Iron and the liver: update 2008

Effects of Aging on the Severity of Liver Injury in Mice With Iron Overload

Although iron is a vital component in the body, excessive iron leads to iron toxicity, which affects vital organs. In particular, the liver is considerably affected by iron toxicity because it stores the highest amount of iron in the body. Nonetheless, the relationship between iron overload and aging in the liver has not yet been clearly identified. This study aimed to observe the effects of aging on iron overload in the liver. Female C57BL/6J mice were randomly divided into vehicle control and iron overload groups (n = 7-22 per group). The iron overload group was injected with iron-dextran (Fe-dextran, ferric hydroxide dextran complex) (0.5 g/kg) for 4 weeks. After the experimental period, liver and blood samples were obtained from 2-, 15-, and 22-month-old mice. Liver weight, iron deposition, structural changes, cell death, extracellular matrix deposition, and fenestration of sinusoidal vessels were analyzed and compared between the groups. Additionally, biochemical analyses (aspartate aminotransferase, alanine aminotransferase, and serum total iron levels) were performed. The iron overload group exhibited significant differences compared with the control group with age. In the elderly iron overload model, iron deposition, inflammatory cell infiltration, and cell death were significantly increased (p < 0.0001). Moreover, deposition of the extracellular matrix and defenestration of sinusoidal fenestrae were observed among 22-month-old mice in the iron overload group. These results suggest that aging is a risk factor for iron-induced liver injury. Therefore, caution should be exercised when performing iron-related treatments in the elderly.

Short-term effects of subacute ruminal acidosis on ferroptosis and iron metabolism in the livers of lactating sheep fed a high-grain diet

Subacute ruminal acidosis can cause liver injury in ruminants. Ferroptosis, an iron-dependent cell death, is involved in many liver diseases. This study aimed to investigate ferroptosis in SARA-induced liver injury and explore the changes in hepatic iron metabolism. Twelve ruminally cannulated, lactating Hu sheep (parity: 2 or 3; BW: 50.6 ± 4.0 kg; 18.8 ± 3.6 DIM; MY: 0.52 ± 0.08 kg/d; mean ± SD) were divided into 2 groups (n = 6/group) and fed a low-grain diet (LG; grain/forage ratio = 3:7, 24.89% starch and 40.66% NDF) or a high-grain diet (HG; grain/forage ratio = 7:3, 38.64% starch and 24.41% NDF) for 8 wk. Rumen pH was measured weekly 10 min before feeding and 1, 2, 3, 4, 5, 6, and 8 h after feeding. On d 57, all sheep were slaughtered after collecting hepatic vein blood, and liver tissue was collected. The HG diet significantly decreased rumen pH compared with the LG diet; the rumen pH on d 56 in the HG group was <5.6 at 1, 2, 3, and 4 h after feeding. Plasma concentrations of LPS, malondialdehyde (MDA), IL-1β, and IL-6 at 4 h after feeding increased, whereas glutathione (GSH) and glutathione peroxidase 4 (GPX4) decreased. Moreover, lipid reactive oxygen species, ferrous ion, and MDA were elevated, whereas GSH was decreased in the liver of the HG group. For ferroptosis-related proteins, feeding a high-grain diet led to increased acyl-CoA synthetase long chain family member 4 (ACSL4) and arachidonate 15-lipoxygenase (ALOX15) and decreased GPX4 and solute carrier family 7 member 11 (SLC7A11). For ferritinophagy-related proteins, feeding a high-grain diet decreased ferritin heavy chain 1 (FTH1) and increased nuclear receptor coactivator 4 (NCOA4) and microtubule-associated protein 1 light chain 3 II (MAP1LC3-II). Regarding iron metabolism, increased protein expression of nuclear mothers against decapentaplegic homolog1/5/8 (SMAD1/5/8) and hepcidin, decreased protein expression of ferroportin, and iron deposits were observed in the liver of the HG group. Furthermore, feeding high-grain diets also increased inflammatory signaling-related proteins IL-6 and phospho-signal transducer and activator of transcription 3 (p-STAT3). Taken together, this study suggests that SARA induced liver injury and ferroptosis. Enhanced ferritinophagy, disordered iron metabolism, and elevated inflammatory response may mediate ferroptosis in the livers of sheep fed a high-grain diet.

Quercetin alleviates LPS/iE-DAP-induced liver injury by suppressing ferroptosis via regulating ferritinophagy and intracellular iron efflux

Ruminal dysbiosis-induced liver injury is prevalent in dairy cows, yet its underlying mechanisms remain incompletely understood. Ferroptosis, a newly identified form of programmed cell death distinct from apoptosis and necrosis, has been implicated in various liver diseases by emerging studies. In the present study, lipopolysaccharide (LPS) and γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) were employed to establish in vitro and in vivo models of liver injury using bovine hepatocytes and mice, respectively. It was observed that noncytotoxic iE-DAP alone did not influence lipid peroxidation or GPX4, but exacerbated LPS-induced ferroptosis and hepatocyte injury. Notably, co-treatment with LPS and iE-DAP (LPS/iE-DAP)-induced hepatocyte injury was mitigated by intervention with the ferroptosis inhibitor ferrostatin-1 (Fer-1). Mechanistically, the activated IL-6/STAT3 signaling pathway was found to mediate LPS/iE-DAP-induced ferroptosis. Suppression of IL-6/STAT3, either through IL6 and STAT3 knockdown or pharmacological intervention, reduced Fe2+ accumulation and alleviated ferroptotic cell death. Further investigations identified that IL-6/STAT3 signaling enhanced ferritinophagy and impaired iron export. Either disrupting ferritinophagy by knocking down NCOA4 or restoring iron export via HAMP knockdown relieved intracellular iron overload and inhibited ferroptosis. Specifically, LPS/iE-DAP treatment increased the interaction between hepcidin and ferroportin, promoting ferroportin ubiquitination and degradation, thereby blocking iron efflux. Furthermore, we provided several evidence to prove that quercetin pretreatment alleviated LPS/iE-DAP-induced ferroptosis and liver injury by decreasing hepatic iron accumulation via targeting the IL-6/STAT3 signaling in vitro and in vivo, effects reversed by the addition of recombinant bovine IL-6. Based on these findings, we concluded that LPS/iE-DAP-induced liver injury by triggering ferroptosis through regulating IL-6/STAT3/ferritinophagy-dependent iron release and IL-6/STAT3/hepcidin/ferroportin-dependent iron export, while quercetin could alleviate this liver injury by inhibiting ferroptosis via IL-6/STAT3 signaling pathway. This study provides novel insights into the mechanisms whereby ruminal dysbiosis induces liver injury and presents a prospective solution for ruminal dysbiosis-induced liver injury.

Solid-State Fermented Cereals: Increased Phenolics and Their Role in Attenuating Liver Diseases

Liver diseases, a leading cause of global mortality, necessitate effective dietary strategies. Fermented cereals, traditionally recognized for benefits in glucose regulation, lipid profiles, and antioxidant activity, hold potential for managing conditions such as type 2 diabetes, hypertension, and obesity. However, their specific impact on liver health requires further investigation. Fermentation, particularly solid-state fermentation (SSF), enhances the bioavailability of beneficial compounds, including phenolics. This review summarizes recent studies on the phenolic content of fermented cereals, highlighting variations based on microbial strains and cereal types. It examines the hepatoprotective effects of these phenolics, drawing on in vivo and in vitro research. Furthermore, the review explores recent findings on the impact of fermented cereals on liver health and related diseases. This work provides a foundation for future research exploring fermented cereals as a dietary intervention for liver disease prevention and management.

