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Altera A, Barone V, Kondova I, Langermans JAM, Gentile M, Pin C, Nicoletti C, Bertelli E. Light-Induced Smooth Endoplasmic Reticulum Rearrangement in a Unique Interlaced Compartmental Pattern in Macaca mulatta RPE. Invest Ophthalmol Vis Sci 2021; 62:32. [PMID: 34967853 PMCID: PMC8727310 DOI: 10.1167/iovs.62.15.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose To investigate light-induced modifications of the smooth endoplasmic reticulum of the RPE in primates. Methods Eyes of three terminally anesthetized Rhesus monkeys were exposed to 5000 lux for 10 minutes or kept in the dark. Transmission electron microscopy and electron tomography were conducted on small fragments of retina sampled from different regions of the retina. Results RPE cells smooth endoplasmic reticulum shows a previously unknown arrangement characterized by an interlaced compartmental pattern (ICP). Electron tomograms and 3D-modelling demonstrated that the smooth endoplasmic reticulum with an ICP (ICPSER) consisted of four parallel, independent and interwoven networks of tubules arranged as interconnected coiled coils. Its architecture realized a compact labyrinthine structure of tightly packed tubules stabilized by intertubular filamentous tethers. On average, the ICPSER is present in about 14.6% of RPE cells. Although ICPSER was preferentially found in cells located in the peripheral and in the para/perifoveal retina, ICPSER cells significantly increased in number upon light exposure in the para/perifovea and in the fovea. Conclusions An ICPSER is apparently a unique feature to primate RPE. Its rapid appearance in the area centralis of the retina upon light exposure suggests a function related to the foveate structure of primate retina or to the diurnal habits of animals that may require additional protection from photo-oxidation or enhanced requests of visual pigments regeneration.
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Affiliation(s)
- Annalisa Altera
- Department of Life Sciences, University of Siena, Siena, Italy.,Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Virginia Barone
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Ivanela Kondova
- Division of Pathology and Microbiology, Animal Science Department, Biomedical Primate Research Centre, Rijswijk, the Netherlands
| | - Jan A M Langermans
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, the Netherlands.,Department Population Health Sciences, Division Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | | | - Carmen Pin
- Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Claudio Nicoletti
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Eugenio Bertelli
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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Mechanisms and Treatment of Light-Induced Retinal Degeneration-Associated Inflammation: Insights from Biochemical Profiling of the Aqueous Humor. Int J Mol Sci 2020; 21:ijms21030704. [PMID: 31973128 PMCID: PMC7038222 DOI: 10.3390/ijms21030704] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 01/17/2020] [Indexed: 12/21/2022] Open
Abstract
Ocular inflammation contributes to the pathogenesis of blind-causing retinal degenerative diseases, such as age-related macular degeneration (AMD) or photic maculopathy. Here, we report on inflammatory mechanisms that are associated with retinal degeneration induced by bright visible light, which were revealed while using a rabbit model. Histologically and electrophysiologically noticeable degeneration of the retina is preceded and accompanied by oxidative stress and inflammation, as evidenced by granulocyte infiltration and edema in this tissue, as well as the upregulation of total protein, pro-inflammatory cytokines, and oxidative stress markers in aqueous humor (AH). Consistently, quantitative lipidomic studies of AH elucidated increase in the concentration of arachidonic (AA) and docosahexaenoic (DHA) acids and lyso-platelet activating factor (lyso-PAF), together with pronounced oxidative and inflammatory alterations in content of lipid mediators oxylipins. These alterations include long-term elevation of prostaglandins, which are synthesized from AA via cyclooxygenase-dependent pathways, as well as a short burst of linoleic acid derivatives that can be produced by both enzymatic and non-enzymatic free radical-dependent mechanisms. The upregulation of all oxylipins is inhibited by the premedication of the eyes while using mitochondria-targeted antioxidant SkQ1, whereas the accumulation of prostaglandins and lyso-PAF can be specifically suppressed by topical treatment with cyclooxygenase inhibitor Nepafenac. Interestingly, the most prominent antioxidant and anti-inflammatory benefits and overall retinal protective effects are achieved by simultaneous administrating of both drugs indicating their synergistic action. Taken together, these findings provide a rationale for using a combination of mitochondria-targeted antioxidant and cyclooxygenase inhibitor for the treatment of inflammatory components of retinal degenerative diseases.
