4-hydroxy-2-nonenal and Arteriosclerosis

The onset of lipid peroxidation within cellular membranes is associated with changes in their physiochemical properties and with the impairment of enzymatic functions located in the membrane environment. There is increasing evidence that aldehydic molecules generated endogenously during the process of lipid peroidation are causally involved in most of the pathophysiological effects associated with oxidative stress in cells and tissues. 4-Hydroxy-2-nonenal (HNE), among them, is believed to be largely responsible for cytopathological effects observed during oxidative stree in vivo and has achieved the status of one of the best recognized and most studied of the cytotoxic products of lipid peroxidation. In the present review, I provide a comprehensive summary of HNE, as the product and mediator or oxidative stress.

Topics: Aldehydes; Animals; Apoptosis; Arteriosclerosis; Cysteine Endopeptidases; Humans; Immunohistochemistry; Lipid Peroxidation; Mammals; MAP Kinase Signaling System; Multienzyme Complexes; Neurodegenerative Diseases; NF-kappa B; Oxidative Stress; Proteasome Endopeptidase Complex

Oxidant stress has been widely implicated as a mechanism of disease, yet clinical trials of antioxidants have not included a biochemical basis for dose selection or patient inclusion. Many of the indices traditionally employed to assess lipid peroxidation have relied on measurements performed in ex vivo systems of questionable relevance to events in vivo. Commonly employed in vivo indices of lipid peroxidation are constrained by such issues as the nonspecificity or instability of the target anylate, contamination of the anylate by events ex vivo, and nonspecificity of analytical methodology. More recently, specific methodology based on mass spectrometry has been applied to both 4-hydroxynonenal and a variety of isoprostanes in human biological fluids. Measurement of these compounds in urine reflects lipid peroxidation in vivo and offers a noninvasive approach that may be readily applied to clinical trials.

Topics: Aldehydes; Antioxidants; Arteriosclerosis; Biomarkers; Ethane; Humans; Lipid Peroxidation; Oxidative Stress; Pentanes; Prostaglandins; Thiobarbituric Acid Reactive Substances

Considerable evidence now points to an important role for the immune system in experimental models of atherosclerosis. We have reviewed the growing body of evidence that oxidation of LDL generates a wide variety of neoself determinants that lead to cellular and humoral immune responses. In particular, we have demonstrated that at least some of the oxidation-specific epitopes generated on the oxidized LDL particle, such as oxidized phospholipid epitopes, are also generated on apoptotic cells and are also present on the surface of some bacteria. Many of these same epitopes serve as important ligands mediating the binding and clearance of oxidatively damaged lipoprotein particles and apoptotic cells, and the innate immune response to these epitopes can be seen as a concerted response to effect their removal. In addition, other epitopes of OxLDL also undoubtedly play a role in the immune activation that characterizes the progressive atherosclerotic plaque. It will be of great importance to define the importance of the role of these responses and to understand which are beneficial and which deleterious. Such information could lead one day to novel therapeutic approaches to inhibit atherogenesis that take advantage of the ability to manipulate the immune response.

Topics: Aldehydes; Animals; Antibodies, Antiphospholipid; Antibodies, Monoclonal; Antiphospholipid Syndrome; Apolipoproteins E; Apoptosis; Arteriosclerosis; Autoantibodies; Cardiolipins; Epitopes; Female; Humans; Immunity, Cellular; Lipoproteins, LDL; Malondialdehyde; Mice; Pre-Eclampsia; Pregnancy

There is increasing evidence that aldehydes generated endogenously during lipid peroxidation contribute to the pathophysiologic effects associated with oxidative stress in cells and tissues. A number of reactive lipid aldehydes, such as 4-hydroxy-2-alkenals and malondialdehyde, have been implicated as causative agents in cytotoxic processes initiated by the exposure of biologic systems to oxidizing agents. Recently, acrolein (CH2 = CH-CHO), a ubiquitous pollutant in the environment, was identified as a product of lipid peroxidation reactions. The basis for this finding is an experimental approach that provides a measure of acrolein bound to lysine residues of protein. The identification of acrolein as an endogenous lipid-derived product suggests an examination of the possible role of this aldehyde as a mediator of oxidative damage in a variety of human diseases.

