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Biswas S, Shahriar S, Bachay G, Arvanitis P, Jamoul D, Brunken WJ, Agalliu D. Glutamatergic neuronal activity regulates angiogenesis and blood-retinal barrier maturation via Norrin/β-catenin signaling. Neuron 2024; 112:1978-1996.e6. [PMID: 38599212 PMCID: PMC11189759 DOI: 10.1016/j.neuron.2024.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/15/2024] [Accepted: 03/11/2024] [Indexed: 04/12/2024]
Abstract
Interactions among neuronal, glial, and vascular components are crucial for retinal angiogenesis and blood-retinal barrier (BRB) maturation. Although synaptic dysfunction precedes vascular abnormalities in many retinal pathologies, how neuronal activity, specifically glutamatergic activity, regulates retinal angiogenesis and BRB maturation remains unclear. Using in vivo genetic studies in mice, single-cell RNA sequencing (scRNA-seq), and functional validation, we show that deep plexus angiogenesis and paracellular BRB maturation are delayed in Vglut1-/- retinas where neurons fail to release glutamate. By contrast, deep plexus angiogenesis and paracellular BRB maturation are accelerated in Gnat1-/- retinas, where constitutively depolarized rods release excessive glutamate. Norrin expression and endothelial Norrin/β-catenin signaling are downregulated in Vglut1-/- retinas and upregulated in Gnat1-/- retinas. Pharmacological activation of endothelial Norrin/β-catenin signaling in Vglut1-/- retinas rescues defects in deep plexus angiogenesis and paracellular BRB maturation. Our findings demonstrate that glutamatergic neuronal activity regulates retinal angiogenesis and BRB maturation by modulating endothelial Norrin/β-catenin signaling.
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Affiliation(s)
- Saptarshi Biswas
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA.
| | - Sanjid Shahriar
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA 02115, USA
| | - Galina Bachay
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Panos Arvanitis
- Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Danny Jamoul
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; John Jay College of Criminal Justice, City University of New York, New York, NY 10019, USA
| | - William J Brunken
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Dritan Agalliu
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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2
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Biswas S, Shahriar S, Bachay G, Arvanitis P, Jamoul D, Brunken WJ, Agalliu D. Glutamatergic neuronal activity regulates angiogenesis and blood-retinal barrier maturation via Norrin/β-catenin signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.10.548410. [PMID: 37503079 PMCID: PMC10369888 DOI: 10.1101/2023.07.10.548410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Interactions among neuronal, glial and vascular components are crucial for retinal angiogenesis and blood-retinal barrier (BRB) maturation. Although synaptic dysfunction precedes vascular abnormalities in many retinal pathologies, how neuronal activity, specifically glutamatergic activity, regulates retinal angiogenesis and BRB maturation remains unclear. Using in vivo genetic studies in mice, single-cell RNA-sequencing and functional validation, we show that deep plexus angiogenesis and paracellular BRB maturation are delayed in Vglut1 -/- retinas where neurons fail to release glutamate. In contrast, deep plexus angiogenesis and paracellular BRB maturation are accelerated in Gnat1 -/- retinas where constitutively depolarized rods release excessive glutamate. Norrin expression and endothelial Norrin/β-catenin signaling are downregulated in Vglut1 -/- retinas, and upregulated in Gnat1 -/- retinas. Pharmacological activation of endothelial Norrin/β-catenin signaling in Vglut1 -/- retinas rescued defects in deep plexus angiogenesis and paracellular BRB maturation. Our findings demonstrate that glutamatergic neuronal activity regulates retinal angiogenesis and BRB maturation by modulating endothelial Norrin/β-catenin signaling.
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3
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Boccuni I, Bas-Orth C, Bruehl C, Draguhn A, Fairless R. Glutamate transporter contribution to retinal ganglion cell vulnerability in a rat model of multiple sclerosis. Neurobiol Dis 2023; 187:106306. [PMID: 37734623 DOI: 10.1016/j.nbd.2023.106306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/05/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023] Open
Abstract
Glial glutamate transporters actively participate in neurotransmission and have a fundamental role in determining the ambient glutamate concentration in the extracellular space. Their expression is dynamically regulated in many diseases, including experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. In EAE, a downregulation has been reported which may render neurons more susceptible to glutamate excitotoxicity. In this study, we have investigated the expression of GLAST (EAAT1) and GLT-1 (EAAT2) in the retina of Brown Norway rats following induction of myelin oligodendrocyte glycoprotein (MOG)-EAE, which results in retinal ganglion cell (RGC) degeneration and dysfunction. In addition, we tested whether AAV-mediated overexpression of GLAST in the retina can protect RGCs from degeneration. To address the impact of glutamate transporter modulation on RGCs, we performed whole-cell recordings and measured tonic NMDA receptor-mediated currents in the absence and presence of a glutamate-uptake blocker. We report that αOFF-RGCs show larger tonic glutamate-induced currents than αON-RGCs, in line with their greater vulnerability under neuroinflammatory conditions. We further show that increased AAV-mediated expression of GLAST in the retina does indeed protect RGCs from degeneration during the inflammatory disease. Collectively, our study highlights the neuroprotective role of glutamate transporters in the EAE retina and provides a characterization of tonic glutamate-currents of αRGCs. The larger effects of increased extracellular glutamate concentration on the αOFF-subtype may underlie its enhanced vulnerability to degeneration.
