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Jiao F, Zhao Y, Zhou G, Meng C, Wang L, Wu S, Li J, Cao L, Zhou B, Luo Y, Jiao H. Multiple Functions of Hepatitis E Virus ORF3. Microorganisms 2024; 12:1405. [PMID: 39065173 PMCID: PMC11278674 DOI: 10.3390/microorganisms12071405] [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: 06/16/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Hepatitis E (Hepatitis E, HE) is an acute and chronic infectious hepatitis caused by hepatitis E virus (Hepatitis E Virus, HEV) infection, which is responsible for most acute hepatitis in the world and is a significant public health problem. The pathogen, HEV, has three Open Reading Frames (ORFs) ORF1, ORF2, and ORF3, each of which has a different function. Most of the current research is focused on ORF1 and ORF2, while the research on ORF3 is still relatively small. To provide more ideas for the study of HEV pathogenesis and the prevention and treatment of HE, this paper reviews the effects of ORF3 on the ERK pathway, growth factors, immune response, and virus release.
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Affiliation(s)
- Fengyuan Jiao
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Yu Zhao
- Ministry of Agriculture and Rural Affairs Key Laboratory of Crop Genitic Resources and Germplasm Innovation in Karst Region, Institute of Animal Husbandry and Veterinary Medicine of Guizhou Academy of Agricultural Science, Guiyang 550005, China;
| | - Gengxu Zhou
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Chi Meng
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Lingjie Wang
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Shengping Wu
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Jixiang Li
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Liting Cao
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Bo Zhou
- Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Yujinxiang Street 573, Changchun 130102, China;
| | - Yichen Luo
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
| | - Hanwei Jiao
- The College of Veterinary Medicine, Southwest University, Chongqing 402460, China; (F.J.); (G.Z.); (C.M.); (L.W.); (S.W.); (J.L.); (L.C.)
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Zhu LB, Zhu HD, Huang ZH, Cao HH, Ayaz S, Yang JY, Chen XY, Zhang Y, Liu SH, Xu JP. BmNPV p35 regulates apoptosis in Bombyx mori via a novel target of interaction with the BmVDAC2-BmRACK1 complex. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 169:104125. [PMID: 38616030 DOI: 10.1016/j.ibmb.2024.104125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 04/03/2024] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
Voltage-dependent anion channel 2 (VDAC2) is an important channel protein that plays a crucial role in the host response to viral infection. The receptor for activated C kinase 1 (RACK1) is also a key host factor involved in viral replication. Our previous research revealed that Bombyx mori VDAC2 (BmVDAC2) and B. mori RACK1 (BmRACK1) may interact with Bombyx mori nucleopolyhedrovirus (BmNPV), though the specific molecular mechanism remains unclear. In this study, the interaction between BmVDAC2 and BmRACK1 in the mitochondria was determined by various methods. We found that BmNPV p35 interacts directly with BmVDAC2 rather than BmRACK1. BmNPV infection significantly reduced the expression of BmVDAC2, and activated the mitochondrial apoptosis pathway. Overexpression of BmVDAC2 in BmN cells inhibited BmNPV-induced cytochrome c (cyto c) release, decrease in mitochondrial membrane potential as well as apoptosis. Additionally, the inhibition of cyto c release by BmVDAC2 requires the involvement of BmRACK1 and protein kinase C. Interestingly, overexpression of p35 inhibited cyto c release during mitochondrial apoptosis in a RACK1 and VDAC2-dependent manner. Even the mutant p35, which loses Caspase inhibitory activity, could still bind to VDAC2 and inhibit cyto c release. In summary, our results indicated that BmNPV p35 interacts with the VDAC2-RACK1 complex to regulate apoptosis by inhibiting cyto c release. These findings confirm the interaction between BmVDAC2 and BmRACK1, the interaction between p35 and the VDAC2-RACK1 complex, and a novel target that BmNPV p35 regulates apoptosis in Bombyx mori via interaction with the BmVDAC2-BmRACK1 complex. The result provide an initial exploration of the function of this interaction in the BmNPV-induced mitochondrial apoptosis pathway.
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Affiliation(s)
- Lin-Bao Zhu
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China; Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Han-Dan Zhu
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Zhi-Hao Huang
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Hui-Hua Cao
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Sadaf Ayaz
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Jia-Yue Yang
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Xi-Ya Chen
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Ying Zhang
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China
| | - Shi-Huo Liu
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China.
| | - Jia-Ping Xu
- Anhui Province Key Laboratory of Resource Insect Biology and Innovative Utilization, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Anhui International Joint Research and Developmental Center of Sericulture Resources Utilization, Hefei 230036, China.
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Belosludtseva NV, Dubinin MV, Belosludtsev KN. Pore-Forming VDAC Proteins of the Outer Mitochondrial Membrane: Regulation and Pathophysiological Role. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1061-1078. [PMID: 38981701 DOI: 10.1134/s0006297924060075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/12/2024] [Accepted: 05/27/2024] [Indexed: 07/11/2024]
Abstract
Voltage-dependent anion channels (VDAC1-3) of the outer mitochondrial membrane are a family of pore-forming β-barrel proteins that carry out controlled "filtration" of small molecules and ions between the cytoplasm and mitochondria. Due to the conformational transitions between the closed and open states and interaction with cytoplasmic and mitochondrial proteins, VDACs not only regulate the mitochondrial membrane permeability for major metabolites and ions, but also participate in the control of essential intracellular processes and pathological conditions. This review discusses novel data on the molecular structure, regulatory mechanisms, and pathophysiological role of VDAC proteins, as well as future directions in this area of research.
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Affiliation(s)
- Natalia V Belosludtseva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
- Mari State University, Yoshkar-Ola, Mari El, 424001, Russia
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Li X, Sun X, Pinpin J, Zhao Q, Sun Y. Multifunctional ORF3 protein of hepatitis E virus. J Med Virol 2024; 96:e29691. [PMID: 38783788 DOI: 10.1002/jmv.29691] [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: 02/02/2024] [Revised: 04/23/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024]
Abstract
Hepatitis E virus (HEV) is an emerging zoonotic pathogen that is transmitted primarily through the fecal-oral route and can cause acute hepatitis in humans. Since HEV was identified as a zoonotic pathogen, different species of HEV strains have been globally identified from various hosts, leading to an expanding range of hosts. The HEV genome consists of a 5' noncoding region, three open reading frames (ORFs), and a 3' noncoding region. The ORF3 protein is the smallest but has many functions in HEV release and pathogenesis. In this review, we systematically summarize recent progress in understanding the functions of the HEV ORF3 protein in virion release, biogenesis of quasi-enveloped viruses, antigenicity, and host environmental regulation. This review will help us to understand HEV replication and pathogenesis mechanisms better.
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Affiliation(s)
- Xiaoxuan Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Xuwen Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Ji Pinpin
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
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Qian Z, Cong C, Li Y, Bi Y, He Q, Li T, Xia Y, Xu L, Mickael HK, Yu W, Liu J, Wei D, Huang F. Quantification of host proteomic responses to genotype 4 hepatitis E virus replication facilitated by pregnancy serum. Virol J 2023; 20:111. [PMID: 37264422 PMCID: PMC10233519 DOI: 10.1186/s12985-023-02080-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/23/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Hepatitis E virus (HEV) infection is a common cause of acute hepatitis worldwide and causes approximately 30% case fatality rate among pregnant women. Pregnancy serum (PS), which contains a high concentration of estradiol, facilitates HEV replication in vitro through the suppression of the PI3K-AKT-mTOR and cAMPK-PKA-CREB signaling pathways. However, the proteomics of the complex host responses to HEV infection, especially how PS facilitates viral replication, remains unclear. METHODS In this study, the differences in the proteomics of HEV-infected HepG2 cells supplemented with fetal bovine serum (FBS) from those of HEV-infected HepG2 cells supplemented with serum from women in their third trimester of pregnancy were quantified by using isobaric tags for relative and absolute quantification technology. RESULTS A total of 1511 proteins were identified, among which 548 were defined as differentially expressed proteins (DEPs). HEV-infected cells supplemented with PS exhibited the most significant changes at the protein level. A total of 328 DEPs, including 66 up-regulated and 262 down-regulated proteins, were identified in HEV-infected cells supplemented with FBS, whereas 264 DEPs, including 201 up-regulated and 63 down-regulated proteins, were found in HEV-infected cells supplemented with PS. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that in HEV-infected cells, PS supplementation adjusted more host genes and signaling pathways than FBS supplementation. The DEPs involved in virus-host interaction participated in complex interactions, especially a large number of immune-related protein emerged in HEV-infected cells supplemented with PS. Three significant or interesting proteins, including filamin-A, thioredoxin, and cytochrome c, in HEV-infected cells were functionally verified. CONCLUSIONS The results of this study provide new and comprehensive insight for exploring virus-host interactions and will benefit future studies on the pathogenesis of HEV in pregnant women.
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Affiliation(s)
- Zhongyao Qian
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Chao Cong
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Yi Li
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Yanhong Bi
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Qiuxia He
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Tengyuan Li
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Yueping Xia
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Liangheng Xu
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Houfack K Mickael
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China
| | - Wenhai Yu
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, People's Republic of China.
| | - Jiankun Liu
- 920th Hospital of Joint Logistics Support Force of PLA, Kunming, People's Republic of China.
| | - Daqiao Wei
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China.
| | - Fen Huang
- Medical School, Kunming University of Science and Technology, Kunming, People's Republic of China.
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Srivastava M, Bhukya PL, Barman MK, Bhise N, Lole KS. Modulation of cellular autophagy by genotype 1 hepatitis E virus ORF3 protein. J Gen Virol 2023; 104. [PMID: 36809248 DOI: 10.1099/jgv.0.001824] [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] [Indexed: 02/23/2023] Open
Abstract
Hepatitis E virus (HEV) egresses from infected hepatocytes as quasienveloped particles containing open reading frame 3 (ORF3) protein. HEV ORF3 (small phosphoprotein) interacts with host proteins to establish a favourable environment for virus replication. It is a functional viroporin that plays an important role during virus release. Our study provides evidence that pORF3 plays a pivotal role in inducing Beclin1-mediated autophagy that helps HEV-1 replication as well as its exit from cells. The ORF3 interacts with host proteins involved in regulation of transcriptional activity, immune response, cellular and molecular processes, and modulation of autophagy, by interacting with proteins, DAPK1, ATG2B, ATG16L2 and also several histone deacetylases (HDACs). For autophagy induction, the ORF3 utilizes non-canonical NF-κB2 pathway and sequesters p52NF-κB and HDAC2 to upregulate DAPK1 expression, leading to enhanced Beclin1 phosphorylation. By sequestering several HDACs, HEV may prevent histone deacetylation to maintain overall cellular transcription intact to promote cell survival. Our findings highlight a novel crosstalk between cell survival pathways participating in ORF3-mediated autophagy.
