Copper, Iron, and Manganese Toxicity in Neuropsychiatric Conditions.

Copper, manganese, and iron are vital elements required for the appropriate development and the general preservation of good health. Additionally, these essential metals play key roles in ensuring proper brain development and function. They also play vital roles in the central nervous system as significant cofactors for several enzymes, including the antioxidant enzyme superoxide dismutase (SOD) and other enzymes that take part in the creation and breakdown of neurotransmitters in the brain. An imbalance in the levels of these metals weakens the structural, regulatory, and catalytic roles of different enzymes, proteins, receptors, and transporters and is known to provoke the development of various neurological conditions through different mechanisms, such as via induction of oxidative stress, increased α-synuclein aggregation and fibril formation, and stimulation of microglial cells, thus resulting in inflammation and reduced production of metalloproteins. In the present review, the authors focus on neurological disorders with psychiatric signs associated with copper, iron, and manganese excess and the diagnosis and potential treatment of such disorders. In our review, we described diseases related to these metals, such as aceruloplasminaemia, neuroferritinopathy, pantothenate kinase-associated neurodegeneration (PKAN) and other very rare classical NBIA forms, manganism, attention-deficit/hyperactivity disorder (ADHD), ephedrone encephalopathy, HMNDYT1-SLC30A10 deficiency (HMNDYT1), HMNDYT2-SLC39A14 deficiency, CDG2N-SLC39A8 deficiency, hepatic encephalopathy, prion disease and "prion-like disease", amyotrophic lateral sclerosis, Huntington's disease, Friedreich's ataxia, and depression.

Prenatal sevoflurane exposure: Effects of iron metabolic dysfunction on offspring cognition and potential mechanism.

For decades, the neurotoxicity caused by anesthetics in mammalian brain development has gained increasing attention. Exposure to anesthetics leads to neurotoxicity and apoptosis of nerve cells, which in turn induces cognitive dysfunction. Although most of the data came from animal studies, general anesthetics have been shown to have adverse effects on cognitive function in infants and young children in recent years. This concern has led to a number of retrospective studies that observed an association between general anesthesia in pregnant women and neurobehavioral problems in fetuses or offspring. Every year, many pregnant women undergo non-obstetric anesthesia due to various reasons such as traffic accidents, fetal interventions, acute appendicitis, symptomatic cholelithiasis, and trauma. A matter of concern for these pregnant women is whether anesthesia has a detrimental effect on fetal brain development in the womb and whether the fetus has cognitive impairment after birth. In humans, the association of anesthetic exposure in infants with the long-term impairment of neurologic functions has been reported in several retrospective clinical studies. Recently, we have found that sevoflurane anesthesia during pregnancy in mice-induced cognitive impairment in the offspring by causing iron deficiency and inhibiting myelinogenesis. Sevoflurane is a commonly used general anesthetic in the hospitals, which can induce neurotoxicity and cause cognitive impairment in fetuses, infants, children, and adults. However, the exact mechanism of sevoflurane-induced damage to the central nervous system (CNS) is not fully understood. Based on our recent results, this paper reviewed the effects of sevoflurane on cognitive impairment and pathological changes such as neurogenesis, neuronal apoptosis, and iron metabolism dysfunction in the offspring.

Iron deficiency during first-line chemotherapy in metastatic cancers: a prospective epidemiological study.

