4-hydroxy-2-nonenal and Hypoxia

Reactive oxygen species are thought to partly be responsible for the hypoxia induced performance decrease. The present study evaluated the effects of a broad based antioxidant supplementation or the combined intake of alpha-ketoglutaric acid (α-KG) and 5-hydroxymethylfurfural (5-HMF) on the performance decrease at altitude. 18 healthy, well-trained males (age: 25±3 years; height: 179±6 cm; weight: 76.4±6.8 kg) were randomly assigned in a double-blind fashion to a placebo group (PL), a α-KG and 5-HMF supplementation group (AO1) or a broad based antioxidant supplementation group (AO2). Participants performed 2 incremental exercise tests to exhaustion on a cycle ergometer; the first test under normoxia and the second under hypoxia conditions (simulated altitude, FiO2=13% ~ 4 300 m). Supplementation started 48 h before the hypoxia test. Maximal oxygen uptake, maximal power output, power output at the ventilatory and lactate threshold and the tissue oxygenation index (NIRS) were measured under both conditions. Oxidative stress markers were measured before the supplementation and after the hypoxia test. Under hypoxia conditions all performance parameters decreased in the range of 19-39% with no differences between groups. A significant change from normoxia to hypoxia (p<0.001) and between groups (p=0.038) were found for the tissue oxygenation index. Post hoc test revealed significant differences between the PL and both, the AO1 and the AO2 group. The oxidative stress parameter carbonyl protein changed from normoxia to hypoxia in all participants and 4-hydroxynonenal decreased in the AO1 group only. In conclusion the results suggest that short-term supplementation with an antioxidant does not prevent the performance decrease at altitude. However, positive effects on muscle oxygen extraction, as indicated by the tissue oxygenation index, might indicate that mitochondrial functioning was actually influenced by the supplementation.

Topics: Adult; Aldehydes; Altitude; Antioxidants; Athletic Performance; Double-Blind Method; Exercise; Exercise Test; Furaldehyde; Humans; Hypoxia; Ketoglutaric Acids; Lactic Acid; Male; Oxidative Stress; Oxygen Consumption; Young Adult

This study was aimed to demonstrate the efficacy of interval hypoxic training (IHT) in complex treatment of Helicobacter pylori-associated duodenal peptic ulcer disease (DPUD) by parameters of aerobic metabolism and indexes of heart rate variability (HRV). Eighty patients with H. pylori-associated DPUD were included into the study, mean age 32+/-1.8 yrs, duration of the disease up to 10 years (66.3 %). IHT was modulated using Frolov's hypoxicator (TDI-01) for 30 days after standard eradication therapy. Daily hypoxic sessions consisted of three one-minute sessions, one two-minute, and one three-minute sessions separated by one-minute intervals of room-air breathing. Use of IHT resulted in more efficient elimination of clinical symptoms, histological hallmarks of inflammation and signs of oxidative stress in glandulocytes of the gastric mucosa as determined by 4-hydroxynonenal accumulation. Moderate prooxidant activity of IHT was demonstrated by the increased level of TBARS and oxidatively modified products, normalization of hydroperoxides, middle mass molecules and atherogenic beta-lipoproteins with simultaneous increase in catalase activity and mild decline of SOD activity. Therefore, IHT appeared to be accompanied by higher intensity of redox reactions and enhanced regeneratory processes in cells and tissues. Significant increase in HRV was also noted. Such changes were associated with reduction of inflammation signs and modulation of the autonomic homeostasis in DPUD patients. In general, use of IHT in complex treatment of H. pylori in DPUD patients can be recommended to increase resistance to oxidative stress and to modulate autonomic balance and oxidative homeostasis.

Topics: Adult; Aldehydes; Anti-Bacterial Agents; Anti-Ulcer Agents; Case-Control Studies; Female; Gastric Mucosa; Helicobacter Infections; Helicobacter pylori; Humans; Hypoxia; Immunohistochemistry; Male; Peptic Ulcer; Treatment Outcome

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance and obliterative pulmonary vascular remodelling (PVR). The imbalance between the proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMCs) is an important cause of PVR leading to PAH. Mitochondria play a key role in the production of hypoxia-induced pulmonary hypertension (HPH). However, there are still many issues worth studying in depth. In this study, we demonstrated that NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4 like 2 (NDUFA4L2) was a proliferation factor and increased in vivo and in vitro through various molecular biology experiments. HIF-1α was an upstream target of NDUFA4L2. The plasma levels of 4-hydroxynonene (4-HNE) were increased both in PAH patients and hypoxic PAH model rats. Knockdown of NDUFA4L2 decreased the levels of malondialdehyde (MDA) and 4-HNE in human PASMCs in hypoxia. Elevated MDA and 4-HNE levels might be associated with excessive ROS generation and increased expression of 5-lipoxygenase (5-LO) in hypoxia, but this effect was blocked by siNDUFA4L2. Further research found that p38-5-LO was a downstream signalling pathway of PASMCs proliferation induced by NDUFA4L2. Up-regulated NDUFA4L2 plays a critical role in the development of HPH, which mediates ROS production and proliferation of PASMCs, suggesting NDUFA4L2 as a potential new therapeutic target for PAH.

