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Han JYS, Kinoshita J, Bisetto S, Bell BA, Nowak RA, Peachey NS, Philp NJ. Role of monocarboxylate transporters in regulating metabolic homeostasis in the outer retina: Insight gained from cell-specific Bsg deletion. FASEB J 2020; 34:5401-5419. [PMID: 32112484 DOI: 10.1096/fj.201902961r] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/29/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023]
Abstract
The neural retina metabolizes glucose through aerobic glycolysis generating large amounts of lactate. Lactate flux into and out of cells is regulated by proton-coupled monocarboxylate transporters (MCTs), which are encoded by members of the Slc16a family. MCT1, MCT3, and MCT4 are expressed in the retina and require association with the accessory protein basigin, encoded by Bsg, for maturation and trafficking to the plasma membrane. Bsg-/- mice have severely reduced electroretinograms (ERGs) and progressive photoreceptor degeneration, which is presumed to be driven by metabolic dysfunction resulting from loss of MCTs. To understand the basis of the Bsg-/- phenotype, we generated mice with conditional deletion of Bsg in rods (RodΔBsg), cones (Cone∆Bsg), or retinal pigment epithelial cells (RPEΔBsg). RodΔBsg mice showed a progressive loss of photoreceptors, while ConeΔBsg mice did not display a degenerative phenotype. The RPEΔBsg mice developed a distinct phenotype characterized by severely reduced ERG responses as early as 4 weeks of age. The loss of lactate transporters from the RPE most closely resembled the phenotype of the Bsg-/- mouse, suggesting that the regulation of lactate levels in the RPE and the subretinal space is essential for the viability and function of photoreceptors.
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Affiliation(s)
- John Y S Han
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Sara Bisetto
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Brent A Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Romana A Nowak
- Animal Sciences, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
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2
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García-Llorca A, Aspelund SG, Ogmundsdottir MH, Steingrimsson E, Eysteinsson T. The microphthalmia-associated transcription factor (Mitf) gene and its role in regulating eye function. Sci Rep 2019; 9:15386. [PMID: 31659211 PMCID: PMC6817937 DOI: 10.1038/s41598-019-51819-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022] Open
Abstract
Mutations in the microphthalmia-associated transcription factor (Mitf) gene can cause retinal pigment epithelium (RPE) and retinal dysfunction and degeneration. We examined retinal and RPE structure and function in 3 month old mice homo- or heterozygous or compound heterozygous for different Mitf mutations (Mitfmi-vga9/+, Mitfmi-enu22(398)/Mitfmi-enu22(398), MitfMi-Wh/+ and MitfMi-Wh/Mitfmi) which all have normal eye size with apparently normal eye pigmentation. Here we show that their vision and retinal structures are differentially affected. Hypopigmentation was evident in all the mutants while bright-field fundus images showed yellow spots with non-pigmented areas in the Mitfmi-vga9/+ mice. MitfMi-Wh/+ and MitfMi-Wh/Mitfmi mice showed large non-pigmented areas. Fluorescent angiography (FA) of all mutants except Mitfmi-vga9/+ mice showed hyperfluorescent areas, whereas FA from both Mitf-Mi-Wh/+ and MitfMi-Wh/Mitfmi mice showed reduced capillary network as well as hyperfluorescent areas. Electroretinogram (ERG) recordings show that MitfMi-Wh/+ and MitfMi-Wh/Mitfmi mice are severely impaired functionally whereas the scotopic and photopic ERG responses of Mitfmi-vga9/+ and Mitfmi-enu22(398)/Mitfmi-enu22(398) mice were not significantly different from wild type mice. Histological sections demonstrated that the outer retinal layers were absent from the MitfMi-Wh/+ and MitfMi-Wh/Mitfmi blind mutants. Our results show that Mitf mutations affect eye function, even in the heterozygous condition and that the alleles studied can be arranged in an allelic series in this respect.
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Affiliation(s)
- Andrea García-Llorca
- Department of Physiology, Biomedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, 101, Reykjavík, Iceland.,Department of Ophthalmology, Landspitali National University Hospital, Eiriksgata 37, 101, Reykjavik, Iceland
| | | | - Margret Helga Ogmundsdottir
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, Reykjavík, Iceland
| | - Eiríkur Steingrimsson
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, Reykjavík, Iceland
| | - Thor Eysteinsson
- Department of Physiology, Biomedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, 101, Reykjavík, Iceland. .,Department of Ophthalmology, Landspitali National University Hospital, Eiriksgata 37, 101, Reykjavik, Iceland.
