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Yin C, Zhang MM, Wang GL, Deng XY, Tu Z, Jiang SS, Gao ZD, Hao M, Chen Y, Li Y, Yang SY. Loss of ADAR1 induces ferroptosis of breast cancer cells. Cell Signal 2024; 121:111258. [PMID: 38866351 DOI: 10.1016/j.cellsig.2024.111258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 05/31/2024] [Accepted: 06/09/2024] [Indexed: 06/14/2024]
Abstract
Adenosine deaminases acting on RNA 1(ADAR1), an RNA editing enzyme that converts adenosine to inosine by deamination in double-stranded RNAs, plays an important role in occurrence and progression of various types of cancer. Ferroptosis has emerged as a hot topic of cancer research in recent years. We have previously reported that ADAR1 promotes breast cancer progression by regulating miR-335-5p and METTL3. However, whether ADAR1 has effects on ferroptosis in breast cancer cells is largely unknown. In this study, we knocked down ADAR1 using CRISPR-Cas9 technology or over-expressed ADAR1 protein using plasmid expressing ADAR1 in MCF-7 and MDA-MB-231 breast cancer cell lines, then detected cell viability, and levels of ROS, MDA, GSH, Fe2+, GPX4 protein and miR-335-5p. We showed that the cell proliferation was inhibited, levels of ROS, MDA, Fe2+, and miR-335-5p were increased, while GSH and GPX4 levels were decreased after loss of ADAR1, compared to the control group. The opposite effects were observed after ADAR1 overexpression in the cells. Further, we demonstrated that ADAR1-controlled miR-335-5p targeted Sp1 transcription factor of GPX4, a known ferroptosis molecular marker, leading to inhibition of ferroptosis by ADAR1 in breast cancer cells. Moreover, RNA editing activity of ADAR1 is not essential for inducing ferroptosis. Collectively, loss of ADAR1 induces ferroptosis in breast cancer cells by regulating miR-335-5p/Sp1/GPX4 pathway. The findings may provide insights into the mechanism by which ADAR1 promotes breast cancer progression via inhibiting ferroptosis.
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Affiliation(s)
- Chuan Yin
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Meng-Meng Zhang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Guo-Liang Wang
- Department of General Surgery, Union Hospital of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiao-Yan Deng
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Zeng Tu
- Department of Pathogen Biology, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Shan-Shan Jiang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Zheng-Dan Gao
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Meng Hao
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Yong Chen
- Department of Radiology and Intervention, General Hospital of Ningxia Medical University, Yinchuan 750004, China.
| | - Yi Li
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China.
| | - Sheng-Yong Yang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing 400016, China.
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2
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Chattopadhyay P, Mehta P, Kanika, Mishra P, Chen Liu CS, Tarai B, Budhiraja S, Pandey R. RNA editing in host lncRNAs as potential modulator in SARS-CoV-2 variants-host immune response dynamics. iScience 2024; 27:109846. [PMID: 38770134 PMCID: PMC11103575 DOI: 10.1016/j.isci.2024.109846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/18/2024] [Accepted: 04/25/2024] [Indexed: 05/22/2024] Open
Abstract
Both host and viral RNA editing plays a crucial role in host's response to infection, yet our understanding of host RNA editing remains limited. In this study of in-house generated RNA sequencing (RNA-seq) data of 211 hospitalized COVID-19 patients with PreVOC, Delta, and Omicron variants, we observed a significant differential editing frequency and patterns in long non-coding RNAs (lncRNAs), with Delta group displaying lower RNA editing compared to PreVOC/Omicron patients. Notably, multiple transcripts of UGDH-AS1 and NEAT1 exhibited high editing frequencies. Expression of ADAR1/APOBEC3A/APOBEC3G and differential abundance of repeats were possible modulators of differential editing across patient groups. We observed a shift in crucial infection-related pathways wherein the pathways were downregulated in Delta compared to PreVOC and Omicron. Our genomics-based evidence suggests that lncRNA editing influences stability, miRNA binding, and expression of both lncRNA and target genes. Overall, the study highlights the role of lncRNAs and how editing within host lncRNAs modulates the disease severity.
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Affiliation(s)
- Partha Chattopadhyay
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Priyanka Mehta
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Kanika
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
| | - Pallavi Mishra
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
| | - Chinky Shiu Chen Liu
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
| | - Bansidhar Tarai
- Max Super Speciality Hospital (A Unit of Devki Devi Foundation), Max Healthcare, Delhi 110017, India
| | - Sandeep Budhiraja
- Max Super Speciality Hospital (A Unit of Devki Devi Foundation), Max Healthcare, Delhi 110017, India
| | - Rajesh Pandey
- Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi 110007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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3
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Hu SB, Li JB. RNA editing and immune control: from mechanism to therapy. Curr Opin Genet Dev 2024; 86:102195. [PMID: 38643591 PMCID: PMC11162905 DOI: 10.1016/j.gde.2024.102195] [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: 01/18/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/23/2024]
Abstract
Adenosine-to-inosine RNA editing, catalyzed by the enzymes ADAR1 and ADAR2, stands as a pervasive RNA modification. A primary function of ADAR1-mediated RNA editing lies in labeling endogenous double-stranded RNAs (dsRNAs) as 'self', thereby averting their potential to activate innate immune responses. Recent findings have highlighted additional roles of ADAR1, independent of RNA editing, that are crucial for immune control. Here, we focus on recent progress in understanding ADAR1's RNA editing-dependent and -independent roles in immune control. We describe how ADAR1 regulates various dsRNA innate immune receptors through distinct mechanisms. Furthermore, we discuss the implications of ADAR1 and RNA editing in diseases, including autoimmune diseases and cancers.
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Affiliation(s)
- Shi-Bin Hu
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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Carpenter S, O'Neill LAJ. From periphery to center stage: 50 years of advancements in innate immunity. Cell 2024; 187:2030-2051. [PMID: 38670064 PMCID: PMC11060700 DOI: 10.1016/j.cell.2024.03.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/24/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024]
Abstract
Over the past 50 years in the field of immunology, something of a Copernican revolution has happened. For a long time, immunologists were mainly concerned with what is termed adaptive immunity, which involves the exquisitely specific activities of lymphocytes. But the other arm of immunity, so-called "innate immunity," had been neglected. To celebrate Cell's 50th anniversary, we have put together a review of the processes and components of innate immunity and trace the seminal contributions leading to the modern state of this field. Innate immunity has joined adaptive immunity in the center of interest for all those who study the body's defenses, as well as homeostasis and pathology. We are now entering the era where therapeutic targeting of innate immune receptors and downstream signals hold substantial promise for infectious and inflammatory diseases and cancer.
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Affiliation(s)
- Susan Carpenter
- University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA.
| | - Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
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5
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Cottrell KA, Ryu S, Pierce JR, Soto Torres L, Bohlin HE, Schab AM, Weber JD. Induction of Viral Mimicry Upon Loss of DHX9 and ADAR1 in Breast Cancer Cells. CANCER RESEARCH COMMUNICATIONS 2024; 4:986-1003. [PMID: 38530197 PMCID: PMC10993856 DOI: 10.1158/2767-9764.crc-23-0488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/24/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
Detection of viral double-stranded RNA (dsRNA) is an important component of innate immunity. However, many endogenous RNAs containing double-stranded regions can be misrecognized and activate innate immunity. The IFN-inducible ADAR1-p150 suppresses dsRNA sensing, an essential function for adenosine deaminase acting on RNA 1 (ADAR1) in many cancers, including breast. Although ADAR1-p150 has been well established in this role, the functions of the constitutively expressed ADAR1-p110 isoform are less understood. We used proximity labeling to identify putative ADAR1-p110-interacting proteins in breast cancer cell lines. Of the proteins identified, the RNA helicase DHX9 was of particular interest. Knockdown of DHX9 in ADAR1-dependent cell lines caused cell death and activation of the dsRNA sensor PKR. In ADAR1-independent cell lines, combined knockdown of DHX9 and ADAR1, but neither alone, caused activation of multiple dsRNA sensing pathways leading to a viral mimicry phenotype. Together, these results reveal an important role for DHX9 in suppressing dsRNA sensing by multiple pathways. SIGNIFICANCE These findings implicate DHX9 as a suppressor of dsRNA sensing. In some cell lines, loss of DHX9 alone is sufficient to cause activation of dsRNA sensing pathways, while in other cell lines DHX9 functions redundantly with ADAR1 to suppress pathway activation.
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Affiliation(s)
- Kyle A. Cottrell
- Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri
- ICCE Institute, Washington University School of Medicine, St. Louis, Missouri
- Department of Biochemistry, Purdue University, West Lafayette, Indiana
| | - Sua Ryu
- Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri
- ICCE Institute, Washington University School of Medicine, St. Louis, Missouri
| | - Jackson R. Pierce
- Department of Biochemistry, Purdue University, West Lafayette, Indiana
| | - Luisangely Soto Torres
- Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri
- ICCE Institute, Washington University School of Medicine, St. Louis, Missouri
| | - Holly E. Bohlin
- Department of Biochemistry, Purdue University, West Lafayette, Indiana
| | - Angela M. Schab
- Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri
- ICCE Institute, Washington University School of Medicine, St. Louis, Missouri
| | - Jason D. Weber
- Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, Missouri
- ICCE Institute, Washington University School of Medicine, St. Louis, Missouri
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
- Department of Biology, Siteman Cancer Center, St. Louis, Missouri
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6
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Rivera M, Zhang H, Pham J, Isquith J, Zhou QJ, Balaian L, Sasik R, Enlund S, Mark A, Ma W, Holm F, Fisch KM, Kuo DJ, Jamieson C, Jiang Q. Malignant A-to-I RNA editing by ADAR1 drives T cell acute lymphoblastic leukemia relapse via attenuating dsRNA sensing. Cell Rep 2024; 43:113704. [PMID: 38265938 PMCID: PMC10962356 DOI: 10.1016/j.celrep.2024.113704] [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: 06/02/2023] [Revised: 10/24/2023] [Accepted: 01/09/2024] [Indexed: 01/26/2024] Open
Abstract
Leukemia-initiating cells (LICs) are regarded as the origin of leukemia relapse and therapeutic resistance. Identifying direct stemness determinants that fuel LIC self-renewal is critical for developing targeted approaches. Here, we show that the RNA-editing enzyme ADAR1 is a crucial stemness factor that promotes LIC self-renewal by attenuating aberrant double-stranded RNA (dsRNA) sensing. Elevated adenosine-to-inosine editing is a common attribute of relapsed T cell acute lymphoblastic leukemia (T-ALL) regardless of molecular subtype. Consequently, knockdown of ADAR1 severely inhibits LIC self-renewal capacity and prolongs survival in T-ALL patient-derived xenograft models. Mechanistically, ADAR1 directs hyper-editing of immunogenic dsRNA to avoid detection by the innate immune sensor melanoma differentiation-associated protein 5 (MDA5). Moreover, we uncover that the cell-intrinsic level of MDA5 dictates the dependency on the ADAR1-MDA5 axis in T-ALL. Collectively, our results show that ADAR1 functions as a self-renewal factor that limits the sensing of endogenous dsRNA. Thus, targeting ADAR1 presents an effective therapeutic strategy for eliminating T-ALL LICs.
