC3 and infected with JUNV showed an increased number of LC3 punctate structures, similar to those obtained after starvation or bafilomycin A1 treatment, which leads to autophagosome induction or accumulation, respectively. We also monitored the conversion of LC3-I to LC3-II, observing LC3-II levels in JUNV-infected cells similar to those observed in starved cells. Additionally, we kinetically studied the number of LC3 dots after JUNV infection and found that the virus activated the pathway as early as 2 h postinfection (p.i.), whereas the UV-inactivated virus did not induce the pathway. Cells subjected to starvation or pretreated with rapamycin, a pharmacological autophagy inductor, enhanced virus yield. Also, we assayed the replication capacity of JUNV in Atg5 knockout or Beclin 1 knockdown cells (both critical components of the autophagic pathway) and found a significant decrease in JUNV replication. Taken together, our results constitute the first study indicating that JUNV infection induces an autophagic response, which is functionally required by the virus for efficient propagation.IMPORTANCE Mammalian arenaviruses are zoonotic viruses that cause asymptomatic and persistent infections in their rodent hosts but may produce severe and lethal hemorrhagic fevers in humans. Currently, there are neither effective therapeutic options nor effective vaccines for viral hemorrhagic fevers caused by human-pathogenic arenaviruses, except the vaccine Candid no. 1 against Argentine hemorrhagic fever (AHF), licensed for human use in areas of endemicity in Argentina. Since arenaviruses remain a severe threat to global public health, more in-depth knowledge of their replication mechanisms would improve our ability to fight these viruses. Autophagy is a lysosomal degradative pathway involved in maintaining cellular homeostasis, representing powerful anti-infective machinery. We show, for the first time for a member of the family Arenaviridae, a proviral role of autophagy in JUNV infection, providing new knowledge in the field of host-virus interaction. Therefore, modulation of virus-induced autophagy could be used as a strategy to block arenavirus infections.
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Li C, Liu J, Zhang X, Wei S, Huang X, Huang Y, Wei J, Qin Q. Fish Autophagy Protein 5 Exerts Negative Regulation on Antiviral Immune Response Against Iridovirus and Nodavirus. Front Immunol 2019; 10:517. [PMID: 30941145 PMCID: PMC6433989 DOI: 10.3389/fimmu.2019.00517] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 02/26/2019] [Indexed: 12/20/2022] Open
Abstract
Autophagy is an important biological activity that maintains homeostasis in eukaryotic cells. However, little is known about the functions of fish autophagy-related genes (Atgs). In this study, we cloned and characterized Atg5, a key gene in the autophagy gene superfamily, from orange-spotted grouper (Epinephelus coioides) (EcAtg5). EcAtg5 encoded a 275-amino acid protein that shared 94 and 81% identity to seabass (Lates calcarifer) and humans (Homo sapiens), respectively. The transcription level of EcAtg5 was significantly increased in cells infected with red-spotted grouper nervous necrosis virus (RGNNV). In cells infected with Singapore grouper iridovirus (SGIV), EcAtg5 expression declined during the early stage of infection and increased in the late stage. Fluorescence microscopy revealed that EcAtg5 mainly localized with a dot-like pattern in the cytoplasm of grouper cells. Overexpression of EcAtg5 significantly increased the replication of RGNNV and SGIV at different levels of detection, as indicated by increased severity of the cytopathic effect, transcription levels of viral genes, and levels of viral proteins. Knockdown of EcAtg5 decreased the replication of RGNNV and SGIV. Further studies showed that overexpression EcAtg5 activated autophagy, decreased expression levels of interferon related cytokines or effectors and pro-inflammatory factors, and inhibited the activation of nuclear factor κB, IFN-sensitive response element, and IFNs. In addition, ectopic expression of EcAtg5 affected cell cycle progression by hindering the G1/S transition. Taken together, our results demonstrated that fish Atg5 exerted a crucial role in virus replication by promoting autophagy, down-regulating antiviral IFN responses, and affecting the cell cycle.
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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
| | - 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
| | - 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, China
| | - Shina 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
| | - 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
| | - 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
| | - 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
| | - 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.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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11
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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: 77] [Impact Index Per Article: 12.8] [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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12
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Hu H, Tian M, Ding C, Yu S. The C/EBP Homologous Protein (CHOP) Transcription Factor Functions in Endoplasmic Reticulum Stress-Induced Apoptosis and Microbial Infection. Front Immunol 2019; 9:3083. [PMID: 30662442 PMCID: PMC6328441 DOI: 10.3389/fimmu.2018.03083] [Citation(s) in RCA: 742] [Impact Index Per Article: 123.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/13/2018] [Indexed: 12/17/2022] Open
Abstract
Apoptosis is a form of cell death by which the body maintains the homeostasis of the internal environment. Apoptosis is an initiative cell death process that is controlled by genes and is mainly divided into endogenous pathways (mitochondrial pathway), exogenous pathways (death receptor pathway), and apoptotic pathways induced by endoplasmic reticulum (ER) stress. The homeostasis imbalance in ER results in ER stress. Under specific conditions, ER stress can be beneficial to the body; however, if ER protein homeostasis is not restored, the prolonged activation of the unfolded protein response may initiate apoptotic cell death via the up-regulation of the C/EBP homologous protein (CHOP). CHOP plays an important role in ER stress-induced apoptosis and this review focuses on its multifunctional roles in that process, as well as its role in apoptosis during microbial infection. We summarize the upstream and downstream pathways of CHOP in ER stress induced apoptosis. We also focus on the newest discoveries in the functions of CHOP-induced apoptosis during microbial infection, including DNA and RNA viruses and some species of bacteria. Understanding how CHOP functions during microbial infection will assist with the development of antimicrobial therapies.
