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Enderlin J, Rieu Q, Réty S, Vanoni EM, Roux S, Dégardin J, César Q, Augustin S, Nous C, Cai B, Fontaine V, Sennlaub F, Nandrot EF. Retinal atrophy, inflammation, phagocytic and metabolic disruptions develop in the MerTK-cleavage-resistant mouse model. Front Neurosci 2024; 18:1256522. [PMID: 38680449 PMCID: PMC11047123 DOI: 10.3389/fnins.2024.1256522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 03/11/2024] [Indexed: 05/01/2024] Open
Abstract
In the eye, cells from the retinal pigment epithelium (RPE) facing the neurosensory retina exert several functions that are all crucial for long-term survival of photoreceptors (PRs) and vision. Among those, RPE cells phagocytose under a circadian rhythm photoreceptor outer segment (POS) tips that are constantly subjected to light rays and oxidative attacks. The MerTK tyrosine kinase receptor is a key element of this phagocytic machinery required for POS internalization. Recently, we showed that MerTK is subjected to the cleavage of its extracellular domain to finely control its function. In addition, monocytes in retinal blood vessels can migrate inside the inner retina and differentiate into macrophages expressing MerTK, but their role in this context has not been studied yet. We thus investigated the ocular phenotype of MerTK cleavage-resistant (MerTKCR) mice to understand the relevance of this characteristic on retinal homeostasis at the RPE and macrophage levels. MerTKCR retinae appear to develop and function normally, as observed in retinal sections, by electroretinogram recordings and optokinetic behavioral tests. Monitoring of MerTKCR and control mice between the ages of 3 and 18 months showed the development of large degenerative areas in the central retina as early as 4 months when followed monthly by optical coherence tomography (OCT) plus fundus photography (FP)/autofluorescence (AF) detection but not by OCT alone. The degenerative areas were associated with AF, which seems to be due to infiltrated macrophages, as observed by OCT and histology. MerTKCR RPE primary cultures phagocytosed less POS in vitro, while in vivo, the circadian rhythm of POS phagocytosis was deregulated. Mitochondrial function and energy production were reduced in freshly dissected RPE/choroid tissues at all ages, thus showing a metabolic impairment not present in macrophages. RPE anomalies were detected by electron microscopy, including phagosomes retained in the apical area and vacuoles. Altogether, this new mouse model displays a novel phenotype that could prove useful to understanding the interplay between RPE and PRs in inflammatory retinal degenerations and highlights new roles for MerTK in the regulation of the energetic metabolism and the maintenance of the immune privilege in the retina.
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Affiliation(s)
- Julie Enderlin
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Quentin Rieu
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Salomé Réty
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Elora M. Vanoni
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Solène Roux
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Julie Dégardin
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Quénol César
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Sébastien Augustin
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Caroline Nous
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Bishuang Cai
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Valérie Fontaine
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Florian Sennlaub
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
| | - Emeline F. Nandrot
- INSERM, CNRS, Institut de la Vision, Therapeutics Department, Sorbonne Université, Paris, France
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Liebold I, Al Jawazneh A, Casar C, Lanzloth C, Leyk S, Hamley M, Wong MN, Kylies D, Gräfe SK, Edenhofer I, Aranda-Pardos I, Kriwet M, Haas H, Krause J, Hadjilaou A, Schromm AB, Richardt U, Eggert P, Tappe D, Weidemann SA, Ghosh S, Krebs CF, A-Gonzalez N, Worthmann A, Lohse AW, Huber S, Rothlin CV, Puelles VG, Jacobs T, Gagliani N, Bosurgi L. Apoptotic cell identity induces distinct functional responses to IL-4 in efferocytic macrophages. Science 2024; 384:eabo7027. [PMID: 38574142 DOI: 10.1126/science.abo7027] [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: 02/19/2022] [Accepted: 02/26/2024] [Indexed: 04/06/2024]
Abstract
Macrophages are functionally heterogeneous cells essential for apoptotic cell clearance. Apoptotic cells are defined by homogeneous characteristics, ignoring their original cell lineage identity. We found that in an interleukin-4 (IL-4)-enriched environment, the sensing of apoptotic neutrophils by macrophages triggered their tissue remodeling signature. Engulfment of apoptotic hepatocytes promoted a tolerogenic phenotype, whereas phagocytosis of T cells had little effect on IL-4-induced gene expression. In a mouse model of parasite-induced pathology, the transfer of macrophages conditioned with IL-4 and apoptotic neutrophils promoted parasitic egg clearance. Knockout of phagocytic receptors required for the uptake of apoptotic neutrophils and partially T cells, but not hepatocytes, exacerbated helminth infection. These findings suggest that the identity of apoptotic cells may contribute to the development of distinct IL-4-driven immune programs in macrophages.
