1
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Ramos A, Bizri N, Novak E, Mollen K, Khan S. The role of cGAS in epithelial dysregulation in inflammatory bowel disease and gastrointestinal malignancies. Front Pharmacol 2024; 15:1409683. [PMID: 39050748 PMCID: PMC11266671 DOI: 10.3389/fphar.2024.1409683] [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: 03/30/2024] [Accepted: 05/31/2024] [Indexed: 07/27/2024] Open
Abstract
The gastrointestinal tract is lined by an epithelial monolayer responsible for selective permeability and absorption, as well as protection against harmful luminal contents. Recognition of foreign or aberrant DNA within these epithelial cells is, in part, regulated by pattern recognition receptors such as cyclic GMP-AMP synthase (cGAS). cGAS binds double-stranded DNA from exogenous and endogenous sources, resulting in the activation of stimulator of interferon genes (STING) and a type 1 interferon response. cGAS is also implicated in non-canonical pathways involving the suppression of DNA repair and the upregulation of autophagy via interactions with PARP1 and Beclin-1, respectively. The importance of cGAS activation in the development and progression of inflammatory bowel disease and gastrointestinal cancers has been and continues to be explored. This review delves into the intricacies of the complex role of cGAS in intestinal epithelial inflammation and gastrointestinal malignancies, as well as recent therapeutic advances targeting cGAS pathways.
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Affiliation(s)
- Anna Ramos
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Nazih Bizri
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Elizabeth Novak
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
- Division of Pediatric General and Thoracic Surgery, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Kevin Mollen
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
- Division of Pediatric General and Thoracic Surgery, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Sidrah Khan
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
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2
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Martínez-López MF, Muslin C, Kyriakidis NC. STINGing Defenses: Unmasking the Mechanisms of DNA Oncovirus-Mediated Immune Escape. Viruses 2024; 16:574. [PMID: 38675916 PMCID: PMC11054469 DOI: 10.3390/v16040574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
DNA oncoviruses represent an intriguing subject due to their involvement in oncogenesis. These viruses have evolved mechanisms to manipulate the host immune response, facilitating their persistence and actively contributing to carcinogenic processes. This paper describes the complex interactions between DNA oncoviruses and the innate immune system, with a particular emphasis on the cGAS-STING pathway. Exploring these interactions highlights that DNA oncoviruses strategically target and subvert this pathway, exploiting its vulnerabilities for their own survival and proliferation within the host. Understanding these interactions lays the foundation for identifying potential therapeutic interventions. Herein, we sought to contribute to the ongoing efforts in advancing our understanding of the innate immune system in oncoviral pathogenesis.
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Affiliation(s)
- Mayra F Martínez-López
- Cancer Research Group (CRG), Faculty of Medicine, Universidad de las Américas, Quito 170503, Ecuador;
| | - Claire Muslin
- One Health Research Group, Faculty of Health Sciences, Universidad de las Américas, Quito 170503, Ecuador;
| | - Nikolaos C. Kyriakidis
- Cancer Research Group (CRG), Faculty of Medicine, Universidad de las Américas, Quito 170503, Ecuador;
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3
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Zaid A, Ariel A. Harnessing anti-inflammatory pathways and macrophage nano delivery to treat inflammatory and fibrotic disorders. Adv Drug Deliv Rev 2024; 207:115204. [PMID: 38342241 DOI: 10.1016/j.addr.2024.115204] [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: 07/30/2023] [Revised: 12/08/2023] [Accepted: 02/05/2024] [Indexed: 02/13/2024]
Abstract
Targeting specific organs and cell types using nanotechnology and sophisticated delivery methods has been at the forefront of applicative biomedical sciences lately. Macrophages are an appealing target for immunomodulation by nanodelivery as they are heavily involved in various aspects of many diseases and are highly plastic in their nature. Their continuum of functional "polarization" states has been a research focus for many years yielding a profound understanding of various aspects of these cells. The ability of monocyte-derived macrophages to metamorphose from pro-inflammatory to reparative and consequently to pro-resolving effectors has raised significant interest in its therapeutic potential. Here, we briefly survey macrophages' ontogeny and various polarization phenotypes, highlighting their function in the inflammation-resolution shift. We review their inducing mediators, signaling pathways, and biological programs with emphasis on the nucleic acid sensing-IFN-I axis. We also portray the polarization spectrum of macrophages and the characteristics of their transition between different subtypes. Finally, we highlighted different current drug delivery methods for targeting macrophages with emphasis on nanotargeting that might lead to breakthroughs in the treatment of wound healing, bone regeneration, autoimmune, and fibrotic diseases.