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Affiliation(s)
- Maria Rivera
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, La Jolla, CA 92037, USA
| | - Haoran Zhang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, La Jolla, CA 92037, USA
| | - Jessica Pham
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jane Isquith
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qingchen Jenny Zhou
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, La Jolla, CA 92037, USA
| | - Larisa Balaian
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Roman Sasik
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, CA 92093-0681, USA
| | - Sabina Enlund
- Department of Women's and Children's Health, Division of Pediatric Oncology and Pediatric Surgery, Karolinska Institutet, Solna, Sweden
| | - Adam Mark
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, CA 92093-0681, USA
| | - Wenxue Ma
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Frida Holm
- Department of Women's and Children's Health, Division of Pediatric Oncology and Pediatric Surgery, Karolinska Institutet, Solna, Sweden
| | - Kathleen M Fisch
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, CA 92093-0681, USA; Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Diego, La Jolla, CA 92037, USA
| | - Dennis John Kuo
- Moores Cancer Center, La Jolla, CA 92037, USA; Division of Pediatric Hematology-Oncology, Rady Children's Hospital San Diego, University of California, San Diego, San Diego, CA 92123, USA
| | - Catriona Jamieson
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, La Jolla, CA 92037, USA
| | - Qingfei Jiang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, La Jolla, CA 92037, USA.
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7
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Zambrano-Mila MS, Witzenberger M, Rosenwasser Z, Uzonyi A, Nir R, Ben-Aroya S, Levanon EY, Schwartz S. Dissecting the basis for differential substrate specificity of ADAR1 and ADAR2. Nat Commun 2023; 14:8212. [PMID: 38081817 PMCID: PMC10713624 DOI: 10.1038/s41467-023-43633-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023] Open
Abstract
Millions of adenosines are deaminated throughout the transcriptome by ADAR1 and/or ADAR2 at varying levels, raising the question of what are the determinants guiding substrate specificity and how these differ between the two enzymes. We monitor how secondary structure modulates ADAR2 vs ADAR1 substrate selectivity, on the basis of systematic probing of thousands of synthetic sequences transfected into cell lines expressing exclusively ADAR1 or ADAR2. Both enzymes induce symmetric, strand-specific editing, yet with distinct offsets with respect to structural disruptions: -26 nt for ADAR2 and -35 nt for ADAR1. We unravel the basis for these differences in offsets through mutants, domain-swaps, and ADAR homologs, and find it to be encoded by the differential RNA binding domain (RBD) architecture. Finally, we demonstrate that this offset-enhanced editing can allow an improved design of ADAR2-recruiting therapeutics, with proof-of-concept experiments demonstrating increased on-target and potentially decreased off-target editing.
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Affiliation(s)
- Marlon S Zambrano-Mila
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7630031, Israel
| | - Monika Witzenberger
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7630031, Israel
| | - Zohar Rosenwasser
- Faculty of Life Sciences, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Anna Uzonyi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7630031, Israel
| | - Ronit Nir
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7630031, Israel
| | - Shay Ben-Aroya
- Faculty of Life Sciences, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Erez Y Levanon
- Faculty of Life Sciences, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Schraga Schwartz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7630031, Israel.
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8
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McEntee CM, Cavalier AN, LaRocca TJ. ADAR1 suppression causes interferon signaling and transposable element transcript accumulation in human astrocytes. Front Mol Neurosci 2023; 16:1263369. [PMID: 38035265 PMCID: PMC10685929 DOI: 10.3389/fnmol.2023.1263369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/25/2023] [Indexed: 12/02/2023] Open
Abstract
Neuroinflammation is a central mechanism of brain aging and Alzheimer's disease (AD), but the exact causes of age- and AD-related neuroinflammation are incompletely understood. One potential modulator of neuroinflammation is the enzyme adenosine deaminase acting on RNA 1 (ADAR1), which regulates the accumulation of endogenous double-stranded RNA (dsRNA), a pro-inflammatory/innate immune activator. However, the role of ADAR1 and its transcriptomic targets in astrocytes, key mediators of neuroinflammation, have not been comprehensively investigated. Here, we knock down ADAR1 in primary human astrocytes via siRNA transfection and use transcriptomics (RNA-seq) to show that this results in: (1) increased expression of type I interferon and pro-inflammatory signaling pathways and (2) an accumulation of transposable element (TE) transcripts with the potential to form dsRNA. We also show that our findings may be clinically relevant, as ADAR1 gene expression declines with brain aging and AD in humans, and this is associated with a similar increase in TE transcripts. Together, our results suggest an important role for ADAR1 in preventing pro-inflammatory activation of astrocytes in response to endogenous dsRNA with aging and AD.
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Affiliation(s)
- Cali M. McEntee
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
- Center for Healthy Aging, Colorado State University, Fort Collins, CO, United States
| | - Alyssa N. Cavalier
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
- Center for Healthy Aging, Colorado State University, Fort Collins, CO, United States
| | - Thomas J. LaRocca
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, United States
- Center for Healthy Aging, Colorado State University, Fort Collins, CO, United States
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9
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Shen S, Zhang LS. The regulation of antiviral innate immunity through non-m 6A RNA modifications. Front Immunol 2023; 14:1286820. [PMID: 37915585 PMCID: PMC10616867 DOI: 10.3389/fimmu.2023.1286820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/04/2023] [Indexed: 11/03/2023] Open
Abstract
The post-transcriptional RNA modifications impact the dynamic regulation of gene expression in diverse biological and physiological processes. Host RNA modifications play an indispensable role in regulating innate immune responses against virus infection in mammals. Meanwhile, the viral RNAs can be deposited with RNA modifications to interfere with the host immune responses. The N6-methyladenosine (m6A) has boosted the recent emergence of RNA epigenetics, due to its high abundance and a transcriptome-wide widespread distribution in mammalian cells, proven to impact antiviral innate immunity. However, the other types of RNA modifications are also involved in regulating antiviral responses, and the functional roles of these non-m6A RNA modifications have not been comprehensively summarized. In this Review, we conclude the regulatory roles of 2'-O-methylation (Nm), 5-methylcytidine (m5C), adenosine-inosine editing (A-to-I editing), pseudouridine (Ψ), N1-methyladenosine (m1A), N7-methylguanosine (m7G), N6,2'-O-dimethyladenosine (m6Am), and N4-acetylcytidine (ac4C) in antiviral innate immunity. We provide a systematic introduction to the biogenesis and functions of these non-m6A RNA modifications in viral RNA, host RNA, and during virus-host interactions, emphasizing the biological functions of RNA modification regulators in antiviral responses. Furthermore, we discussed the recent research progress in the development of antiviral drugs through non-m6A RNA modifications. Collectively, this Review conveys knowledge and inspiration to researchers in multiple disciplines, highlighting the challenges and future directions in RNA epitranscriptome, immunology, and virology.
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Affiliation(s)
- Shenghai Shen
- Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Kowloon, Hong Kong SAR, China
| | - Li-Sheng Zhang
- Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Kowloon, Hong Kong SAR, China
- Department of Chemistry, The Hong Kong University of Science and Technology (HKUST), Kowloon, Hong Kong SAR, China
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10
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Ivanišević V, Žilić L, Čunko M, Fadiga H, Munitić I, Jurak I. RNA Editing-Dependent and -Independent Roles of Adenosine Deaminases Acting on RNA Proteins in Herpesvirus Infection-Hints on Another Layer of Complexity. Viruses 2023; 15:2007. [PMID: 37896783 PMCID: PMC10611208 DOI: 10.3390/v15102007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 09/24/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
The Adenosine Deaminases Acting on RNA (ADAR) catalyze the posttranscriptional deamination of adenosine residues to inosine in double-stranded RNAs (dsRNAs, A-to-I editing), preventing the overactivation of dsRNA sensor molecules and interferons. RNA editing is the cornerstone of innate immunity that distinguishes between self and non-self (virus), and it is essential for normal regulation of cellular homeostasis. Although much is already known about the role of ADAR proteins in RNA virus infection, the role of ADAR proteins in herpesvirus infection remains largely unexplored. In this review, we provide several lines of evidence from studies of different herpesviruses for another level of complexity in regulating the already intricate biphasic life cycle of herpesviruses.
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Affiliation(s)
| | | | | | | | | | - Igor Jurak
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia (L.Ž.)
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11
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Guo X, Liu S, Sheng Y, Zenati M, Billiar T, Herbert A, Wang Q. ADAR1 Zα domain P195A mutation activates the MDA5-dependent RNA-sensing signaling pathway in brain without decreasing overall RNA editing. Cell Rep 2023; 42:112733. [PMID: 37421629 PMCID: PMC10691306 DOI: 10.1016/j.celrep.2023.112733] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 05/03/2023] [Accepted: 06/16/2023] [Indexed: 07/10/2023] Open
Abstract
Variants of the RNA-editing enzyme ADAR1 cause Aicardi-Goutières syndrome (AGS), in which severe inflammation occurs in the brain due to innate immune activation. Here, we analyze the RNA-editing status and innate immune activation in an AGS mouse model that carries the Adar P195A mutation in the N terminus of the ADAR1 p150 isoform, the equivalent of the P193A human Zα variant causal for disease. This mutation alone can cause interferon-stimulated gene (ISG) expression in the brain, especially in the periventricular areas, reflecting the pathologic feature of AGS. However, in these mice, ISG expression does not correlate with an overall decrease in RNA editing. Rather, the enhanced ISG expression in the brain due to the P195A mutant is dose dependent. Our findings indicate that ADAR1 can regulate innate immune responses through Z-RNA binding without changing overall RNA editing.
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Affiliation(s)
- Xinfeng Guo
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Silvia Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yi Sheng
- Magee-Women's Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Mazen Zenati
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Timothy Billiar
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | | | - Qingde Wang
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; VA Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA.
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12
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Rivera M, Zhang H, Pham J, Isquith J, Zhou QJ, Sasik R, Mark A, Ma W, Holm F, Fisch KM, Kuo DJ, Jamieson C, Jiang Q. Malignant A-to-I RNA editing by ADAR1 drives T-cell acute lymphoblastic leukemia relapse via attenuating dsRNA sensing. RESEARCH SQUARE 2023:rs.3.rs-2444524. [PMID: 37398458 PMCID: PMC10312963 DOI: 10.21203/rs.3.rs-2444524/v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Leukemia initiating cells (LICs) are regarded as the origin of leukemia relapse and therapeutic resistance. Identifying direct stemness determinants that fuel LIC self-renewal is critical for developing targeted approaches to eliminate LICs and prevent relapse. Here, we show that the RNA editing enzyme ADAR1 is a crucial stemness factor that promotes LIC self-renewal by attenuating aberrant double-stranded RNA (dsRNA) sensing. Elevated adenosine-to-inosine (A-to-I) editing is a common attribute of relapsed T-ALL regardless of molecular subtypes. Consequently, knockdown of ADAR1 severely inhibits LIC self-renewal capacity and prolongs survival in T-ALL PDX models. Mechanistically, ADAR1 directs hyper-editing of immunogenic dsRNA and retains unedited nuclear dsRNA to avoid detection by the innate immune sensor MDA5. Moreover, we uncovered that the cell intrinsic level of MDA5 dictates the dependency on ADAR1-MDA5 axis in T-ALL. Collectively, our results show that ADAR1 functions as a self-renewal factor that limits the sensing of endogenous dsRNA. Thus, targeting ADAR1 presents a safe and effective therapeutic strategy for eliminating T-ALL LICs.