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Affiliation(s)
- Isabella Boccuni
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Carlos Bas-Orth
- Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg 69120, Germany
| | - Claus Bruehl
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, Heidelberg 69120, Germany; Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), Heidelberg 69120, Germany.
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Nordahl KML, Fedulov V, Holm A, Haanes KA. Intraocular Adeno-Associated Virus-Mediated Transgene Endothelin-1 Delivery to the Rat Eye Induces Functional Changes Indicative of Retinal Ischemia-A Potential Chronic Glaucoma Model. Cells 2023; 12:1987. [PMID: 37566067 PMCID: PMC10417058 DOI: 10.3390/cells12151987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023] Open
Abstract
Endothelin-1 (ET-1) overactivity has been implicated as a factor contributing to glaucomatous neuropathy, and it has been utilized in animal models of retinal ischemia. The functional effects of long-term ET-1 exposure and possible compensatory mechanisms have, however, not been investigated. This was therefore the purpose of our study. ET-1 was delivered into rat eyes via a single intravitreal injection of 500 µM or via transgene delivery using an adeno-associated viral (AAV) vector. Retinal function was assessed using electroretinography (ERG) and the retinal expression of potentially compensatory genes was evaluated by means of qRT-PCR. Acute ET-1 delivery led to vasoconstriction and a significant reduction in the ERG response. AAV-ET-1 resulted in substantial transgene expression and ERG results similar to the acute ET-1 injections and comparable to other models of retinal ischemia. Compensatory changes were observed, including an increase in calcitonin gene-related peptide (CGRP) gene expression, which may both counterbalance the vasoconstrictive effects of ET-1 and provide neuroprotection. This chronic ET-1 ischemia model might be especially relevant to glaucoma research, mimicking the mild and repeated ischemic events in patients with long-term vascular dysfunction. The compensatory mechanisms, and particularly the role of vasodilatory CGRP in mitigating the retinal damage, warrant further investigation with the aim of evaluating new therapeutic strategies.
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Affiliation(s)
- Karin M. L. Nordahl
- Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, 2600 Glostrup, Denmark; (A.H.); (K.A.H.)
| | - Vadim Fedulov
- Clinical and Medical Affairs, Radiometer, 2700 Brønshøj, Denmark;
| | - Anja Holm
- Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, 2600 Glostrup, Denmark; (A.H.); (K.A.H.)
- Center for RNA Medicine, Department of Clinical Medicine, Aalborg University, 2450 Copenhagen, Denmark
| | - Kristian A. Haanes
- Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, 2600 Glostrup, Denmark; (A.H.); (K.A.H.)
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Boccuni I, Fairless R. Retinal Glutamate Neurotransmission: From Physiology to Pathophysiological Mechanisms of Retinal Ganglion Cell Degeneration. Life (Basel) 2022; 12:638. [PMID: 35629305 PMCID: PMC9147752 DOI: 10.3390/life12050638] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate neurotransmission and metabolism are finely modulated by the retinal network, where the efficient processing of visual information is shaped by the differential distribution and composition of glutamate receptors and transporters. However, disturbances in glutamate homeostasis can result in glutamate excitotoxicity, a major initiating factor of common neurodegenerative diseases. Within the retina, glutamate excitotoxicity can impair visual transmission by initiating degeneration of neuronal populations, including retinal ganglion cells (RGCs). The vulnerability of RGCs is observed not just as a result of retinal diseases but has also been ascribed to other common neurodegenerative and peripheral diseases. In this review, we describe the vulnerability of RGCs to glutamate excitotoxicity and the contribution of different glutamate receptors and transporters to this. In particular, we focus on the N-methyl-d-aspartate (NMDA) receptor as the major effector of glutamate-induced mechanisms of neurodegeneration, including impairment of calcium homeostasis, changes in gene expression and signalling, and mitochondrial dysfunction, as well as the role of endoplasmic reticular stress. Due to recent developments in the search for modulators of NMDA receptor signalling, novel neuroprotective strategies may be on the horizon.
