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Curran ALK, Stukin J, Ambrosio L, Mantagos IS, Wu C, Vanderveen DK, Hansen RM, Akula JD, Fulton AB. Electroretinographic Responses in Retinopathy of Prematurity Treated Using Intravitreal Bevacizumab or Laser. Am J Ophthalmol 2023; 252:275-285. [PMID: 37146743 PMCID: PMC10524994 DOI: 10.1016/j.ajo.2023.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/07/2023]
Abstract
PURPOSE Intravitreal injection of bevacizumab (IVB) offers advantages over laser photoablation for treatment of type 1 retinopathy of prematurity (ROP). However, retinal function has not, to date, been quantitatively compared following these interventions. Therefore, electroretinography (ERG) was used compare retinal function among eyes treated using IVB or laser, and control eyes. In addition, among the IVB-treated eyes, ERG was used to compare function in individuals in whom subsequent laser was and was not required. DESIGN Prospective clinical cohort study. METHODS ERG was used to record dark- and light-adapted stimulus/response functions in 21 children treated using IVB (12 of whom required subsequent laser in at least 1 eye for persistent avascular retina [PAR]). Sensitivity and amplitude parameters were derived from the a-wave, b-wave, and oscillatory potentials (OPs), representing activity in photoreceptor, postreceptor, and inner retinal cells, respectively. These parameters were then referenced to those of 76 healthy, term-born controls and compared to those of 10 children treated using laser only. RESULTS In children with treated ROP, every ERG parameter was significantly below the mean in controls. However, these significant ERG deficits did not differ between IVB- and laser-treated eyes. Among children treated using IVB, no ERG parameter was significantly associated with dose or need for subsequent laser. CONCLUSION Retinal function was significantly impaired in treated ROP eyes. Function in IVB-treated eyes did not differ from that in laser-treated eyes. Functional differences also did not distinguish those IVB-treated eyes that would subsequently need laser for PAR.
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Affiliation(s)
| | - Justyna Stukin
- Boston Children’s Hospital, Ophthalmology
- Northeastern University, Behavioral Neuroscience
| | - Lucia Ambrosio
- University of Naples Federico II, Department of Neuroscience, Reproductive and Odontostomatological Sciences
- University of Naples Federico II, Department of Public Health
| | - Iason S. Mantagos
- Boston Children’s Hospital, Ophthalmology
- Harvard Medical School, Ophthalmology
| | - Carolyn Wu
- Boston Children’s Hospital, Ophthalmology
- Harvard Medical School, Ophthalmology
| | | | - Ronald M. Hansen
- Boston Children’s Hospital, Ophthalmology
- Harvard Medical School, Ophthalmology
| | - James D. Akula
- Boston Children’s Hospital, Ophthalmology
- Harvard Medical School, Ophthalmology
| | - Anne B. Fulton
- Boston Children’s Hospital, Ophthalmology
- Harvard Medical School, Ophthalmology
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Sirés A, Pazo-González M, López-Soriano J, Méndez A, de la Rosa EJ, de la Villa P, Comella JX, Hernández-Sánchez C, Solé M. The Absence of FAIM Leads to a Delay in Dark Adaptation and Hampers Arrestin-1 Translocation upon Light Reception in the Retina. Cells 2023; 12:cells12030487. [PMID: 36766830 PMCID: PMC9914070 DOI: 10.3390/cells12030487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/14/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
The short and long isoforms of FAIM (FAIM-S and FAIM-L) hold important functions in the central nervous system, and their expression levels are specifically enriched in the retina. We previously described that Faim knockout (KO) mice present structural and molecular alterations in the retina compatible with a neurodegenerative phenotype. Here, we aimed to study Faim KO retinal functions and molecular mechanisms leading to its alterations. Electroretinographic recordings showed that aged Faim KO mice present functional loss of rod photoreceptor and ganglion cells. Additionally, we found a significant delay in dark adaptation from early adult ages. This functional deficit is exacerbated by luminic stress, which also caused histopathological alterations. Interestingly, Faim KO mice present abnormal Arrestin-1 redistribution upon light reception, and we show that Arrestin-1 is ubiquitinated, a process that is abrogated by either FAIM-S or FAIM-L in vitro. Our results suggest that FAIM assists Arrestin-1 light-dependent translocation by a process that likely involves ubiquitination. In the absence of FAIM, this impairment could be the cause of dark adaptation delay and increased light sensitivity. Multiple retinal diseases are linked to deficits in photoresponse termination, and hence, investigating the role of FAIM could shed light onto the underlying mechanisms of their pathophysiology.
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Affiliation(s)
- Anna Sirés
- Cell Signaling and Apoptosis Group, Vall d’Hebron Institute of Research (VHIR), 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, 28029 Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Mateo Pazo-González
- Department of Molecular Biomedicine, Centro de Investigaciones Biológicas Margarita Salas (CSIC), 28040 Madrid, Spain
- Department of Systems Biology, Facultad de Medicina, Universidad de Alcalá, 28871 Alcalá de Henares, Spain
| | - Joaquín López-Soriano
- Cell Signaling and Apoptosis Group, Vall d’Hebron Institute of Research (VHIR), 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, 28029 Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Ana Méndez
- Department of Physiological Sciences, School of Medicine, Campus Universitari de Bellvitge, University of Barcelona, 08907 Barcelona, Spain
- Institut de Neurociències, Campus Universitari de Bellvitge, University of Barcelona, 08907 Barcelona, Spain
- Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), Campus Universitari de Bellvitge, University of Barcelona, 08907 Barcelona, Spain
| | - Enrique J. de la Rosa
- Department of Molecular Biomedicine, Centro de Investigaciones Biológicas Margarita Salas (CSIC), 28040 Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, 28029 Madrid, Spain
| | - Pedro de la Villa
- Department of Molecular Biomedicine, Centro de Investigaciones Biológicas Margarita Salas (CSIC), 28040 Madrid, Spain
- Department of Systems Biology, Facultad de Medicina, Universidad de Alcalá, 28871 Alcalá de Henares, Spain
| | - Joan X. Comella
- Cell Signaling and Apoptosis Group, Vall d’Hebron Institute of Research (VHIR), 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, 28029 Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Catalina Hernández-Sánchez
- Department of Molecular Biomedicine, Centro de Investigaciones Biológicas Margarita Salas (CSIC), 28040 Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, 28029 Madrid, Spain
| | - Montse Solé
- Cell Signaling and Apoptosis Group, Vall d’Hebron Institute of Research (VHIR), 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, 28029 Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
- Correspondence:
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Huang R, Xu Y, Lu X, Tang X, Lin J, Cui K, Yu S, Shi Y, Ye D, Liu Y, Liang X. Melatonin protects inner retinal neurons of newborn mice after hypoxia-ischemia. J Pineal Res 2021; 71:e12716. [PMID: 33426650 DOI: 10.1111/jpi.12716] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/02/2021] [Accepted: 01/02/2021] [Indexed: 12/21/2022]
Abstract
Retinopathy of prematurity is a vision-threatening disease associated with retinal hypoxia-ischemia, leading to the death of retinal neurons and chronic neuronal degeneration. During this study, we used the oxygen-induced retinopathy mice model to mimic retinal hypoxia-ischemia phenotypes to investigate further the neuroprotective effect of melatonin on neonatal retinal neurons. Melatonin helped maintain relatively normal inner retinal architecture and thickness and preserve inner retinal neuron populations in avascular areas by rescuing retinal ganglion and bipolar cells, and horizontal and amacrine neurons, from apoptosis. Meanwhile, melatonin recovered visual dysfunction, as reflected by the improved amplitudes and implicit times of a-wave, b-wave, and oscillatory potentials. Additionally, elevated cleaved caspase-3 and Bax protein levels and reduced Bcl-2 protein levels in response to hypoxia-ischemia were diminished after melatonin treatment. Moreover, melatonin increased BDNF and downstream phospho-TrkB/Akt/ERK/CREB levels. ANA-12, a TrkB receptor antagonist, antagonized these melatonin actions and reduced melatonin-induced neuroprotection. Furthermore, melatonin rescued the reduction in melatonin receptor expression. This study suggests that melatonin exerted anti-apoptotic and neuroprotective effects in inner retinal neurons after hypoxia-ischemia, at least partly due to modulation of the BDNF-TrkB pathway.
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Affiliation(s)
- Rong Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yue Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Xi Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyu Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jianqiang Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kaixuan Cui
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shanshan Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yuxun Shi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dan Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoling Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Sawant OB, Jidigam VK, Wilcots K, Fuller RD, Samuels I, Rao S. Thyroid Activating Enzyme, Deiodinase II Is Required for Photoreceptor Function in the Mouse Model of Retinopathy of Prematurity. Invest Ophthalmol Vis Sci 2020; 61:36. [PMID: 33237298 PMCID: PMC7691789 DOI: 10.1167/iovs.61.13.36] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 10/30/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Retinopathy of prematurity (ROP) is a severe complication of premature infants, leading to vision loss when untreated. Presently, the molecular mechanisms underlying ROP are still far from being clearly understood. This study sought to investigate whether thyroid hormone (TH) signaling contributes to the neuropathology of ROP using the mouse model of ROP to evaluate longitudinal photoreceptor function. Methods Animals were exposed to hyperoxia from P7 to P12 to induce retinopathy, thereafter the animals were returned to room air (normoxia). The thyroid-activating enzyme type 2 deiodinases (Dio2) knockout (KO) mice and the littermate controls that were exposed to hyperoxia or maintained in room air and were then analyzed. The retinal function was evaluated using electroretinograms (ERGs) at three and seven weeks followed by histologic assessments with neuronal markers to detect cellular changes in the retina. Rhodopsin protein levels were measured to validate the results obtained from the immunofluorescence analyses. Results In the ROP group, the photoreceptor ERG responses are considerably lower both in the control and the Dio2 KO animals at P23 compared to the non-ROP group. In agreement with the ERG responses, loss of Dio2 results in mislocalized cone nuclei, and abnormal rod bipolar cell dendrites extending into the outer nuclear layer. The retinal function is compromised in the adult Dio2 KO animals, although the cellular changes are less severe. Despite the reduction in scotopic a-wave amplitudes, rhodopsin levels are similar in the adult mice, across all genotypes irrespective of exposure to hyperoxia. Conclusions Using the mouse model of ROP, we show that loss of Dio2 exacerbates the effects of hyperoxia-induced retinal deficits that persist in the adults. Our data suggest that aberrant Dio2/TH signaling is an important factor in the pathophysiology of the visual dysfunction observed in the oxygen-induced retinopathy model of ROP.
