1
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Prakash P, Khodke P, Balasubramaniam M, Davids BO, Hollis T, Davis J, Kumbhar B, Dash C. Three prime repair exonuclease 1 preferentially degrades the integration-incompetent HIV-1 DNA through favorable kinetics, thermodynamic, structural, and conformational properties. J Biol Chem 2024; 300:107438. [PMID: 38838778 PMCID: PMC11259700 DOI: 10.1016/j.jbc.2024.107438] [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: 12/11/2023] [Revised: 05/17/2024] [Accepted: 05/24/2024] [Indexed: 06/07/2024] Open
Abstract
HIV-1 integration into the human genome is dependent on 3'-processing of the viral DNA. Recently, we reported that the cellular Three Prime Repair Exonuclease 1 (TREX1) enhances HIV-1 integration by degrading the unprocessed viral DNA, while the integration-competent 3'-processed DNA remained resistant. Here, we describe the mechanism by which the 3'-processed HIV-1 DNA resists TREX1-mediated degradation. Our kinetic studies revealed that the rate of cleavage (kcat) of the 3'-processed DNA was significantly lower (approximately 2-2.5-fold) than the unprocessed HIV-1 DNA by TREX1. The kcat values of human TREX1 for the processed U5 and U3 DNA substrates were 3.8 s-1 and 4.5 s-1, respectively. In contrast, the unprocessed U5 and U3 substrates were cleaved at 10.2 s-1 and 9.8 s-1, respectively. The efficiency of degradation (kcat/Km) of the 3'-processed DNA (U5-70.2 and U3-28.05 pM-1s-1) was also significantly lower than the unprocessed DNA (U5-103.1 and U3-65.3 pM-1s-1). Furthermore, the binding affinity (Kd) of TREX1 was markedly lower (∼2-fold) for the 3'-processed DNA than the unprocessed DNA. Molecular docking and dynamics studies revealed distinct conformational binding modes of TREX1 with the 3'-processed and unprocessed HIV-1 DNA. Particularly, the unprocessed DNA was favorably positioned in the active site with polar interactions with the catalytic residues of TREX1. Additionally, a stable complex was formed between TREX1 and the unprocessed DNA compared the 3'-processed DNA. These results pinpoint the mechanism by which TREX1 preferentially degrades the integration-incompetent HIV-1 DNA and reveal the unique structural and conformational properties of the integration-competent 3'-processed HIV-1 DNA.
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Affiliation(s)
- Prem Prakash
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA
| | - Purva Khodke
- Department of Biological Sciences, Sunandan Divatia School of Science, SVKM's NMIMS (Deemed-to-be-) University, Mumbai, Maharashtra, India
| | - Muthukumar Balasubramaniam
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA
| | - Benem-Orom Davids
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, New York, USA
| | - Thomas Hollis
- Department of Biochemistry and Center for Structural Biology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA
| | - Bajarang Kumbhar
- Department of Biological Sciences, Sunandan Divatia School of Science, SVKM's NMIMS (Deemed-to-be-) University, Mumbai, Maharashtra, India
| | - Chandravanu Dash
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA; Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA.
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2
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Zhou Z, Huang S, Fan F, Xu Y, Moore C, Li S, Han C. The multiple faces of cGAS-STING in antitumor immunity: prospects and challenges. MEDICAL REVIEW (2021) 2024; 4:173-191. [PMID: 38919400 PMCID: PMC11195429 DOI: 10.1515/mr-2023-0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/28/2024] [Indexed: 06/27/2024]
Abstract
As a key sensor of double-stranded DNA (dsDNA), cyclic GMP-AMP synthase (cGAS) detects cytosolic dsDNA and initiates the synthesis of 2'3' cyclic GMP-AMP (cGAMP) that activates the stimulator of interferon genes (STING). This finally promotes the production of type I interferons (IFN-I) that is crucial for bridging innate and adaptive immunity. Recent evidence show that several antitumor therapies, including radiotherapy (RT), chemotherapy, targeted therapies and immunotherapies, activate the cGAS-STING pathway to provoke the antitumor immunity. In the last decade, the development of STING agonists has been a major focus in both basic research and the pharmaceutical industry. However, up to now, none of STING agonists have been approved for clinical use. Considering the broad expression of STING in whole body and the direct lethal effect of STING agonists on immune cells in the draining lymph node (dLN), research on the optimal way to activate STING in tumor microenvironment (TME) appears to be a promising direction. Moreover, besides enhancing IFN-I signaling, the cGAS-STING pathway also plays roles in senescence, autophagy, apoptosis, mitotic arrest, and DNA repair, contributing to tumor development and metastasis. In this review, we summarize the recent advances on cGAS-STING pathway's response to antitumor therapies and the strategies involving this pathway for tumor treatment.
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Affiliation(s)
- Zheqi Zhou
- Peking University International Cancer Institute, Peking University Cancer Hospital and Institute, Health Science Center, Peking University, Beijing, China
| | - Sanling Huang
- Peking University International Cancer Institute, Peking University Cancer Hospital and Institute, Health Science Center, Peking University, Beijing, China
| | - Fangying Fan
- Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China
| | - Yan Xu
- Peking University International Cancer Institute, Peking University Cancer Hospital and Institute, Health Science Center, Peking University, Beijing, China
| | - Casey Moore
- Departments of Immunology, Pathology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sirui Li
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chuanhui Han
- Peking University International Cancer Institute, Peking University Cancer Hospital and Institute, Health Science Center, Peking University, Beijing, China
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3
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Ramini D, Giuliani A, Kwiatkowska KM, Guescini M, Storci G, Mensà E, Recchioni R, Xumerle L, Zago E, Sabbatinelli J, Santi S, Garagnani P, Bonafè M, Olivieri F. Replicative senescence and high glucose induce the accrual of self-derived cytosolic nucleic acids in human endothelial cells. Cell Death Discov 2024; 10:184. [PMID: 38643201 PMCID: PMC11032409 DOI: 10.1038/s41420-024-01954-z] [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: 01/20/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/22/2024] Open
Abstract
Recent literature shows that loss of replicative ability and acquisition of a proinflammatory secretory phenotype in senescent cells is coupled with the build-in of nucleic acids in the cytoplasm. Its implication in human age-related diseases is under scrutiny. In human endothelial cells (ECs), we assessed the accumulation of intracellular nucleic acids during in vitro replicative senescence and after exposure to high glucose concentrations, which mimic an in vivo condition of hyperglycemia. We showed that exposure to high glucose induces senescent-like features in ECs, including telomere shortening and proinflammatory cytokine release, coupled with the accrual in the cytoplasm of telomeres, double-stranded DNA and RNA (dsDNA, dsRNA), as well as RNA:DNA hybrid molecules. Senescent ECs showed an activation of the dsRNA sensors RIG-I and MDA5 and of the DNA sensor TLR9, which was not paralleled by the involvement of the canonical (cGAS) and non-canonical (IFI16) activation of the STING pathway. Under high glucose conditions, only a sustained activation of TLR9 was observed. Notably, senescent cells exhibit increased proinflammatory cytokine (IL-1β, IL-6, IL-8) production without a detectable secretion of type I interferon (IFN), a phenomenon that can be explained, at least in part, by the accumulation of methyl-adenosine containing RNAs. At variance, exposure to exogenous nucleic acids enhances both IL-6 and IFN-β1 expression in senescent cells. This study highlights the accrual of cytoplasmic nucleic acids as a marker of senescence-related endothelial dysfunction, that may play a role in dysmetabolic age-related diseases.