Topics: Aldehydes; Animals; Arachidonate 5-Lipoxygenase; Cell Hypoxia; Cell Proliferation; Disease Models, Animal; Electron Transport Complex I; Endothelial Cells; Gene Expression Regulation; Gene Silencing; Humans; Hypoxia; Male; Malondialdehyde; Models, Biological; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Oxidation-Reduction; Oxygen Consumption; p38 Mitogen-Activated Protein Kinases; Pulmonary Arterial Hypertension; Pulmonary Artery; Rats, Wistar; Reactive Oxygen Species; RNA, Messenger; Vascular Remodeling

Hypoxia-induced pulmonary hypertension (HPH) increases lipid peroxidation with generation of toxic aldehydes that are metabolized by detoxifying enzymes, including ALDH2 (aldehyde dehydrogenase 2). However, the role of lipid peroxidation and ALDH2 in HPH pathogenesis remain undefined. Approach and Results: To determine the role of lipid peroxidation and ALDH2 in HPH, C57BL/6 mice, ALDH2 transgenic mice, and ALDH2 knockout (ALDH2. Increased 4-hydroxynonenal level plays a critical role in the development of HPH. ALDH2 attenuates the development of HPH by regulating mitochondrial fission and smooth muscle cell proliferation suggesting ALDH2 as a potential new therapeutic target for pulmonary hypertension.

Topics: Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Animals; Cell Proliferation; Cells, Cultured; Down-Regulation; Humans; Hypertension, Pulmonary; Hypoxia; Lipid Peroxidation; Lipoxygenases; Lung; Male; Malondialdehyde; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mitochondrial Dynamics; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Pulmonary Artery; Reactive Oxygen Species; Up-Regulation

Ischemic renal injury is a complex syndrome; multiple cellular abnormalities cause accelerating cycles of inflammation, cellular damage, and sustained local ischemia. There is no single therapy that effectively resolves the renal damage after ischemia. However, infusions of normal adult rat renal cells have been a successful therapy in several rat renal failure models. The sustained broad renal benefit achieved by relatively few donor cells led to the hypothesis that extracellular vesicles (EV, largely exosomes) derived from these cells are the therapeutic effector

Topics: Acute Kidney Injury; Aldehydes; Animals; Cell Communication; Disease Models, Animal; Exosomes; Extracellular Vesicles; Female; Gene Expression Profiling; Genotype; Hypoxia; Kidney; Kidney Tubules; Microcirculation; Neutrophils; Phenotype; Rats; Rats, Sprague-Dawley; Renal Insufficiency; Reperfusion Injury; RNA, Messenger; Time Factors

Our previous findings demonstrated that hypothermia enhances the reduction potential in the liver and helps to maintain the plasmatic antioxidant pool. Here, we aimed to elucidate if hypothermia protects against hypoxia-induced oxidative stress damage in rat liver. Several hepatic markers of oxidative stress were compared in three groups of animals (n = 8 in each group): control normothermic group ventilated with room air and two groups under extreme hypoxia (breathing 10 % O

Topics: Aldehydes; Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Glutathione; Hypothermia, Induced; Hypoxia; Lipid Peroxidation; Liver; Male; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidation-Reduction; Oxidative Stress; Oxygen; Protein Carbonylation; Rats; Rats, Sprague-Dawley

Oxidative stress is proposed as a central mediator in NAFLD pathogenesis, but the specific trigger for reactive oxygen species generation has not been clearly delineated. In addition, emerging evidence shows that obesity related obstructive sleep apnea (OSA) and nocturnal hypoxia are associated with NAFLD progression in adults. The aim of this study was to determine if OSA/nocturnal hypoxia-induced oxidative stress promotes the progression of pediatric NAFLD.. Subjects with biopsy proven NAFLD and lean controls were studied. Subjects underwent polysomnograms, liver histology scoring, laboratory testing, urine F(2)-isoprostanes (measure of lipid peroxidation) and 4-hydroxynonenal liver immunohistochemistry (in situ hepatic lipid peroxidation).. We studied 36 adolescents with NAFLD and 14 lean controls. The OSA/hypoxia group (69% of NAFLD subjects) had more severe fibrosis (64% stage 0-2; 36% stage 3) than those without OSA/hypoxia (100% stage 0-2), p=0.03. Higher F(2)-isoprostanes correlated with apnea/hypoxia index (r=0.39, p=0.03), % time SaO2 <90% (r=0.56, p=0.0008) and inversely with SaO2 nadir (r=-0.46, p=0.008). OSA/hypoxia was most severe in subjects with the greatest 4HNE staining (p=0.03). Increasing F(2)-isoprostanes(r=0.32, p=0.04) and 4HNE hepatic staining (r=0.47, p=0.007) were associated with worsening steatosis. Greater oxidative stress occurred in subjects with definite NASH as measured by F(2)-isoprostanes (p=0.06) and hepatic 4HNE (p=0.03) compared to those with borderline/not NASH.. These data support the role of nocturnal hypoxia as a trigger for localized hepatic oxidative stress, an important factor associated with the progression of NASH and hepatic fibrosis in obese pediatric patients.. Obstructive sleep apnea and low nighttime oxygen are associated with NAFLD progression in adults. In this study, we show that adolescents with NAFLD who have OSA and low oxygen have significant scar tissue in their livers. NAFLD subjects affected by OSA and low oxygen have a greater imbalance between the production of free radicals and their body's ability to counteract their harmful effects than subjects without OSA and low oxygen. This study shows that low oxygen levels may be an important trigger in the progression of pediatric NASH.