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3
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Kinoshita J, Peachey NS. Noninvasive Electroretinographic Procedures for the Study of the Mouse Retina. ACTA ACUST UNITED AC 2018; 8:1-16. [PMID: 30040236 DOI: 10.1002/cpmo.39] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Overall retinal function can be monitored by recording the light-evoked response of the eye at the corneal surface. The major components of the electroretinogram (ERG) provide important information regarding the functional status of many retinal cell types including rod photoreceptors, cone photoreceptors, bipolar cells, and the retinal pigment epithelium (RPE). The ERG can be readily recorded from mice, and this unit describes procedures for mouse anesthesia and the use of stimulation and recording procedures for measuring ERGs that reflect the response properties of different retinal cell types. Through these, the mouse ERG provides a noninvasive approach to measure multiple aspects of outer retinal function, including the status of the initial rod and cone pathways, rod photoreceptor deactivation, rod dark adaptation, the photoreceptor-to-bipolar cell synapse, and the RPE. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Junzo Kinoshita
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio.,Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
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4
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Abstract
Adenosine is a neuromodulator present in various areas of the central nervous system, including the retina. Adenosine may serve a neuroprotective role in the retina, based on electroretinogram (ERG) recordings from the rat retina. Our purpose was to assess the role of A2A and A3 adenosine receptors in the generation and modulation of the rat ERG. The flash ERG was recorded with corneal electrodes from Sprague Dawley rats. Agonists and antagonists for A2A and A3 receptors, and adenosine were injected (5 µl) into the vitreous. The effects on the components of the single flash scotopic and photopic ERGs were examined, and ERG flicker. Adenosine (0.5 mM) increased the mean amplitudes of the scotopic ERG a-waves (68 ± 8 to 97 ± 14 µV, P = 0.042), and b-waves (236 ± 38 µV to 305 ± 42 µV). A2A agonist CGS21680 (2 mM) reduced the mean amplitude of the ERG b-wave, from 298 ± 21 µV in response to the brightest stimulus to 212 ± 19 µV (P = 0.005), and mean scotopic oscillatory potentials (OPs) from 100 ± 9 µV to 47 ± 11 µV (P = 0.023). ZM241385 [4 mM], an A2A antagonist, decreased the scotopic b-wave of the ERG. A3 agonist 2-CI-IB-MECA (0.5 mM) increased the a-wave, while decreasing the scotopic and photopic ERG b-waves, and the scotopic OPs. A3 antagonist VUF5574 (1 mM) increased the mean amplitude of the scotopic a-wave (66 ± 8 to 140 ± 29 µV, P = 0.046) and b-wave (224 ± 20 to 312 ± 39 µV, P = 0.0037). No significant effects on ERG flicker were found. We conclude that retinal neurons containing A2A and/or A3 adenosine receptors contribute to the generation of the ERG a- and b-waves and OPs.
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Chekroud K, Arndt C, Basset D, Hamel CP, Brabet P, Pequignot MO. Simple and efficient: validation of a cotton wick electrode for animal electroretinography. Ophthalmic Res 2010; 45:174-9. [PMID: 21051915 DOI: 10.1159/000321118] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 09/16/2010] [Indexed: 11/19/2022]
Abstract
PURPOSE Electroretinography (ERG) is a widely used technique to test retinal function in humans and animals. Recordings are particularly dependent on the type of electrodes used, with the best electrodes often being expensive and not always easy to use. The need of a simple and effective electrode type has led us to search the efficacy of different types of electrodes used in practice and compare them with the modified cotton wick electrode. MATERIAL AND METHODS A modified type of electrode made of a cotton wick and impregnated with NaCl is described, and the ERG results were compared with other types of electrodes. RESULTS Compared with standard metal wire loop electrodes, the cotton wick electrode results in obtaining higher amplitudes, a better inter-eye correlation in the same animal and a better reproducibility of the recordings over time. CONCLUSION This cotton electrode is simple to make and easy to place. It provides reliable recordings during the entire life span of the animal and reliable comparisons between contralateral eyes, thus providing a powerful tool for ERG studies.
