1
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Cai D, Chen SY. ADAR1 Is Essential for Smooth Muscle Homeostasis and Vascular Integrity. Cells 2024; 13:1257. [PMID: 39120288 PMCID: PMC11311430 DOI: 10.3390/cells13151257] [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: 06/05/2024] [Revised: 07/18/2024] [Accepted: 07/21/2024] [Indexed: 08/10/2024] Open
Abstract
Vascular smooth muscle cells (VSMCs) play a critical role in maintaining vascular integrity. VSMC dysfunction leads to numerous vascular diseases. Adenosine deaminases acting on RNA 1 (ADAR1), an RNA editing enzyme, has shown both RNA editing and non-editing functions. Global deletion of ADAR1 causes embryonic lethality, but the phenotype of homozygous ADAR1 deletion specifically in SMCs (ADAR1sm-/-) remains to be determined. By crossing ADAR1fl/fl mice with Myh11-CreERT2 mice followed by Tamoxifen induction, we found that ADAR1sm-/- leads to lethality in adult mice 14 days after the induction. Gross examination revealed extensive hemorrhage and detrimental vascular damage in different organs. Histological analyses revealed destruction of artery structural integrity with detachment of elastin laminae from VSMCs in ADAR1sm-/- aortas. Furthermore, ADAR1sm-/- resulted in severe VSMC apoptosis and mitochondrial dysfunction. RNA sequencing analyses of ADAR1sm-/- aorta segments demonstrated profound transcriptional alteration of genes impacting vascular health including a decrease in fibrillin-1 expression. More importantly, ADAR1sm-/- disrupts the elastin and fibrillin-1 interaction, a molecular event essential for artery structure. Our results indicate that ADAR1 plays a critical role in maintaining SMC survival and vascular stability and resilience.
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Affiliation(s)
- Dunpeng Cai
- Departments of Surgery, University of Missouri School of Medicine, Columbia, MO 65212, USA;
| | - Shi-You Chen
- Departments of Surgery, University of Missouri School of Medicine, Columbia, MO 65212, USA;
- The Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO 65201, USA
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2
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Quillin A, Arnould B, Knutson SD, Heemstra JM. Spatial Visualization of A-to-I Editing in Cells Using Endonuclease V Immunostaining Assay (EndoVIA). ACS CENTRAL SCIENCE 2024; 10:1396-1405. [PMID: 39071059 PMCID: PMC11273454 DOI: 10.1021/acscentsci.4c00444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024]
Abstract
Adenosine-to-inosine (A-to-I) editing is one of the most widespread post-transcriptional RNA modifications and is catalyzed by adenosine deaminases acting on RNA (ADARs). Varying across tissue types, A-to-I editing is essential for numerous biological functions, and dysregulation leads to autoimmune and neurological disorders, as well as cancer. Recent evidence has also revealed a link between RNA localization and A-to-I editing, yet understanding of the mechanisms underlying this relationship and its biological impact remains limited. Current methods rely primarily on in vitro characterization of extracted RNA that ultimately erases subcellular localization and cell-to-cell heterogeneity. To address these challenges, we have repurposed endonuclease V (EndoV), a magnesium-dependent ribonuclease that cleaves inosine bases in edited RNA, to selectively bind and detect A-to-I edited RNA in cells. The work herein introduces an endonuclease V immunostaining assay (EndoVIA), a workflow that provides spatial visualization of edited transcripts, enables rapid quantification of overall inosine abundance, and maps the landscape of A-to-I editing within the transcriptome at the nanoscopic level.
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Affiliation(s)
- Alexandria
L. Quillin
- Department
of Chemistry, Washington University in St.
Louis, St. Louis, Missouri 63130, United States
| | - Benoît Arnould
- Department
of Chemistry, Washington University in St.
Louis, St. Louis, Missouri 63130, United States
| | - Steve D. Knutson
- Merck
Center for Catalysis, Princeton University, Princeton, New Jersey 08544, United States
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Jennifer M. Heemstra
- Department
of Chemistry, Washington University in St.
Louis, St. Louis, Missouri 63130, United States
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3
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Gan WL, Ren X, Ng VHE, Ng L, Song Y, Tano V, Han J, An O, Xie J, Ng BYL, Tay DJT, Tang SJ, Shen H, Khare S, Chong KHC, Young DY, Wu B, DasGupta R, Chen L. Hepatocyte-macrophage crosstalk via the PGRN-EGFR axis modulates ADAR1-mediated immunity in the liver. Cell Rep 2024; 43:114400. [PMID: 38935501 DOI: 10.1016/j.celrep.2024.114400] [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: 10/05/2023] [Revised: 04/23/2024] [Accepted: 06/11/2024] [Indexed: 06/29/2024] Open
Abstract
ADAR1-mediated RNA editing establishes immune tolerance to endogenous double-stranded RNA (dsRNA) by preventing its sensing, primarily by MDA5. Although deleting Ifih1 (encoding MDA5) rescues embryonic lethality in ADAR1-deficient mice, they still experience early postnatal death, and removing other MDA5 signaling proteins does not yield the same rescue. Here, we show that ablation of MDA5 in a liver-specific Adar knockout (KO) murine model fails to rescue hepatic abnormalities caused by ADAR1 loss. Ifih1;Adar double KO (dKO) hepatocytes accumulate endogenous dsRNAs, leading to aberrant transition to a highly inflammatory state and recruitment of macrophages into dKO livers. Mechanistically, progranulin (PGRN) appears to mediate ADAR1 deficiency-induced liver pathology, promoting interferon signaling and attracting epidermal growth factor receptor (EGFR)+ macrophages into dKO liver, exacerbating hepatic inflammation. Notably, the PGRN-EGFR crosstalk communication and consequent immune responses are significantly repressed in ADAR1high tumors, revealing that pre-neoplastic or neoplastic cells can exploit ADAR1-dependent immune tolerance to facilitate immune evasion.
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Affiliation(s)
- Wei Liang Gan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Xi Ren
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Vanessa Hui En Ng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Larry Ng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Yangyang Song
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Vincent Tano
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Jian Han
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Omer An
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Jinghe Xie
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou, P.R. China
| | - Bryan Y L Ng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Daryl Jin Tai Tay
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Sze Jing Tang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Haoqing Shen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Shruti Khare
- Genome Institute of Singapore, Agency for Science Technology and Research, 60 Biopolis Street, Genome, #02-01, Singapore, Singapore
| | - Kelvin Han Chung Chong
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Dan Yock Young
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; Division of Gastroenterology and Hepatology, National University Health System, Singapore, Singapore
| | - Bin Wu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Ramanuj DasGupta
- Genome Institute of Singapore, Agency for Science Technology and Research, 60 Biopolis Street, Genome, #02-01, Singapore, Singapore
| | - Leilei Chen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore; Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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4
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Rehwinkel J, Mehdipour P. ADAR1: from basic mechanisms to inhibitors. Trends Cell Biol 2024:S0962-8924(24)00120-X. [PMID: 39030076 DOI: 10.1016/j.tcb.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 06/17/2024] [Accepted: 06/20/2024] [Indexed: 07/21/2024]
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) converts adenosine to inosine in double-stranded RNA (dsRNA) molecules, a process known as A-to-I editing. ADAR1 deficiency in humans and mice results in profound inflammatory diseases characterised by the spontaneous induction of innate immunity. In cells lacking ADAR1, unedited RNAs activate RNA sensors. These include melanoma differentiation-associated gene 5 (MDA5) that induces the expression of cytokines, particularly type I interferons (IFNs), protein kinase R (PKR), oligoadenylate synthase (OAS), and Z-DNA/RNA binding protein 1 (ZBP1). Immunogenic RNAs 'defused' by ADAR1 may include transcripts from repetitive elements and other long duplex RNAs. Here, we review these recent fundamental discoveries and discuss implications for human diseases. Some tumours depend on ADAR1 to escape immune surveillance, opening the possibility of unleashing anticancer therapies with ADAR1 inhibitors.
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Affiliation(s)
- Jan Rehwinkel
- Medical Research Council Translational Immune Discovery Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Parinaz Mehdipour
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
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5
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Zhang X, Yuan L, Zhang W, Zhang Y, Wu Q, Li C, Wu M, Huang Y. Liquid-liquid phase separation in diseases. MedComm (Beijing) 2024; 5:e640. [PMID: 39006762 PMCID: PMC11245632 DOI: 10.1002/mco2.640] [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: 12/25/2023] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 07/16/2024] Open
Abstract
Liquid-liquid phase separation (LLPS), an emerging biophysical phenomenon, can sequester molecules to implement physiological and pathological functions. LLPS implements the assembly of numerous membraneless chambers, including stress granules and P-bodies, containing RNA and protein. RNA-RNA and RNA-protein interactions play a critical role in LLPS. Scaffolding proteins, through multivalent interactions and external factors, support protein-RNA interaction networks to form condensates involved in a variety of diseases, particularly neurodegenerative diseases and cancer. Modulating LLPS phenomenon in multiple pathogenic proteins for the treatment of neurodegenerative diseases and cancer could present a promising direction, though recent advances in this area are limited. Here, we summarize in detail the complexity of LLPS in constructing signaling pathways and highlight the role of LLPS in neurodegenerative diseases and cancers. We also explore RNA modifications on LLPS to alter diseases progression because these modifications can influence LLPS of certain proteins or the formation of stress granules, and discuss the possibility of proper manipulation of LLPS process to restore cellular homeostasis or develop therapeutic drugs for the eradication of diseases. This review attempts to discuss potential therapeutic opportunities by elaborating on the connection between LLPS, RNA modification, and their roles in diseases.
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Affiliation(s)
- Xinyue Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Lin Yuan
- Laboratory of Research in Parkinson's Disease and Related Disorders Health Sciences Institute China Medical University Shenyang China
| | - Wanlu Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Yi Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Qun Wu
- Department of Pediatrics Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine Shanghai China
| | - Chunting Li
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Min Wu
- Wenzhou Institute University of Chinese Academy of Sciences Wenzhou Zhejiang China
- The Joint Research Center Affiliated Xiangshan Hospital of Wenzhou Medical University Ningbo China
| | - Yongye Huang
- College of Life and Health Sciences Northeastern University Shenyang China
- Key Laboratory of Bioresource Research and Development of Liaoning Province College of Life and Health Sciences Northeastern University Shenyang China
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6
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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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7
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Zawisza-Álvarez M, Peñuela-Melero J, Vegas E, Reverter F, Garcia-Fernàndez J, Herrera-Úbeda C. Exploring functional conservation in silico: a new machine learning approach to RNA-editing. Brief Bioinform 2024; 25:bbae332. [PMID: 38980372 PMCID: PMC11232462 DOI: 10.1093/bib/bbae332] [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: 04/19/2024] [Revised: 06/09/2024] [Accepted: 06/25/2024] [Indexed: 07/10/2024] Open
Abstract
Around 50 years ago, molecular biology opened the path to understand changes in forms, adaptations, complexity, or the basis of human diseases through myriads of reports on gene birth, gene duplication, gene expression regulation, and splicing regulation, among other relevant mechanisms behind gene function. Here, with the advent of big data and artificial intelligence (AI), we focus on an elusive and intriguing mechanism of gene function regulation, RNA editing, in which a single nucleotide from an RNA molecule is changed, with a remarkable impact in the increase of the complexity of the transcriptome and proteome. We present a new generation approach to assess the functional conservation of the RNA-editing targeting mechanism using two AI learning algorithms, random forest (RF) and bidirectional long short-term memory (biLSTM) neural networks with an attention layer. These algorithms, combined with RNA-editing data coming from databases and variant calling from same-individual RNA and DNA-seq experiments from different species, allowed us to predict RNA-editing events using both primary sequence and secondary structure. Then, we devised a method for assessing conservation or divergence in the molecular mechanisms of editing completely in silico: the cross-testing analysis. This novel method not only helps to understand the conservation of the editing mechanism through evolution but could set the basis for achieving a better understanding of the adenosine-targeting mechanism in other fields.
