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Purić E, Nilsson UJ, Anderluh M. Galectin-8 inhibition and functions in immune response and tumor biology. Med Res Rev 2024. [PMID: 38613488 DOI: 10.1002/med.22041] [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: 04/13/2023] [Revised: 03/03/2024] [Accepted: 03/29/2024] [Indexed: 04/15/2024]
Abstract
Galectins are among organisms' most abundantly expressed lectins (carbohydrate-binding proteins) that specifically bind β-galactosides. They act not only outside the cell, where they bind to extracellular matrix glycans, but also inside the cell, where they have a significant impact on signaling pathways. Galectin-8 is a galectin family protein encoded by the LGALS8 gene. Its role is evident in both T- and B-cell immunity and in the innate immune response, where it acts directly on dendritic cells and induces some pro-inflammatory cytokines. Galectin-8 also plays an important role in the defense against bacterial and viral infections. It is known to promote antibacterial autophagy by recognizing and binding glycans present on the vacuolar membrane, thus acting as a danger receptor. The most important role of galectin-8 is the regulation of cancer growth, metastasis, tumor progression, and tumor cell survival. Importantly, the expression of galectins is typically higher in tumor tissues than in noncancerous tissues. In this review article, we focus on galectin-8 and its function in immune response, microbial infections, and cancer. Given all of these functions of galectin-8, we emphasize the importance of developing new and selective galectin-8 inhibitors and report the current status of their development.
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Affiliation(s)
- Edvin Purić
- Department of Pharmaceutical Chemistry, University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia
| | - Ulf J Nilsson
- Department of Chemistry, Lund University, Lund, Sweden
| | - Marko Anderluh
- Department of Pharmaceutical Chemistry, University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia
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2
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Wehrmann M, Vilchez D. The emerging role and therapeutic implications of bacterial and parasitic deubiquitinating enzymes. Front Immunol 2023; 14:1303072. [PMID: 38077335 PMCID: PMC10703165 DOI: 10.3389/fimmu.2023.1303072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/03/2023] [Indexed: 12/18/2023] Open
Abstract
Deubiquitinating enzymes (DUBs) are emerging as key factors for the infection of human cells by pathogens such as bacteria and parasites. In this review, we discuss the most recent studies on the role of deubiquitinase activity in exploiting and manipulating ubiquitin (Ub)-dependent host processes during infection. The studies discussed here highlight the importance of DUB host-pathogen research and underscore the therapeutic potential of inhibiting pathogen-specific DUB activity to prevent infectious diseases.
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Affiliation(s)
- Markus Wehrmann
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Integrated Stress Response Signaling, Faculty of Medicine, University Hospital Cologne, Cologne, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Integrated Stress Response Signaling, Faculty of Medicine, University Hospital Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Institute for Genetics, University of Cologne, Cologne, Germany
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3
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Kaposi's sarcoma-associated herpesvirus (KSHV) utilizes the NDP52/CALCOCO2 selective autophagy receptor to disassemble processing bodies. PLoS Pathog 2023; 19:e1011080. [PMID: 36634147 PMCID: PMC9876383 DOI: 10.1371/journal.ppat.1011080] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 01/25/2023] [Accepted: 12/22/2022] [Indexed: 01/13/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) causes the inflammatory and angiogenic endothelial cell neoplasm, Kaposi's sarcoma (KS). We previously demonstrated that the KSHV Kaposin B (KapB) protein promotes inflammation via the disassembly of cytoplasmic ribonucleoprotein granules called processing bodies (PBs). PBs modify gene expression by silencing or degrading labile messenger RNAs (mRNAs), including many transcripts that encode inflammatory or angiogenic proteins associated with KS disease. Although our work implicated PB disassembly as one of the causes of inflammation during KSHV infection, the precise mechanism used by KapB to elicit PB disassembly was unclear. Here we reveal a new connection between the degradative process of autophagy and PB disassembly. We show that both latent KSHV infection and KapB expression enhanced autophagic flux via phosphorylation of the autophagy regulatory protein, Beclin. KapB was necessary for this effect, as infection with a recombinant virus that does not express the KapB protein did not induce Beclin phosphorylation or autophagic flux. Moreover, we showed that PB disassembly mediated by KSHV or KapB, depended on autophagy genes and the selective autophagy receptor NDP52/CALCOCO2 and that the PB scaffolding protein, Pat1b, co-immunoprecipitated with NDP52. These studies reveal a new role for autophagy and the selective autophagy receptor NDP52 in promoting PB turnover and the concomitant synthesis of inflammatory molecules during KSHV infection.