Topics: Acrolein; Air Pollutants; Aldehydes; Alzheimer Disease; Arteriosclerosis; Cross-Linking Reagents; Fatty Acids, Unsaturated; Glyoxal; Humans; Lipid Peroxidation; Lipid Peroxides; Lysine; Malondialdehyde; Oxidative Stress

Reactive oxygen intermediates (ROI) and other pro-oxidant agents are known to elicit, in vivo and in vitro, oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids (i.e, lipid peroxidation). This leads to the formation of a complex mixture of aldehydic end-products, including malonyldialdehyde (MDA), 4-hydroxy-2,3-nonenal (HNE), and other 4-hydroxy-2,3-alkenals (HAKs) of different chain length. These aldehydic molecules have been considered originally as ultimate mediators of toxic effects elicited by oxidative stress occurring in biological material. Experimental and clinical evidence coming from different laboratories now suggests that HNE and HAKs can also act as bioactive molecules in either physiological and pathological conditions. These aldehydic compounds can affect and modulate, at very low and nontoxic concentrations, several cell functions, including signal transduction, gene expression, cell proliferation, and, more generally, the response of the target cell(s). In this review article, we would like to offer an up-to-date review on this particular aspect of oxidative stress--dependent modulation of cellular functions-as well as to offer comments on the related pathophysiological implications, with special reference to human conditions of disease.

Topics: Aldehydes; Arteriosclerosis; Chemotactic Factors; Chronic Disease; Humans; Inflammation; Liver Diseases; Nervous System Diseases; Oxidative Stress; Proteins; Reperfusion Injury; Signal Transduction

Oxidative stress is implicated in the pathogenesis of numerous disease processes including diabetes mellitus, atherosclerosis, ischaemia reperfusion injury and rheumatoid arthritis. Chemical modification of amino acids in protein during lipid peroxidation results in the formation of lipoxidation products which may serve as indicators of oxidative stress in vivo. The focus of the studies described here was initially to identify chemical modifications of protein derived exclusively from lipids in order to assess the role of lipid peroxidative damage in the pathogenesis of disease. Malondialdehye (MDA) and 4-hydroxynonenal (HNE) are well characterized oxidation products of polyunsaturated fatty acids on low-density lipoprotein (LDL) and adducts of these compounds have been detected by immunological means in atherosclerotic plaque. Thus, we first developed gas chromatography-mass spectrometry assays for the Schiff base adduct of MDA to lysine, the lysine-MDA-lysine diimine cross-link and the Michael addition product of HNE to lysine. Using these assays, we showed that the concentrations of all three compounds increased significantly in LDL during metal-catalysed oxidation in vitro. The concentration of the advanced glycation end-product N epsilon-(carboxymethyl)lysine (CML) also increased during LDL oxidation, while that of its putative carbohydrate precursor the Amadori compound N epsilon-(1-deoxyfructose-1-yl)lysine did not change, demonstrating that CML is a marker of both glycoxidation and lipoxidation reactions. These results suggest that MDA and HNE adducts to lysine residues should serve as biomarkers of lipid modification resulting from lipid peroxidation reactions, while CML may serve as a biomarker of general oxidative stress resulting from both carbohydrate and lipid oxidation reactions.

Topics: Aldehydes; Arteriosclerosis; Biomarkers; Diabetes Mellitus; Glycation End Products, Advanced; Humans; Lipid Peroxidation; Lipoproteins, LDL; Lysine; Maillard Reaction; Malondialdehyde; Oxidative Stress; Proteins

CD36 is an important scavenger receptor mediating uptake of oxidized low-density lipoproteins (oxLDLs) and plays a key role in foam cell formation and the pathogenesis of atherosclerosis. We report the first evidence that the transcription factor Nrf2 is expressed in vascular smooth muscle cells, and demonstrate that oxLDLs cause nuclear accumulation of Nrf2 in murine macrophages, resulting in the activation of genes encoding CD36 and the stress proteins A170, heme oxygenase-1 (HO-1), and peroxiredoxin I (Prx I). 4-Hydroxy-2-nonenal (HNE), derived from lipid peroxidation, was one of the most effective activators of Nrf2. Using Nrf2-deficient macrophages, we established that Nrf2 partially regulates CD36 expression in response to oxLDLs, HNE, or the electrophilic agent diethylmaleate. In murine aortic smooth muscle cells, expressing negligible levels of CD36, both moderately and highly oxidized LDL caused only limited Nrf2 translocation and negligible increases in A170, HO-1, and Prx I expression. However, treatment of smooth muscle cells with HNE significantly enhanced nuclear accumulation of Nrf2 and increased A170, HO-1, and Prx I protein levels. Because PPAR-gamma can be activated by oxLDLs and controls expression of CD36 in macrophages, our results implicate Nrf2 as a second important transcription factor involved in the induction of the scavenger receptor CD36 and antioxidant stress genes in atherosclerosis.

