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Lecoultre M, Walker PR, El Helali A. Oncolytic virus and tumor-associated macrophage interactions in cancer immunotherapy. Clin Exp Med 2024; 24:202. [PMID: 39196415 PMCID: PMC11358230 DOI: 10.1007/s10238-024-01443-8] [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: 05/30/2024] [Accepted: 07/18/2024] [Indexed: 08/29/2024]
Abstract
Oncolytic viruses (OV) are a promising strategy in cancer immunotherapy. Their capacity to promote anti-tumoral immunity locally raises hope that cancers unresponsive to current immunotherapy approaches could be tackled more efficiently. In this context, tumor-associated macrophages (TAM) must be considered because of their pivotal role in cancer immunity. Even though TAM tend to inhibit anti-tumoral responses, their ability to secrete pro-inflammatory cytokines and phagocytose cancer cells can be harnessed to promote therapeutic cancer immunity. OVs have the potential to promote TAM pro-inflammatory functions that favor anti-tumoral immunity. But in parallel, TAM pro-inflammatory functions induce OV clearance in the tumor, thereby limiting OV efficacy and highlighting that the interaction between OV and TAM is a double edge sword. Moreover, engineered OVs were recently developed to modulate specific TAM functions such as phagocytic activity. The potential of circulating monocytes to deliver OV into the tumor after intravenous administration is also emerging. In this review, we will present the interaction between OV and TAM, the potential of engineered OV to modulate specific TAM functions, and the promising role of circulating monocytes in OV delivery to the tumor.
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Affiliation(s)
- Marc Lecoultre
- Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, Hong Kong University, Hong Kong, China
- Division of General Internal Medicine, Geneva University Hospital, Geneva, Switzerland
| | - Paul R Walker
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Immunobiology of Brain Tumours Laboratory, Center for Translational Research in Onco-Hematology, University of Geneva, Geneva, Switzerland
| | - Aya El Helali
- Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, Hong Kong University, Hong Kong, China.
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2
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Parag RR, Yamamoto T, Saito K, Zhu D, Yang L, Van Meir EG. Novel Isoforms of Adhesion G Protein-Coupled Receptor B1 (ADGRB1/BAI1) Generated from an Alternative Promoter in Intron 17. Mol Neurobiol 2024:10.1007/s12035-024-04293-3. [PMID: 38941066 DOI: 10.1007/s12035-024-04293-3] [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: 02/24/2024] [Accepted: 06/06/2024] [Indexed: 06/29/2024]
Abstract
Brain-specific angiogenesis inhibitor 1 (BAI1) belongs to the adhesion G-protein-coupled receptors, which exhibit large multi-domain extracellular N termini that mediate cell-cell and cell-matrix interactions. To explore the existence of BAI1 isoforms, we queried genomic datasets for markers of active chromatin and new transcript variants in the ADGRB1 (adhesion G-protein-coupled receptor B1) gene. Two major types of mRNAs were identified in human/mouse brain, those with a start codon in exon 2 encoding a full-length protein of a predicted size of 173.5/173.3 kDa and shorter transcripts starting from alternative exons at the intron 17/exon 18 boundary with new or exon 19 start codons, predicting two shorter isoforms of 76.9/76.4 and 70.8/70.5 kDa, respectively. Immunoblots on wild-type and Adgrb1 exon 2-deleted mice, reverse transcription PCR, and promoter-luciferase reporter assay confirmed that the shorter isoforms originate from an alternative promoter in intron 17. The shorter BAI1 isoforms lack most of the N terminus and are very close in structure to the truncated BAI1 isoform generated through GPS processing from the full-length receptor. The cleaved BAI1 isoform has a 19 amino acid extracellular stalk that may serve as a receptor agonist, while the alternative transcripts generate BAI1 isoforms with extracellular N termini of 5 or 60 amino acids. Further studies are warranted to compare the functions of these isoforms and examine the distinct roles they play in different tissues and cell types.
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Affiliation(s)
- Rashed Rezwan Parag
- Laboratory of Molecular Neuro-Oncology, Department of Neurosurgery, Heersink School of Medicine, University of Alabama at Birmingham (UAB), WTI 520E, 1824 6th Avenue South, Birmingham, AL, 35233, USA
- Graduate Biomedical Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Takahiro Yamamoto
- Laboratory of Molecular Neuro-Oncology, Department of Neurosurgery, Heersink School of Medicine, University of Alabama at Birmingham (UAB), WTI 520E, 1824 6th Avenue South, Birmingham, AL, 35233, USA
- Department of Neurosurgery, Kumamoto University, Kumamoto, Japan
| | - Kiyotaka Saito
- Laboratory of Molecular Neuro-Oncology, Department of Neurosurgery, Heersink School of Medicine, University of Alabama at Birmingham (UAB), WTI 520E, 1824 6th Avenue South, Birmingham, AL, 35233, USA
| | - Dan Zhu
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Liquan Yang
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Erwin G Van Meir
- Laboratory of Molecular Neuro-Oncology, Department of Neurosurgery, Heersink School of Medicine, University of Alabama at Birmingham (UAB), WTI 520E, 1824 6th Avenue South, Birmingham, AL, 35233, USA.
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA.
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham (UAB), Birmingham, AL, USA.
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Achi SC, McGrosso D, Tocci S, Ibeawuchi SR, Sayed IM, Gonzalez DJ, Das S. Proteome profiling identifies a link between the mitochondrial pathways and host-microbial sensor ELMO1 following Salmonella infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592405. [PMID: 38746404 PMCID: PMC11092768 DOI: 10.1101/2024.05.03.592405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The host EnguLfment and cell MOtility protein 1 (ELMO1) is a cytosolic microbial sensor that facilitates bacterial sensing, internalization, clearance, and inflammatory responses. We have shown previously that ELMO1 binds bacterial effector proteins, including pathogenic effectors from Salmonella and controls host innate immune signaling. To understand the ELMO1-regulated host pathways, we have performed liquid chromatography Multinotch MS3-Tandem Mass Tag (TMT) multiplexed proteomics to determine the global quantification of proteins regulated by ELMO1 in macrophages during Salmonella infection. Comparative proteome analysis of control and ELMO1-depleted murine J774 macrophages after Salmonella infection quantified more than 7000 proteins with a notable enrichment in mitochondrial-related proteins. Gene ontology enrichment analysis revealed 19 upregulated and 11 downregulated proteins exclusive to ELMO1-depleted cells during infection, belonging to mitochondrial functions, metabolism, vesicle transport, and the immune system. By assessing the cellular energetics via Seahorse analysis, we found that Salmonella infection alters mitochondrial metabolism, shifting it from oxidative phosphorylation to glycolysis. Importantly, these metabolic changes are significantly influenced by the depletion of ELMO1. Furthermore, ELMO1 depletion resulted in a decreased ATP rate index following Salmonella infection, indicating its importance in counteracting the effects of Salmonella on immunometabolism. Among the proteins involved in mitochondrial pathways, mitochondrial fission protein DRP1 was significantly upregulated in ELMO1-depleted cells and in ELMO1-KO mice intestine following Salmonella infection. Pharmacological Inhibition of DRP1 revealed the link of the ELMO1-DRP1 pathway in regulating the pro-inflammatory cytokine TNF-α following infection. The role of ELMO1 has been further characterized by a proteome profile of ELMO1-depleted macrophage infected with SifA mutant and showed the involvement of ELMO1-SifA on mitochondrial function, metabolism and host immune/defense responses. Collectively, these findings unveil a novel role for ELMO1 in modulating mitochondrial functions, potentially pivotal in modulating inflammatory responses. Significance Statement Host microbial sensing is critical in infection and inflammation. Among these sensors, ELMO1 has emerged as a key regulator, finely tuning innate immune signaling and discriminating between pathogenic and non-pathogenic bacteria through interactions with microbial effectors like SifA of Salmonella . In this study, we employed Multinotch MS3-Tandem Mass Tag (TMT) multiplexed proteomics to determine the proteome alterations mediated by ELMO1 in macrophages following WT and SifA mutant Salmonella infection. Our findings highlight a substantial enrichment of host proteins associated with metabolic pathways and mitochondrial functions. Notably, we validated the mitochondrial fission protein DRP1 that is upregulated in ELMO1-depleted macrophages and in ELMO1 knockout mice intestine after infection. Furthermore, we demonstrated that Salmonella -induced changes in cellular energetics are influenced by the presence of ELMO1. This work shed light on a possible novel link between mitochondrial dynamics and microbial sensing in modulating immune responses.
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Li Q, Liu H, Yin G, Xie Q. Efferocytosis: Current status and future prospects in the treatment of autoimmune diseases. Heliyon 2024; 10:e28399. [PMID: 38596091 PMCID: PMC11002059 DOI: 10.1016/j.heliyon.2024.e28399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/11/2024] Open
Abstract
Billions of apoptotic cells are swiftly removed from the human body daily. This clearance process is regulated by efferocytosis, an active anti-inflammatory process during which phagocytes engulf and remove apoptotic cells. However, impaired clearance of apoptotic cells is associated with the development of various autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and inflammatory bowel disease. In this review, we conducted a comprehensive search of relevant studies published from January 1, 2000, to the present, focusing on efferocytosis, autoimmune disease pathogenesis, regulatory mechanisms governing efferocytosis, and potential treatments targeting this process. Our review highlights the key molecules involved in different stages of efferocytosis-namely, the "find me," "eat me," and "engulf and digest" phases-while elucidating their relevance to autoimmune disease pathology. Furthermore, we explore the therapeutic potential of modulating efferocytosis to restore immune homeostasis and mitigate autoimmune responses. By providing theoretical underpinnings for the targeting of efferocytosis in the treatment of autoimmune diseases, this review contributes to the advancement of therapeutic strategies in this field.
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Affiliation(s)
- Qianwei Li
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Huan Liu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Geng Yin
- Department of General Practice, General Practice Medical Center, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Qibing Xie
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
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Wang S, Bi J, Li C, Li B. Latrophilin, an adhesion GPCR with galactose-binding lectin domain involved in the innate immune response of Tribolium castaneum. Int J Biol Macromol 2023; 253:126707. [PMID: 37673160 DOI: 10.1016/j.ijbiomac.2023.126707] [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: 05/31/2023] [Revised: 08/28/2023] [Accepted: 09/03/2023] [Indexed: 09/08/2023]
Abstract
Latrophilin is a member of adhesion GPCRs involved in various physiological pro1cesses. The extracellular fragment of Tribolium castaneum Latrophilin (TcLph) contains a galactose-binding lectin (GBL) domain. However, the biological function of GBL domain remains mysterious. Here, we initially studied the role of TcLph in recognizing pathogens through its GBL domain and then triggering immune defense in invertebrates. Results showed that GBL domain was highly conserved, and its predicted 3D structure was similar to rhamnose-binding lectin domain of mouse Latrophilin-1 with a unique α/β fold and two long loops. Molecular docking and ELISA results revealed the GBL domain can bind to D-galactose, L-rhamnose, lipopolysaccharide and peptidoglycan. The recombinant extracellular segment of TcLph and the recombinant GBL exhibited strong agglutinating and binding activities to all tested bacteria in a Ca2+-dependent manner. Moreover, TcLph was markedly induced after infection by Escherichia coli or Staphylococcus aureus, while its silencing exacerbated bacterial loads and larvae mortality. TcLph-deficient larvae significantly decreased the transcription levels of antimicrobial peptides and prophenoloxidase activating system-related genes, leading to a significant reduction in phenoloxidase activity. It indicated that TcLph functioned as a pattern recognition receptor in pathogen recognition and activated immune responses to eliminate invasive microbes, suggesting a potential target for insecticides.