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Affiliation(s)
- Onkar B. Sawant
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Eversight, Cleveland, Ohio, United States
| | - Vijay K. Jidigam
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
| | - Kenya Wilcots
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Department of Chemistry, Cleveland State University, Cleveland, Ohio, United States
| | - Rebecca D. Fuller
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
| | - Ivy Samuels
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, United States
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, United States
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Dai X, Ye S, Chen X, Jiang T, Huang H, Li W, Yu H, Bao J, Chen H. Rodent retinal microcirculation and visual electrophysiology following simulated microgravity. Exp Eye Res 2020; 194:108023. [PMID: 32222454 DOI: 10.1016/j.exer.2020.108023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 11/30/2022]
Abstract
How the absence of gravity affects the physiology of human beings is generating global research interest as space exploration, including missions aboard the International Space Station, continues to push boundaries. Here, we examined changes in retinal microcirculation and visual electrophysiology in mice suspended by their tails to simulate the cephalad movement of blood that occurs under microgravity conditions. Tail suspension was performed with a head-down tilt with a recommended angle of 30°. Mice in the control groups were similarly attached to a tether but could maintain a normal position. Morphologically, the 15-day tail-suspended mice showed retinal microvascular dilation, tortuosity, and a relatively long fluorescence retention; however, the average diameter of the major retinal vessels was not notably changed. In addition, optical coherence tomography showed their optic nerve head had an increased diameter. However, the mice could adapt to the change, with microcirculation and the optic nerve head recovering following 30-day tail suspension. Expression of rhodopsin and cone-opsins was not notably changed, and no retinal apoptotic-positive cells were detected between 15- and 30-day tail suspensions. Moreover, the three experimental groups of suspended mice showed normal retinal layers and thickness. Functionally, following 15-day tail suspension, scotopic electroretinograms showed a decline in the oscillatory potentials (OPs), but not in the b wave; simultaneously, the peak time of flash visual evoked potential component N1 was delayed compared to its baseline and the time-matched control. Following 30-day tail suspension, the OPs (O2) amplitude recovered to approximately 97% of its baseline or 86% of the time-matched control level. By simulating cephalad shifting of blood, short-term tail suspension can affect rodent retinal microcirculation, the optic nerve head, and disturb visual electrophysiology. However, the change is reversible with no permanent injury observed in the retina. The mice could adapt to the short-term change of retinal microcirculation, indicating new conditions that could be combined with, or could enhance, simulated microgravity for further studying the impact of short- or long-term outer space conditions on the retina.
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Affiliation(s)
- Xufeng Dai
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
| | - Siming Ye
- New York University Shanghai, Shanghai, 200120, China
| | - Xiaoping Chen
- Laboratory of Human Factors Engineering, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Ting Jiang
- Laboratory of Human Factors Engineering, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Haixiao Huang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China
| | - Wenjiong Li
- Laboratory of Human Factors Engineering, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Hongqiang Yu
- Laboratory of Human Factors Engineering, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Jinhua Bao
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China.
| | - Hao Chen
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325027, China.
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Wang T, Tsirukis DI, Sun Y. Targeting Neuroinflammation in Neovascular Retinal Diseases. Front Pharmacol 2020; 11:234. [PMID: 32210818 PMCID: PMC7076162 DOI: 10.3389/fphar.2020.00234] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Retinal blood vessels provide the necessary energy, nutrients and oxygen in order to support visual function and remove harmful particles from blood, thus acting to protect neuronal cells. The homeostasis of the retinal vessels is important for the maintenance of retinal visual function. Neovascularization is the most common cause of blindness in patients with retinopathy. Previous studies have shown that inflammatory mediators are known key regulators in retinopathy, but their causal link has been elusive. Although inflammation is often thought to arise from inflammatory cells like macrophages, neutrophils, and resident microglia, retinal neurons have also been reported to contribute to inflammation, through inflammatory signals, which mediate blood vessel growth. Therefore, it is important to explore the detailed mechanisms of neuroinflammation’s effects on retinal neovascularization. This review looks to summarize current research on the relationship between retinal angiogenesis and neuroinflammation in retinopathy, as well as the potential effects of neuroinflammation on retinal neovascularization in different animal models.
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Affiliation(s)
- Tianxi Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Demetrios I Tsirukis
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Ye Sun
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
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Wan W, Chen Z, Lei B. Increase in electroretinogram rod-driven peak frequency of oscillatory potentials and dark-adapted responses in a cohort of myopia patients. Doc Ophthalmol 2019; 140:189-199. [PMID: 31659575 DOI: 10.1007/s10633-019-09732-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 10/16/2019] [Indexed: 11/26/2022]
Abstract
PURPOSE To study whether rod- and cone-driven electroretinogram (ERG) responses are altered in myopia patients. METHODS Dark- and light-adapted ERGs were recorded from 57 myopic eyes of 32 patients aged 22-30 and 19 emmetropic eyes of 10 age-matched normal subjects. The myopic eyes were divided into 3 groups according to spherical equivalent (SE) of manifest refraction: 18 low myopia eyes (≤ - 3.00 diopter (D), 23 moderate myopia eyes (- 3.25 to - 6.00 D), and 16 high myopia eyes (> - 6.25 D). The amplitudes of the dark- and light-adapted ERG a- and b-waves, as well as the frequency spectra of the cone-driven and rod-driven oscillatory potentials (OPs), were analyzed by fast Fourier transform. The peak frequency, implicit time, and total power of the OPs were determined. The axial length was measured with an IOL Master. The ERG parameters including those of the cone- and rod-driven OPs were compared among three groups. RESULTS The amplitudes of the a-wave and b-wave of the dark-adapted ERGs were increased with refractive power (P < 0.05). Interestingly, the average peak frequency of the rod-driven OPs showed a significant positive correlation with refractive power (P < 0.001): 123.41 ± 9.13 Hz in emmetropic controls, 129.12 ± 10.28 Hz in low myopia, 133.90 ± 9.13 Hz in moderate myopia, and 139.51 ± 5.78 Hz in high myopia. However, the parameters of the light-adapted ERGs and the cone-driven OPs in myopic eyes were within normal ranges. CONCLUSION We found significant positive correlation between the peak frequency of rod-driven OPs, as well as the amplitudes of rod-driven ERG a- and b-waves, and the refractive power. The results suggest that the rod system function was changing during the progress of myopia, while the cone system function appeared unaffected. The peak frequency of OPs appeared as a novel ERG parameter for myopia, a common ocular condition.
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Affiliation(s)
- Wenjuan Wan
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Zihe Chen
- Department of Ophthalmology, The First People's Hospital of Xiaoshan, Hangzhou, China
| | - Bo Lei
- Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China.
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Rojo Arias JE, Economopoulou M, Juárez López DA, Kurzbach A, Au Yeung KH, Englmaier V, Merdausl M, Schaarschmidt M, Ader M, Morawietz H, Funk RHW, Jászai J. VEGF-Trap is a potent modulator of vasoregenerative responses and protects dopaminergic amacrine network integrity in degenerative ischemic neovascular retinopathy. J Neurochem 2019; 153:390-412. [PMID: 31550048 DOI: 10.1111/jnc.14875] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/06/2019] [Accepted: 09/18/2019] [Indexed: 12/17/2022]
Abstract
Retinal hypoxia triggers abnormal vessel growth and microvascular hyper-permeability in ischemic retinopathies. Whereas vascular endothelial growth factor A (VEGF-A) inhibitors significantly hinder disease progression, their benefits to retinal neurons remain poorly understood. Similar to humans, oxygen-induced retinopathy (OIR) mice exhibit severe retinal microvascular malformations and profound neuronal dysfunction. OIR mice are thus a phenocopy of human retinopathy of prematurity, and a proxy for investigating advanced stages of proliferative diabetic retinopathy. Hence, the OIR model offers an excellent platform for assessing morpho-functional responses of the ischemic retina to anti-angiogenic therapies. Using this model, we investigated the retinal responses to VEGF-Trap (Aflibercept), an anti-angiogenic agent recognizing ligands of VEGF receptors 1 and 2 that possesses regulatory approval for the treatment of neovascular age-related macular degeneration, macular edema secondary to retinal vein occlusion and diabetic macular edema. Our results indicate that Aflibercept not only reduces the severity of retinal microvascular aberrations but also significantly improves neuroretinal function. Aflibercept administration significantly enhanced light-responsiveness, as revealed by electroretinographic examinations, and led to increased numbers of dopaminergic amacrine cells. Additionally, retinal transcriptional profiling revealed the concerted regulation of both angiogenic and neuronal targets, including transcripts encoding subunits of transmitter receptors relevant to amacrine cell function. Thus, Aflibercept represents a promising therapeutic alternative for the treatment of further progressive ischemic retinal neurovasculopathies beyond the set of disease conditions for which it has regulatory approval. Cover Image for this issue: doi: 10.1111/jnc.14743.
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Affiliation(s)
- Jesús E Rojo Arias
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Matina Economopoulou
- Department of Ophthalmology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - David A Juárez López
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Anica Kurzbach
- Medizinische Klinik III, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany.,German Center for Diabetes Research (DZD e.V.), München-Neuherberg, Germany
| | - Kwan H Au Yeung
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Vanessa Englmaier
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Marie Merdausl
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Martin Schaarschmidt
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Marius Ader
- DFG-Center for Regenerative Therapies Dresden, Cluster of Excellence, Saxony, Germany
| | - Henning Morawietz
- Department of Medicine III, University Hospital Carl Gustav Carus, Division of Vascular Endothelium and Microcirculation, Technische Universität Dresden, Saxony, Germany
| | - Richard H W Funk
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - József Jászai
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
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Akula JD, Ambrosio L, Howard FI, Hansen RM, Fulton AB. Extracting the ON and OFF contributions to the full-field photopic flash electroretinogram using summed growth curves. Exp Eye Res 2019; 189:107827. [PMID: 31600486 DOI: 10.1016/j.exer.2019.107827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
Under cone-mediated (photopic) conditions, an "instantaneous" flash of light, including both stimulus onset and offset, will simultaneously activate both "ON" and "OFF" bipolar cells, which either depolarize (ON) or hyperpolarize (OFF) in response and, respectively, produce positive-going and negative-going deflections in the electroretinogram (ERG). The stimulus-response (SR) relationship of the photopic ON response demonstrates logistic growth, like that manifested in the rod-mediated (scotopic) b-wave, which is driven by a single class of depolarizing bipolar cell. However, the photopic b-wave SR function is importantly shaped by OFF responses, leading to a "photopic hill." Furthermore, both on and off stimuli elicit activity in both ON and OFF bipolar cells. This has made it difficult to produce meaningful parameters for ready interpretation of the photopic b-wave SR relationship. Therefore, we evaluated whether the sum of sigmoidal SR functions, as descriptors of the depolarizing and hyperpolarizing components of the photopic flash ERG, could be used to elucidate and quantitate the mechanisms that produce the photopic hill. We used a novel fitting routine to optimize a sum of simple sigmoidal curves to SR data in five groups of subjects: Healthy adult, 10-week-old infant, congenital stationary night blindness (CSNB), X-linked juvenile retinoschisis (XJR), and preterm-born, both without and with a history of retinopathy of prematurity (ROP). Differences in ON and OFF amplitude, sensitivity, and implicit time among the groups were then compared using parameters extracted from these fits. We found that our modeling procedure enabled plausible derivations of ON and OFF pathway contributions to the ERG, and that the parameters produced appeared to have physiological relevance. In adult subjects, the ON and OFF amplitudes were similar in magnitude with respectively longer and shorter implicit times. Infant, CSNB, and XJR subjects showed significant ON pathway deficits. History of preterm-birth, without or with a diagnosis of ROP, did not much affect cone responses.
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Affiliation(s)
- James D Akula
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States.
| | - Lucia Ambrosio
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Fiona I Howard
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Psychology, Northeastern University, Boston, MA, United States
| | - Ronald M Hansen
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Anne B Fulton
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
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10
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Fu Z, Wang Z, Liu CH, Gong Y, Cakir B, Liegl R, Sun Y, Meng SS, Burnim SB, Arellano I, Moran E, Duran R, Poblete A, Cho SS, Talukdar S, Akula JD, Hellström A, Smith LEH. Fibroblast Growth Factor 21 Protects Photoreceptor Function in Type 1 Diabetic Mice. Diabetes 2018; 67:974-985. [PMID: 29487115 PMCID: PMC5909994 DOI: 10.2337/db17-0830] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/07/2018] [Indexed: 12/20/2022]
Abstract
Retinal neuronal abnormalities occur before vascular changes in diabetic retinopathy. Accumulating experimental evidence suggests that neurons control vascular pathology in diabetic and other neovascular retinal diseases. Therefore, normalizing neuronal activity in diabetes may prevent vascular pathology. We investigated whether fibroblast growth factor 21 (FGF21) prevented retinal neuronal dysfunction in insulin-deficient diabetic mice. We found that in diabetic neural retina, photoreceptor rather than inner retinal function was most affected and administration of the long-acting FGF21 analog PF-05231023 restored the retinal neuronal functional deficits detected by electroretinography. PF-05231023 administration protected against diabetes-induced disorganization of photoreceptor segments seen in retinal cross section with immunohistochemistry and attenuated the reduction in the thickness of photoreceptor segments measured by optical coherence tomography. PF-05231023, independent of its downstream metabolic modulator adiponectin, reduced inflammatory marker interleukin-1β (IL-1β) mRNA levels. PF-05231023 activated the AKT-nuclear factor erythroid 2-related factor 2 pathway and reduced IL-1β expression in stressed photoreceptors. PF-05231023 administration did not change retinal expression of vascular endothelial growth factor A, suggesting a novel therapeutic approach for the prevention of early diabetic retinopathy by protecting photoreceptor function in diabetes.