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Affiliation(s)
- Imke Liebold
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Amirah Al Jawazneh
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Christian Casar
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Bioinformatics Core, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Clarissa Lanzloth
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stephanie Leyk
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Madeleine Hamley
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Milagros N Wong
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Dominik Kylies
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefanie K Gräfe
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ilka Edenhofer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Marie Kriwet
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Jenny Krause
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexandros Hadjilaou
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Institute of Neuroimmunology and Multiple Sclerosis, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andra B Schromm
- Division of Immunobiophysics, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Ulricke Richardt
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Petra Eggert
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Dennis Tappe
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Sören A Weidemann
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sourav Ghosh
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Christian F Krebs
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Anna Worthmann
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ansgar W Lohse
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- European Reference Network on Hepatological Diseases (ERN-RARE LIVER), Hamburg, Germany
| | - Samuel Huber
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carla V Rothlin
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Victor G Puelles
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Thomas Jacobs
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Nicola Gagliani
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lidia Bosurgi
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Jamalvandi M, Khayyatzadeh SS, Hayati MJ, Gheibihayat SM. The role of fat-soluble vitamins in efferocytosis. Cell Biochem Funct 2024; 42:e3972. [PMID: 38500392 DOI: 10.1002/cbf.3972] [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: 12/19/2023] [Revised: 02/08/2024] [Accepted: 03/02/2024] [Indexed: 03/20/2024]
Abstract
Cell death and the efficient removal of dead cells are two basic mechanisms that maintain homeostasis in multicellular organisms. efferocytosis, which includes four steps recruitment, recognition, binding and signaling, and engulfment. Effectively and quickly removes apoptotic cells from the body. Any alteration in efferocytosis can lead to several diseases, including autoimmune and inflammatory conditions, atherosclerosis, and cancer. A wide range of dietary components affects apoptosis and, subsequently, efferocytosis. Some vitamins, including fat-soluble vitamins, affect different stages of efferocytosis. Among other things, by affecting macrophages, they are effective in the apoptotic cleansing of cells. Also, polyphenols indirectly intervene in efferocytosis through their effect on apoptosis. Considering that there are limited articles on the effect of nutrition on efferocytosis, in this article we will examine the effect of some dietary components on efferocytosis.
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Affiliation(s)
- Mona Jamalvandi
- Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Sayyed Saeid Khayyatzadeh
- Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Javad Hayati
- Department of Medical Biotechnology, School of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
| | - Seyed Mohammad Gheibihayat
- Department of Medical Biotechnology, School of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
- Yazd Cardiovascular Research Center, Non-communicable Diseases Research Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
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Martínez-Ramos S, Rafael-Vidal C, Malvar-Fernández B, Pérez N, Mouriño C, Pérez SG, Maceiras Pan FJ, Conde C, Pego-Reigosa JM, García S. Semaphorin3B promotes an anti-inflammatory and pro-resolving phenotype in macrophages from rheumatoid arthritis patients in a MerTK-dependent manner. Front Immunol 2024; 14:1268144. [PMID: 38283352 PMCID: PMC10811190 DOI: 10.3389/fimmu.2023.1268144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/26/2023] [Indexed: 01/30/2024] Open
Abstract
Previous works from our group show that Semaphorin3B (Sema3B) is reduced in RA and plays a protective role in a mouse arthritis model. In turn, MerTK plays a protective function in murine arthritis models, is expressed by synovial tissue macrophages and is linked to remission in patients with RA. In this study, we examined the role of Sema3B in the phenotypic characteristics of RA macrophages and the implication of MerTK. Peripheral blood monocytes from RA patients were differentiated into IFN-γ (RA MØIFN-γ) or M-CSF (RA MØM-CSF) macrophages and stimulated with LPS, Sema3B or their combination. Alternatively, RA fibroblast like synoviocytes (FLS) were stimulated with RA MØIFN-γ and RA MØM-CSF supernatants. Gene expression was determined by qPCR and protein expression and activation by flow cytometry, ELISA and western blot. Sema3B down-regulated the expression of pro-inflammatory mediators, in both RA MØIFN-γ and RA MØM-CSF. We observed a similar reduction in RA FLS stimulated with the supernatant of Sema3B-treated RA MØIFN-γ and RA MØM-CSF. Sema3B also modulated cell surface markers in macrophages towards an anti-inflammatory phenotype. Besides, MerTK expression and activation was up-regulated by Sema3B, just as GAS6 expression, Resolvin D1 secretion and the phagocytic activity of macrophages. Importantly, the inhibition of MerTK and neuropilins 1 and 2 abrogated the anti-inflammatory effect of Sema3B. Our data demonstrate that Sema3B modulates the macrophage characteristics in RA, inducing a skewing towards an anti-inflammatory/pro-resolving phenotype in a MerTK-dependant manner. Therefore, here we identify a new mechanism supporting the protective role of Sema3B in RA pathogenesis.