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Affiliation(s)
- Maria Rivera
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Moores Cancer Center, La Jolla, CA 92037, USA
| | - Haoran Zhang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Moores Cancer Center, La Jolla, CA 92037, USA
| | - Jessica Pham
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jane Isquith
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Qingchen Jenny Zhou
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Moores Cancer Center, La Jolla, CA 92037, USA
| | - Roman Sasik
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, 92093-0681
| | - Adam Mark
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, 92093-0681
| | - Wenxue Ma
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Frida Holm
- Department of Women’s and Children’s Health, Division of Pediatric Oncology and Surgery, Karolinska Institutet, Sweden
| | - Kathleen M Fisch
- Center for Computational Biology & Bioinformatics (CCBB), University of California, San Diego, La Jolla, 92093-0681
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Diego, La Jolla, CA
| | - Dennis John Kuo
- Moores Cancer Center, La Jolla, CA 92037, USA
- Division of Pediatric Hematology-Oncology, Rady Children’s Hospital San Diego, University of California, San Diego, CA
| | - Catriona Jamieson
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Moores Cancer Center, La Jolla, CA 92037, USA
| | - Qingfei Jiang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Moores Cancer Center, La Jolla, CA 92037, USA
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13
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Gan WL, Ng L, Ng BYL, Chen L. Recent Advances in Adenosine-to-Inosine RNA Editing in Cancer. Cancer Treat Res 2023; 190:143-179. [PMID: 38113001 DOI: 10.1007/978-3-031-45654-1_5] [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: 12/21/2023]
Abstract
RNA epigenetics, or epitranscriptome, is a growing group of RNA modifications historically classified into two categories: RNA editing and RNA modification. RNA editing is usually understood as post-transcriptional RNA processing (except capping, splicing and polyadenylation) that changes the RNA nucleotide sequence encoded by the genome. This processing can be achieved through the insertion or deletion of nucleotides or deamination of nucleobases, generating either standard nucleotides such as uridine (U) or the rare nucleotide inosine (I). Adenosine-to-inosine (A-to-I) RNA editing is the most prevalent type of RNA modification in mammals and is catalyzed by adenosine deaminase acting on the RNA (ADAR) family of enzymes that recognize double-stranded RNAs (dsRNAs). Inosine mimics guanosine (G) in base pairing with cytidine (C), thereby A-to-I RNA editing alters dsRNA secondary structure. Inosine is also recognized as guanosine by the splicing and translation machineries, resulting in mRNA alternative splicing and protein recoding. Therefore, A-to-I RNA editing is an important mechanism that causes and regulates "RNA mutations" in both normal physiology and diseases including cancer. In this chapter, we reviewed current paradigms and developments in the field of A-to-I RNA editing in the context of cancer.
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Affiliation(s)
- Wei Liang Gan
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Larry Ng
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Bryan Y L Ng
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Leilei Chen
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore.
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117594, Singapore.
- NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore.
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14
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Kim IS, Jo EK. Inosine: A bioactive metabolite with multimodal actions in human diseases. Front Pharmacol 2022; 13:1043970. [PMID: 36467085 PMCID: PMC9708727 DOI: 10.3389/fphar.2022.1043970] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/02/2022] [Indexed: 08/04/2023] Open
Abstract
The nucleoside inosine is an essential metabolite for purine biosynthesis and degradation; it also acts as a bioactive molecule that regulates RNA editing, metabolic enzyme activity, and signaling pathways. As a result, inosine is emerging as a highly versatile bioactive compound and second messenger of signal transduction in cells with diverse functional abilities in different pathological states. Gut microbiota remodeling is closely associated with human disease pathogenesis and responses to dietary and medical supplementation. Recent studies have revealed a critical link between inosine and gut microbiota impacting anti-tumor, anti-inflammatory, and antimicrobial responses in a context-dependent manner. In this review, we summarize the latest progress in our understanding of the mechanistic function of inosine, to unravel its immunomodulatory actions in pathological settings such as cancer, infection, inflammation, and cardiovascular and neurological diseases. We also highlight the role of gut microbiota in connection with inosine metabolism in different pathophysiological conditions. A more thorough understanding of the mechanistic roles of inosine and how it regulates disease pathologies will pave the way for future development of therapeutic and preventive modalities for various human diseases.
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Affiliation(s)
- In Soo Kim
- Department of Medical Science, Chungnam National University College of Medicine, Daejeon, South Korea
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Eun-Kyoung Jo
- Department of Medical Science, Chungnam National University College of Medicine, Daejeon, South Korea
- Department of Microbiology, Chungnam National University College of Medicine, Daejeon, South Korea
- Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon, South Korea
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15
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Wang W, Pyle AM. The RIG-I receptor adopts two different conformations for distinguishing host from viral RNA ligands. Mol Cell 2022; 82:4131-4144.e6. [DOI: 10.1016/j.molcel.2022.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 08/09/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
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16
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Diallo MA, Pirotte S, Hu Y, Morvan L, Rakus K, Suárez NM, PoTsang L, Saneyoshi H, Xu Y, Davison A, Tompa P, Sussman J, Vanderplasschen A. A fish herpesvirus highlights functional diversities among Zα domains related to phase separation induction and A-to-Z conversion. Nucleic Acids Res 2022; 51:806-830. [PMID: 36130731 PMCID: PMC9881149 DOI: 10.1093/nar/gkac761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/18/2022] [Accepted: 08/25/2022] [Indexed: 02/06/2023] Open
Abstract
Zalpha (Zα) domains bind to left-handed Z-DNA and Z-RNA. The Zα domain protein family includes cellular (ADAR1, ZBP1 and PKZ) and viral (vaccinia virus E3 and cyprinid herpesvirus 3 (CyHV-3) ORF112) proteins. We studied CyHV-3 ORF112, which contains an intrinsically disordered region and a Zα domain. Genome editing of CyHV-3 indicated that the expression of only the Zα domain of ORF112 was sufficient for normal viral replication in cell culture and virulence in carp. In contrast, its deletion was lethal for the virus. These observations revealed the potential of the CyHV-3 model as a unique platform to compare the exchangeability of Zα domains expressed alone in living cells. Attempts to rescue the ORF112 deletion by a broad spectrum of cellular, viral, and artificial Zα domains showed that only those expressing Z-binding activity, the capacity to induce liquid-liquid phase separation (LLPS), and A-to-Z conversion, could rescue viral replication. For the first time, this study reports the ability of some Zα domains to induce LLPS and supports the biological relevance of dsRNA A-to-Z conversion mediated by Zα domains. This study expands the functional diversity of Zα domains and stimulates new hypotheses concerning the mechanisms of action of proteins containing Zα domains.
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Affiliation(s)
| | | | - Yunlong Hu
- Department of Infectious and Parasitic Diseases, Immunology-Vaccinology, University of Liège, Liège B-4000, Belgium
| | - Léa Morvan
- Department of Infectious and Parasitic Diseases, Immunology-Vaccinology, University of Liège, Liège B-4000, Belgium
| | - Krzysztof Rakus
- Department of Infectious and Parasitic Diseases, Immunology-Vaccinology, University of Liège, Liège B-4000, Belgium,Department of Evolutionary Immunology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow 30387, Poland
| | - Nicolás M Suárez
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Lee PoTsang
- Department of Infectious and Parasitic Diseases, Immunology-Vaccinology, University of Liège, Liège B-4000, Belgium,Department of Aquaculture, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Hisao Saneyoshi
- Department of Medical Sciences, Division of Chemistry, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Yan Xu
- Department of Medical Sciences, Division of Chemistry, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Andrew J Davison
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Peter Tompa
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel, Brussel B-1050, Belgium
| | - Joel L Sussman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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17
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RNA Editing Enzyme ADAR1 Regulates METTL3 in an Editing Dependent Manner to Promote Breast Cancer Progression via METTL3/ARHGAP5/YTHDF1 Axis. Int J Mol Sci 2022; 23:ijms23179656. [PMID: 36077054 PMCID: PMC9456332 DOI: 10.3390/ijms23179656] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/15/2022] [Accepted: 08/23/2022] [Indexed: 11/29/2022] Open
Abstract
A-to-I RNA editing and m6A modification are two of the most prevalent types of RNA modifications controlling gene expression in mammals and play very important roles in tumorigenesis and tumor progression. However, the functional roles and correlations of these two RNA modifications remain to be further investigated in cancer. Herein, we show that ADAR1, an A-to-I RNA-editing enzyme, interacts with METTL3 and increases its protein level to promote the proliferation, migration and invasion of breast cancer cells through a mechanism connecting ADAR1, METTL3 and YTHDF1. We show that both ADAR1 and METTL3 are upregulated in breast cancer samples, and ADAR1 positively correlates with METTL3; ADAR1 edits METTL3 mRNA and changes its binding site to miR532-5p, leading to increased METTL3 protein, which further targets ARHGAP5, recognized by YTHDF1. Additionally, we show that loss of ADAR1 significantly inhibits breast cancer growth in vivo. Collectively, our findings identify the ADAR1–METTL3 axis as a novel, important pathway that connects A-to-I editing and m6A RNA modifications during breast cancer progression.
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18
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Abstract
Fibroblasts play an important role in the pathogenic mechanisms of several socially significant diseases, including pulmonary and cardiovascular fibrosis, liver cirrhosis, systemic sclerosis, progressive kidney disease. The alterations of the epitranscriptome, including more than 170 distinct post-transcriptional RNA modifications or editing events, justified their investigation as an important modulator of fibrosis. Recent development of high-throughput methods allows the identification of RNA modification sites and their mechanistic aspect in the fibrosis development. The most common RNA modification is methylation of N6-adenosine deposited by the m6A methyltransferase complex (METTL3/14/16, WTAP, KIAA1429, and RBM15/15B), erased by demethylases (FTO and ALKBH5), and recognized by binding proteins (e.g., YTHDF1/2/3, YTHDC1/2, IGF2BP1/2/3, etc.). Adenosine to inosine (A-to-I) RNA editing is another abundant editing event converting adenosine to inosine in double-stranded RNA regions through the action of the adenosine deaminase (ADAR) proteins. Last, but not least, 5-methylcytosine (m5C) regulates the stability and translation of mRNAs. All those RNA modifications have been observed in mRNA as well as the non-coding regions of pre-mRNA and ncRNAs, and demonstrate to be involved in fibrosis in different cellular and animal models. This Mini-Review focuses on the latest research on epitranscriptomic marks related to fibroblast biology and fibrosis as well as elucidates the future research directions in this context.
