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Bou Ghanem GO, Wareham LK, Calkins DJ. Addressing neurodegeneration in glaucoma: Mechanisms, challenges, and treatments. Prog Retin Eye Res 2024; 100:101261. [PMID: 38527623 DOI: 10.1016/j.preteyeres.2024.101261] [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: 12/28/2023] [Revised: 03/15/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
Glaucoma is the leading cause of irreversible blindness globally. The disease causes vision loss due to neurodegeneration of the retinal ganglion cell (RGC) projection to the brain through the optic nerve. Glaucoma is associated with sensitivity to intraocular pressure (IOP). Thus, mainstay treatments seek to manage IOP, though many patients continue to lose vision. To address neurodegeneration directly, numerous preclinical studies seek to develop protective or reparative therapies that act independently of IOP. These include growth factors, compounds targeting metabolism, anti-inflammatory and antioxidant agents, and neuromodulators. Despite success in experimental models, many of these approaches fail to translate into clinical benefits. Several factors contribute to this challenge. Firstly, the anatomic structure of the optic nerve head differs between rodents, nonhuman primates, and humans. Additionally, animal models do not replicate the complex glaucoma pathophysiology in humans. Therefore, to enhance the success of translating these findings, we propose two approaches. First, thorough evaluation of experimental targets in multiple animal models, including nonhuman primates, should precede clinical trials. Second, we advocate for combination therapy, which involves using multiple agents simultaneously, especially in the early and potentially reversible stages of the disease. These strategies aim to increase the chances of successful neuroprotective treatment for glaucoma.
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Affiliation(s)
- Ghazi O Bou Ghanem
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Lauren K Wareham
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - David J Calkins
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
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2
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Reinehr S, Wulf J, Theile J, Schulte KK, Peters M, Fuchshofer R, Dick HB, Joachim SC. In a novel autoimmune and high-pressure glaucoma model a complex immune response is induced. Front Immunol 2024; 15:1296178. [PMID: 38515755 PMCID: PMC10955086 DOI: 10.3389/fimmu.2024.1296178] [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: 09/18/2023] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Abstract
Background The neurodegenerative processes leading to glaucoma are complex. In addition to elevated intraocular pressure (IOP), an involvement of immunological mechanisms is most likely. In the new multifactorial glaucoma model, a combination of high IOP and optic nerve antigen (ONA) immunization leads to an enhanced loss of retinal ganglion cells accompanied by a higher number of microglia/macrophages in the inner retina. Here, we aimed to evaluate the immune response in this new model, especially the complement activation and the number of T-cells, for the first time. Further, the microglia/macrophage response was examined in more detail. Methods Six-week-old wildtype (WT+ONA) and βB1-connective tissue growth factor high-pressure mice (CTGF+ONA) were immunized with 1 mg ONA. A wildtype control (WT) and a CTGF group (CTGF) received NaCl instead. Six weeks after immunization, retinae from all four groups were processed for immunohistology, RT-qPCR, and flow cytometry, while serum was used for microarray analyses. Results We noticed elevated numbers of C1q+ cells (classical complement pathway) in CTGF and CTGF+ONA retinae as well as an upregulation of C1qa, C1qb, and C1qc mRNA levels in these groups. While the complement C3 was only increased in CTGF and CTGF+ONA retinae, enhanced numbers of the terminal membrane attack complex were noted in all three glaucoma groups. Flow cytometry and RT-qPCR analyses revealed an enhancement of different microglia/macrophages markers, including CD11b, especially in CTGF and CTGF+ONA retinae. Interestingly, increased retinal mRNA as well as serum levels of the tumor necrosis factor α were found throughout the different glaucoma groups. Lastly, more T-cells could be observed in the ganglion cell layer of the new CTGF+ONA model. Conclusion These results emphasize an involvement of the complement system, microglia/macrophages, and T-cells in glaucomatous disease. Moreover, in the new multifactorial glaucoma model, increased IOP in combination with autoimmune processes seem to enforce an additional T-cell response, leading to a more persistent pathology. Hence, this new model mimics the pathomechanisms occurring in human glaucoma more accurately and could therefore be a helpful tool to find new therapeutic approaches for patients in the future.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Julien Wulf
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Janine Theile
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Kim K. Schulte
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Marcus Peters
- Department of Molecular Immunology, Ruhr-University Bochum, Bochum, Germany
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University Regensburg, Regensburg, Germany
| | - H. Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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3
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Cheng Y, Lin D, Wu S, Liu Q, Yan X, Ren T, Zhang J, Wang N. Cerebrospinal Fluid Pressure Reduction Induces Glia-Mediated Retinal Inflammation and Leads to Retinal Ganglion Cell Injury in Rats. Mol Neurobiol 2023; 60:5770-5788. [PMID: 37347366 DOI: 10.1007/s12035-023-03430-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/05/2023] [Indexed: 06/23/2023]
Abstract
Low intracranial pressure (LICP)-induced translaminar cribrosa pressure difference (TLCPD) elevation has been proven as a risk factor in glaucomatous neurodegeneration, whereas the underlying retinal immune features of LICP-induced retinal ganglion cells (RGC) injury remain elusive. Here, we identified the retinal immune characteristics of LICP rats, and minocycline (Mino) treatment was utilized to analyze its inhibitory role in glia-mediated retinal inflammation of LICP rats. The results showed that retrograde axonal transport was decreased in LICP rats without significant RGC loss, indicating the RGC injury was at an early stage before the morphological loss. The activation of retinal microglia and astrocytes with morphologic and M1 or A1-marker alternations was detected in TLCPD elevation rats, the activation level is more dramatic in HIOP rats than in the LICP rats (P<0.05). Besides, we detected reduced retinal tight junction protein expressions, accompanied by specific imbalance patterns of T lymphocytes in the retina of both LICP and HIOP rats (P<0.05). Further Mino treatment showed an effective inhibitory role in glia-driven inflammatory responses in LICP rats, including improving retrograde axonal transport, inhibiting retinal glial activation and proinflammatory subtype polarization, and alleviating the blood-retina barrier compromise. This study identified the glia-mediated retinal inflammation features triggered by LICP stimulus, and Mino application exhibited an effective role in the inhibition of retinal glia-mediated inflammation in LICP-induced TLCPD elevation rats.
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Affiliation(s)
- Ying Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Danting Lin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Tianmin Ren
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.
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4
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Keuthan CJ, Schaub JA, Wei M, Fang W, Quillen S, Kimball E, Johnson TV, Ji H, Zack DJ, Quigley HA. Regional Gene Expression in the Retina, Optic Nerve Head, and Optic Nerve of Mice with Optic Nerve Crush and Experimental Glaucoma. Int J Mol Sci 2023; 24:13719. [PMID: 37762022 PMCID: PMC10531004 DOI: 10.3390/ijms241813719] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
A major risk factor for glaucomatous optic neuropathy is the level of intraocular pressure (IOP), which can lead to retinal ganglion cell axon injury and cell death. The optic nerve has a rostral unmyelinated portion at the optic nerve head followed by a caudal myelinated region. The unmyelinated region is differentially susceptible to IOP-induced damage in rodent models and human glaucoma. While several studies have analyzed gene expression changes in the mouse optic nerve following optic nerve injury, few were designed to consider the regional gene expression differences that exist between these distinct areas. We performed bulk RNA-sequencing on the retina and separately micro-dissected unmyelinated and myelinated optic nerve regions from naïve C57BL/6 mice, mice after optic nerve crush, and mice with microbead-induced experimental glaucoma (total = 36). Gene expression patterns in the naïve unmyelinated optic nerve showed significant enrichment of the Wnt, Hippo, PI3K-Akt, and transforming growth factor β pathways, as well as extracellular matrix-receptor and cell membrane signaling pathways, compared to the myelinated optic nerve and retina. Gene expression changes induced by both injuries were more extensive in the myelinated optic nerve than the unmyelinated region, and greater after nerve crush than glaucoma. Changes present three and fourteen days after injury largely subsided by six weeks. Gene markers of reactive astrocytes did not consistently differ between injury states. Overall, the transcriptomic phenotype of the mouse unmyelinated optic nerve was significantly different from immediately adjacent tissues, likely dominated by expression in astrocytes, whose junctional complexes are inherently important in responding to IOP elevation.
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Affiliation(s)
- Casey J. Keuthan
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
| | - Julie A. Schaub
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
| | - Meihan Wei
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Weixiang Fang
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Sarah Quillen
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
| | - Elizabeth Kimball
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
| | - Thomas V. Johnson
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
| | - Hongkai Ji
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Donald J. Zack
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
- Departments of Neuroscience, Molecular Biology and Genetics, and Genetic Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Harry A. Quigley
- Department of Ophthalmology, Wilmer Eye Institute, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (C.J.K.)
