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Abstract
Although diabetic retinopathy (DR) is clinically diagnosed as a vascular disease, many studies find retinal neuronal and visual dysfunction before the onset of vascular DR. This suggests that DR should be viewed as a neurovascular disease. Prior to the onset of DR, human patients have compromised electroretinograms that indicate a disruption of normal function, particularly in the inner retina. They also exhibit reduced contrast sensitivity. These early changes, especially those due to dysfunction in the inner retina, are also seen in rodent models of diabetes in the early stages of the disease. Rodent models of diabetes exhibit several neuronal mechanisms, such as reduced evoked GABA release, increased excitatory glutamate signaling, and reduced dopamine signaling, that suggest specific neuronal deficits. This suggests that understanding neuronal deficits may lead to early diabetes treatments to ameliorate neuronal dysfunction.
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Affiliation(s)
- Erika D Eggers
- Departments of Physiology and Biomedical Engineering, University of Arizona, Tucson, Arizona, USA;
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2
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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: 88] [Impact Index Per Article: 29.3] [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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3
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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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4
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Abstract
Diabetic retinopathy is now well understood as a neurovascular disease. Significant deficits early in diabetes are found in the inner retina that consists of bipolar cells that receive inputs from rod and cone photoreceptors, ganglion cells that receive inputs from bipolar cells, and amacrine cells that modulate these connections. These functional deficits can be measured in vivo in diabetic humans and animal models using the electroretinogram (ERG) and behavioral visual testing. Early effects of diabetes on both the human and animal model ERGs are changes to the oscillatory potentials that suggest dysfunctional communication between amacrine cells and bipolar cells as well as ERG measures that suggest ganglion cell dysfunction. These are coupled with changes in contrast sensitivity that suggest inner retinal changes. Mechanistic in vitro neuronal studies have suggested that these inner retinal changes are due to decreased inhibition in the retina, potentially due to decreased gamma aminobutyric acid (GABA) release, increased glutamate release, and increased excitation of retinal ganglion cells. Inner retinal deficits in dopamine levels have also been observed that can be reversed to limit inner retinal damage. Inner retinal targets present a promising new avenue for therapies for early-stage diabetic eye disease.
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5
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Abstract
Vision loss, among the most feared complications of diabetes, is primarily caused by diabetic retinopathy, a disease that manifests in well-recognized, characteristic microvascular lesions. The reasons for retinal susceptibility to damage in diabetes are unclear, especially considering that microvascular networks are found in all tissues. However, the unique metabolic demands of retinal neurons could account for their vulnerability in diabetes. Photoreceptors are the first neurons in the visual circuit and are also the most energy-demanding cells of the retina. Here, we review experimental and clinical evidence linking photoreceptors to the development of diabetic retinopathy. We then describe the influence of retinal illumination on photoreceptor metabolism, effects of light modulation on the severity of diabetic retinopathy, and recent clinical trials testing the treatment of diabetic retinopathy with interventions that impact photoreceptor metabolism. Finally, we introduce several possible mechanisms that could link photoreceptor responses to light and the development of retinal vascular disease in diabetes. Collectively, these concepts form the basis for a growing body of investigative efforts aimed at developing novel pharmacologic and nonpharmacologic tools that target photoreceptor physiology to treat a very common cause of blindness across the world.
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Abstract
Blood flow in the retina increases in response to light-evoked neuronal activity, ensuring that retinal neurons receive an adequate supply of oxygen and nutrients as metabolic demands vary. This response, termed "functional hyperemia," is disrupted in diabetic retinopathy. The reduction in functional hyperemia may result in retinal hypoxia and contribute to the development of retinopathy. This review will discuss the neurovascular coupling signaling mechanisms that generate the functional hyperemia response in the retina, the changes to neurovascular coupling that occur in diabetic retinopathy, possible treatments for restoring functional hyperemia and retinal oxygen levels, and changes to functional hyperemia that occur in the diabetic brain.