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Affiliation(s)
- Michał Zawisza-Álvarez
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
| | - Jesús Peñuela-Melero
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
| | - Esteban Vegas
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Calle Sinesio Delgado 4, 28029 Madrid, Spain
| | - Ferran Reverter
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
| | - Jordi Garcia-Fernàndez
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
| | - Carlos Herrera-Úbeda
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Digonal 643, 08028 Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain
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8
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Rey F, Esposito L, Maghraby E, Mauri A, Berardo C, Bonaventura E, Tonduti D, Carelli S, Cereda C. Role of epigenetics and alterations in RNA metabolism in leukodystrophies. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1854. [PMID: 38831585 DOI: 10.1002/wrna.1854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 06/05/2024]
Abstract
Leukodystrophies are a class of rare heterogeneous disorders which affect the white matter of the brain, ultimately leading to a disruption in brain development and a damaging effect on cognitive, motor and social-communicative development. These disorders present a great clinical heterogeneity, along with a phenotypic overlap and this could be partially due to contributions from environmental stimuli. It is in this context that there is a great need to investigate what other factors may contribute to both disease insurgence and phenotypical heterogeneity, and novel evidence are raising the attention toward the study of epigenetics and transcription mechanisms that can influence the disease phenotype beyond genetics. Modulation in the epigenetics machinery including histone modifications, DNA methylation and non-coding RNAs dysregulation, could be crucial players in the development of these disorders, and moreover an aberrant RNA maturation process has been linked to leukodystrophies. Here, we provide an overview of these mechanisms hoping to supply a closer step toward the analysis of leukodystrophies not only as genetically determined but also with an added level of complexity where epigenetic dysregulation is of key relevance. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNA RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Federica Rey
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Letizia Esposito
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Erika Maghraby
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
- Department of Biology and Biotechnology "L. Spallanzani" (DBB), University of Pavia, Pavia, Italy
| | - Alessia Mauri
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Clarissa Berardo
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Eleonora Bonaventura
- Unit of Pediatric Neurology, COALA Center for Diagnosis and Treatment of Leukodystrophies, V. Buzzi Children's Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Davide Tonduti
- Unit of Pediatric Neurology, COALA Center for Diagnosis and Treatment of Leukodystrophies, V. Buzzi Children's Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Stephana Carelli
- Pediatric Clinical Research Center "Romeo ed Enrica Invernizzi," Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Cristina Cereda
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
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9
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Ashley CN, Broni E, Miller WA. ADAR Family Proteins: A Structural Review. Curr Issues Mol Biol 2024; 46:3919-3945. [PMID: 38785511 PMCID: PMC11120146 DOI: 10.3390/cimb46050243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
This review aims to highlight the structures of ADAR proteins that have been crucial in the discernment of their functions and are relevant to future therapeutic development. ADAR proteins can correct or diversify genetic information, underscoring their pivotal contribution to protein diversity and the sophistication of neuronal networks. ADAR proteins have numerous functions in RNA editing independent roles and through the mechanisms of A-I RNA editing that continue to be revealed. Provided is a detailed examination of the ADAR family members-ADAR1, ADAR2, and ADAR3-each characterized by distinct isoforms that offer both structural diversity and functional variability, significantly affecting RNA editing mechanisms and exhibiting tissue-specific regulatory patterns, highlighting their shared features, such as double-stranded RNA binding domains (dsRBD) and a catalytic deaminase domain (CDD). Moreover, it explores ADARs' extensive roles in immunity, RNA interference, and disease modulation, demonstrating their ambivalent nature in both the advancement and inhibition of diseases. Through this comprehensive analysis, the review seeks to underline the potential of targeting ADAR proteins in therapeutic strategies, urging continued investigation into their biological mechanisms and health implications.
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Affiliation(s)
- Carolyn N. Ashley
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA; (C.N.A.); (E.B.)
| | - Emmanuel Broni
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA; (C.N.A.); (E.B.)
| | - Whelton A. Miller
- Department of Medicine, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA; (C.N.A.); (E.B.)
- Department of Molecular Pharmacology & Neuroscience, Loyola University Medical Center, Loyola University Chicago, Maywood, IL 60153, USA
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10
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Jarmoskaite I, Li JB. Multifaceted roles of RNA editing enzyme ADAR1 in innate immunity. RNA (NEW YORK, N.Y.) 2024; 30:500-511. [PMID: 38531645 PMCID: PMC11019752 DOI: 10.1261/rna.079953.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/09/2024] [Indexed: 03/28/2024]
Abstract
Innate immunity must be tightly regulated to enable sensitive pathogen detection while averting autoimmunity triggered by pathogen-like host molecules. A hallmark of viral infection, double-stranded RNAs (dsRNAs) are also abundantly encoded in mammalian genomes, necessitating surveillance mechanisms to distinguish "self" from "nonself." ADAR1, an RNA editing enzyme, has emerged as an essential safeguard against dsRNA-induced autoimmunity. By converting adenosines to inosines (A-to-I) in long dsRNAs, ADAR1 covalently marks endogenous dsRNAs, thereby blocking the activation of the cytoplasmic dsRNA sensor MDA5. Moreover, beyond its editing function, ADAR1 binding to dsRNA impedes the activation of innate immune sensors PKR and ZBP1. Recent landmark studies underscore the utility of silencing ADAR1 for cancer immunotherapy, by exploiting the ADAR1-dependence developed by certain tumors to unleash an antitumor immune response. In this perspective, we summarize the genetic and mechanistic evidence for ADAR1's multipronged role in suppressing dsRNA-mediated autoimmunity and explore the evolving roles of ADAR1 as an immuno-oncology target.
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Affiliation(s)
- Inga Jarmoskaite
- Department of Genetics, Stanford University, Stanford, California 94305, USA
- AIRNA Corporation, Cambridge, Massachusetts 02142, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, California 94305, USA
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11
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de Reuver R, Maelfait J. Novel insights into double-stranded RNA-mediated immunopathology. Nat Rev Immunol 2024; 24:235-249. [PMID: 37752355 DOI: 10.1038/s41577-023-00940-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2023] [Indexed: 09/28/2023]
Abstract
Recent progress in human and mouse genetics has transformed our understanding of the molecular mechanisms by which recognition of self double-stranded RNA (self-dsRNA) causes immunopathology. Novel mouse models recapitulate loss-of-function mutations in the RNA editing enzyme ADAR1 that are found in patients with Aicardi-Goutières syndrome (AGS) - a monogenic inflammatory disease associated with increased levels of type I interferon. Extensive analyses of the genotype-phenotype relationships in these mice have now firmly established a causal relationship between increased intracellular concentrations of endogenous immunostimulatory dsRNA and type I interferon-driven immunopathology. Activation of the dsRNA-specific immune sensor MDA5 perpetuates the overproduction of type I interferons, and chronic engagement of the interferon-inducible innate immune receptors PKR and ZBP1 by dsRNA drives immunopathology by activating an integrated stress response or by inducing excessive cell death. Biochemical and genetic data support a role for the p150 isoform of ADAR1 in the cytosol in suppressing the spontaneous, pathological response to self-dsRNA.
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Affiliation(s)
- Richard de Reuver
- VIB-UGent Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jonathan Maelfait
- VIB-UGent Center for Inflammation Research, Ghent, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
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12
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Quillin AL, Arnould B, Knutson SD, Heemstra JM. Spatial visualization of A-to-I Editing in cells using Endonuclease V Immunostaining Assay (EndoVIA). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.04.583344. [PMID: 38496620 PMCID: PMC10942280 DOI: 10.1101/2024.03.04.583344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Adenosine-to-Inosine (A-to-I) editing is one of the most widespread post-transcriptional RNA modifications and is catalyzed by adenosine deaminases acting on RNA (ADARs). Varying across tissue types, A-to-I editing is essential for numerous biological functions and dysregulation leads to autoimmune and neurological disorders, as well as cancer. Recent evidence has also revealed a link between RNA localization and A-to-I editing, yet understanding of the mechanisms underlying this relationship and its biological impact remains limited. Current methods rely primarily on in vitro characterization of extracted RNA that ultimately erases subcellular localization and cell-to-cell heterogeneity. To address these challenges, we have repurposed Endonuclease V (EndoV), a magnesium dependent ribonuclease that cleaves inosine bases in edited RNA, to selectively bind and detect A-to-I edited RNA in cells. The work herein introduces Endonuclease V Immunostaining Assay (EndoVIA), a workflow that provides spatial visualization of edited transcripts, enables rapid quantification of overall inosine abundance, and maps the landscape of A-to-I editing within the transcriptome at the nanoscopic level.
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13
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Luca D, Lee S, Hirota K, Okabe Y, Uehori J, Izawa K, Lanz AL, Schütte V, Sivri B, Tsukamoto Y, Hauck F, Behrendt R, Roers A, Fujita T, Nishikomori R, Lee-Kirsch MA, Kato H. Aberrant RNA sensing in regulatory T cells causes systemic autoimmunity. SCIENCE ADVANCES 2024; 10:eadk0820. [PMID: 38427731 PMCID: PMC10906915 DOI: 10.1126/sciadv.adk0820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/29/2024] [Indexed: 03/03/2024]
Abstract
Chronic and aberrant nucleic acid sensing causes type I IFN-driven autoimmune diseases, designated type I interferonopathies. We found a significant reduction of regulatory T cells (Tregs) in patients with type I interferonopathies caused by mutations in ADAR1 or IFIH1 (encoding MDA5). We analyzed the underlying mechanisms using murine models and found that Treg-specific deletion of Adar1 caused peripheral Treg loss and scurfy-like lethal autoimmune disorders. Similarly, knock-in mice with Treg-specific expression of an MDA5 gain-of-function mutant caused apoptosis of peripheral Tregs and severe autoimmunity. Moreover, the impact of ADAR1 deficiency on Tregs is multifaceted, involving both MDA5 and PKR sensing. Together, our results highlight the dysregulation of Treg homeostasis by intrinsic aberrant RNA sensing as a potential determinant for type I interferonopathies.