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MESH Headings
- Animals
- Antibodies, Monoclonal, Humanized/pharmacology
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Diabetic Retinopathy/etiology
- Diabetic Retinopathy/metabolism
- Diabetic Retinopathy/pathology
- Disease Models, Animal
- Electroretinography
- Fibroblast Growth Factors/pharmacology
- Interleukin-1beta/drug effects
- Interleukin-1beta/genetics
- Interleukin-1beta/metabolism
- Male
- Mice
- NF-E2-Related Factor 2/drug effects
- NF-E2-Related Factor 2/genetics
- NF-E2-Related Factor 2/metabolism
- Photoreceptor Cells, Vertebrate/drug effects
- Photoreceptor Cells, Vertebrate/metabolism
- Photoreceptor Cells, Vertebrate/pathology
- Proto-Oncogene Proteins c-akt/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- Retinal Neurons/drug effects
- Retinal Neurons/metabolism
- Retinal Neurons/pathology
- Tomography, Optical Coherence
- Vascular Endothelial Growth Factor A/drug effects
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Zhongxiao Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Yan Gong
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Bertan Cakir
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Raffael Liegl
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Ye Sun
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Steven S Meng
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Samuel B Burnim
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Ivana Arellano
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Elizabeth Moran
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Rubi Duran
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Alexander Poblete
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Steve S Cho
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | | - James D Akula
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA
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11
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Perche O, Felgerolle C, Ardourel M, Bazinet A, Pâris A, Rossignol R, Meyer-Dilhet G, Mausset-Bonnefont AL, Hébert B, Laurenceau D, Montécot-Dubourg C, Menuet A, Bizot JC, Pichon J, Ranchon-Cole I, Briault S. Early Retinal Defects in Fmr1-/y Mice: Toward a Critical Role of Visual Dys-Sensitivity in the Fragile X Syndrome Phenotype? Front Cell Neurosci 2018; 12:96. [PMID: 29681800 PMCID: PMC5897671 DOI: 10.3389/fncel.2018.00096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/22/2018] [Indexed: 12/29/2022] Open
Abstract
Fragile X Syndrome (FXS) is caused by a deficiency in Fragile X Mental Retardation Protein (FMRP) leading to global sensorial abnormalities, among which visual defects represent a critical part. These visual defects are associated with cerebral neuron immaturity especially in the primary visual cortex. However, we recently demonstrated that retinas of adult Fmr1−/y mice, the FXS murine model, present molecular, cellular and functional alterations. However, no data are currently available on the evolution pattern of such defects. As retinal stimulation through Eye Opening (EO) is a crucial signal for the cerebral visual system maturation, we questioned the precocity of molecular and functional retinal phenotype. To answer this question, we studied the retinal molecular phenotype of Fmr1−/y mice before EO until adult age and the consequences of the retinal loss of Fmrp on retinal function in young and adult mice. We showed that retinal molecular defects are present before EO and remain stable at adult age, leading to electrophysiological impairments without any underlying structural changes. We underlined that loss of Fmrp leads to a wide range of defects in the retina, settled even before EO. Our work demonstrates a critical role of the sensorial dysfunction in the Fmr1−/y mice overall phenotype, and provides evidence that altered peripheral perception is a component of the sensory processing defect in FXS conditions.
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Affiliation(s)
- Olivier Perche
- Genetic Department, Centre Hospitalier Régional d'Orléans, Orléans, France.,UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Chloé Felgerolle
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Maryvonne Ardourel
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Audrey Bazinet
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Arnaud Pâris
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Rafaëlle Rossignol
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Géraldine Meyer-Dilhet
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | | | - Betty Hébert
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - David Laurenceau
- Genetic Department, Centre Hospitalier Régional d'Orléans, Orléans, France
| | - Céline Montécot-Dubourg
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Arnaud Menuet
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | | | - Jacques Pichon
- UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
| | - Isabelle Ranchon-Cole
- Laboratory of Sensorial Biophysical, INSERM UMR1107 Equipe Biophysique Neurosensorielle, University of Clermont 1, Clermont-Ferrand, France
| | - Sylvain Briault
- Genetic Department, Centre Hospitalier Régional d'Orléans, Orléans, France.,UMR7355, Immunologie et Neurogénétique Expérimentales et Moléculaires (INEM), Centre National de la Recherche Scientifique, Orléans, France.,Experimental and Molecular Immunology and Neurogenetics, University of Orléans, Orléans, France
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12
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Dai J, He J, Wang G, Wang M, Li S, Yin ZQ. Contribution of GABAa, GABAc and glycine receptors to rat dark-adapted oscillatory potentials in the time and frequency domain. Oncotarget 2017; 8:77696-77709. [PMID: 29100418 PMCID: PMC5652335 DOI: 10.18632/oncotarget.20770] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/29/2017] [Indexed: 02/02/2023] Open
Abstract
Retinal oscillatory potentials (OPs) consist of a series of relatively high-frequency rhythmic wavelets, superimposed onto the ascending phase of the b-wave of the electroretinogram (ERG). However, the origin of OPs is uncertain and methods of measurement of OPs are diverse. In this study, we first isolated OPs from the rat ERG and fitted them with Gabor functions and found that the envelope of the OP contained information about maximum amplitude and time-to-peak to enable satisfactory quantification of the later OPs. And the OP/b-wave ratio should be evaluated to exclude an effect of the b-wave on the OPs. Next, we recorded OPs after intravitreal injection of 2-amino-4-phosphonobutyric acid (APB), tetrodotoxin (TTX), γ-aminobutyric acid (GABA), strychnine (STR), SR95531 (SR), isoguvacine (ISO), (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA) and GABA+TPMPA. We showed that GABA and APB only removed the later OPs, when compared to control eyes. TTX delayed the peak time, and STR, SR and ISO reduced the amplitude of OPs. TPMPA delayed the peak time but increased the ratio of OPs to b-wave. Furthermore, administration of combined GABA and TPMPA caused the later OPs to increase in amplitude with time, compared with those after delivery of GABA alone. Finally, we observed that GABAc and glycine receptors contributed to a low-frequency component of the OPs, while GABAa contributed to both components. These results suggest that the early components of the OPs are mainly generated by the photoreceptors, whilst the later components are mainly regulated by GABAa, GABAc and glycine receptors.
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Affiliation(s)
- Jiaman Dai
- College of Bioengineering, Chongqing University, Chongqing 400030, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Juncai He
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Gang Wang
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Min Wang
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Shiying Li
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Zheng Qin Yin
- College of Bioengineering, Chongqing University, Chongqing 400030, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
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13
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Spix NJ, Liu LL, Zhang Z, Hohlbein JP, Prigge CL, Chintala S, Ribelayga CP, Zhang DQ. Vulnerability of Dopaminergic Amacrine Cells to Chronic Ischemia in a Mouse Model of Oxygen-Induced Retinopathy. Invest Ophthalmol Vis Sci 2017; 57:3047-57. [PMID: 27281270 PMCID: PMC4913805 DOI: 10.1167/iovs.16-19346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Retinal dopamine deficiency is a potential cause of myopia and visual deficits in retinopathy of prematurity (ROP). We investigated the cellular mechanisms responsible for lowered levels of retinal dopamine in an oxygen-induced retinopathy (OIR) mouse model of ROP. Methods Retinopathy was induced by exposing mice to 75% oxygen from postnatal day 7 (P7) to P12. Oxygen-induced retinopathy and age-matched control mice were euthanized at P12, P17, P25, or P42 to P50. Immunohistochemistry, electrophysiology, and biochemical approaches were used to determine the effect of OIR on the structure and function of dopaminergic amacrine cells (DACs). Results The total number of DACs was unchanged in OIR retinas at P12 despite significant capillary dropout in the central retina. However, a significant loss of DACs was observed in P17 OIR retinas (in which neovascularization was maximal), with the cell loss being more profound in the central (avascular) than in the peripheral (neovascular) regions. Cell loss was persistent in both regions at P25, at which time retinal neovascularization had regressed. At P42, the percentage of DACs lost (54%) was comparable to the percent decrease in total dopamine content (53%). Additionally, it was found that DACs recorded in OIR retinas at P42 to P50 had a complete dendritic field and exhibited relatively normal spontaneous and light-induced electrical activity. Conclusions The results suggest that remaining DACs are structurally and functionally intact and that loss of DACs is primarily responsible for the decreased levels of retinal dopamine observed after OIR.
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Affiliation(s)
- Nathan J Spix
- Eye Research Institute Oakland University, Rochester, Michigan, United States
| | - Lei-Lei Liu
- Eye Research Institute Oakland University, Rochester, Michigan, United States
| | - Zhijing Zhang
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States
| | - Joshua P Hohlbein
- Eye Research Institute Oakland University, Rochester, Michigan, United States
| | - Cameron L Prigge
- Eye Research Institute Oakland University, Rochester, Michigan, United States
| | - Shravan Chintala
- Eye Research Institute Oakland University, Rochester, Michigan, United States
| | - Christophe P Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States 3Graduate School of Biomedical Sciences, The University of Texas Health Science Center at
| | - Dao-Qi Zhang
- Eye Research Institute Oakland University, Rochester, Michigan, United States
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14
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Hansen RM, Moskowitz A, Akula JD, Fulton AB. The neural retina in retinopathy of prematurity. Prog Retin Eye Res 2017; 56:32-57. [PMID: 27671171 PMCID: PMC5237602 DOI: 10.1016/j.preteyeres.2016.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/15/2016] [Accepted: 09/20/2016] [Indexed: 12/26/2022]
Abstract
Retinopathy of prematurity (ROP) is a neurovascular disease that affects prematurely born infants and is known to have significant long term effects on vision. We conducted the studies described herein not only to learn more about vision but also about the pathogenesis of ROP. The coincidence of ROP onset and rapid developmental elongation of the rod photoreceptor outer segments motivated us to consider the role of the rods in this disease. We used noninvasive electroretinographic (ERG), psychophysical, and retinal imaging procedures to study the function and structure of the neurosensory retina. Rod photoreceptor and post-receptor responses are significantly altered years after the preterm days during which ROP is an active disease. The alterations include persistent rod dysfunction, and evidence of compensatory remodeling of the post-receptor retina is found in ERG responses to full-field stimuli and in psychophysical thresholds that probe small retinal regions. In the central retina, both Mild and Severe ROP delay maturation of parafoveal scotopic thresholds and are associated with attenuation of cone mediated multifocal ERG responses, significant thickening of post-receptor retinal laminae, and dysmorphic cone photoreceptors. These results have implications for vision and control of eye growth and refractive development and suggest future research directions. These results also lead to a proposal for noninvasive management using light that may add to the currently invasive therapeutic armamentarium against ROP.
