Serum caeruloplasmin as a coronary risk factor in the elderly: the Rotterdam Study

Dysregulation of metalloproteins in ischemic heart disease patients with systolic dysfunction

Ischemic heart disease (IHD) is the leading cause of mortality worldwide. Metalloproteins have been linked to human health and diseases. The molecular functions of metalloproteins in IHD is not well understood and require further exploration. The objective of this study was to find out the role of metalloproteins in the pericardial fluid of IHD patients having normal (EF > 45) and impaired (EF < 45) left ventricular ejection fraction (LVEF). IHD patients were grouped into two categories: LVEF<45 (n = 12) and LVEF >45 (n = 33). Pooled samples of pericardial fluid were fractionated by using ZOOM-isoelectric focusing (IEF) followed by further processing using one-dimensional gel electrophoresis (1D SDS-PAGE) and filter-aided sample preparation (FASP). Tryptic peptides of each fraction and differential bands were then analyzed by nano-LC-ESI-MS/MS. Protein identification was performed through a Mascot search engine using NCBI-Prot and SwissProt databases. A total of 1082 proteins including 154 metalloproteins were identified. In the differential bands, 60 metalloproteins were identified, while 115 metalloproteins were identified in all ZOOM-IEF fractions. Twelve differentially expressed metalloproteins were selected in the intense bands according to their molecular weight (MW) and isoelectric point (pI). The 12 differentially expressed metalloprotein includes ceruloplasmin, Prothrombin, Vitamin K-dependent protein, Fibulin-1, Ribosomal protein S6 kinase alpha-6, nidogen, partial, Serum albumin, Hemopexin, C-reactive protein, Serum amyloid P-component, and Intelectin-1 protein which were all up-regulated while serotransferrin is the only metalloprotein that was down-regulated in impaired (LVEF<45) group. Among the metalloproteins, Zn-binding proteins are 36.5 % followed by Ca-binging 32.2 %, and Fe-binging 12.2 %. KEGG, pathway analysis revealed the association of ceruloplasmin and serotransferrin with the ferroptosis pathway. In conclusion, 154 metalloproteins were identified of them the Zn-binding protein followed by Ca-binding and Fe-binding proteins were the most abundant metalloproteins. The two metalloproteins, the Cu-binding protein ceruloplasmin, and Fe-binding protein serotransferrin are involved in the ferroptosis pathway, an iron-dependent form of regulated cell death that has been linked to cardiac pathology, especially in IHD patients having impaired systolic (LVEF<45) dysfunction. However, further research is required to validate these findings.

Molecular Functions of Ceruloplasmin in Metabolic Disease Pathology

Ceruloplasmin (CP) is a multicopper oxidase and antioxidant that is mainly produced in the liver. CP not only plays a crucial role in the metabolic balance of copper and iron through its oxidase function but also exhibits antioxidant activity. In addition, CP is an acute-phase protein. In addition to being associated with aceruloplasminemia and neurodegenerative diseases such as Wilson's disease, Alzheimer's disease, and Parkinson's disease, CP also plays an important role in metabolic diseases, which are caused by metabolic disorders and vigorous metabolism, mainly including diabetes, obesity, hyperlipidemia, etc. Based on the physiological functions of CP, we provide an overview of the association of type 2 diabetes, obesity, hyperlipidemia, coronary heart disease, CP oxidative stress, inflammation, and metabolism of copper and iron. Studies have shown that metabolic diseases are closely related to systemic inflammation, oxidative stress, and disorders of copper and iron metabolism. Therefore, we conclude that CP, which can reduce the formation of free radicals in tissues, can be induced during inflammation and infection, and can correct the metabolic disorder of copper and iron, has protective and diagnostic effects on metabolic diseases.