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Affiliation(s)
- Karim Chekroud
- Inserm U583, Institute for Neurosciences of Montpellier, CHU Saint-Eloi, Montpellier, France
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6
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Traustason S, Eysteinsson T, Agnarsson BA, Stefánsson E. GABA agonists fail to protect the retina from ischemia-reperfusion injury. Exp Eye Res 2008; 88:361-6. [PMID: 19101544 DOI: 10.1016/j.exer.2008.07.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 06/17/2008] [Accepted: 07/08/2008] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to test the hypothesis that ischemia/reperfusion injury in the rat retina may be ameliorated by reducing retinal metabolism with either hypothermia or inhibitory GABA agonists. The intraocular pressure of each right eye in rats was raised to 130 mm Hg for 60 min with the left eye serving as normal control. The rats were divided into four groups in terms of drug and hypothermia treatment: (1) Untreated ischemia, (2) Hypothermia, (3) Baclofen/midazolam and (4) Baclofen/muscimol. Electroretinogram was recorded before ischemia and again after 10-day reperfusion. Histological analysis with H&E staining and cell counts was performed. Untreated ischemia/reperfusion resulted in severely reduced ERG responses. The ERG b-wave was reduced from 423+/-144 microV to 130+/-91 microV (mean+/-SD, n=5). With hypothermia the ERG b-wave was reduced from 499+/-80 microV to 237+/-111 microV (n=4). With combinations of baclofen and midazolam the ERG b-wave was reduced from 432+/-96 microV to 104+/-67 microV (n=7). In baclofen/muscimol treated eyes the ERG b-wave went from 426+/-101 microV to 148+/-118 microV (n=6). The histological tissue damage was severe in untreated ischemia and the baclofen/midazolam and baclofen/muscimol groups, but less severe in the hypothermia group. The GABA agonists do not provide any protection in our ischemia/reperfusion model. Our results are consistent with earlier reports that hypothermia may be helpful in ischemic conditions in the retina.
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Affiliation(s)
- Sindri Traustason
- Department of Ophthalmology and Physiology, National University Hospital, University of Iceland, Reykjavík, Iceland
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7
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Rosolen SG, Rigaudière F, Le Gargasson JF, Brigell MG. Recommendations for a Toxicological Screening ERG Procedure in Laboratory Animals. Doc Ophthalmol 2005; 110:57-66. [PMID: 16249957 DOI: 10.1007/s10633-005-7344-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Electroretinography, using laboratory animals, is a commonly used technique for determining the retinal toxicity of chemical agents. In this paper, guidelines for performing this test are provided. The physiologic basis for visual testing is presented with attention to inter-species differences. Technical aspects of animal recordings are reviewed, including animal preparation, stimulation, signal conditioning, recording and data analysis. Finally, suggested protocols for recording in diurnal and nocturnal species are presented.
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Affiliation(s)
- Serge G Rosolen
- Clinique Vétérinaire Voltaire, 119 Boulevard Voltaire, 92600, Asnières, France
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8
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Möller A, Eysteinsson T, Steingrímsson E. Electroretinographic assessment of retinal function in microphthalmia mutant mice. Exp Eye Res 2004; 78:837-48. [PMID: 15037118 DOI: 10.1016/j.exer.2003.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2003] [Accepted: 10/13/2003] [Indexed: 10/26/2022]
Abstract
The purpose of this study was to examine the effects of mutations in the mouse (Mus musculus) multi-allelic microphthalmia transcription factor (Mitf) gene on retinal function. Mitf mice provide a rare opportunity to assess retinal degeneration caused by defective retinal pigment epithelium (RPE). Electroretinography (ERG) was used to evaluate the functional state of the retina and to determine the role of the Mitf gene in visual function. Corneal ERGs were recorded with a steel wire in response to white flashes of light. Homozygous Mitf(Mi-wh)/Mitf(Mi-wh), Mitf(mi-sp)/Mitf(mi-sp) Mitf(mi-bws)/Mitf(mi-bws) and wild type mice in addition to Mitf(Mi-wh)/Mitf(mi-sp) compound heterozygous mutants were studied at 16 weeks of age. Although each animal was only tested once, multiple animals of each genotype were tested. The ERGs of Mitf(mi-sp)/Mitf(mi-sp) were found to be normal. All components of the ERGs of Mitf(mi-bws)/Mitf(mi-bws) mice were normal except the photopic b-wave and the scotopic c-wave, which were reduced in amplitude. The ERGs of Mitf(Mi-wh)/Mitf(Mi-wh) mice suggest they are probably blind. On the other hand, ERGs from Mitf(Mi-wh)/Mitf(mi-sp) mice were reduced in amplitude and delayed, indicating an RPE/photoreceptor defect. At 16 weeks post partum, Mitf(Mi-wh)/Mitf(mi-sp) mutants show evidence of rod-cone dystrophy. Surprisingly, Mitf(mi-bws)/Mitf(mi-bws) mice, which have a similar phenotype as Mitf(mi-vit) mice with respect to coat color and eye development, show mostly normal ERGs. The reduced scotopic c-wave in Mitf(mi-bws)/Mitf(mi-bws) mice, without reduction in the scotopic a-wave indicates an RPE defect without photoreceptor involvement in these mice.
