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Jeltsch BM, Hanson JVM, Füglistaler J, Heyard R, Sisera L, Wehrle FM, Hagmann CF, Fauchère JC, Gerth-Kahlert C. The Effect of Perinatal High-Dose Erythropoietin on Retinal Structural and Vascular Characteristics in Children Born Preterm. Am J Ophthalmol 2024; 266:264-273. [PMID: 38880371 DOI: 10.1016/j.ajo.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 06/05/2024] [Accepted: 06/05/2024] [Indexed: 06/18/2024]
Abstract
PURPOSE To study the long-term effects of perinatal high-dose recombinant human erythropoietin (rhEPO) on macular structural and vascular development in preterm children. DESIGN Randomized, double-blind clinical trial follow-up plus cohort study. METHODS Setting: Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland. STUDY POPULATION extremely or very preterm born children aged 7-15 years from an ongoing neuropediatric study (EpoKids). These had been previously randomized to receive either high-dose rhEPO or placebo perinatally. INCLUSION CRITERIA participation in the EpoKids Study, written informed consent (IC). EXCLUSION CRITERIA previous ocular trauma or surgery; retinal or developmental disease unrelated to prematurity. Term-born children of comparable age were enrolled as a healthy control (HC) group. INCLUSION CRITERIA term birth, IC. EXCLUSION CRITERIA any ocular or visual abnormality, high refractive error. Examiners were blinded regarding intervention status until completion of all analyses. (Participants/guardians remain blinded). OBSERVATION PROCEDURES Spectral-domain OCT scans (Heidelberg Spectralis system) and OCTA imaging (Zeiss PlexElite 9000) were obtained. Ophthalmological and orthoptic examinations excluded ocular comorbidities. MAIN OUTCOME MEASURES OCT (central retinal thickness, CRT; total macular volume, TMV), superficial plexus OCTA (foveal avascular zone, FAZ; vessel density, VD; vessel length density, VLD) parameters and foveal hypoplasia grade according to published criteria. RESULTS Macular vessel density parameters (VD and VLD) were significantly lower (p =0.015, CI-95: 0.01 to 0.06 and p=0.015, CI-95: 0.74 to 3.64) in the EPO group (n= 52) when compared to placebo (n=35). No other significant differences were observed between the EPO and placebo group. When comparing the intervention subgroups to HC we found six significant differences in OCT and OCTA parameters (FAZ, VD, VLD and CRT comparing HC and EPO group; FAZ and CRT when comparing HC and placebo group). CONCLUSIONS Early high-dose rhEPO in infants born extremely or very preterm affects macular vessel density parameters compared to placebo. Premature birth (regardless of intervention status) affects retinal structure and vascular development. Our findings on macular vascular development do not contraindicate the administration of early high-dose EPO in preterm infants. For further understanding of the role of EPO on macular development and its clinical significance, future studies are needed.
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Affiliation(s)
- Brida M Jeltsch
- From the Department of Ophthalmology (B.M.J., J.V.M.H., L.S., C.G-K.), University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - James V M Hanson
- From the Department of Ophthalmology (B.M.J., J.V.M.H., L.S., C.G-K.), University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Jonas Füglistaler
- Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute (J.F., R.H.), University of Zurich, Zurich, Switzerland
| | - Rachel Heyard
- Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute (J.F., R.H.), University of Zurich, Zurich, Switzerland
| | - Lorena Sisera
- From the Department of Ophthalmology (B.M.J., J.V.M.H., L.S., C.G-K.), University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Flavia M Wehrle
- Department of Neonatology and Pediatric Intensive Care (F.M.W., C.F.H), University Children's Hospital Zurich, Zurich, Switzerland
| | - Cornelia F Hagmann
- Department of Neonatology and Pediatric Intensive Care (F.M.W., C.F.H), University Children's Hospital Zurich, Zurich, Switzerland
| | - Jean-Claude Fauchère
- Department of Neonatology (J-C.F.), University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Christina Gerth-Kahlert
- From the Department of Ophthalmology (B.M.J., J.V.M.H., L.S., C.G-K.), University Hospital Zurich and University of Zurich, Zurich, Switzerland.
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Erythropoietin in Glaucoma: From Mechanism to Therapy. Int J Mol Sci 2023; 24:ijms24032985. [PMID: 36769310 PMCID: PMC9917746 DOI: 10.3390/ijms24032985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023] Open
Abstract
Glaucoma can cause irreversible vision loss and is the second leading cause of blindness worldwide. The disease mechanism is complex and various factors have been implicated in its pathogenesis, including ischemia, excessive oxidative stress, neurotropic factor deprivation, and neuron excitotoxicity. Erythropoietin (EPO) is a hormone that induces erythropoiesis in response to hypoxia. However, studies have shown that EPO also has neuroprotective effects and may be useful for rescuing apoptotic retinal ganglion cells in glaucoma. This article explores the relationship between EPO and glaucoma and summarizes preclinical experiments that have used EPO to treat glaucoma, with an aim to provide a different perspective from the current view that glaucoma is incurable.
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Lin TY, Lai YF, Chen YH, Lu DW. The Latest Evidence of Erythropoietin in the Treatment of Glaucoma. Int J Mol Sci 2022; 23:ijms232416038. [PMID: 36555679 PMCID: PMC9784015 DOI: 10.3390/ijms232416038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/06/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Erythropoietin (EPO) is a circulating hormone conventionally considered to be responsible for erythropoiesis. In addition to facilitating red blood cell production, EPO has pluripotent potential, such as for cognition improvement, neurogenesis, and anti-fibrotic, anti-apoptotic, anti-oxidative, and anti-inflammatory effects. In human retinal tissues, EPO receptors (EPORs) are expressed in the photoreceptor cells, retinal pigment epithelium, and retinal ganglion cell layer. Studies have suggested its potential therapeutic effects in many neurodegenerative diseases, including glaucoma. In this review, we discuss the correlation between glaucoma and EPO, physiology and potential neuroprotective function of the EPO/EPOR system, and latest evidence for the treatment of glaucoma with EPO.
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Affiliation(s)
| | | | | | - Da-Wen Lu
- Correspondence: ; Tel.: +886-2-87927163
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4
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Traumatic optic neuropathy: a review of current studies. Neurosurg Rev 2022; 45:1895-1913. [PMID: 35034261 DOI: 10.1007/s10143-021-01717-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/26/2021] [Accepted: 12/09/2021] [Indexed: 10/24/2022]
Abstract
Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.
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Feizi S, Alemzadeh-Ansari M, Karimian F, Esfandiari H. Use of erythropoietin in ophthalmology: a review. Surv Ophthalmol 2021; 67:427-439. [PMID: 34157346 DOI: 10.1016/j.survophthal.2021.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 12/17/2022]
Abstract
Erythropoietin (EPO) is a glycoprotein hormone that regulates hematopoiesis in the human body. The presence of EPO and its receptors in different tissues indicates that this hormone has extramedullary effects in other tissues, including the eye. We focus on the biological roles of this hormone in the development and normal physiologic functions of the eye. Furthermore, we explore the role of EPO in the management of different ocular diseases - including diabetic retinopathy, retinopathy of prematurity, inherited retinal degeneration, branch and central retinal vein occlusion, retinal detachment, traumatic optic neuropathy, optic neuritis, methanol optic neuropathy, nonarteritic anterior ischemic optic neuropathy, glaucoma, and scleral necrosis.
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Affiliation(s)
- Sepehr Feizi
- Ophthalmic Research Center, Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | | | - Farid Karimian
- Ophthalmic Research Center, Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Esfandiari
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
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Park KT, Han JK, Kim SJ, Lim YH. Gamma-Aminobutyric Acid Increases Erythropoietin by Activation of Citrate Cycle and Stimulation of Hypoxia-Inducible Factors Expression in Rats. Biomolecules 2020; 10:E595. [PMID: 32290638 PMCID: PMC7226430 DOI: 10.3390/biom10040595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/04/2020] [Accepted: 04/09/2020] [Indexed: 02/07/2023] Open
Abstract
Erythropoietin (EPO) is the primary regulator of erythropoiesis in the mammalian fetus and adult. Deficiency of EPO induces anemia. In this study, we investigated the effect of gamma-aminobutyric acid (GABA) on serum EPO levels and erythropoiesis in rats. Expression levels of Epo-related genes were measured by quantitative real-time PCR (qPCR) and expression of Epo and Epo receptor (Epor) proteins were measured by immunohistochemistry. The gene and protein expression profiles of kidney tissue in GABA-treated rats were evaluated by ribonucleic acid (RNA) sequencing and two-dimensional electrophoresis (2-DE), respectively. GABA significantly increased serum EPO levels and expression levels of Epo and Epor. GABA increased expression levels of hypoxia-inducible factor (Hif)-1 and Hif-2. Seven proteins with expression levels showing >2-fold change were identified by 2-DE followed by MALDI-TOF MS in GABA-treated rat kidney. The top KEGG pathway from the identified proteins was the tricarboxylic acid cycle, and nicotinamide adenine dinucleotide (NADH) dehydrogenase, succinate dehydrogenase, and isocitrate dehydrogenase were identified as key proteins. GABA treatment significantly increased ATP levels and NADH dehydrogenase activity in a dose-dependent manner. In conclusion, GABA shows a new physiological role in EPO production, and it can thus can contribute to the prevention of anemia when used alone or in combination with other anemia treating drugs.