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Affiliation(s)
| | - Prudhvi Lal Bhukya
- Division of Hepatitis, National Institute of Virology, Pune, India
- ICMR-National Animal Resource Facility for Biomedical Research, Hyderabad, India
| | | | - Neha Bhise
- Division of Hepatitis, National Institute of Virology, Pune, India
| | - Kavita S Lole
- Division of Hepatitis, National Institute of Virology, Pune, India
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Zhou Y, Zhao C, Tian Y, Xu N, Wang Y. Characteristics and Functions of HEV Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1417:15-32. [PMID: 37223856 DOI: 10.1007/978-981-99-1304-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Hepatitis E virus (HEV) is a non-enveloped virus containing a single-stranded, positive-sense RNA genome of 7.2 kb, which consists of a 5' non-coding region, three open reading frames (ORFs), and a 3' non-coding region. ORF1 is diverse between genotypes and encodes the nonstructural proteins, which include the enzymes needed for virus replication. In addition to its role in virus replication, the function of ORF1 is relevant to viral adaption in culture and may also relate to virus infection and HEV pathogenicity. ORF2 protein is the capsid protein, which is about 660 amino acids in length. It not only protects the integrity of the viral genome, but is also involved in many important physiological activities, such as virus assembly, infection, host interaction, and innate immune response. The main immune epitopes, especially neutralizing epitopes, are located on ORF2 protein, which is a candidate antigen for vaccine development. ORF3 protein is a phosphoprotein of 113 or 114 amino acids with a molecular weight of 13 kDa with multiple functions that can also induce strong immune reactivity. A novel ORF4 has been identified only in genotype 1 HEV and its translation promotes viral replication.
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Affiliation(s)
- Yan Zhou
- RegCMC, Great Regulatory Affairs, Sanofi (China) Investment Co., Ltd, Beijing, China
| | - Chenyan Zhao
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Yabin Tian
- Division II of In Vitro Diagnostics for Infectious Diseases, National Institutes for Food and Drug Control, Beijing, China
| | - Nan Xu
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Youchun Wang
- Institute of Medical Biology, Chinese Academy of Medical Science & Peking Union Medical College, Kunming, China.
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Cancela F, Noceti O, Arbiza J, Mirazo S. Structural aspects of hepatitis E virus. Arch Virol 2022; 167:2457-2481. [PMID: 36098802 PMCID: PMC9469829 DOI: 10.1007/s00705-022-05575-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/04/2022] [Indexed: 12/14/2022]
Abstract
Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. Hepatitis E is an enterically transmitted zoonotic disease that causes large waterborne epidemic outbreaks in developing countries and has become an increasing public-health concern in industrialized countries. In this setting, the infection is usually acute and self-limiting in immunocompetent individuals, although chronic cases in immunocompromised patients have been reported, frequently associated with several extrahepatic manifestations. Moreover, extrahepatic manifestations have also been reported in immunocompetent individuals with acute HEV infection. HEV belongs to the alphavirus-like supergroup III of single-stranded positive-sense RNA viruses, and its genome contains three partially overlapping open reading frames (ORFs). ORF1 encodes a nonstructural protein with eight domains, most of which have not been extensively characterized: methyltransferase, Y domain, papain-like cysteine protease, hypervariable region, proline-rich region, X domain, Hel domain, and RNA-dependent RNA polymerase. ORF2 and ORF3 encode the capsid protein and a multifunctional protein believed to be involved in virion release, respectively. The novel ORF4 is only expressed in HEV genotype 1 under endoplasmic reticulum stress conditions, and its exact function has not yet been elucidated. Despite important advances in recent years, the biological and molecular processes underlying HEV replication remain poorly understood, primarily due to a lack of detailed information about the functions of the viral proteins and the mechanisms involved in host-pathogen interactions. This review summarizes the current knowledge concerning HEV proteins and their biological properties, providing updated detailed data describing their function and focusing in detail on their structural characteristics. Furthermore, we review some unclear aspects of the four proteins encoded by the ORFs, highlighting the current key information gaps and discussing potential novel experimental strategies for shedding light on those issues.
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Affiliation(s)
- Florencia Cancela
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ofelia Noceti
- grid.414402.70000 0004 0469 0889Programa Nacional de Trasplante Hepático y Unidad Docente Asistencial Centro Nacional de Tratamiento Hepatobiliopancreatico. Hospital Central de las Fuerzas Armadas, Montevideo, Uruguay
| | - Juan Arbiza
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Santiago Mirazo
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay ,grid.11630.350000000121657640Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay ,Av. Alfredo Navarro 3051, PC 11600 Montevideo, Uruguay
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Saurav S, Tanwar J, Ahuja K, Motiani RK. Dysregulation of host cell calcium signaling during viral infections: Emerging paradigm with high clinical relevance. Mol Aspects Med 2021; 81:101004. [PMID: 34304899 PMCID: PMC8299155 DOI: 10.1016/j.mam.2021.101004] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/18/2021] [Accepted: 07/16/2021] [Indexed: 12/22/2022]
Abstract
Viral infections are one of the leading causes of human illness. Viruses take over host cell signaling cascades for their replication and infection. Calcium (Ca2+) is a versatile and ubiquitous second messenger that modulates plethora of cellular functions. In last two decades, a critical role of host cell Ca2+ signaling in modulating viral infections has emerged. Furthermore, recent literature clearly implicates a vital role for the organellar Ca2+ dynamics (influx and efflux across organelles) in regulating virus entry, replication and severity of the infection. Therefore, it is not surprising that a number of viral infections including current SARS-CoV-2 driven COVID-19 pandemic are associated with dysregulated Ca2+ homeostasis. The focus of this review is to first discuss the role of host cell Ca2+ signaling in viral entry, replication and egress. We further deliberate on emerging literature demonstrating hijacking of the host cell Ca2+ dynamics by viruses. In particular, a variety of viruses including SARS-CoV-2 modulate lysosomal and cytosolic Ca2+ signaling for host cell entry and replication. Moreover, we delve into the recent studies, which have demonstrated the potential of several FDA-approved drugs targeting Ca2+ handling machinery in inhibiting viral infections. Importantly, we discuss the prospective of targeting intracellular Ca2+ signaling for better management and treatment of viral pathogenesis including COVID-19. Finally, we highlight the key outstanding questions in the field that demand critical and timely attention.
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Affiliation(s)
- Suman Saurav
- Laboratory of Calciomics and Systemic Pathophysiology, Regional Centre for Biotechnology (RCB), Faridabad-121001, Delhi-NCR, India
| | - Jyoti Tanwar
- CSIR-Institute of Genomics and Integrative Biology (IGIB), New Delhi-110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Kriti Ahuja
- Laboratory of Calciomics and Systemic Pathophysiology, Regional Centre for Biotechnology (RCB), Faridabad-121001, Delhi-NCR, India
| | - Rajender K Motiani
- Laboratory of Calciomics and Systemic Pathophysiology, Regional Centre for Biotechnology (RCB), Faridabad-121001, Delhi-NCR, India.
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Glitscher M, Hildt E. Hepatitis E virus egress and beyond - the manifold roles of the viral ORF3 protein. Cell Microbiol 2021; 23:e13379. [PMID: 34272798 DOI: 10.1111/cmi.13379] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/18/2021] [Accepted: 07/06/2021] [Indexed: 11/30/2022]
Abstract
Although the hepatitis E virus represents an uprising threat to the global community by representing the commonest cause of an acute viral hepatitis worldwide, its life cycle is grossly understudied. Albeit HEV is a non-enveloped virus, its progeny is released as quasi-enveloped virions. Thus, the responsible accessory protein pORF3 gained rising attention in the past years. It mediates viral release via the exosomal route by targeting the viral capsid to the endosomal system, more precisely to multivesicular bodies. As this is followed by quasi-envelopment, pORF3 may in terms represent a substitute to a conventional envelope protein. This feature proofs to be rather unique with respect to other enteric viruses, although the protein's role in the viral life cycle seems to reach far beyond simply maintaining release of progeny viruses. How pORF3 affects viral morphogenesis, how it mediates efficient viral release and how it supports viral spread is summarised in this microreview. With this, we aim to shed light on functions of pORF3 to gain further insights in still enigmatic aspects of the HEV life cycle. TAKE AWAYS: HEV is released as exosome via multivesicular bodies Viral pORF3 mediates release via endosomal complexes required for transport pORF3 modulates various cellular processes in infected cells Elucidation of pORF3-related processes imply novel clinical strategies.
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Affiliation(s)
| | - Eberhard Hildt
- Department Virology, Paul-Ehrlich-Institut, Langen, Germany
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Wang B, Meng XJ. Structural and molecular biology of hepatitis E virus. Comput Struct Biotechnol J 2021; 19:1907-1916. [PMID: 33995894 PMCID: PMC8079827 DOI: 10.1016/j.csbj.2021.03.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 02/07/2023] Open
Abstract
Hepatitis E virus (HEV) is one of the most common causes of acute viral hepatitis, mainly transmitted by fecal-oral route but has also been linked to fulminant hepatic failure, chronic hepatitis, and extrahepatic neurological and renal diseases. HEV is an emerging zoonotic pathogen with a broad host range, and strains of HEV from numerous animal species are known to cross species barriers and infect humans. HEV is a single-stranded, positive-sense RNA virus in the family Hepeviridae. The genome typically contains three open reading frames (ORFs): ORF1 encodes a nonstructural polyprotein for virus replication and transcription, ORF2 encodes the capsid protein that elicits neutralizing antibodies, and ORF3, which partially overlaps ORF2, encodes a multifunctional protein involved in virion morphogenesis and pathogenesis. HEV virions are non-enveloped spherical particles in feces but exist as quasi-enveloped particles in circulating blood. Two types of HEV virus-like particles (VLPs), small T = 1 (270 Å) and native virion-sized T = 3 (320-340 Å) have been reported. There exist two distinct forms of capsid protein, the secreted form (ORF2S) inhibits antibody neutralization, whereas the capsid-associated form (ORF2C) self-assembles to VLPs. Four cis-reactive elements (CREs) containing stem-loops from secondary RNA structures have been identified in the non-coding regions and are critical for virus replication. This mini-review discusses the current knowledge and gaps regarding the structural and molecular biology of HEV with emphasis on the virion structure, genomic organization, secondary RNA structures, viral proteins and their functions, and life cycle of HEV.