Topics: Adolescent; Aldehydes; Child; F2-Isoprostanes; Humans; Hypoxia; Liver; Non-alcoholic Fatty Liver Disease; Oxidative Stress

Vitexin compound B-1 (VB-1) is a novel member of the vitexins family isolated from the seeds of the Chinese herb Vitex negundo. This study aims to investigate whether VB-1 is able to protect nerve cells against oxidative injury and whether the antioxidative effects of VB-1 occur through a mechanism involving the inhibition of NADPH oxidase (NOX) in a manner of hypoxia-inducible factor 1α (HIF-1α)-dependent. To establish a neuronal in vitro model of oxidative stress, the differentiated PC12 cells were subjected to 5 h of hypoxia followed by 20 h of reoxygenation (H/R). Three dosages of VB-1 (10(-8), 10(-7), and 10(-6) M) were chosen to evaluate the effect of VB-1 on H/R-induced injury and the underlying mechanisms. At the end of the experiments, culture mediums and cells were collected for analysis of cellular apoptosis, lactate dehydrogenase (LDH) and caspase 3/7-like activities, reactive oxygen species (ROS) levels, 4-hydroxynonenal (4-HNE) and malondialdehye (MDA) contents, and HIF-1α and NOX expression, respectively. Our results showed that cell injury (indicated by apoptosis ratio, caspase 3/7-like activity, and LDH release), oxidative stress (indicated by ROS production, 4-HNE, and MDA contents), NOX activity, and NOX expression (NOX2 and NOX4 isoforms) were dramatically increased in PC12 cells following H/R, which were attenuated in the presence of VB-1 at dosage of 10(-7) or 10(-6) M. There was no significant change in HIF-1α expression in all experimental groups. These results provide evidence that VB-1 is able to protect the PC12 cells against H/R-induced injury through a mechanism involving the suppression of NOX expression and subsequent reduction of ROS production. The effect of VB-1 on H/R-induced NOX expression is independent on HIF-1α inhibition.

Topics: Aldehydes; Animals; Apoptosis; Caspase 3; Caspase 7; Cell Differentiation; Hypoxia; Lignans; Malondialdehyde; NADPH Oxidases; Neuroprotective Agents; PC12 Cells; Rats; Reactive Oxygen Species; RNA, Messenger

The present study was to explore the effect of metallothionein (MT) on intermittent hypoxia (IH) induced aortic pathogenic changes. Markers of oxidative damages, inflammation, and vascular remodeling were observed by immunohistochemical staining after 3 days and 1, 3, and 8 weeks after IH exposures. Endogenous MT was induced after 3 days of IH but was significantly decreased after 8 weeks of IH. Compared with the wild-type mice, MT knock-out mice exhibited earlier and more severe pathogenic changes of oxidative damages, inflammatory responses, and cellular apoptosis, as indicated by the significant accumulation of collagen, increased levels of connective tissue growth factor, transforming growth factor β1, tumor necrosis factor-alpha, vascular cell adhesion molecule 1,3-nitrotyrosine, and 4-hydroxy-2-nonenal in the aorta. These findings suggested that chronic IH may lead to aortic damages characterized by oxidative stress and inflammation, and MT may play a pivotal role in the above pathogenesis process.

Topics: Aldehydes; Animals; Aorta; Apoptosis; Connective Tissue Growth Factor; Hypoxia; Metallothionein; Mice; Mice, Knockout; NADPH Oxidases; Nitric Oxide Synthase Type III; Oxidative Stress; Time Factors; Tumor Necrosis Factor-alpha; Tyrosine

The prevalence of sleep apnea is very high in patients with heart failure (HF). The aims of this study were to investigate the influence of intermittent hypoxia (IH) on the failing heart and to evaluate the antioxidant effect of hydrogen gas. Normal male Syrian hamsters (n = 22) and cardiomyopathic (CM) hamsters (n = 33) were exposed to IH (repeated cycles of 1.5 min of 5% oxygen and 5 min of 21% oxygen for 8 h during the daytime) or normoxia for 14 days. Hydrogen gas (3.05 vol/100 vol) was inhaled by some CM hamsters during hypoxia. IH increased the ratio of early diastolic mitral inflow velocity to mitral annulus velocity (E/e', 21.8 vs. 16.9) but did not affect the LV ejection fraction (EF) in normal Syrian hamsters. However, IH increased E/e' (29.4 vs. 21.5) and significantly decreased the EF (37.2 vs. 47.2%) in CM hamsters. IH also increased the cardiomyocyte cross-sectional area (672 vs. 443 μm(2)) and interstitial fibrosis (29.9 vs. 9.6%), along with elevation of oxidative stress and superoxide production in the left ventricular (LV) myocardium. Furthermore, IH significantly increased the expression of brain natriuretic peptide, β-myosin heavy chain, c-fos, and c-jun mRNA in CM hamsters. Hydrogen gas inhalation significantly decreased both oxidative stress and embryonic gene expression, thus preserving cardiac function in CM hamsters. In conclusion, IH accelerated LV remodeling in CM hamsters, at least partly by increasing oxidative stress in the failing heart. These findings might explain the poor prognosis of patients with HF and sleep apnea.

Topics: Aldehydes; Animals; Body Weight; Cardiomyopathies; Cricetinae; Cysteine Proteinase Inhibitors; Gases; Gene Expression Regulation, Developmental; Heart Ventricles; Hydrogen; Hypoxia; Mesocricetus; Organ Size; Superoxides; Ultrasonography; Ventricular Remodeling

In cytosol from liver of pacu, Piaractus mesopotamicus, a hypoxia-tolerant fish that dwells in Pantanal, we found an enzyme activity capable of modulating the alkenal 4-hydroxy-2-nonenal (HNE) by conjugating it with glutathione (GST-HNE activity). HNE is a downstream metabolite from the oxidation of polyunsaturated fatty acids by reactive oxygen species arisen from mitochondria of animal cells. HNE production may increase more intensively under oxidative stress. Harmful effects to cell survival may occur when HNE increases over 10(-4) M. Pacus submitted to hypoxia in July (cold season in Pantanal) showed 40% less of this GST-HNE conjugating activity in their liver cytosol. Injecting pacus subjected to hypoxia during the cold season with a summer physiological dose of melatonin caused their liver cytosolic GST-HNE activity to increase up to the levels found in the warm season. From October to March (warm season in Pantanal), pacus are prone to oxidative stress particularly during potamodromous active oxygen-demanding swimming, when they migrate up rivers to spawn. Thus, our findings point out that the higher levels of melatonin in circulation during the summer are important to avoid the increase of 4-HNE inside liver cells of this fish species.