Ceruloplasmin and Coronary Heart Disease-A Systematic Review

Several studies indicate that oxidative stress might play a central role in the initiation and maintenance of cardiovascular diseases. It remains unclear whether ceruloplasmin acts as a passive marker of inflammation or as a causal mediator. To better understand the impact of ceruloplasmin blood levels on the risk of cardiovascular disease, and paying special attention to coronary heart disease, we conducted a search on the two most commonly used electronic databases (Medline via PubMed and EMBASE) to analyze current assessment using observational studies in the general adult population. Each study was quality rated using criteria developed by the US Preventive Services Task Force. Most of 18 eligible studies reviewed support a direct relationship between ceruloplasmin elevated levels and incidence of coronary heart disease. Our results highlight the importance of promoting clinical trials that determine the functions of ceruloplasmin as a mediator in the development of coronary heart disease and evaluate whether the treatment of elevated ceruloplasmin levels has a role in the prognosis or prevention of this condition.

Association Between Hypertension in Healthy Participants and Zinc and Copper Status: a Population-Based Study

The prevalence of hypertension (HTN) is increasing globally. It has been shown that there is an association between micronutrient deficiency and HTN. In the current study, we aimed to assess the association between HTN with serum copper and zinc concentrations in a large representative Iranian population. The participants were enrolled into the Mashhad stroke and heart atherosclerotic disorders study (MASHAD study), a cohort study that was initiated in 2010. Anthropometric indices were assessed using standard procedures. Systolic (SBP) and diastolic (DBP) blood pressures were measured using a standard mercury sphygmomanometer. Fasting blood glucose (FBG), lipid profile, uric acid and blood urea nitrogen (BUN), and hs-CRP were measured using routine methods. HTN defined as persons who had SBP ≥ 130 mmHg and/or DBP ≥ 85 mmHg and/or medication use. Flame atomic absorption (Varian AA240FS) was used to measure serum Zn and Cu concentrations. SPSS software was used for all statistical analyses. A total of 9588 participants were recruited into the MASHAD study project. Participants were divided into two groups; 5695 healthy (non-hypertensive) (mean age 45.85 ± 7.5 years) and 3893 hypertensive participants (mean age 51.18 ± 7.67 years). Systolic (p < 0.001) and diastolic blood pressure (p < 0.001) were significantly different for different serum copper quartiles. The participants with serum copper levels < 80 μg/dl had 1.33 times greater risk of an increased blood pressure than other participants. Participants with serum copper levels > 130 μg/dl had a 1.94-fold higher risk of raised blood pressure. Serum zinc was not associated with systolic blood pressure, but individuals in the first quartile level of serum zinc had a diastolic blood pressure that was significantly higher than other quartiles (p = 0.035). Serum copper is associated with blood pressure status in adults in a U-shaped relationship, with a range of serum copper between 80 and 130 μg/dl being associated with normal blood pressure.

Prognostic value of elevated serum ceruloplasmin levels in patients with heart failure

BACKGROUND

Ceruloplasmin (Cp) is a copper-binding acute-phase protein that is increased in inflammatory states and deficient in Wilson's disease. Recent studies demonstrate that increased levels of Cp are associated with increased risk of developing heart failure. Our objective was to test the hypothesis that serum Cp provides incremental and independent prediction of survival in stable patients with heart failure.

METHODS AND RESULTS

We measured serum Cp levels in 890 patients with stable heart failure undergoing elective cardiac evaluation that included coronary angiography. We examined the role of Cp levels in predicting survival over 5 years of follow-up. Mean Cp level was 26.6 ± 6.9 mg/dL and demonstrated relatively weak correlation with B-type natriuretic peptide (BNP; r = 0.187; P < .001). Increased Cp levels were associated with increased 5-year all-cause mortality (quartile [Q] 4 vs Q1 hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.4-2.8; P < .001). When controlled for coronary disease traditional risk factors, creatinine clearance, dialysis, body mass index, medications, history of myocardial infarction, BNP, left ventricular ejection fraction (LVEF), heart rate, QRS duration, left bundle branch blockage, and implantable cardioverter-defibrillator placement, higher Cp remained an independent predictor of increased mortality (Q4 vs Q1 HR 1.7, 95% CI 1.1-2.6; P < .05). Model quality was improved with addition of Cp to the aforementioned covariables (net reclassification improvement of 9.3%; P < .001).