Using Dual-source Photon-counting Detector CT to Simultaneously Quantify Fat and Iron Content: A Phantom Study

RATIONALE AND OBJECTIVES

To evaluate the feasibility of using photon-counting detector computed tomography (PCD CT) to simultaneously quantify fat and iron content MATERIALS AND METHODS: Phantoms with pure fat, pure iron and fat-iron deposition were scanned by two tube voltages (120 and 140 kV) and two image quality (IQ) settings (80 and 145). Using an iron-specific three-material decomposition algorithm, virtual noniron (VNI) and virtual iron content (VIC) images were generated at quantum iterative reconstruction (QIR) strength levels 1-4.

RESULTS

Significant linear correlations were observed between known fat content (FC) and VNI for pure fat phantoms (r = 0.981-0.999, p < 0.001) and between known iron content (IC) and VIC for pure iron phantoms (r = 0.897-0.975, p < 0.001). In fat-iron phantoms, the measurement for fat content of 5-30% demonstrated good linearity between FC and VNI (r = 0.919-0.990, p < 0.001), and VNI were not affected by 75, 150, and 225 µmol/g iron overload (p = 0.174-0.519). The measurement for iron demonstrated a linear range of 75-225 µmol/g between IC and VIC (r = 0.961-0.994, p < 0.001) and VIC was not confounded by the coexisting 5%, 20%, and 30% fat deposition (p = 0.943-0.999). The Bland-Altman of fat and iron measurements were not significantly different at varying tube voltages and IQ settings (all p > 0.05). No significant difference in VNI and VIC at QIR 1-4.

CONCLUSION

PCD CT can accurately and simultaneously quantify fat and iron, including scan parameters with lower radiation dose.

[Diagnosis and evaluation of metabolic dysfunction associated steatotic liver disease (MASLD)]

Non-alcoholic fatty liver disease (NAFLD) or recently called Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD), is the leading cause of liver disease, with an estimated worldwide prevalence of 25%. MASLD is suspected, in a metabolic condition, in the presence of hepatic steatosis, moderate hepatic cytolysis or hyperferritinemia. The severity of the disease depends on the stage of liver fibrosis, which can be suspected in clinical practice by simple blood tests such as the FIB-4 or NAFLD fibrosis Score. The treatment is based on lifestyle intervention combining weight loss, increased physical activity and a Mediterranean-style diet. Only a small minority of patients with MASLD will develop advanced liver disease and require liver specialist. Given the high prevalence of MASLD, the identification of these patients cannot be envisaged without the taking part in the screening of all physicians (general practitioners and specialists).

Ferulic acid protects HepG2 cells and mouse liver from iron-induced damage

Liver as iron storage organ is particularly susceptible to oxidative stress-induced injury from excess iron. Thus, antioxidant therapies are often used to reverse oxidative damage and protect cells and tissues. This study investigated the protective effects of phenolic acids; ferulic acid (FA) and its metabolite, ferulic acid 4-O-sulfate disodium salt (FAS) against oxidative stress under iron overload conditions in mouse and HepG2 cells. Cells were exposed to FA or FAS and then treated with iron-induced oxidative stress complex of 50 μmol/L FAC and 20 μmol/L of 8-hydroxyquinoline 8HQ (8HQ-FAC). Iron dextran was injected intraperitoneally on alternate days for 10 days to induce the iron overload condition in BALB/c mice. The study revealed that the phenolic acids were protective against ROS production, lipid peroxidation and antioxidant depletion in HepG2 cells and liver tissues of BALB/c mice during iron-induced oxidative stress. The protective function of phenolic acids was achieved by the transcriptional activation of nuclear factor erythroid-2-related factor 2 (Nrf2) to regulate antioxidant genes. In conclusion, the study provides evidence that FA has the potential as a therapeutic agent against iron-related diseases such as T2D.

The effect of Alnus incana (L.) Moench extracts in ameliorating iron overload-induced hepatotoxicity in male albino rats

Iron overload causes multiorgan dysfunction and serious damage. Alnus incana from the family Betulaceae, widely distributed in North America, is used for treating diseases. In this study, we investigated the iron chelating, antioxidant, anti-inflammatory, and antiapoptotic activities of the total and butanol extract from Alnus incana in iron-overloaded rats and identified the bioactive components in both extracts using liquid chromatography-mass spectrometry. We induced iron overload in the rats via six intramuscular injections of 12.5 mg iron dextran/100 g body weight for 30 days. The rats were then administered 60 mg ferrous sulfate /kg body weight once daily using a gastric tube. The total and butanol extracts were given orally, and the reference drug (deferoxamine) was administered subcutaneously for another month. After two months, we evaluated the biochemical, histopathological, histochemical, and immunohistochemical parameters. Iron overload significantly increased the serum iron level, liver biomarker activities, hepatic iron content, malondialdehyde, tumor necrosis factor-alpha, and caspase-3 levels. It also substantially (P < 0.05) reduced serum albumin, total protein, and total bilirubin content, and hepatic reduced glutathione levels. It caused severe histopathological alterations compared to the control rats, which were markedly (P < 0.05) ameliorated after treatment. The total extract exhibited significantly higher anti-inflammatory and antiapoptotic activities but lower antioxidant and iron-chelating activities than the butanol extract. Several polyphenolic compounds, including flavonoids and phenolic acids, were detected by ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) analysis. Our findings suggest that both extracts might alleviate iron overload-induced hepatoxicity and other pathological conditions characterized by hepatic iron overload, including thalassemia and sickle-cell anemia.

A critical evaluation of the role of iron overload in fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been associated with a condition known as the dysmetabolic iron overload syndrome, but the frequency and severity of iron overload in NAFLD is not well described. There is emerging evidence that mild to moderate excess hepatic iron can aggravate the risk of progression of NAFLD to nonalcoholic steatohepatitis and eventually cirrhosis. Mechanisms are postulated to be via reactive oxygen species, inflammatory cytokines, lipid oxidation, and oxidative stress. The aim of this review is to assess the evidence for true hepatic iron overload in NAFLD, to discuss the pathogenesis by which excess iron may be toxic, and to critically evaluate the studies designed to deplete iron by regular venesection. In brief, the studies are inconclusive due to heterogeneity in eligibility criteria, sample size, randomization, hepatic iron measurement, serial histological endpoints, target ferritin levels, length of venesection, and degree of confounding lifestyle intervention. We propose a trial designed to overcome the limitations of these studies.

