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Dourado LFN, Oliveira LG, da Silva CN, Toledo CR, Fialho SL, Jorge R, Silva-Cunha A. Intravitreal ketamine promotes neuroprotection in rat eyes after experimental ischemia. Biomed Pharmacother 2021; 133:110948. [PMID: 33249278 DOI: 10.1016/j.biopha.2020.110948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/13/2020] [Accepted: 10/26/2020] [Indexed: 12/21/2022] Open
Abstract
Retinal ischemia, one of the most common cause of visual loss, is associated with blood flow inadequacy and subsequent tissue injury. In this setting, some treatments that can counteract glutamate increase, arouse interest in ischemic pathogenesis. Ketamine, a potent N-methyl-d-aspartate (NMDA) receptor antagonist, provides a neuroprotective pathway via decreasing the excitotoxicity triggered by excess glutamatergic. Thus, the goal of this study was to evaluate the safety of intravitreal use of ketamine and their potential protective effects on retinal cells in retinal ischemia/reperfusion model. Initially, ketamine toxicity was evaluated by cytotoxicity assay and Hen's egg chorioallantoic membrane (HET-CAM) method. Afterward, some ketamine concentrations were tested in rat's eyes to verify the safety of the intravitreal use. To investigate the neuroprotective effect on retinal, a single intravitreal injection of ketamine in concentrations of 0.059 mmol.L-1 and 0.118 mmol.L-1 was performed one day before the retinal injury by ischemia/reperfusion model. After 7 and 15 days, the retina activity was evaluated by electroretinogram (ERG) records and, lastly, by morphological analyzes. Cytotoxicity assay reveals that the maximum ketamine concentration that could reach retinal pigmented epithelium cells is 0.353 mmol.L-1. HET-CAM assay showed that concentrations above 0.237 mmol.L-1 are irritants to the eye. Thus, Ketamine in concentrations of 0.0237 mmol.L-1, 0.118 mmol.L-1, and 0.059 mmol.L-1 were selected for in vivo toxicity test. ERG records reveal a tendency of b-wave amplitude to decrease as the luminous intensity increased, in the group receiving ketamine at 0.237 mmol.L-1. Therefore, ketamine in concentrations at 0.059 mmol.L-1 and 0.118 mmol.L-1 were chosen for the following tests. In the ischemia retinal degeneration model, pretreatment with ketamine was capable to promote a recovery of retinal electrophysiological function minimizing the ischemic effects. In histological analysis, the groups that received intravitreal ketamine showed a number of retinal cells significantly higher than the vehicle group. In TUNEL assay a reduction on TUNEL-positive cells was observed in all the layers for both concentrations which allow to affirm that ketamine contributes to reducing cell death in the retina. Transmission electron microscopy (TEM) reaffirms this finding. Ketamine intravitreal pretreatment showed reduced ultrastructural changes. Our findings demonstrate that ketamine is safe for intravitreal use in doses up to 0.118 mmol.L-1. They seem to be particularly efficient to protect the retina from ischemic injury.
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Affiliation(s)
- Lays Fernanda Nunes Dourado
- Faculty of Pharmacy, Federal University of Minas Gerais, Pampulha, Av. Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
| | - Lucas Gomes Oliveira
- Faculty of Pharmacy, Federal University of Minas Gerais, Pampulha, Av. Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
| | - Carolina Nunes da Silva
- Faculty of Pharmacy, Federal University of Minas Gerais, Pampulha, Av. Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
| | - Cibele Rodrigues Toledo
- Faculty of Pharmacy, Federal University of Minas Gerais, Pampulha, Av. Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
| | - Silvia Ligório Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro, 80, Gameleira, Belo Horizonte, Minas Gerais, 30510-010, Brazil.
