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Carbon monoxide treatment reduces microglial activation in the ischemic rat retina. Graefes Arch Clin Exp Ophthalmol 2016; 254:1967-1976. [PMID: 27443355 DOI: 10.1007/s00417-016-3435-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/06/2016] [Accepted: 07/04/2016] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Ischemia and reperfusion (I/R) injury damages retinal neurons. Retinal injury is accompanied by activation of microglia, which scavenge the dead or dying neurons, but increasing evidence now indicates that amoeboid-shaped microglia cells activated in the brain after ischemia have neurotoxic and damaging properties in their own right. A previous study showed that postconditioning with carbon monoxide (CO) protects retinal ganglion cells (RGCs) after I/R through anti-apoptotic and anti-inflammatory mechanisms. The present study was designed to investigate and quantify the activation of retinal microglia after I/R with and without CO postconditioning. METHODS Adult Sprague-Dawley rats underwent retinal ischemia by increasing the ocular pressure to 120 mmHg for 1 h through a needle inserted into the anterior chamber. Reperfusion was induced by removing the needle. After I/R, one group of animals was kept in a CO (250 ppm) atmosphere for 1 h; the other group was kept in room air (Air). At 1, 2, 3, and 7 days after I/R, the eyes were enucleated and fixed. Intracardiac blood was analyzed for systemic effects of CO or I/R. Retinal cross sections were taken from the middle third of the eye and were stained with anti-Iba-1. Microglia cells were graded as amoeboid or ramified phenotypes according to morphologic criteria. Retinal thicknesses were determined. RESULTS Evaluation of retinal tissue revealed a significant reduction of amoeboid microglia cells after I/R + CO when compared to the I/R + Air group. The peak number of amoeboid microglia was observed at day 2 post-I/R + Air. This rise was attenuated by CO postconditioning (815 versus 572 cells/mm2 for I/R + Air versus I/R + CO, respectively; p = 0.005). CO reduced and further postponed the peak in the numbers of amoeboid and ramified microglia cells in ischemic eyes and prevented microglial activation in the contralateral eyes. I/R-induced leucocytosis was inhibited by CO inhalation. The reduction of retinal thickness after I/R was more serious after Air inhalation when compared to the CO group. CONCLUSIONS Numerous activated microglia cells appear in the inner retina after I/R, and CO-treatment significantly attenuates this glial response. Antagonism of microglial activation may be a further neuroprotective effect of CO, apart from its direct anti-apoptotic capacity.
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Masís M, Kakigi C, Singh K, Lin S. Association between self-reported bupropion use and glaucoma: a population-based study. Br J Ophthalmol 2016; 101:525-529. [PMID: 27357261 DOI: 10.1136/bjophthalmol-2016-308846] [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] [Received: 04/19/2016] [Revised: 06/02/2016] [Accepted: 06/08/2016] [Indexed: 12/26/2022]
Abstract
PURPOSE To investigate the relationship between self-reported bupropion use and self-reported glaucoma in a nationally representative sample of the US population. METHODS This cross-sectional study included 6760 participants in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2008, age ≥40 years, who responded to a question regarding their glaucoma status. Participants were interviewed regarding the use of prescription medications, and those ascertained as having used bupropion were further divided into groups based on duration of usage. Other relevant information, including demographics, comorbidities and health-related behaviours, was obtained via interview. Multivariate logistic regression was performed to determine the OR and 95% CIs for association between bupropion use and prevalent glaucoma. Covariates in the final multivariate model included parameters associated with glaucoma at p<0.1: age, gender, ethnicity and annual income. RESULTS 453 participants self-reported a diagnosis of glaucoma, and 108 reported bupropion medication use. Participants who reported using bupropion for more than 1 year had decreased odds of self-reporting a diagnosis of glaucoma (unadjusted OR=0.5, 95% CI 0.01 to 0.52; adjusted OR=0.1, 95% CI 0.01 to 0.81) compared with those not using bupropion or using it for less than a year. CONCLUSIONS Bupropion use, particularly for an extended period of time, may be associated with a reduced risk of glaucomatous disease.
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Affiliation(s)
- Marissé Masís
- University of California San Francisco, San Francisco, California, USA
| | - Caitlin Kakigi
- University of California San Francisco, San Francisco, California, USA
| | | | - Shan Lin
- University of California San Francisco, San Francisco, California, USA
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Madeira MH, Ortin-Martinez A, Nadal-Nícolas F, Ambrósio AF, Vidal-Sanz M, Agudo-Barriuso M, Santiago AR. Caffeine administration prevents retinal neuroinflammation and loss of retinal ganglion cells in an animal model of glaucoma. Sci Rep 2016; 6:27532. [PMID: 27270337 PMCID: PMC4897621 DOI: 10.1038/srep27532] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/10/2016] [Indexed: 12/22/2022] Open
Abstract
Glaucoma is the second leading cause of blindness worldwide, being characterized by progressive optic nerve damage and loss of retinal ganglion cells (RGCs), accompanied by increased inflammatory response involving retinal microglial cells. The etiology of glaucoma is still unknown, and despite elevated intraocular pressure (IOP) being a major risk factor, the exact mechanisms responsible for RGC degeneration remain unknown. Caffeine, which is an antagonist of adenosine receptors, is the most widely consumed psychoactive drug in the world. Several evidences suggest that caffeine can attenuate the neuroinflammatory responses and afford protection upon central nervous system (CNS) injury. We took advantage of a well characterized animal model of glaucoma to investigate whether caffeine administration controls neuroinflammation and elicits neuroprotection. Caffeine or water were administered ad libitum and ocular hypertension (OHT) was induced by laser photocoagulation of the limbal veins in Sprague Dawley rats. Herein, we show that caffeine is able to partially decrease the IOP in ocular hypertensive animals. More importantly, we found that drinking caffeine prevented retinal microglia-mediated neuroinflammatory response and attenuated the loss of RGCs in animals with ocular hypertension (OHT). This study opens the possibility that caffeine or adenosine receptor antagonists might be a therapeutic option to manage RGC loss in glaucoma.
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Affiliation(s)
- Maria H Madeira
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Arturo Ortin-Martinez
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia &Instituto Murciano de Investigacion Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Arrixaca), 30100 Murcia, Spain
| | - Francisco Nadal-Nícolas
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia &Instituto Murciano de Investigacion Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Arrixaca), 30100 Murcia, Spain
| | - António F Ambrósio
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia &Instituto Murciano de Investigacion Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Arrixaca), 30100 Murcia, Spain
| | - Marta Agudo-Barriuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia &Instituto Murciano de Investigacion Biosanitaria Hospital Virgen de la Arrixaca (IMIB-Arrixaca), 30100 Murcia, Spain
| | - Ana Raquel Santiago
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
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104
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Bae HW, Lee N, Seong GJ, Rho S, Hong S, Kim CY. Protective effect of etanercept, an inhibitor of tumor necrosis factor-α, in a rat model of retinal ischemia. BMC Ophthalmol 2016; 16:75. [PMID: 27259948 PMCID: PMC4893298 DOI: 10.1186/s12886-016-0262-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 05/28/2016] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND To assess the neuroprotective effect of etanercept (Enbrel®) which is a commercialized Tumor necrosis factor-α (TNF-α) inhibitor on axonal injury in an animal model of acute ischemia. METHODS Acute ischemia was induced by intraocular pressure elevation in 36 rats. The treatment groups underwent subcutaneous injection of etanercept (0.3 or 1.0 mg/kg) three times per week up to 4 weeks. The control groups were treated in the same manner using the same volume of phosphate-buffered saline (PBS). Optic nerve damage was evaluated by counting the number of axons under a transmission electron microscope. Microglial cell activity was assessed using Iba1 and CD68. RESULTS After induction of ischemia, the ratio of preserved axons was significantly greater in the 2-week 1.0-mg/kg etanercept-treated group than in the PBS-treated group (p = 0.062). The 4-week 0.3-mg/kg and 1.0-mg/kg etanercept-treated groups also showed significantly higher ratios of preserved axons than did the PBS-treated group (p = 0.021 and 0.003, respectively). The expression of Iba1 and CD68 in the optic nerve was lower in the etanercept-treated groups than in the PBS-treated groups. Immunohistochemical staining using rabbit anti-Iba1 antibody showed that the amount of microglia at the optic nerve head was noticeably lower in the etanercept-treated groups than in the PBS-treated groups. CONCLUSIONS Etanercept significantly suppressed optic nerve injury in this rat model of acute ischemia. This in vivo study suggests that etanercept might be a novel neuroprotective treatment agent for TNF-α-related disease.
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Affiliation(s)
- Hyoung Won Bae
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, South Korea
| | - Naeun Lee
- Department of Ophthalmology, Hallym Hospital, Incheon, South Korea
| | - Gong Je Seong
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, South Korea
| | - Seungsoo Rho
- Department of Ophthalmology, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Samin Hong
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, South Korea
| | - Chan Yun Kim
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul, South Korea.
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Abstract
Perispinal injection is a novel emerging method of drug delivery to the central nervous system (CNS). Physiological barriers prevent macromolecules from efficiently penetrating into the CNS after systemic administration. Perispinal injection is designed to use the cerebrospinal venous system (CSVS) to enhance delivery of drugs to the CNS. It delivers a substance into the anatomic area posterior to the ligamentum flavum, an anatomic region drained by the external vertebral venous plexus (EVVP), a division of the CSVS. Blood within the EVVP communicates with the deeper venous plexuses of the CSVS. The anatomical basis for this method originates in the detailed studies of the CSVS published in 1819 by the French anatomist Gilbert Breschet. By the turn of the century, Breschet's findings were nearly forgotten, until rediscovered by American anatomist Oscar Batson in 1940. Batson confirmed the unique, linear, bidirectional and retrograde flow of blood between the spinal and cerebral divisions of the CSVS, made possible by the absence of venous valves. Recently, additional supporting evidence was discovered in the publications of American neurologist Corning. Analysis suggests that Corning's famous first use of cocaine for spinal anesthesia in 1885 was in fact based on Breschet's anatomical findings, and accomplished by perispinal injection. The therapeutic potential of perispinal injection for CNS disorders is highlighted by the rapid neurological improvement in patients with otherwise intractable neuroinflammatory disorders that may ensue following perispinal etanercept administration. Perispinal delivery merits intense investigation as a new method of enhanced delivery of macromolecules to the CNS and related structures.