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Affiliation(s)
- Ahmad Zaid
- Department of Biology and Human Biology, University of Haifa, Haifa, 3498838 Israel
| | - Amiram Ariel
- Department of Biology and Human Biology, University of Haifa, Haifa, 3498838 Israel.
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4
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Low JT, Brown MC, Reitman ZJ, Bernstock JD, Markert JM, Friedman GK, Waitkus MS, Bowie ML, Ashley DM. Understanding and therapeutically exploiting cGAS/STING signaling in glioblastoma. J Clin Invest 2024; 134:e163452. [PMID: 38226619 PMCID: PMC10786687 DOI: 10.1172/jci163452] [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] [Indexed: 01/17/2024] Open
Abstract
Since the discovery that cGAS/STING recognizes endogenous DNA released from dying cancer cells and induces type I interferon and antitumor T cell responses, efforts to understand and therapeutically target the STING pathway in cancer have ensued. Relative to other cancer types, the glioma immune microenvironment harbors few infiltrating T cells, but abundant tumor-associated myeloid cells, possibly explaining disappointing responses to immune checkpoint blockade therapies in cohorts of patients with glioblastoma. Notably, unlike most extracranial tumors, STING expression is absent in the malignant compartment of gliomas, likely due to methylation of the STING promoter. Nonetheless, several preclinical studies suggest that inducing cGAS/STING signaling in the glioma immune microenvironment could be therapeutically beneficial, and cGAS/STING signaling has been shown to mediate inflammatory and antitumor effects of other modalities either in use or being developed for glioblastoma therapy, including radiation, tumor-treating fields, and oncolytic virotherapy. In this Review, we discuss cGAS/STING signaling in gliomas, its implications for glioma immunobiology, compartment-specific roles for STING signaling in influencing immune surveillance, and efforts to target STING signaling - either directly or indirectly - for antiglioma therapy.
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Affiliation(s)
| | | | - Zachary J. Reitman
- Department of Radiation Oncology, Duke University, Durham, North Carolina, USA
| | - Joshua D. Bernstock
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - James M. Markert
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Gregory K. Friedman
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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5
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Sathyan KR, Premraj A, Chaudhary M, Ramachandran R, Thavarool Puthiyedathu S. Alternative splicing variants of stimulator of interferon genes (STING) from Asian seabass (Lates calcarifer) and their immune response against red spotted grouper nervous necrosis virus (RGNNV). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 149:105062. [PMID: 37726038 DOI: 10.1016/j.dci.2023.105062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 09/14/2023] [Accepted: 09/14/2023] [Indexed: 09/21/2023]
Abstract
The Stimulator of Interferon Genes (STING, also known as MITA/ERYS/MPYS) is an adaptor molecule that plays a crucial role in the RLR pathway and responds to DNA and RNA viruses. In the present study, we have identified two novel isoforms of STING (the canonical form named as LcSTINGa and its alternative splicing isoform named as LcSTINGb) from teleost Lates calcarifer. LcSTINGa has an ORF of 1230 bp, encoding a 409 amino acid protein, while its alternative splicing variant, LcSTINGb, features an ORF of 987 bp, encoding 328 amino acids. LcSTINGa is predicted to contain four transmembrane helices, whereas LcSTINGb has only two. The Lates STING protein showed about 86.85% identity with Perca flavescens, 86.45% with Seriola and 39.51% with Homo sapiens. The tissue distribution studies revealed that the STING variants were constitutively expressed in all the tissues examined, with the highest expression in blood. In-vivo upregulation of LcSTINGa and LcSTINGb mRNA following immune challenge with poly (I:C), Red-spotted grouper nervous necrosis virus (RGNNV) and zymosan A suggests its significance in the immune response.
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Affiliation(s)
- Krishnapriya Raji Sathyan
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India
| | - Avinash Premraj
- Camel Biotechnology Centre, Presidential Camels and Camel Racing Affairs Centre, Department of the President's Affairs, PO Box, 17292, Al Ain, United Arab Emirates
| | - Mansi Chaudhary
- Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge city, Sector 81, SAS Nagar, Manauli P.O, 140306, India
| | - Rajesh Ramachandran
- Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge city, Sector 81, SAS Nagar, Manauli P.O, 140306, India
| | - Sajeevan Thavarool Puthiyedathu
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India; Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, 682 016, Kerala, India.