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Verma AK, Singh S, Rizvi SI. Redox homeostasis in a rodent model of circadian disruption: Effect of melatonin supplementation. Gen Comp Endocrinol 2019; 280:97-103. [PMID: 31002824 DOI: 10.1016/j.ygcen.2019.04.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 12/22/2022]
Abstract
Continuous light or dark photoperiods are the leading cause of disruption in the circadian rhythm of day-night cycle. The purpose of this study was to understand the cellular redox balance in a model of circadian disrupted rat model and determine the effect of melatonin supplementation. Young male Wistar rats were randomly divided into five groups (n = 4). Group (I): normal day-night (12 h:12 h) cycle, Group (II): normal rats treated with melatonin, Group (III): rats subjected to continuous light exposure (CLE), Group (IV): CLE rats treated with melatonin, and Group (V) Rats subjected to continuous dark. Melatonin (10 mg/kg) was administered orally at dusk to the Group (II) & (IV). Rats were sacrificed after 10 days of treatment and biomarkers of oxidative stress were evaluated. Results demonstrated significant (p < 0.05) increase of malondialdehyde (MDA), plasma membrane redox system (PMRS), protein carbonyl oxidation (PCO), advanced oxidation protein products (AOPPs), and advanced glycation end products (AGEs) during CLE. A significantly (p < 0.05) decreased level of reduced glutathione (GSH) and ferric reducing antioxidant potential in plasma (FRAP) was also observed during CLE. Treatment with melatonin in CLE rats showed reduced level of MDA, PMRS, PCO, AOPPs and AGEs while GSH and FRAP activity were increased. During continuous dark exposure (CDE) the biomarkers of oxidative stress were attenuated compared to control. Supplementation of melatonin could be a promising strategy to maintain redox homeostasis during prolonged condition of light exposure and other conditions of redox imbalance.
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Affiliation(s)
- Avnish Kumar Verma
- Department of Biochemistry, University of Allahabad, Allahabad 211002, India
| | - Sandeep Singh
- Department of Biochemistry, University of Allahabad, Allahabad 211002, India
| | - Syed Ibrahim Rizvi
- Department of Biochemistry, University of Allahabad, Allahabad 211002, India.
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Shibagaki K, Okamoto K, Katsuta O, Nakamura M. Beneficial protective effect of pramipexole on light-induced retinal damage in mice. Exp Eye Res 2015. [PMID: 26213307 DOI: 10.1016/j.exer.2015.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We investigated the effects of pramipexole, a potent dopamine receptor D2/D3 agonist, on light-induced retinal damage in mice, H2O2-induced retinal pigment epithelium ARPE-19 cell injury in humans, and hydroxyl radical scavenging activity in a cell-free system. Pramipexole (0.1 and 1 mg/kg body weight) was orally administered to mice 1 h before light exposure (5000 lux, 2 h). Electrophysiological and morphologic studies were performed to evaluate the effects of the pramipexole on light-induced retinal damage in mice. Pramipexole significantly prevented the reduction of the a- and b-wave electroretinogram (ERG) amplitudes caused by light exposure in a dose-dependent manner. In parallel, damage to the inner and outer segments (IS/OS) of the photoreceptors, loss of photoreceptor nuclei, and the number of Tdt-mediated dUTP nick-end labeling (TUNEL)-positive cells in the outer nuclear layer (ONL) caused by light exposure were notably ameliorated by pramipexole. Additionally, pramipexole suppressed H2O2-induced ARPE-19 cell death in vitro in a concentration-dependent manner. The effect of pramipexole was significant at concentrations of 10(-6) M or higher. Pramipexole also significantly prevented H2O2-induced activation of caspases-3/7 and the intracellular accumulation of reactive oxygen species (ROS) in a concentration-dependent manner ranging from 10(-5) to 10(-3) M. Furthermore, pramipexole increased the scavenging activity toward a hydroxyl radical generated from H2O2 in a Fenton reaction. Our results suggest that pramipexole protects against light-induced retinal damage as an antioxidant and that it may be a novel and effective therapy for retinal degenerative disorders, such as dry age-related macular degeneration.