PURPOSE: Anemia is common in oncology and negatively impacts quality of life. However, there is lack of knowledge about iron deficiency (ID) epidemiology. The aim of this study was to prospectively assess iron status in patients with locally advanced or metastatic cancer beginning chemotherapy. METHODS: In this prospective, multicenter cohort study, anemia and ID were evaluated in patients with locally advanced or metastatic solid tumors and lymphoma before starting chemotherapy. Blood samples were collected at inclusion (W0), 6 weeks (W6), and 12 weeks (W12). Prevalence was evaluated in the general population, according to tumor location and was correlated with tumor response. RESULTS: One hundred twenty-nine patients were enrolled between 2013 and 2015; 119 had solid tumors and 10 lymphomas. At W0, there were no significant difference between locations with a prevalence around 50-60% (range 47.2-70.4%) and only a trend for colorectal cancer (70.4%, P = 0.069) due to a higher prevalence of absolute ID (18.5%). Prevalence of ID+ decreased between W0 and W6 and remained stable until W12 due to the proportion of patients with ID and without anemia. However, anemia prevalence increased during W0 and W6 and remained stable to W6 from W12 due to patients with anemia but without ID. A significant correlation between tumor response and ID prevalence was found (P = 0.036). CONCLUSIONS: We confirm the high prevalence of ID and anemia in cancer patients. ID status is correlated to tumor response providing a strong rationale for iron monitoring during cancer management.

Whole genome and normalized mRNA sequencing reveal genetic status of TK6, WTK1, and NH32 human B-lymphoblastoid cell lines.

Closely related TK6, WTK1, and NH32 human B-lymphoblastoid cell lines differ in their p53 functional status. These lines are used frequently in genotoxicity studies and in studies aimed at understanding the role of p53 in DNA repair. Despite their routine use, little is known about the genetic status of these cells. To provide insight into their genetic composition, we sequenced and analyzed the entire genome of TK6 cells, as well as the normalized transcriptomes of TK6, WTK1, and NH32 cells. Whole genome sequencing (WGS) identified 21,561 genes and 5.17×10(6) small variants. Within the small variants, 50.54% were naturally occurring single nucleotide polymorphisms (SNPs) and 49.46% were mutations. The mutations were comprised of 92.97% single base-pair substitutions and 7.03% insertions or deletions (indels). The number of predicted genes, SNPs, and small mutations are similar to frequencies observed in the human population in general. Normalized mRNA-seq analysis identified the expression of transcripts bearing SNPs or mutations for TK6, WTK1, and NH32 as 2.88%, 2.04%, and 1.71%, respectively, and several of the variant transcripts identified appear to have important implications in genetic toxicology. These include a single base deletion mutation in the ferritin heavy chain gene (FTH1) resulting in a frame shift and protein truncation in TK6 that impairs iron metabolism. SNPs in the thiopurine S-methyltransferase (TPMT) gene (TPMT*3A SNP), and in the xenobiotic metabolizing enzyme, NADPH quinine oxidoreductase 1 (NQO1) gene (NQO1*2 SNP), are both associated with decreased enzyme activity. The clinically relevant TPMT*3A and NQO1*2 SNPs can make these cell lines useful in pharmacogenetic studies aimed at improving or tailoring drug treatment regimens that minimize toxicity and enhance efficacy.

Iron homeostasis during risperidone treatment in children and adolescents.

OBJECTIVE: Previous cross-sectional evidence has linked antipsychotic-related weight gain to reduced body iron concentration. Using longitudinal data, we examined the association between changes in weight following risperidone initiation or discontinuation and ferritin concentration. METHOD: Study 1: Between April 2004 and September 2007, participants were enrolled from outpatient settings in a prospective randomized clinical trial comparing the efficacy of risperidone monotherapy to the combination of risperidone and behavior therapy in targeting disruptive behavior in 4- to 13-year-old children with DSM-IV-TR-based autism spectrum disorder. Study 2: Medically healthy 7- to 17-year-old participants in long-term open-label risperidone treatment at study entry returned for follow-up 1.5 years later, between July 2007 and July 2011. Available blood samples were used to measure ferritin. Linear multivariable regression analysis tested the association between ferritin concentration and change in age-sex-specific body mass index (BMI) z score between study entry and endpoint, adjusting for relevant confounders. RESULTS: Study 1 sample consisted of 73 participants (85% males, mean age: 7.7 ± 2.4 years). After 18.0 ± 2.0 weeks on risperidone, their BMI z score increased by 0.93 ± 0.70 points and ferritin concentration declined by 6.8 ± 13.3 µg/L. After adjusting for age and sex, change in BMI z score was inversely correlated with percent change in ferritin concentration (ß = -18.3, P < .003). Study 2 participants had all been receiving risperidone at study entry. At follow-up, 1.5 ± 0.3 years later, risperidone was discontinued in 26 of the 96 who were included in the analysis. Neither change in BMI z score nor in ferritin concentration was different between those who continued versus discontinued risperidone. However, a reduction in BMI z score between study entry and follow-up was associated with higher ferritin concentration at follow-up in participants who discontinued risperidone compared to those who continued it (P = .01). CONCLUSIONS: Risperidone-related weight gain is associated with a reduction in body iron reserves, which appears to improve with weight loss following risperidone discontinuation. Preliminary evidence suggests that risperidone may also directly inhibit iron absorption. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00080145.

