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Matuszewski W, Szklarz M, Wołos-Kłosowicz K, Harazny JM, Bandurska-Stankiewicz E. High-Resolution Imaging of Cones and Retinal Arteries in Patients with Diabetes Mellitus Type 1 Using Adaptive Optics (rtx1). Biomedicines 2024; 12:863. [PMID: 38672217 PMCID: PMC11048079 DOI: 10.3390/biomedicines12040863] [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: 02/08/2024] [Revised: 03/27/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
(1) Background. Diabetes mellitus (DM), called the first non-infectious epidemic of the modern era, has long-term health consequences leading to a reduced quality of life, long-term disabilities, and high mortality. Diabetic retinopathy (DR) is a neurovascular complication of diabetes and accounts for about 80% cases of vision loss in the diabetic population. The adaptive optics (AO) technique allows for a non-invasive in vivo assessment of retinal cones. Changes in number or morphology of retinal cones may be one of the first indicators of DR. (2) Methods. This study included 68 DM1 patients (17 women) aged 42.11 ± 9.69 years with a mean duration of diabetes of 22.07 ± 10.28 years, and 41 healthy volunteers (20 women) aged 41.02 ± 9.84 years. Blood pressure, BMI, waist circumference, and metabolic control measures were analysed. Cones' morphological parameters were examined with a retinal camera with Imagine Eyes adaptive optics (rtx1). Statistical analysis was carried out with IMB SPSS version 23 software. (3) Results. Neither study group differed significantly in age, BMI, blood pressure, or eyeball length. Intraocular pressure (IOP) was statistically significantly higher in DM1 patients but remained within physiological range in both groups. Analysis of cone parameters showed a statistically significant lower mean regularity of cones (Rmean) in the DM1 group compared to control group (p = 0.01), with the lowest value in the group with DM1 and hypertension (p = 0.014). In addition, DM1 patients tended to have fewer cones. (4) Conclusions. Our study revealed abnormalities in cone and vessel parameters and these abnormalities should be considered as risk factors for the development of DR. Complementing an eye examination with AO facilitates non-invasive in vivo cellular imaging of the retina. Lesions like those detected in the eye may occur in the brain and certainly require further investigation.
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Affiliation(s)
- Wojciech Matuszewski
- Clinic of Endocrinology, Diabetology and Internal Medicine, Department of Internal Medicine, University of Warmia and Mazury, 10−082 Olsztyn, Poland
| | - Michał Szklarz
- Clinic of Endocrinology, Diabetology and Internal Medicine, Department of Internal Medicine, University of Warmia and Mazury, 10−082 Olsztyn, Poland
| | - Katarzyna Wołos-Kłosowicz
- Clinic of Endocrinology, Diabetology and Internal Medicine, Department of Internal Medicine, University of Warmia and Mazury, 10−082 Olsztyn, Poland
| | - Joanna Maria Harazny
- . Department of Human Physiology and Pathophysiology, University of Warmia and Mazury, 10−082 Olsztyn, Poland;
- Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich Alexander University Erlangen Nuremberg (FAU), 91054 Erlangen, Germany
| | - Elżbieta Bandurska-Stankiewicz
- Clinic of Endocrinology, Diabetology and Internal Medicine, Department of Internal Medicine, University of Warmia and Mazury, 10−082 Olsztyn, Poland
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2
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Huang RS, Mihalache A, Popovic MM, Munn C, Balas M, Issa M, Melo IM, Friedman A, Wright T, Yan P, Muni RH. ASSOCIATION OF INTRAVENOUS FLUORESCEIN ANGIOGRAPHY AND ADAPTIVE OPTICS IMAGING IN DIABETIC RETINOPATHY: A Prospective Case Series. Retina 2024; 44:689-699. [PMID: 38011843 DOI: 10.1097/iae.0000000000004012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
PURPOSE To our knowledge, we present the first case series investigating the relationship between adaptive optics (AO) imaging and intravenous fluorescein angiography (IVFA) parameters in patients with diabetic retinopathy. METHODS Consecutive patients with diabetic retinopathy older than age 18 years presenting to a single center in Toronto, Canada, from 2020 to 2021 were recruited. Adaptive optics was performed with the RTX1 camera (Imagine Eyes, Orsay, France) at retinal eccentricities of 2° and 4°. Intravenous fluorescein angiography was assessed with the artificial intelligence-based RETICAD system to extract blood flow, perfusion, and blood-retinal-barrier (BRB) permeability at the same retinal locations. Correlations between AO and IVFA parameters were calculated using Pearson's correlation coefficient. RESULTS Across nine cases, a significant positive correlation existed between photoreceptor spacing on AO and BRB permeability (r = 0.303, P = 0.027), as well as perfusion (r = 0.272, P = 0.049) on IVFA. When stratified by location, a significant positive correlation between photoreceptor dispersion and both BRB permeability and perfusion (r = 0.770, P = 0.043; r = 0.846, P = 0.034, respectively) was observed. Cone density was also negatively correlated with BRB permeability (r = -0.819, P = 0.046). CONCLUSION Photoreceptor spacing on AO was significantly correlated with BRB permeability and perfusion on IVFA in patients with diabetic retinopathy. Future studies with larger sample sizes are needed to understand the relationship between AO and IVFA parameters in diverse patient populations.
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Affiliation(s)
- Ryan S Huang
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Mihalache
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Marko M Popovic
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Colyn Munn
- Emagix Inc, Halifax, Nova Scotia, Canada
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michael Balas
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mariam Issa
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Isabela Martins Melo
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Alon Friedman
- Emagix Inc, Halifax, Nova Scotia, Canada
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Tom Wright
- Kensington Vision and Research Centre, Kensington Eye Institute, Toronto, Ontario, Canada; and
| | - Peng Yan
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
- Kensington Vision and Research Centre, Kensington Eye Institute, Toronto, Ontario, Canada; and
| | - Rajeev H Muni
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Ophthalmology, St. Michael's Hospital/Unity Health Toronto, Toronto, Ontario, Canada
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3
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Villa-Fernández E, García AV, Fernández-Fernández A, García-Villarino M, Ares-Blanco J, Pujante P, González-Vidal T, Fraga MF, Torre EM, Delgado E, Lambert C. Metformin and Glucose Concentration as Limiting Factors in Retinal Pigment Epithelial Cell Viability and Proliferation. Int J Mol Sci 2024; 25:2637. [PMID: 38473884 DOI: 10.3390/ijms25052637] [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: 01/19/2024] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Metformin is a well-established drug for the treatment of type 2 diabetes; however, the mechanism of action has not been well described and many aspects of how it truly acts are still unknown. Moreover, regarding in vitro experiments, the glycaemic status when metformin is used is generally not considered, which, added to the suprapharmacological drug concentrations that are commonly employed in research, has resulted in gaps of its mechanism of action. The aim of this study was to determine how glucose and metformin concentrations influence cell culture. Considering that diabetic retinopathy is one of the most common complications of diabetes, a retinal pigment epithelial cell line was selected, and cell viability and proliferation rates were measured at different glucose and metformin concentrations. As expected, glucose concentration by itself positively influenced cell proliferation rates. When the metformin was considered, results were conditioned, as well, by metformin concentration. This conditioning resulted in cell death when high concentrations of metformin were used under physiological concentrations of glucose, while this did not happen when clinically relevant concentrations of metformin were used independently of glucose status. Our study shows the importance of in vitro cell growth conditions when drug effects such as metformin's are being analysed.
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Affiliation(s)
- Elsa Villa-Fernández
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
| | - Ana Victoria García
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
| | | | - Miguel García-Villarino
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Jessica Ares-Blanco
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Pedro Pujante
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
| | - Tomás González-Vidal
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
| | - Mario F Fraga
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Health Research Institute of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Institute of Oncology of Asturias (IUOPA), 33006 Oviedo, Asturias, Spain
- Department of Organisms and Systems Biology (B.O.S), University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Edelmiro Menéndez Torre
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Elias Delgado
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Carmen Lambert
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Department of Educational Sciences, University of Oviedo, 33006 Oviedo, Asturias, Spain
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4
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Pfaller AM, Kaplan L, Carido M, Grassmann F, Díaz-Lezama N, Ghaseminejad F, Wunderlich KA, Glänzer S, Bludau O, Pannicke T, Weber BHF, Koch SF, Bonev B, Hauck SM, Grosche A. The glucocorticoid receptor as a master regulator of the Müller cell response to diabetic conditions in mice. J Neuroinflammation 2024; 21:33. [PMID: 38273366 PMCID: PMC10809506 DOI: 10.1186/s12974-024-03021-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024] Open
Abstract
Diabetic retinopathy (DR) is considered a primarily microvascular complication of diabetes. Müller glia cells are at the centre of the retinal neurovascular unit and play a critical role in DR. We therefore investigated Müller cell-specific signalling pathways that are altered in DR to identify novel targets for gene therapy. Using a multi-omics approach on purified Müller cells from diabetic db/db mice, we found the mRNA and protein expression of the glucocorticoid receptor (GR) to be significantly decreased, while its target gene cluster was down-regulated. Further, oPOSSUM TF analysis and ATAC- sequencing identified the GR as a master regulator of Müller cell response to diabetic conditions. Cortisol not only increased GR phosphorylation. It also induced changes in the expression of known GR target genes in retinal explants. Finally, retinal functionality was improved by AAV-mediated overexpression of GR in Müller cells. Our study demonstrates an important role of the glial GR in DR and implies that therapeutic approaches targeting this signalling pathway should be aimed at increasing GR expression rather than the addition of more ligand.
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Affiliation(s)
- Anna M Pfaller
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Lew Kaplan
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Madalena Carido
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Felix Grassmann
- Institute of Clinical Human Genetics, University Hospital Regensburg, Regensburg, Germany
- Institute for Clinical Research and Systems Medicine, Health and Medical University, Potsdam, Germany
| | - Nundehui Díaz-Lezama
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Farhad Ghaseminejad
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Kirsten A Wunderlich
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Institute for Molecular Medicine, Health and Medical University, Potsdam, Germany
| | - Sarah Glänzer
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Oliver Bludau
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Thomas Pannicke
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Bernhard H F Weber
- Institute of Clinical Human Genetics, University Hospital Regensburg, Regensburg, Germany
- Institute of Human Genetics, University Regensburg, Regensburg, Germany
| | - Susanne F Koch
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Boyan Bonev
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Stefanie M Hauck
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Antje Grosche
- Department of Physiological Genomics, Biomedical Center-BMC, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.
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5
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Dmitriev AV, Dmitriev AA, Linsenmeier RA. Diabetes-Induced Changes of the Rat ERG in Relation to Hyperglycemia and Acidosis. Curr Eye Res 2024; 49:53-61. [PMID: 37756520 PMCID: PMC10872866 DOI: 10.1080/02713683.2023.2264544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/22/2023] [Indexed: 09/29/2023]
Abstract
PURPOSE To understand the mechanism of changes in the c-wave of the electroretinogram (ERG) in diabetic rats, and to explore how glucose manipulations affect the c-wave. METHODS Vitreal ERGs were recorded in control and diabetic Long-Evans rats, 3-60 weeks after IP vehicle or streptozotocin. A few experiments were performed on Brown Norway rats. Voltage responses to current pulses were used to measure the transepithelial resistance of the retinal pigment epithelium (RPE). RESULTS During development of diabetes the b-wave amplitude progressively decreased to about half of the initial amplitude after a year. In contrast, the c-wave was strongly affected from the very beginning (3 weeks) of diabetes. In control rats, the c-wave was cornea-positive at lower illuminations but was cornea-negative at higher (photopic) illumination. In diabetics, the whole amplitude-intensity curve was shifted toward negativity. The magnitude of this shift was markedly affected by acute glucose manipulations in diabetics but not in controls. Increased blood glucose made the c-wave more negative, and decreased blood glucose with insulin had the opposite effect. Experimentally induced acidification of the retina had a small effect that was different from diabetes, shifting the c-wave toward positivity, slightly in controls and more noticeably in diabetics. One reason for the significant negativity of the diabetic ERG was a decrease of the cornea-positive response of the RPE due to a decrease of the transepithelial resistance. CONCLUSIONS The ERG c-wave is more negative in diabetics than in control animals, and is far more sensitive to changes in blood glucose. The increased negativity is largely if not entirely due to changes in the transepithelial resistance of the RPE, an electrical analog of the breakdown of the blood-retinal barrier observed in other studies. The sensitivity of the c-wave to glucose in diabetics may also be due to changes in transepithelial resistance.