Topics: Adaptor Proteins, Signal Transducing; Aldehydes; Animals; Aorta; Arteriosclerosis; CD36 Antigens; DNA-Binding Proteins; Female; Gene Expression Regulation; Heat-Shock Proteins; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Homeodomain Proteins; Lipid Peroxidation; Lipoproteins, LDL; Macrophages, Peritoneal; Maleates; Membrane Proteins; Mice; Mice, Inbred ICR; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NF-E2-Related Factor 2; Oxidative Stress; Receptors, Cytoplasmic and Nuclear; Receptors, Immunologic; Receptors, Scavenger; Rosiglitazone; Sequestosome-1 Protein; Thiazolidinediones; Trans-Activators; Transcription Factors; Transcription, Genetic; Up-Regulation

Cyclooxygenases (COXs) catalyze the conversion of arachidonic acid to eicosanoids, which mediate a variety of biological actions involved in vascular pathophysiology. In the present study, we investigated the role of lipid peroxidation products in the up-regulation of COX-2, an inducible isoform responsible for high levels of prostaglandin production during inflammation and immune responses. COX-2 was found to colocalize with 4-hydroxy-2-nonenal (HNE), a major lipid peroxidation-derived aldehyde, in foamy macrophages within human atheromatous lesions, suggesting that COX-2 expression may be associated with the accumulation of lipid peroxidation products within macrophages. To test the hypothesis that lipid peroxidation products might be involved in the regulation of prostanoid biosynthesis, we conducted a screen of oxidized fatty acid metabolites and found that, among the compounds tested, only HNE showed inducibility of the COX-2 protein in RAW264.7 macrophages. In addition, intraperitoneal administration of HNE resulted in an increase in cell numbers in the peritoneal cavity that was associated with significant increases in the peritoneal and tissue levels of COX-2 in mice. To understand the possible signaling mechanism underlying the inducing effect of HNE on COX-2 up-regulation, we examined the phosphorylation events that may lead to COX-2 induction and found that HNE did not stimulate the induction of nitric oxide synthase and activation of NF-kappaB but significantly activated p38 mitogen-activated protein kinase and its upstream kinase in RAW264.7 macrophages. Tyrosine kinases, such as the epidermal growth factor-like and Src family tyrosine kinases, appeared to mediate the stabilization of COX-2 mRNA via the p38 mitogen-activated protein kinase pathway. These findings suggest that HNE accumulated in macrophages/foam cells may represent an inflammatory mediator that plays a role in stimulation of the inflammatory response and contributes to the progression of atherogenesis.

Topics: Aldehydes; Animals; Arteriosclerosis; Cell Line; Coronary Vessels; Cyclooxygenase 2; Enzyme Activation; Enzyme Induction; Enzyme Inhibitors; Humans; Isoenzymes; Lipid Peroxidation; Lipopolysaccharides; Macrophages; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Prostaglandin-Endoperoxide Synthases; RNA Stability; Signal Transduction; src-Family Kinases; Up-Regulation

Oxidative modification of lipoproteins plays an important role in atherogenesis. We investigated a variety of different oxidatively modified epitopes (malondialdehyde (MDA)-2, hydroxynonenal (HNE)-7, peroxynitrite, hypochlorite, EO-6) in parallel and compared normal vessel wall, early and advanced atherosclerotic lesions in WHHL rabbits. Early atherosclerotic lesions showed abundant intracellular staining in macrophages for all ox-epitopes, apo B and apo E; advanced lesions showed a more prominent peri- and extracellular staining for ox-epitopes, which tended to colocalize more with apo B than apo E. Hypochlorite-modified epitopes showed intense staining in all types of lesions, followed by MDA-2. Early and advanced atherosclerotic lesions differed significantly in that early stages revealed abundant cellular positivity for EO-6 and weak staining for HNE-7 modified proteins whereas the opposite was observed in advanced lesions. Nuclear factor-kappa B (NF-kappa B) was nearly exclusively detected in macrophages with no difference between early and advanced lesions. We conclude that hypochlorite-modified epitopes are abundantly present at all stages of atherogenesis. EO-6 might be a marker for early, HNE-7 a marker for advanced lesions. Colocalization of ox-epitopes with apolipoproteins further supports that oxidation of lipoproteins is one of the key mechanisms in atherogenesis. Chronic stable expression and activation of NF-kappa B could be a useful target for therapeutic interventions.

Topics: Aldehydes; Animals; Arteriosclerosis; Epitopes; Hypochlorous Acid; Immunohistochemistry; Malondialdehyde; Nitrates; Oxidation-Reduction; Rabbits

Phosphatidylcholine hydroxyalkenals (PC-HAs) are a class of oxidized PCs derived from lipid peroxidation of arachidonate or linoleate at the sn-2 position to form terminal gamma-hydroxy, alpha-, and beta-unsaturated aldehydes. The aim of this study was to characterize some of their biological properties, ascertain the mechanism of their action, and assess whether they have in vivo relevance.. Combinations of cell biological approaches with radiolabels, mass spectroscopy, and immunochemical as well as immunohistochemical techniques were used to show that PC-HAs reduce the proteolytic degradation by mouse peritoneal macrophages (MPMs) of internalized macromolecules, such as maleylated bovine serum albumin, and that the activity of the lysosomal protease, cathepsin B, in MPMs form Michael adducts with MPM proteins and with N-acetylated cysteine in vitro form pyrrole adducts with MPM proteins and reduce the maturation of Rab5a, thereby impairing phagosome-lysosome fusion (maturation) in phagocytes; they are present unbound and as pyrrole adducts in human atherosclerotic lesions.. PC-HAs are present in vivo and possess multiple functions characteristic of oxidized LDL and 4-hydroxynonenal.