CONCLUSIONS

Ceruloplasmin is an independent predictor of all-cause mortality in patients with heart failure. Measurement of Cp may help to identify patients at heightened mortality risk.

Low serum ferroxidase I activity is associated with mortality in heart failure and related to both peroxynitrite-induced cysteine oxidation and tyrosine nitration of ceruloplasmin

RATIONALE

Ceruloplasmin antioxidant function is mainly related to its ferroxidase I (FeOxI) activity, which influences iron-dependent oxidative and nitrosative radical species generation. Peroxynitrite, whose production is increased in heart failure (HF), can affect ceruloplasmin antioxidant function through amino acid modification.

OBJECTIVE

We investigated the relationship between FeOxI and ceruloplasmin tyrosine and cysteine modification and explored in a cohort of patients with HF the potential clinical relevance of serum FeOxI.

METHODS AND RESULTS

In patients with chronic HF (n=96, 76 ± 9 years; New York Heart Association class, 2.9 ± 0.8) and age-matched controls (n=35), serum FeOxI, FeOxII, ceruloplasmin, nitrotyrosine-bound ceruloplasmin, B-type natriuretic peptide, norepinephrine, and high-sensitivity C-reactive protein were measured, and the patients were followed up for 24 months. Ceruloplasmin, B-type natriuretic peptide, norepinephrine, and high-sensitivity C-reactive protein were increased in HF versus controls. FeOxI was decreased in HF (-20%) and inversely related to nitrotyrosine-bound ceruloplasmin (r, -0.305; P=0.003). In HF, FeOxI lower tertile had a mortality rate doubled compared with middle-higher tertiles. FeOxI emerged as a mortality predictor (hazard ratio, 2.95; 95% confidence intervals [1.29-6.75]; P=0.011) after adjustment for age, sex, hypertension, smoking, sodium level, estimated glomerular filtration rate, and high-sensitivity C-reactive protein. In experimental settings, peroxynitrite incubation of serum samples and isolated purified ceruloplasmin reduced FeOxI activity while increasing ceruloplasmin tyrosine nitration and cysteine thiol oxidation. Reduced glutathione prevented peroxynitrite-induced FeOxI drop, tyrosine nitration, and cysteine oxidation; flavonoid(-)-epicatechin, which prevented ceruloplasmin tyrosine nitration but not cysteine oxidation, partially impeded peroxynitrite-induced FeOxI drop.

CONCLUSIONS

Reduced activity of serum FeOxI is associated with ceruloplasmin nitration and reduced survival in patients with HF. Both ceruloplasmin tyrosine nitration and cysteine thiol oxidation may be operant in vivo in peroxynitrite-induced FeOxI activity inhibition.

Micronutrient-gene interactions related to inflammatory/immune response and antioxidant activity in ageing and inflammation. A systematic review

Recent longitudinal studies in dietary daily intake in human centenarians have shown that a satisfactory content of some micronutrients within the cells maintain several immune functions, a low grade of inflammation and preserve antioxidant activity. Micronutrients (zinc, copper, selenium) play a pivotal role in maintaining and reinforcing the performances of the immune and antioxidant systems as well as in affecting the complex network of the genes (nutrigenomic) with anti- and pro-inflammatory tasks. Genes of pro- and anti-inflammatory cytokines and some key regulators of trace elements homeostasis, such as Metallothioneins (MT), are involved in the susceptibility to major geriatric disease/disorders. Moreover, the genetic inter-individual variability may affect the nutrients' absorption (nutrigenetic) with altered effects on inflammatory/immune response and antioxidant activity. The interaction between genetic factors and micronutrients (nutrigenomic and nutrigenetic approaches) may influence ageing and longevity because the micronutrients may become also toxic. This review reports the micronutrient-gene interactions in ageing and their impact on the healthy state with a focus on the method of protein-metal speciation analysis. The association between micronutrient-gene interactions and the protein-metal speciation analysis can give a complete picture for a personalized nutrient supplementation or chelation in order to reach healthy ageing and longevity.