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Affiliation(s)
- Bo Wang
- Center for Emerging, Zoonotic and Arthropod-borne Pathogens, Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Xiang-Jin Meng
- Center for Emerging, Zoonotic and Arthropod-borne Pathogens, Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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12
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Shoshan-Barmatz V, Shteinfer-Kuzmine A, Verma A. VDAC1 at the Intersection of Cell Metabolism, Apoptosis, and Diseases. Biomolecules 2020; 10:E1485. [PMID: 33114780 PMCID: PMC7693975 DOI: 10.3390/biom10111485] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/02/2020] [Accepted: 10/22/2020] [Indexed: 02/07/2023] Open
Abstract
The voltage-dependent anion channel 1 (VDAC1) protein, is an important regulator of mitochondrial function, and serves as a mitochondrial gatekeeper, with responsibility for cellular fate. In addition to control over energy sources and metabolism, the protein also regulates epigenomic elements and apoptosis via mediating the release of apoptotic proteins from the mitochondria. Apoptotic and pathological conditions, as well as certain viruses, induce cell death by inducing VDAC1 overexpression leading to oligomerization, and the formation of a large channel within the VDAC1 homo-oligomer. This then permits the release of pro-apoptotic proteins from the mitochondria and subsequent apoptosis. Mitochondrial DNA can also be released through this channel, which triggers type-Ι interferon responses. VDAC1 also participates in endoplasmic reticulum (ER)-mitochondria cross-talk, and in the regulation of autophagy, and inflammation. Its location in the outer mitochondrial membrane, makes VDAC1 ideally placed to interact with over 100 proteins, and to orchestrate the interaction of mitochondrial and cellular activities through a number of signaling pathways. Here, we provide insights into the multiple functions of VDAC1 and describe its involvement in several diseases, which demonstrate the potential of this protein as a druggable target in a wide variety of pathologies, including cancer.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; (A.S.-K.); (A.V.)
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13
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Gatti P, Ilamathi HS, Todkar K, Germain M. Mitochondria Targeted Viral Replication and Survival Strategies-Prospective on SARS-CoV-2. Front Pharmacol 2020; 11:578599. [PMID: 32982760 PMCID: PMC7485471 DOI: 10.3389/fphar.2020.578599] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/14/2020] [Indexed: 12/11/2022] Open
Abstract
SARS-CoV-2 is a positive sense RNA coronavirus that constitutes a new threat for the global community and economy. While vaccines against SARS-CoV-2 are being developed, the mechanisms through which this virus takes control of an infected cell to replicate remains poorly understood. Upon infection, viruses completely rely on host cell molecular machinery to survive and replicate. To escape from the immune response and proliferate, viruses strategically modulate cellular metabolism and alter subcellular organelle architecture and functions. One way they do this is by modulating the structure and function of mitochondria, a critical cellular metabolic hub but also a key platform for the regulation of cellular immunity. This versatile nature of mitochondria defends host cells from viruses through several mechanisms including cellular apoptosis, ROS signaling, MAVS activation and mitochondrial DNA-dependent immune activation. These events are regulated by mitochondrial dynamics, a process by which mitochondria alter their structure (including their length and connectivity) in response to stress or other cues. It is therefore not surprising that viruses, including coronaviruses hijack these processes for their survival. In this review, we highlight how positive sense RNA viruses modulate mitochondrial dynamics and metabolism to evade mitochondrial mediated immune response in order to proliferate.
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Affiliation(s)
- Priya Gatti
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie, Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hema Saranya Ilamathi
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie, Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Kiran Todkar
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie, Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie, Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre d’Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
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14
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Qu C, Li Y, Li Y, Yu P, Li P, Donkers JM, van de Graaf SFJ, de Man RA, Peppelenbosch MP, Pan Q. FDA-drug screening identifies deptropine inhibiting hepatitis E virus involving the NF-κB-RIPK1-caspase axis. Antiviral Res 2019; 170:104588. [PMID: 31415805 DOI: 10.1016/j.antiviral.2019.104588] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/08/2019] [Accepted: 08/11/2019] [Indexed: 12/12/2022]
Abstract
Hepatitis E virus (HEV) infection is the leading cause of acute hepatitis worldwide and can develop into chronic infection in immunocompromised patients, promoting the development of effective antiviral therapies. In this study, we performed a screening of a library containing over 1000 FDA-approved drugs. We have identified deptropine, a classical histamine H1 receptor antagonist used to treat asthmatic symptoms, as a potent inhibitor of HEV replication. The anti-HEV activity of deptropine appears dispensable of the histamine pathway, but requires the inhibition on nuclear factor-κB (NF-κB) activity. This further activates caspase mediated by receptor-interacting protein kinase 1 (RIPK1) to restrict HEV replication. Given deptropine being widely used in the clinic, our results warrant further evaluation of its anti-HEV efficacy in future clinical studies. Importantly, the discovery that NF-κB-RIPK1-caspase pathway interferes with HEV infection reveals new insight of HEV-host interactions.
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Affiliation(s)
- Changbo Qu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, PR China; Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Yang Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Yunlong Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Peifa Yu
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Pengfei Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Joanne M Donkers
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands
| | - Stan F J van de Graaf
- Amsterdam UMC, University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, the Netherlands
| | - Robert A de Man
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Maikel P Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands.
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15
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Qu C, Zhang S, Li Y, Wang Y, Peppelenbosch MP, Pan Q. Mitochondria in the biology, pathogenesis, and treatment of hepatitis virus infections. Rev Med Virol 2019; 29:e2075. [PMID: 31322806 PMCID: PMC6771966 DOI: 10.1002/rmv.2075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/19/2022]
Abstract
Hepatitis virus infections affect a large proportion of the global population. The host responds rapidly to viral infection by orchestrating a variety of cellular machineries, in particular, the mitochondrial compartment. Mitochondria actively regulate viral infections through modulation of the cellular innate immunity and reprogramming of metabolism. In turn, hepatitis viruses are able to modulate the morphodynamics and functions of mitochondria, but the mode of actions are distinct with respect to different types of hepatitis viruses. The resulting mutual interactions between viruses and mitochondria partially explain the clinical presentation of viral hepatitis, influence the response to antiviral treatment, and offer rational avenues for novel therapy. In this review, we aim to consider in depth the multifaceted interactions of mitochondria with hepatitis virus infections and emphasize the implications for understanding pathogenesis and advancing therapeutic development.
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Affiliation(s)
- Changbo Qu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China.,The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.,Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Shaoshi Zhang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yang Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yijin Wang
- Department of Pathology and Hepatology, Beijing 302 Hospital, Beijing, China
| | - Maikel P Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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16
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Qu C, Zhang S, Wang W, Li M, Wang Y, van der Heijde-Mulder M, Shokrollahi E, Hakim MS, Raat NJH, Peppelenbosch MP, Pan Q. Mitochondrial electron transport chain complex III sustains hepatitis E virus replication and represents an antiviral target. FASEB J 2018; 33:1008-1019. [PMID: 30070932 DOI: 10.1096/fj.201800620r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hepatitis E virus (HEV) infection has emerged as a global health problem. However, no approved medication is available, and the infection biology remains largely elusive. Electron transport chain (ETC), a key component of the mitochondria, is the main site that produces ATP and reactive oxygen species (ROS). By profiling the role of the different complexes of the mitochondrial ETC, we found that pharmacological inhibition of complex III, a well-defined drug target for the treatment of malaria and Pneumocystis pneumonia, potently restricts HEV replication. This effect demonstrated in our HEV models is equivalent to the anti-HEV potency of ribavirin, a widely used off-label treatment for patients with chronic HEV. Mechanistically, we found that this effect is independent of ATP production, ROS level, and pyridine depletion. By using pharmacological inhibitors and genetic approaches, we found that mitochondrial permeability transition pore (MPTP), a newly identified component of ETC, provides basal defense against HEV infection. HEV interferes with the opening of the MPTP. Furthermore, inhibition of the MPTP attenuated the anti-HEV effect of complex III inhibitors, suggesting that the MPTP mediates the antiviral effects of these inhibitors. These findings reveal new insights on HEV-host interactions and provide viable anti-HEV targets for therapeutic development.-Qu, C., Zhang, S., Wang, W., Li, M., Wang, Y., van der Heijde-Mulder, M., Shokrollahi, E., Hakim, M. S., Raat, N. J. H., Peppelenbosch, M. P., Pan, Q. Mitochondrial electron transport chain complex III sustains hepatitis E virus replication and represents an antiviral target.