The role of hepcidin and haemojuvelin in the pathogenesis of iron disorders in patients with severe malnutrition.

INTRODUCTION AND OBJECTIVE: The clinical consequences of malnutrition are multi-directional and result in dysfunctions of the majority of internal organs and systems. The results of recent studies suggest that a significant role is played by malnutrition in pathophysiology of iron homeostasis disorders, but the underlying mechanism is unclear. The study describes the potential role of hepcidin and hemojuvelin in the pathogenesis of disorders of iron metabolism during malnutrition. STATE OF KNOWLEDGE: The participation of hepcidin in regulating iron homeostasis encompasses inhibiting the absorption of food iron from enterocytes and inhibiting the release of stored iron from the reticuloendothelial system cells. One of the factors that increases the post-translational level is the expression of hepcidin is IL-6. In studies focused on malnutrition it was observed that in persons with protein and energy deficits the level of proinflammatory cytokine, i.e. interleukin-6, in the serum, increased. The involvement of haemojuvelin in the overall iron homeostasis is related with the regulation of expression of the hepcidin coding gene on the transcription level. The highest haemojuvelin expression was observed in humans in skeletal muscles. Observations and analyses conducted in vivo allowed the conclusion that soluble HJV and cell-related haemojuvelin regulate hepcidin expression in response to changes in iron concentration. The research also demonstrated that soluble HJV neutralizes the inductive effect of IL-6 action on hepcidin expression. SUMMARY: It can be claimed that in persons with protein and/or protein-energetic malnutrition the muscle mass deficit may lead to insufficient production of haemojuvelin and sideropenia.

The effects of the anti-hepcidin Spiegelmer NOX-H94 on inflammation-induced anemia in cynomolgus monkeys.

Anemia of chronic inflammation is the most prevalent form of anemia in hospitalized patients. A hallmark of this disease is the intracellular sequestration of iron. This is a consequence of hepcidin-induced internalization and subsequent degradation of ferroportin, the hepcidin receptor and only known iron-export protein. This study describes the characterization of novel anti-hepcidin compound NOX-H94, a structured L-oligoribonucleotide that binds human hepcidin with high affinity (Kd = 0.65 ± 0.06 nmol/L). In J774A.1 macrophages, NOX-H94 blocked hepcidin-induced ferroportin degradation and ferritin expression (half maximal inhibitory concentration = 19.8 ± 4.6 nmol/L). In an acute cynomolgus monkey model of interleukin 6 (IL-6)-induced hypoferremia, NOX-H94 inhibited serum iron reduction completely. In a subchronic model of IL-6-induced anemia, NOX-H94 inhibited the decrease in hemoglobin concentration. We conclude that NOX-H94 protects ferroportin from hepcidin-induced degradation. Therefore, this pharmacologic approach may represent an interesting treatment option for patients suffering from anemia of chronic inflammation.

Ferritinemia during type 1 Gaucher disease: mechanisms and progression under treatment.