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Affiliation(s)
| | | | - Robert A Linsenmeier
- Department of Biomedical Engineering, Evanston and Chicago, IL
- Department of Neurobiology, Evanston and Chicago, IL
- Department of Ophthalmology Northwestern University, Evanston and Chicago, IL
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6
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Pilotto E, Cosmo E, Torresin T, Coppola M, Gutierrez De Rubalcava Doblas J, Midena G, Moretti C, Midena E. Outer Retinal and Choroidal Changes in Adolescents with Long-Lasting Type 1 Diabetes. J Clin Med 2023; 13:229. [PMID: 38202235 PMCID: PMC10779656 DOI: 10.3390/jcm13010229] [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: 11/24/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
This study aimed to assess outer retinal layer (ORL), retinal pigment epithelium (RPE), choroid (Ch) and choriocapillaris (CC) modifications in adolescents with long-lasting (>10 years) type 1 diabetes (T1D) without (noDR) or with diabetic retinopathy (DR). ORL and RPE thickness were measured at optical coherence tomography (OCT) macular scans. Vascular parameters of Ch and CC were quantified after elaboration of macular OCT-angiography (OCTA) images. Insulin dose and auxological and metabolic parameters were correlated with OCT and OCTA findings in patients. ORL thickness was higher in DR eyes than in noDR and healthy controls (HC), and RPE thickness was higher in noDR and DR eyes than in HC, with statistical significance for some sectors in noDR versus HC. No OCTA parameters of CC and Ch differed among groups, and no significant correlation was observed with auxological and metabolic parameters. In conclusion, ORL and RPE were both increased in adolescents with long-lasting T1D. Such changes were not associated with insulin dose and glycemia control, nor to any choroid or choriocapillaris flow change clinically detectable at OCTA, and they could be potential imaging biomarkers of disease progression.
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Affiliation(s)
- Elisabetta Pilotto
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (E.C.); (T.T.); (M.C.); (E.M.)
| | - Eleonora Cosmo
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (E.C.); (T.T.); (M.C.); (E.M.)
| | - Tommaso Torresin
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (E.C.); (T.T.); (M.C.); (E.M.)
| | - Marco Coppola
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (E.C.); (T.T.); (M.C.); (E.M.)
| | | | | | - Carlo Moretti
- Pediatric Diabetes Unit, Department of Women’s and Children’s Health, University of Padova, 35128 Padova, Italy; (J.G.D.R.D.); (C.M.)
| | - Edoardo Midena
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (E.C.); (T.T.); (M.C.); (E.M.)
- IRCCS—Fondazione Bietti, 00198 Rome, Italy;
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Gao S, Gao S, Wang Y, Li N, Yang Z, Yao H, Chen Y, Cheng Y, Zhong Y, Shen X. Inhibition of Ferroptosis Ameliorates Photoreceptor Degeneration in Experimental Diabetic Mice. Int J Mol Sci 2023; 24:16946. [PMID: 38069270 PMCID: PMC10707664 DOI: 10.3390/ijms242316946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/19/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Diabetic retinopathy (DR) is a leading cause of vision impairment in the working-age population worldwide. Various modes of photoreceptor cell death contribute to the development of DR, including apoptosis and autophagy. However, whether ferroptosis is involved in the pathogenesis of photoreceptor degeneration in DR is still unclear. High-glucose (HG)-stimulated 661W cells and diabetic mice models were used for in vitro and in vivo experiments, respectively. The levels of intracellular iron, glutathione (GSH), reactive oxygen species (ROS), lipid peroxidation (MDA), and ferroptosis-related proteins (GPX4, SLC7A11, ACSL4, FTH1, and NCOA4) were quantified to indicate ferroptosis. The effect of ferroptosis inhibition was also assessed. Our data showed the levels of iron, ROS, and MDA were enhanced and GSH concentration was reduced in HG-induced 661W cells and diabetic retinas. The expression of GPX4 and SLC7A11 was downregulated, while the expression of ACSL4, FTH1, and NCOA4 was upregulated in the 661W cells cultured under HG conditions and in the photoreceptor cells in diabetic mice. Furthermore, the administration of the ferroptosis inhibitor ferrostatin-1 (Fer-1) obviously alleviated ferroptosis-related changes in HG-cultured 661W cells and in retinal photoreceptor cells in diabetic mice. Taken together, our findings suggest that ferroptosis is involved in photoreceptor degeneration in the development of the early stages of DR.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Xi Shen
- Department of Ophthalmology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin 2nd Road, Shanghai 200025, China; (S.G.)
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8
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Pfeifer CW, Walsh JT, Santeford A, Lin JB, Beatty WL, Terao R, Liu YA, Hase K, Ruzycki PA, Apte RS. Dysregulated CD200-CD200R signaling in early diabetes modulates microglia-mediated retinopathy. Proc Natl Acad Sci U S A 2023; 120:e2308214120. [PMID: 37903272 PMCID: PMC10636339 DOI: 10.1073/pnas.2308214120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/25/2023] [Indexed: 11/01/2023] Open
Abstract
Diabetic retinopathy (DR) is a neurovascular complication of diabetes. Recent investigations have suggested that early degeneration of the neuroretina may occur prior to the appearance of microvascular changes; however, the mechanisms underlying this neurodegeneration have been elusive. Microglia are the predominant resident immune cell in the retina and adopt dynamic roles in disease. Here, we show that ablation of retinal microglia ameliorates visual dysfunction and neurodegeneration in a type I diabetes mouse model. We also provide evidence of enhanced microglial contact and engulfment of amacrine cells, ultrastructural modifications, and transcriptome changes that drive inflammation and phagocytosis. We show that CD200-CD200R signaling between amacrine cells and microglia is dysregulated during early DR and that targeting CD200R can attenuate high glucose-induced inflammation and phagocytosis in cultured microglia. Last, we demonstrate that targeting CD200R in vivo can prevent visual dysfunction, microglia activation, and retinal inflammation in the diabetic mouse. These studies provide a molecular framework for the pivotal role that microglia play in early DR pathogenesis and identify a potential immunotherapeutic target for treating DR in patients.
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Affiliation(s)
- Charles W. Pfeifer
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Neurosciences Graduate Program, Roy and Diana Vagelos Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - James T. Walsh
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO63110
| | - Andrea Santeford
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Joseph B. Lin
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Neurosciences Graduate Program, Roy and Diana Vagelos Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Wandy L. Beatty
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO63110
| | - Ryo Terao
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo1138665, Japan
| | - Yizhou A. Liu
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Keitaro Hase
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
| | - Philip A. Ruzycki
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Genetics, Washington University School of Medicine, St. Louis, MO63110
| | - Rajendra S. Apte
- John F. Hardesty, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO63110
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO63110
- Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
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9
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Calbiague García V, Cadiz B, Herrera P, Díaz A, Schmachtenberg O. Evaluation of Photobiomodulation and Boldine as Alternative Treatment Options in Two Diabetic Retinopathy Models. Int J Mol Sci 2023; 24:ijms24097918. [PMID: 37175628 PMCID: PMC10178531 DOI: 10.3390/ijms24097918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023] Open
Abstract
Diabetic retinopathy causes progressive and irreversible damage to the retina through activation of inflammatory processes, overproduction of oxidative species, and glial reactivity, leading to changes in neuronal function and finally ischemia, edema, and hemorrhages. Current treatments are invasive and mostly applied at advanced stages, stressing the need for alternatives. To this end, we tested two unconventional and potentially complementary non-invasive treatment options: Photobiomodulation, the stimulation with near-infrared light, has shown promising results in ameliorating retinal pathologies and insults in several studies but remains controversial. Boldine, on the other hand, is a potent natural antioxidant and potentially useful to prevent free radical-induced oxidative stress. To establish a baseline, we first evaluated the effects of diabetic conditions on the retina with immunofluorescence, histological, and ultrastructural analysis in two diabetes model systems, obese LepRdb/db mice and organotypic retinal explants, and then tested the potential benefits of photobiomodulation and boldine treatment in vitro on retinal explants subjected to high glucose concentrations, mimicking diabetic conditions. Our results suggest that the principal subcellular structures affected by these conditions were mitochondria in the inner segment of photoreceptors, which displayed morphological changes in both model systems. In retinal explants, lactate metabolism, assayed as an indicator of mitochondrial function, was altered, and decreased photoreceptor viability was observed, presumably as a consequence of increased oxidative-nitrosative stress. The latter was reduced by boldine treatment in vitro, while photobiomodulation improved mitochondrial metabolism but was insufficient to prevent retinal structural damage caused by high glucose. These results warrant further research into alternative and complementary treatment options for diabetic retinopathy.
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Affiliation(s)
- Víctor Calbiague García
- Ph. D. Program in Neuroscience, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Bárbara Cadiz
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Pablo Herrera
- Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Alejandra Díaz
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
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Da'as SI, Ahmed I, Hasan WH, Abdelrahman DA, Aliyev E, Nisar S, Bhat AA, Joglekar MV, Hardikar AA, Fakhro KA, Akil ASAS. The link between glycemic control measures and eye microvascular complications in a clinical cohort of type 2 diabetes with microRNA-223-3p signature. J Transl Med 2023; 21:171. [PMID: 36869348 PMCID: PMC9985290 DOI: 10.1186/s12967-023-03893-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 01/16/2023] [Indexed: 03/05/2023] Open
Abstract
BACKGROUND Type 2 diabetes (T2D) is a critical healthcare challenge and priority in Qatar which is listed amongst the top 10 countries in the world, with its prevalence presently at 17% double the global average. MicroRNAs (miRNAs) are implicated in the pathogenesis of (T2D) and long-term microvascular complications including diabetic retinopathy (DR). METHODS In this study, a T2D cohort that accurately matches the characteristics of the general population was employed to find microRNA (miRNA) signatures that are correlated with glycemic and β cell function measurements. Targeted miRNA profiling was performed in (471) T2D individuals with or without DR and (491) (non-diabetic) healthy controls from the Qatar Biobank. Discovery analysis identified 20 differentially expressed miRNAs in T2D compared to controls, of which miR-223-3p was significantly upregulated (fold change:5.16, p = 3.6e-02) and positively correlated with glucose and hemoglobin A1c (HbA1c) levels (p-value = 9.88e-04 and 1.64e-05, respectively), but did not show any significant associations with insulin or C-peptide. Accordingly, we performed functional validation using a miR-223-3p mimic (overexpression) under control and hyperglycemia-induced conditions in a zebrafish model. RESULTS Over-expression of miR-223-3p alone was associated with significantly higher glucose (42.7 mg/dL, n = 75 vs 38.7 mg/dL, n = 75, p = 0.02) and degenerated retinal vasculature, and altered retinal morphology involving changes in the ganglion cell layer and inner and outer nuclear layers. Assessment of retinal angiogenesis revealed significant upregulation in the expression of vascular endothelial growth factor and its receptors, including kinase insert domain receptor. Further, the pancreatic markers, pancreatic and duodenal homeobox 1, and the insulin gene expressions were upregulated in the miR-223-3p group. CONCLUSION Our zebrafish model validates a novel correlation between miR-223-3p and DR development. Targeting miR-223-3p in T2D patients may serve as a promising therapeutic strategy to control DR in at-risk individuals.