Topics: Acetylcysteine; Aldehydes; Animals; Arteriosclerosis; Biological Transport; Cathepsin B; Cholesterol Esters; Chromatography, Liquid; Humans; Intracellular Membranes; Lipoproteins, LDL; Lysine; Lysosomes; Macrophages, Peritoneal; Mice; Oxidation-Reduction; Phosphatidylcholines; Phospholipids; Pyrroles; Spectrometry, Mass, Electrospray Ionization

Formation of an atherosclerotic lesion is in part mediated by inflammatory and oxidative mechanisms including lipid peroxidation. To characterize the potential role of lipid peroxidation products in atherogenesis, we assessed the effect of 4-hydroxy-2-nonenal (HNE), a component of oxidatively modified lipids on vascular smooth muscle cells (VSMCs) proliferation, and its interaction with serotonin (5-hydroxytryptamine, 5-HT), a known mitogen for VSMCs. Growth-arrested rabbit VSMCs were incubated with different concentrations of HNE in the absence or presence of 5-HT. VSMCs proliferation was examined by increases in [3H]thymidine incorporation into DNA and cell number. HNE and 5-HT stimulated DNA synthesis in a dose-dependent manner. HNE had a maximal proliferative effect at a concentration of 1 microM (143% of the control) and 5-HT at 50 microM (211%). When added together, low concentrations of HNE (0.1 microM) and 5-HT (5 microM) synergistically induced DNA synthesis (273%). These effects on DNA synthesis were paralleled by an increase in cell number. A 5-HT2 receptor antagonist LY 281067 (10 microg/ml) and pertussis toxin (10 ng/ml) inhibited the mitogenic effect of 5-HT only. Protein tyrosine kinase inhibitor erbstatin A (10 microM) completely inhibited the mitogenic effect of HNE and partially that of 5-HT and the combined effect of HNE+5-HT. Protein kinase C inhibitor Ro 31-8220 (0.1 microM) completely inhibited mitogenic effects of both HNE and 5-HT, and also the combined effect of HNE+5-HT. The synergistic effect of HNE+5-HT on DNA synthesis was completely reversed by the combined use of LY 281067 (10 microg/ml) and antioxidants N-acetylcysteine (400 microM), vitamin C (200 microM), or vitamin E (20 microM). Our results suggest that HNE acts synergistically with 5-HT in inducing VSMCs proliferation. Combined use of both antiplatelet and antioxidant therapies may be useful for the prevention of VSMCs proliferative disorders associated with atherosclerosis and restenosis after angioplasty.

Topics: Acetylcysteine; Aldehydes; Animals; Antioxidants; Aorta, Thoracic; Arteriosclerosis; Ascorbic Acid; Cell Division; Cells, Cultured; DNA; Dose-Response Relationship, Drug; Drug Synergism; Hydroquinones; Indoles; Lipid Peroxidation; Lysergic Acid; Male; Mitogens; Muscle, Smooth, Vascular; Pertussis Toxin; Protein Kinase C; Protein-Tyrosine Kinases; Rabbits; Serotonin; Serotonin Antagonists; Virulence Factors, Bordetella; Vitamin E

Phospholipid peroxidation generates a variety of aldehydes, which includes free saturated and unsaturated aldehydes, and aldehydes that remain esterified to the phosphoglyceride backbone - the so-called 'core' aldehydes. However, little is known in regarding the vascular metabolism of these aldehydes. To identify biochemical pathways that metabolize free aldehydes, we examined the metabolism of 4-hydroxy-trans-2-nonenal in human aortic endothelial cells. Incubation of these cells with [3H]-HNE led to the generation of four main metabolites, i.e. glutathionyl HNE (GS-HNE), glutathionyl dihydroxynonene (GS-DHN), DHN and 4-hydroxynonanoic acid (HNA), which accounted for 5, 50, 6, and 23% of the total HNE metabolized. The conversion of GS-HNE to GS-DHN was inhibited by tolrestat, indicating that it is catalyzed by aldose reductase (AR). The AR was also found to be an efficient catalyst for the reduction of the core aldehyde - 1-palmitoyl-2- (5-oxovaleroyl)-sn-glycero-3-phosphorylcholine, which is generated in minimally modified low-density lipoprotein, and activates the endothelium to bind monocytes. As determined by electrospray mass spectrometry, reduction of POVPC (m/z=594) by AR led to the formation of 1-palmitoyl-2- (5)-hydrovaleryl-sn-glycero-3-phosphorylcholine (PHVPC; m/z=596). These observations suggest that due to its ability to catalyze the reduction of lipid-derived aldehydes AR may be involved in preventing inflammation and diminishing oxidative stress during the early phases of atherogenesis.