BACKGROUND: Earlier results highlighted hyperferritinemia during type-1 Gaucher disease (GD), but its potential mechanisms and long-term progression remained unexamined. METHODS: We analyzed the clinical, biological and iron characteristics of type-1 GD patients, before and after starting enzyme-replacement therapy (ERT). Iron parameters under ERT were subjected to linear-regression analyses. RESULTS: Serum ferritin (median 739 [46-2371] µg/L) was determined for 54 patients (21 (39%) males; median age 32 [range 12-73] years) before ERT; it exceeded 300 µg/L in 47 (87%), while the other iron parameters always remained normal: transferrin saturation coefficient (26 [16-42]), serum iron at 13 [6-22] mmol/L and transferrin at 2.4 [2,3] g/L. Four patients had mild elevation of liver transaminases, with C-reactive protein >20mg/l in two. The absence of hemolysis was accompanied by a median bilirubin of 9 µmol/L and lactate dehydrogenase at 250 IU/L; diabetes and lipid anomalies were not observed. Clinical, biological and iron parameters at GD diagnosis were comparable for the 12 and 42 patients with ferritinemia ≤400 and >400 µg/L, respectively. Ferritinemia was measured at least once for 46 patients after ERT onset (median treatment duration 90 [3-204] months). At study closure, median serum ferritin was 187.5 [11-1560] µg/L, exceeding 300 µg/L in 15 (33%) patients, while the other iron parameters were normal. Among the latter, only the mean±SD ferritinemia slope decreased significantly under ERT (-1.9±0.3%/month; p<0.001). CONCLUSION: Hyperferritinemia is a specific GD characteristic and serum ferritin monitoring could be informative during follow-up.

Ingestion of Mn and Pb by rats during and after pregnancy alters iron metabolism and behavior in offspring.

Manganese (Mn) and lead (Pb) exposures during developmental period can impair development by direct neurotoxicity or through interaction with iron metabolism. Therefore, we examined the effects of maternal ingestion of Mn or Pb in drinking water during gestation and lactation on iron metabolism as well as behavior in their offspring. Pregnant dams were given distilled water, 4.79mg/ml Mn, or 2.84mg/ml Pb in drinking water during gestation and lactation. Pups were studied at time of weaning for (59)Fe absorption from the gut, duodenal divalent metal transporter 1 (DMT1) expression, hematological parameters, and anxiety-related behavior using an Elevated Plus Maze (EPM) test. Metal-exposed pups had lower body weights and elevated blood and brain concentrations of the respective metal. Pb-exposed pups had lower hematocrits and higher blood Zn protoporphyrin levels. In contrast, Mn exposed pups had normal hematological parameters but significantly reduced Zn protoporphyrin. Pharmacokinetic studies using (59)Fe showed that intestinal absorption in metal-exposed pups was not different from controls, nor was it correlated with duodenal DMT1 expression. However, intravenously injected (59)Fe was cleared more slowly in Pb-exposed pups resulting in higher plasma levels. The overall tissue uptake of (59)Fe was lower in Mn-exposed and lower in the brain in Pb-exposed pups. The EPM test demonstrated that Mn-exposed, but not Pb-exposed, pups had lower anxiety-related behavior compared to controls. We conclude that gestational and lactational exposures to Mn or Pb differentially alter Fe metabolism and anxiety-related behavior. The data suggest that perturbation in Fe metabolism may contribute to the pathophysiologic consequences of Mn and Pb exposure during early development.

Transferrin fails to provide protection against Fas-induced hepatic injury in mice with deletion of functional transferrin-receptor type 2.