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Affiliation(s)
- Changbo Qu
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Shaoshi Zhang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Wenshi Wang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Meng Li
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Yijin Wang
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands.,Department of Pathology and Hepatology, Beijing 302 Hospital, Beijing, China
| | | | - Ehsan Shokrollahi
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, The Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands; and
| | - Mohamad S Hakim
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands.,Department of Microbiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Nicolaas J H Raat
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, The Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands; and
| | - Maikel P Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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17
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Harrison L, DiCaprio E. Hepatitis E Virus: An Emerging Foodborne Pathogen. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2018. [DOI: 10.3389/fsufs.2018.00014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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18
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Shoshan-Barmatz V, Maldonado EN, Krelin Y. VDAC1 at the crossroads of cell metabolism, apoptosis and cell stress. Cell Stress 2017; 1:11-36. [PMID: 30542671 PMCID: PMC6287957 DOI: 10.15698/cst2017.10.104] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review presents current knowledge related to VDAC1 as a multi-functional mitochondrial protein acting on both sides of the coin, regulating cell life and death, and highlighting these functions in relation to disease. It is now recognized that VDAC1 plays a crucial role in regulating the metabolic and energetic functions of mitochondria. The location of VDAC1 at the outer mitochondrial membrane (OMM) allows the control of metabolic cross-talk between mitochondria and the rest of the cell and also enables interaction of VDAC1 with proteins involved in metabolic and survival pathways. Along with regulating cellular energy production and metabolism, VDAC1 is also involved in the process of mitochondria-mediated apoptosis by mediating the release of apoptotic proteins and interacting with anti-apoptotic proteins. VDAC1 functions in the release of apoptotic proteins located in the mitochondrial intermembrane space via oligomerization to form a large channel that allows passage of cytochrome c and AIF and their release to the cytosol, subsequently resulting in apoptotic cell death. VDAC1 also regulates apoptosis via interactions with apoptosis regulatory proteins, such as hexokinase, Bcl2 and Bcl-xL, some of which are also highly expressed in many cancers. This review also provides insight into VDAC1 function in Ca2+ homeostasis, oxidative stress, and presents VDAC1 as a hub protein interacting with over 100 proteins. Such interactions enable VDAC1 to mediate and regulate the integration of mitochondrial functions with cellular activities. VDAC1 can thus be considered as standing at the crossroads between mitochondrial metabolite transport and apoptosis and hence represents an emerging cancer drug target.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Eduardo N Maldonado
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC. USA
| | - Yakov Krelin
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
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Donnelly MC, Scobie L, Crossan CL, Dalton H, Hayes PC, Simpson KJ. Review article: hepatitis E-a concise review of virology, epidemiology, clinical presentation and therapy. Aliment Pharmacol Ther 2017; 46:126-141. [PMID: 28449246 DOI: 10.1111/apt.14109] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/21/2016] [Accepted: 03/30/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Hepatitis E virus (HEV) is a leading cause of acute icteric hepatitis and acute liver failure in the developing world. During the last decade, there has been increasing recognition of autochthonous (locally acquired) HEV infection in developed countries. Chronic HEV infection is now recognised, and in transplant recipients this may lead to cirrhosis and organ failure. AIM To detail current understanding of the molecular biology of HEV, diagnostic and therapeutic strategies and propose future directions for basic science and clinical research. METHODS PubMed was searched for English language articles using the key words "hepatitis E", "viral hepatitis", "autochthonous infection", "antiviral therapy", "liver transplantation", "acute", "chronic", "HEV", "genotype", "transmission" "food-borne", "transfusion". Additional relevant publications were identified from article reference lists. RESULTS There has been increasing recognition of autochthonous HEV infection in Western countries, mainly associated with genotype 3. Chronic HEV infection has been recognised since 2008, and in transplant recipients this may lead to cirrhosis and organ failure. Modes of transmission include food-borne transmission, transfusion of blood products and solid organ transplantation. Ribavirin therapy is used to treat patients with chronic HEV infection, but new therapies are required as there have been reports of treatment failure with ribavirin. CONCLUSIONS Autochthonous HEV infection is a clinical issue with increasing burden. Future work should focus on increasing awareness of HEV infection in the developed world, emphasising the need for clinicians to have a low threshold for HEV testing, particularly in immunosuppressed patients. Patients at potential risk of chronic HEV infection must also be educated and given advice regarding prevention of infection.
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Affiliation(s)
- M C Donnelly
- Department of Hepatology and Scottish Liver Transplant Unit, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - L Scobie
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
| | - C L Crossan
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK
| | - H Dalton
- Royal Cornwall Hospital Trust and European Centre for Environment and Human Health, University of Exeter, Truro, UK
| | - P C Hayes
- Department of Hepatology and Scottish Liver Transplant Unit, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - K J Simpson
- Department of Hepatology and Scottish Liver Transplant Unit, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK
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Shoshan-Barmatz V, Krelin Y, Shteinfer-Kuzmine A. VDAC1 functions in Ca 2+ homeostasis and cell life and death in health and disease. Cell Calcium 2017; 69:81-100. [PMID: 28712506 DOI: 10.1016/j.ceca.2017.06.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/21/2017] [Accepted: 06/21/2017] [Indexed: 01/15/2023]
Abstract
In the outer mitochondrial membrane (OMM), the voltage-dependent anion channel 1 (VDAC1) serves as a mitochondrial gatekeeper, controlling the metabolic and energy cross-talk between mitochondria and the rest of the cell. VDAC1 also functions in cellular Ca2+ homeostasis by transporting Ca2+ in and out of mitochondria. VDAC1 has also been recognized as a key protein in mitochondria-mediated apoptosis, contributing to the release of apoptotic proteins located in the inter-membranal space (IMS) and regulating apoptosis via association with pro- and anti-apoptotic members of the Bcl-2 family of proteins and hexokinase. VDAC1 is highly Ca2+-permeable, transporting Ca2+ to the IMS and thus modulating Ca2+ access to Ca2+ transporters in the inner mitochondrial membrane. Intra-mitochondrial Ca2+ controls energy metabolism via modulating critical enzymes in the tricarboxylic acid cycle and in fatty acid oxidation. Ca2+ also determines cell sensitivity to apoptotic stimuli and promotes the release of pro-apoptotic proteins. However, the precise mechanism by which intracellular Ca2+ mediates apoptosis is not known. Here, the roles of VDAC1 in mitochondrial Ca2+ homeostasis are presented while emphasizing a new proposed mechanism for the mode of action of pro-apoptotic drugs. This view, proposing that Ca2+-dependent enhancement of VDAC1 expression levels is a major mechanism by which apoptotic stimuli induce apoptosis, position VDAC1 oligomerization at a molecular focal point in apoptosis regulation. The interactions of VDAC1 with many proteins involved in Ca2+ homeostasis or regulated by Ca2+, as well as VDAC-mediated control of cell life and death and the association of VDAC with disease, are also presented.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
| | - Yakov Krelin
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Anna Shteinfer-Kuzmine
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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Shoshan-Barmatz V, De S, Meir A. The Mitochondrial Voltage-Dependent Anion Channel 1, Ca 2+ Transport, Apoptosis, and Their Regulation. Front Oncol 2017; 7:60. [PMID: 28443244 PMCID: PMC5385329 DOI: 10.3389/fonc.2017.00060] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/17/2017] [Indexed: 01/08/2023] Open
Abstract
In the outer mitochondrial membrane, the voltage-dependent anion channel 1 (VDAC1) functions in cellular Ca2+ homeostasis by mediating the transport of Ca2+ in and out of mitochondria. VDAC1 is highly Ca2+-permeable and modulates Ca2+ access to the mitochondrial intermembrane space. Intramitochondrial Ca2+ controls energy metabolism by enhancing the rate of NADH production via modulating critical enzymes in the tricarboxylic acid cycle and fatty acid oxidation. Mitochondrial [Ca2+] is regarded as an important determinant of cell sensitivity to apoptotic stimuli and was proposed to act as a "priming signal," sensitizing the organelle and promoting the release of pro-apoptotic proteins. However, the precise mechanism by which intracellular Ca2+ ([Ca2+]i) mediates apoptosis is not known. Here, we review the roles of VDAC1 in mitochondrial Ca2+ homeostasis and in apoptosis. Accumulated evidence shows that apoptosis-inducing agents act by increasing [Ca2+]i and that this, in turn, augments VDAC1 expression levels. Thus, a new concept of how increased [Ca2+]i activates apoptosis is postulated. Specifically, increased [Ca2+]i enhances VDAC1 expression levels, followed by VDAC1 oligomerization, cytochrome c release, and subsequently apoptosis. Evidence supporting this new model suggesting that upregulation of VDAC1 expression constitutes a major mechanism by which apoptotic stimuli induce apoptosis with VDAC1 oligomerization being a molecular focal point in apoptosis regulation is presented. A new proposed mechanism of pro-apoptotic drug action, namely Ca2+-dependent enhancement of VDAC1 expression, provides a platform for developing a new class of anticancer drugs modulating VDAC1 levels via the promoter and for overcoming the resistance of cancer cells to chemotherapy.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Soumasree De
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Meir
- Department of Life Sciences, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Takahashi M, Kobayashi T, Tanggis, Jirintai S, Mulyanto, Nagashima S, Nishizawa T, Kunita S, Okamoto H. Production of monoclonal antibodies against the ORF3 protein of rat hepatitis E virus (HEV) and demonstration of the incorporation of the ORF3 protein into enveloped rat HEV particles. Arch Virol 2016; 161:3391-3404. [DOI: 10.1007/s00705-016-3047-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/01/2016] [Indexed: 02/07/2023]
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Nan Y, Zhang YJ. Molecular Biology and Infection of Hepatitis E Virus. Front Microbiol 2016; 7:1419. [PMID: 27656178 PMCID: PMC5013053 DOI: 10.3389/fmicb.2016.01419] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/26/2016] [Indexed: 12/13/2022] Open
Abstract
Hepatitis E virus (HEV) is a viral pathogen transmitted primarily via fecal-oral route. In humans, HEV mainly causes acute hepatitis and is responsible for large outbreaks of hepatitis across the world. The case fatality rate of HEV-induced hepatitis ranges from 0.5 to 3% in young adults and up to 30% in infected pregnant women. HEV strains infecting humans are classified into four genotypes. HEV strains from genotypes 3 and 4 are zoonotic, whereas those from genotypes 1 and 2 have no known animal reservoirs. Recently, notable progress has been accomplished for better understanding of HEV biology and infection, such as chronic HEV infection, in vitro cell culture system, quasi-enveloped HEV virions, functions of the HEV proteins, mechanism of HEV antagonizing host innate immunity, HEV pathogenesis and vaccine development. However, further investigation on the cross-species HEV infection, host tropism, vaccine efficacy, and HEV-specific antiviral strategy is still needed. This review mainly focuses on molecular biology and infection of HEV and offers perspective new insight of this enigmatic virus.
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Affiliation(s)
- Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F UniversityYangling, China; Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, College ParkMD, USA
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, College Park MD, USA
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van Tong H, Hoan NX, Wang B, Wedemeyer H, Bock CT, Velavan TP. Hepatitis E Virus Mutations: Functional and Clinical Relevance. EBioMedicine 2016; 11:31-42. [PMID: 27528267 PMCID: PMC5049923 DOI: 10.1016/j.ebiom.2016.07.039] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 07/29/2016] [Indexed: 02/07/2023] Open
Abstract
Hepatitis E virus (HEV) infection is a major cause of acute hepatitis and affects more than 20 million individuals, with three million symptomatic cases and 56,000 recognized HEV-related deaths worldwide. HEV is endemic in developing countries and is gaining importance in developed countries, due to increased number of autochthone cases. Although HEV replication is controlled by the host immune system, viral factors (especially specific viral genotypes and mutants) can modulate HEV replication, infection and pathogenesis. Limited knowledge exists on the contribution of HEV genome variants towards pathogenesis, susceptibility and to therapeutic response. Nonsynonymous substitutions can modulate viral proteins structurally and thus dysregulate virus-host interactions. This review aims to compile knowledge and discuss recent advances on the casual role of HEV heterogeneity and its variants on viral morphogenesis, pathogenesis, clinical outcome and antiviral resistance. HEV causes acute hepatitis and recently comes into focus because of persistent infection in immunocompromised patients. HEV variability can be associated with clinical pathogenesis and transmission dynamics. Mutations in the HEV genome can influence HEV physiology and virus-host interaction. HEV mutations and variability are likely associated with fulminant hepatic failure and chronic hepatitis E. The Y1320H and G1634R/K mutations in the RdRp domain contribute to antiviral resistance through enhancing HEV replication.