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Affiliation(s)
- Edward Lewis Tobinick
- Institute of Neurological Recovery, 2300 Glades Road, Suite 305E, Boca Raton, FL, 33431, USA.
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107
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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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108
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Mac Nair CE, Schlamp CL, Montgomery AD, Shestopalov VI, Nickells RW. Retinal glial responses to optic nerve crush are attenuated in Bax-deficient mice and modulated by purinergic signaling pathways. J Neuroinflammation 2016; 13:93. [PMID: 27126275 PMCID: PMC4850653 DOI: 10.1186/s12974-016-0558-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 04/20/2016] [Indexed: 01/14/2023] Open
Abstract
Background Retinal ganglion cell (RGC) soma death is a consequence of optic nerve damage, including in optic neuropathies like glaucoma. The activation of the innate immune network in the retina after nerve damage has been linked to RGC pathology. Since the eye is immune privileged, innate immune functions are the responsibility of the glia, specifically the microglia, astrocytes, and Müller cells that populate the retina. Glial activation, leading to the production of inflammatory cytokines, is a hallmark feature of retinal injury resulting from optic nerve damage and purported to elicit secondary degeneration of RGC somas. Methods A mouse model of optic nerve crush (ONC) was used to study retinal glial activation responses. RGC apoptosis was blocked using Bax-deficient mice. Glial activation responses were monitored by quantitative PCR and immunofluorescent labeling in retinal sections of activation markers. ATP signaling pathways were interrogated using P2X receptor agonists and antagonists and Pannexin 1 (Panx1)-deficient mice with RGC-specific deletion. Results ONC induced activation of both macroglia and microglia in the retina, and both these responses were dramatically muted if RGC death was blocked by deletion of the Bax gene. Macroglial, but not microglial, activation was modulated by purinergic receptor activation. Release of ATP after optic nerve damage was not mediated by PANX1 channels in RGCs. Conclusions RGC death in response to ONC plays a principal stimulatory role in the retinal glial activation response. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0558-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Caitlin E Mac Nair
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA.,Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, 3170-10K/L MFCB, 1685 Highland Avenue, Madison, WI, 53705, USA
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA
| | - Angela D Montgomery
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA
| | - Valery I Shestopalov
- Department of Ophthalmology, University of Miami Miller School of Medicine, 900 N.W. 17th Street, Miami, FL, 33136, USA.,Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, 900 N.W. 17th Street, Miami, FL, 33136, USA
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA.
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109
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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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Jones BW, Pfeiffer RL, Ferrell WD, Watt CB, Marmor M, Marc RE. Retinal remodeling in human retinitis pigmentosa. Exp Eye Res 2016; 150:149-65. [PMID: 27020758 DOI: 10.1016/j.exer.2016.03.018] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/23/2016] [Accepted: 03/18/2016] [Indexed: 12/11/2022]
Abstract
Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.
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Affiliation(s)
- B W Jones
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA.
| | - R L Pfeiffer
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - W D Ferrell
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - C B Watt
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - M Marmor
- Dept. Ophthalmology, Stanford University, USA
| | - R E Marc
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
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111
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Kamat SS, Gregory MS, Pasquale LR. The Role of the Immune System in Glaucoma: Bridging the Divide Between Immune Mechanisms in Experimental Glaucoma and the Human Disease. Semin Ophthalmol 2016; 31:147-54. [DOI: 10.3109/08820538.2015.1114858] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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112
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Madeira MH, Boia R, Elvas F, Martins T, Cunha RA, Ambrósio AF, Santiago AR. Selective A2A receptor antagonist prevents microglia-mediated neuroinflammation and protects retinal ganglion cells from high intraocular pressure-induced transient ischemic injury. Transl Res 2016; 169:112-28. [PMID: 26685039 DOI: 10.1016/j.trsl.2015.11.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/13/2015] [Accepted: 11/17/2015] [Indexed: 12/17/2022]
Abstract
Glaucoma is a leading cause of vision loss and blindness worldwide, characterized by chronic and progressive neuronal loss. Reactive microglial cells have been recognized as a neuropathologic feature, contributing to local inflammation and retinal neurodegeneration. In a recent in vitro work (organotypic cultures), we demonstrated that blockade of adenosine A2A receptor (A2AR) prevents the neuroinflammatory response and affords protection to retinal ganglion cells (RGCs) against exposure to elevated hydrostatic pressure (EHP), to mimic elevated intraocular pressure (IOP), the main risk factor for glaucoma development. Herein, we investigated whether a selective A2AR antagonist (SCH 58261) could modulate retinal microglia reactivity and their inflammatory response. Furthermore, we took advantage of the high IOP-induced transient ischemia (ischemia-reperfusion, I-R) animal model to evaluate the protective role of A2AR blockade in the control of retinal neuroinflammation and neurodegeneration. Primary microglial cell cultures were challenged either with lipopolysaccharide or with EHP, in the presence or absence of A2AR antagonist SCH 58261 (50 nM). In addition, I-R injury was induced in adult Wistar rats after intravitreal administration of SCH 58261 (100 nM, 5 μL). Our results showed that SCH 58261 attenuated microglia reactivity and the increased expression and release of proinflammatory cytokines. Moreover, intravitreal administration of SCH 58261 prevented I-R-induced cell death and RGC loss, by controlling microglial-mediated neuroinflammatory response. These results prompt the proposal that A2AR blockade may have great potential in the management of retinal neurodegenerative diseases characterized by microglia reactivity and RGC death, such as glaucoma and ischemic diseases.
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Affiliation(s)
- Maria H Madeira
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - Raquel Boia
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - Filipe Elvas
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal
| | - Tiago Martins
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC.IBILI, University of Coimbra, Coimbra, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal; Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Ana Raquel Santiago
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal; Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
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113
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Sapienza A, Raveu AL, Reboussin E, Roubeix C, Boucher C, Dégardin J, Godefroy D, Rostène W, Reaux-Le Goazigo A, Baudouin C, Melik Parsadaniantz S. Bilateral neuroinflammatory processes in visual pathways induced by unilateral ocular hypertension in the rat. J Neuroinflammation 2016; 13:44. [PMID: 26897546 PMCID: PMC4761202 DOI: 10.1186/s12974-016-0509-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/11/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glaucoma is one of the leading causes of irreversible blindness in the world. The major risk factor is elevated intraocular pressure (IOP) leading to progressive retinal ganglion cell (RGC) death from the optic nerve (ON) to visual pathways in the brain. Glaucoma has been reported to share mechanisms with neurodegenerative disorders. We therefore hypothesize that neuroinflammatory mechanisms in central visual pathways may contribute to the spread of glaucoma disease. The aim of the present study was to analyze the neuroinflammation processes that occur from the pathological retina to the superior colliculi (SCs) in a rat model of unilateral ocular hypertension induced by episcleral vein cauterization (EVC). RESULTS Six weeks after unilateral (right eye) EVC in male Long-Evans rats, we evaluated both the neurodegenerative process and the neuroinflammatory state in visual pathway tissues. RGCs immunolabeled (Brn3a(+)) in ipsilateral whole flat-mounted retina demonstrated peripheral RGC loss associated with tissue macrophage/microglia activation (CD68(+)). Gene expression analysis of hypertensive and normotensive retinas revealed a significant increase of pro-inflammatory genes such as CCL2, IL-1β, and Nox2 mRNA expression compared to naïve eyes. Importantly, we found an upregulation of pro-inflammatory markers such as IL-1β and TNFα and astrocyte and tissue macrophage/microglia activation in hypertensive and normotensive RGC projection sites in the SCs compared to a naïve SC. To understand how neuroinflammation in the hypertensive retina is sufficient to damage both right and left SCs and the normotensive retina, we used an inflammatory model consisting in an unilateral stereotaxic injection of TNFα (25 ng/μl) in the right SC of naïve rats. Two weeks after TNFα injection, using an optomotor test, we observed that rats had visual deficiency in both eyes. Furthermore, both SCs showed an upregulation of genes and proteins for astrocytes, microglia, and pro-inflammatory cytokines, notably IL-1β. In addition, both retinas exhibited a significant increase of inflammatory markers compared to a naïve retina. CONCLUSIONS All these data evidence the complex role played by the SCs in the propagation of neuroinflammatory events induced by unilateral ocular hypertension and provide a new insight into the spread of neurodegenerative diseases such as glaucoma.
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Affiliation(s)
- Anaïs Sapienza
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Anne-Laure Raveu
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Elodie Reboussin
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Christophe Roubeix
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Céline Boucher
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Julie Dégardin
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - David Godefroy
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - William Rostène
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Annabelle Reaux-Le Goazigo
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Christophe Baudouin
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC, 28 rue de Charenton, 75012, Paris, France.,Department Ophthalmology, Hopital Ambroise Pare, AP HP, F-92100, Boulogne, France.,University Versailles St Quentin En Yvelines, F-78180, Montigny-Le-Bretonneux, France
| | - Stéphane Melik Parsadaniantz
- Sorbonne Universités, UPMC University of Paris 06, Institut de la Vision, 17 rue Moreau, 75012, Paris, France. .,INSERM U968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France. .,CNRS UMR_7210, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.
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114
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Wang J, Dong Y. Characterization of intraocular pressure pattern and changes of retinal ganglion cells in DBA2J glaucoma mice. Int J Ophthalmol 2016; 9:211-7. [PMID: 26949637 DOI: 10.18240/ijo.2016.02.05] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 09/09/2015] [Indexed: 01/20/2023] Open
Abstract
AIM To characterize the pattern of intraocular pressure (IOP) change and the deficit of retinal ganglion cells (RGCs) in DBA2J, which is most well-characterized chronic glaucoma mouse model and wild type (WT) C57bl/6 mice, and to study the relationship between IOP change and RGCs deficit. METHODS IOP was monitored with a rebound tonometer in WT C57bl/6 and DBA2J mice from 3 to 15-month-old. Retinal function was evaluated by dark-adapted electroretinogram (ERG) in DBA2J and WT mice of 15-month-old. A dye (Neurobiotin) was applied to optic nerve stump to retrograde label RGCs. TO-PRO-3 visualized all nuclei of cells in the RGC layer. RESULTS The IOP in WT mice was 9.03±0.6 mm Hg on average and did not increase significantly as aging. The IOP in DBA2J mice, arranging from 7.2 to 28 mm Hg, was increasing significantly as aging, and it was normal at 3-month-old compared with WT mice, slightly increased from 7-month-old and increased in 50% animals at 11-month-old and in 38% animals at 15-month-old. The RGCs density in DBA2J mice started reducing by 7-month-old, continuously decreased until reached about 20% of RGC in WT retina by 15-month-old. RGC density was not linearly correlated with IOP in 15-month-old DBA2J mice. The amplitude of positive scotopic threshold response, and negative scotopic threshold response of ERG were significantly reduced in DBA2J mice of 15-month-old than that in age-paired WT mice. CONCLUSION The present study found that DBA2J mice display pathological and functional deficits of the retina that was not linearly correlated with IOP.