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Buonfiglio F, Pfeiffer N, Gericke A. Immunomodulatory and Antioxidant Drugs in Glaucoma Treatment. Pharmaceuticals (Basel) 2023; 16:1193. [PMID: 37765001 PMCID: PMC10535738 DOI: 10.3390/ph16091193] [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: 07/14/2023] [Revised: 08/02/2023] [Accepted: 08/18/2023] [Indexed: 09/29/2023] Open
Abstract
Glaucoma, a group of diseases characterized by progressive retinal ganglion cell loss, cupping of the optic disc, and a typical pattern of visual field defects, is a leading cause of severe visual impairment and blindness worldwide. Elevated intraocular pressure (IOP) is the leading risk factor for glaucoma development. However, glaucoma can also develop at normal pressure levels. An increased susceptibility of retinal ganglion cells to IOP, systemic vascular dysregulation, endothelial dysfunction, and autoimmune imbalances have been suggested as playing a role in the pathophysiology of normal-tension glaucoma. Since inflammation and oxidative stress play a role in all forms of glaucoma, the goal of this review article is to present an overview of the inflammatory and pro-oxidant mechanisms in the pathophysiology of glaucoma and to discuss immunomodulatory and antioxidant treatment approaches.
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Affiliation(s)
- Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany;
| | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany;
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6
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Tribble JR, Hui F, Quintero H, El Hajji S, Bell K, Di Polo A, Williams PA. Neuroprotection in glaucoma: Mechanisms beyond intraocular pressure lowering. Mol Aspects Med 2023; 92:101193. [PMID: 37331129 DOI: 10.1016/j.mam.2023.101193] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/25/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
Glaucoma is a common, complex, multifactorial neurodegenerative disease characterized by progressive dysfunction and then loss of retinal ganglion cells, the output neurons of the retina. Glaucoma is the most common cause of irreversible blindness and affects ∼80 million people worldwide with many more undiagnosed. The major risk factors for glaucoma are genetics, age, and elevated intraocular pressure. Current strategies only target intraocular pressure management and do not directly target the neurodegenerative processes occurring at the level of the retinal ganglion cell. Despite strategies to manage intraocular pressure, as many as 40% of glaucoma patients progress to blindness in at least one eye during their lifetime. As such, neuroprotective strategies that target the retinal ganglion cell and these neurodegenerative processes directly are of great therapeutic need. This review will cover the recent advances from basic biology to on-going clinical trials for neuroprotection in glaucoma covering degenerative mechanisms, metabolism, insulin signaling, mTOR, axon transport, apoptosis, autophagy, and neuroinflammation. With an increased understanding of both the basic and clinical mechanisms of the disease, we are closer than ever to a neuroprotective strategy for glaucoma.
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Affiliation(s)
- James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Heberto Quintero
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Sana El Hajji
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Katharina Bell
- NHMRC Clinical Trials Centre, University of Sydney, Australia; Eye ACP Duke-NUS, Singapore
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
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7
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Keuthan CJ, Schaub J, Wei M, Fang W, Quillen S, Kimball E, Johnson TV, Ji H, Zack DJ, Quigley HA. Regional Gene Expression in the Retina, Optic Nerve Head, and Optic Nerve of Mice with Experimental Glaucoma and Optic Nerve Crush. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.21.529410. [PMID: 36993314 PMCID: PMC10054954 DOI: 10.1101/2023.02.21.529410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A major risk factor for glaucomatous optic neuropathy is the level of intraocular pressure (IOP), which can lead to retinal ganglion cell axon injury and cell death. The optic nerve has a rostral unmyelinated portion at the optic nerve head followed by a caudal myelinated region. The unmyelinated region is differentially susceptible to IOP-induced damage in rodent models and in human glaucoma. While several studies have analyzed gene expression changes in the mouse optic nerve following optic nerve injury, few were designed to consider the regional gene expression differences that exist between these distinct areas. We performed bulk RNA-sequencing on the retina and on separately micro-dissected unmyelinated and myelinated optic nerve regions from naïve C57BL/6 mice, mice after optic nerve crush, and mice with microbead-induced experimental glaucoma (total = 36). Gene expression patterns in the naïve unmyelinated optic nerve showed significant enrichment of the Wnt, Hippo, PI3K-Akt, and transforming growth factor β pathways, as well as extracellular matrix-receptor and cell membrane signaling pathways, compared to the myelinated optic nerve and retina. Gene expression changes induced by both injuries were more extensive in the myelinated optic nerve than the unmyelinated region, and greater after nerve crush than glaucoma. Changes three and fourteen days after injury largely subsided by six weeks. Gene markers of reactive astrocytes did not consistently differ between injury states. Overall, the transcriptomic phenotype of the mouse unmyelinated optic nerve was significantly different from immediately adjacent tissues, likely dominated by expression in astrocytes, whose junctional complexes are inherently important in responding to IOP elevation.
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Affiliation(s)
- Casey J. Keuthan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Julie Schaub
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Meihan Wei
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Weixiang Fang
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Sarah Quillen
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Elizabeth Kimball
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Thomas V. Johnson
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Donald J. Zack
- Departments of Ophthalmology, Wilmer Eye Institute, Neuroscience, Molecular Biology and Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Harry A. Quigley
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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Chai R, Li Y, Shui L, Ni L, Zhang A. The role of pyroptosis in inflammatory diseases. Front Cell Dev Biol 2023; 11:1173235. [PMID: 37250902 PMCID: PMC10213465 DOI: 10.3389/fcell.2023.1173235] [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: 02/24/2023] [Accepted: 04/18/2023] [Indexed: 05/31/2023] Open
Abstract
Programmed cell death has crucial roles in the physiological maturation of an organism, the maintenance of metabolism, and disease progression. Pyroptosis, a form of programmed cell death which has recently received much attention, is closely related to inflammation and occurs via canonical, non-canonical, caspase-3-dependent, and unclassified pathways. The pore-forming gasdermin proteins mediate pyroptosis by promoting cell lysis, contributing to the outflow of large amounts of inflammatory cytokines and cellular contents. Although the inflammatory response is critical for the body's defense against pathogens, uncontrolled inflammation can cause tissue damage and is a vital factor in the occurrence and progression of various diseases. In this review, we briefly summarize the major signaling pathways of pyroptosis and discuss current research on the pathological function of pyroptosis in autoinflammatory diseases and sterile inflammatory diseases.
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Affiliation(s)
| | | | | | - Longxing Ni
- *Correspondence: Longxing Ni, ; Ansheng Zhang,
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Pitts KM, Margeta MA. Myeloid masquerade: Microglial transcriptional signatures in retinal development and disease. Front Cell Neurosci 2023; 17:1106547. [PMID: 36779012 PMCID: PMC9909491 DOI: 10.3389/fncel.2023.1106547] [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: 11/23/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023] Open
Abstract
Microglia are dynamic guardians of neural tissue and the resident immune cells of the central nervous system (CNS). The disease-associated microglial signature (DAM), also known as the microglial neurodegenerative phenotype (MGnD), has gained significant attention in recent years as a fundamental microglial response common to various neurodegenerative disease pathologies. Interestingly, this signature shares many features in common with developmental microglia, suggesting the existence of recycled gene programs which play a role both in early neural circuit formation as well as in response to aging and disease. In addition, recent advances in single cell RNA sequencing have revealed significant heterogeneity within the original DAM signature, with contributions from both yolk sac-derived microglia as well as bone marrow-derived macrophages. In this review, we examine the role of the DAM signature in retinal development and disease, highlighting crosstalk between resident microglia and infiltrating monocytes which may critically contribute to the underlying mechanisms of age-related neurodegeneration.
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Affiliation(s)
- Kristen M. Pitts
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
- Schepens Eye Research Institute of Mass, Eye and Ear, Boston, MA, United States
| | - Milica A. Margeta
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
- Schepens Eye Research Institute of Mass, Eye and Ear, Boston, MA, United States
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10
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Sheng S, Ma Y, Zou Y, Hu F, Chen L. Protective effects of blocking PD-1 pathway on retinal ganglion cells in a mouse model of chronic ocular hypertension. Front Immunol 2023; 13:1094132. [PMID: 36741384 PMCID: PMC9889850 DOI: 10.3389/fimmu.2022.1094132] [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: 11/09/2022] [Accepted: 12/27/2022] [Indexed: 01/19/2023] Open
Abstract
Purpose In this study, we aimed to investigate whether Programmed cell death 1 ligand 1/programmed cell death 1 ligand 2 (PD-L1/PD-L2) double knockout (dKO) has a protective effect on RGCs in a mouse model of chronic ocular hypertension (COHT). Methods We used superparamagnetic iron oxide to induce COHT in mice. Apoptosis of retinal ganglion cells (RGCs) and activation of microglia were evaluated using western blotting (WB) and immunofluorescence staining of the mouse retina. In addition, we also conducted transcriptome sequencing and further gene expression analyses using the gene ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) database. Results In the mouse model of COHT, PD-L1/PD-L2 prevented the apoptosis of RGCs to some extent. Blocking the programmed cell death 1 (PD-1) pathway also increased the number of anti-inflammatory M2-activated microglia and enhanced the phosphorylation of its related pathway signal transducer and activator of transcription (STAT)6. Sequencing results showed that this protective effect may have been achieved by regulating the NF-B, tumour necrosis factor (TNF), PI3K/Akt and toll-like receptor signaling pathway etc. Conclusion Blocking the PD-1 pathway has a protective effect on RGCs in the mouse model of COHT induced by superparamagnetic iron oxide.
