Ferritin in atherosclerosis

SGLT2 Inhibitors in Aging-Related Cardiovascular Disease: A Review of Potential Mechanisms

Population aging combined with higher susceptibility to cardiovascular diseases in older adults is increasing the incidence of conditions such as atherosclerosis, myocardial infarction, heart failure, myocardial hypertrophy, myocardial fibrosis, arrhythmia, and hypertension. sodium-glucose cotransporter 2 inhibitors (SGLT2i) were originally developed as a novel oral drug for patients with type 2 diabetes mellitus. Unexpectedly, recent studies have shown that, beyond their effect on hyperglycemia, SGLT2i also have a variety of beneficial effects on cardiovascular disease. Experimental models of cardiovascular disease have shown that SGLT2i ameliorate the process of aging-related cardiovascular disease by inhibiting inflammation, reducing oxidative stress, and reversing endothelial dysfunction. In this review, we discuss the role of SGLT2i in aging-related cardiovascular disease and propose the use of SGLT2i to prevent and treat these conditions in older adults.

The association of body mass index and weight waist adjustment index with serum ferritin in a national study of US adults

BACKGROUND

Abnormal serum ferritin levels are associated with a variety of diseases. Meanwhile, abnormal serum ferritin is influenced by a variety of risk factors, but its correlation with obesity remains poorly described.

OBJECTIVE

This study aimed to investigate the association of body mass index (BMI) and weight waist adjustment index (WWI) with serum ferritin in US adults.

METHODS

Participants in this study took part in the National Health and Nutrition Examination Survey (NHANES) prior to the pandemic from 2017 to March 2020. Serum ferritin was used as the sole response variable and BMI and WWI were used as independent variables. Multiple linear regression was used to assess the relationship between serum ferritin and the independent variables, and smoothed curve fitting and threshold effects analysis were performed to assess the presence of non-linear relationships. To validate the sensitive individuals for the correlation between the independent and the dependent variables, a subgroup analysis was performed.

RESULTS

A final total of 7552 participants were included in this study. Both independent variables had a positive relationship with serum ferritin, with effect values of (β = 0.68, 95% CI: 0.17-1.19) when BMI was the independent variable and (β = 8.62, 95% CI: 3.53-13.72) when WWI was the independent variable in the fully adjusted model. This positive association between the two obesity-related indexes and serum ferritin became more significant as BMI and WWI increased (P for trend < 0.001). In subgroup analyses, the positive association between the independent variables and serum ferritin was more pronounced in participants who were male, 40-59 years old, white, and had diabetes and hypertension. In addition, smoothed curve fitting and threshold effects analysis demonstrated a linear positive association of BMI and WWI with serum ferritin.

CONCLUSIONS

In the US adult population, while there was a linear positive association of WWI and BMI with serum ferritin, the effect values between WWI and serum ferritin were more significant. Male, 40-59 years old, white, participants with diabetes and hypertension should be cautious that higher WWI might entail a risk of higher serum ferritin levels.

Association between iron status and incident coronary artery disease: a population based-cohort study

Disorders of iron metabolism has been implicated in cardiovascular disease. However, the association of serum iron stores and coronary artery disease (CAD) remains inconsistent. Here, we investigated the associations of serum iron metabolism with the incidence of CAD, the severity of coronary artery stenosis, metabolic biomarkers, and the risk of major adverse cardiovascular event (MACE). A total of 643 CAD patients and 643 healthy controls were enrolled to assess the associations of serum iron status with the presence of CAD, the severity of CAD, and the risk of MACE. Serum iron metabolism and other metabolic markers were measured in all subjects. All statistical analyses were analyzed using SPSS22.0 software and STATA statistical package. Serum level of iron metabolism markers, including serum iron, unsaturated transferrin iron binding capacity (UIBC), Total iron binding capacity (TIBC) levels, in CAD groups was significantly lower than the control group (P < 0.001). UIBC and TIBC were negatively correlated with ferritin in both sexes. Each unit increase of serum iron and TIBC were found to have a protective role for CAD in women (iron: OR 0.794, 95% CI (0.647-0.973), TIBC: OR 0.891, 95% CI (0.795-0.999), P < 0.05). However, high ferritin level was significant associated the CAD incident in both sexes (OR 1.029, 95% CI (1.002-1.058) in men, OR 1.013, 95% CI (1.0-1.025) in women, P < 0.05). Serum iron metabolism markers exhibited no significant association with the severity of CAD. Increased serum level of iron and TIBC levels were found to have a protective role for CAD in women, but not in men. Elevated serum ferritin is independently and positively associated with CAD in men and women.

Generation of bioluminescent enzyme immunoassay for ferritin by single-chain variable fragment and its NanoLuc luciferase fusion

Ferritin, widely present in liver and spleen tissue, is considered as a serological biomarker for liver diseases and cancers. The detection of ferritin may be an important tool in health diagnosis. In this study, 14 non-immunized chicken spleens were utilized to construct a single-chain fragment (scFv) phage library. After 4 rounds of panning, 7 unique clones were obtained. The optimal clone was further screened and combined with NanoLuc luciferase (Nluc) as a dual functional immunoprobe to bioluminescent enzyme immunoassay (BLEIA), which was twice as sensitive as its parental scFv-based double-sandwich enzyme-linked immunoassay (ds-ELISA). The cross-reactivity analysis revealed that the proposed methods were highly selective and suitable for clinical detection. To further verify the performance of the immunoassays, serum samples were tested by the proposed methods and a commercial ELISA kit, and there was a good correlation between the results. These results suggested that scFv fused with Nluc might be a powerful dual functional tool for rapid, practically reliable, and highly sensitive ferritin detection.

Nutrient Intake and Nutrition Status in Vegetarians and Vegans in Comparison to Omnivores - the Nutritional Evaluation (NuEva) Study

Introduction

In recent years, vegetarian and vegan diets became increasingly important as they are associated with beneficial health outcomes. Therefore, the NuEva study compares the impact of flexitarian, vegetarian, or vegan diets with omnivorous nutritional habits on nutrient intake and risk factors for non-communicable diseases.

Methods

A dietary protocol was kept over five days and blood and 24h urine samples were collected to examine the impact of dietary habits [omnivores, n = 65 (Median/Interquartile range: 33/17 yrs.), flexitarians, n = 70 (30/17 yrs.), ovo-lacto vegetarians, n = 65 (28/14 yrs.), vegans, n = 58 (25/10 yrs.)] on nutrient intake, nutrient concentrations in plasma, serum or 24h urine, body composition, and blood lipids.

Results

The increased exclusion of animal based foods in the diet (omnivores < flexitarians < vegetarians < vegans) is associated with a decreased intake of energy, saturated fat, cholesterol, disaccharides, and total sugar as well an increased intake of dietary fibers, beta carotene, vitamin E and K. The combined index of the B12 status (4cB12 score) in vegetarians (0.02/0.75) was lower compared to omnivores (0.34/0.58; p ≤ 0.05) and flexitarians (0.24/0.52; p ≤ 0.05). In omnivores vitamin A, vitamin E, ferritin, and the urinary excretion of selenium, iodine, and zinc were higher than in vegans (p ≤ 0.05). In contrast, vegans had the highest concentrations of biotin, folate, and vitamin C. Flexitarians, vegetarians, and vegans had a lower body weight, BMI, and body fat percentage in comparison to omnivores (p ≤ 0.05). In omnivores the concentrations on total cholesterol, total cholesterol/HDL cholesterol ratio, LDL cholesterol, LDL cholesterol/HDL cholesterol ratio, apolipoprotein B, and apolipoprotein B/ apolipoprotein A1 ratio were higher than in vegetarians and vegans (p ≤ 0.05).