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Affiliation(s)
- Jing Wang
- Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yu Dong
- Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA
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115
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The Role of the IL-20 Subfamily in Glaucoma. Mediators Inflamm 2016; 2016:4083735. [PMID: 26903709 PMCID: PMC4745377 DOI: 10.1155/2016/4083735] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/04/2015] [Accepted: 12/10/2015] [Indexed: 12/23/2022] Open
Abstract
Glaucoma is a common disease that leads to loss of peripheral vision and, if left untreated, ultimately to blindness. While the exact cause(s) of glaucoma is still unknown, two leading risk factors are age and elevated intraocular pressure. Several studies suggest a possible link between glaucoma and inflammation in humans and animal models. In particular, our lab recently identified a T104M mutation in IL-20 receptor-B (IL-20RB) in primary open angle glaucoma patients from a large pedigree. Several of the interleukin- (IL-) 20 family of cytokines and receptors are expressed in ocular tissues including the trabecular meshwork, optic nerve head, and retinal ganglion cells. The DBA/2J mouse develops high intraocular pressures with age and has characteristic optic nerve defects that make it a useful glaucoma model. IL-24 expression is significantly upregulated in the retina of these mice, while IL-20RA expression in the optic nerve is downregulated following pressure-induced damage. The identification of a mutation in the IL-20RB gene in a glaucoma pedigree and changes in expression levels of IL-20 family members in the DBA/2J mouse suggest that disruption of normal IL-20 signaling in the eye may contribute to degenerative processes associated with glaucoma.
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116
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De Groef L, Dekeyster E, Geeraerts E, Lefevere E, Stalmans I, Salinas-Navarro M, Moons L. Differential visual system organization and susceptibility to experimental models of optic neuropathies in three commonly used mouse strains. Exp Eye Res 2016; 145:235-247. [PMID: 26791081 DOI: 10.1016/j.exer.2016.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/16/2015] [Accepted: 01/07/2016] [Indexed: 01/06/2023]
Abstract
Mouse disease models have proven indispensable in glaucoma research, yet the complexity of the vast number of models and mouse strains has also led to confusing findings. In this study, we evaluated baseline intraocular pressure, retinal histology, and retinofugal projections in three mouse strains commonly used in glaucoma research, i.e. C57Bl/6, C57Bl/6-Tyr(c), and CD-1 mice. We found that the mouse strains under study do not only display moderate variations in their intraocular pressure, retinal architecture, and retinal ganglion cell density, also the retinofugal projections to the dorsal lateral geniculate nucleus and the superior colliculus revealed striking differences, potentially underlying diverging optokinetic tracking responses and visual acuity. Next, we reviewed the success rate of three models of (glaucomatous) optic neuropathies (intravitreal N-methyl-d-aspartic acid injection, optic nerve crush, and laser photocoagulation-induced ocular hypertension), looking for differences in disease susceptibility between these mouse strains. Different genetic backgrounds and albinism led to differential susceptibility to experimentally induced retinal ganglion cell death among these three mouse strains. Overall, CD-1 mice appeared to have the highest sensitivity to retinal ganglion cell damage, while the C57Bl/6 background was more resistant in the three models used.
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Affiliation(s)
- Lies De Groef
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Eline Dekeyster
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Emiel Geeraerts
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Evy Lefevere
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Ingeborg Stalmans
- Laboratory of Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Manuel Salinas-Navarro
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium.
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117
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Cairns EA, Baldridge WH, Kelly MEM. The Endocannabinoid System as a Therapeutic Target in Glaucoma. Neural Plast 2016; 2016:9364091. [PMID: 26881140 PMCID: PMC4737462 DOI: 10.1155/2016/9364091] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/10/2015] [Indexed: 11/17/2022] Open
Abstract
Glaucoma is an irreversible blinding eye disease which produces progressive retinal ganglion cell (RGC) loss. Intraocular pressure (IOP) is currently the only modifiable risk factor, and lowering IOP results in reduced risk of progression of the disorder. The endocannabinoid system (ECS) has attracted considerable attention as a potential target for the treatment of glaucoma, largely due to the observed IOP lowering effects seen after administration of exogenous cannabinoids. However, recent evidence has suggested that modulation of the ECS may also be neuroprotective. This paper will review the use of cannabinoids in glaucoma, presenting pertinent information regarding the pathophysiology of glaucoma and how alterations in cannabinoid signalling may contribute to glaucoma pathology. Additionally, the mechanisms and potential for the use of cannabinoids and other novel agents that target the endocannabinoid system in the treatment of glaucoma will be discussed.
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Affiliation(s)
- Elizabeth A. Cairns
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - William H. Baldridge
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada B3H 4R2
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - Melanie E. M. Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada B3H 4R2
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2
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118
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Therapies negating neuroinflammation after brain trauma. Brain Res 2015; 1640:36-56. [PMID: 26740405 DOI: 10.1016/j.brainres.2015.12.024] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/07/2015] [Accepted: 12/14/2015] [Indexed: 12/11/2022]
Abstract
Traumatic brain injury (TBI) elicits a complex secondary injury response, with neuroinflammation as a crucial central component. Long thought to be solely a deleterious factor, the neuroinflammatory response has recently been shown to be far more intricate, with both beneficial and detrimental consequences depending on the timing, magnitude and specific immune composition of the response post-injury. Despite extensive preclinical and clinical research into mechanisms of secondary injury after TBI, no effective neuroprotective therapy has been identified, with potential candidates repeatedly proving disappointing in the clinic. The neuroinflammatory response offers a promising avenue for therapeutic targeting, aiming to quell the deleterious consequences without influencing its function in providing a neurotrophic environment supportive of repair. The present review firstly describes the findings of recent clinical trials that aimed to modulate inflammation as a means of neuroprotection. Secondly, we discuss promising multifunctional and single-target anti-inflammatory candidates either currently in trial, or with ample experimental evidence supporting clinical application. This article is part of a Special Issue entitled SI:Brain injury and recovery.
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119
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Soluble Tumor Necrosis Factor Alpha Promotes Retinal Ganglion Cell Death in Glaucoma via Calcium-Permeable AMPA Receptor Activation. J Neurosci 2015; 35:12088-102. [PMID: 26338321 DOI: 10.1523/jneurosci.1273-15.2015] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Loss of vision in glaucoma results from the selective death of retinal ganglion cells (RGCs). Tumor necrosis factor α (TNFα) signaling has been linked to RGC damage, however, the mechanism by which TNFα promotes neuronal death remains poorly defined. Using an in vivo rat glaucoma model, we show that TNFα is upregulated by Müller cells and microglia/macrophages soon after induction of ocular hypertension. Administration of XPro1595, a selective inhibitor of soluble TNFα, effectively protects RGC soma and axons. Using cobalt permeability assays, we further demonstrate that endogenous soluble TNFα triggers the upregulation of Ca(2+)-permeable AMPA receptor (CP-AMPAR) expression in RGCs of glaucomatous eyes. CP-AMPAR activation is not caused by defects in GluA2 subunit mRNA editing, but rather reflects selective downregulation of GluA2 in neurons exposed to elevated eye pressure. Intraocular administration of selective CP-AMPAR blockers promotes robust RGC survival supporting a critical role for non-NMDA glutamate receptors in neuronal death. Our study identifies glia-derived soluble TNFα as a major inducer of RGC death through activation of CP-AMPARs, thereby establishing a novel link between neuroinflammation and cell loss in glaucoma. SIGNIFICANCE STATEMENT Tumor necrosis factor α (TNFα) has been implicated in retinal ganglion cell (RGC) death, but how TNFα exerts this effect is poorly understood. We report that ocular hypertension, a major risk factor in glaucoma, upregulates TNFα production by Müller cells and microglia. Inhibition of soluble TNFα using a dominant-negative strategy effectively promotes RGC survival. We find that TNFα stimulates the expression of calcium-permeable AMPA receptors (CP-AMPAR) in RGCs, a response that does not depend on abnormal GluA2 mRNA editing but on selective downregulation of the GluA2 subunit by these neurons. Consistent with this, CP-AMPAR blockers promote robust RGC survival supporting a critical role for non-NMDA glutamate receptors in glaucomatous damage. This study identifies a novel mechanism by which glia-derived soluble TNFα modulates neuronal death in glaucoma.
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120
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Tian K, Shibata-Germanos S, Pahlitzsch M, Cordeiro MF. Current perspective of neuroprotection and glaucoma. Clin Ophthalmol 2015; 9:2109-18. [PMID: 26635467 PMCID: PMC4646599 DOI: 10.2147/opth.s80445] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Glaucoma is the second leading cause of blindness worldwide and is most notably characterized by progressive optic nerve atrophy and advancing loss of retinal ganglion cells (RGCs). The main concomitant factor is the elevated intraocular pressure (IOP). Existing treatments are focused generally on lowering IOP. However, both RGC loss and optic nerve atrophy can independently occur with IOP at normal levels. In recent years, there has been substantial progress in the development of neuroprotective therapies for glaucoma in order to restore vital visual function. The present review intends to offer a brief insight into conventional glaucoma treatments and discuss exciting current developments of mostly preclinical data in novel neuroprotective strategies for glaucoma that include recent advances in noninvasive diagnostics going beyond IOP maintenance for an enhanced global view. Such strategies now target RGC loss and optic nerve damage, opening a critical therapeutic window for preventative monitoring and treatment.