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Affiliation(s)
- Isabella Boccuni
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Kang TK, Le TT, Kim KA, Kim YJ, Lee WB, Jung SH. Roots of Lithospermum erythrorhizon promotes retinal cell survival in optic nerve crush-induced retinal degeneration. Exp Eye Res 2020; 203:108419. [PMID: 33383026 DOI: 10.1016/j.exer.2020.108419] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/01/2020] [Accepted: 12/21/2020] [Indexed: 12/01/2022]
Abstract
Lithospermum erythrorhizon (L. erythrorhizon), used in traditional medicine, is a potent wound healing, anti-inflammatory and antioxidant plant. However, the effects of L. erythrorhizon on retinal degenerative diseases remain unknown. Here, we explored the protective effects of L. erythrorhizon in in vitro and in vivo retinal degeneration. We found that ethanol extract of L. erythrorhizon (EELE) and the dichloromethane fraction of L. erythrorhizon (MCLE) significantly increased cell viability under glutamate/BSO-induced excitotoxicity/oxidative stress in R28 cells. Treatment with EELE and MCLE reduced the intracellular reactive oxygen species (ROS) and the levels of apoptotic proteins, such as cleaved PARP and cleaved caspase-3. Furthermore, oral administration of EELE and MCLE in an in vivo optic nerve crush mouse model decreased RGC cell death and increased retinal thickness. The major compound between EELE and MCLE was found to be lithospermic acid A (LAA), which has been shown to prevent the elevation of ROS in R28. Therefore, EELE and MCLE have protective effects against the death of retinal cells in vitro and in vivo, and the major compound, LAA, has an antioxidant effect on retinal cells, suggesting that EELE and MCLE could be beneficial agents for retinal degenerative diseases, including glaucoma.
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Affiliation(s)
- Tae Kyeom Kang
- Natural Product Research Center, Korea Institute of Science & Technology, Gangneung, 25451, Republic of Korea
| | - Tam Thi Le
- Natural Product Research Center, Korea Institute of Science & Technology, Gangneung, 25451, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Gangneung, 25451, Republic of Korea
| | - Kyung-A Kim
- Division of Medical Oncology, Yonsei Cancer Center, Department of Internal Medicine, Yonsei University, Republic of Korea
| | - Young-Joo Kim
- Natural Product Research Center, Korea Institute of Science & Technology, Gangneung, 25451, Republic of Korea
| | - Wook-Bin Lee
- Natural Product Research Center, Korea Institute of Science & Technology, Gangneung, 25451, Republic of Korea.
| | - Sang Hoon Jung
- Natural Product Research Center, Korea Institute of Science & Technology, Gangneung, 25451, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Gangneung, 25451, Republic of Korea.
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Abo-Ahmed AI, Emam MA. Expression of vesicular glutamate transporter 2 and 3 and glutamate receptor 1 and 2 mRNAs in the retina of adult laughing doves (Streptopelia senegalensis): An in situ hybridization study. Acta Histochem 2020; 122:151597. [PMID: 32778249 DOI: 10.1016/j.acthis.2020.151597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 10/23/2022]
Abstract
The retina possesses few types of neurons so; it is considered an excellent model for understanding the neural mechanisms underlying basic neural information processing in the brain. Glutamate is the major excitatory neurotransmitter in the vertebrate central nervous system and retina. The present study was carried out to characterize the expression pattern of vesicular glutamate transporter 2 (Vglut2) and 3 (Vglut3) and glutamate receptor 1 (GluR1) and 2 (GluR2) mRNAs in the retina of adult laughing dove (Streptopelia senegalensis) by RT-PCR and in situ hybridization histochemistry. The cerebellum of adult laughing dove was used as a positive control in this study. Vglut2 mRNA was highly expressed only in the granular layer of the cerebellum while Vglut3 mRNA was weakly expressed only in the Purkinje cells layer. In the retina, Vglut2 mRNA was highly expressed in the ganglion cell layer and moderately expressed in the inner nuclear layer while Vglut3 mRNA was moderately expressed only in the inner nuclear layer. GluR1 mRNA was intensely expressed in the Purkinje cells layer while GluR2 mRNA signals were highly detectable in both granular and Purkinje cells layers of the cerebellum. In the retina, moderate expression of GluR1 and intense expression of GluR2 was found in both ganglion cell layer and the internal half of inner nuclear layer mostly amacrine cells. These results suggest that some retinal neuronal cells in the adult laughing dove are glutamatergic. Therefore, GluR1 and 2 are suggested as useful markers for glutamatergic retinal neuronal cells in the adult laughing doves.