DFO treatment protects against depression-like behaviors and cognitive impairment in CUMS mice

Depression has several negative effects on emotion as well as learning and memory abilities. Previous studies showed that depression could exacerbate inflammation, which in turn further aggravated depression. Deferoxamine (DFO) is a chelating agent binding iron and aluminium, and is clinically applied to treat acute ion poisoning and hemochromatosis. Researches showed that it could reduce inflammation via increasing the expression of hypoxia-inducible factor-1alpha (HIF-1α). Here, we established a chronic unpredictable mild stress (CUMS) model to investigate whether DFO exerted a neuroprotective function in depression. The results demonstrated that CUMS (4 weeks) effectively induced depression-like behaviors in mice based on sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST), open field test (OFT), and elevated plus-maze test (EPT). It also brought cognitive deficits based on Morris water maze (MWM) test and the impairment of synaptic plasticity based on in vivo electrophysiological recordings. Additionally, CUMS exposure significantly decreased the expression of hippocampal synapse related proteins and the spine density of neurons in the DG region, accompanied by increasing the expression of hippocampal inflammatory cytokines, and promoted the activation of microglia in the hippocampus. The expression of HIF-1α was down-regulated as expected. However, DFO distinctly reversed the CUMS-induced impairments. The mechanism is associated with the DFO inhibition of inflammation by upregulating HIF-1 expression, thereby alleviating a series of pathology changes. Together, these findings suggest that DFO likely plays a protective role in cognitive impairments and synaptic plasticity deficits resulting from depression.

Non-invasive diagnosis and follow-up of non-alcoholic fatty liver disease

NAFLD is a frequent disease that affects 25% of the worldwide population. There is no specific diagnostic test for NAFLD, and the diagnosis mainly relies on the elimination of the other causes of chronic liver diseases with liver biopsy kept for unsure diagnoses. Non-invasive tests are now available to assess NAFLD severity and therefore to help physicians decide on the patient management and follow-up. These non-invasive tests can also be used to define pathways that organize referrals from primary care and diabetology clinics to the liver specialist, with the ambition to improve the screening of asymptomatic patients with NAFLD and advanced liver disease. NAFLD being the liver expression of the metabolic syndrome, physicians need also take care to screen for diabetes and to evaluate the cardiovascular risk in those patients. These recommendations from the French Association for the Study of the Liver (AFEF) aim at providing guidance on the following questions: how to diagnose NAFLD; how non-invasive tests should be used to assess NAFLD severity; how to follow patients with NAFLD; when to perform liver biopsy in NAFLD; and how to decide referral to the liver specialist for a patient with NAFLD.

MR imaging assessment and quantification of liver iron

Iron overload is a common clinical problem resulting from hereditary hemochromatosis or secondary hemosiderosis (mainly associated with transfusion therapy), being also associated with chronic liver diseases and metabolic disorders. Excess of iron accumulates in organs like the liver, pancreas and heart. Without treatment, patients with iron overload disorders will develop liver cirrhosis, diabetes and cardiomyopathy. Iron quantification is therefore crucial not only for diagnosis of iron overload but also to monitor iron-reducing therapies. Liver iron concentration is considered the surrogate marker of total body iron stores. Because liver biopsy is invasive and prone to high variability and sampling bias, MR imaging has emerged as a non-invasive method and gained wide acceptance, now being considered the standard of care for assessing iron overload. Nevertheless, there are different MR techniques for iron quantification and there is still no consensus about the best technique or postprocessing tool for hepatic iron quantification, with the choice of imaging technique depending mainly on the local expertise as well on the available equipment and software. Because different methods should not be used interchangeably, it is important to choose one method and use the same one when following up patients over time.

Serum hepcidin levels are related to serum markers for iron metabolism and fibrosis stage in patients with chronic hepatitis B: A cross-sectional study

BACKGROUND AND STUDY AIMS

The clinical significance of serum parameters of iron metabolism and hepcidin in liver disease remains unknown. Therefore, this study aimed to evaluate the association of serum hepcidin levels with fibrosis stage and serum iron parameters in patients with chronic hepatitis B (CHB).

PATIENTS AND METHODS

This cross-sectional study included 126 treatment-naïve patients with CHB (median age, 39.0 years; 64.3% males) who were positive for hepatitis B surface antigen and 23 healthy controls (median age, 33.0 years; 52.2% males). Data on patient demographics, serum hepcidin levels, liver function tests and serum iron parameters and liver biopsy findings including fibrosis grade, histological activity index (HAI) and liver iron level were recorded.

RESULTS

The median (minimum-maximum) serum hepcidin levels were significantly lower in the CHB group than in the control group [71.2 (13.3-672.7) vs. 657.5 (201.7-2714.2) pg/mL, p < 0.001]. Higher fibrosis stage was associated with higher transferrin saturation (p = 0.029), serum ferritin level (p < 0.001) and viral load (p < 0.001). Fibrosis stage and HAI were positively correlated with ferritin (r = 0.407, p < 0.001 and r = 0.415, p < 0.001, respectively) and transferrin saturation (r = 0.219, p = 0.026 and r = 0.290, p = 0.003, respectively) levels, whereas hepcidin level was negatively correlated with fibrosis stage (r = -0.175, p = 0.051), viral load (r = -0.209, p = 0.020) and ferritin level (r = -0.244, p = 0.006) level. There were no significant differences in serum iron level, total iron binding capacity and liver iron level among patients with different stages of fibrosis.

CONCLUSION

Reduced hepcidin levels and elevated transferrin saturation and ferritin levels are linked to fibrosis severity and HAI in patients with CHB.

Inherited iron overload disorders

Hereditary iron overload includes several disorders characterized by iron accumulation in tissues, organs, or even single cells or subcellular compartments. They are determined by mutations in genes directly involved in hepcidin regulation, cellular iron uptake, management and export, iron transport and storage. Systemic forms are characterized by increased serum ferritin with or without high transferrin saturation, and with or without functional iron deficient anemia. Hemochromatosis includes five different genetic forms all characterized by high transferrin saturation and serum ferritin, but with different penetrance and expression. Mutations in HFE, HFE2, HAMP and TFR2 lead to inadequate or severely reduced hepcidin synthesis that, in turn, induces increased intestinal iron absorption and macrophage iron release leading to tissue iron overload. The severity of hepcidin down-regulation defines the severity of iron overload and clinical complications. Hemochromatosis type 4 is caused by dominant gain-of-function mutations of ferroportin preventing hepcidin-ferroportin binding and leading to hepcidin resistance. Ferroportin disease is due to loss-of-function mutation of SLC40A1 that impairs the iron export efficiency of ferroportin, causes iron retention in reticuloendothelial cell and hyperferritinemia with normal transferrin saturation. Aceruloplasminemia is caused by defective iron release from storage and lead to mild microcytic anemia, low serum iron, and iron retention in several organs including the brain, causing severe neurological manifestations. Atransferrinemia and DMT1 deficiency are characterized by iron deficient erythropoiesis, severe microcytic anemia with high transferrin saturation and parenchymal iron overload due to secondary hepcidin suppression. Diagnosis of the different forms of hereditary iron overload disorders involves a sequential strategy that combines clinical, imaging, biochemical, and genetic data. Management of iron overload relies on two main therapies: blood removal and iron chelators. Specific therapeutic options are indicated in patients with atransferrinemia, DMT1 deficiency and aceruloplasminemia.