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Affiliation(s)
- Deborah Ramini
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
| | - Angelica Giuliani
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | | | - Michele Guescini
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | - Gianluca Storci
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Emanuela Mensà
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | - Rina Recchioni
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
| | | | | | - Jacopo Sabbatinelli
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy.
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy.
| | - Spartaco Santi
- CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza" - Unit of Bologna, Bologna, Italy.
- IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Paolo Garagnani
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Massimiliano Bonafè
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
- IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy
| | - Fabiola Olivieri
- Clinic of Laboratory and Precision Medicine, IRCCS INRCA, Ancona, Italy
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
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4
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Prakash P, Khodke P, Balasubramaniam M, Davids BO, Hollis T, Davis J, Pandhare J, Kumbhar B, Dash C. Three Prime Repair Exonuclease 1 preferentially degrades the integration-incompetent HIV-1 DNA through favorable kinetics, thermodynamic, structural and conformational properties. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.585766. [PMID: 38562877 PMCID: PMC10983988 DOI: 10.1101/2024.03.19.585766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
HIV-1 integration into the human genome is dependent on 3'-processing of the reverse transcribed viral DNA. Recently, we reported that the cellular Three Prime Repair Exonuclease 1 (TREX1) enhances HIV-1 integration by degrading the unprocessed viral DNA, while the integration-competent 3'-processed DNA remained resistant. Here, we describe the mechanism by which the 3'-processed HIV-1 DNA resists TREX1-mediated degradation. Our kinetic studies revealed that the rate of cleavage (kcat) of the 3'-processed DNA was significantly lower than the unprocessed HIV-1 DNA by TREX1. The efficiency of degradation (kcat/KM) of the 3'-processed DNA was also significantly lower than the unprocessed DNA. Furthermore, the binding affinity (Kd) of TREX1 was markedly lower to the 3'-processed DNA compared to the unprocessed DNA. Molecular docking and dynamics studies revealed distinct conformational binding modes of TREX1 with the 3'-processed and unprocessed HIV-1 DNA. Particularly, the unprocessed DNA was favorably positioned in the active site with polar interactions with the catalytic residues of TREX1. Additionally, a stable complex was formed between TREX1 and the unprocessed DNA compared the 3'-processed DNA. These results pinpoint the biochemical mechanism by which TREX1 preferentially degrades the integration-incompetent HIV-1 DNA and reveal the unique structural and conformational properties of the integration-competent 3'-processed HIV-1 DNA.
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Affiliation(s)
- Prem Prakash
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, 37208, USA
| | - Purva Khodke
- Sunandan Divatia School of Science, NMIMS University, Mumbai, 400056, India
| | - Muthukumar Balasubramaniam
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, 37208, USA
| | - Benem-Orom Davids
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, New York, 10032, USA
| | - Thomas Hollis
- Department of Biochemistry and Center for Structural Biology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, 37208, USA
| | - Jui Pandhare
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, 37208, USA
| | - Bajarang Kumbhar
- Sunandan Divatia School of Science, NMIMS University, Mumbai, 400056, India
| | - Chandravanu Dash
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Nashville, Tennessee, 37208, USA
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, 37208, USA
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, 37208, USA
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5
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Zhang H, Vandesompele J, Braeckmans K, De Smedt SC, Remaut K. Nucleic acid degradation as barrier to gene delivery: a guide to understand and overcome nuclease activity. Chem Soc Rev 2024; 53:317-360. [PMID: 38073448 DOI: 10.1039/d3cs00194f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Gene therapy is on its way to revolutionize the treatment of both inherited and acquired diseases, by transferring nucleic acids to correct a disease-causing gene in the target cells of patients. In the fight against infectious diseases, mRNA-based therapeutics have proven to be a viable strategy in the recent Covid-19 pandemic. Although a growing number of gene therapies have been approved, the success rate is limited when compared to the large number of preclinical and clinical trials that have been/are being performed. In this review, we highlight some of the hurdles which gene therapies encounter after administration into the human body, with a focus on nucleic acid degradation by nucleases that are extremely abundant in mammalian organs, biological fluids as well as in subcellular compartments. We overview the available strategies to reduce the biodegradation of gene therapeutics after administration, including chemical modifications of the nucleic acids, encapsulation into vectors and co-administration with nuclease inhibitors and discuss which strategies are applied for clinically approved nucleic acid therapeutics. In the final part, we discuss the currently available methods and techniques to qualify and quantify the integrity of nucleic acids, with their own strengths and limitations.
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Affiliation(s)
- Heyang Zhang
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Leiden Academic Centre for Drug Research, Leiden University, 2333 CC Leiden, The Netherlands
| | - Jo Vandesompele
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Kevin Braeckmans
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Centre for Nano- and Biophotonics, Ghent University, 9000 Ghent, Belgium
| | - Stefaan C De Smedt
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Centre for Nano- and Biophotonics, Ghent University, 9000 Ghent, Belgium
| | - Katrien Remaut
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
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6
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Tohidi N, Manshadi SAD, Hajiabdolbaghi M. Association of TREX1 polymorphism with disease progression in human immunodeficiency virus type-1 (HIV-1) infected patients. Virus Genes 2023; 59:831-835. [PMID: 37728706 DOI: 10.1007/s11262-023-02032-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 09/07/2023] [Indexed: 09/21/2023]
Abstract
The time interval between HIV-1 infection and AIDS development is not the same in all patients and depends largely on the genetic background of the individual. Polymorphisms in the TREX1 gene, the main enzyme in the clearance of cytosolic DNA, affect type 1 interferon-mediated inflammatory response in HIV-1 infection. We aimed to study the role of a single nucleotide polymorphism (rs3135941) of the TREX1 gene and the rate of disease progression in patients infected with HIV-1. A total of 190 HIV-1 infected patients were recruited. Patients' demographic and laboratory data including CD4 counts, viral load, and antiretroviral therapy (ART) were collected. The genotype of rs3135941 was determined by a PCR-SSP method. The rate of progression to AIDS was calculated with Kaplan-Meier survival analysis using Stata software. The patients were divided into rapid and slow progressors based on time interval of CD4 drop below 350/µl. Kaplan-Meier analysis revealed an accelerated disease progression in patients with TC and CC genotypes (HR = 1.49, 95% CI = 1.01-2.17). The mean values of the first 5-year CD4 counts were significantly different in patients who had CC and TC genotypes compared to the TT group (p = 0.036). The result of this study emphasizes the importance of TREX1 polymorphism in HIV-1 progression. These data warrant further investigation into the role of other polymorphisms of TREX1.