Topics: Aldehyde Reductase; Aldehydes; Arteriosclerosis; Cells, Cultured; Endothelium, Vascular; Glutathione; Humans; Lipoproteins, LDL; Oxidation-Reduction; Phospholipid Ethers

Mildly oxidized LDL (moxLDL) is thought to play a role in atherogenesis. MoxLDL induces derivatization of cell proteins and triggers a variety of intracellular signaling. We aimed to investigate whether moxLDL-induced protein derivatization may influence the activity of platelet-derived growth factor receptor beta (PDGFRbeta), a tyrosine kinase receptor of major importance in vascular biology and atherogenesis.. In cultured rabbit arterial smooth muscle cells, moxLDL induces activation of the PDGFRbeta signaling pathway, as shown by PDGFRbeta tyrosine phosphorylation on Western blot and coimmunoprecipitation of SH2-containing proteins. The cellular events involved in the moxLDL-induced PDGFRbeta activation can be summarized as follows. Oxidized lipids from moxLDL trigger two phases of PDGFRbeta activation involving two separate mechanisms, as shown by experiments on cultured cells (in situ) and on immunopurified PDGFRbeta (in vitro): (1) the first phase may be mediated by 4-hydroxynonenal, which induces PDGFRbeta adduct formation and subsequent PDGFRbeta activation (antioxidant-insensitive step); (2) the second phase involves ceramide-mediated generation of H(2)O(2) (these steps being inhibited by tosylphenylalanylchloromethylketone, an inhibitor of ceramide formation, and by antioxidant BHT, exogenous catalase, or overexpressed human catalase). Because 4-hydroxynonenal-PDGFRbeta adducts are also detected in atherosclerotic aortas, it is suggested that this novel mechanism of moxLDL-induced PDGFRbeta activation may occur during atherogenesis.. MoxLDL acts as a local autoparacrine mediator in the vascular wall, and PDGFRbeta acts as a sensor for both oxidized lipids and oxidative stress. This constitutes a novel mechanism of PDGFRbeta activation in atherosclerotic areas.

Topics: Aldehydes; Animals; Anti-Bacterial Agents; Antioxidants; Aorta; Arteriosclerosis; Autocrine Communication; Cells, Cultured; Ceramides; Chloroquine; Diet, Atherogenic; Enzyme Inhibitors; Humans; Hydrogen Peroxide; Lipoproteins, LDL; Macrolides; Male; Muscle, Smooth, Vascular; Oxidative Stress; Phosphorylation; Rabbits; Reactive Oxygen Species; Receptor, Platelet-Derived Growth Factor beta; Signal Transduction; Sphingomyelins; Tyrosine

It has recently been shown that the lipid peroxidation product 4-hydroxy-2-nonenal (HNE) forms a fluorescent hydroxyiminodihydropyrrole derivative with the epsilon-amino group of lysine residue. In this study, we raised a monoclonal antibody (mAb2C12) directed to the fluorophore-protein conjugate and found that the antibody was specific to the chromophore structure of the compound. Immunohistochemical analysis of atherosclerotic lesions from the human aorta showed that the fluorophore was indeed present in the lesions, in which intense positivity was primarily associated with macrophage-derived foam cells and thickening of the neointima of the arterial walls. Antigenic materials were also detected in the oxidatively modified low-density lipoprotein (LDL) with Cu(2+) and in the oxidatively modified bovine serum albumin with an iron/linoleic acid autoxidation system, indicating that the HNE, which originated from the peroxidation of polyunsaturated fatty acids, could be a potential source of the fluorescent chromophore in oxidized LDL.

Topics: Aged; Aldehydes; Animals; Antibodies, Monoclonal; Antibody Specificity; Aorta, Abdominal; Arteriosclerosis; Child, Preschool; Fluorescence; Fluorescent Dyes; Humans; Immunohistochemistry; Lipid Peroxidation; Lipofuscin; Lipoproteins, LDL; Male; Mice; Mice, Inbred BALB C; Spectrometry, Fluorescence