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Affiliation(s)
- Hai Hu
- Department of Veterinary Public Health, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Mingxing Tian
- Department of Veterinary Public Health, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chan Ding
- Department of Veterinary Public Health, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Shengqing Yu
- Department of Veterinary Public Health, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
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13
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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: 5.1] [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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14
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Viret C, Rozières A, Faure M. Autophagy during Early Virus–Host Cell Interactions. J Mol Biol 2018; 430:1696-1713. [DOI: 10.1016/j.jmb.2018.04.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 04/15/2018] [Accepted: 04/17/2018] [Indexed: 01/04/2023]
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15
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mTORC1 Negatively Regulates the Replication of Classical Swine Fever Virus Through Autophagy and IRES-Dependent Translation. iScience 2018; 3:87-101. [PMID: 30428332 PMCID: PMC6137324 DOI: 10.1016/j.isci.2018.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/06/2018] [Accepted: 03/29/2018] [Indexed: 02/07/2023] Open
Abstract
Classical swine fever virus (CSFV) can utilize diverse host signaling pathways for its replication; however, the cross talk between mammalian target of rapamycin (mTOR) and CSFV remains unknown. Here, we describe the potential role of mTOR complex 1 (mTORC1) in promoting CSFV replication via virus-induced hypophosphorylation of the Akt/mTORC1/S6 pathway, especially at an early stage of viral infection. Conversely, activation of mTORC1 inhibited the replication of CSFV. Furthermore, we revealed the underlying mechanisms of mTORC1 pathway in mediating CSFV replication; in addition, our data also showed that CSFV-induced transient inhibition of mTORC1 elicited a negative feedback activation of PI3K/Akt/mTORC1pathway, likely contributing to maintain the dynamic balance between viral replication and host cell survival. This study has provided strong evidence showing how CSFV utilizes mTORC1 pathway for viral replication at an early stage in the viral replicative cycle and how the mTORC1 rescues itself by eliciting a feedback loop to limit viral replication and maintain cell survival.
Akt/mTORC1 pathway negatively regulates the replication of CSFV CSFV induces autophagy for viral replication in an mTORC1/ULK1-dependent manner CSFV enhances the translation of viral proteins in an mTORC1/S6K1/eIF3-dependent manner Feedback activation of Akt/mTORC1 equilibrates viral replication and cell survival
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16
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Li YC, Zhang MQ, Zhang JP. Opposite Effects of Two Human ATG10 Isoforms on Replication of a HCV Sub-genomic Replicon Are Mediated via Regulating Autophagy Flux in Zebrafish. Front Cell Infect Microbiol 2018; 8:109. [PMID: 29670865 PMCID: PMC5893791 DOI: 10.3389/fcimb.2018.00109] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/19/2018] [Indexed: 12/15/2022] Open
Abstract
Autophagy is a host mechanism for cellular homeostatic control. Intracellular stresses are symptoms of, and responses to, dysregulation of the physiological environment of the cell. Alternative gene transcription splicing is a mechanism potentially used by a host to respond to physiological or pathological challenges. Here, we aimed to confirm opposite effects of two isoforms of the human autophagy-related protein ATG10 on an HCV subgenomic replicon in zebrafish. A liver-specific HCV subreplicon model was established and exhibited several changes in gene expression typically induced by HCV infection, including overexpression of several HCV-dependent genes (argsyn, leugpcr, rasgbd, and scaf-2), as well as overexpression of several ER stress related genes (atf4, chop, atf6, and bip). Autophagy flux was blocked in the HCV model. Our results indicated that the replication of the HCV subreplicon was suppressed via a decrease in autophagosome formation caused by the autophagy inhibitor 3MA, but enhanced via dysfunction in the lysosomal degradation caused by another autophagy inhibitor CQ. Human ATG10, a canonical isoform in autophagy, facilitated the amplification of the HCV-subgenomic replicon via promoting autophagosome formation. ATG10S, a non-canonical short isoform of the ATG10 protein, promoted autophagy flux, leading to lysosomal degradation of the HCV-subgenomic replicon. Human ATG10S may therefore inhibit HCV replication, and may be an appropriate target for future antiviral drug screening.
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Affiliation(s)
- Yu-Chen Li
- Laboratory of Pharmacology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Miao-Qing Zhang
- Laboratory of Pharmacology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jing-Pu Zhang
- Laboratory of Pharmacology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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17
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Bombyx mori Nuclear Polyhedrosis Virus (BmNPV) Induces Host Cell Autophagy to Benefit Infection. Viruses 2017; 10:v10010014. [PMID: 29301200 PMCID: PMC5795427 DOI: 10.3390/v10010014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/23/2017] [Accepted: 12/28/2017] [Indexed: 01/08/2023] Open
Abstract
Bombyx mori nuclear polyhedrosis virus (BmNPV) is an important pathogen of silkworms. Despite extensive studies in recent decades, the interaction between BmNPV and host cells is still not clearly understood. Autophagy is an intrinsic innate immune mechanism and it controls infection autonomously in virus-infected cells. In this study, we found that BmNPV infection could trigger autophagy, as demonstrated by the formation of autophagosomes, fluorescent Autophagy-related gene 8-Green Fluorescent Protein (ATG8-GFP) punctate, and lipidated ATG8. Meanwhile, autophagic flux increased significantly when monitored by the ATG8-GFP-Red Fluorescent Protein (RFP) autophagy tandem sensor and protein degradation of p62. In addition, almost all of the identified autophagy-related genes (Atgs) had been up-regulated post infection in mRNA levels. Then, we screened Atgs with the greatest fold-change during virus infection. Interestingly, all of the screened Atgs positively regulated the expression of virus genes. Further studies showed that Atg7 and Atg9 could contribute to the level of autophagy caused by viral infection. Our results demonstrated that BmNPV induced host cell autophagy to benefit its infection. These results offer insight into the complex interactions between virus and host cell, and viral pathogenesis.
