The role of antioxidants in the retina and retinal pigment epithelium and the nature of prooxidant-induced damage

Handelman, Garry J.; Dratz, Edward A.

doi:10.1016/s8755-9668(86)80024-2

Cited by 127 publications

(47 citation statements)

References 217 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One of the important functions of these cells, which are located between the sensory retina and the choroid, is the continuous phagocytosis and degradation of rod and cone outer segments (ROS) (16). The RPE has the highest catalase activity of any ocular tissue measured and contains high concentrations of antioxidants, which seem to be essential for protecting the RPE cells against oxidative e (17)(18)(19)(20)(21). Other evidence suggests that the normal process of phagocytosis of ROS by the RPE cells may be an oxidative stress to the RPE (22).…”

Section: Methodsmentioning

confidence: 99%

Chromosomal localization of the mammalian peptide-methionine sulfoxide reductase gene and its differential expression in various tissues.

Moskovitz

Jenkins

Gilbert

et al. 1996

Proc. Natl. Acad. Sci. U.S.A.

135

View full text Add to dashboard Cite

Peptide methionine sulfoxide reductase (MsrA; EC 1.8.4.6) is a ubiquitous protein that can reduce methionine sulfoxide residues in proteins as well as in a large number of methyl sulfoxide compounds. The (12)(13)(14). Recombination distances were calculated as described by Green (15), using the computer program SPRETUS MADNESS. Gene order was determined by minimizing the number of double and multiple recombination events across the chromosome.Immunocytochemistry. Adult female rats (60 days old) were purchased from Charles River Breeding Laboratories. The rats were deeply anesthetized with a mixture of ketamine (80 mg/ml, Sigma) and xylazine (10 mg/ml, Sigma) in physiological saline and perfused intracardially with phosphate-buffered saline (PBS); 10 mM sodium phosphate, pH 7.2/130 mM NaCI) followed by 4% paraformaldehyde in PBS. Brain, retina, kidney, and lungs were postfixed for 1 h in the same fixative at room temperature and cryoprotected in 30% sucrose in PBS for 2 days at 4°C. Macrophages were obtained from mouse peritoneum and were processed in a similar fashion. Freefloating 60-gLm tissue sections were cut, soaked in PBS, and treated with 70% (vol/vol) methanol and 0.3% hydrogen peroxide for 20 min. Following blocking with 0.5 M Tris-HCl, pH 7.6, containing 5% goat serum and 0.5% Triton X-100 for 1 h, the sections were incubated with anti-MsrA rabbit antibodies (diluted 1:100) for 6 h at room temperature. Rabbit antibodies were raised against the recombinant bovine MsrA (6) and were affinity-purified on an Affi-Gel 10-bovine MsrA column, according to the procedure described by Bio-Rad

show abstract

Section: Methodsmentioning

confidence: 99%

Chromosomal localization of the mammalian peptide-methionine sulfoxide reductase gene and its differential expression in various tissues.

Moskovitz

Jenkins

Gilbert

et al. 1996

Proc. Natl. Acad. Sci. U.S.A.

135

View full text Add to dashboard Cite

show abstract

“…RPE cell death plays a major role in the pathogenesis of age-related macular degeneration, the leading cause of blindness in the population Ͼ60 years of age in the developed world (2). Possible reasons given for the degeneration of RPE cells are their exposure to high oxidative stress and damaging irradiation (2)(3)(4)(5)(6).…”

mentioning

confidence: 99%

Melanin photoprotection in the human retinal pigment epithelium and its correlation with light-induced cell apoptosis