We searched MEDLINE database and PubMed for articles from 1980 through June 30, 2016. Search terms used in various combinations were “hepatitis E”, “hepatitis E virus”, “hepatitis E virus infection”, “hepatitis E virus mutation”, “HEV variability”, “HEV genotype”, “HEV drug resistance”, “HEV replication” and “ribavirin”. Articles resulting from these searches and relevant references cited in those articles were selected based on their related topics and were reviewed. Abstracts and reports from meetings were also included. Articles published in English were included.
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Affiliation(s)
- Hoang van Tong
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
| | - Nghiem Xuan Hoan
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Bo Wang
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - C-Thomas Bock
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany.
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Ben-Hail D, Shoshan-Barmatz V. VDAC1-interacting anion transport inhibitors inhibit VDAC1 oligomerization and apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1612-23. [DOI: 10.1016/j.bbamcr.2016.04.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/01/2016] [Accepted: 04/06/2016] [Indexed: 10/22/2022]
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The ORF3 Protein of Genotype 1 Hepatitis E Virus Suppresses TLR3-induced NF-κB Signaling via TRADD and RIP1. Sci Rep 2016; 6:27597. [PMID: 27270888 PMCID: PMC4897786 DOI: 10.1038/srep27597] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 05/23/2016] [Indexed: 02/08/2023] Open
Abstract
Hepatitis E virus (HEV) genotype 1 infection is common and can emerge as outbreaks in developing areas, thus posing a threat to public health. However, due to the absence of feasible animal models, the mechanism of HE pathogenesis remains obscure. The HEV pathogenic mechanism has been suggested to be mediated by the immune system and not by direct viral duplication. We firstly discovered that the open reading frame 3 (ORF3) protein of genotype 1 HEV downregulates TLR3-mediated NF-κB signaling in Human A549 Lung Epithelial Cells (A549 cells) which were exposed to different TLR agonists associated with viral nucleic acids. Additionally, we identified the P2 domain of ORF3 as being responsible for this inhibition. Intriguingly, tumor necrosis factor receptor 1-associated death domain protein (TRADD) expression and receptor-interacting protein kinase 1 (RIP1) K63-ubiquitination were reduced in the presence of both ORF3 and Poly(I:C). Furthermore, we found that Lys377 of RIP1 acts as the functional ubiquitination site for ORF3-associated inhibition. Overall, we found that ORF3 protein downregulates TLR3-mediated NF-κB signaling via TRADD and RIP1. Our findings provide a new perspective on the cellular response in HEV infection and expand our understanding of the molecular mechanisms of HEV pathogenesis in innate immunity.
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Lei Q, Li L, Cai J, Huang W, Qin B, Zhang S. ORF3 of Hepatitis E Virus Inhibits the Expression of Proinflammatory Cytokines and Chemotactic Factors in LPS-Stimulated Human PMA-THP1 Cells by Inhibiting NF-κB Pathway. Viral Immunol 2016; 29:105-11. [PMID: 26771290 DOI: 10.1089/vim.2015.0107] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hepatitis E virus (HEV) is one of the primary causative agents of acute hepatitis. It is noteworthy that HEV can develop chronic infection and even lead to liver cirrhosis; however, the mechanism has not been revealed. In this study, the ELISA assay was used to detect protein levels, and we found that HEV open reading frame 3 (ORF3) protein inhibited the expression of proinflammatory cytokines (tumor necrosis factor-alpha [TNF-α], interleukin [IL]-1β, IL-6, IL-8, IL-12p40, and IL-18) and chemotactic factors (nitric oxide [NO], interferon-inducible protein-10 (IP-10), macrophage inflammatory protein (MIP)-1α, monocyte chemoattractant protein-1 (MCP-1), granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF)] in lipopolysaccharide (LPS)-stimulated human PMA-THP1 cells. Further study showed that mRNA and protein levels of pattern recognition receptors (PRRs), such as Toll-like receptor 4 (TLR4), TNF receptor-associated factor 6 (TRAF6), and nucleotide-binding oligomerization domain containing 2 (NOD2), decreased after infection of pLL3.7-ORF3 (pORF3); moreover, the inhibition produced corresponding upregulation of IκBα and downregulation of phosphorylated IκB kinase IKKɛ (p-IKKɛ) and phosphorylated nuclear factor (NF)-κB (p-NF-κB), but little variation was found in the concentration of IKKɛ and NF-κB. Taken together, our results demonstrated that HEV ORF3 attenuated LPS-induced cytokine production and chemotactic factors, predominantly by inhibiting various PRRs-mediated NF-κB signaling pathways. The anti-inflammatory properties might be of great importance to clarify the role and mechanism of macrophages in chronic HEV infection and cirrhosis.
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Affiliation(s)
- Qingsong Lei
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
| | - Lin Li
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
| | - Jia Cai
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
| | - Wenxiang Huang
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
| | - Bo Qin
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
| | - Shujun Zhang
- Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases, Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University , Chongqing, China
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Zhou Y, Zhao C, Tian Y, Xu N, Wang Y. Characteristics and Functions of HEV Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 948:17-38. [PMID: 27738977 DOI: 10.1007/978-94-024-0942-0_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hepatitis E virus (HEV) is a non-enveloped virus containing a single-stranded, positive-sense RNA genome of 7.2 kb, which consists of a 5' noncoding region, three open reading frames (ORFs), and a 3' noncoding region. ORF1 is diverse between genotypes and encodes the nonstructural proteins, which include the enzymes needed for virus replication. In addition to its role in virus replication, the function of ORF1 is relevant to viral adaption in cultured cells and may also relate to virus infection and HEV pathogenicity. ORF2 protein is the capsid protein, which is about 660 amino acids in length. It not only protects the integrity of the viral genome but is also involved in many important physiological activities, such as virus assembly, infection, and host interaction. The main immune epitopes, especially neutralizing epitopes, are located on ORF2 protein, which is a candidate antigen for vaccine development. ORF3 protein is a phosphoprotein of 113 or 114 amino acids with a molecular weight of 13 kDa with multiple functions that can also induce strong immune reactivity.
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Affiliation(s)
- Yan Zhou
- Division of Drug and Cosmetics Inspection, Center for Food and Drug Inspection, China Food and Drug Administration, No.11 Fa Hua Nan Li, Dongcheng District, Beijing, 100061, China
| | - Chenyan Zhao
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Yabin Tian
- Division of Diagnosis, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Nan Xu
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Youchun Wang
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China.
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Abstract
INTRODUCTION Hepatitis E virus (HEV) is one of the most common causes of acute viral hepatitis in the world with an estimated 20 million infections per year. Although the mortality rate is < 1% among the general population, pregnant women can have a fatality rate of up to 30%. Additionally, chronic hepatitis E has increasingly become a significant clinical problem in immunocompromised individuals. Effective antivirals against HEV are needed. AREAS COVERED This review article addresses the current state of knowledge of HEV infections with regard to animal and cell culture model systems that are important for antiviral discovery and testing, our current understanding of the molecular mechanisms of virus replication, our understanding of how each viral protein functions, and areas that can potentially be exploited as therapeutic targets. EXPERT OPINION Lack of an efficient cell culture system for HEV propagation, the limited knowledge of HEV lifecycle, and the inherent self-limiting infection within the normal populace make the development of new therapeutic agents against HEV challenging. There are many promising therapeutic targets, and the tools for identifying and testing potential antivirals are rapidly evolving. The development of effective therapeutics against HEV in immunocompromised and pregnant patient populations is warranted.
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Affiliation(s)
- Scott P Kenney
- Virginia Polytechnic Institute and State University (Virginia Tech), College of Veterinary Medicine, Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology , CRC-Integrated Life Sciences Building (0913), 1981 Kraft Drive, Blacksburg, VA 24061-0913 , USA +1 540 231 6912 ; +1 540 231 3414 ;
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Wu C, Nan Y, Zhang YJ. New insights into hepatitis E virus virus–host interaction: interplay with host interferon induction. Future Virol 2015. [DOI: 10.2217/fvl.15.17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT Hepatitis E virus (HEV) is a fecal–oral-transmitted viral pathogen causing several large outbreaks of hepatitis across the world. HEV-mediated hepatitis has a mortality rate from 0.5 to 3% in young adults but is up to 30% in pregnant women. HEV is also a zoonotic pathogen as it has been isolated from different mammalian hosts including the pig, rabbit, rat, ferret, bat and deer. As an invading pathogen, HEV needs to overcome the host innate immune response to establish infection. Notable progress has been recently made in HEV mechanisms of antagonizing the host innate immune responses. In this review, we elaborate on the HEV interplay with host interferon induction while briefly summarizing the major aspects of HEV biology and host interferon induction to assist the understanding of the virus–host interaction.