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Affiliation(s)
- Keiichi Shibagaki
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan; Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma-shi, Nara 630-0192, Japan.
| | - Kazuyoshi Okamoto
- Corporate Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
| | - Osamu Katsuta
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
| | - Masatsugu Nakamura
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
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Njie-Mbye YF, Kulkarni-Chitnis M, Opere CA, Barrett A, Ohia SE. Lipid peroxidation: pathophysiological and pharmacological implications in the eye. Front Physiol 2013; 4:366. [PMID: 24379787 PMCID: PMC3863722 DOI: 10.3389/fphys.2013.00366] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/25/2013] [Indexed: 01/17/2023] Open
Abstract
Oxygen-derived free radicals such as hydroxyl and hydroperoxyl species have been shown to oxidize phospholipids and other membrane lipid components leading to lipid peroxidation. In the eye, lipid peroxidation has been reported to play an important role in degenerative ocular diseases (age-related macular degeneration, cataract, glaucoma, diabetic retinopathy). Indeed, ocular tissues are prone to damage from reactive oxygen species due to stress from constant exposure of the eye to sunlight, atmospheric oxygen and environmental chemicals. Furthermore, free radical catalyzed peroxidation of long chain polyunsaturated acids (LCPUFAs) such as arachidonic acid and docosahexaenoic acid leads to generation of LCPUFA metabolites including isoprostanes and neuroprostanes that may further exert pharmacological/toxicological actions in ocular tissues. Evidence from literature supports the presence of endogenous defense mechanisms against reactive oxygen species in the eye, thereby presenting new avenues for the prevention and treatment of ocular degeneration. Hydrogen peroxide (H2O2) and synthetic peroxides can exert pharmacological and toxicological effects on tissues of the anterior uvea of several mammalian species. There is evidence suggesting that the retina, especially retinal ganglion cells can exhibit unique characteristics of antioxidant defense mechanisms. In the posterior segment of the eye, H2O2 and synthetic peroxides produce an inhibitory action on glutamate release (using [(3)H]-D-aspartate as a marker), in vitro and on the endogenous glutamate and glycine concentrations in vivo. In addition to peroxides, isoprostanes can elicit both excitatory and inhibitory effects on norepinephrine (NE) release from sympathetic nerves in isolated mammalian iris ciliary bodies. Whereas isoprostanes attenuate dopamine release from mammalian neural retina, in vitro, these novel arachidonic acid metabolites exhibit a biphasic regulatory effect on glutamate release from retina and can regulate amino acid neurotransmitter metabolism without inducing cell death in the retina. Furthermore, there appears to be an inhibitory role for neuroprostanes in the release of excitatory amino acid neurotransmitters in mammalian retina. The ability of peroxides and metabolites of LCPUFA to alter the integrity of neurotransmitter pools provides new potential target sites and pathways for the treatment of degenerative ocular diseases.
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Affiliation(s)
- Ya Fatou Njie-Mbye
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University Houston, TX, USA
| | - Madhura Kulkarni-Chitnis
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University Houston, TX, USA
| | - Catherine A Opere
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University Omaha, NE, USA
| | - Aaron Barrett
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University Omaha, NE, USA
| | - Sunny E Ohia
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University Houston, TX, USA
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6
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Falsini B, Bush RA, Sieving PA. Neuroprotection. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00037-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Strassburg K, Huijbrechts AML, Kortekaas KA, Lindeman JH, Pedersen TL, Dane A, Berger R, Brenkman A, Hankemeier T, van Duynhoven J, Kalkhoven E, Newman JW, Vreeken RJ. Quantitative profiling of oxylipins through comprehensive LC-MS/MS analysis: application in cardiac surgery. Anal Bioanal Chem 2012; 404:1413-26. [PMID: 22814969 PMCID: PMC3426673 DOI: 10.1007/s00216-012-6226-x] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/21/2012] [Accepted: 06/22/2012] [Indexed: 10/28/2022]
Abstract
Oxylipins, including eicosanoids, affect a broad range of biological processes, such as the initiation and resolution of inflammation. These compounds, also referred to as lipid mediators, are (non-) enzymatically generated by oxidation of polyunsaturated fatty acids such as arachidonic acid (AA). A plethora of lipid mediators exist which makes the development of generic analytical methods challenging. Here we developed a robust and sensitive targeted analysis platform for oxylipins and applied it in a biological setting, using high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) operated in dynamic multiple reaction monitoring (dMRM). Besides the well-described AA metabolites, oxylipins derived from linoleic acid, dihomo-γ-linolenic acid, α-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid were included. Our comprehensive platform allows the quantitative evaluation of approximately 100 oxylipins down to low nanomolar levels. Applicability of the analytical platform was demonstrated by analyzing plasma samples of patients undergoing cardiac surgery. Altered levels of some of the oxylipins, especially in certain monohydroxy fatty acids such as 12-HETE and 12-HEPE, were observed in samples collected before and 24 h after cardiac surgery. These findings indicate that this generic oxylipin profiling platform can be applied broadly to study these highly bioactive compounds in relation to human disease.