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Affiliation(s)
- Mirolyuba Ilieva
- Center for RNA Medicine, Department of Clinical Medicine, Aalborg University, Copenhagen SV, Denmark
| | - Shizuka Uchida
- Center for RNA Medicine, Department of Clinical Medicine, Aalborg University, Copenhagen SV, Denmark
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19
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Chan CP, Jin DY. Cytoplasmic RNA sensors and their interplay with RNA-binding partners in innate antiviral response: theme and variations. RNA (NEW YORK, N.Y.) 2022; 28:449-477. [PMID: 35031583 PMCID: PMC8925969 DOI: 10.1261/rna.079016.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sensing of pathogen-associated molecular patterns including viral RNA by innate immunity represents the first line of defense against viral infection. In addition to RIG-I-like receptors and NOD-like receptors, several other RNA sensors are known to mediate innate antiviral response in the cytoplasm. Double-stranded RNA-binding protein PACT interacts with prototypic RNA sensor RIG-I to facilitate its recognition of viral RNA and induction of host interferon response, but variations of this theme are seen when the functions of RNA sensors are modulated by other RNA-binding proteins to impinge on antiviral defense, proinflammatory cytokine production and cell death programs. Their discrete and coordinated actions are crucial to protect the host from infection. In this review, we will focus on cytoplasmic RNA sensors with an emphasis on their interplay with RNA-binding partners. Classical sensors such as RIG-I will be briefly reviewed. More attention will be brought to new insights on how RNA-binding partners of RNA sensors modulate innate RNA sensing and how viruses perturb the functions of RNA-binding partners.
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Affiliation(s)
- Chi-Ping Chan
- School of Biomedical Sciences and State Key Laboratory of Liver Research, Faculty of Medicine Building, Pokfulam, Hong Kong
| | - Dong-Yan Jin
- School of Biomedical Sciences and State Key Laboratory of Liver Research, Faculty of Medicine Building, Pokfulam, Hong Kong
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20
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Tong J, Zhang W, Chen Y, Yuan Q, Qin NN, Qu G. The Emerging Role of RNA Modifications in the Regulation of Antiviral Innate Immunity. Front Microbiol 2022; 13:845625. [PMID: 35185855 PMCID: PMC8851159 DOI: 10.3389/fmicb.2022.845625] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 01/10/2022] [Indexed: 12/15/2022] Open
Abstract
Posttranscriptional modifications have been implicated in regulation of nearly all biological aspects of cellular RNAs, from stability, translation, splicing, nuclear export to localization. Chemical modifications also have been revealed for virus derived RNAs several decades before, along with the potential of their regulatory roles in virus infection. Due to the dynamic changes of RNA modifications during virus infection, illustrating the mechanisms of RNA epigenetic regulations remains a challenge. Nevertheless, many studies have indicated that these RNA epigenetic marks may directly regulate virus infection through antiviral innate immune responses. The present review summarizes the impacts of important epigenetic marks on viral RNAs, including N6-methyladenosine (m6A), 5-methylcytidine (m5C), 2ʹ-O-methylation (2ʹ-O-Methyl), and a few uncanonical nucleotides (A-to-I editing, pseudouridine), on antiviral innate immunity and relevant signaling pathways, while highlighting the significance of antiviral innate immune responses during virus infection.
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Affiliation(s)
- Jie Tong
- College of Life Sciences, Hebei University, Baoding, China.,Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Wuchao Zhang
- College of Veterinary Medicine, Hebei Agricultural University, Baoding, China
| | - Yuran Chen
- College of Life Sciences, Hebei University, Baoding, China.,Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Qiaoling Yuan
- College of Life Sciences, Hebei University, Baoding, China.,Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Ning-Ning Qin
- College of Life Sciences, Hebei University, Baoding, China.,Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Guosheng Qu
- College of Life Sciences, Hebei University, Baoding, China.,Institute of Life Sciences and Green Development, Hebei University, Baoding, China
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21
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Aune TM, Tossberg JT, Heinrich RM, Porter KP, Crooke PS. Alu RNA Structural Features Modulate Immune Cell Activation and A-to-I Editing of Alu RNAs Is Diminished in Human Inflammatory Bowel Disease. Front Immunol 2022; 13:818023. [PMID: 35126398 PMCID: PMC8813004 DOI: 10.3389/fimmu.2022.818023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/04/2022] [Indexed: 12/12/2022] Open
Abstract
Alu retrotransposons belong to the class of short interspersed nuclear elements (SINEs). Alu RNA is abundant in cells and its repetitive structure forms double-stranded RNAs (dsRNA) that activate dsRNA sensors and trigger innate immune responses with significant pathological consequences. Mechanisms to prevent innate immune activation include deamination of adenosines to inosines in dsRNAs, referred to as A-to-I editing, degradation of Alu RNAs by endoribonucleases, and sequestration of Alu RNAs by RNA binding proteins. We have previously demonstrated that widespread loss of Alu RNA A-to-I editing is associated with diverse human diseases including viral (COVID-19, influenza) and autoimmune diseases (multiple sclerosis). Here we demonstrate loss of A-to-I editing in leukocytes is also associated with inflammatory bowel diseases. Our structure-function analysis demonstrates that ability to activate innate immune responses resides in the left arm of Alu RNA, requires a 5’-PPP, RIG-I is the major Alu dsRNA sensor, and A-to-I editing disrupts both structure and function. Further, edited Alu RNAs inhibit activity of unedited Alu RNAs. Altering Alu RNA nucleotide sequence increases biological activity. Two classes of Alu RNAs exist, one class stimulates both IRF and NF-kB transcriptional activity and a second class only stimulates IRF transcriptional activity. Thus, Alu RNAs play important roles in human disease but may also have therapeutic potential.
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Affiliation(s)
- Thomas M. Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
- *Correspondence: Thomas M. Aune,
| | - John T. Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Rachel M. Heinrich
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Krislyn P. Porter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Philip S. Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN, United States
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22
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Guo X, Liu S, Yan R, Nguyen V, Zenati M, Billiar TR, Wang Q. ADAR1 RNA editing regulates endothelial cell functions via the MDA-5 RNA sensing signaling pathway. Life Sci Alliance 2022; 5:5/3/e202101191. [PMID: 34969816 PMCID: PMC8739526 DOI: 10.26508/lsa.202101191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 11/24/2022] Open
Abstract
The RNA-sensing signaling pathway has been well studied as an essential antiviral mechanism of innate immunity. However, its role in non-infected cells is yet to be thoroughly characterized. Here, we demonstrated that the RNA sensing signaling pathway also reacts to the endogenous cellular RNAs in endothelial cells (ECs), and this reaction is regulated by the RNA-editing enzyme ADAR1. Cellular RNA sequencing analysis showed that EC RNAs endure extensive RNA editing, especially in the RNA transcripts of short interspersed nuclear elements. The EC-specific deletion of ADAR1 dramatically reduced the editing level on short interspersed nuclear element RNAs, resulting in newborn death in mice with damage evident in multiple organs. Genome-wide gene expression analysis revealed a prominent innate immune activation with a dramatically elevated expression of interferon-stimulated genes. However, blocking the RNA sensing signaling pathway by deletion of the cellular RNA receptor MDA-5 prevented interferon-stimulated gene expression and rescued the newborn mice from death. This evidence demonstrated that the RNA-editing/RNA-sensing signaling pathway dramatically modulates EC function, representing a novel molecular mechanism for the regulation of EC functions.
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Affiliation(s)
- Xinfeng Guo
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Silvia Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Pittsburgh Liver Research Center, University of Pittsburgh Medical Center (UPMC) and University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Rose Yan
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Vy Nguyen
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mazen Zenati
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Qingde Wang
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA .,Pittsburgh Liver Research Center, University of Pittsburgh Medical Center (UPMC) and University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,VA Pittsburgh Health System, Pittsburgh, PA, USA
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23
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Piontkivska H, Wales-McGrath B, Miyamoto M, Wayne ML. ADAR Editing in Viruses: An Evolutionary Force to Reckon with. Genome Biol Evol 2021; 13:evab240. [PMID: 34694399 PMCID: PMC8586724 DOI: 10.1093/gbe/evab240] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 02/06/2023] Open
Abstract
Adenosine Deaminases that Act on RNA (ADARs) are RNA editing enzymes that play a dynamic and nuanced role in regulating transcriptome and proteome diversity. This editing can be highly selective, affecting a specific site within a transcript, or nonselective, resulting in hyperediting. ADAR editing is important for regulating neural functions and autoimmunity, and has a key role in the innate immune response to viral infections, where editing can have a range of pro- or antiviral effects and can contribute to viral evolution. Here we examine the role of ADAR editing across a broad range of viral groups. We propose that the effect of ADAR editing on viral replication, whether pro- or antiviral, is better viewed as an axis rather than a binary, and that the specific position of a given virus on this axis is highly dependent on virus- and host-specific factors, and can change over the course of infection. However, more research needs to be devoted to understanding these dynamic factors and how they affect virus-ADAR interactions and viral evolution. Another area that warrants significant attention is the effect of virus-ADAR interactions on host-ADAR interactions, particularly in light of the crucial role of ADAR in regulating neural functions. Answering these questions will be essential to developing our understanding of the relationship between ADAR editing and viral infection. In turn, this will further our understanding of the effects of viruses such as SARS-CoV-2, as well as many others, and thereby influence our approach to treating these deadly diseases.
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Affiliation(s)
- Helen Piontkivska
- Department of Biological Sciences, Kent State University, Ohio, USA
- School of Biomedical Sciences, Kent State University, Ohio, USA
- Brain Health Research Institute, Kent State University, Ohio, USA
| | | | - Michael Miyamoto
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - Marta L Wayne
- Department of Biology, University of Florida, Gainesville, Florida, USA
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24
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Thompson MG, Sacco MT, Horner SM. How RNA modifications regulate the antiviral response. Immunol Rev 2021; 304:169-180. [PMID: 34405413 PMCID: PMC8616813 DOI: 10.1111/imr.13020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/25/2022]
Abstract
Induction of the antiviral innate immune response is highly regulated at the RNA level, particularly by RNA modifications. Recent discoveries have revealed how RNA modifications play key roles in cellular surveillance of nucleic acids and in controlling gene expression in response to viral infection. These modifications have emerged as being essential for a functional antiviral response and maintaining cellular homeostasis. In this review, we will highlight these and other discoveries that describe how the antiviral response is controlled by modifications to both viral and cellular RNA, focusing on how mRNA cap modifications, N6-methyladenosine, and RNA editing all contribute to coordinating an efficient response that properly controls viral infection.
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Affiliation(s)
- Matthew G Thompson
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Matthew T Sacco
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Stacy M Horner
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
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25
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Li S, Cao L, Zhang Z, Kuang M, Chen L, Zhao Y, Luo Y, Yin Z, You F. Cytosolic and nuclear recognition of virus and viral evasion. MOLECULAR BIOMEDICINE 2021; 2:30. [PMID: 35006471 PMCID: PMC8607372 DOI: 10.1186/s43556-021-00046-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 06/04/2021] [Indexed: 12/20/2022] Open
Abstract
The innate immune system is the first line of host defense, which responds rapidly to viral infection. Innate recognition of viruses is mediated by a set of pattern recognition receptors (PRRs) that sense viral genomic nucleic acids and/or replication intermediates. PRRs are mainly localized either to the endosomes, the plasma membrane or the cytoplasm. Recent evidence suggested that several proteins located in the nucleus could also act as viral sensors. In turn, these important elements are becoming the target for most viruses to evade host immune surveillance. In this review, we focus on the recent progress in the study of viral recognition and evasion.