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Affiliation(s)
- Suisui Wang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Jingxiu Bi
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China; Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Chengjun Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Bin Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
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Anandachar MS, Roy S, Sinha S, Boadi A, Katkar GD, Ghosh P. Diverse gut pathogens exploit the host engulfment pathway via a conserved mechanism. J Biol Chem 2023; 299:105390. [PMID: 37890785 PMCID: PMC10696401 DOI: 10.1016/j.jbc.2023.105390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/22/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
Macrophages clear infections by engulfing and digesting pathogens within phagolysosomes. Pathogens escape this fate by engaging in a molecular arms race; they use WxxxE motif-containing "effector" proteins to subvert the host cells they invade and seek refuge within protective vacuoles. Here, we define the host component of the molecular arms race as an evolutionarily conserved polar "hot spot" on the PH domain of ELMO1 (Engulfment and Cell Motility protein 1), which is targeted by diverse WxxxE effectors. Using homology modeling and site-directed mutagenesis, we show that a lysine triad within the "patch" directly binds all WxxxE effectors tested: SifA (Salmonella), IpgB1 and IpgB2 (Shigella), and Map (enteropathogenic Escherichia coli). Using an integrated SifA-host protein-protein interaction network, in silico network perturbation, and functional studies, we show that the major consequences of preventing SifA-ELMO1 interaction are reduced Rac1 activity and microbial invasion. That multiple effectors of diverse structure, function, and sequence bind the same hot spot on ELMO1 suggests that the WxxxE effector(s)-ELMO1 interface is a convergence point of intrusion detection and/or host vulnerability. We conclude that the interface may represent the fault line in coevolved molecular adaptations between pathogens and the host, and its disruption may serve as a therapeutic strategy.
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Affiliation(s)
- Mahitha Shree Anandachar
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA; Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Suchismita Roy
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Saptarshi Sinha
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Agyekum Boadi
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Gajanan D Katkar
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA.
| | - Pradipta Ghosh
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, USA; Department of Medicine, University of California San Diego, San Diego, California, USA.
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7
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Schneider K, Arandjelovic S. Apoptotic cell clearance components in inflammatory arthritis. Immunol Rev 2023; 319:142-150. [PMID: 37507355 PMCID: PMC10615714 DOI: 10.1111/imr.13256] [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: 05/07/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints that affects ~1% of the human population. Joint swelling and bone erosion, hallmarks of RA, contribute to disability and, sometimes, loss of life. Mechanistically, disease is driven by immune dysregulation characterized by circulating autoantibodies, inflammatory mediators, tissue degradative enzymes, and metabolic dysfunction of resident stromal and recruited immune cells. Cell death by apoptosis has been therapeutically explored in animal models of RA due to the comparisons drawn between synovial hyperplasia and paucity of apoptosis in RA with the malignant transformation of cancer cells. Several efforts to induce cell death have shown benefits in reducing the development and/or severity of the disease. Apoptotic cells are cleared by phagocytes in a process known as efferocytosis, which differs from microbial phagocytosis in its "immuno-silent," or anti-inflammatory, nature. Failures in efferocytosis have been linked to autoimmune disease, whereas administration of apoptotic cells in RA models effectively inhibits inflammatory indices, likely though efferocytosis-mediated resolution-promoting mechanisms. However, the nature of signaling pathways elicited and the molecular identity of clearance mediators in RA are understudied. Furthermore, canonical efferocytosis machinery elements also play important non-canonical functions in homeostasis and pathology. Here, we discuss the roles of efferocytosis machinery components in models of RA and discuss their potential involvement in disease pathophysiology.
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Affiliation(s)
- Kevin Schneider
- University of Virginia, Center for Immunity, Inflammation and Regenerative Medicine, Department of Medicine, Charlottesville, VA, USA
| | - Sanja Arandjelovic
- University of Virginia, Center for Immunity, Inflammation and Regenerative Medicine, Department of Medicine, Charlottesville, VA, USA
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8
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Anandachar MS, Roy S, Sinha S, Agyekum B, Ibeawuchi SR, Gementera H, Amamoto A, Katkar GD, Ghosh P. Diverse Gut Pathogens Exploit the Host Engulfment Pathway via a Conserved Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.09.536168. [PMID: 37066267 PMCID: PMC10104235 DOI: 10.1101/2023.04.09.536168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Macrophages clear infections by engulfing and digesting pathogens within phagolysosomes. Pathogens escape this fate by engaging in a molecular arms race; they use WxxxE motif-containing effector proteins to subvert the host cells they invade and seek refuge within protective vacuoles. Here we define the host component of the molecular arms race as an evolutionarily conserved polar hotspot on the PH-domain of ELMO1 (Engulfment and Cell Motility1), which is targeted by diverse WxxxE-effectors. Using homology modeling and site-directed mutagenesis, we show that a lysine triad within the patch directly binds all WxxxE-effectors tested: SifA (Salmonella), IpgB1 and IpgB2 (Shigella), and Map (enteropathogenic E. coli). Using an integrated SifA-host protein-protein interaction (PPI) network, in-silico network perturbation, and functional studies we show that the major consequences of preventing SifA-ELMO1 interaction are reduced Rac1 activity and microbial invasion. That multiple effectors of diverse structure, function, and sequence bind the same hotpot on ELMO1 suggests that the WxxxE-effector(s)-ELMO1 interface is a convergence point of intrusion detection and/or host vulnerability. We conclude that the interface may represent the fault line in co-evolved molecular adaptations between pathogens and the host and its disruption may serve as a therapeutic strategy.
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9
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Moon B, Yang S, Moon H, Lee J, Park D. After cell death: the molecular machinery of efferocytosis. Exp Mol Med 2023; 55:1644-1651. [PMID: 37612408 PMCID: PMC10474042 DOI: 10.1038/s12276-023-01070-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 08/25/2023] Open
Abstract
Cells constituting a multicellular organism die in a variety of ways throughout life, and most of them die via apoptosis under normal conditions. The occurrence of apoptosis is especially prevalent during development and in tissues with a high cellular turnover rate, such as the thymus and bone marrow. Interestingly, although the number of apoptotic cells produced daily is known to be innumerable in a healthy adult human body, apoptotic cells are rarely observed. This absence is due to the existence of a cellular process called efferocytosis that efficiently clears apoptotic cells. Studies over the past decades have focused on how phagocytes are able to remove apoptotic cells specifically, swiftly, and continuously, resulting in defined molecular and cellular events. In this review, we will discuss the current understanding of the clearance of apoptotic cells at the molecular level.
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Affiliation(s)
- Byeongjin Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Susumin Yang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hyunji Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Juyeon Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
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Sakuragi T, Nagata S. Regulation of phospholipid distribution in the lipid bilayer by flippases and scramblases. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00604-z. [PMID: 37106071 PMCID: PMC10134735 DOI: 10.1038/s41580-023-00604-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2023] [Indexed: 04/29/2023]
Abstract
Cellular membranes function as permeability barriers that separate cells from the external environment or partition cells into distinct compartments. These membranes are lipid bilayers composed of glycerophospholipids, sphingolipids and cholesterol, in which proteins are embedded. Glycerophospholipids and sphingolipids freely move laterally, whereas transverse movement between lipid bilayers is limited. Phospholipids are asymmetrically distributed between membrane leaflets but change their location in biological processes, serving as signalling molecules or enzyme activators. Designated proteins - flippases and scramblases - mediate this lipid movement between the bilayers. Flippases mediate the confined localization of specific phospholipids (phosphatidylserine (PtdSer) and phosphatidylethanolamine) to the cytoplasmic leaflet. Scramblases randomly scramble phospholipids between leaflets and facilitate the exposure of PtdSer on the cell surface, which serves as an important signalling molecule and as an 'eat me' signal for phagocytes. Defects in flippases and scramblases cause various human diseases. We herein review the recent research on the structure of flippases and scramblases and their physiological roles. Although still poorly understood, we address the mechanisms by which they translocate phospholipids between lipid bilayers and how defects cause human diseases.
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Affiliation(s)
- Takaharu Sakuragi
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shigekazu Nagata
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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11
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Tseng WY, Stacey M, Lin HH. Role of Adhesion G Protein-Coupled Receptors in Immune Dysfunction and Disorder. Int J Mol Sci 2023; 24:ijms24065499. [PMID: 36982575 PMCID: PMC10055975 DOI: 10.3390/ijms24065499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/02/2023] [Accepted: 03/12/2023] [Indexed: 03/18/2023] Open
Abstract
Disorders of the immune system, including immunodeficiency, immuno-malignancy, and (auto)inflammatory, autoimmune, and allergic diseases, have a great impact on a host’s health. Cellular communication mediated through cell surface receptors, among different cell types and between cell and microenvironment, plays a critical role in immune responses. Selective members of the adhesion G protein-coupled receptor (aGPCR) family are expressed differentially in diverse immune cell types and have been implicated recently in unique immune dysfunctions and disorders in part due to their dual cell adhesion and signaling roles. Here, we discuss the molecular and functional characteristics of distinctive immune aGPCRs and their physiopathological roles in the immune system.
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Affiliation(s)
- Wen-Yi Tseng
- Division of Rheumatology, Allergy, and Immunology, Chang Gung Memorial Hospital-Keelung, Keelung 20401, Taiwan
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Whole-Genome Research Core Laboratory of Human Diseases, Chang Gung Memorial Hospital, Keelung 20401, Taiwan
| | - Martin Stacey
- Faculty of Biological Sciences, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Hsi-Hsien Lin
- Division of Rheumatology, Allergy, and Immunology, Chang Gung Memorial Hospital-Keelung, Keelung 20401, Taiwan
- Department of Anatomic Pathology, Chang Gung Memorial Hospital-Linkou, Taoyuan 33305, Taiwan
- Graduate School of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Correspondence:
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12
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Wu L, Seon GM, Ju S, Choi SH, Jiang ES, Kim Y, Chung SH, Ahn JS, Yang HC. Synergistic effects of arginine-glycine-aspartic acid and phosphatidylserine on the surface immunomodulation and osseointegration of titanium implants. Biomater Sci 2023; 11:1358-1372. [PMID: 36594560 DOI: 10.1039/d2bm01589g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The control of macrophage polarization is important in bone tissue regeneration such as osseointegration. In this study, a coating method was developed to improve the osseointegration of titanium (Ti) implants by generating an immunomodulatory effect. The surface of the Ti discs was coated with a poly(lactide-co-glycolide)(PLGA) polymer, phosphatidylserine (PS), and arginine-glycine-aspartic acid (RGD) peptide conjugated phospholipid. In in vitro assay using mouse bone marrow-derived macrophages (BMDMs), the most significant expression of the M2 marker genes (Arg-1, YM-1, FIZZ1) and CD206, an M2 surface marker, was obtained with coatings containing 6 mol% RGD conjugates and phospholipids consisting of 50 mol% PS. The M2-inducing effect of RGD and PS was also verified in rat femurs where coated Ti rods were implanted. The RGD and PS coating significantly enhanced the osseointegration of the Ti implants. Moreover, a biomechanical push-out test showed that the RGD and PS coating increased the interfacial binding force between the bone and implants. These results indicate that PS and RGD can be applied to the solid surface of implantable biomedical devices to improve immunomodulation and tissue regeneration.
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Affiliation(s)
- Lele Wu
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Gyeung Mi Seon
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Sungwon Ju
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Sang Hoon Choi
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - En-Shi Jiang
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Yongjoon Kim
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Shin Hye Chung
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Jin-Soo Ahn
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
| | - Hyeong-Cheol Yang
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, 101, Deahak-ro, Jongno-gu, Seoul 03080, South Korea.