Topics: Aldehydes; Analysis of Variance; Animals; Brazil; Characidae; Cytosol; Fish Diseases; Glutathione; Hypoxia; Liver; Melatonin; Oxygen; Seasons; Spectrophotometry, Ultraviolet

Sleep apnea syndrome increases the risk of cardiovascular morbidity and mortality. We previously reported that intermittent hypoxia increases superoxide production in a manner dependent on nicotinamide adenine dinucleotide phosphate and accelerates adverse left ventricular (LV) remodeling. Recent studies have suggested that hydrogen (H(2)) may have an antioxidant effect by reducing hydroxyl radicals. In this study, we investigated the effects of H(2) gas inhalation on lipid metabolism and LV remodeling induced by intermittent hypoxia in mice. Male C57BL/6J mice (n = 62) were exposed to intermittent hypoxia (repetitive cycle of 1-min periods of 5 and 21% oxygen for 8 h during daytime) for 7 days. H(2) gas (1.3 vol/100 vol) was given either at the time of reoxygenation, during hypoxic conditions, or throughout the experimental period. Mice kept under normoxic conditions served as controls (n = 13). Intermittent hypoxia significantly increased plasma levels of low- and very low-density cholesterol and the amount of 4-hydroxy-2-nonenal-modified protein adducts in the LV myocardium. It also upregulated mRNA expression of tissue necrosis factor-α, interleukin-6, and brain natriuretic peptide, increased production of superoxide, and induced cardiomyocyte hypertrophy, nuclear deformity, mitochondrial degeneration, and interstitial fibrosis. H(2) gas inhalation significantly suppressed these changes induced by intermittent hypoxia. In particular, H(2) gas inhaled at the timing of reoxygenation or throughout the experiment was effective in preventing dyslipidemia and suppressing superoxide production in the LV myocardium. These results suggest that inhalation of H(2) gas was effective for reducing oxidative stress and preventing LV remodeling induced by intermittent hypoxia relevant to sleep apnea.

Topics: Administration, Inhalation; Aldehydes; Analysis of Variance; Animals; Cholesterol, LDL; Cholesterol, VLDL; Disease Models, Animal; Dyslipidemias; Fibrosis; Free Radical Scavengers; Gases; Gene Expression Regulation; Heart Diseases; Heart Ventricles; Hemodynamics; Hydrogen; Hypoxia; Interleukin-6; Lipid Metabolism; Male; Mice; Mice, Inbred C57BL; Myocardium; Natriuretic Peptide, Brain; Oxidative Stress; RNA, Messenger; Superoxides; Time Factors; Tumor Necrosis Factor-alpha; Ventricular Remodeling

We have reported previously that intermittent hypoxia related to sleep apnea induces cardiovascular remodeling secondary to the oxidative stress. The aim of this study was to examine the effect of pitavastatin as an antioxidant to prevent intermittent hypoxia-induced left ventricular (LV) remodeling in mice without hypercholesterolemia. Eight-week-old male C57BL/6J mice (n=35) were exposed to intermittent hypoxia (30 s exposure to 5% oxygen, followed by 30 s exposure to 21% oxygen) for 8 h per day during the daytime or maintained under normoxic conditions; in addition, they were either treated with pitavastatin (3 mg kg(-1) per day) or vehicle for 10 days. After cardiac catheterization and blood sampling, the LV myocardium was examined. The systemic blood pressure and plasma level of total cholesterol were similar among the four groups. Intermittent hypoxia significantly increased the expression levels of 4-hydroxy-2-nonenal (4-HNE) proteins, TNF-alpha and TGF-beta mRNA, and also the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling (TUNEL)-positive myocardial cells in the LV myocardium. In addition, enhanced hypertrophy of the cardiomyocytes, perivascular fibrosis and histological degeneration were observed in the mice exposed to hypoxic stress. Treatment with pitavastatin significantly suppressed the expression levels of the 4-HNE proteins, cytokines, superoxide production and TUNEL-positive myocardial cells in the LV myocardium, consequently attenuating the hypoxia-induced histological changes. Pitavastatin preserved, at least partially, the morphological structure of the LV myocardium in lean mice exposed to intermittent hypoxia, through its antioxidant effect.

Topics: Aldehydes; Animals; Antioxidants; Blood Pressure; Cholesterol; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoxia; In Situ Nick-End Labeling; Male; Mice; Mice, Inbred C57BL; Myocardium; Oxidative Stress; Quinolines; Sleep Apnea Syndromes; Thinness; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Ventricular Remodeling

Intermittent hypoxia caused by sleep apnea is associated with cardiovascular disease. Chymase has been reported to play an important role in the development of cardiovascular disease, but it is unclear whether chymase is involved in the pathogenesis of left ventricular remodeling induced by intermittent hypoxia. The aim of this study was to evaluate the effect of a novel chymase inhibitor (NK3201) on hypoxia-induced left ventricular remodeling in mice. Male C57BL/6J mice (9 weeks old) were exposed to intermittent hypoxia or normoxia and were treated with NK3201 (10 mg/kg per day) or the vehicle for 10 days. Left ventricular systolic pressure showed no significant differences among all of the experimental groups. Exposure to intermittent hypoxia increased left ventricular chymase activity and angiotensin II expression, which were both suppressed by treatment with NK3201. Intermittent hypoxia also increased the mean cardiomyocyte diameter, perivascular fibrosis, expression of inflammatory cytokines, oxidative stress, and NADPH-dependent superoxide production in the left ventricular myocardium. These changes were all suppressed by NK3201 treatment. Therefore, chymase might play an important role in intermittent hypoxia-induced left ventricular remodeling, which is independent of the systemic blood pressure.