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Affiliation(s)
- Sahar I Da'as
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar.,Zebrafish Functional Genomics, Integrated Genomic Services Core Facility, Research Branch, Sidra Medicine, P.O. Box 26999, Doha, Qatar.,College of Health and Life Sciences, Hamad Bin Khalifa University, P.O. Box 34110, Doha, Qatar
| | - Ikhlak Ahmed
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Waseem H Hasan
- Zebrafish Functional Genomics, Integrated Genomic Services Core Facility, Research Branch, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Doua A Abdelrahman
- Zebrafish Functional Genomics, Integrated Genomic Services Core Facility, Research Branch, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Elbay Aliyev
- Laboratory of Genomic Medicine-Precision Medicine Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Sabah Nisar
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Ajaz Ahmad Bhat
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Mugdha V Joglekar
- Diabetes and Islet Biology Group, School of Medicine, Western Sydney University, Narellan Road & Gilchrist Drive, Campbelltown, NSW, 2560, Australia
| | - Anandwardhan A Hardikar
- Diabetes and Islet Biology Group, School of Medicine, Western Sydney University, Narellan Road & Gilchrist Drive, Campbelltown, NSW, 2560, Australia.,Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000, Roskilde, Denmark
| | - Khalid A Fakhro
- Laboratory of Genomic Medicine-Precision Medicine Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar.,College of Health and Life Sciences, Hamad Bin Khalifa University, P.O. Box 34110, Doha, Qatar.,Department of Genetic Medicine, Weill Cornell Medical College, P.O. Box 24144, Doha, Qatar
| | - Ammira S Al-Shabeeb Akil
- Department of Human Genetics-Precision Medicine in Diabetes, Obesity and Cancer Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar. .,Laboratory of Genomic Medicine-Precision Medicine Program, Sidra Medicine, P.O. Box 26999, Doha, Qatar.
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11
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Towards a New Biomarker for Diabetic Retinopathy: Exploring RBP3 Structure and Retinoids Binding for Functional Imaging of Eyes In Vivo. Int J Mol Sci 2023; 24:ijms24054408. [PMID: 36901838 PMCID: PMC10002987 DOI: 10.3390/ijms24054408] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
Diabetic retinopathy (DR) is a severe disease with a growing number of afflicted patients, which places a heavy burden on society, both socially and financially. While there are treatments available, they are not always effective and are usually administered when the disease is already at a developed stage with visible clinical manifestation. However, homeostasis at a molecular level is disrupted before visible signs of the disease are evident. Thus, there has been a constant search for effective biomarkers that could signal the onset of DR. There is evidence that early detection and prompt disease control are effective in preventing or slowing DR progression. Here, we review some of the molecular changes that occur before clinical manifestations are observable. As a possible new biomarker, we focus on retinol binding protein 3 (RBP3). We argue that it displays unique features that make it a very good biomarker for non-invasive, early-stage DR detection. Linking chemistry to biological function and focusing on new developments in eye imaging and two-photon technology, we describe a new potential diagnostic tool that would allow rapid and effective quantification of RBP3 in the retina. Moreover, this tool would also be useful in the future to monitor therapeutic effectiveness if levels of RBP3 are elevated by DR treatments.
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12
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McAnany JJ, Park JC. Rod photoreceptor activation and deactivation in early-stage diabetic eye disease. Doc Ophthalmol 2023:10.1007/s10633-023-09925-y. [PMID: 36763216 DOI: 10.1007/s10633-023-09925-y] [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: 09/16/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023]
Abstract
PURPOSE To infer rod phototransduction activation and deactivation characteristics in diabetics who have mild or no clinically-apparent retinopathy. METHODS Fifteen non-diabetic controls, 15 diabetics with no clinically-apparent diabetic retinopathy (NDR), and 15 diabetics with mild non-proliferative diabetic retinopathy (MDR) participated. Dark-adapted flash electroretinograms (3.2 to 4.4 log scot td-s) were recorded to assess rod activation. The a-waves were fit with a Gaussian model to derive Rmp3 (maximum photoreceptor response amplitude) and S (phototransduction sensitivity). Rod deactivation was assessed with a paired flash paradigm, in which a-waves were measured for two flashes separated by inter-stimulus intervals (ISIs) of 0.125 to 16 s. The ISI needed for the a-wave amplitude of the second flash to recover to 50% of the first flash (t50) was determined. The effect of stimulus retinal illuminance on activation and deactivation was evaluated in a subset of control subjects. RESULTS Analysis of variance indicated that both diabetic groups had significant log S reductions compared to controls (p < 0.001). Mean S was reduced by approximately 49% and 78% for the NDR and MDR groups, respectively. In contrast, log Rmp3 and log t50 did not differ significantly among the groups (both p > 0.08). Reducing stimulus retinal illuminance significantly reduced S, but did not significantly affect Rmax or t50. CONCLUSIONS Only phototransduction sensitivity was abnormal in this sample of diabetic subjects. The normal deactivation kinetics suggests that circulating rod current is normal. These findings begin to constrain possible explanations for abnormal rod function in early diabetic retinal disease.
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Affiliation(s)
- J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., MC/648, Chicago, IL, 60612, USA.
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan St., Chicago, IL, 60607, USA.
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., MC/648, Chicago, IL, 60612, USA
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Proinflammatory Cytokines Trigger the Onset of Retinal Abnormalities and Metabolic Dysregulation in a Hyperglycemic Mouse Model. J Ophthalmol 2023; 2023:7893104. [PMID: 36895267 PMCID: PMC9991478 DOI: 10.1155/2023/7893104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 03/06/2023] Open
Abstract
Purpose Recent evidence has shown that retinal inflammation is a key player in diabetic retinopathy (DR) pathogenesis. To further understand and validate the metabolic biomarkers of DR, we investigated the effect of intravitreal proinflammatory cytokines on the retinal structure, function, and metabolism in an in vivo hyperglycemic mouse model. Methods C57Bl/6 mice were rendered hyperglycemic within one week of administration of a single high-dose intraperitoneal injection of streptozotocin, while control mice received vehicle injection. After confirming hyperglycemia, the mice received an intravitreal injection of either proinflammatory cytokines (TNF-α and IL-1β) or vehicle. Similarly, control mice received an intravitreal injection of either proinflammatory cytokines or vehicle. The retinal structure was evaluated using fundus imaging and optical coherence tomography, and retinal function was assessed using a focal electroretinogram (ERG), two days after cytokine injection. Retinas were collected for biochemical analysis to determine key metabolite levels and enzymatic activities. Results Hyperglycemic mice intraocularly injected with cytokines developed visible retinal vascular damage and intravitreal and intraretinal hyper-reflective spots two days after the cytokines injection. These mice also developed a significant functional deficit with reduced a-wave and b-wave amplitudes of the ERG at high light intensities compared to control mice. Furthermore, metabolic disruption was evident in these mice, with significantly higher retinal glucose, lactate, ATP, and glutamine levels and a significant reduction in glutamate levels compared with control mice. Minimal or no metabolic changes were observed in hyperglycemic mice without intraocular cytokines or in control mice with intraocular cytokines at 2 days post hyperglycemia. Conclusions Proinflammatory cytokines accelerated the development of vascular damage in the eyes of hyperglycemic mice. Significant changes were observed in retinal structure, function, and metabolic homeostasis. These findings support the idea that with the onset of inflammation in DR, there is a deficit in metabolism. Therefore, early intervention to prevent inflammation-induced retinal changes in diabetic patients may improve the disease outcome.
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Retinal Microvascular and Neuronal Changes Are Also Present, Even If Differently, in Adolescents with Type 1 Diabetes without Clinical Diabetic Retinopathy. J Clin Med 2022; 11:jcm11143982. [PMID: 35887746 PMCID: PMC9323684 DOI: 10.3390/jcm11143982] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 12/10/2022] Open
Abstract
The purpose of this study was to evaluate retinal changes in adolescents with childhood-onset, long-lasting type 1 diabetes mellitus (T1D). Patients and healthy controls (HC) underwent optical coherence tomography (OCT) and OCT-angiography (OCTA). Individual macular layers, peripapillary retinal nerve fiber layer (pRNFL), and vascular parameters (vessel area density (VAD), vessel length fraction (VLF) and vessel diameter index (VDI)) of macular superficial vascular (SVP), intermediate (ICP), deep (DCP) and radial peripapillary capillary plexuses (RPCP) were quantified. Thirty-nine patients (5 with (DR group) and 34 without (noDR group) diabetic retinopathy) and 20 HC were enrolled. The pRNFL and ganglion cell layer (GCL) were thicker in noDR compared to HC and DR, reaching statistically significant values versus HC for some sectors. At the macular level, VAD and VLF were reduced in DR versus HC in all plexuses, and versus noDR in SVP (p < 0.005 for all). At the RPCP level, VAD and VDI were increased in noDR versus HC, significantly for VDI (p = 0.0067). Glycemic indices correlated to retinal parameters. In conclusion, in T1D adolescents, retinal capillary and neuronal changes are present after long-lasting disease, even in the absence of clinical DR. These changes modify when clinical retinopathy develops. The precocious identification of specific OCT and OCTA changes may be a hallmark of subsequent overt retinopathy.
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15
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Wang Y, Fung NSK, Lam WC, Lo ACY. mTOR Signalling Pathway: A Potential Therapeutic Target for Ocular Neurodegenerative Diseases. Antioxidants (Basel) 2022; 11:antiox11071304. [PMID: 35883796 PMCID: PMC9311918 DOI: 10.3390/antiox11071304] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Recent advances in the research of the mammalian target of the rapamycin (mTOR) signalling pathway demonstrated that mTOR is a robust therapeutic target for ocular degenerative diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma. Although the exact mechanisms of individual ocular degenerative diseases are unclear, they share several common pathological processes, increased and prolonged oxidative stress in particular, which leads to functional and morphological impairment in photoreceptors, retinal ganglion cells (RGCs), or retinal pigment epithelium (RPE). mTOR not only modulates oxidative stress but is also affected by reactive oxygen species (ROS) activation. It is essential to understand the complicated relationship between the mTOR pathway and oxidative stress before its application in the treatment of retinal degeneration. Indeed, the substantial role of mTOR-mediated autophagy in the pathogenies of ocular degenerative diseases should be noted. In reviewing the latest studies, this article summarised the application of rapamycin, an mTOR signalling pathway inhibitor, in different retinal disease models, providing insight into the mechanism of rapamycin in the treatment of retinal neurodegeneration under oxidative stress. Besides basic research, this review also summarised and updated the results of the latest clinical trials of rapamycin in ocular neurodegenerative diseases. In combining the current basic and clinical research results, we provided a more complete picture of mTOR as a potential therapeutic target for ocular neurodegenerative diseases.
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Ichsan AM, Bukhari A, Lallo S, Miskad UA, Dzuhry AA, Islam IC, Muhiddin HS. Effect of retinol and α-tocopherol supplementation on photoreceptor and retinal ganglion cell apoptosis in diabetic rats model. Int J Retina Vitreous 2022; 8:40. [PMID: 35715832 PMCID: PMC9205037 DOI: 10.1186/s40942-022-00392-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is the most common microvascular complication of diabetes. Retinol and α-tocopherol of diabetic models prevent the damage of photoreceptor and retinal ganglion cells (RGC) caused by hyperglycemia. OBJECTIVE This study aims to examine the effect of retinol and α-tocopherol on photoreceptor and RGC densities and the expression of caspase-3 and -7 on the retinal layers of the diabetic rat model. METHODS Alloxan 150 mg/kg body weight single dose was used to develop animal models, which were separated into eight groups. These consist of one group without intervention (group 1), one positive control with only induced alloxan (group 2), and others receiving retinol (group 3 and 6), α-tocopherol (group 4 and 7), or their combination (group 5 and 8). Furthermore, histopathological examination was performed using Hematoxylin-Eosin staining to evaluate the photoreceptor and RGC densities, while immunohistochemistry staining evaluated the caspase-3 and -7 expressions. RESULTS In the treatment group, the highest and lowest densities were identified in diabetic rats given α-tocopherol (group 7) and retinol (group 3) respectively. The caspase-3 and -7 expression showed that the group given α-tocopherol (group 7) had the lowest value. CONCLUSION In diabetic rats, retinol and α-tocopherol compounds maintained densities and prevented photoreceptor and RGC death. However, α-tocopherol was more promising than retinol or combinations in the prevention of retinal cells apoptosis.