Conclusion

The NuEva study confirms the position of the Academy of Nutrition and Dietetics that adequately planned vegetarian diets are healthy, nutritionally adequate, and may provide health benefits in the prevention and treatment of non-communicable diseases. Nevertheless, critical nutrients were identified for all groups studied. This highlights the need to develop individual nutritional concepts to ensure an adequate nutrient intake.

The effects of blunt snout bream (Megalobrama amblycephala) IL-6 trans-signaling on immunity and iron metabolism via JAK/STAT3 pathway

Interleukin-6 (IL-6) is a pleiotropic inflammatory cytokine, which plays a dual role in mammalian inflammation through both classical signaling (IL-6 binds to IL-6 receptor/IL-6R) and trans-signaling (IL-6 binds to soluble IL-6R). However, the function of IL-6, especially the regulatory mechanism of IL-6 trans-signaling in immunity and iron metabolism remains largely unclear in teleost. Here, L8824 cells (Ctenopharyngodon idella hepatic cells) were stimulated with blunt snout bream (Megalobrama amblycephala) IL-6 combination with sIL-6R protein (rmaIL-6+rmasIL-6R/maIL-6 trans-signaling) or STAT3 inhibitor (c188-9), and RNA-sequencing, global transcriptional analyses. The enrichment analysis of GO and KEGG showed that maIL-6 trans-signaling is mainly involved in stress and inflammation response, and the activation of STAT3 is mainly related to cell proliferation, apoptosis and immune regulation. Furthermore, after treated L8824 cells with JAK2 inhibitors, it was found that the induction of IL-6 trans-signaling on the selected immune-related genes could be inhibited. These results implied that in early stage after rmaIL-6+rmasIL-6R treatment, the maIL-6 trans-signaling played an important role in the immune regulation through the JAK2/STAT3 pathway. By extending the rmaIL-6+rmasIL-6R treatment time, it was found that maIL-6 trans-signaling could promote the expression of iron metabolism related genes (ft, tf, tfr1, hamp and fpn1) in L8824 cells, indicating that maIL-6 trans-signaling may be involved in iron metabolism in the non-acute immune phase. Finally, after treated L8824 cells with JAK2 and STAT3 inhibitors, it was found that only tf and fpn1 were regulated by maIL-6 trans-signaling through the JAK2/STAT3 pathway. These findings provided novel insights into IL-6 trans-signaling regulatory mechanism in teleost, enriching our knowledge of fish immunity and iron metabolism.

Regulated cell death joins in atherosclerotic plaque silent progression

Non-apoptotic regulated cell death (ferroptosis and necroptosis) leads to the release of damage-associated molecular patterns (DAMPs), which initiate and perpetuate a non-infectious inflammatory response. We hypothesize that DAMPs and non-apoptotic regulated cell death are critical players of atherosclerotic plaque progression with inadequate response to lipid-lowering treatment. We aimed to uncover the silent mechanisms that govern the existing residual risk of cardiovascular-related mortality in experimental atherosclerosis. Proteomic and genomic approaches were applied on the ascending aorta of hyperlipidemic rabbits and controls with and without lipid-lowering treatment. The hyperlipidemic animals, which presented numerous heterogeneous atherosclerotic lesions, exhibited high concentrations of serum lipids and increased lipid peroxidation oxidative stress markers. The analyses revealed the significant upregulation of DAMPs and proteins implicated in ferroptosis and necroptosis by hyperlipidemia. Some of them did not respond to lipid-lowering treatment. Dysregulation of five proteins involved in non-apoptotic regulated cell death proteins (VDAC1, VDAC3, FTL, TF and PCBP1) and nine associated DAMPs (HSP90AA1, HSP90AB1, ANXA1, LGALS3, HSP90B1, S100A11, FN, CALR, H3-3A) was not corrected by the treatment. These proteins could play a key role in the atherosclerotic silent evolution and may possess an unexplored therapeutic potential. Mass spectrometry data are available via ProteomeXchange with identifier PXD026379.

Non-Transferrin-Bound Iron in the Spotlight: Novel Mechanistic Insights into the Vasculotoxic and Atherosclerotic Effect of Iron

Significance: While atherosclerosis is an almost inevitable consequence of aging, food preferences, lack of exercise, and other aspects of the lifestyle in many countries, the identification of new risk factors is of increasing importance to tackle a disease, which has become a major health burden for billions of people. Iron has long been suspected to promote the development of atherosclerosis, but data have been conflicting, and the contribution of iron is still debated controversially. Recent Advances: Several experimental and clinical studies have been recently published about this longstanding controversial problem, highlighting the critical need to unravel the complexity behind this topic. Critical Issues: The aim of the current review is to provide an overview of the current knowledge about the proatherosclerotic impact of iron, and discuss the emerging role of non-transferrin-bound iron (NTBI) as driver of vasculotoxicity and atherosclerosis. Finally, I will provide detailed mechanistic insights on the cellular processes and molecular pathways underlying iron-exacerbated atherosclerosis. Overall, this review highlights a complex framework where NTBI acts at multiple levels in atherosclerosis by altering the serum and vascular microenvironment in a proatherogenic and proinflammatory manner, affecting the functionality and survival of vascular cells, promoting foam cell formation and inducing angiogenesis, calcification, and plaque destabilization. Future Directions: The use of additional iron markers (e.g., NTBI) may help adequately predict predisposition to cardiovascular disease. Clinical studies are needed in the aging population to address the atherogenic role of iron fluctuations within physiological limits and the therapeutic value of iron restriction approaches. Antioxid. Redox Signal. 35, 387-414.

Prognostic impact of iron deficiency in acute coronary syndromes

BACKGROUND

Iron deficiency (IDef) is a prevalent condition in patients with heart disease and in those with heart failure (HF). Evidence has shown that this deficit is associated with worse prognosis. Data in literature are scarce on the prognostic impact of IDef in acute coronary syndromes (ACS), which is the main objective of this study.

METHODS

Observational, retrospective study which included 817 patients admitted for ACS. Two groups were defined according to the presence (n=298) or absence of IDef (n=519) on admission. The clinical event under study was the occurrence of death or severe HF in the long term. Independent predictors of prognosis were determined with logistic regression analysis.

RESULTS

Thirty-six percent of patients had IDef. There was higher mortality (p=0.004), higher incidence of HF (p=0.011) during follow-up and a higher rate of hospital readmissions (p=0.048) in this group. IDef was an independent predictor of death or severe HF in follow-up, along with anemia, left ventricular dysfunction, renal dysfunction and the absence of revascularization. IDef also enabled us to further stratify the prognosis of patients without anemia based on the occurrence of death or severe HF and those with lower Killip classes (≤2) based on the occurrence of death.