Ceruloplasmin and heart failure in the Atherosclerosis Risk in Communities study

BACKGROUND

Ceruloplasmin (Cp) decreases nitric oxide bioavailability in blood and has been associated with cardiovascular disease (CVD) in clinical studies. We assessed the associations between Cp and incident heart failure (HF), death, and CVD in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS AND RESULTS

Cp was measured at ARIC visit 4 (1996-1998). We studied 9240 individuals without HF or CVD at ARIC visit 4 and followed them for a mean of 10.5 years. Genome-wide association study was performed to identify genetic determinants of Cp levels and evaluate their association with incident HF in ARIC participants. Cp levels (mean±SD) were higher in women versus men (335±79 versus 258±44 mg/L; P<0.0001), women on versus not on hormone-replacement therapy (398±89 versus 291±60 mg/L; P<0.0001), and African Americans versus whites (299±63 versus 293±74 mg/L; P=0.0005). After adjusting for traditional risk factors, high-sensitivity C-reactive protein, N-terminal pro-B-type natriuretic peptide, and high-sensitivity cardiac troponin T, higher levels of Cp were associated with HF (hazard ratio, 1.44; 95% confidence interval, 1.13-1.83) and mortality (hazard ratio, 1.38; 95% confidence interval, 1.11-1.63). A locus on the ceruloplasmin gene on chromosome 3 was significantly associated with Cp levels (normal 295.56±77.60 mg/L; heterozygote 316.72±88.02 mg/L; homozygote 331.04±85.40 mg/L; P=8.3×10(-13)) but not with incident HF. After adjustment for traditional risk factors, Cp levels were also weekly associated with CVD.

CONCLUSIONS

Cp was associated with incident HF, mortality, and CVD in the ARIC population. A single locus on chromosome 3 was associated with Cp levels but not with HF.

Ceruloplasmin and the extent of heart failure in ischemic and nonischemic cardiomyopathy patients

OBJECTIVE

Ceruloplasmin was elevated in patients with coronary heart disease, but the relationship between ceruloplasmin and heart failure was still unknown. We aimed to evaluate ceruloplasmin in heart failure patients and assess association between ceruloplasmin and the extent of heart failure.

METHODS AND RESULTS

202 heart failure patients were divided into ischemic (78 with coronary stenosis) and nonischemic groups (124 without coronary stenosis). 94 subjects without heart failure were included as controls. The extent of heart failure was defined according to NYHA classification. Ceruloplasmin levels in ischemic (P < 0.001) and nonischemic groups (P < 0.001) were higher than those in control group. Ceruloplasmin had a positive linear correlation with C-reactive protein (P < 0.01) and a negative linear correlation with LVEF (P < 0.05). In nonischemic group, CP levels were significantly different among different NYHA subgroups (P < 0.05). The correlation between ceruloplasmin and extent of heart failure was calculated by binary logistic regression. Ceruloplasmin showed an independent association with the extent of heart failure in nonischemic cardiomyopathy patients (P < 0.05).

CONCLUSIONS

Ceruloplasmin was significantly elevated in patients with ischemic or nonischemic cardiomyopathy and had linear correlation with C-reactive protein and LVEF. In nonischemic cardiomyopathy patients, the ceruloplasmin value was an independent biomarker associated with the extent of heart failure.

Micronutrient (Zn, Cu, Fe)-gene interactions in ageing and inflammatory age-related diseases: implications for treatments

In ageing, alterations in inflammatory/immune response and antioxidant capacity lead to increased susceptibility to diseases and loss of mobility and agility. Various essential micronutrients in the diet are involved in age-altered biological functions. Micronutrients (zinc, copper, iron) play a pivotal role either in maintaining and reinforcing the immune and antioxidant performances or in affecting the complex network of genes (nutrigenomic approach) involved in encoding proteins for a correct inflammatory/immune response. By the other side, the genetic inter-individual variability may affect the absorption and uptake of the micronutrients (nutrigenetic approach) with subsequent altered effects on inflammatory/immune response and antioxidant activity. Therefore, the individual micronutrient-gene interactions are fundamental to achieve healthy ageing. In this review, we report and discuss the role of micronutrients (Zn, Cu, Fe)-gene interactions in relation to the inflammatory status and the possibility of a supplement in the event of a micronutrient deficiency or chelation in presence of micronutrient overload in relation to specific polymorphisms of inflammatory proteins or proteins related of the delivery of the micronutriemts to various organs and tissues. In this last context, we report the protein-metal speciation analysis in order to have, coupled with micronutrient-gene interactions, a more complete picture of the individual need in micronutrient supplementation or chelation to achieve healthy ageing and longevity.

