A Conserved Tyrosine in Ferritin Is a Molecular Capacitor

A highly conserved tyrosine residue of unknown function is present in the vicinity of the di‐iron catalytic center of the ubiquitous iron‐storage protein ferritin. The di‐iron center with a gateway Fe^II/Fe^III‐binding site nearby provides the vital iron‐storage mechanism of the protein. It is believed that, in eukaryotic ferritin, this center catalyzes simultaneous oxidation of two Fe^II ions, whereas in microbial ferritin it catalyzes simultaneous oxidation of three Fe^II ions. To understand the role of the conserved tyrosine, we studied the intermediates and products that are formed during catalysis of Fe^II oxidation in the di‐iron catalytic centers of the hyperthermophilic archaeal Pyrococcus furiosus ferritin and of eukaryotic human H ferritin. Based on our spectroscopic studies and modeling, we propose a merger of the models for eukaryotic and bacterial ferritin into a common mechanism of Fe^II oxidation in which the conserved tyrosine acts as a single‐electron molecular capacitor to facilitate oxidation of Fe^II.     

Is Correction of Iron Deficiency a New Addition to the Treatment of the Heart Failure?

Anemia is present in about 40% of heart failure (HF) patients. Iron deficiency (ID) is present in about 60% of the patients with anemia (about 24% of all HF patients) and in about 40% of patients without anemia (about 24% of all HF patients). Thus ID is present in about half the patients with HF. The ID in HF is associated with reduced iron stores in the bone marrow and the heart. ID is an independent risk factor for severity and worsening of the HF. Correction of ID with intravenous (IV) iron usually corrects both the anemia and the ID. Currently used IV iron preparations are very safe and effective in treating the ID in HF whereas little information is available on the effectiveness of oral iron. In HF IV iron correction of ID is associated with improvement in functional status, exercise capacity, quality of life and, in some studies, improvement in rate of hospitalization for HF, cardiac structure and function, and renal function. Large long-term adequately-controlled intervention studies are needed to clarify the effect of IV iron in HF. Several heart associations suggest that ID should be routinely sought for in all HF patients and corrected if present. In this paper we present our approach to diagnosis and treatment of iron deficiency in heart failure.     

Availability of Ferritin-Bound Iron to Enterobacteriaceae

The sequestration of iron in case of infection, termed nutritional immunity, is an established strategy of host defense. However, the interaction between pathogens and the mammalian iron storage protein ferritin is hitherto not completely understood. To better characterize the function of ferritin in Gram-negative infections, we incubated iron-starved cultures of Salmonella Typhimurium and knockout mutant strains defective for major iron uptake pathways or Escherichia coli with horse spleen ferritin or ionic iron as the sole iron source. Additionally, we added bovine superoxide dismutase and protease inhibitors to the growth medium to assess the effect of superoxide and bacterial proteases, respectively, on Salmonella proliferation and reductive iron release. Compared to free ionic iron, ferritin-bound iron was less available to Salmonella, but was still sufficient to significantly enhance the growth of the bacteria. In the absence of various iron acquisition genes, the availability of ferritin iron further decreased. Supplementation with superoxide dismutase significantly reduced the growth of the ΔentC knockout strain with holoferritin as the sole iron source in comparison with ionic ferrous iron. In contrast, this difference was not observed in the wildtype strain, suggesting that superoxide dismutase undermines bacterial iron uptake from ferritin by siderophore-independent mechanisms. Ferritin seems to diminish iron availability for bacteria in comparison to ionic iron, and its iron sequestering effect could possibly be enhanced by host superoxide dismutase activity.     

MiR-7-5p Is Involved in Ferroptosis Signaling and Radioresistance Thru the Generation of ROS in Radioresistant HeLa and SAS Cell Lines

In cancer therapy, radioresistance or chemoresistance cells are major problems. We established clinically relevant radioresistant (CRR) cells that can survive over 30 days after 2 Gy/day X-ray exposures. These cells also show resistance to anticancer agents and hydrogen peroxide (H₂O₂). We have previously demonstrated that all the CRR cells examined had up-regulated miR-7-5p and after miR-7-5p knockdown, they lost radioresistance. However, the mechanism of losing radioresistance remains to be elucidated. Therefore, we investigated the role of miR-7-5p in radioresistance by knockdown of miR-7-5p using CRR cells. As a result, knockdown of miR-7-5p increased reactive oxygen species (ROS), mitochondrial membrane potential, and intracellular Fe²⁺ amount. Furthermore, miR-7-5p knockdown results in the down-regulation of the iron storage gene expression such as ferritin, up-regulation of the ferroptosis marker ALOX12 gene expression, and increases of Liperfluo amount. H₂O₂ treatment after ALOX12 overexpression led to the enhancement of intracellular H₂O₂ amount and lipid peroxidation. By contrast, miR-7-5p knockdown seemed not to be involved in COX-2 and glycolysis signaling but affected the morphology of CRR cells. These results indicate that miR-7-5p control radioresistance via ROS generation that leads to ferroptosis.     

