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Orihara K, Kobayashi-Otsugu M, Nakajima E, Walkup RD, Wilson DJ, Shearer TR, Azuma M. Calpain-specific breakdown fragment in human drusen. Histol Histopathol 2024; 39:165-175. [PMID: 37314158 DOI: 10.14670/hh-18-635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
PURPOSE With aging and age-related macular dystrophy (AMD), proteolytic fragments are deposited in extracellular drusen located between the RPE and Bruch's membrane. Localized hypoxia may be a risk factor for AMD. Our hypothesis is that following hypoxia, activation of proteolytic enzymes called calpains may cause proteolysis/degeneration of retinal cells and RPE. No direct evidence has yet demonstrated activation of calpains in AMD. The purpose of the present study was to identify calpain-cleaved proteins in drusen. METHODS Seventy-six (76) drusen were analyzed in human eye sections from six normal and twelve AMD human donor eyes. The sections were subjected to immunofluorescence for the calpain-specific 150 kDa breakdown product from α-spectrin, SBDP150 - a marker for calpain activation, and for recoverin - a marker for photoreceptor cells. RESULTS Among 29 nodular drusen, 80% from normal eyes and 90% from AMD eyes stained positive for SBDP150. Among 47 soft drusen, mostly from AMD eyes, 72% stained positive for SBDP150. Thus, the majority of both soft and nodular drusen from AMD donors contained SBDP150. CONCLUSIONS SBDP150 was detected for the first time in soft and nodular drusen from human donors. Our results suggest that calpain-induced proteolysis participates in the degeneration of photoreceptors and/or RPE cells during aging and AMD. Calpain inhibitors may ameliorate AMD progression.
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Affiliation(s)
- Kana Orihara
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Ltd., Portland, OR, USA
| | - Momoko Kobayashi-Otsugu
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Ltd., Portland, OR, USA
| | - Emi Nakajima
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Ltd., Portland, OR, USA
- Department of Oral Rehabilitation and Biosciences, Oregon Health and Science University, Portland, OR, USA
| | - Ryan D Walkup
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Ltd., Portland, OR, USA
- Department of Oral Rehabilitation and Biosciences, Oregon Health and Science University, Portland, OR, USA
| | - David J Wilson
- Department of Ophthalmology, School of Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Thomas R Shearer
- Department of Oral Rehabilitation and Biosciences, Oregon Health and Science University, Portland, OR, USA
| | - Mitsuyoshi Azuma
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Ltd., Portland, OR, USA
- Department of Oral Rehabilitation and Biosciences, Oregon Health and Science University, Portland, OR, USA.
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2
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Norrie JL, Lupo M, Shirinifard A, Djekidel N, Ramirez C, Xu B, Dundee JM, Dyer MA. Latent Epigenetic Programs in Müller Glia Contribute to Stress, Injury, and Disease Response in the Retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.15.562396. [PMID: 37905050 PMCID: PMC10614790 DOI: 10.1101/2023.10.15.562396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Previous studies have demonstrated the dynamic changes in chromatin structure during retinal development that correlate with changes in gene expression. However, a major limitation of those prior studies was the lack of cellular resolution. Here, we integrate single-cell (sc) RNA-seq and scATAC-seq with bulk retinal data sets to identify cell type-specific changes in the chromatin structure during development. Although most genes' promoter activity is strongly correlated with chromatin accessibility, we discovered several hundred genes that were transcriptionally silent but had accessible chromatin at their promoters. Most of those silent/accessible gene promoters were in the Müller glial cells. The Müller cells are radial glia of the retina and perform a variety of essential functions to maintain retinal homeostasis and respond to stress, injury, or disease. The silent/accessible genes in Müller glia are enriched in pathways related to inflammation, angiogenesis, and other types of cell-cell signaling and were rapidly activated when we tested 15 different physiologically relevant conditions to mimic retinal stress, injury, or disease in human and murine retinae. We refer to these as "pliancy genes" because they allow the Müller glia to rapidly change their gene expression and cellular state in response to different types of retinal insults. The Müller glial cell pliancy program is established during development, and we demonstrate that pliancy genes are necessary and sufficient for regulating inflammation in the murine retina in vivo. In zebrafish, Müller glia can de-differentiate and form retinal progenitor cells that replace lost neurons. The pro-inflammatory pliancy gene cascade is not activated in zebrafish Müller glia following injury, and we propose a model in which species-specific pliancy programs underly the differential response to retinal damage in species that can regenerate retinal neurons (zebrafish) versus those that cannot (humans and mice).