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Affiliation(s)
- Nastaran Tohidi
- Department of Infectious Diseases and Tropical Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, 1419733141, Iran
| | - Seyed Ali Dehghan Manshadi
- Department of Infectious Diseases and Tropical Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, 1419733141, Iran
| | - Mahboubeh Hajiabdolbaghi
- Department of Infectious Diseases and Tropical Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, 1419733141, Iran.
- Iranian Research Center of HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran.
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7
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Huang KW, Wu CY, Toh SI, Liu TC, Tu CI, Lin YH, Cheng AJ, Kao YT, Chu JW, Hsiao YY. Molecular insight into the specific enzymatic properties of TREX1 revealing the diverse functions in processing RNA and DNA/RNA hybrids. Nucleic Acids Res 2023; 51:11927-11940. [PMID: 37870446 PMCID: PMC10681709 DOI: 10.1093/nar/gkad910] [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: 05/19/2023] [Revised: 09/28/2023] [Accepted: 10/06/2023] [Indexed: 10/24/2023] Open
Abstract
In various autoimmune diseases, dysfunctional TREX1 (Three prime Repair Exonuclease 1) leads to accumulation of endogenous single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and DNA/RNA hybrids in the cytoplasm and triggers immune activation through the cGAS-STING pathway. Although inhibition of TREX1 could be a useful strategy for cancer immunotherapy, profiling cellular functions in terms of its potential substrates is a key step. Particularly important is the functionality of processing DNA/RNA hybrids and RNA substrates. The exonuclease activity measurements conducted here establish that TREX1 can digest both ssRNA and DNA/RNA hybrids but not dsRNA. The newly solved structures of TREX1-RNA product and TREX1-nucleotide complexes show that 2'-OH does not impose steric hindrance or specific interactions for the recognition of RNA. Through all-atom molecular dynamics simulations, we illustrate that the 2'-OH-mediated intra-chain hydrogen bonding in RNA would affect the binding with TREX1 and thereby reduce the exonuclease activity. This notion of higher conformational rigidity in RNA leading TREX1 to exhibit weaker catalytic cleavage is further validated by the binding affinity measurements with various synthetic DNA-RNA junctions. The results of this work thus provide new insights into the mechanism by which TREX1 processes RNA and DNA/RNA hybrids and contribute to the molecular-level understanding of the complex cellular functions of TREX1 as an exonuclease.
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Affiliation(s)
- Kuan-Wei Huang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Chia-Yun Wu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Shu-Ing Toh
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Tung-Chang Liu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Chun-I Tu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Yin-Hsin Lin
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - An-Ju Cheng
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Ya-Ting Kao
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-devices (IDSB), National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Jhih-Wei Chu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-devices (IDSB), National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
| | - Yu-Yuan Hsiao
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-devices (IDSB), National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan
- Drug Development and Value Creation Research Center, Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
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8
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Fang L, Ying S, Xu X, Wu D. TREX1 cytosolic DNA degradation correlates with autoimmune disease and cancer immunity. Clin Exp Immunol 2023; 211:193-207. [PMID: 36745566 PMCID: PMC10038326 DOI: 10.1093/cei/uxad017] [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: 10/24/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 02/07/2023] Open
Abstract
The N-terminal domain of Three Prime Repair Exonuclease 1 (TREX1) is catalytically active and can degrade dsDNA or ssDNA in the cytosol, whereas the C-terminal domain is primarily involved in protein localization. TREX1 deficiency induces cytosolic DNA accumulation as well as activation of the cGAS-STING-IFN signaling pathway, which results in tissue inflammation and autoimmune diseases. Furthermore, TREX1 expression in cancer immunity can be adaptively regulated to promote tumor proliferation, making it a promising therapeutic target.
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Affiliation(s)
- Liwei Fang
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Songcheng Ying
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Xi Xu
- Department of Plastic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - De Wu
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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9
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Wang Q, Du J, Hua S, Zhao K. TREX1 Plays Multiple Roles in Human Diseases. Cell Immunol 2022; 375:104527. [DOI: 10.1016/j.cellimm.2022.104527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/12/2022] [Accepted: 04/10/2022] [Indexed: 11/15/2022]
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10
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Baris AM, Fraile-Bethencourt E, Anand S. Nucleic Acid Sensing in the Tumor Vasculature. Cancers (Basel) 2021; 13:4452. [PMID: 34503262 PMCID: PMC8431390 DOI: 10.3390/cancers13174452] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 12/27/2022] Open
Abstract
Endothelial cells form a powerful interface between tissues and immune cells. In fact, one of the underappreciated roles of endothelial cells is to orchestrate immune attention to specific sites. Tumor endothelial cells have a unique ability to dampen immune responses and thereby maintain an immunosuppressive microenvironment. Recent approaches to trigger immune responses in cancers have focused on activating nucleic acid sensors, such as cGAS-STING, in combination with immunotherapies. In this review, we present a case for targeting nucleic acid-sensing pathways within the tumor vasculature to invigorate tumor-immune responses. We introduce two specific nucleic acid sensors-the DNA sensor TREX1 and the RNA sensor RIG-I-and discuss their functional roles in the vasculature. Finally, we present perspectives on how these nucleic acid sensors in the tumor endothelium can be targeted in an antiangiogenic and immune activation context. We believe understanding the role of nucleic acid-sensing in the tumor vasculature can enhance our ability to design more effective therapies targeting the tumor microenvironment by co-opting both vascular and immune cell types.
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Affiliation(s)
- Adrian M. Baris
- Department of Cell, Developmental and Cancer Biology, Oregon Health & Science University, Portland, OR 97239, USA; (A.M.B.); (E.F.-B.)
| | - Eugenia Fraile-Bethencourt
- Department of Cell, Developmental and Cancer Biology, Oregon Health & Science University, Portland, OR 97239, USA; (A.M.B.); (E.F.-B.)
| | - Sudarshan Anand
- Department of Cell, Developmental and Cancer Biology, Oregon Health & Science University, Portland, OR 97239, USA; (A.M.B.); (E.F.-B.)
- Department of Radiation Medicine, Oregon Health & Science University, Portland, OR 97239, USA
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97201, USA
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11
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Hemphill WO, Simpson SR, Liu M, Salsbury FR, Hollis T, Grayson JM, Perrino FW. TREX1 as a Novel Immunotherapeutic Target. Front Immunol 2021; 12:660184. [PMID: 33868310 PMCID: PMC8047136 DOI: 10.3389/fimmu.2021.660184] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/15/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations in the TREX1 3' → 5' exonuclease are associated with a spectrum of autoimmune disease phenotypes in humans and mice. Failure to degrade DNA activates the cGAS-STING DNA-sensing pathway signaling a type-I interferon (IFN) response that ultimately drives immune system activation. TREX1 and the cGAS-STING DNA-sensing pathway have also been implicated in the tumor microenvironment, where TREX1 is proposed to degrade tumor-derived DNA that would otherwise activate cGAS-STING. If tumor-derived DNA were not degraded, the cGAS-STING pathway would be activated to promote IFN-dependent antitumor immunity. Thus, we hypothesize TREX1 exonuclease inhibition as a novel immunotherapeutic strategy. We present data demonstrating antitumor immunity in the TREX1 D18N mouse model and discuss theory surrounding the best strategy for TREX1 inhibition. Potential complications of TREX1 inhibition as a therapeutic strategy are also discussed.