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Affiliation(s)
- Siji Li
- Department of Clinical Laboratory, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Lili Cao
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Zeming Zhang
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Ming Kuang
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Luoying Chen
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Yingchi Zhao
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Yujie Luo
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China
| | - Zhinan Yin
- Zhuhai Institute of Translational Medicine, Zhuhai People's Hospital Affiliated with Jinan University, Jinan University, Zhuhai, Guangdong, China.,The Biomedical Translational Research Institute, Faculty of Medical Science, Jinan University, Guangzhou, Guangdong, China
| | - Fuping You
- Institute of Systems Biomedicine, Department of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking University Health Science Center, Beijing, China.
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Thoresen D, Wang W, Galls D, Guo R, Xu L, Pyle AM. The molecular mechanism of RIG-I activation and signaling. Immunol Rev 2021; 304:154-168. [PMID: 34514601 PMCID: PMC9293153 DOI: 10.1111/imr.13022] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022]
Abstract
RIG‐I is our first line of defense against RNA viruses, serving as a pattern recognition receptor that identifies molecular features common among dsRNA and ssRNA viral pathogens. RIG‐I is maintained in an inactive conformation as it samples the cellular space for pathogenic RNAs. Upon encounter with the triphosphorylated terminus of blunt‐ended viral RNA duplexes, the receptor changes conformation and releases a pair of signaling domains (CARDs) that are selectively modified and interact with an adapter protein (MAVS), thereby triggering a signaling cascade that stimulates transcription of interferons. Here, we describe the structural determinants for specific RIG‐I activation by viral RNA, and we describe the strategies by which RIG‐I remains inactivated in the presence of host RNAs. From the initial RNA triggering event to the final stages of interferon expression, we describe the experimental evidence underpinning our working knowledge of RIG‐I signaling. We draw parallels with behavior of related proteins MDA5 and LGP2, describing evolutionary implications of their collective surveillance of the cell. We conclude by describing the cell biology and immunological investigations that will be needed to accurately describe the role of RIG‐I in innate immunity and to provide the necessary foundation for pharmacological manipulation of this important receptor.
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Affiliation(s)
- Daniel Thoresen
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Wenshuai Wang
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Drew Galls
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Rong Guo
- Chemistry, Yale University, New Haven, CT, USA
| | - Ling Xu
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Anna Marie Pyle
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Chemistry, Yale University, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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27
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Aicardi-Goutières syndrome-associated mutation at ADAR1 gene locus activates innate immune response in mouse brain. J Neuroinflammation 2021; 18:169. [PMID: 34332594 PMCID: PMC8325854 DOI: 10.1186/s12974-021-02217-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/14/2021] [Indexed: 11/10/2022] Open
Abstract
Background Aicardi-Goutières syndrome (AGS) is a severe infant or juvenile-onset autoimmune disease characterized by inflammatory encephalopathy with an elevated type 1 interferon-stimulated gene (ISG) expression signature in the brain. Mutations in seven different protein-coding genes, all linked to DNA/RNA metabolism or sensing, have been identified in AGS patients, but none of them has been demonstrated to activate the IFN pathway in the brain of an animal. The molecular mechanism of inflammatory encephalopathy in AGS has not been well defined. Adenosine Deaminase Acting on RNA 1 (ADAR1) is one of the AGS-associated genes. It carries out A-to-I RNA editing that converts adenosine to inosine at double-stranded RNA regions. Whether an AGS-associated mutation in ADAR1 activates the IFN pathway and causes autoimmune pathogenesis in the brain is yet to be determined. Methods Mutations in the ADAR1 gene found in AGS patients were introduced into the mouse genome via CRISPR/Cas9 technology. Molecular activities of the specific p.K999N mutation were investigated by measuring the RNA editing levels in brain mRNA substrates of ADAR1 through RNA sequencing analysis. IFN pathway activation in the brain was assessed by measuring ISG expression at the mRNA and protein level through real-time RT-PCR and Luminex assays, respectively. The locations in the brain and neural cell types that express ISGs were determined by RNA in situ hybridization (ISH). Potential AGS-related brain morphologic changes were assessed with immunohistological analysis. Von Kossa and Luxol Fast Blue staining was performed on brain tissue to assess calcification and myelin, respectively. Results Mice bearing the ADAR1 p.K999N were viable though smaller than wild type sibs. RNA sequencing analysis of neuron-specific RNA substrates revealed altered RNA editing activities of the mutant ADAR1 protein. Mutant mice exhibited dramatically elevated levels of multiple ISGs within the brain. RNA ISH of brain sections showed selective activation of ISG expression in neurons and microglia in a patchy pattern. ISG-15 mRNA was upregulated in ADAR1 mutant brain neurons whereas CXCL10 mRNA was elevated in adjacent astroglia. No calcification or gliosis was detected in the mutant brain. Conclusions We demonstrated that an AGS-associated mutation in ADAR1, specifically the p.K999N mutation, activates the IFN pathway in the mouse brain. The ADAR1 p.K999N mutant mouse replicates aspects of the brain interferonopathy of AGS. Neurons and microglia express different ISGs. Basal ganglia calcification and leukodystrophy seen in AGS patients were not observed in K999N mutant mice, indicating that development of the full clinical phenotype may need an additional stimulus besides AGS mutations. This mutant mouse presents a robust tool for the investigation of AGS and neuroinflammatory diseases including the modeling of potential “second hits” that enable severe phenotypes of clinically variable diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02217-9.
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28
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Wang L, Sun Y, Song X, Wang Z, Zhang Y, Zhao Y, Peng X, Zhang X, Li C, Gao C, Li N, Gao L, Liang X, Wu Z, Ma C. Hepatitis B virus evades immune recognition via RNA adenosine deaminase ADAR1-mediated viral RNA editing in hepatocytes. Cell Mol Immunol 2021; 18:1871-1882. [PMID: 34253859 DOI: 10.1038/s41423-021-00729-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
HBV is considered as a "stealth" virus that does not invoke interferon (IFN) responses; however, the mechanisms by which HBV bypasses innate immune recognition are poorly understood. In this study, we identified adenosine deaminases acting on RNA 1 (ADAR1), which is a key factor in HBV evasion from IFN responses in hepatocytes. Mechanically, ADAR1 interacted with HBV RNAs and deaminated adenosine (A) to generate inosine (I), which disrupted host immune recognition and thus promoted HBV replication. Loss of ADAR1 or its deficient deaminase activity promoted IFN responses and inhibited HBV replication in hepatocytes, and blocking the IFN signaling pathways released the inhibition of HBV replication caused by ADAR1 deficiency. Notably, the HBV X protein (HBx) transcriptionally promoted ADAR1 expression to increase the threshold required to trigger intrinsic immune activation, which in turn enhanced HBV escape from immune recognition, leading to persistent infection. Supplementation with 8-azaadenosine, an ADAR1 inhibitor, efficiently enhanced liver immune activation to promote HBV clearance in vivo and in vitro. Taken together, our results delineate a molecular mechanism by which HBx promotes ADAR1-derived HBV immune escape and suggest a targeted therapeutic intervention for HBV infection.
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Affiliation(s)
- Liyuan Wang
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Yang Sun
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xiaojia Song
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Zehua Wang
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Yankun Zhang
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Ying Zhao
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xueqi Peng
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Xiaodong Zhang
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China
| | - Chunyang Li
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Key Laboratory of Infection and Immunity of Shandong Province, Shandong University, Jinan, China
| | - Chengjiang Gao
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Key Laboratory of Infection and Immunity of Shandong Province, Shandong University, Jinan, China.,Advanced Medical Research Institute, Shandong University, Jinan, China
| | - Nailin Li
- Clinical Pharmacology Group, Department of Medicine, Solna, Karolinska Institute, Stockholm, Sweden
| | - Lifen Gao
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Key Laboratory of Infection and Immunity of Shandong Province, Shandong University, Jinan, China
| | - Xiaohong Liang
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.,Key Laboratory of Infection and Immunity of Shandong Province, Shandong University, Jinan, China
| | - Zhuanchang Wu
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China. .,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China.
| | - Chunhong Ma
- Key Laboratory for Experimental Teratology, Ministry of Education, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China. .,Department of Immunology, School of Basic Medical Sciences, Cheeloo Medical College, Shandong University, Jinan, Shandong, China. .,Key Laboratory of Infection and Immunity of Shandong Province, Shandong University, Jinan, China. .,Advanced Medical Research Institute, Shandong University, Jinan, China.
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Guo Y, Hinchman MM, Lewandrowski M, Cross ST, Sutherland DM, Welsh OL, Dermody TS, Parker JSL. The multi-functional reovirus σ3 protein is a virulence factor that suppresses stress granule formation and is associated with myocardial injury. PLoS Pathog 2021; 17:e1009494. [PMID: 34237110 PMCID: PMC8291629 DOI: 10.1371/journal.ppat.1009494] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/20/2021] [Accepted: 06/21/2021] [Indexed: 11/19/2022] Open
Abstract
The mammalian orthoreovirus double-stranded (ds) RNA-binding protein σ3 is a multifunctional protein that promotes viral protein synthesis and facilitates viral entry and assembly. The dsRNA-binding capacity of σ3 correlates with its capacity to prevent dsRNA-mediated activation of protein kinase R (PKR). However, the effect of σ3 binding to dsRNA during viral infection is largely unknown. To identify functions of σ3 dsRNA-binding activity during reovirus infection, we engineered a panel of thirteen σ3 mutants and screened them for the capacity to bind dsRNA. Six mutants were defective in dsRNA binding, and mutations in these constructs cluster in a putative dsRNA-binding region on the surface of σ3. Two recombinant viruses expressing these σ3 dsRNA-binding mutants, K287T and R296T, display strikingly different phenotypes. In a cell-type dependent manner, K287T, but not R296T, replicates less efficiently than wild-type (WT) virus. In cells in which K287T virus demonstrates a replication deficit, PKR activation occurs and abundant stress granules (SGs) are formed at late times post-infection. In contrast, the R296T virus retains the capacity to suppress activation of PKR and does not mediate formation of SGs at late times post-infection. These findings indicate that σ3 inhibits PKR independently of its capacity to bind dsRNA. In infected mice, K287T produces lower viral titers in the spleen, liver, lungs, and heart relative to WT or R296T. Moreover, mice inoculated with WT or R296T viruses develop myocarditis, whereas those inoculated with K287T do not. Overall, our results indicate that σ3 functions to suppress PKR activation and subsequent SG formation during viral infection and that these functions correlate with virulence in mice. The σ3 protein of mammalian orthoreoviruses is a double-stranded RNA binding protein that has classically been thought to function by scavenging dsRNA within infected cells and thus prevents activation of cellular sensors of dsRNA such as the kinase PKR. Here we used mutagenesis to identify the region of σ3 responsible for binding dsRNA. Characterization of mutant viruses expressing σ3 proteins incapable of binding dsRNA show that contrary to expectation, dsRNA binding is not required for σ3-mediated inhibition of PKR. We show that one mutant virus (R296T) despite being deficient in dsRNA-binding can inhibit PKR and replicates similar to WT virus. In contrast, another mutant virus (K287T) that bears a σ3 protein that cannot prevent dsRNA-mediated activation of PKR induces stress granules in infected cells and replicates less efficiently than WT virus. In vivo, the K287T mutant is attenuated in its replication and unlike WT virus and the R296T mutant virus does not cause heart disease (myocarditis).
