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Shinozaki Y, Koizumi S. Potential roles of astrocytes and Müller cells in the pathogenesis of glaucoma. J Pharmacol Sci 2020; 145:262-267. [PMID: 33602506 DOI: 10.1016/j.jphs.2020.12.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 12/12/2020] [Accepted: 12/28/2020] [Indexed: 12/26/2022] Open
Abstract
Glaucoma, a progressive optic neuropathy and the leading cause of blindness, is characterized by impairment or degeneration of retinal ganglion cells (RGCs), which transmit visual information to the brain. Currently, 70 million people worldwide are affected by glaucoma. Elevated intraocular pressure (IOP), a major risk factor of glaucoma, directly damages RGCs. However, a substantial proportion of glaucoma patients have a normal IOP level. In particular, over 90% of Japanese glaucoma patients are reported to have normal IOP levels. Thus, a new focus for glaucoma pathology has emerged. Glial cells contribute to tissue homeostasis. Under pathological conditions, glial cells become reactive, lose their homeostatic functions, and gain neurotoxic functions, which trigger neurodegeneration in several diseases including glaucoma. Reactive glial cells have been identified in the eyes of glaucoma patients. In a glaucoma animal model, reactive glial cells are observed at early stages of the disease when RGCs are intact, indicating the possible role of glial cells in the pathogenesis of glaucoma. In this review, we introduce potential roles of glial cells in the pathogenesis of glaucoma. We focus on the roles of the ocular macroglial cells such as astrocytes and Müller cells, and discuss their roles in the pathogenesis of glaucoma.
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Affiliation(s)
- Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan; Interdisciplinary Brain-Immune Research Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan; Interdisciplinary Brain-Immune Research Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.
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Iwata Y, Inagaki S, Morozumi W, Nakamura S, Hara H, Shimazawa M. Treatment with GDF15, a TGFβ superfamily protein, induces protective effect on retinal ganglion cells. Exp Eye Res 2020; 202:108338. [PMID: 33157126 DOI: 10.1016/j.exer.2020.108338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/12/2020] [Accepted: 10/24/2020] [Indexed: 10/23/2022]
Abstract
Growth differentiation factor 15 (GDF15) is a protein belonging to the transforming growth factor beta (TGF-β) superfamily. The precursor GDF15 is cleaved and activated as a mature GDF15 by protease. GDF15 has been detected in the aqueous humor of the primary open angle glaucoma patients, however the localization and the effect on the retinal ganglion cells (RGCs) are still unknown. Thus, the purpose of this study was to elucidate the effect of GDF15 on mouse optic nerve crush (ONC) model and primary culture of rat RGCs. Immunostaining showed that the GDF15 was in the ganglion cell layer (GCL), and colocalized with GFAP-positive cells in the GCL and the optic nerve. Western blotting analysis showed that the mature GDF15 was upregulated in the retina and the optic nerve after the ONC. Intravitreal injection of GDF15 suppressed RGCs loss of the ONC model mice in vivo. The neurites length of the primary culture of rat RGCs were increased by mature GDF15 treatment. In addition, the neurotrophic effect of GDF15 was canceled by RET inhibitor treatment. These findings indicate that GDF15 has neuroprotective effect on RGCs via GFRAL-RET pathway. Therefore, GDF15 may be one of novel therapeutic targets in RGC degenerative diseases.
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Affiliation(s)
- Yuki Iwata
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Satoshi Inagaki
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Wataru Morozumi
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Shinsuke Nakamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan.
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Xu LJ, Gao F, Cheng S, Zhou ZX, Li F, Miao Y, Niu WR, Yuan F, Sun XH, Wang Z. Activated ephrinA3/EphA4 forward signaling induces retinal ganglion cell apoptosis in experimental glaucoma. Neuropharmacology 2020; 178:108228. [PMID: 32745487 DOI: 10.1016/j.neuropharm.2020.108228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 12/12/2022]
Abstract
Previous studies have demonstrated that EphA4 participates in neuronal injury, and there is a strong interaction between ephrinA3 and EphA4. In this study, we showed that in a rat chronic ocular hypertension (COH) experimental glaucoma model, expression of EphA4 and ephrinA3 proteins was increased in retinal cells, including retinal ganglion cells (RGCs) and Müller cells, which may result in ephrinA3/EphA4 forward signaling activation on RGCs, as evidenced by increased p-EphA4/EphA4 ratio. Intravitreal injection of ephrinA3-Fc, an activator of EphA4, mimicked the effect of COH on p-EphA4/EphA4 and induced an increase in TUNEL-positive signals in normal retinas, which was accompanied by dendritic spine retraction and thinner dendrites in RGCs. Furthermore, Intravitreal injection of ephrinA3-Fc increased the levels of phosphorylated src and GluA2 (p-src and p-GluA2). Co-immunoprecipitation assay demonstrated interactions between EphA4, p-src and GluA2. Intravitreal injection of ephrinA3-Fc reduced the expression of GluA2 proteins on the surface of normal retinal cells, which was prevented by intravitreal injection of PP2, an inhibitor of src-family tyrosine kinases. Pre-injection of PP2 or the Ca2+-permeable GluA2-lacking AMPA receptor inhibitor Naspm significantly and partially reduced the number of TUNEL-positive RGCs in the ephrinA3-Fc-injected and COH retinas. Our results suggest that activated ephrinA3/EphA4 forward signaling promoted GluA2 endocytosis, then resulted in dendritic spine retraction of RGCs, thus contributing to RGC apoptosis in COH rats. Attenuation of the strength of ephrinA/EphA signaling in an appropriate manner may be an effective way for preventing the loss of RGCs in glaucoma.
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Affiliation(s)
- Lin-Jie Xu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Feng Gao
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Key Laboratory of Visual Impairment and Restoration, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200031, China
| | - Shuo Cheng
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Zhi-Xin Zhou
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Fang Li
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yanying Miao
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Wei-Ran Niu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Fei Yuan
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xing-Huai Sun
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Key Laboratory of Visual Impairment and Restoration, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200031, China.
| | - Zhongfeng Wang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
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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: 164] [Impact Index Per Article: 41.0] [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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Wiemann S, Reinhard J, Reinehr S, Cibir Z, Joachim SC, Faissner A. Loss of the Extracellular Matrix Molecule Tenascin-C Leads to Absence of Reactive Gliosis and Promotes Anti-inflammatory Cytokine Expression in an Autoimmune Glaucoma Mouse Model. Front Immunol 2020; 11:566279. [PMID: 33162981 PMCID: PMC7581917 DOI: 10.3389/fimmu.2020.566279] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/26/2020] [Indexed: 01/13/2023] Open
Abstract
Previous studies demonstrated that retinal damage correlates with a massive remodeling of extracellular matrix (ECM) molecules and reactive gliosis. However, the functional significance of the ECM in retinal neurodegeneration is still unknown. In the present study, we used an intraocular pressure (IOP) independent experimental autoimmune glaucoma (EAG) mouse model to examine the role of the ECM glycoprotein tenascin-C (Tnc). Wild type (WT ONA) and Tnc knockout (KO ONA) mice were immunized with an optic nerve antigen (ONA) homogenate and control groups (CO) obtained sodium chloride (WT CO, KO CO). IOP was measured weekly and electroretinographies were recorded at the end of the study. Ten weeks after immunization, we analyzed retinal ganglion cells (RGCs), glial cells, and the expression of different cytokines in retina and optic nerve tissue in all four groups. IOP and retinal function were comparable in all groups. Although RGC loss was less severe in KO ONA, WT as well as KO mice displayed a significant cell loss after immunization. Compared to KO ONA, less βIII-tubulin+ axons, and downregulated oligodendrocyte markers were noted in WT ONA optic nerves. In retina and optic nerve, we found an enhanced GFAP+ staining area of astrocytes in immunized WT. A significantly higher number of retinal Iba1+ microglia was found in WT ONA, while a lower number of Iba1+ cells was observed in KO ONA. Furthermore, an increased expression of the glial markers Gfap, Iba1, Nos2, and Cd68 was detected in retinal and optic nerve tissue of WT ONA, whereas comparable levels were observed in KO ONA. In addition, pro-inflammatory Tnfa expression was upregulated in WT ONA, but downregulated in KO ONA. Vice versa, a significantly increased anti-inflammatory Tgfb1 expression was measured in KO ONA animals. We conclude that Tnc plays an important role in glial and inflammatory response during retinal neurodegeneration. Our results provide evidence that Tnc is involved in glaucomatous damage by regulating retinal glial activation and cytokine release. Thus, this transgenic EAG mouse model for the first time offers the possibility to investigate IOP-independent glaucomatous damage in direct relation to ECM remodeling.
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Affiliation(s)
- Susanne Wiemann
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Zülal Cibir
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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Hu X, Xu MX, Zhou H, Cheng S, Li F, Miao Y, Wang Z. Tumor necrosis factor-alpha aggravates gliosis and inflammation of activated retinal Müller cells. Biochem Biophys Res Commun 2020; 531:383-389. [PMID: 32800547 DOI: 10.1016/j.bbrc.2020.07.102] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 11/17/2022]
Abstract
Tumor necrosis factor-alpha (TNF-α), a major inflammatory factor released from activated retinal glial cells, is implicated in the pathogenesis of glaucoma. In this study, we investigated whether and how TNF-α may affect functional conditions of activated retinal Müller cells. Our results showed that in the group I metabotropic glutamate receptor (mGluR I) agonist DHPG-activated cultured Müller cells, TNF-α treatment aggravated cell gliosis, as evidenced by significantly increased expression of glial fibrillary acidic protein (GFAP). TNF-α treatment of the DHPG-activated Müller cells decreased cell proliferation and induced cell apoptosis. In normal Müller cells, TNF-α treatment increased the mRNA levels of leukocyte inhibitory factor (LIF), intercellular cell adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM), and chemokine C-C-motif ligand 2 (CCL2), which could be significantly attenuated when Müller cells were pre-activated. However, TNF-α-induced elevation in mRNA levels of inflammatory factors, such as TNF-α, inducible nitric oxide synthase (iNOS), and interleukin-6 (IL-6), in normal Müller cells still kept higher levels when Müller cells were pre-activated. Furthermore, the TNF-α-induced changes of cytokines were partially mediated by NF-κB signaling pathway. Our results suggest that TNF-α may promote gliosis and inflammatory response of activated Müller cells, thus aggravating RGC injury in glaucoma.