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Affiliation(s)
- Andi Muhammad Ichsan
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia.
| | - Agussalim Bukhari
- Department of Clinical Nutrition, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Subehan Lallo
- Department of Pharmaceutical Science, Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
| | - Upik Anderiani Miskad
- Department of Pathology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Andi Afdal Dzuhry
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Itzar Chaidir Islam
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
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Diabetes Aggravates Photoreceptor Pathologies in a Mouse Model for Ocular Vitamin A Deficiency. Antioxidants (Basel) 2022; 11:antiox11061142. [PMID: 35740038 PMCID: PMC9219864 DOI: 10.3390/antiox11061142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 02/06/2023] Open
Abstract
Emerging evidence indicates that diabetes disturbs photoreceptor function and vitamin A homeostasis. However, the biochemical basis of this phenotype is not well established. Here, we compared the effects of streptozotocin-induced diabetes in wild-type (WT) mice and Stra6-/- mice, a mouse model for ocular vitamin A deficiency. After 8 weeks, diabetes increased serum retinyl esters in mice of both genotypes. The eyes of diabetic WT mice displayed increased superoxide levels but no changes in retinoid concentrations. Diabetic Stra6-/- mice showed increased ocular retinoid concentrations, but superoxide levels remained unchanged. After 30 weeks, significant alterations in liver and fat retinoid concentrations were observed in diabetic mice. Diabetic WT mice exhibited a decreased expression of visual cycle proteins and a thinning of the photoreceptor layer. Stra6-/- mice displayed significantly lower ocular retinoid concentration than WT mice. An altered retinal morphology and a reduced expression of photoreceptor marker genes paralleled these biochemical changes and were more pronounced in the diabetic animals. Taken together, we observed that diabetes altered vitamin A homeostasis in several organ systems and aggravated photoreceptor pathologies in the vitamin-deficient mouse eyes.
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Simó R, Simó-Servat O, Bogdanov P, Hernández C. Diabetic Retinopathy: Role of Neurodegeneration and Therapeutic Perspectives. Asia Pac J Ophthalmol (Phila) 2022; 11:160-167. [PMID: 35533335 DOI: 10.1097/apo.0000000000000510] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
ABSTRACT Retinal neurodegeneration plays a significant role in the pathogenesis of diabetic retinopathy, the leading cause of preventable blindness. The hallmarks of diabetes-induced neurodegeneration are neural cell apoptosis and glial activation, which seem even before vascular lesions can be detected by ophthalmoscopic examination. The molecular mediators of retinal neurodegeneration include proinflamma- tory cytokines, oxidative stress, mitochondrial dysfunction, and the molecular pathways closely related to chronic hyperglycemia. In this article, an overview of the main components of neurodegeneration, its key underlying mechanisms, and the more useful experimental models for investigative purposes will be given. In addition, the results of most relevant treatments based on neuroprotection, and the research gaps that should be filled will be critically reviewed.
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Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
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Rasoulinejad SA, Maroufi F, Alizadeh A. Clinical parameters in different stages, zones, and remission/progression statuses of retinopathy of prematurity. CASPIAN JOURNAL OF INTERNAL MEDICINE 2022; 13:385-392. [PMID: 35919643 PMCID: PMC9301226 DOI: 10.22088/cjim.13.2.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/20/2021] [Accepted: 11/22/2021] [Indexed: 10/31/2022]
Abstract
Background Retinopathy of prematurity (ROP) is a vasoproliferative retinal disease in premature infants that causes lifetime visual impairment and blindness in the early ages. In this study, we investigated the differences in the values of clinical laboratory parameters between different ROP and its remission/progression statuses regarding stages and zones. Methods This historical cohort study includes 828 infants divided into two groups after the first examination containing ROP infants and controls. The biochemical and hematological parameters of the two groups have been collected from the patient's history. Results In infants with ROP, the hematopoiesis-related parameters, including the mean level of hemoglobin, total bilirubin, potassium, calcium were significantly less than controls (P=0.039, P=0.001, P=0.001, and P=0.046, respectively). The percentages of reticulocyte and the levels of BUN in ROP patients were significantly higher than in normal infants (P=0.015 and p <0.001, respectively). Moreover, the levels of hemoglobin and BUN were significantly different in the different zones of ROP (P=0.017 and P=0.001, respectively). Also, higher hemoglobin levels, total bilirubin, and CRP were observed in the reduced stages of ROP (P=0.041, P=0.045, and P=0.039, respectively). Conclusion Laboratory parameters are different in different stages, zones and remission/ progression ROP infants.
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Affiliation(s)
- Seyed Ahmad Rasoulinejad
- Department of Ophthalmology, Ayatollah Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran.,Correspondence: Seyed Ahmad Rasoulinejad, Department of Ophthalmology, Ayatollah Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran. E-mail: , Tel: 0098 1132238284, Fax: 0098 1132238284
| | - Faezeh Maroufi
- Department of Medical Laboratory Sciences, Faculty of Allied Medicine, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Ahad Alizadeh
- Metabolic Diseases Research Center, Qazvin University of Medical Sciences, Qazvin, Iran
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Muftuoglu IK, Kalra G, Rasheed MA, Cagini C, Gujar R, Vupparaboina KK, Singh SR, Lupidi M, Chhablani J. Wide-field optical coherence tomography imaging in diabetic retinopathy. Eur J Ophthalmol 2021; 32:2298-2305. [PMID: 34747260 DOI: 10.1177/11206721211054972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To report the individual retinal layer thicknesses up to mid-equator in patients with diabetic retinopathy (DR) using Spectralis (Heidelberg Engineering, Heidelberg, Germany) wide-field optical coherence tomography (OCT). METHODS Retinal layers were segmented using a custom designed semi-automated algorithm, where reference points were marked by the examiner to enable software to automatically compute the thickness values of each retinal sublayer at an interval of 1 mm from reference points. The values of individual retinal thicknesses in eyes with varying severity of DR were compared with the values of healthy subjects. Generalized estimating equation was performed to compensate for inclusion of both eyes of patients. RESULTS A total of 64 patients (119 eyes) with a mean age of 68.97 ± 10.27 years were included. Overall, ganglion cell layer (GCL)/ inner plexiform layer (IPL) complex (-31.67 microns, p < 0.001), outer plexiform layer (-6.78 microns, p = 0.002) and photoreceptor layer (-22.90 microns, p < 0.001) showed significant thinning, while outer nuclear layer thickening ( + 68.19 microns, <0.001) was noted in eyes with DM compared to healthy subjects. Thickness changes were significantly more in the macular segment compared to nasal and temporal segments. GCL/ IPL complex and photoreceptor layers were found to be significantly thin in all grades of DR. CONCLUSION Retinal thicknesses vary significantly in patients with diabetic retinopathy and understanding patterns of these changes across different segments of the wide field OCT may help better elucidate the natural progression of the disease in terms of retinal anatomy.
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Affiliation(s)
- Ilkay Kilic Muftuoglu
- Department of Ophthalmology, Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Gagan Kalra
- 29746Government Medical College and Hospital, Chandigarh, India
| | - Mohammed Abdul Rasheed
- School of Optometry and Vision Science, 8430University of Waterloo, Waterloo, ON, Canada
| | - Carlo Cagini
- Department of Biochemical and Surgica l Sciences, Section of Ophthalmology, 60250University of Perugia, Perugia, Italy
| | - Ramkailash Gujar
- Department of Biochemical and Surgica l Sciences, Section of Ophthalmology, 60250University of Perugia, Perugia, Italy
| | | | - Sumit Randhir Singh
- Jacobs Retina Center, Shiley Eye Institute, 8784University of California, San Diego, CA, USA
| | - Marco Lupidi
- Department of Biochemical and Surgica l Sciences, Section of Ophthalmology, 60250University of Perugia, Perugia, Italy
| | - Jay Chhablani
- 345156UPMC Eye Center, University of Pittsburgh, Pittsburgh, PA, USA
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21
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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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22
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McAnany JJ, Persidina OS, Park JC. Clinical electroretinography in diabetic retinopathy: a review. Surv Ophthalmol 2021; 67:712-722. [PMID: 34487740 DOI: 10.1016/j.survophthal.2021.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 11/30/2022]
Abstract
The electroretinogram (ERG) is a noninvasive, objective technique to evaluate retinal function that has become increasingly important in the study of diabetic retinopathy. We summarize the principles and rationale of the ERG, present findings from recent clinical studies that have used the full-field ERG, multifocal ERG, and pattern ERG to evaluate neural dysfunction in patients with diabetes, and weigh the strengths and limitations of the technique as it applies to clinical studies and management of patients with diabetic retinopathy. Taken together, ERG studies have provided convincing evidence for dysfunction of the neural retina in patients with diabetes, including those who have no clinically-apparent retinal vascular abnormalities. Recent full-field ERG findings have pointed to the intriguing possibility that photoreceptor function is abnormal in early-stage disease. Pattern ERG data, in conjunction with recently developed photopic negative response analyses, indicate inner retina dysfunction. In addition, multifocal ERG studies have shown spatially localized neural abnormalities that can predict the location of future microaneurysms. Given the insights provided by the ERG, it is likely to play a growing role in understanding the natural history of neural dysfunction in diabetes, as well as providing an attractive outcome measure for future clinical trials that target neural preservation in diabetic retinopathy.
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Affiliation(s)
- J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA; Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA.
| | - Oksana S Persidina
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
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23
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Gong Y, Xia H, Zhang A, Chen LJ, Chen H. Optical coherence tomography biomarkers of photoreceptor degeneration in retinitis pigmentosa. Int Ophthalmol 2021; 41:3949-3959. [PMID: 34304340 DOI: 10.1007/s10792-021-01964-1] [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: 01/10/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Several parameters on optical coherence tomography (OCT) have been suggested as biomarkers for photoreceptor degeneration in retinitis pigmentosa (RP). This study is to compare the spatial distribution of the changes of OCT biomarkers in RP patients. METHODS OCT line scans of the horizontal meridian were conducted in 22 eyes of 22 RP patients and 30 eyes of 30 healthy controls. Longitudinal reflectance profiles were obtained using ImageJ at every 5 pixels. The following parameters on OCT were quantitatively measured: (1) relative optical intensity (ROI) of ellipsoid zone (EZ) and interdigitation zone (IZ); (2) thickness of outer nuclear layer (ONLT), photoreceptor (PRT), inner segment (IST) and outer segment (OST). The variations of these parameters across different regions were analyzed. RESULTS From fovea to perifoveal region, all the OCT biomarkers declined before disappeared, except IST and IZ-ROI. There was no identifiable declining zone for the IST and IZ-ROI between the normal and disappeared zones in some patients. The most central biomarker was the reduction of OST and IZ-ROI, followed by the PRT, EZ-ROI, then IST and finally ONLT. All these biomarkers had significant correlations with best-corrected visual acuity, except ONLT. CONCLUSION In retinitis pigmentosa, EZ-ROI, IZ-ROI, PRT, OST, IST and ONLT are valuable biomarkers of photoreceptor degeneration. Changes of OST and IZ-ROI are located most centrally and may be the early biomarkers.
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Affiliation(s)
- Yuting Gong
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, North Dongxia Road, Shantou, 515041, China
| | - Honghe Xia
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, North Dongxia Road, Shantou, 515041, China
| | - Anlin Zhang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, North Dongxia Road, Shantou, 515041, China
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Haoyu Chen
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, North Dongxia Road, Shantou, 515041, China.