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7
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Thebeau C, Zhang S, Kolesnikov AV, Kefalov VJ, Semenkovich CF, Rajagopal R. Light deprivation reduces the severity of experimental diabetic retinopathy. Neurobiol Dis 2020; 137:104754. [PMID: 31978605 DOI: 10.1016/j.nbd.2020.104754] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/13/2020] [Accepted: 01/20/2020] [Indexed: 12/30/2022] Open
Abstract
Illumination of the retina is a major determinant of energy expenditure by its neurons. However, it remains unclear whether light exposure significantly contributes to the pathophysiology of common retinal disease. Driven by the premise that light exposure reduces the metabolic demand of the retina, recent clinical trials failed to demonstrate a benefit for constant illumination in the treatment of diabetic retinopathy. Here, we instead ask whether light deprivation or blockade of visual transduction could modulate the severity of this common cause of blindness. We randomized adult mice with two different models of diabetic retinopathy to 1-3 months of complete dark housing. Unexpectedly, we find that diabetic mice exposed to short or prolonged light deprivation have reduced diabetes-induced retinal pathology, using measures of visual function, compared to control animals in standard lighting conditions. To corroborate these results, we performed assays of retinal vascular health in diabetic Gnat1-/- and Rpe65-/- mice, which lack phototransduction. Both mutants displayed less diabetes-associated retinal vascular disease compared to respective wild-type controls. Collectively, these results suggest that light-induced visual transduction promotes the development of diabetic retinopathy and implicate photoreceptors as an early source of visual pathology in diabetes.
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Affiliation(s)
- Christina Thebeau
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Sheng Zhang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Alexander V Kolesnikov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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Liu H, Tang J, Du Y, Saadane A, Samuels I, Veenstra A, Kiser JZ, Palczewski K, Kern TS. Transducin1, Phototransduction and the Development of Early Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2019; 60:1538-1546. [PMID: 30994864 PMCID: PMC6736377 DOI: 10.1167/iovs.18-26433] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/14/2019] [Indexed: 12/31/2022] Open
Abstract
Purpose Recent evidence suggests that retinal photoreceptor cells have an important role in the pathogenesis of retinal microvascular lesions in diabetes. We investigated the role of rod cell phototransduction on the pathogenesis of early diabetic retinopathy (DR) using Gnat1-/- mice (which causes permanent inhibition of phototransduction in rod cells without degeneration). Methods Retinal thickness, oxidative stress, expression of inflammatory proteins, electroretinograms (ERG) and optokinetic responses, and capillary permeability and degeneration were evaluated at up to 8 months of diabetes. Results The diabetes-induced degeneration of retinal capillaries was significantly inhibited in the Gnat1-/- diabetics. The effect of the Gnat1 deletion on the diabetes-induced increase in permeability showed a nonuniform accumulation of albumin in the neural retina; the defect was inhibited in diabetic Gnat1-/- mice in the inner plexiform layer (IPL), but neither in the outer plexiform (OPL) nor inner nuclear (INL) layers. In Gnat1-deficient animals, the diabetes-induced increase in expression of inflammatory associated proteins (iNOS and ICAM-1, and phosphorylation of IĸB) in the retina, and the leukocyte mediated killing of retinal endothelial cells were inhibited, however the diabetes-mediated induction of oxidative stress was not inhibited. Conclusions In conclusion, deletion of transducin1 (and the resulting inhibition of phototransduction in rod cells) inhibits the development of retinal vascular pathology in early DR.
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Affiliation(s)
- Haitao Liu
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jie Tang
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Yunpeng Du
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Aicha Saadane
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Ivy Samuels
- Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, United States
- Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States
| | - Alex Veenstra
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jianying Z. Kiser
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Krzysztof Palczewski
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States
| | - Timothy S. Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
- Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, United States
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States