CONCLUSION

IDef was an independent predictor of death or severe HF in patients admitted with ACS and enabled additional stratification for those without anemia on admission and in those with Killip classes ≤2.

Prognostic impact of iron deficiency in acute coronary syndromes

BACKGROUND

Iron deficiency (IDef) is a prevalent condition in patients with heart disease and in those with heart failure (HF). Evidence has shown that this deficit is associated with a worse prognosis. There is only a small amount of data in the literature regarding the prognostic impact of IDef in acute coronary syndromes (ACS), which is the main objective of this study.

METHODS

Observational, retrospective study which included 817 patients admitted for ACS. Two groups were defined according to the presence (n = 298) or absence of IDeF (n = 519) on admission. The clinical event under study was the occurrence of death or severe HF in long term. Independent predictors of prognosis were determined with logistic regression analysis.

RESULTS

36% of patients had IDef. These patients had a higher mortality rate (p = 0.004), higher incidence of HF (p = 0.011) during follow-up and a higher rate of hospital readmissions (p = 0.048). IDef was an independent predictor of death or severe HF in follow-up, along with anemia, left ventricular dysfunction, renal dysfunction and the absence of revascularization. Besides, IDef also enabled us to further stratify the prognosis of patients without anemia based on the occurrence of death or severe HF and those with lower Killip classes (≤2) based on the occurrence of death.

CONCLUSION

IDef was an independent predictor of death or severe HF in patients admitted with ACS and enabled additional stratification for those without anemia on admission and in those with Killip classes ≤2.

Impact of sodium glucose cotransporter 2 (SGLT2) inhibitors on atherosclerosis: from pharmacology to pre-clinical and clinical therapeutics

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are new oral drugs for the therapy of patients with type 2 diabetes mellitus (T2DM). Research in the past decade has shown that drugs of the SGLT2i class, such as empagliflozin, canagliflozin, and dapagliflozin, have pleiotropic effects in preventing cardiovascular diseases beyond their favorable impact on hyperglycemia. Of clinical relevance, recent landmark cardiovascular outcome trials have demonstrated that SGLT2i reduce major adverse cardiovascular events, hospitalization for heart failure, and cardiovascular death in T2DM patients with/without cardiovascular diseases (including atherosclerotic cardiovascular diseases and various types of heart failure). The major pharmacological action of SGLT2i is through inhibiting glucose re-absorption in the kidney and thus promoting glucose excretion. Studies in experimental models of atherosclerosis have shown that SGLT2i ameliorate the progression of atherosclerosis by mechanisms including inhibition of vascular inflammation, reduction in oxidative stress, reversing endothelial dysfunction, reducing foam cell formation and preventing platelet activation. Here, we summarize the anti-atherosclerotic actions and mechanisms of action of SGLT2i, with an aim to emphasize the clinical utility of this class of agents in preventing the insidious cardiovascular complications accompanying diabetes.

Ferritin modifies the relationship between inflammation and arterial stiffness in hypertensive patients with different glucose tolerance

Background

Ferritin, a crucial element for iron homeostasis, is associated with chronic diseases characterized by subclinical inflammation such as essential arterial hypertension and type 2 diabetes mellitus (T2DM), showing a prognostic value in different clinical settings. We investigated whether ferritin is associated with arterial stiffness (AS), an early indicator of atherosclerosis, and if it could act as effect modifier on the relationship between inflammation and AS in hypertensive patients with different glucose tolerance.

Methods

We enrolled 462 newly diagnosed untreated hypertensive (HT) patients. All subjects underwent an oral glucose tolerance test. Insulin sensitivity was assessed by MATSUDA index and ferritin levels were estimated by immunoradiometric assay. AS was defined by carotid-femoral pulse wave velocity (PWV).

Results

Out of 462 patients, 271 showed normal glucose tolerance (HT/NGT), 146 impaired glucose tolerance (HT/IGT) and 45 were diabetic (HT/T2DM). Iron levels significantly decreased and transferrin and ferritin significantly increased from the first to the third group. PWV values were significantly higher in HT/IGT and HT/T2DM patients. PWV was related directly with ferritin, high sensitivity C reactive protein (hs-CRP), transferrin, and inversely with MATSUDA index. Ferritin resulted the strongest determinant of PWV explaining a 14.9% of its variation; moreover it was a strong modifier of the relationship between hs-CRP and PWV. The estimated augmentation in PWV portended by a fixed increase in hs-CRP, was higher across increasing values of ferritin.

Conclusion

Ferritin represents an independent risk factor of arterial stiffness in our study population and a strong effect modifier on the relationship between inflammation and PWV. However, further studies are needed to fully elucidate the potential role of this biomarker in human atherosclerosis.

Iron hypothesis and coronary artery disease in geriatric patients

Context and aims: Iron is a pro-oxidant factor in the pathogenesis of CAD. The association of body iron status was investigated relative to the occurrence and severity of CAD.Design and methods: The subjects consisted of 110 males and 115 females who were classified as either a CAD case or a control according to the results of coronary angiography.Results: A new parameter, the "serum free iron index," was defined as the ratio of serum iron to UIBC. The level of ferritin showed significant increase [97.2 (67.0-171.2) µg/L vs. 85.6 (52.5-129.4), p = .034], whereas serum total iron, free iron index, transferrin, UIBC and iron saturation were unchanged in CAD patients relative to control group. Among the indices of body iron only serum ferritin had significant association with the likelihood (OR of 1.004 (1.000-1.007), p = .04) and severity of CAD [χ²(3)= 7.99, p = .01], but the correlation was lessened in the presence of classical risk factors. Serum ferritin had also the highest and significant efficiency to predict CAD (AUC = 0.61, p = .020).Conclusions: Serum ferritin as a marker of intracellular iron has significant association with CAD; nevertheless, the correlation is not independent. Since iron deficiency is prevalent in elderly patients, iron hypothesis needs to expand to the both sides of iron deficiency and toxicity.

Heme Catabolic Pathway in Inflammation and Immune Disorders

In recent years, the heme catabolic pathway is considered to play an important regulatory role in cell protection, apoptosis, inflammation, and other physiological and pathological processes. An appropriate amount of heme forms the basic elements of various life activities, while when released in large quantities, it can induce toxicity by mediating oxidative stress and inflammation. Heme oxygenase (HO) -1 can catabolize free heme into carbon monoxide (CO), ferrous iron, and biliverdin (BV)/bilirubin (BR). The diverse functions of these metabolites in immune systems are fascinating. Decades work shows that administration of degradation products of heme such as CO and BV/BR exerts protective activities in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS) and other immune disorders. This review elaborates the molecular and biochemical characterization of heme catabolic pathway, discusses the signal transduction and immunomodulatory mechanism in inflammation and summarizes the promising therapeutic strategies based on this pathway in inflammatory and immune disorders.

