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Gao S, Huang X, Zhang Y, Bao L, Wang X, Zhang M. Investigation on the expression regulation of RIPK1/RIPK3 in the retinal ganglion cells (RGCs) cultured in high glucose. Bioengineered 2021; 12:3947-3956. [PMID: 34281454 PMCID: PMC8806785 DOI: 10.1080/21655979.2021.1944456] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/12/2021] [Indexed: 02/08/2023] Open
Abstract
Diabetic retinopathy (DR) represents the most typical complication of type 2 diabetes mellitus and one of the most primary oculopathy causing blindness. However, the mechanism of DR remains unknown. RIPK1/RIPK3, as homologous serine/threonine kinases, are key elements in mediating necroptosis and may have functions in DR development. To clarify the relationship between DR and RIPK1/RIPK3, this study established a model of apoptosis using high-glucose induced RGCs, which were treated with 7.5, 19.5, and 35 mM D-glucose for 12, 24, and 48 h, respectively. Subsequently, the expression of RIPK1/RIPK3 was determined and the protective effect of necrostatin-1 on RGCs injury induced by high glucose was explored. The results demonstrated that the expression of RIPK1 and RIPK3 in the cells was increased markedly following 12 h treatment with 19.5 mM D-glucose. Additionally, following an addition of 100 μM necrostatin-1 in 19.5 mM D-glucose medium for RGCs treatment 12 h, the protein expression of RIPK1 and RIPK3 was decreased markedly, and the number of Nissl bodies in cells was increased substantially. The findings of the present study indicated that high glucose could induce the expression of RIPK1/RIPK3, and necrostatin-1 could effectively protect RGCs from D-glucose-induced cell necrosis.
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Affiliation(s)
- Sheng Gao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Xi Huang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yi Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Li Bao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoyue Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
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Alsabaani N. Inhibition of Protein Kinase R by C16 Protects the Retinal Ganglion Cells from Hypoxia-induced Oxidative Stress, Inflammation, and Apoptosis. Curr Eye Res 2021; 46:719-730. [PMID: 33026257 DOI: 10.1080/02713683.2020.1826980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/16/2020] [Indexed: 10/23/2022]
Abstract
AIM/PURPOSE Individually, hypoxia and protein kinase R (PKR) induce retinal ganglion cells (RGCs) damage by aggravating reactive oxygen species (ROS), oxidative stress, inflammation, and apoptosis. However, it is still not established in hypoxia mediates such damaging effect by modulating PKR. This study investigated the expression and activation of PKR in hypoxic RGCs and tested if suppression of PKR by C16 is protective. MATERIALS AND METHODS Isolated RGCs were under normoxic or hypoxic conditions for 12 h. In some cases, hypoxic cells were pre-treated with C16, a PKR inhibitor, or n-acetyl cysteine (NAC) a glutathione (GSH) precursor for 1 h and then exposed to hypoxia for the next 12 h. RESULTS Hypoxia increased cell death, lactate dehydrogenase (LDH) levels, and levels of single-stranded DNA (ssDNA). It also increased levels of ROS, the activity of the nuclear factor-kappa beta (NF-κB), JNK, and p38 MAPK, expression of Bax, p53, and cleaved caspase-3, levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and cytoplasmic levels of cytochrome-c. It concomitantly suppressed levels of GSH and Bcl-2. All these events were associated with increased phosphorylation (activation) of PKR and its target eukaryotic initiation factor 2 (eIF2). Pre-incubating the cells with NAC completely prevented all these effects in hypoxic cells. Similar protective effects without affecting levels of ROS and GSH levels were also seen in hypoxic cells pre-treated with C16. CONCLUSION Hypoxia induces oxidative stress, inflammation, and apoptosis in the RGCs mainly by ROS induced activation of PKR, whereas scavenging ROS by NAC or suppressing PKR by C16 is a novel protective mechanism.
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Affiliation(s)
- Nasser Alsabaani
- Ophthalmology Department, College of Medicine, King Khalid University, Abha, Saudi Arabia
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Jiang H, Zhang H, Jiang X, Wu S. Overexpression of D-amino acid oxidase prevents retinal neurovascular pathologies in diabetic rats. Diabetologia 2021; 64:693-706. [PMID: 33319325 DOI: 10.1007/s00125-020-05333-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/06/2020] [Indexed: 10/22/2022]
Abstract
AIMS/HYPOTHESIS Diabetic retinopathy is characterised by retinal neurodegeneration and retinal vascular abnormalities, affecting one third of diabetic patients with disease duration of more than 10 years. Accumulated evidence suggests that serine racemase (SR) and D-serine are correlated with the pathogenesis of diabetic retinopathy and the deletion of the Srr gene reverses neurovascular pathologies in diabetic mice. Since D-serine content is balanced by SR synthesis and D-amino acid oxidase (DAAO) degradation, we examined the roles of DAAO in diabetic retinopathy and further explored relevant therapy. METHODS Rats were used as a model of diabetes by i.p. injection of streptozotocin at the age of 2 months and blood glucose was monitored with a glucometer. Quantitative real-time PCR was used to examine Dao mRNA and western blotting to examine targeted proteins in the retinas. Bisulphite sequencing was used to examine the methylation of Dao mRNA promoter in the retinas. Intravitreal injection of DAAO-expressing adenovirus (AAV8-DAAO) was conducted one week before streptozotocin administration. Brain specific homeobox/POU domain protein 3a (Brn3a) immunofluorescence was conducted to indicate retinal ganglion cells at 3 months after virus injection. The permeability of the blood-retinal barrier was examined by Evans blue leakage from retinal capillaries. Periodic acid-Schiff staining and haematoxylin counterstaining were used to indicate retinal vasculature, which was further examined with double immunostaining at 7 months after virus injection. RESULTS At the age of 12 months, DAAO mRNA and protein levels in retinas from diabetic animals were reduced to 66.2% and 70.4% of those from normal (control) animals, respectively. The Dao proximal promoter contained higher levels of methylation in diabetic than in normal retinas. Consistent with the observation, DNA methyltransferase 1 was increased in diabetic retinas. Injection of DAAO-expressing virus completely prevented the loss of retinal ganglion cells and the disruption of blood-retinal barrier in diabetic rats. Diabetic retinas contained retinal ganglion cells at a density of 54 ± 4/mm2, which was restored to 68 ± 9/mm2 by DAAO overexpression, similar to the levels in normal retinas. The ratio between the number of endothelial cells and pericytes in diabetic retinas was 6.06 ± 1.93/mm2, which was reduced to 3.42 ± 0.55/mm2 by DAAO overexpression; the number of acellular capillaries in diabetic retinas was 10 ± 5/mm2, which was restored to 6 ± 2/mm2 by DAAO overexpression, similar to the levels in normal retinas. Injection of the DAAO-expressing virus increased the expression of occludin and reduced gliosis, which were examined to probe the mechanism by which the disrupted blood-retinal barrier in diabetic rats was rescued and retinal neurodegeneration was prevented. CONCLUSIONS/INTERPRETATION Altogether, overexpression of DAAO before the onset of diabetes protects against neurovascular abnormalities in retinas from diabetic rats, which suggests a novel strategy for preventing diabetic retinopathy. Graphical abstract.
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Affiliation(s)
- Haiyan Jiang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
- State Key Laboratory of Optometry, Ophthalmology, and Visual Science, Wenzhou, Zhejiang, People's Republic of China
| | - He Zhang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
- State Key Laboratory of Optometry, Ophthalmology, and Visual Science, Wenzhou, Zhejiang, People's Republic of China
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, People's Republic of China
| | - Xue Jiang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
- State Key Laboratory of Optometry, Ophthalmology, and Visual Science, Wenzhou, Zhejiang, People's Republic of China
| | - Shengzhou Wu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
- State Key Laboratory of Optometry, Ophthalmology, and Visual Science, Wenzhou, Zhejiang, People's Republic of China.
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Yu L, Yang J. MiR-29 increases apoptosis of retinal ganglion cells in rat glaucoma model through AKT signaling pathway. Panminerva Med 2021; 63:90-91. [PMID: 31262145 DOI: 10.23736/s0031-0808.19.03670-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Li Yu
- Corneal and External Disease, Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Jinan University, Shenzhen, China
- Corneal and External Disease, Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen, China
| | - Jie Yang
- Department of Ophthalmology, Hebei Medical University Affiliate Hospital, Shijiazhuang, China -
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Rojas P, Ramírez AI, Cadena M, Fernández-Albarral JA, Salobrar-García E, López-Cuenca I, Santos-García I, de Lago E, Urcelay-Segura JL, Ramírez JM, de Hoz R, Salazar JJ. Retinal Ganglion Cell Loss and Microglial Activation in a SOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis. Int J Mol Sci 2021; 22:ijms22041663. [PMID: 33562231 PMCID: PMC7915199 DOI: 10.3390/ijms22041663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 12/26/2022] Open
Abstract
The neurodegenerative disease amyotrophic lateral sclerosis (ALS) affects the spinal cord, brain stem, and cerebral cortex. In this pathology, both neurons and glial cells are affected. However, few studies have analyzed retinal microglia in ALS models. In this study, we quantified the signs of microglial activation and the number of retinal ganglion cells (RGCs) in an SOD1G93A transgenic mouse model at 120 days (advanced stage of the disease) in retinal whole-mounts. For SOD1G93A animals (compared to the wild-type), we found, in microglial cells, (i) a significant increase in the area occupied by each microglial cell in the total area of the retina; (ii) a significant increase in the arbor area in the outer plexiform layer (OPL) inferior sector; (iii) the presence of cells with retracted processes; (iv) areas of cell groupings in some sectors; (v) no significant increase in the number of microglial cells; (vi) the expression of IFN-γ and IL-1β; and (vii) the non-expression of IL-10 and arginase-I. For the RGCs, we found a decrease in their number. In conclusion, in the SOD1G93A model (at 120 days), retinal microglial activation occurred, taking a pro-inflammatory phenotype M1, which affected the OPL and inner retinal layers and could be related to RGC loss.
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Affiliation(s)
- Pilar Rojas
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- Instituto Oftálmico de Madrid, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain; (M.C.); (J.L.U.-S.)
| | - Ana I. Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- OFTARED-ISCIII, IIORC, Universidad Complutense de Madrid, 28011 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain
| | - Manuel Cadena
- Instituto Oftálmico de Madrid, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain; (M.C.); (J.L.U.-S.)
| | - José A. Fernández-Albarral
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
| | - Elena Salobrar-García
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- OFTARED-ISCIII, IIORC, Universidad Complutense de Madrid, 28011 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain
| | - Inés López-Cuenca
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
| | - Irene Santos-García
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28011 Madrid, Spain; (I.S.-G.); (E.d.L.)
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28040 Madrid, Spain
| | - Eva de Lago
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28011 Madrid, Spain; (I.S.-G.); (E.d.L.)
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28040 Madrid, Spain
| | - José L. Urcelay-Segura
- Instituto Oftálmico de Madrid, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain; (M.C.); (J.L.U.-S.)
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - José M. Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- OFTARED-ISCIII, IIORC, Universidad Complutense de Madrid, 28011 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Rosa de Hoz
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- OFTARED-ISCIII, IIORC, Universidad Complutense de Madrid, 28011 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain
- Correspondence: (R.d.H.); (J.J.S.)
| | - Juan J. Salazar
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, 28040 Madrid, Spain; (P.R.); (A.I.R.); (J.A.F.-A.); (E.S.-G.); (I.L.-C.); (J.M.R.)
- OFTARED-ISCIII, IIORC, Universidad Complutense de Madrid, 28011 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain
- Correspondence: (R.d.H.); (J.J.S.)