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Affiliation(s)
- Sara Martínez-Ramos
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Carlos Rafael-Vidal
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Beatriz Malvar-Fernández
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Nair Pérez
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Coral Mouriño
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Sara García Pérez
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Francisco J. Maceiras Pan
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Carmen Conde
- Laboratorio de Reumatologia Experimental y Observacional y Servicio de Reumatologia, Instituto de Investigacion Sanitaria de Santiago (IDIS), Hospital Clinico Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saude (SERGAS), Santiago de Compostela, Spain
| | - Jose María Pego-Reigosa
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
| | - Samuel García
- Rheumatology and Immuno-mediated Diseases Research Group (IRIDIS), Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
- Rheumatology Department, University Hospital Complex of Vigo, Vigo, Spain
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5
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Burstyn-Cohen T, Fresia R. TAM receptors in phagocytosis: Beyond the mere internalization of particles. Immunol Rev 2023; 319:7-26. [PMID: 37596991 DOI: 10.1111/imr.13267] [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: 04/17/2023] [Accepted: 07/18/2023] [Indexed: 08/21/2023]
Abstract
TYRO3, AXL, and MERTK constitute the TAM family of receptor tyrosine kinases, activated by their ligands GAS6 and PROS1. TAMs are necessary for adult homeostasis in the immune, nervous, reproductive, skeletal, and vascular systems. Among additional cellular functions employed by TAMs, phagocytosis is central for tissue health. TAM receptors are dominant in providing phagocytes with the molecular machinery necessary to engulf diverse targets, including apoptotic cells, myelin debris, and portions of live cells in a phosphatidylserine-dependent manner. Simultaneously, TAMs drive the release of anti-inflammatory and tissue repair molecules. Disruption of the TAM-driven phagocytic pathway has detrimental consequences, resulting in autoimmunity, male infertility, blindness, and disrupted vascular integrity, and which is thought to contribute to neurodegenerative diseases. Although structurally and functionally redundant, the TAM receptors and ligands underlie complex signaling cascades, of which several key aspects are yet to be elucidated. We discuss similarities and differences between TAMs and other phagocytic pathways, highlight future directions and how TAMs can be harnessed therapeutically to modulate phagocytosis.
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Affiliation(s)
- Tal Burstyn-Cohen
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Roberta Fresia
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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Lantz C, Thorp EB. Metabolism: How removal of damaged cells impacts energy availability in the retina. Curr Biol 2023; 33:R279-R282. [PMID: 37040713 PMCID: PMC10410992 DOI: 10.1016/j.cub.2023.02.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Once thought to be a quiescent process, elimination of damaged cells by professional phagocytes is now understood to modulate metabolite availability within tissues. A new study reveals that the retinal pigment epithelium serves as a local source of insulin after engulfment of damaged photoreceptors.
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Affiliation(s)
- Connor Lantz
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Edward B Thorp
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Feinberg Cardiovascular and Renal Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; The Heart Center, Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA.
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7
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Iker Etchegaray J, Kelley S, Penberthy K, Karvelyte L, Nagasaka Y, Gasperino S, Paul S, Seshadri V, Raymond M, Marco AR, Pinney J, Stremska M, Barron B, Lucas C, Wase N, Fan Y, Unanue E, Kundu B, Burstyn-Cohen T, Perry J, Ambati J, Ravichandran KS. Phagocytosis in the retina promotes local insulin production in the eye. Nat Metab 2023; 5:207-218. [PMID: 36732622 PMCID: PMC10457724 DOI: 10.1038/s42255-022-00728-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 12/16/2022] [Indexed: 02/04/2023]
Abstract
The retina is highly metabolically active, relying on glucose uptake and aerobic glycolysis. Situated in close contact to photoreceptors, a key function of cells in the retinal pigment epithelium (RPE) is phagocytosis of damaged photoreceptor outer segments (POS). Here we identify RPE as a local source of insulin in the eye that is stimulated by POS phagocytosis. We show that Ins2 messenger RNA and insulin protein are produced by RPE cells and that this production correlates with RPE phagocytosis of POS. Genetic deletion of phagocytic receptors ('loss of function') reduces Ins2, whereas increasing the levels of the phagocytic receptor MerTK ('gain of function') increases Ins2 production in male mice. Contrary to pancreas-derived systemic insulin, RPE-derived local insulin is stimulated during starvation, which also increases RPE phagocytosis. Global or RPE-specific Ins2 gene deletion decreases retinal glucose uptake in starved male mice, dysregulates retinal physiology, causes defects in phototransduction and exacerbates photoreceptor loss in a mouse model of retinitis pigmentosa. Collectively, these data identify RPE cells as a phagocytosis-induced local source of insulin in the retina, with the potential to influence retinal physiology and disease.