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Affiliation(s)
- Chunyan Wu
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine & Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Yuchen Nan
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine & Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine & Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
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Shoshan-Barmatz V, Ben-Hail D, Admoni L, Krelin Y, Tripathi SS. The mitochondrial voltage-dependent anion channel 1 in tumor cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:2547-75. [PMID: 25448878 DOI: 10.1016/j.bbamem.2014.10.040] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/20/2014] [Accepted: 10/24/2014] [Indexed: 02/06/2023]
Abstract
VDAC1 is found at the crossroads of metabolic and survival pathways. VDAC1 controls metabolic cross-talk between mitochondria and the rest of the cell by allowing the influx and efflux of metabolites, ions, nucleotides, Ca2+ and more. The location of VDAC1 at the outer mitochondrial membrane also enables its interaction with proteins that mediate and regulate the integration of mitochondrial functions with cellular activities. As a transporter of metabolites, VDAC1 contributes to the metabolic phenotype of cancer cells. Indeed, this protein is over-expressed in many cancer types, and silencing of VDAC1 expression induces an inhibition of tumor development. At the same time, along with regulating cellular energy production and metabolism, VDAC1 is involved in the process of mitochondria-mediated apoptosis by mediating the release of apoptotic proteins and interacting with anti-apoptotic proteins. The engagement of VDAC1 in the release of apoptotic proteins located in the inter-membranal space involves VDAC1 oligomerization that mediates the release of cytochrome c and AIF to the cytosol, subsequently leading to apoptotic cell death. Apoptosis can also be regulated by VDAC1, serving as an anchor point for mitochondria-interacting proteins, such as hexokinase (HK), Bcl2 and Bcl-xL, some of which are also highly expressed in many cancers. By binding to VDAC1, HK provides both a metabolic benefit and apoptosis-suppressive capacity that offer the cell a proliferative advantage and increase its resistance to chemotherapy. Thus, these and other functions point to VDAC1 as an excellent target for impairing the re-programed metabolism of cancer cells and their ability to evade apoptosis. Here, we review current evidence pointing to the function of VDAC1 in cell life and death, and highlight these functions in relation to both cancer development and therapy. In addressing the recently solved 3D structures of VDAC1, this review will point to structure-function relationships of VDAC as critical for deciphering how this channel can perform such a variety of roles, all of which are important for cell life and death. Finally, this review will also provide insight into VDAC function in Ca2+ homeostasis, protection against oxidative stress, regulation of apoptosis and involvement in several diseases, as well as its role in the action of different drugs. We will discuss the use of VDAC1-based strategies to attack the altered metabolism and apoptosis of cancer cells. These strategies include specific siRNA able to impair energy and metabolic homeostasis, leading to arrested cancer cell growth and tumor development, as well VDAC1-based peptides that interact with anti-apoptotic proteins to induce apoptosis, thereby overcoming the resistance of cancer cell to chemotherapy. Finally, small molecules targeting VDAC1 can induce apoptosis. VDAC1 can thus be considered as standing at the crossroads between mitochondrial metabolite transport and apoptosis and hence represents an emerging cancer drug target. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences, and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
| | - Danya Ben-Hail
- Department of Life Sciences, and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Lee Admoni
- Department of Life Sciences, and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Yakov Krelin
- Department of Life Sciences, and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Shambhoo Sharan Tripathi
- Department of Life Sciences, and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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Hepatitis E: an emerging disease. INFECTION GENETICS AND EVOLUTION 2014; 22:40-59. [PMID: 24434240 DOI: 10.1016/j.meegid.2014.01.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 12/09/2013] [Accepted: 01/04/2014] [Indexed: 02/07/2023]
Abstract
Currently, the infection with the hepatitis E virus represents the most frequent cause for acute hepatitis and jaundice in the world. According to WHO estimations, around two billion people, representing one third of the world's population, live in endemic areas for HEV and, therefore, are at risk of infection. In developed countries, the circulation of the virus in both human and animal (swine, boar, deer) sewage has been confirmed; however, the incidence rate is low compared to that of developing countries where outbreaks of acute hepatitis transmitted via the fecal-oral route are originated, more frequently in the flooding season or after natural disasters, combined with deficient sanitary conditions. There are currently 4 known genotypes of HEV. Genotypes 1 and 2 are isolated in all human epidemic outbreaks in developing countries, while genotypes 3 and 4 are isolated not only in humans but also in animals, in both developing and industrialized countries. These data support genotypes 3 and 4 having zoonotic nature. The diagnosis of this disease is based in the detection of anti-HEV IgG and IgM in blood serum using enzyme-linked immunosorbent methods. However, the method that best confirms the diagnosis is the RT-PCR, which detects HEV RNA in blood serum and also provides the genotype. The clinical course is generally that of an acute hepatitis which in some cases may require hospitalization and that, in transplant patients or HIV infected individuals can become a chronic hepatitis. Furthermore, the virus constitutes an important risk for pregnant women. The hepatitis E can present a wide range of symptoms, from a subclinical case to chronic liver disease with extrahepatic manifestations. For this reason, the diagnostic is challenging if no differential diagnosis is included. There is no specific antiviral drug for hepatitis E, but satisfactory results have been observed in some patients treated with pegylated interferon alfa2a and/or ribavirin. This revision is an update of all the molecular, epidemiological, clinic and preventive knowledge on this emergent disease up to date.
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Debing Y, Neyts J. Antiviral strategies for hepatitis E virus. Antiviral Res 2013; 102:106-18. [PMID: 24374149 PMCID: PMC7113752 DOI: 10.1016/j.antiviral.2013.12.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 12/12/2013] [Accepted: 12/14/2013] [Indexed: 02/08/2023]
Abstract
The hepatitis E virus is a common cause of acute hepatitis. Contrary to hepatitis B and C, hepatitis E is mostly a mild infection, although it has a high mortality in pregnant women and can evolve to chronicity in immunocompromised patients. Ribavirin and pegylated interferon-α are the only available therapies, but both have side effects that are not acceptable for prophylaxis or treatment of mild infections. In addition, these drugs cannot be used for all patient types (e.g. in case of pregnancy, specific organ transplants or co-morbidities) and in resource-poor settings. Hence there is an urgent need for better antiviral treatments that are efficacious and safe, also during pregnancy. In this review, a concise introduction to the virus and disease is provided, followed by a discussion of the available assay systems and potential molecular targets (viral proteins and host factors) for the development of inhibitors of HEV replication. Finally, directions for future research are presented.
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Affiliation(s)
- Yannick Debing
- Rega Institute for Medical Research, Department of Microbiology and Immunology, Minderbroedersstraat 10, 3000 Leuven, Belgium
| | - Johan Neyts
- Rega Institute for Medical Research, Department of Microbiology and Immunology, Minderbroedersstraat 10, 3000 Leuven, Belgium.
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Panda SK, Varma SP. Hepatitis e: molecular virology and pathogenesis. J Clin Exp Hepatol 2013; 3:114-24. [PMID: 25755485 PMCID: PMC3940135 DOI: 10.1016/j.jceh.2013.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/01/2013] [Indexed: 12/12/2022] Open
Abstract
Hepatitis E virus is a single, positive-sense, capped and poly A tailed RNA virus classified under the family Hepeviridae. Enteric transmission, acute self-limiting hepatitis, frequent epidemic and sporadic occurrence, high mortality in affected pregnants are hallmarks of hepatitis E infection. Lack of an efficient culture system and resulting reductionist approaches for the study of replication and pathogenesis of HEV made it to be a less understood agent. Early studies on animal models, sub-genomic expression of open reading frames (ORF) and infectious cDNA clones have helped in elucidating the genome organization, important stages in HEV replication and pathogenesis. The genome contains three ORF's and three untranslated regions (UTR). The 5' distal ORF, ORF1 is translated by host ribosomes in a cap dependent manner to form the non-structural polyprotein including the viral replicase. HEV replicates via a negative-sense RNA intermediate which helps in the formation of the positive-sense genomic RNA and a single bi-cistronic sub-genomic RNA. The 3' distal ORF's including the major structural protein pORF2 and the multifunctional host interacting protein pORF3 are translated from the sub-genomic RNA. Pathogenesis in HEV infections is not well articulated, and remains a concern due to the many aspects like host dependent and genotype specific variations. Animal HEV, zoonosis, chronicity in immunosuppressed patients, and rapid decompensation in affected chronic liver diseased patients warrants detailed investigation of the underlying pathogenesis. Recent advances about structure, entry, egress and functional characterization of ORF1 domains has furthered our understanding about HEV. This article is an effort to review our present understanding about molecular biology and pathogenesis of HEV.
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Affiliation(s)
- Subrat K. Panda
- Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029, India,Address for correspondence. Subrat K. Panda, JC Bose Fellow, Professor & Head, Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029, India. Tel.: +91 11 26594924 (off.); fax: +91 11 26588663, +91 11 26588641.
| | - Satya P.K. Varma
- Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029, India
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Keinan N, Pahima H, Ben-Hail D, Shoshan-Barmatz V. The role of calcium in VDAC1 oligomerization and mitochondria-mediated apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1745-54. [PMID: 23542128 DOI: 10.1016/j.bbamcr.2013.03.017] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/19/2013] [Accepted: 03/21/2013] [Indexed: 11/17/2022]
Abstract
The voltage-dependent anion channel (VDAC), located at the outer mitochondria membrane (OMM), mediates interactions between mitochondria and other parts of the cell by transporting anions, cations, ATP, Ca(2+), and metabolites. Substantial evidence points to VDAC1 as being a key player in apoptosis, regulating the release of apoptogenic proteins from mitochondria, such as cytochrome c, and interacting with anti-apoptotic proteins. Recently, we demonstrated that VDAC1 oligomerization is a general mechanism common to numerous apoptogens acting via different initiating cascades and proposed that a protein-conducting channel formed within a VDAC1 homo/hetero oligomer mediates cytochrome c release. However, the molecular mechanism responsible for VDAC1 oligomerization remains unclear. Several studies have shown that mitochondrial Ca(2+) is involved in apoptosis induction and that VDAC1 possesses Ca(2+)-binding sites and mediates Ca(2+) transport across the OMM. Here, the relationship between the cellular Ca(2+) level, [Ca(2+)]i, VDAC1 oligomerization and apoptosis was studied. Decreasing [Ca(2+)]i using the cell-permeable Ca(2+) chelating reagent BAPTA-AM was found to inhibit VDAC1 oligomerization and apoptosis, while increasing [Ca(2+)]i using Ca(2+) ionophore resulted in VDAC1 oligomerization and apoptosis induction in the absence of apoptotic stimuli. Moreover, induction of apoptosis elevated [Ca(2+)]i, concomitantly with VDAC1 oligomerization. AzRu-mediated inhibition of mitochondrial Ca(2+) transport decreased VDAC1 oligomerization, suggesting that mitochondrial Ca(2+) is required for VDAC1 oligomerization. In addition, increased [Ca(2+)]i levels up-regulate VDAC1 expression. These results suggest that Ca(2+) promotes VDAC1 oligomerization via activation of a yet unknown signaling pathway or by increasing VDAC1 expression, leading to apoptosis. This article is part of a Special Issue entitled: 12th European Symposium on Calcium.