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Schlüter A, Aksan B, Fioravanti R, Valente S, Mai A, Mauceri D. Histone Deacetylases Contribute to Excitotoxicity-Triggered Degeneration of Retinal Ganglion Cells In Vivo. Mol Neurobiol 2019; 56:8018-8034. [PMID: 31161423 DOI: 10.1007/s12035-019-01658-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023]
Abstract
Excitotoxicity is known to modulate the nuclear accumulation, and thus activity state, of histone deacetylases (HDACs) in pyramidal neurons. In the retina, deregulation in activity and expression of different HDACs has been linked to pathological conditions such as retinitis pigmentosa, retinal ischemia, glaucoma, and acute optic nerve injury. Up to now, however, the effects of in vivo excitotoxicity on the different HDACs in retinal ganglion cells (RGCs) have not been thoroughly investigated. Here, we injected adult mice intravitreally with N-methyl-D-aspartate (NMDA) as a mean to trigger excitotoxicity-mediated RGC degeneration and we detected time-dependent loss of RGCs at 1 and 7 days after the insult. Further, we characterized the subcellular localization of HDACs belonging to class I (HDAC1, HDAC3), IIa (HDAC4, HDAC5, HDAC7, HDAC9), IIb (HDAC6, HDAC10), and IV (HDAC11) in RGCs. Our analyses revealed a differential pattern of HDACs nuclear distribution in RGCs following excitotoxicity. After 1 day, HDAC3, HDAC5, HDAC6, HDAC7, and HDAC11 showed altered subcellular localization in RGCs while 7 days after the excitotoxic insult, HDAC4 and HDAC9 were the only HDACs displaying changes in their subcellular distribution. Moreover, we found that in vivo selective inhibition of HDAC1/3 or HDAC4/5 via MS-275 (entinostat) or LMK-235, respectively, could prevent ongoing RGC degeneration. In conclusion, our results point towards a role of HDACs in RGC degeneration and identify HDAC1/3 and HDAC4/5 as potential therapeutic targets to treat degenerative retinal diseases.
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Affiliation(s)
- Annabelle Schlüter
- Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
| | - Bahar Aksan
- Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
| | - Rossella Fioravanti
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Sergio Valente
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Antonello Mai
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
- Pasteur Institute, Cenci-Bolognetti Foundation, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Daniela Mauceri
- Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany.
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Acharya NK, Qi X, Goldwaser EL, Godsey GA, Wu H, Kosciuk MC, Freeman TA, Macphee CH, Wilensky RL, Venkataraman V, Nagele RG. Retinal pathology is associated with increased blood-retina barrier permeability in a diabetic and hypercholesterolaemic pig model: Beneficial effects of the LpPLA 2 inhibitor Darapladib. Diab Vasc Dis Res 2017; 14:200-213. [PMID: 28301218 DOI: 10.1177/1479164116683149] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Using a porcine model of diabetes mellitus and hypercholesterolaemia, we previously showed that diabetes mellitus and hypercholesterolaemia is associated with a chronic increase in blood-brain barrier permeability in the cerebral cortex, leading to selective binding of immunoglobulin G and deposition of amyloid-beta1-42 peptide in pyramidal neurons. Treatment with Darapladib (GlaxoSmithKline, SB480848), an inhibitor of lipoprotein-associated phospholipase-A2, alleviated these effects. Here, investigation of the effects of chronic diabetes mellitus and hypercholesterolaemia on the pig retina revealed a corresponding increased permeability of the blood-retina barrier coupled with a leak of plasma components into the retina, alterations in retinal architecture, selective IgG binding to neurons in the ganglion cell layer, thinning of retinal layers due to cell loss and increased glial fibrillary acidic protein expression in Müller cells, all of which were curtailed by treatment with Darapladib. These findings suggest that chronic diabetes mellitus and hypercholesterolaemia induces increased blood-retina barrier permeability that may be linked to altered expression of blood-retina barrier-associated tight junction proteins, claudin and occludin, leading to structural changes in the retina consistent with diabetic retinopathy. Additionally, results suggest that drugs with vascular anti-inflammatory properties, such as Darapladib, may have beneficial effects on eye diseases strongly linked to vascular abnormalities such as diabetic retinopathy and age-related macular degeneration.
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Affiliation(s)
- Nimish K Acharya
- 1 Biomarker Discovery Center, New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 2 Department of Geriatrics and Gerontology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 3 Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Xin Qi
- 4 Thomas Jefferson University, Philadelphia, PA, USA
- 5 Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Eric L Goldwaser
- 1 Biomarker Discovery Center, New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 2 Department of Geriatrics and Gerontology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 6 Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - George A Godsey
- 2 Department of Geriatrics and Gerontology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 6 Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
| | - Hao Wu
- 6 Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ, USA
- 7 Department of Cell Biology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
| | - Mary C Kosciuk
- 1 Biomarker Discovery Center, New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 2 Department of Geriatrics and Gerontology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
| | - Theresa A Freeman
- 8 Department of Orthopaedic Surgery, Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University
| | | | - Robert L Wilensky
- 10 Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Venkat Venkataraman
- 7 Department of Cell Biology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
| | - Robert G Nagele
- 1 Biomarker Discovery Center, New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
- 2 Department of Geriatrics and Gerontology, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
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Jusuf AA, Sakagami H, Kikkawa S, Terashima T. Expression of Beta Subunit 2 of Ca²+/Calmodulin-Dependent Protein Kinase I in the Developing Rat Retina. Kobe J Med Sci 2015; 61:E115-E123. [PMID: 27323839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Expression of beta 2 subunit of Ca²+/calmodulin-dependent protein kinase I (CaMKIβ2) of the rat retina during the developmental period and in the adulthood was studied immunohistochemically. The immunoreactivity of CaMKIβ2 was detected in the earliest development of the primordial retina at embryological day (E) 12. The inner neuroblastic layer from which the presumptive ganglion cells are generated showed the ubiquitous CaMKIβ2 immunoreactivity at E15 and persistently expressed at the same level until postnatal day (P) 0 when the inner neuroblastic layer divides into the ganglionic cell layer and the inner plexiform layer. The strong immunoreactivity was detected in the ganglion cell layer and the moderate one in the internal plexiform layer. CaMKIβ2 immunoreactivities were persistantly expressed throughout the postnatal development at the same level. The low level of intensity was first found in the inner nuclear layer at P7, followed by the outer plexiform, outer nuclear and rod-cone cell layers at the age of P12, respectively. The intensities of CaMKIβ2 immunoreactivities in the inner nuclear and rod-cone cell layers were gradually increased to the strong level by P18 and persisted until adulthood. The present study revealed that the expression of CaMKIβ2 in the retina was detected from the earliest development until adulthood, indicating that CaMKIβ2 may be required in both proliferation and differentiation of the retinal precursor cells and subsequent formation of the functional layers. In addition, CaMKIβ2 immunoreactivity in the rod-cone cell layer implies that this protein may be involved in the visual signaling process.
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Affiliation(s)
- Ahmad Aulia Jusuf
- Department of Anatomy and Developmental Neurobiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
- Department of Histology, Faculty of Medicine, University of Indonesia, Jakarta 10430, Indonesia
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0374, Japan
| | - Satoshi Kikkawa
- Department of Anatomy and Developmental Neurobiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Toshio Terashima
- Department of Anatomy and Developmental Neurobiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
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Mueller BH, Park Y, Ma HY, Dibas A, Ellis DZ, Clark AF, Yorio T. Sigma-1 receptor stimulation protects retinal ganglion cells from ischemia-like insult through the activation of extracellular-signal-regulated kinases 1/2. Exp Eye Res 2014; 128:156-69. [PMID: 25305575 DOI: 10.1016/j.exer.2014.10.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/18/2014] [Accepted: 10/07/2014] [Indexed: 11/20/2022]
Abstract
Sigma-1 receptor (σ-1) activation and mitogen-activated protein kinases (MAPKs) have been shown to protect retinal ganglion cells (RGCs) from cell death. The purpose of this study was to determine if σ-1 receptor stimulation with pentazocine could promote neuroprotection under conditions of an ischemia-like insult (oxygen glucose deprivation (OGD)) through the phosphorylation of extracellular signal regulated kinase (pERK)1/2. Primary RGCs were isolated from P3-P7 Sprague-Dawley rats and purified by sequential immunopanning using Thy1.1 antibodies. RGCs were cultured for 7 days before subjecting the cells to an OGD insult (0.5% oxygen in glucose-free medium) for 6 h. During the OGD, RGCs were treated with pentazocine (σ-1 receptor agonist) with or without BD 1047 (σ-1 receptor antagonist). In other experiments, primary RGCs were treated with pentazocine in the presence or absence of an MEK1/2 inhibitor, PD098059. Cell survival/death was assessed by staining with the calcein-AM/ethidium homodimer reagent. Levels of pERK1/2, total ERK1/2, and beta tubulin expression were determined by immunoblotting and immunofluorescence staining. RGCs subjected to OGD for 6 h induced 50% cell death in primary RGCs (p < 0.001) and inhibited pERK1/2 expression by 65% (p < 0.001). Cell death was attenuated when RGCs were treated with pentazocine under OGD (p < 0.001) and pERK1/2 expression was increased by 1.6 fold (p < 0.05) compared to OGD treated RGCs without pentazocine treatment. The co-treatment of PD098059 (MEK1/2 inhibitor) with pentazocine significantly abolished the protective effects of pentazocine on the RGCs during this OGD insult. Activation of the σ-1 receptor is a neuroprotective target that can protect RGCs from an ischemia-like insult. These results also established a direct relationship between σ-1 receptor stimulation and the neuroprotective effects of the ERK1/2 pathway in purified RGCs subjected to OGD. These findings suggest that activation of the σ-1 receptor may be a therapeutic target for neuroprotection particularly relevant to ocular neurodegenerative diseases that effect RGCs.
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Affiliation(s)
- Brett H Mueller
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA.
| | - Yong Park
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Hai-Ying Ma
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Adnan Dibas
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Dorette Z Ellis
- College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Abbot F Clark
- Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Thomas Yorio
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA.
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10
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Koch JC, Tönges L, Barski E, Michel U, Bähr M, Lingor P. ROCK2 is a major regulator of axonal degeneration, neuronal death and axonal regeneration in the CNS. Cell Death Dis 2014; 5:e1225. [PMID: 24832597 PMCID: PMC4047920 DOI: 10.1038/cddis.2014.191] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 03/26/2014] [Accepted: 03/28/2014] [Indexed: 12/19/2022]
Abstract
The Rho/ROCK/LIMK pathway is central for the mediation of repulsive environmental signals in the central nervous system. Several studies using pharmacological Rho-associated protein kinase (ROCK) inhibitors have shown positive effects on neurite regeneration and suggest additional pro-survival effects in neurons. However, as none of these drugs is completely target specific, it remains unclear how these effects are mediated and whether ROCK is really the most relevant target of the pathway. To answer these questions, we generated adeno-associated viral vectors to specifically downregulate ROCK2 and LIM domain kinase (LIMK)-1 in rat retinal ganglion cells (RGCs) in vitro and in vivo. We show here that specific knockdown of ROCK2 and LIMK1 equally enhanced neurite outgrowth of RGCs on inhibitory substrates and both induced substantial neuronal regeneration over distances of more than 5 mm after rat optic nerve crush (ONC) in vivo. However, only knockdown of ROCK2 but not LIMK1 increased survival of RGCs after optic nerve axotomy. Moreover, knockdown of ROCK2 attenuated axonal degeneration of the proximal axon after ONC assessed by in vivo live imaging. Mechanistically, we demonstrate here that knockdown of ROCK2 resulted in decreased intraneuronal activity of calpain and caspase 3, whereas levels of pAkt and collapsin response mediator protein 2 and autophagic flux were increased. Taken together, our data characterize ROCK2 as a specific therapeutic target in neurodegenerative diseases and demonstrate new downstream effects of ROCK2 including axonal degeneration, apoptosis and autophagy.
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Affiliation(s)
- J C Koch
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - L Tönges
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - E Barski
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - U Michel
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - M Bähr
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - P Lingor
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
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11
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Wang AL, Carroll RC, Nawy S. Down-regulation of the RNA editing enzyme ADAR2 contributes to RGC death in a mouse model of glaucoma. PLoS One 2014; 9:e91288. [PMID: 24608178 PMCID: PMC3946738 DOI: 10.1371/journal.pone.0091288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 02/11/2014] [Indexed: 12/13/2022] Open
Abstract
Glaucoma is a progressive neurodegenerative disease of retinal ganglion cells (RGCs) associated with characteristic axon degeneration in the optic nerve. Excitotoxic damage due to increased Ca(2+) influx, possibly through NMDA-type glutamate receptors, has been proposed to be a cause of RGC dysfunction and death in glaucoma. Recent work has found that expression of another potentially critical receptor, the Ca(2+)-permeable AMPA receptor (CP-AMPAR), is elevated during various pathological conditions (including ALS and ischemia), resulting in increased neuronal death. Here we test the hypothesis that CP-AMPARs contribute to RGC death due to elevated Ca(2+) influx in glaucoma. AMPA receptors are impermeable to Ca(2+) if the tetrameric receptor contains a GluA2 subunit that has undergone Q/R RNA editing at a site in the pore region. The activity of ADAR2, the enzyme responsible for this RNA editing, generally ensures that the vast majority of GluA2 proteins are edited. Here, we demonstrate that ADAR2 levels decrease in a mouse model of glaucoma in which IOP is chronically elevated. Furthermore, using an in vitro model of RGCs, we find that knockdown of ADAR2 using siRNA increased the accumulation of Co(2+) in response to glutamate, and decreased the rectification index of AMPA currents detected electrophysiologically, indicating an increased Ca(2+) permeability through AMPARs. The RGCs in primary culture also exhibited increased excitotoxic cell death following knock down of ADAR2. Furthermore, cell death was reversed by NASPM, a specific blocker for CP-AMPARs. Together, our data suggest that chronically elevated IOP in adult mice reduces expression of the ADAR2 enzyme, and the loss of ADAR2 editing and subsequent disruption of GluA2 RNA editing might potentially play a role in promoting RGC neuronal death as observed in glaucoma.