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24
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Kawai M, Himeno T, Shibata Y, Hirai N, Asada‐Yamada Y, Asano‐Hayami E, Ejima Y, Kasagi R, Nagao E, Sugiura‐Roth Y, Nakai‐Shimoda H, Nakayama T, Yamada Y, Ishikawa T, Morishita Y, Kondo M, Tsunekawa S, Kato Y, Nakamura J, Kamiya H. Neuroretinal dysfunction revealed by a flicker electroretinogram correlated with peripheral nerve dysfunction and parameters of atherosclerosis in patients with diabetes. J Diabetes Investig 2021; 12:1236-1243. [PMID: 33210835 PMCID: PMC8264400 DOI: 10.1111/jdi.13465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/05/2020] [Accepted: 11/15/2020] [Indexed: 11/28/2022] Open
Abstract
AIMS/INTRODUCTION Diabetic polyneuropathy (DPN) develops in the early stage of diabetes. However, no common diagnostic protocol has yet been established. Here, to verify that the flicker electroretinogram using a hand-held device can detect the early dysfunction of the peripheral nervous system in patients with diabetes, we investigated the correlation between the progression of DPN and neuroretinal dysfunction. MATERIALS AND METHODS In total, 184 participants with type 1 or 2 diabetes underwent a flicker electroretinogram (ERG) using a hand-held device RETeval™ and nerve conduction study. Participants were also evaluated for intima-media thickness, ankle-brachial index, toe brachial index and brachial-ankle pulse wave velocity. Parameters of the nerve conduction study were used to diagnose the severity according to Baba's classification. A multiple regression analysis was used to examine the associations of ERG parameters with the severity of DPN categorized by Baba's classification. Diagnostic properties of the device in DPN were evaluated using a receiver operating characteristic curve. RESULTS A multiple regression model to predict the severity of DPN was generated using ERG. In the model, moderate-to-severe DPN was effectively diagnosed (area under the receiver operating characteristic curve 0.692, sensitivity 56.5%, specificity 78.3%, positive predictive value 70.6%, negative predictive value 66.1%, positive likelihood ratio 2.60, negative likelihood ratio 0.56). In the patients without diabetic retinopathy, the implicit time and amplitude in ERG significantly correlated with the parameters of the nerve conduction study, brachial-ankle pulse wave velocity and intima-media thickness. CONCLUSIONS Electroretinogram parameters obtained by the hand-held device successfully predict the severity of DPN. The device might be useful to evaluate DPN.
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Affiliation(s)
- Miyuka Kawai
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Tatsuhito Himeno
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yuka Shibata
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
- Department of LaboratoryThe Medical Clinic of Aichi Medical UniversityNagoyaJapan
- Department of Clinical LaboratoryAichi Medical University HospitalNagakuteJapan
| | - Nobuhiro Hirai
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yuriko Asada‐Yamada
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Emi Asano‐Hayami
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yohei Ejima
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Rina Kasagi
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Eriko Nagao
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yukako Sugiura‐Roth
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Hiromi Nakai‐Shimoda
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Takayuki Nakayama
- Department of Clinical LaboratoryAichi Medical University HospitalNagakuteJapan
| | - Yuichiro Yamada
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Takahiro Ishikawa
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yoshiaki Morishita
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Masaki Kondo
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Shin Tsunekawa
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Yoshiro Kato
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Jiro Nakamura
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
| | - Hideki Kamiya
- Division of DiabetesDepartment of Internal MedicineAichi Medical University School of MedicineNagakuteJapan
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25
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Tonade D, Kern TS. Photoreceptor cells and RPE contribute to the development of diabetic retinopathy. Prog Retin Eye Res 2021; 83:100919. [PMID: 33188897 PMCID: PMC8113320 DOI: 10.1016/j.preteyeres.2020.100919] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/26/2022]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness. It has long been regarded as vascular disease, but work in the past years has shown abnormalities also in the neural retina. Unfortunately, research on the vascular and neural abnormalities have remained largely separate, instead of being integrated into a comprehensive view of DR that includes both the neural and vascular components. Recent evidence suggests that the most predominant neural cell in the retina (photoreceptors) and the adjacent retinal pigment epithelium (RPE) play an important role in the development of vascular lesions characteristic of DR. This review summarizes evidence that the outer retina is altered in diabetes, and that photoreceptors and RPE contribute to retinal vascular alterations in the early stages of the retinopathy. The possible molecular mechanisms by which cells of the outer retina might contribute to retinal vascular damage in diabetes also are discussed. Diabetes-induced alterations in the outer retina represent a novel therapeutic target to inhibit DR.
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Affiliation(s)
- Deoye Tonade
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Veterans Administration Medical Center Research Service, Cleveland, OH, USA; Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Veterans Administration Medical Center Research Service, Long Beach, CA, USA.
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26
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Advancing Diabetic Retinopathy Research: Analysis of the Neurovascular Unit in Zebrafish. Cells 2021; 10:cells10061313. [PMID: 34070439 PMCID: PMC8228394 DOI: 10.3390/cells10061313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/30/2022] Open
Abstract
Diabetic retinopathy is one of the most important microvascular complications associated with diabetes mellitus, and a leading cause of vision loss or blindness worldwide. Hyperglycaemic conditions disrupt microvascular integrity at the level of the neurovascular unit. In recent years, zebrafish (Danio rerio) have come into focus as a model organism for various metabolic diseases such as diabetes. In both mammals and vertebrates, the anatomy and the function of the retina and the neurovascular unit have been highly conserved. In this review, we focus on the advances that have been made through studying pathologies associated with retinopathy in zebrafish models of diabetes. We discuss the different cell types that form the neurovascular unit, their role in diabetic retinopathy and how to study them in zebrafish. We then present new insights gained through zebrafish studies. The advantages of using zebrafish for diabetic retinopathy are summarised, including the fact that the zebrafish has, so far, provided the only animal model in which hyperglycaemia-induced retinal angiogenesis can be observed. Based on currently available data, we propose potential investigations that could advance the field further.
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27
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Krueger K, Boehme E, Klettner AK, Zille M. The potential of marine resources for retinal diseases: a systematic review of the molecular mechanisms. Crit Rev Food Sci Nutr 2021; 62:7518-7560. [PMID: 33970706 DOI: 10.1080/10408398.2021.1915242] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We rely on vision more than on any other sense to obtain information about our environment. Hence, the loss or even impairment of vision profoundly affects our quality of life. Diet or food components have already demonstrated beneficial effects on the development of retinal diseases. Recently, there has been a growing interest in resources from marine animals and plants for the prevention of retinal diseases through nutrition. Especially fish intake and omega-3 fatty acids have already led to promising results, including associations with a reduced incidence of retinal diseases. However, the underlying molecular mechanisms are insufficiently explained. The aim of this review was to summarize the known mechanistic effects of marine resources on the pathophysiological processes in retinal diseases. We performed a systematic literature review following the PRISMA guidelines and identified 107 studies investigating marine resources in the context of retinal diseases. Of these, 46 studies described the underlying mechanisms including anti-inflammatory, antioxidant, antiangiogenic/vasoprotective, cytoprotective, metabolic, and retinal function effects, which we critically summarize. We further discuss perspectives on the use of marine resources for human nutrition to prevent retinal diseases with a particular focus on regulatory aspects, health claims, safety, and bioavailability.
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Affiliation(s)
- Kristin Krueger
- Department of Marine Biotechnology, Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, Lübeck, Germany
| | - Elke Boehme
- Department of Marine Biotechnology, Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, Lübeck, Germany
| | - Alexa Karina Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Quincke Research Center, Kiel, Germany
| | - Marietta Zille
- Department of Marine Biotechnology, Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, Lübeck, Germany.,Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
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28
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Gorbatyuk OS, Pitale PM, Saltykova IV, Dorofeeva IB, Zhylkibayev AA, Athar M, Fuchs PA, Samuels BC, Gorbatyuk MS. A Novel Tree Shrew Model of Diabetic Retinopathy. Front Endocrinol (Lausanne) 2021; 12:799711. [PMID: 35046899 PMCID: PMC8762304 DOI: 10.3389/fendo.2021.799711] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/10/2021] [Indexed: 01/03/2023] Open
Abstract
Existing animal models with rod-dominant retinas have shown that hyperglycemia injures neurons, but it is not yet clearly understood how blue cone photoreceptors and retinal ganglion cells (RGCs) deteriorate in patients because of compromised insulin tolerance. In contrast, northern tree shrews (Tupaia Belangeri), one of the closest living relatives of primates, have a cone-dominant retina with short wave sensitivity (SWS) and long wave sensitivity (LWS) cones. Therefore, we injected animals with a single streptozotocin dose (175 mg/kg i.p.) to investigate whether sustained hyperglycemia models the features of human diabetic retinopathy (DR). We used the photopic electroretinogram (ERG) to measure the amplitudes of A and B waves and the photopic negative responses (PhNR) to evaluate cone and RGC function. Retinal flat mounts were prepared for immunohistochemical analysis to count the numbers of neurons with antibodies against cone opsins and RGC specific BRN3a proteins. The levels of the proteins TRIB3, ISR-1, and p-AKT/p-mTOR were measured with western blot. The results demonstrated that tree shrews manifested sustained hyperglycemia leading to a slight but significant loss of SWS cones (12%) and RGCs (20%) 16 weeks after streptozotocin injection. The loss of BRN3a-positive RGCs was also reflected by a 30% decline in BRN3a protein expression. These were accompanied by reduced ERG amplitudes and PhNRs. Importantly, the diabetic retinas demonstrated increased expression of TRIB3 and level of p-AKT/p-mTOR axis but reduced level of IRS-1 protein. Therefore, a new non-primate model of DR with SWS cone and RGC dysfunction lays the foundation to better understand retinal pathophysiology at the molecular level and opens an avenue for improving the research on the treatment of human eye diseases.
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Affiliation(s)
- Oleg S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Priyamvada M Pitale
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Irina V Saltykova
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Iuliia B Dorofeeva
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Assylbek A Zhylkibayev
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mohammad Athar
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Preston A Fuchs
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Marina S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
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29
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Frizziero L, Midena G, Longhin E, Berton M, Torresin T, Parrozzani R, Pilotto E. Early Retinal Changes by OCT Angiography and Multifocal Electroretinography in Diabetes. J Clin Med 2020; 9:jcm9113514. [PMID: 33143008 PMCID: PMC7692230 DOI: 10.3390/jcm9113514] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022] Open
Abstract
Background: To evaluate the earliest retinal morphological and functional changes in diabetic eyes without or with early signs of diabetic retinopathy (DR). Methods: Twenty-two eyes with no DR (noDR group), 22 eyes with mild DR (DR group), and 18 healthy nondiabetic eyes (controls) were enrolled. All eyes were studied by means of spectral domain optical coherence tomography (OCT), OCT angiography (OCTA), and multifocal electroretinogram (mfERG). Results: A significantly higher number of OCT hyperreflective intraretinal foci (HRF) was found in both noDR and DR groups versus controls, but not between DR groups. The OCTA parameters of the superficial vascular plexus (SVP) were significantly reduced in the noDR group both versus controls and DR group (p < 0.05). The OCTA parameters of the intermediate capillary plexus (ICP) were significantly reduced in the DR group versus controls. An increased number of altered hexagons on mfERG was found in the noDR versus the DR group (p = 0.0192). Conclusions: Retinal vascular and functional parameters are differently involved in diabetic eyes; major vascular changes in the SVP and functional alterations of the mfERG are present in diabetic eyes with no clinical microvascular signs of DR, while ICP is mainly involved when early ophthalmoscopic signs of DR are present. The integrated use of mfERG and OCTA provides new significant insights into the pathogenesis of diabetic related retinal disease.