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Affiliation(s)
- Anna Möller
- Department of Physiology, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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9
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Möller A, Eysteinsson T. Modulation of the components of the rat dark-adapted electroretinogram by the three subtypes of GABA receptors. Vis Neurosci 2004; 20:535-42. [PMID: 14977332 DOI: 10.1017/s0952523803205071] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The separate components of the dark-adapted electroretinogram (ERG) are believed to reflect the electric activity of neurones in both the inner and the outer layers of the retina, although their precise origin still remains unclear. The purpose of this study was to examine whether selective blockage or stimulation of the different subtypes of GABA receptors might help further elucidate the cellular origin of the components of the dark-adapted ERG. The rat retina is of interest since the localization and physiology of GABA receptors in that retina have been examined in great detail. GABA agonists and antagonists, known to affect the responses of neurons in the inner plexiform layer, were injected into the vitreous of one eye while ERG responses evoked by flashes of white light were recorded. GABA and the GABAa agonist isoguvacine completely removed the oscillatory potentials (OPs) and reduced the amplitude of the a- and b-waves. TPMPA, a GABAC antagonist, reduced the a- and b-waves but had no significant effect on the OPs. Baclofen, a GABAb agonist, reduced the amplitude of the a- and b-waves, without having any effects on the amplitude of the OPs. The GABAb antagonist CGP35348 increased the amplitudes of the a- and b-wave without having an effect on the amplitudes of the OPs. The GABAb receptor ligands had significant and opposite effect on the latency of the OPs. These results indicate that retinal neurons, presumably a subpopulation of amacrine cells, that have GABAb receptors are not the source of the OPs of the ERG, although they may modulate these wavelets in some manner, while contributing to the generation of the dark-adapted a- and b-waves. OPs are modified by stimulation of GABAa receptors, and the a- and b-waves by stimulation of all GABA receptor subtypes.
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Affiliation(s)
- Anna Möller
- Department of Physiology, University of Iceland IS-101 Reykjavik, Iceland
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10
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Ikeda Y, Goto Y, Yonemitsu Y, Miyazaki M, Sakamoto T, Ishibashi T, Tabata T, Ueda Y, Hasegawa M, Tobimatsu S, Sueishi K. Simian immunodeficiency virus-based lentivirus vector for retinal gene transfer: a preclinical safety study in adult rats. Gene Ther 2003; 10:1161-9. [PMID: 12833125 DOI: 10.1038/sj.gt.3301973] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although lentivirus vectors hold promise for ocular gene therapy, they also have potential safety issues, particularly in the case of the current human immunodeficiency virus-based vectors. We recently developed a novel lentivirus vector derived from the nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to minimize these potentials. In this preclinical study, we evaluated whether SIV vector could be efficiently and safely applicable to retinal gene transfer by assessing the transgene expression, retinal function and histology over a 1-year period following subretinal injection in adult rats. The functional assessment via electroretinogram after both titers of SIV-lacZ (2.5 x 10(7) or 2.5 x 10(8) transducing units/ml) injection revealed both the dark and light adaptations to soon be impaired, in a dose-dependent manner, after a buffer injection as well, and all of them recovered to the control range by day 30. In both titers tested, the retinas demonstrated a frequent transgene expression mainly in the retinal pigment epithelium; however, the other retinal cells rarely expressed the transgene. Retinas exposed to a low titer virus showed no significant inflammatory reaction throughout the observation period, and also maintained the transgene expression over a 1-year period. In the retinas exposed to a high titer virus, however, mononuclear cell infiltration persisted in the subretinal area, and the retina that corresponded to the injected area finally underwent degeneration by around day 90. No retinal neoplastic lesions could be found in any animals over the 1-year period. We thus propose that SIV-mediated stable gene transfer might be useful for ocular gene transfer; however, more attention should be paid to avoiding complications when administering high titer lentivirus to the retina.