Topics: Acetamides; Aldehydes; Angiotensin II; Animals; Body Weight; Chymases; Gene Expression; Hemodynamics; Hypoxia; Immunohistochemistry; Interleukin-6; Lipid Peroxides; Male; Mice; Mice, Inbred C57BL; Myocardium; Myocytes, Cardiac; NADP; Organ Size; Pyrimidines; Reverse Transcriptase Polymerase Chain Reaction; Superoxides; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Ventricular Remodeling

Aged rat brain is more sensitive to reperfusion injury induced by cardiac arrest and resuscitation. The mitochondrial respiratory chain, the major source of free radicals during reperfusion, is likely to be the target of lipid peroxidation. Previous work has shown a higher mortality and lower hippocampal neuronal survival in older rats. 4-hydroxy-2-nonenal (HNE), a major product of lipid peroxidation, was found to be elevated in cortex and brainstem after resuscitation. In this study we investigated the acute changes of mitochondrial function in aging rat brain following cardiac arrest and resuscitation; the effect of an antioxidant, alpha-phenyl-tert-butyl-nitrone (PBN) was also tested. Fischer 344 rats, 6 and 24-month old, were subjected to cardiac arrest (7-10 minutes) and allowed to recover 1 hour after resuscitation. Mitochondria of cortex and brainstem were isolated and assayed for respiratory function. Compared to their respective non-arrested control group, 1h untreated groups (both 6 month and 24 month) had similar state 3 (ADP-stimulated) but higher state 4 (resting state) respiratory rates. The respiratory control ratio (state 3/state 4) of cortex in the 1h untreated group was 26% lower than the non-arrested control group; similar results were found in brainstem. The decreased mitochondrial respiratory function was improved by PBN treatment. HNE-modified mitochondrial proteins were elevated 1h after resuscitation, with an evident change in the aged. Treatment with PBN reduced the elevated HNE production in mitochondria of cortex. The data suggest (i) there is increased sensitivity to lipid peroxidation with aging, (ii) mitochondrial respiratory function related to coupled oxidation decreases following cardiac arrest and resuscitation, and (iii) treatment with antioxidant, such as PBN, reduces the oxidative damage following cardiac arrest and resuscitation.

Topics: Aging; Aldehydes; Animals; Brain Ischemia; Cross-Linking Reagents; Cyclic N-Oxides; Hypoxia; Male; Mitochondria; Neuroprotective Agents; Oxidation-Reduction; Oxidative Stress; Oxygen Consumption; Rats; Rats, Inbred F344; Time Factors

Intermittent hypoxia due to sleep apnea syndrome is associated with cardiovascular diseases. However, the precise mechanisms by which intermittent hypoxic stress accelerates cardiovascular diseases are largely unclear. The aim of this study was to investigate the role of gp91(phox)-containing NADPH oxidase in the development of left ventricular (LV) remodeling induced by intermittent hypoxic stress in mice. Male gp91(phox)-deficient (gp91(-/-)) mice (n = 26) and wild-type (n = 39) mice at 7-12 wk of age were exposed to intermittent hypoxia (30 s of 4.5-5.5% O(2) followed by 30 s of 21% O(2) for 8 h/day during daytime) or normoxia for 10 days. Mean blood pressure and LV systolic and diastolic function were not changed by intermittent hypoxia in wild-type or gp91(-/-) mice, although right ventricular systolic pressure tended to be increased. In wild-type mice, intermittent hypoxic stress significantly increased the diameter of cardiomyocytes and interstitial fibrosis in LV myocardium. Furthermore, intermittent hypoxic stress increased superoxide production, 4-hydroxy-2-nonenal protein, TNF-alpha and transforming growth factor-beta mRNA, and NF-kappaB binding activity in wild-type, but not gp91(-/-), mice. These results suggest that gp91(phox)-containing NADPH oxidase plays a crucial role in the pathophysiology of intermittent hypoxia-induced LV remodeling through an increase of oxidative stress.

Topics: Aldehydes; Animals; Blood Pressure; Disease Models, Animal; Hypoxia; Interleukin-6; Lipid Peroxides; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardium; NADPH Oxidase 2; NADPH Oxidases; NF-kappa B; Oxidative Stress; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Superoxides; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Ventricular Dysfunction, Left; Ventricular Pressure; Ventricular Remodeling

Damage of the placenta resulting from ischemia-reperfusion is important to the pathophysiology of preeclampsia. Here we investigated whether low concentrations of glyceryl trinitrate (GTN), a nitric oxide mimetic with anti-apoptotic properties, inhibit hypoxia/reoxygenation-induced apoptosis in the syncytiotrophoblast of chorionic villous explants from human placentas. Compared with villi analyzed immediately after delivery or maintained under normoxic conditions, villi exposed to a 6-hour cycle of hypoxia/reoxygenation exhibited greater numbers of syncytiotrophoblasts with terminal dUTP nick-end labeling (TUNEL)-positive nuclei in the syncytiotrophoblast. This increased number of TUNEL-positive nuclei was paralleled by higher levels of 4-hydroxynonenal (marker of lipid peroxidation), nitrotyrosine residues, and active caspase-3 and polyADP-ribose polymerase expression. Morphological analysis of explants exposed to hypoxia/reoxygenation revealed apoptotic and aponecrotic features similar to those of chorionic villi from preeclamptic pregnancies. Treatment with GTN during the hy-poxia/reoxygenation cycle blocked the increases in the number of TUNEL-positive nuclei and in the levels of 4-hydroxynonenal, nitrotyrosine, and active caspase-3. Incubation with GTN also attenuated the hypoxia/reoxygenation-induced polyADP-ribose polymerase expression and the apoptotic and aponecrotic morphological alterations. These results suggest that small concentrations of nitric oxide protect chorionic villi from hypoxia/reoxygenation-induced damage and provide a rationale for the use of low doses of nitric oxide mimetics in the treatment and/or prevention of preeclampsia.