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4
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Griffey CJ, Yamamoto A. Macroautophagy in CNS health and disease. Nat Rev Neurosci 2022; 23:411-427. [PMID: 35505254 DOI: 10.1038/s41583-022-00588-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2022] [Indexed: 12/12/2022]
Abstract
Macroautophagy is an evolutionarily conserved process that delivers diverse cellular contents to lysosomes for degradation. As our understanding of this pathway grows, so does our appreciation for its importance in disorders of the CNS. Once implicated primarily in neurodegenerative events owing to acute injury and ageing, macroautophagy is now also linked to disorders of neurodevelopment, indicating that it is essential for both the formation and maintenance of a healthy CNS. In parallel to understanding the significance of macroautophagy across contexts, we have gained a greater mechanistic insight into its physiological regulation and the breadth of cargoes it can degrade. Macroautophagy is a broadly used homeostatic process, giving rise to questions surrounding how defects in this single pathway could cause diseases with distinct clinical and pathological signatures. To address this complexity, we herein review macroautophagy in the mammalian CNS by examining three key features of the process and its relationship to disease: how it functions at a basal level in the discrete cell types of the brain and spinal cord; which cargoes are being degraded in physiological and pathological settings; and how the different stages of the macroautophagy pathway intersect with diseases of neurodevelopment and adult-onset neurodegeneration.
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Affiliation(s)
- Christopher J Griffey
- Doctoral Program in Neurobiology and Behaviour, Medical Scientist Training Program, Columbia University, New York, NY, USA
| | - Ai Yamamoto
- Departments of Neurology, and Pathology and Cell Biology, Columbia University, New York, NY, USA.
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5
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Qin C, Lu Y, Bai L, Wang K. The molecular regulation of autophagy in antimicrobial immunity. J Mol Cell Biol 2022; 14:6547771. [PMID: 35278083 PMCID: PMC9335221 DOI: 10.1093/jmcb/mjac015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/05/2021] [Accepted: 12/07/2021] [Indexed: 11/25/2022] Open
Abstract
Autophagy is a catabolic process that can degrade worn-out organelles and invading pathogens. The activation of autophagy regulates innate and adaptive immunity, playing a key role in the response to microbial invasion. Microbial infection may cause different consequences such as the elimination of invaders through autophagy or xenophagy, host cell death, and symbiotic relationships. Pathogens adapt to the autophagy mechanism and further relieve intracellular stress, which is conducive to host cell survival and microbial growth. The regulation of autophagy forms a complex network through which host immunity is modulated, resulting in a variety of pathophysiological manifestations. Modification of the autophagic pathway is an essential target for the development of antimicrobial drugs.
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Affiliation(s)
- Chuan Qin
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, Beijing 100021, China
| | - Yalan Lu
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, Beijing 100021, China
| | - Lin Bai
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, Beijing 100021, China
| | - Kewei Wang
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, Beijing 100021, China
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6
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The Role of Mitophagy in Viral Infection. Cells 2022; 11:cells11040711. [PMID: 35203359 PMCID: PMC8870278 DOI: 10.3390/cells11040711] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 02/06/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
Mitophagy, which is able to selectively clear excess or damaged mitochondria, plays a vital role in the quality control of mitochondria and the maintenance of normal mitochondrial functions in eukaryotic cells. Mitophagy is involved in many physiological and pathological processes, including apoptosis, innate immunity, inflammation, cell differentiation, signal transduction, and metabolism. Viral infections cause physical dysfunction and thus pose a significant threat to public health. An accumulating body of evidence reveals that some viruses hijack mitophagy to enable immune escape and self-replication. In this review, we systematically summarize the pathway of mitophagy initiation and discuss the functions and mechanisms of mitophagy in infection with classical swine fever virus and other specific viruses, with the aim of providing a theoretical basis for the prevention and control of related diseases.