Clinical and genetic association of serum ceruloplasmin with cardiovascular risk

OBJECTIVE

Ceruloplasmin (Cp) is an acute-phase reactant that is increased in inflammatory diseases and in acute coronary syndromes. Cp has recently been shown to possess nitric oxide (NO) oxidase catalytic activity, but its impact on long-term cardiovascular outcomes in stable cardiac patients has not been explored.

METHODS AND RESULTS

We examined serum Cp levels and their relationship with incident major adverse cardiovascular events (MACE; death, myocardial infarction [MI], stroke) over 3-year follow-up in 4177 patients undergoing elective coronary angiography. We also carried out a genome-wide association study to identify the genetic determinants of serum Cp levels and evaluate their relationship to prevalent and incident cardiovascular risk. In our cohort (age 63±11 years, 66% male, 32% history of MI, 31% diabetes mellitus), mean Cp level was 24±6 mg/dL. Serum Cp level was associated with greater risk of MI at 3 years (hazard ratio [quartile 4 versus 1] 2.35, 95% confidence interval [CI] 1.79-3.09, P<0.001). After adjustment for traditional risk factors, high-sensitivity C-reactive protein, and creatinine clearance, Cp remained independently predictive of MACE (hazard ratio 1.55, 95% CI 1.10-2.17, P=0.012). A 2-stage genome-wide association study identified a locus on chromosome 3 over the CP gene that was significantly associated with Cp levels (lead single-nucleotide polymorphism rs13072552; P=1.90×10(-11)). However, this variant, which leads to modestly increased serum Cp levels (≈1.5-2 mg/dL per minor allele copy), was not associated with coronary artery disease or future risk of MACE.

CONCLUSIONS

In stable cardiac patients, serum Cp provides independent risk prediction of long-term adverse cardiac events. Genetic variants at the CP locus that modestly affect serum Cp levels are not associated with prevalent or incident risk of coronary artery disease in this study population.

Comparative analysis of serum proteomes of patients with cardiovascular disease

OBJECTIVES

To monitor increases or decreases in cardiovascular disease (CVD)-related proteins that will be released from the deposits or plaque on the inner wall of blood vessels.

DESIGN AND METHODS

Protein profiles of sera from healthy subjects and CVD patients were determined via 2-DE. Differentially expressed spots in CVD patients were identified by ESI-Q-TOF MS/MS. Retinol binding protein 4 (RBP4), ceruloplasmin, and hemopexin were confirmed by Western blotting and RBP4 was further verified by ELISA.

RESULTS

Approximately, 400 spots were detected in each gel via comparisons of the serum proteome. Among these spots, 19 spots were selected and identified by ESI-Q-TOF MS/MS (P<0.05). The expression levels of RBP4 and ceruloplasmin were higher in CVD patients by Western blotting. The level of immunoreactive RBP4 in CVD patients was higher than that in healthy subjects.

CONCLUSIONS

The three proteins identified in the present study may constitute potential biomarkers for the diagnosis of CVD in patients.

Ceruloplasmin induces polymorphonuclear leukocyte priming in localized aggressive periodontitis

BACKGROUND

Polymorphonuclear leukocytes (PMNs) from subjects with localized aggressive periodontitis (LAgP) present multiple functional abnormalities associated with a phenotypically primed PMN phenotype. Local inflammation is characterized by hypoxia, which leads to increased production of superoxide (O(2)(-)) by PMNs. Ceruloplasmin (CP) is also induced by hypoxia and inflammation. The aim of this study was to investigate the role of CP in O(2)(-) generation in PMNs from healthy subjects and patients with LAgP.

