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Wang S, Wei R, Ma X, Guo J, Aizaz M, Li F, Wang J, Wang H, He H. The host protein CALCOCO2 interacts with bovine viral diarrhoea virus Npro, inhibiting type I interferon production and thereby promoting viral replication. Virulence 2024; 15:2289764. [PMID: 38047736 PMCID: PMC10730213 DOI: 10.1080/21505594.2023.2289764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 11/27/2023] [Indexed: 12/05/2023] Open
Abstract
Bovine viral diarrhoea-mucosal disease caused by bovine viral diarrhoea virus (BVDV) is a major infectious disease that affects the cattle industry. The nonstructural protein Npro of BVDV antagonizes the type I interferon (IFN-I) pathway, thereby escaping the host immune response. The exact mechanism by which Npro uses host proteins to inhibit IFN-I production is unclear. The host protein CALCOCO2 was identified as a binding partner of Npro using a yeast two-hybrid screen. The interaction between Npro and CALCOCO2 was confirmed by yeast co-transformation, co-immunoprecipitation assays, and GST pull-down assays. The stable overexpression of CALCOCO2 markedly promoted BVDV propagation, while the knockdown of CALCOCO2 significantly inhibited BVDV replication in MDBK cells. Interestingly, CALCOCO2 inhibited IFN-I and IFN-stimulated gene production in BVDV-infected cells. Ectopic expression of CALCOCO2 effectively reduced IRF3 protein levels via the proteasome pathway. CALCOCO2 was found to promote Npro-mediated ubiquitination degradation of IRF3 by interacting with IRF3. Our results demonstrate the molecular mechanism by which Npro recruits the CALCOCO2 protein to regulate IRF3 degradation to inhibit IFN-I production.
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Affiliation(s)
- Song Wang
- Department of Clinical Laboratory, The Second Hospital of Shandong University, Jinan, Shandong, China
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Ran Wei
- Poultry Institute, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Xiaomei Ma
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jin Guo
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Muhammad Aizaz
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Fangxu Li
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jun Wang
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Hongmei Wang
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Hongbin He
- Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, China
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Butt DQ, Harun MH, Che Jalil NA, Shamsuddin SH, Jaafar S, Ahmad B. Protumorigenic Interferon-Stimulated Genes in Cancer: A Comprehensive Review. Cureus 2024; 16:e63216. [PMID: 39070493 PMCID: PMC11279184 DOI: 10.7759/cureus.63216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2024] [Indexed: 07/30/2024] Open
Abstract
Interferon-stimulated genes (ISGs), whose production is triggered by interferons, are known to defend the host from pathogenic and cancer-specific antigens, one of which is by inducing apoptosis in infected or mutated cells. It has been reported recently that specific ISGs aid cancer cells in evading immunosurveillance and inflammatory cells by inhibiting the apoptosis process. This report reviewed four apoptosis-regulating ISG proteins: interferon-stimulated gene 15 (ISG15), interferon alpha-inducible protein 27 (IFI27), interferon alpha-inducible protein 6 (IFI6), and radical S-adenosyl methionine domain containing 2 (RSAD2), demonstrating anti-apoptosis function, and considered them protumorigenic.
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Affiliation(s)
- Danial Qasim Butt
- Oral Medicine and Oral Pathology Unit, School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian, MYS
| | - Masitah Hayati Harun
- Oral Medicine and Oral Pathology Unit, School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian, MYS
| | - Nur Asyilla Che Jalil
- Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, MYS
| | | | - Saidi Jaafar
- Basic Sciences Unit, School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian, MYS
| | - Basaruddin Ahmad
- Biostatistics Unit, School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian, MYS
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Liu X, Yan Q, Liu X, Wei W, Zou L, Zhao F, Zeng S, Yi L, Ding H, Zhao M, Chen J, Fan S. PKM2 induces mitophagy through the AMPK-mTOR pathway promoting CSFV proliferation. J Virol 2024; 98:e0175123. [PMID: 38319105 PMCID: PMC10949426 DOI: 10.1128/jvi.01751-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/14/2023] [Indexed: 02/07/2024] Open
Abstract