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Affiliation(s)
- Keun-Tae Park
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
- Department of Integrated Biomedical and Life Sciences, College of Health Science, Korea University, Seoul 02841, Korea
| | - Jong-Kwon Han
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
| | - Seong Jin Kim
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
| | - Young-Hee Lim
- Department of Integrated Biomedical and Life Sciences, College of Health Science, Korea University, Seoul 02841, Korea
- Department of Public Health Science (BK21 PLUS Program), Graduate School, Korea University, Seoul 02841, Korea
- Department of Laboratory Medicine, Korea University Guro Hospital, Seoul 08308, Korea
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Rossino MG, Dal Monte M, Casini G. Relationships Between Neurodegeneration and Vascular Damage in Diabetic Retinopathy. Front Neurosci 2019; 13:1172. [PMID: 31787868 PMCID: PMC6856056 DOI: 10.3389/fnins.2019.01172] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes and constitutes a major cause of vision impairment and blindness in the world. DR has long been described exclusively as a microvascular disease of the eye. However, in recent years, a growing interest has been focused on the contribution of neuroretinal degeneration to the pathogenesis of the disease, and there are observations suggesting that neuronal death in the early phases of DR may favor the development of microvascular abnormalities, followed by the full manifestation of the disease. However, the mediators that are involved in the crosslink between neurodegeneration and vascular changes have not yet been identified. According to our hypothesis, vascular endothelial growth factor (VEGF) could probably be the most important connecting link between the death of retinal neurons and the occurrence of microvascular lesions. Indeed, VEGF is known to play important neuroprotective actions; therefore, in the early phases of DR, it may be released in response to neuronal suffering, and it would act as a double-edged weapon inducing both neuroprotective and vasoactive effects. If this hypothesis is correct, then any retinal stress causing neuronal damage should be accompanied by VEGF upregulation and by vascular changes. Similarly, any compound with neuroprotective properties should also induce VEGF downregulation and amelioration of the vascular lesions. In this review, we searched for a correlation between neurodegeneration and vasculopathy in animal models of retinal diseases, examining the effects of different neuroprotective substances, ranging from nutraceuticals to antioxidants to neuropeptides and others and showing that reducing neuronal suffering also prevents overexpression of VEGF and vascular complications. Taken together, the reviewed evidence highlights the crucial role played by mediators such as VEGF in the relationship between retinal neuronal damage and vascular alterations and suggests that the use of neuroprotective substances could be an efficient strategy to prevent the onset or to retard the development of DR.
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Affiliation(s)
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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Pietrucha-Dutczak M, Amadio M, Govoni S, Lewin-Kowalik J, Smedowski A. The Role of Endogenous Neuroprotective Mechanisms in the Prevention of Retinal Ganglion Cells Degeneration. Front Neurosci 2018; 12:834. [PMID: 30524222 PMCID: PMC6262299 DOI: 10.3389/fnins.2018.00834] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Retinal neurons are not able to undergo spontaneous regeneration in response to damage. A variety of stressors, i.e., UV radiation, high temperature, ischemia, allergens, and others, induce reactive oxygen species production, resulting in consecutive alteration of stress-response gene expression and finally can lead to cell apoptosis. Neurons have developed their own endogenous cellular protective systems. Some of them are preventing cell death and others are allowing functional recovery after injury. The high efficiency of these mechanisms is crucial for cell survival. In this review we focus on the contribution of the most recently studied endogenous neuroprotective factors involved in retinal ganglion cell (RGC) survival, among which, neurotrophic factors and their signaling pathways, processes regulating the redox status, and different pathways regulating cell death are the most important. Additionally, we summarize currently ongoing clinical trials for therapies for RGC degeneration and optic neuropathies, including glaucoma. Knowledge of the endogenous cellular protective mechanisms may help in the development of effective therapies and potential novel therapeutic targets in order to achieve progress in the treatment of retinal and optic nerve diseases.
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Affiliation(s)
- Marita Pietrucha-Dutczak
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Marialaura Amadio
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Joanna Lewin-Kowalik
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Adrian Smedowski
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
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EphrinB/EphB forward signaling in Müller cells causes apoptosis of retinal ganglion cells by increasing tumor necrosis factor alpha production in rat experimental glaucomatous model. Acta Neuropathol Commun 2018; 6:111. [PMID: 30355282 PMCID: PMC6201539 DOI: 10.1186/s40478-018-0618-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/12/2018] [Indexed: 01/26/2023] Open
Abstract
It was previously shown that EphB/ephrinB reverse signaling in retinal ganglion cells (RGCs) is activated and involved in RGC apoptosis in a rat chronic ocular hypertension (COH) model. In the present work, we first show that ephrinB/EphB forward signaling was activated in COH retinas, and RGC apoptosis in COH retinas was reduced by PP2, an inhibitor of ephrinB/EphB forward signaling. We further demonstrate that treatment of cultured Müller cells with ephrinB1-Fc, an EphB1 activator, or intravitreal injection of ephrinB1-Fc in normal rats induced an increase in phosphorylated EphB levels in these cells, indicating the activation of ephrinB/EphB forward signaling, similar to those in COH retinas. The ephrinB1-Fc treatment did not induce Müller cell gliosis, as evidenced by unchanged GFAP expression, but significantly up-regulated mRNA and protein levels of tumor necrosis factor-α (TNF-α) in Müller cells, thereby promoting RGC apoptosis. Production of TNF-α induced by the activation of ephrinB/EphB forward signaling was mediated by the NR2B subunit of NMDA receptors, which was followed by a distinct PI3K/Akt/NF-κB signaling pathway, as pharmacological interference of each step of this pathway caused a reduction of TNF-α production, thus attenuating RGC apoptosis. Functional analysis of forward and reverse signaling in such a unique system, in which ephrin and Eph exist respectively in a glial element and a neuronal element, is of theoretical importance. Moreover, our results also raise a possibility that suppression of ephrinB/EphB forward signaling may be a new strategy for ameliorating RGC apoptosis in glaucoma.
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Adeghate J, Rahmatnejad K, Waisbourd M, Katz LJ. Intraocular pressure-independent management of normal tension glaucoma. Surv Ophthalmol 2018; 64:101-110. [PMID: 30300625 DOI: 10.1016/j.survophthal.2018.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 08/15/2018] [Accepted: 08/20/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Jennifer Adeghate
- Wills Eye Hospital, Glaucoma Research Department, Philadelphia, Pennsylvania, USA; Weill Cornell Medical College, Department of Ophthalmology, New York, New York, USA
| | - Kamran Rahmatnejad
- Wills Eye Hospital, Glaucoma Research Department, Philadelphia, Pennsylvania, USA
| | - Michael Waisbourd
- Wills Eye Hospital, Glaucoma Research Department, Philadelphia, Pennsylvania, USA; Thomas Jefferson University, Department of Ophthalmology, Philadelphia, Pennsylvania, USA; Tel-Aviv University Medical Center, Glaucoma Research Center, Tel-Aviv, Israel
| | - L Jay Katz
- Wills Eye Hospital, Glaucoma Research Department, Philadelphia, Pennsylvania, USA; Thomas Jefferson University, Department of Ophthalmology, Philadelphia, Pennsylvania, USA.
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de Carvalho LA, Fleming R, Sant’Anna M, Guimarães R, Dantas AM, Morizot-Leite E, Cavalcante LA, Allodi S. Neuroprotective effects of erythropoietin on rat retinas subjected to oligemia. Clinics (Sao Paulo) 2018; 73:e161. [PMID: 29694605 PMCID: PMC5890171 DOI: 10.6061/clinics/2018/e161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES Erythropoietin may have neuroprotective potential after ischemia of the central nervous system. Here, we conducted a study to characterize the protective effects of erythropoietin on retinal ganglion cells and gliotic reactions in an experimentally induced oligemia model. METHODS Rats were subjected to global oligemia by bilateral common carotid artery occlusion and then received either vehicle or erythropoietin via intravitreal injection after 48 h; they were euthanized one week after the injection. The densities of retinal ganglion cells and contents of glial fibrillary acidic protein (astrocytes/Müller cells) and cluster of differentiation 68 clone ED1 (microglia/macrophages), assessed by fluorescence intensity, were evaluated in frozen retinal sections by immunofluorescence and epifluorescence microscopy. RESULTS Retinal ganglion cells were nearly undetectable one week after oligemia compared with the sham controls; however, these cells were partially preserved in erythropoietin-treated retinas. The contents of glial fibrillary acidic protein and cluster of differentiation 68 clone ED1, markers for reactive gliosis, were significantly higher in retinas after bilateral common carotid artery occlusion than those in both sham and erythropoietin-treated retinas. CONCLUSIONS The number of partially preserved retinal ganglion cells in the erythropoietin-treated group suggests that erythropoietin exerts a neuroprotective effect on oligemic/ischemic retinas. This effect could be related to the down-modulation of glial reactivity, usually observed in hypoxic conditions, clinically observed during glaucoma or retinal artery occlusion conditions. Therefore, glial reactivity may enhance neurodegeneration in hypoxic conditions, like normal-tension glaucoma and retinal ischemia, and erythropoietin is thus a candidate to be clinically applied after the detection of decreased retinal blood flow.