METHODS

PMNs were isolated from healthy subjects and those with LAgP (N = 36). Superoxide was measured by cytochrome-C reduction at 550 nm. Intracellular CP expression was analyzed by real-time polymerase chain reaction and Western blotting. Serum levels of CP were measured by enzyme-linked immunosorbent assay. Intracellular iron ion conversion was spectrophotometrically determined by measuring the absorbance of sigma-phenanthroline at 510 nm.

RESULTS

O(2)(-) generation was significantly higher in LAgP PMNs before and after stimulation with formyl-methionyl-leucyl-phenylalanine (100 nM). CP expression in PMNs and CP levels in serum were significantly higher in subjects with LAgP compared to the PMNs and serum samples from matched healthy donors (P <0.05). LAgP PMNs also had significantly higher levels of Fe(3+) and lower levels of Fe(2+) compared to healthy PMNs (P <0.05), suggesting increased iron conversion. Exogenous CP treatment of healthy PMNs resulted in significant increases in O(2)(-) generation and iron ion conversion similar to LAgP PMNs.

CONCLUSION

LAgP PMNs are primed to express higher levels of CP, leading to hypoxia-mediated O(2)(-) generation in PMNs and increased oxidative stress and neutrophil-mediated tissue injury in LAgP.

Lipid profile, low-density lipoprotein oxidation and ceruloplasmin in the progeny of families with a positive history of cardiovascular diseases and/or hyperlipidemia

Fifty-eight healthy progeny (mean age +/- SD 13.9 +/- 7.9 years) of 39 families with a positive history for cardiovascular diseases ([CVD] n = 44) or hyperlipidemia (n = 14) were included in the study and were compared with 30 age-matched control participants, with a negative family history, to evaluate lipid profile, ceruloplasmin (Cp), and lipid peroxidation product (malondialdehyde [MDA]) levels, as well as in vitro copper-induced Low-density lipoprotein (LDL) oxidizability. Mean serum levels of total cholesterol, LDL cholesterol (LDL-C), apolipoprotein B-100, and MDA of the participants were significantly higher than those of the controls. Lag time, an LDL resistance oxidation marker, was lower in the study group and negatively correlated with LDL-C (r = -.437, P < .05) and Cp (r = -.272, P < .05) serum levels. In conclusion, progeny with a positive family history for CVD or hyperlipidemia have an atherogenic lipid profile and increased LDL susceptibility to oxidation. High Cp levels seem to be related to lower resistance of LDL to oxidation.

Ceruloplasmin is a better predictor of the long-term prognosis compared with fibrinogen, CRP, and IL-6 in patients with severe unstable angina

BACKGROUND

We investigated the time course and prognostic value of fibrinogen (Fib), C-reactive protein (CRP), interleukin-6 (IL-6), and ceruloplasmin (CP) in patients with severe unstable angina.

METHODS

All 4 substances were measured on admission and after 6, 12, 24, 48, and 72 hours, and after 7 days and 6 months in 40 patients with Braunwald's classification class IIIB unstable angina.

RESULTS

All recorded substances increased significantly; 15 patients had cardiovascular events during hospitalization and 11 patients during follow-up. The time course and the mean values of Fib, CRP, and IL-6 were similar in patients with and without complications both during hospitalization and follow-up. However, CP levels from 6 hours until 6 months were significantly higher in patients with complications during follow-up (P < .05).

CONCLUSIONS

Fib, CRP, IL-6, and CP levels alter in patients with severe unstable angina. However, only CP levels were related to 12-month follow-up prognosis.

Autoantibodies against oxidized LDL correlate with serum concentrations of ceruloplasmin in patients with cardiovascular disease

BACKGROUND

Ceruloplasmin (CP) has been suggested to play a role in the oxidative modification of LDL. The correlation between autoantibodies against oxidized LDL (anti-oxLDL), markers of oxidative stress, and the concentration of CP has not been previously investigated. We examined the status of these parameters in patients with myocardial infarction (MI) and stable angina.