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Affiliation(s)
- Wayne O. Hemphill
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Sean R. Simpson
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Mingyong Liu
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Freddie R. Salsbury
- Department of Physics, Wake Forest University, Winston-Salem, NC, United States
| | - Thomas Hollis
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Jason M. Grayson
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Fred W. Perrino
- Department of Biochemistry, Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, United States
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12
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Abstract
Exogenous retroviruses are RNA viruses that require reverse transcription for their replication. Among these viruses, human immunodeficiency virus (HIV) is infectious to humans and causes the development of acquired immune deficiency syndrome (AIDS). There are also endogenous retroelements that require reverse transcription for their retrotransposition, among which the type 1 long interspersed element (LINE-1) is the only type of retroelement that can replicate autonomously. It was once believed that retroviruses like HIV and retroelements like LINE-1 share similarities in processes such as reverse transcription and integration. Accordingly, many HIV suppressors are also potent LINE-1 inhibitors. However, in many cases, one suppressor uses two or more distinct mechanisms to repress HIV and LINE-1. In this review, we discuss some of these suppressors, focusing on their alternative mechanisms opposing the replication of HIV and LINE-1. Based on the differences in HIV and LINE-1 activity, the subcellular localization of these suppressors, and the impact of LINE-1 retrotransposition on human cells, we propose possible reasons for the inhibition of HIV and LINE-1 through different pathways by these suppressors, with the hope of accelerating future studies in associated research fields.
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Affiliation(s)
- Juan Du
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
| | - Ke Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration & Transplantation of the Ministry of Education, First Hospital of Jilin University, Changchun, China
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13
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Jabalameli N, Rajabi F, Firooz A, Rezaei N. The Overlap between Genetic Susceptibility to COVID-19 and Skin Diseases. Immunol Invest 2021; 51:1087-1094. [DOI: 10.1080/08820139.2021.1876086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Navid Jabalameli
- Network of Dermatology Research (NDR), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Fateme Rajabi
- Network of Dermatology Research (NDR), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Center for Research & Training in Skin Diseases & Leprosy, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Firooz
- Center for Research & Training in Skin Diseases & Leprosy, Tehran University of Medical Sciences, Tehran, Iran
| | - Nima Rezaei
- Research Center for Immunodeficiencies, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Sheffield, UK
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14
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Turnier JL, Kahlenberg JM. The Role of Cutaneous Type I IFNs in Autoimmune and Autoinflammatory Diseases. THE JOURNAL OF IMMUNOLOGY 2020; 205:2941-2950. [PMID: 33229366 DOI: 10.4049/jimmunol.2000596] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/18/2020] [Indexed: 01/31/2023]
Abstract
IFNs are well known as mediators of the antimicrobial response but also serve as important immunomodulatory cytokines in autoimmune and autoinflammatory diseases. An increasingly critical role for IFNs in evolution of skin inflammation in these patients has been recognized. IFNs are produced not only by infiltrating immune but also resident skin cells, with increased baseline IFN production priming for inflammatory cell activation, immune response amplification, and development of skin lesions. The IFN response differs by cell type and host factors and may be modified by other inflammatory pathway activation specific to individual diseases, leading to differing clinical phenotypes. Understanding the contribution of IFNs to skin and systemic disease pathogenesis is key to development of new therapeutics and improved patient outcomes. In this review, we summarize the immunomodulatory role of IFNs in skin, with a focus on type I, and provide insight into IFN dysregulation in autoimmune and autoinflammatory diseases.
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Affiliation(s)
- Jessica L Turnier
- Department of Pediatrics, Division of Rheumatology, University of Michigan, Ann Arbor, MI 48109; and
| | - J Michelle Kahlenberg
- Department of Internal Medicine, Division of Rheumatology, University of Michigan, Ann Arbor, MI 48109
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15
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Gondhowiardjo SA, Jayalie VF, Apriantoni R, Barata AR, Senoaji F, Utami IGAAJW, Maubere F, Nuryadi E, Giselvania A. Tackling Resistance to Cancer Immunotherapy: What Do We Know? Molecules 2020; 25:molecules25184096. [PMID: 32911646 PMCID: PMC7570938 DOI: 10.3390/molecules25184096] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/12/2020] [Accepted: 08/30/2020] [Indexed: 12/22/2022] Open
Abstract
Cancer treatment has evolved tremendously in the last few decades. Immunotherapy has been considered to be the forth pillar in cancer treatment in addition to conventional surgery, radiotherapy, and chemotherapy. Though immunotherapy has resulted in impressive response, it is generally limited to a small subset of patients. Understanding the mechanisms of resistance toward cancer immunotherapy may shed new light to counter that resistance. In this review, we highlighted and summarized two major hurdles (recognition and attack) of cancer elimination by the immune system. The mechanisms of failure of some available immunotherapy strategies were also described. Moreover, the significance role of immune compartment for various established cancer treatments were also elucidated in this review. Then, the mechanisms of combinatorial treatment of various conventional cancer treatment with immunotherapy were discussed. Finally, a strategy to improve immune cancer killing by characterizing cancer immune landscape, then devising treatment based on that cancer immune landscape was put forward.
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Affiliation(s)
- Soehartati A. Gondhowiardjo
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Vito Filbert Jayalie
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Riyan Apriantoni
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Andreas Ronald Barata
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Fajar Senoaji
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - IGAA Jayanthi Wulan Utami
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Ferdinand Maubere
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Endang Nuryadi
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
| | - Angela Giselvania
- Faculty of Medicine, Universitas Indonesia, Jakarta 16424, Indonesia; (S.A.G.); (V.F.J.); (R.A.); (A.R.B.); (F.S.); (I.J.W.U.); (F.M.); (E.N.); (A.G.)