Viruses exploit the host cell's energy metabolism system to support their replication. Mitochondria, known as the powerhouse of the cell, play a critical role in regulating cell survival and virus replication. Our prior research indicated that the classical swine fever virus (CSFV) alters mitochondrial dynamics and triggers glycolytic metabolic reprogramming. However, the role and mechanism of PKM2, a key regulatory enzyme of glycolytic metabolism, in CSFV replication remain unclear. In this study, we discovered that CSFV enhances PKM2 expression and utilizes PKM2 to inhibit pyruvate production. Using an affinity purification coupled mass spectrometry system, we successfully identified PKM as a novel interaction partner of the CSFV non-structural protein NS4A. Furthermore, we validated the interaction between PKM2 and both CSFV NS4A and NS5A through co-immunoprecipitation and confocal analysis. PKM2 was found to promote the expression of both NS4A and NS5A. Moreover, we observed that PKM2 induces mitophagy by activating the AMPK-mTOR signaling pathway, thereby facilitating CSFV proliferation. In summary, our data reveal a novel mechanism whereby PKM2, a metabolic enzyme, promotes CSFV proliferation by inducing mitophagy. These findings offer a new avenue for developing antiviral strategies. IMPORTANCE Viruses rely on the host cell's material-energy metabolic system for replication, inducing host metabolic disorders and subsequent immunosuppression-a major contributor to persistent viral infections. Classical swine fever virus (CSFV) is no exception. Classical swine fever is a severe acute infectious disease caused by CSFV, resulting in significant economic losses to the global pig industry. While the role of the metabolic enzyme PKM2 (pyruvate dehydrogenase) in the glycolytic pathway of tumor cells has been extensively studied, its involvement in viral infection remains relatively unknown. Our data unveil a new mechanism by which the metabolic enzyme PKM2 mediates CSFV infection, offering novel avenues for the development of antiviral strategies.
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Affiliation(s)
- Xiaodi Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Quanhui Yan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Xueyi Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Wenkang Wei
- State Key Laboratory of Swine and Poultry Breeding Industry, Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Linke Zou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Feifan Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Sen Zeng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Lin Yi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Hongxing Ding
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guang Dong, China
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Han X, Xu H, Weng Y, Chen R, Xu J, Cao T, Sun R, Shan Y, He F, Fang W, Li X. N pro of classical swine fever virus enhances HMGB1 acetylation and its degradation by lysosomes to evade from HMGB1-mediated antiviral immunity. Virus Res 2024; 339:199280. [PMID: 37995963 PMCID: PMC10709370 DOI: 10.1016/j.virusres.2023.199280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Classical swine fever virus (CSFV) can dampen the host innate immunity by destabilizing IRF3 upon its binding with viral Npro. High mobility group box 1 (HMGB1), a non-histone nuclear protein, has diverse functions, including inflammation, innate immunity, etc., which are closely related to its cellular localization. We investigated potential mutual interactions between CSFV and HMGB1 and their effects on virus replication. We found that HMGB1 at the protein level, but not at mRNA level, was markedly reduced in CSFV-infected or Npro-expressing IPEC-J2 cells. HMGB1 in the nuclear compartment is anti-CSFV by promoting IFN-mediated innate immune response, as evidenced by overexpression of nuclear or cytoplasmic dominant HMGB1 mutant in IPEC-J2 cells stimulated with poly(I:C). However, CSFV Npro upregulates HMGB1 acetylation, a modification that promotes HMGB1 translocation into the cytoplasmic compartment where it is degraded by lysosomes. Ethyl pyruvate could downregulate HMGB1 acetylation and prevent Npro-mediated HMGB1 reduction. Inhibition of deacetylase HDAC1 with MS275 or by RNA silencing could promote Npro-mediated HMGB1 degradation. Taken together, our study elucidates the mechanism with which HMGB1 in the nuclei initiates antiviral innate immune response to suppress CSFV replication and elaborates the pathway by which CSFV uses its Npro to evade from HMGB1-mediated antiviral immunity through upregulating HMGB1 acetylation with subsequent translocation into cytoplasm for lysosomal degradation.
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Affiliation(s)
- Xiao Han
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Hankun Xu
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Yifan Weng
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Rong Chen
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Jidong Xu
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Tong Cao
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Renjie Sun
- Zhejiang Provincial Center for Animal Disease Prevention & Control, Hangzhou, Zhejiang 311199, China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Fang He
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Weihuan Fang
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China.
| | - Xiaoliang Li
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China.