Management of Iron Overload in Resource Poor Nations: A Systematic Review of Phlebotomy and Natural Chelators

Iron is an essential element and the most abundant trace metal in the body involved in oxygen transport and oxygen sensing, electron transfer, energy metabolism, and DNA synthesis. Excess labile and unchelated iron can catalyze the formation of tissue-damaging radicals and induce oxidative stress. English abstracts were identified in PubMed and Google Scholar using multiple and various search terms based on defined inclusion and exclusion criteria. Full-length articles were selected for systematic review, and secondary and tertiary references were developed. Although bloodletting or phlebotomy remains the gold standard in the management of iron overload, this systematic review is an updated account of the pitfalls of phlebotomy and classical synthetic chelators with scientific justification for the use of natural iron chelators of dietary origin in resource-poor nations.

Deferoxamine: An Angiogenic and Antioxidant Molecule for Tissue Regeneration

Deferoxamine (DFO) has been in use for half a century as a Food and Drug Administration-approved iron chelator, but recent studies indicate a variety of properties that could expand this drug's application into the fields of tissue and regenerative engineering. DFO has been implicated as an angiogenic agent in studies on ischemia, wound healing, and bone regeneration because of its ability to upregulate hypoxia-inducible factor-1 alpha (HIF-1α) and other key downstream angiogenic factors. DFO has also demonstrated antioxidant capabilities unrelated to its iron-chelating properties, making it a potential modulator of the oxidative stress involved in the inflammation response. Together, these properties make DFO a potential bioactive molecule to promote wound healing and enhance tissue integration of biomaterials in vivo. Impact Statement Deferoxamine (DFO) is approved by the Food and Drug Administration as an iron chelator and is been used to treat iron overload. Recent studies indicate that DFO may have important applications in the growing field of tissue regeneration because of its unique properties of downregulating inflammation while promoting vascularization, thereby enhancing wound healing in vivo.

Effects of a moderate iron overload and its interaction with yacon flour, and/or phytate, in the diet on liver antioxidant enzymes and hepatocyte apoptosis in rats

The effect of moderate Fe overload in the diet and its interaction with phytate, and/or yacon flour (YF), recognized as an inhibitor, and facilitator, of Fe absorption, respectively, was evaluated in healthy rats. For this purpose the following parameters were analyzed: (1) apparent iron (Fe), copper (Cu) and zinc (Zn) absorption; (2) blood Fe; (3) blood lipids (cholesterol, tryacylglicerol); (4) blood AST and ALT; (5) liver histology (histopathology, hemosiderin depots, apoptosis index; (6) liver fatty acid incorporation; (7) liver antioxidant enzyme activity. Moderate Fe overload may cause change in some liver markers (hemosiderin depots, apoptosis index and GPx) and blood lipids (total cholesterol and VLDL) and the interaction with yacon flour, and phytate, in the Fe overloaded diets may exert a protective effect on these alterations.

Serum Markers of Iron Metabolism in Chronic Liver Diseases

BACKGROUND:

Disorders in the metabolism of iron in the direction of iron overload are observed not only in primary hemochromatosis but also in some chronic liver diseases other aetiology. Elevation of serum iron, ferritin and transferrin saturation is reported in nonalcoholic fatty liver disease and alcohol, chronic hepatitis C and liver cirrhosis.

AIM:

Aim of the study was to evaluate and compare the frequency of the iron serum markers in patients with various chronic liver diseases.

MATERIAL AND METHODS:

The study included a total of 246 persons -186 patients with chronic liver disease without cirrhosis (-115 men, women -71; average age of 50.41 ± 12.85, from 23 to 77 years) and 60 healthy controls (-30 men, women -30, middle-aged 50.50 ± 11.31, from 29 to 83 years). Medical history, physical examination and demographic data including height, weight, laboratory and instrumental studies were performed.

RESULTS:

The highest incidence of elevated serum iron, transferrin saturation and ferritin and decreased serum hepcidin found in cases of alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC).

CONCLUSION:

Finally, analysis of the changes in serum markers of iron metabolism shows that the difference between healthy and sick with liver disease is primarily due to changes in alcoholic and nonalcoholic fatty liver disease, particularly steatohepatitis, and chronic hepatitis C.

Green tea activity and iron overload induced molecular fibrogenesis of rat liver

Iron overload toxicity was shown to associate with chronic liver diseases which lead to hepatic fibrosis and subsequently the progression to cancer through oxidative stress and apoptotic pathways. Green tea potential activity as chelating, anti-oxidative, or anti-apoptotic mechanisms against metal toxicity was poorly clarified. Here, we are trying to evaluate the anti-oxidant and anti-apoptotic properties of green tea in the regulation of serum hepcidin levels, reduction in iron overloads, and improve of liver fibrosis in iron overloaded experimental rats. Three groups of male adult rats were randomly classified into three groups and treated as follows: control rats, iron treated rats for two months in drinking water followed by either vehicle or green tea extract (AGTE; 100 mg/kg) treatment for 2 more months. Thereafter, we studied the effects of AGTE on iron overload-induced lipid peroxidation, anti-oxidant depletion, liver cell injury and apoptosis. Treatment of iron-overloaded rats with AGTE resulted in marked decreases in iron accumulation within liver, depletion in serum ferritin, and hepcidin levels. Iron-overloaded rats had significant increase in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver when compared to control group. Also, significant change in cytochrome c and DNA content as apoptotic markers were reported in iron treated rats. The effects of iron overload on lipid peroxidation, NO levels, cytochrome c and DNA content were significantly reduced by the intervention treatment with AGTE (P < 0.001). Furthermore, the endogenous anti-oxidant capacities/levels (TAC) in liver were also significantly decreased in chronic iron overload and administration of AGTE restored the decrease in the hepatic antioxidant activities/levels. Also, hepatic hepcidin was shown to be significantly correlated with oxidative and apoptotic relating biomarkers as well as an improvement in liver fibrosis of iron treated rats following AGTE treatment. In-vitro analysis showed that, the improvement in iron toxicity of the liver depend mainly on antioxidant and protective ability of green tea polyphenolic compounds especiallyepigallocatechin-3-gallate (EGCG). Our study showed that green tea extract (GTE) ameliorates iron overload induced hepatotoxicity, apoptosis and oxidative stress in rat liver via inhibition of hepatic iron accumulation; improve of liver antioxidant capacity, and down regulation of serum hepcidin as well as reduction in the release of apoptotic relating proteins.

Screening for hemosiderosis in patients receiving multiple red blood cell transfusions

BACKGROUND

The dramatic impact of hemosiderosis on survival in chronically transfused patients with hereditary anemia is well known. We evaluated whether patients receiving multiple red blood cell (RBC) transfusions are adequately screened for hemosiderosis.

METHODS

We retrospectively assessed hemosiderosis screening and prevalence in adult patients that received over twenty RBC units in the University Medical Centre Utrecht from 2010 till 2015. Hemosiderosis was defined as ferritin ≥1000 μg/L. Adequate screening for chronically transfused patients was defined as any ferritin determined up to 3 months before or any moment after the last transfusion, while for patients that received all transfusions within 3 months (bulk transfusion), ferritin had to be determined after at least twenty transfusions.

RESULTS

Of 471 patients, only 38.6% was adequately screened and hemosiderosis prevalence was 46.7%. Hemosiderosis prevalence was 47% in the chronic transfusion group and 12% in the bulk transfusion group. In patients transfused because of hematological malignancy or cardiothoracic surgery, respectively, 74% and 31% were adequately screened and hemosiderosis prevalence was 53% and 13%, respectively.