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18
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Yang Y, Liu L, Naik I, Braunstein Z, Zhong J, Ren B. Transcription Factor C/EBP Homologous Protein in Health and Diseases. Front Immunol 2017; 8:1612. [PMID: 29230213 PMCID: PMC5712004 DOI: 10.3389/fimmu.2017.01612] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/07/2017] [Indexed: 12/13/2022] Open
Abstract
C/EBP homologous protein (CHOP), known also as DNA damage-inducible transcript 3 and as growth arrest and DNA damage-inducible protein 153 (GADD153), is induced in response to certain stressors. CHOP is universally acknowledged as a main conduit to endoplasmic reticulum stress-induced apoptosis. Ongoing research established the existence of CHOP-mediated apoptosis signaling networks, for which novel downstream targets are still being determined. However, there are studies that contradict this notion and assert that apoptosis is not the only mechanism by which CHOP plays in the development of pathologies. In this review, insights into the roles of CHOP in pathophysiology are summarized at the molecular and cellular levels. We further focus on the newest advances that implicate CHOP in human diseases including cancer, diabetes, neurodegenerative disorders, and notably, fibrosis.
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Affiliation(s)
- Yuan Yang
- Center for Molecular Medicine, Medical School of Yangtze University, Jingzhou, China.,Department of Radiology, Medical School of Yangtze University, Jingzhou, China
| | - Lian Liu
- Department of Pharmacology, Medical School of Yangtze University, Jingzhou, China
| | - Ishan Naik
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, United States
| | - Zachary Braunstein
- Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Jixin Zhong
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, United States
| | - Boxu Ren
- Center for Molecular Medicine, Medical School of Yangtze University, Jingzhou, China.,Department of Radiology, Medical School of Yangtze University, Jingzhou, China
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19
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Dual Roles of Two Isoforms of Autophagy-related Gene ATG10 in HCV-Subgenomic replicon Mediated Autophagy Flux and Innate Immunity. Sci Rep 2017; 7:11250. [PMID: 28900156 PMCID: PMC5595887 DOI: 10.1038/s41598-017-11105-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
Autophagy and immune response are two defense systems that human-body uses against viral infection. Previous studies documented that some viral mechanisms circumvented host immunity mechanisms and hijacked autophagy for its replication and survival. Here, we focus on interactions between autophagy mechanism and innate-immune-response in HCV-subgenomic replicon cells to find a mechanism linking the two pathways. We report distinct effects of two autophagy-related protein ATG10s on HCV-subgenomic replication. ATG10, a canonical long isoform in autophagy process, can facilitate HCV-subgenomic replicon amplification by promoting autophagosome formation and by combining with and detaining autophagosomes in cellular periphery, causing impaired autophagy flux. ATG10S, a non-canonical short isoform of ATG10 proteins, can activate expression of IL28A/B and immunity genes related to viral ds-RNA including ddx-58, tlr-3, tlr-7, irf-3 and irf-7, and promote autophagolysosome formation by directly combining and driving autophagosomes to perinuclear region where lysosomes gather, leading to lysosomal degradation of HCV-subgenomic replicon in HepG2 cells. ATG10S also can suppress infectious HCV virion replication in Huh7.5 cells. Another finding is that IL28A protein directly conjugates ATG10S and helps autophagosome docking to lysosomes. ATG10S might be a new host factor against HCV replication, and as a target for screening chemicals with new anti-virus mechanisms.
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20
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Yu A, Zhang T, Zhong W, Duan H, Wang S, Ye P, Wang J, Zhong S, Yang Z. miRNA-144 induces microglial autophagy and inflammation following intracerebral hemorrhage. Immunol Lett 2017; 182:18-23. [PMID: 28062218 DOI: 10.1016/j.imlet.2017.01.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/31/2016] [Accepted: 01/02/2017] [Indexed: 12/21/2022]
Abstract
Autophagic activation mediated inflammation contributes to brain injury of intracerebral hemorrhage (ICH). MiRNAs play a key role in inflammation, which negatively and posttranscriptionally regulate gene expression and function. Modulating the mTOR signal, a central regulator of autophagy, could be of great significance for ICH. However, the specific of miRNA is unknown. In the current study, we detected the miRNA-144 expression, autophagic activity and inflammation of microglia in ICH. We also knocked down endogenous miRNA-144 to regulate autophagy and inflammation in ICH. In addition, we assessed the neurological damge in ICH mice. We found that ICH promoted miRNA-144 expression but downregulated mTOR expression. In addition, upregulation of mTOR attenuated microglial autophagy and inflammation in ICH. Furthermore, downregulation of miRNA-144 also inhibited inflammation, brain edema and improved neurological functions in ICH mice. Taken together, our findings suggested that miRNA-144 was a crucial regulator of autophagy via regulation of mTOR, and represented a promising therapeutical strategy for ICH.
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Affiliation(s)
- Anyong Yu
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Tianxi Zhang
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Wenyi Zhong
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Haizhen Duan
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Song Wang
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Peng Ye
- Department of Emergency, The First Affiliated Hospital of Zunyi Medical College, Guizhou 563003, China
| | - Juan Wang
- Department of Neurology, Yongchuan Hospital, Chongqing Medical University, Chongqing 402160, China
| | - Shanchuan Zhong
- Department of Neurology, Yongchuan Hospital, Chongqing Medical University, Chongqing 402160, China
| | - Zhao Yang
- Department of Neurology, Yongchuan Hospital, Chongqing Medical University, Chongqing 402160, China.