Coordination structures of organically bound paramagnetic metals in coal and their transformation upon solvent extraction

In this paper the organically bound paramagnetic (transition) metals (Fe, Cr, Mn, Co, Ni, V, Zn and Cu) were studied by a combination of sequential acid leaching and electron spin resonance spectroscopy. Additional investigation was also conducted on the occurrence of these metals in coal extracts generated by solvent extraction at 360 °C. The results indicate that, a sequential leaching by acetic acid (1 M), HCl (3 M), HNO₃ (2 M) and HF (48%) can remove most the inorganic species in a coal. The remaining elements are mainly transition metals. Of those, Fe is the most prevalent, which is mainly present as octahedral Fe³⁺ complex associated with phenolic hydroxyl or nitrogen-bearing functional groups. Nanometric ferric oxide/hydroxide and highly ordered Fe-rich crystals were also observed in coal extract. They are finely dispersed in the closed voids in the carbonaceous matrix, which may have been of biological origin, such as ferritin iron in proteins and iron porphyrin complexes that have undergone complex transformation during coalification. The water-derived colloidal iron phase can be one possible source as well. Regarding the other transition metals, they mostly have the hyperfine configurations that co-exist with Fe. The amounts of these organically bound species may depend on coal rank, but their relationship has not been clarified yet. Comparison between acid-washed coal and the respective coal extract also indicates the non-uniform distribution of organically bound transition metals within coal matrix.     

Integrins Increase Sarcoplasmic Reticulum Activity for Excitation—Contraction Coupling in Human Stem Cell-Derived Cardiomyocytes

Engagement of the sarcoplasmic reticulum (SR) Ca²⁺ stores for excitation–contraction (EC)-coupling is a fundamental feature of cardiac muscle cells. Extracellular matrix (ECM) proteins that form the extracellular scaffolding supporting cardiac contractile activity are thought to play an integral role in the modulation of EC-coupling. At baseline, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) show poor utilisation of SR Ca²⁺ stores, leading to inefficient EC-coupling, like developing or human CMs in cardiac diseases such as heart failure. We hypothesised that integrin ligand–receptor interactions between ECM proteins and CMs recruit the SR to Ca²⁺ cycling during EC-coupling. hiPSC-CM monolayers were cultured on fibronectin-coated glass before 24 h treatment with fibril-forming peptides containing the integrin-binding tripeptide sequence arginine–glycine–aspartic acid (2 mM). Micropipette application of 40 mM caffeine in standard or Na⁺/Ca²⁺-free Tyrode’s solutions was used to assess the Ca²⁺ removal mechanisms. Microelectrode recordings were conducted to analyse action potentials in current-clamp. Confocal images of labelled hiPSC-CMs were analysed to investigate hiPSC-CM morphology and ultrastructural arrangements in Ca²⁺ release units. This study demonstrates that peptides containing the integrin-binding sequence arginine–glycine–aspartic acid (1) abbreviate hiPSC-CM Ca²⁺ transient and action potential duration, (2) increase co-localisation between L-type Ca²⁺ channels and ryanodine receptors involved in EC-coupling, and (3) increase the rate of SR-mediated Ca²⁺ cycling. We conclude that integrin-binding peptides induce recruitment of the SR for Ca²⁺ cycling in EC-coupling through functional and structural improvements and demonstrate the importance of the ECM in modulating cardiomyocyte function in physiology.     

Structural Insights into Iron Ions Accumulation in Dps Nanocage

Dps (DNA-binding protein from starved cells) is well known for the structural protection of bacterial DNA by the formation of highly ordered intracellular assemblies under stress conditions. Moreover, this ferritin-like protein can perform fast oxidation of ferrous ions and subsequently accumulate clusters of ferric ions in its nanocages, thus providing the bacterium with physical and chemical protection. Here, cryo-electron microscopy was used to study the accumulation of iron ions in the nanocage of a Dps protein from Escherichia coli. We demonstrate that Fe²⁺ concentration in the solution and incubation time have an insignificant effect on the volume and the morphology of iron minerals formed in Dps nanocages. However, an increase in the Fe²⁺ level leads to an increase in the proportion of larger clusters and the clusters themselves are composed of discrete ~1–1.5 nm subunits.     