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Affiliation(s)
- Siqi Sheng
- Department of Ophthalmology & Vision Science, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,Key National Health Coucil (NHC) Key Laboratory of Myopia, Fudan University, Shanghai, China,Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Yixian Ma
- Department of Ophthalmology & Vision Science, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,Key National Health Coucil (NHC) Key Laboratory of Myopia, Fudan University, Shanghai, China,Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Yue Zou
- Department of Ophthalmology & Vision Science, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,Key National Health Coucil (NHC) Key Laboratory of Myopia, Fudan University, Shanghai, China,Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Fangyuan Hu
- Department of Ophthalmology & Vision Science, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,Key National Health Coucil (NHC) Key Laboratory of Myopia, Fudan University, Shanghai, China,Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China
| | - Ling Chen
- Department of Ophthalmology & Vision Science, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,Key National Health Coucil (NHC) Key Laboratory of Myopia, Fudan University, Shanghai, China,Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China,Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & Ears, Nose and Throat (ENT) Hospital, Shanghai Medical School, Fudan University, Shanghai, China,*Correspondence: Ling Chen,
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11
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Tian Y, Li M, Zhang S, Hu J, Wu H, Wan M, Xue J, Wang L, Xiao H, Zhou G, Wang K, Liu Q. Microglia activation in the hippocampus mediates retinal degeneration-induced depressive-like behaviors via the NLRP3/IL-1β pathway. Brain Res Bull 2023; 192:70-79. [PMID: 36332880 DOI: 10.1016/j.brainresbull.2022.10.021] [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: 06/01/2022] [Revised: 10/24/2022] [Accepted: 10/31/2022] [Indexed: 11/13/2022]
Abstract
Epidemiological studies have shown that patients with glaucoma are more prone to depression, but the mechanism of comorbid depression in patients with glaucoma remains unknown. Excessive neuroinflammation has been shown to participate in glaucoma-induced retinal degeneration and hippocampal neural apoptosis in depression. However, little research has been conducted to determine whether neuroinflammation contributes to glaucoma-induced depression. Since the degeneration of retinal ganglion cells is a hallmark of glaucoma, we investigated the role of microglia-induced neuroinflammation in retinal degeneration-induced depression and its potential mechanism. An N-methyl-D-aspartate (NMDA)-induced retinal degeneration model was established, and behavioral tests were conducted at 3, 7, 14, and 21 days after retinal degeneration. After tissue collection, we used immunohistochemistry to assess the activation of microglia and real-time polymerase chain reaction to measure the levels of pro-inflammatory cytokines and the NOD-, LRR-, and pyrin-domain containing protein 3 (NLRP3) inflammasome. The mice exhibited depressive-like behaviors 14 and 21 days after retinal degeneration, based on the open field test, tail suspension test, and forced swimming test. Mice also displayed a lower body weight gain than the control group. In addition, microglial activation was observed in the hippocampus. Microglial proliferation was first observed in the dentate gyrus on day 3, while the number of microglia in cornu ammonis 1 grew the most. Moreover, not only was the expression of pro-inflammatory cytokines, including interleukin-1β, interleukin-18, and interleukin-6 promoted, but the messenger ribonucleic acid levels of the NLRP3 inflammasome were also increased. In conclusion, our research shows that NMDA-induced retinal degeneration can induce depressive-like behaviors, which may be attributed to hippocampal neuroinflammation.
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Affiliation(s)
- Yi Tian
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China; Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
| | - Meihui Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Shanshan Zhang
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Juntao Hu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Haoran Wu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Mitchell Wan
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jingxin Xue
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Leilei Wang
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Honglei Xiao
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Guomin Zhou
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China; Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai, China.
| | - Kaidi Wang
- Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China.
| | - Qiong Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China; Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai, China.
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12
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Huang KC, Gomes C, Meyer JS. Retinal Ganglion Cells in a Dish: Current Strategies and Recommended Best Practices for Effective In Vitro Modeling of Development and Disease. Handb Exp Pharmacol 2023; 281:83-102. [PMID: 36907969 PMCID: PMC10497719 DOI: 10.1007/164_2023_642] [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: 03/14/2023]
Abstract
The ability to derive retinal ganglion cells (RGCs) from human pluripotent stem cells (hPSCs) provides an extraordinary opportunity to study the development of RGCs as well as cellular mechanisms underlying their degeneration in optic neuropathies. In the past several years, multiple approaches have been established that allow for the generation of RGCs from hPSCs, with these methods greatly improved in more recent studies to yield mature RGCs that more faithfully recapitulate phenotypes within the eye. Nevertheless, numerous differences still remain between hPSC-RGCs and those found within the human eye, with these differences likely explained at least in part due to the environment in which hPSC-RGCs are grown. With the ultimate goal of generating hPSC-RGCs that most closely resemble those within the retina for proper studies of retinal development, disease modeling, as well as cellular replacement, we review within this manuscript the current effective approaches for the differentiation of hPSC-RGCs, as well as how they have been applied for the investigation of RGC neurodegenerative diseases such as glaucoma. Furthermore, we provide our opinions on the characteristics of RGCs necessary for their use as effective in vitro disease models and importantly, how these current systems should be improved to more accurately reflect disease states. The establishment of characteristics in differentiated hPSC-RGCs that more effectively mimic RGCs within the retina will not only enable their use as effective models of RGC development, but will also create a better disease model for the identification of mechanisms underlying the neurodegeneration of RGCs in disease states such as glaucoma, further facilitating the development of therapeutic approaches to rescue RGCs from degeneration in disease states.
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Affiliation(s)
- Kang-Chieh Huang
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Cátia Gomes
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jason S Meyer
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA.
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13
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Pinilla I, Maneu V, Campello L, Fernández-Sánchez L, Martínez-Gil N, Kutsyr O, Sánchez-Sáez X, Sánchez-Castillo C, Lax P, Cuenca N. Inherited Retinal Dystrophies: Role of Oxidative Stress and Inflammation in Their Physiopathology and Therapeutic Implications. Antioxidants (Basel) 2022; 11:antiox11061086. [PMID: 35739983 PMCID: PMC9219848 DOI: 10.3390/antiox11061086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a large group of genetically and clinically heterogeneous diseases characterized by the progressive degeneration of the retina, ultimately leading to loss of visual function. Oxidative stress and inflammation play fundamental roles in the physiopathology of these diseases. Photoreceptor cell death induces an inflammatory state in the retina. The activation of several molecular pathways triggers different cellular responses to injury, including the activation of microglia to eliminate debris and recruit inflammatory cells from circulation. Therapeutical options for IRDs are currently limited, although a small number of patients have been successfully treated by gene therapy. Many other therapeutic strategies are being pursued to mitigate the deleterious effects of IRDs associated with oxidative metabolism and/or inflammation, including inhibiting reactive oxygen species’ accumulation and inflammatory responses, and blocking autophagy. Several compounds are being tested in clinical trials, generating great expectations for their implementation. The present review discusses the main death mechanisms that occur in IRDs and the latest therapies that are under investigation.
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Affiliation(s)
- Isabel Pinilla
- Aragón Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
- Department of Ophthalmology, Lozano Blesa, University Hospital, 50009 Zaragoza, Spain
- Department of Surgery, University of Zaragoza, 50009 Zaragoza, Spain
- Correspondence: (I.P.); (V.M.)
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain;
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Correspondence: (I.P.); (V.M.)
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Laura Fernández-Sánchez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain;
| | - Natalia Martínez-Gil
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Oksana Kutsyr
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Carla Sánchez-Castillo
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Pedro Lax
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
| | - Nicolás Cuenca
- Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain; (P.L.); (N.C.)
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain; (L.C.); (N.M.-G.); (O.K.); (X.S.-S.); (C.S.-C.)
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14
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Fan W, Huang W, Chen J, Li N, Mao L, Hou S. Retinal microglia: Functions and diseases. Immunology 2022; 166:268-286. [PMID: 35403700 DOI: 10.1111/imm.13479] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/26/2022] [Accepted: 02/22/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Wei Fan
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Chongqing Key Laboratory of Ophthalmology Chongqing China
- Chongqing Eye Institute Chongqing China
- Chongqing Branch of National Clinical Research Center for Ocular Diseases Chongqing China
| | - Weidi Huang
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Department of Ophthalmology, Second Xiangya Hospital Central South University Changsha Hunan China
| | - Jiayi Chen
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
| | - Na Li
- College of Basic Medicine Chongqing Medical University Chongqing China
| | - Liming Mao
- Department of Immunology School of Medicine, Nantong University, 19 Qixiu Road Nantong Jiangsu China
| | - Shengping Hou
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Chongqing Key Laboratory of Ophthalmology Chongqing China
- Chongqing Eye Institute Chongqing China
- Chongqing Branch of National Clinical Research Center for Ocular Diseases Chongqing China
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15
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Dias MS, Luo X, Ribas VT, Petrs-Silva H, Koch JC. The Role of Axonal Transport in Glaucoma. Int J Mol Sci 2022; 23:ijms23073935. [PMID: 35409291 PMCID: PMC8999615 DOI: 10.3390/ijms23073935] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Glaucoma is a neurodegenerative disease that affects the retinal ganglion cells (RGCs) and leads to progressive vision loss. The first pathological signs can be seen at the optic nerve head (ONH), the structure where RGC axons leave the retina to compose the optic nerve. Besides damage of the axonal cytoskeleton, axonal transport deficits at the ONH have been described as an important feature of glaucoma. Axonal transport is essential for proper neuronal function, including transport of organelles, synaptic components, vesicles, and neurotrophic factors. Impairment of axonal transport has been related to several neurodegenerative conditions. Studies on axonal transport in glaucoma include analysis in different animal models and in humans, and indicate that its failure happens mainly in the ONH and early in disease progression, preceding axonal and somal degeneration. Thus, a better understanding of the role of axonal transport in glaucoma is not only pivotal to decipher disease mechanisms but could also enable early therapies that might prevent irreversible neuronal damage at an early time point. In this review we present the current evidence of axonal transport impairment in glaucomatous neurodegeneration and summarize the methods employed to evaluate transport in this disease.