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7
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Tecalco-Cruz AC, Pedraza-Chaverri J, Briones-Herrera A, Cruz-Ramos E, López-Canovas L, Zepeda-Cervantes J. Protein degradation-associated mechanisms that are affected in Alzheimer´s disease. Mol Cell Biochem 2022; 477:915-925. [PMID: 35083609 DOI: 10.1007/s11010-021-04334-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 12/15/2021] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is the most common type of dementia associated with age-related neurodegeneration. Alteration of several molecular mechanisms has been correlated with the progression of AD. In recent years, dysregulation of proteostasis-associated pathways has emerged as a potential risk factor for neurodegenerative diseases. This review investigated the ubiquitin-proteasome system, lysosome-associated degradation, endoplasmic-reticulum-associated degradation, and the formation of advanced glycation end products. These pathways involved in proteostasis have been reported to be altered in AD, suggesting that their study may be critical for identifying new biomarkers and target molecules for AD.
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Affiliation(s)
- Angeles C Tecalco-Cruz
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), Apdo. Postal 03100, Ciudad de México, Mexico.
| | - José Pedraza-Chaverri
- Departamento de Biología. Facultad de Química, Universidad Nacional Autónoma de México, Apdo. Postal 04510, Ciudad de México, Mexico
| | - Alfredo Briones-Herrera
- Departamento de Biología. Facultad de Química, Universidad Nacional Autónoma de México, Apdo. Postal 04510, Ciudad de México, Mexico
| | - Eduardo Cruz-Ramos
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), Apdo. Postal 03100, Ciudad de México, Mexico
| | - Lilia López-Canovas
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), Apdo. Postal 03100, Ciudad de México, Mexico
| | - Jesús Zepeda-Cervantes
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Apdo. Postal 04510, Ciudad de México, Mexico
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8
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Choi MS, Chae YJ, Choi JW, Chang JE. Potential Therapeutic Approaches through Modulating the Autophagy Process for Skin Barrier Dysfunction. Int J Mol Sci 2021; 22:ijms22157869. [PMID: 34360634 PMCID: PMC8345957 DOI: 10.3390/ijms22157869] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 12/17/2022] Open
Abstract
Autophagy is an attractive process to researchers who are seeking novel potential treatments for various diseases. Autophagy plays a critical role in degrading damaged cellular organelles, supporting normal cell development, and maintaining cellular homeostasis. Because of the various effects of autophagy, recent human genome research has focused on evaluating the relationship between autophagy and a wide variety of diseases, such as autoimmune diseases, cancers, and inflammatory diseases. The skin is the largest organ in the body and provides the first line of defense against environmental hazards, including UV damage, chemical toxins, injuries, oxidative stress, and microorganisms. Autophagy takes part in endogenous defense mechanisms by controlling skin homeostasis. In this manner, regulating autophagy might contribute to the treatment of skin barrier dysfunctions. Various studies are ongoing to elucidate the association between autophagy and skin-related diseases in order to find potential therapeutic approaches. However, little evidence has been gathered about the relationship between autophagy and the skin. In this review, we highlight the previous findings of autophagy and skin barrier disorders and suggest potential therapeutic strategies. The recent research regarding autophagy in acne and skin aging is also discussed.
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Affiliation(s)
- Min Sik Choi
- Lab of Pharmacology, College of Pharmacy, Dongduk Women’s University, Seoul 02748, Korea;
| | - Yoon-Jee Chae
- College of Pharmacy, Woosuk University, Wanju-gun 55338, Korea;
| | - Ji Woong Choi
- College of Pharmacy, Gachon University, Incheon 21936, Korea;
| | - Ji-Eun Chang
- Lab of Pharmaceutics, College of Pharmacy, Dongduk Women’s University, Seoul 02748, Korea
- Correspondence:
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Abstract
Activation of autophagy is part of the innate immune response during viral infections. Autophagy involves the sequestration of endogenous or foreign components from the cytosol within double-membraned vesicles and the delivery of their content to the lysosomes for degradation. As part of innate immune responses, this autophagic elimination of foreign components is selective and requires specialized cargo receptors that function as links between a tagged foreign component and the autophagic machinery. Pathogens have evolved ways to evade their autophagic degradation to promote their replication, and recent research has shown autophagic receptors to be an important and perhaps previously overlooked target of viral autophagy inhibition. This is a brief summary of the recent progress in knowledge of virus-host interaction in the context of autophagy receptors.
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Affiliation(s)
- Päivi Ylä-Anttila
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden. .,Department of Medicine, Solna, Microbial Pathogenesis Unit, Karolinska Institutet, Stockholm, Sweden. .,Division of Neurology, Karolinska University Hospital, Stockholm, Sweden.