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Affiliation(s)
- Kailin Tian
- Glaucoma and Retinal Neurodegeneration Research Group, UCL Institute of Ophthalmology, London, UK ; Eye Centre, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Shannon Shibata-Germanos
- Glaucoma and Retinal Neurodegeneration Research Group, UCL Institute of Ophthalmology, London, UK
| | - Milena Pahlitzsch
- Glaucoma and Retinal Neurodegeneration Research Group, UCL Institute of Ophthalmology, London, UK
| | - M Francesca Cordeiro
- Glaucoma and Retinal Neurodegeneration Research Group, UCL Institute of Ophthalmology, London, UK ; Western Eye Hospital, ICORG, Imperial College NHS Trust, London, UK
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121
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A Pro-Nerve Growth Factor (proNGF) and NGF Binding Protein, α2-Macroglobulin, Differentially Regulates p75 and TrkA Receptors and Is Relevant to Neurodegeneration Ex Vivo and In Vivo. Mol Cell Biol 2015. [PMID: 26217017 DOI: 10.1128/mcb.00544-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nerve growth factor (NGF) is generated from a precursor, proNGF, that is proteolytically processed. NGF preferentially binds a trophic tyrosine kinase receptor, TrkA, while proNGF binds a neurotrophin receptor (NTR), p75(NTR), that can have neurotoxic activity. Previously, we along with others showed that the soluble protein α2-macroglobulin (α2M) is neurotoxic. Toxicity is due in part to α2M binding to NGF and inhibiting trophic activity, presumably by preventing NGF binding to TrkA. However, the mechanisms remained unclear. Here, we show ex vivo and in vivo three mechanisms for α2M neurotoxicity. First, unexpectedly the α2M-NGF complexes do bind TrkA receptors but do not induce TrkA dimerization or activation, resulting in deficient trophic support. Second, α2M makes stable complexes with proNGF, conveying resistance to proteolysis that results in more proNGF and less NGF. Third, α2M-proNGF complexes bind p75(NTR) and are more potent agonists than free proNGF, inducing tumor necrosis factor alpha (TNF-α) production. Hence, α2M regulates proNGF/p75(NTR) positively and mature NGF/TrkA negatively, causing neuronal death ex vivo. These three mechanisms are operative in vivo, and α2M causes neurodegeneration in a p75(NTR)- and proNGF-dependent manner. α2M could be exploited as a therapeutic target, or as a modifier of neurotrophin signals.
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122
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Wiggs JL. Glaucoma Genes and Mechanisms. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:315-42. [PMID: 26310163 DOI: 10.1016/bs.pmbts.2015.04.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic studies have yielded important genes contributing to both early-onset and adult-onset forms of glaucoma. The proteins encoded by the current collection of glaucoma genes participate in a broad range of cellular processes and biological systems. Approximately half the glaucoma-related genes function in the extracellular matrix, however proteins involved in cytokine signaling, lipid metabolism, membrane biology, regulation of cell division, autophagy, and ocular development also contribute to the disease pathogenesis. While the function of these proteins in health and disease are not completely understood, recent studies are providing insight into underlying disease mechanisms, a critical step toward the development of gene-based therapies. In this review, genes known to cause early-onset glaucoma or contribute to adult-onset glaucoma are organized according to the cell processes or biological systems that are impacted by the function of the disease-related protein product.
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Affiliation(s)
- Janey L Wiggs
- Harvard Medical School, and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.
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123
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Mac Nair CE, Nickells RW. Neuroinflammation in Glaucoma and Optic Nerve Damage. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:343-63. [PMID: 26310164 DOI: 10.1016/bs.pmbts.2015.06.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glaucoma is a group of optic neuropathies characterized by the degeneration of retinal ganglion cell axons and somas, ultimately preventing light signals in the retina from reaching the brain. Glaucoma is a leading cause of blindness in the world, and treatment options for patients remain limited and minimally efficacious. A number of mechanisms have been linked to glaucomatous pathophysiology. A leading role is now attributed to neuroinflammatory conditions generated by the resident innate immune cells in the optic nerve and retina. Since the eye is immune privileged, the adaptation of these innate immune cells, termed glia, is crucial following trauma. In this chapter, we discuss the mechanisms associated with normal glial function in a healthy eye, and how changes in glial activation can contribute to the process of glaucomatous neurodegeneration in both the optic nerve and retina.
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Affiliation(s)
- Caitlin E Mac Nair
- Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA; Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert W Nickells
- Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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124
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Abstract
Glaucoma is a group of progressive optic neuropathies, characterized by the degeneration of retinal ganglion cells related to the level of intraocular pressure and other factors. The exact pathogenesis of glaucoma is not known, and current therapeutic options are not sufficient to prevent or recover vision loss in glaucoma patients. Functional, repeatable, and easy-to-use animal models are therefore needed. Because of their inherent advantages, rodent animals, including mice and rats, have been widely developed as models to study various aspects of glaucoma and to evaluate possible novel therapies. However, no single model has been shown to emulate all aspects of glaucoma. In this review, we discuss currently available rodent animal models of glaucoma, their strengths and weaknesses, and the possible implications for current glaucoma research.
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Affiliation(s)
- Shida Chen
- From the Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou, China
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125
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Madeira MH, Elvas F, Boia R, Gonçalves FQ, Cunha RA, Ambrósio AF, Santiago AR. Adenosine A2AR blockade prevents neuroinflammation-induced death of retinal ganglion cells caused by elevated pressure. J Neuroinflammation 2015; 12:115. [PMID: 26054642 PMCID: PMC4465153 DOI: 10.1186/s12974-015-0333-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 05/27/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, a degenerative disease characterized by the loss of retinal ganglion cells (RGCs). There is clinical and experimental evidence that neuroinflammation is involved in the pathogenesis of glaucoma. Since the blockade of adenosine A2A receptor (A2AR) confers robust neuroprotection and controls microglia reactivity in the brain, we now investigated the ability of A2AR blockade to control the reactivity of microglia and neuroinflammation as well as RGC loss in retinal organotypic cultures exposed to elevated hydrostatic pressure (EHP) or lipopolysaccharide (LPS). METHODS Retinal organotypic cultures were either incubated with LPS (3 μg/mL), to elicit a pro-inflammatory response, or exposed to EHP (+70 mmHg), to mimic increased IOP, for 4 or 24 h, in the presence or absence of the A2AR antagonist SCH 58261 (50 nM). A2AR expression, microglial reactivity and neuroinflammatory response were evaluated by immunohistochemistry, quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). RGC loss was assessed by immunohistochemistry. In order to investigate the contribution of pro-inflammatory mediators to RGC loss, the organotypic retinal cultures were incubated with rabbit anti-tumour necrosis factor (TNF) (2 μg/mL) and goat anti-interleukin-1β (IL-1β) (1 μg/mL) antibodies. RESULTS We report that the A2AR antagonist (SCH 58261) prevented microglia reactivity, increase in pro-inflammatory mediators as well as RGC loss upon exposure to either LPS or EHP. Additionally, neutralization of TNF and IL-1β prevented RGC loss induced by LPS or EHP. CONCLUSIONS This work demonstrates that A2AR blockade confers neuroprotection to RGCs by controlling microglia-mediated retinal neuroinflammation and prompts the hypothesis that A2AR antagonists may be a novel therapeutic option to manage glaucomatous disorders.
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Affiliation(s)
- Maria H Madeira
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Filipe Elvas
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal.
| | - Raquel Boia
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Francisco Q Gonçalves
- CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
| | - Rodrigo A Cunha
- CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal. .,Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.
| | - António Francisco Ambrósio
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,Association for Innovation and Biomedical Research on Light (AIBILI), 3000-548, Coimbra, Portugal.
| | - Ana Raquel Santiago
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3004-548, Coimbra, Portugal. .,CNC.IBILI, University of Coimbra, 3004-517, Coimbra, Portugal. .,Association for Innovation and Biomedical Research on Light (AIBILI), 3000-548, Coimbra, Portugal. .,Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal. .,IBILI, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, 3004-548, Coimbra, Portugal.
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Tobinick E, Rodriguez-Romanacce H, Levine A, Ignatowski TA, Spengler RN. Immediate neurological recovery following perispinal etanercept years after brain injury. Clin Drug Investig 2015; 34:361-6. [PMID: 24647830 DOI: 10.1007/s40261-014-0186-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Positron emission tomographic brain imaging and pathological examination have revealed that a chronic, intracerebral neuroinflammatory response lasting for years after a single brain injury may occur in humans. Evidence suggests the immune signaling molecule, tumor necrosis factor (TNF), is centrally involved in this pathology through its modulation of microglial activation, role in synaptic dysfunction, and induction of depressive symptoms and neuropathic pain. Etanercept is a recombinant TNF receptor fusion protein and potent TNF inhibitor that has been found to reduce microglial activation and neuropathic pain in multiple experimental models. We report that a single dose of perispinal etanercept produced an immediate, profound, and sustained improvement in expressive aphasia, speech apraxia, and left hemiparesis in a patient with chronic, intractable, debilitating neurological dysfunction present for more than 3 years after acute brain injury. These results indicate that acute brain injury-induced pathologic levels of TNF may provide a therapeutic target that can be addressed years after injury. Perispinal administration of etanercept is capable of producing immediate relief from brain injury-mediated neurological dysfunction.