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Affiliation(s)
- Luisa Frizziero
- IRCCS—Fondazione Bietti, 00198 Rome, Italy
- Correspondence: ; Tel.: +39-049-821-2110
| | - Giulia Midena
- Institute of Ophthalmology, Policlinico Gemelli, IRCCS, 00168 Rome, Italy;
| | - Evelyn Longhin
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | | | - Tommaso Torresin
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | - Raffaele Parrozzani
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | - Elisabetta Pilotto
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
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30
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ValdezGuerrero AS, Quintana-Pérez JC, Arellano-Mendoza MG, Castañeda-Ibarra FJ, Tamay-Cach F, Alemán-González-Duhart D. Diabetic Retinopathy: Important Biochemical Alterations and the Main Treatment Strategies. Can J Diabetes 2020; 45:504-511. [PMID: 33341391 DOI: 10.1016/j.jcjd.2020.10.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/08/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023]
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by impaired glucose homeostasis, insulin resistance and hyperglycemia. Among its serious multisystemic complications is diabetic retinopathy (DR), which develops slowly and often insidiously. This disorder-the most common cause of vision loss in working-age adults-is characterized by functional and morphological changes in the retina. It results from the exacerbation of ischemic and inflammatory conditions prompted by alterations in the blood vessels, such as the development of leukostasis, thickening of the basement membrane, retinal neovascularization and fibrovascular tissue formation at the vitreoretinal interface. The pathogenic alterations are usually triggered at the biochemical level, involving a greater activity in 4 pathways: the polyol pathway, the hexosamine pathway, the formation of advanced glycation end-products and the activation of protein kinase C isoforms. When acting together, these pathways give rise to increased levels of reactive oxygen species and decreased levels of endogenous antioxidant agents, thus generating oxidative stress. All current therapies are aimed at the later stages of DR, and their application implies side effects. One possible strategy for preventing the complications of DM is to counteract the elevated superoxide production stemming from a high level of blood glucose. Accordingly, some treatments are under study for their capacity to reduce vascular leakage and avoid retinal ischemia, retinal neovascularization and macular edema. The present review summarizes the biochemical aspects of DR and the main approaches for treating it.
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Affiliation(s)
- Amaranta Sarai ValdezGuerrero
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Julio César Quintana-Pérez
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Mónica Griselda Arellano-Mendoza
- Research Laboratory in Chronic Degenerative Diseases, Section of Postgraduate Studies and Research, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Francisco Javier Castañeda-Ibarra
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Feliciano Tamay-Cach
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico.
| | - Diana Alemán-González-Duhart
- Department of Basic Interdisciplinary Training, Interdisciplinary Center for Health Sciences-Santo Tomás Unit, National Polytechnic Institute, Mexico City, Mexico.
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31
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Abstract
Based on clinical findings, diabetic retinopathy (DR) has traditionally been defined as a retinal microvasculopathy. Retinal neuronal dysfunction is now recognized as an early event in the diabetic retina before development of overt DR. While detrimental effects of diabetes on the survival and function of inner retinal cells, such as retinal ganglion cells and amacrine cells, are widely recognized, evidence that photoreceptors in the outer retina undergo early alterations in diabetes has emerged more recently. We review data from preclinical and clinical studies demonstrating a conserved reduction of electrophysiological function in diabetic retinas, as well as evidence for photoreceptor loss. Complementing in vivo studies, we discuss the ex vivo electroretinography technique as a useful method to investigate photoreceptor function in isolated retinas from diabetic animal models. Finally, we consider the possibility that early photoreceptor pathology contributes to the progression of DR, and discuss possible mechanisms of photoreceptor damage in the diabetic retina, such as enhanced production of reactive oxygen species and other inflammatory factors whose detrimental effects may be augmented by phototransduction.
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Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease. Antioxidants (Basel) 2020; 9:antiox9100905. [PMID: 32977483 PMCID: PMC7598160 DOI: 10.3390/antiox9100905] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy (DR), a common chronic complication of diabetes mellitus and the leading cause of vision loss in the working-age population, is clinically defined as a microvascular disease that involves damage of the retinal capillaries with secondary visual impairment. While its clinical diagnosis is based on vascular pathology, DR is associated with early abnormalities in the electroretinogram, indicating alterations of the neural retina and impaired visual signaling. The pathogenesis of DR is complex and likely involves the simultaneous dysregulation of multiple metabolic and signaling pathways through the retinal neurovascular unit. There is evidence that microvascular disease in DR is caused in part by altered energetic metabolism in the neural retina and specifically from signals originating in the photoreceptors. In this review, we discuss the main pathogenic mechanisms that link alterations in neural retina bioenergetics with vascular regression in DR. We focus specifically on the recent developments related to alterations in mitochondrial metabolism including energetic substrate selection, mitochondrial function, oxidation-reduction (redox) imbalance, and oxidative stress, and critically discuss the mechanisms of these changes and their consequences on retinal function. We also acknowledge implications for emerging therapeutic approaches and future research directions to find novel mitochondria-targeted therapeutic strategies to correct bioenergetics in diabetes. We conclude that retinal bioenergetics is affected in the early stages of diabetes with consequences beyond changes in ATP content, and that maintaining mitochondrial integrity may alleviate retinal disease.
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Simó R, Frontoni S. Neuropathic damage in the diabetic eye: clinical implications. Curr Opin Pharmacol 2020; 55:1-7. [PMID: 32932105 DOI: 10.1016/j.coph.2020.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/11/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023]
Abstract
In recent years, emerging evidence support that the eye is target of diabetes neuropathy. There are two components of the eye that are mainly involved in the neurodegenerative process induced by diabetes: the retina and the cornea. The study of functional and structural changes in these components of the eye will provide useful information to identify subjects with diabetes at risk of diabetic peripheral neuropathy and dementia. In this review the state of the art regarding the evidence and clinical implications of this emerging concept will be provided. In addition, the relationship between retinal and corneal neurodegeneration with peripheral neuropathy and cognitive decline will be analyzed. Finally, the scientific gaps than need to be covered and will be critically examined.
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Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; CIBERDEM (ISCIII), Madrid, Spain.
| | - Simona Frontoni
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita, Fate Bene Fratelli Hospital, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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Bueno JM, Cruz-Castillo R, Avilés-Trigueros M, Bautista-Elivar N. Arrangement of the photoreceptor mosaic in a diabetic rat model imaged with multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:4901-4914. [PMID: 33014589 PMCID: PMC7510868 DOI: 10.1364/boe.399835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Diabetic retinopathy (DR) is defined as a microvascular pathology. However, some data have suggested that the retinal photoreceptors (PRs) might be important in the pathogenesis of this ocular disease. In this study the organization of the PRs in control and diabetic-induced rats was compared using multiphoton microscopy. The PR mosaic was imaged at different locations in non-stained retinas. The density of PRs was directly quantified from cell counting. The spatially resolved density presents a double-slope pattern (from the central retina towards the periphery) in both healthy and pathological samples, although the values for the latter were significantly lower all across the retina. Moreover, Voronoi analysis was performed to explore changes in PR topography. In control specimens a hexagonally packed structure was dominant. However, despite the non-controlled effects of the disease in retinal structures, this PR regularity was fairly maintained in diabetic retinas.
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Affiliation(s)
- Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Murcia, Spain
| | - Ricardo Cruz-Castillo
- Área Académica de Matemáticas y Física, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, Mexico
| | - Marcelino Avilés-Trigueros
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca, “Campus Mare Nostrum” de Excelencia International, Murcia, Spain
| | - Nazario Bautista-Elivar
- Departamento de Ingeniería Eléctrica, Tecnológico Nacional de México, Instituto Tecnológico de Pachuca, Hidalgo, Mexico
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Becker S, Carroll LS, Vinberg F. Rod phototransduction and light signal transmission during type 2 diabetes. BMJ Open Diabetes Res Care 2020; 8:8/1/e001571. [PMID: 32784250 PMCID: PMC7418690 DOI: 10.1136/bmjdrc-2020-001571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/22/2020] [Accepted: 07/02/2020] [Indexed: 01/31/2023] Open
Abstract
INTRODUCTION Diabetic retinopathy is a major complication of diabetes recently associated with compromised photoreceptor function. Multiple stressors in diabetes, such as hyperglycemia, oxidative stress and inflammatory factors, have been identified, but systemic effects of diabetes on outer retina function are incompletely understood. We assessed photoreceptor physiology in vivo and in isolated retinas to better understand how alterations in the cellular environment compared with intrinsic cellular/molecular properties of the photoreceptors, affect light signal transduction and transmission in the retina in chronic type 2 diabetes. RESEARCH DESIGN AND METHODS Photoreceptor function was assessed in BKS.Cs-Dock7m+/+Lepr db/J mice, using homozygotes for Leprdb as a model of type 2 diabetes and heterozygotes as non-diabetic controls. In vivo electroretinogram (ERG) was recorded in dark-adapted mice at both 3 and 6 months of age. For ex vivo ERG, isolated retinas were superfused with oxygenated Ames' media supplemented with 30 mM glucose or mannitol as iso-osmotic control and electrical responses to light stimuli were recorded. RESULTS We found that both transduction and transmission of light signals by rod photoreceptors were compromised in 6-month-old (n=9-10 eyes from 5 animals, ***p<0.001) but not in 3-month-old diabetic mice in vivo (n=4-8 eyes from 2 to 4 animals). In contrast, rod signaling was similar in isolated retinas from 6-month-old control and diabetic mice under normoglycemic conditions (n=11). Acutely elevated glucose ex vivo increased light-evoked rod photoreceptor responses in control mice (n=11, ***p<0.001), but did not affect light responses in diabetic mice (n=11). CONCLUSIONS Our data suggest that long-term diabetes does not irreversibly change the ability of rod photoreceptors to transduce and mediate light signals. However, type 2 diabetes appears to induce adaptational changes in the rods that render them less sensitive to increased availability of glucose.
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Affiliation(s)
- Silke Becker
- Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Lara S Carroll
- Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Frans Vinberg
- Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
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Huang CP, Lin YW, Huang YC, Tsai FJ. Mitochondrial Dysfunction as a Novel Target for Neuroprotective Nutraceuticals in Ocular Diseases. Nutrients 2020; 12:nu12071950. [PMID: 32629966 PMCID: PMC7400242 DOI: 10.3390/nu12071950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/23/2020] [Accepted: 06/29/2020] [Indexed: 12/12/2022] Open
Abstract
The eyes require a rich oxygen and nutrient supply; hence, the high-energy demand of the visual system makes it sensitive to oxidative stress. Excessive free radicals result in mitochondrial dysfunction and lead to retinal neurodegeneration, as an early stage of retinal metabolic disorders. Retinal cells are vulnerable because of their coordinated interaction and intricate neural networks. Nutraceuticals are believed to target multiple pathways and have shown neuroprotective benefits by scavenging free radicals and promoting mitochondrial gene expression. Furthermore, encouraging results demonstrate that nutraceuticals improve the organization of retinal cells and visual functions. This review discusses the mitochondrial impairments of retinal cells and the mechanisms underlying the neuroprotective effects of nutraceuticals. However, some unsolved problems still exist between laboratory study and clinical therapy. Poor bioavailability and bioaccessibility strongly limit their development. A new delivery system and improved formulation may offer promise for health care applications.
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Affiliation(s)
- Chun-Ping Huang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan;
| | - Yi-Wen Lin
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan;
| | - Yu-Chuen Huang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan;
- Department of Medical Research, China Medical University Hospital, Taichung 404, Taiwan
- Correspondence: (Y.-C.H.); (F.-J.T.)
| | - Fuu-Jen Tsai
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan;
- Department of Medical Research, China Medical University Hospital, Taichung 404, Taiwan
- Children’s Hospital of China Medical University, Taichung 404, Taiwan
- Department of Medical Genetics, China Medical University Hospital, Taichung 404, Taiwan
- Correspondence: (Y.-C.H.); (F.-J.T.)
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Abstract
Patients with diabetes continue to suffer from impaired visual performance before the appearance of overt damage to the retinal microvasculature and later sight-threatening complications. This diabetic retinopathy (DR) has long been thought to start with endothelial cell oxidative stress. Yet newer data surprisingly finds that the avascular outer retina is the primary site of oxidative stress before microvascular histopathology in experimental DR. Importantly, correcting this early oxidative stress is sufficient to restore vision and mitigate the histopathology in diabetic models. However, translating these promising results into the clinic has been stymied by an absence of methods that can measure and optimize anti-oxidant treatment efficacy in vivo. Here, we review imaging approaches that address this problem. In particular, diabetes-induced oxidative stress impairs dark-light regulation of subretinal space hydration, which regulates the distribution of interphotoreceptor binding protein (IRBP). IRBP is a vision-critical, anti-oxidant, lipid transporter, and pro-survival factor. We show how optical coherence tomography can measure subretinal space oxidative stress thus setting the stage for personalizing anti-oxidant treatment and prevention of impactful declines and loss of vision in patients with diabetes.