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Affiliation(s)
- Katrin Strassburg
- Leiden Amsterdam Centre for Drug Research, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Annemarie M. L. Huijbrechts
- Department of Metabolic and Endocrine Diseases, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Kirsten A. Kortekaas
- Department of Cardiothoracic Surgery, Leiden University Medical Center, Albinusdreef 2-Dialyse BO-P, 2333 ZA Leiden, The Netherlands
| | - Jan H. Lindeman
- Department of General Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Theresa L. Pedersen
- USDA-ARS Western Human Nutrition Research Center, 430 West Health Sciences, Davis, CA USA
| | - Adrie Dane
- Leiden Amsterdam Centre for Drug Research, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Ruud Berger
- Department of Metabolic and Endocrine Diseases, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Arjan Brenkman
- Department of Metabolic and Endocrine Diseases, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Thomas Hankemeier
- Leiden Amsterdam Centre for Drug Research, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - John van Duynhoven
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Unilever Research and Development, Olivier van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Eric Kalkhoven
- Department of Metabolic and Endocrine Diseases, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - John W. Newman
- USDA-ARS Western Human Nutrition Research Center, 430 West Health Sciences, Davis, CA USA
- Department of Nutrition, University of California, 430 West Health Sciences, Davis, CA USA
| | - Rob J. Vreeken
- Leiden Amsterdam Centre for Drug Research, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Department of Analytical BioSciences, Leiden Amsterdam Centre for Drug Research, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
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8
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Jamil J, Wright A, Harrison N, Kegey E, Flowers AF, Flyod NJ, Kotera C, Guy A, Galano JM, Durand T, Njie-Mbye YF, Ohia SE, Opere CA. Regulation of [³H]d-aspartate release by the 5-F(2t)-isoprostane and its 5-epimer in isolated bovine retina. Neurochem Res 2011; 37:574-82. [PMID: 22081406 DOI: 10.1007/s11064-011-0645-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/25/2011] [Accepted: 11/02/2011] [Indexed: 11/25/2022]
Abstract
We have evidence that 15-F₂-isoprostanes (15-F₂-IsoPs) regulate excitatory neurotransmitter release in ocular tissues. Although 5-F₂-IsoPs are abundantly produced in mammals, their pharmacological actions on neurotransmitter release remain unknown. In the present study, we compared the effect of the 5-F₂-IsoP epimer pair, 5-F(2t)-IsoP (C5-OH in β-position) and 5-epi-5-F(2t)-IsoP (C5-OH in α-position), on K⁺-evoked [³H]D-aspartate release in isolated bovine retina. We further examined the role of prostanoid receptors on the inhibitory action of 5-epi-5-F(2t)-IsoP on [³H]D-aspartate overflow. Isolated bovine retina were prepared for studies of K⁺-evoked release of [³H]D-aspartate using the superfusion method. 5-epi-5-F(2t)-IsoP (0.01 nM to 1 μM), attenuated K⁺-evoked [³H]D-aspartate release in a concentration-dependent manner, with the inhibitory effect of 26.9% (P < 0.001; IC₂₅ = 0.2 μM) being achieved at 1 μM concentration. Its 5-(S)-OH-epimer, 5-F(2t)-IsoP (0.1 nM-1 μM), exhibited an inhibitory biphasic action, yielding a maximal response of 35.7% (P < 0.001) at 10 nM concentration of the drug (IC₂₅ value of 3 nM). Although the prostanoid-receptor antagonists, AH 6809 (10 μM; EP₁₋₃/DP) and BAY-u3405 (10 μM; DP/Tx) exhibited no effect on 5-epi-5-F(2t)-IsoP (10 nM-1 μM)-mediated inhibition, SC-19220 (1 μM; EP₁) completely reversed 5-epi-5-F(2t)-IsoP (0.1 μM and 1 μM)-induced attenuation of K⁺-evoked [³H]D-aspartate release. Similarly, both SC-51322 (10 μM; EP₁ and AH 23848 (1 μM; EP₄) reversed the inhibitory action elicited by 5-epi-5-F(2t)-IsoP (0.1 μM) on the neurotransmitter release. We conclude that the 5-F₂-IsoP epimer pair, 5-F(2t)-IsoP and 5-epi-5-F(2t)-IsoP, attenuate K⁺-induced [³H]D-aspartate release in isolated bovine retina presumably via prostanoid receptor dependent mechanisms. The trans-orientation of the allylic hydroxyl group at position C5 accounts for the apparent biphasic response exhibited by 5-F(2t)-IsoP on excitatory neurotransmitter release.