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Affiliation(s)
- Edward Tobinick
- Institute of Neurological Recovery, 2300 Glades Road Suite 305E, Boca Raton, FL, 33431, USA,
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Trost A, Motloch K, Bruckner D, Schroedl F, Bogner B, Kaser-Eichberger A, Runge C, Strohmaier C, Klein B, Aigner L, Reitsamer HA. Time-dependent retinal ganglion cell loss, microglial activation and blood-retina-barrier tightness in an acute model of ocular hypertension. Exp Eye Res 2015; 136:59-71. [PMID: 26001526 DOI: 10.1016/j.exer.2015.05.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 02/04/2023]
Abstract
Glaucoma is a group of neurodegenerative diseases characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons, and is the second leading cause of blindness worldwide. Elevated intraocular pressure is a well known risk factor for the development of glaucomatous optic neuropathy and pharmacological or surgical lowering of intraocular pressure represents a standard procedure in glaucoma treatment. However, the treatment options are limited and although lowering of intraocular pressure impedes disease progression, glaucoma cannot be cured by the currently available therapy concepts. In an acute short-term ocular hypertension model in rat, we characterize RGC loss, but also microglial cell activation and vascular alterations of the retina at certain time points. The combination of these three parameters might facilitate a better evaluation of the disease progression, and could further serve as a new model to test novel treatment strategies at certain time points. Acute ocular hypertension (OHT) was induced by the injection of magnetic microbeads into the rat anterior chamber angle (n = 22) with magnetic position control, leading to constant elevation of IOP. At certain time points post injection (4d, 7d, 10d, 14d and 21d), RGC loss, microglial activation, and microvascular pericyte (PC) coverage was analyzed using immunohistochemistry with corresponding specific markers (Brn3a, Iba1, NG2). Additionally, the tightness of the retinal vasculature was determined via injections of Texas Red labeled dextran (10 kDa) and subsequently analyzed for vascular leakage. For documentation, confocal laser-scanning microscopy was used, followed by cell counts, capillary length measurements and morphological and statistical analysis. The injection of magnetic microbeads led to a progressive loss of RGCs at the five time points investigated (20.07%, 29.52%, 41.80%, 61.40% and 76.57%). Microglial cells increased in number and displayed an activated morphology, as revealed by Iba1-positive cell number (150.23%, 175%, 429.25%,486.72% and 544.78%) and particle size analysis (205.49%, 203.37%, 412.84%, 333.37% and 299.77%) compared to contralateral control eyes. Pericyte coverage (NG2-positive PC/mm) displayed a significant reduction after 7d of OHT in central, and after 7d and 10d in peripheral retina. Despite these alterations, the tightness of the retinal vasculature remained unaltered at 14 and 21 days after OHT induction. While vascular tightness was unchanged in the course of OHT, a progressive loss of RGCs and activation of microglial cells was detected. Since a significant loss in RGCs was observed already at day 4 of experimental glaucoma, and since activated microglia peaked at day 10, we determined a time frame of 7-14 days after MB injection as potential optimum to study glaucoma mechanisms in this model.
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Affiliation(s)
- A Trost
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria; Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
| | - K Motloch
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - D Bruckner
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - F Schroedl
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria; Anatomy, Paracelsus Medical University, Salzburg, Austria
| | - B Bogner
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - A Kaser-Eichberger
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - C Runge
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - C Strohmaier
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria
| | - B Klein
- Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria
| | - L Aigner
- Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria
| | - H A Reitsamer
- University Clinic of Ophthalmology and Optometry, Research Program for Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University/SALK, 5020 Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University Salzburg, Austria.
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Reichenbach A, Bringmann A. Purinergic signaling in retinal degeneration and regeneration. Neuropharmacology 2015; 104:194-211. [PMID: 25998275 DOI: 10.1016/j.neuropharm.2015.05.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 02/01/2023]
Abstract
Purinergic signaling is centrally involved in mediating the degeneration of the injured and diseased retina, the induction of retinal gliosis, and the protection of the retinal tissue from degeneration. Dysregulated calcium signaling triggered by overactivation of P2X7 receptors is a crucial step in the induction of neuronal and microvascular cell death under pathogenic conditions like ischemia-hypoxia, elevated intraocular pressure, and diabetes, respectively. Overactivation of P2X7 plays also a pathogenic role in inherited and age-related photoreceptor cell death and in the age-related dysfunction and degeneration of the retinal pigment epithelium. Gliosis of micro- and macroglial cells, which is induced and/or modulated by purinergic signaling and associated with an impaired homeostatic support to neurons, and the ATP-mediated propagation of retinal gliosis from a focal injury into the surrounding noninjured tissue are involved in inducing secondary cell death in the retina. On the other hand, alterations in the glial metabolism of extracellular nucleotides, resulting in a decreased level of ATP and an increased level of adenosine, may be neuroprotective in the diseased retina. Purinergic signals stimulate the proliferation of retinal glial cells which contributes to glial scarring which has protective effects on retinal degeneration and adverse effects on retinal regeneration. Pharmacological modulation of purinergic receptors, e.g., inhibition of P2X and activation of adenosine receptors, may have clinical importance for the prevention of photoreceptor, neuronal, and microvascular cell death in diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and glaucoma, respectively, for the clearance of retinal edema, and the inhibition of dysregulated cell proliferation in proliferative retinopathies. This article is part of a Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Andreas Reichenbach
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany.
| | - Andreas Bringmann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
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Nickells RW, Pelzel HR. Tools and resources for analyzing gene expression changes in glaucomatous neurodegeneration. Exp Eye Res 2015; 141:99-110. [PMID: 25999234 DOI: 10.1016/j.exer.2015.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 05/10/2015] [Accepted: 05/17/2015] [Indexed: 01/12/2023]
Abstract
Evaluating gene expression changes presents one of the most powerful interrogative approaches to study the molecular, biochemical, and cellular pathways associated with glaucomatous disease pathology. Technologies to study gene expression profiles in glaucoma are wide ranging. Qualitative techniques provide the power of localizing expression changes to individual cells, but are not robust to evaluate differences in expression changes. Alternatively, quantitative changes provide a high level of stringency to quantify changes in gene expression. Additionally, advances in high throughput analysis and bioinformatics have dramatically improved the number of individual genes that can be evaluated in a single experiment, while dramatically reducing amounts of input tissue/starting material. Together, gene expression profiling and proteomics have yielded new insights on the roles of neuroinflammation, the complement cascade, and metabolic shutdown as important players in the pathology of the optic nerve head and retina in this disease.
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Affiliation(s)
- Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin - Madison, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI, USA.
| | - Heather R Pelzel
- Department of Biological Sciences, University of Wisconsin - Whitewater, Whitewater, WI, USA
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130
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M K. Present and New Treatment Strategies in the Management of Glaucoma. Open Ophthalmol J 2015; 9:89-100. [PMID: 26069521 PMCID: PMC4460216 DOI: 10.2174/1874364101509010089] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 03/30/2015] [Accepted: 03/30/2015] [Indexed: 12/17/2022] Open
Abstract
Glaucoma is a neurodegenerative disease characterized by retinal ganglion cell (RGC) death and axonal loss. It remains a major cause of blindness worldwide. All current modalities of treatment are focused on lowering intraocular pressure (IOP), and it is evident that increased IOP is an important risk factor for progression of the disease. However, it is clear that a significant number of glaucoma patients show disease progression despite of pressure lowering treatments. Much attention has been given to the development of neuroprotective treatment strategies, but the identification of such has been hampered by lack of understanding of the etiology of glaucoma. Hence, in spite of many attempts no neuroprotective drug has yet been clinically approved. Even though neuroprotection is without doubt an important treatment strategy, many glaucoma subjects are diagnosed after substantial loss of RGCs. In this matter, recent approaches aim to rescue RGCs and regenerate axons in order to restore visual function in glaucoma. The present review seeks to provide an overview of the present and new treatment strategies in the management of glaucoma. The treatment strategies are divided into current available glaucoma medications, new pressure lowering targets, prospective neuroprotective interventions, and finally possible neuroregenrative strategies.
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Affiliation(s)
- Kolko M
- Department of Neuroscience and Pharmacology, the Panum Institute, University of Copenhagen, Denmark ; Department of Ophthalmology, Roskilde University Hospital, Copenhagen, Denmark ; Center of Healthy Aging, Department of Cellular and Molecular Medicine, the Panum Institute, University of Copenhagen, Denmark
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131
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Stein JD, Talwar N, Kang JH, Okereke OI, Wiggs JL, Pasquale LR. Bupropion use and risk of open-angle glaucoma among enrollees in a large U.S. managed care network. PLoS One 2015; 10:e0123682. [PMID: 25875446 PMCID: PMC4395241 DOI: 10.1371/journal.pone.0123682] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 02/21/2015] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Tumor Necrosis Factor (TNF) mediates retinal ganglion cell death in glaucoma. Anti-TNF drugs are neuroprotective in an animal model of glaucoma. It is unclear whether medications with anti-TNF properties such as bupropion have an impact on the risk of developing open-angle glaucoma (OAG) in humans. The purpose of this study is to determine whether bupropion use alters the risk of developing OAG. METHODS Claims data for beneficiaries age ≥35 years with no pre-existing OAG enrolled in a large nationwide U.S. managed care network continuously for ≥4 years between 2001-2011 was analyzed to identify patients who had been newly-diagnosed with OAG. The amount of bupropion use as captured from outpatient pharmacy claims over a four-year period was also quantified for each beneficiary. Multivariable Cox regression modeling assessed the impact of bupropion and other antidepressant medications on the risk of developing OAG with adjustment for sociodemographic characteristics of the enrollees along with medical and ocular comorbidities. RESULTS Of 638,481 eligible enrollees, 15,292 (2.4%) developed OAG. After adjustment for confounding factors including use of other antidepressant medication classes, each additional month of bupropion use was associated with a 0.6% reduced risk of OAG (HR = 0.994, (95% CI: 0.989-0.998), p = 0.007). Compared to nonusers, those with 24-48 months of bupropion use had a 21% reduced hazard (HR=0.79, (CI: 0.65-0.94), p = 0.0099) of OAG. This association did not differ among persons taking bupropion for depression or for other reasons (p-interaction = 0.82). There was no significant association between use of tricyclic antidepressants (HR = 1.000, (CI: 0.997-1.004), p = 0.95) or selective serotonin reuptake inhibitors (HR = 0.999, (CI: 0.997-1.001), p = 0.39) and development of OAG. CONCLUSION These findings suggest bupropion use may be beneficial in reducing the risk of OAG. If prospective studies confirm the findings of this analysis, this may identify a novel therapeutic target for OAG.