| | - Rodrigo Jorge
- Department of Ophthalmology, Otolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
| | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Pampulha, Av. Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
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Mastropasqua R, D’Aloisio R, Agnifili L, Zuppardi E, Di Marzio G, Di Nicola M, Porreca A, Guarini D, Totta M, Brescia L, Di Antonio L. Functional and Structural Reliability of Optic Nerve Head Measurements in Healthy Eyes by Means of Optical Coherence Tomography Angiography. ACTA ACUST UNITED AC 2020; 56:medicina56010044. [PMID: 31968630 PMCID: PMC7023288 DOI: 10.3390/medicina56010044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 12/03/2022]
Abstract
Background and Objectives: the aim of the study was to evaluate the repeatability and reproducibility of optical microangiography (OMAG)-based optical coherence tomography angiography (OCTA) in the optic nerve head (ONH) and radial peripapillary capillary (RPC) perfusion assessment of healthy eyes. Materials and Methods: in this observational study, a total of 40 healthy subjects underwent ONH evaluation, using an OMAG-based OCTA system at baseline (T0), after 30 min (T1), and after 7 days (T2). The main outcome measures were the vessel density (VD) and flux index (FI) of the RPCs, as well as peri-papillary retinal nerve fibre layer (pRNFL) thickness. The analysis was performed by two observers independently. The coefficient of repeatability (CR), within the subject coefficient of variation (CVw) and intrasession correlation coefficient (ICC), to evaluate intrasession repeatability of measurements was calculated for each observer. Results: the high intrasession and intersession repeatability and reproducibility were assessed in the two observers for all three outcome measures. Of note, the CRs for the first and the second observer were 0.011 (95% confidence interval (CI) 0.009–0.014) and 0.016 (95% CI 0.013–0.020) for FI, 0.016 (95% CI 0.013–0.021) and 0.017 (95% CI 0.014–0.021) for VD, and 2.400 (95% CI 1.948–3.092) and 3.732 (95% CI 3.064–4.775) for pRNFL thickness, respectively. The agreement between them was excellent for pRNFL assessment and very good for FI and VD. Conclusion: OCTA has a great potential in the accurate assessment of ONH and peri-papillary microcirculation. It allows for repeated and reproducible measurements without multiple scans-related bias, thus guaranteeing an independent operator analysis with good reproducibility and repeatability.
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Affiliation(s)
- Rodolfo Mastropasqua
- Vitreoretinal Unit, Bristol Eye Hospital, University of Bristol, Bristol BS8 1TH, UK;
- Eye Clinic, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Rossella D’Aloisio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
- Correspondence: ; Tel.: +39-087-135-8410; Fax: +39-087-135-7294
| | - Luca Agnifili
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Eduardo Zuppardi
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Guido Di Marzio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Marta Di Nicola
- Laboratory of Biostatistics, Department of Medical, Oral and Biotechnological Sciences, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy;
| | - Annamaria Porreca
- Department of Economic Studies, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy;
| | - Daniele Guarini
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Michele Totta
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Lorenza Brescia
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Luca Di Antonio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
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Kim K, Kim ES, Kim DG, Yu SY. Progressive retinal neurodegeneration and microvascular change in diabetic retinopathy: longitudinal study using OCT angiography. Acta Diabetol 2019; 56:1275-1282. [PMID: 31401734 DOI: 10.1007/s00592-019-01395-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/29/2019] [Indexed: 01/08/2023]
Abstract
AIMS To investigate the association between progressive macular ganglion cell/inner plexiform layer (mGCIPL) thinning and change of optical coherence tomography angiography (OCTA)-derived microvascular parameters in early-stage diabetic retinopathy (DR). METHODS A retrospective cohort study involved 40 eyes presenting with no DR or mild non-proliferative DR at baseline, and 30 healthy controls were included. All participants underwent spectral-domain OCT and OCTA at baseline and at 6, 12, 18, and 24 months. Change of mGCIPL thickness and OCTA metrics including foveal avascular zone (FAZ) area and FAZ circularity, vessel density (VD), and perfusion index (PI) was measured. Correlations between mGCIPL thickness and OCTA metrics were explored using regression models. RESULTS Average progressive mGCIPL loss was 0.45 µm per year. Three microvascular parameters were significantly impaired at 24 months compared to baseline (FAZ area: 0.34-0.36 mm2, VD: 18.9-18.5/mm, PI: 0.35-0.34). A strong positive correlation was found between loss of mGCIPL and VD from baseline to 24 months (r = 0.817, p < 0.001). Multivariable regression analysis showed that thinner baseline mGCIPL and greater loss of mGCIPL thickness (B = 0.658, p < 0.001) were significantly associated with change of VD. CONCLUSIONS In the early stage of DR, progressive structural retinal neurodegeneration and parafoveal microvascular change seem to be highly linked. Advanced mGCIPL thinning might precede microvascular impairment in early DR.