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Affiliation(s)
- Xin Hu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Meng-Xi Xu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Han Zhou
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Shuo Cheng
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Fang Li
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yanying Miao
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Zhongfeng Wang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
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57
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Sladek AL, Nawy S. Ocular Hypertension Drives Remodeling of AMPA Receptors in Select Populations of Retinal Ganglion Cells. Front Synaptic Neurosci 2020; 12:30. [PMID: 32792936 PMCID: PMC7393603 DOI: 10.3389/fnsyn.2020.00030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/25/2020] [Indexed: 12/31/2022] Open
Abstract
AMPA-type glutamate receptors in the CNS are normally impermeable to Ca2+, but the aberrant expression of Ca2+-permeable AMPA receptors (CP-AMPARs) occurs in pathological conditions such as ischemia or epilepsy, or degenerative diseases such as ALS. Here, we show that select populations of retinal ganglion cells (RGCs) similarly express high levels of CP-AMPARs in a mouse model of glaucoma. CP-AMPAR expression increased dramatically in both On sustained alpha and Off transient alpha RGCs, and this increase was prevented by genomic editing of the GluA2 subunit. On sustained alpha RGCs with elevated CP-AMPAR levels displayed profound synaptic depression, which was reduced by selectively blocking CP-AMPARs, buffering Ca2+ with BAPTA, or with the CB1 antagonist AM251, suggesting that depression was mediated by a retrograde transmitter which might be triggered by the influx of Ca2+ through CP-AMPARs. Thus, glaucoma may alter the composition of AMPARs and depress excitatory synaptic input in select populations of RGCs.
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Affiliation(s)
| | - Scott Nawy
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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Tezel G. A broad perspective on the molecular regulation of retinal ganglion cell degeneration in glaucoma. PROGRESS IN BRAIN RESEARCH 2020; 256:49-77. [PMID: 32958215 DOI: 10.1016/bs.pbr.2020.05.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Glaucoma is a complex neurodegenerative disease involving RGC axons, somas, and synapses at dendrites and axon terminals. Recent research advancements in the field have revealed a bigger picture of glaucomatous neurodegeneration that encompasses multiple stressors, multiple injury sites, multiple cell types, and multiple signaling pathways for asynchronous degeneration of RGCs during a chronic disease period. Optic nerve head is commonly viewed as the critical site of injury in glaucoma, where early injurious insults initiate distal and proximal signaling for axonal and somatic degeneration. Despite compartmentalized processes for degeneration of RGC axons and somas, there are intricate interactions between the two compartments and mechanistic overlaps between the molecular pathways that mediate degeneration in axonal and somatic compartments. This review summarizes the recent progress in the molecular understanding of RGC degeneration in glaucoma and highlights various etiological paths with biomechanical, metabolic, oxidative, and inflammatory components. Through this growing body of knowledge, the glaucoma community moves closer toward causative treatment of this blinding disease.
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Affiliation(s)
- Gülgün Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, New York, NY, United States.
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Li Q, Jin R, Zhang S, Sun X, Wu J. Group II metabotropic glutamate receptor agonist promotes retinal ganglion cell survival by reducing neuronal excitotoxicity in a rat chronic ocular hypertension model. Neuropharmacology 2020; 170:108016. [PMID: 32101763 DOI: 10.1016/j.neuropharm.2020.108016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/24/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Glaucoma, the second leading cause of irreversible blindness worldwide, is characterized by the selective death of retinal ganglion cells (RGCs). The group II metabotropic glutamate receptor (mGluR II) activation has been linked to RGC survival, however, the mechanism by which it promotes neuronal survival remains poorly defined. In the present work, we show that extracellular application of LY341495, an mGluR II antagonist could increase the RGC firing frequency, suggesting that activation of mGluR II by endogenously released glutamate could modulate RGC excitability. LY354740, an mGluR II agonist, significantly decreased RGC excitability and the reduced presynaptic excitatory inputs and post-synaptic Ca2+-permeable currents mediated the LY354740-induced effects. By using a well-characterized in vivo male Sprague-Dawley rat glaucoma model, we further demonstrate that in the early stage of experimental glaucoma, the expression of mGluR II dimer-formed protein was significantly reduced, and pre-activation of mGluR II by intravitreal injection of LY354740 before establishment of the glaucoma model could effectively reduce excitatory inputs, thereby reversing hyperexcitability induced by elevated intraocular pressure. Furthermore, LY354740 could increase the expression level of brain-derived neurotrophic factor in the glaucomatous retinas, further protecting RGCs. Our study indicates that the abnormal expression of mGluR II may accelerate RGC apoptosis in glaucoma, and demonstrates that mGluR II agonist LY354740 can be used as a novel method to counter RGC apoptosis in glaucoma.
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Affiliation(s)
- Qian Li
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Ruiri Jin
- Department of Gastroenterology, Songjiang Central Hospital, Shanghai, 201600, China
| | - Shenghai Zhang
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
| | - Xinghuai Sun
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
| | - Jihong Wu
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200031, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200031, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
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60
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VanderWall KB, Huang KC, Pan Y, Lavekar SS, Fligor CM, Allsop AR, Lentsch KA, Dang P, Zhang C, Tseng HC, Cummins TR, Meyer JS. Retinal Ganglion Cells With a Glaucoma OPTN(E50K) Mutation Exhibit Neurodegenerative Phenotypes when Derived from Three-Dimensional Retinal Organoids. Stem Cell Reports 2020; 15:52-66. [PMID: 32531194 PMCID: PMC7363877 DOI: 10.1016/j.stemcr.2020.05.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/18/2022] Open
Abstract
Retinal ganglion cells (RGCs) serve as the connection between the eye and the brain, with this connection disrupted in glaucoma. Numerous cellular mechanisms have been associated with glaucomatous neurodegeneration, and useful cellular models of glaucoma allow for the precise analysis of degenerative phenotypes. Human pluripotent stem cells (hPSCs) serve as powerful tools for studying human disease, particularly cellular mechanisms underlying neurodegeneration. Thus, efforts focused upon hPSCs with an E50K mutation in the Optineurin (OPTN) gene, a leading cause of inherited forms of glaucoma. CRISPR/Cas9 gene editing introduced the OPTN(E50K) mutation into existing lines of hPSCs, as well as generating isogenic controls from patient-derived lines. RGCs differentiated from OPTN(E50K) hPSCs exhibited numerous neurodegenerative deficits, including neurite retraction, autophagy dysfunction, apoptosis, and increased excitability. These results demonstrate the utility of OPTN(E50K) RGCs as an in vitro model of neurodegeneration, with the opportunity to develop novel therapeutic approaches for glaucoma.
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Affiliation(s)
- Kirstin B VanderWall
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Kang-Chieh Huang
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Yanling Pan
- Indiana BioMedical Gateway Program, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Sailee S Lavekar
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Clarisse M Fligor
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Anna R Allsop
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Kelly A Lentsch
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Pengtao Dang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Henry C Tseng
- Duke Eye Center and Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
| | - Theodore R Cummins
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jason S Meyer
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Ophthalmology, Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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61
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Mead B, Chamling X, Zack DJ, Ahmed Z, Tomarev S. TNFα-Mediated Priming of Mesenchymal Stem Cells Enhances Their Neuroprotective Effect on Retinal Ganglion Cells. Invest Ophthalmol Vis Sci 2020; 61:6. [PMID: 32031578 PMCID: PMC7324256 DOI: 10.1167/iovs.61.2.6] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose To determine whether priming of bone marrow mesenchymal stem cells (MSCs) by signals from injured retina, particularly tumor necrosis factor α (TNFα), increase their exosomes’ neuroprotective efficacy on retinal ganglion cells (RGCs). Methods MSCs were primed with retinal cell culture conditioned medium, with or without the TNFα blocker etanercept or TNFα prior to isolation of exosomes. MSC conditioned medium or exosomes were added to rat retinal cultures or human stem cell–derived retinal ganglion cell (hRGC) cultures, and RGC neuroprotective effects were quantified. Luminex assays were used to compare primed versus unprimed exosomes. Results MSC conditioned medium and exosomes exerted a significant neuroprotective effect on injured rat and hRGC. This effect was significantly increased after MSCs were primed with retinal conditioned medium or TNFα. Blocking of TNFα signaling with etanercept prevented priming-induced RGC neuroprotective efficacy. Priming increased Pigment epithelium-derived factor (PEDF) and VEGF-AA exosomal abundance. Conclusions MSC exosomes promote RGC survival not just in rodent retinal cultures but also with hRGC. Their efficacy can be further enhanced through TNFα priming with the mechanism of action potentially mediated, at least in part, through increased levels of PEDF and VEGF-AA.
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Shinozaki Y, Koizumi S. [Pathogenic roles of retinal glia in glaucoma]. Nihon Yakurigaku Zasshi 2020; 155:87-92. [PMID: 32115484 DOI: 10.1254/fpj.19120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Glaucoma, progressive optic neuropathy, is the first cause of blindness in Japan. Blindness in this disease is induced by damages or degeneration of retinal ganglion cells (RGCs), retinal neurons transmit visual information to brain. An elevated intraocular pressure (IOP) is widely recognized as one of the most important risk factors and that IOP directly damages RGCs by mechanical stress, however, accumulating evidences have shown that a majority of Japanese patients for primary open angle glaucoma shows normal level of IOP. Thus, new target for glaucoma pathology is emerged. In this issue, we introduce potential roles of glial cells for pathogenesis of glaucoma. In the CNS, reactive gliosis has been recognized in a variety of neurodegenerative diseases. Such glial activation is also found in retinae of human glaucoma patients and animal models. Importantly, glial activation precedes RGS degeneration, indicating the possibility that reactive glial cells actively contribute to pathogenesis of glaucoma. In this issue, we will focus on macroglial cells such as Muller cells and astrocytes, and discuss their roles in glaucoma.
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Affiliation(s)
- Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi
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Time course of bilateral microglial activation in a mouse model of laser-induced glaucoma. Sci Rep 2020; 10:4890. [PMID: 32184450 PMCID: PMC7078298 DOI: 10.1038/s41598-020-61848-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/03/2020] [Indexed: 12/31/2022] Open
Abstract
Microglial activation is associated with glaucoma. In the model of unilateral laser-induced ocular hypertension (OHT), the time point at which the inflammatory process peaks remains unknown. Different time points (1, 3, 5, 8, and 15 d) were compared to analyze signs of microglial activation both in OHT and contralateral eyes. In both eyes, microglial activation was detected in all retinal layers at all time points analyzed, including: i) increase in the cell number in the outer segment photoreceptor layer and plexiform layers (only in OHT eyes) from 3 d onward; ii) increase in soma size from 1 d onward; iii) retraction of the processes from 1 d in OHT eyes and 3 d in contralateral eyes; iv) increase in the area of the retina occupied by Iba-1+ cells in the nerve fiber layer/ganglion cell layer from 1 d onward; v) increase in the number of vertical processes from 1 d in contralateral eyes and 3 d in OHT eyes. In OHT eyes at 24 h and 15 d, most Iba-1+ cells were P2RY12+ and were down-regulated at 3 and 5 d. In both eyes, microglial activation was stronger at 3 and 5 d (inflammation peaked in this model). These time points could be useful to identify factors implicated in the inflammatory process.