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Affiliation(s)
- Domnica Luca
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Sumin Lee
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Laboratory of Regulatory Information, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Keiji Hirota
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
- Laboratory of Integrative Biological Science, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yasutaka Okabe
- Laboratory of Immune Homeostasis, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
- Center for Infectious Disease Education and Research, Osaka University, Osaka, Japan
| | - Junji Uehori
- Laboratory of Immunology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Kazushi Izawa
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Anna-Lisa Lanz
- Division of Pediatric Immunology and Rheumatology, Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
- Munich Centre for Rare Diseases (M-ZSE), University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Verena Schütte
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Burcu Sivri
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Yuta Tsukamoto
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Fabian Hauck
- Division of Pediatric Immunology and Rheumatology, Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
- Munich Centre for Rare Diseases (M-ZSE), University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Rayk Behrendt
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Axel Roers
- Institute of Immunology, University of Heidelberg, Heidelberg, Germany
| | - Takashi Fujita
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Laboratory of Regulatory Information, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Ryuta Nishikomori
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Japan
| | - Min Ae Lee-Kirsch
- Department of Pediatrics, University Hospital Carl Gustav Carus and Medical Faculty, Technische Universität Dresden, Dresden, Germany
- University Center for Rare Diseases, University Hospital Carl Gustav Carus and Medical Faculty, Technische Universität Dresden, Dresden, Germany
| | - Hiroki Kato
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
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14
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Levanon EY, Cohen-Fultheim R, Eisenberg E. In search of critical dsRNA targets of ADAR1. Trends Genet 2024; 40:250-259. [PMID: 38160061 DOI: 10.1016/j.tig.2023.12.002] [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: 09/28/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
Recent studies have underscored the pivotal role of adenosine-to-inosine RNA editing, catalyzed by ADAR1, in suppressing innate immune interferon responses triggered by cellular double-stranded RNA (dsRNA). However, the specific ADAR1 editing targets crucial for this regulatory function remain elusive. We review analyses of transcriptome-wide ADAR1 editing patterns and their evolutionary dynamics, which offer valuable insights into this unresolved query. The growing appreciation of the significance of immunogenic dsRNAs and their editing in inflammatory and autoimmune diseases and cancer calls for a more comprehensive understanding of dsRNA immunogenicity, which may promote our understanding of these diseases and open doors to therapeutic avenues.
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Affiliation(s)
- Erez Y Levanon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel.
| | - Roni Cohen-Fultheim
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv, University, Tel Aviv 6997801, Israel.
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15
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Zhang J, Jiang C, Wang Z, Fang B, He J, Li M. Investigation of the pathogenesis of ADAR1 gene in dyschromatosis symmetrica hereditaria. Exp Dermatol 2024; 33:e15031. [PMID: 38375898 DOI: 10.1111/exd.15031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/21/2024]
Abstract
The pathogenesis of dyschromatosis symmetrica hereditaria (DSH) has not been well defined. In this study, we sought to investigate the influence of the ADAR1 gene on DSH both in vitro and in vivo. Morpholino knockdown of adar1 in zebrafish produced phenotypes characterized by polarity changes, and abnormal migration and distribution of melanocytes. Differential expression of C-KIT and distinct patterns of apoptosis between hyperpigmented and hypopigmented areas in DSH patient were detected by means of immunohistochemical methods and TUNEL assays, respectively. This study revealed that adar1 knockdown in a zebrafish model resulted in abnormal migration and changes in the cell polarity of melanocytes, and provided novel insight into the mechanism of DSH pathogenesis.
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Affiliation(s)
- Jia Zhang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Chengyi Jiang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhen Wang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Biqing Fang
- Department of Dermatology, QuanZhou Women's and Children's Hospital, Quanzhou, China
| | - Jin He
- Department of Pediatric Orthopaedics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ming Li
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
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16
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Mueller F, Witteveldt J, Macias S. Antiviral Defence Mechanisms during Early Mammalian Development. Viruses 2024; 16:173. [PMID: 38399949 PMCID: PMC10891733 DOI: 10.3390/v16020173] [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: 12/14/2023] [Revised: 01/11/2024] [Accepted: 01/20/2024] [Indexed: 02/25/2024] Open
Abstract
The type-I interferon (IFN) response constitutes the major innate immune pathway against viruses in mammals. Despite its critical importance for antiviral defence, this pathway is inactive during early embryonic development. There seems to be an incompatibility between the IFN response and pluripotency, the ability of embryonic cells to develop into any cell type of an adult organism. Instead, pluripotent cells employ alternative ways to defend against viruses that are typically associated with safeguard mechanisms against transposable elements. The absence of an inducible IFN response in pluripotent cells and the constitutive activation of the alternative antiviral pathways have led to the hypothesis that embryonic cells are highly resistant to viruses. However, some findings challenge this interpretation. We have performed a meta-analysis that suggests that the susceptibility of pluripotent cells to viruses is directly correlated with the presence of receptors or co-receptors for viral adhesion and entry. These results challenge the current view of pluripotent cells as intrinsically resistant to infections and raise the fundamental question of why these cells have sacrificed the major antiviral defence pathway if this renders them susceptible to viruses.
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Affiliation(s)
- Felix Mueller
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, King’s Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK; (F.M.); (J.W.)
- Centre for Virus Research, MRC-University of Glasgow, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Jeroen Witteveldt
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, King’s Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK; (F.M.); (J.W.)
| | - Sara Macias
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, King’s Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK; (F.M.); (J.W.)
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17
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Jiao Y, Xu Y, Liu C, Miao R, Liu C, Wang Y, Liu J. The role of ADAR1 through and beyond its editing activity in cancer. Cell Commun Signal 2024; 22:42. [PMID: 38233935 PMCID: PMC10795376 DOI: 10.1186/s12964-023-01465-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/27/2023] [Indexed: 01/19/2024] Open
Abstract
Adenosine-to-inosine (A-to-I) editing of RNA, catalyzed by adenosine deaminase acting on RNA (ADAR) enzymes, is a prevalent RNA modification in mammals. It has been shown that A-to-I editing plays a critical role in multiple diseases, such as cardiovascular disease, neurological disorder, and particularly cancer. ADARs are the family of enzymes, including ADAR1, ADAR2, and ADAR3, that catalyze the occurrence of A-to-I editing. Notably, A-to-I editing is mainly catalyzed by ADAR1. Given the significance of A-to-I editing in disease development, it is important to unravel the complex roles of ADAR1 in cancer for the development of novel therapeutic interventions.In this review, we briefly describe the progress of research on A-to-I editing and ADARs in cancer, mainly focusing on the role of ADAR1 in cancer from both editing-dependent and independent perspectives. In addition, we also summarized the factors affecting the expression and editing activity of ADAR1 in cancer.
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Affiliation(s)
- Yue Jiao
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Yuqin Xu
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Chengbin Liu
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Rui Miao
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Chunyan Liu
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Yilong Wang
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China
| | - Jiao Liu
- School of Basic Medicine Sciences, Weifang Medical University, Weifang, 261053, China.
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18
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Cottrell KA, Andrews RJ, Bass BL. The competitive landscape of the dsRNA world. Mol Cell 2024; 84:107-119. [PMID: 38118451 PMCID: PMC10843539 DOI: 10.1016/j.molcel.2023.11.033] [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: 10/16/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/22/2023]
Abstract
The ability to sense and respond to infection is essential for life. Viral infection produces double-stranded RNAs (dsRNAs) that are sensed by proteins that recognize the structure of dsRNA. This structure-based recognition of viral dsRNA allows dsRNA sensors to recognize infection by many viruses, but it comes at a cost-the dsRNA sensors cannot always distinguish between "self" and "nonself" dsRNAs. "Self" RNAs often contain dsRNA regions, and not surprisingly, mechanisms have evolved to prevent aberrant activation of dsRNA sensors by "self" RNA. Here, we review current knowledge about the life of endogenous dsRNAs in mammals-the biosynthesis and processing of dsRNAs, the proteins they encounter, and their ultimate degradation. We highlight mechanisms that evolved to prevent aberrant dsRNA sensor activation and the importance of competition in the regulation of dsRNA sensors and other dsRNA-binding proteins.
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Affiliation(s)
- Kyle A Cottrell
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA.
| | - Ryan J Andrews
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Brenda L Bass
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.
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19
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Weng S, Yang X, Yu N, Wang PC, Xiong S, Ruan H. Harnessing ADAR-Mediated Site-Specific RNA Editing in Immune-Related Disease: Prediction and Therapeutic Implications. Int J Mol Sci 2023; 25:351. [PMID: 38203521 PMCID: PMC10779106 DOI: 10.3390/ijms25010351] [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: 10/31/2023] [Revised: 12/15/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
ADAR (Adenosine Deaminases Acting on RNA) proteins are a group of enzymes that play a vital role in RNA editing by converting adenosine to inosine in RNAs. This process is a frequent post-transcriptional event observed in metazoan transcripts. Recent studies indicate widespread dysregulation of ADAR-mediated RNA editing across many immune-related diseases, such as human cancer. We comprehensively review ADARs' function as pattern recognizers and their capability to contribute to mediating immune-related pathways. We also highlight the potential role of site-specific RNA editing in maintaining homeostasis and its relationship to various diseases, such as human cancers. More importantly, we summarize the latest cutting-edge computational approaches and data resources for predicting and analyzing RNA editing sites. Lastly, we cover the recent advancement in site-directed ADAR editing tool development. This review presents an up-to-date overview of ADAR-mediated RNA editing, how site-specific RNA editing could potentially impact disease pathology, and how they could be harnessed for therapeutic applications.
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Affiliation(s)
- Shenghui Weng
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
| | - Xinyi Yang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
| | - Nannan Yu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
| | - Peng-Cheng Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
| | - Sidong Xiong
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
| | - Hang Ruan
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, China; (S.W.); (P.-C.W.)
- MOE Key Laboratory of Geriatric Diseases and Immunology, Suzhou Medical College of Soochow University, Suzhou 215123, China
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20
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Merdler-Rabinowicz R, Gorelik D, Park J, Meydan C, Foox J, Karmon M, Roth H, Cohen-Fultheim R, Shohat-ophir G, Eisenberg E, Ruppin E, Mason C, Levanon E. Elevated A-to-I RNA editing in COVID-19 infected individuals. NAR Genom Bioinform 2023; 5:lqad092. [PMID: 37859800 PMCID: PMC10583280 DOI: 10.1093/nargab/lqad092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 08/29/2023] [Accepted: 09/29/2023] [Indexed: 10/21/2023] Open
Abstract
Given the current status of coronavirus disease 2019 (COVID-19) as a global pandemic, it is of high priority to gain a deeper understanding of the disease's development and how the virus impacts its host. Adenosine (A)-to-Inosine (I) RNA editing is a post-transcriptional modification, catalyzed by the ADAR family of enzymes, that can be considered part of the inherent cellular defense mechanism as it affects the innate immune response in a complex manner. It was previously reported that various viruses could interact with the host's ADAR enzymes, resulting in epigenetic changes both to the virus and the host. Here, we analyze RNA-seq of nasopharyngeal swab specimens as well as whole-blood samples of COVID-19 infected individuals and show a significant elevation in the global RNA editing activity in COVID-19 compared to healthy controls. We also detect specific coding sites that exhibit higher editing activity. We further show that the increment in editing activity during the disease is temporary and returns to baseline shortly after the symptomatic period. These significant epigenetic changes may contribute to the immune system response and affect adverse outcomes seen in post-viral cases.
