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Sung CYW, Hayase N, Yuen PST, Lee J, Fernandez K, Hu X, Cheng H, Star RA, Warchol ME, Cunningham LL. Macrophage depletion protects against cisplatin-induced ototoxicity and nephrotoxicity. SCIENCE ADVANCES 2024; 10:eadk9878. [PMID: 39047106 PMCID: PMC11268410 DOI: 10.1126/sciadv.adk9878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 06/18/2024] [Indexed: 07/27/2024]
Abstract
Cisplatin is a widely used anticancer drug with notable side effects including ototoxicity and nephrotoxicity. Macrophages, the major resident immune cells in the cochlea and kidney, are important drivers of both inflammatory and tissue repair responses. To investigate the roles of macrophages in cisplatin-induced toxicities, we used PLX3397, a U.S. Food and Drug Administration-approved inhibitor of the colony-stimulating factor 1 receptor, to eliminate tissue-resident macrophages. Mice treated with cisplatin alone had considerable hearing loss (ototoxicity) and kidney injury (nephrotoxicity). Macrophage ablation resulted in significantly reduced hearing loss and had greater outer hair cell survival. Macrophage ablation also protected against cisplatin-induced nephrotoxicity, as evidenced by markedly reduced tubular injury and fibrosis. Mechanistically, our data suggest that the protective effect of macrophage ablation against cisplatin-induced ototoxicity and nephrotoxicity is mediated by reduced platinum accumulation in both the inner ear and the kidney. Together, our data indicate that ablation of tissue-resident macrophages represents an important strategy for mitigating cisplatin-induced ototoxicity and nephrotoxicity.
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Affiliation(s)
- Cathy Yea Won Sung
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, Bethesda, MD, USA
| | - Naoki Hayase
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA
| | - Peter S. T. Yuen
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA
| | - John Lee
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, Bethesda, MD, USA
| | - Katharine Fernandez
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, Bethesda, MD, USA
| | - Xuzhen Hu
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA
| | - Hui Cheng
- Bioinformatics and Biostatistics Collaboration Core, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, Bethesda, MD, USA
| | - Robert A. Star
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD, USA
| | - Mark E. Warchol
- Department of Otolaryngology, School of Medicine, Washington University, Saint Louis, MO, USA
| | - Lisa L. Cunningham
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, Bethesda, MD, USA
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2
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Cao Y, Qiao L, Song Y, Yan Y, Ni Y, Xi H, Chen J, Li S, Liu H. Caspase-1 Inhibition Ameliorates Photoreceptor Damage Following Retinal Detachment by Inhibiting Microglial Pyroptosis. THE AMERICAN JOURNAL OF PATHOLOGY 2024:S0002-9440(24)00242-6. [PMID: 39032599 DOI: 10.1016/j.ajpath.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 05/31/2024] [Accepted: 06/10/2024] [Indexed: 07/23/2024]
Abstract
Retinal detachment (RD) is a sight-threatening condition that occurs in several retinal diseases. Microglia that reside in retina are activated after RD and are involved in the death of photoreceptor cells. The involvement of microglial pyroptosis in the early pathological process of RD is still unclear. It has been shown that VX-765, an inhibitor of caspase-1, may exert neuroprotective effects by targeting microglial pyroptosis in nervous system disease; however, whether it plays a role in RD is uncertain. This study detected and localized pyroptosis to specific cells by immunofluorescence co-staining and flow cytometry in rat RD models. The majority of gasdermin D N-terminal (GSDMD-N)-positive cells exhibited IBA1-positive or P2RY12-positive microglia in the early stage of RD, indicating the pyroptosis of microglia. Administration of VX-765 shifted the microglia phenotype from M1 to M2, inhibited microglial migration toward the outer nuclear layer (ONL) post-RD, and most importantly, inhibited microglial pyroptosis. The thickness of ONL increased with VX-765 administration, and the photoreceptors were more structured and orderly under hematoxylin and eosin staining and transmission electron microscopy, revealing the protective effects of VX-765 on photoreceptors. Overall, this study demonstrates that inflammation induced by pyroptosis of microglia is the early pathological process of RD. VX-765 may serve as a candidate therapeutic approach for the treatment of RD by targeting microglia.