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Affiliation(s)
- Ai Ling Wang
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Reed C. Carroll
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Scott Nawy
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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12
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Kim SY, Shim MS, Kim KY, Weinreb RN, Wheeler LA, Ju WK. Inhibition of cyclophilin D by cyclosporin A promotes retinal ganglion cell survival by preventing mitochondrial alteration in ischemic injury. Cell Death Dis 2014; 5:e1105. [PMID: 24603333 PMCID: PMC3973219 DOI: 10.1038/cddis.2014.80] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/22/2014] [Accepted: 01/30/2014] [Indexed: 01/10/2023]
Abstract
Cyclosporin A (CsA) inhibits the opening of the mitochondrial permeability transition pore (MPTP) by interacting with cyclophilin D (CypD) and ameliorates neuronal cell death in the central nervous system against ischemic injury. However, the molecular mechanisms underlying CypD/MPTP opening-mediated cell death in ischemic retinal injury induced by acute intraocular pressure (IOP) elevation remain unknown. We observed the first direct evidence that acute IOP elevation significantly upregulated CypD protein expression in ischemic retina at 12 h. However, CsA prevented the upregulation of CypD protein expression and promoted retinal ganglion cell (RGC) survival against ischemic injury. Moreover, CsA blocked apoptotic cell death by decreasing cleaved caspase-3 protein expression in ischemic retina. Of interest, although the expression level of Bcl-xL protein did not show a significant change in ischemic retina treated with vehicle or CsA at 12 h, ischemic damage induced the reduction of Bcl-xL immunoreactivity in RGCs. More importantly, CsA preserved Bcl-xL immunoreactivity in RGCs of ischemic retina. In parallel, acute IOP elevation significantly increased phosphorylated Bad (pBad) at Ser112 protein expression in ischemic retina at 12 h. However, CsA significantly preserved pBad protein expression in ischemic retina. Finally, acute IOP elevation significantly increased mitochondrial transcription factor A (Tfam) protein expression in ischemic retina at 12 h. However, CsA significantly preserved Tfam protein expression in ischemic retina. Studies on mitochondrial DNA (mtDNA) content in ischemic retina showed that there were no statistically significant differences in mtDNA content among control and ischemic groups treated with vehicle or CsA. Therefore, these results provide evidence that the activation of CypD-mediated MPTP opening is associated with the apoptotic pathway and the mitochondrial alteration in RGC death of ischemic retinal injury. On the basis of these observations, our findings suggest that CsA-mediated CypD inhibition may provide a promising therapeutic potential for protecting RGCs against ischemic injury-mediated mitochondrial dysfunction.
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Affiliation(s)
- S Y Kim
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California San Diego, La Jolla, CA, USA
| | - M S Shim
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California San Diego, La Jolla, CA, USA
| | - K-Y Kim
- Center for Research on Biological Systems, National Center for Microscopy and Imaging Research and Department of Neuroscience, University of California San Diego, La Jolla, CA, USA
| | - R N Weinreb
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California San Diego, La Jolla, CA, USA
| | - L A Wheeler
- Department of Biological Sciences, Allergan Inc., Irvine, CA, USA
| | - W-K Ju
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California San Diego, La Jolla, CA, USA
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13
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Li X, Persad ARL, Monckton EA, Godbout R. Transcription factor AP-2delta regulates the expression of polysialyltransferase ST8SIA2 in chick retina. FEBS Lett 2014; 588:770-5. [PMID: 24462686 DOI: 10.1016/j.febslet.2014.01.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/07/2014] [Accepted: 01/10/2014] [Indexed: 11/17/2022]
Abstract
The AP-2δ transcription factor is restricted to a subset of retinal ganglion cells. Overexpression of AP-2δ in chick retina results in induction of polysialylated neural cell adhesion molecule (PSA-NCAM) accompanied by misrouting and bundling of ganglion cell axons. Two polysialyltransferases, ST8SIA2 and ST8SIA4, are responsible for polysialylation of NCAM. Here, we investigate the mechanism driving the increase in PSA-NCAM observed upon AP-2δ overexpression. We show that ST8SIA2 is induced by AP-2δ overexpression in chick retina. We use chromatin immunoprecipitation and gel shift assays to demonstrate direct interaction between AP-2δ and the ST8SIA2 promoter. We propose that up-regulation of ST8SIA2 upon AP-2δ overexpression in retina increases ectopic polysialylation of NCAM which in turn causes premature bundling of axons and alters axonal response to guidance cues.
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Affiliation(s)
- Xiaodong Li
- Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Amit R L Persad
- Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Elizabeth A Monckton
- Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Roseline Godbout
- Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada.
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14
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Li X, Zhang M, Zhou H. The morphological features and mitochondrial oxidative stress mechanism of the retinal neurons apoptosis in early diabetic rats. J Diabetes Res 2014; 2014:678123. [PMID: 24527463 PMCID: PMC3910261 DOI: 10.1155/2014/678123] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/10/2013] [Accepted: 11/25/2013] [Indexed: 01/01/2023] Open
Abstract
This paper aims to explore the relationship of retinal neuron apoptosis and manganese superoxidase dismutase (MnSOD) at early phase of diabetic retinopathy. Sprague-Dawley rats were grouped into normal controls and diabetics. Data were collected after 4, 8, and 12 weeks (n = 12). The pathological changes and ultrastructure of the retina, the apoptosis rate of retinal neurons by TdT-mediated dUTP nick end label (TUNEL), mRNA expressions of MnSOD and copper-zinc superoxide dismutase (Cu-Zn SOD), and the activities of total SOD (T-SOD) and subtypes of SOD were tested. For the controls, there was no abnormal structure or apoptosis of retinal neurons at any time. There was no change of structure for rats with diabetes at 4 or 8 weeks, but there was a decrease of retinal ganglion cells (RGCs) number and thinner inner nuclear layer (INL) at 12 weeks. The apoptosis ratio of RGCs was higher than that of the controls at 8 and 12 weeks (P < 0.001). The activity and mRNA levels of MnSOD were lower in diabetics at 4, 8, and 12 weeks (P < 0.05). In summary, the apoptosis of the retinal neurons occurred at 8 weeks after the onset of diabetes. Retinal neuron apoptosis in early diabetic rats may be associated with the decreased activity and mRNA of MnSOD.
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Affiliation(s)
- Xiaoyan Li
- Department of Ophthalmology, The First Affiliated Hospital of Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing 100048, China
| | - Maonian Zhang
- Department of Ophthalmology, PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing 100853, China
- *Maonian Zhang:
| | - Huanfen Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing 100048, China
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15
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Yuki K, Yoshida T, Miyake S, Tsubota K, Ozawa Y. Neuroprotective role of superoxide dismutase 1 in retinal ganglion cells and inner nuclear layer cells against N-methyl-d-aspartate-induced cytotoxicity. Exp Eye Res 2013; 115:230-8. [PMID: 23856406 DOI: 10.1016/j.exer.2013.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/28/2013] [Accepted: 07/02/2013] [Indexed: 01/12/2023]
Abstract
The N-methyl-d-aspartate (NMDA) receptor-induced apoptosis is implicated in the pathological mechanisms of neural tissues, increasing the release of reactive oxygen species (ROS), resulting in a type of apoptotic cell death called excitotoxicity. Although intrinsic mechanisms to remove ROS, such as antioxidant enzymes, are provided by the tissue, the association between NMDA-induced excitotoxicity and antioxidative enzymes is not well understood. In this study, we focused on superoxide dismutase 1 (SOD1), an antioxidant enzyme, and investigated the role of SOD1 in the NMDA-induced neuronal cell death in the retina. NMDA was intravitreally injected into wild-type (WT) and SOD1 total knock-out (SOD1-deficient) mice. The number of TUNEL-positive cells in the retinal ganglion cell layer (GCL) and inner nuclear layer (INL) counted in the retinal sections and flatmount retinas were significantly higher in the SOD1-deficient mice than the WT mice after NMDA injection. Visual function assessed by dark-adapted electroretinogram (ERG) showed that the amplitudes of a-wave, b-wave, and oscillatory potential 2 were significantly reduced in the NMDA-injected SOD1-deficient mice. The level of ROS in the GCL and INL, measured using dihydroethidium, and the number of positive cells for γ-H2AX, a marker for DNA double strand breaks, and 8-OHdG, a marker for DNA oxidation, in the GCL were significantly increased in the SOD1-deficient mice after NMDA injection. We also measured mRNA and protein levels of SOD1 and SOD2 in the retina of WT mice, to find that mRNA and protein levels of SOD1, but not SOD2, were significantly reduced after NMDA injection. SOD1 deficiency exacerbated NMDA-induced damage to the inner retinal neurons, and NMDA reduced SOD1 levels in the retina of WT mice. Therefore, SOD1 protected retinal neurons against NMDA-induced retinal neurotoxicity, and NMDA-induced SOD1 reduction may be involved in neuronal vulnerability to excitotoxicity.
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Affiliation(s)
- Kenya Yuki
- Laboratory of Retinal Cell Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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16
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Guo D, Bi H, Wu Q, Wang D, Cui Y. Zinc oxide nanoparticles induce rat retinal ganglion cell damage through bcl-2, caspase-9 and caspase-12 pathways. J Nanosci Nanotechnol 2013; 13:3769-3777. [PMID: 23862406 DOI: 10.1166/jnn.2013.7169] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Nanomaterials, including zinc oxide (ZnO) nanoparticles, are being developed for a variety of commercial products. Recent reports showed that cells exposed to ZnO nanoparticles produced severe cytotoxicity accompanied by oxidative stress and genotoxicity. To understand the possible mechanism underlying oxidative stress of ZnO nanoparticles, the present investigation focused on the direct bioactivity of ZnO nanoparticles using a rat retinal ganglion cell (RGC-5) culture. At concentrations relevant to those used in vitro exposure of RGC-5 cells to ZnO nanoparticles, it was found that ZnO nanoparticles could inhibit cell proliferation in time- and concentration-dependent manners. Meanwhile, cell cycle arrest of S and G2/M phases occurred in RGC-5 cells induced by ZnO nanoparticles. Moreover, our results also demonstrated that the overproduction of reactive oxygen species (ROS) and elevated level of caspase-12 as well as decreased levels of bcl-2 and caspase-9 occurred after treatment with different concentrations of ZnO nanoparticles when compared to those in untreated cells. In summary, our findings suggest that ZnO nanoparticles could lead to the over generations of ROS and caspase-12 as well as decreased levels of bcl-2 and caspase-9. These results indicate that bcl-2, caspase-9 and caspase-12 may play significant roles in ZnO nanoparticle-induced RGC-5 cell damage.