METHODS

Blood samples were collected from patients with MI (n=56), stable angina (n=96) and from healthy controls (n=109). Levels of CP and copper were determined using turbidimetry and atomic absorption spectrophotometry, respectively. Levels of anti-oxLDL were obtained by ELISA.

RESULTS

Serum concentrations of CP, copper and anti-oxLDL were significantly higher in both groups of patients than those in controls. Among patient groups, concentrations of CP and copper were not significantly different, however, the concentrations of anti-oxLDL were higher in MI patients than that in angina (P=0.001), and were greatly influenced by underlying conditions such as diabetes mellitus, hypertension and smoking. Significant positive correlation was observed between serum concentrations of both CP and copper and the concentrations of anti-oxLDL in both patient groups but not in controls.

CONCLUSIONS

High concentrations of anti-oxLDL suggest an increase in oxidative stress that would contribute to disease severity. The observed correlation of CP with anti-oxLDL may suggest a possible pro-oxidative activity of CP in patients with cardiovascular disease.

Does oxidative stress change ceruloplasmin from a protective to a vasculopathic factor?

Although ceruloplasmin (CP), a copper containing metalloenzyme, possesses antioxidant properties (e.g. ferroxidase activity), elevated circulating CP is associated with cardiovascular disease (CVD). This ambivalence is possibly due to the capacity of CP, via its coppers, to promote vasculopathic effects that include lipid oxidation, negation of nitric oxide bioactivity and endothelial cell apoptosis. In turn, these effects that are mediated by increased formation of reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. There is also evidence that risk factors for CVD (in particular, diabetes mellitus and hyperhomocysteinaemia) may augment the vasculopathic impact of CP. In turn, it appears that ROS disrupt copper binding to CP, thereby impairing its normal protective function while liberating copper which in turn may promote oxidative pathology. The objective of this review, therefore, is to consider the epidemiology and pathophysiology of CP in relation to CVD, with particular emphasis on the relationship between CP and oxidative stress.

Copper, oxidative stress, and human health

Copper (Cu), a redox active metal, is an essential nutrient for all species studied to date. During the past decade, there has been increasing interest in the concept that marginal deficits of this element can contribute to the development and progression of a number of disease states including cardiovascular disease and diabetes. Deficits of this nutrient during pregnancy can result in gross structural malformations in the conceptus, and persistent neurological and immunological abnormalities in the offspring. Excessive amounts of Cu in the body can also pose a risk. Acute Cu toxicity can result in a number of pathologies, and in severe cases, death. Chronic Cu toxicity can result in liver disease and severe neurological defects. The concept that elevated ceruloplasmin is a risk factor for certain diseases is discussed. In this paper, we will review recent literature on the potential causes of Cu deficiency and Cu toxicity, and the pathological consequences associated with the above. Finally, we will review some of the potential biochemical lesions that might underlie these pathologies. Given that oxidative stress is a characteristic of Cu deficiency, the role of Cu in the oxidative defense system will receive special attention. The concept that excess Cu may be a precipitating factor in Alzheimer's disease is discussed.

Toxicity of copper intake: lipid profile, oxidative stress and susceptibility to renal dysfunction