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Affiliation(s)
- J Iker Etchegaray
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Shannon Kelley
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kristen Penberthy
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Laura Karvelyte
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Yosuke Nagasaka
- Center for Advanced Vision Science, University of Virginia, Charlottesville, VA, USA
| | - Sofia Gasperino
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Soumen Paul
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Vikram Seshadri
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Michael Raymond
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Ana Royo Marco
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Jonathan Pinney
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Marta Stremska
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Brady Barron
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christopher Lucas
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- University of Edinburgh, Edinburgh, UK
| | - Nishikant Wase
- Biomolecular Analysis Facility, University of Virginia, Charlottesville, VA, USA
| | - Yong Fan
- Drexel University, Philadelphia, PA, USA
| | - Emil Unanue
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Bijoy Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Tal Burstyn-Cohen
- Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Justin Perry
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jayakrishna Ambati
- Center for Advanced Vision Science, University of Virginia, Charlottesville, VA, USA
- Ophthalmology, University of Virginia, Charlottesville, VA, USA
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.
- Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel.
- VIB/UGent Inflammation Research Centre, and Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
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A local source of insulin protects the retina against starvation. Nat Metab 2023; 5:205-206. [PMID: 36732625 DOI: 10.1038/s42255-023-00745-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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9
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Mercau ME, Akalu YT, Mazzoni F, Gyimesi G, Alberto EJ, Kong Y, Hafler BP, Finnemann SC, Rothlin CV, Ghosh S. Inflammation of the retinal pigment epithelium drives early-onset photoreceptor degeneration in Mertk-associated retinitis pigmentosa. SCIENCE ADVANCES 2023; 9:eade9459. [PMID: 36662852 PMCID: PMC9858494 DOI: 10.1126/sciadv.ade9459] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/19/2022] [Indexed: 05/17/2023]
Abstract
Severe, early-onset photoreceptor (PR) degeneration associated with MERTK mutations is thought to result from failed phagocytosis by retinal pigment epithelium (RPE). Notwithstanding, the severity and onset of PR degeneration in mouse models of Mertk ablation are determined by the hypomorphic expression or the loss of the Mertk paralog Tyro3. Here, we find that loss of Mertk and reduced expression/loss of Tyro3 led to RPE inflammation even before eye-opening. Incipient RPE inflammation cascaded to involve microglia activation and PR degeneration with monocyte infiltration. Inhibition of RPE inflammation with the JAK1/2 inhibitor ruxolitinib mitigated PR degeneration in Mertk-/- mice. Neither inflammation nor severe, early-onset PR degeneration was observed in mice with defective phagocytosis alone. Thus, inflammation drives severe, early-onset PR degeneration-associated with Mertk loss of function.
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Affiliation(s)
- Maria E. Mercau
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Yemsratch T. Akalu
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Francesca Mazzoni
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Gavin Gyimesi
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Emily J. Alberto
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Yong Kong
- Department of Molecular Biophysics and Biochemistry, W. M. Keck Foundation Biotechnology Resource Laboratory, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Brian P. Hafler
- Department of Ophthalmology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Pathology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Carla V. Rothlin
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Sourav Ghosh
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Neurology, School of Medicine, Yale University, New Haven, CT 06520, USA
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10
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Shi J, Gao S, Chen Z, Chen Z, Yun D, Wu X, Sun F. Absence of MerTK disrupts spermatogenesis in an age-dependent manner. Mol Cell Endocrinol 2023; 560:111815. [PMID: 36379275 DOI: 10.1016/j.mce.2022.111815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/02/2022] [Accepted: 11/06/2022] [Indexed: 11/15/2022]
Abstract
Spermatogenesis is a highly specialized cell differentiation process regulated by the testicular microenvironment. During the process of spermatogenesis, phagocytosis performs an essential role in male germ cell development, and its dysfunction in the testis can cause reproduction defects. MerTK, as a critical protein of phagocytosis, facilitates the removal of apoptotic substrates from the retina and ovaries through cooperation with several phagocytosis receptors. However, its role in mammalian spermatogenesis remains undefined. Here, we found that 30-week-old MerTK-/- male mice developed oligoasthenospermia due to abnormal spermatogenesis. These mice showed damaged seminiferous tubule structure, as well as altered spermatogonia proliferation and differentiation. We also found that Sertoli cells from MerTK-/- mice had decreased phagocytic activity on apoptotic germ cells in vitro. Moreover, a transcriptomic analysis demonstrated that the pivotal genes involved in spermatid differentiation and development changed expression. These results indicate that MerTK is crucial for spermatogenesis, as it regulates the crosstalk between germ cells and Sertoli cells. This provides us insight into the molecular mechanism of MerTK on spermatogenesis and its implications for the diagnosis and treatment of human male infertility.