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Affiliation(s)
- Litia Alves de Carvalho
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
- Experimental Therapeutics and Molecular Imaging Laboratory, Neuroscience Center, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, USA
- Corresponding authors. E-mails: /
| | - Renata Fleming
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
- Experimental Therapeutics and Molecular Imaging Laboratory, Neuroscience Center, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, USA
| | - Moysés Sant’Anna
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Roberta Guimarães
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Adalmir Morterá Dantas
- Hospital Universitário Clementino Fraga Filho, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | | | - Leny A. Cavalcante
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Silvana Allodi
- Programa de Neurobiologia, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
- Corresponding authors. E-mails: /
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12
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Stifter J, Ulbrich F, Goebel U, Böhringer D, Lagrèze WA, Biermann J. Neuroprotection and neuroregeneration of retinal ganglion cells after intravitreal carbon monoxide release. PLoS One 2017; 12:e0188444. [PMID: 29176876 PMCID: PMC5703485 DOI: 10.1371/journal.pone.0188444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/07/2017] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Retinal ischemia induces apoptosis leading to neurodegeneration and vision impairment. Carbon monoxide (CO) in gaseous form showed cell-protective and anti-inflammatory effects after retinal ischemia-reperfusion-injury (IRI). These effects were also demonstrated for the intravenously administered CO-releasing molecule (CORM) ALF-186. This article summarizes the results of intravitreally released CO to assess its suitability as a neuroprotective and neuroregenerative agent. METHODS Water-soluble CORM ALF-186 (25 μg), PBS, or inactivated ALF (iALF) (all 5 μl) were intravitreally applied into the left eyes of rats directly after retinal IRI for 1 h. Their right eyes remained unaffected and were used for comparison. Retinal tissue was harvested 24 h after intervention to analyze mRNA or protein expression of Caspase-3, pERK1/2, p38, HSP70/90, NF-kappaB, AIF-1 (allograft inflammatory factor), TNF-α, and GAP-43. Densities of fluorogold-prelabeled retinal ganglion cells (RGC) were examined in flat-mounted retinae seven days after IRI and were expressed as mean/mm2. The ability of RGC to regenerate their axon was evaluated two and seven days after IRI using retinal explants in laminin-1-coated cultures. Immunohistochemistry was used to analyze the different cell types growing out of the retinal explants. RESULTS Compared to the RGC-density in the contralateral right eyes (2804±214 RGC/mm2; data are mean±SD), IRI+PBS injection resulted in a remarkable loss of RGC (1554±159 RGC/mm2), p<0.001. Intravitreally injected ALF-186 immediately after IRI provided RGC protection and reduced the extent of RGC-damage (IRI+PBS 1554±159 vs. IRI+ALF 2179±286, p<0.001). ALF-186 increased the IRI-mediated phosphorylation of MAP-kinase p38. Anti-apoptotic and anti-inflammatory effects were detectable as Caspase-3, NF-kappaB, TNF-α, and AIF-1 expression were significantly reduced after IRI+ALF in comparison to IRI+PBS or IRI+iALF. Gap-43 expression was significantly increased after IRI+ALF. iALF showed effects similar to PBS. The intrinsic regenerative potential of RGC-axons was induced to nearly identical levels after IRI and ALF or iALF-treatment under growth-permissive conditions, although RGC viability differed significantly in both groups. Intravitreal CO further increased the IRI-induced migration of GFAP-positive cells out of retinal explants and their transdifferentiation, which was detected by re-expression of beta-III tubulin and nestin. CONCLUSION Intravitreal CORM ALF-186 protected RGC after IRI and stimulated their axons to regenerate in vitro. ALF conveyed anti-apoptotic, anti-inflammatory, and growth-associated signaling after IRI. CO's role in neuroregeneration and its effect on retinal glial cells needs further investigation.
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Affiliation(s)
- Julia Stifter
- Eye Center, Medical Center—University of Freiburg, Killianstrasse 5, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Felix Ulbrich
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Anesthesiology and Intensive Care, Medical Center—University of Freiburg, Hugstetter Strasse 55, Freiburg, Germany
| | - Ulrich Goebel
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Anesthesiology and Intensive Care, Medical Center—University of Freiburg, Hugstetter Strasse 55, Freiburg, Germany
| | - Daniel Böhringer
- Eye Center, Medical Center—University of Freiburg, Killianstrasse 5, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Wolf Alexander Lagrèze
- Eye Center, Medical Center—University of Freiburg, Killianstrasse 5, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia Biermann
- Eye Center, Medical Center—University of Freiburg, Killianstrasse 5, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Ophthalmology, University of Muenster Medical Center, Domagkstrasse 15, Muenster, Germany
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The Erythropoietin System Protects the Heart Upon Injury by Cardiac Progenitor Cell Activation. VITAMINS AND HORMONES 2017. [PMID: 28629520 DOI: 10.1016/bs.vh.2017.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Erythropoietin (EPO) is a growth hormone, widely known for its role in erythropoiesis. The broad expression of erythropoietin receptor (EPOR) in adult organs suggested that EPO may also affect other cells besides late erythroid progenitors. In the embryonic heart, EPOR is expressed in all cells including the immature proliferating cardiomyocytes. In contrast to the embryonic heart in adulthood, EPOR expression is decreased and mainly detected in immature proliferating cells (i.e., resident cardiac progenitor cells) rather than in terminally differentiated cells (i.e., cardiomyocytes). Since cardiac progenitor cells are considered a regenerative cell source upon cardiac injury, the protective action of the EPO system was tested by creating an erythroid-rescued EPOR knockout mouse model. Although these mice appear to have less immature proliferating myocytes during embryogenesis, they reach adulthood without apparent morphological defects. However, upon ischemia reperfusion, these animals show a greater infarct size, suggesting that the EPO/EPOR protects the heart upon injury. Indeed preclinical studies showed that EPO administration postinfarction improves cardiac function via neoangiogenesis, antiapoptotic mechanisms, and/or CPC activation. Despite the promising preclinical data, large cohort clinical studies in humans failed to show a significant amelioration in cardiac function upon systemic injection of EPO in patients with myocardial infarctions. The discrepancy between preclinical and clinical trials may be due to differences between the doses, the way of delivery, the homogeneity of the cohorts, and last but not least the species differences. These data pinpoint the importance of carrying out preclinical studies in human models of disease as engineered human cardiac tissue that will provide a better understanding of the expression pattern of EPOR and the role of its ligand in human cardiac cells. Such studies may be able to bridge the gap between preclinical rodent data and human clinical trials and thus lead to the design of more successful clinical studies.
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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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Virus-mediated EpoR76E gene therapy preserves vision in a glaucoma model by modulating neuroinflammation and decreasing oxidative stress. J Neuroinflammation 2016; 13:39. [PMID: 26876380 PMCID: PMC4753658 DOI: 10.1186/s12974-016-0499-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 02/01/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Glaucoma is a complex neurodegeneration and a leading cause of blindness worldwide. Current therapeutic strategies, which are all directed towards lowering the intraocular pressure (IOP), do not stop progression of the disease. We have demonstrated that recombinant adeno-associated virus (rAAV) gene delivery of a form of erythropoietin with attenuated erythropoietic activity (EpoR76E) can preserve retinal ganglion cells, their axons, and vision without decreasing IOP. The goal of this study was to determine if modulation of neuroinflammation or oxidative stress played a role in the neuroprotective activity of EPO.R76E. METHODS Five-month-old DBA/2J mice were treated with either rAAV.EpoR76E or a control vector and collected at 8 months of age. Neuroprotection was assessed by quantification of axon transport and visual evoked potentials. Microglia number and morphology and cytokine and chemokine levels were quantified. Message levels of oxidative stress-related proteins were assessed. RESULTS Axon transport and visual evoked potentials were preserved in rAAV.EpoR76E-treated mice. The number of microglia was decreased in retinas from 8-month-old rAAV.EpoR76E-treated mice, but proliferation was unaffected. The blood-retina barrier was also unaffected by treatment. Levels of some pro-inflammatory cytokines were decreased in retinas from rAAV.EpoR76E-treated mice including IL-1, IL-12, IL-13, IL-17, CCL4, and CCL5. TNFα messenger RNA (mRNA) was increased in retinas from 8-month-old mice compared to 3-month-old controls regardless of treatment. Expression of several antioxidant proteins was increased in retinas of rAAV.EpoR76E-treated 8-month-old mice. CONCLUSIONS Treatment with rAAV.EpoR76E preserves vision in the DBA/2J model of glaucoma at least in part by decreasing infiltration of peripheral immune cells, modulating microglial reactivity, and decreasing oxidative stress.