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Nahomi RB, Nam MH, Rankenberg J, Rakete S, Houck JA, Johnson GC, Stankowska DL, Pantcheva MB, MacLean PS, Nagaraj RH. Kynurenic Acid Protects Against Ischemia/Reperfusion-Induced Retinal Ganglion Cell Death in Mice. Int J Mol Sci 2020; 21:ijms21051795. [PMID: 32151061 PMCID: PMC7084183 DOI: 10.3390/ijms21051795] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/21/2020] [Accepted: 03/02/2020] [Indexed: 12/17/2022] Open
Abstract
Background: Glaucoma is an optic neuropathy and involves the progressive degeneration of retinal ganglion cells (RGCs), which leads to blindness in patients. We investigated the role of the neuroprotective kynurenic acid (KYNA) in RGC death against retinal ischemia/reperfusion (I/R) injury. Methods: We injected KYNA intravenously or intravitreally to mice. We generated a knockout mouse strain of kynurenine 3-monooxygenase (KMO), an enzyme in the kynurenine pathway that produces neurotoxic 3-hydroxykynurenine. To test the effect of mild hyperglycemia on RGC protection, we used streptozotocin (STZ) induced diabetic mice. Retinal I/R injury was induced by increasing intraocular pressure for 60 min followed by reperfusion and RGC numbers were counted in the retinal flat mounts. Results: Intravenous or intravitreal administration of KYNA protected RGCs against I/R injury. The I/R injury caused a greater loss of RGCs in wild type than in KMO knockout mice. KMO knockout mice had mildly higher levels of fasting blood glucose than wild type mice. Diabetic mice showed significantly lower loss of RGCs when compared with non-diabetic mice subjected to I/R injury. Conclusion: Together, our study suggests that the absence of KMO protects RGCs against I/R injury, through mechanisms that likely involve higher levels of KYNA and glucose.
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Affiliation(s)
- Rooban B. Nahomi
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
- Correspondence: (R.B.N.); (R.H.N.); Tel.: +1-303-724-8824 (R.H.N.)
| | - Mi-Hyun Nam
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Johanna Rankenberg
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Stefan Rakete
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Julie A. Houck
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Ginger C. Johnson
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Dorota L. Stankowska
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107, USA;
| | - Mina B. Pantcheva
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Paul S. MacLean
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Ram H. Nagaraj
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO 80045, USA
- Correspondence: (R.B.N.); (R.H.N.); Tel.: +1-303-724-8824 (R.H.N.)
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Katsumi S, Sahin MI, Lewis RM, Iyer JS, Landegger LD, Stankovic KM. Intracochlear Perfusion of Tumor Necrosis Factor-Alpha Induces Sensorineural Hearing Loss and Synaptic Degeneration in Guinea Pigs. Front Neurol 2020; 10:1353. [PMID: 32116980 PMCID: PMC7025643 DOI: 10.3389/fneur.2019.01353] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/09/2019] [Indexed: 12/15/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine that plays a prominent role in the nervous system, mediating a range of physiologic and pathologic functions. In the auditory system, elevated levels of TNF-α have been implicated in several types of sensorineural hearing loss, including sensorineural hearing loss induced by vestibular schwannoma, a potentially fatal intracranial tumor that originates from the eighth cranial nerve; however, the mechanisms underlying the tumor's deleterious effects on hearing are not well-understood. Here, we investigated the effect of acute elevations of TNF-α in the inner ear on cochlear function and morphology by perfusing the cochlea with TNF-α in vivo in guinea pigs. TNF-α perfusion did not significantly change thresholds for compound action potential (CAP) responses, which reflect cochlear nerve activity, or distortion product otoacoustic emissions, which reflect outer hair cell integrity. However, intracochlear TNF-α perfusion reduced CAP amplitudes and increased the number of inner hair cell synapses without paired post-synaptic terminals, suggesting a pattern of synaptic degeneration that resembles that observed in primary cochlear neuropathy. Additionally, etanercept, a TNF-α blocker, protected against TNF-α-induced synaptopathy when administered systemically prior to intracochlear TNF-α perfusion. Findings motivate further investigation into the harmful effects of chronically elevated intracochlear levels of TNF-α, and the potential for etanercept to counter these effects.
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Affiliation(s)
- Sachiyo Katsumi
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Mehmet I Sahin
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Rebecca M Lewis
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Janani S Iyer
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, United States
| | - Lukas D Landegger
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, United States.,Harvard Program in Therapeutic Science, Harvard Medical School, Boston, MA, United States
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66
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Wang AY, Lee PY, Bui BV, Jobling AI, Greferath U, Brandli A, Dixon MA, Findlay Q, Fletcher EL, Vessey KA. Potential mechanisms of retinal ganglion cell type-specific vulnerability in glaucoma. Clin Exp Optom 2019; 103:562-571. [PMID: 31838755 DOI: 10.1111/cxo.13031] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/17/2019] [Accepted: 11/16/2019] [Indexed: 12/22/2022] Open
Abstract
Glaucoma is a neurodegenerative disease characterised by progressive damage to the retinal ganglion cells (RGCs), the output neurons of the retina. RGCs are a heterogenous class of retinal neurons which can be classified into multiple types based on morphological, functional and genetic characteristics. This review examines the body of evidence supporting type-specific vulnerability of RGCs in glaucoma and explores potential mechanisms by which this might come about. Studies of donor tissue from glaucoma patients have generally noted greater vulnerability of larger RGC types. Models of glaucoma induced in primates, cats and mice also show selective effects on RGC types - particularly OFF RGCs. Several mechanisms may contribute to type-specific vulnerability, including differences in the expression of calcium-permeable receptors (for example pannexin-1, P2X7, AMPA and transient receptor potential vanilloid receptors), the relative proximity of RGCs and their dendrites to blood supply in the inner plexiform layer, as well as differing metabolic requirements of RGC types. Such differences may make certain RGCs more sensitive to intraocular pressure elevation and its associated biomechanical and vascular stress. A greater understanding of selective RGC vulnerability and its underlying causes will likely reveal a rich area of investigation for potential treatment targets.
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Affiliation(s)
- Anna Ym Wang
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Pei Ying Lee
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Ursula Greferath
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Alice Brandli
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Michael A Dixon
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Quan Findlay
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Kirstan A Vessey
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
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Lucas-Ruiz F, Galindo-Romero C, Salinas-Navarro M, González-Riquelme MJ, Vidal-Sanz M, Agudo Barriuso M. Systemic and Intravitreal Antagonism of the TNFR1 Signaling Pathway Delays Axotomy-Induced Retinal Ganglion Cell Loss. Front Neurosci 2019; 13:1096. [PMID: 31680831 PMCID: PMC6803525 DOI: 10.3389/fnins.2019.01096] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/30/2019] [Indexed: 12/29/2022] Open
Abstract
Here, we have blocked the signaling pathway of tumor necrosis factor α (TNFα) in a mouse model of traumatic neuropathy using a small cell permeable molecule (R7050) that inhibits TNFα/TNF receptor 1 (TNFR1) complex internalization. Adult pigmented mice were subjected to intraorbital optic nerve crush (ONC). Animals received daily intraperitoneal injections of R7050, and/or a single intravitreal administration the day of the surgery. Some animals received a combinatorial treatment with R7050 (systemic or local) and a single intravitreal injection of brain derived neurotrophic factor (BDNF). As controls, untreated animals were used. Retinas were analyzed for RGC survival 5 and 14 days after the lesion i.e., during the quick and slow phase of axotomy-induced RGC death. qPCR analyses were done to verify that Tnfr1 and TNFα were up-regulated after ONC. At 5 days post-lesion, R7050 intravitreal or systemic treatment neuroprotected RGCs as much as BDNF alone. At 14 days, RGC rescue by systemic or intravitreal administration of R7050 was similar. At this time point, intravitreal treatment with BDNF was significantly better than intravitreal R7050. Combinatory treatment was not better than BDNF alone, although at both time points, the mean number of surviving RGCs was higher. In conclusion, antagonism of the extrinsic pathway of apoptosis rescues axotomized RGCs as it does the activation of survival pathways by BDNF. However, manipulation of both pathways at the same time, does not improve RGC survival.
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Affiliation(s)
- Fernando Lucas-Ruiz
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Caridad Galindo-Romero
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Manuel Salinas-Navarro
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - María Josefa González-Riquelme
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Manuel Vidal-Sanz
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Marta Agudo Barriuso
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain.,Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
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Bariş M, Tezel G. Immunomodulation as a Neuroprotective Strategy for Glaucoma Treatment. CURRENT OPHTHALMOLOGY REPORTS 2019; 7:160-169. [PMID: 31360618 PMCID: PMC6662642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE OF REVIEW This review aims to highlight the current knowledge about inflammatory mechanisms of neurodegeneration in glaucoma with emphasis on potential immunomodulation strategies. RECENT FINDINGS Glaucomatous retina and optic nerve present multiple evidences of inflammatory responses of astroglia, microglia, and blood-born immune cells. Although adaptive/protective responses of resident or systemic immune cells can support neurons and promote tissue repair mechanisms after injurious insults, prolonged inflammatory processes can also produce neurotoxic mediators. Treatments targeting these neurodestructive outcomes may restore immune homeostasis and protect neurons from inflammatory injury. Due to widespread and chronic nature of neuroinflammation in glaucoma, immunomodulation offers a treatment strategy to protect different neuronal compartments of RGCs during the chronic and asynchronous course of neurodegeneration. Uncovering of distinct molecular responses and interactions of different immune cells that determine the neuroinflammatory phenotype and participate in neurodegenerative outcomes will be critical to develop effective strategies for immunomodulation in glaucoma. SUMMARY Neuroinflammation has increasingly been recognized to play an important role in glaucomatous neurodegeneration, and its modulation appears to be a promising treatment strategy for neuroprotection.
