Peroxidation of Subcellular Organelles: Formation of Lipofuscinlike Fluorescent Pigments

Chio, K. S.; Reiss, Uzi; Fletcher, Brian; Tappel, Al L.

doi:10.1126/science.166.3912.1535

Cited by 199 publications

(52 citation statements)

References 13 publications

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“…Our observations of CEP and iso [4]LGE 2 in purified granules are consistent with early theories suggesting a role for lipoxidation in lipofuscin formation (33). CEP adducts of protein primary amino groups are generated from 4-hydroxy-7-oxohept-5-enoic acid, a fragment derived uniquely from DHA-containing lipids (27) that are abundant in photoreceptor outer segments.…”

Section: Fig 4 Phototoxicity Of Lipofuscinsupporting

confidence: 77%

Retinal Pigment Epithelium Lipofuscin Proteomics

Gugiu

Renganathan

et al. 2008

Molecular & Cellular Proteomics

157

136

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Lipofuscin accumulates with age in the retinal pigment epithelium (RPE) in discrete granular organelles and may contribute to age-related macular degeneration. Because previous studies suggest that lipofuscin contains protein that may impact pathogenic mechanisms, we pursued proteomics analysis of lipofuscin. The composition of RPE lipofuscin and its mechanisms of pathogenesis are poorly understood in part because of the heterogeneity of isolated preparations. We purified RPE lipofuscin granules by treatment with proteinase K or SDS and showed by light, confocal, and transmission electron microscopy that the purified granules are free of extragranular material and associated membranes. Crude and purified lipofuscin preparations were quantitatively compared by (i) LC MS/MS proteomics analyses, (ii) immunoanalyses of oxidative protein modifications, (iii) amino acid analysis, (iv) HPLC of bisretinoids, and (v) assaying phototoxicity to RPE cells. From crude lipofuscin preparations 186 proteins were identified, many of which appeared to be modified. In contrast, very little protein (ϳ2% (w/w) by amino acid analysis) and no identifiable protein were found in the purified granules, which retained full phototoxicity to cultured RPE cells. Our analyses showed that granules in purified and crude lipofuscin preparations exhibit no statistically significant differences in diameter or circularity or in the content of the bisretinoids A2E, isoA2E, and all-trans-retinal dimer-phosphatidylethanolamine. The finding that the purified granules contain minimal protein yet retain phototoxic activity suggests that RPE lipofuscin pathogenesis is largely independent of associated protein. The purified granules also exhibited oxidative protein modifications, including nitrotyrosine generated from reactive nitrogen oxide species and carboxyethylpyrrole and iso[4]levuglandin E 2 adducts generated from reactive lipid fragments. This finding is consistent with previous studies demonstrating RPE lipofuscin to be a potent generator of reactive oxygen species and supports the hypothesis that such species, including reactive fragments from lipids and retinoids, contribute to the mechanisms of RPE lipofuscin pathogenesis.

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Section: Fig 4 Phototoxicity Of Lipofuscinsupporting

confidence: 77%

Retinal Pigment Epithelium Lipofuscin Proteomics

Gugiu

Renganathan

et al. 2008

Molecular & Cellular Proteomics

157

136

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“…Studies on the oxidation of lipid-protein mixtures have demonstrated that one type of effect on the protein is the covalent binding of lipid oxidation products, some of which can result in fluorescent substituents, including crosslinks (15,27,28). This reaction also occurs in our system, as shown by the increase in protein fluorescence with increasing time of oxidation (Fig.…”

Section: Discussionmentioning

confidence: 60%

“…10). The increase occurs with an excitation maximum of 370 nm and an emission maximum of 450 nm, similar to the spectrum of lipofuscin or "age" pigments found in vivo, which are believed to be substituted I-amino-3-iminopropene structures, formed when auto-oxidized lipids react with protein (15,27,28).…”

Section: Mateirials and Methodsmentioning

confidence: 81%

Oxygen-mediated heterogeneity of apo-low-density lipoprotein.