Topics: Aldehydes; Apoptosis; Blotting, Western; Caspase 3; Collagen Type XI; Female; Humans; Hypoxia; Immunohistochemistry; In Situ Nick-End Labeling; Microscopy, Electron, Transmission; Nitroglycerin; Organ Culture Techniques; Pre-Eclampsia; Pregnancy; Reperfusion Injury; Tocolytic Agents; Trophoblasts; Tyrosine

Transient global brain ischemia induced by cardiac arrest and resuscitation (CAR) results in reperfusion injury associated with oxidative stress. Oxidative stress is known to produce delayed selective neuronal cell loss and impairment of brainstem function, leading to post-resuscitation mortality. Levels of 4-hydroxy-2-nonenal (HNE) modified protein adducts, a marker of oxidative stress, was found to be elevated after CAR in rat brain. In this study we investigated the effects of an antioxidant, alpha-phenyl-tert-butyl-nitrone (PBN) on the recovery following CAR in the aged rat brain. Male Fischer 344 rats (6, 12 and 24-month old) underwent 7-minute cardiac arrest before resuscitation. Brainstem function was assessed by hypoxic ventilatory response (HVR) and HNE-adducts were measured by western blot analysis. Our data showed that in the 24-month old rats, overall survival rate, hippocampal CAl neuronal counts and HVR were significantly reduced compared to the younger rats. With PBN treatment, the recovery was improved in the aged rat brain, which was consistent with reduced HNE adducts in brain following CAR. Our data suggest that aged rats are more vulnerable to oxidative stress insult and treatment with PBN improves the outcome following reperfusion injury. The mechanism of action is most likely through the scavenging of reactive oxygen species resulting in reduced lipid peroxidation.

Topics: Aging; Aldehydes; Animals; Antioxidants; Brain Ischemia; Cross-Linking Reagents; Cyclic N-Oxides; Free Radical Scavengers; Hippocampus; Hypoxia; Male; Neurons; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Inbred F344; Survival Rate

Elevated superoxide formation in cardiac extracts of apolipoprotein E-knockout (apoE-KO) mice has been reported. In addition, we previously reported that hypoxia increased oxidative stress in the aortas of apoE-KO mice, although we did not examine the effect of hypoxia on the heart. The aim of this study was to investigate the effect of chronic hypoxia on the left ventricular (LV) remodeling in apoE-KO mice treated with or without an angiotensin II receptor blocker. Male apoE-KO mice (n=83) and wild-type mice (n=34) at 15 weeks of age were kept under hypoxic conditions (oxygen, 10.0+/-0.5%) and treated with olmesartan (3 mg/kg/day) or vehicle for 3 weeks. Although LV pressure was not changed, hypoxia caused hypertrophy of cardiomyocytes and increased interstitial fibrosis in the LV myocardium. Furthermore, nuclear factor-kappaB (NF-kappaB) and matrix metalloproteinase (MMP)-9 activities were increased in apoE-KO mice exposed to chronic hypoxia. Olmesartan effectively suppressed the 4-hydroxy-2-nonenal protein expression and NF-kappaB and MMP-9 activities, and preserved the fine structure of the LV myocardium without affecting the LV pressure. In conclusion, olmesartan reduced oxidative stress, and attenuated the hypoxia-induced LV remodeling, in part through the inhibition of NF-kappaB and MMP-9 activities, in apoE-KO mice.

Topics: Aldehydes; Angiotensin II Type 1 Receptor Blockers; Animals; Apolipoproteins E; Heart Ventricles; Hypertrophy, Left Ventricular; Hypoxia; Imidazoles; Male; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Mice; Mice, Knockout; Myocytes, Cardiac; NADPH Oxidases; NF-kappa B; Oxidative Stress; Superoxides; Tetrazoles; Ventricular Remodeling

Endogenous free radical production and resulting oxidative damage may result from exposure to hypoxia, hyperoxia, or hydrogen sulfide. Previous investigations of sulfide-induced oxidative damage have produced conflicting results, perhaps because these studies utilized species presumably adapted to sulfide. We examined the effects of sulfide, hypoxia and hyperoxia on the surf clam Donax variabilis to test whether these stressors induce a cellular response to oxidative stress. These clams inhabit high-energy sandy beaches and are unlikely to have specific adaptations to these stressors. In duplicate flow-through experiments performed in fall and spring, clams were exposed to normoxia (22 kPa P(O(2))), hypoxia (10 kPa), hyperoxia (37 kPa), or sulfide with normoxia ( approximately 100 mumol L(-1), 22 kPa respectively) for 24 h. We quantified whole-animal expression of three antioxidants (Cu/Zn and Mn superoxide dismutases, glutathione peroxidase), a lipid peroxidation marker (4-hydroxy-2E-nonenol-adducted protein), a DNA repair enzyme (OGG1-m), four heat shock proteins (small Hsp, Hsp60, Hsp70, and mitochondrial Hsp70), ubiquitin, and actin. Clams exposed to sulfide showed upregulation of the greatest number of stress proteins and the pattern was consistent with a cellular response to oxidative stress. Furthermore, there was a marked seasonality, with greater stress protein expression in clams from the spring.