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Affiliation(s)
- Mine Bariş
- Columbia University, College of Physicians and Surgeons, Department of Ophthalmology, New York, NY
| | - Gülgün Tezel
- Columbia University, College of Physicians and Surgeons, Department of Ophthalmology, New York, NY
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70
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Williams PA, Braine CE, Kizhatil K, Foxworth NE, Tolman NG, Harder JM, Scott RA, Sousa GL, Panitch A, Howell GR, John SWM. Inhibition of monocyte-like cell extravasation protects from neurodegeneration in DBA/2J glaucoma. Mol Neurodegener 2019; 14:6. [PMID: 30670050 PMCID: PMC6341618 DOI: 10.1186/s13024-018-0303-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 12/05/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Glaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells. Recent work in animal models suggests that a critical neuroinflammatory event damages retinal ganglion cell axons in the optic nerve head during ocular hypertensive injury. We previously demonstrated that monocyte-like cells enter the optic nerve head in an ocular hypertensive mouse model of glaucoma (DBA/2 J), but their roles, if any, in mediating axon damage remain unclear. METHODS To understand the function of these infiltrating monocyte-like cells, we used RNA-sequencing to profile their transcriptomes. Based on their pro-inflammatory molecular signatures, we hypothesized and confirmed that monocyte-platelet interactions occur in glaucomatous tissue. Furthermore, to test monocyte function we used two approaches to inhibit their entry into the optic nerve head: (1) treatment with DS-SILY, a peptidoglycan that acts as a barrier to platelet adhesion to the vessel wall and to monocytes, and (2) genetic targeting of Itgam (CD11b, an immune cell receptor that enables immune cell extravasation). RESULTS Monocyte specific RNA-sequencing identified novel neuroinflammatory pathways early in glaucoma pathogenesis. Targeting these processes pharmacologically (DS-SILY) or genetically (Itgam / CD11b knockout) reduced monocyte entry and provided neuroprotection in DBA/2 J eyes. CONCLUSIONS These data demonstrate a key role of monocyte-like cell extravasation in glaucoma and demonstrate that modulating neuroinflammatory processes can significantly lessen optic nerve injury.
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Affiliation(s)
- Pete A Williams
- The Jackson Laboratory, Bar Harbor, ME, USA.,Department of Clinical Neuroscience, Section of Ophthalmology and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | | | | - Rebecca A Scott
- Department of Materials Science and Engineering, University of Delaware, Newark, DE, USA
| | | | - Alyssa Panitch
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, USA. .,Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA.
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME, USA. .,Department of Ophthalmology, Tufts University of Medicine, Boston, MA, USA. .,The Howard Hughes Medical Institute, Bar Harbor, ME, USA.
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Pietrucha-Dutczak M, Amadio M, Govoni S, Lewin-Kowalik J, Smedowski A. The Role of Endogenous Neuroprotective Mechanisms in the Prevention of Retinal Ganglion Cells Degeneration. Front Neurosci 2018; 12:834. [PMID: 30524222 PMCID: PMC6262299 DOI: 10.3389/fnins.2018.00834] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Retinal neurons are not able to undergo spontaneous regeneration in response to damage. A variety of stressors, i.e., UV radiation, high temperature, ischemia, allergens, and others, induce reactive oxygen species production, resulting in consecutive alteration of stress-response gene expression and finally can lead to cell apoptosis. Neurons have developed their own endogenous cellular protective systems. Some of them are preventing cell death and others are allowing functional recovery after injury. The high efficiency of these mechanisms is crucial for cell survival. In this review we focus on the contribution of the most recently studied endogenous neuroprotective factors involved in retinal ganglion cell (RGC) survival, among which, neurotrophic factors and their signaling pathways, processes regulating the redox status, and different pathways regulating cell death are the most important. Additionally, we summarize currently ongoing clinical trials for therapies for RGC degeneration and optic neuropathies, including glaucoma. Knowledge of the endogenous cellular protective mechanisms may help in the development of effective therapies and potential novel therapeutic targets in order to achieve progress in the treatment of retinal and optic nerve diseases.
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Affiliation(s)
- Marita Pietrucha-Dutczak
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Marialaura Amadio
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Joanna Lewin-Kowalik
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Adrian Smedowski
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
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Harun-Or-Rashid M, Inman DM. Reduced AMPK activation and increased HCAR activation drive anti-inflammatory response and neuroprotection in glaucoma. J Neuroinflammation 2018; 15:313. [PMID: 30424795 PMCID: PMC6234605 DOI: 10.1186/s12974-018-1346-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/25/2018] [Indexed: 02/07/2023] Open
Abstract
Background Glaucoma is a chronic degenerative disease for which inflammation is considered to play a pivotal role in the pathogenesis and progression. In this study, we examined the impact of a ketogenic diet on the inflammation evident in glaucoma as a follow-up to a recent set of experiments in which we determined that a ketogenic diet protected retinal ganglion cell structure and function. Methods Both sexes of DBA/2J (D2) mice were placed on a ketogenic diet (keto) or standard rodent chow (untreated) for 8 weeks beginning at 9 months of age. DBA/2J-Gpnmb+ (D2G) mice were also used as a non-pathological genetic control for the D2 mice. Retina and optic nerve (ON) tissues were micro-dissected and used for the analysis of microglia activation, expression of pro- and anti-inflammatory molecules, and lactate- or ketone-mediated anti-inflammatory signaling. Data were analyzed by immunohistochemistry, quantitative RT-PCR, ELISA, western blot, and capillary tube-based electrophoresis techniques. Results Microglia activation was observed in D2 retina and ON as documented by intense microglial-specific Iba1 immunolabeling of rounded-up and enlarged microglia. Ketogenic diet treatment reduced Iba1 expression and the activated microglial phenotype. We detected low energy-induced AMP-activated protein kinase (AMPK) phosphorylation in D2 retina and ON that triggered NF-κB p65 signaling through its nuclear translocation. NF-κB induced pro-inflammatory TNF-α, IL-6, and NOS2 expression in D2 retina and ON. However, treatment with the ketogenic diet reduced AMPK phosphorylation, NF-κB p65 nuclear translocation, and expression of pro-inflammatory molecules. The ketogenic diet also induced expression of anti-inflammatory agents Il-4 and Arginase-1 in D2 retina and ON. Increased expression of hydroxycarboxylic acid receptor 1 (HCAR1) after ketogenic diet treatment was observed. HCAR1 stimulation by lactate or ketones from the ketogenic diet reduced inflammasome formation, as shown by reduced mRNA and protein expression of NLRP3 and IL-1β. We also detected increased levels of Arrestin β-2 protein, an adapter protein required for HCAR1 signaling. Conclusion Our data demonstrate that the AMPK activation apparent in the glaucomatous retina and ON triggers NF-κB signaling and consequently induces a pro-inflammatory response. The ketogenic diet resolves energy demand and ameliorates the inflammation by inhibition of AMPK activation and stimulation of HCAR1-ARRB2 signaling that inhibits NLRP3 inflammasome-mediated inflammation. Thus, these findings depict a neuroprotective mechanism of the ketogenic diet in controlling inflammation and suggest potential therapeutic targets for inflammatory neurodegenerative diseases, including glaucoma.
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Affiliation(s)
- Mohammad Harun-Or-Rashid
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH, 44272, USA
| | - Denise M Inman
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, OH, 44272, USA.
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EphrinB/EphB forward signaling in Müller cells causes apoptosis of retinal ganglion cells by increasing tumor necrosis factor alpha production in rat experimental glaucomatous model. Acta Neuropathol Commun 2018; 6:111. [PMID: 30355282 PMCID: PMC6201539 DOI: 10.1186/s40478-018-0618-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/12/2018] [Indexed: 01/26/2023] Open
Abstract
It was previously shown that EphB/ephrinB reverse signaling in retinal ganglion cells (RGCs) is activated and involved in RGC apoptosis in a rat chronic ocular hypertension (COH) model. In the present work, we first show that ephrinB/EphB forward signaling was activated in COH retinas, and RGC apoptosis in COH retinas was reduced by PP2, an inhibitor of ephrinB/EphB forward signaling. We further demonstrate that treatment of cultured Müller cells with ephrinB1-Fc, an EphB1 activator, or intravitreal injection of ephrinB1-Fc in normal rats induced an increase in phosphorylated EphB levels in these cells, indicating the activation of ephrinB/EphB forward signaling, similar to those in COH retinas. The ephrinB1-Fc treatment did not induce Müller cell gliosis, as evidenced by unchanged GFAP expression, but significantly up-regulated mRNA and protein levels of tumor necrosis factor-α (TNF-α) in Müller cells, thereby promoting RGC apoptosis. Production of TNF-α induced by the activation of ephrinB/EphB forward signaling was mediated by the NR2B subunit of NMDA receptors, which was followed by a distinct PI3K/Akt/NF-κB signaling pathway, as pharmacological interference of each step of this pathway caused a reduction of TNF-α production, thus attenuating RGC apoptosis. Functional analysis of forward and reverse signaling in such a unique system, in which ephrin and Eph exist respectively in a glial element and a neuronal element, is of theoretical importance. Moreover, our results also raise a possibility that suppression of ephrinB/EphB forward signaling may be a new strategy for ameliorating RGC apoptosis in glaucoma.
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74
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Twomey EC, Yelshanskaya MV, Vassilevski AA, Sobolevsky AI. Mechanisms of Channel Block in Calcium-Permeable AMPA Receptors. Neuron 2018; 99:956-968.e4. [PMID: 30122377 PMCID: PMC6181147 DOI: 10.1016/j.neuron.2018.07.027] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/20/2018] [Accepted: 07/17/2018] [Indexed: 01/14/2023]
Abstract
AMPA receptors mediate fast excitatory neurotransmission and are critical for CNS development and function. Calcium-permeable subsets of AMPA receptors are strongly implicated in acute and chronic neurological disorders. However, despite the clinical importance, the therapeutic landscape for specifically targeting them, and not the calcium-impermeable AMPA receptors, remains largely undeveloped. To address this problem, we used cryo-electron microscopy and electrophysiology to investigate the mechanisms by which small-molecule blockers selectively inhibit ion channel conductance in calcium-permeable AMPA receptors. We determined the structures of calcium-permeable GluA2 AMPA receptor complexes with the auxiliary subunit stargazin bound to channel blockers, including the orb weaver spider toxin AgTx-636, the spider toxin analog NASPM, and the adamantane derivative IEM-1460. Our structures provide insights into the architecture of the blocker binding site and the mechanism of trapping, which are critical for development of small molecules that specifically target calcium-permeable AMPA receptors.