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Affiliation(s)
- Y Ikeda
- Division of Pathophysiological and Experimental Pathology, Department of Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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11
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Abstract
The mouse has become a key animal model for ocular research. This situation reflects the fact that genes implicated in human retinal disorders or in mammalian retinal function may be readily manipulated in the mouse. Visual electrophysiology provides a means to examine retinal function in mutant mice, and stimulation and recording protocols have been developed that allow the activity of many classes of retinal neurons to be examined and which take into account unique features of the mouse retina. Here, we review the mouse visual electrophysiology literature, covering techniques used to record the mouse electroretinogram and visual evoked potential, and how these have been applied to characterize the functional implications of gene mutation or manipulation in the mouse retina.
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Affiliation(s)
- Neal S Peachey
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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12
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Hisatomi T, Sakamoto T, Goto Y, Yamanaka I, Oshima Y, Hata Y, Ishibashi T, Inomata H, Susin SA, Kroemer G. Critical role of photoreceptor apoptosis in functional damage after retinal detachment. Curr Eye Res 2002; 24:161-72. [PMID: 12221523 DOI: 10.1076/ceyr.24.3.161.8305] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Although apoptosis is assumed to play a pivotal role in retinal function loss, its mechanism and real influence on retinal function are still unclear. To investigate the relation between retinal function and apoptosis, we studied photoreceptor apoptosis in experimental retinal detachment (RD). METHODS We induced RD by subretinal injection of sodium hyaluronate in Brown Norway rats. Apoptotic photoreceptors were detected by TdT-dUTP Terminal Nick-End Labeling (TUNEL). To evaluate the function of the detached retina, electroretinograms (ERGs) were taken on day 1, 3 with corneal electrodes and full-field stimulation. RESULTS Apoptotic DNA fragmentation appeared 12 hours after RD, was most prominent on day 3, and decreased thereafter. The ERGs showed that the amplitudes of dark-adapted a-waves and light adapted 2 Hz b-waves decreased immediately after RD and continued to decrease over time. The administration of Fas/Fc chimera recombinant protein or a caspase inhibitor, Z-VAD.fmk, failed to prevent either photoreceptor apoptosis or retinal functional damage. In contrast, brain derived neurotrophic factor (BDNF) and basic fibroblast growth factor (bFGF) significantly impeded both apoptosis and dysfunction. The ERGs recognized the functional changes sensitively, and these ERG changes correlated well to the amount of photoreceptor apoptosis. Immunohistochemical study showed that apoptosis-inducing factor (AIF), a novel caspase-independent apoptotic factor, was relocalized from mitochondria to the nucleus in this process. CONCLUSIONS The present results showed that apoptosis was a key phenomenon in the retinal dysfunction in RD and that this process was transmitted mainly by mitochondria-dependent pathways rather than Fas/Fas-L or downstream caspase dependent pathways.
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Affiliation(s)
- Toshio Hisatomi
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
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13
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Bayer AU, Cook P, Brodie SE, Maag KP, Mittag T. Evaluation of different recording parameters to establish a standard for flash electroretinography in rodents. Vision Res 2001; 41:2173-85. [PMID: 11448710 DOI: 10.1016/s0042-6989(01)00103-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Different electrodes and stimulus protocols commonly used for electroretinography in rodent eyes were compared for convenience of use, degree of damage to corneal epithelium, and for magnitude of amplitude, reproducibility, left versus right eye accuracy, and reliability of recorded parameters of the flash electroretinogram (ERG). Adult C57BL/6 pigmented mice and albino Wistar rats were used to determine scotopic ERGs in response to Ganzfeld or strobe-light stimulation and light-adapted (photopic) ERGs recorded from both eyes at the same time. Test-retest data were used for statistical analyses to compare a monopolar gold-wire contact lens electrode (CLE), a cotton-wick silver-silver chloride electrode (CSCE), a DTL fiber electrode (DTLE), and a circular stainless steel wire electrode (SSE). Corneas were evaluated for abrasion after ERG recordings using fluorescein staining and also for the time taken, ease of insertion, and re-insertions required for the different electrodes. Compared to CSCE, DTLE, and SSE, the ERG potentials recorded by CLE had significantly larger scotopic amplitudes and oscillatory potentials under strobe or Ganzfeld stimulation and for light-adapted ERG b-wave amplitudes in both mice and rats. In analyzing test-retest data of scotopic ERG a-wave and b-wave amplitudes, the intraclass correlation coefficient showed the best agreement for the CLE (range 0.61-0.94) compared to the SSE (0.13-0.77), DTLE (0.02-0.69), and CSCE (0.12-0.51). In mice and rats, logistic regression analyses revealed significant correlations for amplitudes of most scotopic ERG parameters between contralateral eyes obtained with CLE and for