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Affiliation(s)
- Yingying Guo
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Meleana M. Hinchman
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Mercedes Lewandrowski
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Shaun T. Cross
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, United States of America
| | - Danica M. Sutherland
- Departments of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Olivia L. Welsh
- Departments of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Terence S. Dermody
- Departments of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Departments of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Institute of Infection, Inflammation, and Immunity, UPMC Children’s Hospital of Pittsburgh, Pennsylvania, United States of America
| | - John S. L. Parker
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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30
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Ding HY, Yang WY, Zhang LH, Li L, Xie F, Li HY, Chen XY, Tu Z, Li Y, Chen Y, Yang SY. 8-Chloro-Adenosine Inhibits Proliferation of MDA-MB-231 and SK-BR-3 Breast Cancer Cells by Regulating ADAR1/p53 Signaling Pathway. Cell Transplant 2021; 29:963689720958656. [PMID: 32907379 PMCID: PMC7784596 DOI: 10.1177/0963689720958656] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
8-Chloro-adenosine (8-Cl-Ado) has been shown to exhibit its antitumor activity by inducing apoptosis in human lung cancer A549 and H1299 cells or autophagy in chronic lymphocytic leukemia, and MDA-MB-231 and MCF-7 breast cancer cells. Adenosine deaminases acting on RNA 1 (ADAR1) is tightly associated with cancer development and progression. The aim of this study was to investigate the role of ADAR1 in the proliferation of MDA-MB-231 and SK-BR-3 breast cancer cell lines after 8-Cl-Ado exposure and its possible mechanisms. After 8-Cl-Ado exposure, CCK-8 assay was performed to determine the cell proliferation; flow cytometry was used to analyze the cell cycle profiles and apoptosis; and the protein levels of ADAR1, p53, p21, and cyclin D1 were measured by western blotting. The results showed that the cell proliferation was greatly inhibited, G1 cell cycle was arrested, and apoptosis was induced after 8-Cl-Ado exposure. ADAR1 and cyclin D1 protein levels were dramatically decreased, while p53 and p21 levels were increased after 8-Cl-Ado exposure. Moreover, the cell growth inhibition was rescued, apoptosis was reduced, and p53 and p21 protein levels were downregulated, while cyclin D1 was upregulated when cells were transfected with plasmids expressing ADAR1 proteins. More importantly, RNA-binding domain of ADAR1 is critical to the cell growth inhibition of breast cancer cells exposed to 8-Cl-Ado. Together, 8-Cl-Ado inhibits the cell proliferation, induces G1 phase arrest and apoptosis at least by targeting ADAR1/p53/p21 signaling pathway. The findings may provide us with insights into the role of ADAR1 in breast cancer progression and help us better understand the effects of 8-Cl-Ado in the treatment of breast cancer.
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Affiliation(s)
- Hong-Yue Ding
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Wan-Yong Yang
- Dongguan Waterfront Zone Central Hospital, Dongguan, Guangdong, China
| | - Li-Hong Zhang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Li Li
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Feng Xie
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Hua-Yi Li
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Xiao-Yu Chen
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Zeng Tu
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Yi Li
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
| | - Yong Chen
- Department of Radiology and Intervention, The General Hospital of Ningxia Medical University, Yinchuan, China
| | - Sheng-Yong Yang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China
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31
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Alluri RK, Li Z, McCrae KR. Stress Granule-Mediated Oxidized RNA Decay in P-Body: Hypothetical Role of ADAR1, Tudor-SN, and STAU1. Front Mol Biosci 2021; 8:672988. [PMID: 34150849 PMCID: PMC8211916 DOI: 10.3389/fmolb.2021.672988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Reactive oxygen species (ROS) generated under oxidative stress (OS) cause oxidative damage to RNA. Recent studies have suggested a role for oxidized RNA in several human disorders. Under the conditions of oxidative stress, mRNAs released from polysome dissociation accumulate and initiate stress granule (SG) assembly. SGs are highly enriched in mRNAs, containing inverted repeat (IR) Alus in 3′ UTRs, AU-rich elements, and RNA-binding proteins. SGs and processing bodies (P-bodies) transiently interact through a docking mechanism to allow the exchange of RNA species. However, the types of RNA species exchanged, and the mechanisms and outcomes of exchange are still unknown. Specialized RNA-binding proteins, including adenosine deaminase acting on RNA (ADAR1-p150), with an affinity toward inverted repeat Alus, and Tudor staphylococcal nuclease (Tudor-SN) are specifically recruited to SGs under OS along with an RNA transport protein, Staufen1 (STAU1), but their precise biochemical roles in SGs and SG/P-body docking are uncertain. Here, we critically review relevant literature and propose a hypothetical mechanism for the processing and decay of oxidized-RNA in SGs/P-bodies, as well as the role of ADAR1-p150, Tudor-SN, and STAU1.
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Affiliation(s)
- Ravi Kumar Alluri
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Zhongwei Li
- Biomedical Science Department, College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
| | - Keith R McCrae
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, United States
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32
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Crooke PS, Tossberg JT, Porter KP, Aune TM. Reduced A-to-I editing of endogenous Alu RNAs in lung after SARS-CoV-2 infection. CURRENT RESEARCH IN IMMUNOLOGY 2021; 2:52-59. [PMID: 33969287 PMCID: PMC8084883 DOI: 10.1016/j.crimmu.2021.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 12/16/2022] Open
Abstract
Due to potential severity of disease caused by SARS-CoV-2 infection, it is critical to understand both mechanisms of viral pathogenesis as well as diversity of host responses to infection. Reduced A-to-I editing of endogenous double-stranded RNAs (dsRNAs), as a result of inactivating mutations in ADAR, produces one form of Aicardi-Goutières Syndrome, with an immune response similar to an anti-viral response. By analyzing whole genome RNA sequencing data, we find reduced levels of A-to-I editing of endogenous Alu RNAs in normal human lung cells after infection by SARS-CoV-2 as well as in lung biopsies from patients with SARS-CoV-2 infections. Unedited Alu RNAs, as seen after infection, induce IRF and NF-kB transcriptional responses and downstream target genes, while edited Alu RNAs as seen in the absence of infection, fail to activate these transcriptional responses. Thus, decreased A-to-I editing may represent an important host response to SARS-CoV-2 infection.
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Affiliation(s)
- Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN, 37212, USA
| | - John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
| | - Krislyn P Porter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37212, USA.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37212, USA
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33
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Abstract
C6 deamination of adenosine (A) to inosine (I) in double-stranded RNA (dsRNA) is catalyzed by a family of enzymes known as ADARs (adenosine deaminases acting on RNA) encoded by three genes in mammals. Alternative promoters and splicing produce two ADAR1 proteins, an interferon-inducible cytoplasmic p150 and a constitutively expressed p110 that like ADAR2 is a nuclear enzyme. ADAR3 lacks deaminase activity. A-to-I editing occurs with both viral and cellular RNAs. Deamination activity is dependent on dsRNA substrate structure and regulatory RNA-binding proteins and ranges from highly site selective with hepatitis D RNA and glutamate receptor precursor messenger RNA (pre-mRNA) to hyperediting of measles virus and polyomavirus transcripts and cellular inverted Alu elements. Because I base-pairs as guanosine instead of A, editing can alter mRNA decoding, pre-mRNA splicing, and microRNA silencing. Editing also alters dsRNA structure, thereby suppressing innate immune responses including interferon production and action. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Christian K Pfaller
- Division of Veterinary Medicine, Paul-Ehrlich-Institute, Langen 63225, Germany
| | - Cyril X George
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA;
| | - Charles E Samuel
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA;
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34
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Crooke PS, Tossberg JT, Porter KP, Aune TM. Cutting Edge: Reduced Adenosine-to-Inosine Editing of Endogenous Alu RNAs in Severe COVID-19 Disease. THE JOURNAL OF IMMUNOLOGY 2021; 206:1691-1696. [PMID: 33782089 DOI: 10.4049/jimmunol.2001428] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/16/2021] [Indexed: 01/10/2023]
Abstract
Severe COVID-19 disease is associated with elevated inflammatory responses. One form of Aicardi-Goutières syndrome caused by inactivating mutations in ADAR results in reduced adenosine-to-inosine (A-to-I) editing of endogenous dsRNAs, induction of IFNs, IFN-stimulated genes, other inflammatory mediators, morbidity, and mortality. Alu elements, ∼10% of the human genome, are the most common A-to-I-editing sites. Using leukocyte whole-genome RNA-sequencing data, we found reduced A-to-I editing of Alu dsRNAs in patients with severe COVID-19 disease. Dendritic cells infected with COVID-19 also exhibit reduced A-to-I editing of Alu dsRNAs. Unedited Alu dsRNAs, but not edited Alu dsRNAs, are potent inducers of IRF and NF-κB transcriptional responses, IL6, IL8, and IFN-stimulated genes. Thus, decreased A-to-I editing that may lead to accumulation of unedited Alu dsRNAs and increased inflammatory responses is associated with severe COVID-19 disease.
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Affiliation(s)
- Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN 37212
| | - John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and
| | - Krislyn P Porter
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212; and .,Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN 37212
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Sadeq S, Al-Hashimi S, Cusack CM, Werner A. Endogenous Double-Stranded RNA. Noncoding RNA 2021; 7:15. [PMID: 33669629 PMCID: PMC7930956 DOI: 10.3390/ncrna7010015] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 02/07/2023] Open
Abstract
The birth of long non-coding RNAs (lncRNAs) is closely associated with the presence and activation of repetitive elements in the genome. The transcription of endogenous retroviruses as well as long and short interspersed elements is not only essential for evolving lncRNAs but is also a significant source of double-stranded RNA (dsRNA). From an lncRNA-centric point of view, the latter is a minor source of bother in the context of the entire cell; however, dsRNA is an essential threat. A viral infection is associated with cytoplasmic dsRNA, and endogenous RNA hybrids only differ from viral dsRNA by the 5' cap structure. Hence, a multi-layered defense network is in place to protect cells from viral infections but tolerates endogenous dsRNA structures. A first line of defense is established with compartmentalization; whereas endogenous dsRNA is found predominantly confined to the nucleus and the mitochondria, exogenous dsRNA reaches the cytoplasm. Here, various sensor proteins recognize features of dsRNA including the 5' phosphate group of viral RNAs or hybrids with a particular length but not specific nucleotide sequences. The sensors trigger cellular stress pathways and innate immunity via interferon signaling but also induce apoptosis via caspase activation. Because of its central role in viral recognition and immune activation, dsRNA sensing is implicated in autoimmune diseases and used to treat cancer.
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Affiliation(s)
| | | | | | - Andreas Werner
- Biosciences Institute, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (S.S.); (S.A.-H.); (C.M.C.)
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Abstract
The innate immune receptors in higher organisms have evolved to detect molecular signatures associated with pathogenic infection and trigger appropriate immune response. One common class of molecules utilized by the innate immune system for self vs. nonself discrimination is RNA, which is ironically present in all forms of life. To avoid self-RNA recognition, the innate immune sensors have evolved sophisticated discriminatory mechanisms that involve cellular RNA metabolic machineries. Posttranscriptional RNA modification and editing represent one such mechanism that allows cells to chemically tag the host RNAs as "self" and thus tolerate the abundant self-RNA molecules. In this chapter, we discuss recent advances in our understanding of the role of RNA editing/modification in the modulation of immune signaling pathways, and application of RNA editing/modification in RNA-based therapeutics and cancer immunotherapies.