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13
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The Oligosaccharide Region of LPS Governs Predation of E. coli by the Bacterivorous Protist, Acanthamoeba castellanii. Microbiol Spectr 2023; 11:e0293022. [PMID: 36648221 PMCID: PMC9927288 DOI: 10.1128/spectrum.02930-22] [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] [Indexed: 01/18/2023] Open
Abstract
Protozoan predation is a major cause of bacterial mortality. The first step of predation for phagocytic amoebae is the recognition of their prey. Lipopolysaccharide (LPS) is a major component of Gram-negative bacteria and is only present on the outer leaflet of the outer membrane lipid bilayer. LPS consists of three distinct regions: lipid A, an oligosaccharide core, and O-polysaccharide. Previous research in our lab determined that the oligosaccharide (OS) region of LPS mediates the recognition and internalization of Escherichia coli by Acanthamoeba castellanii. The oligosaccharide region is conceptually divided into the inner core and outer core. The LPS of any given E. coli strain contains only one of five different OS structures: K-12 and R1 to R4. All OSs contain the same inner core sugars but different outer core sugars. Here, we show that the Kdo2 moiety of the inner core is necessary and sufficient for E. coli recognition and internalization by A. castellanii. We also show that the precise composition of the variable outer core OS region modulates the efficiency with which A. castellanii consumes bacteria. The latter finding indicates that outer core OS composition plays a role in bacterial defense against phagocytic predators. IMPORTANCE Rather than being transmitted from host to host, most opportunistic bacterial pathogens reside in the environment for significant amounts of time. Protist predation is a major cause of bacterial mortality. To enhance their survival in the environment, bacteria have evolved various defense strategies such as filamentation, increased motility, biofilm formation, toxin release, and modification of cell wall structure; strategies which also enhance their virulence to humans. This work shows that the major component of the bacterial cell wall, LPS, also known as bacterial endotoxin, is a "dual use" factor, regulating amoeba predation of bacteria in addition to its well-known role as a human virulence factor. Both these functions are governed by the same parts of LPS. Thus, the structure and composition of this "dual use" factor likely evolved as a response to constant voracious protist grazing pressure in the environment, rather than during short-term infections of human and animals.
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14
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Yang TM, Miao M, Yu WQ, Wang X, Xia FJ, Li YJ, Guo SD. Targeting macrophages in atherosclerosis using nanocarriers loaded with liver X receptor agonists: A narrow review. Front Mol Biosci 2023; 10:1147699. [PMID: 36936982 PMCID: PMC10018149 DOI: 10.3389/fmolb.2023.1147699] [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: 01/19/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
Macrophages are involved in the whole process of atherosclerosis, which is characterized by accumulation of lipid and inflammation. Presently, clinically used lipid-lowering drugs cannot completely retard the progress of atherosclerosis. Liver X receptor (LXR) plays a key role in regulation of lipid metabolism and inflammation. Accumulating evidence have demonstrated that synthetic LXR agonists can significantly retard the development of atherosclerosis. However, these agonists induce sever hypertriglyceridemia and liver steatosis. These side effects have greatly limited their potential application for therapy of atherosclerosis. The rapid development of drug delivery system makes it possible to delivery interested drugs to special organs or cells using nanocarriers. Macrophages express various receptors which can recognize and ingest specially modified nanocarriers loaded with LXR agonists. In the past decades, a great progress has been made in this field. These macrophage-targeted nanocarriers loaded with LXR agonists are found to decrease atherosclerosis by reducing cholesterol accumulation and inflammatory reactions. Of important, these nanocarriers can alleviate side effects of LXR agonists. In this article, we briefly review the roles of macrophages in atherosclerosis, mechanisms of action of LXR agonists, and focus on the advances of macrophage-targeted nanocarriers loaded with LXR agonists. This work may promote the potential clinical application of these nanocarriers.
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Affiliation(s)
| | | | | | | | | | - Yan-Jie Li
- *Correspondence: Yan-Jie Li, ; Shou-Dong Guo,
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15
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Wen B, Li S, Ruan L, Yang Y, Chen Z, Zhang B, Yang X, Jie H, Li S, Zeng Z, Liu S. Engulfment and cell motility protein 1 fosters reprogramming of tumor-associated macrophages in colorectal cancer. Cancer Sci 2022; 114:410-422. [PMID: 36310143 PMCID: PMC9899619 DOI: 10.1111/cas.15628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/26/2022] [Accepted: 10/18/2022] [Indexed: 11/29/2022] Open
Abstract
Functional reprogramming of tumor-associated macrophages (TAMs) is crucial to their potent tumor-supportive capacity. However, the molecular mechanism behind the reprogramming process remains poorly understood. Here, we identify engulfment and cell motility protein 1 (ELMO1) as a crucial player for TAM reprogramming in colorectal cancer (CRC). The expression of ELMO1 in stromal but not epithelial tumor cells was positively associated with advanced clinical stage and poor disease-free survival in CRC. An increase in ELMO1 expression was specifically found in TAMs, but not in other multiple nonmalignant stromal cells. Gain- and loss-of-function assays indicated ELMO1 reprogrammed macrophages to a TAM-like phenotype through Rac1 activation. In turn, ELMO1-reprogrammed macrophages were shown to not only facilitate the malignant behaviors of CRC cells but exhibited potent phagocytosis of tumor cells. Taken together, our work underscores the importance of ELMO1 in determining functional reprogramming of TAMs and could provide new insights on potential therapeutic strategies against CRC.
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Affiliation(s)
- Bo Wen
- Department of Gastrointestinal SurgeryCentral Hospital of ShaoyangShaoyangChina
| | - Sheng Li
- Department of Gastrointestinal SurgeryCentral Hospital of ShaoyangShaoyangChina
| | - Lei Ruan
- Department of Colorectal Surgery and Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina
| | - Yanping Yang
- Department of PathologyCentral Hospital of ShaoyangShaoyangChina
| | - Zilin Chen
- Department of Medical OncologyCentral Hospital of ShaoyangShaoyangChina
| | - Bin Zhang
- Department of Gastrointestinal SurgeryCentral Hospital of ShaoyangShaoyangChina
| | - Xin Yang
- Department of Colorectal Surgery and Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina
| | - Haiqing Jie
- Department of Colorectal Surgery and Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina
| | - Shujuan Li
- Department of PharmacyThe Third Affiliated Hospital of Zhengzhou UniversityZhengzhou, HenanChina
| | - Ziwei Zeng
- Department of Colorectal Surgery and Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,University Clinic MannheimMedical Faculty Mannheim, University of HeidelbergMannheimGermany
| | - Sisi Liu
- Department of PathologyCentral Hospital of ShaoyangShaoyangChina
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16
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Lala T, Doan JK, Takatsu H, Hartzell HC, Shin HW, Hall RA. Phosphatidylserine exposure modulates adhesion GPCR BAI1 (ADGRB1) signaling activity. J Biol Chem 2022; 298:102685. [PMID: 36370845 PMCID: PMC9723945 DOI: 10.1016/j.jbc.2022.102685] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 11/10/2022] Open
Abstract
Brain-specific angiogenesis inhibitor 1 (BAI1; also called ADGRB1 or B1) is an adhesion G protein-coupled receptor known from studies on macrophages to bind to phosphatidylserine (PS) on apoptotic cells via its N-terminal thrombospondin repeats. A separate body of work has shown that B1 regulates postsynaptic function and dendritic spine morphology via signaling pathways involving Rac and Rho. However, it is unknown if PS binding by B1 has any effect on the receptor's signaling activity. To shed light on this subject, we studied G protein-dependent signaling by B1 in the absence and presence of coexpression with the PS flippase ATP11A in human embryonic kidney 293T cells. ATP11A expression reduced the amount of PS exposed extracellularly and also strikingly reduced the signaling activity of coexpressed full-length B1 but not a truncated version of the receptor lacking the thrombospondin repeats. Further experiments with an inactive mutant of ATP11A showed that the PS flippase function of ATP11A was required for modulation of B1 signaling. In coimmunoprecipitation experiments, we made the surprising finding that ATP11A not only modulates B1 signaling but also forms complexes with B1. Parallel studies in which PS in the outer leaflet was reduced by an independent method, deletion of the gene encoding the endogenous lipid scramblase anoctamin 6 (ANO6), revealed that this manipulation also markedly reduced B1 signaling. These findings demonstrate that B1 signaling is modulated by PS exposure and suggest a model in which B1 serves as a PS sensor at synapses and in other cellular contexts.
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Affiliation(s)
- Trisha Lala
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Juleva K Doan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Hiroyuki Takatsu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - H Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Hye-Won Shin
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Randy A Hall
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia, USA.
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17
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Gauthier AE, Rotjan RD, Kagan JC. Lipopolysaccharide detection by the innate immune system may be an uncommon defence strategy used in nature. Open Biol 2022; 12:220146. [PMID: 36196535 PMCID: PMC9533005 DOI: 10.1098/rsob.220146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/09/2022] [Indexed: 11/12/2022] Open
Abstract
Since the publication of the Janeway's Pattern Recognition hypothesis in 1989, study of pathogen-associated molecular patterns (PAMPs) and their immuno-stimulatory activities has accelerated. Most studies in this area have been conducted in model organisms, which leaves many open questions about the universality of PAMP biology across living systems. Mammals have evolved multiple proteins that operate as receptors for the PAMP lipopolysaccharide (LPS) from Gram-negative bacteria, but LPS is not immuno-stimulatory in all eukaryotes. In this review, we examine the history of LPS as a PAMP in mammals, recent data on LPS structure and its ability to activate mammalian innate immune receptors, and how these activities compare across commonly studied eukaryotes. We discuss why LPS may have evolved to be immuno-stimulatory in some eukaryotes but not others and propose two hypotheses about the evolution of PAMP structure based on the ecology and environmental context of the organism in question. Understanding PAMP structures and stimulatory mechanisms across multi-cellular life will provide insights into the evolutionary origins of innate immunity and may lead to the discovery of new PAMP variations of scientific and therapeutic interest.
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Affiliation(s)
- Anna E. Gauthier
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA, USA
| | - Randi D. Rotjan
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Jonathan C. Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
- Harvard Medical School, and Boston Children's Hospital, Division of Immunology, Division of Gastroenterology, USA
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18
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Lala T, Hall RA. Adhesion G protein-coupled receptors: structure, signaling, physiology, and pathophysiology. Physiol Rev 2022; 102:1587-1624. [PMID: 35468004 PMCID: PMC9255715 DOI: 10.1152/physrev.00027.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 03/11/2022] [Accepted: 04/16/2022] [Indexed: 01/17/2023] Open
Abstract
Adhesion G protein-coupled receptors (AGPCRs) are a family of 33 receptors in humans exhibiting a conserved general structure but diverse expression patterns and physiological functions. The large NH2 termini characteristic of AGPCRs confer unique properties to each receptor and possess a variety of distinct domains that can bind to a diverse array of extracellular proteins and components of the extracellular matrix. The traditional view of AGPCRs, as implied by their name, is that their core function is the mediation of adhesion. In recent years, though, many surprising advances have been made regarding AGPCR signaling mechanisms, activation by mechanosensory forces, and stimulation by small-molecule ligands such as steroid hormones and bioactive lipids. Thus, a new view of AGPCRs has begun to emerge in which these receptors are seen as massive signaling platforms that are crucial for the integration of adhesive, mechanosensory, and chemical stimuli. This review article describes the recent advances that have led to this new understanding of AGPCR function and also discusses new insights into the physiological actions of these receptors as well as their roles in human disease.
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Affiliation(s)
- Trisha Lala
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Randy A Hall
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia
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19
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Sreepada A, Tiwari M, Pal K. Adhesion G protein-coupled receptor gluing action guides tissue development and disease. J Mol Med (Berl) 2022; 100:1355-1372. [PMID: 35969283 DOI: 10.1007/s00109-022-02240-0] [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: 01/25/2022] [Revised: 06/23/2022] [Accepted: 07/21/2022] [Indexed: 10/15/2022]
Abstract
Phylogenetic analysis of human G protein-coupled receptors (GPCRs) divides these transmembrane signaling proteins into five groups: glutamate, rhodopsin, adhesion, frizzled, and secretin families, commonly abbreviated as the GRAFS classification system. The adhesion GPCR (aGPCR) sub-family comprises 33 different receptors in humans. Majority of the aGPCRs are orphan receptors with unknown ligands, structures, and tissue expression profiles. They have a long N-terminal extracellular domain (ECD) with several adhesion sites similar to integrin receptors. Many aGPCRs undergo autoproteolysis at the GPCR proteolysis site (GPS), enclosed within the larger GPCR autoproteolysis inducing (GAIN) domain. Recent breakthroughs in aGPCR research have created new paradigms for understanding their roles in organogenesis. They play crucial roles in multiple aspects of organ development through cell signaling, intercellular adhesion, and cell-matrix associations. They are involved in essential physiological processes like regulation of cell polarity, mitotic spindle orientation, cell adhesion, and migration. Multiple aGPCRs have been associated with the development of the brain, musculoskeletal system, kidneys, cardiovascular system, hormone secretion, and regulation of immune functions. Since aGPCRs have crucial roles in tissue patterning and organogenesis, mutations in these receptors are often associated with diseases with loss of tissue integrity. Thus, aGPCRs include a group of enigmatic receptors with untapped potential for elucidating novel signaling pathways leading to drug discovery. We summarized the current knowledge on how aGPCRs play critical roles in organ development and discussed how aGPCR mutations/genetic variants cause diseases.