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Affiliation(s)
- Dadong Guo
- Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan 250002, China
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17
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Chindasub P, Lindsey JD, Duong-Polk K, Leung CK, Weinreb RN. Inhibition of histone deacetylases 1 and 3 protects injured retinal ganglion cells. Invest Ophthalmol Vis Sci 2013; 54:96-102. [PMID: 23197683 PMCID: PMC3544425 DOI: 10.1167/iovs.12-10850] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 10/24/2012] [Accepted: 10/29/2012] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Thy-1 is a marker of retinal ganglion cell (RGC) differentiation. Optic nerve injury triggers reduction of Thy-1 promoter activation followed by retinal ganglion cell (RGC) death. This study determined whether MS-275, an inhibitor of the histone deacetylases 1 and 3, can inhibit these changes. METHODS Mice expressing cyan fluorescent protein (CFP) under control of the Thy-1 promoter received MS-275 (subcutaneous) or vehicle three times per week starting 1 week before optic nerve crush and continuing for 6 weeks. The same retinal area was imaged using the blue-light confocal scanning laser ophthalmoscope before and after optic nerve crush every week, and fluorescent spots were counted manually. The eyes were then processed for histopathologic analysis. RESULTS The mean proportions of fluorescent retinal neurons remaining in the vehicle group following optic nerve crush were 36 ± 8, 18 ± 6, 13 ± 10, 12 ± 4, 13 ± 5, and 13 ± 5% at weeks 1 through 6, respectively (n = 6). In contrast, the mean proportions of fluorescent retinal neurons remaining in the group treated with MS-275 were 59 ± 19, 39 ± 11, 34 ± 12, 33 ± 15, 32 ± 13, and 27 ± 15% at weeks 1 through 6, respectively (n = 7, P < 0.05 at weeks 1 through 5). Rate analysis showed that MS-275 slowed the rate of loss during the first 2 weeks by 23% (P < 0.05) and subsequently was similar. Histopathologic analysis revealed 27 ± 13% greater ganglion cell layer (GCL) neurons in the eyes from mice that received MS-275 treatment (P < 0.02). CONCLUSIONS These results indicate that treatment with MS-275 protects against the loss of RGC differentiation and promotes RGC survival following optic nerve injury.
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Affiliation(s)
- Panida Chindasub
- From the
Hamilton Glaucoma Center and Department of Ophthalmology, University of California-San Diego, La Jolla, California
| | - James D. Lindsey
- From the
Hamilton Glaucoma Center and Department of Ophthalmology, University of California-San Diego, La Jolla, California
| | - Karen Duong-Polk
- From the
Hamilton Glaucoma Center and Department of Ophthalmology, University of California-San Diego, La Jolla, California
| | - Christopher K. Leung
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Robert N. Weinreb
- From the
Hamilton Glaucoma Center and Department of Ophthalmology, University of California-San Diego, La Jolla, California
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18
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Nebbioso M, Scarsella G, Tafani M, Pescosolido N. Mechanisms of ocular neuroprotection by antioxidant molecules in animal models. J BIOL REG HOMEOS AG 2013; 27:197-209. [PMID: 23489699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This work was conducted to evaluate the efficacy of a treatment on retinal ganglion cells (RGC) and on astrocytes of the optic nerve of glaucomatous eyes, using a combination of alpha-lipoic acid (ALA) and superoxide dismutase (SOD). Thirty-two male Wistar rats were fed with a diet supplemented with ALA, SOD, ALA and SOD or with no product for 8 weeks. Ocular hypertension was induced with 2% methylcellulose (MTC) and then rats were sacrificed. TUNEL assay showed a marked fluorescence in the ganglion cells and astrocytes of MTC-treated rats evidencing induction of apoptosis. In contrast, sections of eyes pretreated with ALA and SOD showed a lack of fluorescence quite similar to that of the controls. Similarly, eyes sections from rats pre-treated with ALA and SOD showed reduced differential expression of inducible nitric oxide synthase (iNOS) and of caspase-3 in compared to normally-fed/MTC-inoculated cases. An increase of ALA and SOD exerts an antiapoptotic effect and protects against oxidative stress and hence against the structural remodelling of the RGCs and astrocytes of the optic nerve in the presence of an ischemic and pressure stress.
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Affiliation(s)
- M Nebbioso
- Department of Sense Organs, Sapienza University of Rome, Rome, Italy.
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19
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Santos ARC, Corredor RG, Obeso BA, Trakhtenberg EF, Wang Y, Ponmattam J, Dvoriantchikova G, Ivanov D, Shestopalov VI, Goldberg JL, Fini ME, Bajenaru ML. β1 integrin-focal adhesion kinase (FAK) signaling modulates retinal ganglion cell (RGC) survival. PLoS One 2012; 7:e48332. [PMID: 23118988 PMCID: PMC3485184 DOI: 10.1371/journal.pone.0048332] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/24/2012] [Indexed: 12/16/2022] Open
Abstract
Extracellular matrix (ECM) integrity in the central nervous system (CNS) is essential for neuronal homeostasis. Signals from the ECM are transmitted to neurons through integrins, a family of cell surface receptors that mediate cell attachment to ECM. We have previously established a causal link between the activation of the matrix metalloproteinase-9 (MMP-9), degradation of laminin in the ECM of retinal ganglion cells (RGCs), and RGC death in a mouse model of retinal ischemia-reperfusion injury (RIRI). Here we investigated the role of laminin-integrin signaling in RGC survival in vitro, and after ischemia in vivo. In purified primary rat RGCs, stimulation of the β1 integrin receptor with laminin, or agonist antibodies enhanced RGC survival in correlation with activation of β1 integrin’s major downstream regulator, focal adhesion kinase (FAK). Furthermore, β1 integrin binding and FAK activation were required for RGCs’ survival response to laminin. Finally, in vivo after RIRI, we observed an up-regulation of MMP-9, proteolytic degradation of laminin, decreased RGC expression of β1 integrin, FAK and Akt dephosphorylation, and reduced expression of the pro-survival molecule bcl-xL in the period preceding RGC apoptosis. RGC death was prevented, in the context of laminin degradation, by maintaining β1 integrin activation with agonist antibodies. Thus, disruption of homeostatic RGC-laminin interaction and signaling leads to cell death after retinal ischemia, and maintaining integrin activation may be a therapeutic approach to neuroprotection.
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Affiliation(s)
- Andrea Rachelle C. Santos
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Raul G. Corredor
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Betty Albo Obeso
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Ephraim F. Trakhtenberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Neuroscience Program, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Ying Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jamie Ponmattam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Galina Dvoriantchikova
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Dmitry Ivanov
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Valery I. Shestopalov
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jeffrey L. Goldberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Neuroscience Program, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Mary Elizabeth Fini
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Michaela Livia Bajenaru
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Abstract
The visual pigment melanopsin is expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs) in the mammalian retina, where it is involved in non-image forming light responses including circadian photoentrainment, pupil constriction, suppression of pineal melatonin synthesis, and direct photic regulation of sleep. It has recently been shown that the melanopsin-based light response in ipRGCs is attenuated by the neurotransmitter dopamine. Here, we use a heterologous expression system to demonstrate that mouse melanopsin can be phosphorylated by protein kinase A, and that phosphorylation can inhibit melanopsin signaling in HEK cells. Site-directed mutagenesis experiments revealed that this inhibitory effect is primarily mediated by phosphorylation of sites T186 and S287 located in the second and third intracellular loops of melanopsin, respectively. Furthermore, we show that this phosphorylation can occur in vivo using an in situ proximity-dependent ligation assay (PLA). Based on these data, we suggest that the attenuation of the melanopsin-based light response by dopamine is mediated by direct PKA phosphorylation of melanopsin, rather than phosphorylation of a downstream component of the signaling cascade.
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Affiliation(s)
- Joseph R. Blasic
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
| | - R. Lane Brown
- Department of Veterinary & Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, Washington, United States of America
| | - Phyllis R. Robinson
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
- * E-mail:
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Guo D, Standley C, Bellve K, Fogarty K, Bao ZZ. Protein kinase Cα and integrin-linked kinase mediate the negative axon guidance effects of Sonic hedgehog. Mol Cell Neurosci 2012; 50:82-92. [PMID: 22521536 PMCID: PMC3383945 DOI: 10.1016/j.mcn.2012.03.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 03/22/2012] [Accepted: 03/26/2012] [Indexed: 01/22/2023] Open
Abstract
In addition to its role as a morphogen, Sonic hedgehog (Shh) has also been shown to function as a guidance factor that directly acts on the growth cones of various types of axons. However, the noncanonical signaling pathways that mediate the guidance effects of Shh protein remain poorly understood. We demonstrate that a novel signaling pathway consisting of protein kinase Cα (PKCα) and integrin-linked kinase (ILK) mediates the negative guidance effects of high concentration of Shh on retinal ganglion cell (RGC) axons. Shh rapidly increased Ca(2+) level and activated PKCα and ILK in the growth cones of RGC axons. By in vitro kinase assay, PKCα was found to directly phosphorylate ILK on threonine-173 and -181. Inhibition of PKCα or expression of a mutant ILK with the PKCα phosphorylation sites mutated (ILK-DM), abolished the Shh-induced macropinocytosis, growth cone collapse and repulsive axon turning. In vivo, expression of a dominant negative PKCα or ILK-DM disrupted RGC axon pathfinding at the optic chiasm but not the projection toward the optic disk, supporting that this signaling pathway plays a specific role in Shh-mediated negative guidance effects.
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Affiliation(s)
- Daorong Guo
- Department of Medicine and Cell Biology, Program in Neuroscience, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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22
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Bischof J, Müller A, Fänder M, Knippschild U, Fischer D. Neurite outgrowth of mature retinal ganglion cells and PC12 cells requires activity of CK1δ and CK1ε. PLoS One 2011; 6:e20857. [PMID: 21698236 PMCID: PMC3116831 DOI: 10.1371/journal.pone.0020857] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 05/10/2011] [Indexed: 01/07/2023] Open
Abstract
Mature retinal ganglion cells (RGCs) do not normally regenerate severed axons after optic nerve injury and show only little neurite outgrowth in culture. However, RGCs can be transformed into an active regenerative state after lens injury (LI) enabling these neurons to regrow axons in vitro and in vivo. In the current study we investigated the role of CK1δ and CK1ε activity in neurite outgrowth of LI stimulated RGCs and nerve growth factor (NGF) stimulated PC12 cells, respectively. In both cell types CK1δ and ε were localized in granular particles aligned at microtubules in neurites and growth cones. Although LI treatment did not measurably affect the expression of CK1δ and ε, it significantly elevated the specific kinase activity in the retina. Similarly, CK1δ/ε specific kinase activity was also elevated in NGF treated PC12 cells compared with untreated controls. Neurite extension in PC12 cells was associated with a change in the activity of CK1δ C-terminal targeting kinases, suggesting that activity of these kinases might be necessary for neurite outgrowth. Pharmacological inactivation of CK1δ and ε markedly compromised neurite outgrowth of both, PC12 cells and LI stimulated RGCs in a concentration dependent manner. These data provide evidence for a so far unknown, but essential role of CK1 isoforms in neurite growth.
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Affiliation(s)
- Joachim Bischof
- Department of General, Visceral and Transplantation Surgery, University of Ulm, Ulm, Germany
| | - Adrienne Müller
- Department of Experimental Neurology, University of Ulm, Ulm, Germany
| | - Miriam Fänder
- Department of Experimental Neurology, University of Ulm, Ulm, Germany
| | - Uwe Knippschild
- Department of General, Visceral and Transplantation Surgery, University of Ulm, Ulm, Germany
- * E-mail: (UK); (DF)
| | - Dietmar Fischer
- Department of Experimental Neurology, University of Ulm, Ulm, Germany
- Department of Experimental Neurology, University of Düsseldorf, Düsseldorf, Germany
- * E-mail: (UK); (DF)
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23
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Rejdak R, Rummelt C, Zrenner E, Grieb P, Rejdak K, Okuno E, Thaler S, Nowomiejska K, Kruse F, Turski W, Junemann AG. Presence of L-kynurenine aminotransferase III in retinal ganglion cells and corpora amylacea in the human retina and optic nerve. Folia Neuropathol 2011; 49:132-137. [PMID: 21845542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Corpora amylacea (CAm) are a hallmark of aging and neurodegeneration. The presence of kynurenine aminotransferases I and II (KAT I and II) in CAm in the human retina and optic nerve has been already shown. The present study aimed to examine kynurenine aminotransferase III (KAT III) immunoreactivity in CAm in the human retina and optic nerve. MATERIAL AND METHODS Polyclonal antibody against KAT III was used on sections of human eyes enucleated due to malignant uveal melanoma. PAS-stained sections of CAm were compared with KAT III stained ones. RESULTS KAT III immunoreactivity was observed in CAm in the retina, prelaminar, laminar and retrolaminar region of the optic nerve with similar location to PAS-stained sections. The most intense staining was observed in the retrolaminar part of the optic nerve. KAT III immunoreactivity was also present in the cytoplasm of retinal ganglion cells. CONCLUSIONS Expression of KAT III in CAm in the human retina and optic nerve indicates that this enzyme may be relevant in mechanisms of neurodegeneration leading to CAm formation.