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Affiliation(s)
- Rona Merdler-Rabinowicz
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- Cancer Data Science Lab, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
| | - David Gorelik
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
| | - Jiwoon Park
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, USA
| | - Cem Meydan
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Jonathan Foox
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
| | - Miriam Karmon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
| | - Hillel S Roth
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
| | - Roni Cohen-Fultheim
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
| | - Galit Shohat-ophir
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- Leslie and Susan Gonda Multidisciplinary Brain Research Center and The Nanotechnology Institute, Bar-Ilan University, Ramat Gan, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel Aviv, Israel
| | - Eytan Ruppin
- Cancer Data Science Lab, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Christopher E Mason
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
- Caryl and Israel Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY, USA
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY, USA
| | - Erez Y Levanon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar‐Ilan University, Ramat Gan, Israel
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21
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Keegan LP, Hajji K, O’Connell MA. Adenosine Deaminase Acting on RNA (ADAR) Enzymes: A Journey from Weird to Wondrous. Acc Chem Res 2023; 56:3165-3174. [PMID: 37906879 PMCID: PMC10666284 DOI: 10.1021/acs.accounts.3c00433] [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: 07/27/2023] [Indexed: 11/02/2023]
Abstract
The adenosine deaminase acting on RNA (ADAR) enzymes that catalyze the conversion of adenosine to inosine in double-stranded (ds)RNA are evolutionarily conserved and are essential for many biological functions including nervous system function, hematopoiesis, and innate immunity. Initially it was assumed that the wide-ranging biological roles of ADARs are due to inosine in mRNA being read as guanosine by the translational machinery, allowing incomplete RNA editing in a target codon to generate two different proteins from the same primary transcript. In humans, there are approximately seventy-six positions that undergo site-specific editing in tissues at greater than 20% efficiency that result in recoding. Many of these transcripts are expressed in the central nervous system (CNS) and edited by ADAR2. Exploiting mouse genetic models revealed that transgenic mice lacking the gene encoding Adar2 die within 3 weeks of birth. Therefore, the role of ADAR2 in generating protein diversity in the nervous system is clear, but why is ADAR RNA editing activity essential in other biological processes, particularly editing mainly involving ADAR1? ADAR1 edits human transcripts having embedded Alu element inverted repeats (AluIRs), but the link from this activity to innate immunity activation was elusive. Mice lacking the gene encoding Adar1 are embryonically lethal, and a major breakthrough was the discovery that the role of Adar1 in innate immunity is due to its ability to edit such repetitive element inverted repeats which have the ability to form dsRNA in transcripts. The presence of inosine prevents activation of the dsRNA sensor melanoma differentiation-associated protein 5 (Mda5). Thus, inosine helps the cell discriminate self from non-self RNA, acting like a barcode on mRNA. As innate immunity is key to many different biological processes, the basis for this widespread biological role of the ADAR1 enzyme became evident.Our group has been studying ADARs from the outset of research on these enzymes. In this Account, we give a historical perspective, moving from the initial purification of ADAR1 and ADAR2 and cloning of their encoding genes up to the current research focus in the field and what questions still remain to be addressed. We discuss the characterizations of the proteins, their localizations, posttranslational modifications, and dimerization, and how all of these affect their biological activities. Another aspect we explore is the use of mouse and Drosophila genetic models to study ADAR functions and how these were crucial in determining the biological functions of the ADAR proteins. Finally, we describe the severe consequences of rare mutations found in the human genes encoding ADAR1 and ADAR2.
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Affiliation(s)
- Liam P. Keegan
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
| | - Khadija Hajji
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
| | - Mary A. O’Connell
- CEITEC, Masaryk
University, Kamenice 735/5, E35, Brno 62500, Czechia
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22
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Hu SB, Heraud-Farlow J, Sun T, Liang Z, Goradia A, Taylor S, Walkley CR, Li JB. ADAR1p150 prevents MDA5 and PKR activation via distinct mechanisms to avert fatal autoinflammation. Mol Cell 2023; 83:3869-3884.e7. [PMID: 37797622 DOI: 10.1016/j.molcel.2023.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 07/14/2023] [Accepted: 09/12/2023] [Indexed: 10/07/2023]
Abstract
Effective immunity requires the innate immune system to distinguish foreign nucleic acids from cellular ones. Cellular double-stranded RNAs (dsRNAs) are edited by the RNA-editing enzyme ADAR1 to evade being recognized as viral dsRNA by cytoplasmic dsRNA sensors, including MDA5 and PKR. The loss of ADAR1-mediated RNA editing of cellular dsRNA activates MDA5. Additional RNA-editing-independent functions of ADAR1 have been proposed, but a specific mechanism has not been delineated. We now demonstrate that the loss of ADAR1-mediated RNA editing specifically activates MDA5, whereas loss of the cytoplasmic ADAR1p150 isoform or its dsRNA-binding activity enabled PKR activation. Deleting both MDA5 and PKR resulted in complete rescue of the embryonic lethality of Adar1p150-/- mice to adulthood, contrasting with the limited or no rescue by removing MDA5 or PKR alone. Our findings demonstrate that MDA5 and PKR are the primary in vivo effectors of fatal autoinflammation following the loss of ADAR1p150.
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Affiliation(s)
- Shi-Bin Hu
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Jacki Heraud-Farlow
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, VIC 3065, Australia
| | - Tao Sun
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Zhen Liang
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, VIC 3065, Australia
| | - Ankita Goradia
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Scott Taylor
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Carl R Walkley
- St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, VIC 3065, Australia.
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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23
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Dorrity TJ, Chung H. A tale of two pathways: Two distinct mechanisms of ADAR1 prevent fatal autoinflammation. Mol Cell 2023; 83:3760-3762. [PMID: 37922869 PMCID: PMC11056273 DOI: 10.1016/j.molcel.2023.10.005] [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: 10/11/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
In this issue, Hu and Heraud-Farlow et al.1 demonstrate that ADAR1 dsRNA editing and dsRNA binding activities are critical to repress MDA5 and PKR, respectively, and that PKR and MDA5 act in concert to induce fatality in ADAR1 KO mice.
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Affiliation(s)
- Tyler J Dorrity
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Hachung Chung
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA.
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24
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Cai D, Fraunfelder M, Fujise K, Chen SY. ADAR1 exacerbates ischemic brain injury via astrocyte-mediated neuron apoptosis. Redox Biol 2023; 67:102903. [PMID: 37801857 PMCID: PMC10570147 DOI: 10.1016/j.redox.2023.102903] [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: 09/04/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023] Open
Abstract
Astrocytes affect stroke outcomes by acquiring functionally dominant phenotypes. Understanding molecular mechanisms dictating astrocyte functional status after brain ischemia/reperfusion may reveal new therapeutic strategies. Adenosine deaminase acting on RNA (ADAR1), an RNA editing enzyme, is not normally expressed in astrocytes, but highly induced in astrocytes in ischemic stroke lesions. The expression of ADAR1 steeply increased from day 1 to day 7 after middle cerebral artery occlusion (MCAO) for 1 h followed by reperfusion. ADAR1 deficiency markedly ameliorated the volume of the cerebral infarction and neurological deficits as shown by the rotarod and cylinder tests, which was due to the reduction of the numbers of activated astrocytes and microglia. Surprisingly, ADAR1 was mainly expressed in astrocytes while only marginally in microglia. In primary cultured astrocytes, ADAR1 promoted astrocyte proliferation via phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Furthermore, ADAR1 deficiency inhibited brain cell apoptosis in mice with MCAO as well as in activated astrocyte-conditioned medium-induced neurons in vitro. It appeared that ADAR1 induces neuron apoptosis by secretion of IL-1β, IL-6 and TNF-α from astrocytes through the production of reactive oxygen species. These results indicated that ADAR1 is a novel regulator promoting the proliferation of the activated astrocytes following ischemic stroke, which produce various inflammatory cytokines, leading to neuron apoptosis and worsened ischemic stroke outcome.
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Affiliation(s)
- Dunpeng Cai
- Departments of Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Mikayla Fraunfelder
- Departments of Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Ken Fujise
- Harborview Medical Center, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Shi-You Chen
- Departments of Surgery, University of Missouri School of Medicine, Columbia, MO, USA; The Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA.
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25
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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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26
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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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27
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Datta R, Adamska JZ, Bhate A, Li JB. A-to-I RNA editing by ADAR and its therapeutic applications: From viral infections to cancer immunotherapy. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 15:e1817. [PMID: 37718249 PMCID: PMC10947335 DOI: 10.1002/wrna.1817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
ADAR deaminases catalyze adenosine-to-inosine (A-to-I) editing on double-stranded RNA (dsRNA) substrates that regulate an umbrella of biological processes. One of the two catalytically active ADAR enzymes, ADAR1, plays a major role in innate immune responses by suppression of RNA sensing pathways which are orchestrated through the ADAR1-dsRNA-MDA5 axis. Unedited immunogenic dsRNA substrates are potent ligands for the cellular sensor MDA5. Upon activation, MDA5 leads to the induction of interferons and expression of hundreds of interferon-stimulated genes with potent antiviral activity. In this way, ADAR1 acts as a gatekeeper of the RNA sensing pathway by striking a fine balance between innate antiviral responses and prevention of autoimmunity. Reduced editing of immunogenic dsRNA by ADAR1 is strongly linked to the development of common autoimmune and inflammatory diseases. In viral infections, ADAR1 exhibits both antiviral and proviral effects. This is modulated by both editing-dependent and editing-independent functions, such as PKR antagonism. Several A-to-I RNA editing events have been identified in viruses, including in the insidious viral pathogen, SARS-CoV-2 which regulates viral fitness and infectivity, and could play a role in shaping viral evolution. Furthermore, ADAR1 is an attractive target for immuno-oncology therapy. Overexpression of ADAR1 and increased dsRNA editing have been observed in several human cancers. Silencing ADAR1, especially in cancers that are refractory to immune checkpoint inhibitors, is a promising therapeutic strategy for cancer immunotherapy in conjunction with epigenetic therapy. The mechanistic understanding of dsRNA editing by ADAR1 and dsRNA sensing by MDA5 and PKR holds great potential for therapeutic applications. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Rohini Datta
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Julia Z Adamska
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Amruta Bhate
- 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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28
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Liang Z, Goradia A, Walkley CR, Heraud-Farlow JE. Generation of a new Adar1p150 -/- mouse demonstrates isoform-specific roles in embryonic development and adult homeostasis. RNA (NEW YORK, N.Y.) 2023; 29:1325-1338. [PMID: 37290963 PMCID: PMC10573302 DOI: 10.1261/rna.079509.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/09/2023] [Indexed: 06/10/2023]
Abstract
The RNA editing enzyme adenosine deaminase acting on RNA 1 (ADAR1) is an essential regulator of the innate immune response to both cellular and viral double-stranded RNA (dsRNA). Adenosine-to-inosine (A-to-I) editing by ADAR1 modifies the sequence and structure of endogenous dsRNA and masks it from the cytoplasmic dsRNA sensor melanoma differentiation-associated protein 5 (MDA5), preventing innate immune activation. Loss-of-function mutations in ADAR are associated with rare autoinflammatory disorders including Aicardi-Goutières syndrome (AGS), defined by a constitutive systemic up-regulation of type I interferon (IFN). The murine Adar gene encodes two protein isoforms with distinct functions: ADAR1p110 is constitutively expressed and localizes to the nucleus, whereas ADAR1p150 is primarily cytoplasmic and is inducible by IFN. Recent studies have demonstrated the critical requirement for ADAR1p150 to suppress innate immune activation by self dsRNAs. However, detailed in vivo characterization of the role of ADAR1p150 during development and in adult mice is lacking. We identified a new ADAR1p150-specific knockout mouse mutant based on a single nucleotide deletion that resulted in the loss of the ADAR1p150 protein without affecting ADAR1p110 expression. The Adar1p150 -/- died embryonically at E11.5-E12.5 accompanied by cell death in the fetal liver and an activated IFN response. Somatic loss of ADAR1p150 in adults was lethal and caused rapid hematopoietic failure, demonstrating an ongoing requirement for ADAR1p150 in vivo. The generation and characterization of this mouse model demonstrates the essential role of ADAR1p150 in vivo and provides a new tool for dissecting the functional differences between ADAR1 isoforms and their physiological contributions.