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21
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Medvedev R, Hildt E, Ploen D. Look who's talking-the crosstalk between oxidative stress and autophagy supports exosomal-dependent release of HCV particles. Cell Biol Toxicol 2016; 33:211-231. [PMID: 27987184 DOI: 10.1007/s10565-016-9376-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/04/2016] [Indexed: 12/12/2022]
Abstract
Autophagy is a highly conserved and regulated intracellular lysosomal degradation pathway that is essential for cell survival. Dysregulation has been linked to the development of various human diseases, including neurodegeneration and tumorigenesis, infection, and aging. Besides, many viruses hijack the autophagosomal pathway to support their life cycle. The hepatitis C virus (HCV), a major cause of chronic liver diseases worldwide, has been described to induce autophagy. The autophagosomal pathway can be further activated in response to elevated levels of reactive oxygen species (ROS). HCV impairs the Nrf2/ARE-dependent induction of ROS-detoxifying enzymes by a so far unprecedented mechanism. In line with this, this review aims to discuss the relevance of HCV-dependent elevated ROS levels for the induction of autophagy as a result of the impaired Nrf2 signaling and the described crosstalk between p62 and the Nrf2/Keap1 signaling pathway. Moreover, autophagy is functionally connected to the endocytic pathway as components of the endosomal trafficking are involved in the maturation of autophagosomes. The release of HCV particles is still not fully understood. Recent studies suggest an involvement of exosomes that originate from the endosomal pathway in viral release. In line with this, it is tempting to speculate whether HCV-dependent elevated ROS levels induce autophagy to support exosome-mediated release of viral particles. Based on recent findings, in this review, we will further highlight the impact of HCV-induced autophagy and its interplay with the endosomal pathway as a novel mechanism for the release of HCV particles.
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Affiliation(s)
- Regina Medvedev
- Department of Virology, Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, 63225, Langen, Germany
| | - Eberhard Hildt
- Department of Virology, Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, 63225, Langen, Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Gießen, Marburg, Langen, Germany
| | - Daniela Ploen
- Department of Virology, Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, 63225, Langen, Germany.
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22
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Miyamura T, Lemon SM, Walker CM, Wakita T. The HCV Replicase Complex and Viral RNA Synthesis. HEPATITIS C VIRUS I 2016. [PMCID: PMC7122888 DOI: 10.1007/978-4-431-56098-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Replication of hepatitis C virus (HCV) is tightly linked to membrane alterations designated the membranous web, harboring the viral replicase complex. In this chapter we describe the morphology and 3D architecture of the HCV-induced replication organelles, mainly consisting of double membrane vesicles, which are generated by a concerted action of the nonstructural proteins NS3 to NS5B. Recent studies have furthermore identified a number of host cell proteins and lipids contributing to the biogenesis of the membranous web, which are discussed in this chapter. Viral RNA synthesis is tightly associated with these membrane alterations and mainly driven by the viral RNA dependent RNA polymerase NS5B. We summarize our current knowledge of the structure and function of NS5B, the role of cis-acting replication elements at the termini of the genome in regulating RNA synthesis and the contribution of additional viral and host factors to viral RNA synthesis, which is still ill defined.
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Affiliation(s)
- Tatsuo Miyamura
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
| | - Stanley M. Lemon
- Departments of Medicine and Microbiology & Immunology , The University of North Carolina, Chapel Hill, North Carolina USA
| | - Christopher M. Walker
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio USA
| | - Takaji Wakita
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
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23
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Wang Y, Kuramitsu Y, Baron B, Kitagawa T, Tokuda K, Akada J, Nakamura K. CGK733-induced LC3 II formation is positively associated with the expression of cyclin-dependent kinase inhibitor p21Waf1/Cip1 through modulation of the AMPK and PERK/CHOP signaling pathways. Oncotarget 2016; 6:39692-701. [PMID: 26486079 PMCID: PMC4741855 DOI: 10.18632/oncotarget.5625] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/02/2015] [Indexed: 11/25/2022] Open
Abstract
Microtubule-associated protein 1A/1B-light chain 3 (LC3)-II is essential for autophagosome formation and is widely used to monitor autophagic activity. We show that CGK733 induces LC3 II and LC3-puncta accumulation, which are not involved in the activation of autophagy. The treatment of CGK733 did not alter the autophagic flux and was unrelated to p62 degradation. Treatment with CGK733 activated the AMP-activated protein kinase (AMPK) and protein kinase RNA-like endoplasmic reticulum kinase/CCAAT-enhancer-binding protein homologous protein (PERK/CHOP) pathways and elevated the expression of p21Waf1/Cip1. Inhibition of both AMPK and PERK/CHOP pathways by siRNA or chemical inhibitor could block CGK733-induced p21Waf1/Cip1 expression as well as caspase-3 cleavage. Knockdown of LC3 B (but not LC3 A) abolished CGK733-triggered LC3 II accumulation and consequently diminished AMPK and PERK/CHOP activity as well as p21Waf1/Cip1 expression. Our results demonstrate that CGK733-triggered LC3 II formation is an initial event upstream of the AMPK and PERK/CHOP pathways, both of which control p21Waf1/Cip1 expression.
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Affiliation(s)
- Yufeng Wang
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Yasuhiro Kuramitsu
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Byron Baron
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan.,Centre for Molecular Medicine and Biobanking, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Takao Kitagawa
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Kazuhiro Tokuda
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Junko Akada
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Kazuyuki Nakamura
- Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Japan.,Centre of Clinical Laboratories in Tokuyama Medical Association Hospital, Shunan, Japan
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24
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Taniguchi K, Yamachika S, He F, Karin M. p62/SQSTM1-Dr. Jekyll and Mr. Hyde that prevents oxidative stress but promotes liver cancer. FEBS Lett 2016; 590:2375-97. [PMID: 27404485 DOI: 10.1002/1873-3468.12301] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/08/2016] [Accepted: 07/09/2016] [Indexed: 12/17/2022]
Abstract
p62/SQSTM1 is a multifunctional signaling hub and autophagy adaptor with many binding partners, which allow it to activate mTORC1-dependent nutrient sensing, NF-κB-mediated inflammatory responses, and the NRF2-activated antioxidant defense. p62 recognizes polyubiquitin chains via its C-terminal domain and binds to LC3 via its LIR motif, thereby promoting the autophagic degradation of ubiquitinated cargos. p62 accumulates in many human liver diseases, including nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC), where it is a component of Mallory-Denk bodies and intracellular hyaline bodies. Chronic p62 elevation contributes to HCC development by preventing oncogene-induced senescence and death of cancer-initiating cells and enhancing their proliferation. In this review, we discuss p62-mediated signaling pathways and their roles in liver pathophysiology, especially NASH and HCC.