Binding of Citrate-Fe3+ to Plastic Culture Dishes,an Artefact Useful as a Simple Technique to Screen for New Iron Chelators

NaCT mediates citrate uptake in the liver cell line HepG2. When these cells were exposed to iron (Fe³⁺), citrate uptake/binding as monitored by the association of [¹⁴C]-citrate with cells increased. However, there was no change in NaCT expression and function, indicating that NaCT was not responsible for this Fe³⁺-induced citrate uptake/binding. Interestingly however, the process exhibited substrate selectivity and saturability as if the process was mediated by a transporter. Notwithstanding these features, subsequent studies demonstrated that the iron-induced citrate uptake/binding did not involve citrate entry into cells; instead, the increase was due to the formation of citrate-Fe³⁺ chelate that adsorbed to the cell surface. Surprisingly, the same phenomenon was observed in culture wells without HepG2 cells, indicating the adsorption of the citrate-Fe³⁺ chelate to the plastic surface of culture wells. We used this interesting phenomenon as a simple screening technique for new iron chelators with the logic that if another iron chelator is present in the assay system, it would compete with citrate for binding to Fe³⁺ and prevent the formation and adsorption of citrate-Fe³⁺ to the culture well. This technique was validated with the known iron chelators deferiprone and deferoxamine, and with the bacterial siderophore 2,3-dihydroxybenzoic acid and the catechol carbidopa.     

On Iron Metabolism and Its Regulation

Iron is a critical metal for several vital biological processes. Most of the body’s iron is bound to hemoglobin in erythrocytes. Iron from senescent red blood cells is recycled by macrophages in the spleen, liver and bone marrow. Dietary iron is taken up by the divalent metal transporter 1 (DMT1) in enterocytes and transported to portal blood via ferroportin (FPN), where it is bound to transferrin and taken up by hepatocytes, macrophages and bone marrow cells via transferrin receptor 1 (TfR1). While most of the physiologically active iron is bound hemoglobin, the major storage of most iron occurs in the liver in a ferritin-bound fashion. In response to an increased iron load, hepatocytes secrete the peptide hormone hepcidin, which binds to and induces internalization and degradation of the iron transporter FPN, thus controlling the amount of iron released from the cells into the blood. This review summarizes the key mechanisms and players involved in cellular and systemic iron regulation.     

Use of NaX porous materials in the recovery of iron ions

Nowadays, the porous materials have an economic impact in certain industrial fields and particularly that of the environment. NaX materials economically prove very interesting; small quantities of these last are enough to treat great toxic volumes of effluent. This work aims at the use of NaX solid materials in the recovery of the ions iron poisons and vermin to the environment. We used a treatment process based on ions exchange reactions. Several parameters related to these operations of treatment were studied and the used materials are types of NaX faujasites. The obtained results show that NaX faujasite and its hydrogenated form NaHX can be used like ion exchangers in the recovery of the ions iron Fe³⁺. NaX and NaHX materials preserve their crystalline structures during the treatment process until 0.2 mol/l Fe³⁺ concentrations.     

Effect of dietary di-2-ethylhexyl phthalate on oxidation of14C-palmitoyl CoA by mitochondria from mammalian heart and liver

Oxidation of [1-¹⁴C] palmitoyl CoA by heart and liver mitochondria from rats fed dietary di-2-ethylhexyl phthalate (DEHP) was investigated in vitro. Oxidation of¹⁴C-palmitoyl CoA to¹⁴CO₂ increased two- to threefold in hepatic mitochondria from rats fed 0.1% DEHP for 2 to 3 days; this increase appeared to be a maximum response since similar data were obtained using hepatic mitochondria from rats receiving 0.5% or 1.0% DEHP in the diet. The response of hepatic mitochondria to DEHP was found to continue throughout the duration of 35-day trials in which 1.0% DEHP was fed. In contrast to hepatic mitochondria, the oxidation of¹⁴C-palmitoyl CoA by heart mitochondria decreased ca. 40% upon addition of 0.1% or 0.5% DEHP to the diet; this effect of DEHP on heart mitochondria was not sustained beyond ca. 8 days of DEHP feeding. Limited studies were also performed in rabbits and pigs. Oxidation of¹⁴C-palmitoyl CoA was increased ca. twofold in hepatic mitochondria from rabbits fed 1% dietary DEHP for 12 days and in hepatic mitochondria from pigs that received 5 doses of DEHP (0.8g/kg) at 12-hr intervals; the oxidation¹⁴C-palmitoyl CoA by heart mitochondria from these same animals was unchanged in the rabbit but increased an average of 37% in the pig. DEHP feeding to rats was associated with increased yields of hepatic mitochondrial protein; standardized preparations of heart mitochondria were not similarly affected.     