We reported previously that Fas-induced hepatic failure in normal mice was attenuated or prevented by exogenous transferrin (Tf), particularly apoTf. Here we show in C57BL6J/129 mice with genetic inactivation of transferrin receptor 2 (TfR2(Y245X)), that Fas-induced hepatotoxicity (apoptosis; rise in plasma aspartate aminotransferase (AST) levels) was comparable to that in wild-type mice, but was not modified by pretreatment with Tf. Rises in plasma AST were preceded by a decline in serum iron levels. AST elevations and iron declines were more profound in female than in male mice. Female mice also showed higher baseline levels of Bcl-xL in hepatocytes, which declined significantly upon treatment with agonistic anti-Fas antibody. These data confirm the cytoprotective function of Tf, and show a novel property of TfR2. Both apoptotic Fas responses and cytoprotective effects of Tf were associated with significant shifts in plasma iron levels, which quantitatively differed between male and female mice.

Methamphetamine increases basal ganglia iron to levels observed in aging.

Increases in basal ganglia iron are well documented for neurodegenerative diseases but have not been associated with methamphetamine (METH). In this study, vervet monkeys that received two doses of METH (2 mg/kg, intramuscularly, 6 h apart) showed at 1 month, iron increases in substantia nigra pars reticulata and globus pallidus, with concurrent increases of ferritin-immunoreactivity and decreases of tyrosine hydroxylase-immunoreactivity in substantia nigra. At 1.5 years, substantia nigra tyrosine hydroxylase-immunoreactivity had recovered while iron and ferritin-immunoreactivity increases persisted. Globus pallidus and substantia nigra iron levels of the adult METH-exposed animals (age 5-9 years) were now comparable with those of drug-naive, aged animals (19-22 years), suggesting an aging-related condition that might render those regions more vulnerable to oxidative stress.

Ferroportin1 and hephaestin are involved in the nigral iron accumulation of 6-OHDA-lesioned rats.

Elevated iron levels in the substantia nigra (SN) participate in neuronal death in Parkinson's disease (PD). While the mechanisms underlying the increased iron are still unknown, some iron transport proteins may be involved. The nigral iron accumulation could be a result of either increased import or decreased export. The mechanisms of iron import have received considerable attention, but little is known about iron export mechanisms. Ferroportin1 (FP1) and hephaestin (HP), two newly discovered iron export proteins, cooperate in the iron export in the gut. Here, we investigated their expression in the SN of rats lesioned by 6-hydroxydopamine (6-OHDA). Using immunofluorescence, we showed that FP1 and HP were both expressed on astrocytes, microglia, oligodendrocytes and neurons in the SN. By immunohistochemistry, we showed that 1 day after 6-OHDA lesion, the expression of the two proteins decreased compared with the control. When rats began showing rotation behaviour induced by apomorphine, usually 6 weeks after 6-OHDA lesion, they are considered PD models. In these PD models, a further decrease in the two proteins was observed. Reverse transcriptase-polymerase chain reaction showed that the mRNA levels of FP1 and HP decreased 1 day after 6-OHDA lesion compared with the control, and further decrease was also observed in the PD model rats. These results show for the first time that FP1 and HP co-localize in the rat brain, and suggest that decreased expression of these transporters in the SN can account for the increased iron levels.

[Altered systemic iron metabolism in welders exposed to manganese].

OBJECTIVE: To investigate the systemic changes of iron metabolism following manganese exposure. METHODS: Ninety-seven welders and 91 workers with no history of exposure to manganese were recruited from the same factory in Beijing serving as the exposure group and the control group respectively. The welding rods used were type J422. The concentration of the manganese in the air of the work place was determined respectively with the national standard method. The serum iron and manganese, ferritin, transferrin and transferrin receptors were measured with the graphite furnace atomic absorption spectrophotometry and ELISA in both groups. RESULTS: The permissible concentration-STEL of ambient Mn in welders' breathing zone ranged from 0.53 mg/m(3) to 2.19 mg/m(3), while the permissible concentration-TWA of ambient Mn was between 0.29 mg/m(3) and 0.92 mg/m(3) in the breathing zone of the workplace. Serum Mn and Fe concentrations in welders were about 1.40 times (P < 0.0l) and 1.2 times (P < 0.01), respectively, higher than those of control subjects. At the same time, the transferrin concentrations in serum were significantly higher (about 1.2 times, P < 0.05) in welders than in controls. In contrast, transferrin receptors were significantly lower (about 1.2 times) in exposed subjects than controls (P = 0.001). There was no difference in serum ferritin between the two groups (P = 0.112). Although there was no significant trend, the serum ferritin level was increased by 18% in comparison with that of the control. The abnormal percentage of serum Fe and Serum Mn in welders were 55.67% and 67.01% respectively, higher than those of control subjects. In addition, the correlations between all indicators and the duration of employment were not observed. CONCLUSION: The long term exposure to the manganese can induce the disorder of the iron metabolism, which is found in the expression of increase of the serum iron and transferrin as well as the decrease of transferrin receptors.