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Fachim HA, Guizzo R, Cunha AOS, Pereira AC, Anjos LC, Mortari MR, Santos WF. Ceftriaxone pretreatment confers neuroprotection in rats with acute glaucoma and reduces the score of seizures induced by pentylenotetrazole in mice. J Biochem Mol Toxicol 2020; 34:e22578. [DOI: 10.1002/jbt.22578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/01/2020] [Accepted: 06/23/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Helene A. Fachim
- Neurobiology and Venoms Laboratory, Department of Biology, FFCLRP University of São Paulo São Paulo Brazil
- Instituto de Neurociências e Comportamento de Ribeirão Preto—INeC Ribeirão Preto São Paulo Brazil
| | - Renato Guizzo
- Instituto de Neurociências e Comportamento de Ribeirão Preto—INeC Ribeirão Preto São Paulo Brazil
| | - Alexandra O. S. Cunha
- Neurobiology and Venoms Laboratory, Department of Biology, FFCLRP University of São Paulo São Paulo Brazil
- Instituto de Neurociências e Comportamento de Ribeirão Preto—INeC Ribeirão Preto São Paulo Brazil
| | - Adriana C. Pereira
- Neurobiology and Venoms Laboratory, Department of Biology, FFCLRP University of São Paulo São Paulo Brazil
- Instituto de Neurociências e Comportamento de Ribeirão Preto—INeC Ribeirão Preto São Paulo Brazil
| | - Lilian C. Anjos
- Neuropharmacology Laboratory, Department of Physiological Sciences University of Brasília‐UnB Brasília Brazil
| | - Márcia R. Mortari
- Neuropharmacology Laboratory, Department of Physiological Sciences University of Brasília‐UnB Brasília Brazil
| | - Wagner F. Santos
- Neurobiology and Venoms Laboratory, Department of Biology, FFCLRP University of São Paulo São Paulo Brazil
- Instituto de Neurociências e Comportamento de Ribeirão Preto—INeC Ribeirão Preto São Paulo Brazil
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Rodríguez Villanueva J, Martín Esteban J, Rodríguez Villanueva LJ. Retinal Cell Protection in Ocular Excitotoxicity Diseases. Possible Alternatives Offered by Microparticulate Drug Delivery Systems and Future Prospects. Pharmaceutics 2020; 12:pharmaceutics12020094. [PMID: 31991667 PMCID: PMC7076407 DOI: 10.3390/pharmaceutics12020094] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/11/2022] Open
Abstract
Excitotoxicity seems to play a critical role in ocular neurodegeneration. Excess-glutamate-mediated retinal ganglion cells death is the principal cause of cell loss. Uncontrolled glutamate in the synapsis has significant implications in the pathogenesis of neurodegenerative disorders. The exploitation of various approaches of controlled release systems enhances the pharmacokinetic and pharmacodynamic activity of drugs. In particular, microparticles are secure, can maintain therapeutic drug concentrations in the eye for prolonged periods, and make intimate contact by improving drug bioavailability. According to the promising results reported, possible new investigations will focus intense attention on microparticulate formulations and can be expected to open the field to new alternatives for doctors, as currently required by patients.
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Affiliation(s)
- Javier Rodríguez Villanueva
- Human resources for I+D+i Department, National Institute for Agricultural and Food Research and Technology, Ctra. de la Coruña (Autovía A6) Km. 7.5, 28040 Madrid, Spain
- Correspondence: ; Tel.: +34-91-347-4158
| | - Jorge Martín Esteban
- University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; (J.M.E.); (L.J.R.V.)
| | - Laura J. Rodríguez Villanueva
- University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; (J.M.E.); (L.J.R.V.)
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Zhang LN, Hao L, Guo YS, Wang HY, Li LL, Liu LZ, Li WB. Are glutamate transporters neuroprotective or neurodegenerative during cerebral ischemia? J Mol Med (Berl) 2019; 97:281-289. [PMID: 30675649 DOI: 10.1007/s00109-019-01745-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 12/14/2022]
Abstract
The accumulation of glutamate (Glu) in the synaptic cleft during cerebral ischemia triggers the death of neurons, causing mental or physical handicap. However, the mechanisms of the alteration in Glu homeostasis and the imbalance between the release and clearance of Glu in ischemia are not yet completely understood. Additionally, the role of Glu transporters in regulating Glu concentration in the synaptic cleft is controversial. This review aims to provide readers with an in-depth understanding of Glu transporters in the early or later stages of ischemic events, or in mild or severe cerebral ischemia via alteration of Glu transporter expression, reversal of Glu transporters function, and trafficking between membrane and cytoplasm, to further clarify whether the Glu transporters are neuroprotective or neurodegenerative during cerebral ischemia. We provide the insights for deeper understanding of the mechanism of Glu transporters regulation after different periods and severities of cerebral ischemia.
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Affiliation(s)
- Li-Nan Zhang
- Department of Pathophysiology, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang, 050017, Hebei, China
| | - Liang Hao
- Department of Neurosurgery, Third Hospital of Shijiazhuang, Beijing, 050011, Hebei, China
| | - Yu-Song Guo
- Department of Traumatology, Third Hospital of Shijiazhuang, Beijing, 050011, Hebei, China
| | - Hai-Yan Wang
- Pharmaceutical Preparation Section, Third Hospital of Shijiazhuang, Beijing, 050011, Hebei, China
| | - Lin-Lin Li
- Clinical Medicine, College of Basic Medicine, Hebei Medical University, Beijing, 050017, Hebei, China
| | - Li-Zhe Liu
- Department of Pathophysiology, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang, 050017, Hebei, China
| | - Wen-Bin Li
- Department of Pathophysiology, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang, 050017, Hebei, China.