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Dreffs A, Lin CM, Liu X, Shanmugam S, Abcouwer SF, Kern TS, Antonetti DA. All-trans-Retinaldehyde Contributes to Retinal Vascular Permeability in Ischemia Reperfusion. Invest Ophthalmol Vis Sci 2020; 61:8. [PMID: 32492112 PMCID: PMC7415894 DOI: 10.1167/iovs.61.6.8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/17/2020] [Indexed: 01/28/2023] Open
Abstract
Purpose Extracellular accumulation of all-trans-retinaldehyde (atRAL), a highly reactive visual cycle intermediate, is toxic to cells of the outer retina and contributes to retinal and macular degenerations. However, the contribution of atRAL to retinal capillary function has not been studied. We hypothesized that atRAL released from the outer retina can contribute to retinal vascular permeability. We, therefore, tested the contribution of atRAL to retinal ischemia-reperfusion (IR)-induced vascular permeability. Methods IR was induced in mice by transient increase in intraocular pressure followed by natural reperfusion. The visual cycle was ablated in the Lrat-/- mice, reduced by dark adaptation or the use of the RPE65 inhibitor and atRAL scavenger emixustat. Accumulation of FITC-BSA was used to assess vascular permeability and DNA fragmentation quantified cell death after IR. Primary bovine retinal endothelial cell (BREC) culture was used to measure the direct effects of atRAL on endothelial permeability and cell death. Results Inhibition of the visual cycle by Lrat-/-, dark adaptation, or with emixustat, all reduced approximately half of IR induced vascular permeability at 48 hours. An increase in BREC permeability with atRAL coincided with lactate dehydrogenase (LDH) release, a measure of cell death. Both permeability and toxicity were blocked by emixustat. Conclusions Outer retinal pathology may contribute to vascular permeability by release of atRAL, which can act directly on vascular endothelial cells to alter barrier properties and induce cell death. These studies may have implications for a variety of blinding eye diseases that include outer retinal damage and retinal vascular permeability.
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Affiliation(s)
- Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Sumathi Shanmugam
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Steven F. Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Timothy S. Kern
- Center for Translational Vision Research, Department of Ophthalmology, Gavin Herbert Eye Institute, School of Medicine, University of California-Irvine, Gillespie Neuroscience Research Facility, Irvine, California, United States
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States
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Ali Z, Zang J, Lagali N, Schmitner N, Salvenmoser W, Mukwaya A, Neuhauss SCF, Jensen LD, Kimmel RA. Photoreceptor Degeneration Accompanies Vascular Changes in a Zebrafish Model of Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2020; 61:43. [PMID: 32106290 PMCID: PMC7329949 DOI: 10.1167/iovs.61.2.43] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose Diabetic retinopathy (DR) is a leading cause of vision impairment and blindness worldwide in the working-age population, and the incidence is rising. Until now it has been difficult to define initiating events and disease progression at the molecular level, as available diabetic rodent models do not present the full spectrum of neural and vascular pathologies. Zebrafish harboring a homozygous mutation in the pancreatic transcription factor pdx1 were previously shown to display a diabetic phenotype from larval stages through adulthood. In this study, pdx1 mutants were examined for retinal vascular and neuronal pathology to demonstrate suitability of these fish for modeling DR. Methods Vessel morphology was examined in pdx1 mutant and control fish expressing the fli1a:EGFP transgene. We further characterized vascular and retinal phenotypes in mutants and controls using immunohistochemistry, histology, and electron microscopy. Retinal function was assessed using electroretinography. Results Pdx1 mutants exhibit clear vascular phenotypes at 2 months of age, and disease progression, including arterial vasculopenia, capillary tortuosity, and hypersprouting, could be detected at stages extending over more than 1 year. Neural-retinal pathologies are consistent with photoreceptor dysfunction and loss, but do not progress to blindness. Conclusions This study highlights pdx1 mutant zebrafish as a valuable complement to rodent and other mammalian models of DR, in particular for research into the mechanistic interplay of diabetes with vascular and neuroretinal disease. They are furthermore suited for molecular studies to identify new targets for treatment of early as well as late DR.
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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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Fu Z, Sun Y, Cakir B, Tomita Y, Huang S, Wang Z, Liu CH, S. Cho S, Britton W, S. Kern T, Antonetti DA, Hellström A, E.H. Smith L. Targeting Neurovascular Interaction in Retinal Disorders. Int J Mol Sci 2020; 21:E1503. [PMID: 32098361 PMCID: PMC7073081 DOI: 10.3390/ijms21041503] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/13/2020] [Accepted: 02/21/2020] [Indexed: 02/07/2023] Open
Abstract
The tightly structured neural retina has a unique vascular network comprised of three interconnected plexuses in the inner retina (and choroid for outer retina), which provide oxygen and nutrients to neurons to maintain normal function. Clinical and experimental evidence suggests that neuronal metabolic needs control both normal retinal vascular development and pathological aberrant vascular growth. Particularly, photoreceptors, with the highest density of mitochondria in the body, regulate retinal vascular development by modulating angiogenic and inflammatory factors. Photoreceptor metabolic dysfunction, oxidative stress, and inflammation may cause adaptive but ultimately pathological retinal vascular responses, leading to blindness. Here we focus on the factors involved in neurovascular interactions, which are potential therapeutic targets to decrease energy demand and/or to increase energy production for neovascular retinal disorders.
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
- Manton Center for Orphan Disease, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Ye Sun
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Bertan Cakir
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Yohei Tomita
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Shuo Huang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Zhongxiao Wang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Steve S. Cho
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - William Britton
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
| | - Timothy S. Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA 92697, USA;
| | - David A. Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA;
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30 Göteborg, Sweden;
| | - Lois E.H. Smith
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Z.F.); (Y.S.); (B.C.); (Y.T.); (S.H.); (Z.W.); (C.-H.L.); (S.S.C.); (W.B.)
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Low-oxygen and knock-out serum maintain stemness in human retinal progenitor cells. Mol Biol Rep 2020; 47:1613-1623. [DOI: 10.1007/s11033-020-05248-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022]
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Ishibashi F, Tavakoli M. Thinning of Macular Neuroretinal Layers Contributes to Sleep Disorder in Patients With Type 2 Diabetes Without Clinical Evidences of Neuropathy and Retinopathy. Front Endocrinol (Lausanne) 2020; 11:69. [PMID: 32184758 PMCID: PMC7058995 DOI: 10.3389/fendo.2020.00069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/03/2020] [Indexed: 12/15/2022] Open
Abstract
Aims: To investigate the impact of thinning at individual grids of macular neuroretinal layers, clinical factors, and inadequate light exposure on the specific components of sleep disorder in patients with type 2 diabetes. Methods: One hundred twenty-four patients with type 2 diabetes without clinical evidences of diabetic retinopathy and neuropathy (HbA1c: 8.3%, diabetes duration; 8.7 years) and 54 age- and sex-matched control subjects (HbA1c: 5.6%) underwent detailed clinical, neurological, and ophthalmological examinations. The sleep disorder was assessed by the Pittsburgh Sleep Quality Index Japanese Version (PSQI-J). The temporal structures of daily life were assessed by the Munich Chronotype Questionnaire Japanese Version. The thickness at nine grids defined by the Early Treatment Diabetic Retinopathy Study of nine macular neuroretinal layers was determined by swept-source optical coherence tomography and OCT-Explorer. The associations between the individual components of sleep disorders and the thickness at each grid of macular neuroretinal layers, clinical factors, or the temporal structures of daily life were examined. Results: The prevalence of the sleep disorder, global score, and four individual PSQI-J scores in patients with type 2 diabetes were higher than control subjects. The thickness of two and five grids of two inner retinal layers and four to seven grids of four outer retinal layers in patients with type 2 diabetes was thinner than those in control subjects. The thickness at one to eight grids of four outer retinal layers in type 2 diabetic patients was inversely associated with global score and five individual scores of sleep disorder. The thinning at one to two grids of the inner plexiform layer was related to three high individual scores of sleep disorder. The inappropriate light exposure was associated with the sleep disorder and altered macular neuroretinal layers. The high HbA1c and LDL-cholesterol levels were related to the high global score and two individual scores of sleep disorder, respectively. Conclusion: In patients with type 2 diabetes, the thinning at grids of the inner plexiform layer and outer retinal layers was associated with the high scores of specific components of the sleep disorder. The sleep disorder was also related to hyperglycemia, dyslipidemia, and inappropriate light exposure.
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Affiliation(s)
| | - Mitra Tavakoli
- University of Exeter Medical School, Exeter, United Kingdom
- *Correspondence: Mitra Tavakoli
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Aires ID, Madeira MH, Boia R, Rodrigues-Neves AC, Martins JM, Ambrósio AF, Santiago AR. Intravitreal injection of adenosine A 2A receptor antagonist reduces neuroinflammation, vascular leakage and cell death in the retina of diabetic mice. Sci Rep 2019; 9:17207. [PMID: 31748653 PMCID: PMC6868354 DOI: 10.1038/s41598-019-53627-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 11/01/2019] [Indexed: 12/20/2022] Open
Abstract
Diabetic retinopathy is a major complication of diabetes mellitus and a leading cause of blindness. The pathogenesis of diabetic retinopathy is accompanied by chronic low-grade inflammation. Evidence shows that the blockade of adenosine A2A receptors (A2AR) affords protection to the retina through the control of microglia-mediated neuroinflammation. Herein, we investigated the therapeutic potential of an antagonist of A2AR in a model of diabetic retinopathy. Type 1 diabetes was induced in 4–5 months old C57BL/6 J mice with a single intraperitoneal injection streptozotocin. Animals were treated one month after the onset of diabetes. The A2AR antagonist was delivered by intravitreal injection once a week for 4 weeks. Microglia reactivity and inflammatory mediators were increased in the retinas of diabetic animals. The treatment with the A2AR antagonist was able to control microglial reactivity and halt neuroinflammation. Furthermore, the A2AR antagonist rescued retinal vascular leakage, attenuated alterations in retinal thickness, decreased retinal cell death and the loss of retinal ganglion cells induced by diabetes. These results demonstrate that intravitreal injection of the A2AR antagonist controls inflammation, affords protection against cell loss and reduces vascular leakage associated with diabetes, which could be envisaged as a therapeutic approach for the early complications of diabetes in the retina.
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Affiliation(s)
- Inês Dinis Aires
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Maria Helena Madeira
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Ana Catarina Rodrigues-Neves
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Joana Margarida Martins
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Ana Raquel Santiago
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548, Coimbra, Portugal. .,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal. .,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.
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45
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Huang YC, Liu SP, Chen SY, Lin JM, Lin HJ, Lei YJ, Wang YH, Huang WT, Liao WL, Tsai FJ. Increased Expression of Ecto-NOX Disulfide-thiol Exchanger 1 (ENOX1) in Diabetic Mice Retina and its Involvement in Diabetic Retinopathy Development. In Vivo 2019; 33:1801-1806. [PMID: 31662505 DOI: 10.21873/invivo.11671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/08/2019] [Accepted: 09/04/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND/AIM Diabetic retinopathy (DR) is a type of retinal damage caused by a complication of diabetes and is a major cause of blindness in working-age adults. Ecto-NOX disulfide-thiol exchanger 1 (ENOX1) is a member of the ecto-NOX family involved in the plasma membrane electron transport pathway. This study aimed to investigate the role of ENOX1 in the development of DR. MATERIALS AND METHODS Human retinal endothelial cells (HRECs) and human retinal pigment epithelial cells (HREpiCs) exposed to a high concentration (25 mM) of D-glucose and type 2 diabetes (T2D) mice (+Leprdb/+Leprdb, db/db) with retinopathy were used as models to determine the ENOX1 expression levels there. RESULTS Our results showed that ENOX1 expression levels did not significantly change in both HRECs and HREpiCs under hyperglycemic conditions for 48 h. Nevertheless, ENOX1 expression increased significantly in T2D mouse retinas, particularly in the photoreceptor layer, compared to the control mouse retinas. CONCLUSION Different retinal ENOX1 expression in T2D mice and control mice suggested that ENOX1 may be involved in DR development.