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Affiliation(s)
- Abhijit Sreepada
- Department of Biology, Ashoka University, Rajiv Gandhi Education City, Sonipat, Haryana, 131029, India
| | - Mansi Tiwari
- Department of Biology, Ashoka University, Rajiv Gandhi Education City, Sonipat, Haryana, 131029, India
| | - Kasturi Pal
- Department of Biology, Ashoka University, Rajiv Gandhi Education City, Sonipat, Haryana, 131029, India.
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20
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Sharma A, Achi SC, Ibeawuchi S, Anandachar MS, Gementera H, Chaudhury U, Usmani F, Vega K, Sayed IM, Das S. The crosstalk between microbial sensors ELMO1 and NOD2 shape intestinal immune responses.. [DOI: 10.1101/2022.07.09.499433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
ABSTRACTMicrobial sensors play an essential role in maintaining cellular homeostasis. Our knowledge is limited on how microbial sensing helps in differential immune response and its link to inflammatory diseases. Recently, we have shown that cytosolic sensor ELMO1 (Engulfment and Cell Motility Protein-1) binds to effectors from pathogenic bacteria and controls intestinal inflammation. Here, we show that ELMO1 interacts with another sensor, NOD2 (Nucleotide-binding oligomerization domain-containing protein 2), that recognizes bacterial cell wall component muramyl dipeptide (MDP). The polymorphism of NOD2 is linked to Crohn’s disease (CD) pathogenesis. Interestingly, we found that overexpression of ELMO1 and mutant NOD2 (L1007fs) were not able to clear the CD-associated adherent invasive E. coli (AIEC-LF82). To understand the interplay of microbial sensing of ELMO1-NOD2 in epithelial cells and macrophages, we used enteroid-derived monolayers (EDMs) from ELMO1 and NOD2 KO mice and ELMO1 and NOD2-depleted murine macrophage cell lines. The infection of murine EDMs with AIEC-LF82 showed higher bacterial load in ELMO1-KO, NOD2 KO EDMs, and ELMO1 KO EDMs treated with NOD2 inhibitors. The murine macrophage cells showed that the downregulation of ELMO1 and NOD2 is associated with impaired bacterial clearance that is linked to reduced pro-inflammatory cytokines and reactive oxygen species. Our results indicated that the crosstalk between microbial sensors in enteric infection and inflammatory diseases impacts the fate of the bacterial load and disease pathogenesis.
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21
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Tocci S, Ibeawuchi SR, Das S, Sayed IM. Role of ELMO1 in inflammation and cancer-clinical implications. Cell Oncol (Dordr) 2022; 45:505-525. [PMID: 35668246 DOI: 10.1007/s13402-022-00680-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Engulfment and cell motility protein 1 (ELMO1) is a key protein for innate immunity since it is required for the clearance of apoptotic cells and pathogenic bacteria as well as for the control of inflammatory responses. ELMO1, through binding with Dock180 and activation of the Rac1 signaling pathway, plays a significant role in cellular shaping and motility. Rac-mediated actin cytoskeletal rearrangement is essential for bacterial phagocytosis, but also plays a crucial role in processes such as cancer cell invasion and metastasis. While the role of ELMO1 in bacterial infection and inflammatory responses is well established, its implication in cancer is not widely explored yet. Molecular changes or epigenetic alterations such as DNA methylation, which ultimately leads to alterations in gene expression and deregulation of cellular signaling, has been reported for ELMO1 in different cancer types. CONCLUSIONS In this review, we provide an updated and comprehensive summary of the roles of ELMO1 in infection, inflammatory diseases and cancer. We highlight the possible mechanisms regulated by ELMO1 that are relevant for cancer development and progression and provide insight into the possible use of ELMO1 as a diagnostic biomarker and therapeutic target.
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Affiliation(s)
- Stefania Tocci
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | | | - Soumita Das
- Department of Pathology, University of California San Diego, La Jolla, CA, USA.
| | - Ibrahim M Sayed
- Department of Pathology, University of California San Diego, La Jolla, CA, USA. .,Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt.
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22
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Shiu FH, Wong JC, Yamamoto T, Lala T, Purcell RH, Owino S, Zhu D, Van Meir EG, Hall RA, Escayg A. Mice lacking full length Adgrb1 (Bai1) exhibit social deficits, increased seizure susceptibility, and altered brain development. Exp Neurol 2022; 351:113994. [PMID: 35114205 PMCID: PMC9817291 DOI: 10.1016/j.expneurol.2022.113994] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 01/11/2023]
Abstract
The adhesion G protein-coupled receptor BAI1/ADGRB1 plays an important role in suppressing angiogenesis, mediating phagocytosis, and acting as a brain tumor suppressor. BAI1 is also a critical regulator of dendritic spine and excitatory synapse development and interacts with several autism-relevant proteins. However, little is known about the relationship between altered BAI1 function and clinically relevant phenotypes. Therefore, we studied the effect of reduced expression of full length Bai1 on behavior, seizure susceptibility, and brain morphology in Adgrb1 mutant mice. We compared homozygous (Adgrb1-/-), heterozygous (Adgrb1+/-), and wild-type (WT) littermates using a battery of tests to assess social behavior, anxiety, repetitive behavior, locomotor function, and seizure susceptibility. We found that Adgrb1-/- mice showed significant social behavior deficits and increased vulnerability to seizures. Adgrb1-/- mice also showed delayed growth and reduced brain weight. Furthermore, reduced neuron density and increased apoptosis during brain development were observed in the hippocampus of Adgrb1-/- mice, while levels of astrogliosis and microgliosis were comparable to WT littermates. These results show that reduced levels of full length Bai1 is associated with a broader range of clinically relevant phenotypes than previously reported.
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Affiliation(s)
- Fu Hung Shiu
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA; Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA
| | - Jennifer C Wong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Takahiro Yamamoto
- Department of Neurosurgery, School of Medicine, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Trisha Lala
- Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA; Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Ryan H Purcell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Sharon Owino
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Dan Zhu
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Erwin G Van Meir
- Department of Neurosurgery, School of Medicine, University of Alabama at Birmingham (UAB), Birmingham, AL, USA; O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Randy A Hall
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA.
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23
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Katkar GD, Sayed IM, Anandachar MS, Castillo V, Vidales E, Toobian D, Usmani F, Sawires JR, Leriche G, Yang J, Sandborn WJ, Das S, Sahoo D, Ghosh P. Artificial intelligence-rationalized balanced PPARα/γ dual agonism resets dysregulated macrophage processes in inflammatory bowel disease. Commun Biol 2022; 5:231. [PMID: 35288651 PMCID: PMC8921270 DOI: 10.1038/s42003-022-03168-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 02/07/2022] [Indexed: 12/12/2022] Open
Abstract
A computational platform, Boolean network explorer (BoNE), has recently been developed to infuse AI-enhanced precision into drug discovery; it enables invariant Boolean Implication Networks of disease maps for prioritizing high-value targets. Here we used BoNE to query an Inflammatory Bowel Disease (IBD)-map and prioritize a therapeutic strategy that involves dual agonism of two nuclear receptors, PPARα/γ. Balanced agonism of PPARα/γ was predicted to modulate macrophage processes, ameliorate colitis, 'reset' the gene expression network from disease to health. Predictions were validated using a balanced and potent PPARα/γ-dual-agonist (PAR5359) in Citrobacter rodentium- and DSS-induced murine colitis models. Using inhibitors and agonists, we show that balanced-dual agonism promotes bacterial clearance efficiently than individual agonists, both in vivo and in vitro. PPARα is required and sufficient to induce the pro-inflammatory cytokines and cellular ROS, which are essential for bacterial clearance and immunity, whereas PPARγ-agonism blunts these responses, delays microbial clearance; balanced dual agonism achieved controlled inflammation while protecting the gut barrier and 'reversal' of the transcriptomic network. Furthermore, dual agonism reversed the defective bacterial clearance observed in PBMCs derived from IBD patients. These findings not only deliver a macrophage modulator for use as barrier-protective therapy in IBD, but also highlight the potential of BoNE to rationalize combination therapy.
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Affiliation(s)
- Gajanan D Katkar
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, USA
| | - Ibrahim M Sayed
- Department of Pathology, University of California San Diego, San Diego, USA.,Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | | | - Vanessa Castillo
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, USA
| | - Eleadah Vidales
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, USA
| | - Daniel Toobian
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, USA
| | - Fatima Usmani
- Department of Pathology, University of California San Diego, San Diego, USA
| | - Joseph R Sawires
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, USA
| | - Geoffray Leriche
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, USA
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, USA
| | - William J Sandborn
- Department of Medicine, University of California San Diego, San Diego, USA.
| | - Soumita Das
- Department of Pathology, University of California San Diego, San Diego, USA.
| | - Debashis Sahoo
- Department of Computer Science and Engineering, Jacob's School of Engineering, University of California San Diego, San Diego, USA. .,Department of Pediatrics, University of California San Diego, San Diego, USA. .,Rebecca and John Moore Comprehensive Cancer Center, University of California San Diego, San Diego, USA.
| | - Pradipta Ghosh
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, USA. .,Department of Medicine, University of California San Diego, San Diego, USA. .,Rebecca and John Moore Comprehensive Cancer Center, University of California San Diego, San Diego, USA. .,Veterans Affairs Medical Center, La Jolla, San Diego, USA.
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24
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Cheng Q, Xu M, Sun C, Yang K, Yang Z, Li J, Zheng J, Zheng Y, Wang R. Enhanced antibacterial function of a supramolecular artificial receptor-modified macrophage (SAR-Macrophage). MATERIALS HORIZONS 2022; 9:934-941. [PMID: 35037009 DOI: 10.1039/d1mh01813b] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Bacterial infection has become a global concern owing to the significant morbidity and mortality. Although the phagocytosis of bacteria by immune cells acts as the front line to protect human body from invading pathogens, the relatively slow encounter and insufficient capture of bacteria by immune cells often lead to an inefficient clearance of pathogens. Herein, a supramolecular artificial receptor-modified macrophage (SAR-Macrophage) was developed to enhance the recognition and latch of bacteria in the systemic circulation, mediated via strong and multipoint host-guest interactions between the artificial receptors (cucurbit[7]uril) on the macrophage and the guest ligands (adamantane) selectively anchored on Escherichia coli (E. coli). As a result, the SAR-Macrophage could significantly accelerate the recognition of E. coli, catch and internalize more pathogens, which subsequently induced the M1 polarization of macrophages to generate ROS and effectively kill the intracellular bacteria. Therefore, the SAR-Macrophage represents a simple, yet powerful anti-bacterial approach.
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Affiliation(s)
- Qian Cheng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Meng Xu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Chen Sun
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Kuikun Yang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Zhiqing Yang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Junyan Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
| | - Jun Zheng
- Department of Pharmaceutical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
| | - Ying Zheng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
- Department of Pharmaceutical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
| | - Ruibing Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau 999078, China.
- Department of Pharmaceutical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
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25
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Morozumi S, Ueda M, Okahashi N, Arita M. Structures and functions of the gut microbial lipidome. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159110. [PMID: 34995792 DOI: 10.1016/j.bbalip.2021.159110] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/19/2021] [Accepted: 12/24/2021] [Indexed: 12/26/2022]
Abstract
Microbial lipids provide signals that are responsible for maintaining host health and controlling disease. The differences in the structures of microbial lipids have been shown to alter receptor selectivity and agonist/antagonist activity. Advanced lipidomics is an emerging field that helps to elucidate the complex bacterial lipid diversity. The use of cutting-edge technologies is expected to lead to the discovery of new functional metabolites involved in host homeostasis. This review aims to describe recent updates on functional lipid metabolites derived from gut microbiota, their structure-activity relationships, and advanced lipidomics technologies.