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Wang Y, Zhang H, Liu Y, Li P, Cao Z, Cao Y. Erythropoietin (EPO) protects against high glucose-induced apoptosis in retinal ganglional cells. Cell Biochem Biophys 2015; 71:749-55. [PMID: 25287674 DOI: 10.1007/s12013-014-0259-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The aim of this study was to investigate the protective effect and mechanism of EPO on the apoptosis induced by high levels of glucose in retinal ganglial cells (RGCs). High glucose-induced apoptosis model was established in RGCs isolated from SD rats (1-3 days old) and identified with Thy1.1 mAb and MAP-2 pAb. The apoptosis was determined by Hochest assay. The levels of ROS were quantitated by staining the cells with dichloro-dihydro-fluorescein diacetate (DCFH-DA) and measure by flow cytometry. The SOD, GSH-Px, CAT activities, and levels of T-AOC and MDA were determined by ELISA. Change in mitochondrial membrane potential (Δψm) was also assessed by flow cytometry, and expressions of Bcl-2, Bax, caspase-3, caspase-9, and cytochrome C were assessed by western blotting. The RGCs treated with high glucose levels exhibited significantly increased apoptotic rate and concentrations of ROS and MDA. Pretreatment of the cells with EPO caused a significant blockade of the high glucose-induced increase in ROS and MDA levels and apoptotic rate. EPO also increased the activities of SOD, GSH-Px, and CAT, and recovered the levels of T-AOC levels. As a consequence, the mitochondrial membrane potential was improved and Cyt c release into the cytoplasm was prevented which led to significantly suppressed up-regulation of Bax reducing the Bax/Bcl-2 ratio. The expressions of caspase-3 and caspase-9 induced by high glucose exposure were also ameliorated in the RGCs treated with EPO. The protective effect of EPO against apoptosis was mediated through its antioxidant action. Thus, it blocked the generation of pro-apoptotic proteins and apoptotic degeneration of the RGCs by preventing the mitochondrial damage.
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Affiliation(s)
- Yunxiao Wang
- The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
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Morrone LA, Rombolà L, Corasaniti MT, Bagetta G, Nucci C, Russo R. Natural compounds and retinal ganglion cell neuroprotection. PROGRESS IN BRAIN RESEARCH 2015; 220:257-81. [PMID: 26497795 DOI: 10.1016/bs.pbr.2015.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Glaucoma, the second leading cause of blindness in the world, is a chronic optic neuropathy often associated with increased intraocular pressure and characterized by progressive retinal ganglion cell (RGC) axons degeneration and death leading to typical optic nerve head damage and distinctive visual field defects. Although the pathogenesis of glaucoma is still largely unknown, it is hypothesized that RCGs become damaged through various insults/mechanisms, including ischemia, oxidative stress, excitotoxicity, defective axonal transport, trophic factor withdrawal, and neuroinflammation. In this review, we summarize the potential benefits of several natural compounds for RGCs neuroprotection.
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Affiliation(s)
- Luigi Antonio Morrone
- Department of Pharmacy and Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, Arcavacata di Rende, Italy; University Consortium for Adaptive Disorders and Head Pain (UCHAD), Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy.
| | - Laura Rombolà
- Department of Pharmacy and Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, Arcavacata di Rende, Italy
| | | | - Giacinto Bagetta
- Department of Pharmacy and Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, Arcavacata di Rende, Italy; University Consortium for Adaptive Disorders and Head Pain (UCHAD), Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Rossella Russo
- Department of Pharmacy and Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, Arcavacata di Rende, Italy
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Wong M, Huang P, Li W, Li Y, Zhang SS, Zhang C. T-helper1/T-helper2 cytokine imbalance in the iris of patients with glaucoma. PLoS One 2015; 10:e0122184. [PMID: 25811482 PMCID: PMC4374700 DOI: 10.1371/journal.pone.0122184] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/08/2015] [Indexed: 12/19/2022] Open
Abstract
The mechanistic study of glaucoma pathogenesis has shifted to seeking to understand the effects of immune responses on retinal ganglion cell damage and protection. Cytokines mediate the biological effects of the immune system, and our previous study revealed an imbalance of T-helper (Th) 1-derived and Th2-derived cytokines in the serum of patients with glaucoma. In this study, we collected irises from normal individuals and patients with primary open-angle closure (POAG) or chronic angle-closure glaucoma (CACG). We used real-time polymerase chain reaction (PCR) to measure the expression of Th1 (interleukin (IL)-2, interferon-gamma (IFN-γ)), Th2 (IL-4, IL-6, IL-10), and Th3 (transforming growth factor-beta (TGF-β)) cytokines. We then performed immunohistochemical staining to characterize the localization of the upregulated cytokines in iris cryosections. We observed an upward trend in the expression of IL-2 and IFN-γ and a downward trend in IL-6 expression in the iris of POAG and CACG patients. Expression of TGF-β also increased. Immunohistochemistry revealed that IL-2 expression in POAG and CACG patients was localized in the anterior surface of the blood vessel wall in the stroma of the iris, in the cytoplasm of some cells, in the anterior epithelium, and in the posterior pigment epithelium. These findings indicate that immune status differed between the iris tissues of POAG and CACG patients and those of normal individuals. A T-helper cytokine imbalance may modulate the immune microenvironment in glaucomatous eyes and thus influence optic neuropathy.
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Affiliation(s)
- ManSin Wong
- Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, China
| | - Ping Huang
- Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, China
- * E-mail:
| | - Weiyi Li
- Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, China
- Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Li
- Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, China
| | - Samuel S. Zhang
- Department of Neural & Behavioral Sciences, Penn State University, Hershey, Pennsylvania, United States of America
| | - Chun Zhang
- Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, China
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Gui D, Li Y, Chen X, Gao D, Yang Y, Li X. HIF‑1 signaling pathway involving iNOS, COX‑2 and caspase‑9 mediates the neuroprotection provided by erythropoietin in the retina of chronic ocular hypertension rats. Mol Med Rep 2014; 11:1490-6. [PMID: 25370745 DOI: 10.3892/mmr.2014.2859] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 08/22/2014] [Indexed: 11/05/2022] Open
Abstract
This study aimed to investigate the impacts of erythropoietin (EPO) on the electroretinogram b‑wave (ERG‑b), and on the mRNA and protein expression levels of hypoxia‑inducible factor‑1α (HIF‑1α), inducible nitric oxide synthase (iNOS), cyclooxygenase‑2 (COX‑2) and caspase‑9 in chronic ocular hypertension rats. Episcleral vein cauterization (EVC) was used to establish the chronic ocular hypertension rat model based on the intraocular pressure (IOP) value. ERG‑b and mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 in normal, EVC‑treated and EVC combined with EPO (EVC+EPO)‑treated rats were measured by electroretinography, RT‑PCR and western blotting, respectively. Moreover, the correlations of HIF‑1α with IOP, ERG‑b, iNOS, COX‑2 and caspase‑9 were evaluated. The mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 in EVC‑treated rats were increased significantly compared with normal rats. The peak expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 were respectively obtained 7, 7, 7 and 14 days postoperatively. Compared with EVC‑treated rats, EPO administration weakened the mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9. The mRNA expression level of HIF‑1α demonstrated a significant positive correlation with IOP and ERG‑b. HIF‑1α was positively correlated with iNOS, COX‑2 and caspase‑9 at the mRNA and protein levels. The protective effect of EPO on the retina of chronic ocular hypertension rats may be mediated by the HIF‑1 signaling pathway involving iNOS, COX‑2 and caspase‑9.
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Affiliation(s)
- Dongmei Gui
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Yanfeng Li
- Department of Neurosurgery, The People's Hospital of Liaoning Province, Shenyang, Liaoning 110025, P.R. China
| | - Xiaolong Chen
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Dianwen Gao
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Yang Yang
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Xun Li
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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Seitz R, Ohlmann A, Tamm ER. The role of Müller glia and microglia in glaucoma. Cell Tissue Res 2013; 353:339-45. [PMID: 23779255 DOI: 10.1007/s00441-013-1666-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 05/16/2013] [Indexed: 02/04/2023]
Abstract
Cells of Müller glia and microglia react to neuronal injury in glaucoma. The change to a reactive phenotype initiates signaling cascades that may serve a neuroprotective role, but may also proceed to promote damaging effects on retinal neurons. Both effects appear to occur most likely in parallel in glaucoma, but the underlying mechanisms and signaling pathways that specifically promote protective versus destructive roles of reactive glial cells are mostly unclear. More research is needed to understand the homeostatic signaling network in which retinal glia cells are embedded to maintain or restore neuronal function after injury.
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Affiliation(s)
- Roswitha Seitz
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätstr. 31, 93053, Regensburg, Germany
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Erythropoietin promotes axonal regeneration after optic nerve crush in vivo by inhibition of RhoA/ROCK signaling pathway. Neuropharmacology 2012; 63:1182-90. [DOI: 10.1016/j.neuropharm.2012.06.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 11/23/2022]
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Chen F, Xie Z, Wu X, Du W, Wang J, Zhu J, Ji H, Wang Y. Intravitreal injection of soluble erythropoietin receptor exacerbates photoreceptor cell apoptosis in a rat model of retinal detachment. Curr Eye Res 2012; 37:1156-64. [PMID: 22906152 DOI: 10.3109/02713683.2012.713156] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To evaluate the effects of intravitreal injection of soluble erythropoietin (EPO) receptor (sEPOR) on photoreceptor cell apoptosis in an animal model of retinal detachment (RD). METHODS Various dosages of sEPOR (2, 20, or 200 ng) were injected into the vitreous cavities of normal rats. Three days after injection, retinal function was measured by flash electroretinography (ERG). On day 7, histopathology and retinal morphology were examined by light and transmission electron microscopy (TEM), respectively. Rat models of RD were successfully established by injection of 1.4% sodium hyaluronate into the subretinal space, followed by immediate injection of phosphate-buffered saline (PBS) or sEPOR into the vitreous cavity. On day 3, photoreceptor cell apoptosis was evaluated using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and caspase-3 activity assayed by Western blotting and immunofluorescence. Light microscopic examination of retinal histopathology was used to determine the thickness of the outer nuclear layer (ONL) 14 days after establishment of RD. RESULTS There were no significant differences in the latency and amplitude of maximal a, b and oscillatory potential (OP) wave responses by flash ERG before or 3 days after sEPOR injection (p > 0.05). Retinal tissues showed no obvious pathological changes by either light or transmission electron microscopy. Both Western blotting and immunofluorescence indicated consistent sEPOR enhanced caspase-3 activation aggravated apoptosis of photoreceptor cells in RD rat retinas. On day 14, RD ONLs were thinner, according to increasing dosages of sEPOR. CONCLUSION Intravitreal injection of sEPOR exacerbates photoreceptor cell apoptosis in RD models via activation of caspase-3.