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Guo X, Zhang M, Liu X, Zhang Y, Wang C, Guo Y. Attachment, Entry, and Intracellular Trafficking of Classical Swine Fever Virus. Viruses 2023; 15:1870. [PMID: 37766277 PMCID: PMC10534341 DOI: 10.3390/v15091870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Classical swine fever virus (CSFV), which is a positive-sense, single-stranded RNA virus with an envelope, is a member of the Pestivirus genus in the Flaviviridae family. CSFV causes a severe and highly contagious disease in pigs and is prevalent worldwide, threatening the pig farming industry. The detailed mechanisms of the CSFV life cycle have been reported, but are still limited. Some receptors and attachment factors of CSFV, including heparan sulfate (HS), laminin receptor (LamR), complement regulatory protein (CD46), MER tyrosine kinase (MERTK), disintegrin, and metalloproteinase domain-containing protein 17 (ADAM17), were identified. After attachment, CSFV internalizes via clathrin-mediated endocytosis (CME) and/or caveolae/raft-dependent endocytosis (CavME). After internalization, CSFV moves to early and late endosomes before uncoating. During this period, intracellular trafficking of CSFV relies on components of the endosomal sorting complex required for transport (ESCRT) and Rab proteins in the endosome dynamics, with a dependence on the cytoskeleton network. This review summarizes the data on the mechanisms of CSFV attachment, internalization pathways, and intracellular trafficking, and provides a general view of the early events in the CSFV life cycle.
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Affiliation(s)
| | | | | | | | | | - Yidi Guo
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130012, China
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Li Y, Yang C, Jiang Y, Wang X, Yuan C, Qi J, Yang Q. Characteristics of the nasal mucosa of commercial pigs during normal development. Vet Res 2023; 54:37. [PMID: 37095544 PMCID: PMC10123470 DOI: 10.1186/s13567-023-01164-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 03/01/2023] [Indexed: 04/26/2023] Open
Abstract
The nasal mucosa is constantly exposed to inhaled pathogens and is the first defence against respiratory infections. Here, we investigated the structural and compositional characteristics of the nasal mucosa of commercial pigs at various growth stages. The epithelial thickness, number of capillaries, and secretion function of the nasal mucosa dramatically increased with age; however, underlying lymphoid follicles in the respiratory region were rarely observed across the growth stages. The nasal mucosa was explored at the epithelial, immunological, and biological (commensal microbiota) barriers. In the epithelial barrier, the proliferative capacity of the nasal epithelia and the expression of tight junction proteins were high after birth; however, they decreased significantly during the suckling stage and increased again during the weaning stage. In the immunological barrier, most pattern recognition receptors were expressed at very low levels in neonatal piglets, and the innate immune cell distribution was lower. During the suckling stage, increased expression of Toll-like receptor (TLR) 2 and TLR4 was observed; however, TLR3 expression decreased. TLR expression and innate immune cell quantity significantly increased from the weaning to the finishing stage. In the biological barrier, Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes comprised the dominant phyla in neonatal piglets. A dramatic decrease in nasal microbial diversity was observed during the suckling stage, accompanied by an increase in potentially pathogenic bacteria. Proteobacteria, Bacteroidetes, and Firmicutes were identified as the core phyla of the nasal microbiota; among these, the three dominant genera, Actinobacter, Moraxella, and Bergerella, may be opportunistic pathogens in the respiratory tract. These characteristics comprise an essential reference for respiratory infection prevention at large-scale pig farms.
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Affiliation(s)
- Yuchen Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Chengjie Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yuqi Jiang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xiuyu Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Chen Yuan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jiaxin Qi
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qian Yang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.
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Hong T, Yang Y, Wang P, Zhu G, Zhu C. Pestiviruses infection: Interferon-virus mutual regulation. Front Cell Infect Microbiol 2023; 13:1146394. [PMID: 36936761 PMCID: PMC10018205 DOI: 10.3389/fcimb.2023.1146394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
Pestiviruses are a class of viruses that in some cases can cause persistent infection of the host, thus posing a threat to the livestock industry. Interferons (IFNs) are a group of secreted proteins that play a crucial role in antiviral defense. In this review, on the one hand, we elaborate on how pestiviruses are recognized by the host retinoic acid-inducible gene-I (RIG-I), melanoma-differentiation-associated protein 5 (MDA5), and Toll-like receptor 3 (TLR3) proteins to induce the synthesis of IFNs. On the other hand, we focus on reviewing how pestiviruses antagonize the production of IFNs utilizing various strategies mediated by self-encoded proteins, such as the structural envelope protein (Erns) and non-structural protein (Npro). Hence, the IFN signal transduction pathway induced by pestiviruses infection and the process of pestiviruses blockade on the production of IFNs intertwines into an intricate regulatory network. By reviewing the interaction between IFN and pestiviruses (based on studies on BVDV and CSFV), we expect to provide a theoretical basis and reference for a better understanding of the mechanisms of induction and evasion of the innate immune response during infection with these viruses.