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Affiliation(s)
- Robert Rejdak
- University of Erlangen-Nuremberg, Department of Ophthalmology, Germany
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Zhao WJ, Zhang M, Miao Y, Yang XL, Wang Z. Melatonin potentiates glycine currents through a PLC/PKC signalling pathway in rat retinal ganglion cells. J Physiol 2010; 588:2605-19. [PMID: 20519319 PMCID: PMC2916991 DOI: 10.1113/jphysiol.2010.187641] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 05/24/2010] [Indexed: 12/15/2022] Open
Abstract
In vertebrate retina, melatonin regulates various physiological functions. In this work we investigated the mechanisms underlying melatonin-induced potentiation of glycine currents in rat retinal ganglion cells (RGCs). Immunofluorescence double labelling showed that rat RGCs were solely immunoreactive to melatonin MT(2) receptors. Melatonin potentiated glycine currents of RGCs, which was reversed by the MT(2) receptor antagonist 4-P-PDOT. The melatonin effect was blocked by intracellular dialysis of GDP-beta-S. Either preincubation with pertussis toxin or application of the phosphatidylcholine (PC)-specific phospholipase C (PLC) inhibitor D609, but not the phosphatidylinositol (PI)-PLC inhibitor U73122, blocked the melatonin effect. The protein kinase C (PKC) activator PMA potentiated the glycine currents and in the presence of PMA melatonin failed to cause further potentiation of the currents, whereas application of the PKC inhibitor bisindolylmaleimide IV abolished the melatonin-induced potentiation. The melatonin effect persisted when [Ca(2+)](i) was chelated by BAPTA, and melatonin induced no increase in [Ca(2+)](i). Neither cAMP-PKA nor cGMP-PKG signalling pathways seemed to be involved because 8-Br-cAMP or 8-Br-cGMP failed to cause potentiation of the glycine currents and both the PKA inhibitor H-89 and the PKG inhibitor KT5823 did not block the melatonin-induced potentiation. In consequence, a distinct PC-PLC/PKC signalling pathway, following the activation of G(i/o)-coupled MT(2) receptors, is most likely responsible for the melatonin-induced potentiation of glycine currents of rat RGCs. Furthermore, in rat retinal slices melatonin potentiated light-evoked glycine receptor-mediated inhibitory postsynaptic currents in RGCs. These results suggest that melatonin, being at higher levels at night, may help animals to detect positive or negative contrast in night vision by modulating inhibitory signals largely mediated by glycinergic amacrine cells in the inner retina.
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Affiliation(s)
- Wen-Jie Zhao
- Institutes of Brain Science and Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
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25
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Gubitosi-Klug RA, Talahalli R, Du Y, Nadler JL, Kern TS. 5-Lipoxygenase, but not 12/15-lipoxygenase, contributes to degeneration of retinal capillaries in a mouse model of diabetic retinopathy. Diabetes 2008; 57:1387-93. [PMID: 18346986 PMCID: PMC4444435 DOI: 10.2337/db07-1217] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Lipoxygenases are regulators of chronic inflammation and oxidative stress generation. We evaluated the role of 5- and 12-lipoxygenases in the development of diabetic retinopathy. RESEARCH DESIGN AND METHODS Wild-type mice, 5-lipoxygenase-deficient mice, and 12/15-lipoxygenase-deficient mice were assessed 1) after 9 months of diabetes for retinal histopathology and leukotriene receptor expression and 2) after 3 months of diabetes for leukostasis and retinal superoxide generation. RESULTS Diabetic wild-type mice developed the expected degeneration of retinal capillaries and pericytes and increases in both leukostasis and superoxide production (P < 0.006). We found no evidence of diabetes-induced degeneration of retinal ganglion cells in these animals. The vascular histopathology was significantly inhibited in 5-lipoxygenase-deficient mice, but not in 12/15-lipoxygenase-deficient mice. Retinas from diabetic 5-lipoxygenase-deficient mice also had significantly less leukostasis, superoxide production, and nuclear factor-kappaB (NF-kappaB) expression (all P < 0.006), whereas retinas from diabetic 12/15-lipoxygenase-deficient mice had significantly less leukostasis (P < 0.005) but not superoxide production or NF- kappaB expression. Retinas from diabetic wild-type mice were enriched with receptors for the 5-lipoxygenase metabolite leukotriene B(4). Diabetes-induced histological and biochemical alterations were significantly reduced in 5-lipoxygenase-deficient mice, but not 12/15-lipoxygenase-deficient mice. CONCLUSIONS 5-Lipoxygenase represents a novel pathway for therapeutic intervention of diabetic retinopathy.
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Affiliation(s)
- Rose A Gubitosi-Klug
- Department of Pediatrics, Case Western Reserve University/Rainbow Babies and Children's Hospital, Cleveland, Ohio 44106, USA.
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26
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Abstract
PURPOSE During N-methyl-d-aspartate-induced cell death in the neural retina, levels of the nuclear isoform of CaMKIIalpha, CaMKIIalphaB, previously reported to be detected only in the midbrain and diencephalon, become elevated. The purpose of this study was to investigate whether CaMKIIalphaB is present specifically in retinal ganglion cells (RGCs) and to determine whether it can be implicated in the cell death or cell survival of signal transduction pathways. METHODS Pan-purified RGCs were obtained from the retinas of postnatal day (P)6 to P8 Sprague-Dawley rats. The expression level of CaMKIIalphaB was investigated in RGCs with the aid of RT-PCR and immunostaining under normal and glutamate-stressed conditions. siRNA targeted to CaMKIIalphaB was used to knock down the level of endogenous mRNA in RGCs, and cell viability was tested. The putative role of CaMKIIalphaB in the downstream expression of survival genes such as BDNF was evaluated in CaMKIIalphaB knocked-down RGCs with the aid of RT-PCR, real-time PCR, and immunofluorescence microscopy. RESULTS Basal levels of CaMKIIalphaB were expressed in RGCs. Expression levels became increased in response to glutamate treatment and were translocated to the nuclei after a glutamate stimulus. In pan-purified RGCs with knocked down levels of CaMKIIalphaB, a glutamate stimulus led to an increase in cell death. When CaMKIIalphaB was knocked down in RGCs, a corresponding decrease occurred in the level of BDNF expression. CONCLUSIONS These data indicate that the presence of basal levels of CaMKIIalphaB in RGCs may afford them some ongoing protection from a stressful environment. In response to the glutamate stimulus, the expression of survival genes such as BDNF may be enhanced through elevation of this particular isoform of the CaMKIIalpha gene.
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Affiliation(s)
- Wei Fan
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
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Shimazawa M, Ito Y, Inokuchi Y, Hara H. Involvement of double-stranded RNA-dependent protein kinase in ER stress-induced retinal neuron damage. Invest Ophthalmol Vis Sci 2007; 48:3729-36. [PMID: 17652745 DOI: 10.1167/iovs.06-1122] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To clarify whether the activation of double-stranded RNA-dependent protein kinase (PKR) participates in the cell death induced by endoplasmic reticulum (ER) stress, the authors used cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed with the E1A virus) in vitro and the effect of a PKR inhibitor (an imidazolo-oxindole derivative) on N-methyl-D-aspartate (NMDA)-induced retinal damage in mice in vivo. METHODS In RGC-5 culture, cell damage was induced by tunicamycin (an ER stress inducer), and cell viability was measured by Hoechst 33342, YO-PRO-1, or propidium iodide (PI) double staining or by the resazurin-reduction test. Levels of glucose-regulated protein (GRP) 78/BiP, activating transcription factor 4 (ATF4), C/EBP-homologous protein (CHOP) and the phosphorylated form of PKR were analyzed by immunoblot. The PKR inhibitor and two siRNAs that recognize nonoverlapping sequences of rat PKR were tested for their effects on tunicamycin-induced cell death. In vivo, retinal cell damage was induced by intravitreal injection of NMDA (20 nmol/eye) in mice. To examine its effect in vivo, the PKR inhibitor (1 nmol/eye) was intravitreally injected with NMDA, and ganglion cell layer cell loss and inner plexiform layer thinning were evaluated 7 days after NMDA injection. RESULTS Treatment with tunicamycin at 1, 2, and 4 microg/mL for 24 hours increased the number of YO-PRO-1 and PI-positive (apoptosis or necrosis indicator) cells in a concentration-dependent manner. Immunoblotting analysis showed that tunicamycin at 2 microg/mL induced BiP, ATF4, and CHOP protein production and PKR phosphorylation. Both the PKR inhibitor (0.03-1 microM) and the PKR knockdown (using siRNA) inhibited tunicamycin-induced RGC-5 cell death. The same inhibitor also reduced NMDA-induced retinal damage in vivo. The PKR inhibitor reduced the tunicamycin-induced increase in CHOP but not that in BiP protein production. CONCLUSIONS These results indicate that inhibiting PKR activation is neuroprotective against ER stress-induced retinal damage, suggesting that PKR activation may be involved in the mechanisms underlying ER stress-induced cell death.
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Affiliation(s)
- Masamitsu Shimazawa
- Department of Biofunctional Molecules, Gifu Pharmaceutical University, Gifu, Japan
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Park SH, Kim JH, Kim YH, Park CK. Expression of neuronal nitric oxide synthase in the retina of a rat model of chronic glaucoma. Vision Res 2007; 47:2732-40. [PMID: 17825345 DOI: 10.1016/j.visres.2007.07.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 07/13/2007] [Accepted: 07/13/2007] [Indexed: 11/25/2022]
Abstract
We investigated the expression of neuronal nitric oxide synthase (nNOS) in a rat retina model of chronic glaucoma, which was produced by electrocauterization of the episcleral vessels. Western-blot analysis showed that nNOS expression was significantly increased in cauterized retinas. nNOS immunoreactivity was observed in the cells of both the inner nuclear layer and the ganglion cell layer. Double labeling of retinal ganglion cells (RGCs) revealed that RGCs in the retina of cauterized rat was nNOS-immunopositive. Systemic administration of L-NAME (N(G)-nitro-L-arginine-methyl-ester), a non-specific NOS inhibitor, reduced RGC loss in cauterized rat retina, but there was no statistical significance (P =.06). These results suggest that the cytotoxicity of excessive NO plays a role in selective RGC loss in glaucoma.
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Affiliation(s)
- Shin Hae Park
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Socho-Gu, Seoul, Republic of Korea
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29
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Abstract
The role of extrinsic cues in guiding developing axons is well established; however, the means by which the activity of these extrinsic cues is regulated is poorly understood. A disintegrin and metalloproteinase (ADAM) enzymes are Zn-dependent proteinases that can cleave guidance cues or their receptors in vitro. Here, we identify the first example of a metalloproteinase that functions in vertebrate axon guidance in vivo. Specifically, ADAM10 is required for formation of the optic projection by Xenopus retinal ganglion cell (RGC) axons. Xadam10 mRNA is expressed in the dorsal neuroepithelium through which RGC axons extend. Pharmacological or molecular inhibition of ADAM10 within the brain each resulted in a failure of RGC axons to recognize their target. In contrast, molecular inhibition of ADAM10 within the RGC axons themselves had no effect. These data argue strongly that in the dorsal brain ADAM10 acts cell non-autonomously to regulate the guidance of RGC axons.
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Affiliation(s)
- Yuanyuan Chen
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Carrie L. Hehr
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | | | - Jennifer C. Hocking
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Sarah McFarlane
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 4N1
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Cheung ZH, Leung MCP, Yip HK, Wu W, Siu FKW, So KF. A neuroprotective herbal mixture inhibits caspase-3-independent apoptosis in retinal ganglion cells. Cell Mol Neurobiol 2007; 28:137-55. [PMID: 17710535 DOI: 10.1007/s10571-007-9175-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2007] [Accepted: 07/28/2007] [Indexed: 01/01/2023]
Abstract
It was previously demonstrated that Menta-FX, a mixture of Panax quinquefolius L. (PQE), Ginkgo biloba (GBE), and Hypericum perforatum extracts (HPE), enhances retinal ganglion cell survival after axotomy. However, the mechanisms of neuroprotection remain unknown. The aim of this study is to elucidate the neuroprotective mechanisms of Menta-FX. Since PQE, GBE and HPE have all been observed to display anti-oxidative property, the involvement of anti-oxidation in Menta-FX's neuroprotective effect was investigated. Menta-FX lowered nitric oxide (NO) content in axotomized retinas without affecting nitric oxide synthase activity, suggesting that Menta-FX possibly exhibited a NO scavenging property. In addition, the effect of Menta-FX on the frequency of axotomy-induced nuclear fragmentation and caspase-3 activation was investigated. Menta-FX treatment significantly reduced nuclear fragmentation in axotomized retinas. Surprisingly, Menta-FX had no effect on caspase-3 activation, but selectively lowered caspase-3-independent nuclear fragmentation in axotomized retinal ganglion cells. In addition, inhibition of PI3K activity by intravitreal injection of wortmannin, a phosphoinositide-3 kinase (PI3K) inhibitor, completely abolished the neuroprotective effect of Menta-FX, indicating that Menta-FX's neuroprotective effect was PI3K-dependent. Data here suggest that Menta-FX displayed a PI3K-dependent, selective inhibition on a caspase-3-independent apoptotic pathway in axotomized RGCs, thus, highlighting the potential use of herbal remedies as neuroprotective agents for other neurodegenerative diseases.