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Affiliation(s)
- Yu-Chuen Huang
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C.,Department of Medical Research, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Shih-Ping Liu
- Center for Translational Medicine, China Medical University Hospital, Taichung, Taiwan, R.O.C.,Graduate Institute of Biomedical Science, China Medical University, Taichung, Taiwan, R.O.C
| | - Shih-Yin Chen
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C.,Department of Medical Research, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Jane-Ming Lin
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C.,Department of Ophthalmology, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Hui-Ju Lin
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C.,Department of Ophthalmology, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Yu-Jie Lei
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Yeh-Han Wang
- Department of Anatomical Pathology, Taipei Institute of Pathology, Taipei, Taiwan, R.O.C
| | - Wan-Ting Huang
- Department of Public Health, China Medical University, Taichung, Taiwan, R.O.C
| | - Wen-Ling Liao
- Center for Personalized Medicine, China Medical University Hospital, Taichung, Taiwan, R.O.C. .,Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan, R.O.C
| | - Fuu-Jen Tsai
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C. .,School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C.,Children's Hospital of China Medical University, Taichung, Taiwan, R.O.C.,Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan, R.O.C
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46
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A Deep Learning Approach to Denoise Optical Coherence Tomography Images of the Optic Nerve Head. Sci Rep 2019; 9:14454. [PMID: 31595006 PMCID: PMC6783551 DOI: 10.1038/s41598-019-51062-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 09/19/2019] [Indexed: 01/14/2023] Open
Abstract
Optical coherence tomography (OCT) has become an established clinical routine for the in vivo imaging of the optic nerve head (ONH) tissues, that is crucial in the diagnosis and management of various ocular and neuro-ocular pathologies. However, the presence of speckle noise affects the quality of OCT images and its interpretation. Although recent frame-averaging techniques have shown to enhance OCT image quality, they require longer scanning durations, resulting in patient discomfort. Using a custom deep learning network trained with 2,328 'clean B-scans' (multi-frame B-scans; signal averaged), and their corresponding 'noisy B-scans' (clean B-scans + Gaussian noise), we were able to successfully denoise 1,552 unseen single-frame (without signal averaging) B-scans. The denoised B-scans were qualitatively similar to their corresponding multi-frame B-scans, with enhanced visibility of the ONH tissues. The mean signal to noise ratio (SNR) increased from 4.02 ± 0.68 dB (single-frame) to 8.14 ± 1.03 dB (denoised). For all the ONH tissues, the mean contrast to noise ratio (CNR) increased from 3.50 ± 0.56 (single-frame) to 7.63 ± 1.81 (denoised). The mean structural similarity index (MSSIM) increased from 0.13 ± 0.02 (single frame) to 0.65 ± 0.03 (denoised) when compared with the corresponding multi-frame B-scans. Our deep learning algorithm can denoise a single-frame OCT B-scan of the ONH in under 20 ms, thus offering a framework to obtain superior quality OCT B-scans with reduced scanning times and minimal patient discomfort.
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47
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Fu Z, Chen CT, Cagnone G, Heckel E, Sun Y, Cakir B, Tomita Y, Huang S, Li Q, Britton W, Cho SS, Kern TS, Hellström A, Joyal JS, Smith LE. Dyslipidemia in retinal metabolic disorders. EMBO Mol Med 2019; 11:e10473. [PMID: 31486227 PMCID: PMC6783651 DOI: 10.15252/emmm.201910473] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/10/2019] [Accepted: 08/15/2019] [Indexed: 12/24/2022] Open
Abstract
The light‐sensitive photoreceptors in the retina are extremely metabolically demanding and have the highest density of mitochondria of any cell in the body. Both physiological and pathological retinal vascular growth and regression are controlled by photoreceptor energy demands. It is critical to understand the energy demands of photoreceptors and fuel sources supplying them to understand neurovascular diseases. Retinas are very rich in lipids, which are continuously recycled as lipid‐rich photoreceptor outer segments are shed and reformed and dietary intake of lipids modulates retinal lipid composition. Lipids (as well as glucose) are fuel substrates for photoreceptor mitochondria. Dyslipidemia contributes to the development and progression of retinal dysfunction in many eye diseases. Here, we review photoreceptor energy demands with a focus on lipid metabolism in retinal neurovascular disorders.
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Chuck T Chen
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Gael Cagnone
- Department of Pediatrics, Pharmacology and Ophthalmology, CHU Sainte-Justine Research Center, Université de Montréal, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, University of Montreal, Montreal, QC, Canada
| | - Emilie Heckel
- Department of Pediatrics, Pharmacology and Ophthalmology, CHU Sainte-Justine Research Center, Université de Montréal, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, University of Montreal, Montreal, QC, Canada
| | - Ye Sun
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Bertan Cakir
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Yohei Tomita
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Shuo Huang
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Qian Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - William Britton
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Steve S Cho
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA, USA
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Jean-Sébastien Joyal
- Department of Pediatrics, Pharmacology and Ophthalmology, CHU Sainte-Justine Research Center, Université de Montréal, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, University of Montreal, Montreal, QC, Canada
| | - Lois Eh Smith
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
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Wang S, Liu Y, Tan JW, Hu T, Zhang HF, Sorenson CM, Smith JA, Sheibani N. Tunicamycin-induced photoreceptor atrophy precedes degeneration of retinal capillaries with minimal effects on retinal ganglion and pigment epithelium cells. Exp Eye Res 2019; 187:107756. [PMID: 31421136 DOI: 10.1016/j.exer.2019.107756] [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: 02/06/2019] [Revised: 08/10/2019] [Accepted: 08/13/2019] [Indexed: 12/13/2022]
Abstract
Endoplasmic reticulum (ER) stress is recognized as a contributing factor to various ocular neurovascular pathologies including retinitis pigmentosa, glaucoma, and diabetic retinopathy (DR). ER stress in particular is implicated in the development of DR, which is significantly influenced by inflammation driven retinal vascular degeneration and dysfunction. Ultimately, loss of vision occurs if left untreated. However, the identity of the target cells and their temporal involvement in diabetes-mediated dysfunction need further investigation. Early diabetes-induced stress in photoreceptor cells is proposed as the driver of inflammatory mediated neurovascular changes during diabetes. Although tunicamycin induced ER stress results in photoreceptor loss, its consequences for retinal vascular degeneration and retinal ganglion (RGC) and pigment epithelium (RPE) cell loss remains unclear. Here we show intravitreal delivery of tunicamycin primarily induced ER stress in photoreceptor cells resulting in their loss by apoptosis. This was concomitant with induced expression of the unfolded protein response marker CHOP in these cells. We also demonstrated significant degeneration of retinal capillaries following the loss of photoreceptor cells with minimal impact on loss of RGC and RPE cells. However, activation of retinal microglial and Muller cells were noticeable. Thus, our data support the notion that ER stress mediated dysfunction and/or loss of photoreceptor cells in response to inflammation and oxidative stress could precede retinal vascular and neuronal dysfunction and degeneration.
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Affiliation(s)
- Shoujian Wang
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Yiping Liu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jin Wen Tan
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Tiancheng Hu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Christine M Sorenson
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Judith A Smith
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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49
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Dmitriev AV, Henderson D, Linsenmeier RA. Diabetes Alters pH Control in Rat Retina. Invest Ophthalmol Vis Sci 2019; 60:723-730. [PMID: 30786276 PMCID: PMC6383832 DOI: 10.1167/iovs.18-26073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose The purpose of this study was to determine whether the ability of the rat retina to control its pH is affected by diabetes. Methods Double-barreled H+-selective microelectrodes were used to measure extracellular [H+] in the dark-adapted retina of intact control and diabetic Long-Evans rats 1 to 6 months after intraperitoneal injection of vehicle or streptozotocin, respectively. Two manipulations-increasing of blood glucose and intravenous injection of the carbonic anhydrase blocker dorzolamide (DZM)-were used to examine their effects on retinal pH regulation. Results An increase of retinal acidity was correlated with the diabetes-related increase in blood glucose, but only between 1 and 3 months of diabetes, not earlier or later. Adding intravenous glucose had no noticeable effect on the retinal acidity of control animals. In contrast, similar injections of glucose in diabetic rats significantly increased the acidity of the retina. Again, the largest increase of retinal acidity due to artificially elevated blood glucose was observed at 1 to 3 months of diabetes. Suppression of carbonic anhydrase by DZM dramatically increased the retinal acidity in both control and diabetic retinas to a similar degree. However, in controls, the strongest effect of DZM was recorded within 10 minutes after the injection, but in diabetics, the effect tended to increase with time and after 2 hours could be two to three times larger than at the beginning. Conclusions During development of diabetes in rats, the control over retinal pH is partly compromised so that conditions that perturb retinal pH lead to larger and/or more sustained changes than in control animals.
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Affiliation(s)
- Andrey V Dmitriev
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | - Desmond Henderson
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | - Robert A Linsenmeier
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States.,Neurobiology Department, Northwestern University, Evanston, Illinois, United States.,Ophthalmology Department, Northwestern University, Chicago, Illinois, United States
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50
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Kommula SR, Vadakattu SS, Myadara S, Putcha UK, Tamanam RR, Palla S. Cinnamon Attenuated Long-Term IGT-Induced Retinal Abnormalities via Regulation of Glucose Homeostasis in Neonatal Streptozotocin Induced Rat Model. Indian J Clin Biochem 2019; 35:442-450. [PMID: 33013014 DOI: 10.1007/s12291-019-00842-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 07/02/2019] [Indexed: 11/26/2022]
Abstract
Diabetic retinopathy (DR) is one of the major causes of blindness all over the world. According to the previous studies, impaired glucose tolerance (IGT) has been linked to retinal dysfunction/vascular damage. Decreased retinal function is an initial event of early DR. Although the biochemical and molecular events are not fully understood, glial activation, angiogenesis and oxidative stress are some of the pathways associated with early retinal abnormalities. Since IGT is associated with development of retinal dysfunction/vascular damage; as a preventive strategy, we have studied beneficial effect of Cinnamon as a hypoglycaemic agent on long-term IGT induced retinal abnormalities using neonatal streptozotocin (nSTZ) rat model. Control, IGT rats were maintained on AIN-93M diet alone and another set of IGT rats were maintained on AIN-93M diet with 3% Cinnamon for 8 months. At the end of the study, untreated IGT rats developed retinal functional abnormalities as assessed by electroretinogram (ERG) and the retinal structure did not alter as assessed by H&E staining. Further, increase in expressions of GFAP, VEGF and decreased expression of rhodopsin in untreated IGT rat retinas. 4-HNE, a marker of oxidative stress was also elevated in IGT state. Supplementation of Cinnamon to IGT rats had lowered fasting and postprandial glucose levels and also prevented retinal functional abnormalities. Further, Cinnamon protected photoreceptor cell damage, suppressed glial activation, angiogenesis and oxidative stress as there was an improved rhodopsin expression, inhibited elevated expressions of GFAP, VEGF and 4-HNE respectively. In conclusion, Cinnamon attenuated IGT induced retinal abnormalities probably through its hypoglycemic property.
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Affiliation(s)
- Sivakesava Rao Kommula
- Lipid Chemistry Division, National Institute of Nutrition, Jamai-Osmania, Hyderabad, 500007 India
| | - Sai Santhosh Vadakattu
- Lipid Chemistry Division, National Institute of Nutrition, Jamai-Osmania, Hyderabad, 500007 India
| | - Srinivas Myadara
- Pathology Division, National Institute of Nutrition, Hyderabad, India
| | - Uday Kumar Putcha
- Pathology Division, National Institute of Nutrition, Hyderabad, India
| | | | - Suryanarayana Palla
- Lipid Chemistry Division, National Institute of Nutrition, Jamai-Osmania, Hyderabad, 500007 India
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