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Affiliation(s)
- Ronald M Hansen
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - James D Akula
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
| | - Anne B Fulton
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
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15
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Moskowitz A, Hansen RM, Fulton AB. Retinal, visual, and refractive development in retinopathy of prematurity. Eye Brain 2016; 8:103-111. [PMID: 28539805 PMCID: PMC5398748 DOI: 10.2147/eb.s95021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The pivotal role of the neurosensory retina in retinopathy of prematurity (ROP) disease processes has been amply demonstrated in rat models. We have hypothesized that analogous cellular processes are operative in human ROP and have evaluated these presumptions in a series on non-invasive investigations of the photoreceptor and post-receptor peripheral and central retina in infants and children. Key results are slowed kinetics of phototransduction and deficits in photoreceptor sensitivity that persist years after ROP has completely resolved based on clinical criteria. On the other hand, deficits in post-receptor sensitivity are present in infancy regardless of the severity of the ROP but are not present in older children if the ROP was so mild that it never required treatment and resolved without a clinical trace. Accompanying the persistent deficits in photoreceptor sensitivity, there is increased receptive field size and thickening of the post-receptor retinal laminae in the peripheral retina of ROP subjects. In the late maturing central retina, which mediates visual acuity, attenuation of multifocal electroretinogram activity in the post-receptor retina led us to the discovery of a shallow foveal pit and significant thickening of the post-receptor retinal laminae in the macular region; this is most likely due to failure of the normal centrifugal movement of the post-receptor cells during foveal development. As for refractive development, myopia, at times high, is more common in ROP subjects than in control subjects, in accord with refractive findings in other populations of former preterms. This information about the neurosensory retina enhances understanding of vision in patients with a history of ROP, and taken as a whole, raises the possibility that the neurosensory retina is a target for therapeutic intervention.
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Affiliation(s)
- Anne Moskowitz
- Department of Ophthalmology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Ronald M Hansen
- Department of Ophthalmology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Anne B Fulton
- Department of Ophthalmology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
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16
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Liu K, Wang N, Peng X, Yang D, Wang C, Zeng H. Long-term effect of laser-induced ocular hypertension on the cone electroretinogram and central macular thickness in monkeys. Photomed Laser Surg 2016; 32:371-8. [PMID: 24992271 DOI: 10.1089/pho.2013.3693] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The purpose of this study was to investigate the long-term effect of laser-induced ocular hypertension on the cone electroretinogram (ERG) and retinal thickness in monkeys. BACKGROUND DATA Degeneration of retinal nerve fiber layer (RNFL) and loss of retinal ganglion cells in the primate glaucoma model have been confirmed by histological studies and optical coherence tomography (OCT) images. However, it remains unclear whether the outer retina distal to the RGCs (e.g., photoreceptors) is involved in histological studies and in functional test. MATERIALS AND METHODS Subjects were five monkeys with high intraocular pressure (IOP) induced in the right eye by laser. Six years after the laser coagulation of the mid-trabecular meshwork, RNFL, ganglion cell complex (GCC), central macular thickness (CMT), and the thickness of outer retinal layer (ORL) were measured by OCT. The photopic responses of ERG were recorded in response to red flashes on a blue background. The maximum cone amplitude (Rcone) and cone sensitivity (Scone) were calculated. RESULTS Enlarged cup-to-disc (C/D) ratio was found in the lasered eyes. RNFL and GCC were significantly thinner in the lasered eyes (p<0.05), but no significant differences were found in CMT and the thickness of ORL compared with fellow eyes (p>0.05). Mean amplitude of the photopic negative response (PhNR), Mean Rcone were significantly lower in the lasered eye (p<0.05), and no significant differences of Scone were found between the two eyes (p>0.05). CONCLUSIONS Long-term ocular hypertension induced by laser affects the function of cone photoreceptor in monkeys.
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Affiliation(s)
- Kegao Liu
- 1 Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University , Beijing, China
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17
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Inner retinal oxygen metabolism in the 50/10 oxygen-induced retinopathy model. Sci Rep 2015; 5:16752. [PMID: 26576731 PMCID: PMC4649746 DOI: 10.1038/srep16752] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/20/2015] [Indexed: 02/06/2023] Open
Abstract
Retinopathy of prematurity (ROP) represents a major cause of childhood vision loss worldwide. The 50/10 oxygen-induced retinopathy (OIR) model mimics the findings of ROP, including peripheral vascular attenuation and neovascularization. The oxygen metabolism of the inner retina has not been previously explored in this model. Using visible-light optical coherence tomography (vis-OCT), we measured the oxygen saturation of hemoglobin and blood flow within inner retinal vessels, enabling us to compute the inner retinal oxygen delivery (irDO2) and metabolic rate of oxygen (irMRO2). We compared these measurements between age-matched room-air controls and rats with 50/10 OIR on postnatal day 18. To account for a 61% decrease in the irDO2 in the OIR group, we found an overall statistically significant decrease in retinal vascular density affecting the superficial and deep retinal vascular capillary networks in rats with OIR compared to controls. Furthermore, matching the reduced irDO2, we found a 59% decrease in irMRO2, which we correlated with a statistically significant reduction in retinal thickness in the OIR group, suggesting that the decreased irMRO2 was due to decreased neuronal oxygen utilization. By exploring these biological and metabolic changes in great detail, our study provides an improved understanding of the pathophysiology of OIR model.
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18
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Bedore J, Martyn AC, Li AKC, Dolinar EA, McDonald IS, Coupland SG, Prado VF, Prado MA, Hill KA. Whole-Retina Reduced Electrophysiological Activity in Mice Bearing Retina-Specific Deletion of Vesicular Acetylcholine Transporter. PLoS One 2015; 10:e0133989. [PMID: 26226617 PMCID: PMC4520552 DOI: 10.1371/journal.pone.0133989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 07/03/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Despite rigorous characterization of the role of acetylcholine in retinal development, long-term effects of its absence as a neurotransmitter are unknown. One of the unanswered questions is how acetylcholine contributes to the functional capacity of mature retinal circuits. The current study investigates the effects of disrupting cholinergic signalling in mice, through deletion of vesicular acetylcholine transporter (VAChT) in the developing retina, pigmented epithelium, optic nerve and optic stalk, on electrophysiology and structure of the mature retina. METHODS & RESULTS A combination of electroretinography, optical coherence tomography imaging and histological evaluation assessed retinal integrity in mice bearing retina- targeted (embryonic day 12.5) deletion of VAChT (VAChTSix3-Cre-flox/flox) and littermate controls at 5 and 12 months of age. VAChTSix3-Cre-flox/flox mice did not show any gross changes in nuclear layer cellularity or synaptic layer thickness. However, VAChTSix3-Cre-flox/flox mice showed reduced electrophysiological response of the retina to light stimulus under scotopic conditions at 5 and 12 months of age, including reduced a-wave, b-wave, and oscillatory potential (OP) amplitudes and decreased OP peak power and total energy. Reduced a-wave amplitude was proportional to the reduction in b-wave amplitude and not associated with altered a-wave 10%-90% rise time or inner and outer segment thicknesses. SIGNIFICANCE This study used a novel genetic model in the first examination of function and structure of the mature mouse retina with disruption of cholinergic signalling. Reduced amplitude across the electroretinogram wave form does not suggest dysfunction in specific retinal cell types and could reflect underlying changes in the retinal and/or extraretinal microenvironment. Our findings suggest that release of acetylcholine by VAChT is essential for the normal electrophysiological response of the mature mouse retina.
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Affiliation(s)
- Jake Bedore
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Amanda C Martyn
- Molecular Medicine, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Anson K C Li
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Eric A Dolinar
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Ian S McDonald
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Stuart G Coupland
- Ophthalmology, Cellular and Molecular Medicine, University of Ottawa, Ottawa Eye Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Vania F Prado
- Molecular Medicine, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Marco A Prado
- Molecular Medicine, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Kathleen A Hill
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
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Deficiency of aldose reductase attenuates inner retinal neuronal changes in a mouse model of retinopathy of prematurity. Graefes Arch Clin Exp Ophthalmol 2015; 253:1503-13. [PMID: 25921391 DOI: 10.1007/s00417-015-3024-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/08/2015] [Accepted: 04/14/2015] [Indexed: 01/02/2023] Open
Abstract
Retinopathy of prematurity (ROP) is a leading cause of childhood blindness where vascular abnormality and retinal dysfunction are reported. We showed earlier that genetic deletion of aldose reductase (AR), the rate-limiting enzyme in the polyol pathway, reduced the neovascularization through attenuating oxidative stress induction in the mouse oxygen-induced retinopathy (OIR) modeling ROP. In this study, we further investigated the effects of AR deficiency on retinal neurons in the mouse OIR. Seven-day-old wild-type and AR-deficient mice were exposed to 75 % oxygen for 5 days and then returned to room air. Electroretinography was used to assess the neuronal function at postnatal day (P) 30. On P17 and P30, retinal cytoarchitecture was examined by morphometric analysis and immunohistochemistry for calbindin, protein kinase C alpha, calretinin, Tuj1, and glial fibrillary acidic protein. In OIR, attenuated amplitudes and delayed implicit time of a-wave, b-wave, and oscillatory potentials were observed in wild-type mice, but they were not significantly changed in AR-deficient mice. The morphological changes of horizontal, rod bipolar, and amacrine cells were shown in wild-type mice and these changes were partly preserved with AR deficiency. AR deficiency attenuated the Müller cell gliosis induced in OIR. Our observations demonstrated AR deficiency preserved retinal functions in OIR and AR deficiency could partly reduce the extent of retinal neuronal histopathology. These findings suggested a therapeutic potential of AR inhibition in ROP treatment with beneficial effects on the retinal neurons.
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Akula JD, Noonan ER, Di Nardo A, Favazza TL, Zhang N, Sahin M, Hansen RM, Fulton AB. Vigabatrin can enhance electroretinographic responses in pigmented and albino rats. Doc Ophthalmol 2015; 131:1-11. [PMID: 25761928 DOI: 10.1007/s10633-015-9491-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 02/23/2015] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effects of the antiepileptic medication vigabatrin (VGB) on the retina of pigmented rats. METHODS Scotopic and photopic electroretinograms were recorded from dark- and light-adapted Long-Evans (pigmented) and Sprague Dawley (albino) rats administered, daily, 52-55 injections of 250 mg·kg(-1)·day(-1) VGB or 25-26 injections of 500 mg·kg(-1)·day(-1) VGB, or a corresponding number of sham injections. Sensitivity and saturated amplitude of the rod photoresponse (S, Rm(P3)) and postreceptor response (1/σ, Vm) were derived, as were sensitivity and amplitude of the cone-mediated postreceptor response (1/σ(cone), Vm(cone)). The oscillatory potentials and responses to a series of flickering lights (6.25, 12.5, 25 and 50 Hz) were studied in the time and frequency domains. A subset of rats' eyes was harvested for Western blotting or histology. RESULTS Of the parameters derived from dark-adapted ERG responses, in both pigmented and albino rats, VGB repeatedly and reliably enhanced electroretinographic parameters; no significant ERG deficits were noted. No significant alterations were observed in ER/oxidative stress or in the Akt cell death/survival pathway. There were migrations of photoreceptor nuclei toward the RPE and outgrowths of bipolar cell dendrites into the outer nuclear layer in VGB-treated rats; these were never observed in sham-treated animals. CONCLUSIONS Although VGB is associated with retinal dysfunction in patients and VGB toxicity has been demonstrated by other laboratories in the albino rat, in our pigmented and albino rats, VGB did not induce deficits in, but rather enhanced, retinal function. Nonetheless, retinal neuronal dysplasia was observed.