- Department of Radiation Oncology, Dr. Cipto Mangunkusumo National General Hospital, Jakarta 10430, Indonesia
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16
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Belrose JL, Prasad A, Sammons MA, Gibbs KM, Szaro BG. Comparative gene expression profiling between optic nerve and spinal cord injury in Xenopus laevis reveals a core set of genes inherent in successful regeneration of vertebrate central nervous system axons. BMC Genomics 2020; 21:540. [PMID: 32758133 PMCID: PMC7430912 DOI: 10.1186/s12864-020-06954-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 07/27/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The South African claw-toed frog, Xenopus laevis, is uniquely suited for studying differences between regenerative and non-regenerative responses to CNS injury within the same organism, because some CNS neurons (e.g., retinal ganglion cells after optic nerve crush (ONC)) regenerate axons throughout life, whereas others (e.g., hindbrain neurons after spinal cord injury (SCI)) lose this capacity as tadpoles metamorphose into frogs. Tissues from these CNS regions (frog ONC eye, tadpole SCI hindbrain, frog SCI hindbrain) were used in a three-way RNA-seq study of axotomized CNS axons to identify potential core gene expression programs for successful CNS axon regeneration. RESULTS Despite tissue-specific changes in expression dominating the injury responses of each tissue, injury-induced changes in gene expression were nonetheless shared between the two axon-regenerative CNS regions that were not shared with the non-regenerative region. These included similar temporal patterns of gene expression and over 300 injury-responsive genes. Many of these genes and their associated cellular functions had previously been associated with injury responses of multiple tissues, both neural and non-neural, from different species, thereby demonstrating deep phylogenetically conserved commonalities between successful CNS axon regeneration and tissue regeneration in general. Further analyses implicated the KEGG adipocytokine signaling pathway, which links leptin with metabolic and gene regulatory pathways, and a novel gene regulatory network with genes regulating chromatin accessibility at its core, as important hubs in the larger network of injury response genes involved in successful CNS axon regeneration. CONCLUSIONS This study identifies deep, phylogenetically conserved commonalities between CNS axon regeneration and other examples of successful tissue regeneration and provides new targets for studying the molecular underpinnings of successful CNS axon regeneration, as well as a guide for distinguishing pro-regenerative injury-induced changes in gene expression from detrimental ones in mammals.
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Affiliation(s)
- Jamie L Belrose
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Aparna Prasad
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Morgan A Sammons
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Kurt M Gibbs
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, 40351, USA
| | - Ben G Szaro
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
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17
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Forrer Charlier C, Martins RAP. Protective Mechanisms Against DNA Replication Stress in the Nervous System. Genes (Basel) 2020; 11:E730. [PMID: 32630049 PMCID: PMC7397197 DOI: 10.3390/genes11070730] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 02/06/2023] Open
Abstract
The precise replication of DNA and the successful segregation of chromosomes are essential for the faithful transmission of genetic information during the cell cycle. Alterations in the dynamics of genome replication, also referred to as DNA replication stress, may lead to DNA damage and, consequently, mutations and chromosomal rearrangements. Extensive research has revealed that DNA replication stress drives genome instability during tumorigenesis. Over decades, genetic studies of inherited syndromes have established a connection between the mutations in genes required for proper DNA repair/DNA damage responses and neurological diseases. It is becoming clear that both the prevention and the responses to replication stress are particularly important for nervous system development and function. The accurate regulation of cell proliferation is key for the expansion of progenitor pools during central nervous system (CNS) development, adult neurogenesis, and regeneration. Moreover, DNA replication stress in glial cells regulates CNS tumorigenesis and plays a role in neurodegenerative diseases such as ataxia telangiectasia (A-T). Here, we review how replication stress generation and replication stress response (RSR) contribute to the CNS development, homeostasis, and disease. Both cell-autonomous mechanisms, as well as the evidence of RSR-mediated alterations of the cellular microenvironment in the nervous system, were discussed.
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Affiliation(s)
| | - Rodrigo A. P. Martins
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil;
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18
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Abstract
Leukodystrophies are genetically determined disorders affecting the white matter of the central nervous system. The combination of MRI pattern recognition and next-generation sequencing for the definition of novel disease entities has recently demonstrated that many leukodystrophies are due to the primary involvement and/or mutations in genes selectively expressed by cell types other than the oligodendrocytes, the myelin-forming cells in the brain. This has led to a new definition of leukodystrophies as genetic white matter disorders resulting from the involvement of any white matter structural component. As a result, the research has shifted its main focus from oligodendrocytes to other types of neuroglia. Astrocytes are the housekeeping cells of the nervous system, responsible for maintaining homeostasis and normal brain physiology and to orchestrate repair upon injury. Several lines of evidence show that astrocytic interactions with the other white matter cellular constituents play a primary pathophysiologic role in many leukodystrophies. These are thus now classified as astrocytopathies. This chapter addresses how the crosstalk between astrocytes, other glial cells, axons and non-neural cells are essential for the integrity and maintenance of the white matter in health. It also addresses the current knowledge of the cellular pathomechanisms of astrocytic leukodystrophies, and specifically Alexander disease, vanishing white matter, megalencephalic leukoencephalopathy with subcortical cysts and Aicardi-Goutière Syndrome.
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Affiliation(s)
- M S Jorge
- Department of Pathology, Free University Medical Centre, Amsterdam, The Netherlands
| | - Marianna Bugiani
- Department of Pathology, Free University Medical Centre, Amsterdam, The Netherlands.
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19
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Laffleur B, Basu U. Biology of RNA Surveillance in Development and Disease. Trends Cell Biol 2019; 29:428-445. [PMID: 30755352 DOI: 10.1016/j.tcb.2019.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/03/2019] [Accepted: 01/10/2019] [Indexed: 01/09/2023]
Abstract
The 'RNA world', in which RNA molecules stored information and acquired enzymatic properties, has been proposed to have preceded organism life. RNA is now recognized for its central role in biology, with accumulating evidence implicating coding and noncoding (nc)RNAs in myriad mechanisms regulating cellular physiology and disequilibrium in transcriptomes resulting in pathological conditions. Nascently synthesized RNAs are subjected to stringent regulation by sophisticated RNA surveillance pathways. In this review, we integrate these pathways from a developmental viewpoint, proposing RNA surveillance as the convergence of mechanisms that ensure the exact titration of RNA molecules in a spatiotemporally controlled manner, leading to development without the onset of pathological conditions, including cancer.
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Affiliation(s)
- Brice Laffleur
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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20
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Sase S, Takanohashi A, Vanderver A, Almad A. Astrocytes, an active player in Aicardi-Goutières syndrome. Brain Pathol 2019; 28:399-407. [PMID: 29740948 DOI: 10.1111/bpa.12600] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/02/2018] [Indexed: 01/10/2023] Open
Abstract
Aicardi-Goutières syndrome (AGS) is an early-onset, autoimmune and genetically heterogeneous disorder with severe neurologic injury. Molecular studies have established that autosomal recessive mutations in one of the following genes are causative: TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 and IFIH1/MDA5. The phenotypic presentation and pathophysiology of AGS is associated with over-production of the cytokine Interferon-alpha (IFN-α) and its downstream signaling, characterized as type I interferonopathy. Astrocytes are one of the major source of IFN in the central nervous system (CNS) and it is proposed that they could be key players in AGS pathology. Astrocytes are the most ubiquitous glial cell in the CNS and perform a number of crucial and complex functions ranging from formation of blood-brain barrier, maintaining ionic homeostasis, metabolic support to synapse formation and elimination in healthy CNS. Involvement of astrocytic dysfunction in neurological diseases-Alexander's disease, Epilepsy, Alzheimer's and amyotrophic lateral sclerosis (ALS)-has been well-established. It is now known that compromised astrocytic function can contribute to CNS abnormalities and severe neurodegeneration, nevertheless, its contribution in AGS is unclear. The current review discusses known molecular and cellular pathways for AGS mutations and how it stimulates IFN-α signaling. We shed light on how astrocytes might be key players in the phenotypic presentations of AGS and emphasize the cell-autonomous and non-cell-autonomous role of astrocytes. Understanding the contribution of astrocytes will help reveal mechanisms underlying interferonopathy and develop targeted astrocyte specific therapeutic treatments in AGS.