Serum ferritin level as an early indicator of metabolic dysregulation in young obese adults - a cross-sectional study

The aim of this study was to investigate the relationship between serum ferritin level and antioxidative status and metabolic dysregulation in young adult obese population. This cross-sectional study included 300 subjects of either sex, grouped as obese and non-obese subjects. The body mass index, total iron binding capacity, fasting blood glucose, superoxide dismutase activity, and levels of serum ferritin, iron, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, glutathione, and vitamin C were estimated. Analysis showed a significant alteration in all the parameters in obese adults. The correlation of ferritin level and body mass index showed a positive correlation (r = -0.81, p < 0.001, respectively) with levels of fasting blood glucose, superoxide dismutase, total cholesterol, low-density lipoprotein cholesterol, and triglyceride in obese individuals, whereas an insignificant correlation with vitamin C and glutathione level was observed in obese individuals. The significant positive correlation of ferritin level with the metabolic parameters and some antioxidative parameters in obese individuals signifies the development of metabolic disorders. Therefore, estimation of serum ferritin level will be an important early indicator for the risk of developing metabolic disorders in young adults.

Differences between the Molecular Mechanisms Underlying Ruptured and Non-Ruptured Carotid Plaques, and the Significance of ABCA1

Background and Purpose

Carotid plaques are a strong risk factor for ischemic stroke, and plaque rupture poses an even higher risk. Although many studies have investigated the pathogenic mechanisms of carotid plaque formation, few have studied the differences in molecular mechanisms underlying the rupture and non-rupture of carotid plaques. In addition, since early diagnosis and treatment of carotid plaque rupture are critical for the prevention of ischemic stroke, many studies have sought to identify the important target molecules involved in the rupture. However, a target molecule critical in symptomatic ruptured plaques is yet to be identified.

Methods

A total of 79 carotid plaques were consecutively collected, and microscopically divided into ruptured and non-ruptured groups. Quantitative polymerase chain reaction array, proteomics, and immunohistochemistry were performed to compare the differences in molecular mechanisms between ruptured and non-ruptured plaques. Enzyme-linked immunosorbent assay was used to measure the differences in ATP-binding cassette subfamily A member 1 (ABCA1) levels in the serum.

Results

The expression of several mRNAs and proteins, including ABCA1, was higher in ruptured plaques than non-ruptured plaques. In contrast, the expression of other proteins, including β-actin, was lower in ruptured plaques than non-ruptured plaques. The increased expression of ABCA1 was consistent across several experiments, ABCA1 was positive only in the serum of patients with symptomatic ruptured plaques.

Conclusions

This study introduces a plausible molecular mechanism underlying carotid plaque rupture, suggesting that ABCA1 plays a role in symptomatic rupture. Further study of ABCA1 is needed to confirm this hypothesis.

Serum ferritin and obstructive sleep apnea-epidemiological study

PURPOSE

Ferritin is an intracellular iron storage protein and a marker of inflammation. Studies have shown that subjects with obstructive sleep apnea (OSA) have higher levels of circulating pro-inflammatory cytokines, but little is known about the association between ferritin and OSA. The aims of the study were to evaluate serum ferritin (S-Ferritin) levels in OSA patients compared to levels in the general population and also examine the effect of obesity level and treatment with positive airway pressure (PAP) on S-Ferritin levels.

METHODS

The OSA subjects (n = 796) were part of the Icelandic Sleep Apnea Cohort. The control subjects (n = 637) were randomly chosen Icelanders who participated in an epidemiological study. Propensity score (PS) methodologies were employed to minimize selection bias and strengthen causal inferences when comparing non-randomized groups. S-Ferritin levels were measured and all participants answered the same detailed questionnaire about sleep and health. Only OSA patients underwent a sleep study and were re-invited for a 2-year follow-up.

RESULTS

S-Ferritin levels were significantly higher in OSA males than controls (213.3 vs. 197.3 μg/L, p = 0.007). However, after adjusting for confounders and using our PS methodology, no significant difference was found. S-Ferritin levels were not correlated with severity of OSA, obesity level, or clinical symptoms. Also, no significant change in S-Ferritin levels was found with 2 years of PAP treatment.

CONCLUSIONS

S-Ferritin levels are comparable in OSA patients and controls and do not change consistently with obesity level or PAP treatment in our sample.

The effects of polysaccharides from the root of Angelica sinensis on tumor growth and iron metabolism in H22-bearing mice

The crude polysaccharide was obtained from the root of Angelica sinensis (AS) to investigate its effect on tumor growth and iron metabolism in H22-bearing mice. In our study, we showed that Angelica sinensis polysaccharide (ASP) was mainly composed of arabinose, glucose and galactose in a molar ratio of 1:1:1.75, with a molecular weight of 80,900 Da and a sugar content of 88.0%. Animal experimental results revealed that three doses of ASP all had anti-tumor effects with inhibition ratios of 27.11%, 31.65% and 37.05%. With respect to iron metabolism, the mean levels of serum hepcidin, interleukin-6 (IL-6), ferritin, transferrin (Tf), transferrin receptor 1 (TfR1) and transferrin receptor 2 (TfR2) in H22-bearing mice were promoted, and serum iron concentration decreased significantly. After treatment with ASP, these iron-related indicators recovered in different degrees. The findings suggested that the anti-tumor activity of ASP may be affected by its regulation on iron metabolism in H22-bearing mice.

Binding of anti-dsDNA antibodies to proximal tubular epithelial cells contributes to renal tubulointerstitial inflammation

Immune deposits are often observed along the tubular basement membrane in patients with lupus nephritis, but the role of anti-dsDNA antibody (Ab) deposition on tubulointerstitial inflammation remains to be investigated. We examined the effect of human polyclonal anti-dsDNA Abs on inflammatory processes in cultured proximal renal tubular epithelial cells (PTEC, HK-2 cells) and their association with serum levels of interleukin (IL)-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1) in patients. Binding of anti-dsDNA Abs to HK-2 cells was investigated by cellular ELISA, flow cytometry and immunohistochemistry. IL-6, IL-8 and MCP-1 secretion, mitogen-activated protein kinase (MAPK) activation and the effect of mycophenolic acid (MPA) were investigated by ELISAs and Western blot analysis. NZBWF1/J mice with active nephritis were randomized to receive either mycophenolate mofetil (MMF) (100 mg/kg per day) or vehicle for up to 12 weeks to study renal histopathology focusing on tubulointerstitial changes. Our results demonstrated that anti-dsDNA Abs bound to HK-2 cell surface and induced IL-6, IL-8 and MCP-1 secretion through distinct MAPK pathways. MPA inhibited anti-dsDNA Ab binding to HK-2 cells and suppressed apical and basolateral IL-6 and IL-8, but not MCP-1, secretion. Anti-dsDNA Ab level correlated with serum and tubulointerstitial expression of IL-6, IL-8 and MCP-1. MMF treatment in NZBWF1/J mice reduced anti-dsDNA Ab production and MAPK activation in the renal tubulointerstitium, together with decreased IL-6 and MCP-1 expression. Our data demonstrate that anti-dsDNA Abs contribute to inflammatory processes in the tubulointerstitium in lupus nephritis through their binding to proximal renal tubular epithelial cells and induction of pro-inflammatory mediators, and MPA ameliorates anti-dsDNA Ab induced IL-6 and IL-8 secretion in these cells.