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Affiliation(s)
- Nurit Keinan
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Geng Y, Yang J, Huang W, Harrison TJ, Zhou Y, Wen Z, Wang Y. Virus host protein interaction network analysis reveals that the HEV ORF3 protein may interrupt the blood coagulation process. PLoS One 2013; 8:e56320. [PMID: 23418552 PMCID: PMC3571956 DOI: 10.1371/journal.pone.0056320] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 01/08/2013] [Indexed: 01/14/2023] Open
Abstract
Hepatitis E virus (HEV) is endemic worldwide and a major cause of acute liver disease in developing countries. However, the molecular mechanisms of liver pathology and clinical disease are not well understood for HEV infection. Open reading frame 3 (ORF3) of HEV encodes a small phosphoprotein, which is assumed to be involved in liver pathology and clinical disease. In this study, the interactions between the HEV ORF3 protein and human proteins were investigated using a stringent, high-throughput yeast two-hybrid (Y2H) analysis. Thirty two proteins were shown to interact with genotype 1 ORF3, 28 of which have not been reported previously. These novel interactions were evaluated by coimmunoprecipitation of protein complexes from transfected cells. We found also that the ORF3 proteins of genotype 4 and rabbit HEV interacted with all of the human proteins identified by the genotype 1 ORF3 protein. However, the putative ORF3 protein derived from avian HEV did not interact with the majority of these human proteins. The identified proteins were used to infer an overall interaction map linking the ORF3 protein with components of the host cellular networks. Analysis of this interaction map, based on functional annotation with the Gene Ontology features and KEGG pathways, revealed an enrichment of host proteins involved in complement coagulation, cellular iron ion homeostasis and oxidative stress. Additional canonical pathway analysis highlighted the enriched biological pathways relevant to blood coagulation and hemostasis. Consideration of the clinical manifestations of hepatitis E reported previously and the results of biological analysis from this study suggests that the ORF3 protein is likely to lead to an imbalance of coagulation and fibrinolysis by interacting with host proteins and triggering the corresponding pathological processes. These results suggest critical approaches to further study of the pathogenesis of the HEV ORF3 protein.
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Affiliation(s)
- Yansheng Geng
- Department of Cell Biology, National Institutes for Food and Drug Control, No 2 Tian Tan Xi Li, Beijing, China
- Health Science Center, Hebei University, Baoding, China
| | - Jun Yang
- Department of Surgery, St Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Weijin Huang
- Department of Cell Biology, National Institutes for Food and Drug Control, No 2 Tian Tan Xi Li, Beijing, China
| | - Tim J. Harrison
- Division of Medicine, University College London Medical School, London, United Kingdom
| | - Yan Zhou
- Department of Cell Biology, National Institutes for Food and Drug Control, No 2 Tian Tan Xi Li, Beijing, China
| | - Zhiheng Wen
- Department of Cell Biology, National Institutes for Food and Drug Control, No 2 Tian Tan Xi Li, Beijing, China
| | - Youchun Wang
- Department of Cell Biology, National Institutes for Food and Drug Control, No 2 Tian Tan Xi Li, Beijing, China
- * E-mail:
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Shoshan-Barmatz V, Mizrachi D, Keinan N. Oligomerization of the Mitochondrial Protein VDAC1. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 117:303-34. [DOI: 10.1016/b978-0-12-386931-9.00011-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Shoshan-Barmatz V, Mizrachi D. VDAC1: from structure to cancer therapy. Front Oncol 2012; 2:164. [PMID: 23233904 PMCID: PMC3516065 DOI: 10.3389/fonc.2012.00164] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 10/24/2012] [Indexed: 12/14/2022] Open
Abstract
Here, we review current evidence pointing to the function of VDAC1 in cell life and death, and highlight these functions in relation to cancer. Found at the outer mitochondrial membrane, VDAC1 assumes a crucial position in the cell, controlling the metabolic cross-talk between mitochondria and the rest of the cell. Moreover, its location at the boundary between the mitochondria and the cytosol enables VDAC1 to interact with proteins that mediate and regulate the integration of mitochondrial functions with other cellular activities. As a metabolite transporter, VDAC1 contributes to the metabolic phenotype of cancer cells. This is reflected by VDAC1 over-expression in many cancer types, and by inhibition of tumor development upon silencing VDAC1 expression. Along with regulating cellular energy production and metabolism, VDAC1 is also a key protein in mitochondria-mediated apoptosis, participating in the release of apoptotic proteins and interacting with anti-apoptotic proteins. The involvement of VDAC1 in the release of apoptotic proteins located in the inter-membranal space is discussed, as is VDAC1 oligomerization as an important step in apoptosis induction. VDAC also serves as an anchor point for mitochondria-interacting proteins, some of which are also highly expressed in many cancers, such as hexokinase (HK), Bcl2, and Bcl-xL. By binding to VDAC, HK provides both metabolic benefit and apoptosis-suppressive capacity that offers the cell a proliferative advantage and increases its resistance to chemotherapy. VDAC1-based peptides that bind specifically to HK, Bcl2, or Bcl-xL abolished the cell’s abilities to bypass the apoptotic pathway. Moreover, these peptides promote cell death in a panel of genetically characterized cell lines derived from different human cancers. These and other functions point to VDAC1 as a rational target for the development of a new generation of therapeutics.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences, Ben-Gurion University of the Negev Beer-Sheva, Israel ; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev Beer-Sheva, Israel
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40
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Cao D, Meng XJ. Molecular biology and replication of hepatitis E virus. Emerg Microbes Infect 2012; 1:e17. [PMID: 26038426 PMCID: PMC3630916 DOI: 10.1038/emi.2012.7] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 03/21/2012] [Accepted: 04/08/2012] [Indexed: 02/07/2023]
Abstract
Hepatitis E virus (HEV), a single-stranded, positive-sense RNA virus, is responsible for acute hepatitis E epidemics in many developing countries, and the virus is also endemic in some industrialized countries. Hepatitis E is a recognized zoonotic disease, and several animal species, including pigs, are potential reservoirs for HEV. The genome of HEV contains three open reading frames (ORFs). ORF1 encodes the nonstructural proteins, ORF2 encodes the capsid protein, and ORF3 encodes a small multifunctional protein. The ORF2 and ORF3 proteins are translated from a single, bicistronic mRNA. The coding sequences for these two ORFs overlap each other, but neither overlaps with ORF1. Whereas the mechanisms underlying HEV replication are poorly understood, the construction of infectious viral clones, the identification of cell lines that support HEV replication, and the development of small animal models have allowed for more detailed study of the virus. As result of these advances, recently, our understanding of viral entry, genomic replication and viral egress has improved. Furthermore, the determination of the T=1 and T=3 structure of HEV virus-like particles has furthered our understanding of the replication of HEV. This article reviews the latest developments in the molecular biology of HEV with an emphasis on the genomic organization, the expression and function of genes, and the structure and replication of HEV.
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Affiliation(s)
- Dianjun Cao
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University (Virginia Tech) , Blacksburg, VA 24061-0913, USA
| | - Xiang-Jin Meng
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University (Virginia Tech) , Blacksburg, VA 24061-0913, USA
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The PSAP motif within the ORF3 protein of an avian strain of the hepatitis E virus is not critical for viral infectivity in vivo but plays a role in virus release. J Virol 2012; 86:5637-46. [PMID: 22438540 DOI: 10.1128/jvi.06711-11] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The ORF3 protein of hepatitis E virus (HEV) is a multifunctional protein important for virus replication. The ORF3 proteins from human, swine, and avian strains of HEV contain a conserved PXXP amino acid motif, resembling either Src homology 3 (SH3) cell signaling interaction motifs or "late domains" involved in host cell interactions aiding in particle release. Using an avian strain of HEV, we determined the roles of the conserved prolines within the PREPSAPP motif in HEV replication and infectivity in Leghorn male hepatoma (LMH) chicken liver cells and in chickens. Each proline was changed to alanine to produce 8 avian HEV mutants containing single mutations (P64, P67, P70, and P71 to A), double mutations (P64/67A, P64/70A, and P67/70A), and triple mutations (P64/67/70A). The results showed that avian HEV mutants are replication competent in vitro, and none of the prolines in the PXXPXXPP motif are essential for infectivity in vivo; however, the second and third prolines appear to aid in fecal virus shedding, suggesting that the PSAP motif, but not the PREP motif, is involved in virus release. We also showed that the PSAP motif interacts with the host protein tumor suppressor gene 101 (TSG101) and that altering any proline within the PSAP motif disrupts this interaction. However, we showed that the ORF2 protein expressed in LMH cells is efficiently released from the cells in the absence of ORF3 and that coexpression of ORF2 and ORF3 did not act synergistically in this release, suggesting that another factor(s) such as ORF1 or viral genomic RNA may be necessary for proper particle release.
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Abstract
The mechanism of hepatitis E virus (HEV) replication remains largely unknown. Here we demonstrate that HEV replication requires an active ubiquitin-proteasome system and that proteasome inhibitors affect HEV replication, possibly by inhibition of viral transcription or/and translation without a significant effect on cellular translation. Overexpression of ubiquitin in inhibitor-treated cells partially reverses the inhibitor effect on HEV replication. The results suggest that HEV replication requires interactions with proteasome machinery, which could be a potential therapeutic target against HEV.
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Lau E, Kluger H, Varsano T, Lee K, Scheffler I, Rimm DL, Ideker T, Ronai ZA. PKCε promotes oncogenic functions of ATF2 in the nucleus while blocking its apoptotic function at mitochondria. Cell 2012; 148:543-55. [PMID: 22304920 DOI: 10.1016/j.cell.2012.01.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 08/12/2011] [Accepted: 01/06/2012] [Indexed: 01/05/2023]
Abstract
The transcription factor ATF2 elicits oncogenic activities in melanoma and tumor suppressor activities in nonmalignant skin cancer. Here, we identify that ATF2 tumor suppressor function is determined by its ability to localize at the mitochondria, where it alters membrane permeability following genotoxic stress. The ability of ATF2 to reach the mitochondria is determined by PKCε, which directs ATF2 nuclear localization. Genotoxic stress attenuates PKCε effect on ATF2; enables ATF2 nuclear export and localization at the mitochondria, where it perturbs the HK1-VDAC1 complex; increases mitochondrial permeability; and promotes apoptosis. Significantly, high levels of PKCε, as seen in melanoma cells, block ATF2 nuclear export and function at the mitochondria, thereby attenuating apoptosis following exposure to genotoxic stress. In melanoma tumor samples, high PKCε levels associate with poor prognosis. Overall, our findings provide the framework for understanding how subcellular localization enables ATF2 oncogenic or tumor suppressor functions.