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Affiliation(s)
- Yumei Cao
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Lei Qiao
- Central Laboratory, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China
| | - Yingying Song
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yuanye Yan
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China
| | - Yewen Ni
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Huiyu Xi
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China
| | - Jiayu Chen
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Suyan Li
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China.
| | - Haiyang Liu
- Department of Ophthalmology, The Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University, Xuzhou First People's Hospital, Eye Disease Prevention and Treatment Institute of Xuzhou, Xuzhou, Jiangsu, China; Xuzhou Medical University, Xuzhou, Jiangsu, China.
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3
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Marciante AB, Tadjalli A, Burrowes KA, Oberto JR, Luca EK, Seven YB, Nikodemova M, Watters JJ, Baker TL, Mitchell GS. Microglia regulate motor neuron plasticity via reciprocal fractalkine/adenosine signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.592939. [PMID: 38765982 PMCID: PMC11100694 DOI: 10.1101/2024.05.07.592939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Microglia are innate CNS immune cells that play key roles in supporting key CNS functions including brain plasticity. We now report a previously unknown role for microglia in regulating neuroplasticity within spinal phrenic motor neurons, the neurons driving diaphragm contractions and breathing. We demonstrate that microglia regulate phrenic long-term facilitation (pLTF), a form of respiratory memory lasting hours after repetitive exposures to brief periods of low oxygen (acute intermittent hypoxia; AIH) via neuronal/microglial fractalkine signaling. AIH-induced pLTF is regulated by the balance between competing intracellular signaling cascades initiated by serotonin vs adenosine, respectively. Although brainstem raphe neurons release the relevant serotonin, the cellular source of adenosine is unknown. We tested a model in which hypoxia initiates fractalkine signaling between phrenic motor neurons and nearby microglia that triggers extracellular adenosine accumulation. With moderate AIH, phrenic motor neuron adenosine 2A receptor activation undermines serotonin-dominant pLTF; in contrast, severe AIH drives pLTF by a unique, adenosine-dominant mechanism. Phrenic motor neuron fractalkine knockdown, cervical spinal fractalkine receptor inhibition on nearby microglia, and microglial depletion enhance serotonin-dominant pLTF with moderate AIH but suppress adenosine-dominant pLTF with severe AIH. Thus, microglia play novel functions in the healthy spinal cord, regulating hypoxia-induced neuroplasticity within the motor neurons responsible for breathing.
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Affiliation(s)
- Alexandria B. Marciante
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Arash Tadjalli
- Current Address: Nova Southeastern University, College of Allopathic Medicine (NSU MD), Department of Medical Education, 3200 South University Drive, Fort Lauderdale, FL 33328-2018
| | - Kayla A. Burrowes
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Jose R. Oberto
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Edward K. Luca
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Yasin B. Seven
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Maria Nikodemova
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
| | - Jyoti J. Watters
- Current Address: Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706
| | - Tracy L. Baker
- Current Address: Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706
| | - Gordon S. Mitchell
- Breathing Research and Therapeutics Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida; Gainesville, FL, USA 32610
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Schreiner TG, Schreiner OD, Ciobanu RC. Spinal Cord Injury Management Based on Microglia-Targeting Therapies. J Clin Med 2024; 13:2773. [PMID: 38792314 PMCID: PMC11122315 DOI: 10.3390/jcm13102773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/05/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Spinal cord injury is a complicated medical condition both from the clinician's point of view in terms of management and from the patient's perspective in terms of unsatisfactory recovery. Depending on the severity, this disorder can be devastating despite the rapid and appropriate use of modern imaging techniques and convenient surgical spinal cord decompression and stabilization. In this context, there is a mandatory need for novel adjunctive therapeutic approaches to classical treatments to improve rehabilitation chances and clinical outcomes. This review offers a new and original perspective on therapies targeting the microglia, one of the most relevant immune cells implicated in spinal cord disorders. The first part of the manuscript reviews the anatomical and pathophysiological importance of the blood-spinal cord barrier components, including the role of microglia in post-acute neuroinflammation. Subsequently, the authors present the emerging therapies based on microglia modulation, such as cytokines modulators, stem cell, microRNA, and nanoparticle-based treatments that could positively impact spinal cord injury management. Finally, future perspectives and challenges are also highlighted based on the ongoing clinical trials related to medications targeting microglia.