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11
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Zhang Y, Mao X, Lin R, Li Z, Lin J. Electroacupuncture ameliorates cognitive impairment through inhibition of Ca 2+-mediated neurotoxicity in a rat model of cerebral ischaemia-reperfusion injury. Acupunct Med 2018; 36:401-407. [PMID: 30257960 PMCID: PMC6287559 DOI: 10.1136/acupmed-2016-011353] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2017] [Indexed: 01/05/2023]
Abstract
Background The hippocampus is vulnerable to severe damage after cerebral ischaemia–reperfusion (I/R) injury. This study aimed to explore the effect of electroacupuncture (EA) on cognitive impairment and its relationship with Ca2+neurotoxicity in a rat model of I/R injury induced by middle cerebral artery occlusion (MCAO). Methods 60 adult male Sprague-Dawley rats were randomly divided into three groups: control (sham surgery) group, untreated MCAO group and EA-treated MCAO+EA group. Rats in the MCAO and MCAO+EA groups underwent modelling of poststroke cognitive impairment by MCAO surgery. EA was performed for 30 min daily at GV20 and GV24 (1–20 Hz) for 1 week. The Morris water maze experiment was used to assess cognitive function. 2,3,5-triphenyl tetrazolium chloride staining was used to measure infarct volume. The intracellular Ca2+content in the Cornu Ammonis (CA)1 area of the hippocampus was assessed by laser confocal scanning microscopy. ELISA was performed to evaluate the concentration of glutamate (Glu) in the hippocampus, and the protein expression of two Glu receptors (N-methyl-D-aspartic acid receptor (NMDAR) 2A and NMDAR2B) were analysed by Western blotting. Results Compared with the untreated MCAO group, EA effectively ameliorated cognitive impairment (P=0.01) and shrunk the infarct volume (P=0.032). The content of intracellular Ca2+, Glu and NMDAR2B in the hippocampus was significantly raised by MCAO (P=0.031-0.043), while EA abrogated these effects. NMDAR2A was decreased by MCAO (P=0.015) but increased by EA (P=0.033). Conclusions EA had a beneficial effect on cognitive repair after cerebral I/R, and its mechanism of action likely involves a reduction of Ca2+influx via inhibition of Glu neurotoxicity and downregulation of NMDAR2B expression.
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Affiliation(s)
- Yun Zhang
- Clinical Medicine Department, Fujian Health College, Fuzhou, China
| | - Xiang Mao
- Acupuncture Department, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Ruhui Lin
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Zuanfang Li
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Jing Lin
- Clinical Medicine Department, Fujian Health College, Fuzhou, China
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12
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Russo R, Varano GP, Adornetto A, Nazio F, Tettamanti G, Girardello R, Cianfanelli V, Cavaliere F, Morrone LA, Corasaniti MT, Cecconi F, Bagetta G, Nucci C. Rapamycin and fasting sustain autophagy response activated by ischemia/reperfusion injury and promote retinal ganglion cell survival. Cell Death Dis 2018; 9:981. [PMID: 30250019 PMCID: PMC6155349 DOI: 10.1038/s41419-018-1044-5] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/30/2018] [Indexed: 12/29/2022]
Abstract
Autophagy, the cellular process responsible for degradation and recycling of cytoplasmic components through the autophagosomal–lysosomal pathway, is fundamental for neuronal homeostasis and its deregulation has been identified as a hallmark of neurodegeneration. Retinal hypoxic–ischemic events occur in several sight-treating disorders, such as central retinal artery occlusion, diabetic retinopathy, and glaucoma, leading to degeneration and loss of retinal ganglion cells. Here we analyzed the autophagic response in the retinas of mice subjected to ischemia induced by transient elevation of intraocular pressure, reporting a biphasic and reperfusion time-dependent modulation of the process. Ischemic insult triggered in the retina an acute induction of autophagy that lasted during the first hours of reperfusion. This early upregulation of the autophagic flux limited RGC death, as demonstrated by the increased neuronal loss observed in mice with genetic impairment of basal autophagy owing to heterozygous ablation of the autophagy-positive modulator Ambra1 (Ambra1+/gt). Upregulation of autophagy was exhausted 24 h after the ischemic event and reduced autophagosomal turnover was associated with build up of the autophagic substrate SQSTM-1/p62, decreased ATG12-ATG5 conjugate, ATG4 and BECN1/Beclin1 expression. Animal fasting or subchronic systemic treatment with rapamycin sustained and prolonged autophagy activation and improved RGC survival, providing proof of principle for autophagy induction as a potential therapeutic strategy in retinal neurodegenerative conditions associated with hypoxic/ischemic stresses.