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10
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Lu J, Jia J, Zhang J, Liu X. HIV p17 enhances T cell proliferation by suppressing autophagy through the p17-OLA1-GSK3β axis under nutrient starvation. J Med Virol 2021; 93:3607-3620. [PMID: 32790080 DOI: 10.1002/jmv.26423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/08/2020] [Indexed: 02/02/2023]
Abstract
Nutrient starvation is a common phenomenon that occurs during T cell activation. Upon pathogen infection, large amounts of immune cells migrate to infection sites, and antigen-specific T cells are activated; this is followed by rapid proliferation through clonal expansion. The dramatic expansion of cells will commonly lead to nutrient shortage. Cellular autophagy is often upregulated as a way to sustain the body's energy requirements. During infection, human immunodeficiency virus (HIV) co-opts a series of host cell metabolic pathways for replication. Several HIV proteins, such as Env, Nef, and Vpr, have already been reported as being involved in autophagy-related processes. In this report, we identified that the HIV p17 protein acts as a major factor in suppressing the autophagic process in T cells, especially under glucose starvation condition. HIV p17 interacts with Obg-like ATPase 1 (OLA1) and disrupts OLA1-glycogen synthase kinase-3 beta (GSK3β) complex, leading to GSK3β hyperactivation. Consequently, a prior proliferation of HIV-infected T cells under glucose starvation will occur. The inhibition of autophagy also aids HIV replication by antagonizing the antiviral effect of autophagy. Our study shows a new cellular pathway that HIV can hijack for viral spreading by a prior proliferation of HIV-loaded T cells and may provide new therapeutic targets for acquired immunodeficiency syndrome intervention.
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Affiliation(s)
- Jing Lu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiayuan Jia
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiahui Zhang
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xinqi Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China
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11
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Wu K, Fan S, Zou L, Zhao F, Ma S, Fan J, Li X, Zhao M, Yan H, Chen J. Molecular Events Occurring in Lipophagy and Its Regulation in Flaviviridae Infection. Front Microbiol 2021; 12:651952. [PMID: 34093468 PMCID: PMC8175637 DOI: 10.3389/fmicb.2021.651952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/21/2021] [Indexed: 12/17/2022] Open
Abstract
Diseases caused by Flaviviridae have a wide global and economic impact due to high morbidity and mortality. Flaviviridae infection usually leads to severe, acute or chronic diseases, such as liver injury and liver cancer resulting from hepatitis C virus (HCV) infection, dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) caused by dengue virus (DENV). Given the highly complex pathogenesis of Flaviviridae infections, they are still not fully understood at present. Accumulating evidence suggests that host autophagy is disrupted to regulate the life cycle of Flaviviridae. Organelle-specific autophagy is able to selectively target different organelles for quality control, which is essential for regulating cellular homeostasis. As an important sub process of autophagy, lipophagy regulates lipid metabolism by targeting lipid droplets (LDs) and is also closely related to the infection of a variety of pathogenic microorganisms. In this review, we briefly understand the LDs interaction relationship with Flaviviridae infection, outline the molecular events of how lipophagy occurs and the related research progress on the regulatory mechanisms of lipophagy in Flaviviridae infection. Exploring the crosstalk between viral infection and lipophagy induced molecular events may provide new avenues for antiviral therapy.