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Affiliation(s)
- Jie Shi
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China
| | - Sheng Gao
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China
| | - Zhengru Chen
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China
| | - Zifeng Chen
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China
| | - Damin Yun
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China
| | - Xiaolong Wu
- Department of Urology & Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310016, China
| | - Fei Sun
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, China.
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11
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Abstract
The daily removal of billions of apoptotic cells in the human body via the process of efferocytosis is essential for homeostasis. To allow for this continuous efferocytosis, rapid phenotypic changes occur in the phagocytes enabling them to engulf and digest the apoptotic cargo. In addition, efferocytosis is actively anti-inflammatory and promotes resolution. Owing to its ubiquitous nature and the sheer volume of cell turnover, efferocytosis is a point of vulnerability. Aberrations in efferocytosis are associated with numerous inflammatory pathologies, including atherosclerosis, cancer and infections. The recent exciting discoveries defining the molecular machinery involved in efferocytosis have opened many avenues for therapeutic intervention, with several agents now in clinical trials.
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Affiliation(s)
- Parul Mehrotra
- Unit for Cell Clearance in Health and Disease, VIB Center for Inflammation Research, Ghent, Belgium
| | - Kodi S Ravichandran
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- The Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.
- Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
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12
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Gomes MT, Palasiewicz K, Gadiyar V, Lahey K, Calianese D, Birge RB, Ucker DS. Phosphatidylserine externalization by apoptotic cells is dispensable for specific recognition leading to innate apoptotic immune responses. J Biol Chem 2022; 298:102034. [PMID: 35588784 PMCID: PMC9234239 DOI: 10.1016/j.jbc.2022.102034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 12/22/2022] Open
Abstract
Surface determinants newly expressed by apoptotic cells that are involved in triggering potent immunosuppressive responses, referred to as “innate apoptotic immunity (IAI)” have not been characterized fully. It is widely assumed, often implicitly, that phosphatidylserine, a phospholipid normally cloistered in the inner leaflet of cells and externalized specifically during apoptosis, is involved in triggering IAI, just as it plays an essential role in the phagocytic recognition of apoptotic cells. It is notable, however, that the triggering of IAI in responder cells is not dependent on the engulfment of apoptotic cells by those responders. Contact between the responder and the apoptotic target, on the other hand, is necessary to elicit IAI. Previously, we demonstrated that exposure of protease-sensitive determinants on the apoptotic cell surface are essential for initiating IAI responses; exposed glycolytic enzyme molecules were implicated in particular. Here, we report our analysis of the involvement of externalized phosphatidylserine in triggering IAI. To analyze the role of phosphatidylserine, we employed a panel of target cells that either externalized phosphatidylserine constitutively, independently of apoptosis, or did not, as well as their WT parental cells that externalized the phospholipid in an apoptosis-dependent manner. We found that the externalization of phosphatidylserine, which can be fully uncoupled from apoptosis, is neither sufficient nor necessary to trigger the profound immunomodulatory effects of IAI. These results reinforce the view that apoptotic immunomodulation and phagocytosis are dissociable and further underscore the significance of protein determinants localized to the cell surface during apoptosis in triggering innate apoptotic immunity.
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Affiliation(s)
- Marta T Gomes
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, Illinois, USA
| | - Karol Palasiewicz
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, Illinois, USA
| | - Varsha Gadiyar
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, New Jersey, USA
| | - Kevin Lahey
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, New Jersey, USA
| | - David Calianese
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, New Jersey, USA
| | - Raymond B Birge
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, New Jersey, USA
| | - David S Ucker
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, Illinois, USA.
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13
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Acute RhoA/Rho Kinase Inhibition Is Sufficient to Restore Phagocytic Capacity to Retinal Pigment Epithelium Lacking the Engulfment Receptor MerTK. Cells 2021; 10:cells10081927. [PMID: 34440696 PMCID: PMC8394172 DOI: 10.3390/cells10081927] [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: 06/13/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 12/27/2022] Open
Abstract
The diurnal phagocytosis of spent photoreceptor outer segment fragments (POS) by retinal pigment epithelial (RPE) cells is essential for visual function. POS internalization by RPE cells requires the assembly of F-actin phagocytic cups beneath surface-tethered POS and Mer tyrosine kinase (MerTK) signaling. The activation of the Rho family GTPase Rac1 is necessary for phagocytic cup formation, and Rac1 is activated normally in MerTK-deficient RPE. We show here that mutant RPE lacking MerTK and wild-type RPE deprived of MerTK ligand both fail to form phagocytic cups regardless of Rac1 activation. However, in wild-type RPE in vivo, a decrease in RhoA activity coincides with the daily phagocytosis burst, while RhoA activity in MerTK-deficient RPE is constant. Elevating RhoA activity blocks phagocytic cup formation and phagocytosis by wild-type RPE. Conversely, inhibiting RhoA effector Rho kinases (ROCKs) rescues both F-actin assembly and POS internalization of primary RPE if MerTK or its ligand are lacking. Most strikingly, acute ROCK inhibition is sufficient to induce the formation and acidification of endogenous POS phagosomes by MerTK-deficient RPE ex vivo. Altogether, RhoA pathway inactivation is a necessary and sufficient downstream effect of MerTK phagocytic signaling such that the acute manipulation of cytosolic ROCK activity suffices to restore phagocytic capacity to MerTK-deficient RPE.
