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Harada T, Harada C, Nakamura K, Quah HMA, Okumura A, Namekata K, Saeki T, Aihara M, Yoshida H, Mitani A, Tanaka K. The potential role of glutamate transporters in the pathogenesis of normal tension glaucoma. J Clin Invest 2007; 117:1763-70. [PMID: 17607354 PMCID: PMC1890997 DOI: 10.1172/jci30178] [Citation(s) in RCA: 241] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Accepted: 04/24/2007] [Indexed: 12/22/2022] Open
Abstract
Glaucoma, a progressive optic neuropathy due to retinal ganglion cell (RGC) degeneration, is one of the leading causes of irreversible blindness. Although glaucoma is often associated with elevated intraocular pressure (IOP), IOP elevation is not detected in a significant subset of glaucomas, such as normal tension glaucoma (NTG). Moreover, in some glaucoma patients, significant IOP reduction does not prevent progression of the disease. Thus, understanding IOP-independent mechanisms of RGC loss is important. Here, we show that mice deficient in the glutamate transporters GLAST or EAAC1 demonstrate spontaneous RGC and optic nerve degeneration without elevated IOP. In GLAST-deficient mice, the glutathione level in Müller glia was decreased; administration of glutamate receptor blocker prevented RGC loss. In EAAC1-deficient mice, RGCs were more vulnerable to oxidative stress. These findings suggest that glutamate transporters are necessary both to prevent excitotoxic retinal damage and to synthesize glutathione, a major cellular antioxidant and tripeptide of glutamate, cysteine, and glycine. We believe these mice are the first animal models of NTG that offer a powerful system for investigating mechanisms of neurodegeneration in NTG and developing therapies directed at IOP-independent mechanisms of RGC loss.
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Affiliation(s)
- Takayuki Harada
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Chikako Harada
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazuaki Nakamura
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hun-Meng A. Quah
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Akinori Okumura
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazuhiko Namekata
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tadashiro Saeki
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Makoto Aihara
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroshi Yoshida
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Akira Mitani
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
Center of Excellence Program for Brain Integration and its Disorders, Tokyo Medical and Dental University, Tokyo, Japan
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