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Affiliation(s)
- Kiyoung Kim
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University, Seoul, Republic of Korea
| | - Eung Suk Kim
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University, Seoul, Republic of Korea
| | - Do Gyun Kim
- Department of Ophthalmology, Hanyang University College of Medicine Myongji Hospital, Goyang-si, Gyeonggi-do, Republic of Korea
| | - Seung-Young Yu
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University, Seoul, Republic of Korea.
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Abstract
The mouse retina has a layered structure that is composed of five classes of neurons supported by Müller glial and pigment epithelial cells. Recent studies have made progress in the classification of bipolar and ganglion cells, and also in the wiring of rod-driven signaling, color coding, and directional selectivity. Molecular biological techniques, such as genetic manipulation, transcriptomics, and fluorescence imaging, have contributed a lot to these advancements. The mouse retina has consistently been an important experimental system for both basic and clinical neurosciences.
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Affiliation(s)
- Yoshihiko Tsukamoto
- Department of Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
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Cheong SK, Xiong W, Strazzeri JM, Cepko CL, Williams DR, Merigan WH. In Vivo Functional Imaging of Retinal Neurons Using Red and Green Fluorescent Calcium Indicators. Adv Exp Med Biol 2018; 1074:135-144. [PMID: 29721937 PMCID: PMC7856913 DOI: 10.1007/978-3-319-75402-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2023]
Abstract
Adaptive optics retinal imaging of fluorescent calcium indicators is a minimally invasive method used to study retinal physiology over extended periods of time. It has potential for discovering novel retinal circuits, tracking retinal function in animal models of retinal disease, and assessing vision restoration therapy. We previously demonstrated functional adaptive optics imaging of retinal neurons in the living eye using green fluorescent calcium indicators; however, the use of green fluorescent indicators presents challenges that stem from the fact that they are excited by short-wavelength light. Using red fluorescent calcium indicators such as jRGECO1a, which is excited with longer-wavelength light (~560 nm), makes imaging approximately five times safer than using short-wavelength light (~500 nm) used to excite green fluorescent calcium indicators such as GCaMP6s. Red fluorescent indicators also provide alternative wavelength imaging regimes to overcome cross talk with the sensitivities of intrinsic photoreceptors and blue light-activated channelrhodopsins. Here we evaluate jRGECO1a for in vivo functional adaptive optics imaging of retinal neurons using single-photon excitation in mice. We find that jRGECO1a provides similar fidelity as the established green indicator GCaMP6s.
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Affiliation(s)
- Soon K Cheong
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
| | - Wenjun Xiong
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Jennifer M Strazzeri
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
| | - Constance L Cepko
- Departments of Genetics and Ophthalmology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - David R Williams
- Center for Visual Science, University of Rochester, Rochester, NY, USA
- Institute of Optics, University of Rochester, Rochester, NY, USA
| | - William H Merigan
- Center for Visual Science, University of Rochester, Rochester, NY, USA.