Topics: Actins; Aldehydes; Animals; Antioxidants; Bivalvia; DNA Glycosylases; Glutathione Peroxidase; Heat-Shock Proteins; Hydrogen Sulfide; Hyperoxia; Hypoxia; Lipid Peroxidation; Seasons; Superoxide Dismutase; Ubiquitin; Up-Regulation

A prolonged sojourn above 5500 m induces muscle deterioration and accumulation of lipofuscin in Caucasians, probably because of overproduction of reactive oxygen species (ROS). Because Sherpas, who live at high altitude, have very limited muscle damage, it was hypothesized that Himalayan natives possess intrinsic mechanisms protecting them from oxidative damage. This possibility was investigated by comparing the muscle proteomes of native Tibetans permanently residing at high altitude, second-generation Tibetans born and living at low altitude, and Nepali control subjects permanently residing at low altitude, using 2D gel electrophoresis and mass spectrometry. Seven differentially regulated proteins were identified: glutathione-S-transferase P1-1, which was 380% and 50% overexpressed in Tibetans born and living at high and low altitude, respectively; Delta2-enoyl-CoA-hydratase, which was up-regulated in both Tibetan groups; glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase, which were both slightly down-regulated in Tibetans born and living at high altitude; phosphoglycerate mutase, which was 50% up-regulated in the native Tibetans; NADH-ubiquinone oxidoreductase, slightly overexpressed in Tibetans born and living at high altitude; and myoglobin, which was overexpressed in both Tibetan groups. We concluded that Tibetans at high altitude, and to some extent, those born and living at low altitude, are protected from ROS-induced tissue damage and possess specific metabolic adaptations.

Topics: Adaptation, Physiological; Adolescent; Adult; Aldehydes; Altitude; Ethnicity; Glutathione Transferase; Humans; Hypoxia; Isoenzymes; Lipofuscin; Male; Muscle Proteins; Muscle, Skeletal; Myoglobin; Nepal; Oxidative Stress; Protein Isoforms; Proteomics; Reactive Oxygen Species; Tibet

One of the major characteristics of tumor is the presence of a hypoxic cell population, which is caused by abnormal distribution of blood vessels. Manganese superoxide dismutase (MnSOD) is a nuclear-encoded mitochondrial enzyme, which scavenges superoxide generated from the electron-transport chain in mitochondria. We examined whether MnSOD protects against hypoxia/reoxygenation (H/R)-induced oxidative stress using a human pancreas carcinoma-originated cell line, KP4. We also examined whether MnSOD is necessarily present in mitochondria to have a function. Normal human MnSOD and MnSOD without a mitochondrial targeting signal were transfected to KP4 cells, and reactive oxygen species, nitric oxide, lipid peroxidation, and apoptosis were examined as a function of time in air following 1 day of hypoxia as a H/R model. Our results showed H/R caused no increase in nitric oxide, but resulted in increases in reactive oxygen species, 4-hydroxy-2-nonenal protein adducts, and apoptosis. Authentic MnSOD protected against these processes and cell death, but MnSOD lacking a mitochondrial targeting signal could not. These results suggest that only when MnSOD is located in mitochondria is it efficient in protecting against cellular injuries by H/R, and they also indicate that mitochondria are primary sites of H/R-induced cellular oxidative injuries.

Topics: Aldehydes; Apoptosis; Cell Death; Cell Line, Tumor; DNA Adducts; DNA Primers; DNA, Complementary; Humans; Hypoxia; Lipid Peroxidation; Microscopy, Fluorescence; Mitochondria; Nitric Oxide; Oxidative Stress; Oxygen; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Superoxide Dismutase; Time Factors; Transfection

This study assesses the vulnerability of fetal guinea pig heart to metabolic changes during acute nonlethal in utero hypoxia. Guinea pigs (50-55 days gestation) were exposed to 7% O2 for 2 h and room air for 4 h. Fetal hearts were harvested before hypoxia, at the end of hypoxia, and 4 h after hypoxia, and analyzed for: apoptosis (TUNEL), histology, lipid peroxidation and ATP. A group of posthypoxic dams was taken to gestation. Within 48 h postpartum, the function of neonatal hearts was tested and cerebral histology examined. Fetal heart ATP was decreased by 27% at the end of hypoxia and by 32% 4 h after hypoxia. The lipid peroxides, 4-hydroxynonenal and malondialdehyde, were decreased by 37 and 46%, respectively, by 4 h after hypoxia. The apoptotic index increased from 2% in prehypoxic hearts to 8.4% by 4 h after hypoxia. Fetal heart morphology was unremarkable. Postpartum neonatal cardiac function was not affected and cerebral histology was unremarkable. These results support the conclusion that nonlethal in utero hypoxia has acute effects on the fetal heart but no persistent cardiac or cerebral effects in the postpartum neonate.

Topics: Adenosine Triphosphate; Aldehydes; Animals; Animals, Newborn; Apoptosis; Brain; Female; Gestational Age; Guinea Pigs; Heart; Hypoxia; In Situ Nick-End Labeling; Lipid Peroxidation; Malondialdehyde; Myocardium; Oxygen; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects

Oxidative stress is a prominent feature of the placenta in many complications of pregnancy, such as preeclampsia. The cause is primarily unknown, although ischemia-reperfusion injury is one possible mechanism. Our aim was to test this hypothesis by examining the oxidative status of human placental tissues during periods of hypoxia and reoxygenation in vitro. Rapid generation of reactive oxygen species was detected using the fluorogenic probe, 2',7'-dichlorofluorescein diacetate, when hypoxic tissues were reoxygenated. The principal sites were the villous endothelium, and to a lesser extent the syncytiotrophoblast and stromal cells. Increased concentrations of heat shock protein 72, nitrotyrosine residues, and 4-hydroxy-2-nonenal were also observed in the villous endothelial and underlying smooth muscle cells, and in the syncytiotrophoblast. Furthermore, preloading placental tissues with the reactive oxygen species scavengers desferrioxamine and alpha-phenyl-N-tert-butylnitrone reduced levels of oxidative stress after reoxygenation. These changes are consistent with an ischemia-reperfusion injury, and mirror those seen in preeclampsia. Consequently, in vitro hypoxia/reoxygenation may represent a suitable model system for investigating the generation of placental oxidative stress in preeclampsia and other complications of pregnancy.