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Affiliation(s)
- Mariana Santana Dias
- Intermediate Laboratory of Gene Therapy and Viral Vectors, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (M.S.D.); (H.P.-S.)
| | - Xiaoyue Luo
- Department of Neurology, University Medical Center Göttingen, 37077 Göttingen, Germany;
| | - Vinicius Toledo Ribas
- Laboratory of Neurobiology, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Hilda Petrs-Silva
- Intermediate Laboratory of Gene Therapy and Viral Vectors, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (M.S.D.); (H.P.-S.)
| | - Jan Christoph Koch
- Department of Neurology, University Medical Center Göttingen, 37077 Göttingen, Germany;
- Correspondence:
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16
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Xu MX, Zhao GL, Hu X, Zhou H, Li SY, Li F, Miao Y, Lei B, Wang Z. P2X7/P2X4 Receptors Mediate Proliferation and Migration of Retinal Microglia in Experimental Glaucoma in Mice. Neurosci Bull 2022; 38:901-915. [PMID: 35254644 PMCID: PMC9352844 DOI: 10.1007/s12264-022-00833-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/13/2021] [Indexed: 10/18/2022] Open
Abstract
Microglia are involved in the inflammatory response and retinal ganglion cell damage in glaucoma. Here, we investigated how microglia proliferate and migrate in a mouse model of chronic ocular hypertension (COH). In COH retinas, the microglial proliferation that occurred was inhibited by the P2X7 receptor (P2X7R) blocker BBG or P2X7R knockout, but not by the P2X4R blocker 5-BDBD. Treatment of primary cultured microglia with BzATP, a P2X7R agonist, mimicked the effects of cell proliferation and migration in COH retinas through the intracellular MEK/ERK signaling pathway. Transwell migration assays showed that the P2X4R agonist CTP induced microglial migration, which was completely blocked by 5-BDBD. In vivo and in vitro experiments demonstrated that ATP, released from activated Müller cells through connexin43 hemichannels, acted on P2X7R to induce microglial proliferation, and acted on P2X4R/P2X7R (mainly P2X4R) to induce microglial migration. Our results suggest that inhibiting the interaction of Müller cells and microglia may attenuate microglial proliferation and migration in glaucoma.
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17
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Molecular regulation of neuroinflammation in glaucoma: Current knowledge and the ongoing search for new treatment targets. Prog Retin Eye Res 2022; 87:100998. [PMID: 34348167 PMCID: PMC8803988 DOI: 10.1016/j.preteyeres.2021.100998] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022]
Abstract
Neuroinflammation relying on the inflammatory responses of glial cells has emerged as an impactful component of the multifactorial etiology of neurodegeneration in glaucoma. It has become increasingly evident that despite early adaptive and reparative features of glial responses, prolonged reactivity of the resident glia, along with the peripheral immune cells, create widespread toxicity to retinal ganglion cell (RGC) axons, somas, and synapses. As much as the synchronized responses of astrocytes and microglia to glaucoma-related stress or neuron injury, their bi-directional interactions are critical to build and amplify neuroinflammation and to dictate the neurodegenerative outcome. Although distinct molecular programs regulate somatic and axonal degeneration in glaucoma, inhibition of neurodegenerative inflammation can provide a broadly beneficial treatment strategy to rescue RGC integrity and function. Since inflammatory toxicity and mitochondrial dysfunction are converging etiological paths that can boost each other and feed into a vicious cycle, anti-inflammatory treatments may also offer a multi-target potential. This review presents an overview of the current knowledge on neuroinflammation in glaucoma with particular emphasis on the cell-intrinsic and cell-extrinsic factors involved in the reciprocal regulation of glial responses, the interdependence between inflammatory and mitochondrial routes of neurodegeneration, and the research aspects inspiring for prospective immunomodulatory treatments. With the advent of powerful technologies, ongoing research on molecular and functional characteristics of glial responses is expected to accumulate more comprehensive and complementary information and to rapidly move the field forward to safe and effective modulation of the glial pro-inflammatory activities, while restoring or augmenting the glial immune-regulatory and neurosupport functions.
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18
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Zhang Y, Jiao Y, Li X, Gao S, Zhou N, Duan J, Zhang M. Pyroptosis: A New Insight Into Eye Disease Therapy. Front Pharmacol 2021; 12:797110. [PMID: 34925047 PMCID: PMC8678479 DOI: 10.3389/fphar.2021.797110] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/15/2021] [Indexed: 02/05/2023] Open
Abstract
Pyroptosis is a lytic form of programmed cell death mediated by gasdermins (GSDMs) with pore-forming activity in response to certain exogenous and endogenous stimuli. The inflammasomes are intracellular multiprotein complexes consisting of pattern recognition receptors, an adaptor protein ASC (apoptosis speck-like protein), and caspase-1 and cause autocatalytic activation of caspase-1, which cleaves gasdermin D (GSDMD), inducing pyroptosis accompanied by cytokine release. In recent years, the pathogenic roles of inflammasomes and pyroptosis in multiple eye diseases, including keratitis, dry eyes, cataracts, glaucoma, uveitis, age-related macular degeneration, and diabetic retinopathy, have been continuously confirmed. Inhibiting inflammasome activation and abnormal pyroptosis in eyes generally attenuates inflammation and benefits prognosis. Therefore, insight into the pathogenesis underlying pyroptosis and inflammasome development in various types of eye diseases may provide new therapeutic strategies for ocular disorders. Inhibitors of pyroptosis, such as NLRP3, caspase-1, and GSDMD inhibitors, have been proven to be effective in many eye diseases. The purpose of this article is to illuminate the mechanism underlying inflammasome activation and pyroptosis and emphasize its crucial role in various ocular disorders. In addition, we review the application of pyroptosis modulators in eye diseases.
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Affiliation(s)
- Yun Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.,Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yan Jiao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xun Li
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.,Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Sheng Gao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.,Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Nenghua Zhou
- Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Jianan Duan
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.,Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.,Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
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19
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González Fleitas MF, Dorfman D, Rosenstein RE. A novel viewpoint in glaucoma therapeutics: enriched environment. Neural Regen Res 2021; 17:1431-1439. [PMID: 34916414 PMCID: PMC8771091 DOI: 10.4103/1673-5374.330594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Glaucoma is one of the world's most frequent visual impairment causes and leads to selective damage to retinal ganglion cells and their axons. Despite glaucoma's most accepted risk factor is increased intraocular pressure (IOP), the mechanisms behind the disease have not been fully elucidated. To date, IOP lowering remains the gold standard; however, glaucoma patients may still lose vision regardless of effective IOP management. Therefore, the exclusive IOP control apparently is not enough to stop the disease progression, and developing new resources to protect the retina and optic nerve against glaucoma is a goal of vast clinical importance. Besides pharmacological treatments, environmental conditions have been shown to prevent neurodegeneration in the central nervous system. In this review, we discuss current concepts on key pathogenic mechanisms involved in glaucoma, the effect of enriched environment on these mechanisms in different experimental models, as well as recent evidence supporting the preventive and therapeutic effect of enriched environment exposure against experimental glaucomatous damage. Finally, we postulate that stimulating vision may become a non-invasive and rehabilitative therapy that could be eventually translated to the human disease, preventing glaucoma-induced terrible sequelae resulting in permanent visual disability.
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Affiliation(s)
- María F González Fleitas
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Damián Dorfman
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Ruth E Rosenstein
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
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20
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Trost A, Motloch K, Koller A, Bruckner D, Runge C, Schroedl F, Bogner B, Kaser-Eichberger A, Strohmaier C, Ladek AM, Preishuber-Pfluegl J, Brunner SM, Aigner L, Reitsamer HA. Inhibition of the cysteinyl leukotriene pathways increases survival of RGCs and reduces microglial activation in ocular hypertension. Exp Eye Res 2021; 213:108806. [PMID: 34715090 DOI: 10.1016/j.exer.2021.108806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/05/2021] [Accepted: 10/21/2021] [Indexed: 10/20/2022]
Abstract
Glaucoma is the second leading cause of blindness worldwide. This multifactorial, neurodegenerative group of diseases is characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons, leading to irreversible visual impairment and blindness. There is a huge unmet and urging need for the development of new and translatable strategies and treatment options to prevent this progressive loss of RGC. Accumulating evidence points towards a critical role of neuroinflammation, in particular microglial cells, in the pathogenesis of glaucoma. Leukotrienes are mediators of neuroinflammation and are involved in many neurodegenerative diseases. Therefore, we tested the leukotriene receptors CysLT1R/GPR17-selective antagonist Montelukast (MTK) for its efficacy to modulate the reactive state of microglia in order to ameliorate RGCs loss in experimental glaucoma. Ocular hypertension (OHT) was induced unilaterally by injection of 8 μm magnetic microbead (MB) into the anterior chamber of female Brown Norway rats. The contralateral, untreated eye served as control. Successful induction of OHT was verified by daily IOP measurement using a TonoLab rebound tonometer. Simultaneously to OHT induction, one group received daily MTK treatment and the control group vehicle solution by oral gavage. Animals were sacrificed 13-15 days after MB injection. Retina and optic nerves (ON) of OHT and contralateral eyes were analyzed by immunofluorescence with specific markers for RGCs (Brn3a), microglial cells/macrophages (Iba1 and CD68), and cysteinyl leukotriene pathway receptors (CysLT1R and GPR17). Protein labeling was documented by confocal microscopy and analyzed with ImageJ plugins. Further, mRNA expression of genes of the inflammatory and leukotriene pathway was analyzed in retinal tissue. MTK treatment resulted in a short-term IOP reduction at day 2, which dissipated by day 5 of OHT induction in MTK treated animals. Furthermore, MTK treatment resulted in a decreased activation of Iba1+ microglial cells in the retina and ON, and in a significantly increased RGC survival in OHT eyes. Within the retina, GPR17 and CysLT1R expression was demonstrated in single RCGs and in microglial cells respectively. Further, increased mRNA expression of pro-inflammatory genes was detected in OHT induced retinas. In the ON, OHT induction increased the number of GPR17+ cells, showing a trend of reduction following MTK treatment. This study shows for the first time a significantly increased RGC survival in an acute OHT model following treatment with the leukotriene receptor antagonist MTK. These results strongly suggest a neuroprotective effect of MTK and a potential new therapeutic strategy for glaucoma treatment.