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Carnevali A, Sacconi R, Corbelli E, Tomasso L, Querques L, Zerbini G, Scorcia V, Bandello F, Querques G. Optical coherence tomography angiography analysis of retinal vascular plexuses and choriocapillaris in patients with type 1 diabetes without diabetic retinopathy. Acta Diabetol 2017; 54:695-702. [PMID: 28474119 DOI: 10.1007/s00592-017-0996-8] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/19/2017] [Indexed: 10/19/2022]
Abstract
AIMS To analyze retinal vascular plexuses and choriocapillaris by optical coherence tomography angiography (OCT-A) and retinal nerve fiber layer and ganglion cell layer (GCL) by structural optical coherence tomography (OCT) in patients with type 1 diabetes mellitus (T1DM) without diabetic retinopathy (DR). METHODS A total of 25 eyes of 25 consecutive T1DM patients without signs of DR were prospectively recruited and compared to 25 healthy subjects (control eyes). All patients underwent OCT-A (CIRRUS HD-OCT model 5000, Carl Zeiss Meditec, Dublin, CA) and structural OCT. Qualitative and quantitative analyses with vessel density were performed on OCT-A images in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris for all patients. RESULTS By means of OCT-A, a rarefaction of the perifoveal capillary network in SCP was detected in 7 out of 25 eyes. No significant difference was found in FAZ area of both SCP and DCP comparing diabetic and control groups. By analyzing the DCP, diabetic eyes revealed a significant decreased vessel density compared to control eyes [0.464 ± 0.016 and 0.477 ± 0.014, respectively (p = 0.005)]. Instead, no significant difference was found in the vessel density of all-retina plexus, SCP and choriocapillaris. By RFNL and GCL thickness analysis, no significant differences were disclosed between diabetics and healthy subjects. CONCLUSIONS We demonstrated the ability of OCT-A to disclose early vascular alterations in patients with T1DM diagnosed as without any signs of DR on the basis of fundus biomicroscopy. Our results also suggest that microvascular changes could precede detectable damage of diabetic neuroretinopathy.
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Affiliation(s)
- Adriano Carnevali
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
- Department of Ophthalmology, University of "Magna Graecia", Catanzaro, Italy
| | - Riccardo Sacconi
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
- Department of Ophthalmology, University of Verona, University Hospital of Verona, Verona, Italy
| | - Eleonora Corbelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Livia Tomasso
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Lea Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Division of Metabolic and Cardiovascular Sciences, San Raffaele Scientific Institute, Milan, Italy
| | - Vincenzo Scorcia
- Department of Ophthalmology, University of "Magna Graecia", Catanzaro, Italy
| | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Giuseppe Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy.
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Singh RK, Mallela RK, Hayes A, Dunham NR, Hedden ME, Enke RA, Fariss RN, Sternberg H, West MD, Nasonkin IO. Dnmt1, Dnmt3a and Dnmt3b cooperate in photoreceptor and outer plexiform layer development in the mammalian retina. Exp Eye Res 2017; 159:132-146. [PMID: 27865785 DOI: 10.1016/j.exer.2016.11.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 10/21/2016] [Accepted: 11/14/2016] [Indexed: 11/18/2022]
Abstract
Characterizing the role of epigenetic regulation in the mammalian retina is critical for understanding fundamental mechanisms of retinal development and disease. DNA methylation, an epigenetic modifier of genomic DNA, plays an important role in modulating networks of tissue and cell-specific gene expression. However, the impact of DNA methylation on retinal development and homeostasis of retinal neurons remains unclear. Here, we have created a tissue-specific DNA methyltransferase (Dnmt) triple mutant mouse in an effort to characterize the impact of DNA methylation on retinal development and homeostasis. An Rx-Cre transgene was used to drive targeted mutation of all three murine Dnmt genes in the mouse retina encoding major DNA methylation enzymes DNMT1, DNMT3A and DNMT3B. The triple mutant mice represent a hypomorph model since Dnmt1 catalytic activity was still present and excision of Dnmt3a and Dnmt3b had only about 90% efficiency. Mutation of all three Dnmts resulted in global genomic hypomethylation and dramatic reorganization of the photoreceptor and synaptic layers within retina. Transcriptome and proteomic analyses demonstrated enrichment of dysregulated phototransduction and synaptic genes. The 5 mC signal in triple mutant retina was confined to the central heterochromatin but reduced in the peripheral heterochromatin region of photoreceptor nuclei. In addition, we found a reduction of the 5 mC signal in ganglion cell nuclei. Collectively, this data suggests cooperation of all three Dnmts in the formation and homeostasis of photoreceptors and other retinal neurons within the mammalian retina, and highlight the relevance of epigenetic regulation to sensory retinal disorders and vision loss.