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Affiliation(s)
- Satoshi Morozumi
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Masahiro Ueda
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; JSR Bioscience and Informatics R&D Center, JSR Corporation, 3-103-9 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-0821, Japan
| | - Nobuyuki Okahashi
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Makoto Arita
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan; Cellular and Molecular Epigenetics Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
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26
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Quach A, Jayaratne RR, Lee BJ, Ibeawuchi SR, Lim E, Das S, Barrett KE. Diarrheal pathogenesis in Salmonella infection may result from an imbalance in intestinal epithelial differentiation through reduced Notch signaling. J Physiol 2022; 600:1851-1865. [PMID: 35100665 DOI: 10.1113/jp282585] [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: 11/04/2021] [Accepted: 01/20/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Salmonella is a leading foodborne pathogen known to cause high chloride content diarrhea. Salmonella infection of murine enteroid-derived monolayers decreased DRA expression. Salmonella infection resulted in upregulation of the secretory epithelial marker ATOH1, the goblet cell marker Muc2, and the enteroendocrine cell marker ChgA. Downregulation of DRA may result from infection-induced Notch inhibition, as reflected by decreased expression of Notch intracellular domain and Hes1, as well as from decreased HNF1α signaling. The imbalance in intestinal epithelial differentiation favoring secretory over absorptive cell types is a possible mechanism by which Salmonella elicits diarrhea and may be relevant therapeutically. ABSTRACT Infections with non-typhoidal Salmonella spp. represent the most burdensome foodborne illnesses worldwide, yet despite their prevalence, the mechanism through which Salmonella elicits diarrhea is not entirely known. Intestinal ion transporters play important roles in fluid and electrolyte homeostasis in the intestine. We have previously shown that infection with Salmonella caused decreased colonic expression of the chloride/bicarbonate exchanger SLC26A3 (Down-Regulated in Adenoma; DRA) in a mouse model. In this study, we focused on the mechanism of DRA downregulation during Salmonella infection, by using murine epithelial enteroid-derived monolayers (EDM). The decrease in DRA expression caused by infection was recapitulated in EDM and accompanied by increased expression of ATOH1, the goblet cell marker Muc2, and the enteroendocrine cell marker ChgA. This suggested biased epithelial differentiation towards the secretory, rather than absorptive phenotype. In addition, the downstream Notch effector, Notch Intracellular Domain (NICD) and Hes1 were decreased following Salmonella infection. The relevance of Notch signaling was further investigated using a γ-secretase inhibitor, which recapitulated the downregulation in Hes1 and DRA as well as upregulation in ATOH1 and Muc2 seen following infection. Our findings suggest that Salmonella infection may result in a shift from absorptive to secretory cell types through Notch inhibition, which explains why there is a decreased capacity for absorption and ultimately the accumulation of diarrheal fluid. Our work also shows the value of EDM as a model to investigate mechanisms that might be targeted for therapy of diarrhea caused by Salmonella infection. Abstract figure legend Upon infection of the intestinal epithelium with Salmonella, diarrhea may be explained by an imbalance of intestinal epithelial differentiation. Downregulation of cell-fate commitment to the absorptive lineage, as reflected by decreased Hes1 and DRA, was observed. Conversely, upregulation of epithelial differentiation into secretory cell types was observed, as reflected by increased ATOH1, Muc2, and ChgA. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Andrew Quach
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Rashini R Jayaratne
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Beom Jae Lee
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA.,Department of Gastroenterology, Korea University Guro Hospital, Seoul, 08308, Republic of Korea
| | - Stella-Rita Ibeawuchi
- Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Eileen Lim
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Soumita Das
- Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Kim E Barrett
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA.,Current affiliation: UC Davis School of Medicine, Education Building, 4610 X Street, Sacramento, CA, 95817, USA
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Sayed IM, Ibeawuchi SR, Lie D, Anandachar MS, Pranadinata R, Raffatellu M, Das S. The interaction of enteric bacterial effectors with the host engulfment pathway control innate immune responses. Gut Microbes 2022; 13:1991776. [PMID: 34719317 PMCID: PMC8565811 DOI: 10.1080/19490976.2021.1991776] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Host engulfment protein ELMO1 generates intestinal inflammation following internalization of enteric bacteria. In Shigella, bacterial effector IpgB1 interacts with ELMO1 and promotes bacterial invasion. IpgB1 belongs to the WxxxE effector family, a motif found in several effectors of enteric pathogens. Here, we have studied the role of WxxxE effectors, with emphasis on Salmonella SifA and whether it interacts with ELMO1 to regulate inflammation. In-silico-analysis of WxxxE effectors was performed using BLAST search and Clustal W program. The interaction of ELMO1 with SifA was assessed by GST pulldown assay and co-immunoprecipitation. ELMO1 knockout mice, and ELMO1-depleted murine macrophage J774 cell lines were challenged with WT and SifA mutant Salmonella. Bacterial effectors containing the WxxxE motif were transfected in WT and ELMO1-depleted J774 cells to assess the inflammatory cytokines. ELMO1 generates differential pro-inflammatory cytokines between pathogenic and nonpathogenic bacteria. WxxxE motif is present in pathogens and in the TIR domain of host proteins. The C-terminal part of ELMO1 interacts with SifA where WxxxE motif is important for interaction. ELMO1-SifA interaction affects bacterial colonization, dissemination, and inflammatory cytokines in vivo. Moreover, ELMO1-SifA interaction increases TNF-α and IL-6 production from the macrophage cell line and is associated with enhanced Rac1 activity. ELMO1 also interacts with WxxxE effectors IpgB1, IpgB2, and Map and induces inflammation after challenge with microbes or microbial ligands. ELMO1 generates a differential response through interaction with the WxxxE motif, which is absent in commensals. ELMO1-WxxxE interaction plays a role in bacterial pathogenesis and induction of inflammatory response.
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Affiliation(s)
- Ibrahim M Sayed
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | | | - Dominique Lie
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | | | - Rama Pranadinata
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Manuela Raffatellu
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California San Diego, LA Jolla, CA, USA,Center for Mucosal Immunology, Chiba University-UC San Diego, La Jolla, CAUSA
| | - Soumita Das
- Department of Pathology, University of California San Diego, La Jolla, CA, USA,CONTACT Soumita Das Department of Pathology, University of California, San Diego, 9500 Gilman Drive, Mc 0644, George Palade Laboratory, Office Rm 256, San Diego, Ca, 92093-0644, USA
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28
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Wang J, Miao Y, Wicklein R, Sun Z, Wang J, Jude KM, Fernandes RA, Merrill SA, Wernig M, Garcia KC, Südhof TC. RTN4/NoGo-receptor binding to BAI adhesion-GPCRs regulates neuronal development. Cell 2021; 184:5869-5885.e25. [PMID: 34758294 PMCID: PMC8620742 DOI: 10.1016/j.cell.2021.10.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/01/2021] [Accepted: 10/13/2021] [Indexed: 10/19/2022]
Abstract
RTN4-binding proteins were widely studied as "NoGo" receptors, but their physiological interactors and roles remain elusive. Similarly, BAI adhesion-GPCRs were associated with numerous activities, but their ligands and functions remain unclear. Using unbiased approaches, we observed an unexpected convergence: RTN4 receptors are high-affinity ligands for BAI adhesion-GPCRs. A single thrombospondin type 1-repeat (TSR) domain of BAIs binds to the leucine-rich repeat domain of all three RTN4-receptor isoforms with nanomolar affinity. In the 1.65 Å crystal structure of the BAI1/RTN4-receptor complex, C-mannosylation of tryptophan and O-fucosylation of threonine in the BAI TSR-domains creates a RTN4-receptor/BAI interface shaped by unusual glycoconjugates that enables high-affinity interactions. In human neurons, RTN4 receptors regulate dendritic arborization, axonal elongation, and synapse formation by differential binding to glial versus neuronal BAIs, thereby controlling neural network activity. Thus, BAI binding to RTN4/NoGo receptors represents a receptor-ligand axis that, enabled by rare post-translational modifications, controls development of synaptic circuits.
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Affiliation(s)
- Jie Wang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yi Miao
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rebecca Wicklein
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Zijun Sun
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinzhao Wang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kevin M Jude
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ricardo A Fernandes
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sean A Merrill
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marius Wernig
- Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
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29
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Rothlin CV, Ghosh S. Lifting the innate immune barriers to antitumor immunity. J Immunother Cancer 2021; 8:jitc-2020-000695. [PMID: 32273348 PMCID: PMC7254113 DOI: 10.1136/jitc-2020-000695] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2020] [Indexed: 12/17/2022] Open
Abstract
The immune system evolved for adequate surveillance and killing of pathogens while minimizing host damage, such as due to chronic or exaggerated inflammation and autoimmunity. This is achieved by negative regulators and checkpoints that limit the magnitude and time course of the immune response. Tumor cells often escape immune surveillance and killing. Therefore, disrupting the brakes built into the immune system should effectively boost the anticancer immune response. The success of anti-CTLA4, anti-PD-1 and anti-PD-L1 have firmly established this proof of concept. Since the response rate of anti-CTLA4, anti-PD-1 and anti-PD-L1 is still limited, there is an intense effort for the identification of new targets and development of approaches that can expand the benefits of immunotherapy to a larger patient pool. Additional T cell checkpoints are obvious targets; however, here we focus on the unusual suspects—cells that function to initiate and guide T cell activity. Innate immunity is both an obligate prerequisite for the initiation of adaptive immune responses and a requirement for the recruitment of activated T cells to the site of action. We discuss some of the molecules present in innate immune cells, including natural killer cells, dendritic cells, macrophages, myeloid-derived suppressor cells, endothelial cells and stromal cells, that can activate or enhance innate immune cell functions, and more importantly, the inhibitors or checkpoints present in these cells that restrain their functions. Boosting innate immunity, either by enhancing activator functions or, preferably, by blocking the inhibitors, may represent a new anticancer treatment modality or at least function as adjuvants to T cell checkpoint inhibitors.
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Affiliation(s)
- Carla V Rothlin
- Immunobiology, Yale School of Medicine, New Haven, CT 06519, United States .,Pharmacology, Yale School of Medicine, New Haven, CT 06519, United States
| | - Sourav Ghosh
- Pharmacology, Yale School of Medicine, New Haven, CT 06519, United States .,Neurology, Yale School of Medicine, New Haven, CT 06519, United States
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30
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Di Lorenzo F, Duda KA, Lanzetta R, Silipo A, De Castro C, Molinaro A. A Journey from Structure to Function of Bacterial Lipopolysaccharides. Chem Rev 2021; 122:15767-15821. [PMID: 34286971 DOI: 10.1021/acs.chemrev.0c01321] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lipopolysaccharide (LPS) is a crucial constituent of the outer membrane of most Gram-negative bacteria, playing a fundamental role in the protection of bacteria from environmental stress factors, in drug resistance, in pathogenesis, and in symbiosis. During the last decades, LPS has been thoroughly dissected, and massive information on this fascinating biomolecule is now available. In this Review, we will give the reader a third millennium update of the current knowledge of LPS with key information on the inherent peculiar carbohydrate chemistry due to often puzzling sugar residues that are uniquely found on it. Then, we will drive the reader through the complex and multifarious immunological outcomes that any given LPS can raise, which is strictly dependent on its chemical structure. Further, we will argue about issues that still remain unresolved and that would represent the immediate future of LPS research. It is critical to address these points to complete our notions on LPS chemistry, functions, and roles, in turn leading to innovative ways to manipulate the processes involving such a still controversial and intriguing biomolecule.