Hfe deficiency increases susceptibility to cardiotoxicity and exacerbates changes in iron metabolism induced by doxorubicin.

The clinical use of doxorubicin (DOX), an anthracycline chemotherapeutic agent, is limited by cardiotoxicity. The possible involvement of iron in DOX-induced cardiotoxicity became evident from studies in which iron chelators were shown to be cardioprotective. Iron overload is found in hereditary hemochromatosis, a genetic disorder prevalent in individuals of European descent. We hypothesized that Hfe deficiency may increase susceptibility to DOX-induced toxicity. Acute cardiotoxicity and iron changes were studied after treatment with DOX in Hfe knock-out (Hfe-/-) mice and wild-type mice. DOX-induced iron metabolism changes were intensified in Hfe-/- mice, which accumulated significantly more iron in the heart, liver, and pancreas, but less in the spleen compared with wild-type mice. In addition, Hfe-deficient mice exhibited significantly greater sensitivity to DOX-induced elevations in serum creatine kinase and aspartate aminotransferase. Increased mortality after chronic DOX treatment was observed in Hfe-/- mice and Hfe+/-mice compared with wild-type mice. DOX-treated Hfe-/- mice had a higher degree of mitochondrial damage and iron deposits in the heart than did wild-type mice. These data demonstrate that Hfe deficiency in mice increases susceptibility to DOX-induced cardiotoxicity and suggest that genetic mutations related to defects in iron metabolism may contribute to its cardiotoxicity in humans.

Hepatic iron accumulation over time in European starlings (Sturnus vulgaris) fed two levels of iron.

European starlings (Sturnus vulgaris) were used as a passerine bird model to examine the effect of dietary iron on the level of hepatic iron in birds. Nestling and fledgling starlings (n = 56) were raised on a controlled-iron diet. When birds maintained constant body weight, they were assigned in pairs to cages, and baseline sampling was performed. Pairs were then assigned to one of two diets: the controlled-iron diet (168 ppm, dry basis) or a high-iron diet (3,035 ppm, dry basis). Dry-matter intake and iron consumption were recorded. Dry-matter intake did not differ between the dietary treatment groups and was stable during treatment periods. Iron intake was higher in the high-iron group (P < 0.05). Birds were euthanized at baseline, 8 wk, and 16 wk. Body, liver, and spleen weights were measured. Hepatic iron and copper concentrations were determined. Body weight did not differ between the two treatment groups or among individuals for the study duration. Liver iron concentration differed over time and between treatment groups. Birds receiving both treatments had similar liver iron content at week 8 (3,107 +/- 228.6 ppm and 3,122 +/- 306.2 ppm high and controlled iron, respectively; P > 0.05), but by week 16, birds consuming the high-iron diet had greater hepatic iron levels than those consuming the controlled-iron diet (5,929 +/- 937.2 ppm and 3,683 +/- 229.5 ppm high and controlled iron, respectively; P < 0.05). Birds on the controlled-iron diet also had higher hepatic iron at 16 wk than at 8 wk. Liver copper decreased over time in all birds regardless of treatment. Results show that both dietary iron level and duration of time influenced hepatic iron storage. The controlled-iron diets still allowed accumulation of hepatic iron in an 8-wk period.