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Kwong JMK, Caprioli J, Lee JCY, Song Y, Yu FJ, Bian J, Sze YH, Li KK, Do CW, To CH, Lam TC. Differential Responses of Retinal Neurons and Glia Revealed via Proteomic Analysis on Primary and Secondary Retinal Ganglion Cell Degeneration. Int J Mol Sci 2023; 24:12109. [PMID: 37569482 PMCID: PMC10418669 DOI: 10.3390/ijms241512109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/14/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
To explore the temporal profile of retinal proteomes specific to primary and secondary retinal ganglion cell (RGC) loss. Unilateral partial optic nerve transection (pONT) was performed on the temporal side of the rat optic nerve. Temporal and nasal retinal samples were collected at 1, 4 and 8 weeks after pONT (n = 4 each) for non-biased profiling with a high-resolution hybrid quadrupole time-of-flight mass spectrometry running on label-free SWATHTM acquisition (SCIEX). An information-dependent acquisition ion library was generated using ProteinPilot 5.0 and OneOmics cloud bioinformatics. Combined proteome analysis detected 2531 proteins with a false discovery rate of <1%. Compared to the nasal retina, 10, 25 and 61 significantly regulated proteins were found in the temporal retina at 1, 4, and 8 weeks, respectively (p < 0.05, FC ≥ 1.4 or ≤0.7). Eight proteins (ALDH1A1, TRY10, GFAP, HBB-B1, ALB, CDC42, SNCG, NEFL) were differentially expressed for at least two time points. The expressions of ALDH1A1 and SNCG at nerve fibers were decreased along with axonal loss. Increased ALDH1A1 localization in the inner nuclear layer suggested stress response. Increased GFAP expression demonstrated regional reactivity of astrocytes and Muller cells. Meta-analysis of gene ontology showed a pronounced difference in endopeptidase and peptidase inhibitor activity. Temporal proteomic profiling demonstrates established and novel protein targets associated with RGC damage.
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Affiliation(s)
- Jacky M. K. Kwong
- Ophthalmology, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; (J.C.); (J.C.Y.L.); (Y.S.)
| | - Joseph Caprioli
- Ophthalmology, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; (J.C.); (J.C.Y.L.); (Y.S.)
| | - Joanne C. Y. Lee
- Ophthalmology, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; (J.C.); (J.C.Y.L.); (Y.S.)
| | - Yifan Song
- Ophthalmology, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; (J.C.); (J.C.Y.L.); (Y.S.)
| | - Feng-Juan Yu
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
| | - Jingfang Bian
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
| | - Ying-Hon Sze
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
| | - King-Kit Li
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
| | - Chi-Wai Do
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), The Hong Kong Polytechnic University, 17W, Hong Kong Science Park, Hong Kong, China
| | - Chi-Ho To
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), The Hong Kong Polytechnic University, 17W, Hong Kong Science Park, Hong Kong, China
| | - Thomas Chuen Lam
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China; (F.-J.Y.); (J.B.); (Y.-H.S.); (K.-K.L.); (C.-W.D.); (C.-H.T.)
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), The Hong Kong Polytechnic University, 17W, Hong Kong Science Park, Hong Kong, China
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen 518052, China
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Nadal-Nicolás FM, Galindo-Romero C, Lucas-Ruiz F, Marsh-Amstrong N, Li W, Vidal-Sanz M, Agudo-Barriuso M. Pan-retinal ganglion cell markers in mice, rats, and rhesus macaques. Zool Res 2023; 44:226-248. [PMID: 36594396 PMCID: PMC9841181 DOI: 10.24272/j.issn.2095-8137.2022.308] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Univocal identification of retinal ganglion cells (RGCs) is an essential prerequisite for studying their degeneration and neuroprotection. Before the advent of phenotypic markers, RGCs were normally identified using retrograde tracing of retinorecipient areas. This is an invasive technique, and its use is precluded in higher mammals such as monkeys. In the past decade, several RGC markers have been described. Here, we reviewed and analyzed the specificity of nine markers used to identify all or most RGCs, i.e., pan-RGC markers, in rats, mice, and macaques. The best markers in the three species in terms of specificity, proportion of RGCs labeled, and indicators of viability were BRN3A, expressed by vision-forming RGCs, and RBPMS, expressed by vision- and non-vision-forming RGCs. NEUN, often used to identify RGCs, was expressed by non-RGCs in the ganglion cell layer, and therefore was not RGC-specific. γ-SYN, TUJ1, and NF-L labeled the RGC axons, which impaired the detection of their somas in the central retina but would be good for studying RGC morphology. In rats, TUJ1 and NF-L were also expressed by non-RGCs. BM88, ERRβ, and PGP9.5 are rarely used as markers, but they identified most RGCs in the rats and macaques and ERRβ in mice. However, PGP9.5 was also expressed by non-RGCs in rats and macaques and BM88 and ERRβ were not suitable markers of viability.