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Affiliation(s)
- Andrea Trost
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria.
| | - Karolina Motloch
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Andreas Koller
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Daniela Bruckner
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Christian Runge
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Falk Schroedl
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria; Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Bogner
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Alexandra Kaser-Eichberger
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria; Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Clemens Strohmaier
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria; Department of Ophthalmology and Optometry, Johannes Kepler University, Linz, Austria
| | - Anja-Maria Ladek
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Julia Preishuber-Pfluegl
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Susanne Maria Brunner
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria
| | - Herbert Anton Reitsamer
- University Clinic of Ophthalmology and Optometry, Research Program for Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria
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Coyle S, Khan MN, Chemaly M, Callaghan B, Doyle C, Willoughby CE, Atkinson SD, Gregory-Ksander M, McGilligan V. Targeting the NLRP3 Inflammasome in Glaucoma. Biomolecules 2021; 11:biom11081239. [PMID: 34439904 PMCID: PMC8393362 DOI: 10.3390/biom11081239] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/16/2022] Open
Abstract
Glaucoma is a group of optic neuropathies characterised by the degeneration of retinal ganglion cells, resulting in damage to the optic nerve head (ONH) and loss of vision in one or both eyes. Increased intraocular pressure (IOP) is one of the major aetiological risk factors in glaucoma, and is currently the only modifiable risk factor. However, 30–40% of glaucoma patients do not present with elevated IOP and still proceed to lose vision. The pathophysiology of glaucoma is therefore not completely understood, and there is a need for the development of IOP-independent neuroprotective therapies to preserve vision. Neuroinflammation has been shown to play a key role in glaucoma and, specifically, the NLRP3 inflammasome, a key driver of inflammation, has recently been implicated. The NLRP3 inflammasome is expressed in the eye and its activation is reported in pre-clinical studies of glaucoma. Activation of the NLRP3 inflammasome results in IL-1β processing. This pro inflammatory cytokine is elevated in the blood of glaucoma patients and is believed to drive neurotoxic inflammation, resulting in axon degeneration and the death of retinal ganglion cells (RGCs). This review discusses glaucoma as an inflammatory disease and evaluates targeting the NLRP3 inflammasome as a therapeutic strategy. A hypothetical mechanism for the action of the NLRP3 inflammasome in glaucoma is presented.
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Affiliation(s)
- Sophie Coyle
- Northern Ireland Centre for Stratified Medicine, Ulster University, Londonderry BT47 6SB, UK; (S.C.); (M.N.K.); (S.D.A.)
| | - Mohammed Naeem Khan
- Northern Ireland Centre for Stratified Medicine, Ulster University, Londonderry BT47 6SB, UK; (S.C.); (M.N.K.); (S.D.A.)
| | - Melody Chemaly
- Department of Molecular Medicine and Surgery, Karolinska Institute, SE-171 76 Solna, Sweden;
| | - Breedge Callaghan
- Centre for Molecular Biosciences, Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, UK; (B.C.); (C.D.); (C.E.W.)
| | - Chelsey Doyle
- Centre for Molecular Biosciences, Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, UK; (B.C.); (C.D.); (C.E.W.)
| | - Colin E. Willoughby
- Centre for Molecular Biosciences, Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, UK; (B.C.); (C.D.); (C.E.W.)
| | - Sarah D. Atkinson
- Northern Ireland Centre for Stratified Medicine, Ulster University, Londonderry BT47 6SB, UK; (S.C.); (M.N.K.); (S.D.A.)
| | - Meredith Gregory-Ksander
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, MA 02114, USA;
| | - Victoria McGilligan
- Northern Ireland Centre for Stratified Medicine, Ulster University, Londonderry BT47 6SB, UK; (S.C.); (M.N.K.); (S.D.A.)
- Correspondence:
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Multifactorial Pathogenic Processes of Retinal Ganglion Cell Degeneration in Glaucoma towards Multi-Target Strategies for Broader Treatment Effects. Cells 2021; 10:cells10061372. [PMID: 34199494 PMCID: PMC8228726 DOI: 10.3390/cells10061372] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/14/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cell (RGC) somas, degeneration of axons, and loss of synapses at dendrites and axon terminals. Glaucomatous neurodegeneration encompasses multiple triggers, multiple cell types, and multiple molecular pathways through the etiological paths with biomechanical, vascular, metabolic, oxidative, and inflammatory components. As much as intrinsic responses of RGCs themselves, divergent responses and intricate interactions of the surrounding glia also play decisive roles for the cell fate. Seen from a broad perspective, multitarget treatment strategies have a compelling pathophysiological basis to more efficiently manipulate multiple pathogenic processes at multiple injury sites in such a multifactorial neurodegenerative disease. Despite distinct molecular programs for somatic and axonal degeneration, mitochondrial dysfunction and glia-driven neuroinflammation present interdependent processes with widespread impacts in the glaucomatous retina and optic nerve. Since dysfunctional mitochondria stimulate inflammatory responses and proinflammatory mediators impair mitochondria, mitochondrial restoration may be immunomodulatory, while anti-inflammatory treatments protect mitochondria. Manipulation of these converging routes may thus allow a unified treatment strategy to protect RGC axons, somas, and synapses. This review presents an overview of recent research advancements with emphasis on potential treatment targets to achieve the best treatment efficacy to preserve visual function in glaucoma.
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23
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Melatonin Prevents Non-image-Forming Visual System Alterations Induced by Experimental Glaucoma in Rats. Mol Neurobiol 2021; 58:3653-3664. [PMID: 33786741 DOI: 10.1007/s12035-021-02374-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/25/2021] [Indexed: 12/11/2022]
Abstract
Glaucoma is a blindness-causing disease that involves selective damage to retinal ganglion cells (RGCs) and their axons. A subset of RGCs expressing the photopigment melanopsin regulates non-image-forming visual system functions, such as pupillary light reflex and circadian rhythms. We analyzed the effect of melatonin on the non-image-forming visual system alterations induced by experimental glaucoma. For this purpose, male Wistar rats were weekly injected with vehicle or chondroitin sulfate into the eye anterior chamber. The non-image-forming visual system was analyzed in terms of (1) melanopsin-expressing RGC number, (2) anterograde transport from the retina to the olivary pretectal nucleus and the suprachiasmatic nuclei, (3) blue- and white light-induced pupillary light reflex, (4) light-induced c-Fos expression in the suprachiasmatic nuclei, (5) daily rhythm of locomotor activity, and (6) mitochondria in melanopsin-expressing RGC cells. Melatonin prevented the effect of experimental glaucoma on melanopsin-expressing RGC number, blue- and white light-induced pupil constriction, retina-olivary pretectal nucleus, and retina- suprachiasmatic nuclei communication, light-induced c-Fos expression in the suprachiasmatic nuclei, and alterations in the locomotor activity daily rhythm. In addition, melatonin prevented the effect of glaucoma on melanopsin-expressing RGC mitochondrial alterations. These results support that melatonin protected the non-image-forming visual system against glaucoma, probably through a mitochondrial protective mechanism.