CONCLUSION

Hemosiderosis screening in our routine practice is suboptimal. Hemosiderosis is not an exclusive complication of multiple transfusions in the hematology ward. We recommend screening for hemosiderosis in all patients receiving multiple transfusions.

Proprotein convertase 7 rs236918 associated with liver fibrosis in Italian patients with HFE-related hemochromatosis

BACKGROUND AND AIM

p.Cys282Tyr homozygosity is the prevalent genotype in (HFE)-related Hereditary Hemochromatosis with low penetrance and variable expression. However, liver cirrhosis and hepatocellular carcinoma remain the main causes of mortality in these patients. Detection of genetic modifiers identifying patients at risk for liver damage would be relevant for their clinical management. We evaluated proprotein convertase 7 (PCSK7) rs236918 as genetic marker of risk of liver fibrosis in an Italian cohort of p.Cys282Tyr homozygotes.

METHODS

Liver fibrosis was histologically assessed by Ishak score. We evaluated PCSK7 alleles and genotypes frequencies according to single or grouped staging scores: absent/mild fibrosis (stage: 0-2), moderate (stage: 3-4), and severe fibrosis/cirrhosis (stage: 5-6). Single nucleotide polymorphism genotyping was performed by restriction fragment length polymorphism or Taqman 5'-nuclease assays.

RESULTS

The rs236918 allele C frequency increased from stages 0-2 to 5-6 (7.1% vs 13.6%, vs 21.9%, P = 0.003). The wild-type genotype was significantly more frequent in the absent/mild fibrosis group (54.2%) compared with only 17% in patients with severe fibrosis/cirrhosis. At univariate proportional odds model, patients with GC + CC genotypes were 2.77 times (P = 0.0018) more likely to have worse liver staging scores than wild-type patients. In the adjusted analysis, odds ratio was 2.37 (P = 0.0218), and 2.56 (P = 0.0233) when the analysis was restricted to males. An exploratory mediation analysis suggested a direct effect of genotype on severe fibrosis/cirrhosis (odds ratio = 3.11, P = 0.0157), and a mild non-significant indirect effect mediated through iron accounting for 28%.

CONCLUSIONS

These findings confirm that PCSK7 rs236918 C allele is a risk factor for cirrhosis development in Italian patients with HFE-Hemochromatosis.

Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis

Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n=8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth.

Heterozygous Mutations in BMP6 Pro-peptide Lead to Inappropriate Hepcidin Synthesis and Moderate Iron Overload in Humans

BACKGROUND & AIMS

Hereditary hemochromatosis is a heterogeneous group of genetic disorders characterized by parenchymal iron overload. It is caused by defective expression of liver hepcidin, the main regulator of iron homeostasis. Iron stimulates the gene encoding hepcidin (HAMP) via the bone morphogenetic protein (BMP)6 signaling to SMAD. Although several genetic factors have been found to cause late-onset hemochromatosis, many patients have unexplained signs of iron overload. We investigated BMP6 function in these individuals.

METHODS

We sequenced the BMP6 gene in 70 consecutive patients with a moderate increase in serum ferritin and liver iron levels who did not carry genetic variants associated with hemochromatosis. We searched for BMP6 mutations in relatives of 5 probands and in 200 healthy individuals (controls), as well as in 2 other independent cohorts of hyperferritinemia patients. We measured serum levels of hepcidin by liquid chromatography-tandem mass spectrometry and analyzed BMP6 in liver biopsy specimens from patients by immunohistochemistry. The functions of mutant and normal BMP6 were assessed in transfected cells using immunofluorescence, real-time quantitative polymerase chain reaction, and immunoblot analyses.

RESULTS

We identified 3 heterozygous missense mutations in BMP6 (p.Pro95Ser, p.Leu96Pro, and p.Gln113Glu) in 6 unrelated patients with unexplained iron overload (9% of our cohort). These mutations were detected in less than 1% of controls. p.Leu96Pro also was found in 2 patients from the additional cohorts. Family studies indicated dominant transmission. Serum levels of hepcidin were inappropriately low in patients. A low level of BMP6, compared with controls, was found in a biopsy specimen from 1 patient. In cell lines, the mutated residues in the BMP6 propeptide resulted in defective secretion of BMP6; reduced signaling via SMAD1, SMAD5, and SMAD8; and loss of hepcidin production.

CONCLUSIONS

We identified 3 heterozygous missense mutations in BMP6 in patients with unexplained iron overload. These mutations lead to loss of signaling to SMAD proteins and reduced hepcidin production. These mutations might increase susceptibility to mild-to-moderate late-onset iron overload.

Multitargeted inhibition of hepatic fibrosis in chronic iron-overloaded mice by Salvia miltiorrhiza

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza (SM, also known as Danshen) is a well-known Chinese medicinal herb, which has shown hepatoprotective effects with anti-fibrotic, anti-oxidative, anti-inflammatory and anti-apoptotic properties. To explore the effects and potential mechanism of SM against hepatic fibrosis induced by chronic iron overload in mice.

MATERIALS AND METHODS

Sixty male mice were randomized into five groups (n=12 in each group): control (saline), iron overload, iron overload with low-dose SM (3g/kg/day), iron overload with high-dose SM (6g/kg/day) and iron overload with deferoxamine (100mg/kg/day) groups. The iron overload model was established by intraperitoneal injection with iron dextran at 50mg/kg body weight/day, and the entire course lasted for 7 weeks. The major constituents of SM injection were quantified by high performance liquid chromatography. Changes of hepatic iron, hydroxyproline (Hyp), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed by standard procedures. Protein expression levels of type I collagen, type III collagen, tumor necrosis factor-α (TNF-α) and interleukin-1α (IL-1α) were analyzed by immunohistochemistry, and mRNA levels of transforming growth factor-β (TGF-β), matrix metal proteinase-9 (MMP-9) and caspase-3 were detected by RT-PCR. Morphological changes were observed with Prussian blue, Masson's trichrome and hematoxylin-eosin staining.

RESULTS

Treatment of chronic iron-overloaded mice with SM dose-dependently ameliorated changes in hepatic morphology and coefficient, reduced iron deposition and Hyp content, suppressed overexpression of type I collagen and type III collagen, downregulated expression of TGF-β mRNA, and upregulated expression of MMP-9 mRNA in the liver. Moreover, SM treatment contributed to decreased MDA content, increased SOD activity and GSH content, while it reduced expression of TNF-α, IL-1α and caspase-3.

CONCLUSIONS

SM displayed anti-fibrotic activity in the liver induced by chronic iron overload, which may be attributed to multitargeted inhibition of iron deposition and collagen accumulation, as well as oxidative stress, inflammation and apoptosis.

Molecular diagnosis of hemochromatosis

INTRODUCTION

The discovery of hemochromatosis genes and the availability of molecular-genetic tests considerably modified the knowledge of the disease relative to physiopathology, penetrance, and expression, and had major impact in the diagnostic settings.