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Affiliation(s)
- Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Katarzyna A Duda
- Research Center Borstel Leibniz Lung Center, Parkallee 4a, 23845 Borstel, Germany
| | - Rosa Lanzetta
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Cristina De Castro
- Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Department of Agricultural Sciences, University of Naples Federico II, Via Università 96, 80055 Portici, Naples, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Department of Chemistry, School of Science, Osaka University, 1-1 Osaka University Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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31
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Banesh S, Trivedi V. CD36 Ectodomain Detects Apoptosis in Mammalian Cells. Mol Biotechnol 2021; 63:992-1003. [PMID: 34173181 DOI: 10.1007/s12033-021-00356-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/13/2021] [Indexed: 11/27/2022]
Abstract
The cells that undergo apoptosis show phosphatidylserine (PS) on the cell membrane. The fluorescently labeled hCD36_ecto is staining and detecting apoptotic cells in a flow-based assay with several advantages over Annexin V. The human CD36 ectodomain (hCD36_ecto) is stable for a range of temperatures and experimental conditions and doesn't require Ca2+ for detecting apoptosis and specific towards PS compared to other lipids. The blocking with unlabeled hCD36_ecto reduces the staining of Annexin V-FITC for apoptotic cells, whereas R63A does not affect the binding of Annexin V- FITC to apoptotic cells. It indicates the role of CD36-PS interaction in detecting apoptotic cells. Dual-staining with hCD36_ecto-FITC/PI is universally detecting apoptosis in different nucleated cells or eryptosis in non-nucleated RBCs. Hence, our study highlights the utility of CD36 as a probe to detect apoptosis in mammalian cells. It might be a robust, economical reagent for the scientific community to facilitate their research.
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Affiliation(s)
- Sooram Banesh
- Malaria Research Group, Department of Biosciences and Bioengineering, Indian Institute of Technology-Guwahati, Guwahati, 781039, Assam, India
| | - Vishal Trivedi
- Malaria Research Group, Department of Biosciences and Bioengineering, Indian Institute of Technology-Guwahati, Guwahati, 781039, Assam, India.
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32
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Having an Old Friend for Dinner: The Interplay between Apoptotic Cells and Efferocytes. Cells 2021; 10:cells10051265. [PMID: 34065321 PMCID: PMC8161178 DOI: 10.3390/cells10051265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 02/02/2023] Open
Abstract
Apoptosis, the programmed and intentional death of senescent, damaged, or otherwise superfluous cells, is the natural end-point for most cells within multicellular organisms. Apoptotic cells are not inherently damaging, but if left unattended, they can lyse through secondary necrosis. The resulting release of intracellular contents drives inflammation in the surrounding tissue and can lead to autoimmunity. These negative consequences of secondary necrosis are avoided by efferocytosis—the phagocytic clearance of apoptotic cells. Efferocytosis is a product of both apoptotic cells and efferocyte mechanisms, which cooperate to ensure the rapid and complete removal of apoptotic cells. Herein, we review the processes used by apoptotic cells to ensure their timely removal, and the receptors, signaling, and cellular processes used by efferocytes for efferocytosis, with a focus on the receptors and signaling driving this process.
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33
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Saxena V, Gao H, Arregui S, Zollman A, Kamocka MM, Xuei X, McGuire P, Hutchens M, Hato T, Hains DS, Schwaderer AL. Kidney intercalated cells are phagocytic and acidify internalized uropathogenic Escherichia coli. Nat Commun 2021; 12:2405. [PMID: 33893305 PMCID: PMC8065053 DOI: 10.1038/s41467-021-22672-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 03/18/2021] [Indexed: 02/02/2023] Open
Abstract
Kidney intercalated cells are involved in acid-base homeostasis via vacuolar ATPase expression. Here we report six human intercalated cell subtypes, including hybrid principal-intercalated cells identified from single cell transcriptomics. Phagosome maturation is a biological process that increases in biological pathway analysis rank following exposure to uropathogenic Escherichia coli in two of the intercalated cell subtypes. Real time confocal microscopy visualization of murine renal tubules perfused with green fluorescent protein expressing Escherichia coli or pHrodo Green E. coli BioParticles demonstrates that intercalated cells actively phagocytose bacteria then acidify phagolysosomes. Additionally, intercalated cells have increased vacuolar ATPase expression following in vivo experimental UTI. Taken together, intercalated cells exhibit a transcriptional response conducive to the kidney's defense, engulf bacteria and acidify the internalized bacteria. Intercalated cells represent an epithelial cell with characteristics of professional phagocytes like macrophages.
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Affiliation(s)
- Vijay Saxena
- Indiana University School of Medicine, Department of Pediatrics, Division of Nephrology, Indianapolis, IN, USA.
| | - Hongyu Gao
- Indiana University School of Medicine, Department of Medical & Molecular Genetics, Indianapolis, IN, USA
| | - Samuel Arregui
- Indiana University School of Medicine, Department of Pediatrics, Division of Nephrology, Indianapolis, IN, USA
| | - Amy Zollman
- Indiana University School of Medicine, Department of Medicine, Division of Nephrology, Indianapolis, IN, USA
| | - Malgorzata Maria Kamocka
- Indiana University School of Medicine, Department of Medicine, Division of Nephrology, Indianapolis, IN, USA
| | - Xiaoling Xuei
- Indiana University School of Medicine, Department of Medical & Molecular Genetics, Indianapolis, IN, USA
| | - Patrick McGuire
- Indiana University School of Medicine, Department of Medical & Molecular Genetics, Indianapolis, IN, USA
| | - Michael Hutchens
- Oregon Health and Science University, Department of Anesthesiology & Perioperative Medicine, Portland, OR, USA
| | - Takashi Hato
- Indiana University School of Medicine, Department of Medicine, Division of Nephrology, Indianapolis, IN, USA
| | - David S Hains
- Indiana University School of Medicine, Department of Pediatrics, Division of Nephrology, Indianapolis, IN, USA
| | - Andrew L Schwaderer
- Indiana University School of Medicine, Department of Pediatrics, Division of Nephrology, Indianapolis, IN, USA.
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34
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John A, Järvå MA, Shah S, Mao R, Chappaz S, Birkinshaw RW, Czabotar PE, Lo AW, Scott NE, Goddard-Borger ED. Yeast- and antibody-based tools for studying tryptophan C-mannosylation. Nat Chem Biol 2021; 17:428-437. [PMID: 33542533 DOI: 10.1038/s41589-020-00727-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 12/21/2020] [Indexed: 01/30/2023]
Abstract
Tryptophan C-mannosylation is an unusual co-translational protein modification performed by metazoans and apicomplexan protists. The prevalence and biological functions of this modification are poorly understood, with progress in the field hampered by a dearth of convenient tools for installing and detecting the modification. Here, we engineer a yeast system to produce a diverse array of proteins with and without tryptophan C-mannosylation and interrogate the modification's influence on protein stability and function. This system also enabled mutagenesis studies to identify residues of the glycosyltransferase and its protein substrates that are crucial for catalysis. The collection of modified proteins accrued during this work facilitated the generation and thorough characterization of monoclonal antibodies against tryptophan C-mannosylation. These antibodies empowered proteomic analyses of the brain C-glycome by enriching for peptides possessing tryptophan C-mannosylation. This study revealed many new modification sites on proteins throughout the secretory pathway with both conventional and non-canonical consensus sequences.
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Affiliation(s)
- Alan John
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Michael A Järvå
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Sayali Shah
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Runyu Mao
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Stephane Chappaz
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Richard W Birkinshaw
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Alvin W Lo
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia.
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35
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Kotlyarov S. Participation of ABCA1 Transporter in Pathogenesis of Chronic Obstructive Pulmonary Disease. Int J Mol Sci 2021; 22:3334. [PMID: 33805156 PMCID: PMC8037621 DOI: 10.3390/ijms22073334] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is the important medical and social problem. According to modern concepts, COPD is a chronic inflammatory disease, macrophages play a key role in its pathogenesis. Macrophages are heterogeneous in their functions, which is largely determined by their immunometabolic profile, as well as the features of lipid homeostasis, in which the ATP binding cassette transporter A1 (ABCA1) plays an essential role. The objective of this work is the analysis of the ABCA1 protein participation and the function of reverse cholesterol transport in the pathogenesis of COPD. The expression of the ABCA1 gene in lung tissues takes the second place after the liver, which indicates the important role of the carrier in lung function. The participation of the transporter in the development of COPD consists in provision of lipid metabolism, regulation of inflammation, phagocytosis, and apoptosis. Violation of the processes in which ABCA1 is involved may be a part of the pathophysiological mechanisms, leading to the formation of a heterogeneous clinical course of the disease.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
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36
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Analysis of the Structure and Biosynthesis of the Lipopolysaccharide Core Oligosaccharide of Pseudomonas syringae pv. tomato DC3000. Int J Mol Sci 2021; 22:ijms22063250. [PMID: 33806795 PMCID: PMC8005017 DOI: 10.3390/ijms22063250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/17/2022] Open
Abstract
Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is important for bacterial viability in general and host-pathogen interactions in particular. Negative charges at its core oligosaccharide (core-OS) contribute to membrane integrity through bridging interactions with divalent cations. The molecular structure and synthesis of the core-OS have been resolved in various bacteria including the mammalian pathogen Pseudomonas aeruginosa. A few core-OS structures of plant-associated Pseudomonas strains have been solved to date, but the genetic components of the underlying biosynthesis remained unclear. We conducted a comparative genome analysis of the core-OS gene cluster in Pseudomonas syringae pv. tomato (Pst) DC3000, a widely used model pathogen in plant-microbe interactions, within the P. syringae species complex and to other plant-associated Pseudomonas strains. Our results suggest a genetic and structural conservation of the inner core-OS but variation in outer core-OS composition within the P. syringae species complex. Structural analysis of the core-OS of Pst DC3000 shows an uncommonly high phosphorylation and presence of an O-acetylated sugar. Finally, we combined the results of our genomic survey with available structure information to estimate the core-OS composition of other Pseudomonas species.
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den Hartog G, Butcher LD, Ablack AL, Pace LA, Ablack JNG, Xiong R, Das S, Stappenbeck TS, Eckmann L, Ernst PB, Crowe SE. Apurinic/Apyrimidinic Endonuclease 1 Restricts the Internalization of Bacteria Into Human Intestinal Epithelial Cells Through the Inhibition of Rac1. Front Immunol 2021; 11:553994. [PMID: 33603730 PMCID: PMC7884313 DOI: 10.3389/fimmu.2020.553994] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
Pathogenic intestinal bacteria lead to significant disease in humans. Here we investigated the role of the multifunctional protein, Apurinic/apyrimidinic endonuclease 1 (APE1), in regulating the internalization of bacteria into the intestinal epithelium. Intestinal tumor-cell lines and primary human epithelial cells were infected with Salmonella enterica serovar Typhimurium or adherent-invasive Escherichia coli. The effects of APE1 inhibition on bacterial internalization, the regulation of Rho GTPase Rac1 as well as the epithelial cell barrier function were assessed. Increased numbers of bacteria were present in APE1-deficient colonic tumor cell lines and primary epithelial cells. Activation of Rac1 was augmented following infection but negatively regulated by APE1. Pharmacological inhibition of Rac1 reversed the increase in intracellular bacteria in APE1-deficient cells whereas overexpression of constitutively active Rac1 augmented the numbers in APE1-competent cells. Enhanced numbers of intracellular bacteria resulted in the loss of barrier function and a delay in its recovery. Our data demonstrate that APE1 inhibits the internalization of invasive bacteria into human intestinal epithelial cells through its ability to negatively regulate Rac1. This activity also protects epithelial cell barrier function.