some ERG components recorded by SSE. When comparing ERG amplitudes for stimulation by strobe or Ganzfeld, the difference was least with the CLE compared to DTLE, CSCE, or SSE. The time taken to insert the four different electrodes was greatest for the CLE in both mice and rats. The extent of corneal abrasion resulting from electrode use in mice was largest for the SSE followed by the CLE. However, in rats there was almost no corneal damage after ERG recordings with the CLE. Because of the stability of eye contact, the CLE allows ERGs to be determined over a longer recording session. Recording of scotopic and photopic (light-adapted) ERGs in rodents with monopolar gold-wire contact lens electrodes provides greater amplitudes and higher reproducibility when compared to other commonly used corneal electrodes. These electrodes are significantly better overall than others that were evaluated and should be considered for a standard protocol to monitor retinal function in rodent eyes.
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Affiliation(s)
- A U Bayer
- Department of Ophthalmology, Box 1183, The Mount Sinai Medical Center, Mount Sinai School of Medicine of New York University, 1 Gustave L. Levy Place, New York, NY 10029, USA
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14
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Green ES, Rendahl KG, Zhou S, Ladner M, Coyne M, Srivastava R, Manning WC, Flannery JG. Two animal models of retinal degeneration are rescued by recombinant adeno-associated virus-mediated production of FGF-5 and FGF-18. Mol Ther 2001; 3:507-15. [PMID: 11319911 DOI: 10.1006/mthe.2001.0289] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The goal of these experiments was to evaluate the potential of the fibroblast growth factor family members FGF-5 and FGF-18 to rescue photoreceptors from cell death in retinal degenerative disease. Two strains of transgenic rats, expressing either a P23H or an S334ter rhodopsin mutation, were used as model systems. The neurotrophic growth factors were delivered by subretinal injection of adeno-associated virus vectors, driving expression of the genes with a constitutive CMV promoter. Morphological and functional analyses were performed to determine whether FGF-5 or FGF-18 overexpression could ameliorate cell death in the retina. Immunocytochemistry was used to determine the cellular sites of expression of the factors and to test for up-regulation of FGF receptors due to injection. Significant rescue from photoreceptor cell death was found after injections of vectors expressing either FGF-5 or FGF-18 in the animal models. Increased survival of photoreceptors did not produce a significant increase in electroretinographic responses, however, reflecting either trauma due to the surgery or a suppression of signaling due to expression of proteins. Three weeks after injections, both growth factors were localized to the inner and outer segments of photoreceptors, and the receptors FGFR1 and FGFR2 were also found to be up-regulated in these regions. No visible pathological changes were seen in the FGF-5- or FGF-18-treated eyes. These results indicate that the delivery of either FGF-5 or FGF-18 with adeno-associated virus protects photoreceptors from apoptosis in transgenic rat models of retinitis pigmentosa and that the rescue is probably mediated by conventional receptor tyrosine kinase pathways in photoreceptors.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Blotting, Western
- Cell Death
- Cell Line
- Cell Survival
- Cytomegalovirus/genetics
- Dependovirus/genetics
- Disease Models, Animal
- Electroretinography
- Fibroblast Growth Factor 5
- Fibroblast Growth Factors/genetics
- Genetic Vectors/genetics
- Humans
- Immunohistochemistry
- Models, Genetic
- Plasmids/metabolism
- Point Mutation
- Promoter Regions, Genetic
- Rats
- Receptor Protein-Tyrosine Kinases/biosynthesis
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Fibroblast Growth Factor, Type 1
- Receptor, Fibroblast Growth Factor, Type 2
- Receptors, Fibroblast Growth Factor/biosynthesis
- Receptors, Fibroblast Growth Factor/genetics
- Retina/metabolism
- Retina/pathology
- Retinal Degeneration/therapy
- Retinitis Pigmentosa/genetics
- Retinitis Pigmentosa/therapy
- Rhodopsin/genetics
- Signal Transduction
- Transfection
- Up-Regulation
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Affiliation(s)
- E S Green
- Department of Molecular and Cell Biology, University of California at Berkeley, 94720, USA
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15
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Ball SL, Lindberg FP, Lagenaur CF, Peachey NS. Electroretinograms remain normal in mice lacking a synapse associated protein. Neurosci Lett 2001; 298:111-4. [PMID: 11163290 DOI: 10.1016/s0304-3940(00)01743-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Integrin-associated protein (IAP) is normally localized to the synapse rich plexiform layers of the mammalian retina. In other neuronal systems, IAP and its ligand, P84, have been implicated in synaptic function. Previously, an abnormal distribution of P84 was noted in the IAP-null retina. To examine the potential role of IAP in the function of the retinal outer plexiform layer, we recorded electroretinograms (ERGs) from IAP-null mice and wild-type littermates. Under a wide range of stimulus conditions, there was no difference between the responses of these two groups, including ERG components that reflect post-receptoral activity. These results indicate that IAP and/or P84 may not be critical for the development and maintenance of the photoreceptor-to-bipolar cell synapse.