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Affiliation(s)
- Zelda H Cheung
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 1/F, Laboratory block, 21 Sassoon Road, Pokfulam, Hong Kong, China
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Schwechter BR, Millet LE, Levin LA. Histone deacetylase inhibition-mediated differentiation of RGC-5 cells and interaction with survival. Invest Ophthalmol Vis Sci 2007; 48:2845-57. [PMID: 17525221 PMCID: PMC2206540 DOI: 10.1167/iovs.06-1364] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The acetylation state of histones is modulated by histone deacetylase (HDAC) and histone acetyltransferase and is an important component in regulating gene transcription, including neuronal differentiation. The authors studied the relationship between histone acetylation and the differentiation and survival of the RGC-5 cell line and compared it with nontranscriptional-dependent differentiation with staurosporine. METHODS The retinal ganglion cell line RGC-5 was treated with trichostatin A (TSA), other HDAC inhibitors, and staurosporine; differentiation, neuritogenesis, neurotrophic factor dependence, and dependence on RNA transcription were assessed. RESULTS TSA caused significant differentiation and neuritogenesis. Differences between HDAC inhibition and staurosporine differentiation included the proportion of differentiated cells, cell viability, cell morphology, and transcriptional dependence. HDAC inhibition, but not staurosporine differentiation, resulted in RGC-5 cells that were neurotrophic factor dependent. CONCLUSIONS These results implicate two different mechanisms for RGC-5 differentiation, with a common downstream effect on neurite outgrowth but a differential effect on neurotrophic factor dependence.
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Affiliation(s)
- Brandon R Schwechter
- Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, Wisconsin 53792, USA
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Zhou RH, Yan H, Wang BR, Kuang F, Duan XL, Xu Z. Role of extracellular signal-regulated kinase in glutamate-stimulated apoptosis of rat retinal ganglion cells. Curr Eye Res 2007; 32:233-9. [PMID: 17453943 DOI: 10.1080/02713680701226808] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate the involvement of the extracellular signal-regulated kinase (ERK) signaling pathway after intravitrevous injection of glutamate in rat retina. METHODS Three groups of five Sprague-Dawley rats each were studied. Group I was a normal control group, intravitreal saline injections. In Group II, one eye received an intravitreal glutamate injection (375 nmol, dissolved in saline) while the contralateral eye served as control. In Group III, intravitreal PD98059 (100 micro mol, an inhibitor of ERK) injections were administered 1 hr before glutamate injections. Seven days after injections, phosphorylated (activated) ERK in retina was localized by immunohistochemistry and fluorescent double labeling of retinal cryosections. Specific ERK blockade was documented to assess the functional significance of activated ERK. TUNEL staining was performed to assess apoptotic cell death. RESULTS Expression of phosphorylated ERK in rat retina was observed in the inner nuclear layer, the outer nuclear layer, and the nerve fiber layer after 3 days intravitreous injection of glutamate, increasing significantly after 7 days. Double immunofluorescence labling demonstrated that the increased retinal immunostaining for phospho-ERK was predominantly localized to the retinal Müller cells after 7 days intravitreous injection of glutamate. Moreover, blocking activation of ERK significantly improved the number of TUNEL-positive cells in the eyes receiving intravitreal PD98059 injections compared with the eyes receiving glutamate injections. CONCLUSIONS The ERK pathway is involved in signal transduction in the retina after excessive stimulation by glutamate, which may contribute to the antiapoptotic role in retinal ganglion cell death induced by glutamate.
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Affiliation(s)
- Run-Hai Zhou
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
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Qi X, Lewin AS, Sun L, Hauswirth WW, Guy J. Suppression of mitochondrial oxidative stress provides long-term neuroprotection in experimental optic neuritis. Invest Ophthalmol Vis Sci 2007; 48:681-91. [PMID: 17251466 DOI: 10.1167/iovs.06-0553] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Axonal loss is thought to contribute to the persistence of visual loss in optic neuritis and multiple sclerosis (MS). The mechanisms of injury are poorly understood. The authors investigated the contribution of mitochondrial oxidative stress and the effects of modulating mitochondrial antioxidant gene expression in the optic nerves of mice induced with experimental allergic encephalomyelitis (EAE), with a focus on long-term neuroprotection. METHODS Optic nerves from mice with EAE were probed for reactive oxygen species (ROS) with the use of dichlorofluorescein diacetate (DCFDA), dihydroethidium, and cerium chloride. To modulate mitochondrial oxidative stress, recombinant AAV containing the human SOD2 gene or a ribozyme targeting murine SOD2 was injected into the vitreous. Control eyes received the recombinant virus without a therapeutic gene. Mice were sensitized for EAE and were monitored by serial contrast-enhanced MRI. The effects of SOD2 modulation on the EAE optic nerve were gauged by computerized analysis of optic nerve volume, myelin fiber area, and retinal ganglion cell loss at 1, 3, and 12 months after sensitization for EAE. RESULTS ROS were detected in the EAE optic nerve as early as 3 days after antigenic sensitization. Colocalization suggested mitochondria as the source of ROS activity in the absence of inflammation. The ribozyme suppressing SOD2 gene expression increased myelin fiber injury by 27%. Increasing SOD2 levels twofold in the optic nerve by virally mediated gene transfer ameliorated myelin fiber injury by 51% and RGC loss fourfold, limiting it to 7% in EAE at 1 year. CONCLUSIONS Amelioration of mitochondrial oxidative stress by SOD2 gene delivery may be a therapeutic strategy for suppressing neurodegeneration in optic neuritis.
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Affiliation(s)
- Xiaoping Qi
- Department of Ophthalmology, University of Florida, College of Medicine, Gainesville, FL 32610-0284, USA
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Abstract
PURPOSE Chorioretinal atrophy including retinal neuronal apoptosis occurred in chronic form-deprivation myopia induced by lid suture in chicks. We investigated whether exogenous basic fibroblast growth factor (bFGF) could simultaneously inhibit the excessive axial elongation and retinal neuronal loss in the myopic chick eyes. METHODS Unilateral form deprivation was produced in neonatal male Hyline chicks by lid suture 24 hr after hatching. Ten microliters of solution containing 5 ng bFGF or PBS (vehicle) was injected into the vitreal chamber at 10 weeks of age, once every 3 days until week 12, when the animals were sacrificed. Ocular refraction and axial length were assessed by retinoscopy and calipers at the age of 12 weeks. Retinal apoptotic neurons and their caspase-3-like protease activity were analyzed by transmission electron microscopy, the terminal-deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) staining, and a colorimetric method using Ac-DEVD-pNA as a substrate. The number of TUNEL-positive cells was counted to analyize the survival activity of bFGF on retina. RESULTS After 12 weeks of lid suture, the control eyes were either emmetropic or hyperopic, whereas the deprived eyes became myopic with axial length increased. TUNEL-positive nuclei, condensed nuclear chromatin, and apoptotic bodies were observed in posterior retinal outer nuclear layer (ONL) and inner nuclear layer (INL) in the myopic chick eyes. Activity of retinal caspase-3-like protease in these eyes was elevated. In addition to ameliorating myopic ocular growth, intravitreal bFGF therapy significantly reduced the number of retinal apoptotic neurons and downregulated caspase-3 activity. CONCLUSIONS Exogenous bFGF effectively ameliorates the excessive axial elongation and retinal neuron apoptosis in chronic form-deprivation myopia in chicks. It is possible that bFGF will be a promising therapeutic agent for high human myopia.
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Affiliation(s)
- Junfeng Mao
- Department of Ophthalmology, Xiang-Ya Hospital, Central South University, Changsha, Hunan, China.
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Oliveira-Silva P, Jurgilas PB, Trindade P, Campello-Costa P, Perales J, Savino W, Serfaty CA. Matrix metalloproteinase-9 is involved in the development and plasticity of retinotectal projections in rats. Neuroimmunomodulation 2007; 14:144-9. [PMID: 18073506 DOI: 10.1159/000110638] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE During postnatal development, retinotectal projections undergo a process of misplaced axon elimination, leading to a topographical matching between the retinal surface and the superior colliculus. Matrix metalloproteinases (MMPs) have been implicated in the development and plasticity of the nervous system. We studied the expression and role of MMPs during normal development of retinotectal projections and after monocular enucleation-induced plasticity. MATERIAL AND METHODS Lister hooded rats at different postnatal ages received subpial ethylene vinyl acetate 40W implants to deliver an MMP inhibitor or vehicle to the superior colliculus. Animals received intraocular injections of horseradish peroxidase for anterograde tracing of ipsilateral projections. For immunoblotting and zymography, colliculi were removed without fixation. RESULTS We observed the highest MMP activity in the first postnatal week, with decreasing activity thereafter. Monocular enucleation at postnatal day 10 yielded a rapid increase in MMP activity, 24 h following denervation of the contralateral colliculus. Importantly, inhibition of MMP activity in vivo induced a marked delay of axonal clustering along the medial aspect of colliculus. CONCLUSIONS Our data indicate that MMPs are crucial in retinotectal development concurring to the fine tuning of topographical order and synaptic specificity of these connections.
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Bertrand J, Di Polo A, McKerracher L. Enhanced survival and regeneration of axotomized retinal neurons by repeated delivery of cell-permeable C3-like Rho antagonists. Neurobiol Dis 2007; 25:65-72. [PMID: 17011202 DOI: 10.1016/j.nbd.2006.08.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 08/16/2006] [Accepted: 08/20/2006] [Indexed: 11/24/2022] Open
Abstract
Inactivation of Rho GTPase with a single intraocular injection of Rho antagonists stimulates survival and regeneration of retinal ganglion cells (RGCs) after optic nerve injury. However, this effect is short-lived. Here we tested the impact of multiple injections of C3-like Rho antagonists on RGC viability and axon regeneration after optic nerve lesion. Our data show that both neuronal survival and axon regeneration were enhanced with repeated delivery of cell-permeable C3. We found an approximately 1.5-fold increase in RCG survival when additional Rho antagonist injections were performed after the first week from the time of lesion. In contrast, increased regeneration required early inactivation of Rho and injections performed in the second week did not further enhance regenerative outcome. These results reveal differences in the length of the therapeutic windows through which Rho inactivation acts on RGC survival or regeneration after axotomy.
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Affiliation(s)
- J Bertrand
- Université de Montréal, Département de Pathologie et biologie cellulaire, 2900 Edouard Montpetit, Pavillon Roger-Gaudry, S-520, Montréal, Québec, Canada H3T 1J4
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Kilic Ü, Kilic E, Järve A, Guo Z, Spudich A, Bieber K, Barzena U, Bassetti CL, Marti HH, Hermann DM. Human vascular endothelial growth factor protects axotomized retinal ganglion cells in vivo by activating ERK-1/2 and Akt pathways. J Neurosci 2006; 26:12439-46. [PMID: 17135405 PMCID: PMC6674905 DOI: 10.1523/jneurosci.0434-06.2006] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Based on its trophic effects on neurons and vascular cells, vascular endothelial growth factor (VEGF) is a promising candidate for the treatment of neurodegenerative diseases. To evaluate the therapeutic potential of VEGF, we here examined effects of this growth factor on the degeneration of axotomized retinal ganglion cells (RGCs), which, as CNS-derived neurons, offer themselves in an excellent way to study neuroprotection in vivo. Making use of a transgenic mouse line that constitutively expresses human VEGF under a neuron-specific enolase promoter, we show that (1) the VEGF-transgenic retina overexpresses human VEGF, (2) RGCs carry the VEGF receptor-2, and (3) vascular networks in normal and axotomized VEGF-transgenic (tg) retinas do not differ from control animals. After axotomy, RGCs of VEGF-tg mice were protected against delayed degeneration, as compared with wild-type littermates. Western blots revealed increased phosphorylated ERK-1/2 and Akt and reduced phosphorylated p38 and activated caspase-3 levels in axotomized VEGF-transgenic retinas. Intravitreous injections of pharmacological ERK-1/2 (PD98059) or Akt (LY294002) inhibitors showed that VEGF exerts neuroprotection by dual activation of ERK-1/2 and Akt pathways. In view that axotomy-induced RGC death occurs slowly and considering that RGCs are CNS-derived neurons, we predict the clinical implementation of VEGF in neurodegenerative diseases of both brain and retina.