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Affiliation(s)
- Francisco M Nadal-Nicolás
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Pascual Parrilla (IMIB), Murcia 30120, Spain
- Dpto. Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia 30120, Spain
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-2510, USA
| | - Caridad Galindo-Romero
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Pascual Parrilla (IMIB), Murcia 30120, Spain
- Dpto. Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia 30120, Spain
| | - Fernando Lucas-Ruiz
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Pascual Parrilla (IMIB), Murcia 30120, Spain
- Dpto. Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia 30120, Spain
| | - Nicholas Marsh-Amstrong
- Department of Ophthalmology and Vision Science, University of California, Davis, CA 95817, USA
| | - Wei Li
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-2510, USA
| | - Manuel Vidal-Sanz
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Pascual Parrilla (IMIB), Murcia 30120, Spain
- Dpto. Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia 30120, Spain. E-mail:
| | - Marta Agudo-Barriuso
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria Pascual Parrilla (IMIB), Murcia 30120, Spain
- Dpto. Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia 30120, Spain. E-mail:
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GCL loss in BRAO. PLoS One 2023; 18:e0279920. [PMID: 36603006 DOI: 10.1371/journal.pone.0279920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 12/16/2022] [Indexed: 01/06/2023] Open
Abstract
PURPOSE Our recent publication used optical coherence tomography (OCT) to follow thinning of the retinal ganglion cell layer (GCL) in central retinal artery occlusion (CRAO). Thinning of the inner layers also occurs in patients with branch retinal artery occlusion (BRAO). The mechanism for such thinning may be partially due to proteolysis by a calcium-activated protease called calpain. Calpain inhibitor SNJ-1945 ameliorated the proteolysis in a past series of model experiments. The purposes of the present retrospective study were to: 1) use segmentation analysis of OCT images to follow the loss of retinal layers in BRAO compared to CRAO patients, and 2) predict the number of patients and days of observation needed for a clinical trial of a calpain inhibitor against BRAO. METHODS A retrospective, case control study was conducted by computer-aided search in a medical records database for BRAO (ICD10 Code H34.239) with at least one OCT procedure (CPT: 92134). Non-proliferative, co-morbid eye diseases were allowed in the patient data base, and manual correction of auto-segmentation errors was performed. GCL thickness changes were followed over time and Cohen-d/sample size statistics were used to predict minimal patients needed for drug trials. RESULTS The thickness of the GCL layer in BRAO decreased rapidly with time as in CRAO, but in more limited quadrants. The data, as fit to a single-phase decay curve, showed that GCL thickness could be used to provide sample size statistics in a clinical trial to test a calpain inhibitor. For example, a 60-day trial with a 60% effective inhibitor would need a minimum of 29 patients. CONCLUSIONS Using thickness changes in the GCL layer to monitor the efficacy of potential inhibitors against BRAO and CRAO is practical in human trials requiring a reasonable number of patients and relatively short trial period. TRANSLATIONAL RELEVANCE Measurement of GCL thickness would be a useful indicator of amelioration of BRAO and CRAO progression in a clinical trial of a putative inhibitor.