Seagle

Rezai

Kobori

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

104

View full text Add to dashboard Cite

Time-resolved electron paramagnetic resonance (TREPR) spectroscopy was used to study melanin free radicals in human retinal pigment epithelium (RPE) cells and tyrosine-derived synthetic melanin. TREPR signal traces from RPE cells reveal in vivo light-induced melanin free radical photochemistry in more detail than previously known. Electron spin polarization reflecting a non-Boltzmann population within the energy levels of the spin system is observed in RPE cells as the result of the triplet state photoproduction and subsequent disappearance of free radicals in the melanin polymer. In a set of RPE cells cultured from individual sources, differences in optical absorption, continuous wave EPR spectra, and TREPR signals were correlated with apoptosis assays performed by flow cytometry. Continuous wave EPR spectra of RPE cells and TREPR of acidified synthetic melanin suggest that increased melanin aggregation provides an increase in photoprotection in the RPE cells that are relatively less susceptible to blue light-induced apoptosis.continuous wave EPR ͉ electron spin polarization ͉ time-resolved EPR I n the eye, retinal pigment epithelium (RPE) is a monolayer of cuboidal cells between the photoreceptors and choriocapillaris of the eye and is specialized to uptake, phagocytize, and recycle the outer segment of photoreceptors and retinaldehyde, the chromophore of rhodopsin (1). RPE cell death plays a major role in the pathogenesis of age-related macular degeneration, the leading cause of blindness in the population Ͼ60 years of age in the developed world (2). Possible reasons given for the degeneration of RPE cells are their exposure to high oxidative stress and damaging irradiation (2-6).The pigment melanin, found in RPE cells, is a heterogeneous polymer consisting of various monomers believed to be oxidation products of dopa (dihydroxyphenylalinine) derived from tyrosine (7). Melanin contains intrinsic, indolesemiquinone-like doublet-state radicals (8, 9). Extrinsic indolesemiquinone-like radicals are reversibly photogenerated under visible or UV irradiation (9). RPE melanin serves a photoprotective role by absorbing radiation and scavenging free radicals and reactive oxygen species (ROS) (8-11). Evidence also exists for a phototoxic role for melanin in RPE cells, especially in aged cells, including measurable ROS photoproduction (8,(12)(13)(14)(15)(16)(17)(18). Electron paramagnetic resonance (EPR) spectroscopy enables a sensitive and nondestructive analysis and differentiation of natural melanin (9,19,20). The photophysical, redox, and aggregation properties of melanin as well as its ability to bind metals, proteins, and drugs have stimulated numerous studies in chemical, physical, and medical research (8, 9). The diversity and interrelations of its properties and the lack of chemical structures have hampered a clear understanding of the roles of melanin in RPE cells (8,9). Nanosecond time-resolved (TR) EPR studies have not been reported despite the relevance of TREPR to the study of melanin photochemistry (9). El...

show abstract

“…The biological role of macular carotenoids includes limiting chromatic aberration at the fovea by filtering out blue light [3], quenching of singlet oxygen or free radicals produced in the retina, protecting the macula from the photo toxicity of blue light [4,5], and protecting against photo-oxidation of lysosomal membranes and reducing the risk of AMD [6].…”

Section: Macular Carotenoidsmentioning

confidence: 99%

Meso-Zeaxanthin (MZ): Current Perspectives and New Insights

Juturu¹

2014

AOVS

View full text Add to dashboard Cite

Recent in vitro, in vivo and human studies indicate that dietary meso-zeaxanthin (MZ) may be of benefit in maintaining vision and provides antioxidant and anti-inflammatory support. MZ is a macular carotenoid with additional protective effects such as antioxidant, anti-mutagenic, singlet oxygen quenching and inhibitory effects on specific CYP450 isoenzymes, potential to induce phase II enzymes, chemo-protective and anti-carcinogenic effects. MZ scavenges superoxide, hydroxyl, nitric oxide diphenyl-2-picrylhydrazyl (DPPH) radical, and 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals, inhibits tissue lipid peroxidation and prevents cellular damage. MZ increase the levels of antioxidant enzymes like catalase, superoxide dismutase and glutathione peroxidase. MZ supplementation will provide benefit for maintaining visual performance in health and disease. Recent data strongly support the observation that adequate macular carotenoid supplementation may significantly reduce the risk of macular degeneration and age related macular degeneration mediated by reactive oxygen species. This review will focus on the effect of macular carotenoids and MZ in the context of carotenoids' unique visual health including antioxidant and anti-inflammatory properties. KeywordsMeso-zeaxanthin; Macular carotenoids; Antioxidant; Eye health Meso-Zeaxanthin (MZ): Current Perspectives and New InsightsCitation: Juturu V (2014) Meso-Zeaxanthin (MZ): Current Perspectives and New Insights. Adv Ophthalmol Vis Syst 1(2): 00010.

show abstract

The role of antioxidants in the retina and retinal pigment epithelium and the nature of prooxidant-induced damage

Cited by 127 publications

References 217 publications

Chromosomal localization of the mammalian peptide-methionine sulfoxide reductase gene and its differential expression in various tissues.

Chromosomal localization of the mammalian peptide-methionine sulfoxide reductase gene and its differential expression in various tissues.

Melanin photoprotection in the human retinal pigment epithelium and its correlation with light-induced cell apoptosis

Meso-Zeaxanthin (MZ): Current Perspectives and New Insights

Contact Info

Product

Resources

About