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Affiliation(s)
- S L Ball
- Research Service, Hines VA Hospital, Hines IL 60141, USA.
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16
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Rosolen SG, Rigaudiere F, Saint-Macary G, Lachapelle P. Recording the photopic electroretinogram from conscious adult Yucatan micropigs. Doc Ophthalmol 2000; 98:197-205. [PMID: 10947004 DOI: 10.1023/a:1002445219981] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The micropig is viewed by many as one of the best animal models of human system physiology. The purpose of this study was to develop a simple, rapid and reliable method to record clinical electroretinograms from conscious adult Yucatan micropigs. Photopic ERGs were recorded from 18 conscious animals following a 3-h period of preadaptation to a moderate photopic environment. Rectal temperature and blood pressure were monitored throughout the experiment. In order to test the reproducibility of our procedure, the same protocol was repeated (n=6 micropigs) on three different recording sessions each separated by a 48-h period. Our results indicate that the recording of reproducible ERGs, in the conscious Yucatan micropig, is feasible provided that an adequate experimental approach is used. We believe that our method will enable investigators to perform retinal physiology experiments using an approach which is compatible with that used in a human clinical setup thus facilitating the transposition of experimental data from animal to human.
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17
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Tahara YR, Sakamoto TR, Oshima YR, Ishibashi TR, Inomata HR, Murata TR, Hinton DR, Ryan SJ. The antidepressant hypericin inhibits progression of experimental proliferative vitreoretinopathy. Curr Eye Res 1999; 19:323-9. [PMID: 10520228 DOI: 10.1076/ceyr.19.4.323.5302] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Hypericin, a polycyclic dione used as an antidepressant, has been shown to inhibit the protein kinase C (PKC) pathway. Many of the pathologic responses found in proliferative vitreoretinopathy (PVR) are dependent upon PKC. Therefore, we studied the effect of hypericin on the treatment of experimental PVR. METHODS PVR was induced in pigmented rabbits by intravitreal injection of 50,000 rabbit conjunctival fibroblasts after vitrectomy. Subsequently, the eyes received an intravitreal injection of either balanced salt solution (BSS, 0.1 mL) (group A, control) or hypericin (0.1 mL) in doses of 1 muM (group B), 10 muM (group C), and 100 muM (group D). The eyes were examined ophthalmoscopically on days 1, 3, 7, 14, and 28 after surgery and the stage of PVR was evaluated (0 to V). The effect of hypericin on retinal morphology and function was also determined for the eyes injected with 100 muM hypericin with no fibroblasts by light microscopy and electroretinogram (ERG). RESULTS In the control eyes, the retina was detached after 5 days, membranes had formed on and beneath it, and the PVR had progressed to higher stages over time. In the eyes injected with hypericin, the PVR also progressed; however, the severity of PVR on each day was lower than that in control eyes on that day. PVR was significantly inhibited in groups C and D as compared with the control eyes after day 5 (P < 0.05). Histological examination of the hypericin-treated control eyes disclosed no morphological change, and ERG analysis revealed no significant functional change. CONCLUSIONS Intravitreal injection of hypericin is a safe and effective means of reducing experimental PVR.