Different degrees of moderate iron deficiency modulate lipid metabolism of rats

Severe iron deficiency affects lipid metabolism. To investigate whether moderate iron depletion also alters lipid variables—including lipid levels in serum and liver, hepatic lipogenesis, and fatty acid composition indicative of an impaired desaturation—we carried out experiments with rats fed 9, 13, and 18 mg iron/kg diet over a total of 5 wk. The study also included three pair-fed control groups and an ad libitum control group, fed with 50 mg iron/kg diet. The iron-depleted rats were classified as iron-deficient on the basis of reduced serum iron, hemoglobin concentration, and hematocrit. All moderately iron-deficient rats had significantly lower cholesterol concentrations in liver and serum lipoproteins than their pair-fed controls. Rats with the lowest dietary iron supply had higher concentrations of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE), lower activities of glucose-6-phosphate dehydrogenase, malic enzyme and fatty acid synthase, and higher triacylglycerol concentrations in serum lipoproteins than the corresponding pair-fed control rats. Moderate iron deficiency also depressed the serum phospholipid level. Moreover, several consistent significant differences in fatty acid composition of hepatic PC and PE occurred within moderate iron deficiency, which indicate impaired desaturation by Δ-9 and Δ-6 desaturases of saturated and essential fatty acids. We conclude that lipid variables, including cholesterol in liver and serum lipoproteins as well as fatty acid desaturation, reflect the gradations of iron status best and can be used as an indicator of the degree of moderate iron deficiency.     

Ferritin Assembly in Enterocytes of Drosophila melanogaster

Ferritins are protein nanocages that accumulate inside their cavity thousands of oxidized iron atoms bound to oxygen and phosphates. Both characteristic types of eukaryotic ferritin subunits are present in secreted ferritins from insects, but here dimers between Ferritin 1 Heavy Chain Homolog (Fer1HCH) and Ferritin 2 Light Chain Homolog (Fer2LCH) are further stabilized by disulfide-bridge in the 24-subunit complex. We addressed ferritin assembly and iron loading in vivo using novel transgenic strains of Drosophila melanogaster. We concentrated on the intestine, where the ferritin induction process can be controlled experimentally by dietary iron manipulation. We showed that the expression pattern of Fer2LCH-Gal4 lines recapitulated iron-dependent endogenous expression of the ferritin subunits and used these lines to drive expression from UAS-mCherry-Fer2LCH transgenes. We found that the Gal4-mediated induction of mCherry-Fer2LCH subunits was too slow to effectively introduce them into newly formed ferritin complexes. Endogenous Fer2LCH and Fer1HCH assembled and stored excess dietary iron, instead. In contrast, when flies were genetically manipulated to co-express Fer2LCH and mCherry-Fer2LCH simultaneously, both subunits were incorporated with Fer1HCH in iron-loaded ferritin complexes. Our study provides fresh evidence that, in insects, ferritin assembly and iron loading in vivo are tightly regulated.     

Development of iron oxide sorbents for Hg removal from coal derived fuel gas: Sulfidation characteristics of iron oxide sorbents and activity for COS formation during Hg removal

