4-hydroxy-2-nonenal and Iron-Overload

Ferroptosis is a recently recognized form of non-apoptotic cell death caused by an iron-dependent accumulation of lipid hydroperoxides, which plays important roles in a wide spectrum of pathological conditions. The present study was aimed to investigate the impact of ferroptosis on cisplatin-induced sensory hair cell damage. Cell viability was determined by Cell Counting Kit-8 and lactase dehydrogenase assays. The reactive oxygen species (ROS) levels were evaluated by 2,7-Dichlorodi-hydrofluorescein diacetate (DCFH-DA) and MitoSox-Red staining. Mitochondrial membrane potential (MMP) was measured by tetramethylrhodamine methyl ester (TMRM) staining. Lipid peroxidation, intracellular and mitochondrial iron were detected by Liperfluo, C11-BODIPY

Topics: Aldehydes; Animals; Carbolines; Cell Line; Cell Survival; Cisplatin; Cyclohexylamines; Cytoprotection; Ferroptosis; Hair Cells, Auditory; Iron; Iron Overload; Membrane Potential, Mitochondrial; Mice, Inbred C57BL; Ototoxicity; Phenylenediamines; Reactive Oxygen Species

Background and Purpose- Recanalization with tPA (tissue-type plasminogen activator) is the only pharmacological therapy available for patients with ischemic stroke. However, the percentage of patients who may receive this therapy is limited by the risk of hemorrhagic transformation (HT)-the main complication of ischemic stroke. Our aim is to establish whether iron overload affects HT risk, to identify mechanisms that could help to select patients and to prevent this devastating complication. Methods- Mice fed with control or high-iron diet were subjected to thromboembolic stroke, with or without tPA therapy at different times after occlusion. Blood samples were collected for determination of malondialdehyde, matrix metalloproteinases, and fibronectin. Brain samples were collected 24 hours after occlusion to determine brain infarct and edema size, hemorrhage extension, IgG extravasation, and inflammatory and oxidative markers (neutrophil infiltration, 4-hydroxynonenal, and matrix metalloproteinase-9 staining). Results- Despite an increased rate of recanalization, iron-overload mice showed less neuroprotection after tPA administration. Importantly, iron overload exacerbated the risk of HT after early tPA administration, accelerated ischemia-induced serum matrix metalloproteinase-9 increase, and enhanced basal serum lipid peroxidation. High iron increased brain lipid peroxidation at most times and neutrophil infiltration at the latest time studied. Conclusions- Our data showing that iron overload increases the death of the compromised tissues, accelerates the time of tPA-induced reperfusion, and exacerbates the risk of HT may have relevant clinical implications for a safer thrombolysis. Patients with stroke with iron overload might be at high risk of HT after fibrinolysis, and, therefore, clinical studies must be performed to confirm our results.

Topics: Aldehydes; Animals; Blood-Brain Barrier; Disease Models, Animal; Fibrinolytic Agents; Immunoglobulin G; Infarction, Middle Cerebral Artery; Intracranial Hemorrhages; Iron Overload; Iron, Dietary; Lipid Peroxidation; Matrix Metalloproteinase 9; Mice; Neutrophil Infiltration; Oxidative Stress; Stroke; Thromboembolism; Tissue Plasminogen Activator

Dietary aflatoxin B(1) (AFB(1)) exposure and iron overload are important causes of hepatocellular carcinoma in sub-Saharan Africa. The aim of this study was to investigate if the two risk factors have an interactive effect.. Four groups of Wistar albino rats were studied for 12 months. Group 1 (control) was fed the normal chow diet; group 2 (Fe) was supplemented with 0.75% ferrocene iron; group 3 (Fe+AFB(1)) was fed 0.75% ferrocene throughout and gavaged 25 microg AFB(1) for 10 days; group 4 (AFB(1)) was gavaged 25 microg AFB(1) for 10 days. Iron profile, lipid peroxidation (LPO), 8-hydroxydeoxyguanosine (8OHdG), oxidative lipid/DNA damage immunohistochemistry, superoxide/nitrite free radicals, cytokines IL6, IL-10, transaminases (ALT/AST) and Ames mutagenesis tests were performed.. LPO and ALT showed a significant (p<0.05)/additive effect and 8OHdG a significant (p<0.05)/multiplicative effect in the Fe+AFB(1) group. IL-6 produced a negative synergy as against an additive antagonistic effect with IL-10. Massive deposits of 4-hydroxynonenal (4-HNE) and 8OHdG were observed in liver sections of the Fe+AFB(1) group, suggestive of multiplicative synergy. Significant levels of mutagenesis (p<0.001) were observed in the Fe+AFB(1) group. This multiplicative synergy was five-fold.. Dietary iron overload and AFB(1) have a multiplicative effect on mutagenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aflatoxin B1; Alanine Transaminase; Aldehydes; Animals; Aspartate Aminotransferases; Cytokines; Deoxyguanosine; DNA Damage; Glutathione Transferase; Immunohistochemistry; Iron; Iron Overload; Lipid Peroxides; Liver; Mutagenesis; Mutagenicity Tests; Nitrates; Nitrites; Oxidative Stress; Rats; Rats, Wistar; Superoxides; Transferrin