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24
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Zhang J, Gong X, Xiong H. Significant higher-level C-C motif chemokine ligand 2/3 and chemotactic power in cerebral white matter than grey matter in rat and human. Eur J Neurosci 2021; 54:10.1111/ejn.15187. [PMID: 33725384 PMCID: PMC8443722 DOI: 10.1111/ejn.15187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 02/25/2021] [Accepted: 03/10/2021] [Indexed: 12/17/2022]
Abstract
Recent observations indicate that cerebral white matter (WM) exhibits a higher chemoattractant capability for immune cells. The C-C motif chemokine ligands 2 and 3 (CCL2, CCL3) are key chemokines for monocytes and T cells. However, tissue differential of these chemokines is unclear, although the higher CCL2/3 mRNA levels were found in rodent WM. It has been shown that more immune cells infiltrated to WM than to grey matter (GM) in multiple sclerosis (MS) and human/simian immunodeficiency virus (HIV/SIV)-infected brains. More nodular lesions have also been identified in the WM of patients with MS or HIV/SIV encephalitis. We hypothesize that higher levels of CCL2/3 in the WM may associate with neuropathogenesis. To test this hypothesis, we compared CCL2 and CCL3 peptide levels in WM and GM of rat and human, and found both were significantly higher in the WM. Next, we tested the effect of CCL2 on primary rat microglia migration and observed a dose-dependent migratory pattern. Then, we assessed effects of WM and GM homogenates on microglia chemotaxis and observed significant stronger effects of WM than GM in a concentration-dependent manner. The concentration-dependent pattern of tissue homogenates on chemotaxis was similar to the effect of CCL2. Finally, we found the chemoattractant effects of WM on microglia were significantly attenuated by addition of a CCL2 receptor blocker to culture medium and a neutralizing antibody against CCL3 functional motif in the WM homogenate. Taking together, these results suggest that CCL2/3 played significant roles in the microglia chemotaxis toward WM homogenate.
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Affiliation(s)
- Jingdong Zhang
- Department of Pharmacology and Experiment Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xinrui Gong
- Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Xiangyang, China
| | - Huangui Xiong
- Department of Pharmacology and Experiment Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
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25
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Simon MV, Basu SK, Qaladize B, Grambergs R, Rotstein NP, Mandal N. Sphingolipids as critical players in retinal physiology and pathology. J Lipid Res 2021; 62:100037. [PMID: 32948663 PMCID: PMC7933806 DOI: 10.1194/jlr.tr120000972] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/04/2020] [Indexed: 12/24/2022] Open
Abstract
Sphingolipids have emerged as bioactive lipids involved in the regulation of many physiological and pathological processes. In the retina, they have been established to participate in numerous processes, such as neuronal survival and death, proliferation and migration of neuronal and vascular cells, inflammation, and neovascularization. Dysregulation of sphingolipids is therefore crucial in the onset and progression of retinal diseases. This review examines the involvement of sphingolipids in retinal physiology and diseases. Ceramide (Cer) has emerged as a common mediator of inflammation and death of neuronal and retinal pigment epithelium cells in animal models of retinopathies such as glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa. Sphingosine-1-phosphate (S1P) has opposite roles, preventing photoreceptor and ganglion cell degeneration but also promoting inflammation, fibrosis, and neovascularization in AMD, glaucoma, and pro-fibrotic disorders. Alterations in Cer, S1P, and ceramide 1-phosphate may also contribute to uveitis. Notably, use of inhibitors that either prevent Cer increase or modulate S1P signaling, such as Myriocin, desipramine, and Fingolimod (FTY720), preserves neuronal viability and retinal function. These findings underscore the relevance of alterations in the sphingolipid metabolic network in the etiology of multiple retinopathies and highlight the potential of modulating their metabolism for the design of novel therapeutic approaches.
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Affiliation(s)
- M Victoria Simon
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
| | - Sandip K Basu
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bano Qaladize
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Richard Grambergs
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nora P Rotstein
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina.
| | - Nawajes Mandal
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Grotegut P, Perumal N, Kuehn S, Smit A, Dick HB, Grus FH, Joachim SC. Minocycline reduces inflammatory response and cell death in a S100B retina degeneration model. J Neuroinflammation 2020; 17:375. [PMID: 33317557 PMCID: PMC7737388 DOI: 10.1186/s12974-020-02012-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/28/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Previous studies noted that intravitreal injection of S100B triggered a glaucoma-like degeneration of retina and optic nerve as well as microglia activation after 14 days. The precise role of microglia in our intravitreal S100B model is still unclear. Hence, microglia were inhibited through minocycline. The aim is to investigate whether microglia have a significant influence on the degeneration process or whether they are only a side effect in the model studied here. METHODS Minocycline was applied daily in rats by intraperitoneal injection using two different concentrations (13.5 mg/kg body weight, 25 mg/kg body weight). One day after treatment start, S100B or PBS was intravitreally injected in one eye per rat. The naïve groups received no injections. This resulted in a total of five groups (naïve n = 14, PBS n = 14, S100B n = 13, 13.5 mg/kg mino n = 15, 25 mg/kg mino n = 15). At day 14, electroretinogram measurements were performed, followed by immunofluorescence and label-free quantitative proteomics analysis. The focus of these investigations was on the survival of RGCs as well as their axons, the response of the microglia, and the identification of further pathological modes of action of S100B. RESULTS The best signal transmission was detected via ERG in the 13.5 mg/kg mino group. The inhibition of the microglia protected optic nerve neurofilaments and decreased the negative impact of S100B on RGCs. However, the minocycline treatment could not trigger complete protection of RGCs. Furthermore, in retina and optic nerve, the minocycline treatment reduced the number and activity of S100B-triggered microglia in a concentration-dependent manner. Proteomics analysis showed that S100B application led to numerous metabolic functions and cellular stress, mainly an increased inflammatory response, glycolysis, and mitochondrial dysfunction, which caused oxidative stress in the retina. Importantly, the protective capability of lower dose of minocycline was unraveled by suppressing the apoptotic, inflammatory, and the altered metabolic processes caused by S100B insult in the retina. CONCLUSION Intravitreally injected S100B not only led to a pro-inflammatory microglial reaction, but also a mitochondrial and metabolic dysfunction. Also, these results suggest that an excessive microglial response may be a significant degenerative factor, but not the only trigger for increased cell death.
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Affiliation(s)
- Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Natarajan Perumal
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Andreas Smit
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Franz H Grus
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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Baudouin C, Kolko M, Melik-Parsadaniantz S, Messmer EM. Inflammation in Glaucoma: From the back to the front of the eye, and beyond. Prog Retin Eye Res 2020; 83:100916. [PMID: 33075485 DOI: 10.1016/j.preteyeres.2020.100916] [Citation(s) in RCA: 161] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/09/2020] [Accepted: 10/13/2020] [Indexed: 02/08/2023]
Abstract
The pathophysiology of glaucoma is complex, multifactorial and not completely understood. Elevated intraocular pressure (IOP) and/or impaired retinal blood flow may cause initial optic nerve damage. In addition, age-related oxidative stress in the retina concurrently with chronic mechanical and vascular stress is crucial for the initiation of retinal neurodegeneration. Oxidative stress is closely related to cell senescence, mitochondrial dysfunction, excitotoxicity, and neuroinflammation, which are involved in glaucoma progression. Accumulating evidence from animal glaucoma models and from human ocular samples suggests a dysfunction of the para-inflammation in the retinal ganglion cell layer and the optic nerve head. Moreover, quite similar mechanisms in the anterior chamber could explain the trabecular meshwork dysfunction and the elevated IOP in primary open-angle glaucoma. On the other hand, ocular surface disease due to topical interventions is the most prominent and visible consequence of inflammation in glaucoma, with a negative impact on filtering surgery failure, topical treatment efficacy, and possibly on inflammation in the anterior segment. Consequently, glaucoma appears as an outstanding eye disease where inflammatory changes may be present to various extents and consequences along the eye structure, from the ocular surface to the posterior segment, and the visual pathway. Here we reviewed the inflammatory processes in all ocular structures in glaucoma from the back to the front of the eye and beyond. Our approach was to explain how para-inflammation is necessary to maintain homoeostasis, and to describe abnormal inflammatory findings observed in glaucomatous patients or in animal glaucoma models, supporting the hypothesis of a dysregulation of the inflammatory balance toward a pro-inflammatory phenotype. Possible anti-inflammatory therapeutic approaches in glaucoma are also discussed.
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Affiliation(s)
- Christophe Baudouin
- Quinze-Vingts National Ophthalmology Hospital, INSERM-DGOS CIC 1423, IHU Foresight, Paris, France; Sorbonne Université, INSERM, CNRS, Institut de La Vision, Paris, France; Department of Ophthalmology, Ambroise Paré Hospital, APHP, Université de Versailles Saint-Quentin en Yvelines, Boulogne-Billancourt, France.
| | - Miriam Kolko
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark; Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet-Glostrup, Glostrup, Denmark
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Yazdankhah M, Shang P, Ghosh S, Hose S, Liu H, Weiss J, Fitting CS, Bhutto IA, Zigler JS, Qian J, Sahel JA, Sinha D, Stepicheva NA. Role of glia in optic nerve. Prog Retin Eye Res 2020; 81:100886. [PMID: 32771538 DOI: 10.1016/j.preteyeres.2020.100886] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/09/2020] [Accepted: 07/20/2020] [Indexed: 12/13/2022]
Abstract
Glial cells are critically important for maintenance of neuronal activity in the central nervous system (CNS), including the optic nerve (ON). However, the ON has several unique characteristics, such as an extremely high myelination level of retinal ganglion cell (RGC) axons throughout the length of the nerve (with virtually all fibers myelinated by 7 months of age in humans), lack of synapses and very narrow geometry. Moreover, the optic nerve head (ONH) - a region where the RGC axons exit the eye - represents an interesting area that is morphologically distinct in different species. In many cases of multiple sclerosis (demyelinating disease of the CNS) vision problems are the first manifestation of the disease, suggesting that RGCs and/or glia in the ON are more sensitive to pathological conditions than cells in other parts of the CNS. Here, we summarize current knowledge on glial organization and function in the ON, focusing on glial support of RGCs. We cover both well-established concepts on the important role of glial cells in ON health and new findings, including novel insights into mechanisms of remyelination, microglia/NG2 cell-cell interaction, astrocyte reactivity and the regulation of reactive astrogliosis by mitochondrial fragmentation in microglia.