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Affiliation(s)
- Jamal Jamil
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University Medical Center, 2500 California Plaza, Omaha, NE 68178, USA
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Tanito M, Brush RS, Elliott MH, Wicker LD, Henry KR, Anderson RE. Correlation between tissue docosahexaenoic acid levels and susceptibility to light-induced retinal degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 664:567-73. [PMID: 20238060 DOI: 10.1007/978-1-4419-1399-9_65] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
In a mouse model of acute light-induced retinal degeneration, positive correlations between the levels of DHA, the levels of n3 PUFA lipid peroxidation, and the vulnerability to photooxidative stress were observed. On the other hand, higher sensitivity of the electroretinogram a-wave response, a measure of the amplification of the phototransduction cascade, was correlated with higher retinal DHA levels. These results highlight the dual roles of DHA in cellular physiology and pathology.
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Affiliation(s)
- Masaki Tanito
- Department of Ophthalmology, Shimane University Faculty of Medicine, Shimane, Japan.
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Randazzo J, Zhang Z, Hoff M, Kawada H, Sachs A, Yuan Y, Haider N, Kador P. Orally active multi-functional antioxidants are neuroprotective in a rat model of light-induced retinal damage. PLoS One 2011; 6:e21926. [PMID: 21779355 PMCID: PMC3136485 DOI: 10.1371/journal.pone.0021926] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 06/09/2011] [Indexed: 11/19/2022] Open
Abstract
Background Progression of age-related macular degeneration has been linked to iron dysregulation and oxidative stress that induce apoptosis of neural retinal cells. Since both antioxidants and chelating agents have been reported to reduce the progression of retinal lesions associated with AMD in experimental animals, the present study evaluates the ability of multi-functional antioxidants containing functional groups that can independently chelate redox metals and quench free radicals to protect the retina against light-induced retinal degeneration, a rat model of dry atrophic AMD. Methods/Results Proof of concept studies were conducted to evaluate the ability of 4-(5-hydroxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4) and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8) to reduce retinal damage in 2-week dark adapted Wistar rats exposed to 1000 lx of light for 3 hours. Assessment of the oxidative stress markers 4- hydroxynonenal and nitrotyrosine modified proteins and Thioredoxin by ELISA and Western blots indicated that these compounds reduced the oxidative insult caused by light exposure. The beneficial antioxidant effects of these compounds in providing significant functional and structural protection were confirmed by electroretinography and quantitative histology of the retina. Conclusions/Significance The present study suggests that multi-functional compounds may be effective candidates for preventive therapy of AMD.