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Affiliation(s)
- Edward C Twomey
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University, New York, NY 10032, USA
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Alexander A Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Oblast 141700, Russia
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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75
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Wen X, Cahill AL, Barta C, Thoreson WB, Nawy S. Elevated Pressure Increases Ca 2+ Influx Through AMPA Receptors in Select Populations of Retinal Ganglion Cells. Front Cell Neurosci 2018; 12:162. [PMID: 29950974 PMCID: PMC6008319 DOI: 10.3389/fncel.2018.00162] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/25/2018] [Indexed: 12/14/2022] Open
Abstract
The predominate type of AMPA receptor expressed in the CNS is impermeable to Ca2+ (CI-AMPAR). However, some AMPA receptors are permeable to Ca2+ (CP-AMPAR) and play important roles in development, plasticity and disease. In the retina, ganglion cells (RGCs) are targets of disease including glaucoma and diabetic retinopathy, but there are many types of RGCs and not all types are targeted equally. In the present study, we sought to determine if there are differences in expression of AMPARs amongst RGC subtypes, and if these differences might contribute to differential vulnerability in a model of stress. Using cultured RGCs we first show that acute exposure to elevated pressure increased expression of Ca2+-permeable AMPA receptors (CP-AMPARs) in some, but not all classes of RGCs. When RGCs were sampled without regard to subtype, AMPA currents, measured using patch clamp recording, were blocked by the CP-AMPAR blocker PhTX-74 to a greater extent in pressure-treated RGCs vs. control. Furthermore, imaging experiments revealed an increase in Ca2+ influx during AMPA application in pressure-treated RGCs. However, examination of specific RGC subtypes using reporter lines revealed striking differences in both baseline AMPAR composition and modulation of this baseline composition by stress. Notably, ON alpha RGCs identified using the Opn4 mouse line and immunohistochemistry, had low expression of CP-AMPARs. Conversely, an ON-OFF direction selective RGC and putative OFF alpha RGC each expressed high levels of CP-AMPARs. These differences between RGC subtypes were also observed in RGCs from whole retina. Elevated pressure further lowered expression of CP-AMPARs in ON alpha RGCs, but raised expression in ON-OFF and OFF RGCs. Changes in CP-AMPAR expression following challenge with elevated pressure were correlated with RGC survival: ON alpha RGCs were unaffected by application of pressure, while the number of putative OFF alpha RGCs declined by approximately 50% following challenge with pressure. Differences in expression of CP-AMPARs between RGC subtypes may form the underpinnings for subtype-specific synaptic plasticity. Furthermore, the differential responses of these RGC subtypes to elevated pressure may contribute to the reported resistance of ON alpha, and susceptibility of OFF and ON-OFF RGCs to injury in models of glaucoma.
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Affiliation(s)
- Xiangyi Wen
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Asia L Cahill
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Cody Barta
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Scott Nawy
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
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76
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Rathnasamy G, Foulds WS, Ling EA, Kaur C. Retinal microglia - A key player in healthy and diseased retina. Prog Neurobiol 2018; 173:18-40. [PMID: 29864456 DOI: 10.1016/j.pneurobio.2018.05.006] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/09/2018] [Accepted: 05/29/2018] [Indexed: 01/04/2023]
Abstract
Microglia, the resident immune cells of the brain and retina, are constantly engaged in the surveillance of their surrounding neural tissue. During embryonic development they infiltrate the retinal tissues and participate in the phagocytosis of redundant neurons. The contribution of microglia in maintaining the purposeful and functional histo-architecture of the adult retina is indispensable. Within the retinal microenvironment, robust microglial activation is elicited by subtle changes caused by extrinsic and intrinsic factors. When there is a disturbance in the cell-cell communication between microglia and other retinal cells, for example in retinal injury, the activated microglia can manifest actions that can be detrimental. This is evidenced by activated microglia secreting inflammatory mediators that can further aggravate the retinal injury. Microglial activation as a harbinger of a variety of retinal diseases is well documented by many studies. In addition, a change in the microglial phenotype which may be associated with aging, may predispose the retina to age-related diseases. In light of the above, the focus of this review is to highlight the role played by microglia in the healthy and diseased retina, based on findings of our own work and from that of others.
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Affiliation(s)
- Gurugirijha Rathnasamy
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore; Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, United States
| | - Wallace S Foulds
- Singapore Eye Research Institute Level 6, The Academia, Discovery Tower, 20 College Road, 169856, Singapore; University of Glasgow, Glasgow, Scotland, G12 8QQ, United Kingdom
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore
| | - Charanjit Kaur
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore.
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77
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Li R, Jin Y, Li Q, Sun X, Zhu H, Cui H. MiR-93-5p targeting PTEN regulates the NMDA-induced autophagy of retinal ganglion cells via AKT/mTOR pathway in glaucoma. Biomed Pharmacother 2018; 100:1-7. [PMID: 29421576 DOI: 10.1016/j.biopha.2018.01.044] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/15/2017] [Accepted: 01/05/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Glaucoma is hallmarked with the death of retinal neurons in the ganglion cell layer, which results in irreversible vision loss. The abnormal levels of miRNA have been associated with glaucoma. Our study purposed to explore the underlying molecule mechanism of miR-93-5p in NMDA-induced glaucoma. METHODS The Sprague-Dawley (SD) rats were used for the establishment of glaucoma model with the injection of NMDA. Vision behavior test were performed on the glaucoma rats. MiR-93-5p expression was determined by real-time PCR. The levels of autophagy-related protein and PTEN were assessed by Western blot assays. TUNEL assay and flow cytometry were performed to analyze cell apoptosis in vivo and in vitro, respectively. And cell viability was examined by CKK-8 assay. The relationship between miR-93-5p and PTEN was confirmed by Dual-Luciferase reporter gene system. RESULTS NMDA-induced glaucoma rats exhibited less time in the dark box, suggesting the recession of their vision. Moreover, the retinal ganglion cell (RGC) viability was reduced not only in the glaucoma rat models but also in the glaucoma RGC models. The autophagy-related protein was obviously increased in the NMDA-treated rats or RGCs. PTEN regulated the autophagy of RGCs through AKT/mTOR pathway in NMDA-treated RGCs. MiR-93-5p could target regulate PTEN negatively, and exhibit the similar effect of 3-MA on the survival of RGCs. CONCLUSION Up-regulation of miR-93-5p binding with PTEN suppressed the autophagy of RGCs through AKT/mTOR pathway in NMDA-induced glaucoma.
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Affiliation(s)
- Rui Li
- Department of Ophthalmology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China
| | - Yiping Jin
- Department of Ophthalmology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China
| | - Qian Li
- Department of Ophthalmology, Shanghai East Hospital, Tongji University, Shanghai, 200120, China
| | - Xinghuai Sun
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Haohao Zhu
- Department of Ophthalmology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
| | - Hongping Cui
- Department of Ophthalmology, Shanghai East Hospital, Tongji University, Shanghai, 200120, China.
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78
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Involvement of mGluR I in EphB/ephrinB reverse signaling activation induced retinal ganglion cell apoptosis in a rat chronic hypertension model. Brain Res 2018; 1683:27-35. [PMID: 29366625 DOI: 10.1016/j.brainres.2018.01.017] [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: 11/01/2017] [Revised: 01/05/2018] [Accepted: 01/17/2018] [Indexed: 02/08/2023]
Abstract
EphB/ephrinB reverse signaling is involved in retinal ganglion cell (RGC) apoptosis in experimental glaucoma. Here, we further investigated the mechanisms underlying EphB/ephrinB reverse signaling activation induced RGC apoptosis in a rat chronic ocular hypertension (COH) model, using patch-clamp techniques in retinal slices. In COH retinas, RGCs showed higher spontaneous firing frequency and much more depolarized membrane potential as compared to control, which was mimicked by intravitreally injection of EphB2-Fc, an activator of ephrinB2. The changes in RGC spontaneous firing and membrane potential could be reversed by the tyrosine kinase inhibitor PP2, suggesting that EphB/ephrinB reverse signaling activation induced RGC hyperexcitability. Intravitreal pre-injection of either LY367385 or MPEP, selective mGluR1 and mGluR5 antagonists, also blocked the changes in RGC spontaneous firing and membrane potential. Co-immunoprecipitation experiments showed an interaction between ephrinB2 and group I metabotropic glutamate receptor (mGluR I) (mGluR1/mGluR5). Furthermore, intravitreal pre-injection of the mixture of L-NAME (an NO synthase inhibitor) and XPro1595 (a selective inhibitor of soluble TNF-α) could reduce the EphB2-Fc injection induced increase in RGC firing, suggesting that Müller cells might be involved in EphB/ephrinB reverse signaling activation induced change in RGC hyperexcitability. In addition, LY367385/MPEP reduced the numbers of TUNEL-positive RGCs both in EphB2-Fc injected and COH retinas. All results suggest that activation of EphB/ephrinB reverse signaling induces RGC hyperexcitability and apoptosis by interacting with mGluR I in COH rats. Appropriate reduction of EphB/ephrinB reverse signaling could alleviate the loss of RGCs in glaucoma.
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79
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Galán A, Jmaeff S, Barcelona PF, Brahimi F, Sarunic MV, Saragovi HU. In retinitis pigmentosa TrkC.T1-dependent vectorial Erk activity upregulates glial TNF-α, causing selective neuronal death. Cell Death Dis 2017; 8:3222. [PMID: 29242588 PMCID: PMC5870594 DOI: 10.1038/s41419-017-0074-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/26/2017] [Accepted: 08/04/2017] [Indexed: 12/13/2022]
Abstract
In some diseases the TrkC.T1 isoform is upregulated in glia, associated with glial TNF-α production and neuronal death. What remains unknown are the activating signals in glia, and how paracrine signals may be selective for a targeted neuron while sparing other proximate neurons. We studied these questions in the retina, where Müller glia contacts photoreceptors on one side and retinal ganglion cells on the other. In a mutant Rhodopsin mouse model of retinitis pigmentosa (RP) causing progressive photoreceptor death—but sparing retinal ganglion cells—TrkC.T1 and NT-3 ligand are upregulated in Müller glia. TrkC.T1 activity generates p-Erk, which causes increased TNF-α. These sequential events take place predominantly in Müller fibers contacting stressed photoreceptors, and culminate in selective death. Each event and photoreceptor death can be prevented by reduction of TrkC.T1 expression, by pharmacological antagonism of TrkC or by pharmacological inhibition Erk. Unmasking the sequence of non-cell autologous events and mechanisms causing selective neuronal death may help rationalize therapies.
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Affiliation(s)
- Alba Galán
- Lady Davis Institute-Jewish General Hospital, McGill University, Montréal, QC, H3T 1E2, Canada
| | - Sean Jmaeff
- Lady Davis Institute-Jewish General Hospital, McGill University, Montréal, QC, H3T 1E2, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada
| | - Pablo F Barcelona
- Lady Davis Institute-Jewish General Hospital, McGill University, Montréal, QC, H3T 1E2, Canada
| | - Fouad Brahimi
- Lady Davis Institute-Jewish General Hospital, McGill University, Montréal, QC, H3T 1E2, Canada
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - H Uri Saragovi
- Lady Davis Institute-Jewish General Hospital, McGill University, Montréal, QC, H3T 1E2, Canada. .,Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada. .,Department of Ophthalmology, McGill University, Montréal, QC, Canada.