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6
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Kosmara D, Papanikolaou S, Nikolaou C, Bertsias G. Extensive Alternative Splicing Patterns in Systemic Lupus Erythematosus Highlight Sexual Differences. Cells 2023; 12:2678. [PMID: 38067106 PMCID: PMC10705143 DOI: 10.3390/cells12232678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
Substantial evidence highlights divergences in immune responses between men and women. Women are more susceptible to autoimmunity, whereas men suffer from the more severe presentation of autoimmune disorders. The molecular mechanism of this sexual dimorphism remains elusive. Herein, we conducted a comprehensive analysis of sex differences in whole-blood gene expression focusing on alternative splicing (AS) events in systemic lupus erythematosus (SLE), which is a prototype sex-biased disease. This study included 79 SLE patients with active disease and 58 matched healthy controls who underwent whole-blood RNA sequencing. Sex differences in splicing events were widespread, existent in both SLE and a healthy state. However, we observed distinct gene sets and molecular pathways targeted by sex-dependent AS in SLE patients as compared to healthy subjects, as well as a notable sex dissimilarity in intron retention events. Sexually differential spliced genes specific to SLE patients were enriched for dynamic cellular processes including chromatin remodeling, stress and inflammatory responses. Remarkably, the extent of sexual differences in AS in the SLE patients and healthy individuals exceeded those in gene expression. Overall, this study reveals an unprecedent variation in sex-dependent splicing events in SLE and the healthy state, with potential implications for understanding the molecular basis of sexual dimorphism in autoimmunity.
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Affiliation(s)
- Despoina Kosmara
- Rheumatology and Clinical Immunology, University Hospital of Heraklion and University of Crete Medical School, 71500 Heraklion, Greece
- Foundation for Research and Technology-Hellas (FORTH), Infections and Immunity, Institute of Molecular Biology and Biotechnology, 71110 Heraklion, Greece
| | - Sofia Papanikolaou
- Rheumatology and Clinical Immunology, University Hospital of Heraklion and University of Crete Medical School, 71500 Heraklion, Greece
- Biomedical Sciences Research Center “Alexander Fleming”, Institute of Bioinnovation, 16672 Athens, Greece
| | - Christoforos Nikolaou
- Biomedical Sciences Research Center “Alexander Fleming”, Institute of Bioinnovation, 16672 Athens, Greece
| | - George Bertsias
- Rheumatology and Clinical Immunology, University Hospital of Heraklion and University of Crete Medical School, 71500 Heraklion, Greece
- Foundation for Research and Technology-Hellas (FORTH), Infections and Immunity, Institute of Molecular Biology and Biotechnology, 71110 Heraklion, Greece
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Yang Y, Wang L, Peugnet-González I, Parada-Venegas D, Dijkstra G, Faber KN. cGAS-STING signaling pathway in intestinal homeostasis and diseases. Front Immunol 2023; 14:1239142. [PMID: 37781354 PMCID: PMC10538549 DOI: 10.3389/fimmu.2023.1239142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/18/2023] [Indexed: 10/03/2023] Open
Abstract
The intestinal mucosa is constantly exposed to commensal microbes, opportunistic pathogens, toxins, luminal components and other environmental stimuli. The intestinal mucosa consists of multiple differentiated cellular and extracellular components that form a critical barrier, but is also equipped for efficient absorption of nutrients. Combination of genetic susceptibility and environmental factors are known as critical components involved in the pathogenesis of intestinal diseases. The innate immune system plays a critical role in the recognition and elimination of potential threats by detecting pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). This host defense is facilitated by pattern recognition receptors (PRRs), in which the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway has gained attention due to its role in sensing host and foreign double-stranded DNA (dsDNA) as well as cyclic dinucleotides (CDNs) produced by bacteria. Upon binding with dsDNA, cGAS converts ATP and GTP to cyclic GMP-AMP (cGAMP), which binds to STING and activates TANK binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), inducing type I interferon (IFN) and nuclear factor kappa B (NF-κB)-mediated pro-inflammatory cytokines, which have diverse effects on innate and adaptive immune cells and intestinal epithelial cells (IECs). However, opposite perspectives exist regarding the role of the cGAS-STING pathway in different intestinal diseases. Activation of cGAS-STING signaling is associated with worse clinical outcomes in inflammation-associated diseases, while it also plays a critical role in protection against tumorigenesis and certain infections. Therefore, understanding the context-dependent mechanisms of the cGAS-STING pathway in the physiopathology of the intestinal mucosa is crucial for developing therapeutic strategies targeting the cGAS-STING pathway. This review aims to provide insight into recent findings of the protective and detrimental roles of the cGAS-STING pathway in intestinal diseases.