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Affiliation(s)
- Koji Taniguchi
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA.,Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan
| | - Shinichiro Yamachika
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Feng He
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, USA
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25
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The Autophagosomal SNARE Protein Syntaxin 17 Is an Essential Factor for the Hepatitis C Virus Life Cycle. J Virol 2016; 90:5989-6000. [PMID: 27099307 DOI: 10.1128/jvi.00551-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/12/2016] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Syntaxin 17 is an autophagosomal SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein required for the fusion of autophagosomes with lysosomes to form autolysosomes and thereby to deliver the enclosed contents for degradation. Hepatitis C virus (HCV) induces autophagy. In light of the observation that the number of viral particles formed by HCV-infected cells is much greater than the number of infectious viral particles finally released by HCV-infected cells, the regulation of fusion between autophagosomes and lysosomes might fulfill a key function controlling the number of released virions. HCV-replicating cells possess a decreased amount of syntaxin 17 due to impaired expression and increased turnover of syntaxin 17. Overexpression of syntaxin 17 in HCV-replicating cells diminishes the number of released infectious viral particles and decreases the amount of intracellular retained viral particles by favoring the formation of autolysosomes, in which HCV particles are degraded. Inhibition of lysosomal acidification by bafilomycin rescues the decreased release of virions from syntaxin 17-overexpressing cells, while induction of autophagy by rapamycin enforces the impairment of release under these conditions. Vice versa, inhibition of syntaxin 17 expression by specific small interfering RNAs results in an elevated amount of intracellular retained viral particles and facilitates the release of HCV virions by impairment of autophagosome-lysosome fusion. HCV genome replication, however, is not affected by modulation of syntaxin 17 expression. These data identify syntaxin 17 to be a novel factor controlling the release of HCV. This is achieved by regulation of autophagosome-lysosome fusion, which affects the equilibrium between the release of infectious viral particles and lysosomal degradation of intracellular retained viral particles. IMPORTANCE Hepatitis C virus (HCV) induces autophagy. Syntaxin 17 is an autophagosomal SNARE protein required for the fusion of autophagosomes with lysosomes. In HCV-infected cells, a major fraction of the de novo-synthesized viral particles is not released but is intracellularly degraded. In this context, the effect of HCV on the amount and distribution of syntaxin 17 and the relevance of syntaxin 17 for the viral life cycle were investigated. This study demonstrates that the amount of syntaxin 17 decreased in HCV-replicating cells. In addition, syntaxin 17 is identified to be a novel factor controlling the release of HCV, and the relevance of autophagosome-lysosome fusion as a regulator of the amount of released viral particles is revealed. Taken together, these findings indicate that syntaxin 17 is involved in the regulation of autophagosome-lysosome fusion and thereby affects the equilibrium between the release of infectious viral particles and the lysosomal degradation of intracellularly retained viral particles.
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26
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HCV and Oxidative Stress: Implications for HCV Life Cycle and HCV-Associated Pathogenesis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9012580. [PMID: 26955431 PMCID: PMC4756209 DOI: 10.1155/2016/9012580] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/14/2016] [Indexed: 12/15/2022]
Abstract
HCV (hepatitis C virus) is a member of the Flaviviridae family that contains a single-stranded positive-sense RNA genome of approximately 9600 bases. HCV is a major causative agent for chronic liver diseases such as steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma which are caused by multifactorial processes. Elevated levels of reactive oxygen species (ROS) are considered as a major factor contributing to HCV-associated pathogenesis. This review summarizes the mechanisms involved in formation of ROS in HCV replicating cells and describes the interference of HCV with ROS detoxifying systems. The relevance of ROS for HCV-associated pathogenesis is reviewed with a focus on the interference of elevated ROS levels with processes controlling liver regeneration. The overview about the impact of ROS for the viral life cycle is focused on the relevance of autophagy for the HCV life cycle and the crosstalk between HCV, elevated ROS levels, and the induction of autophagy.
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Yeganeh B, Rezaei Moghadam A, Alizadeh J, Wiechec E, Alavian SM, Hashemi M, Geramizadeh B, Samali A, Bagheri Lankarani K, Post M, Peymani P, Coombs KM, Ghavami S. Hepatitis B and C virus-induced hepatitis: Apoptosis, autophagy, and unfolded protein response. World J Gastroenterol 2015; 21:13225-39. [PMID: 26715805 PMCID: PMC4679754 DOI: 10.3748/wjg.v21.i47.13225] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 10/14/2015] [Accepted: 11/13/2015] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the co-incidence of apoptosis, autophagy, and unfolded protein response (UPR) in hepatitis B (HBV) and C (HCV) infected hepatocytes. METHODS We performed immunofluorescence confocal microscopy on 10 liver biopsies from HBV and HCV patients and tissue microarrays of HBV positive liver samples. We used specific antibodies for LC3β, cleaved caspase-3, BIP (GRP78), and XBP1 to detect autophagy, apoptosis and UPR, respectively. Anti-HCV NS3 and anti-HBs antibodies were also used to confirm infection. We performed triple blind counting of events to determine the co-incidence of autophagy (LC3β punctuate), apoptosis (cleaved caspase-3), and unfolded protein response (GRP78) with HBV and HCV infection in hepatocytes. All statistical analyses were performed using SPSS software for Windows (Version 16 SPSS Inc, Chicago, IL, United States). P-values < 0.05 were considered statistically significant. Statistical analyses were performed with Mann-Whitney test to compare incidence rates for autophagy, apoptosis, and UPR in HBV- and HCV-infected cells and adjacent non-infected cells. RESULTS Our results showed that infection of hepatocytes with either HBV and HCV induces significant increase (P < 0.001) in apoptosis (cleavage of caspase-3), autophagy (LC3β punctate), and UPR (increase in GRP78 expression) in the HCV- and HBV-infected cells, as compared to non-infected cells of the same biopsy sections. Our tissue microarray immunohistochemical expression analysis of LC3β in HBV(Neg) and HBV(Pos) revealed that majority of HBV-infected hepatocytes display strong positive staining for LC3β. Interestingly, although XBP splicing in HBV-infected cells was significantly higher (P < 0.05), our analyses show a slight increase of XBP splicing was in HCV-infected cells (P > 0.05). Furthermore, our evaluation of patients with HBV and HCV infection based on stage and grade of the liver diseases revealed no correlation between these pathological findings and induction of apoptosis, autophagy, and UPR. CONCLUSION The results of this study indicate that HCV and HBV infection activates apoptosis, autophagy and UPR, but slightly differently by each virus. Further studies are warranted to elucidate the interconnections between these pathways in relation to pathology of HCV and HBV in the liver tissue.