Topics: Aldehydes; Cyclic N-Oxides; Deferoxamine; Female; Fluorescent Antibody Technique; Heat-Shock Proteins; HSP72 Heat-Shock Proteins; Humans; Hypoxia; Immunohistochemistry; Ischemia; Nitrogen Oxides; Oxidative Stress; Oxygen; Placenta; Pregnancy; Pregnancy Complications; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase; Tissue Distribution; Tyrosine

1. Hypoxic alterations in isolated rat hepatocytes were demonstrated by a 90% ATP loss during 60 min of ischaemia and temporary increases of nucleotide degradation products. 2. The oxidative stress during reoxygenation was demonstrated in these cells by a decrease in reduced glutathione (GSH) concentration (30%) and a threefold increase in lipid peroxidation products such as 4-hydroxynonenal and thiobarbituric acid-reactive substances (TBA-RSs). The tremendous GSH loss could not be balanced by the slight oxidized glutathione (GSSG) increase during reoxygenation. 3. For the first time the involvement of free radicals was directly demonstrated using electron spin resonance (ESR) spectroscopy in reoxygenated liver cells. Using the spin trap 5,5-dimethylpyrroline-1-oxide (DMPO), a carbon-centred radical and the adduct of the hydroxyl radical could be detected during early reoxygenation. 4. Morphological alteration of cells was observed, beginning during hypoxia and increasing during post-hypoxic reoxygenation. Electron microscopic findings of hypoxic and post-hypoxic cell damage included pyknosis of nuclei, spherical transformation of mitochondria and increased number of vesicles.

Topics: Aldehydes; Animals; Cell Survival; Cross-Linking Reagents; Energy Metabolism; Free Radicals; Glutathione; Hypoxia; Lipid Peroxidation; Liver; Male; Oxidative Stress; Purine Nucleotides; Rats; Rats, Wistar; Spin Trapping; Thiobarbituric Acid Reactive Substances

For quantitative evaluation of lipid peroxidation after perinatal hypoxia in umbilical arterial cord blood samples from 109 healthy, acidotic, and asphyctic neonates with a gestational age ranging from 26 to 41 wk, the levels of aldehydic lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynon-2-enal (HNE) were measured. Furthermore, the concentrations of oxidized and reduced glutathione (GSSH and GSH) and the purine compounds hypoxanthine and uric acid were determined. With increasing gestational age MDA and HNE levels increased. Furthermore, an increased level of GSH was also found. After perinatal hypoxia the concentrations of MDA and HNE rose distinctly (p < 0.001), reflecting sensitively the extent of in vivo lipid peroxidation. HNE is proposed to be a new parameter for quantitative evaluation of posthypoxic cellular damage in the perinatal period. HNE is a more specific parameter for estimation of lipid peroxidation processes in comparison with MDA. Additionally, HNE is cytotoxic and mutagenic at nanomolar concentrations. The increased levels of both MDA and HNE were accompanied by a strong decrease of GSH concentrations (p < 0.001), indicating the rapid consumption of GSH via a glutathione peroxidase reaction but additionally the high reactivity of HNE with sulfhydryl groups. During oxygen deficiency, increased levels of hypoxanthine (p < 0.01) and uric acid (p < 0.05) were due to the accelerated degradation of purine nucleotides. The rate of purine degradation including xanthine oxidase reactions characterizes the extent of an important radical source during oxygen deficiency, contributing to peroxidation of polyunsaturated fatty acids and the formation of peroxidation of polyunsaturated fatty acids and the formation of secondary aldehydic lipid peroxidation products.

Topics: Acidosis; Aldehydes; Asphyxia Neonatorum; Case-Control Studies; Fetal Blood; Gestational Age; Glutathione; Glutathione Disulfide; Humans; Hypoxanthine; Hypoxia; Infant, Newborn; Lipid Peroxidation; Malondialdehyde; Uric Acid

We measured the accumulation of 4-hydroxynonenal (HNE), a major lipid peroxidation product during hypoxia/reoxygenation of brain capillary endothelial cells (BCEC). The concentration of HNE after 2 h of hypoxia was 0.23 nmol/mg protein and rose up to 0.28 nmol/mg protein after 30 min of reoxygenation. That reflects a 1.5-fold increase, whereas aortic endothelial cells (AEC) increased the HNE level 5-fold, compared to the control. Therefore, the ability of BCEC to degrade exogenously added HNE was tested. The HNE consumption in BCEC achieved a rate of about 600 nmol.min-1.mg protein-1, about two times higher than in AEC. The higher ability of BCEC to degrade HNE is probably the reason of the 2-fold higher IC50 value against the aldehyde. Therefore, we concluded that the high ability of BCEC to degrade HNE is a substantial part of the secondary antioxidative defense of the brain.

Topics: Aldehydes; Animals; Brain; Capillaries; Cattle; Cells, Cultured; Cerebrovascular Circulation; Endothelium; Hypoxia; Oxygen