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Affiliation(s)
- Rossella Russo
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy.
| | - Giuseppe Pasquale Varano
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy.,Ophtalmology Unit, Department of Experimental Medicine, University of Rome "Tor Vergata", 00133, Rome, Italy
| | - Annagrazia Adornetto
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy
| | - Francesca Nazio
- Department of Pediatric Hematology and Oncology, IRCSS Bambino Gesù Children's Hospital, Rome, Italy
| | - Gianluca Tettamanti
- Department of Biotechnology and Life Sciences, University of Insubria, 21100, Varese, Italy
| | - Rossana Girardello
- Department of Biotechnology and Life Sciences, University of Insubria, 21100, Varese, Italy
| | - Valentina Cianfanelli
- Cell Stress and Survival Unit, Center for Autophagy, Recycling and Disease (CARD), Danish Cancer Society Research Center, 2100, Copenhagen, Denmark
| | - Federica Cavaliere
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy
| | - Luigi Antonio Morrone
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy
| | | | - Francesco Cecconi
- Department of Pediatric Hematology and Oncology, IRCSS Bambino Gesù Children's Hospital, Rome, Italy
| | - Giacinto Bagetta
- Department of Pharmacy, Health and Nutritional Sciences, Section of Preclinical and Translational Pharmacology, University of Calabria, 87036, Arcavacata di Rende, Italy
| | - Carlo Nucci
- Ophtalmology Unit, Department of Experimental Medicine, University of Rome "Tor Vergata", 00133, Rome, Italy
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13
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Wang Y, Wang XL, Xie GL, Li HY, Wang YL. Collapsin Response Mediator Protein-2-induced Retinal Ischemic Injury in a Novel Mice Model of Ocular Ischemia Syndrome. Chin Med J (Engl) 2018; 130:1342-1351. [PMID: 28524835 PMCID: PMC5455045 DOI: 10.4103/0366-6999.206340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Collapsin response mediator protein-2 (CRMP2) has been shown to be involved in ischemia/hypoxia (IH) injury. We determined whether CRMP2 modulates ischemic injury in the retinal of Ocular ischemic syndrome (OIS). This study was to explore the molecular mechanisms underlying OIS in a novel mice model. METHODS Experiments were performed on adult male C57/BL6 mice that received bilateral internal carotid arteries ligation for 1, 2, or 4 weeks. The mice received injection of calpeptin group before occlusion for 4 weeks or not. The expression of CRMP2 in the retinal was examined by western blotting (WB) analysis and immunohistochemical analysis (IHC). The effects of ischemic injury on retinal were evaluated by fundus examination, fundus fluorescein angiography, electroretinogram, cell counting of retinal ganglion cell (RGC), and measurement of the thickness of the retina. RESULTS The veins dilated after chronic ischemia. In the electroretinography, the amplitudes of a- and b-waves kept diminishing in an ischemia time-dependent manner. Moreover, the tail vein-retinal circulation time prolonged in the 1- and 2-week group. In comparison, thickness of the retina decreased gradually with the ischemia time elapsed. WB analysis showed the CRMP2 and p-CRMP2 levels decreased in the 2- and 4-week groups. The results of IHC analysis were compatible with our results of WB. The loss of RGCs, decrease of the total reaction time and reduction of CRMP2 was alleviated by intravitreal injection of calpeptin. CONCLUSIONS These results revealed that bilateral ligation of the internal carotid artery causes retinal ischemia in mice. Moreover, CRMP2 might play a pivotal role during the ischemic injury in the retina and inhibit the cleavage of CRMP2 can ameliorate the IH injury.
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Affiliation(s)
- Yu Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Xiao-Lei Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Guo-Li Xie
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Hong-Yang Li
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Yan-Ling Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
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14
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Liu WY, Tzeng TF, Liu IM. Zerumbone, a Bioactive Sesquiterpene, Ameliorates Diabetes-Induced Retinal Microvascular Damage through Inhibition of Phospho-p38 Mitogen-Activated Protein Kinase and Nuclear Factor-κB Pathways. Molecules 2016; 21:molecules21121708. [PMID: 27973425 PMCID: PMC6273957 DOI: 10.3390/molecules21121708] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/07/2016] [Accepted: 12/09/2016] [Indexed: 12/22/2022] Open
Abstract
Zerumbone ameliorates retinal damage by blocking advanced glycation end products and their receptor system in streptozotocin-diabetic rats. Because of the multiple factors involved in diabetic retinopathy (DR) etiology, the mechanisms of zerumbone that are mainly responsible for its ameliorative effect on DR need to be further clarified. In the present study, zerumbone (20 mg or 40 mg/kg) or fenofibric acid (100 mg/kg) was orally administered to diabetic rats by intragastric gavage once daily for three consecutive months. Zerumbone displayed similar characteristics to fenofibric acid in reducing retinal vascular permeability and leukostasis in diabetic rats. Fundus photographs showed that large retinal vessel diameters were decreased in zerumbone-treated diabetic rats. Zerumbone not only down-regulated the gene expression of retinal angiogenic parameters, but also reduced the expression of inflammatory cytokines and chemokines in the retina of diabetic rats. Moreover, zerumbone reduced the p38 MAPK phosphorylation and abrogated the nuclear translocation of NF-κB p65 in the retina of diabetic rats. In conclusion, treatment of diabetic rats with zerumbone attenuates the severity of retinal inflammation and angiogenesis, via inhibition of p38 MAPK and NF-κB signaling pathways. These benefits of zerumbone for DR appear to be linked to its antihyperglycemic and antihyperlipidemic effects.