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Erdmann EA, Mahapatra A, Mukherjee P, Yang B, Hundley HA. To protect and modify double-stranded RNA - the critical roles of ADARs in development, immunity and oncogenesis. Crit Rev Biochem Mol Biol 2020; 56:54-87. [PMID: 33356612 DOI: 10.1080/10409238.2020.1856768] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adenosine deaminases that act on RNA (ADARs) are present in all animals and function to both bind double-stranded RNA (dsRNA) and catalyze the deamination of adenosine (A) to inosine (I). As inosine is a biological mimic of guanosine, deamination by ADARs changes the genetic information in the RNA sequence and is commonly referred to as RNA editing. Millions of A-to-I editing events have been reported for metazoan transcriptomes, indicating that RNA editing is a widespread mechanism used to generate molecular and phenotypic diversity. Loss of ADARs results in lethality in mice and behavioral phenotypes in worm and fly model systems. Furthermore, alterations in RNA editing occur in over 35 human pathologies, including several neurological disorders, metabolic diseases, and cancers. In this review, a basic introduction to ADAR structure and target recognition will be provided before summarizing how ADARs affect the fate of cellular RNAs and how researchers are using this knowledge to engineer ADARs for personalized medicine. In addition, we will highlight the important roles of ADARs and RNA editing in innate immunity and cancer biology.
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Affiliation(s)
- Emily A Erdmann
- Department of Biology, Indiana University, Bloomington, IN, USA
| | | | - Priyanka Mukherjee
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, IN, USA
| | - Boyoon Yang
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Heather A Hundley
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington, IN, USA
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Tossberg JT, Heinrich RM, Farley VM, Crooke PS, Aune TM. Adenosine-to-Inosine RNA Editing of Alu Double-Stranded (ds)RNAs Is Markedly Decreased in Multiple Sclerosis and Unedited Alu dsRNAs Are Potent Activators of Proinflammatory Transcriptional Responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 205:2606-2617. [PMID: 33046502 PMCID: PMC7872017 DOI: 10.4049/jimmunol.2000384] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/14/2020] [Indexed: 12/27/2022]
Abstract
Sensors that detect dsRNA stimulate IFN responses as a defense against viral infection. IFN responses are also well documented in a variety of human autoimmune diseases, including relapsing-remitting multiple sclerosis (MS), in which increased IFN responses result from increased levels of double-stranded endogenous Alu RNAs. Mechanisms underlying increases in double-stranded Alu RNAs in MS are obscure. We find widespread loss of adenosine-to-inosine editing of Alu RNAs in MS. Unedited Alu RNAs are potent activators of both IFN and NF-κB responses via the dsRNA sensors, RIG-I, and TLR3. Minor editing of highly active Alu elements abrogates the ability to activate both transcriptional responses. Thus, adenosine-to-inosine editing may also represent an important defense against autoimmune diseases such as MS.
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Affiliation(s)
- John T Tossberg
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Rachel M Heinrich
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Virginia M Farley
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212
| | - Philip S Crooke
- Department of Mathematics, Vanderbilt University, Nashville, TN 37212; and
| | - Thomas M Aune
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212;
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37212
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Garcia LM, Hacker JL, Sase S, Adang L, Almad A. Glial cells in the driver seat of leukodystrophy pathogenesis. Neurobiol Dis 2020; 146:105087. [PMID: 32977022 DOI: 10.1016/j.nbd.2020.105087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 08/16/2020] [Accepted: 09/18/2020] [Indexed: 01/24/2023] Open
Abstract
Glia cells are often viewed as support cells in the central nervous system, but recent discoveries highlight their importance in physiological functions and in neurological diseases. Central to this are leukodystrophies, a group of progressive, neurogenetic disease affecting white matter pathology. In this review, we take a closer look at multiple leukodystrophies, classified based on the primary glial cell type that is affected. While white matter diseases involve oligodendrocyte and myelin loss, we discuss how astrocytes and microglia are affected and impinge on oligodendrocyte, myelin and axonal pathology. We provide an overview of the leukodystrophies covering their hallmark features, clinical phenotypes, diverse molecular pathways, and potential therapeutics for clinical trials. Glial cells are gaining momentum as cellular therapeutic targets for treatment of demyelinating diseases such as leukodystrophies, currently with no treatment options. Here, we bring the much needed attention to role of glia in leukodystrophies, an integral step towards furthering disease comprehension, understanding mechanisms and developing future therapeutics.
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Affiliation(s)
- Luis M Garcia
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Julia L Hacker
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Laura Adang
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Akshata Almad
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA.
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Vogel OA, Han J, Liang CY, Manicassamy S, Perez JT, Manicassamy B. The p150 Isoform of ADAR1 Blocks Sustained RLR signaling and Apoptosis during Influenza Virus Infection. PLoS Pathog 2020; 16:e1008842. [PMID: 32898178 PMCID: PMC7500621 DOI: 10.1371/journal.ppat.1008842] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/18/2020] [Accepted: 07/28/2020] [Indexed: 12/24/2022] Open
Abstract
Signaling through retinoic acid inducible gene I (RIG-I) like receptors (RLRs) is tightly regulated, with activation occurring upon sensing of viral nucleic acids, and suppression mediated by negative regulators. Under homeostatic conditions aberrant activation of melanoma differentiation-associated protein-5 (MDA5) is prevented through editing of endogenous dsRNA by RNA editing enzyme Adenosine Deaminase Acting on RNA (ADAR1). In addition, ADAR1 is postulated to play pro-viral and antiviral roles during viral infections that are dependent or independent of RNA editing activity. Here, we investigated the importance of ADAR1 isoforms in modulating influenza A virus (IAV) replication and revealed the opposing roles for ADAR1 isoforms, with the nuclear p110 isoform restricting versus the cytoplasmic p150 isoform promoting IAV replication. Importantly, we demonstrate that p150 is critical for preventing sustained RIG-I signaling, as p150 deficient cells showed increased IFN-β expression and apoptosis during IAV infection, independent of RNA editing activity. Taken together, the p150 isoform of ADAR1 is important for preventing sustained RIG-I induced IFN-β expression and apoptosis during viral infection.
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Affiliation(s)
- Olivia A. Vogel
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Julianna Han
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Chieh-Yu Liang
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Santhakumar Manicassamy
- Cancer Immunology, Inflammation, and Tolerance Program, GRU Cancer Center, Augusta University, Augusta, Georgia
| | - Jasmine T. Perez
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Balaji Manicassamy
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
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Zhou S, Yang C, Zhao F, Huang Y, Lin Y, Huang C, Ma X, Du J, Wang Y, Long G, He J, Liu C, Zhang P. Double-stranded RNA deaminase ADAR1 promotes the Zika virus replication by inhibiting the activation of protein kinase PKR. J Biol Chem 2019; 294:18168-18180. [PMID: 31636123 DOI: 10.1074/jbc.ra119.009113] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 10/03/2019] [Indexed: 12/14/2022] Open
Abstract
Zika virus (ZIKV) is a mosquito-borne flavivirus that has emerged as a threat to global health. The family of adenosine deaminases acting on dsRNA (ADARs) are human host factors important for the genetic diversity and evolution of ZIKV. Here, we further investigated the role of ADAR1 in ZIKV replication by utilizing CRISPR/Cas9-based gene editing and RNAi-based gene knockdown techniques. Both ADAR1 knockout and knockdown significantly reduced ZIKV RNA synthesis, protein levels, and viral titers in several human cell lines. Trans-complementation with the full-length ADAR1 form p150 or the shorter form p110 lacking the Zα domain restored viral replication levels suppressed by the ADAR1 knockout. Moreover, we observed that the nuclear p110 form was redistributed to the cytoplasm in response to ZIKV infection. ADAR1 was not involved in viral entry but promoted viral protein translation by impairing ZIKV-induced activation of protein kinase regulated by dsRNA (PKR). Of note, the RNA-editing activity of ADAR1 was not required to promote ZIKV replication. We also found that the proviral role of ADAR1 was partially mediated through its ability to suppress IFN production and PKR activation. Our work identifies ADAR1 as a proviral factor involved in ZIKV replication, suggesting that ADAR1 could be a potential antiviral target.
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Affiliation(s)
- Shili Zhou
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Chao Yang
- Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Fanfan Zhao
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yanxia Huang
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Yuxia Lin
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Changbai Huang
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiaocao Ma
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Jingjie Du
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Yi Wang
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Gang Long
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Junfang He
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Chao Liu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China.
| | - Ping Zhang
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China.
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LYAR Suppresses Beta Interferon Induction by Targeting Phosphorylated Interferon Regulatory Factor 3. J Virol 2019; 93:JVI.00769-19. [PMID: 31413131 DOI: 10.1128/jvi.00769-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/08/2019] [Indexed: 01/08/2023] Open
Abstract
The innate immune response is vital for host defense and must be tightly controlled, but the mechanisms responsible for its negative regulation are not fully understood. The cell growth-regulating nucleolar protein LYAR was found to promote replication of multiple viruses in our previous study. Here, we report that LYAR acts as a negative regulator of innate immune responses. We found that LYAR expression is induced by beta interferon (IFN-β) during virus infection. Further studies showed that LYAR interacts with phosphorylated IFN regulatory factor 3 (IRF3) to impede the DNA binding capacity of IRF3, thereby suppressing the transcription of IFN-β and downstream IFN-stimulated genes (ISGs). In addition, LYAR inhibits nuclear factor-κB (NF-κB)-mediated expression of proinflammatory cytokines. In summary, our study reveals the mechanism of LYAR in modulating IFN-β-mediated innate immune responses by targeting phosphorylated IRF3, which not only helps us to better understand the mechanisms of LYAR-regulated virus replication but also uncovers a novel role of LYAR in host innate immunity.IMPORTANCE Type I interferon (IFN-I) plays a critical role in the antiviral innate immune responses that protect the host against virus infection. The negative regulators of IFN-I are important not only for fine-tuning the antiviral responses to pathogens but also for preventing excessive inflammation. Identification of negative regulators and study of their modulation in innate immune responses will lead to new strategies for the control of both viral and inflammatory diseases. Here, we report for the first time that the cell growth-regulating nucleolar protein LYAR behaves as a repressor of host innate immune responses. We demonstrate that LYAR negatively regulates IFN-β-mediated immune responses by inhibiting the DNA binding ability of IFN regulatory factor 3 (IRF3). Our study reveals a common mechanism of LYAR in promoting different virus replication events and improves our knowledge of host negative regulation of innate immune responses.