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Affiliation(s)
- Eric Lau
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
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Chandra V, Holla P, Ghosh D, Chakrabarti D, Padigaru M, Jameel S. The hepatitis E virus ORF3 protein regulates the expression of liver-specific genes by modulating localization of hepatocyte nuclear factor 4. PLoS One 2011; 6:e22412. [PMID: 21799848 PMCID: PMC3140526 DOI: 10.1371/journal.pone.0022412] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 06/21/2011] [Indexed: 12/17/2022] Open
Abstract
The hepatitis E virus (HEV) is a small RNA virus and the cause of acute viral hepatitis E. The open reading frame 3 protein (pORF3) of HEV appears to be a pleiotropic regulatory protein that helps in the establishment, propagation and progression of viral infection. However, the global cellular effects of this protein remain to be explored. In the absence of traditional in vitro viral infection systems or efficient replicon systems, we made an adenovirus based ORF3 protein expression system to study its effects on host cell gene expression. We infected Huh7 hepatoma cells with recombinant adenoviruses expressing pORF3 and performed microarray-based gene expression analyses. Several genes down regulated in pORF3-expressing cells were found to be under regulation of the liver-enriched hepatocyte nuclear factor 4 (HNF4), which regulates hepatocyte-specific gene expression. While HNF4 localizes to the nucleus, its phosphorylation results in impaired nuclear localization of HNF4. Here we report that pORF3 increases HNF4 phosphorylation through the ERK and Akt kinases, which results in impaired nuclear translocation of HNF4 and subsequently the down modulation of HNF4-responsive genes in pORF3-expressing cells. We propose that modulation of several hepatocyte specific genes by pORF3 will create an environment favorable for viral replication and pathogenesis.
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Affiliation(s)
- Vivek Chandra
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Prasida Holla
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Dhrubaa Ghosh
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | | | | | - Shahid Jameel
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
- * E-mail:
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45
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Okamoto H. Efficient cell culture systems for hepatitis E virus strains in feces and circulating blood. Rev Med Virol 2011; 21:18-31. [PMID: 21294213 DOI: 10.1002/rmv.678] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Attempts have been made to propagate hepatitis E virus (HEV) in primary hepatocyte culture and various other cultured cells. However, the replication ability of HEV recovered from culture media remains extremely low. Recently, efficient culture systems have been established in PLC/PRF/5 (hepatocellular carcinoma) and A549 (lung cancer) cell lines for HEV strains of genotypes 3 and 4 in our laboratory. They originated in fecal extracts from patients containing HEV RNA in extremely high-titers (10(7) copies/ml), and named the JE03-1760F (genotype 3) and HE-JF5/15F (genotype 4) strains, respectively. HEV RNA in culture supernatants reached 10(8) copies/ml in titer, and were transmitted successively through many passages. An infectious HEV cDNA clone (pJE03-1760F/wt) was constructed that has replication activity comparable to that of the wild-type JE03-1760F in feces. The ORF3 protein is indispensable for shedding HEV particles from cells in the reverse genetics system. HEV recovered from culture media, as well as circulating HEV, possess ORF3 proteins on the surface and are covered with cellular membranes, and therefore, ORF2 epitopes are buried in these particles. In contrast, HEV excreted into feces are naked nucleocapsids without a lipid layer or surface expression of the ORF3 protein. HEV in sera of patients with acute hepatitis E can infect and replicate in PLC/PRF/5 and A549 cells, with efficiency comparable to the circulating HEV RNA levels. High-efficiency cell culture systems for infectious viruses, thus developed, are expected to open up a new era and resolve many mysteries in the epidemiology, molecular biology, and treatment of HEV.
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Affiliation(s)
- Hiroaki Okamoto
- Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke-Shi, Tochigi, Japan.
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Three amino acid mutations (F51L, T59A, and S390L) in the capsid protein of the hepatitis E virus collectively contribute to virus attenuation. J Virol 2011; 85:5338-49. [PMID: 21450834 DOI: 10.1128/jvi.02278-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hepatitis E virus (HEV) is an important but extremely understudied human pathogen, and the mechanisms of HEV replication and pathogenesis are largely unknown. We previously identified an attenuated genotype 3 HEV mutant (pSHEV-1) containing three unique amino acid mutations (F51L, T59A, and S390L) in the capsid protein. To determine the role of each of these mutations, we constructed three HEV single mutants (rF51L, rT59A, and rS390L) which were all found to be replication competent in Huh7 liver cells. To determine the pathogenicities of the mutants, we utilized the specific-pathogen-free (SPF) pig model for HEV and a unique inoculation procedure that bypasses the need for propagating infectious HEV in vitro. A total of 60 pigs were intrahepatically inoculated, via an ultrasound-guided technique, with in vitro-transcribed full-length capped RNA transcripts from the infectious clones of each single mutant, the pSHEV-1 triple mutant, wild-type pSHEV-3, or phosphate-buffered saline (PBS) buffer (n = 10). The results showed that the F51L mutation partially contributed to virus attenuation, whereas the T59A and S390L mutations resulted in more drastic attenuation of HEV in pigs, as evidenced by a significantly lower incidence of viremia, a delayed appearance and shorter duration of fecal virus shedding and viremia, and lower viral loads in liver, bile, and intestinal content collected at three different necropsy times. The results indicate that the three mutations in the capsid protein collectively contribute to HEV attenuation. This study has important implications for developing a modified live-attenuated vaccine against HEV.
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47
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Ahmad I, Holla RP, Jameel S. Molecular virology of hepatitis E virus. Virus Res 2011; 161:47-58. [PMID: 21345356 PMCID: PMC3130092 DOI: 10.1016/j.virusres.2011.02.011] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/13/2011] [Accepted: 02/13/2011] [Indexed: 12/15/2022]
Abstract
This review details the molecular virology of the hepatitis E virus (HEV). While replicons and in vitro infection systems have recently become available, a lot of information on HEV has been generated through comparisons with better-studied positive-strand RNA viruses and through subgenomic expression of viral open reading frames. These models are now being verified with replicon and infection systems. We provide here the current knowledge on the HEV genome and its constituent proteins--ORF1, ORF2 and ORF3. Based on the available information, we also modify the existing model of the HEV life cycle.
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Affiliation(s)
- Imran Ahmad
- Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
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48
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Liu T, Lei M, Jiao H, Du L, Cheng Y, Zhang D, Hao Y, Man C, Wang F. RNA interference induces effective inhibition of mRNA accumulation and protein expression of SHEV ORF3 gene in vitro. Curr Microbiol 2011; 62:1355-62. [PMID: 21225263 DOI: 10.1007/s00284-010-9863-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 12/23/2010] [Indexed: 11/25/2022]
Abstract
RNA interference (RNAi) provides a powerful promising approach to inhibit viral infection specifically. To explore the possibility of using RNAi as a strategy against HEV infection, which is a serious public health problem in developing countries of Asia, Middle East, Africa, and in Mexico, after the fusion protein expression plasmids pEGFP-ORF3 which contain the EGFP reporter gene and SHEV ORF3 as silencing target, were constructed; EGFP-ORF3 fusion protein expressing HEK 293 cell lines were established; and four siRNAs targeting ORF3 gene were designed, synthesized, and used to transfect the stable cell lines. At 24, 48, and 72 h after transfection, flow cytometry, real-time quantitative PCR, and Western blot were used to assess the expression level of ORF3. The results demonstrated that specific siRNAs which are sequence dependant effectively inhibited mRNA accumulation and protein expression of SHEV ORF3 in HEK 293 cells. These findings provide useful information for the development of RNAi-based prophylaxis and therapy for SHEV infection.
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Affiliation(s)
- Tao Liu
- Hainan Key Lab of Tropical Animal Reproduction & Breeding and Epidemic Disease Research (Construction Period), Animal Genetic Engineering Key Lab of Haikou, College of Agriculture, Hainan University, Haidian Island, Haikou 570228, People's Republic of China
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Feagins AR, Córdoba L, Sanford BJ, Dryman BA, Huang YW, LeRoith T, Emerson SU, Meng XJ. Intergenotypic chimeric hepatitis E viruses (HEVs) with the genotype 4 human HEV capsid gene in the backbone of genotype 3 swine HEV are infectious in pigs. Virus Res 2010; 156:141-6. [PMID: 21195119 DOI: 10.1016/j.virusres.2010.12.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/21/2010] [Accepted: 12/22/2010] [Indexed: 12/11/2022]
Abstract
Genotypes 1 and 2 hepatitis E virus (HEV) infect only humans whereas genotypes 3 and 4 HEV infect both humans and pigs. To evaluate the mechanism of cross-species HEV infection between humans and swine, in this study we constructed five intergenotypic chimeric viruses and tested for their infectivity in vitro and in pigs. We demonstrated that chimeric viruses containing the ORF2 capsid gene either alone or in combination with its adjacent 5' junction region (JR) and 3' noncoding region (NCR) from a genotype 4 human HEV in the backbone of a genotype 3 swine HEV are replication-competent in Huh7 cells and infectious in HepG2/C3A cells and in pigs, and thus supporting the hypothesis that genotypes 3 and 4 human HEV are of swine origin. However, chimeric viruses containing the JR+ORF2+3' NCR of genotypes 3 or 4 HEV in the backbone of genotype 1 human HEV failed to infect pigs, suggesting that other genomic regions such as 5' NCR and ORF1 may also be involved in HEV cross-species infection. The results from this study provide the first experimental evidence of the exchangeability of the capsid gene between genotype 3 swine HEV and genotype 4 human HEV, and have important implications for understanding the mechanism of HEV cross-species infection.
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Affiliation(s)
- Alicia R Feagins
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 1981 Kraft Drive, Blacksburg, VA 24061, United States
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Abstract
Apoptosis plays a critical role for the development of a variety of cardiac diseases. Cardiomyocytes are enriched in mitochondria, while mitochondrial fission can regulate apoptosis. The molecular mechanism governing cardiomyocyte apoptosis remain to be fully elucidated. Our results showed that Smac/DIABLO is necessary for apoptosis in cardiomyocytes, and it is released from mitochondria into cytosol in response to apoptotic stimulation. Smac/DIABLO release is a consequence of mitochondrial fission mediated by dynamin-related protein-1 (Drp1). Upon release Smac/DIABLO binds to X-linked inhibitor of apoptosis protein (XIAP), resulting in the activation of caspase-9 and caspase-3. Their activation is a prerequisite for the initiation of apoptosis because the administration of z-LEHD-fmk and z-DQMD-fmk, two relatively specific inhibitors for caspase-9, and caspase-3, respectively, could significantly attenuate apoptosis. Smac/DIABLO release could not be blocked by these caspase inhibitors, indicating that it is an event upstream of caspase activation. ARC (apoptosis repressor with caspase recruitment domain), an abundantly expressed apoptotic repressor in cardiomyocytes, could inhibit mitochondrial fission and Smac/DIABLO release. Our data reveal that Smac/DIABLO is a target of ARC in counteracting apoptosis.
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