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Affiliation(s)
- Ülkan Kilic
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
| | - Ertugrul Kilic
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
| | - Anne Järve
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Zeyun Guo
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
| | - Annett Spudich
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
| | - Katja Bieber
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Uxue Barzena
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Claudio L. Bassetti
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
| | - Hugo H. Marti
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Dirk M. Hermann
- Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland, and
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Abstract
Growth hormone has recently been shown to be expressed in the retinal ganglion cells of embryonic chicks, in which it induces cell survival during neurogenesis. The mechanism of this action has been examined in neural retina explants from 6-day-old and 8-day-old embryos that were incubated for 48 h in 10 M growth hormone, to reduce the number of spontaneous apoptotic cells. This anti-apoptotic action was accompanied by a reduction in caspase-3 expression and, at embryonic day 8, by reduced expression of apoptosis inducing factor-1, which is caspase independent. These actions were specific, as other genes involved in apoptotic signaling (bcl-2, bcl-x, bid and inhibitor of apoptosis protein-1) were unaffected. These results therefore demonstrate caspase-dependent and caspase-independent pathways in growth hormone-induced retinal cell survival.
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Affiliation(s)
- Steve Harvey
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada.
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Abstract
PURPOSE Secretory phospholipases A(2) (sPLA(2)) are enzymes involved in lipid turnover. We recently identified sPLA(2) group IB (GIB) in the rat retina as well as in cerebral neurons and found upregulation to occur in response to light damage and seizures, respectively. The purpose of the present study was to identify human GIB (hGIB) in the normal human eye and investigate the pattern of expression in patients with eye diseases involving hGIB-rich cells. METHODS Human GIB mRNA was identified in the human retina by means of in situ hybridization and polymerase chain reaction. Antibodies against hGIB were obtained and immunohistochemical staining was performed on paraffin-embedded sections of normal and pathological eyes. Donor eyes from patients with descemetization of the cornea, Fuchs' corneal endothelial dystrophy, age-related macular degeneration, malignant choroidal melanoma, retinitis pigmentosa and glaucoma were evaluated. RESULTS Expression of hGIB was found in various cells of the eye. The most abundant expression was found in retinal pigment epithelium (RPE) cells, the inner photoreceptor segments, ganglion cells and the corneal endothelium. We explored diseases involving hGIB-rich cells and found downregulation of hGIB in proliferating RPE cells as well as in diseased corneal endothelial cells. CONCLUSIONS Human GIB is highly expressed in cells with neurodermal origin. The pattern of expression of hGIB in diseases involving hGIB-rich cells demonstrated a downregulation of hGIB in migrating RPE cells and in diseased corneal endothelium.
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Affiliation(s)
- Miriam Kolko
- Eye Pathology Institute, University of Copenhagen, Copenhagen, Denmark.
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40
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Wood PL, Khan MA, Moskal JR, Todd KG, Tanay VAMI, Baker G. Aldehyde load in ischemia-reperfusion brain injury: neuroprotection by neutralization of reactive aldehydes with phenelzine. Brain Res 2006; 1122:184-90. [PMID: 17026969 DOI: 10.1016/j.brainres.2006.09.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 08/31/2006] [Accepted: 09/03/2006] [Indexed: 10/24/2022]
Abstract
In ongoing studies of the neuroprotective properties of monoamine oxidase inhibitors, we found that phenelzine provided robust neuroprotection in the gerbil model of transient forebrain ischemia, with drug administration delayed up to 3 h post reperfusion. Since ischemia-reperfusion brain injury is associated with large increases in the concentrations of reactive aldehydes in the penumbra area, we investigated if the hydrazine function of phenelzine was capable of sequestering reactive aldehydes. Both aminoaldehydes and acrolein are generated from the metabolism of polyamines to putrescine by polyamine oxidase. These toxic aldehydes in turn compromise mitochondrial and lysosomal integrity and initiate apoptosis and necrosis. Previous studies have demonstrated that pharmacological neutralization of reactive aldehydes via the formation of thioacetal derivatives results in significant neuroprotection in ischemia-reperfusion injury, in both focal and global ischemia models. In our studies of acrolein and 3-aminopropanal toxicity, using an immortalized retinal cell line, we found that aldehyde sequestration with phenelzine was neuroprotective. The neuroprotection observed with phenelzine is in agreement with previous studies of aldehyde sequestering agents in the treatment of ischemia-reperfusion brain injury and supports the concept that "aldehyde load" is a major factor in the delayed cell losses of the ischemic penumbra.
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Affiliation(s)
- Paul L Wood
- The Falk Center for Molecular Therapeutics, Dept. of Biomedical Engineering, McCormick School of Engineering and Applied Sciences, Northwestern University, 1801 Maple Ave., Suite 4306, Evanston, IL 60201, USA.
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Sugitani K, Matsukawa T, Koriyama Y, Shintani T, Nakamura T, Noda M, Kato S. Upregulation of retinal transglutaminase during the axonal elongation stage of goldfish optic nerve regeneration. Neuroscience 2006; 142:1081-92. [PMID: 16997488 DOI: 10.1016/j.neuroscience.2006.07.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2006] [Revised: 07/21/2006] [Accepted: 07/25/2006] [Indexed: 11/29/2022]
Abstract
Fish CNS neurons can repair their axons following nerve injury, whereas mammalian CNS neurons cannot regenerate, and become apoptotic within 1-2 weeks after the nerve lesion. One explanation for these differences is that one, or several molecules are upregulated in fish CNS neurons during nerve regeneration, and this same molecule is downregulated in mammalian CNS neurons before the development of apoptosis caused by nerve injury. A molecule satisfying these criteria might successfully rescue and repair the mammalian CNS neurons. In this study, we looked for such a candidate molecule from goldfish retinas. Transglutaminase derived from goldfish retina (TG(R)) was characterized as a regenerating molecule after optic nerve injury. A full-length cDNA for TG(R) was isolated from the goldfish retinal cDNA library prepared from axotomized retinas. Levels of TG(R) mRNA and protein increased only in the retinal ganglion cells (RGCs) between 10 and 40 days after optic nerve transection. Recombinant TG(R) protein enhanced neurite outgrowth from adult fish RGCs in culture. Specific interference RNA and antibodies for TG(R) inhibited neurite outgrowth both in vitro and in vivo. In contrast, the level of TG(R) protein decreased in rat RGCs within 1-3 days after nerve injury. Furthermore, the addition of recombinant TG(R) to retinal cultures induced striking neurite outgrowth from adult rat RGCs. These molecular and cellular data strongly suggest that TG(R) promotes axonal elongation at the surface of injured RGCs after optic nerve injury.
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Affiliation(s)
- K Sugitani
- Department of Molecular Neurobiology, Graduate School of Medicine, Kanazawa University, Kanazawa 920-8640, Japan
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Pratt T, Conway CD, Tian NMML, Price DJ, Mason JO. Heparan sulphation patterns generated by specific heparan sulfotransferase enzymes direct distinct aspects of retinal axon guidance at the optic chiasm. J Neurosci 2006; 26:6911-23. [PMID: 16807321 PMCID: PMC6673919 DOI: 10.1523/jneurosci.0505-06.2006] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Retinal ganglion cell (RGC) axons from each eye execute a series of maneuvers as they converge on the ventral surface of the brain at the optic chiasm for sorting into the optic tracts. Heparan sulfate proteoglycans (HSPGs) are extracellular glycoproteins involved in cell-surface interactions. HSPGs exhibit massive structural diversity, conferred partly by extensive post-translational modification including differential sulfation. Here we examine the roles of HSPG sulfation in RGC axon guidance at the chiasm. We identified different axon navigation phenotypes in two heparan sulfate sulfotransferase (Hst) mutant embryos, Hs2st-/- and Hs6st1-/-, each lacking an enzyme that catalyzes a particular HSPG modification. Hs2st-/- embryos display axon disorganization at the chiasm. Hs6st1-/- embryos exhibit prolific inter-retinal innervation. We show that RGCs express Hs2st and Hs6st1 and that navigation errors made by their axons coincide with regions of high Hs2st and/or Hs6st1 expression at the chiasm. Slit proteins are expressed at particular locations in the retina and around the chiasm and are normally deployed to prevent axons entering inappropriate territories. We show that Hs2st and/or Hs6st1 expression coincides with Slit expression domains at locations where RGC axons make navigation errors in Hs2st-/- and Hs6st1-/- mutants and that Hs6st1-/- RGC axons are less sensitive to Slit2 repulsion than their wild-type counterparts in vitro. We suggest that (1) Hs2st and Hs6st1 are each deployed to generate distinct patterns of heparan sulfation on RGCs and at the optic chiasm and (2) this differential sulfation directs retinal axons through the chiasm, at least in part by modulating the response of the navigating growth cone to Slit proteins.
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Affiliation(s)
- Thomas Pratt
- Genes and Development Group, Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.
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Nakazawa T, Takahashi H, Shimura M. Estrogen has a neuroprotective effect on axotomized RGCs through ERK signal transduction pathway. Brain Res 2006; 1093:141-9. [PMID: 16696958 DOI: 10.1016/j.brainres.2006.03.084] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2005] [Revised: 03/19/2006] [Accepted: 03/22/2006] [Indexed: 12/28/2022]
Abstract
The neuroprotective effects of estrogen on neuronal cells in central nervous system have been described previously, however, the mechanisms of neuroprotective effect of estrogen against retinal ganglion cell (RGC) death has not been well identified. To examine the role of endogenous sex steroids produced in ovary, retina samples were prepared from female rats with or without ovariectomy and the density of RGC was calculated. Ovariectomy alone had no effect on the density of fluorogold (FG)-labeled RGC without injury, while the density of surviving RGC after optic nerve axotomy with ovariectomy was significantly decreased compared to that without ovariectomy. To examine the role of exogenous sex steroids, 17beta-estradiol was injected into the vitreous cavity in ovariectomized rats and showed neuroprotective effect on axotomy-induced RGC death while exogenous progesterone showed no effect. Immunoblot and immunohistochemical analysis demonstrated that ERK-c-Fos signal transduction pathway was activated by exogenous 17beta-estradiol in ganglion cell layer. U0126, an ERK inhibitor, inhibited the neuroprotective effect of estrogen on axotomized RGC death. These data suggest that estrogen has neuroprotective effect through activation of ERK-c-Fos signaling pathway on axotomy-induced RGC death. The neuroprotective effect of estrogen may have therapeutic benefits in retinal diseases associated with RGC death such as glaucoma.
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Affiliation(s)
- Toru Nakazawa
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574 Miyagi, Japan.
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McKernan DP, Caplis C, Donovan M, O'brien CJ, Cotter TG. Age-dependent susceptibility of the retinal ganglion cell layer to cell death. Invest Ophthalmol Vis Sci 2006; 47:807-14. [PMID: 16505011 DOI: 10.1167/iovs.05-0520] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The purpose of this study was to determine the susceptibility of the retinal ganglion cell layer (GCL) to apoptosis after optic nerve transection and excitotoxic stimulus and to investigate the regulation of apoptosis in the GCL during development. The authors also sought to determine the role played by caspases in cell death and their expression during development. METHODS TdT-mediated dUTP nick end labeling (TUNEL) was used to identify cells undergoing apoptosis during mouse retinal development from postnatal day (P)3 to P5 and in retinal explant sections under various conditions. The expression of active caspases was determined by immunohistochemistry (IHC) using an antibody that detects the cleaved large subunit. IHC was also used to detect the expression levels of procaspase-3, procaspase-9, and Apaf-1 in P6 and P60 whole eye sections. Retinal ganglion cells at ages P6 and P60 were purified by immunopanning, total RNA was extracted, and mRNA levels of the above proteins were determined by semiquantitative PCR. RESULTS After optic nerve transection, a significant number of TUNEL-positive cells were seen 24 hours after lesion in P6 retinas. This death was caspase dependent, as shown by IHC and caspase inhibition with zVAD-fmk. In contrast, adult GCL was resistant to apoptosis under these conditions. Similarly, after excitotoxic stimulus, the GCL of the P6 retinas underwent apoptosis at 6 hours and was caspase dependent, whereas adult GCL was resistant. Developmental apoptosis in the GCL between P2 and P6 was shown to involve caspase-3 and caspase-9. Significant downregulation of Apaf-1 and caspase-3 was detected in the P60 GCL at both the mRNA and the protein levels. CONCLUSIONS Adult GCL is more resistant to apoptosis than neonatal GCL after ON transection and excitotoxic stimulus. The expression of caspase-3 and Apaf-1 is significantly reduced in adult GCL. The authors suggest that age-dependent susceptibility to apoptosis may be caused by this reduced expression.