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Affiliation(s)
- Yuchen Yang
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Li Wang
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Ivonne Peugnet-González
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Daniela Parada-Venegas
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Gerard Dijkstra
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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8
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Maebele LT, Mulaudzi TV, Yasasve M, Dlamini Z, Damane BP. Immunomodulatory Gene-Splicing Dysregulation in Tumorigenesis: Unmasking the Complexity. Molecules 2023; 28:5984. [PMID: 37630236 PMCID: PMC10458946 DOI: 10.3390/molecules28165984] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/05/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Cancer is a global health concern with rising incidence, morbidity, and mortality. The interaction between the tumor and immune cells within the tumor microenvironment is facilitated by signaling pathways driven by immunomodulatory proteins. Alternative splicing regulates the production of multiple immunomodulatory proteins with diverse functionality from a single mRNA transcript. Splicing factors are pivotal in modulating alternative splicing processes but are also subject to regulation. The dysregulation of alternative splicing may result from splicing factor (SF) abnormal expression levels and mutations in the cis and trans-acting elements and small nuclear RNA (snRNA) molecules. Aberrant splicing may generate abnormal mRNA transcripts encoding isoforms with altered functions that contribute to tumorigenesis or cancer progression. This review uncovers the complexity of immunomodulatory genes splicing dysregulation in oncogenesis. Identifying specific immunomodulatory splicing isoforms that contribute to cancer could be utilized to improve current immunotherapeutic drugs or develop novel therapeutic interventions for cancer.
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Affiliation(s)
| | - Thanyani Victor Mulaudzi
- Department of Surgery, Steve Biko Academic Hospital, University of Pretoria, Hatfield 0028, South Africa
| | - Madhavan Yasasve
- Department of Oral Medicine and Radiology, Sri Ramachandra Institute of Higher Education and Research, Chennai 600116, India
| | - Zodwa Dlamini
- SAMRC Precision Oncology Research Unit (PORU), DSI/NRF SARChI Chair in Precision Oncology and Cancer Prevention (POCP), Pan African Cancer Research Institute (PACRI), University of Pretoria, Hatfield 0028, South Africa
| | - Botle Precious Damane
- Department of Surgery, Steve Biko Academic Hospital, University of Pretoria, Hatfield 0028, South Africa
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9
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Kumar V, Bauer C, Stewart JH. Targeting cGAS/STING signaling-mediated myeloid immune cell dysfunction in TIME. J Biomed Sci 2023; 30:48. [PMID: 37380989 PMCID: PMC10304357 DOI: 10.1186/s12929-023-00942-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2023] [Indexed: 06/30/2023] Open
Abstract
Myeloid immune cells (MICs) are potent innate immune cells serving as first responders to invading pathogens and internal changes to cellular homeostasis. Cancer is a stage of altered cellular homeostasis that can originate in response to different pathogens, chemical carcinogens, and internal genetic/epigenetic changes. MICs express several pattern recognition receptors (PRRs) on their membranes, cytosol, and organelles, recognizing systemic, tissue, and organ-specific altered homeostasis. cGAS/STING signaling is a cytosolic PRR system for identifying cytosolic double-stranded DNA (dsDNA) in a sequence-independent but size-dependent manner. The longer the cytosolic dsDNA size, the stronger the cGAS/STING signaling activation with increased type 1 interferon (IFN) and NF-κB-dependent cytokines and chemokines' generation. The present article discusses tumor-supportive changes occurring in the tumor microenvironment (TME) or tumor immune microenvironment (TIME) MICs, specifically emphasizing cGAS/STING signaling-dependent alteration. The article further discusses utilizing MIC-specific cGAS/STING signaling modulation as critical tumor immunotherapy to alter TIME.
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Affiliation(s)
- Vijay Kumar
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
| | - Caitlin Bauer
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA
| | - John H Stewart
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
- Louisiana Children's Medical Center Cancer Center, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
- Surgery, Section of Surgical Oncology, Louisiana State University New Orleans-Louisiana Children's Medical Center Cancer Center, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
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10
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Kim J, Kim HS, Chung JH. Molecular mechanisms of mitochondrial DNA release and activation of the cGAS-STING pathway. Exp Mol Med 2023; 55:510-519. [PMID: 36964253 PMCID: PMC10037406 DOI: 10.1038/s12276-023-00965-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 12/15/2022] [Indexed: 03/26/2023] Open
Abstract
In addition to constituting the genetic material of an organism, DNA is a tracer for the recognition of foreign pathogens and a trigger of the innate immune system. cGAS functions as a sensor of double-stranded DNA fragments and initiates an immune response via the adaptor protein STING. The cGAS-STING pathway not only defends cells against various DNA-containing pathogens but also modulates many pathological processes caused by the immune response to the ectopic localization of self-DNA, such as cytosolic mitochondrial DNA (mtDNA) and extranuclear chromatin. In addition, macrophages can cause inflammation by forming a class of protein complexes called inflammasomes, and the activation of the NLRP3 inflammasome requires the release of oxidized mtDNA. In innate immunity related to inflammasomes, mtDNA release is mediated by macropores that are formed on the outer membrane of mitochondria via VDAC oligomerization. These macropores are specifically formed in response to mitochondrial stress and tissue damage, and the inhibition of VDAC oligomerization mitigates this inflammatory response. The rapidly expanding area of research on the mechanisms by which mtDNA is released and triggers inflammation has revealed new treatment strategies not only for inflammation but also, surprisingly, for neurodegenerative diseases such as amyotrophic lateral sclerosis.