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Affiliation(s)
- Sunetra Sase
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Asako Takanohashi
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Akshata Almad
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
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21
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DDX41 Recognizes RNA/DNA Retroviral Reverse Transcripts and Is Critical for In Vivo Control of Murine Leukemia Virus Infection. mBio 2018; 9:mBio.00923-18. [PMID: 29871919 PMCID: PMC5989071 DOI: 10.1128/mbio.00923-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Host recognition of viral nucleic acids generated during infection leads to the activation of innate immune responses essential for early control of virus. Retrovirus reverse transcription creates numerous potential ligands for cytosolic host sensors that recognize foreign nucleic acids, including single-stranded RNA (ssRNA), RNA/DNA hybrids, and double-stranded DNA (dsDNA). We and others recently showed that the sensors cyclic GMP-AMP synthase (cGAS), DEAD-box helicase 41 (DDX41), and members of the Aim2-like receptor (ALR) family participate in the recognition of retroviral reverse transcripts. However, why multiple sensors might be required and their relative importance in in vivo control of retroviral infection are not known. Here, we show that DDX41 primarily senses the DNA/RNA hybrid generated at the first step of reverse transcription, while cGAS recognizes dsDNA generated at the next step. We also show that both DDX41 and cGAS are needed for the antiretroviral innate immune response to murine leukemia virus (MLV) and HIV in primary mouse macrophages and dendritic cells (DCs). Using mice with cell type-specific knockout of the Ddx41 gene, we show that DDX41 sensing in DCs but not macrophages was critical for controlling in vivo MLV infection. This suggests that DCs are essential in vivo targets for infection, as well as for initiating the antiviral response. Our work demonstrates that the innate immune response to retrovirus infection depends on multiple host nucleic acid sensors that recognize different reverse transcription intermediates. Viruses are detected by many different host sensors of nucleic acid, which in turn trigger innate immune responses, such as type I interferon (IFN) production, required to control infection. We show here that at least two sensors are needed to initiate a highly effective innate immune response to retroviruses—DDX41, which preferentially senses the RNA/DNA hybrid generated at the first step of retrovirus replication, and cGAS, which recognizes double-stranded DNA generated at the second step. Importantly, we demonstrate using mice lacking DDX41 or cGAS that both sensors are needed for the full antiviral response needed to control in vivo MLV infection. These findings underscore the need for multiple host factors to counteract retroviral infection.
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22
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Lo MS. Insights Gained From the Study of Pediatric Systemic Lupus Erythematosus. Front Immunol 2018; 9:1278. [PMID: 29922296 PMCID: PMC5996073 DOI: 10.3389/fimmu.2018.01278] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/22/2018] [Indexed: 12/21/2022] Open
Abstract
The pathophysiology of systemic lupus erythematosus (SLE) has been intensely studied but remains incompletely defined. Currently, multiple mechanisms are known to contribute to the development of SLE. These include inadequate clearance of apoptotic debris, aberrant presentation of self nucleic antigens, loss of tolerance, and inappropriate activation of T and B cells. Genetic, hormonal, and environmental influences are also known to play a role. The study of lupus in children, in whom there is presumed to be greater genetic influence, has led to new understandings that are applicable to SLE pathophysiology as a whole. In particular, characterization of inherited disorders associated with excessive type I interferon production has elucidated specific mechanisms by which interferon is induced in SLE. In this review, we discuss several monogenic forms of lupus presenting in childhood and also review recent insights gained from cytokine and autoantibody profiling of pediatric SLE.
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Affiliation(s)
- Mindy S Lo
- Division of Immunology, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States
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23
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Structural basis for overhang excision and terminal unwinding of DNA duplexes by TREX1. PLoS Biol 2018; 16:e2005653. [PMID: 29734329 PMCID: PMC5957452 DOI: 10.1371/journal.pbio.2005653] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/17/2018] [Accepted: 04/03/2018] [Indexed: 01/12/2023] Open
Abstract
Three prime repair exonuclease 1 (TREX1) is an essential exonuclease in mammalian cells, and numerous in vivo and in vitro data evidenced its participation in immunity regulation and in genotoxicity remediation. In these very complicated cellular functions, the molecular mechanisms by which duplex DNA substrates are processed are mostly elusive because of the lack of structure information. Here, we report multiple crystal structures of TREX1 complexed with various substrates to provide the structure basis for overhang excision and terminal unwinding of DNA duplexes. The substrates were designed to mimic the intermediate structural DNAs involved in various repair pathways. The results showed that the Leu24-Pro25-Ser26 cluster of TREX1 served to cap the nonscissile 5′-end of the DNA for precise removal of the short 3′-overhang in L- and Y-structural DNA or to wedge into the double-stranded region for further digestion along the duplex. Biochemical assays were also conducted to demonstrate that TREX1 can indeed degrade double-stranded DNA (dsDNA) to a full extent. Overall, this study provided unprecedented knowledge at the molecular level on the enzymatic substrate processing involved in prevention of immune activation and in responses to genotoxic stresses. For example, Arg128, whose mutation in TREX1 was linked to a disease state, were shown to exhibit consistent interaction patterns with the nonscissile strand in all of the structures we solved. Such structure basis is expected to play an indispensable role in elucidating the functional activities of TREX1 at the cellular level and in vivo. Three prime repair exonuclease 1 (TREX1) was shown to participate in various cellular events such as DNA repair, immunity regulation, and viral infection. In addition to relating to autoimmune diseases, this exonuclease also acts as a potential protein target for anticancer or antiviral therapies. A key for such broad attendance of TREX1 is the activities of precise trimming of the 3′-overhang in a double-stranded (dsDNA) and breaking of the terminal base pairing of the duplex. Here, we designed a series of structural DNA substrates and activity assays to delineate the underlying mechanisms. The structures newly resolved in this work indicated that the Leu24-Pro25-Ser26 cluster of TREX1 is essential for the enzyme to carry out the aforementioned activities. Together, our results established an integrated structure view into the versatile exonuclease functions of TREX1 and illuminated the molecular origin for the unique catalytic properties of TREX1 in processing various DNA intermediates in DNA repair and in cytosolic immunity regulation.
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24
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Abstract
Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are recognized by different cellular pathogen recognition receptors (PRRs), which are expressed on cell membrane or in the cytoplasm of cells of the innate immune system. Nucleic acids derived from pathogens or from certain cellular conditions represent a large category of PAMPs/DAMPs that trigger production of type I interferons (IFN-I) in addition to pro-inflammatory cytokines, by specifically binding to intracellular Toll-like receptors or cytosolic receptors. These cytosolic receptors, which are not related to TLRs and we call them “Toll-free” receptors, include the RNA-sensing RIG-I like receptors (RLRs), the DNA-sensing HIN200 family, and cGAS, amongst others. Viruses have evolved myriad strategies to evoke both host cellular and viral factors to evade IFN-I-mediated innate immune responses, to facilitate their infection, replication, and establishment of latency. This review outlines these “Toll-free” innate immune pathways and recent updates on their regulation, with focus on cellular and viral factors with enzyme activities.