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McDowell RE, Barabas P, Augustine J, Chevallier O, McCarron P, Chen M, McGeown JG, Curtis TM. Müller glial dysfunction during diabetic retinopathy in rats is reduced by the acrolein-scavenging drug, 2-hydrazino-4,6-dimethylpyrimidine. Diabetologia 2018; 61:2654-2667. [PMID: 30112688 PMCID: PMC6223850 DOI: 10.1007/s00125-018-4707-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/09/2018] [Indexed: 01/15/2023]
Abstract
AIMS/HYPOTHESIS Recent studies suggest that abnormal function in Müller glial cells plays an important role in the pathogenesis of diabetic retinopathy. This is associated with the selective accumulation of the acrolein-derived advanced lipoxidation end-product, Nε-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine), on Müller cell proteins. The aim of the current study was to identify more efficacious acrolein-scavenging drugs and determine the effects of the most potent on Müller cell FDP-lysine accumulation and neuroretinal dysfunction during diabetes. METHODS An ELISA-based in vitro assay was optimised to compare the acrolein-scavenging abilities of a range of drugs. This identified 2-hydrazino-4,6-dimethylpyrimidine (2-HDP) as a new and potent acrolein scavenger. The ability of this agent to modify the development of diabetic retinopathy was tested in vivo. Male Sprague Dawley rats were divided into three groups: (1) non-diabetic; (2) streptozotocin-induced diabetic; and (3) diabetic treated with 2-HDP in their drinking water for the duration of diabetes. Liquid chromatography high-resolution mass spectrometry was used to detect 2-HDP reaction products in the retina. Immunohistochemistry, real-time quantitative (q)RT-PCR and electroretinography were used to assess retinal changes 3 months after diabetes induction. RESULTS 2-HDP was the most potent of six acrolein-scavenging agents tested in vitro (p < 0.05). In vivo, administration of 2-HDP reduced Müller cell accumulation of FDP-lysine at 3 months in rats rendered diabetic with streptozotocin (p < 0.001). A 2-HDP adduct was identified in the retinas of diabetic animals treated with this compound. 2-HDP supplementation was associated with reduced Müller cell gliosis (p < 0.05), reduced expression of the oxidative stress marker haem oxygenase-1 (p < 0.001) and partial normalisation of inwardly rectifying K+ channel 4.1 (Kir4.1) expression (p < 0.001 for staining in perivascular regions and the innermost region of the ganglion cell layer). Diabetes-induced retinal expression of inflammatory markers, inflammatory signalling compounds and activation of retinal microglial cells were all reduced in 2-HDP-treated animals. Retinal neurophysiological defects in diabetic animals, as indicated by changes in the electroretinogram 7 weeks after induction of diabetes, were also reduced by 2-HDP (p < 0.05-0.01 for b-wave amplitudes at flash intensities from -10 to +10 dB; p < 0.01 for time to peak of summed oscillatory potentials at +10 dB). CONCLUSIONS/INTERPRETATION These findings support the hypothesis that Müller cell accumulation of FDP-lysine plays an important role in the development of diabetic retinopathy. Our results also suggest that 2-HDP may have therapeutic potential for delaying or treating this sight-threatening complication.
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Affiliation(s)
- Rosemary E McDowell
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Peter Barabas
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Josy Augustine
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Olivier Chevallier
- Advanced Mass Spectrometry Core Technology Unit, Faculty of Medicine, Health and Life Sciences, Queen's University Belfast, Belfast, UK
| | - Philip McCarron
- Advanced Mass Spectrometry Core Technology Unit, Faculty of Medicine, Health and Life Sciences, Queen's University Belfast, Belfast, UK
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - J Graham McGeown
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Tim M Curtis
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK.
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Loss of CD40 attenuates experimental diabetes-induced retinal inflammation but does not protect mice from electroretinogram defects. Vis Neurosci 2018; 34:E009. [PMID: 28965505 DOI: 10.1017/s0952523817000074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chronic low grade inflammation is considered to contribute to the development of experimental diabetic retinopathy (DR). We recently demonstrated that lack of CD40 in mice ameliorates the upregulation of inflammatory molecules in the diabetic retina and prevented capillary degeneration, a hallmark of experimental diabetic retinopathy. Herein, we investigated the contribution of CD40 to diabetes-induced reductions in retinal function via the electroretinogram (ERG) to determine if inflammation plays a role in the development of ERG defects associated with diabetes. We demonstrate that diabetic CD40-/- mice are not protected from reduction to the ERG b-wave despite failing to upregulate inflammatory molecules in the retina. Our data therefore supports the hypothesis that retinal dysfunction found in diabetics occurs independent of the induction of inflammatory processes.