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Affiliation(s)
- Fang Chen
- Department of Ophthalmology, Clinical Medicine School, Yangzhou University, Subei People's Hospital of Jiangsu Province, No. 98 Nantong West Road, Yangzhou, Jiangsu, China
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Xie Z, Chen F, Wu X, Zhuang C, Zhu J, Wang J, Ji H, Wang Y, Hua X. Effects of supplemental erythropoietin on its receptor expression and signal transduction pathways in rat model of retinal detachment. Curr Eye Res 2012; 37:138-44. [PMID: 22251399 DOI: 10.3109/02713683.2011.647225] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The aim of this study was to investigate the effects of supplemental erythropoietin (EPO) on its receptor (EPOR) and signal transduction pathways in rat model of retinal detachment (RD). METHODS To investigate the effect of EPO on EPOR expression in RD rats 100, 200 or 400 ng EPO was injected into the vitreous cavity immediately after RD model was induced. Western blot and immunohistochemistry analyses were performed to measure EPOR expression. To investigate the effect of EPO on signal transduction pathways in RD rats single dose of 400 ng EPO was injected into the vitreous cavity immediately after RD model was induced. The total and phosphorylated levels of JAK2, Akt, ERK-1/2, STAT5 and NF-κB were assessed by western blot. RESULTS Western blot analysis showed that, compared with the normal control group, EPOR expression in the neurosensory retina was significantly increased in experimental RD groups (P < 0.05), but the differences were not significant between experimental RD groups (P > 0.05). Immunohistochemical examination indicated that EPOR staining on retinas became strongly positive 3 days after RD, with no significant difference in staining intensities between the treatment groups. Phosphorylated levels of JAK2, Akt, ERK-1/2, STAT5, and NF-κB were enhanced 3 days after RD, but only JAK2, Akt, and ERK-1/2 phosphorylation was further enhanced by 400 ng EPO treatment (P < 0.05). CONCLUSIONS Supplementary EPO cannot affect EPOR expression in detached retina, but EPO may activate both PI-3K/Akt and MAPK/ERK-1/2 signal transduction pathways in RD model.
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Affiliation(s)
- Zhenggao Xie
- Department of Ophthalmology, Clinical Medicine School, Yangzhou University, Subei People's Hospital of Jiangsu Province, Yangzhou, China.
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Pascale A, Drago F, Govoni S. Protecting the retinal neurons from glaucoma: lowering ocular pressure is not enough. Pharmacol Res 2012; 66:19-32. [PMID: 22433276 DOI: 10.1016/j.phrs.2012.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 02/28/2012] [Accepted: 03/05/2012] [Indexed: 01/01/2023]
Abstract
The retina is theater of a number of biochemical reactions allowing, within its layers, the conversion of light impulses into electrical signals. The axons of the last neuronal elements, the ganglion cells, form the optic nerve and transfer the signals to the brain. Therefore, an appropriate cellular communication, not only within the different retinal cells, but also between the retina itself and the other brain structures, is fundamental. One of the most diffuse pathologies affecting retinal function and communication, which thus reverberates in the whole visual system, is glaucoma. This insidious disease is characterized by a progressive optic nerve degeneration and sight loss which may finally lead to irreversible blindness. Nevertheless, the progressive nature of this pathology offers an opportunity for therapeutic intervention. To better understand the cellular processes implicated in the development of glaucoma useful to envision a targeted pharmacological strategy, this manuscript first examines the complex cellular and functional organization of the retina and subsequently identifies the targets sensitive to neurodegeneration. Within this context, high ocular pressure represents a key risk factor. However, recent literature findings highlight the concept that lowering ocular pressure is not enough to prevent/slow down glaucomatous damage, suggesting the importance of combining the hypotensive treatment with other pharmacological approaches, such as the use of neuroprotectants. Therefore, this important and more novel aspect is extensively considered in this review, also emphasizing the idea that the neuroprotective strategy should be extended to the entire visual system and not restricted to the retina.
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Affiliation(s)
- Alessia Pascale
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
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Tan H, Kang X, Zhong Y, Shen X, Cheng Y, Jiao Q, Deng L. Erythropoietin upregulates growth associated protein-43 expression and promotes retinal ganglion cell axonal regeneration in vivo after optic nerve crush. Neural Regen Res 2012; 7:295-301. [PMID: 25806072 PMCID: PMC4353103 DOI: 10.3969/j.issn.1673-5374.2012.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 12/01/2011] [Indexed: 12/22/2022] Open
Abstract
In this study, we established a rat model of optic nerve crush to explore the effects of erythropoietin on retinal ganglion cell axonal regeneration. At 15 days after injury in erythropoietin treated rats, retinal ganglion cell densities in regions corresponding to the 1/6, 3/6 and 5/6 ratios of the retinal radius were significantly increased. In addition, the number of growth associated protein-43 positive axons was significantly increased at different distances (50, 250 and 500 μm) from the crush site after erythropoietin treatment. Erythropoietin significantly increased growth associated protein-43 protein levels in the retina after crush injury, as determined by western blot and immunofluorescence analysis. These results demonstrate that erythropoietin protects injured retinal ganglion cells and promotes axonal regeneration.
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Affiliation(s)
- Haibo Tan
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xin Kang
- Department of Clinical Pharmacology, Changhai Hospital Affiliated to Second Military Medical University, Shanghai 200433, China
| | - Yisheng Zhong
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xi Shen
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yu Cheng
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Qin Jiao
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Lianfu Deng
- Shanghai Institute of Traumatology and Orthopedics, Shanghai 200025, China
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Caprara C, Grimm C. From oxygen to erythropoietin: relevance of hypoxia for retinal development, health and disease. Prog Retin Eye Res 2011; 31:89-119. [PMID: 22108059 DOI: 10.1016/j.preteyeres.2011.11.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 11/01/2011] [Accepted: 11/07/2011] [Indexed: 12/20/2022]
Abstract
Photoreceptors and other cells of the retina consume large quantities of energy to efficiently convert light information into a neuronal signal understandable by the brain. The necessary energy is mainly provided by the oxygen-dependent generation of ATP in the numerous mitochondria of retinal cells. To secure the availability of sufficient oxygen for this process, the retina requires constant blood flow through the vasculature of the retina and the choroid. Inefficient supply of oxygen and nutrients, as it may occur in conditions of disturbed hemodynamics or vascular defects, results in tissue ischemia or hypoxia. This has profound consequences on retinal function and cell survival, requiring an adaptational response by cells to cope with the reduced oxygen tension. Central to this response are hypoxia inducible factors, transcription factors that accumulate under hypoxic conditions and drive the expression of a large variety of target genes involved in angiogenesis, cell survival and metabolism. Prominent among these factors are vascular endothelial growth factor and erythropoietin, which may contribute to normal angiogenesis during development, but may also cause neovascularization and vascular leakage under pathologically reduced oxygen levels. Since ischemia and hypoxia may have a role in various retinal diseases such as diabetic retinopathy and retinopathy of prematurity, studying the cellular and molecular response to reduced tissue oxygenation is of high relevance. In addition, the concept of preconditioning with ischemia or hypoxia demonstrates the capacity of the retina to activate endogenous survival mechanisms, which may protect cells against a following noxious insult. Part of these mechanisms is the local production of protective factors such as erythropoietin. Due to its plethora of effects in the retina including neuro- and vaso-protective activities, erythropoietin has gained strong interest as potential therapeutic factor for retinal degenerative diseases.
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Affiliation(s)
- Christian Caprara
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland
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Xie Z, Chen F, Wu X, Zhuang C, Zhu J, Wang J, Ji H, Wang Y, Hua X. Safety and efficacy of intravitreal injection of recombinant erythropoietin for protection of photoreceptor cells in a rat model of retinal detachment. Eye (Lond) 2011; 26:144-52. [PMID: 22020175 DOI: 10.1038/eye.2011.254] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To elucidate the safety and efficacy of exogenous erythropoietin (EPO) for the protection of photoreceptor cells in a rat model of retinal detachment (RD). METHODS Recombinant rat EPO (400 ng) was injected into the vitreous cavity of normal rats to observe the eye manifestations. Retinal function was assessed by flash electroretinograms. Histopathological examination of retinal tissue was performed at 14 days and 2 months after injection, respectively. To investigate the inhibitory effect of EPO on photoreceptor cell apoptosis in RD rats, 100, 200, or 400 ng EPO was injected into the vitreous cavity immediately after RD model establishment. Apoptosis of photoreceptor cells was determined at 3 days after injection. Caspase-3 activation was measured by western blot analysis and immunofluorescence, respectively, and the level of Bcl-X(L) expression was analyzed by western blot. RESULTS Intravitreal injection of EPO 400 ng into normal rats had no significant impact on retinal function, morphology, or structure. Apoptosis of retinal photoreceptor cells apparently increased after RD and was significantly reduced following EPO treatment. The thickness of the outer nuclear layer in the RD + 400 ng group was significantly thicker than that in other experimental RD groups both at 14 days and at 2 months after RD (P < 0.05). Western blot and immunofluorescence analyses showed decreased caspase-3 activation and increased Bcl-X(L) expression following EPO treatment. CONCLUSION Intravitreal injection of EPO 400 ng is safe, and EPO may suppress caspase-3 activation and enhance Bcl-X(L) expression, resulting in inhibition of apoptosis and protection of photoreceptor cells.