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14
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Esposito NJ, Mazzoni F, Vargas JA, Finnemann SC. Diurnal Photoreceptor Outer Segment Renewal in Mice Is Independent of Galectin-3. Invest Ophthalmol Vis Sci 2021; 62:7. [PMID: 33538769 PMCID: PMC7862728 DOI: 10.1167/iovs.62.2.7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Galectin-3 (gal-3) is a soluble glycoprotein that has been associated with diverse forms of phagocytosis, including some mediated by the engulfment receptor MerTK. Retinal pigment epithelium (RPE) in vivo uses MerTK (or the related Tyro3) for phagocytosis of shed outer segment fragments during diurnal outer segment renewal. Here, we test if gal-3 plays a role in outer segment renewal in mice and if exogenous gal-3 can promote MerTK-dependent engulfment of isolated outer segment fragments by primary RPE cells in culture. Methods We explored age- and strain-matched wild-type (wt), lgals3−/− and mertk−/− mice. Immunofluorescence and immunoblotting characterized gal-3 and RPE/retina protein expression, respectively. Outer segment renewal was investigated by live imaging of phosphatidylserine (PS) exposure on photoreceptor outer segment distal tips and by microscopy of rhodopsin-labeled RPE phagosomes in tissue sections. Retinal function was assessed by recording electroretinograms (ERGs). Phagocytosis assays feeding purified outer segment fragments (POS) were conducted with added recombinant proteins testing unpassaged primary mouse RPE. Results Gal-3 localizes to neural retina and RPE in wt mice. The lgals3−/− photoreceptor outer segments display normal diurnal PS exposure at distal tips. The number of rhodopsin-positive phagosomes in wt and lgals3−/− RPE does not differ at peak or trough of diurnal phagocytosis activity. lgals3−/− mice show light responses like wt, and their eyes contain wt levels of retinal and RPE proteins. Unlike purified protein S, recombinant gal-3 fails to promote POS engulfment by mouse primary RPE in culture. Conclusions Gal-3 has no essential role in MerTK-dependent outer segment renewal in mice.
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Affiliation(s)
- Nicholas J Esposito
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, New York, United States
| | - Francesca Mazzoni
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, New York, United States
| | - Jade A Vargas
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, New York, United States
| | - Silvia C Finnemann
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, New York, United States
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15
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Kelley SM, Ravichandran KS. Putting the brakes on phagocytosis: "don't-eat-me" signaling in physiology and disease. EMBO Rep 2021; 22:e52564. [PMID: 34041845 DOI: 10.15252/embr.202152564] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/12/2021] [Accepted: 04/29/2021] [Indexed: 12/12/2022] Open
Abstract
Timely removal of dying or pathogenic cells by phagocytes is essential to maintaining host homeostasis. Phagocytes execute the clearance process with high fidelity while sparing healthy neighboring cells, and this process is at least partially regulated by the balance of "eat-me" and "don't-eat-me" signals expressed on the surface of host cells. Upon contact, eat-me signals activate "pro-phagocytic" receptors expressed on the phagocyte membrane and signal to promote phagocytosis. Conversely, don't-eat-me signals engage "anti-phagocytic" receptors to suppress phagocytosis. We review the current knowledge of don't-eat-me signaling in normal physiology and disease contexts where aberrant don't-eat-me signaling contributes to pathology.
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Affiliation(s)
- Shannon M Kelley
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.,VIB-UGent Center for Inflammation Research, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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16
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Hughes LD, Wang Y, Meli AP, Rothlin CV, Ghosh S. Decoding Cell Death: From a Veritable Library of Babel to Vade Mecum? Annu Rev Immunol 2021; 39:791-817. [PMID: 33902311 DOI: 10.1146/annurev-immunol-102819-072601] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Programmed cell death (PCD) is a requisite feature of development and homeostasis but can also be indicative of infections, injuries, and pathologies. In concordance with these heterogeneous contexts, an array of disparate effector responses occur downstream of cell death and its clearance-spanning tissue morphogenesis, homeostatic turnover, host defense, active dampening of inflammation, and tissue repair. This raises a fundamental question of how a single contextually appropriate response ensues after an event of PCD. To explore how complex inputs may together tailor the specificity of the resulting effector response, here we consider (a) the varying contexts during which different cell death modalities are observed, (b) the nature of the information that can be passed on by cell corpses, and (c) the ways by which efferocyte populations synthesize signals from dying cells with those from the surrounding microenvironment.