Free radical oxidation of human plasma low-density lipoprotein (LDL) produces 2-pentylpyrrole epitopes that are generated by reaction of 4-hydroxy-2-nonenal (HNE), a product of lipid oxidation, with protein lysyl residues. The HNE-derived 2-pentylpyrrole ("HNE-pyrrole") epitopes were detected with an enzyme-linked immunosorbent assay (ELISA) using antibodies (ON-KLH) raised against protein-bound 2-pentylpyrrole obtained by the reaction of 2-oxononanal (ON) with keyhole limpet hemocyanin (KLH). HNE-pyrrole epitopes in human plasma are not associated primarily with LDL protein, apolipoprotein (apo) B, since only 15% of the total HNE-pyrrole immunoreactivity is removed by immunoprecipitation of apo B. The levels of ON-KLH immunoreactivity detected in human plasma were found to be significantly elevated in renal failure and atherosclerosis patients when compared to those in healthy volunteers. HNE-pyrrole immunoreactivity was also detected in atherosclerotic plaques. The highest levels were associated with extracellular connective tissue. Levels of ON-KLH immunoreactivity in human plasma far exceed levels of free HNE, presumably because of the rapid clearance of free relative to protein-bound HNE. Therefore, HNE-pyrrole epitopes provide a more indelible marker of oxidative injury than levels of free HNE.

Topics: Aldehydes; Arteriosclerosis; Carotid Arteries; Humans; Immunohistochemistry; Kidney Failure, Chronic; Lipoproteins, LDL; Oxidation-Reduction; Pyrroles

Topics: Adult; Aldehydes; Arteriosclerosis; Biomarkers; Blood Pressure; Female; Follow-Up Studies; Glomerular Filtration Rate; Homocysteine; Humans; Kidney Transplantation; Lipid Peroxidation; Lipid Peroxides; Male; Malondialdehyde; Postoperative Complications; Risk Factors; Time Factors

Syrian hamsters of the APA strain (APA hamsters) have recently been shown to have atheromatous lesions in the aortic arches under diabetic condition induced by a single injection of streptozotocin (SZ). In that model, fatty streaks, which are the initial lesions of atherogenesis, develop by 6 weeks after the injection (WAI). In this study, we evaluated plasma lipid concentrations and lipoprotein profiles in diabetic APA hamsters at 6 WAI to reveal the early stage of atherogenesis clinicopathologically. As a result, by biochemical analysis, hyperglycemic APA hamsters showed signs of hypercholesterolemia and hypertriglyceridemia. Low-density lipoprotein (LDL) cholesterol significantly increased, but high-density lipoprotein (HDL) cholesterol significantly decreased. Agarose gel electrophoresis showed an obvious increase in the fractions of chylomicron, LDL and abnormal lipoprotein. Plasma LDL in diabetic animals was in a state more susceptible to oxidization. In addition, a significant increase in glycated LDL was also found in the diabetic animals by enzyme linked immunosorbent assay (ELISA). Moreover, lipid peroxidation product (4-hydroxynonenal (4 HNE))-adducted proteins and advanced glycation end-products (AGE) were immunohistochemically detected in the foam cells of the fatty streaks. These results revealed that diabetic APA hamsters had hyperlipidemia characterized by increases in chylomicron, LDL and abnormal lipoprotein, and suggested that oxidized LDL and/or glycated LDL might be actively uptaken by macrophages and play an important role in the initial stage of atherogenesis.

Topics: Aldehydes; Animals; Aortic Diseases; Arteriosclerosis; Cholesterol, LDL; Cricetinae; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Foam Cells; Glycation End Products, Advanced; Immunohistochemistry; Lipid Peroxidation; Lipids; Lipoproteins; Male

Topics: Aldehydes; Arteriosclerosis; Biomarkers; Biopsy; Cadaver; Glomerulosclerosis, Focal Segmental; Humans; Kidney; Lipid Peroxidation; Malondialdehyde; Renal Artery Obstruction; Tissue and Organ Harvesting; Tissue Donors

To determine whether oxidized LDL enhances atherogenesis by promoting monocyte recruitment into the vascular intima, we investigated whether LDL accumulation and oxidation precede intimal accumulation of monocytes in human fetal aortas (from spontaneous abortions and premature newborns who died within 12 h; fetal age 6.2+/-1.3 mo). For this purpose, a systematic assessment of fatty streak formation was carried out in fetal aortas from normocholesterolemic mothers (n = 22), hypercholesterolemic mothers (n = 33), and mothers who were hypercholesterolemic only during pregnancy (n = 27). Fetal plasma cholesterol levels showed a strong inverse correlation with fetal age (R = -0.88, P < 0.0001). In fetuses younger than 6 mo, fetal plasma cholesterol levels correlated with maternal ones (R = 0.86, P = 0.001), whereas in older fetuses no such correlation existed. Fetal aortas from hypercholesterolemic mothers and mothers with temporary hypercholesterolemia contained significantly more and larger lesions (758,651+/-87,449 and 451,255+/-37,448 micron2 per section, respectively; mean+/-SD) than aortas from normocholesterolemic mothers (61,862+/-9,555 micron2; P < 0.00005). Serial sections of the arch, thoracic, and abdominal aortas were immunostained for recognized markers of atherosclerosis: macrophages, apo B, and two different oxidation-specific epitopes (malondialdehyde- and 4-hydroxynonenal-lysine). Of the atherogenic sites that showed positive immunostaining for at least one of these markers, 58.6% were established lesions containing both macrophage/foam cells and oxidized LDL (OxLDL). 17.3% of all sites contained only native LDL, and 13.3% contained only OxLDL without monocyte/ macrophages. In contrast, only 4.3% of sites contained isolated monocytes in the absence of native or oxidized LDL. In addition, 6.3% of sites contained LDL and macrophages but few oxidation-specific epitopes. These results demonstrate that LDL oxidation and formation of fatty streaks occurs already during fetal development, and that both phenomena are greatly enhanced by maternal hypercholesterolemia. The fact that in very early lesions LDL and OxLDL are frequently found in the absence of monocyte/macrophages, whereas the opposite is rare, suggests that intimal LDL accumulation and oxidation contributes to monocyte recruitment in vivo.