We have investigated whether long-term administration of angiotensin (Ang) II causes ferritin induction and iron accumulation in the rat aorta, and their possible relation to regulatory effects on gene expression and vascular function in Ang II-infused animals.. Sprague-Dawley rats were given Ang II for 7 days via subcutaneously implanted osmotic minipumps. Ang II infusion caused a >20-fold increase in ferritin protein expression over control values. Immunohistochemistry showed that Ang II infusion markedly increased the ferritin expression in the aortic endothelial and adventitial cells, with some of the latter being identified as monocytes/macrophages. Prussian blue staining showed that stainable iron was observed in the adventitial layer of aorta from Ang II-infused animals, but not in the endothelial layer. Chelation of iron suppressed aortic induction of ferritin and also the oxidative stress markers, heme oxygenase-1 and 4-hydroxynonenal-modified protein adducts. In addition, iron chelation attenuated Ang II-induced impairment of aortic relaxations in response to acetylcholine and sodium nitroprusside and suppressed upregulation of mRNA levels of monocyte chemoattractant protein-1. Iron chelation also partially attenuated the medial thickening and perivascular fibrosis induced by Ang II infusion for 4 weeks.. Ang II infusion caused ferritin induction and iron deposition in the aortas. These phenomena might have a role in the regulation of gene expression, impairment of vascular function, and arterial remodeling induced by Ang II, which are presumably mediated in part by enhancement of oxidative stress.

Topics: Aldehydes; Angiotensin II; Animals; Aorta; Aortic Diseases; Apoferritins; Chemokine CCL2; Deferoxamine; Ferritins; Heme Oxygenase-1; Hypertension; Iron; Iron Chelating Agents; Iron Overload; Iron-Dextran Complex; Male; Norepinephrine; Oxidative Stress; Rats; Rats, Sprague-Dawley; Receptors, Transferrin; RNA, Messenger; Up-Regulation; Vasoconstrictor Agents; Vasodilation

Iron overload has been reported in alcoholic liver cirrhosis but it remains to be established whether iron is involved in inducing oxidative damage to erythrocytes in alcoholic cirrhosis. The aim of this study was to assess oxidative damage and red cell indicators of antioxidant defences in alcoholics with mild-to-severe liver cirrhosis, taking into account the iron status.. Twenty-nine patients with alcoholic liver cirrhosis (AC) and 27 with nonalcoholic cirrhosis (NAC) were studied. Serum lipid peroxides (LPO) were assayed by a colourimetric method. Serum-free malonyldialdehyde (MDA) was assayed by selected ion monitoring in positive chemical ionization; serum 4-hydroxy-2(E)-nonenal (4-HNE) was determined by a colorimetric method. Reduced (GSH) and oxidized glutathione (GSSG), adenine and pyridine cofactors were assayed in whole blood extracts by HPLC. Hexose-monophosphate shunt (HMPS), glycolytic pathway (EMP) and antioxidant enzyme activities were determined by standard methods. Iron status was evaluated by standard clinical chemistry and by histological grading of liver iron. Nontransferrin-bound iron (NTBI) was measured in serum by HPLC.. GSH progressively decreased with increasing severity of liver involvement in AC and NAC. MDA, 4-HNE and NTBI were significantly higher in AC serum. Stimulation of red cell HMPS and reducing potential, in terms of NADPH production, were more pronounced in AC.. These results suggest that NTBI is more important than the decrease of antioxidant defences in inducing lipid peroxidation. NTBI may play a catalytic role in free radical reactions in the presence of cellular reductants such as NADPH.

Topics: Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Adult; Aged; Alcohol Drinking; Aldehydes; Antioxidants; Catalase; Erythrocytes; Female; Glutathione; Glycolysis; Humans; Iron; Iron Overload; Lipid Peroxides; Liver Cirrhosis, Alcoholic; Male; Malondialdehyde; Middle Aged; NAD; NADP; Oxidative Stress; Pentose Phosphate Pathway