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Affiliation(s)
- Lindsey D Hughes
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Yaqiu Wang
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Alexandre P Meli
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Carla V Rothlin
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , , .,Department of Pharmacology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA;
| | - Sourav Ghosh
- Department of Pharmacology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; .,Department of Neurology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA
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17
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Abstract
Cell death occurs when a pathogen invades a host organism or the organism is subjected to sterile injury. Thus, cell death is often closely associated with the induction of an immune response. Furthermore, cell death can occur as a consequence of the immune response and precedes the tissue renewal and repair responses that are initiated by innate immune cells during resolution of an immune response. Beyond immunity, cell death is required for development, morphogenesis and homeostasis. How can such a ubiquitous event as cell death trigger such a wide range of context-specific effector responses? Dying cells are sensed by innate immune cells using specialized receptors and phagocytosed through a process termed efferocytosis. Here, we outline a general principle whereby signals within the dead cell as well as the environment are integrated by specific efferocytes to define the appropriate effector response.
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18
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Lakkaraju A, Umapathy A, Tan LX, Daniele L, Philp NJ, Boesze-Battaglia K, Williams DS. The cell biology of the retinal pigment epithelium. Prog Retin Eye Res 2020; 78:100846. [PMID: 32105772 PMCID: PMC8941496 DOI: 10.1016/j.preteyeres.2020.100846] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE), a monolayer of post-mitotic polarized epithelial cells, strategically situated between the photoreceptors and the choroid, is the primary caretaker of photoreceptor health and function. Dysfunction of the RPE underlies many inherited and acquired diseases that cause permanent blindness. Decades of research have yielded valuable insight into the cell biology of the RPE. In recent years, new technologies such as live-cell imaging have resulted in major advancement in our understanding of areas such as the daily phagocytosis and clearance of photoreceptor outer segment tips, autophagy, endolysosome function, and the metabolic interplay between the RPE and photoreceptors. In this review, we aim to integrate these studies with an emphasis on appropriate models and techniques to investigate RPE cell biology and metabolism, and discuss how RPE cell biology informs our understanding of retinal disease.
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Affiliation(s)
- Aparna Lakkaraju
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Ankita Umapathy
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Li Xuan Tan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Lauren Daniele
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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19
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Living on the Edge: Efferocytosis at the Interface of Homeostasis and Pathology. Immunity 2019; 50:1149-1162. [PMID: 31117011 DOI: 10.1016/j.immuni.2019.04.018] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/13/2019] [Accepted: 04/29/2019] [Indexed: 01/23/2023]
Abstract
Nearly every tissue in the body undergoes routine turnover of cells as part of normal healthy living. The majority of these cells undergoing turnover die via apoptosis, and then are rapidly removed by phagocytes by the process of efferocytosis that is anti-inflammatory. However, a number of pathologies have recently been linked to defective clearance of apoptotic cells. Perturbed clearance arises for many reasons, including overwhelming of the clearance machinery, disruptions at different stages of efferocytosis, and responses of phagocytes during efferocytosis, all of which can alter the homeostatic tissue environment. This review covers linkages of molecules involved in the different phases of efferocytosis to disease pathologies that can arise due to their loss or altered function.
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20
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Rival CM, Xu W, Shankman LS, Morioka S, Arandjelovic S, Lee CS, Wheeler KM, Smith RP, Haney LB, Isakson BE, Purcell S, Lysiak JJ, Ravichandran KS. Phosphatidylserine on viable sperm and phagocytic machinery in oocytes regulate mammalian fertilization. Nat Commun 2019; 10:4456. [PMID: 31575859 PMCID: PMC6773685 DOI: 10.1038/s41467-019-12406-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/29/2019] [Indexed: 01/06/2023] Open
Abstract
Fertilization is essential for species survival. Although Izumo1 and Juno are critical for initial interaction between gametes, additional molecules necessary for sperm:egg fusion on both the sperm and the oocyte remain to be defined. Here, we show that phosphatidylserine (PtdSer) is exposed on the head region of viable and motile sperm, with PtdSer exposure progressively increasing during sperm transit through the epididymis. Functionally, masking phosphatidylserine on sperm via three different approaches inhibits fertilization. On the oocyte, phosphatidylserine recognition receptors BAI1, CD36, Tim-4, and Mer-TK contribute to fertilization. Further, oocytes lacking the cytoplasmic ELMO1, or functional disruption of RAC1 (both of which signal downstream of BAI1/BAI3), also affect sperm entry into oocytes. Intriguingly, mammalian sperm could fuse with skeletal myoblasts, requiring PtdSer on sperm and BAI1/3, ELMO2, RAC1 in myoblasts. Collectively, these data identify phosphatidylserine on viable sperm and PtdSer recognition receptors on oocytes as key players in sperm:egg fusion.