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Affiliation(s)
- Z Xie
- Department of Ophthalmology, Clinical Medical School, Yangzhou University, Yangzhou, Jiangsu, China.
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Qu J, Wang D, Grosskreutz CL. WITHDRAWN: Reprint of: Mechanisms of retinal ganglion cell injury and defense in glaucoma. Exp Eye Res 2011:S0014-4835(11)00227-2. [PMID: 21819981 DOI: 10.1016/j.exer.2011.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 04/07/2010] [Indexed: 11/30/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, doi:10.1016/j.exer.2010.04.002. The duplicate article has therefore been withdrawn.
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Affiliation(s)
- Juan Qu
- Department of Ophthalmology, Howe Laboratory of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
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Gong Y, Qiu Y, Song Z, Gu Q, Wu X, Sun X. Effects of Single Intravitreal rhEPO Injection on Light-Induced Retinal Injury in Rats. Curr Eye Res 2011; 36:739-46. [DOI: 10.3109/02713683.2011.582661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Rong X, Mo X, Ren T, Yang S, Yuan W, Dong J, Wang Y, Wang X. Neuroprotective effect of erythropoietin-loaded composite microspheres on retinal ganglion cells in rats. Eur J Pharm Sci 2011; 43:334-42. [DOI: 10.1016/j.ejps.2011.05.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/13/2011] [Accepted: 05/15/2011] [Indexed: 10/18/2022]
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Wu JH, Gao Y, Ren AJ, Zhong M, Liu L. Erythropoietin receptor antibody inhibits oxidative stress induced retinal neovascularization in mice. Int J Ophthalmol 2011; 4:243-6. [PMID: 22553653 DOI: 10.3980/j.issn.2222-3959.2011.03.05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/20/2011] [Indexed: 11/02/2022] Open
Abstract
AIM To observe the effect of erythropoietin receptor antibody (EpoRA) on oxygen-induced retinal neovascularization. METHODS C57BL / 6J mice, newly born 7 days, were exposed in high oxygen for 5 days and then placed in normal air for another 5 days, thus the animal models of retinal neovascularization were made. Experimental animals were allocated into 3 groups: normal, experimental and therapeutic. The normal group was fed in the normal environment. Into the vitreous cavity of mice in the therapeutic group were injected 2µL of EpoRA for 5 successive days. And the experimental group was injected the same amount of normal saline. Mice were sacrificed 17 days after birth and their eyeballs were removed for detection of malonaldehyde(MDA) content in the retina and by HE staining endothelial cells were counted the breaking through internal limiting membrane. RESULTS In the experimental group, MDA content in the retina was 25.11±3.46µmol/g , which was obviously less than those in the normal group(5.34±1.79µmol/g, P<0.01) and those in the therapeutic group (12.04±1.91µmol/g). Pathological sections showed the nuclear number of the endothelial cells breaking through internal limiting membrane was 0.7±0.2 in normal group, and 46.2±6.5 in high oxygen induced experimental group. In the therapeutic group injected with EpoRA, it was lowered to 24.0±5.0 (P<0.01). CONCLUSION EpoRA can effectively inhibit oxygen-induced neovascularization in retina of mouse by reducing oxidative damage.
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Affiliation(s)
- Jin-Hui Wu
- Department of Ophthalmology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
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Abstract
PURPOSE OF REVIEW The concept of neuroprotective therapy for glaucoma is that damage to retinal ganglion cells (RGCs) may be prevented by intervening in neuronal death pathways. This review focuses on strategies for neuroprotection and summarizes preclinical studies that have investigated potential agents over the last 2 years. RECENT FINDINGS Part of the challenge of studies in neuroprotection has been the utilization of an animal model that resembles human glaucoma. Several models have been utilized including acute and chronic intraocular pressure elevation, the DBA/2J mouse, optic nerve axotomy and crush. NMDA inhibitors continued to be explored however with limited success in human trials. Memantine failed to demonstrate neuroprotection in phase III clinical trials. Although its mechanism of neuroprotection has not been fully elaborated, topical brimonidine has shown some neuroprotective benefits. Exogeneous neurotrophins delay, but do not prevent, RGC death. Bioenergetic neuroprotection that is enhancing the energy supply to RGC has been explored with benefits in animal models. Other strategies include TNF-α, modulation of the immune system and inflammation, and blocking apoptotic signals and stem cells. SUMMARY Animal models of glaucoma and neuroprotective strategies continue to be refined. Establishing consensus guidelines for the execution and design of translational research in neuroprotection may optimize the facilitation of neuroprotection research.
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Sargin D, Friedrichs H, El-Kordi A, Ehrenreich H. Erythropoietin as neuroprotective and neuroregenerative treatment strategy: comprehensive overview of 12 years of preclinical and clinical research. Best Pract Res Clin Anaesthesiol 2010; 24:573-94. [PMID: 21619868 DOI: 10.1016/j.bpa.2010.10.005] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 10/11/2010] [Indexed: 12/13/2022]
Abstract
Erythropoietin (EPO), originally discovered as hematopoietic growth factor, has direct effects on cells of the nervous system that make it a highly attractive candidate drug for neuroprotection/neuroregeneration. Hardly any other compound has led to so much preclinical work in the field of translational neuroscience than EPO. Almost all of the >180 preclinical studies performed by many independent research groups from all over the world in the last 12 years have yielded positive results on EPO as a neuroprotective drug. The fact that EPO was approved for the treatment of anemia >20 years ago and found to be well tolerated and safe, facilitated the first steps of translation from preclinical findings to the clinic. On the other hand, the same fact, naturally associated with loss of patent protection, hindered to develop EPO as a highly promising therapeutic strategy for application in human brain disease. Therefore, only few clinical neuroprotection studies have been concluded, all with essentially positive and stimulating results, but no further development towards the clinic has occurred thus far. This article reviews the preclinical and clinical work on EPO for the indications neuroprotection/neuroregeneration and cognition, and hopefully will stimulate new endeavours promoting development of EPO for the treatment of human brain diseases.
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Affiliation(s)
- Derya Sargin
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Hermann-Rein Str. 3, 37075 Göttingen, Germany
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Wang ZY, Zhao KK, Zhao PQ. Erythropoietin Is Increased in Aqueous Humor of Glaucomatous Eyes. Curr Eye Res 2010; 35:680-4. [DOI: 10.3109/02713681003778780] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Fu QL, Hu B, Li X, Shao Z, Shi JB, Wu W, So KF, Mi S. LINGO-1 negatively regulates TrkB phosphorylation after ocular hypertension. Eur J Neurosci 2010; 31:1091-7. [PMID: 20377621 DOI: 10.1111/j.1460-9568.2010.07127.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The antagonism of LINGO-1, a CNS-specific negative regulator of neuronal survival, was shown to promote short-term survival of retinal ganglion cell (RGC) in an ocular hypertension model. LINGO-1 antagonists, combined with brain-derived neurotrophic factor (BDNF), can increase the length of neuron survival through an unclear molecular mechanism. To determine the relationship between LINGO-1 and BDNF/TrkB receptor in neuronal protection, we show here that LINGO-1 forms a receptor complex with TrkB and negatively regulates its activation in the retina after ocular hypertension injury. LINGO-1 antagonist antibody 1A7 or soluble LINGO-1 (LINGO-1-Fc) treatment upregulates phospho-TrkB phosphorylation and leads to RGC survival after high intraocular pressure injury. This neuronal protective effect was blocked by anti-BDNF antibody. LINGO-1 antagonism therefore promotes RGC survival by regulating the BDNF and TrkB signaling pathway after ocular hypertension.