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Lamers MM, van den Hoogen BG, Haagmans BL. ADAR1: "Editor-in-Chief" of Cytoplasmic Innate Immunity. Front Immunol 2019; 10:1763. [PMID: 31404141 PMCID: PMC6669771 DOI: 10.3389/fimmu.2019.01763] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022] Open
Abstract
Specialized receptors that recognize molecular patterns such as double stranded RNA duplexes-indicative of viral replication-are potent triggers of the innate immune system. Although their activation is beneficial during viral infection, RNA transcribed from endogenous mobile genetic elements may also act as ligands potentially causing autoimmunity. Recent advances indicate that the adenosine deaminase ADAR1 through RNA editing is involved in dampening the canonical antiviral RIG-I-like receptor-, PKR-, and OAS-RNAse L pathways to prevent autoimmunity. However, this inhibitory effect must be overcome during viral infections. In this review we discuss ADAR1's critical role in balancing immune activation and self-tolerance.
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Sinigaglia K, Wiatrek D, Khan A, Michalik D, Sambrani N, Sedmík J, Vukić D, O'Connell MA, Keegan LP. ADAR RNA editing in innate immune response phasing, in circadian clocks and in sleep. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:356-369. [DOI: 10.1016/j.bbagrm.2018.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/12/2018] [Accepted: 10/27/2018] [Indexed: 01/24/2023]
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Samuel CE. Adenosine deaminase acting on RNA (ADAR1), a suppressor of double-stranded RNA-triggered innate immune responses. J Biol Chem 2019; 294:1710-1720. [PMID: 30710018 PMCID: PMC6364763 DOI: 10.1074/jbc.tm118.004166] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Herbert "Herb" Tabor, who celebrated his 100th birthday this past year, served the Journal of Biological Chemistry as a member of the Editorial Board beginning in 1961, as an Associate Editor, and as Editor-in-Chief for 40 years, from 1971 until 2010. Among the many discoveries in biological chemistry during this period was the identification of RNA modification by C6 deamination of adenosine (A) to produce inosine (I) in double-stranded (ds) RNA. This posttranscriptional RNA modification by adenosine deamination, known as A-to-I RNA editing, diversifies the transcriptome and modulates the innate immune interferon response. A-to-I editing is catalyzed by a family of enzymes, adenosine deaminases acting on dsRNA (ADARs). The roles of A-to-I editing are varied and include effects on mRNA translation, pre-mRNA splicing, and micro-RNA silencing. Suppression of dsRNA-triggered induction and action of interferon, the cornerstone of innate immunity, has emerged as a key function of ADAR1 editing of self (cellular) and nonself (viral) dsRNAs. A-to-I modification of RNA is essential for the normal regulation of cellular processes. Dysregulation of A-to-I editing by ADAR1 can have profound consequences, ranging from effects on cell growth and development to autoimmune disorders.
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Affiliation(s)
- Charles E Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106.
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46
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RNA Modifications Modulate Activation of Innate Toll-Like Receptors. Genes (Basel) 2019; 10:genes10020092. [PMID: 30699960 PMCID: PMC6410116 DOI: 10.3390/genes10020092] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 12/13/2022] Open
Abstract
Self/foreign discrimination by the innate immune system depends on receptors that identify molecular patterns as associated to pathogens. Among others, this group includes endosomal Toll-like receptors, among which Toll-like receptors (TLR) 3, 7, 8, and 13 recognize and discriminate mammalian from microbial, potentially pathogen-associated, RNA. One of the discriminatory principles is the recognition of endogenous RNA modifications. Previous work has identified a couple of RNA modifications that impede activation of TLR signaling when incorporated in synthetic RNA molecules. Of note, work that is more recent has now shown that RNA modifications in their naturally occurring context can have immune-modulatory functions: Gm, a naturally occurring ribose-methylation within tRNA resulted in a lack of TLR7 stimulation and within a defined sequence context acted as antagonist. Additional RNA modifications with immune-modulatory functions have now been identified and recent work also indicates that RNA modifications within the context of whole prokaryotic or eukaryotic cells are indeed used for immune-modulation. This review will discuss new findings and developments in the field of immune-modulatory RNA modifications.
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47
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Xu LD, Öhman M. ADAR1 Editing and its Role in Cancer. Genes (Basel) 2018; 10:genes10010012. [PMID: 30585209 PMCID: PMC6356570 DOI: 10.3390/genes10010012] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/15/2018] [Accepted: 12/18/2018] [Indexed: 12/14/2022] Open
Abstract
It is well established that somatic mutations and escape of immune disruption are two essential factors in cancer initiation and progression. With an increasing number of second-generation sequencing data, transcriptomic modifications, so called RNA mutations, are emerging as significant forces that drive the transition from normal cell to malignant tumor, as well as providing tumor diversity to escape an immune attack. Editing of adenosine to inosine (A-to-I) in double-stranded RNA, catalyzed by adenosine deaminases acting on RNA (ADARs), is one dynamic modification that in a combinatorial manner can give rise to a very diverse transcriptome. Since the cell interprets inosine as guanosine (G), A-to-I editing can result in non-synonymous codon changes in transcripts as well as yield alternative splicing, but also affect targeting and disrupt maturation of microRNAs. ADAR-mediated RNA editing is essential for survival in mammals, however, its dysregulation causes aberrant editing of its targets that may lead to cancer. ADAR1 is commonly overexpressed, for instance in breast, lung, liver and esophageal cancer as well as in chronic myelogenous leukemia, where it promotes cancer progression. It is well known that ADAR1 regulates type I interferon (IFN) and its induced gene signature, which are known to operate as a significant barrier to tumor formation and progression. Adding to the complexity, ADAR1 expression is also regulated by IFN. In this review, we discussed the regulatory mechanisms of ADAR1 during tumorigenesis through aberrant editing of specific substrates. Additionally, we hypothesized that elevated ADAR1 levels play a role in suppressing an innate immunity response in cancer cells.
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Affiliation(s)
- Li-Di Xu
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91 Stockholm, Sweden.
| | - Marie Öhman
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91 Stockholm, Sweden.
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Gatsiou A, Vlachogiannis N, Lunella FF, Sachse M, Stellos K. Adenosine-to-Inosine RNA Editing in Health and Disease. Antioxid Redox Signal 2018; 29:846-863. [PMID: 28762759 DOI: 10.1089/ars.2017.7295] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SIGNIFICANCE Adenosine deamination in transcriptome results in the formation of inosine, a process that is called A-to-I RNA editing. Adenosine deamination is one of the more than 140 described RNA modifications. A-to-I RNA editing is catalyzed by adenosine deaminase acting on RNA (ADAR) enzymes and is essential for life. Recent Advances: Accumulating evidence supports a critical role of RNA editing in all aspects of RNA metabolism, including mRNA stability, splicing, nuclear export, and localization, as well as in recoding of proteins. These advances have significantly enhanced the understanding of mechanisms involved in development and in homeostasis. Furthermore, recent studies have indicated that RNA editing may be critically involved in cancer, aging, neurological, autoimmune, or cardiovascular diseases. CRITICAL ISSUES This review summarizes recent and significant achievements in the field of A-to-I RNA editing and discusses the importance and translational value of this RNA modification for gene expression, cellular, and organ function, as well as for disease development. FUTURE DIRECTIONS Elucidation of the exact RNA editing-dependent mechanisms in a single-nucleotide level may pave the path toward the development of novel therapeutic strategies focusing on modulation of ADAR function in the disease context. Antioxid. Redox Signal. 29, 846-863.
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Affiliation(s)
- Aikaterini Gatsiou
- 1 Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,2 Department of Biosciences, JW Goethe University Frankfurt , Frankfurt, Germany .,3 Department of Cardiology, Center of Internal Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,4 German Center of Cardiovascular Research (DZHK) , Rhein-Main Partner Site, Frankfurt, Germany
| | - Nikolaos Vlachogiannis
- 5 Rheumatology Unit, First Department of Propaedeutic Internal Medicine and Joint Rheumatology Academic Program, School of Medicine, National and Kapodistrian University of Athens , Athens, Greece
| | - Federica Francesca Lunella
- 1 Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,2 Department of Biosciences, JW Goethe University Frankfurt , Frankfurt, Germany .,3 Department of Cardiology, Center of Internal Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,4 German Center of Cardiovascular Research (DZHK) , Rhein-Main Partner Site, Frankfurt, Germany
| | - Marco Sachse
- 1 Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,3 Department of Cardiology, Center of Internal Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,4 German Center of Cardiovascular Research (DZHK) , Rhein-Main Partner Site, Frankfurt, Germany
| | - Konstantinos Stellos
- 1 Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,3 Department of Cardiology, Center of Internal Medicine, JW Goethe University Frankfurt , Frankfurt, Germany .,4 German Center of Cardiovascular Research (DZHK) , Rhein-Main Partner Site, Frankfurt, Germany
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49
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RIG-I-Like Receptor and Toll-Like Receptor Signaling Pathways Cause Aberrant Production of Inflammatory Cytokines/Chemokines in a Severe Fever with Thrombocytopenia Syndrome Virus Infection Mouse Model. J Virol 2018; 92:JVI.02246-17. [PMID: 29643242 DOI: 10.1128/jvi.02246-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 04/05/2018] [Indexed: 12/24/2022] Open
Abstract
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a tick-borne phlebovirus of the family Bunyaviridae, SFTS virus (SFTSV). Wild-type and type I interferon (IFN-I) receptor 1-deficient (IFNAR1-/-) mice have been established as nonlethal and lethal models of SFTSV infection, respectively. However, the mechanisms of IFN-I production in vivo and the factors causing the lethal disease are not well understood. Using bone marrow-chimeric mice, we found that IFN-I signaling in hematopoietic cells was essential for survival of lethal SFTSV infection. The disruption of IFN-I signaling in hematopoietic cells allowed an increase in viral loads in serum and produced an excess of multiple inflammatory cytokines and chemokines. The production of IFN-I and inflammatory cytokines was abolished by deletion of the signaling molecules IPS-1 and MyD88, essential for retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) and Toll-like receptor (TLR) signaling, respectively. However, IPS-1-/- MyD88-/- mice exhibited resistance to lethal SFTS with a moderate viral load in serum. Taken together, these results indicate that adequate activation of RLR and TLR signaling pathways under low to moderate levels of viremia contributed to survival through the IFN-I-dependent antiviral response during SFTSV infection, whereas overactivation of these signaling pathways under high levels of viremia resulted in abnormal induction of multiple inflammatory cytokines and chemokines, causing the lethal disease.IMPORTANCE SFTSV causes a severe infectious disease in humans, with a high fatality rate of 12 to 30%. To know the pathogenesis of the virus, we need to clarify the innate immune response as a front line of defense against viral infection. Here, we report that a lethal animal model showed abnormal induction of multiple inflammatory cytokines and chemokines by an uncontrolled innate immune response, which triggered the lethal SFTS. Our findings suggest a new strategy to target inflammatory humoral factors to treat patients with severe SFTS. Furthermore, this study may help the investigation of other tick-borne viruses.
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50
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Wang TT, Li ZG, Wang Q. The RNA-Specific Adenosine Deaminase ADAR1 Inhibits Human Protein Kinase R Activation. Viral Immunol 2018; 31:537-538. [PMID: 29883277 DOI: 10.1089/vim.2018.0056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tony T Wang
- 1 Center for Infectious Diseases , SRI International, Harrisonburg, Virginia
| | - Z Galvin Li
- 1 Center for Infectious Diseases , SRI International, Harrisonburg, Virginia
| | - Qingde Wang
- 2 Department of Surgery, University of Pittsburgh Medical Center , Pittsburgh, Pennsylvania
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