Topics: Adult; Aldehydes; Aorta; Apolipoproteins B; Arteriosclerosis; Cholesterol; Female; Fetal Diseases; Humans; Hypercholesterolemia; Lipid Peroxidation; Lipoproteins; Macrophages; Malondialdehyde; Pregnancy; Pregnancy Complications, Hematologic

Atherosclerosis is a common problem among the elderly. Because lipid peroxidation is considered a contributor to the development of atherosclerosis, we compared oxidative properties of lipoproteins in an otherwise healthy (SENIEUR-classified) aged population (65-74 years) with young controls (18-30 years). Relative amounts of oxidatively altered low density lipoprotein (LDL), estimated by means of an antibody against LDL modified by 4-hydroxynonenal, a product of lipid peroxidation, were increased marginally in serum from the elderly (9.8 vs. 7.4%, P = 0.07). In contrast, isolated LDL from the elderly revealed a decreased susceptibility to in vitro oxidation: the lag time was increased (2.34 vs. 2.10 h, P < 0.01), and the maximal rate of LDL oxidation decreased (0.88 vs. 1.01 O.D./h, P = 0.001). However, there were no age-related changes in lipid composition of native LDL and consumption of fatty acids during in vitro oxidation. The serum concentrations of ascorbic acid and most lipophilic anti-oxidants (the latter expressed per g serum lipids) were significantly decreased in the elderly except tocopherols which tended to be higher. In conclusion, our data reveal paradox age-related alterations of LDL as to its behaviour in oxidation in vivo vs. in vitro.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Aldehydes; Antioxidants; Arteriosclerosis; Ascorbic Acid; Fatty Acids; Female; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Oxidation-Reduction; Thiobarbituric Acid Reactive Substances; Vitamins

In the present study, we have raised anti-peptide antibodies directed to the major membrane lipid peroxidation product 4-hydroxy-2-nonenal (HNE) attached covalently to histidine, and their specificities were compared with those of the polyclonal antibodies (anti-HNE-protein antibodies) raised against HNE-treated keyhole limpet hemocyanin (K. Uchida et al. (1993) Proc. Natl. Acad. Sci. USA 90, 8742-8746). The anti-HNE-histidyl peptide antibodies (anti-HNE-histidine antibodies) were prepared by immunizing rabbits with a HNE-conjugated heptapeptide (Gly3-His-Gly3 amide) coupled to the carrier protein. The antisera were purified on an affinity gel prepared by covalent attachment of a HNE-conjugated heptapeptide (Ala3-His-Ala3 amide). Among the structurally defined 4-hydroxy-2-alkenal-amino acid adducts tested, binding of anti-HNE-histidine antibodies to the HNE-treated protein was not only inhibited by HNE-histidine, HNE-cysteine, and HNE-lysine, but also by 4-hydroxy-2-octenal-histidine and 4-hydroxy-2-decenal-histidine adducts. Cross-reactivity studies revealed that both anti-HNE-protein antibodies had the highest affinity for the HNE-treated protein and that neither of the antibodies cross-reacted with the protein treated with aldehydes including malondialdehyde, 1-hexanal, 2-hexenal, or 2-nonenal. These results suggest that the dominant epitope recognized by antibodies is the 2-CH3(CH2)n-5-hydroxytetrahydrofuran (n > or = 3) moiety of the Michael adducts. The immunohistochemical analysis of atherosclerotic lesions of human aorta demonstrated that these antibodies reacted strongly with granular cytoplasmic elements of foam cells and weakly with elements in the surrounding sclerotic stroma.