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Affiliation(s)
- Keke Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Linke Zou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Feifan Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shengming Ma
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jindai Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Xiaowen Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Huichao Yan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
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12
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Ji L, Li L, Zhao Y, Liu S, Li J, Zhang J, Zhao Q, Wang S. Immunosubunit β5i Knockout Suppresses Neovascularization and Restores Autophagy in Retinal Neovascularization by Targeting ATG5 for Degradation. Invest Ophthalmol Vis Sci 2021; 61:30. [PMID: 33369639 PMCID: PMC7774061 DOI: 10.1167/iovs.61.14.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the functional role of immunoproteasome subunit β5i in pathologic retinal neovascularization (RNV) and its ability to link the immunoproteasome and autophagy. Methods Oxygen-induced retinopathy (OIR) was induced in wild-type (WT) and β5i knockout (KO) mouse pups on a C57BL/6J background. Proteasome catalytic subunit expression and proteasome activity were evaluated by quantitative real-time PCR (qPCR) and proteasome activity. Retinal vascular anatomy and neovascularization were characterized and quantified by retinal vascular flat-mount staining, fluorescence angiography, platelet endothelial cell adhesion molecule (PECAM) immunostaining, and hematoxylin and eosin staining. Correlation factors, including VEGF and ICAM-1, were detected by qPCR. Autophagy was examined by transmission electron microscopy (TEM). Autophagy biomarkers, including LC3, P62, ATG5, and ATG7, were measured by immunostaining and immunoblotting. The protein interaction between β5i and ATG5 was detected by immunoprecipitation. Results We observed that β5i had the greatest effect in WT OIR mice. Fundus fluorescence angiography, retinal flat-mount staining, and PECAM staining revealed that pathologic RNV decreased in β5i KO OIR mice compared with WT OIR mice. Concurrently, TEM, immunostaining, and immunoblotting showed that autophagy was induced in β5i KO OIR mice compared to WT OIR mice through increases in autophagosome and LC3 expression and a decrease in P62. Mechanistically, β5i interacted with ATG5 and promoted its degradation, leading to autophagy inhibition and pathogenic RNV. Conclusions This study identifies a functional role for β5i in RNV regulation. β5i deletion ameliorates RNV and restores autophagy by stabilizing ATG5. These results demonstrate the potential of β5i to serve as a bridge linking the immunoproteasome and autophagy.
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Affiliation(s)
- Liyang Ji
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
| | - Li Li
- Department of Ophthalmology, Zaozhuang Municipal Hospital, Zaozhuang, Shandong, China
| | - Ying Zhao
- Department of Ophthalmology, Jianping County Hospital, Chaoyang, China
| | - Shengqiang Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jingmin Li
- Department of Ophthalmology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jinsong Zhang
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China.,Aier Excellence Eye Hospital, Shenyang, China
| | - Qi Zhao
- Department of Ophthalmology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Shuai Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
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13
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Miyashita H, Oikawa D, Terawaki S, Kabata D, Shintani A, Tokunaga F. Crosstalk Between NDP52 and LUBAC in Innate Immune Responses, Cell Death, and Xenophagy. Front Immunol 2021; 12:635475. [PMID: 33815386 PMCID: PMC8017197 DOI: 10.3389/fimmu.2021.635475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/03/2021] [Indexed: 11/24/2022] Open
Abstract
Nuclear dot protein 52 kDa (NDP52, also known as CALCOCO2) functions as a selective autophagy receptor. The linear ubiquitin chain assembly complex (LUBAC) specifically generates the N-terminal Met1-linked linear ubiquitin chain, and regulates innate immune responses, such as nuclear factor-κB (NF-κB), interferon (IFN) antiviral, and apoptotic pathways. Although NDP52 and LUBAC cooperatively regulate bacterial invasion-induced xenophagy, their functional crosstalk remains enigmatic. Here we show that NDP52 suppresses canonical NF-κB signaling through the broad specificity of ubiquitin-binding at the C-terminal UBZ domain. Upon TNF-α-stimulation, NDP52 associates with LUBAC through the HOIP subunit, but does not disturb its ubiquitin ligase activity, and has a modest suppressive effect on NF-κB activation by functioning as a component of TNF-α receptor signaling complex I. NDP52 also regulates the TNF-α-induced apoptotic pathway, but not doxorubicin-induced intrinsic apoptosis. A chemical inhibitor of LUBAC (HOIPIN-8) cancelled the increased activation of the NF-κB and IFN antiviral pathways, and enhanced apoptosis in NDP52-knockout and -knockdown HeLa cells. Upon Salmonella-infection, colocalization of Salmonella, LC3, and linear ubiquitin was detected in parental HeLa cells to induce xenophagy. Treatment with HOIPIN-8 disturbed the colocalization and facilitated Salmonella expansion. In contrast, HOIPIN-8 showed little effect on the colocalization of LC3 and Salmonella in NDP52-knockout cells, suggesting that NDP52 is a weak regulator in LUBAC-mediated xenophagy. These results indicate that the crosstalk between NDP52 and LUBAC regulates innate immune responses, apoptosis, and xenophagy.
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Affiliation(s)
- Hirohisa Miyashita
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Daisuke Oikawa
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Seigo Terawaki
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Daijiro Kabata
- Department of Medical Statistics, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Ayumi Shintani
- Department of Medical Statistics, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Fuminori Tokunaga
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
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