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Wang L, el Azazi M, Eklund A, Burstedt M, Wachtmeister L. The response of the neuronal adaptive system to background illumination and readaptation to dark in the immature retina. Acta Ophthalmol 2015; 93:146-53. [PMID: 24924739 DOI: 10.1111/aos.12456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 05/01/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE Developmental characteristics of the neuronal adaptive system of the retina, focusing on background light (BGL) adaptation and readaptation functions, were studied by measuring the oscillatory response (SOP) of the electroretinogram (ERG). METHODS Digitally filtered and conventional ERGs were simultaneously recorded. Rats aged 15 and 17 days were studied during exposure to BGLs of two mesopic intensities and during readaptation to dark. RESULTS Results were compared to adult rats. In 'low mesopic' BGL SOP instantly dropped significantly to about half of its dark-adapted (DA) value contrary to mature rats, in which the SOP significantly increased. In 'high mesopic' BGL SOP decreased to about 20% and 30% of DA values in immature and adult rats, respectively. The process of recovery of SOP in darkness lacked the transient enhancement immediately as BGL was turned off, characteristic of adult rats. There were no major age differences in adaptive behaviour of a-wave. In young rats, recovery of b-wave was relatively slower. CONCLUSIONS Properties of BGL adaptation and readaptation functions of the neuronal adaptive system in baby retina differed compared to the adult one by being less forceful and more restrained. Handling of mesopic illumination and recovery in the dark was immature. Development of these functions of the neuronal adaptive system progresses postnatally and lags behind that of the photoreceptor response and seems to be delayed also compared to that of the bipolar response.
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Affiliation(s)
- Ling Wang
- Department of Ophthalmology; Ruijin Hospital; Medicine School of Shanghai; Jiaotong University; Shanghai China
- Department of Clinical Sciences, Ophthalmology; Umeå University; Umeå Sweden
| | - Mildred el Azazi
- Department of Clinical Neuroscience, Ophthalmology and Vision; Karolinska Institutet; Stockholm Sweden
| | - Anders Eklund
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - Marie Burstedt
- Department of Clinical Sciences, Ophthalmology; Umeå University; Umeå Sweden
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Wright CB, Chrenek MA, Feng W, Getz SE, Duncan T, Pardue MT, Feng Y, Redmond TM, Boatright JH, Nickerson JM. The Rpe65 rd12 allele exerts a semidominant negative effect on vision in mice. Invest Ophthalmol Vis Sci 2014; 55:2500-15. [PMID: 24644049 PMCID: PMC3993890 DOI: 10.1167/iovs.13-13574] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 03/10/2014] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The rd12 mouse was reported as a recessively inherited Rpe65 mutation. We asked if the rd12 mutation resides in Rpe65 and how the mutation manifests itself. METHODS A complementation test was performed by mating Rpe65(KO) (KO/KO) and rd12 mice together to determine if the rd12 mutation is in the Rpe65 gene. Visual function of wild-type (+/+), KO/+, rd12/+, KO/KO, rd12/rd12, and KO/rd12 mice was measured by optokinetic tracking (OKT) and ERG. Morphology was assessed by retinal cross section. qRT-PCR quantified Rpe65 mRNA levels. Immunoblotting measured the size and level of RPE65 protein. Rpe65 mRNA localization was visualized with RNA fluorescence in situ hybridization (FISH). Fractions of Rpe65 mRNA-bound proteins were separated by linear sucrose gradient fractionation. RESULTS The KO and rd12 alleles did not complement. The rd12 allele induced a negative semidominant effect on visual function; OKT responses became undetectable 120 days earlier in rd12/rd12 mice compared with KO/KO mice. rd12/+ mice lost approximately 21% visual acuity by P210. rd12/rd12 mice had fewer cone photoreceptor nuclei than KO/KO mice at P60. rd12/rd12 mice expressed 71% +/+ levels of Rpe65 mRNA, but protein was undetectable. Mutant mRNA was appropriately spliced, exported to the cytoplasm, trafficked, and contained no other coding mutation aside from the known nonsense mutation. Mutant mRNA was enriched on ribosome-free messenger ribonucleoproteins (mRNPs), whereas wild-type mRNA was enriched on actively translating polyribosomes. CONCLUSIONS The rd12 lesion is in Rpe65. The rd12 mutant phenotype inherits in a semidominant manner. The effects of the mutant mRNA on visual function may result from inefficient binding to ribosomes for translation.
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Affiliation(s)
- Charles B. Wright
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - Micah A. Chrenek
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - Wei Feng
- Department of Pharmacology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - Shannon E. Getz
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - Todd Duncan
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Machelle T. Pardue
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
- Rehabiliation Research and Development Center of Excellence, Atlanta VA Medical Center, Decatur, Georgia, United States
| | - Yue Feng
- Department of Pharmacology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - T. Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jeffrey H. Boatright
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
| | - John M. Nickerson
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia, United States
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Suzuki R, Oka T, Tamada Y, Shearer TR, Azuma M. Degeneration and dysfunction of retinal neurons in acute ocular hypertensive rats: involvement of calpains. J Ocul Pharmacol Ther 2014; 30:419-28. [PMID: 24660785 DOI: 10.1089/jop.2013.0100] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Retinal ischemic diseases primarily lead to damage of the inner retinal neurons. Electrophysiological studies also suggest impairment of the inner retinal neurons. Our recent studies with acute ocular hypertensive rats confirmed damage predominantly in the inner retinal layer along with the ganglion cell layer, changes that are ameliorated by the calpain inhibitor SNJ-1945. However, we do not know which specific neuronal cells in the inner retinal layer are damaged by calpains. Thus, the purpose of the present study was to identify specific calpain-damaged neuronal cells in the inner retina from acute ocular hypertensive rats. METHODS Intraocular pressure was elevated to 110 mm Hg for 40 min. One hour after ocular hypertension (OH), SNJ-1945 was administrated as a single oral dose of 50 mg/kg. Retinal function was assessed by scotopic electroretinography (ERG). Histological degeneration was evaluated by hematoxylin and eosin, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL), and immunostaining in thin sections and flat mounts of the retina. Calpain activation was determined by proteolysis of the calpain substrate α-spectrin. RESULTS OH caused calpain activation, increased TUNEL-positive staining, decreased thickness of the inner nuclear layer (INL), and decreased amplitudes of the ERG a- and b-waves and oscillatory potentials (OPs). SNJ-1945 significantly inhibited calpain activation and the decrease in ERG values. Interestingly, the changes in the b-wave and OPs amplitudes were significantly correlated to changes in the thickness of the INL. In the inner retinal layer, the numbers of rod bipolar, cone-ON bipolar, and amacrine cells were decreased after OH. SNJ-1945 suppressed the loss of cone-ON bipolar and amacrine cells, but did not inhibit the loss of rod bipolar cells. We also observed increased glial fibrillary acid protein-positive staining in the Müller cells after OH and the treatment with SNJ-1945. CONCLUSIONS Calpains may contribute to ischemic retinal dysfunction by causing the loss of cone-ON bipolar and amacrine cells and causing the activation of Müller cells. Calpain inhibitor SNJ-1945 may be a candidate compound for treatment of retinal ischemic disease.
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Affiliation(s)
- Rie Suzuki
- 1 Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co., Ltd. , Kobe, Japan
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Zhang N, Favazza TL, Baglieri AM, Benador IY, Noonan ER, Fulton AB, Hansen RM, Iuvone PM, Akula JD. The rat with oxygen-induced retinopathy is myopic with low retinal dopamine. Invest Ophthalmol Vis Sci 2013; 54:8275-84. [PMID: 24168993 DOI: 10.1167/iovs.13-12544] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
PURPOSE Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. METHODS In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). RESULTS The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. CONCLUSIONS The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia.
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Affiliation(s)
- Nan Zhang
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts
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Ishizuka F, Shimazawa M, Egashira Y, Ogishima H, Nakamura S, Tsuruma K, Hara H. Cilostazol prevents retinal ischemic damage partly via inhibition of tumor necrosis factor-α-induced nuclear factor-kappa B/activator protein-1 signaling pathway. Pharmacol Res Perspect 2013; 1:e00006. [PMID: 25505560 PMCID: PMC4184571 DOI: 10.1002/prp2.6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 12/15/2022] Open
Abstract
Cilostazol is a specific inhibitor of phosphodiesterase III and is widely used to treat ischemic symptoms of peripheral vascular disease. We evaluated the protective effects of cilostazol in a murine model of ocular ischemic syndrome in which retinal ischemia was induced by 5-h unilateral ligation of both the pterygopalatine artery (PPA) and the external carotid artery (ECA) in anesthetized mice. The effects of cilostazol (30 mg/kg, p.o.) on ischemia/reperfusion (I/R)-induced retinal damage were examined by histological, retinal vascular permeability, and electrophysiological analyses. Using immunoblotting, the protective mechanism for cilostazol was evaluated by examining antiinflammatory effects of cilostazol on the expression of tumor necrosis factors-α (TNF-α) and tight junction proteins (ZO-1 and claudin-5), and the phosphorylations of nuclear factor-kappa B (NF-κB) and c-Jun. The histological analysis revealed that I/R decreased the cell number in the ganglion cell layer (GCL) and the thicknesses of the inner plexiform layer (IPL) and inner nuclear layer (INL), and that cilostazol attenuated these decreases. Additionally, cilostazol prevented the hyperpermeability of blood vessels. Electroretinogram (ERG) measurements revealed that cilostazol prevented the I/R-induced reductions in a-, b-, and oscillatory potential (OP) wave amplitudes seen at 5 days after I/R. Cilostazol inhibited the increased expression of TNF-α and the phosphorylation levels of NF-κB and c-Jun in the retina after I/R. In addition, cilostazol prevented TNF-α-induced reduction of ZO-1 and claudin-5 expression in human retinal microvascular endothelial cells (HRMECs). These findings indicate that cilostazol may prevent I/R-induced retinal damage partly through inhibition of TNF-α-induced NF-κB/AP-1 signaling pathway.
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Affiliation(s)
- Fumiya Ishizuka
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Yusuke Egashira
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan ; Department of Neurosurgery, Gifu University Graduate School of Medicine Gifu, Japan
| | - Hiromi Ogishima
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Shinsuke Nakamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Kazuhiro Tsuruma
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
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Wright CB, Chrenek MA, Foster SL, Duncan T, Redmond TM, Pardue MT, Boatright JH, Nickerson JM. Complementation test of Rpe65 knockout and tvrm148. Invest Ophthalmol Vis Sci 2013; 54:5111-22. [PMID: 23778877 DOI: 10.1167/iovs.13-12336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE A mouse mutation, tvrm148, was previously reported as resulting in retinal degeneration. Tvrm148 and Rpe65 map between markers D3Mit147 and D3Mit19 on a genetic map, but the physical map places RPE65 outside the markers. We asked if Rpe65 or perhaps another nearby gene is mutated and if the mutant reduced 11-cis-retinal levels. We studied the impact of the tvrm148 mutation on visual function, morphology, and retinoid levels. METHODS Normal phase HPLC was used to measure retinoid levels. Rpe65(+/+), tvrm148/+ (T(+/-)), tvrm148/tvrm148 (T(-/-)), RPE65(KO/KO) (Rpe65(-/-)), and Rpe65(T/-) mice visual function was measured by optokinetic tracking (OKT) and electroretinography (ERG). Morphology was assessed by light microscopy and transmission electron microscopy (TEM). qRT-PCR was used to measure Rpe65 mRNA levels. Immunoblotting measured the size and amount of RPE65 protein. RESULTS The knockout and tvrm148 alleles did not complement. No 11-cis-retinal was detected in T(-/-) or Rpe65(-/-) mice. Visual acuity in Rpe65(+/+) and T(+/-) mouse was -0.382 c/d, but 0.037 c/d in T(-/-) mice at postnatal day 210 (P210). ERG response in T(-/-) mice was undetectable except at bright flash intensities. Outer nuclear layer (ONL) thickness in T(-/-) mice was -70% of Rpe65(+/+) by P210. Rpe65 mRNA levels in T(-/-) mice were unchanged, yet 14.5% of Rpe65(+/+) protein levels was detected. Protein size was unchanged. CONCLUSIONS A complementation test revealed the RPE65 knockout and tvrm148 alleles do not complement, proving that the tvrm148 mutation is in Rpe65. Behavioral, physiological, molecular, biochemical, and histological approaches indicate that tvrm148 is a null allele of Rpe65.