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Saadane A, Du Y, Thoreson WB, Miyagi M, Lessieur EM, Kiser J, Wen X, Berkowitz BA, Kern TS. Photoreceptor Cell Calcium Dysregulation and Calpain Activation Promote Pathogenic Photoreceptor Oxidative Stress and Inflammation in Prodromal Diabetic Retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1805-1821. [PMID: 34214506 PMCID: PMC8579242 DOI: 10.1016/j.ajpath.2021.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 05/20/2021] [Accepted: 06/15/2021] [Indexed: 12/13/2022]
Abstract
This study tested the hypothesis that diabetes promotes a greater than normal cytosolic calcium level in rod cells that activates a Ca2+-sensitive protease, calpain, resulting in oxidative stress and inflammation, two pathogenic factors of early diabetic retinopathy. Nondiabetic and 2-month diabetic C57Bl/6J and calpain1 knockout (Capn1-/-) mice were studied; subgroups were treated with a calpain inhibitor (CI). Ca2+ content was measured in photoreceptors using Fura-2. Retinal calpain expression was studied by quantitative RT-PCR and immunohistochemistry. Superoxide and expression of inflammatory proteins were measured using published methods. Proteomic analysis was conducted on photoreceptors isolated from untreated diabetic mice or treated daily with CI for 2 months. Cytosolic Ca2+ content was increased twofold in photoreceptors of diabetic mice as compared with nondiabetic mice. Capn1 expression increased fivefold in photoreceptor outer segments of diabetic mice. Pharmacologic inhibition or genetic deletion of Capn1 significantly suppressed diabetes-induced oxidative stress and expression of proinflammatory proteins in retina. Proteomics identified a protein (WW domain-containing oxidoreductase [WWOX]) whose expression was significantly increased in photoreceptors from mice diabetic for 2 months and was inhibited with CI. Knockdown of Wwox using specific siRNA in vitro inhibited increase in superoxide caused by the high glucose. These results suggest that reducing Ca2+ accumulation, suppressing calpain activation, and/or reducing Wwox up-regulation are novel targets for treating early diabetic retinopathy.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology, University of California, Irvine, Irvine, California.
| | - Yunpeng Du
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Emma M Lessieur
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Jianying Kiser
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Xiangyi Wen
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Timothy S Kern
- Department of Ophthalmology, University of California, Irvine, Irvine, California; Veterans Administration Medical Center Research Service, Long Beach, California
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Kobayashi-Otsugu M, Orihara K, Nakajima E, Shearer TR, Azuma M. Activation of Cytosolic Calpain, Not Caspase, Is Underlying Mechanism for Hypoxic RGC Damage in Human Retinal Explants. Invest Ophthalmol Vis Sci 2021; 61:13. [PMID: 33156340 PMCID: PMC7671854 DOI: 10.1167/iovs.61.13.13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose Activation of proteolytic enzymes, calpains and caspases, have been observed in many models of retinal disease. We previously demonstrated calpain activation in monkey retinal explants cultured under hypoxia. However, cellular responses are often species-specific. The purpose of the present study was to determine whether calpains or caspase-3 was involved in retinal ganglion cell (RGC) damage caused by hypoxia/reoxygenation in human retinal explants. The explant model was improved by use of an oxygen-controlled chamber. Methods Human and monkey retinal explants were cultured under hypoxic conditions in an oxygen-controlled chamber and then reoxygenated. Calpain inhibitor SNJ-1945 was maintained throughout the culture period. Immunohistochemistry and immunoblotting were performed for calpains 1 and 2, calpastatin, α-spectrin, calpain-specific α-spectrin breakdown product at 150 kDa (SBDP150), caspase-3, and apoptosis-inducing factor (AIF). Propidium iodide (PI) staining measured membrane disruption, and TUNEL staining detected DNA fragmentation. Results Activation of calpains in nerve fibers and increases of PI-positive RGCs were observed in retinal explants incubated for 16-hour hypoxia/8-hour reoxygenation. Except for autolysis of calpain 2, SNJ-1945 ameliorated these changes. In longer incubations under 24-hour hypoxia/16-hour reoxygenation, TUNEL-positive cells appeared, although activated caspase-3 and truncated AIF were not observed. DNA fragmentation was inhibited by SNJ-1945. Conclusions An improved human retinal explant model showed that calpains, not caspase-3, were involved in cell damage induced by hypoxia/reoxygenation. This finding could be relevant for patient treatment with a calpain inhibitor if calpain activation is documented in human retinal ischemic diseases.
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Affiliation(s)
- Momoko Kobayashi-Otsugu
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Limited, Portland, Oregon, United States.,Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Kana Orihara
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Limited, Portland, Oregon, United States.,Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Emi Nakajima
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Limited, Portland, Oregon, United States.,Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Thomas R Shearer
- Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Mitsuyoshi Azuma
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Corporation Limited, Portland, Oregon, United States.,Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, Oregon, United States
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Shearer TR, Hwang TS, Steinkamp PN, Azuma M. Segmenting OCT for detecting drug efficacy in CRAO. PLoS One 2020; 15:e0242920. [PMID: 33306701 PMCID: PMC7732080 DOI: 10.1371/journal.pone.0242920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 11/11/2020] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Thinning of the inner layers of the retina occurs in patients with central retinal artery occlusion (CRAO). The mechanism for such thinning may be partially due to proteolysis by a calcium-activated protease called calpain. Calpain inhibitor SNJ-1945 ameliorated the proteolysis in a past series of model experiments. The purposes of the present retrospective study were to: 1) use segmentation analysis of optical coherence tomography (OCT) images to mathematically model the loss of specific retinal layers in CRAO patients, and 2) predict the number of patients and days of observation needed for clinical trials of inhibitors against CRAO. METHODS A retrospective case control study was conducted by computer-aided search for CRAO (ICD10 H43.1) with at least one OCT procedure (CPT: 92134) in the OHSU Epic patient data base. RESULTS After initial swelling, thinning of the inner retinal layers, especially the ganglion cell (GCL) layer followed exponential decay curves. Using sample size statistics and GCL thickness as a marker in a 30-day clinical trial, 19 eyes/group could theoretically detect a 20% beneficial effect of an inhibitor against CRAO. Other markers, such as the whole retinal thickness and combined inner layers could also be used as less-specific markers. CONCLUSIONS Using thickness changes in the GCL layer to monitor the efficacy of potential inhibitors against CRAO is practical in human trials requiring a reasonable number of patients and relatively short trial period. TRANSLATIONAL RELEVANCE Measurement of GCL thickness would be a useful indicator of CRAO progression in a clinical trial of putative inhibitors.