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Affiliation(s)
- Zhen Liang
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Ankita Goradia
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Carl R Walkley
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Jacki E Heraud-Farlow
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
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29
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Morales DR, Rennie S, Uchida S. Benchmarking RNA Editing Detection Tools. BIOTECH 2023; 12:56. [PMID: 37754200 PMCID: PMC10527054 DOI: 10.3390/biotech12030056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/16/2023] [Accepted: 08/23/2023] [Indexed: 09/28/2023] Open
Abstract
RNA, like DNA and proteins, can undergo modifications. To date, over 170 RNA modifications have been identified, leading to the emergence of a new research area known as epitranscriptomics. RNA editing is the most frequent RNA modification in mammalian transcriptomes, and two types have been identified: (1) the most frequent, adenosine to inosine (A-to-I); and (2) the less frequent, cysteine to uracil (C-to-U) RNA editing. Unlike other epitranscriptomic marks, RNA editing can be readily detected from RNA sequencing (RNA-seq) data without any chemical conversions of RNA before sequencing library preparation. Furthermore, analyzing RNA editing patterns from transcriptomic data provides an additional layer of information about the epitranscriptome. As the significance of epitranscriptomics, particularly RNA editing, gains recognition in various fields of biology and medicine, there is a growing interest in detecting RNA editing sites (RES) by analyzing RNA-seq data. To cope with this increased interest, several bioinformatic tools are available. However, each tool has its advantages and disadvantages, which makes the choice of the most appropriate tool for bench scientists and clinicians difficult. Here, we have benchmarked bioinformatic tools to detect RES from RNA-seq data. We provide a comprehensive view of each tool and its performance using previously published RNA-seq data to suggest recommendations on the most appropriate for utilization in future studies.
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Affiliation(s)
| | - Sarah Rennie
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark;
| | - Shizuka Uchida
- Center for RNA Medicine, Department of Clinical Medicine, Aalborg University, DK-2450 Copenhagen SV, Denmark
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30
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Chen J, Jin J, Jiang J, Wang Y. Adenosine deaminase acting on RNA 1 (ADAR1) as crucial regulators in cardiovascular diseases: structures, pathogenesis, and potential therapeutic approach. Front Pharmacol 2023; 14:1194884. [PMID: 37663249 PMCID: PMC10469703 DOI: 10.3389/fphar.2023.1194884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 07/11/2023] [Indexed: 09/05/2023] Open
Abstract
Cardiovascular diseases (CVDs) are a group of diseases that have a major impact on global health and are the leading cause of death. A large number of chemical base modifications in ribonucleic acid (RNA) are associated with cardiovascular diseases. A variety of ribonucleic acid modifications exist in cells, among which adenosine deaminase-dependent modification is one of the most common ribonucleic acid modifications. Adenosine deaminase acting on ribonucleic acid 1 (Adenosine deaminase acting on RNA 1) is a widely expressed double-stranded ribonucleic acid adenosine deaminase that forms inosine (A-to-I) by catalyzing the deamination of adenosine at specific sites of the target ribonucleic acid. In this review, we provide a comprehensive overview of the structure of Adenosine deaminase acting on RNA 1 and summarize the regulatory mechanisms of ADAR1-mediated ribonucleic acid editing in cardiovascular diseases, indicating Adenosine deaminase acting on RNA 1 as a promising therapeutic target in cardiovascular diseases.
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Affiliation(s)
- Jieying Chen
- Department of Cardiology ofThe Second Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, China
| | - Junyan Jin
- Department of Cardiology ofThe Second Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, China
- Cardiovascular Key Laboratory of Zhejiang Province, Hangzhou, China
| | - Jun Jiang
- Department of Cardiology ofThe Second Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, China
- Cardiovascular Key Laboratory of Zhejiang Province, Hangzhou, China
| | - Yaping Wang
- Department of Cardiology ofThe Second Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, China
- Cardiovascular Key Laboratory of Zhejiang Province, Hangzhou, China
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31
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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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32
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Chen ZB, He M, Li JYS, Shyy JYJ, Chien S. Epitranscriptional Regulation: From the Perspectives of Cardiovascular Bioengineering. Annu Rev Biomed Eng 2023; 25:157-184. [PMID: 36913673 DOI: 10.1146/annurev-bioeng-081922-021233] [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] [Indexed: 03/11/2023]
Abstract
The central dogma of gene expression involves DNA transcription to RNA and RNA translation into protein. As key intermediaries and modifiers, RNAs undergo various forms of modifications such as methylation, pseudouridylation, deamination, and hydroxylation. These modifications, termed epitranscriptional regulations, lead to functional changes in RNAs. Recent studies have demonstrated crucial roles for RNA modifications in gene translation, DNA damage response, and cell fate regulation. Epitranscriptional modifications play an essential role in development, mechanosensing, atherogenesis, and regeneration in the cardiovascular (CV) system, and their elucidation is critically important to understanding the molecular mechanisms underlying CV physiology and pathophysiology. This review aims at providing biomedical engineers with an overview of the epitranscriptome landscape, related key concepts, recent findings in epitranscriptional regulations, and tools for epitranscriptome analysis. The potential applications of this important field in biomedical engineering research are discussed.
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Affiliation(s)
- Zhen Bouman Chen
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, California, USA
| | - Ming He
- Department of Medicine, University of California, San Diego, La Jolla, California, USA;
| | - Julie Yi-Shuan Li
- Department of Bioengineering and Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, USA;
| | - John Y-J Shyy
- Department of Medicine, University of California, San Diego, La Jolla, California, USA;
| | - Shu Chien
- Department of Medicine, University of California, San Diego, La Jolla, California, USA;
- Department of Bioengineering and Institute of Engineering in Medicine, University of California, San Diego, La Jolla, California, USA;
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33
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Booth BJ, Nourreddine S, Katrekar D, Savva Y, Bose D, Long TJ, Huss DJ, Mali P. RNA editing: Expanding the potential of RNA therapeutics. Mol Ther 2023; 31:1533-1549. [PMID: 36620962 PMCID: PMC9824937 DOI: 10.1016/j.ymthe.2023.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/06/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
RNA therapeutics have had a tremendous impact on medicine, recently exemplified by the rapid development and deployment of mRNA vaccines to combat the COVID-19 pandemic. In addition, RNA-targeting drugs have been developed for diseases with significant unmet medical needs through selective mRNA knockdown or modulation of pre-mRNA splicing. Recently, RNA editing, particularly antisense RNA-guided adenosine deaminase acting on RNA (ADAR)-based programmable A-to-I editing, has emerged as a powerful tool to manipulate RNA to enable correction of disease-causing mutations and modulate gene expression and protein function. Beyond correcting pathogenic mutations, the technology is particularly well suited for therapeutic applications that require a transient pharmacodynamic effect, such as the treatment of acute pain, obesity, viral infection, and inflammation, where it would be undesirable to introduce permanent alterations to the genome. Furthermore, transient modulation of protein function, such as altering the active sites of enzymes or the interface of protein-protein interactions, opens the door to therapeutic avenues ranging from regenerative medicine to oncology. These emerging RNA-editing-based toolsets are poised to broadly impact biotechnology and therapeutic applications. Here, we review the emerging field of therapeutic RNA editing, highlight recent laboratory advancements, and discuss the key challenges on the path to clinical development.
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Affiliation(s)
| | - Sami Nourreddine
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | | | | | | | | | | | - Prashant Mali
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
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34
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Bellingrath JS, McClements ME, Fischer MD, MacLaren RE. Programmable RNA editing with endogenous ADAR enzymes - a feasible option for the treatment of inherited retinal disease? Front Mol Neurosci 2023; 16:1092913. [PMID: 37293541 PMCID: PMC10244592 DOI: 10.3389/fnmol.2023.1092913] [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: 11/08/2022] [Accepted: 04/27/2023] [Indexed: 06/10/2023] Open
Abstract
RNA editing holds great promise for the therapeutic correction of pathogenic, single nucleotide variants (SNV) in the human transcriptome since it does not risk creating permanent off-targets edits in the genome and has the potential for innovative delivery options. Adenine deaminases acting on RNA (ADAR) enzymes catalyse the most widespread form of posttranscriptional RNA editing in humans and their ability to hydrolytically deaminate adenosine to inosine in double stranded RNA (dsRNA) has been harnessed to change pathogenic single nucleotide variants (SNVs) in the human genome on a transcriptional level. Until now, the most promising target editing rates have been achieved by exogenous delivery of the catalytically active ADAR deaminase domain (ADARDD) fused to an RNA binding protein. While it has been shown that endogenous ADARs can be recruited to a defined target site with the sole help of an ADAR-recruiting guide RNA, thus freeing up packaging space, decreasing the chance of an immune response against a foreign protein, and decreasing transcriptome-wide off-target effects, this approach has been limited by a low editing efficiency. Through the recent development of novel circular ADAR-recruiting guide RNAs as well as the optimisation of ADAR-recruiting antisense oligonucleotides, RNA editing with endogenous ADAR is now showing promising target editing efficiency in vitro and in vivo. A target editing efficiency comparable to RNA editing with exogenous ADAR was shown both in wild-type and disease mouse models as well as in wild-type non-human primates (NHP) immediately following and up to 6 weeks after application. With these encouraging results, RNA editing with endogenous ADAR has the potential to present an attractive option for the treatment of inherited retinal diseases (IRDs), a field where gene replacement therapy has been established as safe and efficacious, but where an unmet need still exists for genes that exceed the packaging capacity of an adeno associated virus (AAV) or are expressed in more than one retinal isoform. This review aims to give an overview of the recent developments in the field of RNA editing with endogenous ADAR and assess its applicability for the field of treatment of IRD.