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Affiliation(s)
- Charles B Wright
- Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
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Harada T, Machida S, Nishimura T, Kurosaka D. Contribution of N-methyl-DL-aspartic acid (NMDA)-sensitive neurons to generating oscillatory potentials in Royal College of Surgeons rats. Doc Ophthalmol 2013; 127:131-40. [PMID: 23744447 DOI: 10.1007/s10633-013-9394-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 05/28/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE We investigated how the N-methyl-DL-aspartic acid (NMDA) receptor contributes to generating oscillatory potentials (OPs) of the electroretinogram (ERG) in the Royal College of Surgeons (RCS) rat. METHODS Scotopic ERGs were recorded from dystrophic and wild-type congenic (WT) RCS rats (n = 20 of each) at 25, 30, 35, and 40 days of age. The stimulus intensity was increased from -2.82 to 0.71 log cd-s/m(2) to obtain intensity-response function. NMDA was injected into the vitreous cavity of the right eyes. The left eyes were injected with saline as controls. The P3 obtained by a-wave fitting was digitally subtracted from the scotopic ERG to isolate the P2. For the OPs, the P2 was digitally filtered between 65 and 500 Hz. The amplitudes of OP1, OP2, OP3, and OP4 were then measured and summed and designated as ΣOPs. The implicit times of OP1, OP2, and OP3 were also measured. The frequency spectra of the OPs were analyzed using fast Fourier transform (FFT). RESULTS The maximum ERG a- and b-waves as well as ΣOPs amplitudes reduced with age in dystrophic rats. Compared with intravitreal saline injection, administration of NMDA decreased ΣOPs amplitudes from 30 days of age in dystrophic rats, while it did not attenuate ΣOPs amplitudes in WT rats. The implicit times of the OPs of the maximum ERG were prolonged by NMDA injections in WT and dystrophic rats. NMDA/saline ratios of ΣOPs amplitudes area under the FFT curves were significantly lower in dystrophic rats from 30 days of age than that in WT rats. CONCLUSION In the early stage of photoreceptor degeneration, intravitreal NMDA injection attenuated OPs amplitudes in dystrophic rats. This indicates that NMDA receptors play a significant role in generating OPs amplitudes with advancing photoreceptor degeneration.
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Affiliation(s)
- Tomomi Harada
- Departments of Ophthalmology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan
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Alterations of the tunica vasculosa lentis in the rat model of retinopathy of prematurity. Doc Ophthalmol 2013; 127:3-11. [PMID: 23748796 DOI: 10.1007/s10633-013-9392-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To study the relationship between retinal and tunica vasculosa lentis (TVL) disease in retinopathy of prematurity (ROP). Although the clinical hallmark of ROP is abnormal retinal blood vessels, the vessels of the anterior segment, including the TVL, are also altered. METHODS ROP was induced in Long-Evans pigmented and Sprague Dawley albino rats; room-air-reared (RAR) rats served as controls. Then, fluorescein angiographic images of the TVL and retinal vessels were serially obtained with a scanning laser ophthalmoscope near the height of retinal vascular disease, ~20 days of age, and again at 30 and 64 days of age. Additionally, electroretinograms (ERGs) were obtained prior to the first imaging session. The TVL images were analyzed for percent coverage of the posterior lens. The tortuosity of the retinal arterioles was determined using Retinal Image multiScale Analysis (Gelman et al. in Invest Ophthalmol Vis Sci 46:4734-4738, 2005). RESULTS In the youngest ROP rats, the TVL was dense, while in RAR rats, it was relatively sparse. By 30 days, the TVL in RAR rats had almost fully regressed, while in ROP rats, it was still pronounced. By the final test age, the TVL had completely regressed in both ROP and RAR rats. In parallel, the tortuous retinal arterioles in ROP rats resolved with increasing age. ERG components indicating postreceptoral dysfunction, the b-wave, and oscillatory potentials were attenuated in ROP rats. CONCLUSIONS These findings underscore the retinal vascular abnormalities and, for the first time, show abnormal anterior segment vasculature in the rat model of ROP. There is delayed regression of the TVL in the rat model of ROP. This demonstrates that ROP is a disease of the whole eye.
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Mactier H, Bradnam MS, Hamilton R. Dark-adapted oscillatory potentials in preterm infants with and without retinopathy of prematurity. Doc Ophthalmol 2013; 127:33-40. [PMID: 23334439 DOI: 10.1007/s10633-013-9373-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/04/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE To describe the appearance and maturation of dark-adapted oscillatory potentials (OPs) in electroretinograms (ERGs) recorded from preterm infants, and to determine any effect of retinopathy of prematurity (ROP). METHODS Dark-adapted ERGs were recorded in conjunction with screening for ROP and at outpatient follow-up, using a flash luminance of 11.3 scot cd s m(-2) (4.06 phot cd s m(-2)). Eligible infants were born before 31 weeks' gestation and/or weighed ≤1,250 grams at birth. RESULTS Presence or absence of OPs was established for 68 ERG recordings from 38 infants at maturities ranging from 30 weeks' postmenstrual age (PMA) to 28 weeks' post-term corrected age. 20 infants did not develop ROP, eight developed stage 1, one stage 2 and one stage 3 disease which regressed spontaneously. Eight infants received treatment for threshold ROP. OPs were present in 50 % of infants at 36 weeks' PMA and in all by 50 weeks' PMA. The earliest appearance of OPs was at 30+5 weeks' PMA. Individual OP amplitudes increased and peak time of individual OPs decreased with increasing maturity. For infants with threshold ROP summed OP amplitudes tended to be smaller prior to treatment (6.5 vs 9.9μV, P = 0.09) and were significantly smaller by 50 weeks' PMA (14 vs 30μV, P = 0.007). OP1 was less likely to be present in infants who developed stage 3 or worse ROP (P = 0.000). CONCLUSIONS Dark-adapted OPs are recordable in some preterm infants from 30 weeks' PMA. Relative suppression of early OPs is a potential marker for developing ROP.
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Affiliation(s)
- Helen Mactier
- Neonatal Unit, Princess Royal Maternity, 8-16, Alexandra Parade, Glasgow, G31 2ER, Scotland, UK.
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Sapieha P, Chen J, Stahl A, Seaward MR, Favazza TL, Juan AM, Hatton CJ, Joyal JS, Krah NM, Dennison RJ, Tang J, Kern TS, Akula JD, Smith LEH. Omega-3 polyunsaturated fatty acids preserve retinal function in type 2 diabetic mice. Nutr Diabetes 2012; 2:e36. [PMID: 23448719 PMCID: PMC3408641 DOI: 10.1038/nutd.2012.10] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Objective: Diabetic retinopathy (DR) is associated with hyperglycemia-driven microvascular pathology and neuronal compromise in the retina. However, DR is also linked to dyslipidemia. As omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are protective in proliferative retinopathy, we investigated the capacity of ω-3PUFAs to preserve retinal function in a mouse model of type 2 diabetes mellitus (T2DM). Design: Male leptin-receptor-deficient (db/db) mice were maintained for 22 weeks (4 weeks–26 weeks of life) on calorically and compositionally matched diets, except for 2% enrichment in either ω-3 or ω-6PUFAs. Visual function was assessed at 9, 14 and 26 weeks by electroretinography. Retinal capillary and neuronal integrity, as well as glucose challenge responses, were assessed on each diet. Results: The ω-3PUFA diet significantly preserved retinal function in the mouse model of T2DM to levels similar to those observed in nondiabetic control mice on normal chow. Conversely, retinal function gradually deteriorated in db/db mice on a ω-6PUFA-rich diet. There was also an enhanced ability of ω-3PUFA-fed mice to respond to glucose challenge. The protection of visual function appeared to be independent of cytoprotective or anti-inflammatory effects of ω-3PUFAs. Conclusion: This study identifies beneficial effects of dietary ω-3PUFAs on visual function in T2DM. The data are consistent with dyslipidemia negatively impacting retinal function. As ω-3PUFA lipid dietary interventions are readily available, safe and inexpensive, increasing ω-3PUFA intake in diabetic patients may slow the progression of vision loss in T2DM.
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Affiliation(s)
- P Sapieha
- 1] Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, Boston, MA, USA [2] Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, Quebec, Canada
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Signal processing techniques for oscillatory potential extraction in the electroretinogram: automated highpass cutoff frequency estimation. Doc Ophthalmol 2012; 125:101-11. [PMID: 22777656 DOI: 10.1007/s10633-012-9341-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 06/19/2012] [Indexed: 11/25/2022]
Abstract
Oscillatory potentials (OPs) are typically isolated from the electroretinogram (ERG) via linear, time-invariant, bandpass filtering. The use of a highpass cutoff frequency that is too low results in a- and b-wave contamination of the OP signal, while a cutoff frequency that is too high removes significant OP signal energy. Two methods for automated highpass cutoff frequency estimation were developed and evaluated. An OP amplitude analysis method exploited a trend in variation of maximum OP amplitude with cutoff frequency. A second method fit a time-varying exponential model to the rising edge of the b-wave and selected a cutoff frequency based on minimizing the error between the residual ERG signal (the signal formed by subtracting the OP signal from the original ERG signal) and the exponential fit. The performance of each method was evaluated at 11 luminances (0.001-100 scot cd · s/m(2)) in ten wild-type adult mice by comparing the automated selections to expert-selected highpass cutoff frequencies. It was noted that cutoff frequency selection was not critical at the lower luminance levels, but strongly influenced the OP signal shape for higher luminances. At the highest luminance, errors between the OP amplitude and exponential model versus expert selection were -6.3 ± 13 and -8.2 ± 7.3 Hz, respectively. ANOVAs showed that estimations made by the OP amplitude analysis method were generally statistically indistinguishable from the expert identifications. Furthermore, both OP amplitude analysis and exponential fitting error analysis provided excellent fits to the manual selections for the four highest stimulus luminance values.
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Cell-type specific roles for PTEN in establishing a functional retinal architecture. PLoS One 2012; 7:e32795. [PMID: 22403711 PMCID: PMC3293905 DOI: 10.1371/journal.pone.0032795] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 01/31/2012] [Indexed: 11/23/2022] Open
Abstract
Background The retina has a unique three-dimensional architecture, the precise organization of which allows for complete sampling of the visual field. Along the radial or apicobasal axis, retinal neurons and their dendritic and axonal arbors are segregated into layers, while perpendicular to this axis, in the tangential plane, four of the six neuronal types form patterned cellular arrays, or mosaics. Currently, the molecular cues that control retinal cell positioning are not well-understood, especially those that operate in the tangential plane. Here we investigated the role of the PTEN phosphatase in establishing a functional retinal architecture. Methodology/Principal Findings In the developing retina, PTEN was localized preferentially to ganglion, amacrine and horizontal cells, whose somata are distributed in mosaic patterns in the tangential plane. Generation of a retina-specific Pten knock-out resulted in retinal ganglion, amacrine and horizontal cell hypertrophy, and expansion of the inner plexiform layer. The spacing of Pten mutant mosaic populations was also aberrant, as were the arborization and fasciculation patterns of their processes, displaying cell type-specific defects in the radial and tangential dimensions. Irregular oscillatory potentials were also observed in Pten mutant electroretinograms, indicative of asynchronous amacrine cell firing. Furthermore, while Pten mutant RGC axons targeted appropriate brain regions, optokinetic spatial acuity was reduced in Pten mutant animals. Finally, while some features of the Pten mutant retina appeared similar to those reported in Dscam-mutant mice, PTEN expression and activity were normal in the absence of Dscam. Conclusions/Significance We conclude that Pten regulates somal positioning and neurite arborization patterns of a subset of retinal cells that form mosaics, likely functioning independently of Dscam, at least during the embryonic period. Our findings thus reveal an unexpected level of cellular specificity for the multi-purpose phosphatase, and identify Pten as an integral component of a novel cell positioning pathway in the retina.