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Affiliation(s)
- Thomas R Shearer
- Department of Integrative Biomedical & Diagnostic Sciences, Oregon Health & Science University, Portland, OR, United States of America
| | - Thomas S Hwang
- Department of Ophthalmology-OHSU, Portland, OR, United States of America
| | - Peter N Steinkamp
- Department of Ophthalmology-OHSU, Portland, OR, United States of America
| | - Mitsuyoshi Azuma
- Senju Laboratory of Ocular Sciences, Portland, OR, United States of America
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Evaluation of radial peripapillary capillary density in patients with newly diagnosed iron deficiency anemia. Int Ophthalmol 2020; 41:399-407. [PMID: 32924077 DOI: 10.1007/s10792-020-01589-w] [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: 04/11/2020] [Accepted: 09/04/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate the effects of iron deficiency anemia (IDA) on radial peripapillary capillary vessel density (RPCvd) and retinal nerve fiber layer (RNFL) thickness. METHODS Forty patients with IDA, and 46 healthy participants, were enrolled in this study. Optical coherence tomography angiography was used to determine RNFL thickness and RPCvd measurements. In addition, hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and ferritin laboratory values were evaluated. RESULTS Analysis of retinal regions (whole images, peripapillary, superior-hemi, inferior-hemi, inferior-nasal, inferior-temporal, temporal-inferior, temporal-superior, superior-nasal) showed that RPCvd values were significantly lower in patients with IDA compared to the control group values (p < 0.05 for all). However, there were no significant differences in RNFL thickness values between the IDA patient group and the control group (p > 0.05 for all). In addition, there were significant positive correlations between RPCvd values and hematological values for Hb, HCT, MCV, MCH, MCHC, and ferritin. CONCLUSION It is important to identify changes in retinal vascularity to prevent possible ocular problems in patients with IDA. Specifically, the significant positive correlations between RPCvd values and hematological values suggest that anemia treatment is important for optic nerve perfusion.
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FluoroGold-Labeled Organotypic Retinal Explant Culture for Neurotoxicity Screening Studies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2487473. [PMID: 29560079 PMCID: PMC5831603 DOI: 10.1155/2018/2487473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 11/24/2017] [Accepted: 12/05/2017] [Indexed: 12/13/2022]
Abstract
Preclinical toxicity screening of the new retinal compounds is an absolute requirement in the pathway of further drug development. Since retinal neuron cultivation and in vivo studies are relatively expensive and time consuming, we aimed to create a fast and reproducible ex vivo system for retinal toxicity screening. For this purpose, we used rat retinal explant culture that was retrogradely labeled with the FluoroGold before the isolation. Explants were exposed to a toxic concentration of gentamicin and ciliary neurotrophic factor (CNTF), a known neuroprotective agent. The measured outcomes showed the cell density in retinal ganglion cell layer (GCL) and the activity of lactate dehydrogenase (LDH) in the culture medium. Gentamicin-induced oxidative stress resulted in retinal cell damage and rapid LDH release to the culture medium (p < 0.05). Additional CNTF supplementation minimized the cell damage, and the increase of LDH release was insignificant when compared to LDH levels before gentamicin insult (p > 0.05). As well as this, the LDH activity was directly correlated with the cell count in GCL (R = −0.84, p < 0.00001), making a sensitive marker of retinal neuron damage. The FLOREC protocol could be considered as a fast, reproducible, and sensitive method to detect neurotoxicity in the screening studies of the retinal drugs.
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