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Affiliation(s)
- Julia-Sophia Bellingrath
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - M. Dominik Fischer
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
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35
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Kleinova R, Rajendra V, Leuchtenberger AF, Lo Giudice C, Vesely C, Kapoor U, Tanzer A, Derdak S, Picardi E, Jantsch MF. The ADAR1 editome reveals drivers of editing-specificity for ADAR1-isoforms. Nucleic Acids Res 2023; 51:4191-4207. [PMID: 37026479 PMCID: PMC10201426 DOI: 10.1093/nar/gkad265] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 03/10/2023] [Accepted: 04/06/2023] [Indexed: 04/08/2023] Open
Abstract
Adenosine deaminase acting on RNA ADAR1 promotes A-to-I conversion in double-stranded and structured RNAs. ADAR1 has two isoforms transcribed from different promoters: cytoplasmic ADAR1p150 is interferon-inducible while ADAR1p110 is constitutively expressed and primarily localized in the nucleus. Mutations in ADAR1 cause Aicardi - Goutières syndrome (AGS), a severe autoinflammatory disease associated with aberrant IFN production. In mice, deletion of ADAR1 or the p150 isoform leads to embryonic lethality driven by overexpression of interferon-stimulated genes. This phenotype is rescued by deletion of the cytoplasmic dsRNA-sensor MDA5 indicating that the p150 isoform is indispensable and cannot be rescued by ADAR1p110. Nevertheless, editing sites uniquely targeted by ADAR1p150 remain elusive. Here, by transfection of ADAR1 isoforms into ADAR-less mouse cells we detect isoform-specific editing patterns. Using mutated ADAR variants, we test how intracellular localization and the presence of a Z-DNA binding domain-α affect editing preferences. These data show that ZBDα only minimally contributes to p150 editing-specificity while isoform-specific editing is primarily directed by the intracellular localization of ADAR1 isoforms. Our study is complemented by RIP-seq on human cells ectopically expressing tagged-ADAR1 isoforms. Both datasets reveal enrichment of intronic editing and binding by ADAR1p110 while ADAR1p150 preferentially binds and edits 3'UTRs.
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Affiliation(s)
- Renata Kleinova
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Vinod Rajendra
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Alina F Leuchtenberger
- Center for Integrative Bioinformatics Vienna (CIBIV) Max Perutz Labs, University of Vienna and Medical University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Claudio Lo Giudice
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, University Campus “Ernesto Quagliariello”, Via Orabona 4, Bari, Italy
| | - Cornelia Vesely
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Utkarsh Kapoor
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Andrea Tanzer
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
| | - Sophia Derdak
- Core Facilities Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria
| | - Ernesto Picardi
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, University Campus “Ernesto Quagliariello”, Via Orabona 4, Bari, Italy
- Institute of Biomembranes and Bioenergetics (IBBE), National Research Council (CNR), Via Amendola 122, Bari, Italy
| | - Michael F Jantsch
- Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria
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Liang Z, Chalk AM, Taylor S, Goradia A, Heraud‐Farlow JE, Walkley CR. The phenotype of the most common human ADAR1p150 Zα mutation P193A in mice is partially penetrant. EMBO Rep 2023; 24:e55835. [PMID: 36975179 PMCID: PMC10157378 DOI: 10.15252/embr.202255835] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/13/2023] [Accepted: 02/28/2023] [Indexed: 03/29/2023] Open
Abstract
ADAR1 -mediated A-to-I RNA editing is a self-/non-self-discrimination mechanism for cellular double-stranded RNAs. ADAR mutations are one cause of Aicardi-Goutières Syndrome, an inherited paediatric encephalopathy, classed as a "Type I interferonopathy." The most common ADAR1 mutation is a proline 193 alanine (p.P193A) mutation, mapping to the ADAR1p150 isoform-specific Zα domain. Here, we report the development of an independent murine P195A knock-in mouse, homologous to human P193A. The Adar1P195A/P195A mice are largely normal and the mutation is well tolerated. When the P195A mutation is compounded with an Adar1 null allele (Adar1P195A/- ), approximately half the animals are runted with a shortened lifespan while the remaining Adar1P195A/- animals are normal, contrasting with previous reports. The phenotype of the Adar1P195A/- animals is both associated with the parental genotype and partly non-genetic/environmental. Complementation with an editing-deficient ADAR1 (Adar1P195A/E861A ), or the loss of MDA5, rescues phenotypes in the Adar1P195A/- mice.
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Affiliation(s)
- Zhen Liang
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical SchoolUniversity of MelbourneFitzroyVic.Australia
| | - Alistair M Chalk
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical SchoolUniversity of MelbourneFitzroyVic.Australia
| | - Scott Taylor
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
| | - Ankita Goradia
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
| | - Jacki E Heraud‐Farlow
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical SchoolUniversity of MelbourneFitzroyVic.Australia
| | - Carl R Walkley
- St Vincent's Institute of Medical ResearchFitzroyVic.Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical SchoolUniversity of MelbourneFitzroyVic.Australia
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Gatsiou A, Tual-Chalot S, Napoli M, Ortega-Gomez A, Regen T, Badolia R, Cesarini V, Garcia-Gonzalez C, Chevre R, Ciliberti G, Silvestre-Roig C, Martini M, Hoffmann J, Hamouche R, Visker JR, Diakos N, Wietelmann A, Silvestris DA, Georgiopoulos G, Moshfegh A, Schneider A, Chen W, Guenther S, Backs J, Kwak S, Selzman CH, Stamatelopoulos K, Rose-John S, Trautwein C, Spyridopoulos I, Braun T, Waisman A, Gallo A, Drakos SG, Dimmeler S, Sperandio M, Soehnlein O, Stellos K. The RNA editor ADAR2 promotes immune cell trafficking by enhancing endothelial responses to interleukin-6 during sterile inflammation. Immunity 2023; 56:979-997.e11. [PMID: 37100060 DOI: 10.1016/j.immuni.2023.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 01/02/2023] [Accepted: 03/30/2023] [Indexed: 04/28/2023]
Abstract
Immune cell trafficking constitutes a fundamental component of immunological response to tissue injury, but the contribution of intrinsic RNA nucleotide modifications to this response remains elusive. We report that RNA editor ADAR2 exerts a tissue- and stress-specific regulation of endothelial responses to interleukin-6 (IL-6), which tightly controls leukocyte trafficking in IL-6-inflamed and ischemic tissues. Genetic ablation of ADAR2 from vascular endothelial cells diminished myeloid cell rolling and adhesion on vascular walls and reduced immune cell infiltration within ischemic tissues. ADAR2 was required in the endothelium for the expression of the IL-6 receptor subunit, IL-6 signal transducer (IL6ST; gp130), and subsequently, for IL-6 trans-signaling responses. ADAR2-induced adenosine-to-inosine RNA editing suppressed the Drosha-dependent primary microRNA processing, thereby overwriting the default endothelial transcriptional program to safeguard gp130 expression. This work demonstrates a role for ADAR2 epitranscriptional activity as a checkpoint in IL-6 trans-signaling and immune cell trafficking to sites of tissue injury.
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Affiliation(s)
- Aikaterini Gatsiou
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; RNA Metabolism and Vascular Inflammation Laboratory, Institute of Cardiovascular Regeneration and Department of Cardiology, JW Goethe University Frankfurt, Frankfurt am Main, Germany.
| | - Simon Tual-Chalot
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Matteo Napoli
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Center for Experimental Medicine Biomedical Center (BMC), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Almudena Ortega-Gomez
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany
| | - Tommy Regen
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Rachit Badolia
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Valeriana Cesarini
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Raphael Chevre
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany
| | - Giorgia Ciliberti
- Department of Cardiovascular Research, European Center for Angioscience (ECAS), Heidelberg University, Mannheim, Germany
| | - Carlos Silvestre-Roig
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany
| | - Maurizio Martini
- Fondazione Policlinico Universitario "A. Gemelli," IRCCS, UOC Anatomia Patologica, Rome, Italy; Istituto di Anatomia Patologica, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Jedrzej Hoffmann
- Department of Cardiology, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Rana Hamouche
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Joseph R Visker
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nikolaos Diakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Astrid Wietelmann
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Domenico Alessandro Silvestris
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Georgios Georgiopoulos
- Department of Clinical Therapeutics, Alexandra Hospital, National and Kapodistrian University of Athens Medical School, Athens, Greece; Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ali Moshfegh
- Kancera AB, Stockholm, Sweden; Department of Oncology and Pathology at Karolinska Institutet, Stockholm, Sweden
| | - Andre Schneider
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China; Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Stefan Guenther
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Johannes Backs
- Institute of Experimental Cardiology, University Hospital Heidelberg, Heidelberg, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Heidelberg/Mannheim Partner Site, Heidelberg and Mannheim, Germany
| | - Shin Kwak
- Department of Molecular Neuropathogenesis, Tokyo Medical University, Tokyo, Japan
| | - Craig H Selzman
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA; Division of Cardiothoracic Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Kimon Stamatelopoulos
- Department of Clinical Therapeutics, Alexandra Hospital, National and Kapodistrian University of Athens Medical School, Athens, Greece; Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Stefan Rose-John
- Institute of Biochemistry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Christian Trautwein
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Ioakim Spyridopoulos
- Translational Research Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Department of Cardiology, Freeman Hospital, Newcastle upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Thomas Braun
- Max-Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Angela Gallo
- Department of Pediatric Hematology/Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Stavros G Drakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT, USA; Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Stefanie Dimmeler
- Institute of Cardiovascular Regeneration, Center of Molecular Medicine, JW Goethe University Frankfurt, Frankfurt am Main, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Frankfurt Partner Site, Germany
| | - Markus Sperandio
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Center for Experimental Medicine Biomedical Center (BMC), Ludwig-Maximilians-Universität München, Munich, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Munich Heart Alliance Partner Site, Munich, Germany
| | - Oliver Soehnlein
- Institute for Cardiovascular Prevention (IPEK), LMU Munich Hospital, Munich, Germany; Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation, WWU Muenster, Muenster, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Munich Heart Alliance Partner Site, Munich, Germany; Department of Physiology and Pharmacology (FyFa), Karolinska Institutet, Stockholm, Sweden
| | - Konstantinos Stellos
- Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; RNA Metabolism and Vascular Inflammation Laboratory, Institute of Cardiovascular Regeneration and Department of Cardiology, JW Goethe University Frankfurt, Frankfurt am Main, Germany; Department of Cardiovascular Research, European Center for Angioscience (ECAS), Heidelberg University, Mannheim, Germany; German Centre for Cardiovascular Research (Deutsches Zentrum für Herz-Kreislauf-Forschung, DZHK), Heidelberg/Mannheim Partner Site, Heidelberg and Mannheim, Germany; Cardio-Pulmonary Institute (CPI), Frankfurt am Main, Germany.
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38
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Paget M, Cadena C, Ahmad S, Wang HT, Jordan TX, Kim E, Koo B, Lyons SM, Ivanov P, tenOever B, Mu X, Hur S. Stress granules are shock absorbers that prevent excessive innate immune responses to dsRNA. Mol Cell 2023; 83:1180-1196.e8. [PMID: 37028415 PMCID: PMC10170497 DOI: 10.1016/j.molcel.2023.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 09/08/2022] [Accepted: 03/08/2023] [Indexed: 04/09/2023]
Abstract
Proper defense against microbial infection depends on the controlled activation of the immune system. This is particularly important for the RIG-I-like receptors (RLRs), which recognize viral dsRNA and initiate antiviral innate immune responses with the potential of triggering systemic inflammation and immunopathology. Here, we show that stress granules (SGs), molecular condensates that form in response to various stresses including viral dsRNA, play key roles in the controlled activation of RLR signaling. Without the SG nucleators G3BP1/2 and UBAP2L, dsRNA triggers excessive inflammation and immune-mediated apoptosis. In addition to exogenous dsRNA, host-derived dsRNA generated in response to ADAR1 deficiency is also controlled by SG biology. Intriguingly, SGs can function beyond immune control by suppressing viral replication independently of the RLR pathway. These observations thus highlight the multi-functional nature of SGs as cellular "shock absorbers" that converge on protecting cell homeostasis by dampening both toxic immune response and viral replication.