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Affiliation(s)
- Wayne Young Liu
- Center for Basic Medical Science, Collage of Health Science, Central Taiwan University of Science and Technology, Taichung 40601, Taiwan.
- Department of Urology, Jen-Ai Hospital, Taichung 41625, Taiwan.
| | - Thing-Fong Tzeng
- Department of Pharmacy and Master Program, Collage of Pharmacy and Health Care, Tajen University, Pingtung 90741, Taiwan.
| | - I-Min Liu
- Department of Pharmacy and Master Program, Collage of Pharmacy and Health Care, Tajen University, Pingtung 90741, Taiwan.
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15
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Nucci C, Russo R, Martucci A, Giannini C, Garaci F, Floris R, Bagetta G, Morrone LA. New strategies for neuroprotection in glaucoma, a disease that affects the central nervous system. Eur J Pharmacol 2016; 787:119-26. [DOI: 10.1016/j.ejphar.2016.04.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/23/2016] [Accepted: 04/14/2016] [Indexed: 01/30/2023]
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16
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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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17
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Consumption of Polyphenol-Rich Zingiber Zerumbet Rhizome Extracts Protects against the Breakdown of the Blood-Retinal Barrier and Retinal Inflammation Induced by Diabetes. Nutrients 2015; 7:7821-41. [PMID: 26389948 PMCID: PMC4586564 DOI: 10.3390/nu7095369] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 12/20/2022] Open
Abstract
The present study investigates the amelioration of diabetic retinopathy (DR) by Zingiber zerumbet rhizome ethanol extracts (ZZRext) in streptozotocin-induced diabetic rats (STZ-diabetic rats). ZZRext contains high phenolic and flavonoid contents. STZ-diabetic rats were treated orally with ZZRext (200, 300 mg/kg per day) for three months. Blood-retinal barrier (BRB) breakdown and increased vascular permeability were found in diabetic rats, with downregulation of occludin, and claudin-5. ZZRext treatment effectively preserved the expression of occludin, and claudin-5, leading to less BRB breakdown and less vascular permeability. Retinal histopathological observation showed that the disarrangement and reduction in thickness of retinal layers were reversed in ZZRext-treated diabetic rats. Retinal gene expression of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, vascular endothelial growth factor, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in ZZRext-treated diabetic rats. Moreover, ZZRext treatment not only inhibited the nuclear factor κB (NF-κB) activation, but also downregulated the protein expression of p38 mitogen-activated protein kinase (MAPK) in diabetic retina. In conclusion, the results suggest that the retinal protective effects of ZZRext occur through improved retinal structural change and inhibiting retinal inflammation. The antiretinopathy property of ZZRext might be related to the downregulation of p38 MAPK and NF-κB signal transduction induced by diabetes.
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18
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The ethanol extract of Zingiber zerumbet rhizomes mitigates vascular lesions in the diabetic retina. Vascul Pharmacol 2015; 76:18-27. [PMID: 26319672 DOI: 10.1016/j.vph.2015.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/29/2015] [Accepted: 08/23/2015] [Indexed: 11/19/2022]
Abstract
Diabetic retinopathy (DR) is a common diabetic eye disease which is well-known as the result of microvascular retinal changes. Although the ethanol extract from Zingiber zerumbet (L.) Smith rhizome (EEZZR) has been indicated to ameliorate hyperglycemia in diabetes, its protective effect on DR remains unclear. The aim of this study was to determine the effects of EEZZR on DR in streptozotocin (STZ) diabetic rats. Diabetic rats were treated orally with EEZZR (200, 300 mg/kg per day) or calcium dobesilate (CD; 500 mg/kg per day) for 12 weeks. EEZZR displayed similar characteristics to CD in reducing blood-retinal barrier permeability in diabetic rats. Retinal histopathological observation showed that retinal vessels were decreased in EEZZR-treated diabetic rats. EEZZR decreased the increased retinal expression of vascular endothelial growth factor (VEGF) and upregulate the expressions of renal pigment epithelium-derived factor (PEDF) in diabetic rats. Retinal mRNA expression of tumor necrosis factor-α, interleukin (IL)-1, IL-6, monocyte chemotactic proteins-1, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in EEZZR-treated diabetic rats. Moreover, EEZZR could attenuate phosphorylation of nuclear factor Kappa B (NF-κB) p65 and extracellular signal-regulated kinase (ERK)1/2 as well as inhibit the nuclear translocation of pNF-κB p65 induced by diabetes. In conclusion, restoring the balance between stimulators and inhibitors of angiogenesis may be associated with the protective effect of EEZZR on DR. In addition, EEZZR can ameliorate retinal inflammation via transrepression of NF-κB and inhibition of ERK1/2 signaling pathway.