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Affiliation(s)
- Meysam Yazdankhah
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Peng Shang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sayan Ghosh
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Stacey Hose
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Haitao Liu
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Joseph Weiss
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christopher S Fitting
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Imran A Bhutto
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - J Samuel Zigler
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - José-Alain Sahel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Institut de la Vision, INSERM, CNRS, Sorbonne Université, F-75012, Paris, France
| | - Debasish Sinha
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Nadezda A Stepicheva
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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29
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Han C, Guo L, Yang Y, Guan Q, Shen H, Sheng Y, Jiao Q. Mechanism of microRNA-22 in regulating neuroinflammation in Alzheimer's disease. Brain Behav 2020; 10:e01627. [PMID: 32307887 PMCID: PMC7303389 DOI: 10.1002/brb3.1627] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/28/2020] [Accepted: 03/10/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Study on the expression of miRNA-22 in serum of Alzheimer's disease (AD) patients and the mechanism of neuroinflammation regulation. METHODS ELISA assay was used to detect the serum level of inflammatory factors, including interleukin-1β (IL-1β), interleukin-18 (IL-18), and tumor necrosis factor-α in AD patients. TargetScan database and luciferase reporter gene assay indicated that gasdermin D (GSDMD) was the target gene of miRNA-22. miRNA-22 mimic was transfected into microglia, followed by administration of LPS and Nigericin to induce pyroptosis. RESULTS In this study, we found that the expression level of miRNA-22 in peripheral blood was lower in AD patients than that in healthy population. The expression of inflammatory factors was higher in AD patients than that in healthy people, which was negatively correlated with miRNA-22. miRNA-22 mimic could significantly inhibit pyroptosis, the expression of GSDMD and p30-GSDMD was down-regulated, the release of inflammatory factor was decreased, and the expression of NLRP3 inflammasome was down-regulated as feedback. In the APP/PS1 double transgenic mouse model, the injection of miRNA-22 mimic significantly improved the memory ability and behavior of mice. In addition, the expression of the vital protein of pyroptosis in mouse brain tissue, including GSDMD and p30-GSDMD, was down-regulated, and the expression of inflammatory factors was also decreased. CONCLUSION miRNA-22 was negatively correlated with the expression of inflammatory factors in AD patients, and miRNA-22 could inhibit the release of inflammatory cytokines by regulating the inflammatory pyroptosis of glial cells via targeting GSDMD, thereby improving cognitive ability in AD mice. miRNA-22 and pyroptosis are potential novel therapeutic targets in the treatment of AD.
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Affiliation(s)
- Chenyang Han
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, China.,Department of Pharmacy, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Li Guo
- Department of Center Laboratory, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Yi Yang
- Department of Neurology, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Qiaobing Guan
- Department of Neurology, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Heping Shen
- Department of Neurology, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Yongjia Sheng
- Department of Pharmacy, The Second Affiliated Hospital of Jiaxing University, Jiaxing, China
| | - Qingcai Jiao
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, China
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Destructive Effect of Intravitreal Heat Shock Protein 27 Application on Retinal Ganglion Cells and Neurofilament. Int J Mol Sci 2020; 21:ijms21020549. [PMID: 31952234 PMCID: PMC7014083 DOI: 10.3390/ijms21020549] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 01/01/2023] Open
Abstract
Heat shock protein 27 (HSP27) is commonly involved in cellular stress. Increased levels of HSP27 as well as autoantibodies against this protein were previously detected in glaucoma patients. Moreover, systemic immunization with HSP27 induced glaucoma-like damage in rodents. Now, for the first time, the direct effects of an intravitreal HSP27 application were investigated. For this reason, HSP27 or phosphate buffered saline (PBS, controls) was applied intravitreally in rats (n = 12/group). The intraocular pressure (IOP) as well as the electroretinogram recordings were comparable in HSP27 and control eyes 21 days after the injection. However, significantly fewer retinal ganglion cells (RGCs) and amacrine cells were observed in the HSP27 group via immunohistochemistry and western blot analysis. The number of bipolar cells, on the other hand, was similar in both groups. Interestingly, a stronger neurofilament degeneration was observed in HSP27 optic nerves, while no differences were noted regarding the myelination state. In summary, intravitreal HSP27 injection led to an IOP-independent glaucoma-like damage. A degeneration of RGCs as well as their axons and amacrine cells was noted. This suggests that high levels of extracellular HSP27 could have a direct damaging effect on RGCs.
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González Fleitas MF, Devouassoux JD, Aranda ML, Calanni JS, Chianelli MS, Dorfman D, Rosenstein RE. Enriched environment provides neuroprotection against experimental glaucoma. J Neurochem 2019; 152:103-121. [PMID: 31587281 DOI: 10.1111/jnc.14885] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/13/2019] [Accepted: 10/01/2019] [Indexed: 12/25/2022]
Abstract
Glaucoma is one of the most frequent causes of visual impairment worldwide, and involves selective damage to retinal ganglion cells (RGCs) and their axons. We analyzed the effect of enriched environment (EE) housing on the optic nerve, and retinal alterations in an induced model of ocular hypertension. For this purpose, male Wistar rats were weekly injected with vehicle or chondroitin sulfate (CS) into the eye anterior chamber for 10 weeks and housed in standard environment or EE. EE housing prevented the effect of experimental glaucoma on visual evoked potentials, retinal anterograde transport, phosphorylated neurofilament-immunoreactivity, axon number, microglial/macrophage reactivity (ionized calcium binding adaptor molecule 1-immunoreactivity), and astrocytosis (glial fibrillary acidic protein-immunostaining), as well as oligodendrocytes alterations (luxol fast blue staining, and myelin basic protein-immunoreactivity) in the proximal portion of the optic nerve. Moreover EE prevented the increase in ionized calcium binding adaptor molecule-1 levels, and RGC loss (Brn3a-immunoreactivity) in the retina from hypertensive eyes. EE increased retinal brain-derived neurotrophic factor levels. When EE housing started after 6 weeks of ocular hypertension, a preservation of visual evoked potentials amplitude, axon, and Brn3a(+) RGC number was observed. Taken together, these results suggest that EE preserved visual functions, reduced optic nerve axoglial alterations, and protected RGCs against glaucomatous damage.
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Affiliation(s)
- María F González Fleitas
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Julián D Devouassoux
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Marcos L Aranda
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Juan S Calanni
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Monica S Chianelli
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Damián Dorfman
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Ruth E Rosenstein
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
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Krishnan A, Kocab AJ, Zacks DN, Marshak-Rothstein A, Gregory-Ksander M. A small peptide antagonist of the Fas receptor inhibits neuroinflammation and prevents axon degeneration and retinal ganglion cell death in an inducible mouse model of glaucoma. J Neuroinflammation 2019; 16:184. [PMID: 31570110 PMCID: PMC6767653 DOI: 10.1186/s12974-019-1576-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 08/29/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Glaucoma is a complex, multifactorial disease where apoptosis, microglia activation, and inflammation have been linked to the death of retinal ganglion cells (RGCs) and axon degeneration. We demonstrated previously that FasL-Fas signaling was required for axon degeneration and death of RGCs in chronic and inducible mouse models of glaucoma and that Fas activation triggered RGC apoptosis, glial activation, and inflammation. Here, we investigated whether targeting the Fas receptor with a small peptide antagonist, ONL1204, has anti-inflammatory and neuroprotective effects in a microbead-induced mouse model of glaucoma. METHODS Intracameral injection of microbeads was used to elevate intraocular pressure (IOP) in Fas-deficient (Faslpr) mice and WT C57BL/6J mice that received an intravitreal injection of the Fas inhibitor, ONL1204 (2 μg/1 μl) (or vehicle only), on day 0 or day 7 after microbead injection. The IOP was monitored by rebound tonometry, and at 28 days post-microbead injection, Brn3a-stained RGCs and paraphenylenediamine (PPD)-stained axons were analyzed. The effects of ONL1204 on retinal microglia activation and the expression of inflammatory genes were analyzed by immunostaining of retinal flatmounts and quantitative PCR (qPCR). RESULTS Rebound tonometry showed equivalent elevation of IOP in all groups of microbead-injected mice. At 28 days post-microbead injection, the RGC and axon counts from microbead-injected Faslpr mice were equivalent to saline-injected (no IOP elevation) controls. Treatment with ONL1204 also significantly reduced RGC death and loss of axons in microbead-injected WT mice when compared to vehicle-treated controls, even when administered after IOP elevation. Confocal analysis of Iba1-stained retinal flatmounts and qPCR demonstrated that ONL1204 also abrogated microglia activation and inhibited the induction of multiple genes implicated in glaucoma, including cytokines and chemokines (GFAP, Caspase-8, TNFα, IL-1β, IL-6, IL-18, MIP-1α, MIP-1β, MIP-2, MCPI, and IP10), components of the complement cascade (C3, C1Q), Toll-like receptor pathway (TLR4), and inflammasome pathway (NLRP3). CONCLUSIONS These results serve as proof-of-principal that the small peptide inhibitor of the Fas receptor, ONL1204, can provide robust neuroprotection in an inducible mouse model of glaucoma, even when administered after IOP elevation. Moreover, Fas signaling contributes to the pathogenesis of glaucoma through activation of both apoptotic and inflammatory pathways.