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Affiliation(s)
- Jeonghan Kim
- Department of Biochemistry, The Catholic University of Korea College of Medicine, Seoul, 06591, South Korea.
| | - Ho-Shik Kim
- Department of Biochemistry, The Catholic University of Korea College of Medicine, Seoul, 06591, South Korea
| | - Jay H Chung
- Laboratory of Obesity and Aging Research, Cardiovascular Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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Shi J, Liu C, Luo S, Zhang Y, Li M, Zhou M, Weng M, Li X, Zheng T. Protocol for the identification and expression analysis of a cytoplasmic membrane-localized protein STING. STAR Protoc 2023; 4:102172. [PMID: 36943863 PMCID: PMC10041549 DOI: 10.1016/j.xpro.2023.102172] [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: 10/22/2022] [Revised: 11/28/2022] [Accepted: 02/21/2023] [Indexed: 03/23/2023] Open
Abstract
Here, we present a protocol for the detection of the two STING isoforms (erSTING and pmSTING) in human peripheral blood mononuclear cells or mouse splenocytes using Western blot and PCR. We detail steps to construct plasmids encoding each isoform and transfer them into mouse and human cell lines. Finally, we describe how to detect cell membrane localization of pmSTING using flow cytometry, immunoprecipitation, and immunofluorescence. This protocol is applicable for proteins with well-predicted topological structures. For complete details on the use and execution of this protocol, please refer to Li et al.1.
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Affiliation(s)
- Jiaqi Shi
- Department of Phase 1 Trials Center, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Caiqi Liu
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Shengnan Luo
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Yingying Zhang
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Mingwei Li
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Meng Zhou
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Mingjiao Weng
- Department of Pathology, Harbin Medical University, No.157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081, China
| | - Xiaobo Li
- Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China.
| | - Tongsen Zheng
- Department of Phase 1 Trials Center, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Key Laboratory of Molecular Oncology of Heilongjiang Province, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China; Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, No.150 Haping Road, Nangang District, Harbin, Heilongjiang 150081, China.
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12
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Pan J, Fei CJ, Hu Y, Wu XY, Nie L, Chen J. Current understanding of the cGAS-STING signaling pathway: Structure, regulatory mechanisms, and related diseases. Zool Res 2023; 44:183-218. [PMID: 36579404 PMCID: PMC9841179 DOI: 10.24272/j.issn.2095-8137.2022.464] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
The innate immune system protects the host from external pathogens and internal damage in various ways. The cGAS-STING signaling pathway, comprised of cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and downstream signaling adaptors, plays an essential role in protective immune defense against microbial DNA and internal damaged-associated DNA and is responsible for various immune-related diseases. After binding with DNA, cytosolic cGAS undergoes conformational change and DNA-linked liquid-liquid phase separation to produce 2'3'-cGAMP for the activation of endoplasmic reticulum (ER)-localized STING. However, further studies revealed that cGAS is predominantly expressed in the nucleus and strictly tethered to chromatin to prevent binding with nuclear DNA, and functions differently from cytosolic-localized cGAS. Detailed delineation of this pathway, including its structure, signaling, and regulatory mechanisms, is of great significance to fully understand the diversity of cGAS-STING activation and signaling and will be of benefit for the treatment of inflammatory diseases and cancer. Here, we review recent progress on the above-mentioned perspectives of the cGAS-STING signaling pathway and discuss new avenues for further study.