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80
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Puyang Z, Gong HQ, He SG, Troy JB, Liu X, Liang PJ. Different functional susceptibilities of mouse retinal ganglion cell subtypes to optic nerve crush injury. Exp Eye Res 2017; 162:97-103. [PMID: 28629926 DOI: 10.1016/j.exer.2017.06.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/28/2016] [Accepted: 06/16/2017] [Indexed: 10/19/2022]
Abstract
In optic neuropathies, the progressive deterioration of retinal ganglion cell (RGC) function leads to irreversible vision loss. Increasing experimental evidence suggests differing susceptibility for RGC functional subtypes. Here with multi-electrode array recordings, RGC functional loss was characterized at multiple time points in a mouse model of optic nerve crush. Firing rate, latency of response and receptive field size were analyzed for ON, OFF and ON-OFF RGCs separately. It was observed that responses and receptive fields of OFF cells were impaired earlier than ON cells after the injury. For the ON-OFF cells, the OFF component of response was also more susceptible to optic nerve injury than the ON component. Moreover, more ON transient cells survived than ON sustained cells post the crush, implying a diversified vulnerability for ON cells. Together, these data support the contention that RGCs' functional degeneration in optic nerve injury is subtype dependent, a fact that needs to be considered when developing treatments of glaucomatous retinal ganglion cell degeneration and other optic neuropathies.
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Affiliation(s)
- Zhen Puyang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hai-Qing Gong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shi-Gang He
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - John B Troy
- Department of Biomedical Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, IL 60208, USA
| | - Xiaorong Liu
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL 60208, USA.
| | - Pei-Ji Liang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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81
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Su W, Li Z, Jia Y, Zhu Y, Cai W, Wan P, Zhang Y, Zheng SG, Zhuo Y. microRNA-21a-5p/PDCD4 axis regulates mesenchymal stem cell-induced neuroprotection in acute glaucoma. J Mol Cell Biol 2017; 9:289-301. [PMID: 28655163 DOI: 10.1093/jmcb/mjx022] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 06/21/2017] [Indexed: 12/29/2022] Open
Abstract
Mesenchymal stem cells (MSCs) have been demonstrated to have promising therapeutic benefits for a variety of neurological diseases; however, the underlying mechanisms are poorly understood. Here, we showed that intravitreal infusion of MSCs promoted retinal ganglion cell (RGC) survival in a mouse model of acute glaucoma, with significant inhibition of microglial activation, production of TNF-α, IL-1β, and reactive oxygen species, as well as caspase-8 and caspase-3 activation. In vitro, MSCs inhibited both caspase-8-mediated RGC apoptosis and microglial activation, partly via the action of stanniocalcin 1 (STC1). Furthermore, we found that microRNA-21a-5p (miR-21) and its target, PDCD4, were essential for STC1 production and the neuroprotective property of MSCs in vitro and in vivo. Importantly, miR-21 overexpression or PDCD4 knockdown augmented MSC-mediated neuroprotective effects on acute glaucoma. These data highlight a previously unrecognized neuroprotective mechanism by which the miR-21/PDCD4 axis induces MSCs to secrete STC1 and other factors that exert neuroprotective effects. Therefore, modulating the miR-21/PDCD4 axis might be a promising strategy for clinical treatment of acute glaucoma and other neurological diseases.
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Affiliation(s)
- Wenru Su
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zuohong Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Y Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Yingting Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wenjia Cai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Peixing Wan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Yingying Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Song Guo Zheng
- Department of Clinic Immunology, The Third Affiliated Hospital at Sun Yat-sen University, Guangzhou 510630, China
- Division of Rheumatology, Department of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA 17033, USA
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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82
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Tau Accumulation, Altered Phosphorylation, and Missorting Promote Neurodegeneration in Glaucoma. J Neurosci 2017; 36:5785-98. [PMID: 27225768 DOI: 10.1523/jneurosci.3986-15.2016] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/13/2016] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by the selective death of retinal ganglion cells (RGCs). Ocular hypertension is the most significant known risk factor for developing the disease, but the mechanism by which elevated pressure damages RGCs is currently unknown. The axonal-enriched microtubule-associated protein tau is a key mediator of neurotoxicity in Alzheimer's disease and other tauopathies. Using a well characterized in vivo rat glaucoma model, we show an age-related increase in endogenous retinal tau that was markedly exacerbated by ocular hypertension. Early alterations in tau phosphorylation, characterized by epitope-dependent hyperphosphorylation and hypophosphorylation, correlated with the appearance of tau oligomers in glaucomatous retinas. Our data demonstrate the mislocalization of tau in the somatodendritic compartment of RGCs subjected to high intraocular pressure. In contrast, tau was depleted from RGC axons in the optic nerve of glaucomatous eyes. Importantly, intraocular administration of short interfering RNA against tau effectively reduced retinal tau accumulation and promoted robust survival of RGC somas and axons, supporting a critical role for tau alterations in ocular hypertension-induced neuronal damage. Our study reveals that glaucoma displays signature pathological features of tauopathies, including tau accumulation, altered phosphorylation, and missorting; and identifies tau as a novel target to counter RGC neurodegeneration in glaucoma and prevalent optic neuropathies. SIGNIFICANCE STATEMENT In this study, we investigated the role of tau in retinal ganglion cell (RGC) damage in glaucoma. We demonstrate that high intraocular pressure leads to a rapid increase in endogenous retinal tau with altered phosphorylation profile and the formation of tau oligomers. Tau accumulation was primarily observed in RGC dendrites, while tau in RGC axons within the optic nerve was depleted. Attenuation of endogenous retinal tau using a targeted siRNA led to striking protection of RGC somas and axons from hypertension-induced damage. Our study identifies novel and substantial alterations of endogenous tau protein in glaucoma, including abnormal subcellular distribution, an altered phosphorylation profile, and neurotoxicity.
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83
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Hippocampal TNFα Signaling Contributes to Seizure Generation in an Infection-Induced Mouse Model of Limbic Epilepsy. eNeuro 2017; 4:eN-NWR-0105-17. [PMID: 28497109 PMCID: PMC5422919 DOI: 10.1523/eneuro.0105-17.2017] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 01/02/2023] Open
Abstract
Central nervous system infection can induce epilepsy that is often refractory to established antiseizure drugs. Previous studies in the Theiler's murine encephalomyelitis virus (TMEV)-induced mouse model of limbic epilepsy have demonstrated the importance of inflammation, especially that mediated by tumor necrosis factor-α (TNFα), in the development of acute seizures. TNFα modulates glutamate receptor trafficking via TNF receptor 1 (TNFR1) to cause increased excitatory synaptic transmission. Therefore, we hypothesized that an increase in TNFα signaling after TMEV infection might contribute to acute seizures. We found a significant increase in both mRNA and protein levels of TNFα and the protein expression ratio of TNF receptors (TNFR1:TNFR2) in the hippocampus, a brain region most likely involved in seizure initiation, after TMEV infection, which suggests that TNFα signaling, predominantly through TNFR1, may contribute to limbic hyperexcitability. An increase in hippocampal cell-surface glutamate receptor expression was also observed during acute seizures. Although pharmacological inhibition of TNFR1-mediated signaling had no effect on acute seizures, several lines of genetically modified animals deficient in either TNFα or TNFRs had robust changes in seizure incidence and severity after TMEV infection. TNFR2-/- mice were highly susceptible to developing acute seizures, suggesting that TNFR2-mediated signaling may provide beneficial effects during the acute seizure period. Taken together, the present results suggest that inflammation in the hippocampus, caused predominantly by TNFα signaling, contributes to hyperexcitability and acute seizures after TMEV infection. Pharmacotherapies designed to suppress TNFR1-mediated or augment TNFR2-mediated effects of TNFα may provide antiseizure and disease-modifying effects after central nervous system infection.
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84
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Williams PA, Braine CE, Foxworth NE, Cochran KE, John SWM. GlyCAM1 negatively regulates monocyte entry into the optic nerve head and contributes to radiation-based protection in glaucoma. J Neuroinflammation 2017; 14:93. [PMID: 28446179 PMCID: PMC5406973 DOI: 10.1186/s12974-017-0868-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/18/2017] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND We previously reported a profound long-term neuroprotection subsequent to a single radiation-therapy in the DBA/2J mouse model of glaucoma. This neuroprotection prevents entry of monocyte-like immune cells into the optic nerve head during glaucoma. Gene expression studies in radiation-treated mice implicated Glycam1 in this protection. Glycam1 encodes a proteoglycan ligand for L-selectin and is an excellent candidate to modulate immune cell entry into the eye. Here, we experimentally test the hypothesis that radiation-induced over-expression of Glycam1 is a key component of the neuroprotection. METHODS We generated a null allele of Glycam1 on a DBA/2J background. Gene and protein expression of Glycam1, monocyte entry into the optic nerve head, retinal ganglion cell death, and axon loss in the optic nerve were assessed. RESULTS Radiation therapy potently inhibits monocyte entry into the optic nerve head and prevents retinal ganglion cell death and axon loss. DBA/2J mice carrying a null allele of Glycam1 show increased monocyte entry and increased retinal ganglion cell death and axon loss following radiation therapy, but the majority of optic nerves were still protected by radiation therapy. CONCLUSIONS Although GlyCAM1 is an L-selectin ligand, its roles in immunity are not yet fully defined. The current study demonstrates a partial role for GlyCAM1 in radiation-mediated protection. Furthermore, our results clearly show that GlyCAM1 levels modulate immune cell entry from the vasculature into neural tissues. As Glycam1 deficiency has a more profound effect on cell entry than on neurodegeneration, further experiments are needed to precisely define the role of monocyte entry in DBA/2J glaucoma. Nevertheless, GlyCAM1's function as a negative regulator of extravasation may lead to novel therapeutic strategies for an array of common conditions involving inflammation.
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Affiliation(s)
| | | | | | | | - Simon W. M. John
- The Jackson Laboratory, Bar Harbor, ME USA
- Department of Ophthalmology, Tufts University of Medicine, Boston, MA USA
- The Howard Hughes Medical Institute, Bar Harbor, ME USA
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85
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Williams PA, Marsh-Armstrong N, Howell GR. Neuroinflammation in glaucoma: A new opportunity. Exp Eye Res 2017; 157:20-27. [PMID: 28242160 PMCID: PMC5497582 DOI: 10.1016/j.exer.2017.02.014] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 02/16/2017] [Accepted: 02/23/2017] [Indexed: 10/20/2022]
Abstract
Mounting evidence suggests neuroinflammation is a key process in glaucoma, yet the precise roles are not known. Understanding these complex processes, which may also be a key in other common neurodegenerations such as Alzheimer's disease, will lead to targeted therapeutics for a disease that affects as many as 80 million people worldwide. Here, we define neuroinflammation as any immune-relevant response by a variety of cell types including astrocytes, microglia, and peripherally derived cells occurring in the optic nerve head and/or retina. In this review article, we first discuss clinical evidence for neuroinflammation in glaucoma and define neuroinflammation in glaucoma. We then review the inflammatory pathways that have been associated with glaucoma. Finally, we set out key research directions that we believe will greatly advance our understanding of the role of neuroinflammation in glaucoma. This review arose from a discussion of neuroinflammation in glaucoma at the 2015 meeting of The Lasker/IRRF Initiative for Innovation in Vision Science. This manuscript sets out to summarize one of these sessions; "Inflammation and Glaucomatous Neurodegeneration", as well as to review the current state of the literature surrounding neuroinflammation in glaucoma.