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Affiliation(s)
- Thomas Gabriel Schreiner
- Department of Medical Specialties III, Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania;
- First Neurology Clinic, “Prof. Dr. N. Oblu” Clinical Emergency Hospital, 700309 Iasi, Romania
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania;
| | - Oliver Daniel Schreiner
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania;
- Medical Oncology Department, Regional Institute of Oncology, 700483 Iasi, Romania
| | - Romeo Cristian Ciobanu
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania;
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Durán Laforet V, Schafer DP. Microglia: Activity-dependent regulators of neural circuits. Ann N Y Acad Sci 2024; 1533:38-50. [PMID: 38294960 PMCID: PMC10976428 DOI: 10.1111/nyas.15105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
It has been more than a century since Pío del Río-Hortega first characterized microglia in histological stains of brain tissue. Since then, significant advances have been made in understanding the role of these resident central nervous system (CNS) macrophages. In particular, it is now known that microglia can sense neural activity and modulate neuronal circuits accordingly. We review the mechanisms by which microglia detect changes in neural activity to then modulate synapse numbers in the developing and mature CNS. This includes responses to both spontaneous and experience-driven neural activity. We further discuss activity-dependent mechanisms by which microglia regulate synaptic function and neural circuit excitability. Together, our discussion provides a comprehensive review of the activity-dependent functions of microglia within neural circuits in the healthy CNS, and highlights exciting new open questions related to understanding more fully microglia as key components and regulators of neural circuits.
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Affiliation(s)
- Violeta Durán Laforet
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Dorothy P Schafer
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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Boland R, Kokiko-Cochran ON. Deplete and repeat: microglial CSF1R inhibition and traumatic brain injury. Front Cell Neurosci 2024; 18:1352790. [PMID: 38450286 PMCID: PMC10915023 DOI: 10.3389/fncel.2024.1352790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/25/2024] [Indexed: 03/08/2024] Open
Abstract
Traumatic brain injury (TBI) is a public health burden affecting millions of people. Sustained neuroinflammation after TBI is often associated with poor outcome. As a result, increased attention has been placed on the role of immune cells in post-injury recovery. Microglia are highly dynamic after TBI and play a key role in the post-injury neuroinflammatory response. Therefore, microglia represent a malleable post-injury target that could substantially influence long-term outcome after TBI. This review highlights the cell specific role of microglia in TBI pathophysiology. Microglia have been manipulated via genetic deletion, drug inhibition, and pharmacological depletion in various pre-clinical TBI models. Notably, colony stimulating factor 1 (CSF1) and its receptor (CSF1R) have gained much traction in recent years as a pharmacological target on microglia. CSF1R is a transmembrane tyrosine kinase receptor that is essential for microglia proliferation, differentiation, and survival. Small molecule inhibitors targeting CSF1R result in a swift and effective depletion of microglia in rodents. Moreover, discontinuation of the inhibitors is sufficient for microglia repopulation. Attention is placed on summarizing studies that incorporate CSF1R inhibition of microglia. Indeed, microglia depletion affects multiple aspects of TBI pathophysiology, including neuroinflammation, oxidative stress, and functional recovery with measurable influence on astrocytes, peripheral immune cells, and neurons. Taken together, the data highlight an important role for microglia in sustaining neuroinflammation and increasing risk of oxidative stress, which lends to neuronal damage and behavioral deficits chronically after TBI. Ultimately, the insights gained from CSF1R depletion of microglia are critical for understanding the temporospatial role that microglia develop in mediating TBI pathophysiology and recovery.