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Affiliation(s)
- Jing Pan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Chen-Jie Fei
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Yang Hu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Xiang-Yu Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China
| | - Li Nie
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China. E-mail:
| | - Jiong Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, Zhejiang 315211, China
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, Zhejiang 315832, China
- Zhejiang Key Laboratory of Marine Bioengineering, Ningbo University, Ningbo, Zhejiang 315832, China. E-mail:
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13
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Zhang Z, Zhou H, Ouyang X, Dong Y, Sarapultsev A, Luo S, Hu D. Multifaceted functions of STING in human health and disease: from molecular mechanism to targeted strategy. Signal Transduct Target Ther 2022; 7:394. [PMID: 36550103 PMCID: PMC9780328 DOI: 10.1038/s41392-022-01252-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/25/2022] [Accepted: 11/09/2022] [Indexed: 12/24/2022] Open
Abstract
Since the discovery of Stimulator of Interferon Genes (STING) as an important pivot for cytosolic DNA sensation and interferon (IFN) induction, intensive efforts have been endeavored to clarify the molecular mechanism of its activation, its physiological function as a ubiquitously expressed protein, and to explore its potential as a therapeutic target in a wide range of immune-related diseases. With its orthodox ligand 2'3'-cyclic GMP-AMP (2'3'-cGAMP) and the upstream sensor 2'3'-cGAMP synthase (cGAS) to be found, STING acquires its central functionality in the best-studied signaling cascade, namely the cGAS-STING-IFN pathway. However, recently updated research through structural research, genetic screening, and biochemical assay greatly extends the current knowledge of STING biology. A second ligand pocket was recently discovered in the transmembrane domain for a synthetic agonist. On its downstream outputs, accumulating studies sketch primordial and multifaceted roles of STING beyond its cytokine-inducing function, such as autophagy, cell death, metabolic modulation, endoplasmic reticulum (ER) stress, and RNA virus restriction. Furthermore, with the expansion of the STING interactome, the details of STING trafficking also get clearer. After retrospecting the brief history of viral interference and the milestone events since the discovery of STING, we present a vivid panorama of STING biology taking into account the details of the biochemical assay and structural information, especially its versatile outputs and functions beyond IFN induction. We also summarize the roles of STING in the pathogenesis of various diseases and highlight the development of small-molecular compounds targeting STING for disease treatment in combination with the latest research. Finally, we discuss the open questions imperative to answer.
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Affiliation(s)
- Zili Zhang
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, China
| | - Haifeng Zhou
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, China
| | - Xiaohu Ouyang
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, China
| | - Yalan Dong
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, China
| | - Alexey Sarapultsev
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Science, 620049, Ekaterinburg, Russia
| | - Shanshan Luo
- Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Desheng Hu
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, China.
- Key Laboratory of Biological Targeted Therapy, The Ministry of Education, 430022, Wuhan, China.
- Clinical Research Center of Cancer Immunotherapy, 430022, Hubei, Wuhan, China.
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14
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Vila IK, Guha S, Kalucka J, Olagnier D, Laguette N. Alternative pathways driven by STING: From innate immunity to lipid metabolism. Cytokine Growth Factor Rev 2022; 68:54-68. [PMID: 36085258 DOI: 10.1016/j.cytogfr.2022.08.006] [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: 08/21/2022] [Accepted: 08/29/2022] [Indexed: 01/30/2023]
Abstract
The Stimulator of Interferon Genes (STING) is a major adaptor protein that is central to the initiation of type I interferon responses and proinflammatory signalling. STING-dependent signalling is triggered by the presence of cytosolic nucleic acids that are generated following pathogen infection or cellular stress. Beyond this central role in controlling immune responses through the production of cytokines and chemokines, recent reports have uncovered inflammation-independent STING functions. Amongst these, a rapidly growing body of evidence demonstrates a key role of STING in controlling metabolic pathways at several levels. Since immunity and metabolic homeostasis are tightly interconnected, these findings deepen our understanding of the involvement of STING in human pathologies. Here, we discuss these findings and reflect on their impact on our current understanding of how nucleic acid immunity controls homeostasis and promotes pathological outcomes.
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Affiliation(s)
- Isabelle K Vila
- Institut de Génétique Humaine, Univ Montpellier, CNRS, Montpellier, France.
| | - Soumyabrata Guha
- Institut de Génétique Humaine, Univ Montpellier, CNRS, Montpellier, France
| | - Joanna Kalucka
- Aarhus University, Department of Biomedicine, Aarhus, Denmark
| | - David Olagnier
- Aarhus University, Department of Biomedicine, Aarhus, Denmark
| | - Nadine Laguette
- Institut de Génétique Humaine, Univ Montpellier, CNRS, Montpellier, France.