The aim of this study is to develop a process for the removal of Hg⁰ using H₂S over iron oxides sorbents, which will be located just before the wet desulfurization unit and catalytic COS converter of a coal gasification system. It is necessary to understand the reactions between the iron oxide sorbent and other components of the fuel gas such as H₂S, CO, H₂, H₂O, etc. In this study, the sulfidation behavior and activity for COS formation during Hg⁰ removal from coal derived fuel gas over iron oxides prepared by precipitation and supported iron oxide (1 wt% Fe₂O₃/TiO₂) prepared by conventional impregnation were investigated. The iron oxide samples were dried at 110 °C (designated as Fe₂O₃-110) and calcined at 300 and 550 °C (Fe₂O₃-300 and Fe₂O₃-550). The sulfidation behavior of iron oxide sorbents in coal derived fuel gas was investigated by thermo-gravimetric analysis (TGA). COS formation during Hg⁰ removal over iron oxide sorbents was also investigated using a laboratory-scale fixed-bed reactor. It was seen that the Hg⁰ removal activity of the sorbents increased with the decrease of calcinations temperature of iron oxide and extent of sulfidation of the sorbents also increased with the decrease of calcination temperature. The presence of CO suppressed the weight gain of iron oxide due to sulfidation. COS was formed during the Hg⁰ removal experiments over Fe₂O₃-110. However, in the cases of calcined iron oxides (Fe₂O₃-300, Fe₂O₃-550) and 1 wt% Fe₂O₃/TiO₂, formation of COS was not observed but the Hg⁰ removal activity of 1 wt% Fe₂O₃/TiO₂ was high. Both FeS and FeS₂ were active for Hg⁰ removal in coal derived fuel gas without forming any COS.     

Ferritinophagy and α-Synuclein: Pharmacological Targeting of Autophagy to Restore Iron Regulation in Parkinson’s Disease

A major hallmark of Parkinson’s disease (PD) is the fatal destruction of dopaminergic neurons within the substantia nigra pars compacta. This event is preceded by the formation of Lewy bodies, which are cytoplasmic inclusions composed of α-synuclein protein aggregates. A triad contribution of α-synuclein aggregation, iron accumulation, and mitochondrial dysfunction plague nigral neurons, yet the events underlying iron accumulation are poorly understood. Elevated intracellular iron concentrations up-regulate ferritin expression, an iron storage protein that provides cytoprotection against redox stress. The lysosomal degradation pathway, autophagy, can release iron from ferritin stores to facilitate its trafficking in a process termed ferritinophagy. Aggregated α-synuclein inhibits SNARE protein complexes and destabilizes microtubules to halt vesicular trafficking systems, including that of autophagy effectively. The scope of this review is to describe the physiological and pathological relationship between iron regulation and α-synuclein, providing a detailed understanding of iron metabolism within nigral neurons. The underlying mechanisms of autophagy and ferritinophagy are explored in the context of PD, identifying potential therapeutic targets for future investigation.     

Changes in serum lipids in rats treated with oral cooper

Disturbances in lipid metabolism during copper deficiency in rats are well recognized. Copper deficiency is associated with the spontaneous retention of hepatic iron. Previous studies have reported that hypercholesterolemia and hypertriglyceridemia are associated with elevated hepatic iron concentrations in copper deficient rats. There was a direct relationship between the magnitude of blood lipids and the concentration of hepatic iron. Based on these data, it has been hypothesized that iron was responsible for the development of lipemia of copper deficiency. In this study was determined the effect of increasing doses of Cu(10, 20 and 50 ppm) in the diet, on the serum total lipids, total cholesterol, triglycerides (triacylglicerols), phospholipids, non-esterified fatty acids (NEFA) and liver iron and zinc concentrations in normal rats. The results were compared with normal rats that received a balanced diet containing 0.6 and 6 ppm of Cu, respectively. The results show that Cu-supplement diminished the cholesterol and triglyceride serum levels, increased the level of phospholipids, NEFA and concomitantly decreased the hepatic concentrations of Fe and Zn. There was a statistically significant (p < 0.05) simple correlation between triglycerides and liver Fe (r = 0.917; R2 = 64.03%), cholesterol and liver Zn (r = 0.872; R2 = 76.07%), cholesterol and liver Fe (r = 0.995; R2 = 99.10%), liver Fe and liver Cu (r = -0.612), liver Fe and liver Zn (r = 0.837), liver Cu and liver Zn (r = -0.612), and serum triglycerides and liver Zn (r = 0.967). The mechanism(s) by which Fe and Zn determine these changes is not known; none of the enzymes that act in cholesterol and triglyceride metabolism and biosynthesis require Fe and/or Zn. The increase of NEFA is due to changes in the process of lipolysis and re-esterification of the fatty acids in blood. However, additional studies are needed for the precise mechanisms of this interrelationships to be clarified.     