Schuh¹,

Fairclough²,

Haschemeyer³

1978

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

245

121

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Mild oxidation of human serum low-density lipoprotein (LDL) converts the apoprotein from a nearly homogeneous component of high apparent molecular weight to a mixture of apparently lower mo ecular weight polypeptide components, as characterized by sodium dodecyl sulfate/ polyacrylamide gel electrophoresis. This protein alteration, which correlates temporally with increases in the formation of lipid oxidation products and in the fluorescence of the apoprotein, is markedly reduced when oxygen is excluded or when EDTA or the free-radical-scavenging antioxidants, butylated hydroxytoluene or propyl gallate, are added. The conversion thus appears to be due to a reaction between the protein moiety and auto-oxidizing lipid. The presence of the antibacterial agent sodium azide markedly accelerates the oxidation, suggesting that it should only be used with caution in lipid-containing solutions. Structural and functional characterization of serum lipoproteins has received attention because molecular or metabolic abnormalities associated with this class of molecules might be significant in the development of atherosclerosis (1). The lowdensity lipoprotein fraction (LDL) has been of particular interest because of its apparent role in atherogenesis. Such a role is indicated by a correlation between high serum levels of LDL and clinical atherosclerosis (2), as well as the accelerated atherosclerosis in patients who have an inherited abnormality in LDL catabolism (familial hypercholesterolemia) (3). LDL is catabolized after it is bound through its protein moiety (apo-B or apo-LDL) to a cell-surface receptor (4).Although characterization of the apoprotein of LDL has been difficult (5), studies on the lipid moiety appear to be less controversial. LDL contains a large proportion of unsaturated lipids (somewhat variable on diet) (6) and is unique among the serum lipoproteins in its susceptibility for undergoing auto-oxidation in vitro (7-9). This finding has led some authors to speculate that such auto-oxidation plays a role in atherogenesis (7,10,11). Although structural (7-13), spectrophotometric (9,13,14), and lipid compositional (8, 11) changes in LDL have been observed upon oxidation, its polypeptide chain has not been characterized. Model studies with lipid-protein mixtures have shown that oxidized lipid can lead to major modification of protein components; such modifications include crosslinking (15), polypeptide scission (16), and loss of amino acids (17, 18). It thus seems possible that some of the difficulties encountered in characterizing apo-B are associated with partial oxidation of LDL during purification and/or storage. The observation that plasma lipids from human subjects contain significant diene conjugation (an early manifestation of lipid auto-oxidation) suggests that oxidation of LDL can be initiated in vivo (19).We show here that mild oxidation of LDL in vitro results in altering the sodium dodecyl sulfate (NaDodSO4)-apoprotein electrophoretic pattern from a single major band of low mobility into nume...

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“…Demonstration of the lipid peroxidative activity in the native boar sperm can be regarded as a contribution to the general physiology and cell metabolism because up to now the in vivo lipid peroxidation had been connected with the toxic effect of oxygen on cellular level (Hatigaard 1968), with the cellular mechanisms of senescence (Barber and Bernheim 1967;Chio et al 1969;Okuma et a1. 1969), with damage to liver parenchyma in CCl4 intoxication (Recknage11967) and especially with insufficient antioxidant ability of tissues connected with lack of vitamin E and selenium (Kitabchi et a1.…”

Section: Resultsmentioning

confidence: 99%

Lipid Peroxidation in Semen of the Boar

Smutná¹,

Synek²

1979

Acta Vet. Brno

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Smutna M., o. Synek: Lipid Peroxidation in Semen of the Boar. Acta vet. Bmo, 48, 1979: 35-43. During the catalyzed aerobic incubation of the complete boar semen malonyldialdehyde (MDA) is produced. MDA is a good indicator of peroxidative decomposition of polyunsaturated fatty acids. Detection of peroxidation products was conducted both by colour reaction with 2-thiobarbituric acid (evidence of MDA), and spectrofotometrically (evidence of the conjugated dienes, oxidation of the coenzyme NADPH + H+). It was found that the progressive formation of MDA surpasses the formation of conjugated dienes especially in the early stages of peroxidation. Significant correlation for the first 30 minutes of the aerobic incubation was found between the number of spermatozoa and the amount of produced malonyldialdehyde.Enzymatic lipid peroxidation studied in isolated tails of spermatozoa was NADPH--dependent with a small dependence on pyrophosphate. Production of MDA in all studied systems was infiuenced by pH of the environment.The boar seminal plasma showed high anti-peroxidative activity limited by its dilution. Native semen, malonyldialdehyde, conjugated dienes, inhibitory effect.Properties ofthe membranes determine largely the properties of the cells and tissues. Viability of each animal cell depends on structural and functional integrity of its membrane and subcellular structures. The quality of the membrane is also important for viability of spermatozoa and for metabolic processes ensuring their contact to the environment. Changes in the properties of these membranes result in functional and morphological aberations the character of which is given by the degree of damage to the membrane.The labile compound of the membranes are unsaturated fatty acids esterified in phospholipids which together with globular proteins represent the basic structural components of all biological membrane complexes. Non-enzymatic peroxidative breakdown of unsaturated fatty acids of the membrane to small fragments impairs their function in _the lipoprotein membrane and injurs seriously their structural and functional integrity. Destruction of specific membrane phospholipids during the NADPH-induced lipid peroxidation of the microsomal fraction from rat liver was demonstrated by May and Mc Cay (1968). Decomposition by peroxidation of the chain of polyunsaturated fatty acids esterified in the beta position of phosphatidylcholine and phosphatidylethanolamine of the microsomal membrane resulted in a 40 % decrease in the amount of arachidonic acid. The harmful effect of HaO. and dialuric acid on the erythrocyte membranes in rats suffering from E hypovitaminosis lead to partial damage to phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine (Heikkila et al. 1971). Changes in the concentration of phospholipids in the boar semen were found to be caused by its aerobic incubation with Cu++ ions (Smutna 1974). Loss of plasmalogen and palmitaldehyde from the ram sperm and loss of motility of spermatozoa with their spontaneous aggluti...

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Peroxidation of Subcellular Organelles: Formation of Lipofuscinlike Fluorescent Pigments

Cited by 199 publications

References 13 publications

Retinal Pigment Epithelium Lipofuscin Proteomics

Retinal Pigment Epithelium Lipofuscin Proteomics

Oxygen-mediated heterogeneity of apo-low-density lipoprotein.

Lipid Peroxidation in Semen of the Boar

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