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15
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Kabelitz D, Zarobkiewicz M, Heib M, Serrano R, Kunz M, Chitadze G, Adam D, Peters C. Signal strength of STING activation determines cytokine plasticity and cell death in human monocytes. Sci Rep 2022; 12:17827. [PMID: 36280676 PMCID: PMC9590392 DOI: 10.1038/s41598-022-20519-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/14/2022] [Indexed: 01/20/2023] Open
Abstract
The cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway is a cytosolic sensor of microbial and host-derived DNA and plays a key role in innate immunity. Activation of STING by cyclic dinucleotide (CDN) ligands in human monocytes induces a type I interferon response and production of pro-inflammatory cytokines associated with the induction of massive cell death. In this study we have re-evaluated the effect of signal strength of STING activation on the cytokine plasticity of human monocytes. CDN (2'3'c-GAMP) and non-CDN (diABZI, MSA-2) STING ligands in the range of EC50 concentrations (15 μM 2'3'c-GAMP, 100 nM diABZI, 25 μM MSA-2) induced IFN-β, IP-10, and large amounts of IL-1β and TNF-α, but no IL-10 or IL-19. Interestingly, LPS-induced production of IL-10 and IL-19 was abolished in the presence of diABZI or MSA-2, whereas IL-1β and TNF-α were not inhibited. Surprisingly, we observed that tenfold lower (MSA-2, i.e. 2.5 μM) or 100-fold lower (diABZI, i.e. 1 nM) concentrations strongly stimulated secretion of anti-inflammatory IL-10 and IL-19, but little of IL-1β and TNF-α. Induction of IL-10 was associated with up-regulation of PRDM1 (Blimp-1). While cytokine secretion stimulated by the higher concentrations was accompanied by apoptosis as shown by cleavage of caspase-3 and PARP-1, the low concentrations did not trigger overt cell death yet induced cleavage of gasdermin-D. Our results reveal a previously unrecognized plasticity of human monocytes in their signal strength-dependent production of pro- versus anti-inflammatory cytokines upon STING activation.
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Affiliation(s)
- Dieter Kabelitz
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany
| | - Michal Zarobkiewicz
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany ,grid.411484.c0000 0001 1033 7158Present Address: Department of Clinical Immunology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Michelle Heib
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany
| | - Ruben Serrano
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany ,grid.10423.340000 0000 9529 9877Present Address: Institute of Immunology, Medical University Hannover, 30625 Hannover, Germany
| | - Monika Kunz
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany
| | - Guranda Chitadze
- grid.412468.d0000 0004 0646 2097Unit for Hematological Diagnostics, Department of Internal Medicine II, University Hospital Schleswig-Holstein, 24105 Kiel, Germany
| | - Dieter Adam
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany
| | - Christian Peters
- grid.9764.c0000 0001 2153 9986Institute of Immunology, Christian-Albrechts University Kiel, Arnold-Heller-Str. 3, Building U30, 24105 Kiel, Germany
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16
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Ge Z, Ding S. Regulation of cGAS/STING signaling and corresponding immune escape strategies of viruses. Front Cell Infect Microbiol 2022; 12:954581. [PMID: 36189363 PMCID: PMC9516114 DOI: 10.3389/fcimb.2022.954581] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
Innate immunity is the first line of defense against invading external pathogens, and pattern recognition receptors (PRRs) are the key receptors that mediate the innate immune response. Nowadays, there are various PRRs in cells that can activate the innate immune response by recognizing pathogen-related molecular patterns (PAMPs). The DNA sensor cGAS, which belongs to the PRRs, plays a crucial role in innate immunity. cGAS detects both foreign and host DNA and generates a second-messenger cGAMP to mediate stimulator of interferon gene (STING)-dependent antiviral responses, thereby exerting an antiviral immune response. However, the process of cGAS/STING signaling is regulated by a wide range of factors. Multiple studies have shown that viruses directly target signal transduction proteins in the cGAS/STING signaling through viral surface proteins to impede innate immunity. It is noteworthy that the virus utilizes these cGAS/STING signaling regulators to evade immune surveillance. Thus, this paper mainly summarized the regulatory mechanism of the cGAS/STING signaling pathway and the immune escape mechanism of the corresponding virus, intending to provide targeted immunotherapy ideas for dealing with specific viral infections in the future.
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Affiliation(s)
- Zhe Ge
- School of Sport, Shenzhen University, Shenzhen, China
| | - Shuzhe Ding
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai, China
- *Correspondence: Shuzhe Ding,
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Wobma H, Shin DS, Chou J, Dedeoğlu F. Dysregulation of the cGAS-STING Pathway in Monogenic Autoinflammation and Lupus. Front Immunol 2022; 13:905109. [PMID: 35693769 PMCID: PMC9186411 DOI: 10.3389/fimmu.2022.905109] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 05/02/2022] [Indexed: 01/19/2023] Open
Abstract
One of the oldest mechanisms of immune defense against pathogens is through detection of foreign DNA. Since human DNA is compartmentalized into the nucleus, its presence in the cytosol heralds a potential threat. The cGAS-STING pathway is one of the most important cytosolic DNA sensing pathways and leads to interferon signaling, inflammasome activation, autophagy, and cell death. While STING signaling is protective at physiologic levels, chronic activation of this pathway can instead drive autoinflammation and autoimmunity. Here we discuss several monogenic disorders of the STING pathway that highlight its impact on both innate and adaptive immunity in the progressive loss of tolerance. The potential relevance of STING signaling in systemic lupus erythematosus is then discussed with a focus on future avenues for monitoring and targeting this pathway.