EDTA Chelation Therapy to Reduce Cardiovascular Events in Persons with Diabetes

The Trial to Assess Chelation Therapy (TACT) was a randomized double-blind placebo-controlled trial enrolling patients age ≥50 years with prior myocardial infarction. TACT used a 2 × 2 factorial design to study ethylene diamine tetraacetic acid (EDTA) chelation and high-dose vitamin supplementation. Chelation provided a modest but significant reduction in cardiovascular endpoints. The benefit was stronger and significant among participants with diabetes but absent in those without diabetes. Mechanisms by which chelation might reduce cardiovascular risk in persons with diabetes include the effects of EDTA chelation on transition and toxic metals. Transition metals, particularly copper and iron, play important roles in oxidative stress pathways. Toxic metals, in particular cadmium and lead, are toxic for the cardiovascular system. This review discusses the epidemiologic evidence and animal and human studies supporting the role of these metals in the development of diabetes and ischemic heart disease and potential ways by which EDTA chelation could confer cardiovascular benefit.

Iron Regulation of Pancreatic Beta-Cell Functions and Oxidative Stress

Dietary advice is the cornerstone in first-line treatment of metabolic diseases. Nutritional interventions directed at these clinical conditions mainly aim to (a) improve insulin resistance by reducing energy-dense macronutrient intake to obtain weight loss and (b) reduce fluctuations in insulin secretion through avoidance of rapidly absorbable carbohydrates. However, even in the majority of motivated patients selected for clinical trials, massive efforts using this approach have failed to achieve lasting efficacy. Less attention has been given to the role of micronutrients in metabolic diseases. Here, we review the evidence that highlights (a) the importance of iron in pancreatic beta-cell function and dysfunction in diabetes and (b) the integrative pathophysiological effects of tissue iron levels in the interactions among the beta cell, gut microbiome, hypothalamus, innate and adaptive immune systems, and insulin-sensitive tissues. We propose that clinical trials are warranted to clarify the impact of dietary or pharmacological iron reduction on the development of metabolic disorders.

Iron, inflammation and atherosclerosis risk in men vs. perimenopausal women

OBJECTIVE

Age at first atherosclerotic event is typically older for women vs. men; monthly iron loss has been postulated to contribute to this advantage. We investigated the relationship between an MRI-based arterial wall biomarker and the serum inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) in perimenopausal women vs. men.

METHODS AND RESULTS

Women without evident atherosclerotic disease were prospectively enrolled and observed over 24 months of menopause transition, indicated by hormone levels and reduction in median number of menstrual cycles from 4 [3-6] per year to 0 [0-1] per year (P < 0.01). Higher hsCRP predicted shorter carotid artery wall T2* in women entering the menopause transition (r = -0.3139, P = 0.0014); this relationship weakened after 24 months of perimenopause in women (r = -0.1718, P = 0.0859) and was not significant in a cohort of men matched for age and cardiovascular risk category (r = -0.0310, P = 0.8362). Serum ferritin increased from baseline to 24-month follow-up during women's menopause transition (37 [20-79] to 67 [36-97] ng/mL, P < 0.01), but still remained lower compared to men (111 [45-220] ng/mL, P < 0.01). Circulating ferritin levels correlated with arterial wall T2* values in women at baseline (r = -0.3163, P = 0.0013) but not in women after 24 months (r = -0.0730, P = 0.4684) of menopause transition nor in men (r = 0.0862, P = 0.5644).

CONCLUSIONS

An arterial wall iron-based imaging biomarker reflects degree of systemic inflammation in younger women, whereas this relationship is lost as women transition through menopause to become more similar to men. Iron homeostasis and inflammation in the arterial wall microenvironment warrants further investigation as a potential early target for interventions that mitigate atherosclerosis risk.

Marked hyperferritinemia does not predict for HLH in the adult population

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of uncontrolled immune activation that has gained increasing attention during the last decade. The diagnosis of HLH is based on a constellation of clinical and laboratory abnormalities, including elevated serum ferritin levels. In the pediatric population, marked hyperferritinemia is specific for HLH. To determine what conditions are associated with profoundly elevated ferritin in the adult population, we performed a retrospective analysis in a large academic health care system. We identified 113 patients with serum ferritin levels higher than 50,000 µg/L. The most frequently observed conditions included renal failure, hepatocellular injury, infections, and hematologic malignancies. Our results suggest that marked hyperferritinemia can be seen in a variety of conditions and is not specific for HLH in adults.

Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells

"Serum ferritin" presents a paradox, as the iron storage protein ferritin is not synthesised in serum yet is to be found there. Serum ferritin is also a well known inflammatory marker, but it is unclear whether serum ferritin reflects or causes inflammation, or whether it is involved in an inflammatory cycle. We argue here that serum ferritin arises from damaged cells, and is thus a marker of cellular damage. The protein in serum ferritin is considered benign, but it has lost (i.e. dumped) most of its normal complement of iron which when unliganded is highly toxic. The facts that serum ferritin levels can correlate with both disease and with body iron stores are thus expected on simple chemical kinetic grounds. Serum ferritin levels also correlate with other phenotypic readouts such as erythrocyte morphology. Overall, this systems approach serves to explain a number of apparent paradoxes of serum ferritin, including (i) why it correlates with biomarkers of cell damage, (ii) why it correlates with biomarkers of hydroxyl radical formation (and oxidative stress) and (iii) therefore why it correlates with the presence and/or severity of numerous diseases. This leads to suggestions for how one might exploit the corollaries of the recognition that serum ferritin levels mainly represent a consequence of cell stress and damage.

Meta-analyses of HFE variants in coronary heart disease

AIM

HFE gene variants can cause hereditary hemochromatosis (HH) that often comes along with an increased risk of coronary heart disease (CHD). The goal of our study is to assess the contribution of four HFE gene variants to the risk of CHD.

METHODS AND RESULTS

We conducted four meta-analyses of the studies examining the association between four HFE gene variants and the risk of CHD. A systematic search was conducted using MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI), Wanfang Chinese Periodical.

RESULTS

Meta-analyses showed that HFE rs1799945-G allele was associated with a 6% increased risk of CHD (P=0.02, odds ratio (OR)=1.06, 95% confidence interval (CI)=1.01-1.11). However, no association between the other three HFE gene variants (rs1800562, rs1800730, and rs9366637) and CHD risk was observed by the meta-analyses (all P values>0.05). In addition, the results of our case-control study indicated that rs1800562 and rs1800730 were monomorphic, and that rs1799945 and rs9366637 were not associated with CHD in Han Chinese.

CONCLUSIONS

Our meta-analysis suggested that a significant association existed between rs1799945 mutation and CHD, although this mutation was rare in Han Chinese.