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Affiliation(s)
- Ratnesh K Singh
- Department of Ophthalmology, University of Pittsburgh Medical School, USA.
| | - Ramya K Mallela
- Department of Ophthalmology, University of Pittsburgh Medical School, USA
| | - Abigail Hayes
- Department of Ophthalmology, West Virginia University, USA
| | | | | | - Raymond A Enke
- Department of Biology, James Madison University, USA; Center for Genome and Metagenome Studies, James Madison University, USA
| | - Robert N Fariss
- Biological Imaging Core, National Eye Institute, Bethesda, MD 20892, USA
| | - Hal Sternberg
- BioTime, 1010 Atlantic Avenue, Alameda, CA 94501, USA
| | | | - Igor O Nasonkin
- Department of Ophthalmology, University of Pittsburgh Medical School, USA.
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Mavlyutov TA, Epstein M, Guo LW. Subcellular localization of the sigma-1 receptor in retinal neurons - an electron microscopy study. Sci Rep 2015; 5:10689. [PMID: 26033680 PMCID: PMC4649997 DOI: 10.1038/srep10689] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/27/2015] [Indexed: 11/09/2022] Open
Abstract
The Sigma-1 receptor (S1R) is known to play a protective role in the central nervous system including the retina. A major barrier for understanding the underlying mechanism is an ambiguity of S1R subcellular localizations. We thus conducted the first electron microscopy (EM) study of S1R subcellular distribution in the mouse retina. Immuno-EM imaging showed previously under-appreciated S1R presence in photoreceptor cells. Unlike in other cell types in previous reports, in photoreceptor cells S1R was found in the nuclear envelope but not localized in the endoplasmic reticulum (ER), raising a possibility of S1R-mediated modulatory mechanisms different than conventionally thought. While in bipolar cells S1R was detected only in the nuclear envelope, in ganglion cells S1R was identified predominantly in the nuclear envelope and found in the ER as well. A predominant localization of S1R in the nuclear envelope in all three retinal neurons implicates a potential role of S1R in modulating nuclear activities. Moreover, its absence in the plasma membrane and presence in the subsurface ER cisternae that are juxtaposed to the plasma membrane in ganglion cells may lend mechanistic insights generally important for frequently reported S1R modulations of ion channels in neurons.
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Affiliation(s)
- Timur A. Mavlyutov
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, Madison, WI 53705, USA
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, Madison, WI 53705, USA
| | - Miles Epstein
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, 41 Bardeen Medical Laboratory, 470 N Charter Street, Madison, WI 53706, USA
| | - Lian-Wang Guo
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, Madison, WI 53705, USA
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, Madison, WI 53705, USA
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Shang YM, Wang GS, Sliney D, Yang CH, Lee LL. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model. Environ Health Perspect 2014; 122:269-76. [PMID: 24362357 PMCID: PMC3948037 DOI: 10.1289/ehp.1307294] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 12/19/2013] [Indexed: 05/06/2023]
Abstract
BACKGROUND Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000-10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model. OBJECTIVE We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functional, histological, and biochemical measurements. METHODS We used blue LEDs (460 nm) and full-spectrum white LEDs, coupled with matching compact fluorescent lights, for exposures. Pathological examinations included electroretinogram, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and transmission electron microscopy (TEM). We also measured free radical production in the retina to determine the oxidative stress level. RESULTS H&E staining and TEM revealed apoptosis and necrosis of photoreceptors, which indicated blue-light induced photochemical injury of the retina. Free radical production in the retina was increased in LED-exposed groups. IHC staining demonstrated that oxidative stress was associated with retinal injury. Although we found serious retinal light injury in LED groups, the compact fluorescent lamp (CFL) groups showed moderate to mild injury. CONCLUSION Our results raise questions about adverse effects on the retina from chronic exposure to LED light compared with other light sources that have less blue light. Thus, we suggest a precautionary approach with regard to the use of blue-rich "white" LEDs for general lighting. CITATION Shang YM, Wang GS, Sliney D, Yang CH, Lee LL. 2014. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model. Environ Health Perspect 122:269-276; http://dx.doi.org/10.1289/ehp.1307294.