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Affiliation(s)
- Ling Wang
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Center of Excellence for Inflammation, Infectious Diseases and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Shunbin Ning
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Center of Excellence for Inflammation, Infectious Diseases and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
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25
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Li P, Du J, Goodier JL, Hou J, Kang J, Kazazian HH, Zhao K, Yu XF. Aicardi-Goutières syndrome protein TREX1 suppresses L1 and maintains genome integrity through exonuclease-independent ORF1p depletion. Nucleic Acids Res 2017; 45:4619-4631. [PMID: 28334850 PMCID: PMC5416883 DOI: 10.1093/nar/gkx178] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 03/11/2017] [Indexed: 12/22/2022] Open
Abstract
Maintaining genome integrity is important for cells and damaged DNA triggers autoimmunity. Previous studies have reported that Three-prime repair exonuclease 1(TREX1), an endogenous DNA exonuclease, prevents immune activation by depleting damaged DNA, thus preventing the development of certain autoimmune diseases. Consistently, mutations in TREX1 are linked with autoimmune diseases such as systemic lupus erythematosus, Aicardi–Goutières syndrome (AGS) and familial chilblain lupus. However, TREX1 mutants competent for DNA exonuclease activity are also linked to AGS. Here, we report a nuclease-independent involvement of TREX1 in preventing the L1 retrotransposon-induced DNA damage response. TREX1 interacted with ORF1p and altered its intracellular localization. Furthermore, TREX1 triggered ORF1p depletion and reduced the L1-mediated nicking of genomic DNA. TREX1 mutants related to AGS were deficient in inducing ORF1p depletion and could not prevent L1-mediated DNA damage. Therefore, our findings not only reveal a new mechanism for TREX1-mediated L1 suppression and uncover a new function for TREX1 in protein destabilization, but they also suggest a novel mechanism for TREX1-mediated suppression of innate immune activation through maintaining genome integrity.
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Affiliation(s)
- Peng Li
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Juan Du
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - John L Goodier
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jingwei Hou
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Jian Kang
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Haig H Kazazian
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ke Zhao
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Xiao-Fang Yu
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, Jilin 130061, China.,Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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26
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Achleitner M, Kleefisch M, Hennig A, Peschke K, Polikarpova A, Oertel R, Gabriel B, Schulze L, Lindeman D, Gerbaulet A, Fiebig U, Lee-Kirsch MA, Roers A, Behrendt R. Lack of Trex1 Causes Systemic Autoimmunity despite the Presence of Antiretroviral Drugs. THE JOURNAL OF IMMUNOLOGY 2017; 199:2261-2269. [PMID: 28835460 DOI: 10.4049/jimmunol.1700714] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/26/2017] [Indexed: 01/25/2023]
Abstract
Biallelic mutations of three prime repair exonuclease 1 (TREX1) cause the lupus-like disease Aicardi-Goutières syndrome in which accumulation of a yet unknown endogenous DNA substrate of TREX1 triggers a cyclic GMP-AMP synthase-dependent type I IFN response and systemic autoimmunity. Products of reverse transcription originating from endogenous retroelements have been suggested to be a major substrate for TREX1, and reverse transcriptase inhibitors (RTIs) were proposed as a therapeutic option in autoimmunity ensuing from defects of TREX1. In this study, we treated Trex1-/- mice with RTIs. The serum RTI levels reached were sufficient to block retrotransposition of endogenous retroelements. However, the treatment did not reduce the spontaneous type I IFN response and did not ameliorate lethal inflammation. Furthermore, long interspersed nuclear elements 1 retrotransposition was not enhanced in the absence of Trex1. Our data do not support the concept of retroelement-derived cDNA as key triggers of systemic autoimmunity in Trex1-deficient humans and mice and motivate the continuing search for the pathogenic IFN-inducing Trex1 substrate.
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Affiliation(s)
- Martin Achleitner
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Martin Kleefisch
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Alexander Hennig
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Katrin Peschke
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Anastasia Polikarpova
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Reinhard Oertel
- Institute of Clinical Pharmacology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Benjamin Gabriel
- Division for HIV and Other Retroviruses, Department of Infectious Diseases, Robert Koch Institute, 13353 Berlin, Germany
| | - Livia Schulze
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Dirk Lindeman
- Institute of Virology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany; and
| | - Alexander Gerbaulet
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Uwe Fiebig
- Division for HIV and Other Retroviruses, Department of Infectious Diseases, Robert Koch Institute, 13353 Berlin, Germany
| | - Min Ae Lee-Kirsch
- Molecular Pediatrics, Department of Pediatrics, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Axel Roers
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany
| | - Rayk Behrendt
- Institute for Immunology, Medical Faculty Carl Gustav Carus, Technical University of Dresden, 01307 Dresden, Germany;
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27
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MicroRNA regulation of endothelial TREX1 reprograms the tumour microenvironment. Nat Commun 2016; 7:13597. [PMID: 27886180 PMCID: PMC5133658 DOI: 10.1038/ncomms13597] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/18/2016] [Indexed: 02/07/2023] Open
Abstract
Rather than targeting tumour cells directly, elements of the tumour microenvironment can be modulated to sensitize tumours to the effects of therapy. Here we report a unique mechanism by which ectopic microRNA-103 can manipulate tumour-associated endothelial cells to enhance tumour cell death. Using gain-and-loss of function approaches, we show that miR-103 exacerbates DNA damage and inhibits angiogenesis in vitro and in vivo. Local, systemic or vascular-targeted delivery of miR-103 in tumour-bearing mice decreased angiogenesis and tumour growth. Mechanistically, miR-103 regulation of its target gene TREX1 in endothelial cells governs the secretion of pro-inflammatory cytokines into the tumour microenvironment. Our data suggest that this inflammatory milieu may potentiate tumour cell death by supporting immune activation and inducing tumour expression of Fas and TRAIL receptors. Our findings reveal miR-mediated crosstalk between vasculature and tumour cells that can be exploited to improve the efficacy of chemotherapy and radiation. The tumour microenvironment can be modulated to sensitize tumours to the effects of therapy. Here the authors show that radiation induced miR-103 downregulates TREX1 in endothelial cells, decreases angiogenesis and leads to the secretion of proinflammatory mediators that reduce tumour growth.