Associations between serum hepcidin, ferritin and Hb concentrations and type 2 diabetes risks in a Han Chinese population

Systemic Fe overload can contribute to abnormal glucose metabolism and the onset of type 2 diabetes (T2D). Although hepcidin is the master regulator of systemic Fe homeostasis, few studies have systematically evaluated the associations of serum hepcidin concentrations with Fe metabolism parameters and risks for the development of T2D. In this regard, whether hepcidin concentrations are associated with T2D remains controversial. We measured serum hepcidin and ferritin concentrations in a case–control study of 1259 Han Chinese participants to evaluate the possible associations of serum hepcidin concentrations with Fe metabolism parameters and risks of T2D. Individuals with diabetes (n 555) and control participants (n 704) were recruited and serum hepcidin and ferritin concentrations were quantified. Additionally, selected biochemical and anthropometric variables were determined. A logistic regression analysis was performed to evaluate the association of serum hepcidin and ferritin concentrations with T2D. A linear regression analysis was used to test for associations between serum hepcidin and ferritin concentrations and a number of clinical, demographic and diabetes-associated variables. We found that serum hepcidin concentrations correlated with Hb and serum ferritin concentrations. No differences in hepcidin concentrations were found between the group with diabetes and the control group. Hepcidin concentrations were not significantly correlated with T2D risk factors. We also found that serum ferritin concentrations were elevated in individuals with diabetes and were positively correlated with both Hb concentrations and T2D risk factors. The present findings suggest that serum ferritin concentrations correlate with T2D risk factors, while serum hepcidin concentrations are positively associated with Hb and serum ferritin concentrations, but do not correlate with T2D.

The statin-iron nexus: anti-inflammatory intervention for arterial disease prevention

OBJECTIVES

We postulated the existence of a statin-iron nexus by which statins improve cardiovascular disease outcomes at least partially by countering proinflammatory effects of excess iron stores.

METHODS

Using data from a clinical trial of iron (ferritin) reduction in advanced peripheral arterial disease, the Iron and Atherosclerosis Study, we compared effects of ferritin levels versus high-density lipoprotein to low-density lipoprotein ratios (both were randomization variables) on clinical outcomes in participants receiving and not receiving statins.

RESULTS

Statins increased high-density lipoprotein to low-density lipoprotein ratios and reduced ferritin levels by noninteracting mechanisms. Improved clinical outcomes were associated with lower ferritin levels but not with improved lipid status.

CONCLUSIONS

There are commonalities between the clinical benefits of statins and the maintenance of physiologic iron levels. Iron reduction may be a safe and low-cost alternative to statins.

Ferritin levels and hepcidin mRNA expression in peripheral mononuclear cells from anemic type 2 diabetic patients

This study aims to measure iron nutrition parameters and to determine the presence of anemia in obese type 2 diabetic patients and to analyze the mRNA relative abundance of genes related to inflammation, immune system, iron metabolism, and mitochondrial activity. Obese type 2 diabetic (OBDM, n=30) and healthy subjects (Cn, n=30) were studied. Biochemical, anthropometric, and iron nutrition parameters were determined. Peripheral mononuclear cells from type 2 diabetic and control group were challenged with high concentrations of iron (Fe) and glucose and total mRNA was isolated. The frequency of anemia among diabetic patients was 4/30. OBDM patients with or without anemia had higher levels of ferritin and high-sensitivity C-reactive protein than the Cn group. mRNA relative abundance of nuclear factor kappa-light-chain-enhancer of activated B cells was elevated in OBDM with anemia, and mRNA expression of interleukin-6 and toll-like receptor (TLR) 2 was increased in OBDM group in basal high Fe and high glucose concentrations. The expression of tumor necrosis factor alpha and TLR-4 was increased in OBDM with anemia in all experimental conditions. Hepcidin mRNA expression was increased in OBDM with anemia even in basal Fe concentration, and mitofusin 2 was decreased in all experimental conditions. This study shows that obese type 2 diabetic patients have iron distribution disorders associated to their proinflammatory state, and anemic subjects have a marked elevation of hepcidin mRNA expression.

Inflammation associated anemia and ferritin as disease markers in SLE

Introduction

In a recent screening to detect biomarkers in systemic lupus erythematosus (SLE), expression of the iron storage protein, ferritin, was increased. Given that proteins that regulate the storage, transfer and release of iron play an important role in inflammation, this study aims to determine the serum and urine levels of ferritin and of the iron transfer protein, transferrin, in lupus patients and to correlate these levels with disease activity, inflammatory cytokine levels and markers of anemia.

Methods

A protein array was utilized to measure ferritin expression in the urine and serum of SLE patients and healthy controls. To confirm these results as well as the role of the iron transfer pathway in SLE, ELISAs were performed to measure ferritin and transferrin levels in inactive or active SLE patients and healthy controls. The relationship between ferritin/transferrin levels and inflammatory markers and anemia was next analyzed.

Results

Protein array results showed elevated ferritin levels in the serum and urine of lupus patients as compared to controls, which were further validated by ELISA. Increased ferritin levels correlated with measures of disease activity and anemia as well as inflammatory cytokine titers. Though active SLE patients had elevated urine transferrin, serum transferrin was reduced.

Conclusion

Urine ferritin and transferrin levels are elevated significantly in SLE patients and correlate with disease activity, bolstering previous reports. Most importantly, these changes correlated with the inflammatory state of the patients and anemia of chronic disease. Taken together, altered iron handling, inflammation and anemia of chronic disease constitute an ominous triad in SLE.

Serum Ferritin Is Differentially Associated with Anti-oxidative Status and Insulin Resistance in Healthy Obese and Non-obese Women

BACKGROUND

Ferritin is known to be associated with insulin resistance (IR) and oxidative stress; however, recent studies have shown that there is an association between ferritin and anti-oxidative status. To date, the biphasic response of ferritin to oxidative stress has not been fully evaluated. Thus, we investigated the association between ferritin and IR and anti-oxidative status in obese and non-obese women.

METHODS

We evaluated the homeostasis model assessment of insulin resistance (HOMA-IR) and total anti-oxidant status (TAS) in a total of 111 healthy women between the ages of 32 and 68 years.

RESULTS

In all of the study subjects, ferritin levels were positively correlated with age (r = 0.38, P < 0.001), body mass index (r = 0.24, P = 0.01), TAS (r = 0.38, P < 0.001) and HOMA-IR (r = 0.20, P = 0.04). In the subgroup analysis, ferritin levels were correlated with age (r = 0.39, P < 0.001) and TAS (r = 0.43, P < 0.001) in the non-obese group and with insulin (r = 0.50, P = 0.02) and HOMA-IR (r = 0.52, P = 0.01) levels in the obese group. On stepwise multiple linear regression analysis, ferritin was found to be independently associated with TAS (B = 177.16, P < 0.0001) in the non-obese group and independently associated with HOMA-IR (B = 30.36, P = 0.01) in the obese group.

CONCLUSION

Our findings suggest ferritin is associated with IR in obese women and with anti-oxidative status in non-obese women. Further studies are warranted to elucidate the precise role of ferritin in obesity.

Associations of serum ferritin and transferrin % saturation with all-cause, cancer, and cardiovascular disease mortality: Third National Health and Nutrition Examination Survey follow-up study

Objectives

Even though experimental studies have suggested that iron can be involved in generating oxidative stress, epidemiologic studies on the association of markers of body iron stores with cardiovascular disease or cancer remain controversial. This study was performed to examine the association of serum ferritin and transferrin saturation (%TS) with all-cause, cancer, and cardiovascular mortality.

Methods

The study subjects were men aged 50 years or older and postmenopausal women of the Third National Health and Nutrition Examination Survey 1988-1994. Participants were followed-up for mortality through December 31, 2006.