AREAS COVERED

Hemochromatosis is a heterogenous disorder at both genetic and phenotypic level. The review discusses criteria to define patients' iron phenotype and to use molecular tests to diagnose HFE-related and non-HFE hemochromatosis. The material examined includes articles published in the journals covered by PubMed US National Library of Medicine. The author has been working in the field of iron overload diseases for several years and has contributed 18 of the papers cited in the references.

EXPERT OPINION

Hemochromatosis genotyping is inseparable from phenotype characterization. A full clinical assessment is needed and DNA test performed when data suggest a clear indication of suspicion of being at risk for HH. HFE testing for p.Cys282Tyr mutation and p.His63Asp variant is the first molecular diagnostic step. Genotyping for rare mutations can be offered to patients with negative first-level HFE testing who have iron overload with no other explanation and should be performed in referral centers for iron overload disorders that can provide genetic advice and in-house genotyping services.

Value of abdominal susceptibility-weighted magnetic resonance imaging for quantitative assessment of hepatic iron deposition in patients with chronic hepatitis B: comparison with serum iron markers

OBJECTIVE

To assess hepatic iron deposition quantitatively in patients with chronic hepatitis B (HBV) infection, using abdominal susceptibility-weighted magnetic resonance imaging (SWI).

METHODS

Patients with HBV infection and healthy controls underwent abdominal SWI and were assessed for serum iron markers. Phase values were measured and five grades of hepatic iron deposition were described by SWI.

RESULTS

Patients with HBV infection (n = 327) and healthy controls (n = 50) were prospectively enrolled. In total, 77 (25.4%) patients with HBV infection had hepatic iron deposition as determined by SWI. Phase values were significantly different between patients with hepatic iron deposition compared with patients without hepatic iron deposition or controls, and were significantly different across different grades of hepatic iron deposition. Serum iron, ferritin, transferrin and transferrin saturation were significantly higher in patients with, versus those without, hepatic iron deposition. Only serum ferritin was significantly different across different grades of hepatic iron deposition, and there was a low inverse correlation between serum ferritin and phase values.

CONCLUSIONS

Compared with serum iron markers, abdominal SWI may represent a powerful tool to assess hepatic iron deposition quantitatively in patients with chronic HBV infection.

CYBRD1 as a modifier gene that modulates iron phenotype in HFE p.C282Y homozygous patients

BACKGROUND

Most patients with hereditary hemochromatosis in the Caucasian population are homozygous for the p.C282Y mutation in the HFE gene. The penetrance and expression of hereditary hemochromatosis differ largely among cases of homozygous p.C282Y. Genetic factors might be involved in addition to environmental factors.

DESIGN AND METHODS

In the present study, we analyzed 50 candidate genes involved in iron metabolism and evaluated the association between 214 single nucleotide polymorphisms in these genes and three phenotypic outcomes of iron overload (serum ferritin, iron removed and transferrin saturation) in a large group of 296 p.C282Y homozygous Italians. Polymorphisms were tested for genetic association with each single outcome using linear regression models adjusted for age, sex and alcohol consumption.

RESULTS

We found a series of 17 genetic variants located in different genes with possible additive effects on the studied outcomes. In order to evaluate whether the selected polymorphisms could provide a predictive signature for adverse phenotype, we re-evaluated data by dividing patients in two extreme phenotype classes based on the three phenotypic outcomes. We found that only a small improvement in prediction could be achieved by adding genetic information to clinical data. Among the selected polymorphisms, a significant association was observed between rs3806562, located in the 5'UTR of CYBRD1, and transferrin saturation. This variant belongs to the same haplotype block that contains the CYBRD1 polymorphism rs884409, found to be associated with serum ferritin in another population of p.C282Y homozygotes, and able to modulate promoter activity. A luciferase assay indicated that rs3806562 does not have a significant functional role, suggesting that it is a genetic marker linked to the putative genetic modifier rs884409.

CONCLUSIONS

While our results support the hypothesis that polymorphisms in genes regulating iron metabolism may modulate penetrance of HFE-hereditary hemochromatosis, with emphasis on CYBRD1, they strengthen the notion that none of these polymorphisms alone is a major modifier of the phenotype of hereditary hemochromatosis.

Insulin promotes iron uptake in human hepatic cell by regulating transferrin receptor-1 transcription mediated by hypoxia inducible factor-1

Hepatic iron is known to regulate insulin signaling pathways and to influence insulin sensitivity in insulin resistance (IR) patients. However, the role of insulin on hepatic iron homeostasis remains unexplored. Here, we report that insulin promotes transferrin-bound iron uptake but shows no influence on non transferrin-bound iron uptake in human hepatic HepG2 cells. As a mechanism we detected increased transferrin receptor-1 (TfR1) expression both at protein and mRNA levels. Unaltered stability of protein and transcript of TfR1 suggested the regulation at transcriptional level that was confirmed by promoter activity. Involvement of transcription factor hypoxia inducible factor-1 (HIF-1) was shown by mutational analyses of the TfR1 promoter region and by electrophoretic mobility shift assay. When HepG2 cells were transfected with specific siRNA targeted to 3'UTR of HIF-1α, the regulatory subunit of HIF-1; insulin-induced TfR1 expression and iron uptake were inhibited. Transfection of cDNA expressing stable form of HIF-1α reversed the increased TfR1 expression and iron uptake. These results suggest a novel role of insulin in hepatic iron uptake by a HIF-1 dependent transcriptional regulation of TfR1.

The prognostic role of hemochromatosis H63D allele in allogeneic hematopoietic stem cell transplantation

Iron overload is considered as a significant cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. The presence of hemochromatosis gene (HFE) mutations might exacerbate iron toxicity in the post-transplant setting. This prospective study was planned to evaluate the genetic spectrum of HFE mutations in Turkish patients undergoing HSCT and the impact of HFE genotype on transplant morbidity and mortality. HFE genotypes of 102 patients [median age, 27.5 years (16-64 years); male/female, 73:29], who underwent allogeneic HSCT, were analyzed. Twenty-two patients were heterozygous and 1 patient was homozygous for the H63D mutation, while the C282Y mutation was observed in none of our patients. The frequency of invasive fungal infections (IFI) was significantly higher in H63D-mutated patients (p=0.004). H63D mutation was identified as an independent risk factor for the development of IFI (p=0.006, OR=0.554, SE=0.208), without an impact on overall survival and transplant-related mortality. The multifactorial iron-overloaded state in HSCT recipients might affect the phenotypic expression of HFE mutations and alter the severity of clinical presentation. The impact of HFE genotype on iron parameters and transplant-related morbidity and mortality should be validated with further studies.

Synthetic and natural iron chelators: therapeutic potential and clinical use

Iron-chelation therapy has its origins in the treatment of iron-overload syndromes. For many years, the standard for this purpose has been deferoxamine. Recently, considerable progress has been made in identifying synthetic chelators with improved pharmacologic properties relative to deferoxamine. Most notable are deferasirox (Exjade(®)) and deferiprone (Ferriprox(®)), which are now available clinically. In addition to treatment of iron overload, there is an emerging role for iron chelators in the treatment of diseases characterized by oxidative stress, including cardiovascular disease, atherosclerosis, neurodegenerative diseases and cancer. While iron is not regarded as the underlying cause of these diseases, it does play an important role in disease progression, either through promotion of cellular growth and proliferation or through participation in redox reactions that catalyze the formation of reactive oxygen species and increase oxidative stress. Thus, iron chelators may be of therapeutic benefit in many of these conditions. Phytochemicals, many of which bind iron, may also owe some of their beneficial properties to iron chelation. This review will focus on the advances in iron-chelation therapy for the treatment of iron-overload disease and cancer, as well as neurodegenerative and chronic inflammatory diseases. Established and novel iron chelators will be discussed, as well as the emerging role of dietary plant polyphenols that effectively modulate iron biochemistry.