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Affiliation(s)
- Rebecca Boland
- Department of Neuroscience, College of Medicine, Chronic Brain Injury Program, Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
| | - Olga N Kokiko-Cochran
- Department of Neuroscience, College of Medicine, Chronic Brain Injury Program, Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
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Larson KC, Martens LH, Marconi M, Dejesus C, Bruhn S, Miller TA, Tate B, Levenson JM. Preclinical translational platform of neuroinflammatory disease biology relevant to neurodegenerative disease. J Neuroinflammation 2024; 21:37. [PMID: 38297405 PMCID: PMC10832185 DOI: 10.1186/s12974-024-03029-3] [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: 08/23/2023] [Accepted: 01/23/2024] [Indexed: 02/02/2024] Open
Abstract
Neuroinflammation is a key driver of neurodegenerative disease, however the tools available to model this disease biology at the systems level are lacking. We describe a translational drug discovery platform based on organotypic culture of murine cortical brain slices that recapitulate disease-relevant neuroinflammatory biology. After an acute injury response, the brain slices assume a chronic neuroinflammatory state marked by transcriptomic profiles indicative of activation of microglia and astrocytes and loss of neuronal function. Microglia are necessary for manifestation of this neuroinflammation, as depletion of microglia prior to isolation of the brain slices prevents both activation of astrocytes and robust loss of synaptic function genes. The transcriptomic pattern of neuroinflammation in the mouse platform is present in published datasets derived from patients with amyotrophic lateral sclerosis, Huntington's disease, and frontotemporal dementia. Pharmacological utility of the platform was validated by demonstrating reversal of microglial activation and the overall transcriptomic signature with transforming growth factor-β. Additional anti-inflammatory targets were screened and inhibitors of glucocorticoid receptors, COX-2, dihydrofolate reductase, and NLRP3 inflammasome all failed to reverse the neuroinflammatory signature. Bioinformatics analysis of the neuroinflammatory signature identified protein tyrosine phosphatase non-receptor type 11 (PTPN11/SHP2) as a potential target. Three structurally distinct inhibitors of PTPN11 (RMC-4550, TN0155, IACS-13909) reversed the neuroinflammatory disease signature. Collectively, these results highlight the utility of this novel neuroinflammatory platform for facilitating identification and validation of targets for neuroinflammatory neurodegenerative disease drug discovery.
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Affiliation(s)
- Kelley C Larson
- Vigil Neuroscience, Watertown, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Lauren H Martens
- , Neumora Therapeutics, Watertown, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Michael Marconi
- Department of Molecular Pathology, Massachusetts General Hospital, Boston, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Christopher Dejesus
- Atalanta Therapeutics, Boston, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Suzanne Bruhn
- Charcot-Marie-Tooth Association, Glenolden, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Thomas A Miller
- Walden Biosciences, Cambridge, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Barbara Tate
- FARA, Homestead, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Jonathan M Levenson
- FireCyte Therapeutics, Beverly, USA.
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA.
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Laudenberg N, Kinuthia UM, Langmann T. Microglia depletion/repopulation does not affect light-induced retinal degeneration in mice. Front Immunol 2024; 14:1345382. [PMID: 38288111 PMCID: PMC10822957 DOI: 10.3389/fimmu.2023.1345382] [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: 11/27/2023] [Accepted: 12/28/2023] [Indexed: 01/31/2024] Open
Abstract
Reactive microglia are a hallmark of age-related retinal degenerative diseases including age-related macular degeneration (AMD). These cells are capable of secreting neurotoxic substances that may aggravate inflammation that leads to loss of photoreceptors and impaired vision. Despite their role in driving detrimental inflammation, microglia also play supporting roles in the retina as they are a crucial cellular component of the regulatory innate immune system. In this study, we used the colony stimulating factor 1 receptor (CSF1R)-antagonist PLX3397 to investigate the effects of microglia depletion and repopulation in a mouse model of acute retinal degeneration that mimics some aspects of dry AMD. Our main goal was to investigate whether microglia depletion and repopulation affects the outcome of light-induced retinal degeneration. We found that microglia depletion effectively decreased the expression of several key pro-inflammatory factors but was unable to influence the extent of retinal degeneration as determined by optical coherence tomography (OCT) and histology. Interestingly, we found prominent cell debris accumulation in the outer retina under conditions of microglia depletion, presumably due to the lack of efficient phagocytosis that could not be compensated by the retinal pigment epithelium. Moreover, our in vivo experiments showed that renewal of retinal microglia by repopulation did also not prevent rapid microglia activation or preserve photoreceptor death under conditions of light damage. We conclude that microglia ablation strongly reduces the expression of pro-inflammatory factors but cannot prevent photoreceptor loss in the light-damage paradigm of retinal degeneration.
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Affiliation(s)
- Nils Laudenberg
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Urbanus Muthai Kinuthia
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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