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19
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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: 12] [Impact Index Per Article: 1.3] [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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20
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Farrand AQ, Gregory RA, Scofield MD, Helke KL, Boger HA. Effects of aging on glutamate neurotransmission in the substantia nigra of Gdnf heterozygous mice. Neurobiol Aging 2014; 36:1569-76. [PMID: 25577412 DOI: 10.1016/j.neurobiolaging.2014.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 11/11/2014] [Accepted: 11/25/2014] [Indexed: 12/12/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) helps protect dopaminergic neurons in the nigrostriatal tract. Although the cause of nigrostriatal degeneration is unknown, one theory is that excess glutamate from the subthalamic nucleus results in excitotoxic events in the substantia nigra (SN). Because dopaminergic degeneration is accompanied by a reduction in GDNF, we examined glutamate neurotransmission in the SN using a Gdnf heterozygous mouse model (Gdnf(+/-)) at 8 and 12 months of age. At 8 months, Gdnf(+/-) mice have greater glutamate release and higher basal glutamate levels, which precede the SN dopaminergic degeneration observed at 12 months of age. However, at 12 months, Gdnf(+/-) mice have lower basal levels of glutamate and less glutamate release than wild-type mice. Also at 8 months, Gdnf(+/-) mice have lower levels of glutamate transporter-1 and greater glial fibrillary acidic protein levels in the SN compared with wild-type mice, differences that increase with age. These data suggest that reduced levels of GDNF induce excess glutamate release and dysregulation of glutamate transporter-1, causing excitotoxicity in the SN that precedes dopaminergic degeneration.
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Affiliation(s)
- Ariana Q Farrand
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Rebecca A Gregory
- Department of Comparative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Michael D Scofield
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Kristi L Helke
- Department of Comparative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Heather A Boger
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
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21
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Nork TM, Kim CBY, Munsey KM, Dashek RJ, Hoeve JNV. Regional choroidal blood flow and multifocal electroretinography in experimental glaucoma in rhesus macaques. Invest Ophthalmol Vis Sci 2014; 55:7786-98. [PMID: 25370515 DOI: 10.1167/iovs.14-14527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To test a hypothesis of regional variation in the effect of experimental glaucoma on choroidal blood flow (ChBF) and retinal function. METHODS Five rhesus macaques underwent laser trabecular destruction (LTD) to induce elevated intraocular pressure (IOP). Intraocular pressures were elevated for 56 to 57 weeks. Multifocal electroretinographic (mfERG) and multifocal visual evoked cortical potential (mfVEP) testing were performed at regular intervals before and during the period of IOP elevation. At euthanasia, the IOP was manometrically controlled at 35 (experimentally glaucomatous eye) and 15 (fellow control eye) mm Hg. Fluorescent microspheres were injected into the left ventricle. Regional ChBF was determined. RESULTS All of the experimentally glaucomatous eyes exhibited supranormal first-order kernel (K1) root mean square (RMS) early portions of the mfERG waveforms and decreased amplitudes of the late waveforms. The supranormality was somewhat greater in the central macula. Second-order kernel, first slice (K2.1) RMS mfVEP response was inversely correlated (R(2) = 0.97) with axonal loss. Total ChBF was reduced in the experimentally glaucomatous eyes. The mean blood flow was 893 ± 123 and 481 ± 37 μL/min in the control and glaucomatous eyes, respectively. The ChBF showed regional variability with the greatest proportional decrement most often found in the central macula. CONCLUSIONS This is the first demonstration of globally reduced ChBF in chronic experimental glaucoma in the nonhuman primate. Both the alteration of mfERG waveform components associated with outer retinal function and the reduction in ChBF were greatest in the macula, suggesting that there may be a spatial colocalization between ChBF and some outer retinal effects in glaucoma.
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Affiliation(s)
- T Michael Nork
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Charlene B Y Kim
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Kaitlyn M Munsey
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Ryan J Dashek
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - James N Ver Hoeve
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
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22
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Ishikawa M. Abnormalities in glutamate metabolism and excitotoxicity in the retinal diseases. SCIENTIFICA 2013; 2013:528940. [PMID: 24386591 PMCID: PMC3872404 DOI: 10.1155/2013/528940] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/17/2013] [Indexed: 05/14/2023]
Abstract
In the physiological condition, glutamate acts as an excitatory neurotransmitter in the retina. However, excessive glutamate can be toxic to retinal neurons by overstimulation of the glutamate receptors. Glutamate excess is primarily attributed to perturbation in the homeostasis of the glutamate metabolism. Major pathway of glutamate metabolism consists of glutamate uptake by glutamate transporters followed by enzymatic conversion of glutamate to nontoxic glutamine by glutamine synthetase. Glutamate metabolism requires energy supply, and the energy loss inhibits the functions of both glutamate transporters and glutamine synthetase. In this review, we describe the present knowledge concerning the retinal glutamate metabolism under the physiological and pathological conditions.
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Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita Graduate University Faculty of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
- *Makoto Ishikawa:
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