Cardiovascular MRI for the assessment of heart failure: focus on clinical management and prognosis

Cardiovascular MR (CMR) has an emerging role in the noninvasive diagnostic assessment of heart failure (HF). Different imaging sequences allow for a detailed assessment of cardiac morphology, function, myocardial perfusion, tissue characterization, and blood flow measurement. This article reviews the key applications of CMR in HF, with special focus on how CMR may influence the diagnostic and therapeutic approach of HF patients.

Effect of suppressor of cytokine signaling on hepcidin production in hepatitis C virus replicon cells

AIM

  Hepcidin is a key regulator of systemic iron metabolism and its expression is modulated by hepatitis C virus (HCV) infection. Suppressor of cytokine signaling 1 (SOCS-1) and SOCS-3 act as negative regulators of the Jak/signal transducers and activators of transcription signaling pathway. In this study, we investigated how HCV infection modulates SOCS-1 and SOCS-3 production and how these SOCS proteins affect hepcidin production.

METHODS

  The effects of SOCS-1 and SOCS-3 on hepcidin production were investigated using a complete genome, HCV replicon system.

RESULTS

  Unexpectedly, basal expression levels of hepcidin (HAMP) mRNA and the bioactive form of hepcidin protein, hepcidin-25, were significantly higher in replicon cells. Regardless of HCV infection, STAT3 was activated in response to interleukin-6 (IL-6), but this activation was greater in replicon cells than in cured cells. Basal expression of the SOCS-3 protein was enhanced, but basal expression of SOCS-1 protein was reduced, in replicon cells. Expression of SOCS-3 increased dramatically in response to IL-6 stimulation but expression of SOCS-1 was not induced by IL-6. Interestingly, silencing of SOCS-1 and SOCS-3 gene expression enhanced STAT3 activation and HAMP gene expression. In addition, overexpression of SOCS-1 protein strongly suppressed STAT3 activation and HAMP gene expression.

CONCLUSIONS

  This in vitro study shows that SOCS-3 expression was enhanced but SOCS-1 expression was reduced by HCV infection. The upregulation of hepcidin induced by IL-6 was found to be negatively regulated by SOCS-1 and SOCS-3. The modulation of SOCS1 and SOCS3 in HCV-infected hepatocytes may explain, at least in part, the relative shortage of hepcidin production in CH-C.

Serum hepcidin levels are related to the severity of liver histological lesions in chronic hepatitis C

Hepcidin is synthesized in the liver and has a crucial role in iron homoeostasis. Its synthesis is up-regulated in chronic inflammation and iron excess. We examined the determinants of serum hepcidin and liver hepcidin mRNA levels and their association with histological lesions in patients with chronic hepatitis C (CHC) and healthy controls. We studied 96 patients with CHC and 30 controls. Serum hepcidin levels were measured by an in-house competitive ELISA. Hepcidin mRNA levels were determined by a one-step qRT-PCR in total RNA extracted from liver biopsy specimens of 27 patients with CHC and six disease controls. Histological lesions were evaluated according to Ishak's classification. Serum hepcidin was significantly lower in patients with CHC than healthy controls (14.6 ± 7.3 vs 34.6 ± 17.3 ng/mL, P < 0.001). In patients with CHC, serum hepcidin correlated positively with aspartate aminotransferase (r = 0.334, P = 0.001) and insulin resistance (r = 0.27, P = 0.016) and had a trend for correlation with alanine aminotransferase (r = 0.197, P = 0.057) and serum haemoglobin (r = 0.188, P = 0.067) but not with ferritin. A significant positive correlation was also found between serum hepcidin levels and both necroinflammation (r = 0.259, P = 0.011) and fibrosis (r = 0.214, P = 0.036). Serum hepcidin was among others an independent predictor of cirrhosis (odds ratio: 1.145, P = 0.039). Liver hepcidin mRNA levels did not differ between patients and controls and were relatively lower in patients with than without cirrhosis (19.3 ± 21.7 vs 38.3 ± 26.0, P = 0.067). Patients with CHC have reduced serum hepcidin levels, which correlate with worse necroinflammation and fibrosis. The previously mentioned observations suggest a viral effect on hepatic hepcidin production, but might also support its involvement in the inflammatory process.

Haemochromatosis genotype and iron overload: association with hypertension and left ventricular hypertrophy

OBJECTIVE

We hypothesized that there is an association between haemochromatosis genotype C282Y/C282Y and/or iron overload and risk of hypertension and/or left ventricular hypertrophy (LVH).

METHODS

We analysed data from a cross-sectional study of the general population including 8992 individuals from the Copenhagen City Heart Study (CCHS), a follow-up study of 36,480 individuals from the Copenhagen General Population Study (CGPS), and a case-only study of 3815 Scandinavians from the Losartan Intervention For End-point Reduction in Hypertension Genetic Substudy (LIFEGEN) with LVH and hypertension.

RESULTS

In the CCHS, individuals with C282Y/C282Y versus wild type/wild type had an odds ratio for antihypertensive medication use of 4.8 (1.8-13; P = 0.003). In the CGPS, the corresponding hazard ratio was 1.7 (1.0-2.3; P = 0.003). Also, hazard ratios for antihypertensive medication use in the CGPS were 1.6 (1.0-2.6; P = 0.05) for transferrin saturation > or =80% vs. <50%, and 2.3 (1.3-4.2; P = 0.005) for C282Y/C282Y + transferrin saturation > or =80% vs. wild type/wild type + transferrin saturation <50%. These results were most pronounced in men above 55 years of age. We did not find any association between C282Y/C282Y or iron overload and LVH or hypertension (measured as blood pressure at a single occasion or continuous blood pressure), or LVH with hypertension in the CCHS or with severity of LVH in LIFEGEN.

CONCLUSIONS

We found that haemochromatosis genotype C282Y/C282Y and extremely elevated transferrin saturation either separately or combined were associated with increased risk of antihypertensive medication use. Therefore, testing for haemochromatosis genotype C282Y/C282Y and extreme transferrin saturation could be considered in patients with essential hypertension.

Hepcidin treatment in Hfe-/- mice diminishes plasma iron without affecting erythropoiesis

BACKGROUND

Iron is essential for mammalian metabolism and its cellular concentration is controlled by regulating its acquisition and storage. Haemochromatosis is a condition involving iron overload that is characterised by increased duodenal iron absorption and a progressive accumulation of iron in vital organs. Hepcidin is the main hormone that regulates iron homoestasis and it is secreted by the liver.

MATERIALS AND METHODS

We have studied how extended hepcidin administration affects the iron load status, plasma and tissue iron concentration, erythropoiesis and the expression of proteins involved on iron homeostasis in haemochromatotic (Hfe(-/-)) and wild-type mice.