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Affiliation(s)
- James Randazzo
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Zifeng Zhang
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Michael Hoff
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Hiroyoshi Kawada
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Andrew Sachs
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Yang Yuan
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Neena Haider
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Ophthalmology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Peter Kador
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Ophthalmology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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López EM, Julián LK, Capani F, Cymeryng CB, Coirini H, López-Costa JJ. Endogenous Glucocorticoids Participate in Retinal Degeneration During Continuous Illumination. Int J Neurosci 2009; 118:1725-47. [DOI: 10.1080/00207450802174449] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Rodriguez IR, Fliesler SJ. Photodamage generates 7-keto- and 7-hydroxycholesterol in the rat retina via a free radical-mediated mechanism. Photochem Photobiol 2009; 85:1116-25. [PMID: 19500292 DOI: 10.1111/j.1751-1097.2009.00568.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Albino Sprague-Dawley rats are known to undergo photoreceptor degeneration after exposure to constant light, but the molecular mechanism(s) by which the photoreceptors degenerate is not fully understood. We hypothesized that cytotoxic oxysterols are generated in situ in the retina under such conditions and may be involved in the degenerative mechanism. Thus, photodamaged and control rat retinas were analyzed for oxysterols by liquid chromatography mass spectroscopy. Elevated levels of two known cytotoxic oxysterols, 7-ketocholesterol (7KCh) and 7alphabeta-hydroxycholesterol (7HCh), were found in the photodamaged retinas, at levels six-fold and 50-fold greater, respectively, than those found in non photodamaged controls. Notably, two key intermediates, 5,6alpha,beta-epoxycholesterol (5,6-epoxyCh) and 7alphabeta-hydroperoxy-cholesterol, were also identified, indicating that the formation of 7KCh and 7HCh is mediated by a free radical mechanism. By immunohistochemistry, 7KCh was localized to the ganglion cell layer, photoreceptor inner segments and retinal pigment epithelium (RPE), which coincides with the localization of ferritin in the retina. Exposure of a mixture of ferritin and low-density lipoprotein to intense white light in vitro produced similar oxysterol species as seen in vivo. We propose that the increased levels of 7KCh and 7HCh, especially in photoreceptor inner segments and RPE, may arise due to ferritin-catalyzed reactions and may be important contributors to the photoreceptor degeneration observed in photodamaged rats.
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Affiliation(s)
- Ignacio R Rodriguez
- Laboratory of Retinal Cell and Molecular Biology, Section on Mechanisms of Retinal Diseases, National Eye Institute, NIH, Bethesda, MD, USA.
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Peng PH, Huang HS, Lee YJ, Chen YS, Ma MC. Novel role for the δ-opioid receptor in hypoxic preconditioning in rat retinas. J Neurochem 2009; 108:741-54. [DOI: 10.1111/j.1471-4159.2008.05807.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tanito M, Brush RS, Elliott MH, Wicker LD, Henry KR, Anderson RE. High levels of retinal membrane docosahexaenoic acid increase susceptibility to stress-induced degeneration. J Lipid Res 2008; 50:807-19. [PMID: 19023138 DOI: 10.1194/jlr.m800170-jlr200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The fat-1 gene cloned from C. elegans encodes an n-3 fatty acid desaturase that converts n-6 to n-3 PUFA. Mice carrying the fat-1 transgene and wild-type controls were fed an n-3-deficient/n-6-enriched diet [fat-1- safflower oil (SFO) and wt-SFO, respectively]. Fatty acid profiles of rod outer segments (ROS), cerebellum, plasma, and liver demonstrated significantly lower n-6/n-3 ratios and higher docosahexaenoic acid (DHA) levels in fat-1-SFO compared with wt-SFO. When mice were exposed to light stress: 1) the outer nuclear layer (ONL) thickness was reduced; 2) amplitudes of the electroretinogram (ERG) were lower; 3) the number of apoptotic photoreceptor cells was greater; and 4) modification of retinal proteins by 4-hydroxyhexenal (4-HHE), an end-product of n-3 PUFA oxidation was increased in both fat-1-SFO and wt mice fed a regular lab chow diet compared with wt-SFO. The results indicate a positive correlation between the level of DHA, the degree of n-3 PUFA lipid peroxidation, and the vulnerability of the retina to photooxidative stress. In mice not exposed to intense light, the reduction in DHA resulted in reduced efficacy in phototransduction gain steps, while no differences in the retinal morphology or retinal biochemistry. These results highlight the dual roles of DHA in cellular physiology and pathology.