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Mowat FM, Gonzalez F, Luhmann UFO, Lange CA, Duran Y, Smith AJ, Maxwell PH, Ali RR, Bainbridge JWB. Endogenous erythropoietin protects neuroretinal function in ischemic retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:1726-39. [PMID: 22342523 DOI: 10.1016/j.ajpath.2011.12.033] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 11/14/2011] [Accepted: 12/08/2011] [Indexed: 01/12/2023]
Abstract
Because retinal ischemia is a common cause of vision loss, we sought to determine the effects of ischemia on neuroretinal function and survival in murine oxygen-induced retinopathy (OIR) and to define the role of endogenous erythropoietin (EPO) in this model. OIR is a reproducible model of ischemia-induced retinal neovascularization; it is used commonly to develop antiangiogenic strategies. We investigated the effects of ischemia in murine OIR on retinal function and neurodegeneration by electroretinography and detailed morphology. OIR was associated with significant neuroretinal dysfunction, with reduced photopic and scotopic ERG responses and reduced b-wave/a-wave ratios consistent with specific inner-retinal dysfunction. OIR resulted in significantly increased apoptosis and atrophy of the inner retina in areas of ischemia. EPO deficiency in heterozygous Epo-Tag transgenic mice was associated with more profound retinal dysfunction after OIR, indicated by a significantly greater suppression of ERG amplitudes, but had no measurable effect on the extent of retinal ischemia, preretinal neovascularization, or neuroretinal degeneration in OIR. Systemic administration of recombinant EPO protected EPO-deficient mice against this additional suppression, but EPO supplementation in wild-type animals with OIR did not rescue neuroretinal dysfunction or degeneration. Murine OIR offers a valuable model of ischemic neuroretinal dysfunction and degeneration in which to investigate adaptive tissue responses and evaluate novel therapeutic approaches. Endogenous EPO can protect neuroretinal function in ischemic retinopathy.
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Affiliation(s)
- Freya M Mowat
- Department of Genetics, University College London Institute of Ophthalmology, London, United Kingdom
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Nakamura S, Imai S, Ogishima H, Tsuruma K, Shimazawa M, Hara H. Morphological and functional changes in the retina after chronic oxygen-induced retinopathy. PLoS One 2012; 7:e32167. [PMID: 22348151 PMCID: PMC3279421 DOI: 10.1371/journal.pone.0032167] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/20/2012] [Indexed: 11/23/2022] Open
Abstract
The mouse model of oxygen-induced retinopathy (OIR) has been widely used for studies of retinopathy of prematurity (ROP). This disorder, characterized by abnormal vascularization of the retina, tends to occur in low birth weight neonates after exposure to high supplemental oxygen. Currently, the incidence of ROP is increasing because of increased survival of these infants due to medical progress. However, little is known about changes in the chronic phase after ROP. Therefore, in this study, we examined morphological and functional changes in the retina using a chronic OIR model. Both the a- and b-waves in the OIR model recovered in a time-dependent manner at 4 weeks (w), 6 w, and 8 w, but the oscillatory potential (OP) amplitudes remained depressed following a return to normoxic conditions. Furthermore, decrease in the thicknesses of the inner plexiform layer (IPL) and inner nuclear layer (INL) at postnatal day (P) 17, 4 w, and 8 w and hyperpermeability of blood vessels were observed in conjunction with the decrease in the expression of claudin-5 and occludin at 8 w. The chronic OIR model revealed the following: (1) a decrease in OP amplitudes, (2) morphological abnormalities in the retinal cells (limited to the IPL and INL) and blood vessels, and (3) an increase in retinal vascular permeability via the impairment of the tight junction proteins. These findings suggest that the experimental animal model used in this study is suitable for elucidating the pathogenesis of ROP and may lead to the development of potential therapeutic agents for ROP treatment.
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Affiliation(s)
- Shinsuke Nakamura
- Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
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Abstract
Although retinopathy of prematurity (ROP) is clinically characterized by abnormal retinal vessels at the posterior pole of the eye, it is also commonly characterized by vascular abnormalities in the anterior segment, visual dysfunction which is based in retinal dysfunction, and, most commonly of all, arrested eye growth and high refractive error, particularly (and paradoxically) myopia. The oxygen-induced retinopathy rat model of ROP presents neurovascular outcomes similar to the human disease, although it is not yet known if the "ROP rat" also models the small-eyed myopia characteristic of ROP. In this study, magnetic resonance images (MRIs) of albino (Sprague-Dawley) and pigmented (Long-Evans) ROP rat eyes, and age- and strain-matched room-air-reared (RAR) controls, were examined. The positions and curvatures of the various optical media were measured and the refractive state (℞) of each eye estimated based on a previously published model. Even in adulthood (postnatal day 50), Sprague-Dawley and Long-Evans ROP rats were significantly myopic compared to strain-matched controls. The myopia in the Long-Evans ROP rats was more severe than in the Sprague-Dawley ROP rats, which also had significantly shorter axial lengths. These data reveal the ROP rat to be a novel and potentially informative approach to investigating physiological mechanisms in myopia in general and the myopia peculiar to ROP in particular.
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Protective role of somatostatin receptor 2 against retinal degeneration in response to hypoxia. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:481-94. [DOI: 10.1007/s00210-012-0735-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/25/2012] [Indexed: 12/20/2022]
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Blom JJ, Giove TJ, Favazza TL, Akula JD, Eldred WD. Inhibition of the adrenomedullin/nitric oxide signaling pathway in early diabetic retinopathy. J Ocul Biol Dis Infor 2012; 4:70-82. [PMID: 23316263 DOI: 10.1007/s12177-011-9072-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 12/05/2011] [Indexed: 12/18/2022] Open
Abstract
The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.
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Affiliation(s)
- Jan J Blom
- Department of Biology, Boston University, Boston, MA USA
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Mocko JA, Kim M, Faulkner AE, Cao Y, Ciavatta VT, Pardue MT. Effects of subretinal electrical stimulation in mer-KO mice. Invest Ophthalmol Vis Sci 2011; 52:4223-30. [PMID: 21467171 DOI: 10.1167/iovs.10-6750] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Subretinal electrical stimulation (SES) from microphotodiode arrays protects photoreceptors in the RCS rat model of retinitis pigmentosa. The authors examined whether mer(kd) mice, which share a Mertk mutation with RCS rats, showed similar neuroprotective effects from SES. METHODS Mer(kd) mice were implanted with a microphotodiode array at postnatal day (P) 14. Weekly electroretinograms (ERGs) followed by retinal histology at week 4 were compared with those of age-matched controls. RT-PCR for fibroblast growth factor beta (Fgf2), ciliary nerve trophic factor (Cntf), glial-derived neurotrophic factor (Gdnf), insulin growth factor 1 (Igf1), and glial fibrillary acidic protein (Gfap) was performed on retinas at 1 week after surgery. Rates of degeneration using ERG parameters were compared between mer(kd) mice and RCS rats from P28 to P42. RESULTS SES-treated mer(kd) mice showed no differences in ERG a- and b-wave amplitudes or photoreceptor numbers compared with controls. However, the expression of Fgf2 and Cntf was greater (6.5 ± 1.9- and 2.5 ± 0.5-fold, respectively; P < 0.02) in SES-treated mer(kd) retinas. Rates of degeneration were faster for dark-adapted maximal b-wave, log σ, and oscillatory potentials in mer(kd) mice than in RCS rats. CONCLUSIONS Although SES upregulated Fgf2 in mer(kd) retinas, as reported previously for RCS retinas, this was not accompanied by neuroprotection of photoreceptors. Comparisons of ERG responses from mer(kd) mice and RCS rats across different ages showed inner retinal dysfunction in mer(kd) mice but not in RCS rats. This inner retinal dysfunction and the faster rate of degeneration in mer(kd) mice may produce a retinal environment that is not responsive to neuroprotection from SES.
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Affiliation(s)
- Julie A Mocko
- Rehabilitation Research and Development Service, Atlanta Department of Veterans Affairs, Decatur, Georgia 30033, USA
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Hussong SA, Roehrich H, Kapphahn RJ, Maldonado M, Pardue MT, Ferrington DA. A novel role for the immunoproteasome in retinal function. Invest Ophthalmol Vis Sci 2011; 52:714-23. [PMID: 20881299 DOI: 10.1167/iovs.10-6032] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE The immunoproteasome is a proteasome subtype with a well-characterized role in the immune system. The presence of high immunoproteasome concentrations in the photoreceptors and synaptic regions of the immune-privileged retina implies a role in visual transmission. In this study, immunoproteasome knockout (KO) mice lacking either one (lmp7(-/-), L7) or two (lmp7(-/-)/mecl-1(-/-), L7M1) catalytic subunits of the immunoproteasome were used to test the hypothesis that it is essential for the maintenance of normal retinal function. METHODS Wild-type (WT) and immunoproteasome KO mice lacking either one (L7) or two (L7M1) catalytic subunits of the immunoproteasome were studied to determine the importance of the immunoproteasome in maintaining normal retinal function and morphology. Changes in retinal morphology were assessed in mice 2 to 24 months of age. Retinal function was measured with electroretinography (ERG), and relative content of select retinal proteins was assessed by immunoblot analysis. RESULTS Retinal morphometry showed no major abnormalities in age-matched WT or KO mice. No significant difference was observed in the levels of proteins involved in vision transmission. ERGs from KO mice exhibited an approximate 25% decrease in amplitude of the dark- and light-adapted b-waves and faster dark-adapted b-wave implicit times. CONCLUSIONS Immunoproteasome deficiency causes defects in bipolar cell response. These results support a previously unrecognized role for the immunoproteasome in vision transmission.
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Affiliation(s)
- Stacy A Hussong
- Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota, USA
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Stahl A, Chen J, Sapieha P, Seaward MR, Krah NM, Dennison RJ, Favazza T, Bucher F, Löfqvist C, Ong H, Hellström A, Chemtob S, Akula JD, Smith LEH. Postnatal weight gain modifies severity and functional outcome of oxygen-induced proliferative retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2715-23. [PMID: 21056995 DOI: 10.2353/ajpath.2010.100526] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In clinical studies, postnatal weight gain is strongly associated with retinopathy of prematurity (ROP). However, animal studies are needed to investigate the pathophysiological mechanisms of how postnatal weight gain affects the severity of ROP. In the present study, we identify nutritional supply as one potent parameter that affects the extent of retinopathy in mice with identical birth weights and the same genetic background. Wild-type pups with poor postnatal nutrition and poor weight gain (PWG) exhibit a remarkably prolonged phase of retinopathy compared to medium weight gain or extensive weight gain pups. A high (r(2) = 0.83) parabolic association between postnatal weight gain and oxygen-induced retinopathy severity is observed, as is a significantly prolonged phase of proliferative retinopathy in PWG pups (20 days) compared with extensive weight gain pups (6 days). The extended retinopathy is concomitant with prolonged overexpression of retinal vascular endothelial growth factor in PWG pups. Importantly, PWG pups show low serum levels of nonfasting glucose, insulin, and insulin-like growth factor-1 as well as high levels of ghrelin in the early postoxygen-induced retinopathy phase, a combination indicative of poor metabolic supply. These differences translate into visual deficits in adult PWG mice, as demonstrated by impaired bipolar and proximal neuronal function. Together, these results provide evidence for a pathophysiological correlation between poor postnatal nutritional supply, slow weight gain, prolonged retinal vascular endothelial growth factor overexpression, protracted retinopathy, and reduced final visual outcome.