RESULTS

Hepcidin reverted the high plasma iron concentrations in Hfe(-/-) mice to normal values. The high concentration of hepatic iron was not altered in the liver of these Hfe(-/-) mice. Hepcidin administration did not disturb erythropoiesis in either Hfe(-/-) or wild-type mice and likewise, hepcidin did not modify the expression of any protein analysed in the liver, duodenum or spleen of Hfe(-/-) and wild-type mice. These data confirm that hepcidin administration diminishes plasma iron concentrations.

CONCLUSION

Treatment with sustained doses of hepcidin diminishes plasma iron concentrations in Hfe(-/-) mice.

HFE mutations in alpha-1-antitrypsin deficiency: an examination of cirrhotic explants

Increased iron deposition is often seen in liver explants with alpha-1-antitrypsin deficiency, but it remains unclear if this is a nonspecific effect of end-stage liver disease or if individuals with alpha-1-antitrypsin deficiency and excess iron are at increased risk for HFE mutations. To further examine this question, 45 liver explants with alpha-1-antitrypsin deficiency and 33 control livers with chronic hepatitis C were examined for histological iron accumulation, graded on a scale of 0 to 4+, and HFE mutations. Interestingly, the alpha-1-antitrypsin cirrhotic livers showed a bimodal distribution of iron accumulation, with peaks at grades 1 and 3. In contrast, hepatitis C cirrhotic livers showed a unimodal distribution with a peak at grade 2. HFE mutations in livers with alpha-1-antitrypsin deficiency were as follows: C282Y=2%, H63D=42%. H63D mutations were more frequent in alpha-1-antitrypsin deficiency cases than in controls (42 vs 27%), but was not statistically significant, P=0.17. However, there was a significant association with HFE mutations in alpha-1-antitrypsin deficiency livers with grade 3+ or 4+ iron, P=0.02. In contrast, livers with hepatitis C showed a similar frequency of HFE mutations as the general population: C282Y=15%, H63D=27%. A rare S65C mutation and a novel A271S mutation were also found in this study; the latter patient had 4+ iron in the liver and later developed heart failure with cardiac iron. In conclusion, total H63D mutations were high (42%) in cirrhotics with alpha-1-antitrypsin deficiency and there was a significant association between HFE mutations and high levels of iron accumulation.

The role of MR imaging in detection of hepatic iron overload in patients with cirrhosis of different origins

Background

There are many pathological conditions with hepatic iron overload. Classical definite diagnostic methods of these disorders are invasive and based on a direct tissue biopsy material. For the last years the role of MR imaging in liver diagnostics has been increasing. MRI shows changes of liver intensity in patients with hepatic iron overload. Changes in MR signal are an indirect consequence of change of relaxation times T2 and T2*, that can be directly measured.

The purpose of the study was to evaluate usefulness of MR imaging in the detection of hepatic iron overload in patients with cirrhosis of different origins.

Methods

MR imaging at 1.5T was prospectively performed in 44 patients with liver cirrhosis who had undergone liver biopsy with histopathological assessment of hepatic iron deposits. In all patients the following sequences were used: SE, Express, GRE in T2 and T1-weighted images. Signal intensity (SI) was measured on images obtained with each T2 weighted sequence by means of regions of interest, placed in the liver and paraspinal muscles. The correlation between iron overload, histopathological score, serum ferritin and SI ratio was analyzed.

Results

In 20 patients with iron overload confirmed by the biopsy, the liver parenchyma demonstrated lower signal intensity than that of paraspinal muscles. This effect was visible only in 8 patients with hepatic iron overload in Express T2-weighted images. Higher signal intensity of liver than that of skeletal muscles on GRE - T2 weighted images was noted in 24 patients with cirrhosis and without elevated hepatic iron concentration. We observed a correlation between low and high iron concentration and liver to muscle SI ratio.

Conclusion

MR imaging is a useful and fast noninvasive diagnostic tool for the detection of liver iron overload in patients with cirrhosis of different origins.

Liver to muscle SI ratio in GRE-T2-weighted sequence facilitates to differentiate patients with low and high degree of hepatic iron overload, which correlates with the origin of liver cirrhosis.

Pharmacological actions of curcumin in liver diseases or damage

Since 1900 bc, several therapeutic activities have been attributed to the rhizomes of the plant Curcuma longa for a variety of diseases, including liver disorders. Curcumin, the main active compound obtained from this plant, was first isolated two centuries ago and its structure as diferuloylmethane was determined in 1910. Curcumin has shown anti-inflammatory, anti-oxidant, antifungal, antibacterial and anticancer activities. The pharmacological properties of curcumin were reviewed recently and focused mainly on its anticancer properties. However, its beneficial activity on liver diseases (known centuries ago, and demonstrated recently utilizing animal models) has not being reviewed in depth until now. The curcumin ability to inhibit several factors like nuclear factor-kappaB, which modulates several pro-inflammatory and profibrotic cytokines as well as its anti-oxidant properties, provide a rational molecular basis to use it in hepatic disorders. Curcumin attenuates liver injury induced by ethanol, thioacetamide, iron overdose, cholestasis and acute, subchronic and chronic carbon tetrachloride (CCl(4)) intoxication; moreover, it reverses CCl(4) cirrhosis to some extent. Unfortunately, the number of studies of curcumin on liver diseases is still very low and investigations in this area must be encouraged because hepatic disorders constitute one of the main causes of worldwide mortality.

Hepcidin modulation in human diseases: From research to clinic

By modulating hepcidin production, an organism controls intestinal iron absorption, iron uptake and mobilization from stores to meet body iron need. In recent years there has been important advancement in our knowledge of hepcidin regulation that also has implications for understanding the physiopathology of some human disorders. Since the discovery of hepcidin and the demonstration of its pivotal role in iron homeostasis, there has been a substantial interest in developing a reliable assay of the hormone in biological fluids. Measurement of hepcidin in biological fluids can improve our understanding of iron diseases and be a useful tool for diagnosis and clinical management of these disorders. We reviewed the literature and our own research on hepcidin to give an updated status of the situation in this rapidly evolving field.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Current approach to hemochromatosis

Iron overload diseases of genetic origin are an ever changing world, due to major advances in genetics and molecular biology. Five major categories are now established: HFE-related or type1 hemochromatosis, frequently found in Caucasians, and four rarer diseases which are type 2 (A and B) hemochromatosis (juvenile hemochromatosis), type 3 hemochromatosis (transferrin receptor 2 hemochromatosis), type 4 (A and B) hemochromatosis (ferroportin disease), and a(hypo)ceruloplasminemia. Increased duodenal iron absorption and enhanced macrophagic iron recycling, both due to an impairment of hepcidin synthesis, account for the development of cellular excess in types 1, 2, 3, and 4B hemochromatosis whereas decreased cellular iron egress is involved in the main form of type 4A) hemochromatosis and in aceruloplasminemia. Non-transferrin bound iron plays an important role in cellular iron excess and damage. The combination of magnetic resonance imaging (for diagnosing visceral iron overload) and of genetic testing has drastically reduced the need for liver biopsy. Phlebotomies remain an essential therapeutic tool but the improved understanding of the intimate mechanisms underlying these diseases paves the road for innovative therapeutic approaches.