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18
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Mitochondrial damage and activation of the cytosolic DNA sensor cGAS-STING pathway lead to cardiac pyroptosis and hypertrophy in diabetic cardiomyopathy mice. Cell Death Dis 2022; 8:258. [PMID: 35538059 PMCID: PMC9091247 DOI: 10.1038/s41420-022-01046-w] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/22/2022] [Accepted: 04/26/2022] [Indexed: 02/07/2023]
Abstract
Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes that currently lacks specific treatment. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has been suggested to contribute to the pathogenesis of cardiovascular diseases. However, whether cGAS-STING is involved in the development of DCM has not been established. Our study aimed to determine the role of cGAS-STING in the initiation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome-induced cardiac pyroptosis and chronic inflammation during the pathogenesis of DCM. C57BL/6J mice were preinjected with adeno-associated virus 9 (AAV9) intravenously via the tail vein to specifically knock down myocardial STING. After four weeks, mice with myocardium-specific knockdown of STING received injections of streptozotocin (STZ; 50 mg/kg) and a high-fat diet to induce diabetes. Measurements included echocardiography, immunohistochemical analyses, wheat germ agglutinin (WGA) staining, and western blotting. Here, we showed that the cGAS-STING signaling pathway was activated in diabetic hearts, which was indicated by the increased phosphorylation of TANK-binding kinase 1 (TBK1) and interferon (IFN) regulatory factor 3 (IRF3), leading to the activation of the NLRP3 inflammasome in the hearts of diabetic mice and proinflammatory cytokine release into serum. Moreover, STING knockdown via adeno-associated virus-9 (AAV9) in diabetic mouse heart alleviated cardiac pyroptosis and the inflammatory response, prevented diabetes-induced hypertrophy, and restored cardiac function. Mechanistically, we showed that palmitic acid (PA)-induced lipotoxicity impairs mitochondrial homeostasis, producing excessive mitochondrial reactive oxygen species (mtROS), which results in oxidative damage to mitochondrial DNA (mtDNA) and its release into the cytoplasm while switching on cGAS-STING-mediated pyroptosis in cardiomyocytes, thereby worsening the progression of diabetic cardiomyopathy. Our study demonstrated that activation of the cGAS-STING pathway caused by mitochondrial oxidative damage and mtDNA escape induced by free fatty acids promoted pyroptosis and proinflammatory responses in cardiomyocytes in a NLRP3 inflammasome-dependent manner, thus promoting myocardial hypertrophy during the progression of DCM.
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Sun J, Li L, Hu J, Gao Y, Song J, Zhang X, Hu H. Time-course RNA-Seq profiling reveals isoform-level gene expression dynamics of the cGAS-STING pathway. Comput Struct Biotechnol J 2022; 20:6490-6500. [PMCID: PMC9686058 DOI: 10.1016/j.csbj.2022.11.044] [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: 09/22/2022] [Revised: 11/21/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
The cGAS-STING pathway, orchestrating complicated transcriptome-wide immune responses, is essential for host antiviral defense but can also drive immunopathology in severe COVID-19. Here, we performed time-course RNA-Seq experiments to dissect the transcriptome expression dynamics at the gene-isoform level after cGAS-STING pathway activation. The in-depth time-course transcriptome after cGAS-STING pathway activation within 12 h enabled quantification of 48,685 gene isoforms. By employing regression models, we obtained 13,232 gene isoforms with expression patterns significantly associated with the process of cGAS-STING pathway activation, which were named activation-associated isoforms. The combination of hierarchical and k-means clustering algorithms revealed four major expression patterns of activation-associated isoforms, including two clusters with increased expression patterns enriched in cell cycle, autophagy, antiviral innate-immune functions, and COVID-19 coronavirus disease pathway, and two clusters showing decreased expression pattern that mainly involved in ncRNA metabolism, translation process, and mRNA processing. Importantly, by merging four clusters of activation-associated isoforms, we identified three types of genes that underwent isoform usage alteration during the cGAS-STING pathway activation. We further found that genes exhibiting protein-coding and non-protein-coding gene isoform usage alteration were strongly enriched for the factors involved in innate immunity and RNA splicing. Notably, overexpression of an enriched splicing factor, EFTUD2, shifted transcriptome towards the cGAS-STING pathway activated status and promoted protein-coding isoform abundance of several key regulators of the cGAS-STING pathway. Taken together, our results revealed the isoform-level gene expression dynamics of the cGAS-STING pathway and uncovered novel roles of splicing factors in regulating cGAS-STING pathway mediated immune responses.
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