dinoprost and Iron-Overload

Iron overload has been associated with acute/chronic organ failure, but whether iron overload induces liver injury remains unclear. The objectives of this study were to assess the relationship between urinary iron and serum alanine aminotransferase (ALT, a biomarker for liver injury), and investigate the potential mediating roles of lipid peroxidation and oxidative DNA damage in such association. Levels of urinary iron, serum ALT, and urinary biomarkers of lipid peroxidation (8-iso-prostaglandin-F

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Biomarkers; Cross-Sectional Studies; Dinoprost; East Asian People; Humans; Iron; Iron Overload; Lipid Peroxidation; Liver; Oxidative Stress

Iron overload can induce oxidative stress, thereby inducing cell peroxidation. Arachidonic acid (ARA) is widely expressed in mammalian cells and esterified to membrane phospholipids. To explore the effect of iron overload on the metabolism of membrane phospholipids MES23.5 cells were treated with various concentrations of ferric ammonium citrate (FAC) to induce oxidative stress. Using UHPLC (I-Class LC, Waters) coupled to a QTRAP (AB Sciex 5500) technology, the contents of 13 substances of ARA and its metabolites were detected. When the cells were given two different concentrations of FAC, we found that both high and low concentrations decrease the expression of ARA (p=0.002, p=0.02) compared with the control group. ARA has three metabolic pathways: the COX pathway, LOX pathway and CYP450 pathway. Compared with the control group, the LTB4 content in the LOX pathway was decreased (p=0.10) after treatment with lowconcentration FAC, while the LTB4 content was increased in the high-concentration treatment group (p=0.06). However, the content of 12S-HETE (p=0.23, p=0.05) in the LOX metabolic pathway decreased with increase of FAC concentration. Similarly, the content of 15S-HETE also decreased with increase of FAC concentration (p=0.17, p=0.02). The other downstream metabolites of ARA, 9S-HODE (p=0.54, p=0.18) and 13S-HODE (p=0.81, p=0.13) were not significantly changed. The contents of thromboxane B2 (TXB2), leukotriene D4 (LTD4), prostaglandin E2 (PGE2), 8-iso-prostaglandin F2α (8-iso-PGF2α), prostaglandin F2α (PGF2α), 6-keto-PGF1α, and prostaglandin D2 (PGD2) were too low to be detected in MES23.5 cells. The above results indicate that oxidative stress caused by iron overload reduces the LOX metabolic pathway of ARA.

Topics: Animals; Arachidonic Acid; Dinoprost; Hydroxyeicosatetraenoic Acids; Iron Overload; Leukotriene B4; Mammals; Oxidative Stress; Phospholipids

Our recent investigation showed that hepcidin can reduce iron in the brain of iron-overloaded rat by down-regulating iron-transport proteins. It has also been demonstrated that iron is a major generator of reactive oxygen species. We therefore hypothesized that hepcidin could prevent iron accumulation and thus reduce iron-mediated oxidative stress in iron-overloaded rats. To test this hypothesis, we investigated the effects of pre-treatment of rats with recombinant-hepcidin-adenovirus (ad-hepcidin) on the contents of iron, dichlorofluorescein and 8-isoprostane in the brain. Hepcidin expression was detected by real-time PCR and immunofluorescence analysis. Iron contents were measured using Perl's staining as well as graphite furnace atomic absorption spectrophotometry. Dichlorofluorescein and 8-isoprostane were determined using a fluorescence spectrophotometer and an ELISA kit, respectively. We found that hepcidin contents in the cortex, hippocampus, striatum and substantia nigra of rats treated with ad-hepcidin are 3.50, 2.98, 2.93 and 4.07 fold of those of the control rats respectively. Also, we demonstrated that the increased iron as well as dichlorofluorescein and 8-isoprostane levels in all four brain regions, induced by injection of iron dextran, could be effectively prevented by pre-treatment of the rats with ad-hepcidin. We concluded that pre-treatment with ad-hepcidin could increase hepcidin expression and prevent the increase in iron and reduce reactive oxygen species in the brain of iron-overloaded rats.

Topics: Animals; Brain; Dinoprost; Fluoresceins; Hepcidins; Iron; Iron Overload; Male; Oxidative Stress; Rats; Rats, Sprague-Dawley; Recombinant Proteins

Iron is an essential element in human metabolism but also is a potent generator of oxidative damage with levels that increase with age. Several studies suggest that iron accumulation may be a factor in age-related macular degeneration (AMD). In prior studies, both iron overload and features of AMD were identified in mice deficient in the ferroxidase ceruloplasmin (Cp) and its homologue hephaestin (Heph) (double knockout, DKO). In this study, the location and timing of iron accumulation, the rate and reproducibility of retinal degeneration, and the roles of oxidative stress and complement activation were determined.. Morphologic analysis and histochemical iron detection by Perls' staining was performed on retina sections from DKO and control mice. Immunofluorescence and immunohistochemistry were performed with antibodies detecting activated complement factor C3, transferrin receptor, L-ferritin, and macrophages. Tissue iron levels were measured by atomic absorption spectrophotometry. Isoprostane F2alpha-VI, a specific marker of oxidative stress, was quantified in the tissue by gas chromatography/mass spectrometry.. DKOs exhibited highly reproducible age-dependent iron overload, which plateaued at 6 months of age, with subsequent progressive retinal degeneration continuing to at least 12 months. The degeneration shared some features of AMD, including RPE hypertrophy and hyperplasia, photoreceptor degeneration, subretinal neovascularization, RPE lipofuscin accumulation, oxidative stress, and complement activation.. DKOs have age-dependent iron accumulation followed by retinal degeneration modeling some of the morphologic and molecular features of AMD. Therefore, these mice are a good platform on which to test therapeutic agents for AMD, such as antioxidants, iron chelators, and antiangiogenic agents.

Topics: Animals; Apoferritins; Ceruloplasmin; Choroid; Complement Activation; Complement C3; Complement Factor B; Dinoprost; Disease Models, Animal; Gas Chromatography-Mass Spectrometry; Iron; Iron Overload; Macrophages; Macular Degeneration; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Pigment Epithelium of Eye; Receptors, Transferrin; Retina; Spectrophotometry, Atomic

Ascorbate is a strong antioxidant; however, it can also act as a prooxidant in vitro by reducing transition metals. To investigate the in vivo relevance of this prooxidant activity, we performed a study using guinea pigs fed high or low ascorbate doses with or without prior loading with iron dextran. Iron-loaded animals gained less weight and exhibited increased plasma beta-N-acetyl-D-glucosaminidase activity, a marker of tissue lysosomal membrane damage, compared with control animals. The iron-loaded animals fed the low ascorbate dose had decreased plasma alpha-tocopherol levels and increased plasma levels of triglycerides and F(2)-isoprostanes, specific and sensitive markers of in vivo lipid peroxidation. In contrast, the two groups of animals fed the high ascorbate dose had significantly lower hepatic F(2)-isoprostane levels than the groups fed the low ascorbate dose, irrespective of iron load. These data indicate that 1) ascorbate acts as an antioxidant toward lipids in vivo, even in the presence of iron overload; 2) iron loading per se does not cause oxidative lipid damage but is associated with growth retardation and tissue damage, both of which are not affected by vitamin C; and 3) the combination of iron loading with a low ascorbate status causes additional pathophysiological changes, in particular, increased plasma triglycerides.

Topics: Animals; Antioxidants; Ascorbic Acid; Dinoprost; F2-Isoprostanes; Female; Guinea Pigs; Iron Overload; Iron-Dextran Complex; Lipid Peroxidation; Liver; Oxidative Stress