Results

Serum ferritin was not associated with all-cause, cancer, or cardiovascular mortality for either men or postmenopausal women. However, all-cause, cancer, and cardiovascular mortality were inversely associated with %TS in men. Compared with men in the lowest quintile, adjusted hazard ratios for all-cause, cancer, and cardiovascular mortality were 0.85, 0.86, 0.76, and 0.74 (p for trend < 0.01), 0.82, 0.73, 0.75, and 0.63 (p for trend < 0.01), and 0.86, 0.81, 0.72, and 0.76 (p for trend < 0.01), respectively. For postmenopausal women, inverse associations were also observed for all-cause and cardiovascular mortality, but cancer mortality showed the significantly lower mortality only in the 2nd quintile of %TS compared with that of the 1st quintile.

Conclusions

Unlike speculation on the role of iron from experimental studies, %TS was inversely associated with all-cause, cancer and cardiovascular mortality in men and postmenopausal women. On the other hand, serum ferritin was not associated with all-cause, cancer, or cardiovascular mortality.

Hepcidin expression in patients with acute leukaemia

BACKGROUND

Hepcidin plays a central role in iron homeostasis, which is regulated by iron stores, the rate of erythropoiesis, inflammation, and hypoxia. Aberrant expression of hepcidin was found in many diseases, however, there is scant information on hepcidin expression in acute leukemia (AL).

MATERIALS AND METHODS

32 patients with AL which diagnosis according to FAB criteria were studied. Serum hepcidin levels, erythropoietin (EPO), interleukin-6 (IL-6), hematological parameters, intracellular and extracellular iron store were evaluated.

RESULTS

Hepcidin was elevated significantly with increased iron storage in patients at onset of AL when erythropoiesis was depressed by blast cells, then decreased significantly with AL remission, while soluble transferrin receptor (sTfR) concentration was elevated. Negative correlations were found between serum hepcidin and erythropoietic markers including RBC, Hb, Ret and sTfR. Positive correlations were shown between hepcidin and ferritin, between hepcidin and ratio of sideroblasts, as well as between hepcidin and IL-6.

CONCLUSIONS

Hepcidin production was regulated by iron stores, inflammation and erythropoietic activity in AL patients. Erythropoietic activity may play the main role among the regulators of hepcidin expresssion.

Association between circulating electronegative low-density lipoproteins and serum ferritin in hemodialysis patients: a pilot study

BACKGROUND

Iron supplementation is a common recommendation to chronic kidney disease patients undergoing hemodialysis (HD). However, iron excess is closely associated with lipid peroxidation and, it is well known that electronegative low-density lipoproteins (LDL[-]) are present at higher plasma concentrations in diseases with high cardiovascular risk such as chronic kidney disease. Thus, the aim of this study was to investigate whether ferritin levels are associated with LDL(-) levels in HD patients.

DESIGN

This was a cross-sectional study.

SETTING

This study was conducted from a private clinic in Rio de Janeiro, Brazil.

PATIENTS

The study included 27 HD patients and 15 healthy subjects.

METHODS AND PROCEDURES

Twenty-seven HD patients (14 men, 58.6 ± 10 years, 62.2 ± 51.4 months on dialysis, and body mass index: 24.4 ± 4.2 kg/m(2)) were studied and compared with 15 healthy individuals (6 men, 53.8 ± 15.4 years, body mass index: 24.5 ± 4.3 kg/m(2)). Serum LDL(-) levels were measured using the enzyme-linked immunosorbent assay method; ferritin levels by commercially available kits, and tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, and plasminogen activator inhibitor-1 were determined with a multiplex assay kit manufactured by R&D Systems.

RESULTS

The HD patients presented higher LDL(-) and tumor necrosis factor-α levels (0.15 ± 0.13 U/L and 5.9 ± 2.3 pg/mL, respectively) than healthy subjects (0.07 ± 0.05 U/L and 2.3 ± 1.3 pg/mL, respectively) (P = .0001). The mean ferritin level in HD patients was 1,117.5 ± 610.4 ng/mL, and 90% of patients showed ferritin levels exceeding 500 ng/mL. We found a positive correlation between LDL(-) and ferritin in the patients (r = 0.48; P = .01), and ferritin was a significant contributor to LDL(-) concentrations independent of inflammation.

CONCLUSIONS

Excess body iron stores for HD patients was associated with signs of increased oxidative stress, as reflected by increased LDL(-) levels in HD patients.

Ferritin in adult-onset still's disease: just a useful innocent bystander?

Background. Adult-Onset Still's Disease (AOSD) is an immune-mediated systemic disease with quotidian-spiking fever, rash, and inflammatory arthritis. Hyperferritinemia is a prominent feature, often used for screening. Methods. The key terms “ferritin” and “hyperferritinemia” were used to search PubMed and Medline and were cross-referenced with “Still's Disease.” Results. Hyperferritinemia, although nonspecific, is particularly prevalent in AOSD. While most clinicians associate ferritin with iron metabolism, this is mostly true for the H isoform and not for the L isoform that tends to increase dramatically in hyperferritenemia. In these situations, hyperferritinemia is not associated with iron metabolism and may even mask an underlying iron deficiency. We review, in systematic fashion, the current basic science and clinical literature regarding the regulation of ferritin and its use in the diagnosis and management of AOSD. Conclusion. Serum hyperferritinemia in AOSD has been described for 2 decades, although its mechanism has not yet been completely elucidated. Regulation by proinflammatory cytokines such as interleukin (IL)-1b, IL-6, IL-18, MCSF, and INF-α provides a link to the disease pathogenesis and may explain rapid resolution of hyperferritinemia after targeted treatment and inhibition of key cytokines.

Left ventricular morphology and function in diabetic and nondiabetic hemodialyzed patients

Morbidity in end-stage renal disease (ESRD) diabetic patients is worse than in patients without diabetes mellitus (DM). This study aims to compare clinical, laboratory, and echocardiographic features between the ESRD patients with and without DM. Fifty-eight ESRD patients on dialysis were prospectively divided into two groups according to the presence of DM. Demographic, clinical, laboratory, and echocardiographic features (ejection fraction and wall motion score index) were compared between the two groups. Overall, 20 out of 58 patients (37.8%) with ESRD had DM. There were no significant differences between the patients with DM and those without DM when it comes to age (60.6 ± 10.6 vs. 59.0 ± 10.6 years, P = 0.665), ejection fraction (52.6% ± 12.8% vs. 54.2% ± 12.8%, P = 0.59), and wall motion score index (1.21 ± 0.3 vs.1.15 ± 0.3, P = 0.37). In multivariant analysis of the interventricular septum, posterior wall thickness and left atrium size correlated positively with DM. There was also no statistical difference in myocardial perfusion disturbances on real-time contrast echocardiography between the groups with and without DM (12 (60%) patients vs. 14 patients (36.8%), P = 0.079). Among diabetics 77.8% had significant atherosclerotic changes, while in the group without DM, only 38.1%, P = 0.01. From the laboratory parameters ferritin and high-sensitivity C-reactive protein levels were significantly higher in the group with DM, P = 0.014 and P = 0.026, respectively. Patients with ESRD and DM have significantly bigger left atrial size, thicker left ventricular walls, and higher serum ferritin and high-sensitivity C-reactive protein levels than the patients without DM. The aforementioned features may be possible risk factors for the development of adverse cardiac events in patients on hemodialysis.