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Affiliation(s)
- Gerco den Hartog
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Lindsay D Butcher
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Amber L Ablack
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Laura A Pace
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Jailal N G Ablack
- Department of Medicine, Division of Rheumatology, University of California San Diego, La Jolla, CA, United States
| | - Richard Xiong
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Soumita Das
- Division of Comparative Pathology and Medicine, Department of Pathology, University of California San Diego, La Jolla, CA, United States
| | | | - Lars Eckmann
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States
| | - Peter B Ernst
- Division of Comparative Pathology and Medicine, Department of Pathology, University of California San Diego, La Jolla, CA, United States.,Center for Mucosal Immunology, Allergy and Vaccine Development, Department of Pathology, University of California San Diego, La Jolla, CA, United States.,Department of Immunology, Chiba University, Chiba, Japan
| | - Sheila E Crowe
- Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States.,Division of ImmunoBiology, Washington University, St. Louis, MO, United States
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Vizurraga A, Adhikari R, Yeung J, Yu M, Tall GG. Mechanisms of adhesion G protein-coupled receptor activation. J Biol Chem 2020; 295:14065-14083. [PMID: 32763969 DOI: 10.1074/jbc.rev120.007423] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/31/2020] [Indexed: 12/19/2022] Open
Abstract
Adhesion G protein-coupled receptors (AGPCRs) are a thirty-three-member subfamily of Class B GPCRs that control a wide array of physiological processes and are implicated in disease. AGPCRs uniquely contain large, self-proteolyzing extracellular regions that range from hundreds to thousands of residues in length. AGPCR autoproteolysis occurs within the extracellular GPCR autoproteolysis-inducing (GAIN) domain that is proximal to the N terminus of the G protein-coupling seven-transmembrane-spanning bundle. GAIN domain-mediated self-cleavage is constitutive and produces two-fragment holoreceptors that remain bound at the cell surface. It has been of recent interest to understand how AGPCRs are activated in relation to their two-fragment topologies. Dissociation of the AGPCR fragments stimulates G protein signaling through the action of the tethered-peptide agonist stalk that is occluded within the GAIN domain in the holoreceptor form. AGPCRs can also signal independently of fragment dissociation, and a few receptors possess GAIN domains incapable of self-proteolysis. This has resulted in complex theories as to how these receptors are activated in vivo, complicating pharmacological advances. Currently, there is no existing structure of an activated AGPCR to support any of the theories. Further confounding AGPCR research is that many of the receptors remain orphans and lack identified activating ligands. In this review, we provide a detailed layout of the current theorized modes of AGPCR activation with discussion of potential parallels to mechanisms used by other GPCR classes. We provide a classification means for the ligands that have been identified and discuss how these ligands may activate AGPCRs in physiological contexts.
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Affiliation(s)
- Alexander Vizurraga
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Rashmi Adhikari
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Jennifer Yeung
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Maiya Yu
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
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39
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Tim-4 functions as a scavenger receptor for phagocytosis of exogenous particles. Cell Death Dis 2020; 11:561. [PMID: 32703939 PMCID: PMC7378189 DOI: 10.1038/s41419-020-02773-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 12/17/2022]
Abstract
The phosphatidylserine (PS) receptor Tim-4 mediates phagocytosis of apoptotic cells by binding to PS exposed on the surface of these cells, and thus functions as a PS receptor for apoptotic cells. Some of PS receptors are capable of recognizing other molecules, such as LPS on bacteria, besides PS on apoptotic cells. However, it is unclear whether Tim-4 perceives other molecules like the PS receptors. Here, we report that Tim-4 facilitates the phagocytosis of exogenous particles as well as apoptotic cells. Similar to the process that occurs during Tim-4-mediated efferocytosis, the uptake of exogenous E. coli and S. aureus bioparticles was promoted by overexpression of Tim-4 on phagocytes, whereas phagocytosis of the bioparticles was reduced in Tim-4-deficient cells. A truncation mutant of Tim-4 lacking the cytoplasmic tail promoted phagocytosis of the particles, but a mutant lacking the IgV or the mucin domain failed to enhance phagocytosis. However, expression of Tim-4AAA (a mutant form of Tim-4 that does not bind phosphatidylserine and does not promote efferocytosis) still promoted phagocytosis. Tim-4-mediated phagocytosis was not blocked by expression of the phosphatidylserine-binding protein Anxa5. Furthermore, binding of lipopolysaccharide (LPS), which is found in the outer membrane of Gram-negative bacteria, was higher in Tim-4-overexpressing cells than in Tim-4-deficient cells. In summary, our study suggests that Tim-4 acts as a scavenger receptor and mediates phagocytosis of exogenous particles in a phosphatidylserine-independent manner.
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40
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Moon B, Lee J, Lee SA, Min C, Moon H, Kim D, Yang S, Moon H, Jeon J, Joo YE, Park D. Mertk Interacts with Tim-4 to Enhance Tim-4-Mediated Efferocytosis. Cells 2020; 9:cells9071625. [PMID: 32640697 PMCID: PMC7408610 DOI: 10.3390/cells9071625] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/24/2020] [Accepted: 07/02/2020] [Indexed: 11/16/2022] Open
Abstract
Apoptotic cells expressing phosphatidylserine (PS) on their cell surface are directly or indirectly recognized by phagocytes through PS-binding proteins. The PS-binding protein Tim-4 secures apoptotic cells to phagocytes to facilitate the engulfment of apoptotic cells. However, the molecular mechanism by which Tim-4 transduces signals to phagocytes during Tim-4-mediated efferocytosis is incompletely understood. Here, we report that Tim-4 collaborates with Mertk during efferocytosis through a biochemical interaction with Mertk. Proximal localization between the two proteins in phagocytes was observed by immunofluorescence and proximal ligation assays. Physical association between Tim-4 and Mertk, which was mediated by an interaction between the IgV domain of Tim-4 and the fibronectin type-III domain of Mertk, was also detected with immunoprecipitation. Furthermore, the effect of Mertk on Tim-4-mediated efferocytosis was abolished by GST-MertkFnIII, a soluble form of the fibronectin type-III domain of Mertk that disrupts the interaction between Tim-4 and Mertk. Taken together, the results from our study suggest that a physical interaction between Tim-4 and Mertk is necessary for Mertk to enhance efferocytosis mediated by Tim-4.
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Affiliation(s)
- Byeongjin Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Juyeon Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Sang-Ah Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Chanhyuk Min
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Hyunji Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Deokhwan Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Susumin Yang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Heera Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
| | - Jaeseon Jeon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
| | - Young-Eun Joo
- Department of Internal Medicine, Chonnam National Univerity, Gwangju 61469, Korea;
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; (B.M.); (J.L.); (S.-A.L.); (C.M.); (H.M.); (D.K.); (S.Y.); (H.M.); (J.J.)
- Center for Cell Mechanobiology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Correspondence: ; Tel.: +82-62-715-2890
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41
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Liu M, Banerjee R, Rossa C, D'Silva NJ. RAP1-RAC1 Signaling Has an Important Role in Adhesion and Migration in HNSCC. J Dent Res 2020; 99:959-968. [PMID: 32401565 DOI: 10.1177/0022034520917058] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cell-cell adhesion is a key mechanism to control tissue integrity and migration. In head and neck squamous cell carcinoma (HNSCC), cell migration facilitates distant metastases and is correlated with poor prognosis. RAP1, a ras-like protein, has an important role in the progression of HNSCC. RAC1 is an integrin-linked, ras-like protein that promotes cell migration. Here we show that loss of cell-cell adhesion is correlated with inactivation of RAP1 confirmed by 2 different biochemical approaches. RAP1 activation is required for cell-matrix adhesion confirmed by adhesion to fibronectin-coated plates with cells that have biochemically activated RAP1. This effect is reversed when RAP1 is inactivated. In addition, RAP1GTP-mediated adhesion is only facilitated through α5β1 integrin complex and is not a function of either α5 or β1 integrin alone. Moreover, the inside-out signaling of RAP1 activation is coordinated with RAC1 activation. These findings show that RAP1 has a prominent role in cell-matrix adhesion via extracellular matrix molecule fibronectin-induced α5β1 integrin and supports a critical role for the RAP1/RAC1 signaling axis in HNSCC cell migration.
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Affiliation(s)
- M Liu
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - R Banerjee
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - C Rossa
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Diagnosis and Surgery, School of Dentistry at Araraquara, UNESP-Univ Estadual Paulista, Araraquara, SP, Brazil
| | - N J D'Silva
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Pathology, Medical School; University of Michigan, Ann Arbor, MI, USA
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42
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Maser RL, Calvet JP. Adhesion GPCRs as a paradigm for understanding polycystin-1 G protein regulation. Cell Signal 2020; 72:109637. [PMID: 32305667 DOI: 10.1016/j.cellsig.2020.109637] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 12/21/2022]
Abstract
Polycystin-1, whose mutation is the most frequent cause of autosomal dominant polycystic kidney disease, is an extremely large and multi-faceted membrane protein whose primary or proximal cyst-preventing function remains undetermined. Accumulating evidence supports the idea that modulation of cellular signaling by heterotrimeric G proteins is a critical function of polycystin-1. The presence of a cis-autocatalyzed, G protein-coupled receptor (GPCR) proteolytic cleavage site, or GPS, in its extracellular N-terminal domain immediately preceding the first transmembrane domain is one of the notable conserved features of the polycystin-1-like protein family, and also of the family of cell adhesion GPCRs. Adhesion GPCRs are one of five families within the GPCR superfamily and are distinguished by a large N-terminal extracellular region consisting of multiple adhesion modules with a GPS-containing GAIN domain and bimodal functions in cell adhesion and signal transduction. Recent advances from studies of adhesion GPCRs provide a new paradigm for unraveling the mechanisms by which polycystin-1-associated G protein signaling contributes to the pathogenesis of polycystic kidney disease. This review highlights the structural and functional features shared by polycystin-1 and the adhesion GPCRs and discusses the implications of such similarities for our further understanding of the functions of this complicated protein.
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Affiliation(s)
- Robin L Maser
- Department of Clinical Laboratory Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA.
| | - James P Calvet
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA.
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43
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Abstract
Phagocytosis is a pivotal immunological process, and its discovery by Elia Metchnikoff in 1882 was a step toward the establishment of the innate immune system as a separate branch of immunology. Elia Metchnikoff received the Nobel Prize in physiology and medicine for this discovery in 1908. Since its discovery almost 140 years before, phagocytosis remains the hot topic of research in immunology. The phagocytosis research has seen a great advancement since its first discovery. Functionally, phagocytosis is a simple immunological process required to engulf and remove pathogens, dead cells and tumor cells to maintain the immune homeostasis. However, mechanistically, it is a very complex process involving different mechanisms, induced and regulated by several pattern recognition receptors, soluble pattern recognition molecules, scavenger receptors (SRs) and opsonins. These mechanisms involve the formation of phagosomes, their maturation into phagolysosomes causing pathogen destruction or antigen synthesis to present them to major histocompatibility complex molecules for activating an adaptive immune response. Any defect in this mechanism may predispose the host to certain infections and inflammatory diseases (autoinflammatory and autoimmune diseases) along with immunodeficiency. The article is designed to discuss its mechanistic complexity at each level, varying from phagocytosis induction to phagolysosome resolution.
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Affiliation(s)
- Vijay Kumar
- Faculty of Medicine, Children's Health Queensland Clinical Unit, School of Clinical Medicine, Mater Research, University of Queensland, ST Lucia, Brisbane, Queensland, Australia.,Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Queensland, Australia
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44
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Jun JI, Lau LF. CCN1 is an opsonin for bacterial clearance and a direct activator of Toll-like receptor signaling. Nat Commun 2020; 11:1242. [PMID: 32144270 PMCID: PMC7060279 DOI: 10.1038/s41467-020-15075-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 02/17/2020] [Indexed: 12/30/2022] Open
Abstract
Expression of the matricellular protein CCN1 (CYR61) is associated with inflammation and is required for successful wound repair. Here, we show that CCN1 binds bacterial pathogen-associated molecular patterns including peptidoglycans of Gram-positive bacteria and lipopolysaccharides of Gram-negative bacteria. CCN1 opsonizes methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa and accelerates their removal by phagocytosis and increased production of bactericidal reactive oxygen species in macrophages through the engagement of integrin αvβ3. Mice with myeloid-specific Ccn1 deletion and knock-in mice expressing CCN1 unable to bind αvβ3 are more susceptible to infection by S. aureus or P. aeruginosa, resulting in increased mortality and organ colonization. Furthermore, CCN1 binds directly to TLR2 and TLR4 to activate MyD88-dependent signaling, cytokine expression and neutrophil mobilization. CCN1 is therefore a pattern recognition receptor that opsonizes bacteria for clearance and functions as a damage-associated molecular pattern to activate inflammatory responses, activities that contribute to wound healing and tissue repair. CCN1 is a matricellular protein with a variety of functions, including an effect on wound healing and an association with inflammation. Here, the authors identify a possible mechanism by showing that CCN1 mediates the clearance of bacterial infections in mice and activates TLR signalling.
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Affiliation(s)
- Joon-Il Jun
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL, 60607, USA
| | - Lester F Lau
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL, 60607, USA.