Hemoglobin-fortified biscuits: bioavailability and its effect on iron nutriture in school children

School-age children in Chile received 30 g of wheat-flour biscuits daily through a National School Lunch Program. To improve iron nutrition, these biscuits were fortified with 6% of a bovine hemoglobin concentrate. Hemoglobin iron bioavailability, measured with a double isotope technique, showed that heme-iron absorption in fortified biscuits was high (19.7%). In a pilot field trial, a cohort of 215 school-children received fortified biscuits (30 g) daily during two school periods, and their iron nutrition status was compared with that of children who received non-fortified biscuits (n = 212). Acceptability of both types of biscuits was excellent. Initially, both groups had comparably good iron nutrition. The fortified children presented higher mean ferritin values at the end of the first and second school periods. Good iron stores (serum ferritin greater than or equal to 20 micrograms/lt) were present in 92% and 79% of the fortified and control subjects, respectively (P less than 0.004). The high-iron bioavailability, the good organoleptic characteristics and the biological effect on iron nutriture make this product an appealing alternative to combat iron deficiency.     

Betaine Alleviates High-Fat Diet-Induced Disruption of Hepatic Lipid and Iron Homeostasis in Mice

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive fat deposition in the liver, which is often associated with disrupted iron homeostasis. Betaine has been reported to be hepatoprotective, yet whether and how betaine ameliorates high-fat diet-induced disruption of hepatic lipid and iron homeostasis remains elusive. In this study, mice were fed either standard (CON) or high-fat diet (HFD) for 9 weeks to establish a NAFLD model. Mice raised on HF diet were then assigned randomly to HF and HFB groups, HFB group being supplemented with 1% (w/v) of betaine in the drinking water for 13 weeks. Betaine supplementation significantly alleviated excessive hepatic lipid deposition and restored hepatic iron content. Betaine partly yet significantly reversed HFD-induced dysregulation of lipogenic genes such as PRARγ and CD36, as well as the iron-metabolic genes including FPN and HAMP that encodes hepcidin. Similar mitigation effects of betaine were observed for BMP2 and BMP6, the up-stream regulators of hepcidin expression. Betaine significantly rectified disrupted expression of methyl transfer gene, including BHMT, GNMT and DNMT1. Moreover, HFD-modified CpG methylation on the promoter of PRARγ and HAMP genes was significantly reversed by betaine supplementation. These results indicate that betaine alleviates HFD-induced disruption of hepatic lipid and iron metabolism, which is associated with modification of CpG methylation on promoter of lipogenic and iron-metabolic genes.     

Kupffer Cells and Blood Monocytes Orchestrate the Clearance of Iron–Carbohydrate Nanoparticles from Serum

Intravenous (IV) iron nanoparticle preparations are widely used to treat iron deficiency. The mechanism of mononuclear phagocyte system-mediated clearance of IV iron nanoparticles is unknown. The early uptake and homeostasis of iron after injection of ferric carboxymaltose (FCM) in mice was studied. An increase in serum iron was observed at 2.5 h followed by a return to baseline by 24 h. An increase in circulating monocytes was observed, particularly Ly6C^hi and Ly6C^low. FCM was also associated with a time-dependent decrease in liver Kupffer cells (KCs) and increase in liver monocytes. The increase in liver monocytes suggests an influx of iron-rich blood monocytes, while some KCs underwent apoptosis. Adoptive transfer experiments demonstrated that following liver infiltration, blood monocytes differentiated to KCs. KCs were also critical for IV iron uptake and biodegradation. Indeed, anti-Colony Stimulating Factor 1 Receptor (CSF1R)-mediated depletion of KCs resulted in elevated serum iron levels and impaired iron uptake by the liver. Gene expression profiling indicated that C-C chemokine receptor type 5 (CCR5) might be involved in monocyte recruitment to the liver, confirmed by pharmaceutical inhibition of CCR5. Liver KCs play a pivotal role in the clearance and storage of IV iron and KCs appear to be supported by the expanded blood monocyte population.     

Mössbauer investigation of iron impurities in vitreous germanium selenide

Films of vitreous germanium selenide GeSe modified with iron impurities are investigated using ⁵⁷Fe Mössbauer spectroscopy. It is found that, at low temperatures T < 295 K, the iron impurity centers are stabilized in three structurally nonequivalent positions, more specifically, the Fe³⁺ impurity centers are stabilized in octahedral and tetrahedral positions, whereas the Fe²⁺ impurity centers are stabilized in octahedral positions. At higher temperatures T > 295 K, the iron impurity centers located in octahedral and tetrahedral positions undergo a rapid electron exchange, which leads to the formation of an “averaged” iron state.