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Affiliation(s)
| | - Nick Marsh-Armstrong
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, USA; Graduate Program of Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA.
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86
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Epigenetic intervention with a BET inhibitor ameliorates acute retinal ganglion cell death in mice. Mol Vis 2017; 23:149-159. [PMID: 28356707 PMCID: PMC5360452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/18/2017] [Indexed: 10/26/2022] Open
Abstract
PURPOSE The bromo and extraterminal (BET) epigenetic "reader" family is becoming an appealing new therapeutic target for several common diseases, yet little is known of its role in retinal neurodegeneration. We explored the potential of BET inhibition in the protection of retinal ganglion cells (RGCs). METHODS To test the therapeutic effect of JQ1, an inhibitor highly selective for the BET family of proteins, we used an acute RGC damage model induced by N-methyl-D-aspartic acid (NMDA) excitotoxicity. Adult C57BL/6 mice received an intravitreal injection of NMDA with (or without) JQ1 in one eye and vehicle control in the contralateral eye; RGC loss was assessed on retinal sections and whole mounts. Gene expression and apoptosis were analyzed by quantitative real time (RT)-PCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), respectively. For counting RGCs, immunostaining of the marker protein BRN3A was performed on whole mounts. RESULTS NMDA treatment eliminated RGCs (day 7 and day 14 post injection) and diminished the expression (mRNAs) of RGC-selective genes, including Thy1, Nrn1, Sncg, and Nfl (day 3 and day 7). In contrast, co-injection with JQ1 maintained the number and gene expression of RGCs at ~2 fold of the control (NMDA only, no JQ1), and it decreased NMDA-induced TUNEL-positive cells in the RGC layer by 35%. While NMDA treatment dramatically upregulated mRNAs of inflammatory cytokines (TNFα, IL-1β, MCP-1, RANTES) in retinal homogenates, co-injection with JQ1 suppressed their upregulation by ~50%. CONCLUSIONS Intravitreal injection of a BET inhibitor (JQ1) ameliorates NMDA-induced RGC death, revealing the RGC-protective potential of pharmacological blockage of the BET family. This new strategy of epigenetic intervention may be extended to other retinal degenerative conditions.
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87
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Lambert WS, Carlson BJ, Formichella CR, Sappington RM, Ahlem C, Calkins DJ. Oral Delivery of a Synthetic Sterol Reduces Axonopathy and Inflammation in a Rodent Model of Glaucoma. Front Neurosci 2017; 11:45. [PMID: 28223915 PMCID: PMC5293777 DOI: 10.3389/fnins.2017.00045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/20/2017] [Indexed: 12/12/2022] Open
Abstract
Glaucoma is a group of optic neuropathies associated with aging and sensitivity to intraocular pressure (IOP). The disease is the leading cause of irreversible blindness worldwide. Early progression in glaucoma involves dysfunction of retinal ganglion cell (RGC) axons, which comprise the optic nerve. Deficits in anterograde transport along RGC axons to central visual structures precede outright degeneration, and preventing these deficits is efficacious at abating subsequent progression. HE3286 is a synthetic sterol derivative that has shown therapeutic promise in models of inflammatory disease and neurodegenerative disease. We examined the efficacy of HE3286 oral delivery in preventing loss of anterograde transport in an inducible model of glaucoma (microbead occlusion). Adult rats received HE3286 (20 or 100 mg/kg) or vehicle daily via oral gavage for 4 weeks. Microbead occlusion elevated IOP ~30% in all treatment groups, and elevation was not affected by HE3286 treatment. In the vehicle group, elevated IOP reduced anterograde axonal transport to the superior colliculus, the most distal site in the optic projection, by 43% (p = 0.003); HE3286 (100 mg/kg) prevented this reduction (p = 0.025). HE3286 increased brain-derived neurotrophic factor (BDNF) in the optic nerve head and retina, while decreasing inflammatory and pathogenic proteins associated with elevated IOP compared to vehicle treatment. Treatment with HE3286 also increased nuclear localization of the transcription factor NFκB in collicular and retinal neurons, but decreased NFκB in glial nuclei in the optic nerve head. Thus, HE3286 may have a neuroprotective influence in glaucoma, as well as other chronic neurodegenerations.
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Affiliation(s)
- Wendi S Lambert
- Vanderbilt University Medical Center, The Vanderbilt Eye Institute Nashville, TN, USA
| | - Brian J Carlson
- Vanderbilt University Medical Center, The Vanderbilt Eye Institute Nashville, TN, USA
| | - Cathryn R Formichella
- Vanderbilt University Medical Center, The Vanderbilt Eye Institute Nashville, TN, USA
| | - Rebecca M Sappington
- Vanderbilt University Medical Center, The Vanderbilt Eye Institute Nashville, TN, USA
| | | | - David J Calkins
- Vanderbilt University Medical Center, The Vanderbilt Eye Institute Nashville, TN, USA
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88
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Maes ME, Schlamp CL, Nickells RW. BAX to basics: How the BCL2 gene family controls the death of retinal ganglion cells. Prog Retin Eye Res 2017; 57:1-25. [PMID: 28064040 DOI: 10.1016/j.preteyeres.2017.01.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 12/19/2022]
Abstract
Retinal ganglion cell (RGC) death is the principal consequence of injury to the optic nerve. For several decades, we have understood that the RGC death process was executed by apoptosis, suggesting that there may be ways to therapeutically intervene in this cell death program and provide a more direct treatment to the cells and tissues affected in diseases like glaucoma. A major part of this endeavor has been to elucidate the molecular biological pathways active in RGCs from the point of axonal injury to the point of irreversible cell death. A major component of this process is the complex interaction of members of the BCL2 gene family. Three distinct family members of proteins orchestrate the most critical junction in the apoptotic program of RGCs, culminating in the activation of pro-apoptotic BAX. Once active, BAX causes irreparable damage to mitochondria, while precipitating downstream events that finish off a dying ganglion cell. This review is divided into two major parts. First, we summarize the extent of knowledge of how BCL2 gene family proteins interact to facilitate the activation and function of BAX. This area of investigation has rapidly changed over the last few years and has yielded a dramatically different mechanistic understanding of how the intrinsic apoptotic program is run in mammalian cells. Second, we provided a comprehensive analysis of nearly two decades of investigation of the role of BAX in the process of RGC death, much of which has provided many important insights into the overall pathophysiology of diseases like glaucoma.
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Affiliation(s)
- Margaret E Maes
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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89
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Nakamura S, Nakanishi A, Takazawa M, Okihiro S, Urano S, Fukui K. Ionomycin-induced calcium influx induces neurite degeneration in mouse neuroblastoma cells: analysis of a time-lapse live cell imaging system. Free Radic Res 2016; 50:1214-1225. [PMID: 27573976 DOI: 10.1080/10715762.2016.1227074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reactive oxygen species induce neuronal cell death. However, the detailed mechanisms of cell death have not yet been elucidated. Previously, we reported neurite degeneration before the induction of cell death. Here, we attempted to elucidate the mechanisms of neurite degeneration before the induction of cell death using the neuroblastoma N1E-115 cell line and a time-lapse live cell imaging system. Treatment with the calcium ionophore ionomycin induced cell death and neurite degeneration in a concentration- and time-dependent manner. Treatment with a low concentration of ionomycin immediately produced a significant calcium influx into the intracellular region in N1E-115 cells. After 1-h incubation with ionomycin, the fluorescence emission of MitoSOXTM increased significantly compared to the control. Finally, analysis using a new mitochondrial specific fluorescence dye, MitoPeDPP, indicated that treatment with ionomycin significantly increased the mitochondrial lipid hydroperoxide production in N1E-115 cells. The fluorescence emissions of Fluo-4 AM and MitoPeDPP were detected in the cell soma and neurite regions in ionomycin-treated N1E-115 cells. However, the emissions of neurites were much lower than those of the cell soma. TBARS values of ionomycin-treated cells significantly increased compared to the control. These results indicate that ionomycin induces calcium influx into the intracellular region and reactive oxygen species production in N1E-115 cells. Lipid hydroperoxide production was induced in ionomycin-treated N1E-115 cells. Calcium influx into the intracellular region is a possible activator of neurite degeneration.
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Affiliation(s)
- Saki Nakamura
- a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan
| | - Ayumi Nakanishi
- b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan
| | - Minami Takazawa
- b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan
| | - Shunsuke Okihiro
- a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan
| | - Shiro Urano
- b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan
| | - Koji Fukui
- a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan.,b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan
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90
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Yin H, Yin H, Zhang W, Miao Q, Qin Z, Guo S, Fu Q, Ma J, Wu F, Yin J, Yang Y, Fang X. Transcorneal electrical stimulation promotes survival of retinal ganglion cells after optic nerve transection in rats accompanied by reduced microglial activation and TNF-α expression. Brain Res 2016; 1650:10-20. [PMID: 27569587 DOI: 10.1016/j.brainres.2016.08.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 08/20/2016] [Accepted: 08/24/2016] [Indexed: 11/26/2022]
Abstract
Microglial activation plays a crucial role in the pathological processes of various retinal and optic nerve diseases. TNF-α is a pro-inflammatory cytokine that is rapidly upregulated and promotes retinal ganglion cells (RGCs) death after optic nerve injury. However, the cellular source of TNF-α after optic nerve injury remains unclear. Thus, we aimed to determine the changes of retinal microglial activation in a rat model of optic nerve transection (ONT) after transcorneal electrical stimulation (TES). Furthermore, we assessed TNF-α expression after ONT and evaluated the effects of TES on TNF-α production. Rats were divided into 2 control groups receiving a sham surgery procedure, 2 ONT+Sham TES groups, and 2 ONT+TES groups. The rats were sacrificed on day 7 or 14 after ONT. RGCs were retrogradely labelled by Fluorogold (FG) 7 days before ONT, one TES group and corresponding controls were stimulated on day 0, 4, and the second were stimulated on day 0, 4, 7, 10. Whole-mount immunohistofluorescence, quantification of RGCs and microglia, and western blot analysis were performed on day 7 and 14 after ONT. TES significantly increased RGCs survival on day 7 and 14 after ONT, which was accompanied by reduced microglia on day 7, but not 14. TNF-α was co-localized with ameboid microglia and significantly increased on day 7 and 14 after ONT. TES significantly reduced TNF-α production on day 7 and 14 after ONT. Our study demonstrated that TES promotes RGCs survival after ONT accompanied by reduced microglial activation and microglia-derived TNF-α production.