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Affiliation(s)
- Masaki Tanito
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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Chen J, Wang L, Chen Y, Sternberg P, Cai J. Phosphatidylinositol 3 kinase pathway and 4-hydroxy-2-nonenal-induced oxidative injury in the RPE. Invest Ophthalmol Vis Sci 2008; 50:936-42. [PMID: 18806289 DOI: 10.1167/iovs.08-2439] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE 4-Hydroxy-2-nonenal (4-HNE) is a major lipid peroxidation product in the retina and the retinal pigment epithelium. The purpose of the present study was to investigate how NF-E2-related factor-2 (Nrf2) and phosphatidylinositol 3 (PI3K) pathways affect the responses of cultured human retinal pigment epithelial (RPE) cells to 4-HNE. METHODS Cultured ARPE-19 cells were treated with different concentrations of 4-HNE and a PI3K inhibitor, LY294002. Intracellular glutathione (GSH) was measured by high-performance liquid chromatography (HPLC). The transcriptional activity of Nrf2 was measured by dual luciferase assay after transient transfection with reporter plasmids. The mRNA level of glutamate cysteine ligase (GCL) was quantified by real-time RT-PCR. Formation of HNE adduct on heat shock cognate protein 70 (Hsc70) was measured by immunoprecipitation and Western blot analyses. RESULTS Treatment with 4-HNE increased Nrf2 activity and GSH synthesis in a dose-dependent manner in cultured RPE cells. The modulatory subunit of GCL was upregulated by 4-HNE. Antioxidant responses were largely abolished by pretreatment with LY294002. The modification of Hsc70 by 4-HNE was increased when PI3K was inhibited. CONCLUSIONS The Nrf2-dependent antioxidant response protects against 4-HNE toxicity, and this protective mechanism is dependent on the functions of the PI3K pathway.
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Affiliation(s)
- Jianbin Chen
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Tanito M, Kaidzu S, Ohira A, Anderson RE. Topography of retinal damage in light-exposed albino rats. Exp Eye Res 2008; 87:292-5. [DOI: 10.1016/j.exer.2008.06.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 04/25/2008] [Accepted: 06/04/2008] [Indexed: 10/22/2022]
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Tanito M, Ogawa Y, Yoshida Y, Ohira A, Niki E, Kinumi T. Overoxidation of peroxiredoxins in vivo in cultured human umbilical vein endothelial cells and in damaging light-exposed mouse retinal tissues. Neurosci Lett 2008; 437:33-7. [DOI: 10.1016/j.neulet.2008.03.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 02/27/2008] [Accepted: 03/21/2008] [Indexed: 11/29/2022]
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An in-vivo assay to identify compounds protective against light induced apoptosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008. [PMID: 18188929 DOI: 10.1007/978-0-387-74904-4_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Yoshida Y, Saito Y, Hayakawa M, Habuchi Y, Imai Y, Sawai Y, Niki E. Levels of lipid peroxidation in human plasma and erythrocytes: comparison between fatty acids and cholesterol. Lipids 2007; 42:439-49. [PMID: 17476548 DOI: 10.1007/s11745-007-3037-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 02/10/2007] [Indexed: 02/08/2023]
Abstract
Lipid peroxidation has gained renewed attention with increasing evidence showing its biological role in producing toxic compounds and cellular signaling mediators. The assessment of lipid peroxidation levels in vivo is difficult partly because lipids are oxidized by different oxidants by different mechanisms to give versatile types of products, which may undergo metabolism and secondary reactions. In the present study, total hydroxyoctadecadienoic acids (tHODE) and 7alpha- and 7beta-hydroxycholesterol (t7-OHCh) from 44 healthy human subjects were assessed as biomarkers after reduction with sodium borohydride followed by saponification with potassium hydroxide comparing with the prevailing standard 8-isoprostaglandin F(2alpha) (t8-iso-PGF(2alpha)). The average concentrations of tHODE, total 8-isoprostaglandin F(2alpha) (t8-iso-PGF(2alpha)), t7alpha-OHCh, and t7beta-OHCh were 203, 0.727, 87.1, and 156 nmol/l plasma and 1,917, 12.8, 1,372, and 3,854 nmol/l packed erythrocytes, respectively. The ratios of tHODE and t7-OHCh to the parent substrates were 194 and 3,519 micromol tHODE/mol linoleates and 40.9 and 686 micromol t7-OHCh/mol cholesterol in plasma and erythrocytes, respectively. It was found that (1) t7-OHCh in blood was unexpectedly high, as high as or even higher than tHODE, (2) the amounts of tHODE was more than 100 fold higher than t8-iso-PGF(2alpha) (3) the level of lipid oxidation products in erythrocytes was higher than that in plasma, and (4) lipid peroxidation products level tended to increase while antioxidant level decrease with age. These products may be used as potential biomarker for assessment of lipid peroxidation and oxidative stress in vivo.
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Affiliation(s)
- Yasukazu Yoshida
- Human Stress Signal Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka, Japan.