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Affiliation(s)
- Qing-Ling Fu
- Department of Anatomy, Li Ka Shing Faculty of Medicine, and State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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Scheerer N, Dünker N, Imagawa S, Yamamoto M, Suzuki N, Fandrey J. The anemia of the newborn induces erythropoietin expression in the developing mouse retina. Am J Physiol Regul Integr Comp Physiol 2010; 299:R111-8. [DOI: 10.1152/ajpregu.00108.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hematopoietic hormone erythropoietin (Epo), regularly produced by the kidneys and the liver, is also expressed in neuronal tissue, where it has been found to mediate paracrine neuroprotective effects. In most studies exploring the rescue effects of Epo, apoptosis was exogenously induced by different cell death stimuli. Herein, we set out to study the expression and function of Epo in physiologically occurring apoptosis in a model of retinal development. We made use of an organotypic retinal wholemount culture system that resembles the physiological in vivo situation with cell connections still retained. Epo mRNA expression in the retina, liver, and kidney showed a significant increase during early development, coinciding with the anemia of the newborn. In the retina of Epo-green fluorescent protein transgenic mice, Epo-expressing cells were identified and found to be distributed in the retinal ganglion cell layer. Treatment of retinal wholemount cultures with recombinant Epo resulted in a significant decrease of apoptotic ganglion cells as well as photoreceptor cells throughout retinal development. Moreover, transforming growth factor-β-induced apoptosis was completely antagonized by Epo when both factors were simultaneously applied. Investigations on the signaling pathway revealed a decrease in Bax mRNA levels in Epo-treated retinal cells. We conclude that Epo exerts wide and prolonged neuroprotective activity in physiologically occurring apoptosis and thus contributes to proper retinal development.
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Affiliation(s)
| | - N. Dünker
- Anatomy, University of Duisburg-Essen, Essen, Germany
| | - S. Imagawa
- Graduate School of Comprehensive Human Sciences,
| | - M. Yamamoto
- Center for Tsukuba Advanced Research Alliances, University of Tsukuba, Tsukuba, Japan
| | - N. Suzuki
- Center for Tsukuba Advanced Research Alliances, University of Tsukuba, Tsukuba, Japan
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Qu J, Wang D, Grosskreutz CL. Mechanisms of retinal ganglion cell injury and defense in glaucoma. Exp Eye Res 2010; 91:48-53. [PMID: 20394744 DOI: 10.1016/j.exer.2010.04.002] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 03/23/2010] [Accepted: 04/07/2010] [Indexed: 12/22/2022]
Abstract
Glaucoma is a disease in which retinal ganglion cells (RGCs) die leading ultimately to blindness. Over the past decade and a half, information has begun to emerge regarding specific molecular responses of the retina to conditions of elevated intraocular pressure (IOP). It is now clear that the state of the RGC in glaucoma depends on a balance of pro-survival and pro-death pathways in the retina and details of these responses are still being worked out. In this review, we will discuss the evidence supporting the involvement of specific apoptotic cascades as well as the insults that trigger RGC apoptosis. In addition, we will present evidence supporting the existence of endogenous protective mechanisms as well as exogenous neuroprotective strategies.
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Affiliation(s)
- Juan Qu
- Department of Ophthalmology, Howe Laboratory of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
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Hypoxia inducible factor-1α (HIF-1α) and some HIF-1 target genes are elevated in experimental glaucoma. J Mol Neurosci 2010; 42:183-91. [PMID: 20237864 DOI: 10.1007/s12031-010-9343-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
Low levels of hypoxia have been suggested to be a mechanism of retinal damage in glaucoma. To test the hypothesis that the activation of the hypoxia-responsive transcription factor hypoxia inducible factor-1alpha (HIF-1alpha) is involved in the pathophysiology of glaucoma, we used a rat model of glaucoma to study (1) HIF-1alpha retinal protein levels by immunoblot analysis, (2) cellular localization of HIF-1alpha in the retina by immunohistochemistry, and (3) expression of retinal HIF-1 gene targets by quantitative real-time polymerase chain reaction. Glaucoma was unilaterally induced in rats by injecting hypertonic saline in episcleral veins. We find that HIF-1alpha protein was increased in the retina following elevation of intraocular pressure, specifically in Müller glia and astrocytes but not in activated microglia. Eight established HIF-1 target genes were measured in experimental glaucoma. Retinal Epo, Flt-1, Hsp-27, Pai-1, and Vegfa mRNA levels were increased and Et-1, Igf2, and Tgfbeta3 levels were decreased in the glaucomatous retinas. Thus, the increase in HIF-1alpha levels in Müller glia and astrocytes is accompanied by a marked up regulation of some, but not all, HIF-1 transcriptional targets. These data support the hypothesis that HIF-1alpha becomes transcriptionally active in astrocytes and Müller cells but not microglia or neurons in glaucoma, arguing against a global hypoxia stimulus to the retina.
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Krügel K, Wurm A, Linnertz R, Pannicke T, Wiedemann P, Reichenbach A, Bringmann A. Erythropoietin inhibits osmotic swelling of retinal glial cells by Janus kinase- and extracellular signal-regulated kinases1/2-mediated release of vascular endothelial growth factor. Neuroscience 2010; 165:1147-58. [DOI: 10.1016/j.neuroscience.2009.11.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 11/24/2022]
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Luo XG, Chiu K, Lau FHS, Lee VWH, Yung KKL, So KF. The selective vulnerability of retinal ganglion cells in rat chronic ocular hypertension model at early phase. Cell Mol Neurobiol 2009; 29:1143-51. [PMID: 19396539 DOI: 10.1007/s10571-009-9407-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Accepted: 04/13/2009] [Indexed: 10/20/2022]
Abstract
Glutamate neurotoxicity has been postulated to play a prominent role in glaucoma. In this study the possible roles of two subunits of glutamate receptors during the early phase of retinal ganglion cell (RGC) loss in a rat chronic ocular hypertension (COH) model were investigated. COH was induced by applying argon laser to the episcleral and limbal veins of the right eye of rats, the observation times were at 4, 14 and 28 days after the first laser. RGCs were retrogradely labeled by putting Fluoro-Gold (FG) on the surface of both side superior colliculus. Immunohistochemical staining using specific antibodies against N-methyl-D-aspartate receptor 1 (NR1) or glutamate receptor 2/3 (GluR2/3) was performed on the retinal sections of normal and COH eyes. Fluorescent images were captured using confocal laser scanning microscope and the number of NR1 and GluR2/3 labeled cells were counted and cell size was measured using Stereo Investigator. During the observation period, the numbers of NR1 and GluR2/3 positive RGCs in the RGC layer were reduced parallel to the loss of RGC. The dramatic loss of GluR2/3 immunoreactive neurons occurred starting immediately after the first laser to 4 days while the dramatic loss of NR1 immunoreactive neurons occurred from 14 to 28 days after the first laser. Size difference was detected in NR1 immunoreactive RGCs, large ones were more sensitive to the high ocular pressure. These results suggest that both NR1 and GluR2/3 are involved in the mediation of RGC death in the early stage of COH.
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Affiliation(s)
- Xue-Gang Luo
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, 21 Sassoon Road, Hong Kong, China
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Tezel G, Yang X, Luo C, Cai J, Kain AD, Powell DW, Kuehn MH, Pierce WM. Hemoglobin expression and regulation in glaucoma: insights into retinal ganglion cell oxygenation. Invest Ophthalmol Vis Sci 2009; 51:907-19. [PMID: 19741249 DOI: 10.1167/iovs.09-4014] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To determine expression, cellular distribution, and regulation of hemoglobin (Hb) in normal and glaucomatous tissues. METHODS Proteomic analysis of Hb expression was conducted on protein samples from ocular hypertensive and control rat eyes and human donor eyes with or without glaucoma. Proteomic findings were validated by quantitative (q)RT-PCR, Western blot analysis, immunohistochemistry, and the analysis of new Hb synthesis in culture. Hypoxic regulation of Hb expression was also studied in primary cultures of rat RGCs and macroglia and after transfer of the glia-conditioned medium to RGCs. The role of erythropoietin (EPO) signaling in Hb induction and cell survival was determined by applying recombinant (r)EPO treatment and performing EPO neutralization experiments by using soluble EPO receptor treatment of hypoxic cultures. RESULTS In vivo findings revealed Hb expression in the retina and optic nerve head macroglia and RGCs, suggesting an approximately two-fold upregulation in ocular hypertensive rat eyes and glaucomatous human donor eyes relative to the control eyes. In vitro findings collectively supported that hypoxia boosts glial Hb expression through hypoxia-inducible EPO signaling in an autocrine manner. Based on passive transfer experiments, hypoxia-induced production of glial EPO was also found to upregulate Hb expression in RGCs in a paracrine manner, thereby increasing the hypoxic survival of these neurons. CONCLUSIONS Findings of this study provide new insights into tissue oxygen transport in the inner retina and optic nerve head through the regulated expression of Hb in macroglia and RGCs. Upregulation of Hb expression appears to be an intrinsic protective mechanism to facilitate cellular oxygenation and may also provide free radical scavenging.
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Affiliation(s)
- Gülgün Tezel
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
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Bringmann A, Iandiev I, Pannicke T, Wurm A, Hollborn M, Wiedemann P, Osborne NN, Reichenbach A. Cellular signaling and factors involved in Müller cell gliosis: neuroprotective and detrimental effects. Prog Retin Eye Res 2009; 28:423-51. [PMID: 19660572 DOI: 10.1016/j.preteyeres.2009.07.001] [Citation(s) in RCA: 515] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Müller cells are active players in normal retinal function and in virtually all forms of retinal injury and disease. Reactive Müller cells protect the tissue from further damage and preserve tissue function by the release of antioxidants and neurotrophic factors, and may contribute to retinal regeneration by the generation of neural progenitor/stem cells. However, Müller cell gliosis can also contribute to neurodegeneration and impedes regenerative processes in the retinal tissue by the formation of glial scars. This article provides an overview of the neuroprotective and detrimental effects of Müller cell gliosis, with accounts on the cellular signal transduction mechanisms and factors which are implicated in Müller cell-mediated neuroprotection, immunomodulation, regulation of Müller cell proliferation, upregulation of intermediate filaments, glial scar formation, and the generation of neural progenitor/stem cells. A proper understanding of the signaling mechanisms implicated in gliotic alterations of Müller cells is essential for the development of efficient therapeutic strategies that increase the supportive/protective and decrease the destructive roles of gliosis.
