Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enhanced formation and accumulation of advanced glycation endproducts (AGE's) have been proposed to play a major role in the pathogenesis of diabetic complications, aging, atherosclerosis, and Alzheimer disease leading to progressive and irreversible intermolecular protein crosslinkings. This process is accelerated in diabetes and has been postulated to contribute to the development of a range of diabetic complications including nephropathy, retinopathy and neuropathy. Several potential drug candidates as AGE inhibitors have been reported recently. Aminoguanidine is the first drug extensively studied both in vitro and in vivo. We have developed a new class of compounds as potent inhibitors of glycation and AGE formation. The novel inhibitors reported here are aryl (and heterocyclic) ureido, and aryl (and heterocyclic) carboxamido phenoxy isobutyric acids and related molecules, which were found by in vitro assay methods to be potent inhibitors of multiple stage of glycation and AGE formation.
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PMID:Novel inhibitors of advanced glycation endproducts. 1047 80

The development of extensive atherosclerosis of major arteries of the heart, brain, and lower extremities is a particularly frequent problem in elderly individuals and is responsible for the majority of the cardiovascular morbidity and mortality in this population. Although the frequency and severity of this problem is well recognized, there has been relatively little investigation of the effects of aging on the development of atherosclerosis. Work by a number of investigators over the last 10-15 years has demonstrated that modifications of lipoproteins, resulting from oxidative stress, glycoxidation, formation of AGE, or other processes may play an important role in atherosclerosis. As described in this review, the aging process may enhance lipoprotein modification and atherosclerosis in several ways. Conditions such as hypertension, diabetes, and menopause all increase in frequency with advancing age and may contribute both directly and indirectly to lipoprotein modification and vascular injury.Additionally, in some studies of older animals and humans, there seems to be evidence for greater in vivo oxidative stress. Whether this is a specific consequence of aging and associated medical conditions, or related to differences in dietary fatty acid or antioxidant content or other lifestyle differences is currently unknown. One important consequence of this may be enhanced susceptibility of lipoproteins to oxidation. Additional study of lipoprotein modifications associated with aging is clearly needed, and may provide new insight and solutions to the common problem of atherosclerosis in the elderly.
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PMID:Lipoprotein modification and atherosclerosis in aging. 1081 8

Recent studies have shown that patients with high peritoneal transport characteristics have substantially increased morbidity and mortality. This finding is counter-intuitive, since HTs will a priori achieve higher clearances. There are many possible causes: increased protein losses with consequent hypoalbuminemia; poor ultrafiltration capacity causing fluid retention, ventricular hypertrophy and hypertension; increased glucose absorption leading to anorexia, hyperinsulinism, and local AGE formation; and the development of an atherogenic lipid profile. While common pathogenic causes of high peritoneal transport and atherosclerosis have been hypothesized, it is more likely that CAPD as currently practiced is unsuitable for HTs, who should be switched to HD or NIPD. Renal and peritoneal clearances have different clinical effects and should be assessed separately. Current measures of dialysis adequacy, such as total Kt/V, do not therefore describe the patient's clinical situation accurately and are insufficient.
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PMID:Pathogenic effects of a high peritoneal transport rate. 1083 80

Although there have been suggestions that the glycation and oxidation of low density lipoprotein (LDL) might increase its atherogenic potential, little is known about the presence of glycoxidative LDL in human atherosclerotic lesions. We developed specific antibodies against different immunological epitopes of AGE structures, including N(epsilon)-(carboxymethyl)lysine-protein adduct (CML), a glycoxidation product, and structure(s) other than CML (nonCML), and a monoclonal antibody against oxidized phosphatidylcholine (oxPC), as an epitope of oxidized LDL. Immunohistochemical analysis demonstrated that the CML- and oxPC-epitopes were accumulated mainly in macrophage-derived foam cells in atherosclerotic lesions, including fatty streaks and atherosclerotic plaques. On the other hand, the nonCML-epitope and apolipoprotein B were localized mainly in extracellular matrices of atherosclerotic lesions. The CML- and oxPC-epitopes were characterized by a model antigen-generating system using the copper ion-induced peroxidation and/or glucose-induced glycation of LDL. The glycoxidation of LDL caused the formation of CML-epitope with increasing concentrations of copper ion and glucose. It was also formed to some extent in LDL incubated with high concentrations (500 mM) of glucose. However, no CML-epitope was observed in oxidized LDL induced by copper ion alone. On the other hand, the formation of oxPC-epitope in LDL was dependent on copper ion-induced peroxidation, but independent of glucose-induced glycation. The addition of chelators, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid, reduced the increase in electrophoretic mobility and TBARS caused by the peroxidation and glycoxidation of LDL, but had no effects on the formation of fructosamine caused by the glycation and glycoxidation of LDL. Chelators as well as aminoguanidine protected the formation of CML-epitope in glycated or glycoxidative LDL. Although the formation of oxPC-epitope was completely inhibited by the addition of chelators, it was partially protected by aminoguanidine. These in vitro results suggest that the glycoxidative modification of LDL may occur in the arterial intima, and may contribute to the development of human atherosclerotic lesions.
Atherosclerosis 2000 Jun
PMID:In vivo and in vitro evidence for the glycoxidation of low density lipoprotein in human atherosclerotic plaques. 1085 26