The present study was carried out to investigate the effects of copper (Cu) intake on lipid profile, oxidative stress and tissue damage in normal and in diabetic condition. Since diabetes mellitus is a situation of high-risk susceptibility to toxic compounds, we examined potential early markers of Cu excess in diabetic animals. Male Wistar rats, at 60-days-old were divided into six groups of eight rats each. The control(C) received saline from gastric tube, the no-diabetic(Cu-10), treated with 10 mg/kg of Cu(Cu(++)-CuSO4, gastric tube), no-diabetic with Cu-60 mg/kg(Cu-60), diabetic(D), diabetic low-Cu(DCu-10) and diabetic high-Cu(DCu-60). Diabetes was induced by an ip injection of streptozotocin (60 mg/kg). After 30 days of treatments, no changes were observed in serum lactate dehydrogenase, alanine transaminase and alkaline phosphatase, indicating no adverse effects on cardiac and hepatic tissues. D-rats had glucose intolerance and dyslipidemic profile. Cholesterol and LDL-cholesterol were higher in Cu-60 and DCu-60 than in C, Cu-10 and D and DCu-10 groups respectively. Cu-60 rats had higher lipid hydroperoxide (HP) and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) serum activities than C and Cu-10 rats. LH was increased and GSH-Px was decreased, while no alterations were observed in SOD and catalase in serum of DCu-60 animals. DCu-60 rats had increased urinary glucose, creatinine and albumin. In conclusion, Cu intake at high concentration induced adverse effects on lipid profile, associated with oxidative stress and diminished activities of antioxidant enzymes. Diabetic animals were more susceptible to copper toxicity. High Cu intake induced dyslipidemic profile, oxidative stress and kidney dysfunction in diabetic condition. Copper renal toxicity was associated with oxidative stress and reduction at least, one of the antioxidant enzymes.

Risk of myocardial infarction in relation to plasma levels of homocysteine and inflammation-sensitive proteins: a long-term nested case-control study

Several studies have found that the homocysteine plasma level is associated with cardiovascular disease. The authors previously described a relationship between concentrations of fibrinogen and other inflammation-sensitive plasma proteins, namely, alpha1-antitrypsin, ceruloplasmin, haptoglobin, and orosomucoid (alpha1-acid glucoprotein) and the incidence of myocardial infarction (MI). Whether levels of these proteins are related to homocysteine has not been clarified. The aim of this study was to investigate whether a supposed relationship between homocysteine in plasma and the occurrence of MI is modified by these inflammation-sensitive proteins. A nested case-control study was designed, comprising 241 cases of MI, with a mean age of 48 years at baseline, and 241 controls matched for age, month of examination, and duration of follow-up. The mean homocysteine concentration did not differ between cases and controls and there was no association between the baseline homocysteine level and the time lapse before the occurrence of the MI. For the cases, there was no correlation between homocysteine and any of the measured proteins, but for the controls, homocysteine was weakly but significantly negatively correlated to haptoglobin and ceruloplasmin and slightly positively correlated to albumin. For the separated groups of cases and controls there was no association between the number of inflammation-sensitive proteins in the top quartiles and homocysteine concentration. In this population-based, prospective cohort study the occurrence of MI had no relationship to homocysteine baseline plasma level. Furthermore, there was no strong association between homocysteine and the concentrations of any of these inflammation-sensitive proteins.

Ceruloplasmin and cardiovascular disease

Transition metal ion-mediated oxidation is a commonly used model system for studies of the chemical, structural, and functional modifications of low-density lipoprotein (LDL). The physiological relevance of studies using free metal ions is unclear and has led to an exploration of free metal ion-independent mechanisms of oxidation. We and others have investigated the role of human ceruloplasmin (Cp) in oxidative processes because it the principal copper-containing protein in serum. There is an abundance of epidemiological data that suggests that serum Cp may be an important risk factor predicting myocardial infarction and cardiovascular disease. Biochemical studies have shown that Cp is a potent catalyst of LDL oxidation in vitro. The pro-oxidant activity of Cp requires an intact structure, and a single copper atom at the surface of the protein, near His(426), is required for LDL oxidation. Under conditions where inhibitory protein (such as albumin) is present, LDL oxidation by Cp is optimal in the presence of superoxide, which reduces the surface copper atom of Cp. Cultured vascular endothelial and smooth muscle cells also oxidize LDL in the presence of Cp. Superoxide release by these cells is a critical factor regulating the rate of oxidation. Cultured monocytic cells, when activated by zymosan, can oxidize LDL, but these cells are unique in their secretion of Cp. Inhibitor studies using Cp-specific antibodies and antisense oligonucleotides show that Cp is a major contributor to LDL oxidation by these cells. The role of Cp in lipoprotein oxidation and atherosclerotic lesion progression in vivo has not been directly assessed and is an important area for future studies.