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Affiliation(s)
- Declan P McKernan
- Cell Development and Disease Laboratory, Department of Biochemistry, Biosciences Institute, University College Cork, Cork, Ireland
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Kwong JMK, Caprioli J. Expression of phosphorylated c-Jun N-terminal protein kinase (JNK) in experimental glaucoma in rats. Exp Eye Res 2006; 82:576-82. [PMID: 16197943 DOI: 10.1016/j.exer.2005.08.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Revised: 08/06/2005] [Accepted: 08/17/2005] [Indexed: 11/15/2022]
Abstract
To examine the expression of phosphorylated c-Jun N-terminal kinase (JNK) in cells in the retinal ganglion cell layer of glaucoma, intraocular pressure (IOP) of adult Wistar rats was elevated unilaterally by repeated trabecular argon laser photocoagulation 5 days after intracameral injection of India ink. Animals were euthanized after 3 days, and 1, 2, and 5 weeks of IOP elevation. Immunohistochemistry with specific antibodies against phosphorylated JNK was performed on retinas. Retrograde labeling using Fluorogold and fluorescence immunohistochemistry was performed on retinas 5 weeks after IOP elevation. TdT-mediated biotin-dUTP nick end labeling (TUNEL) was performed on the retinal sections to determine the rate of cell death. There was increased IOP (52.3%) from 3 days to 5 weeks after repeated trabecular laser photocoagulation. Mean number of TUNEL-positive cells in the retinal ganglion cell layer of eyes with experimental glaucoma was 0.43, 0.36, 0.57, and 0.19 per retinal section at 3 days, and 1, 2 and 5 weeks, respectively. No TUNEL-positive cells were noted in controls. In parallel to TUNEL, significantly increased numbers of phosphorylated JNK-labeled cells in the retinal ganglion cell layer were noted at 3 days (9.95 versus 4.15; P=0.005), 1 week (7.65 versus 4.00; P=0.006), 2 weeks (9.13 versus 4.48; P=0.032), and 5 weeks (8.06 versus 4.96; P=0.017) of IOP elevation when compared with contralateral control eyes. Fluorogold labeled RGCs were co-localized with increased phosphorylated JNK immunoreactivity. Some TUNEL-positive cells were phosphorylated JNK immuno-positive. Phosphorylation of JNK occurs in experimental glaucoma and may play a role in retinal ganglion cell death.
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Affiliation(s)
- Jacky M K Kwong
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine at University of California Los Angeles, Room B-146, 100 Stein Plaza, Los Angeles, CA 90095-7000, USA.
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Kim CI, Lee SH, Seong GJ, Kim YH, Lee MY. Nuclear translocation and overexpression of GAPDH by the hyper-pressure in retinal ganglion cell. Biochem Biophys Res Commun 2006; 341:1237-43. [PMID: 16469296 DOI: 10.1016/j.bbrc.2006.01.087] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 01/13/2006] [Indexed: 01/12/2023]
Abstract
To investigate the effect of hyper-pressure on retinal ganglion cells (RGC-5), RGC-5 cells were exposed to an ambient hydrostatic pressure of 100 mmHg. Upon treatment, the proliferation of RGC-5 cells was inhibited and neuronal apoptosis was detected by specific apoptosis marker TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling). To probe into the mechanism mediating the apoptosis of RGC-5 cells in 100 mmHg, protein profile alterations following hyper-pressure treatment were examined using two-dimensional gel electrophoresis (2-DE) followed by MALDI-TOF. Out of the 400 protein spots of RGC-5 cells detected on 2-DE gels, 37 differentially expressed protein spots were further identified using in gel tryptic digestion and mass spectrometry. Among these proteins, glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) was significantly expressed 10 times more in 100 mmHg than in normal pressure. The accumulation of GAPDH in the nucleus and its translocation from the cytosol to the nucleus in 100 mmHg were observed using a microscope. These results suggest that the hyper-pressure-induced apoptosis in RGC-5 cells may be involved with not only the increase of GAPDH expression, but also the accumulation and the translocalization of GAPDH to the nucleus.
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Affiliation(s)
- Choong-Il Kim
- Division of Life Science, Soonchunhyang University, Asan, Chungnam, Republic of Korea
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Manabe SI, Gu Z, Lipton SA. Activation of matrix metalloproteinase-9 via neuronal nitric oxide synthase contributes to NMDA-induced retinal ganglion cell death. Invest Ophthalmol Vis Sci 2006; 46:4747-53. [PMID: 16303975 DOI: 10.1167/iovs.05-0128] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Understanding the mechanism of neuronal cell death in retinal diseases like glaucoma is important for devising new treatments. One factor involves excitatory amino acid stimulation of N-methyl-D-aspartate (NMDA)-type glutamate receptors, excessive Ca2+ influx, and formation of nitric oxide (NO) via neuronal NO synthase (nNOS). Another factor is the abnormal activation of matrix metalloproteinases (MMPs), in particular MMP-9, which triggers an extracellular signaling cascade leading to apoptosis. This study was designed to investigate the mechanism of excitotoxic retinal ganglion cell (RGC) death in vivo and its relationship to MMP activation. METHODS NMDA and glycine were injected into the vitreous of the eye in rats and in nNOS-deficient mice (nNOS-/-) versus control. Gelatinolytic activity of MMP-9 and MMP-2 by zymography and cellular localization by immunohistochemistry were examined, and the effect of MMP inhibition on NMDA-induced RGC death was tested. RESULTS NMDA was found to upregulate the proform of MMP-9 in the retina and to increase MMP-9 gelatinolytic activity. Retrograde labeling with aminostilbamidine to identify RGCs confirmed that MMP activity occurred only in these retinal neurons and not in glial or other retinal cell types after excitotoxic insult. Deconvolution fluorescence microscopy revealed that MMP activity colocalized with immunoreactive S-nitrosylated protein. NMDA-induced MMP activation was diminished in the retina of nNOS-/- mice, implying that S-nitrosylation of MMP had indeed occurred. In addition, the broad-spectrum MMP inhibitor GM6001 protected RGCs after intravitreal NMDA injection. CONCLUSIONS These findings suggest that an extracellular proteolytic pathway in the retina contributes to RGC death via NO-activated MMP-9.
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Affiliation(s)
- Shin-Ichi Manabe
- Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, California 92037, USA
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Frassetto LJ, Schlieve CR, Lieven CJ, Utter AA, Jones MV, Agarwal N, Levin LA. Kinase-Dependent Differentiation of a Retinal Ganglion Cell Precursor. ACTA ACUST UNITED AC 2006; 47:427-38. [PMID: 16384993 DOI: 10.1167/iovs.05-0340] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE Cell lines are frequently used to elucidate mechanisms of disease pathophysiology. Yet extrapolation of results with cell lines to neurodegenerative disorders is difficult because they are mitotic and usually have other non-neuronal properties. The RGC-5 cell line has many features of retinal ganglion cells (RGCs). Despite its expression of Thy-1 and NMDA receptors, as found in primary RGCs, this line's ability to proliferate and non-neuronal appearance differentiate it from other central neurons, complicating its use for the study of neuronal survival, electrophysiology, or neurite extension. METHODS A method was identified for differentiating RGC-5 cells using the nonspecific protein kinase inhibitor staurosporine. Cultures were treated with 100 nM to 3.16 muM staurosporine and assessed for a variety of differentiation markers. RESULTS Differentiated RGC-5 cells expressed numerous neuronal properties, including arrest of proliferation without inducing apoptosis, induction of a neuronal morphology, upregulation of neuronal markers, and establishment of outward rectifying channels. Differentiation was not dependent on a single kinase-dependent pathway, based on profiling multiple kinase phosphorylation targets and attempts to replicate differentiation with multiple specific kinase inhibitors. CONCLUSIONS This method for producing an RGC-like cell from a proliferating cell line facilitates the following previously impractical techniques: high-throughput screening for agents that are neuroprotective or affect ionic channels; straightforward transduction of gene expression in central neurons by nonviral transfection techniques, including production of stable transfectants; biochemical and other assays of pure RGC-like cells without purification on the basis of cell-surface antigens or anatomic location.
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Affiliation(s)
- Laura J Frassetto
- Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, WI 53792, USA
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Matveeva NI, Kalinichenko SG, Pushchin II, Motavkin PA. [Role of nitric oxide in apoptosis of retinal neurons in human fetuses]. Morfologiia 2006; 129:42-9. [PMID: 17201318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The localization of NADPH-diaphorase (NADPH-d), inducible NO-synthase (iNOS) and TUNEL-immunoreactive neurons was studied in the retina of human fetuses in the I-III trimesters of pregnancy. High NADPH-d activity was found in internal segments of photosensory cells, amacrine and ganglion cells. The population of NADPH-d-positive amacrine cells included three types of neurons. Neurons of the 1st type had large size and scarce dendritic field, occupying the inner nuclear and outer plexiform layers. Small neurons of the 2nd type were located in the inner plexiform layer. Ectopic amacrine cells of 3rd type could be found in the outer part of the ganglion cell layer. High density of the NADPH-d-positive neurons was detected in the central portion of retina surrounding fovea centralis and the optic disk area. The activity of NADPH-d was found to grow progressively in ontogenesis and to correlate with the appearance of immunoreactive iNOS in neurons. Immunoreactive iNOS marked a subpopulation of amacrine and ganglion cells which appeared in weeks 20-21 of gestation and attained maximal immunoreactivity by the end of the III trimester. TUNEL-immunoreactive nuclei of the neurons with the signs of the apoptotic destruction were found in weeks 30-31 of gestation. The highest apoptotic index was found in the population of ganglion cells. The data obtained strongly suggest that NO is a factor, mediating the neuronal apoptosis during the critical period of a differentiation of interneuronal connections in the human retina.
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Ochrietor JD, Clamp MF, Moroz TP, Grubb JH, Shah GN, Waheed A, Sly WS, Linser PJ. Carbonic anhydrase XIV identified as the membrane CA in mouse retina: strong expression in Müller cells and the RPE. Exp Eye Res 2005; 81:492-500. [PMID: 16126196 DOI: 10.1016/j.exer.2005.03.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 03/11/2005] [Accepted: 03/21/2005] [Indexed: 11/24/2022]
Abstract
The presence of carbonic anhydrase (CA) activity in the neural retina has been known for several decades. CA-II, a soluble cytoplasmic isoform expressed by Müller cells and a subset of amacrine cells, was thought to be the sole source of CA activity in the neural retina. However, CA-II deficient mice retain CA activity in the neural retina, which implies that another isoform must be present in that tissue. Recently CA-XIV, an integral membrane protein, was cloned and characterized. We, therefore, sought to determine whether CA-XIV is expressed in the neural retina, and hence is responsible for the CA activity observed in CA-II null animals. Immunohistochemical analyses of histological sections from CA-II null, CA-XIV null, and control mice were performed to localize the CA-XIV isoform, as well as other known retinal markers. Immunoblotting and real-time RT-PCR analyses were also performed to test for CA-XIV expression in retina and other mouse tissues. We determined herein that CA-XIV, a approximately 45kDa membrane protein, is expressed in retina, as it is in kidney. In the retina, CA-XIV is expressed on the plasma membrane of Müller cells. CA-XIV is also found on both the apical and basal membranes of the retinal pigmented epithelium. The data presented here indicate that like CA-II, CA-XIV is highly expressed in the neural retina and, like CA-II, more specifically by the Müller cells. The cellular compartmentalization of the two isoforms in the Müller cell-one cytoplasmic and the other on the plasma membrane-suggest that the two enzymes have specific and unique functions. Future studies will be necessary to assign functions to CA-II and CA-XIV in the mouse neural retina.
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Affiliation(s)
- Judith D Ochrietor
- Whitney Laboratory for Marine Bioscience, The University of Florida, 9505 Ocean Shore Blvd, St Augustine, FL 32080, USA
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