The excess of glucose appears to play an important and specific role in the genesis of macroangiopathy in diabetics. Activation of protein kinase-C, the sorbitol pathway, and AGE formation are thought to be the major pathways linking the degree of glycaemic compensation with the pathogenetic process of macrovascular disease. HSPG is likely to be a key element in this process since it is a regulator of endothelial permeability, vascular antithrombotic capacity, insulin sensitivity (with respect to lipoprotein lipase availability), and vascular extracellular matrix content and smooth-muscle-cell activation. Loss of HSPG is suggested clinically by the presence of microalbuminuria, to the development of which diabetic control also contributes significantly. However, genetic factors also seem to be involved. Much more insight into the precise mechanismus is necessary to unravel the cellular and molecular chains of events for the premature and accelerated atherosclerosis in diabetic patients.
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PMID:The atherosclerotic process and its exacerbation by diabetes. 1146 May 93

Hypertension and diabetes mellitus represent increasing threats to the health of many populations. For reasons not completely understood, the prevalence of these diseases is higher in some ethnic groups than in others. The key to this puzzle may rest with the interplay of a defect of an enzyme-mediated process and the environment. Oxidative stress and impairment of synthesis or release of nitric oxide (NO) are being regarded as causative factors in the pathogenesis of hypertension, diabetes mellitus and atherosclerosis, among other conditions. Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been overlooked as a cause of both oxidative stress and a decrease in the generation of nitric oxide (NO). G6PD generates nicotinamide adenine dinucleotide phosphate (NADPH), a co-factor in the synthesis of nitric oxide. There is impairment of the production of nitric oxide superoxide and hydrogen peroxide in G6PD-deficient granulocytes. In the polyol pathway, G6PD deficiency causes hyperglycemia, making more glucose available for the non-enzymatic production of advanced glycosylation end products (AGE's), which also causes an increase in superoxide anions and a quenching of nitric oxide. Currently, there are 200 million people worldwide with red cell x-linked chromosome defects who, with the persistent ingestion of refined carbohydrates, are at greater risk of developing hypertension or diabetes mellitus than those racial groups without the defect.
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PMID:G6PD deficiency: its role in the high prevalence of hypertension and diabetes mellitus. 1176 98

Tea catechins and other flavonoids have been shown to potentially protect against chronic cardiovascular diseases such as coronary heart disease and atherosclerosis. In this study, 6-month-old female Sprague-Dawley rats were fed green tea extract (50 mg/100 ml in drinking water) up to the age of 22 months, and the age-associated changes in Maillard-type fluorescence and carbonyl groups in the aortic and skin collagen were compared with those occurring in the water-fed control animals. Collagen-linked Maillard-type fluorescence was found to increase in both the aortic and skin tissues as animals aged. The age-associated increase in the fluorescence in the aortic collagen was remarkably inhibited by the green tea extract treatment, while that occurring in the skin collagen was not significantly inhibited by the treatment. The collagen carbonyl content also increased in both the aortic and skin tissues as animals aged. In contrast with the case of Maillard-type fluorescence, however, the age-associated increase in the carbonyl content was not inhibited by the green tea extract treatment either in the aortic or skin collagen. These results suggest that the inhibition of AGE formation in collagen is an important mechanism for the protective effects of tea catechins against cardiovascular diseases.
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PMID:Effect of drinking green tea on age-associated accumulation of Maillard-type fluorescence and carbonyl groups in rat aortic and skin collagen. 1179 3