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Ploen D, Hildt E. Hepatitis C virus comes for dinner: How the hepatitis C virus interferes with autophagy. World J Gastroenterol 2015; 21:8492-8507. [PMID: 26229393 PMCID: PMC4515832 DOI: 10.3748/wjg.v21.i28.8492] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/10/2015] [Accepted: 06/16/2015] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a highly-regulated, conserved cellular process for the degradation of intracellular components in lysosomes to maintain the energetic balance of the cell. It is a pro-survival mechanism that plays an important role during development, differentiation, apoptosis, ageing and innate and adaptive immune response. Besides, autophagy has been described to be involved in the development of various human diseases, e.g., chronic liver diseases and the development of hepatocellular carcinoma. The hepatitis C virus (HCV) is a major cause of chronic liver diseases. It has recently been described that HCV, like other RNA viruses, hijacks the autophagic machinery to improve its replication. However, the mechanisms underlying its activation are conflicting. HCV replication and assembly occurs at the so-called membranous web that consists of lipid droplets and rearranged endoplasmic reticulum-derived membranes including single-, double- and multi-membrane vesicles. The double-membrane vesicles have been identified to contain NS3, NS5A, viral RNA and the autophagosomal marker microtubule-associated protein 1 light chain 3, corroborating the involvement of the autophagic pathway in the HCV life-cycle. In this review, we will highlight the crosstalk of the autophagosomal compartment with different steps of the HCV life-cycle and address its implications on favoring the survival of infected hepatocytes.
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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: 3.4] [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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Emerging roles of interferon-stimulated genes in the innate immune response to hepatitis C virus infection. Cell Mol Immunol 2014; 13:11-35. [PMID: 25544499 PMCID: PMC4712384 DOI: 10.1038/cmi.2014.127] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/21/2014] [Accepted: 11/22/2014] [Indexed: 12/14/2022] Open
Abstract
Infection with hepatitis C virus (HCV), a major viral cause of chronic liver disease, frequently progresses to steatosis and cirrhosis, which can lead to hepatocellular carcinoma. HCV infection strongly induces host responses, such as the activation of the unfolded protein response, autophagy and the innate immune response. Upon HCV infection, the host induces the interferon (IFN)-mediated frontline defense to limit virus replication. Conversely, HCV employs diverse strategies to escape host innate immune surveillance. Type I IFN elicits its antiviral actions by inducing a wide array of IFN-stimulated genes (ISGs). Nevertheless, the mechanisms by which these ISGs participate in IFN-mediated anti-HCV actions remain largely unknown. In this review, we first outline the signaling pathways known to be involved in the production of type I IFN and ISGs and the tactics that HCV uses to subvert innate immunity. Then, we summarize the effector mechanisms of scaffold ISGs known to modulate IFN function in HCV replication. We also highlight the potential functions of emerging ISGs, which were identified from genome-wide siRNA screens, in HCV replication. Finally, we discuss the functions of several cellular determinants critical for regulating host immunity in HCV replication. This review will provide a basis for understanding the complexity and functionality of the pleiotropic IFN system in HCV infection. Elucidation of the specificity and the mode of action of these emerging ISGs will also help to identify novel cellular targets against which effective HCV therapeutics can be developed.
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Emerging roles of interferon-stimulated genes in the innate immune response to hepatitis C virus infection. Cell Mol Immunol 2014; 11:218-20. [PMID: 25544499 DOI: 10.1038/cmi.2014.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 12/16/2022] Open
Abstract
Infection with hepatitis C virus (HCV), a major viral cause of chronic liver disease, frequently progresses to steatosis and cirrhosis, which can lead to hepatocellular carcinoma. HCV infection strongly induces host responses, such as the activation of the unfolded protein response, autophagy and the innate immune response. Upon HCV infection, the host induces the interferon (IFN)-mediated frontline defense to limit virus replication. Conversely, HCV employs diverse strategies to escape host innate immune surveillance. Type I IFN elicits its antiviral actions by inducing a wide array of IFN-stimulated genes (ISGs). Nevertheless, the mechanisms by which these ISGs participate in IFN-mediated anti-HCV actions remain largely unknown. In this review, we first outline the signaling pathways known to be involved in the production of type I IFN and ISGs and the tactics that HCV uses to subvert innate immunity. Then, we summarize the effector mechanisms of scaffold ISGs known to modulate IFN function in HCV replication. We also highlight the potential functions of emerging ISGs, which were identified from genome-wide siRNA screens, in HCV replication. Finally, we discuss the functions of several cellular determinants critical for regulating host immunity in HCV replication. This review will provide a basis for understanding the complexity and functionality of the pleiotropic IFN system in HCV infection. Elucidation of the specificity and the mode of action of these emerging ISGs will also help to identify novel cellular targets against which effective HCV therapeutics can be developed.