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28
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Peschke K, Achleitner M, Frenzel K, Gerbaulet A, Ada SR, Zeller N, Lienenklaus S, Lesche M, Poulet C, Naumann R, Dahl A, Ravens U, Günther C, Müller W, Knobeloch KP, Prinz M, Roers A, Behrendt R. Loss of Trex1 in Dendritic Cells Is Sufficient To Trigger Systemic Autoimmunity. THE JOURNAL OF IMMUNOLOGY 2016; 197:2157-66. [DOI: 10.4049/jimmunol.1600722] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/12/2016] [Indexed: 01/14/2023]
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Richards RI, Robertson SA, O'Keefe LV, Fornarino D, Scott A, Lardelli M, Baune BT. The Enemy within: Innate Surveillance-Mediated Cell Death, the Common Mechanism of Neurodegenerative Disease. Front Neurosci 2016; 10:193. [PMID: 27242399 PMCID: PMC4862319 DOI: 10.3389/fnins.2016.00193] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 04/18/2016] [Indexed: 12/16/2022] Open
Abstract
Neurodegenerative diseases comprise an array of progressive neurological disorders all characterized by the selective death of neurons in the central nervous system. Although, rare (familial) and common (sporadic) forms can occur for the same disease, it is unclear whether this reflects several distinct pathogenic pathways or the convergence of different causes into a common form of nerve cell death. Remarkably, neurodegenerative diseases are increasingly found to be accompanied by activation of the innate immune surveillance system normally associated with pathogen recognition and response. Innate surveillance is the cell's quality control system for the purpose of detecting such danger signals and responding in an appropriate manner. Innate surveillance is an "intelligent system," in that the manner of response is relevant to the magnitude and duration of the threat. If possible, the threat is dealt with within the cell in which it is detected, by degrading the danger signal(s) and restoring homeostasis. If this is not successful then an inflammatory response is instigated that is aimed at restricting the spread of the threat by elevating degradative pathways, sensitizing neighboring cells, and recruiting specialized cell types to the site. If the danger signal persists, then the ultimate response can include not only the programmed cell death of the original cell, but the contents of this dead cell can also bring about the death of adjacent sensitized cells. These responses are clearly aimed at destroying the ability of the detected pathogen to propagate and spread. Innate surveillance comprises intracellular, extracellular, non-cell autonomous and systemic processes. Recent studies have revealed how multiple steps in these processes involve proteins that, through their mutation, have been linked to many familial forms of neurodegenerative disease. This suggests that individuals harboring these mutations may have an amplified response to innate-mediated damage in neural tissues, and renders innate surveillance mediated cell death a plausible common pathogenic pathway responsible for neurodegenerative diseases, in both familial and sporadic forms. Here we have assembled evidence in favor of the hypothesis that neurodegenerative disease is the cumulative result of chronic activation of the innate surveillance pathway, triggered by endogenous or environmental danger or damage associated molecular patterns in a progressively expanding cascade of inflammation, tissue damage and cell death.
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Affiliation(s)
- Robert I Richards
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Sarah A Robertson
- School of Paediatrics and Reproductive Health, Robinson Research Institute, The University of Adelaide Adelaide, SA, Australia
| | - Louise V O'Keefe
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Dani Fornarino
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Andrew Scott
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Michael Lardelli
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Bernhard T Baune
- School of Medicine, Discipline of Psychiatry, The University of Adelaide Adelaide, SA, Australia
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Vohhodina J, Harkin DP, Savage KI. Dual roles of DNA repair enzymes in RNA biology/post-transcriptional control. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:604-19. [PMID: 27126972 DOI: 10.1002/wrna.1353] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/17/2016] [Accepted: 03/18/2016] [Indexed: 12/12/2022]
Abstract
Despite consistent research into the molecular principles of the DNA damage repair pathway for almost two decades, it has only recently been found that RNA metabolism is very tightly related to this pathway, and the two ancient biochemical mechanisms act in alliance to maintain cellular genomic integrity. The close links between these pathways are well exemplified by examining the base excision repair pathway, which is now well known for dual roles of many of its members in DNA repair and RNA surveillance, including APE1, SMUG1, and PARP1. With additional links between these pathways steadily emerging, this review aims to provide a summary of the emerging roles for DNA repair proteins in the post-transcriptional regulation of RNAs. WIREs RNA 2016, 7:604-619. doi: 10.1002/wrna.1353 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jekaterina Vohhodina
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - D Paul Harkin
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Kienan I Savage
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
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31
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Lussi C, Schweizer M. What can pestiviral endonucleases teach us about innate immunotolerance? Cytokine Growth Factor Rev 2016; 29:53-62. [PMID: 27021825 PMCID: PMC7173139 DOI: 10.1016/j.cytogfr.2016.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/01/2016] [Indexed: 02/07/2023]
Abstract
In this review, we describe the identification of the PRRs involved in the recognition of pestiviruses, and the mechanisms of these viruses to prevent the activation of host’s innate immune response with special emphasis on viral RNases. Most importantly, we extend these data and present our model of innate immunotolerance requiring continuous prevention of detection of immunostimulatory self nucleic acids, in contrast to the well-known long-term tolerance of the adaptive immune system targeted predominantly against proteins. This hypothesis is very likely relevant beyond the bovine species and might answer more fundamental questions on the discrimination between “self” and “viral nonself RNA”, which are relevant also for the prevention and treatment of chronic IFN induction and autoimmunity induced by “self-RNAs”.
Pestiviruses including bovine viral diarrhea virus (BVDV), border disease virus (BDV) and classical swine fever virus (CSFV), occur worldwide and are important pathogens of livestock. A large part of their success can be attributed to the induction of central immunotolerance including B- and T-cells upon fetal infection leading to the generation of persistently infected (PI) animals. In the past few years, it became evident that evasion of innate immunity is a central element to induce and maintain persistent infection. Hence, the viral non-structural protease Npro heads the transcription factor IRF-3 for proteasomal degradation, whereas an extracellularly secreted, soluble form of the envelope glycoprotein Erns degrades immunostimulatory viral single- and double-stranded RNA, which makes this RNase unique among viral endoribonucleases. We propose that these pestiviral interferon (IFN) antagonists maintain a state of innate immunotolerance mainly pertaining its viral nucleic acids, in contrast to the well-established immunotolerance of the adaptive immune system, which is mainly targeted at proteins. In particular, the unique extension of ‘self’ to include the viral genome by degrading immunostimulatory viral RNA by Erns is reminiscent of various host nucleases that are important to prevent inappropriate IFN activation by the host’s own nucleic acids in autoimmune diseases such as Aicardi-Goutières syndrome or systemic lupus erythematosus. This mechanism of “innate tolerance” might thus provide a new facet to the role of extracellular RNases in the sustained prevention of the body’s own immunostimulatory RNA to act as a danger-associated molecular pattern that is relevant across various species.
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Affiliation(s)
- Carmela Lussi
- Institute of Virology and Immunology, Federal Food Safety and Veterinary Office (FSVO) and Vetsuisse Faculty University of Bern, Laenggass-Str. 122, CH-3001 Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
| | - Matthias Schweizer
- Institute of Virology and Immunology, Federal Food Safety and Veterinary Office (FSVO) and Vetsuisse Faculty University of Bern, Laenggass-Str. 122, CH-3001 Bern, Switzerland.
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