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Affiliation(s)
- Y R Tahara
- Department of Ophthalmology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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18
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Goto Y, Tobimatsu S, Shigematsu J, Akazawa K, Kato M. Properties of rat cone-mediated electroretinograms during light adaptation. Curr Eye Res 1999; 19:248-53. [PMID: 10487963 DOI: 10.1076/ceyr.19.3.248.5313] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Our aim was to better understand how to isolate the cone-mediated response in rats. Therefore, we studied the difference of ERGs in the course of light adaptation between 2 and 20 Hz stimulus frequencies. METHODS A total of 90 rats divided into 18 different groups were used following overnight dark adaptation. ERGs were recorded against 3 different adapting field luminances (1.15, 1. 50 or 1.75 log cd/m(2)) with a combination of 3 stimulus flash intensities (0.86, 1.30 or 2.03 log cd sec/m( 2)). The responses were obtained at 2 minute intervals for 25 minutes of light adaptation. RESULTS The response of the rat cone ERG was large despite the small number of cones. The mean amplitude increased systematically from the dark-adapted value requiring more than 15 minutes to reach an asymptote at 2 Hz stimulation, but only 10 minutes at 20 Hz stimulation. The 2 Hz adaptation curves had biphasic pattern compared to the monophasic 20 Hz curve. This second increase in the amplitude at 2 Hz appeared at around 7-8 minutes as a function of adaptation time. This tendency was most evident when using a low adapting field luminance with a high flash intensity. CONCLUSIONS Our results suggest that the rods intrude much more during light adaptation at 2 Hz stimulation in rodents than in humans. Therefore, 20 Hz flicker stimulation can better isolate more the cone-mediated function than 2 Hz stimulation during the course of light adaptation in rats. Furthermore, the functional characteristics of the cone in rats may be different from that in humans.
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Affiliation(s)
- Y Goto
- Kyushu University Neurological Institute Department of Clinical Neurophysiology Fukuoka, Japan.
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19
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Oshima Y, Sakamoto T, Nakamura T, Tahara Y, Goto Y, Ishibashi T, Inomata H. The comparative benefits of glaucoma filtering surgery with an electric-pulse targeted drug delivery system demonstrated in an animal model. Ophthalmology 1999; 106:1140-6. [PMID: 10366083 DOI: 10.1016/s0161-6420(99)90249-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
PURPOSE To evaluate the safety and effectiveness of glaucoma filtering surgery performed with the adjunctive use of bleomycin administered in conjunction with electric pulses (EP). DESIGN Experimental study in rabbits. CONTROLS AND METHODS: Trabeculectomies were performed on pigmented rabbits (2 to 2.5 kg) using the following adjunctive treatments: 5 microM of topical bleomycin and EP (5V, 50 msec, 8 pulses) (group A: B+E+, n=15); bleomycin but no EP (group B: B+E-, n=15); 5 ,uM mitomycin C (MMC) and EP (group C: M+E+, n= 10); MMC but no EP (group D: M+E-, n=10); EP alone (group E: E+, n=10); and no adjunctive treatment (group F: E-, negative control, n=10). MAIN OUTCOME MEASURES Intraocular pressure (IOP) was measured regularly for 60 days after the operation. Bleb formation and the condition of the conjunctiva, cornea, and retina were also regularly evaluated. Histologic studies were performed by light microscopy, and retinal functions were evaluated by electroretinography. RESULTS Postoperative IOP was significantly lower than the preoperative level in all the animals until day 7. However, in groups E and F (the negative control) it returned to the preoperative level after day 7, and in groups B, C, and D after 15 days. The IOP of group A remained lower even on day 40. The average amount IOP was lowered or increased on day 20 was -6.4 mmHg (P < 0.05) in group A; -0.2 mmHg in group B; +1.2 mmHg in group C; and -3.25 mmHg in group D. The survival rate of the filtering blebs on day 20 was significantly higher in group A than in the other groups. Clinical and histologic studies uncovered no pathologic findings in any intra- or paraocular tissues. Electroretinographic evaluation of retinal function in group A showed no apparent change over the 60 days of the study. CONCLUSION Glaucoma filtering surgery in rabbits with the adjunctive use of bleomycin in conjunction with EP significantly lowered IOP for up to 40 days without clinically, morphologically, or functionally harming intraocular tissues.
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Affiliation(s)
- Y Oshima
- Department of Ophthalmology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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