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Affiliation(s)
- Andreas Stahl
- Department of Ophthalmology, Harvard Medical School, Children’s Hospital Boston, Boston, Massachusetts 02115, USA
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Long-term effects of retinopathy of prematurity (ROP) on rod and rod-driven function. Doc Ophthalmol 2010; 122:19-27. [PMID: 21046193 DOI: 10.1007/s10633-010-9251-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 10/11/2010] [Indexed: 01/25/2023]
Abstract
The purpose of this study was to determine whether recovery of scotopic sensitivity occurs in human ROP, as it does in the rat models of ROP. Following a cross-sectional design, scotopic electroretinographic (ERG) responses to full-field stimuli were recorded from 85 subjects with a history of preterm birth. In 39 of these subjects, dark adapted visual threshold was also measured. Subjects were tested post-term as infants (median age 2.5 months) or at older ages (median age 10.5 years) and stratified by severity of ROP: severe, mild, or none. Rod photoreceptor sensitivity, S (ROD), was derived from the a-wave, and post-receptor sensitivity, log σ, was calculated from the b-wave stimulus-response function. Dark adapted visual threshold was measured using a forced-choice preferential procedure. For S (ROD), the deficit from normal for age varied significantly with ROP severity but not with age group. For log σ, in mild ROP, the deficit was smaller in older subjects than in infants, while in severe ROP, the deficit was quite large in both age groups. In subjects who never had ROP, S (ROD) and log σ in both age groups were similar to those in term born controls. Deficits in dark adapted threshold and log σ were correlated in mild but not in severe ROP. The data are evidence that sensitivity of the post-receptor retina improves in those with a history of mild ROP. We speculate that beneficial reorganization of the post-receptor neural circuitry occurs in mild but not in severe ROP.
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Benny O, Nakai K, Yoshimura T, Bazinet L, Akula JD, Nakao S, Hafezi-Moghadam A, Panigrahy D, Pakneshan P, D'Amato RJ. Broad spectrum antiangiogenic treatment for ocular neovascular diseases. PLoS One 2010; 5. [PMID: 20824139 PMCID: PMC2931703 DOI: 10.1371/journal.pone.0012515] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 07/19/2010] [Indexed: 11/30/2022] Open
Abstract
Pathological neovascularization is a hallmark of late stage neovascular (wet) age-related macular degeneration (AMD) and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV), while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF) exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD.
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Affiliation(s)
- Ofra Benny
- Vascular Biology Program and Department of Surgery, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America.
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Abstract
The continuing worldwide epidemic of retinopathy of prematurity (ROP), a leading cause of childhood visual impairment, strongly motivates further research into mechanisms of the disease. Although the hallmark of ROP is abnormal retinal vasculature, a growing body of evidence supports a critical role for the neural retina in the ROP disease process. The age of onset of ROP coincides with the rapid developmental increase in rod photoreceptor outer segment length and rhodopsin content of the retina with escalation of energy demands. Using a combination of non-invasive electroretinographic (ERG), psychophysical, and image analysis procedures, the neural retina and its vasculature have been studied in prematurely born human subjects, both with and without ROP, and in rats that model the key vascular and neural parameters found in human ROP subjects. These data are compared to comprehensive numeric summaries of the neural and vascular features in normally developing human and rat retina. In rats, biochemical, anatomical, and molecular biological investigations are paired with the non-invasive assessments. ROP, even if mild, primarily and persistently alters the structure and function of photoreceptors. Post-receptor neurons and retinal vasculature, which are intimately related, are also affected by ROP; conspicuous neurovascular abnormalities disappear, but subtle structural anomalies and functional deficits may persist years after clinical ROP resolves. The data from human subjects and rat models identify photoreceptor and post-receptor targets for interventions that promise improved outcomes for children at risk for ROP.
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Affiliation(s)
- Anne B Fulton
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
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Akula JD, Favazza TL, Mocko JA, Benador IY, Asturias AL, Kleinman MS, Hansen RM, Fulton AB. The anatomy of the rat eye with oxygen-induced retinopathy. Doc Ophthalmol 2009; 120:41-50. [PMID: 19820974 DOI: 10.1007/s10633-009-9198-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 09/21/2009] [Indexed: 11/25/2022]
Abstract
Prior studies have documented the intertwined developmental courses of retinal blood vessel tortuosity (in fundus photographs) and retinal dysfunction (in electroretinographs) in Sprague-Dawley rat models of retinopathy of prematurity (ROP). Two such models, the "50/10 model" and the "75 model," are named after the oxygen regimens used to induce retinopathy and are characterized by distinct neurovascular courses that span a range of disease severity. In this study of 50/10 and 75 model rats, retinal flatmounts were used to study the full vasculature at postnatal day (P) 15, P19 and P30. In addition, the layers of the neural retina were measured in toluidine blue-stained cross sections. Finally, gross anatomic features of the eye, including axial length, retinal surface area, and the ratio of anterior to posterior axial-lengths were evaluated. Both clock hours of neovascularization (NV) and percent avascular retina (AR) peaked at P19 and resolved by P30. Through P19, NV was found in every 50/10 model rat, but in only 60% of 75 model rats. AR was positively related to NV. All inner layers of the retina (outer plexiform layer through ganglion cell layer) were attenuated in 50/10 model rats but, in the 75 model, no layer differed significantly from that in controls. The eyes in both ROP models were smaller than those of age-matched controls. The ratio of anterior to posterior axial-lengths ranged from 0.45 in controls through 0.37 in the 75 model to 0.32 in the 50/10 model. Thus, eye growth is altered in these rat models of ROP.
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Affiliation(s)
- James D Akula
- Department of Ophthalmology, Children's Hospital Boston, Boston, MA 02115, USA.
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Abstract
PURPOSE To provide an overview of some of our electroretinographic (ERG) and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP). METHODS ERG responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity (SROD) was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2 degrees spots in parafoveal (10 degrees eccentric) and peripheral (30 degrees eccentric) retina were measured and the difference between the thresholds, Delta10-30, was examined as a function of age. SROD and Delta10-30 in term born and former preterm subjects were compared. RESULTS In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod-mediated function in central retina is immature compared with that in peripheral retina. In subjects born prematurely, deficits in SROD persist long after active ROP has resolved. Maturation of rod-mediated thresholds in the central retina is prolonged by mild ROP. CONCLUSIONS Characterization of the development of normal rod and rod-mediated function provides a foundation for understanding ROP.
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Fletcher EL, Downie LE, Hatzopoulos K, Vessey KA, Ward MM, Chow CL, Pianta MJ, Vingrys AJ, Kalloniatis M, Wilkinson-Berka JL. The significance of neuronal and glial cell changes in the rat retina during oxygen-induced retinopathy. Doc Ophthalmol 2009; 120:67-86. [PMID: 19763649 DOI: 10.1007/s10633-009-9193-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Accepted: 08/17/2009] [Indexed: 12/31/2022]
Abstract
Retinopathy of prematurity is a devastating vascular disease of premature infants. A number of studies indicate that retinal function is affected in this disease. Using the rat model of oxygen-induced retinopathy, it is possible to explore more fully the complex relationship between neuronal, glial and vascular pathology in this condition. This review examines the structural and functional changes that occur in the rat retina following oxygen-induced retinopathy. We highlight that vascular pathology in rats is characterized by aberrant growth of blood vessels into the vitreous at the expense of blood vessel growth into the body of the retina. Moreover, amino acid neurochemistry, a tool for examining neuronal changes in a spatially complete manner reveals widespread changes in amacrine and bipolar cells. In addition, neurochemical anomalies within inner retinal neurons are highly correlated with the absence of retinal vessels. The key cell types that link blood flow with neuronal function are macroglia. Macroglia cells, which in the retina include astrocytes and Müller cells, are affected by oxygen-induced retinopathy. Astrocyte loss occurs in the peripheral retina, while Müller cells show signs of reactive gliosis that is highly localized to regions that are devoid of intraretinal blood vessels. Finally, we propose that treatments, such as blockade of the renin-angiotensin system, that not only targets pathological angiogenesis, but that also promotes re-vascularization of the retina are likely to prove important in the treatment of those with retinopathy of prematurity.
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Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Cell Biology, The University of Melbourne, Grattan St., Parkville, VIC 3010, Australia.
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Current world literature. Curr Opin Pediatr 2009; 21:272-80. [PMID: 19307901 DOI: 10.1097/mop.0b013e32832ad5c0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Moskowitz A, Hansen RM, Akula JD, Eklund SE, Fulton AB. Rod and rod-driven function in achromatopsia and blue cone monochromatism. Invest Ophthalmol Vis Sci 2008; 50:950-8. [PMID: 18824728 DOI: 10.1167/iovs.08-2544] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE To evaluate rod photoreceptor and postreceptor retinal function in pediatric patients with achromatopsia (ACHR) and blue cone monochromatism (BCM) using contemporary electroretinographic (ERG) procedures. METHODS Fifteen patients (age range, 1-20 years) with ACHR and six patients (age range, 4-22 years) with BCM were studied. ERG responses to full-field stimuli were obtained in scotopic and photopic conditions. Rod photoreceptor (S(rod), R(rod)) and rod-driven postreceptor (log sigma, V(max)) response parameters were calculated from the a-wave and b-wave. ERG records were digitally filtered to demonstrate the oscillatory potentials (OPs); a sensitivity parameter, log SOPA(1/2), and an amplitude parameter, SOPA(max), were used to characterize the OP response. Response parameters were compared with those of 12 healthy control subjects. RESULTS As expected, photopic responses were nondetectable in patients with ACHR and BCM. In addition, mean scotopic photoreceptor (R(rod)) and postreceptor (V(max) and SOPA(max)) amplitude parameters were significantly reduced compared with those in healthy controls. The flash intensity required to evoke a half-maximum b-wave amplitude (log sigma) was significantly increased. CONCLUSIONS Results of this study provide evidence that deficits in rod and rod-mediated function occur in the primary cone dysfunction syndromes ACHR and BCM.
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Affiliation(s)
- Anne Moskowitz
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
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Fulton AB, Akula JD, Mocko JA, Hansen RM, Benador IY, Beck SC, Fahl E, Seeliger MW, Moskowitz A, Harris ME. Retinal degenerative and hypoxic ischemic disease. Doc Ophthalmol 2008; 118:55-61. [PMID: 18483822 DOI: 10.1007/s10633-008-9127-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 03/26/2008] [Indexed: 01/03/2023]
Abstract
A broad spectrum of retinal diseases affects both the retinal vasculature and the neural retina, including photoreceptor and postreceptor layers. The accepted clinical hallmarks of acute retinopathy of prematurity (ROP) are dilation and tortuosity of the retinal vasculature. Additionally, significant early and persistent effects on photoreceptor and postreceptor neural structures and function are demonstrated in ROP. In this paper, we focus on the results of longitudinal studies of electroretinographic (ERG) and vascular features in rats with induced retinopathies that model the gamut of human ROP, mild to severe. Two potential targets for pharmaceutical interventions emerge from the observations. The first target is immature photoreceptors because the status of the photoreceptors at an early age predicts later vascular outcome; this approach is appealing as it holds promise to prevent ROP. The second target is the interplay of the neural and vascular retinal networks, which develop cooperatively. Beneficial pharmaceutical interventions may be measured in improved visual outcome as well as lessening of the vascular abnormalities.
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Affiliation(s)
- Anne B Fulton
- Department of Ophthalmology, Children's Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA.
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