Pathophysiological mechanisms for hepatocellular injury, fibrosis and/or cirrhosis in hepatic iron overload are poorly understood. An increase in intracellular transit pool of iron can catalyze peroxidation of lipids to produce reactive aldehydes such as malondialdehyde (MDA) and 4-hydroxynonenal (HNE). Covalent binding of such lipid aldehydes with proteins may cause impairment in cellular function and integrity. This investigation was focused on quantitative determination of MDA and HNE-protein adducts, and to establish a correlation between iron deposition and formation and localization of MDA and HNE-protein adducts, using immunohistochemistry. To achieve iron overload, male SD rats were fed a 2.5% carbonyl iron-supplemented diet for six weeks, while control animals received standard diet. Total iron as well as low molecular weight chelatable iron (LMWC-Fe) in the hepatic tissue of rats fed the iron supplemented diet increased significantly ( approximately 14- and approximately 15-fold, respectively). Quantitative ELISA for MDA-and HNE-protein adducts showed remarkable increases of 186 and 149%, respectively, in the liver homogenates of rats fed the iron-supplemented diet. Sections of liver stained for iron showed striking iron deposits in periportal (zone 1) hepatocytes, which was less dramatic in midzonal (zone 2) cells. Livers from iron-loaded rats showed strong, diffuse staining for both MDA and HNE adducts, which was highly pronounced in centrilobular (zone 3) hepatocytes, but was also evident in midzonal cells (zone 2). The demonstration of greater formation of both MDA and HNE-protein adducts provides evidence of iron-catalyzed lipid peroxidation in vivo. Although in this model of iron overload there was no evidence of tissue injury, our results provide an account of some of the initiating factors or early molecular events in hepatocellular damage that may lead to the pathological manifestations seen in chronic iron overload.

Topics: Aldehydes; Animals; Immunohistochemistry; Iron Overload; Iron, Dietary; Liver; Male; Malondialdehyde; Proteins; Rats; Rats, Sprague-Dawley; Time Factors; Tissue Distribution

Liver injury caused by iron overload is presumed to involve lipid peroxidation and the formation of products such as 4-hydroxynonenal (4HNE), which has been implicated in hepatic fibrogenesis. Cellular antioxidants that modulate the formation and detoxification of compounds such as 4HNE may represent important protective mechanisms involved in the response to iron overload. This study examines the relationship between 4HNE, collagen content, and antioxidant defenses in the livers of rats fed carbonyl iron for 10 weeks. Iron-loading resulted in significant increases in iron (8.8-fold), 4HNE (1.7-fold), and hydroxyproline (1.5-fold). Total glutathione content was unchanged by iron, but gamma-glutamyl transpeptidase activity (GGT) increased sixfold and CuZn superoxide dismutase (CuZnSOD) activity decreased >9%. GGT colocalized with iron deposition and was associated with increased GGT mRNA. Decreased CuZnSOD activity was paralleled by a reduction in CuZnSOD protein on Western blot and immunohistochemistry, but no decrease in CuZnSOD mRNA. Glutathione S-transferase (GST) and Mn superoxide dismutase (MnSOD) activities were also significantly increased by iron loading. These results demonstrate that iron overload significantly alters the expression of antioxidant enzymes associated with glutathione (GGT and GST) and superoxide metabolism (CuZnSOD and MnSOD). Furthermore, the localized induction of GGT may enhance detoxification of lipid peroxidation-derived aldehydes via glutathione-dependent pathways in iron-loaded hepatocytes. These alterations in antioxidant defenses may represent an adaptive response, limiting accumulation 4HNE, and thus, stimulation of collagen synthesis, accounting for the mild fibrogenic response seen in this model of iron overload.

Topics: Aldehydes; Animals; Catalase; gamma-Glutamyltransferase; Glutathione; Glutathione Peroxidase; Glutathione Transferase; Immunohistochemistry; Iron Overload; Lipid Peroxidation; Liver Diseases; Male; Rats; Rats, Sprague-Dawley; RNA, Messenger; Superoxide Dismutase

Reproduction of pancreatic iron overload in an animal model has been difficult to achieve primarily because of the first-pass extraction of iron by the liver. We hypothesized that portacaval shunting would avoid this hepatic phenomenon and increase pancreatic iron deposition. An end-to-side portacaval shunt was surgically created in male Sprague-Dawley rats, and they were subsequently fed a carbonyl iron-supplemented diet for 17 weeks. This resulted in marked iron accumulation in the pancreas (1621 +/- 188 micrograms/g) compared to minimal deposition in sham-operated rats fed the same diet (138 +/- 53 micrograms/g). Iron deposition in the acinar and centroacinar cells was confirmed histologically by Gomori staining, as well as by ultrastructural examination. Iron overloading was associated with enhanced oxidative stress evidenced by a twofold increase in the levels of glutathione disulfide and thiobarbituric acid-reactive substances. Also, adducts of proteins with malondialdehyde and 4-hydroxynonenal were demonstrated in acinar and ductal cells. Other apparent consequences of iron overload were a 50% reduction in pancreatic amylase content and a decrease in pancreatic protein concentration. These hypotrophic changes were associated with a reduced mass of zymogen granules in the acinar cells noted histologically. Our results show that a combination of portacaval shunting and carbonyl iron feeding achieve pancreatic iron overload and support the role of oxidative stress in the pathogenesis of iron-induced damage in the pancreas.

Topics: Aldehydes; Animals; Dietary Supplements; Disease Models, Animal; Immunohistochemistry; Iron Overload; Iron, Dietary; Male; Malondialdehyde; Oxidative Stress; Pancreas; Pancreatic Diseases; Portacaval Shunt, Surgical; Rats; Rats, Sprague-Dawley; Thiobarbituric Acid Reactive Substances