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Affiliation(s)
- Joshua D. Stein
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
| | - Nidhi Talwar
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jae H. Kang
- Department of Medicine, Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Olivia I. Okereke
- Department of Medicine, Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Harvard School of Public Health, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Psychiatry, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Janey L. Wiggs
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Louis R. Pasquale
- Department of Medicine, Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
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Kyung H, Kwong JMK, Bekerman V, Gu L, Yadegari D, Caprioli J, Piri N. Celastrol supports survival of retinal ganglion cells injured by optic nerve crush. Brain Res 2015; 1609:21-30. [PMID: 25813825 DOI: 10.1016/j.brainres.2015.03.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 03/14/2015] [Accepted: 03/16/2015] [Indexed: 10/23/2022]
Abstract
The present study evaluates the effect of celastrol on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). Celastrol, a quinine methide triterpene extracted from the perennial vine Tripterygium wilfordii (Celastraceae), has been identified as a potential neuroprotective candidate in a comprehensive drug screen against various neurodegenerative diseases. Two weeks after ONC, the average density of remaining RGCs in retinas of animals treated with daily intraperitoneal (i.p.) injections of celastrol (1mg/kg) was approximately 1332 cells/mm(2), or 40.8% of the Celastrol/Control group. In retinas of the Vehicle/ONC group about 381 RGCs/mm(2) were counted, which is 9.6% of the total number of RGCs in the DMSO/Control group. This corresponds to approximately a 250% increase in RGC survival mediated by celastrol treatment compared to Vehicle/ONC group. Furthermore, the average RGC number in retinas of ONC animals treated with a single intravitreal injection of 1mg/kg or 5mg/kg of celastrol was increased by approximately 80% (760 RGCs/mm(2)) and 78% (753 RGCs/mm(2)), respectively, compared to Vehicle/ONC controls (422 cells/mm(2)). Injection of 0.2mg/kg of celastrol had no significant effect on cell survival, with the average number of RGCs being 514 cells/mm(2) in celastrol-treated animals versus 422 cells/mm(2) in controls. The expression levels of Hsp70, Hsf1, Hsf2, HO-1 and TNF-alpha in the retina were analyzed to evaluate the roles of these proteins in the celastrol-mediated protection of injured RGCs. No statistically significant change in HO-1, Hsf1 and Hsp70 levels was seen in animals with ONC. An approximately 2 fold increase in Hsf2 level was observed in celastrol-treated animals with or without injury. Hsf2 level was also increased 1.8 fold in DMSO-treated animals with ONC injury compared to DMSO-treated animals with no injury suggesting that Hsf2 induction has an injury-induced component. Expression of TNF-alpha in retinas of celastrol-treated uninjured and ONC animals was reduced by approximately 2 and 1.5 fold compared to vehicle treated animals, respectively. The observed results suggest that mechanisms underlying celastrol׳s RGC protective effect are associated with inhibition of TNF-alpha-mediated cell death.
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Affiliation(s)
- Haksu Kyung
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA; National Medical Center, Seoul, Republic of Korea
| | - Jacky M K Kwong
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Vlad Bekerman
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Lei Gu
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Daniel Yadegari
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Joseph Caprioli
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA; Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Natik Piri
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA; Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA.
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133
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Contribution of microglia-mediated neuroinflammation to retinal degenerative diseases. Mediators Inflamm 2015; 2015:673090. [PMID: 25873768 PMCID: PMC4385698 DOI: 10.1155/2015/673090] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/16/2014] [Indexed: 12/27/2022] Open
Abstract
Retinal degenerative diseases are major causes of vision loss and blindness worldwide and are characterized by chronic and progressive neuronal loss. One common feature of retinal degenerative diseases and brain neurodegenerative diseases is chronic neuroinflammation. There is growing evidence that retinal microglia, as in the brain, become activated in the course of retinal degenerative diseases, having a pivotal role in the initiation and propagation of the neurodegenerative process. A better understanding of the events elicited and mediated by retinal microglia will contribute to the clarification of disease etiology and might open new avenues for potential therapeutic interventions. This review aims at giving an overview of the roles of microglia-mediated neuroinflammation in major retinal degenerative diseases like glaucoma, age-related macular degeneration, and diabetic retinopathy.
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135
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Song W, Huang P, Zhang C. Neuroprotective therapies for glaucoma. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:1469-79. [PMID: 25792807 PMCID: PMC4362661 DOI: 10.2147/dddt.s80594] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Glaucoma is the second leading cause for blindness worldwide. It is mainly caused by glaucomatous optic neuropathy (GON) characterized by retinal ganglion cell loss, which leads to visual field defect and blindness. Up to now, the main purpose of antiglaucomatous therapies has been to lower intraocular pressure (IOP) through surgeries and medications. However, it has been found that progressive GON is still present in some patients with effective IOP decrease. Therefore, risk factors other than IOP elevation, like neurotrophin deprivation and excitotoxicity, contribute to progressive GON. Novel approaches of neuroprotection may be more effective for preserving the function of the optic nerve.
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Affiliation(s)
- Wei Song
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Ping Huang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Chun Zhang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
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136
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Wei Z, Spizzo I, Diep H, Drummond GR, Widdop RE, Vinh A. Differential phenotypes of tissue-infiltrating T cells during angiotensin II-induced hypertension in mice. PLoS One 2014; 9:e114895. [PMID: 25501574 PMCID: PMC4263711 DOI: 10.1371/journal.pone.0114895] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 11/15/2014] [Indexed: 12/26/2022] Open
Abstract
Hypertension remains the leading risk factor for cardiovascular disease (CVD). Experimental hypertension is associated with increased T cell infiltration into blood pressure-controlling organs, such as the aorta and kidney; importantly in absence of T cells of the adaptive immune system, experimental hypertension is significantly blunted. However, the function and phenotype of these T cell infiltrates remains speculative and undefined in the setting of hypertension. The current study compared T cell-derived cytokine and reactive oxygen species (ROS) production from normotensive and hypertensive mice. Splenic, blood, aortic, kidney and brain T cells were isolated from C57BL/6J mice following 14-day vehicle or angiotensin (Ang) II (0.7 mg/kg/day, s.c.) infusion. T cell infiltration was increased in aorta, kidney and brain from hypertensive mice. Cytokine analysis in stimulated T cells indicated an overall Th1 pro-inflammatory phenotype, but a similar proportion (flow cytometry) and quantity (cytometric bead array) of IFN-γ, TNF-α, IL-4 and IL-17 between vehicle- and Ang II- treated groups. Strikingly, elevated T cell-derived production of a chemokine, chemokine C-C motif ligand 2 (CCL2), was observed in aorta (∼6-fold) and kidney in response to Ang II, but not in brain, spleen or blood. Moreover, T cell-derived ROS production in aorta was elevated ∼3 -fold in Ang II-treated mice (n = 7; P<0.05). Ang II-induced hypertension does not affect the overall T cell cytokine profile, but enhanced T cell-derived ROS production and/or leukocyte recruitment due to elevated CCL2, and this effect may be further amplified with increased infiltration of T cells. We have identified a potential hypertension-specific T cell phenotype that may represent a functional contribution of T cells to the development of hypertension, and likely several other associated vascular disorders.
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Affiliation(s)
- Zihui Wei
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Iresha Spizzo
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Henry Diep
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Grant R Drummond
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Robert E Widdop
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Antony Vinh
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
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Mac Nair CE, Fernandes KA, Schlamp CL, Libby RT, Nickells RW. Tumor necrosis factor alpha has an early protective effect on retinal ganglion cells after optic nerve crush. J Neuroinflammation 2014; 11:194. [PMID: 25407441 PMCID: PMC4245774 DOI: 10.1186/s12974-014-0194-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/03/2014] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Glaucoma is an optic neuropathy that is characterized by the loss of retinal ganglion cells (RGCs) initiated by damage to axons in the optic nerve. The degeneration and death of RGCs has been thought to occur in two waves. The first is axogenic, caused by direct insult to the axon. The second is somatic, and is thought to be caused by the production of inflammatory cytokines from the activated retinal innate immune cells. One of the cytokines consistently linked to glaucoma and RGC damage has been TNFα. Despite strong evidence implicating this protein in neurodegeneration, a direct injection of TNFα does not mimic the rapid loss of RGCs observed after acute optic nerve trauma or exposure to excitotoxins. This suggests that our understanding of TNFα signaling is incomplete. METHODS RGC death was induced by optic nerve crush in mice. The role of TNFα in this process was examined by quantitative PCR of Tnfα gene expression, and quantification of cell loss in Tnfα (-/-) mice or in wild-type animals receiving an intraocular injection of exongenous TNFα either before or after crush. Signaling pathways downstream of TNFα were examined by immunolabeling for JUN protein accumulation or activation of EGFP expression in NFκB reporter mice. RESULTS Optic nerve crush caused a modest increase in Tnfα gene expression, with kinetics similar to the activation of both macroglia and microglia. A pre-injection of TNFα attenuated ganglion cell loss after crush, while ganglion cell loss was more severe in Tnfα (-/-) mice. Conversely, over the long term, a single exposure to TNFα induced extrinsic apoptosis in RGCs. Müller cells responded to exogenous TNFα by accumulating JUN and activating NFκB. CONCLUSION Early after optic nerve crush, TNFα appears to have a protective role for RGCs, which may be mediated through Müller cells.
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Affiliation(s)
- Caitlin E Mac Nair
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A MSC - 1300 University Ave., Madison, WI, 53706, USA. .,Cellular and Molecular Pathology Graduate Program, University of Wisconsin, 3170-10 K/L MFCB - 1685 Highland Ave., Madison, WI, 53705, USA.
| | - Kimberly A Fernandes
- Flaum Eye Institute, University of Rochester Medical Center, 601 Elmwood Ave., Box 659, Rochester, NY, 14642, USA.
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A MSC - 1300 University Ave., Madison, WI, 53706, USA.
| | - Richard T Libby
- Flaum Eye Institute, University of Rochester Medical Center, 601 Elmwood Ave., Box 659, Rochester, NY, 14642, USA. .,Department of Biomedical Genetics, University of Rochester Medical Center, 601 Elmwood Ave., Box 633, Rochester, NY, 14642, USA. .,The Center for Visual Sciences, University of Rochester Medical Center, 274 Meliora Hall, RC Box 270270, Rochester, NY, 14627, USA.
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A MSC - 1300 University Ave., Madison, WI, 53706, USA.