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Affiliation(s)
- Tianqi Hong
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Yi Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Pengzhi Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, China
- *Correspondence: Guoqiang Zhu, ; Congrui Zhu,
| | - Congrui Zhu
- College of Animal Science, South China Agricultural University, Guangzhou, China
- *Correspondence: Guoqiang Zhu, ; Congrui Zhu,
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IRF3 inhibits nuclear translocation of NF-κB to prevent viral inflammation. Proc Natl Acad Sci U S A 2022; 119:e2121385119. [PMID: 36067309 PMCID: PMC9478676 DOI: 10.1073/pnas.2121385119] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interferon (IFN) regulatory factor 3 (IRF3) is a transcription factor activated by phosphorylation in the cytoplasm of a virus-infected cell; by translocating to the nucleus, it induces transcription of IFN-β and other antiviral genes. We have previously reported IRF3 can also be activated, as a proapoptotic factor, by its linear polyubiquitination mediated by the RIG-I pathway. Both transcriptional and apoptotic functions of IRF3 contribute to its antiviral effect. Here, we report a nontranscriptional function of IRF3, namely, the repression of IRF3-mediated NF-κB activity (RIKA), which attenuated viral activation of NF-κB and the resultant inflammatory gene induction. In Irf3-/- mice, consequently, Sendai virus infection caused enhanced inflammation in the lungs. Mechanistically, RIKA was mediated by the direct binding of IRF3 to the p65 subunit of NF-κB in the cytoplasm, which prevented its nuclear import. A mutant IRF3 defective in both the transcriptional and the apoptotic activities was active in RIKA and inhibited virus replication. Our results demonstrated IRF3 deployed a three-pronged attack on virus replication and the accompanying inflammation.
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Structure and Function of Mitochondria-Associated Endoplasmic Reticulum Membranes (MAMs) and Their Role in Cardiovascular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:4578809. [PMID: 34336092 PMCID: PMC8289621 DOI: 10.1155/2021/4578809] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022]
Abstract
Abnormal function of suborganelles such as mitochondria and endoplasmic reticulum often leads to abnormal function of cardiomyocytes or vascular endothelial cells and cardiovascular disease (CVD). Mitochondria-associated membrane (MAM) is involved in several important cellular functions. Increasing evidence shows that MAM is involved in the pathogenesis of CVD. MAM mediates multiple cellular processes, including calcium homeostasis regulation, lipid metabolism, unfolded protein response, ROS, mitochondrial dynamics, autophagy, apoptosis, and inflammation, which are key risk factors for CVD. In this review, we discuss the structure of MAM and MAM-associated proteins, their role in CVD progression, and the potential use of MAM as the therapeutic targets for CVD treatment.
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Transcriptional and Non-Transcriptional Activation, Posttranslational Modifications, and Antiviral Functions of Interferon Regulatory Factor 3 and Viral Antagonism by the SARS-Coronavirus. Viruses 2021; 13:v13040575. [PMID: 33805458 PMCID: PMC8066409 DOI: 10.3390/v13040575] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
The immune system defends against invading pathogens through the rapid activation of innate immune signaling pathways. Interferon regulatory factor 3 (IRF3) is a key transcription factor activated in response to virus infection and is largely responsible for establishing an antiviral state in the infected host. Studies in Irf3−/− mice have demonstrated the absence of IRF3 imparts a high degree of susceptibility to a wide range of viral infections. Virus infection causes the activation of IRF3 to transcribe type-I interferon (e.g., IFNβ), which is responsible for inducing the interferon-stimulated genes (ISGs), which act at specific stages to limit virus replication. In addition to its transcriptional function, IRF3 is also activated to trigger apoptosis of virus-infected cells, as a mechanism to restrict virus spread within the host, in a pathway called RIG-I-like receptor-induced IRF3 mediated pathway of apoptosis (RIPA). These dual functions of IRF3 work in concert to mediate protective immunity against virus infection. These two pathways are activated differentially by the posttranslational modifications (PTMs) of IRF3. Moreover, PTMs regulate not only IRF3 activation and function, but also protein stability. Consequently, many viruses utilize viral proteins or hijack cellular enzymes to inhibit IRF3 functions. This review will describe the PTMs that regulate IRF3′s RIPA and transcriptional activities and use coronavirus as a model virus capable of antagonizing IRF3-mediated innate immune responses. A thorough understanding of the cellular control of IRF3 and the mechanisms that viruses use to subvert this system is critical for developing novel therapies for virus-induced pathologies.
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