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Affiliation(s)
- Yu-Man Shang
- Institute of Environmental Health, National Taiwan University, Taipei, Taiwan
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Maneesang S, Jatutong O, Iemsomboon W. The assessment of retinal nerve fiber layer thickness changing after glaucoma surgery by optical coherence tomography, Phramongkutklao Hospial. J Med Assoc Thai 2012; 95 Suppl 5:S75-S79. [PMID: 22934449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVE To assess retinal nerve fiber (RNFL) thickness change in glaucoma patients after glaucoma surgery. MATERIAL AND METHOD A prospective and cohort study of 19 patients who underwent trabeculectomy with mitomicin C or combined procedures or glaucoma drainage device surgery in Phramongkutklao Hospital were included. All subjects had obtained informed consents. Preoperative and 3 month-postoperative IOP and RNFL thickness were determined. Areas of peripapilllary RNFL thickness were evaluated by Stratus OCT scanning. The relationship between IOP reduction and RNFL thickness change after glaucoma surgery was analyzed. RESULTS Postoperative RNFL thickness analysis found no significant increase in inferior, superior, nasal and temporal quadrants. The average of preoperative RNFL thickness was 59.58 +/- 17.59 microns, whereas the average of postoperative RNFL thickness was 57.19 +/- 14.97 microns (p = 0.426). Postoperative IOP was decreased significantly from 29.26 +/- 8.58 mmHg to 12.11 +/- 4.52 mmHq (p < 0.001). The mean of postoperative RNFL thickness was not significantly correlated with IOP reduction (r = 0.306, p = 0.250). CONCLUSION Post glaucoma surgery, RNFL thickness was not significantly increased although the IOP had significantly reduced. No correlation between IOP reduction and RNFL thickness was found.
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Takayama K, Ooto S, Hangai M, Arakawa N, Oshima S, Shibata N, Hanebuchi M, Inoue T, Yoshimura N. High-resolution imaging of the retinal nerve fiber layer in normal eyes using adaptive optics scanning laser ophthalmoscopy. PLoS One 2012; 7:e33158. [PMID: 22427978 PMCID: PMC3299751 DOI: 10.1371/journal.pone.0033158] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 02/10/2012] [Indexed: 11/18/2022] Open
Abstract
Purpose To conduct high-resolution imaging of the retinal nerve fiber layer (RNFL) in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO). Methods AO-SLO images were obtained in 20 normal eyes at multiple locations in the posterior polar area and a circular path with a 3–4-mm diameter around the optic disc. For each eye, images focused on the RNFL were recorded and a montage of AO-SLO images was created. Results AO-SLO images for all eyes showed many hyperreflective bundles in the RNFL. Hyperreflective bundles above or below the fovea were seen in an arch from the temporal periphery on either side of a horizontal dividing line to the optic disc. The dark lines among the hyperreflective bundles were narrower around the optic disc compared with those in the temporal raphe. The hyperreflective bundles corresponded with the direction of the striations on SLO red-free images. The resolution and contrast of the bundles were much higher in AO-SLO images than in red-free fundus photography or SLO red-free images. The mean hyperreflective bundle width around the optic disc had a double-humped shape; the bundles at the temporal and nasal sides of the optic disc were narrower than those above and below the optic disc (P<0.001). RNFL thickness obtained by optical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (P<0.001) Conclusions AO-SLO revealed hyperreflective bundles and dark lines in the RNFL, believed to be retinal nerve fiber bundles and Müller cell septa. The widths of the nerve fiber bundles appear to be proportional to the RNFL thickness at equivalent distances from the optic disc.
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Affiliation(s)
- Kohei Takayama
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sotaro Ooto
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
- * E-mail:
| | - Masanori Hangai
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Naoko Arakawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | | | | | | | - Takashi Inoue
- Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Japan
| | - Nagahisa Yoshimura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
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