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45
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Sayed IM, Suarez K, Lim E, Singh S, Pereira M, Ibeawuchi SR, Katkar G, Dunkel Y, Mittal Y, Chattopadhyay R, Guma M, Boland BS, Dulai PS, Sandborn WJ, Ghosh P, Das S. Host engulfment pathway controls inflammation in inflammatory bowel disease. FEBS J 2020; 287:3967-3988. [PMID: 32003126 DOI: 10.1111/febs.15236] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 12/20/2019] [Accepted: 01/29/2020] [Indexed: 12/13/2022]
Abstract
Chronic diseases, including inflammatory bowel disease (IBD) urgently need new biomarkers as a significant proportion of patients, do not respond to current medications. Inflammation is a common factor in these diseases, and microbial sensing in the intestinal tract is critical to initiate the inflammation. We have identified ELMO1 (engulfment and cell motility protein 1) as a microbial sensor in epithelial and phagocytic cells that turns on inflammatory signals. Using a stem cell-based 'gut-in-a-dish' coculture model, we studied the interactions between microbes, epithelium, and monocytes in the context of IBD. To mimic the in vivo cell physiology, enteroid-derived monolayers (EDMs) were generated from the organoids isolated from WT and ELMO1-/- mice and colonic biopsies of IBD patients. The EDMs were infected with the IBD-associated microbes to monitor the inflammatory responses. ELMO1-depleted EDMs displayed a significant reduction in bacterial internalization, a decrease in pro-inflammatory cytokine productions and monocyte recruitment. The expression of ELMO1 is elevated in the colonic epithelium and in the inflammatory infiltrates within the lamina propria of IBD patients where the higher expression is positively correlated with the elevated expression of pro-inflammatory cytokines, MCP-1 and TNF-α. MCP-1 is released from the epithelium and recruits monocytes to the site of inflammation. Once recruited, monocytes require ELMO1 to engulf the bacteria and propagate a robust TNF-α storm. These findings highlight that the dysregulated epithelial ELMO1 → MCP-1 axis can serve as an early biomarker in the diagnostics of IBD and other inflammatory disorders.
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Affiliation(s)
- Ibrahim M Sayed
- Department of Pathology, University of California, San Diego, CA, USA
| | - Katherine Suarez
- Department of Pathology, University of California, San Diego, CA, USA
| | - Eileen Lim
- Department of Pathology, University of California, San Diego, CA, USA
| | - Sujay Singh
- Department of Pathology, University of California, San Diego, CA, USA
| | - Matheus Pereira
- Department of Pathology, University of California, San Diego, CA, USA
| | | | - Gajanan Katkar
- Department of Cellular & Molecular Medicine, University of California, San Diego, CA, USA
| | - Ying Dunkel
- Department of Medicine, University of California, San Diego, CA, USA
| | - Yash Mittal
- Department of Medicine, University of California, San Diego, CA, USA
| | - Ranajoy Chattopadhyay
- Department of Cellular & Molecular Medicine, University of California, San Diego, CA, USA
| | - Monica Guma
- Department of Medicine, University of California, San Diego, CA, USA
| | - Brigid S Boland
- Department of Medicine, University of California, San Diego, CA, USA
| | - Parambir S Dulai
- Department of Medicine, University of California, San Diego, CA, USA
| | | | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, CA, USA.,Department of Cellular & Molecular Medicine, University of California, San Diego, CA, USA
| | - Soumita Das
- Department of Pathology, University of California, San Diego, CA, USA
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Cytosolic Gram-negative bacteria prevent apoptosis by inhibition of effector caspases through lipopolysaccharide. Nat Microbiol 2019; 5:354-367. [PMID: 31873204 DOI: 10.1038/s41564-019-0620-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 10/24/2019] [Indexed: 02/08/2023]
Abstract
The cytosolic appearance and propagation of bacteria cause overwhelming cellular stress responses that induce apoptosis under normal conditions. Therefore, successful bacterial colonization depends on the ability of intracellular pathogens to block apoptosis and to safeguard bacterial replicative niches. Here, we show that the cytosolic Gram-negative bacterium Shigella flexneri stalls apoptosis by inhibiting effector caspase activity. Our data identified lipopolysaccharide (LPS) as a bona fide effector caspase inhibitor that directly binds caspases by involving its O-antigen (O Ag) moiety. Bacterial strains that lacked the O Ag or failed to replicate within the cytosol were incapable of blocking apoptosis and exhibited reduced virulence in a murine model of bacterial infection. Our findings demonstrate how Shigella inhibits pro-apoptotic caspase activity, effectively delays coordinated host-cell demise and supports its intracellular propagation. Next to the recently discovered pro-inflammatory role of cytosolic LPS, our data reveal a distinct mode of LPS action that, through the disruption of the early coordinated non-lytic cell death response, ultimately supports the inflammatory breakdown of infected cells at later time points.
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Rider PJF, Uche IK, Sweeny L, Kousoulas KG. Anti-viral immunity in the tumor microenvironment: implications for the rational design of herpes simplex virus type 1 oncolytic virotherapy. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019; 6:193-199. [PMID: 33344108 DOI: 10.1007/s40588-019-00134-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Purpose of review The design of novel herpes simplex type I (HSV-1)-derived oncolytic virotherapies is a balancing act between safety, immunogenicity and replicative potential. We have undertaken this review to better understand how these considerations can be incorporated into rational approaches to the design of novel herpesvirus oncolytic virotherapies. Recent findings Several recent papers have demonstrated that enhancing the potential of HSV-1 oncolytic viruses to combat anti-viral mechanisms present in the tumor microenvironment leads to greater efficacy than their parental viruses. Summary It is not entirely clear how the immunosuppressive tumor microenvironment affects oncolytic viral replication and spread within tumors. Recent work has shown that the manipulation of specific cellular and molecular mechanisms of immunosuppression operating within the tumor microenvironment can enhance the efficacy of oncolytic virotherapy. We anticipate that future work will integrate greater knowledge of immunosuppression in tumor microenvironments with design of oncolytic virotherapies.
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Affiliation(s)
- Paul J F Rider
- Division of Biotechnology and Molecular Medicine and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Ifeanyi K Uche
- Division of Biotechnology and Molecular Medicine and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Larissa Sweeny
- Division of Biotechnology and Molecular Medicine and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.,Louisiana State University Health Sciences Center, New Orleans, Louisiana USA
| | - Konstantin G Kousoulas
- Division of Biotechnology and Molecular Medicine and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
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Abstract
Tissue macrophages rapidly recognize and engulf apoptotic cells. These events require the display of so-called eat-me signals on the apoptotic cell surface, the most fundamental of which is phosphatidylserine (PtdSer). Externalization of this phospholipid is catalysed by scramblase enzymes, several of which are activated by caspase cleavage. PtdSer is detected both by macrophage receptors that bind to this phospholipid directly and by receptors that bind to a soluble bridging protein that is independently bound to PtdSer. Prominent among the latter receptors are the MER and AXL receptor tyrosine kinases. Eat-me signals also trigger macrophages to engulf virus-infected or metabolically traumatized, but still living, cells, and this 'murder by phagocytosis' may be a common phenomenon. Finally, the localized presentation of PtdSer and other eat-me signals on delimited cell surface domains may enable the phagocytic pruning of these 'locally dead' domains by macrophages, most notably by microglia of the central nervous system.
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Affiliation(s)
- Greg Lemke
- Molecular Neurobiology Laboratory, Immunobiology and Microbial Pathogenesis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
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49
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Duman JG, Mulherkar S, Tu YK, Erikson KC, Tzeng CP, Mavratsas VC, Ho TSY, Tolias KF. The adhesion-GPCR BAI1 shapes dendritic arbors via Bcr-mediated RhoA activation causing late growth arrest. eLife 2019; 8:47566. [PMID: 31461398 PMCID: PMC6713510 DOI: 10.7554/elife.47566] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 08/03/2019] [Indexed: 12/17/2022] Open
Abstract
Dendritic arbor architecture profoundly impacts neuronal connectivity and function, and aberrant dendritic morphology characterizes neuropsychiatric disorders. Here, we identify the adhesion-GPCR BAI1 as an important regulator of dendritic arborization. BAI1 loss from mouse or rat hippocampal neurons causes dendritic hypertrophy, whereas BAI1 overexpression precipitates dendrite retraction. These defects specifically manifest as dendrites transition from growth to stability. BAI1-mediated growth arrest is independent of its Rac1-dependent synaptogenic function. Instead, BAI1 couples to the small GTPase RhoA, driving late RhoA activation in dendrites coincident with growth arrest. BAI1 loss lowers RhoA activation and uncouples it from dendrite dynamics, causing overgrowth. None of BAI1's known downstream effectors mediates BAI1-dependent growth arrest. Rather, BAI1 associates with the Rho-GTPase regulatory protein Bcr late in development and stimulates its cryptic RhoA-GEF activity, which functions together with its Rac1-GAP activity to terminate arborization. Our results reveal a late-acting signaling pathway mediating a key transition in dendrite development.
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Affiliation(s)
- Joseph G Duman
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Shalaka Mulherkar
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Yen-Kuei Tu
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, United States
| | - Kelly C Erikson
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Christopher P Tzeng
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Vasilis C Mavratsas
- Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Rice University, Houston, United States
| | - Tammy Szu-Yu Ho
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Kimberley F Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, United States.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
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50
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Colosimo DA, Kohn JA, Luo PM, Piscotta FJ, Han SM, Pickard AJ, Rao A, Cross JR, Cohen LJ, Brady SF. Mapping Interactions of Microbial Metabolites with Human G-Protein-Coupled Receptors. Cell Host Microbe 2019; 26:273-282.e7. [PMID: 31378678 PMCID: PMC6706627 DOI: 10.1016/j.chom.2019.07.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/09/2019] [Accepted: 07/11/2019] [Indexed: 02/07/2023]
Abstract
Despite evidence linking the human microbiome to health and disease, how the microbiota affects human physiology remains largely unknown. Microbiota-encoded metabolites are expected to play an integral role in human health. Therefore, assigning function to these metabolites is critical to understanding these complex interactions and developing microbiota-inspired therapies. Here, we use large-scale functional screening of molecules produced by individual members of a simplified human microbiota to identify bacterial metabolites that agonize G-protein-coupled receptors (GPCRs). Multiple metabolites, including phenylpropanoic acid, cadaverine, 9-10-methylenehexadecanoic acid, and 12-methyltetradecanoic acid, were found to interact with GPCRs associated with diverse functions within the nervous and immune systems, among others. Collectively, these metabolite-receptor pairs indicate that diverse aspects of human health are potentially modulated by structurally simple metabolites arising from primary bacterial metabolism. Metabolite library from human microbiota screened for direct agonism of 241 GPCRs Taxa-specific primary metabolites agonize individual GPCRs or broad GPCR families Bacteria agonize receptors linked to metabolism, neurotransmission, and immunity Simple bacterial metabolites may play a role in modulating host pathways
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Affiliation(s)
- Dominic A Colosimo
- Laboratory of Genetically Encoded Small Molecules, the Rockefeller University, 1230 York Avenue, New York City, NY 10065, USA
| | - Jeffrey A Kohn
- Laboratory of Genetically Encoded Small Molecules, the Rockefeller University, 1230 York Avenue, New York City, NY 10065, USA
| | - Peter M Luo
- Laboratory of Genetically Encoded Small Molecules, the Rockefeller University, 1230 York Avenue, New York City, NY 10065, USA
| | - Frank J Piscotta
- Laboratory of Genetically Encoded Small Molecules, the Rockefeller University, 1230 York Avenue, New York City, NY 10065, USA
| | - Sun M Han
- Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY 10029, USA
| | - Amanda J Pickard
- Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York City, NY 10065, USA
| | - Arka Rao
- Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York City, NY 10065, USA
| | - Justin R Cross
- Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York City, NY 10065, USA
| | - Louis J Cohen
- Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY 10029, USA
| | - Sean F Brady
- Laboratory of Genetically Encoded Small Molecules, the Rockefeller University, 1230 York Avenue, New York City, NY 10065, USA.
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