Magnetic nanoparticles: an update of application for drug delivery and possible toxic effects

Magnetic nanoparticles (MNPs) represent a subclass within the overall category of nanomaterials and are widely used in many applications, particularly in the biomedical sciences such as targeted delivery of drugs or genes, in magnetic resonance imaging, and in hyperthermia (treating tumors with heat). Although the potential benefits of MNPs are considerable, there is a distinct need to identify any potential toxicity associated with these MNPs. The potential of MNPs in drug delivery stems from the intrinsic properties of the magnetic core combined with their drug loading capability and the biomedical properties of MNPs generated by different surface coatings. These surface modifications alter the particokinetics and toxicity of MNPs by changing protein-MNP or cell-MNP interactions. This review contains current advances in MNPs for drug delivery and their possible organ toxicities associated with disturbance in body iron homeostasis. The importance of protein-MNP interactions and various safety considerations relating to MNP exposure are also addressed.

Dietary micronutrient intakes are associated with markers of inflammation but not with markers of subclinical atherosclerosis

Few studies have examined associations of dietary micronutrients with markers of inflammation and subclinical atherosclerosis. The present study investigated associations of heme iron, nonheme iron, zinc (Zn), magnesium (Mg), β-carotene, vitamin C, and vitamin E with C-reactive protein (CRP), IL-6, total homocysteine (tHcy), fibrinogen, coronary artery calcium, and common and internal carotid artery intima media thickness. Micronutrient intakes and markers of inflammation and subclinical atherosclerosis were studied in 5,181 participants from the Multi-Ethnic Study of Atherosclerosis who were aged 45-84 y and free of diabetes and cardiovascular disease. Models were adjusted for energy intake, demographics, lifestyle characteristics, and BMI. Dietary nonheme iron and Mg intakes were inversely associated with tHcy concentrations (mean tHcy: 9.11, 8.86, 8.74, 8.71, and 8.50 μmol/L, and 9.20, 9.00, 8.65, 8.76, and 8.33 μmol/L across increasing quintiles of nonheme iron and Mg, respectively; P-trend < 0.001 for both). However, dietary Zn and heme iron were positively associated with CRP [mean: 1.73, 1.75, 1.78, 1.88, and 1.96 mg/L across increasing quintiles of Zn and 1.72, 1.76, 1.83, 1.86, and 1.94 mg/L across increasing quintiles of heme iron (P-trend = 0.002 and 0.01, respectively). Other tested micronutrient-marker associations were not significant. In conclusion, of the 49 tested associations, only 7 were significant. Although this study does not provide strong support for associations between the micronutrients and markers of inflammation and subclinical atherosclerosis, the results are consistent with dietary guidelines that advocate for a balanced diet that includes a variety of plant foods containing Mg, Zn, and nonheme iron.

Hepcidin expression and iron parameters change in Type 2 diabetic patients

AIM

Iron may contribute to the pathogenesis of Type 2 diabetes mellitus (DM). The aim of this study was to determine iron regulator hepcidin and iron metabolic parameters in Type 2 DM patients, the relationships among them were evaluated in this specific sub-groups.

MATERIALS AND METHODS

The study included sixty-four people: 34 cases of diabetes and 30 age-matched controls. Serum hepcidin, IL-6, hsCRP, ferritin, sTfR, EPO as well as other clinical parameters were detected, and the associations between hepcidin levels and iron/inflammatory parameters were analyzed in diabetes and the controls.

RESULTS

Serum ferritin and hepcidin levels in diabetic patients were significant higher than the controls (p<0.001 respectively). A positive correlation between hepcidin and ferritin, as well as between ferritin and IL-6 levels was existed in diabetes and the control groups (p<0.001 respectively).

CONCLUSION

All of these data demonstrated that the higher hepcidin levels in diabetic patients may be due to those higher ferritin and IL-6 levels, the elevated hepcidin might have adaptive value through down-regulated iron absorb and play an important role in pathogenesis of Type 2 DM.

Immunophenotypic characterization of human monocyte subsets: possible implications for cardiovascular disease pathophysiology

OBJECTIVES

Monocytes include several subsets with different and sometimes divergent roles in immunity, atherogenesis and reparative processes.

OBJECTIVES

We aimed to perform detailed immunophenotypic and functional characterization of human monocyte subsets.

PATIENTS/METHODS

Analysis of surface markers of blood and bone marrow monocyte subsets and functional characterization of blood monocyte subsets in healthy volunteers was performed using flow cytometry.

RESULTS

In the present study, we show the presence of three subsets which could be unequivocally distinguished by surface expression of CD14, CD16 and CCR2 as CD14(+)CD16(-)CCR2(+) (Mon1), CD14(+)CD16(+)CCR2(+) (Mon2) and CD14(low)CD16(+)CCR2(-) (Mon3) subsets. In comparison with the classic Mon1, the Mon2 subset had the highest expression of Tie2, CXCR4, CD163, CD115, receptors to inter-cellular adhesion molecule-1 (ICAM-1), vascular endothelial growth factor (VEGF), and the highest surface levels of apolipoprotein B and ferritin. In contrast, Mon3 had maximal expression of VCAM-1 receptors and CD204. The Mon2 and Mon3 subsets had significantly lower activity of the NFκB pathway than Mon1. Mon1 and Mon2 had similar phagocytic activity, which was significantly higher compared with Mon3. All three subsets were present in bone marrow, although the relative proportion of Mon2 in bone marrow was about 2.5-fold higher compared with that seen in blood. Significant differences in cytokine production in response to endotoxin stimulation were observed between the three monocyte subsets.

CONCLUSION

Given their immunophenotypic similarity, the newly characterized Mon2 population may represent the previously reported pluripotent progenitor/pro-angiogenic monocytes.

A proteomic focus on the alterations occurring at the human atherosclerotic coronary intima

Coronary atherosclerosis still represents the major cause of mortality in western societies. Initiation of atherosclerosis occurs within the intima, where major histological and molecular changes are produced during pathogenesis. So far, proteomic analysis of the atherome plaque has been mainly tackled by the analysis of the entire tissue, which may be a challenging approach because of the great complexity of this sample in terms of layers and cell type composition. Based on this, we aimed to study the intimal proteome from the human atherosclerotic coronary artery. For this purpose, we analyzed the intimal layer from human atherosclerotic coronaries, which were isolated by laser microdissection, and compared with those from preatherosclerotic coronary and radial arteries, using a two-dimensional Differential-In-Gel-Electrophoresis (DIGE) approach. Results have pointed out 13 proteins to be altered (seven up-regulated and six down-regulated), which are implicated in the migrative capacity of vascular smooth muscle cells, extracellular matrix composition, coagulation, apoptosis, heat shock response, and intraplaque hemorrhage deposition. Among these, three proteins (annexin 4, myosin regulatory light 2, smooth muscle isoform, and ferritin light chain) constitute novel atherosclerotic coronary intima proteins, because they were not previously identified at this human coronary layer. For this reason, these novel proteins were validated by immunohistochemistry, together with hemoglobin and vimentin, in an independent cohort of arteries.