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Taurone S, Ripandelli G, Pacella E, Bianchi E, Plateroti AM, De Vito S, Plateroti P, Grippaudo FR, Cavallotti C, Artico M. Potential regulatory molecules in the human trabecular meshwork of patients with glaucoma: immunohistochemical profile of a number of inflammatory cytokines. Mol Med Rep 2014; 11:1384-90. [PMID: 25351602 DOI: 10.3892/mmr.2014.2772] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 05/02/2014] [Indexed: 11/06/2022] Open
Abstract
Glaucoma occurs when there are imbalances between the production and the drainage of the eye liquid. The vast majority of the aqueous humor leaves the eye through the trabecular meshwork (TM). The cause of hypertonicity may be due to an alteration in the thickness of the TM. In the majority of cases the molecular changes that determine primary open‑angle glaucoma (POAG) are unclear. However, it has been hypothesized that the significant increase in the extracellular matrix (ECM) of the fibrillary bands in the TM is associated with possible inflammatory conditions. In this study the tissue distribution of interleukin (IL)‑6, IL‑1β, transforming growth factor-β1 (TGF‑β1), vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF‑α) was analyzed in TM samples from patients with POAG by immunohistochemistry. Seven specimens from patients with POAG and three control tissues were analyzed by immunohistochemistry using specific antibodies against these cytokines. Morphological changes in the TM, such as increased cell content, macrophages, fibrosis and accumulation of neutrophils, were observed by transmission electron microscopy. In human TM tissues, an evident immunoreactivity for IL‑6, IL‑1β and TNF‑α was observed in patients with POAG when compared with the control subjects, indicating that these cytokines may be correlated with disease activity. TM endothelial cells secrete a number of factors and cytokines that modulate the functions of the cells and the ECM of the conventional outflow pathway. In the TM in glaucoma, macrophages produce cytokines, including IL‑6, IL‑1β and TNF‑α, leading to an acute inflammatory response and recruitment of other immune cells, including T lymphocytes. In addition, TGF‑β1 regulates and induces the expression of IL‑6 in TM that indirectly induces angiogenesis by stimulating VEGF expression. The present results support previous evidence that suggests that growth factors and cytokines can induce ECM remodelling and alter cytoskeletal interactions in the TM.
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Affiliation(s)
- Samanta Taurone
- Department of Sensory Organs, Sapienza University of Rome, Rome 00161, Italy
| | | | - Elena Pacella
- Department of Sensory Organs, Sapienza University of Rome, Rome 00161, Italy
| | - Enrica Bianchi
- Department of Sensory Organs, Sapienza University of Rome, Rome 00161, Italy
| | | | - Stefania De Vito
- Department of Anatomical, Histological, Medico‑legal and Locomotor System Sciences, Rome 00161, Italy
| | - Pasquale Plateroti
- Department of Sensory Organs, Sapienza University of Rome, Rome 00161, Italy
| | - Francesca Romana Grippaudo
- Department of Neurosciences, Mental Health and Sensory Organs, II Faculty of Medicine and Surgery, Sapienza University of Rome, Rome 00189, Italy
| | - Carlo Cavallotti
- Department of Anatomical, Histological, Medico‑legal and Locomotor System Sciences, Rome 00161, Italy
| | - Marco Artico
- Department of Sensory Organs, Sapienza University of Rome, Rome 00161, Italy
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139
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Hong S, Iizuka Y, Lee T, Kim CY, Seong GJ. Neuroprotective and neurite outgrowth effects of maltol on retinal ganglion cells under oxidative stress. Mol Vis 2014; 20:1456-62. [PMID: 25352751 PMCID: PMC4203576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 10/15/2014] [Indexed: 11/04/2022] Open
Abstract
PURPOSE To evaluate the neuroprotective and neurite outgrowth effects of maltol, a natural aroma compound, on retinal ganglion cells (RGCs) under oxidative stress in vitro. METHODS Mouse primary RGCs were isolated using immunopanning-magnetic separation and exposed to H2O2 in the presence of maltol. The cell viability and apoptosis were determined by using adenosine 5'-triphosphate (ATP) assay and terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), respectively. Neurite outgrowth was assessed by immunofluorescence for α-tubulin. The activation of nuclear factor-κB (NF-κB) was also evaluated using immunofluorescence. RESULTS When the RGCs were exposed to 20 μM of H2O2 for 16 h, their viability dropped to 40.3±3.4%. However, the maltol treatment restored the cells in a dose-dependent manner. The viability recovered to 73.9±5.1% with 10 μM of maltol and even reached 175.1±11.3% with 2 mM of maltol, as measured by ATP assay. This oxidative stress significantly increased the number of TUNEL-positive RGCs, but the maltol drastically reduced the proportion of those apoptotic cells. The oxidative stress hampered the neurite outgrowth of the RGCs, whereas maltol restored their ability to sprout neurites. Regarding NF-κB, the active form of phosphorylated NF-κB (pNF-κB) increased the oxidative stress level but the maltol treatment again reduced it to an unstressful level. CONCLUSIONS Our data revealed that maltol attenuated the oxidative stress-induced injury in the primary mouse RGCs. Its neuroprotective and neurite outgrowth effects seemed to be related to NF-κB signaling. Maltol has potential as a new neuroprotective therapeutic agent for oxidative stress-related ocular diseases, including glaucoma.
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Affiliation(s)
- Samin Hong
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yoko Iizuka
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Taekjune Lee
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chan Yun Kim
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Gong Je Seong
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
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140
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Martínez-Fernández de la Cámara C, Olivares-González L, Hervás D, Salom D, Millán JM, Rodrigo R. Infliximab reduces Zaprinast-induced retinal degeneration in cultures of porcine retina. J Neuroinflammation 2014; 11:172. [PMID: 25301432 PMCID: PMC4200228 DOI: 10.1186/s12974-014-0172-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 09/25/2014] [Indexed: 01/24/2023] Open
Abstract
Background cGMP-degrading phosphodiesterase 6 (PDE6) mutations cause around 4 to 5% of retinitis pigmentosa (RP), a rare form of retinal dystrophy. Growing evidence suggests that inflammation is involved in the progression of RP. The aims of this study were to corroborate the presence of high TNFα concentration in the eyes of RP patients and to evaluate whether the blockade of TNFα with Infliximab, a monoclonal anti-TNFα antibody, prevented retinal degeneration induced by PDE6 inhibition in cultures of porcine retina. Methods Aqueous humor from 30 patients with RP and 13 healthy controls were used to quantify the inflammatory mediators IL-6, TNFα, IL-1β, IL-10 by a multiplex enzyme-linked immunosorbent assay (ELISA) system. Retinal explants from pig were exposed to Zaprinast, a PDE6 inhibitor, for 24 hours in the absence or the presence of Infliximab. Cell death was evaluated by TUNEL assay. The number and distribution of caspase-3 positive cells, indirect poly(ADP)ribose polymerase (PARP) activation and glial fibrillary acidic protein (GFAP) content were visualized by immunolabeling. Antioxidant total capacity, nitrites and thiobarbituric acid reactive substances (TBARS) formation were determined to evaluate antioxidant-oxidant status. Results IL-6 and TNFα concentrations were higher in the aqueous humor of RP patients than in controls. Infliximab prevented retinal degeneration, as judging by the reduced presence of TUNEL-positive cells, the reduction of caspase-3 activation and also reduction of glial activation, in an ex vivo model of porcine retina. Additionally, Infliximab partially reduced oxidative stress in retinal explants exposed to Zaprinast. Conclusions Inflammatory mediators IL-6 and TNFα were elevated in the aqueous humor of RP patients corroborating previous studies suggesting sustained chronic inflammation. Our study suggests that TNFα is playing an important role in cell death in an ex vivo model of retinal degeneration by activating different cell pathways at different cell layers of the retina that should be further studied. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0172-9) contains supplementary material, which is available to authorized users.
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141
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Abstract
The characterization of genes responsible for glaucoma is the critical first step toward the development of gene-based diagnostic and screening tests, which could identify individuals at risk for disease before irreversible optic nerve damage occurs. Early-onset forms of glaucoma affecting children and young adults are typically inherited as Mendelian autosomal dominant or recessive traits whereas glaucoma affecting older adults has complex inheritance. In this report, we present a comprehensive overview of the genes and genomic regions contributing to inherited glaucoma.
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Affiliation(s)
- Ryan Wang
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114
| | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114
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142
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The role of glial cells and the complement system in retinal diseases and Alzheimer’s disease: common neural degeneration mechanisms. Exp Brain Res 2014; 232:3363-77. [DOI: 10.1007/s00221-014-4078-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 08/19/2014] [Indexed: 02/07/2023]
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143
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Abstract
Lowe syndrome is a rare X-linked congenital disease that presents with congenital cataracts and glaucoma, as well as renal and cerebral dysfunction. OCRL, an inositol polyphosphate 5-phosphatase, is mutated in Lowe syndrome. We previously showed that OCRL is involved in vesicular trafficking to the primary cilium. Primary cilia are sensory organelles on the surface of eukaryotic cells that mediate mechanotransduction in the kidney, brain, and bone. However, their potential role in the trabecular meshwork (TM) in the eye, which regulates intraocular pressure, is unknown. Here, we show that TM cells, which are defective in glaucoma, have primary cilia that are critical for response to pressure changes. Primary cilia in TM cells shorten in response to fluid flow and elevated hydrostatic pressure, and promote increased transcription of TNF-α, TGF-β, and GLI1 genes. Furthermore, OCRL is found to be required for primary cilia to respond to pressure stimulation. The interaction of OCRL with transient receptor potential vanilloid 4 (TRPV4), a ciliary mechanosensory channel, suggests that OCRL may act through regulation of this channel. A novel disease-causing OCRL allele prevents TRPV4-mediated calcium signaling. In addition, TRPV4 agonist GSK 1016790A treatment reduced intraocular pressure in mice; TRPV4 knockout animals exhibited elevated intraocular pressure and shortened cilia. Thus, mechanotransduction by primary cilia in TM cells is implicated in how the eye senses pressure changes and highlights OCRL and TRPV4 as attractive therapeutic targets for the treatment of glaucoma. Implications of OCRL and TRPV4 in primary cilia function may also shed light on mechanosensation in other organ systems.