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Guo X, Liu X. Nogo receptor knockdown and ciliary neurotrophic factor attenuate diabetic retinopathy in streptozotocin-induced diabetic rats. Mol Med Rep 2017; 16:2030-2036. [PMID: 28656312 PMCID: PMC5562098 DOI: 10.3892/mmr.2017.6850] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 06/08/2017] [Indexed: 12/14/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes mellitus (DM). We investigated whether Nogo receptor (NgR) knockdown and ciliary neurotrophic factor (CNTF) treatment, either alone or in combination, ameliorated diabetic retinopathy (DR) in diabetic rat model. STZ‑induced diabetic rats were administrated for a total of 12 weeks with 3 µM siRNA (5 µl) once every 6 weeks and/or 1 µg CNTF weekly. The retinal tissues were excised. We measured cell number in ganglion cell layer (GCL) using H&E staining and cell apoptosis using TUNEL assay. Bax, Bcl‑2, Caspase‑3, F‑actin, GAP‑43, NgR, RhoA and Rock1 levels were then analyzed by Western blotting, Immunohistochemistry or Real‑time PCR. We found that NgR siRNA or CNTF injection alone significantly increased cell count in GCL in diabetic rats, inhibited ganglion cell apoptosis, elevated Bcl‑2, F‑actin and GAP‑43, and decreased Bax, Caspase‑3, NgR, RhoA and Rock1 levels. Combination treatment further prevented retinal ganglion cell loss, enhanced growth cone cytoskeleton and axonal regeneration, and suppressed NgR/RhoA/Rock1. Our results indicate that combination therapy has therapeutic potential for the treatment of DR.
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Affiliation(s)
- Xiliang Guo
- Department of Human Anatomy, School of Basic Medical Sciences, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
- Department of Anatomy, School of Basic Medical Sciences, Jinzhou Medical University, Jinzhou, Liaoning 121001, P.R. China
| | - Xuezheng Liu
- Department of Human Anatomy, School of Basic Medical Sciences, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
- Department of Anatomy, School of Basic Medical Sciences, Jinzhou Medical University, Jinzhou, Liaoning 121001, P.R. China
- Correspondence to: Dr Xuezheng Liu, Department of Human Anatomy, School of Basic Medical Sciences, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi 530021, P.R. China, E-mail:
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12
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Do photoreceptor cells cause the development of retinal vascular disease? Vision Res 2017; 139:65-71. [PMID: 28438678 DOI: 10.1016/j.visres.2017.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
The retinal vasculature is affected in a number of clinically important retinopathies, including diabetic retinopathy. There has been a considerable amount of research into the pathogenesis of retinal microvascular diseases, but the potential contribution of the most abundant cell population in the retina, photoreceptor cells, has been largely overlooked. This review summarizes ongoing research suggesting that photoreceptor cells play a critical role in the development of retinal vascular disease in diabetic retinopathy and other retinopathies.
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Goharinia M, Zareei A, Rahimi M, Mirkhani H. Can allopurinol improve retinopathy in diabetic rats? Oxidative stress or uric acid; which one is the culprit? Res Pharm Sci 2017; 12:401-408. [PMID: 28974978 PMCID: PMC5615870 DOI: 10.4103/1735-5362.213985] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Allopurinol, an inhibitor of xanthine oxidase, reduces both plasma uric acid and oxidative stress and shows useful effects on some complications of diabetes. However, it is not defined which of the above mentioned properties are involved. Moreover, to the best of our knowledge no study has been done on the effects of allopurinol on diabetic retinopathy. In the present study, the effect of allopurinol on experimental diabetic retinopathy and its possible mechanism has been investigated. Thirty two rats were divided into four groups of eight rats each; (1) normal, (2) diabetic control, (3) diabetic + allopurinol (50 mg/kg.day), (4) diabetic + benzbromarone (10 mg/kg.day). Drugs were administered daily and orally from the day after diabetes induction for eight weeks. Thereafter retinal function and structure were evaluated by electroretinography and microscopic studies. Uric acid and oxidative stress biomarkers were measured biochemically. Diabetes significantly increased plasma uric acid and oxidative stress markers and reduced body weight and amplitude of electroretinogram (ERG) b-wave and oscillatory potentials. Treatment of diabetic rats with allopurinol caused a significant increase in the amplitude of ERG b-wave (87%) and decrease in blood sugar (20%), uric acid (49%), and 8-iso-prostaglandin F2a (56%), but had no effect on the number of retinal ganglionic cells and oscillatory potentials. Benzbromarone showed no significant effects on the considered parameters except the reduction of uric acid. Allopurinol improved the b-wave amplitude of diabetic rats. It seems that this beneficial effect is due to the reduction of oxidative stress rather than its effect on plasma uric acid.
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Affiliation(s)
- Mohsen Goharinia
- Department of Pharmacology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Athar Zareei
- Department of Ophthalmology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Mansour Rahimi
- Department of Ophthalmology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Hossein Mirkhani
- Department of Pharmacology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran.,Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
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