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Affiliation(s)
- Houmin Yin
- Department of Neurology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Houfa Yin
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Wei Zhang
- Department of Orthopedics, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Qi Miao
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Zhenwei Qin
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Shenchao Guo
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Qiuli Fu
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Jian Ma
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Fang Wu
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Jinfu Yin
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Yabo Yang
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Xiaoyun Fang
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, Zhejiang Province, China.
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91
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Masuzzo A, Dinet V, Cavanagh C, Mascarelli F, Krantic S. Amyloidosis in Retinal Neurodegenerative Diseases. Front Neurol 2016; 7:127. [PMID: 27551275 PMCID: PMC4976396 DOI: 10.3389/fneur.2016.00127] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/27/2016] [Indexed: 01/18/2023] Open
Abstract
As a part of the central nervous system, the retina may reflect both physiological processes and abnormalities related to pathologies that affect the brain. Amyloidosis due to the accumulation of amyloid-beta (Aβ) was initially regarded as a specific and exclusive characteristic of neurodegenerative alterations seen in the brain of Alzheimer's disease (AD) patients. More recently, it was discovered that amyloidosis-related alterations, similar to those seen in the brain of Alzheimer's patients, also occur in the retina. Remarkably, these alterations were identified not only in primary retinal pathologies, such as age-related macular degeneration (AMD) and glaucoma, but also in the retinas of Alzheimer's patients. In this review, we first briefly discuss the biogenesis of Aβ, a peptide involved in amyloidosis. We then discuss some pathological aspects (synaptic dysfunction, mitochondrial failure, glial activation, and vascular abnormalities) related to the neurotoxic effects of Aβ. We finally highlight common features shared by AD, AMD, and glaucoma in the context of Aβ amyloidosis and further discuss why the retina, due to the transparency of the eye, can be considered as a "window" to the brain.
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Affiliation(s)
- Ambra Masuzzo
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Virginie Dinet
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Chelsea Cavanagh
- Department of Neuroscience, Douglas Hospital Research Center , Montreal, QC , Canada
| | - Frederic Mascarelli
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Slavica Krantic
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
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92
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Structural biology of glutamate receptor ion channel complexes. Curr Opin Struct Biol 2016; 41:119-127. [PMID: 27454049 DOI: 10.1016/j.sbi.2016.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/28/2016] [Accepted: 07/01/2016] [Indexed: 12/23/2022]
Abstract
Chemical transmission at excitatory synapses in the brain is mediated by a diverse family of glutamate receptor ion channels (iGluRs), tetrameric membrane protein assemblies of molecular weight 400-600kDa. Until recently, structural information for intact iGluRs was limited to biochemically tractable homomeric receptors trapped in different conformational states. These provided key insights into the mechanisms of iGluR activation and desensitization. Structures of heteromeric AMPA and NMDA receptors, the major iGluR families in the brain, together with long awaited cryo-EM structures of an AMPA receptor TARP complex, expand this picture and reveal surprising conformational diversity, raising many fundamental and controversial questions.
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93
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Reinehr S, Reinhard J, Wiemann S, Stute G, Kuehn S, Woestmann J, Dick HB, Faissner A, Joachim SC. Early remodelling of the extracellular matrix proteins tenascin-C and phosphacan in retina and optic nerve of an experimental autoimmune glaucoma model. J Cell Mol Med 2016; 20:2122-2137. [PMID: 27374750 PMCID: PMC5082392 DOI: 10.1111/jcmm.12909] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 04/19/2016] [Indexed: 12/17/2022] Open
Abstract
Glaucoma is characterized by the loss of retinal ganglion cells (RGCs) and optic nerve fibres. Previous studies noted fewer RGCs after immunization with ocular antigens at 28 days. It is known that changes in extracellular matrix (ECM) components conduct retina and optic nerve degeneration. Here, we focused on the remodelling of tenascin‐C and phosphacan/receptor protein tyrosine phosphatase β/ζ in an autoimmune glaucoma model. Rats were immunized with optic nerve homogenate (ONA) or S100B protein (S100). Controls received sodium chloride (Co). After 14 days, no changes in RGC number were noted in all groups. An increase in GFAPmRNA expression was observed in the S100 group, whereas no alterations were noted via immunohistochemistry in both groups. Extracellular matrix remodelling was analyzed after 3, 7, 14 and 28 days. Tenascin‐C and 473HD immunoreactivity in retinae and optic nerves was unaltered in both immunized groups at 3 days. At 7 days, tenascin‐C staining increased in both tissues in the ONA group. Also, in the optic nerves of the S100 group, an intense tenascin‐C staining could be shown. In the retina, an increased tenascin‐C expression was also observed in ONA animals via Western blot. 473HD immunoreactivity was elevated in the ONA group in both tissues and in the S100 optic nerves at 7 days. At 14 days, tenascin‐C and 473HD immunoreactivity was up‐regulated in the ONA retinae, whereas phosphacan expression was up‐regulated in both groups. We conclude that remodelling of tenascin‐C and phosphacan occurred shortly after immunization, already before RGC loss. We assume that both ECM molecules represent early indicators of neurodegeneration.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Susanne Wiemann
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Julia Woestmann
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum, Bochum, Germany.
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany.
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94
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Cueva Vargas JL, Belforte N, Di Polo A. The glial cell modulator ibudilast attenuates neuroinflammation and enhances retinal ganglion cell viability in glaucoma through protein kinase A signaling. Neurobiol Dis 2016; 93:156-71. [PMID: 27163643 DOI: 10.1016/j.nbd.2016.05.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/21/2016] [Accepted: 05/05/2016] [Indexed: 12/18/2022] Open
Abstract
Glaucoma is a neurodegenerative disease and the leading cause of irreversible blindness worldwide. Vision deficits in glaucoma result from the selective loss of retinal ganglion cells (RGC). Glial cell-mediated neuroinflammation has been proposed to contribute to disease pathophysiology, but whether this response is harmful or beneficial for RGC survival is not well understood. To test this, we characterized the role of ibudilast, a clinically approved cAMP phosphodiesterase (PDE) inhibitor with preferential affinity for PDE type 4 (PDE4). Here, we demonstrate that intraocular administration of ibudilast dampened macroglia and microglia reactivity in the retina and optic nerve hence decreasing production of proinflammatory cytokines in a rat model of ocular hypertension. Importantly, ibudilast promoted robust RGC soma survival, prevented axonal degeneration, and improved anterograde axonal transport in glaucomatous eyes without altering intraocular pressure. Intriguingly, ocular hypertension triggered upregulation of PDE4 subtype A in Müller glia, and ibudilast stimulated cAMP accumulation in these cells. Co-administration of ibudilast with Rp-cAMPS, a cell-permeable and non-hydrolysable cAMP analog that inhibits protein kinase A (PKA), completely blocked ibudilast-induced neuroprotection. Collectively, these data demonstrate that ibudilast, a safe and well-tolerated glial cell modulator, attenuates gliosis, decreases levels of proinflammatory mediators, and enhances neuronal viability in glaucoma through activation of the cAMP/PKA pathway. This study provides insight into PDE4 signaling as a potential target to counter the harmful effects associated with chronic gliosis and neuroinflammation in glaucoma.
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Affiliation(s)
- Jorge L Cueva Vargas
- Department of Neuroscience and Centre de recherche de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec H2X 0A9, Canada
| | - Nicolas Belforte
- Department of Neuroscience and Centre de recherche de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec H2X 0A9, Canada
| | - Adriana Di Polo
- Department of Neuroscience and Centre de recherche de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec H2X 0A9, Canada.
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95
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Vargas JLC, Di Polo A. Neuroinflammation in glaucoma: soluble tumor necrosis factor alpha and the connection with excitotoxic damage. Neural Regen Res 2016; 11:424-6. [PMID: 27127480 PMCID: PMC4829006 DOI: 10.4103/1673-5374.179053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Jorge L Cueva Vargas
- Department of Neuroscience and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec H3R2T6, Canada
| | - Adriana Di Polo
- Department of Neuroscience and Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), University of Montreal, Montreal, Quebec H3R2T6, Canada
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96
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Grieb P, Jünemann A, Rekas M, Rejdak R. Citicoline: A Food Beneficial for Patients Suffering from or Threated with Glaucoma. Front Aging Neurosci 2016; 8:73. [PMID: 27092075 PMCID: PMC4824764 DOI: 10.3389/fnagi.2016.00073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/28/2016] [Indexed: 12/13/2022] Open
Abstract
Oral form of citicoline, a nootropic and neuroprotective drug in use for almost five decades, recently was pronounced a food supplement in both USA and EU. The idea of adding citicoline to topical treatment of primary open angle glaucoma (POAG) aimed at decreasing intraocular pressure (IOP) appeared as a logical consequence of accepting neurodegenerative character of this disease. Experimental data, and also few clinical studies indicate that this substance has potential to counteract some important pathological mechanisms which seem to contribute to POAG initiation and progression, such as excitotoxicity and oxidative stress.
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Affiliation(s)
- Pawel Grieb
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences Warsaw, Poland
| | - Anselm Jünemann
- Department of Ophthalmology, University of Rostock Rostock, Germany
| | - Marek Rekas
- Department of Ophthalmology, Military Institute of Medicine Warsaw, Poland
| | - Robert Rejdak
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of SciencesWarsaw, Poland; Department of General Ophthalmology, Medical University of LublinLublin, Poland
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Russo R, Varano GP, Adornetto A, Nucci C, Corasaniti MT, Bagetta G, Morrone LA. Retinal ganglion cell death in glaucoma: Exploring the role of neuroinflammation. Eur J Pharmacol 2016; 787:134-42. [PMID: 27044433 DOI: 10.1016/j.ejphar.2016.03.064] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 03/10/2016] [Accepted: 03/31/2016] [Indexed: 01/06/2023]
Abstract
In clinical glaucoma, as well as in experimental models, the loss of retinal ganglion cells occurs by apoptosis. This final event is preceded by inflammatory responses involving the activation of innate and adaptive immunity, with retinal and optic nerve resident glial cells acting as major players. Here we review the current literature on the role of neuroinflammation in neurodegeneration, focusing on the inflammatory molecular mechanisms involved in the pathogenesis and progression of the optic neuropathy.
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Affiliation(s)
- Rossella Russo
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy.
| | - Giuseppe Pasquale Varano
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Annagrazia Adornetto
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome Italy
| | | | - Giacinto Bagetta
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy; University Center for Adaptive Disorders and Head Pain, Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy
| | - Luigi Antonio Morrone
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy; University Center for Adaptive Disorders and Head Pain, Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy
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