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Affiliation(s)
- Claudia M Rival
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Urology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Wenhao Xu
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Laura S Shankman
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Sho Morioka
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Sanja Arandjelovic
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Chang Sup Lee
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Karen M Wheeler
- Department of Urology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Ryan P Smith
- Department of Urology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Lisa B Haney
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Brant E Isakson
- Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA
| | - Scott Purcell
- Reproductive Medicine and Surgery Center of Virginia, 595 Martha Jefferson Dr., Charlottesville, VA, 22911, USA
| | - Jeffrey J Lysiak
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA.
- Department of Urology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA.
| | - Kodi S Ravichandran
- The Center for Cell Clearance, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA.
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, 1340 Jefferson Park Avenue, Pinn Hall, Charlottesville, VA, 22903, USA.
- Department of Biomedical Molecular Biology, Ghent University, and the UGent-VIB Center for Inflammation Research, Technologiepark 71, 9052, Ghent, Belgium.
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21
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Norris GT, Kipnis J. Immune cells and CNS physiology: Microglia and beyond. J Exp Med 2019; 216:60-70. [PMID: 30504438 PMCID: PMC6314530 DOI: 10.1084/jem.20180199] [Citation(s) in RCA: 151] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/15/2018] [Accepted: 11/13/2018] [Indexed: 12/25/2022] Open
Abstract
Recent advances have directed our knowledge of the immune system from a narrative of "self" versus "nonself" to one in which immune function is critical for homeostasis of organs throughout the body. This is also the case with respect to the central nervous system (CNS). CNS immunity exists in a segregated state, with a marked partition occurring between the brain parenchyma and meningeal spaces. While the brain parenchyma is patrolled by perivascular macrophages and microglia, the meningeal spaces are supplied with a diverse immune repertoire. In this review, we posit that such partition allows for neuro-immune crosstalk to be properly tuned. Convention may imply that meningeal immunity is an ominous threat to brain function; however, recent studies have shown that its presence may instead be a steady hand directing the CNS to optimal performance.
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Affiliation(s)
- Geoffrey T Norris
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA
- Department of Neuroscience, University of Virginia, Charlottesville, VA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA
- Department of Neuroscience, University of Virginia, Charlottesville, VA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA
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Moon SY, Shin SA, Oh YS, Park HH, Lee CS. Understanding the Role of the BAI Subfamily of Adhesion G Protein-Coupled Receptors (GPCRs) in Pathological and Physiological Conditions. Genes (Basel) 2018; 9:genes9120597. [PMID: 30513696 PMCID: PMC6316137 DOI: 10.3390/genes9120597] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 02/06/2023] Open
Abstract
Brain-specific angiogenesis inhibitors (BAIs) 1, 2, and 3 are members of the adhesion G protein-coupled receptors, subfamily B, which share a conserved seven-transmembrane structure and an N-terminal extracellular domain. In cell- and animal-based studies, these receptors have been shown to play diverse roles under physiological and pathological conditions. BAI1 is an engulfment receptor and performs major functions in apoptotic-cell clearance and interacts (as a pattern recognition receptor) with pathogen components. BAI1 and -3 also participate in myoblast fusion. Furthermore, BAI1–3 have been linked to tumor progression and neurological diseases. In this review, we summarize the current understanding of the functions of BAI1–3 in pathological and physiological conditions and discuss future directions in terms of the importance of BAIs as pharmacological targets in diseases.
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Affiliation(s)
- Sun Young Moon
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Korea.
| | - Seong-Ah Shin
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Korea.
| | - Yong-Seok Oh
- Department of Brain-Cognitive Sciences, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Hyeonpung-myeon, Dalseong-gun, Daegu 42988, Korea.
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea.
| | - Chang Sup Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Korea.
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23
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Rethinking Phagocytes: Clues from the Retina and Testes. Trends Cell Biol 2018; 28:317-327. [PMID: 29454661 DOI: 10.1016/j.tcb.2018.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/13/2018] [Accepted: 01/16/2018] [Indexed: 01/30/2023]
Abstract
Specialized phagocytes are a newly appreciated classification of phagocyte that currently encompasses Sertoli cells (SCs) of the testes and the retinal pigment epithelial cells (RPE) of the retina. While these cells support very different tissues, they have a striking degree of similarity both as phagocytes and in ways that go beyond cell clearance. The clearance of apoptotic germ cells, cell debris, and used photoreceptor outer segments are critical functions of these cells, and the unique nature of their clearance events make specialized phagocytes uniquely suited for studying the larger implications of cell clearance in vivo. The shared functions of specialized phagocytes could provide novel insights into how phagocytosis impacts tissue homeostasis and immune modulation. In this review, we examine the remarkable similarities between SCs and RPE as specialized phagocytes and the physiological effects of cell clearance within a tissue.
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