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Davis TA, Gao L, Yin H, Morrow JD, Porter NA. In Vivo and in Vitro Lipid Peroxidation of Arachidonate Esters: The Effect of Fish Oil ω-3 Lipids on Product Distribution. J Am Chem Soc 2006; 128:14897-904. [PMID: 17105300 DOI: 10.1021/ja064399o] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of lipid composition on the distribution of free radical oxidation products derived from arachidonic acid (20:4) esters has been studied in vitro and in vivo. Pro-inflammatory prostaglandin (PG) F2-like compounds, termed F2-isoprostanes (IsoPs), are produced in vivo and in vitro by the free radical-catalyzed peroxidation of arachidonic acid. Controlled free radical oxidation of mixtures of fatty acid esters in vitro showed that the formation of IsoPs from arachidonate is dramatically influenced by the presence of other fatty acid esters in the reaction mixture. Thus, three lipid mixtures containing the same arachidonate concentration but different amounts of other fatty esters (16:0; 18:1; 18:2; 20:5, and 22:6) were oxidized, and the product yields were determined by GC and LC/MS/MS analysis. The yield of F2-IsoP formed after 1 h of oxidation was 18% (based on arachidonate consumed) for mixtures containing arachidonate as the only oxidizable PUFA, but yields of these biologically active compounds dropped to 6% in polyunsaturated fatty acid (PUFA) mixtures typical of those found in tissues of fish oil-fed animals. F2-IsoP levels were also monitored in the livers of mice on diets supplemented with eicosapentaenoic acid (C20:5 omega-3; EPA), the PUFA most abundant in fish oil. While the level of arachidonic acid present in livers was not significantly different from that in control animals, levels of IsoPs in the liver were reduced in the EPA-fed mice compared to those in controls under conditions of oxidative stress (60 +/- 25% reduction, n = 5) or at baseline (48 +/- 14% reduction, n = 5). These results suggest that dietary omega-3 PUFAs may influence the formation of bio-active peroxidation products derived from omega-6 PUFAs by channeling the free radical pathway away from the F2-IsoPs.
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Affiliation(s)
- Todd A Davis
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
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Tanito M, Kaidzu S, Anderson RE. Protective effects of soft acrylic yellow filter against blue light-induced retinal damage in rats. Exp Eye Res 2006; 83:1493-504. [PMID: 16997296 DOI: 10.1016/j.exer.2006.08.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 06/29/2006] [Accepted: 08/09/2006] [Indexed: 11/19/2022]
Abstract
Recently, a yellow intraocular lens (IOL) was developed for the purpose of reducing potential blue light-induced retinal damage after cataract surgery. However, the effect of yellow filters on retinal protection remains to be clarified. To test the protective effects of yellow filters on blue light-induced retinal damage, a yellow and a clear soft acrylic filter were attached to the right and left eyes, respectively, of albino rats and exposed to 4.5 k lux blue fluorescent lights with peak wavelength at 420 nm (ranging 380-500 nm; short blue) or 446 nm (ranging 400-540 nm; long blue) for 6h. To assess retinal damage, the electroretinogram (ERG) was recorded at 7 days, outer nuclear layer (ONL) thickness and area were measured at 7 days, apoptosis was analyzed by TUNEL staining at 24 h, and the level of lipid peroxidation in retinas was assessed by Western dot blots using specific antibodies against 4-hydroxynonenal (4-HNE)- and carboxyethylpyrrole (CEP)-modified proteins immediately after light exposure. After short blue light exposure, a- and b-wave ERG amplitudes and the ONL thickness at 1-2.5 mm inferior and 0.5-2.5 mm superior to optic nerve head (ONH) were significantly reduced. TUNEL staining in the ONL at 0-2 mm inferior and 1-2 mm superior to the ONH, and retinal levels of 4-HNE- and CEP-modified proteins were significantly increased in the clear filter-covered eyes compared to yellow filter-covered eyes. After long blue light exposure, the only difference seen was a greater ONL thickness at 1.5 mm superior to the ONH in yellow filter-covered eye. Transmission of light through the yellow filter was 58% for short blue and 89% for long blue compared to the clear filter. The ONL area was not different between clear filter-covered and -uncovered eyes after exposure to short or long blue light. Given the results, yellow IOL material protects the retina against acute shorter wavelength blue light exposure more effectively than the clear IOL material.
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Affiliation(s)
- Masaki Tanito
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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