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Affiliation(s)
- Andreas Bringmann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Liebigstrasse 10-14, D-04103 Leipzig, Germany.
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Fu QL, Li X, Yip H, Shao Z, Wu W, Mi S, So KF. Combined effect of brain-derived neurotrophic factor and LINGO-1 fusion protein on long-term survival of retinal ganglion cells in chronic glaucoma. Neuroscience 2009; 162:375-82. [DOI: 10.1016/j.neuroscience.2009.04.075] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 04/22/2009] [Accepted: 04/26/2009] [Indexed: 12/09/2022]
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Song BJ, Cai H, Tsai JC, Chang S, Forbes M, Del Priore LV. Intravitreal Recombinant Human Erythropoietin: A Safety Study in Rabbits. Curr Eye Res 2009; 33:750-60. [DOI: 10.1080/02713680802366602] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Brian J. Song
- Brown Glaucoma Research Laboratory, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Hui Cai
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - James C. Tsai
- Brown Glaucoma Research Laboratory, Columbia University College of Physicians and Surgeons, New York, NY, USA
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT, USA
| | - Stanley Chang
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Max Forbes
- Brown Glaucoma Research Laboratory, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Lucian V. Del Priore
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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Schallenberg M, Charalambous P, Thanos S. GM-CSF regulates the ERK1/2 pathways and protects injured retinal ganglion cells from induced death. Exp Eye Res 2009; 89:665-77. [PMID: 19560459 DOI: 10.1016/j.exer.2009.06.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 06/12/2009] [Accepted: 06/18/2009] [Indexed: 01/22/2023]
Abstract
Granulocyte-macrophage-colony-stimulating-factor (GM-CSF) is a potent hematopoietic cytokine. In the present study, we examined whether GM-CSF is neuroprotective in retinal ganglion cells (RGCs). First, we studied the expression of GM-CSF and the GM-CSF-alpha-receptor in rat and human retina and in RGC-5 cells. Then, RGC-5 cells were incubated with apoptosis-inducing agents (e.g., staurosporine, glutamate and NOR3). The cell death was assessed by Live-Death-Assays and apoptosis-related-proteins were examined by immunoblotting. In addition, the expression of phosphorylated ERK1/2-pathway-proteins after incubation with GM-CSF and after inhibiting MEK1/2 with U0126 was analyzed. To assess the in vivo-effect, first staurosporine or GM-CSF plus staurosporine was injected into the vitreous body of Sprague-Dawley rats. In a second axotomy model the optic nerve was cut and GM-CSF was injected into the vitreous body. In both models, the RGCs were labeled retrogradely with either Fluoro-Gold or 4-Di-10-Asp and counted. As a first result, we identified GM-CSF and the GM-CSF-alpha-receptor in rat and human retina as well as in RGC-5 cells. Then, in the RGC-5 cells GM-CSF counteracts induced cell death in a dose-and time-dependent manner. With respect to apoptosis, Western blot analysis revealed a decreased Bad-expression and an increased Bcl-2-expression after co-incubation with GM-CSF. Concerning signaling pathways, incubation with GM-CSF activates the ERK1/2 pathway, whereas inhibition of MEK1/2 with U0126 strongly decreased the phosphorylation downstream in the ERK1/2 pathway, and the antiapoptotic activity of GM-CSF in vitro. Like in vitro, GM-CSF counteracts the staurosporine-induced cell death in vivo and protects RGCs from axotomy-induced degeneration. Our data suggest that GM-CSF might be a novel therapeutic agent in neuropathic disease of the eye.
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Affiliation(s)
- Maurice Schallenberg
- Department of Experimental Ophthalmology, School of Medicine, University Eye Hospital Münster and Interdisciplinary Centre for Clinical Research (IZKF), Domagkstrasse 15, D-48149 Münster, Germany
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Fu QL, Li X, Shi J, Xu G, Wen W, Lee DHS, So KF. Synaptic degeneration of retinal ganglion cells in a rat ocular hypertension glaucoma model. Cell Mol Neurobiol 2009; 29:575-81. [PMID: 19172389 DOI: 10.1007/s10571-009-9349-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 01/07/2009] [Indexed: 01/09/2023]
Abstract
AIMS Glaucoma is a common neurodegenerative disease that affects retinal ganglion cells (RGCs) and their axons. Little is known of the synaptic degeneration involved in the pathophysiology of glaucoma. Here we used an experimental ocular hypertension model in rats to investigate this issue. METHODS Elevated intraocular pressure (IOP) was induced by laser coagulation of the episcleral and limbal veins. RGCs were retrogradely labeled with Fluoro-Gold (FG). The c-fos protein was used as a neuronal connectivity marker. Expression of c-fos in the retinas was investigated by immunohistochemistry at 5 days and 2 weeks after the induction of ocular hypertension. Both surviving RGCs as revealed by retrograde FG-labeled and c-fos-labeled RGCs were counted. RESULTS The c-fos protein was mainly expressed in the nuclei and nucleoli of cells in the ganglion cell layer and inner nuclear layer in the normal retina. We also confirmed that c-fos was also expressed in the nuclei and nucleoli of RGCs retrogradely labeled with FG. There was no significant RGC loss at 5 days but about 13% RGC loss at 2 weeks after the induction of ocular hypertension. The number of RGCs expressing c-fos was significantly lower in the experimental animals at both 5 days and 2 weeks than normal. CONCLUSION Our study suggests that there is synaptic disconnection for RGCs after ocular hypertension and it may precede the cell death in the early stage. It may provide insight into novel therapeutic strategies to slow the progress of glaucoma.
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Affiliation(s)
- Qing-Ling Fu
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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Sanchez PE, Navarro FP, Fares RP, Nadam J, Georges B, Moulin C, Le Cavorsin M, Bonnet C, Ryvlin P, Belmeguenai A, Bodennec J, Morales A, Bezin L. Erythropoietin receptor expression is concordant with erythropoietin but not with common beta chain expression in the rat brain throughout the life span. J Comp Neurol 2009; 514:403-14. [PMID: 19330822 DOI: 10.1002/cne.22020] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Brain effects of erythropoietin (Epo) are proposed to involve a heteromeric receptor comprising the classical Epo receptor (Epo-R) and the common beta chain (betac). However, data documenting the pattern of betac gene expression in the healthy brain, in comparison with that of the Epo-R gene, are still lacking. The present study is the first to investigate at the same time betac, Epo-R, and Epo gene expression within different rat brain areas throughout the life span, from neonatal to elderly stages, using quantitative RT-PCR for transcripts. Corresponding proteins were localized by using immunohistochemistry. We demonstrate that the betac transcript level does not correlate with that of Epo-R or Epo, whereas the Epo-R transcript level strongly correlates with that of Epo throughout the life span in all brain structures analyzed. Both Epo and Epo-R were detected primarily in neurons. In the hippocampus, the greatest Epo-R mRNA levels were measured during the early postnatal period and in middle-aged rats, associated with an intense neuronal immunolabeling. Conversely, betac protein was barely detectable in the brain at all ages, even in neurons expressing high levels of Epo-R. Finally, betac transcript could not be detected in PC12 cells, even after nerve growth factor-induced neuritogenesis, which is a condition that dramatically enhances Epo-R transcript level. Altogether, our data suggest that most neurons are likely to express high levels of Epo-R but low, if not null, levels of betac. Given that Epo protects extended populations of neurons after injury, a yet-to-be-identified receptor heterocomplex including Epo-R may exist in the large population of brain neurons that does not express betac.
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Wang ZY, Zhao KK, Song ZM, Shen LJ, Qu J. Erythropoietin as a novel therapeutic agent for atrophic age-related macular degeneration. Med Hypotheses 2009; 72:448-50. [PMID: 19128888 DOI: 10.1016/j.mehy.2008.09.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 09/01/2008] [Accepted: 09/12/2008] [Indexed: 10/21/2022]
Abstract
The purpose of this article is to propose a novel therapeutic approach to the treatment of age-related macular degeneration (ARMD), the leading cause of blindness in the elderly population (over 60 years of age) in developed countries. Although recent advances have been made in the treatment of the neovascular form of ARMD, there is still no effective treatment for the most prevalent atrophic form of ARMD. Although the exact etiology and molecular pathogenesis of the atrophic ARMD are not fully understood, it is believed that oxidative stress and local inflammation play a major role in the pathologic processes and that the disease is triggered by dysfunction in the retinal pigment epithelia, leading to the degeneration of macular photoreceptor cells, followed by irreversible loss of vision. Considering that erythropoietin (EPO) has antioxidant, anti-inflammatory, and neuroprotective properties, we hypothesize that it can be developed as a novel therapeutic agent for the treatment of the atrophic form of ARMD. Future studies are needed to confirm or rule out this hypothesis. If successful, such studies may also help shield the lights on molecular mechanisms of atrophic ARMD.
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Affiliation(s)
- Zhao-Yang Wang
- Department of Ophthalmology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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