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Affiliation(s)
- Max Paget
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Cristhian Cadena
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Sadeem Ahmad
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - Hai-Tao Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Tristan X Jordan
- Department of Microbiology, New York University, Grossman School of Medicine, New York, NY 10016, USA
| | - Ehyun Kim
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Beechui Koo
- Morrisey School of Arts and Science, Boston College, Boston, MA 02467, USA
| | - Shawn M Lyons
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Pavel Ivanov
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Benjamin tenOever
- Department of Microbiology, New York University, Grossman School of Medicine, New York, NY 10016, USA
| | - Xin Mu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Sun Hur
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
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39
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Abstract
Cardiovascular disease still remains the leading cause of morbidity and mortality worldwide. Current pharmacological or interventional treatments help to tackle symptoms and even reduce mortality, but cardiovascular disease cases continue to rise. The emergence of novel therapeutic strategies that precisely and efficiently combat cardiovascular disease is therefore deemed more essential than ever. RNA editing, the cell-intrinsic deamination of adenosine or cytidine RNA residues, changes the molecular identity of edited nucleotides, severely altering the fate of RNA molecules involved in key biological processes. The most common type of RNA editing is the deamination of adenosine residue to inosine (A-to-I), which is catalysed by adenosine deaminases acting on RNA (ADARs). Recent efforts have convincingly liaised RNA editing-based mechanisms to the pathophysiology of the cardiovascular system. In this review, we will briefly introduce the basic concepts of the RNA editing field of research. We will particularly focus our discussion on the therapeutic exploitation of RNA editing as a novel therapeutic tool as well as the future perspectives for its use in cardiovascular disease treatment.
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40
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Nakahama T, Kawahara Y. The RNA-editing enzyme ADAR1: a regulatory hub that tunes multiple dsRNA-sensing pathways. Int Immunol 2023; 35:123-133. [PMID: 36469491 DOI: 10.1093/intimm/dxac056] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that catalyzes adenosine-to-inosine conversions in double-stranded RNAs (dsRNAs). In mammals, ADAR1 is composed of two isoforms: a nuclear short p110 isoform and a cytoplasmic long p150 isoform. Whereas both isoforms contain right-handed dsRNA-binding and deaminase domains, ADAR1 p150 harbors a Zα domain that binds to left-handed dsRNAs, termed Z-RNAs. Myeloma differentiation-associated gene 5 (MDA5) sensing of endogenous dsRNAs as non-self leads to the induction of type I interferon (IFN)-stimulated genes, but recent studies revealed that ADAR1 p150-mediated RNA editing, but not ADAR1 p110, prevents this MDA5-mediated sensing. ADAR1 p150-specific RNA-editing sites are present and at least a Zα domain-Z-RNA interaction is required for this specificity. Mutations in the ADAR1 gene cause Aicardi-Goutières syndrome (AGS), an infant encephalopathy with type I IFN overproduction. Insertion of a point mutation in the Zα domain of the Adar1 gene induces AGS-like encephalopathy in mice, which is rescued by concurrent deletion of MDA5. This finding indicates that impaired ADAR1 p150-mediated RNA-editing is a mechanism underlying AGS caused by an ADAR1 mutation. ADAR1 p150 also prevents ZBP1 sensing of endogenous Z-RNA, which leads to programmed cell death, via the Zα domain and its RNA-editing activity. Furthermore, ADAR1 prevents protein kinase R (PKR) sensing of endogenous right-handed dsRNAs, which leads to translational shutdown and growth arrest. Thus, ADAR1 acts as a regulatory hub that blocks sensing of endogenous dsRNAs as non-self by multiple sensor proteins, both in RNA editing-dependent and -independent manners, and is a potential therapeutic target for diseases, especially cancer.
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Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Integrated Frontier Research for Medical Science Division and RNA Frontier Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research (CiDER), Osaka University, Suita, Osaka 565-0871, Japan
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41
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Karki R, Kanneganti TD. ADAR1 and ZBP1 in innate immunity, cell death, and disease. Trends Immunol 2023; 44:201-216. [PMID: 36710220 PMCID: PMC9974732 DOI: 10.1016/j.it.2023.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 12/28/2022] [Accepted: 01/04/2023] [Indexed: 01/28/2023]
Abstract
ADAR1 and ZBP1 are the only two mammalian proteins that contain Zα domains, which are thought to bind to nucleic acids in the Z-conformation. These two molecules are crucial in regulating diverse biological processes. While ADAR1-mediated RNA editing supports host survival and development, ZBP1-mediated immune responses provide host defense against infection and disease. Recent studies have expanded our understanding of the functions of ADAR1 and ZBP1 beyond their classical roles and established their fundamental regulation of innate immune responses, including NLRP3 inflammasome activation, inflammation, and cell death. Their roles in these processes have physiological impacts across development, infectious and inflammatory diseases, and cancer. In this review, we discuss the functions of ADAR1 and ZBP1 in regulating innate immune responses in development and disease.
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Affiliation(s)
- Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
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42
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Hu SB, Heraud-Farlow J, Sun T, Liang Z, Goradia A, Taylor S, Walkley CR, Li JB. ADAR1p150 Prevents MDA5 and PKR Activation via Distinct Mechanisms to Avert Fatal Autoinflammation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.25.525475. [PMID: 36747811 PMCID: PMC9900771 DOI: 10.1101/2023.01.25.525475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Effective immunity requires the innate immune system to distinguish foreign (non-self) nucleic acids from cellular (self) nucleic acids. Cellular double-stranded RNAs (dsRNAs) are edited by the RNA editing enzyme ADAR1 to prevent their dsRNA structure pattern being recognized as viral dsRNA by cytoplasmic dsRNA sensors including MDA5, PKR and ZBP1. A loss of ADAR1-mediated RNA editing of cellular dsRNA activates MDA5. However, additional RNA editing-independent functions of ADAR1 have been proposed, but a specific mechanism has not been delineated. We now demonstrate that the loss of ADAR1-mediated RNA editing specifically activates MDA5, while loss of the cytoplasmic ADAR1p150 isoform or its dsRNA binding activity enabled PKR activation. Deleting both MDA5 and PKR resulted in complete rescue of the embryonic lethality of Adar1p150 -/- mice to adulthood, contrasting with the limited or no rescue by removing MDA5, PKR or ZBP1 alone, demonstrating that this is a species conserved function of ADAR1p150. Our findings demonstrate that MDA5 and PKR are the primary in vivo effectors of fatal autoinflammation following the loss of ADAR1p150.
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Rupani DN, Thege FI, Chandra V, Rajaei H, Cowan RW, Wörmann SM, Le Roux O, Malaney P, Manning SL, Hashem J, Bailey-Lundberg J, Rhim AD, McAllister F. Adar1 deletion causes degeneration of the exocrine pancreas via Mavs-dependent interferon signaling. Development 2023; 150:dev201097. [PMID: 36458554 PMCID: PMC10110501 DOI: 10.1242/dev.201097] [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: 07/15/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022]
Abstract
Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-binding protein that deaminates adenosine (A) to inosine (I). A-to-I editing alters post-transcriptional RNA processing, making ADAR1 a crucial regulator of gene expression. Consequently, Adar1 has been implicated in organogenesis. To determine the role of Adar1 in pancreatic development and homeostasis, we conditionally deleted Adar1 from the murine pancreas (Ptf1aCre/+; Adar1Fl/Fl). The resulting mice had stunted growth, likely due to malabsorption associated with exocrine pancreatic insufficiency. Analyses of pancreata revealed ductal cell expansion, heightened interferon-stimulated gene expression and an increased influx of immune cells. Concurrent deletion of Adar1 and Mavs, a signaling protein implicated in the innate immune pathway, rescued the degenerative phenotype and resulted in normal pancreatic development. Taken together, our work suggests that the primary function of Adar1 in the pancreas is to prevent aberrant activation of the Mavs-mediated innate immune pathway, thereby maintaining pancreatic homeostasis.
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Affiliation(s)
- Dhwani N. Rupani
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Fredrik I. Thege
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Vidhi Chandra
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hajar Rajaei
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Robert W. Cowan
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Gastroenterology, Hepatology & Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sonja M. Wörmann
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Olivereen Le Roux
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Prerna Malaney
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sara L. Manning
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Gastroenterology, Hepatology & Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jack Hashem
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Gastroenterology, Hepatology & Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jennifer Bailey-Lundberg
- Department of Anesthesiology, Center for Perioperative Medicine, McGovern Medical School, The University of Texas Health Sciences Center, Houston, TX 77030, USA
- Center for Interventional Gastroenterology at UTHealth (iGUT), McGovern Medical School, Houston, TX 77030, USA
| | - Andrew D. Rhim
- Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Gastroenterology, Hepatology & Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Florencia McAllister
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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44
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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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Wang Y, Liu Y, Zhao Z, Wu X, Lin J, Li Y, Yan W, Wu Y, Shi Y, Wu X, Xue Y, He J, Liu S, Zhang X, Xu H, Tang Y, Yin S. The involvement of ADAR1 in chronic unpredictable stress-induced cognitive impairment by targeting DARPP-32 with miR-874-3p in BALB/c mice. Front Cell Dev Biol 2023; 11:919297. [PMID: 37123418 PMCID: PMC10132208 DOI: 10.3389/fcell.2023.919297] [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: 04/13/2022] [Accepted: 03/07/2023] [Indexed: 05/02/2023] Open
Abstract
Introduction: Chronic stress exposure is the main environmental factor leading to cognitive impairment, but the detailed molecular mechanism is still unclear. Adenosine Deaminase acting on double-stranded RNA1(ADAR1) is involved in the occurrence of chronic stress-induced cognitive impairment. In addition, dopamine and Adenosine 3'5'-monophosphate-regulated phospho-protein (DARPP-32) gene variation affects cognitive function. Therefore, we hypothesized that ADAR1 plays a key role in chronic stress-induced cognitive impairment by acting on DARPP-32. Methods: In this study, postnatal 21-day-old male BALB/c mice were exposed to chronic unpredictable stressors. After that, the mice were treated with ADAR1 inducer/inhibitor. The cognitive ability and cerebral DARPP-32 protein expression of BALB/c mice were evaluated. In order to explore the link between ADAR1 and DARPP-32, the effects of ADAR1 high/low expression on DARPP-32 protein expression in vitro were detected. Results: ADAR1 inducer alleviates cognitive impairment and recovers decreased DARPP-32 protein expression of the hippocampus and prefrontal cortex in BALB/c mice with chronic unpredictable stress exposure. In vivo and in vitro studies confirm the results predicted by bio-informatics; that is, ADAR1 affects DARPP-32 expression via miR-874-3p. Discussion: The results in this study demonstrate that ADAR1 affects the expression of DARPP-32 via miR-874-3p, which is involved in the molecular mechanism of pathogenesis in chronic unpredictable stress-induced cognitive impairment. The new findings of this study provide a new therapeutic strategy for the prevention and treatment of stress cognitive impairment from epigenetics.