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32
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Wang LF, Lin YS, Huang NC, Yu CY, Tsai WL, Chen JJ, Kubota T, Matsuoka M, Chen SR, Yang CS, Lu RW, Lin YL, Chang TH. Hydroxychloroquine-inhibited dengue virus is associated with host defense machinery. J Interferon Cytokine Res 2014; 35:143-56. [PMID: 25321315 DOI: 10.1089/jir.2014.0038] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Hydroxychloroquine (HCQ) is an antimalarial drug also used in treating autoimmune diseases. Its antiviral activity was demonstrated in restricting HIV infection in vitro; however, the clinical implications remain controversial. Infection with dengue virus (DENV) is a global public health problem, and we lack an antiviral drug for DENV. Here, we evaluated the anti-DENV potential of treatment with HCQ. Immunofluorescence assays demonstrated that HCQ could inhibit DENV serotype 1-4 infection in vitro. RT-qPCR analysis of HCQ-treated cells showed induced expression of interferon (IFN)-related antiviral proteins and certain inflammatory cytokines. Mechanistic study suggested that HCQ activated the innate immune signaling pathways of IFN-β, AP-1, and NFκB. Knocking down mitochondrial antiviral signaling protein (MAVS), inhibiting TANK binding kinase 1 (TBK1)/inhibitor-κB kinase ɛ (IKKɛ), and blocking type I IFN receptor reduced the efficiency of HCQ against DENV-2 infection. Furthermore, HCQ significantly induced cellular production of reactive oxygen species (ROS), which was involved in the host defense system. Suppression of ROS production attenuated the innate immune activation and anti-DENV-2 effect of HCQ. In summary, HCQ triggers the host defense machinery by inducing ROS- and MAVS-mediated innate immune activation against DENV infection and may be a candidate drug for DENV infection.
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Affiliation(s)
- Li-Fong Wang
- 1 Division of Allergy, Immunology, and Rheumatology, Kaohsiung Veterans General Hospital , Kaohsiung, Taiwan
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33
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Membranous replication factories induced by plus-strand RNA viruses. Viruses 2014; 6:2826-57. [PMID: 25054883 PMCID: PMC4113795 DOI: 10.3390/v6072826] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/02/2014] [Accepted: 06/24/2014] [Indexed: 12/13/2022] Open
Abstract
In this review, we summarize the current knowledge about the membranous replication factories of members of plus-strand (+) RNA viruses. We discuss primarily the architecture of these complex membrane rearrangements, because this topic emerged in the last few years as electron tomography has become more widely available. A general denominator is that two “morphotypes” of membrane alterations can be found that are exemplified by flaviviruses and hepaciviruses: membrane invaginations towards the lumen of the endoplasmatic reticulum (ER) and double membrane vesicles, representing extrusions also originating from the ER, respectively. We hypothesize that either morphotype might reflect common pathways and principles that are used by these viruses to form their membranous replication compartments.
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Bovine viral diarrhea virus infection induces autophagy in MDBK cells. J Microbiol 2014; 52:619-25. [DOI: 10.1007/s12275-014-3479-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 02/20/2014] [Accepted: 04/05/2014] [Indexed: 01/07/2023]
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35
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Verchot J. The ER quality control and ER associated degradation machineries are vital for viral pathogenesis. FRONTIERS IN PLANT SCIENCE 2014; 5:66. [PMID: 24653727 DOI: 10.3389/fpls.2014.00066/abstract] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 02/07/2014] [Indexed: 05/24/2023]
Abstract
The endoplasmic reticulum (ER) is central to protein production and membrane lipid synthesis. The unfolded protein response (UPR) supports cellular metabolism by ensuring protein quality control in the ER. Most positive strand RNA viruses cause extensive remodeling of membranes and require active membrane synthesis to promote infection. How viruses interact with the cellular machinery controlling membrane metabolism is largely unknown. Furthermore, there is mounting data pointing to the importance of the UPR and ER associated degradation (ERAD) machineries in viral pathogenesis in eukaryotes emerging topic. For many viruses, the UPR is an early event that is essential for persistent infection and benefits virus replication. In addition, many viruses are reported to commandeer ER resident chaperones to contribute to virus replication and intercellular movement. In particular, calreticulin, the ubiquitin machinery, and the 26S proteasome are most commonly identified components of the UPR and ERAD machinery that also regulate virus infection. In addition, researchers have noted a link between UPR and autophagy. It is well accepted that positive strand RNA viruses use autophagic membranes as scaffolds to support replication and assembly. However this topic has yet to be explored using plant viruses. The goal of research on this topic is to uncover how viruses interact with this ER-related machinery and to use this information for designing novel strategies to boost immune responses to virus infection.
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Affiliation(s)
- Jeanmarie Verchot
- Department of Entomology and Plant Pathology, Oklahoma State University Stillwater, OK, USA
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Verchot J. The ER quality control and ER associated degradation machineries are vital for viral pathogenesis. FRONTIERS IN PLANT SCIENCE 2014; 5:66. [PMID: 24653727 PMCID: PMC3949406 DOI: 10.3389/fpls.2014.00066] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 02/07/2014] [Indexed: 05/19/2023]
Abstract
The endoplasmic reticulum (ER) is central to protein production and membrane lipid synthesis. The unfolded protein response (UPR) supports cellular metabolism by ensuring protein quality control in the ER. Most positive strand RNA viruses cause extensive remodeling of membranes and require active membrane synthesis to promote infection. How viruses interact with the cellular machinery controlling membrane metabolism is largely unknown. Furthermore, there is mounting data pointing to the importance of the UPR and ER associated degradation (ERAD) machineries in viral pathogenesis in eukaryotes emerging topic. For many viruses, the UPR is an early event that is essential for persistent infection and benefits virus replication. In addition, many viruses are reported to commandeer ER resident chaperones to contribute to virus replication and intercellular movement. In particular, calreticulin, the ubiquitin machinery, and the 26S proteasome are most commonly identified components of the UPR and ERAD machinery that also regulate virus infection. In addition, researchers have noted a link between UPR and autophagy. It is well accepted that positive strand RNA viruses use autophagic membranes as scaffolds to support replication and assembly. However this topic has yet to be explored using plant viruses. The goal of research on this topic is to uncover how viruses interact with this ER-related machinery and to use this information for designing novel strategies to boost immune responses to virus infection.