Topics: Aged; Aldehydes; Amino Acid Sequence; Antibody Specificity; Aorta; Arteriosclerosis; Binding, Competitive; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Epitopes; Hemocyanins; Humans; Lipid Peroxidation; Male; Molecular Sequence Data; Oligopeptides

Cultured bovine aortic endothelial cells (BAEC) were incubated for 5 days with 10(-5) 4-hydroxynonenal (HN). HN treated BAEC and controls were either (i) further incubated with 125I-polymyxin B (IPxB) or with radioiodinated, inactivated coagulation factor Xa (IFXai) as markers of membrane phospholipid perturbation, or (ii) assayed for the synthesis of prostacyclin (PGI2) and thromboxane A2 (TXA2). Rabbit blood mononuclear cells enriched in monocytes (MC) were isolated and assayed for chemotactic response to HN. The results showed six - fold increases of IPxB and IFXai binding to BAEC treated with HN, as compared to untreated controls. We also found in HN treated cells a marked inhibition of PGI2 synthesis, but an unmodified TXA2 production. In addition, HN in the 10(-5)-10(-10) M range induced oriented migration of MC.

Topics: Aldehydes; Animals; Arteriosclerosis; Cattle; Cells, Cultured; Chemotaxis, Leukocyte; Endothelium, Vascular; Epoprostenol; Female; In Vitro Techniques; Lipid Peroxidation; Membrane Lipids; Monocytes; Pregnancy; Thromboxane A2

It has been proposed that plasma low-density lipoprotein (LDL) undergoes oxidative modification before it can give rise to foam cells in atherosclerosis. Oxidation of LDL generates a variety of reactive aldehyde products including 4-hydroxy-2-nonenal (HNE), which may covalently attach to the LDL apolipoproteins. We here present direct evidence that HNE derivatization of LDL forms Michael addition-type adducts of HNE with histidine and lysine residues of apolipoprotein B-100 (apoB) and also demonstrate the utility of an antibody specific to the HNE adducts generated in the LDL treated with HNE or oxidatively modified by Cu2+ or cultured endothelial cells. HNE adducts present in the LDL that had been treated with HNE were attested to be Michael addition-type adducts on the basis of the fact that incubation of LDL with 1 mM HNE (2 h, 37 degrees C) resulted primarily in the formation of Michael addition-type HNE-histidine (39.9 mol/mol of LDL) and HNE-lysine (19.3 mol/mol of LDL) adducts. An enzyme-linked immunosorbent assay (ELISA) and an SDS-polyacrylamide gel electrophoresis (SDS-PAGE)/immunoblot analysis of HNE-modified LDL demonstrated that these HNE adducts were detectable with the HNE-specific antibody affinity-purified with the Michael adduct (HNE-histidine) as a ligand. The following lines of evidence indicated the presence of Michael addition-type HNE adducts in the oxidatively modified LDL in vitro: (i) Amino acid analysis of LDL that had been treated with Cu2+ (24 h, 37 degrees C) demonstrated the presence of a Michael addition-type HNE-histidine adduct (7-9 mol/mol of LDL).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aldehydes; Animals; Antibodies; Aorta; Apolipoprotein B-100; Apolipoproteins B; Arteriosclerosis; Binding, Competitive; Cattle; Cells, Cultured; Copper; Electrophoresis, Polyacrylamide Gel; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Histidine; Humans; Immunoblotting; Lipoproteins, LDL; Lysine; Malondialdehyde; Oxidation-Reduction; Thiobarbituric Acid Reactive Substances

A systematic immunohistochemical study of different stages of atherosclerosis in human aortas was performed using several antibodies. Because oxidation of lipoproteins could be a key event in atherogenesis, an antibody against apolipoprotein B (apoB) from low-density lipoprotein (LDL) modified with the lipid peroxidation-specific aldehyde, 4-hydroxynonenal (4-HNE) (anti-4-HNE-apoB), was raised in rabbits. This antibody recognizing 4-HNE protein adducts was used in concert with an antibody to apo(a) from lipoprotein(a), considered also potentially atherogenic, as well as with an antibody and a monoclonal antibody (mAb) to apoB. Autopsy material from 12 corpses was investigated. The immunohistochemical investigation by the alkaline-phosphatase technique included control specimens regarding postmortem artifacts by autolysis and oxidation. The results from six specimens from five corpses are presented. A positive staining with the antibody to apoB but not with anti-4-HNE-apoB was seen in the normal intima. The thickened intima of early, transitional, and advanced atherosclerotic lesions and atheromata showed a predominantly extracellular staining with all antibodies and the applied mAb. To test the specificity of the staining, antibodies preadsorbed by the appropriate antigens and nonimmune sera were used, giving negative results. These findings indicated a colocalization of epitopes derived from lipid peroxidation of polyunsaturated fatty acids and epitopes specific for apoB and apo(a) during atherogenesis in humans.

Topics: Aged; Aldehydes; Antibodies, Monoclonal; Aorta; Apolipoproteins A; Apolipoproteins B; Arteriosclerosis; Epitopes; Female; Humans; Immunoenzyme Techniques; Lipid Peroxidation; Lipoprotein(a); Lipoproteins, LDL; Male; Middle Aged; Postmortem Changes