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144
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Toll-like receptor 4 in bone marrow-derived cells contributes to the progression of diabetic retinopathy. Mediators Inflamm 2014; 2014:858763. [PMID: 25214718 PMCID: PMC4156976 DOI: 10.1155/2014/858763] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 06/25/2014] [Accepted: 07/24/2014] [Indexed: 01/24/2023] Open
Abstract
Diabetic retinopathy (DR) is a major microvascular complication in diabetics, and its mechanism is not fully understood. Toll-like receptor 4 (TLR4) plays a pivotal role in the maintenance of the inflammatory state during DR, and the deletion of TLR4 eventually alleviates the diabetic inflammatory state. To further elucidate the mechanism of DR, we used bone marrow transplantation to establish reciprocal chimeric animals of TLR4 mutant mice and TLR4 WT mice combined with diabetes mellitus (DM) induction by streptozotocin (STZ) treatment to identify the role of TLR4 in different cell types in the development of the proinflammatory state during DR. TLR4 mutation did not block the occurrence of high blood glucose after STZ injection compared with WT mice but did alleviate the progression of DR and alter the expression of the small vessel proliferation-related genes, vascular endothelial growth factor (VEGF), and hypoxia inducible factor-1α (HIF-1α). Grafting bone marrow-derived cells from TLR4 WT mice into TLR4 mutant mice increased the levels of TNF-α, IL-1β, and MIP-2 and increased the damage to the retina. Similarly, VEGF and HIF-1α expression were restored by the bone marrow transplantation. These findings identify an essential role for TLR4 in bone marrow-derived cells contributing to the progression of DR.
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145
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Dang Y, Xu Y, Wu W, Li W, Sun Y, Yang J, Zhu Y, Zhang C. Tetrandrine suppresses lipopolysaccharide-induced microglial activation by inhibiting NF-κB and ERK signaling pathways in BV2 cells. PLoS One 2014; 9:e102522. [PMID: 25115855 PMCID: PMC4130469 DOI: 10.1371/journal.pone.0102522] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 06/19/2014] [Indexed: 01/08/2023] Open
Abstract
Background and Objective Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid extracted from Stephania tetrandra Moore. Recent studies have suggested that TET can reduce the inflammatory response in microglia, but the mechanisms remain unclear. The aim of this study is to investigate whether TET can inhibit lipopolysaccharide (LPS)-induced microglial activation and clarify its possible mechanisms. Study Design/Materials and Methods Cell viability assays and cell apoptosis assays were used to determine the working concentrations of TET. Then, BV2 cells were seeded and pretreated with TET for 2 h. LPS was then added and incubated for an additional 24 hours. qRT-PCR and ELISA were used to measure the mRNA or protein levels of IL1β and TNFα. Western blotting was utilized to quantify the expression of CD11b and cell signaling proteins. Results TET at optimal concentrations (0.1 µM, 0.5 µM or 1 µM) did not affect the cell viability. After TET pretreatment, the levels of IL1β and TNFα (both in transcription and translation) were significantly inhibited in a dose-dependent manner. Further studies indicated that phospho-p65, phospho-IKK, and phospho-ERK 1/2 expression were also suppressed by TET. Conclusions Our results indicate that TET can effectively suppress microglial activation and inhibit the production of IL1β and TNFα by regulating the NF-kB and ERK signaling pathways. Together with our previous studies, we suggest that TET would be a promising candidate to effectively suppress overactivated microglia and alleviate neurodegeneration in glaucoma.
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Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Yongsheng Xu
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Wentao Wu
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
| | - Weiyi Li
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Yanran Sun
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Jing Yang
- Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China
| | - Yu Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China
- * E-mail: (YZ); (CZ)
| | - Chun Zhang
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
- * E-mail: (YZ); (CZ)
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Cuenca N, Fernández-Sánchez L, Campello L, Maneu V, De la Villa P, Lax P, Pinilla I. Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases. Prog Retin Eye Res 2014; 43:17-75. [PMID: 25038518 DOI: 10.1016/j.preteyeres.2014.07.001] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 01/17/2023]
Abstract
Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies.
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Affiliation(s)
- Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain; Multidisciplinary Institute for Environmental Studies "Ramon Margalef", University of Alicante, Alicante, Spain.
| | - Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Pedro De la Villa
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Aragon Institute of Health Sciences, Zaragoza, Spain
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147
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Soto I, Howell GR. The complex role of neuroinflammation in glaucoma. Cold Spring Harb Perspect Med 2014; 4:cshperspect.a017269. [PMID: 24993677 DOI: 10.1101/cshperspect.a017269] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Glaucoma is a multifactorial neurodegenerative disorder affecting 80 million people worldwide. Loss of retinal ganglion cells and degeneration of their axons in the optic nerve are the major pathological hallmarks. Neuroinflammatory processes, inflammatory processes in the central nervous system, have been identified in human glaucoma and in experimental models of the disease. Furthermore, neuroinflammatory responses occur at early stages of experimental glaucoma, and inhibition of certain proinflammatory pathways appears neuroprotective. Here, we summarize the current understanding of neuroinflammation in the central nervous system, with emphasis on events at the optic nerve head during early stages of glaucoma.
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Affiliation(s)
- Ileana Soto
- The Jackson Laboratory, Bar Harbor, Maine 04609
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, Maine 04609 School of Medicine, Tufts University, Boston, Massachusetts 02111
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148
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Abstract
In glaucoma, regardless of its etiology, retinal ganglion cells degenerate and eventually die. Although age and elevated intraocular pressure (IOP) are the main risk factors, there are still many mysteries in the pathogenesis of glaucoma. The advent of genome-wide microarray expression screening together with the availability of animal models of the disease has allowed analysis of differential gene expression in all parts of the eye in glaucoma. This review will outline the findings of recent genome-wide expression studies and discuss their commonalities and differences. A common finding was the differential regulation of genes involved in inflammation and immunity, including the complement system and the cytokines transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα). Other genes of interest have roles in the extracellular matrix, cell-matrix interactions and adhesion, the cell cycle, and the endothelin system.
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Affiliation(s)
- Tatjana C Jakobs
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114
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149
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Dysregulation of neurotrophic and inflammatory systems accompanied by decreased CREB signaling in ischemic rat retina. Exp Eye Res 2014; 125:156-63. [PMID: 24954538 DOI: 10.1016/j.exer.2014.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 05/30/2014] [Accepted: 06/03/2014] [Indexed: 12/22/2022]
Abstract
Although permanent bilateral common carotid artery occlusion (2VO) has been demonstrated to induce retinal injury, there is still a lack of systematic research on the complex processing of retinal degeneration. In the present study, time-dependent (at three, 14, 60 days after 2VO surgery) changes of neurotrophic and inflammatory systems, as well as cAMP-responsive element binding protein (CREB) signaling, which has been previously reported to effectively regulate these two systems, were evaluated. First, a morphological study confirmed that 2VO surgery progressively induced severe inner retinal degeneration and down-regulation of synaptic proteins, PSD95 and synaptophysin. The mRNA or protein levels of neurotrophic factors (NGF, BDNF, NT-3 and GDNF) and their receptors (TrkA, TrkB and TrkC) showed marked and persistent down-regulation in the rat retina since three days after 2VO surgery, whereas the gene transcription levels of CNTF were increased and p75(NTR) mRNA levels remained unchanged. In contrast to inner retinal degeneration, retinal Müller cells displayed rapid and prolonged activation since three days after 2VO lesion, whereas the microglia cell number, and TNF-α and IL-1β levels showed a robust increase with a maximal effect at three days and returned to levels that were slightly over baseline at 14 and 60 days after 2VO lesion. Interestingly, the gene expression levels of iNOS significantly decreased in the rat retina at both three and 14 days after 2VO surgery. Finally, as we hypothesized, remarkable reduction of CREB and extracellular signal-regulated kinase (ERK) phosphorylation levels were observed in the rat retina at three days after 2VO surgery. Thus, for the first time, our study demonstrated that chronic ischemia induced long-term aberrant CREB signaling and time-dependent progressive dysregulation of neurotrophic and inflammatory systems in the retina, which may provide important clues for a better understanding of the pathogenesis of retinal ischemic damage.
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150
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Zhao J, Ha Y, Liou GI, Gonsalvez GB, Smith SB, Bollinger KE. Sigma receptor ligand, (+)-pentazocine, suppresses inflammatory responses of retinal microglia. Invest Ophthalmol Vis Sci 2014; 55:3375-84. [PMID: 24812552 PMCID: PMC4042630 DOI: 10.1167/iovs.13-12823] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 04/29/2014] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To evaluate the effects of the σ 1 receptor (σR1) agonist, (+)-pentazocine, on lipopolysaccharide (LPS)-induced inflammatory changes in retinal microglia cells. METHODS Retinal microglia cells were isolated from Sprague-Dawley rat pups. Cells were treated with LPS with or without (+)-pentazocine and with or without the σR1 antagonist BD1063. Morphologic changes were assayed. Cell viability was assessed by using MTT assay. Supernatant levels of tumor necrosis factor α (TNF-α), interleukin 10, (IL-10), monocyte chemoattractant protein-1 (MCP-1), and nitric oxide (NO) were determined. Reactive oxygen species (ROS) formation was assayed, and levels of mitogen-activated protein kinases (MAPKs) were analyzed by using Western blot. RESULTS The σR1 protein was expressed in retinal microglia. Incubation with LPS and/or (+)-pentazocine did not alter cell viability or σR1 protein levels. Incubation with LPS for 24 hours induced a marked change in microglial morphology and a significant increase in secreted levels of TNF-α, IL-10, MCP-1, and NO. Pretreatment with (+)-pentazocine inhibited the LPS-induced morphologic changes. Release of TNF-α, IL-10, MCP-1, and NO was reduced with (+)-pentazocine. Intracellular ROS formation was suppressed with (+)-pentazocine. Phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was reduced in the presence of (+)-pentazocine. The σR1 antagonist BD1063 blocked the (+)-pentazocine-mediated inhibition of LPS-induced morphologic changes. In addition, BD1063 treatment blocked (+)-pentazocine-mediated suppression of LPS-induced TNF-α, IL-10, MCP-1, NO, and intracellular ROS release. CONCLUSIONS Treatment with (+)-pentazocine suppressed inflammatory responses of retinal microglia and inhibited LPS-induced activation of ERK/JNK MAPK. In neurodegenerative disease, (+)-pentazocine may exert neuroprotective effects through manipulation of microglia.
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Affiliation(s)
- Jing Zhao
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
| | - Yonju Ha
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Gregory I. Liou
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
- Department of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Graydon B. Gonsalvez
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Sylvia B. Smith
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
| | - Kathryn E. Bollinger
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
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