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Affiliation(s)
- Jeanmarie Verchot
- *Correspondence: Jeanmarie Verchot, Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK 74078, USA e-mail:
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Richetta C, Faure M. Autophagy in antiviral innate immunity. Cell Microbiol 2012; 15:368-76. [DOI: 10.1111/cmi.12043] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/13/2012] [Accepted: 09/17/2012] [Indexed: 12/13/2022]
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Quarato G, Scrima R, Agriesti F, Moradpour D, Capitanio N, Piccoli C. Targeting mitochondria in the infection strategy of the hepatitis C virus. Int J Biochem Cell Biol 2012; 45:156-66. [PMID: 22710347 DOI: 10.1016/j.biocel.2012.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/29/2012] [Accepted: 06/07/2012] [Indexed: 12/23/2022]
Abstract
Hepatitis C virus (HCV) infection induces a state of oxidative stress more pronounced than that observed in many other inflammatory diseases. Here, we propose a temporal sequence of events in the HCV-infected cell whereby the primary alteration consists of a release of Ca(2+) from the endoplasmic reticulum, followed by uptake into mitochondria. This ensues successive mitochondrial dysfunction leading to the generation of reactive oxygen species and a progressive metabolic adaptive response. Evidence is provided for a positive feed-back mechanism between alterations of calcium and redox homeostasis. This likely involves deregulation of the mitochondrial permeability transition and induces progressive dysfunction of cellular bioenergetics. Pathogenetic implications of the model and new opportunities for therapeutic intervention are discussed. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.
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Affiliation(s)
- Giovanni Quarato
- Department of Biomedical Sciences, University of Foggia, Foggia, Italy
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39
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Abstract
Autophagy is a self-digestion process that plays an important role in the development, differentiation and homeostasis of cells, helping their survival during starvation and hypoxia. Accumulated mutant proteins in the endoplasmic reticulum can be degraded by autophagy in alpha-1 antitrypsin deficiency. Hepatitis C and B virus may exploit the autophagy pathway to escape the innate immune response and to promote their own replication. Autophagy is decreased in response to chronic alcohol consumption, likely due to a decrease in 5’-adenosine monophosphate-activated protein kinase, increase in mTOR activity and due to an alteration in vesicle transport in hepatocytes. In obesity and alcoholic liver disease the decreased function of autophagy causes formation of Mallory-Denk bodies and cell death. The deficient autophagy can contribute to liver steatosis, to endoplasmic reticulum stress, and to progression of liver disease. Autophagy defect in hepatocellular carcinoma suggests that it can serve a tumor-suppressor function. The autophagy protein Beclin-1 levels have prognostic significance in liver tumors. Understanding of the molecular mechanism and the role of autophagy may lead to more effective therapeutic strategies in liver diseases in the future. Orv. Hetil., 2011, 152, 1955–1961.
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Affiliation(s)
- Klára Werling
- Semmelweis Egyetem, Általános Orvostudományi Kar II. Belgyógyászati Klinika Budapest Szentkirályi u. 46. 1088
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Alavian SM, Ande SR, Coombs KM, Yeganeh B, Davoodpour P, Hashemi M, Los M, Ghavami S. Virus-triggered autophagy in viral hepatitis - possible novel strategies for drug development. J Viral Hepat 2011; 18:821-30. [PMID: 22093031 DOI: 10.1111/j.1365-2893.2011.01530.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autophagy is a very tightly regulated process that is important in many cellular processes including development, differentiation, survival and homoeostasis. The importance of this process has already been proven in numerous common diseases such as cancer and neurodegenerative disorders. Emerging data indicate that autophagy plays an important role in some liver diseases including liver injury induced by ischaemia reperfusion and alpha-1 antitrypsin Z allele-dependent liver disease. Autophagy may also occur in viral infection, and it may play a crucial role in antimicrobial host defence against pathogens, while supporting cellular homoeostasis processes. Here, the latest findings on the role of autophagy in viral hepatitis B and C infection, which are both serious health threats, will be reviewed.
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Affiliation(s)
- S M Alavian
- Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Tehran, Iran
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Martín-Acebes MA, Blázquez AB, Jiménez de Oya N, Escribano-Romero E, Saiz JC. West Nile virus replication requires fatty acid synthesis but is independent on phosphatidylinositol-4-phosphate lipids. PLoS One 2011; 6:e24970. [PMID: 21949814 PMCID: PMC3176790 DOI: 10.1371/journal.pone.0024970] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/19/2011] [Indexed: 12/19/2022] Open
Abstract
West Nile virus (WNV) is a neurovirulent mosquito-borne flavivirus, which main natural hosts are birds but it also infects equines and humans, among other mammals. As in the case of other plus-stranded RNA viruses, WNV replication is associated to intracellular membrane rearrangements. Based on results obtained with a variety of viruses, different cellular processes have been shown to play important roles on these membrane rearrangements for efficient viral replication. As these processes are related to lipid metabolism, fatty acid synthesis, as well as generation of a specific lipid microenvironment enriched in phosphatidylinositol-4-phosphate (PI4P), has been associated to it in other viral models. In this study, intracellular membrane rearrangements following infection with a highly neurovirulent strain of WNV were addressed by means of electron and confocal microscopy. Infection of WNV, and specifically viral RNA replication, were dependent on fatty acid synthesis, as revealed by the inhibitory effect of cerulenin and C75, two pharmacological inhibitors of fatty acid synthase, a key enzyme of this process. However, WNV infection did not induce redistribution of PI4P lipids, and PI4P did not localize at viral replication complex. Even more, WNV multiplication was not inhibited by the use of the phosphatidylinositol-4-kinase inhibitor PIK93, while infection by the enterovirus Coxsackievirus B5 was reduced. Similar features were found when infection by other flavivirus, the Usutu virus (USUV), was analyzed. These features of WNV replication could help to design specific antiviral approaches against WNV and other related flaviviruses.
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Affiliation(s)
- Miguel A Martín-Acebes
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
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