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Affiliation(s)
- Yanfang Wang
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yingxin Liu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Ziwei Zhao
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Xinyu Wu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Jiabin Lin
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yufei Li
- National and Local Joint Engineering Research Center for Drug Research and Development of Neurodegenerative Diseases, Dalian, China
| | - Wei Yan
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yi Wu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yanfei Shi
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Xindi Wu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Ying Xue
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Jiaqian He
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Shuqi Liu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Xiaonan Zhang
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Hong Xu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yiyuan Tang
- College of Health Solutions, Phoenix, AZ, United States
| | - Shengming Yin
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
- *Correspondence: Shengming Yin,
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Abstract
RNA is not always a faithful copy of DNA. Advances in tools enabling the interrogation of the exact RNA sequence have permitted revision of how genetic information is transferred. We now know that RNA is a dynamic molecule, amenable to chemical modifications of its four canonical nucleotides by dedicated RNA-binding enzymes. The ever-expanding catalogue of identified RNA modifications in mammals has led to a burst of studies in the past 5 years that have explored the biological relevance of the RNA modifications, also known as epitranscriptome. These studies concluded that chemical modification of RNA nucleotides alters several properties of RNA molecules including sequence, secondary structure, RNA-protein interaction, localization and processing. Importantly, a plethora of cellular functions during development, homeostasis and disease are controlled by RNA modification enzymes. Understanding the regulatory interface between a single-nucleotide modification and cellular function will pave the way towards the development of novel diagnostic, prognostic and therapeutic tools for the management of diseases, including cardiovascular disease. In this Review, we use two well-studied and abundant RNA modifications - adenosine-to-inosine RNA editing and N6-methyladenosine RNA methylation - as examples on which to base the discussion about the current knowledge on installation or removal of RNA modifications, their effect on biological processes related to cardiovascular health and disease, and the potential for development and application of epitranscriptome-based prognostic, diagnostic and therapeutic tools for cardiovascular disease.
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Guo X, Steinman RA, Sheng Y, Cao G, Wiley CA, Wang Q. An AGS-associated mutation in ADAR1 catalytic domain results in early-onset and MDA5-dependent encephalopathy with IFN pathway activation in the brain. J Neuroinflammation 2022; 19:285. [PMID: 36457126 PMCID: PMC9714073 DOI: 10.1186/s12974-022-02646-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 11/15/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Aicardi-Goutières syndrome (AGS) is a severe neurodegenerative disease with clinical features of early-onset encephalopathy and progressive loss of intellectual abilities and motor control. Gene mutations in seven protein-coding genes have been found to be associated with AGS. However, the causative role of these mutations in the early-onset neuropathogenesis has not been demonstrated in animal models, and the mechanism of neurodegeneration of AGS remains ambiguous. METHODS Via CRISPR/Cas-9 technology, we established a mutant mouse model in which a genetic mutation found in AGS patients at the ADAR1 coding gene (Adar) loci was introduced into the mouse genome. A mouse model carrying double gene mutations encoding ADAR1 and MDA-5 was prepared using a breeding strategy. Phenotype, gene expression, RNA sequencing, innate immune pathway activation, and pathologic studies including RNA in situ hybridization (ISH) and immunohistochemistry were used for characterization of the mouse models to determine potential disease mechanisms. RESULTS We established a mouse model bearing a mutation in the catalytic domain of ADAR1, the D1113H mutation found in AGS patients. With this mouse model, we demonstrated a causative role of this mutation for the early-onset brain injuries in AGS and determined the signaling pathway underlying the neuropathogenesis. First, this mutation altered the RNA editing profile in neural transcripts and led to robust IFN-stimulated gene (ISG) expression in the brain. By ISH, the brains of mutant mice showed an unusual, multifocal increased expression of ISGs that was cell-type dependent. Early-onset astrocytosis and microgliosis and later stage calcification in the deep white matter areas were observed in the mutant mice. Brain ISG activation and neuroglial reaction were completely prevented in the Adar D1113H mutant mice by blocking RNA sensing through deletion of the cytosolic RNA receptor MDA-5. CONCLUSIONS The Adar D1113H mutation in the ADAR1 catalytic domain results in early-onset and MDA5-dependent encephalopathy with IFN pathway activation in the mouse brain.
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Affiliation(s)
- Xinfeng Guo
- Department of Surgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213 USA
| | - Richard A. Steinman
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Yi Sheng
- Magee Women Research Institute, University of Pittsburgh, Pittsburgh, PA USA
| | - Guodong Cao
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Clayton A. Wiley
- Department of Pathology, School of Medicine, University of Pittsburgh, Scaife Hall, 200 Lothrop Street, Pittsburgh, PA 15213 USA
| | - Qingde Wang
- Department of Surgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213 USA
- V.A. Pittsburgh Health System, Pittsburgh, PA USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA USA
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Granulosa Cell Specific Loss of Adar in Mice Delays Ovulation, Oocyte Maturation and Leads to Infertility. Int J Mol Sci 2022; 23:ijms232214001. [PMID: 36430478 PMCID: PMC9695778 DOI: 10.3390/ijms232214001] [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: 08/25/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Adenosine deaminases acting on RNA-(ADAR) comprise one family of RNA editing enzymes that specifically catalyze adenosine to inosine (A-to-I) editing. A granulosa cell (GC) specific Adar depleted mouse model [Adar flox/flox:Cyp19a1-Cre/+ (gcAdarKO)] was used to evaluate the role of ADAR1 during the periovulatory period. Loss of Adar in GCs led to failure to ovulate at 16 h post-hCG, delayed oocyte germinal vesicle breakdown and severe infertility. RNAseq analysis of GC collected from gcAdarKO and littermate control mice at 0 and 4 h post-hCG following a super-ovulatory dose of eCG (48 h), revealed minimal differences after eCG treatment alone (0 h), consistent with normal folliculogenesis observed histologically and uterine estrogenic responses. In contrast, 300 differential expressed genes (DEGs; >1.5-fold change and FDRP < 0.1) were altered at 4 h post-hCG. Ingenuity pathway analysis identified many downstream targets of estrogen and progesterone pathways, while multiple genes involved in inflammatory responses were upregulated in the gcAdarKO GCs. Temporal expression analysis of GCs at 0, 4, 8, and 12 h post-hCG of Ifi44, Ifit1, Ifit3b, and Oas1g and Ovgp1 confirmed upregulation of these inflammatory and interferon genes and downregulation of Ovgp1 a glycoprotein involved in oocyte zona pellucida stability. Thus, loss of ADAR1 in GCs leads to increased expression of inflammatory and interferon response genes which are temporally linked to ovulation failure, alterations in oocyte developmental progression and infertility.
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Tang Q. Z-nucleic acids: Uncovering the functions from past to present. Eur J Immunol 2022; 52:1700-1711. [PMID: 36165274 PMCID: PMC9827954 DOI: 10.1002/eji.202249968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/15/2022] [Accepted: 09/23/2022] [Indexed: 01/12/2023]
Abstract
Since Z-nucleic acid was identified in the 1970s, much is still unknown about its biological functions and nature in vivo. Recent studies on adenosine deaminase acting on RNA 1 (ADAR1) and Z-DNA-binding protein 1 (ZBP1) have highlighted its function in immune responses. Specifically, Z-RNAs, either endogenous or induced by viral infection, are sensed by ZBP1 and activate necroptosis. Z-RNAs act as the stimuli that induce innate immune responses through various pathways, including melanoma differentiation-associated protein 5 (MAD5)-mitochondrial antiviral-signaling protein (MAVS)-mediated type I IFN activation and proteinase kinase R (PKR)-dependent integrated stress response, and their immunostimulatory potential is curtailed by RNA editing conducted by ADAR1. Aberrant immune responses induced by Z-RNAs are associated with human diseases. They also induce pathogenesis in mice. Unlike Z-RNAs, the biological functions of Z-DNAs were barely studied, especially in mammals. Moreover, the origin or sequence preference of Z-nucleic acids requires further investigation. Such knowledge will expand our understanding of Z-nucleic acids, including from which genomic loci and under which circumstances they form, and the mechanisms by which they participate in the physiological activities. In this review, we provide insights in Z-nucleic acid research and highlight the unsolved puzzles.
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Affiliation(s)
- Qiannan Tang
- Shanghai Institute of ImmunologyDepartment of Immunology and MicrobiologyShanghai Jiao Tong University School of MedicineShanghaiChina,Centre for Immune‐Related Diseases at Shanghai Institute of ImmunologyRuijin Hospital, Shanghai Jiao Tong University School of MedicineShanghaiChina
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Xiang R, Liu Y, Fan L, Jiang B, Wang F. RNA adenosine deaminase (ADAR1) alleviates high-fat diet-induced nonalcoholic fatty liver disease by inhibiting NLRP3 inflammasome. J Transl Med 2022; 102:1088-1100. [PMID: 36775349 DOI: 10.1038/s41374-022-00805-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 04/13/2022] [Accepted: 05/06/2022] [Indexed: 12/26/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a chronic inflammatory disease in which nucleotide-binding domain of leucine-rich repeat protein 3 (NLRP3) inflammasome plays an important role. The present research was aimed to explore the protective function of ADAR1, an RNA editing enzyme, against inflammatory damages in high-fat diet (HFD)-induced NAFLD through inhibiting NLRP3 inflammasome and subsequent inflammation. A total of 30 patients with NAFLD were investigated, and ADAR1 mRNA expression in peripheral blood monocytes surveyed. The in vivo study used lentivirus to explore the function of ADAR1 overexpression in the HFD-induced mouse model of NAFLD. The in vitro study used lentivirus and siRNA to explore the function of ADAR1 on the NLRP3 inflammasome activation in THP-1 cells. Results shown that the ADAR1 expression was upregulated in NAFLD patients in comparison to healthy controls. In vivo, the upregulation of ADAR1 impaired NLRP3 inflammasome activation and alleviated liver disease in HFD mice in comparison to the control group. Moreover, ADAR1 overexpression attenuated NLRP3 inflammasome in lipopolysaccharide (LPS)+ palmitic acid (PA)-induced THP-1 cells, while ADAR1 knockdown increased the NLRP3 inflammasome activation. Furthermore, we speculated that c-Jun may participate in ADAR1's inhibition of NLRP3 inflammasome. Our results suggested that ADAR1 is a potential treatment target for NAFLD via regulating the activation of NLRP3 inflammasome.
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Affiliation(s)
- Rong Xiang
- The Endocrinology Department of the Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China.,Department of Cell Biology, School of Life Sciences, Central South University, Changsha, 410013, China.,Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, 410078, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Yuxing Liu
- The Endocrinology Department of the Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China.,Department of Cell Biology, School of Life Sciences, Central South University, Changsha, 410013, China
| | - Liangliang Fan
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, 410013, China.,Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, 410078, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Boyue Jiang
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, 410013, China
| | - Fang Wang
- The Endocrinology Department of the Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China. .,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China.
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