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Affiliation(s)
- Anitha Krishnan
- Department of Ophthalmology, The Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA, USA
| | | | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Ann Marshak-Rothstein
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Meredith Gregory-Ksander
- Department of Ophthalmology, The Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA, USA.
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Tsai T, Reinehr S, Maliha AM, Joachim SC. Immune Mediated Degeneration and Possible Protection in Glaucoma. Front Neurosci 2019; 13:931. [PMID: 31543759 PMCID: PMC6733056 DOI: 10.3389/fnins.2019.00931] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/19/2019] [Indexed: 12/13/2022] Open
Abstract
The underlying pathomechanisms for glaucoma, one of the most common causes of blindness worldwide, are still not identified. In addition to increased intraocular pressure (IOP), oxidative stress, excitotoxicity, and immunological processes seem to play a role. Several pharmacological or molecular/genetic methods are currently investigated as treatment options for this disease. Altered autoantibody levels were detected in serum, aqueous humor, and tissue sections of glaucoma patients. To further analyze the role of the immune system, an IOP-independent, experimental autoimmune glaucoma (EAG) animal model was developed. In this model, immunization with ocular antigens leads to antibody depositions, misdirected T-cells, retinal ganglion cell death and degeneration of the optic nerve, similar to glaucomatous degeneration in patients. Moreover, an activation of the complement system and microglia alterations were identified in the EAG as well as in ocular hypertension models. The inhibition of these factors can alleviate degeneration in glaucoma models with and without high IOP. Currently, several neuroprotective approaches are tested in distinct models. It is necessary to have systems that cover underlying pathomechanisms, but also allow for the screening of new drugs. In vitro models are commonly used, including single cell lines, mixed-cultures, and even organoids. In ex vivo organ cultures, pathomechanisms as well as therapeutics can be investigated in the whole retina. Furthermore, animal models reveal insights in the in vivo situation. With all these models, several possible new drugs and therapy strategies were tested in the last years. For example, hypothermia treatment, neurotrophic factors or the blockage of excitotoxity. However, further studies are required to reveal the pressure independent pathomechanisms behind glaucoma. There is still an open issue whether immune mechanisms directly or indirectly trigger cell death pathways. Hence, it might be an imbalance between protective and destructive immune mechanisms. Moreover, identified therapy options have to be evaluated in more detail, since deeper insights could lead to better treatment options for glaucoma patients.
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Affiliation(s)
| | | | | | - Stephanie C. Joachim
- Experimental Eye Research, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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Tehrani S, Davis L, Cepurna WO, Delf RK, Lozano DC, Choe TE, Johnson EC, Morrison JC. Optic Nerve Head Astrocytes Display Axon-Dependent and -Independent Reactivity in Response to Acutely Elevated Intraocular Pressure. Invest Ophthalmol Vis Sci 2019; 60:312-321. [PMID: 30665231 PMCID: PMC6343680 DOI: 10.1167/iovs.18-25447] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Purpose Optic nerve head (ONH) astrocytes provide support for axons, but exhibit structural and functional changes (termed reactivity) in a number of glaucoma models. The purpose of this study was to determine if ONH astrocyte structural reactivity is axon-dependent. Methods Using rats, we combine retrobulbar optic nerve transection (ONT) with acute controlled elevation of intraocular pressure (CEI), to induce total optic nerve axon loss and ONH astrocyte reactivity, respectively. Animals were euthanized immediately or 1 day post CEI, in the presence or absence of ONT. ONH sections were labeled with fluorescent-tagged phalloidin and antibodies against β3 tubulin, phosphorylated cortactin, phosphorylated paxillin, or complement C3. ONH label intensities were quantified after confocal microscopy. Retrobulbar nerves were assessed for axon injury by light microscopy. Results While ONT alone had no effect on ONH astrocyte structural orientation, astrocytes demonstrated significant reorganization of cellular extensions within hours after CEI, even when combined with ONT. However, ONH astrocytes displayed differential intensities of actin (phosphorylated cortactin) and focal adhesion (phosphorylated paxillin) mediators in response to CEI alone, ONT alone, or the combination of CEI and ONT. Lastly, label intensities of complement C3 within the ONH were unchanged in eyes subjected to CEI alone, ONT alone, or the combination of CEI and ONT, relative to controls. Conclusions Early ONH astrocyte structural reactivity to elevated IOP is multifaceted, displaying both axon dependent and independent responses. These findings have important implications for pursuing astrocytes as diagnostic and therapeutic targets in neurodegenerative disorders with fluctuating levels of axon injury.
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Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Lauren Davis
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - William O Cepurna
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - R Katherine Delf
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Diana C Lozano
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C Johnson
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - John C Morrison
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
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Lozano DC, Choe TE, Cepurna WO, Morrison JC, Johnson EC. Early Optic Nerve Head Glial Proliferation and Jak-Stat Pathway Activation in Chronic Experimental Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:921-932. [PMID: 30835784 PMCID: PMC6402265 DOI: 10.1167/iovs.18-25700] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/25/2019] [Indexed: 12/18/2022] Open
Abstract
PURPOSE We previously reported increased expression of cell proliferation and Jak-Stat pathway-related genes in chronic experimental glaucoma model optic nerve heads (ONH) with early, mild injury. Here, we confirm these observations by localizing, identifying, and quantifying ONH cellular proliferation and Jak-Stat pathway activation in this model. METHODS Chronic intraocular pressure (IOP) elevation was achieved via outflow pathway sclerosis. After 5 weeks, ONH longitudinal sections were immunolabeled with proliferation and cell-type markers to determine nuclear densities in the anterior (unmyelinated) and transition (partially myelinated) ONH. Nuclear pStat3 labeling was used to detect Jak-Stat pathway activation. Nuclear density differences between control ONH (uninjected) and ONH with either early or advanced injury (determined by optic nerve injury grading) were identified by ANOVA. RESULTS Advanced injury ONH had twice the nuclear density (P < 0.0001) of controls and significantly greater astrocyte density in anterior (P = 0.0001) and transition (P = 0.006) ONH regions. An increased optic nerve injury grade positively correlated with increased microglia/macrophage density in anterior and transition ONH (P < 0.0001, both). Oligodendroglial density was unaffected. In glaucoma model ONH, 80% of anterior and 66% of transition region proliferating cells were astrocytes. Nuclear pStat3 labeling significantly increased in early injury anterior ONH, and 95% colocalized with astrocytes. CONCLUSIONS Astrocytes account for the majority of proliferating cells, contributing to a doubled nuclear density in advanced injury ONH. Jak-Stat pathway activation is apparent in the early injury glaucoma model ONH. These data confirm dramatic astrocyte cell proliferation and early Jak-Stat pathway activation in ONH injured by elevated IOP.
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Affiliation(s)
- Diana C. Lozano
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Tiffany E. Choe
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - William O. Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - John C. Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C. Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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Caspases orchestrate microglia instrumental functions. Prog Neurobiol 2018; 171:50-71. [DOI: 10.1016/j.pneurobio.2018.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 09/21/2018] [Accepted: 09/29/2018] [Indexed: 12/16/2022]
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Abstract
Microglia, the primary resident immune cell type, constitute a key population of glia in the retina. Recent evidence indicates that microglia play significant functional roles in the retina at different life stages. During development, retinal microglia regulate neuronal survival by exerting trophic influences and influencing programmed cell death. During adulthood, ramified microglia in the plexiform layers interact closely with synapses to maintain synaptic structure and function that underlie the retina's electrophysiological response to light. Under pathological conditions, retinal microglia participate in potentiating neurodegeneration in diseases such as glaucoma, retinitis pigmentosa, and age-related neurodegeneration by producing proinflammatory neurotoxic cytokines and removing living neurons via phagocytosis. Modulation of pathogenic microglial activation states and effector mechanisms has been linked to neuroprotection in animal models of retinal diseases. These findings have led to the design of early proof-of-concept clinical trials with microglial modulation as a therapeutic strategy.
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Affiliation(s)
- Sean M. Silverman
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
| | - Wai T. Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
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Zeng HL, Shi JM. The role of microglia in the progression of glaucomatous neurodegeneration- a review. Int J Ophthalmol 2018; 11:143-149. [PMID: 29376003 DOI: 10.18240/ijo.2018.01.22] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 08/28/2017] [Indexed: 12/11/2022] Open
Abstract
Glaucoma is a serious leading cause of irreversible blindness worldwide. Reducing intraocular pressure (IOP) does not always stop glaucomatous neurodegeneration and the optic nerve may continue to be damaged in the normal IOP. Microglial activity has been recognized to play essential roles in pathogenesis of the central nervous system (CNS) as well as retinal ganglion cell (RGC) survival. The relationship between the neurodegeneration and the microglia cells in glaucoma is very complicated and still remains unclear. In the present review, we summarize the recent studies of mechanisms of microglia in glaucoma neurodegeneration, which might provide new ways to treat glaucoma.
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Affiliation(s)
- Hui-Lan Zeng
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
| | - Jing-Ming Shi
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
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