Arteriosclerosis, atherosclerosis and vascular calcification are causally related to the high morbidity and mortality of patients with chronic renal failure. Oxidative stress and carbonyl stress of uremia, dialysis procedure and/or intravenous iron therapy result in AGE (advanced glycation end-product), ALE (advanced lipoxidation end-product) and AOPP (advanced oxidation protein product) formation, favouring together with elevated CRP (C-reactive protein) levels the development of cardiovascular and cerebrovascular complications. Enhanced plasma levels of homocysteine and ADMA (asymmetric dimethylarginine) contribute to this process. In addition, in chronic renal insufficiency hyperphosphatemia and an enhanced calcium x phosphorus ion product are associated with the morbidity and mortality of the patients, particularly in the presence of fetuin deficiency. Phosphorus, AGEs and AOPPs, beside other factors, catalyze the conversion of vascular smooth muscle cells to osteoblast--like cells (particularly in the presence of monocytes/macrophages), resulting in bone matrix protein formation. Other risk factors, such as age, male sex, smoking, hypertension, diabetes, chronic inflammation, insulin resistance or dyslipidemia (enhanced non-HDL-cholesterol) also contribute to the atherosclerotic risk profile of the patient with chronic renal insufficiency. While there is growing understanding of the mechanisms involved in arteriosclerosis, atherosclerosis and vascular calcification in uremia, we are still missing effective therapeutic maneuvers for reduction of excess mortality in uremic patients.
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PMID:[Atherosclerosis and uremia: signifance of non-traditional risk factors]. 1277 74

Hyperglycaemia is considered to be the key causal factor in the development of diabetic complications. Poor glycemic control a significant changes of erythrocyte membrane fluidity, erythrocyte deformability and antioxidant status. Nonenzymatic glycation and glycoxidation with cascade of free radical reactions, oxidative and carbonyl stress may play an important role in the development diabetic micro- and macrovascular complications. The serum levels of specific and nonspecific advanced glycation end products (s-AGEs) have been found elevated in type 1 and type 2 diabetic patients. Levels of s-AGEs. may serve as useful biochemical marker for monitoring progression of diabetic complications and pathological processes. Accumulation of AGEs on tissue proteins increases with pathogenesis of diabetic complications and atherosclerosis. AGEs are believed to induce cellular oxidative stress through the interaction with specific cellular receptors. Carbonyl stress-induced tissue damage is caused by AGE precursors formed by hyperglycaemia, hyperlipidemia, nonenzymatic glycation, peroxidation of lipids and metabolis processes. The toxic effects of AGE precursors can not be directly antagonized by antioxidants. Only a small number of biological carbonyl scavengers like glutathione have been identified to date. For therapeutic intervention, nucleophilic compounds as aminoguanidine, pyridoxamine, OPB-9195, 2,3-diaminophenazone, carnosine and tenilsetam give promising results. These potential therapeutics have been proposed to trap AGE precursors. Studies in vitro showed that these AGE inhibitors have also the antioxidant and chelating activity. Angiotensin converting enzyme (ACE) and angiotensin II receptor antagonists also significantly attenuate AGE production. These drugs do not trap AGE precursors, but impact on the production of AGE precursors by chelating transition metals and inhibiting various oxidative steps in the process of glycoxidation, including the formation of free radicals. Finally, supplementation with antioxidants and antioxidant systems could be a complementary treatment in diabetic patients.
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PMID:[The role of nonenzymatic glycation and glyco-oxidation in the development of diabetic vascular complications]. 1282 98

Diabetes is associated with a high incidence of cardiovascular disease, which is the major cause of morbidity and mortality in this disease. There is considerable interest in defining factors responsible for the accelerated development of atherosclerosis in diabetes. There is no evidence to suggest that the inflammatory process in diabetic patients is different from those in non-diabetic individuals. The main difference may lie on factors able to trigger the inflammatory process. Diabetes is a major predisposing factor for the generation of modified proteins though advanced glycation and oxidation, two intimately interrelated processes. Advanced glycation end-products modified low density lipoprotein (AGE-LDL) and other AGE-modified proteins as well as oxidized LDL (oxLDL) are able to interact with a variety of cells and induce cell dysfunction and the release of pro-inflammatory mediators. But AGE-LDL and oxLDL are also immunogenic. Activated T lymphocytes reacting with peptides derived from oxidized LDL have been detected in atheromatous lesions. Their pro-inflammatory potential is directly linked to the release of interferon-gamma and other cytokines able to activate macrophages, smooth muscle cells, and endothelial cells. On the other hand, antibodies to oxidized and AGE-modified LDL have been isolated from diabetic patients and shown to belong predominantly to the IgG isotype, subclasses 1 and 3, which have well-defined proinflammatory properties. These autoantibodies to modified lipoproteins have sufficient affinity to form stable antigen-antibody complexes, which have been also shown to have pro-atheromatous and pro-inflammatory properties.
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PMID:The role of immune and inflammatory processes in the development of macrovascular disease in diabetes. 1295 81


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