Iron Overload and the Risk of Diabetes in the General Population: Results of the Chinese Health and Nutrition Survey Cohort Study

BACKGROUND

Recent studies have found that there are significant associations between body iron status and the development of diabetes. In the present study, we aimed to analyze the association among iron overload (IO), insulin resistance (IR), and diabetes in Chinese adults, and to explore the sex difference.

METHODS

Men and women (age >19 years) who participated in the Chinese Health and Nutrition Survey and did not have diabetes at baseline were followed between 2009 and 2015 (n=5,779). Over a mean of 6 years, 75 participants were diagnosed with incident diabetes. Logistic regression was used to assess the risk factors associated with IO. Cox proportional hazard regression was used to estimate the risk of incident diabetes and to determine whether the risk differed among subgroups. Causal mediation analysis (CMA) was used to explore the mechanism linking IO and diabetes.

RESULTS

According to sex-stratified multivariable-adjusted Cox proportional hazards regression, IO increased the risk of incident diabetes. Women with IO had a higher risk of diabetes than men. Subgroup analysis with respect to age showed that the association between IO and diabetes was stronger in older women and younger men (P<0.001). CMA showed that liver injury (alanine transaminase) and lipid metabolism abnormalities (triglyceride, apolipoprotein B) contributed to the association between IO and diabetes.

CONCLUSION

IO is associated with diabetes and this association is sex-specific. IO may indirectly induce IR via liver injury and lipid metabolism abnormalities, resulting in diabetes.

The Effect of Curcumin on Iron Overload in Patients with Beta-Thalassemia Intermedia

BACKGROUND

β-thalassemia is an inherited disorder that stems from a defect in beta-globin chain synthesis. Iron overload toxicity is one of the major clinical complications in β-thalassemia that may be due to a reduction in the hepcidin level. As a result, intestinal iron absorption increases and finally iron overload occurs. The current study aimed to investigate the effect of curcumin on serum iron status, ferritin, and transferrin in patients with β-thalas-semia intermedia.

METHODS

This study was a randomized, controlled, double-blind clinical trial. Before and after the intervention period with curcumin, 5 ml blood was taken for the measurement of the entire index related to iron status.

RESULTS

Our results demonstrated the levels of serum iron (p-value < 0.001), ferritin (p-value = 0.002), and transferrin saturation (p-value < 0.001) significantly decreased in the curcumin group compared to placebo.

CONCLUSIONS

The data presented in this article show that curcumin supplementation would be effective in alleviating iron overload in patients with β-thalassemia intermedia.

Iron Activates cGAS-STING Signaling and Promotes Hepatic Inflammation

Iron deposition and chronic inflammation are associated with chronic liver diseases, such as alcoholic liver disease, nonalcoholic fatty liver disease, and chronic hepatitis B and C. However, the relationship between iron deposition and chronic inflammation in these diseases is still unclear. In the current study, we aimed to investigate the effect of iron on chronic inflammation in HepG2 cells and mice liver. We demonstrated that iron treatment enhanced the expression of cGAS, STING, and their downstream targets, including TBK1, IRF-3, and NF-κB in HepG2 cells and mice liver. We also found that treatment of HepG2 cells and mice with ferric ammonium citrate increased the expression of inflammatory cytokines, such as IFN-β. Finally, we found that genes involved in iron metabolism and the STING signaling pathway were up-regulated in liver cancer tissues, and the survival time of patients with high expression of these genes in tumor tissues was significantly shortened. These results suggest that iron overload may promote the progress of the chronic liver disease by activating cGAS-STING-mediated chronic inflammation, which provides a new idea for the development of drugs for the treatment of the chronic liver disease.

Iron Homeostasis Disorder and Alzheimer's Disease

Iron is an essential trace metal for almost all organisms, including human; however, oxidative stress can easily be caused when iron is in excess, producing toxicity to the human body due to its capability to be both an electron donor and an electron acceptor. Although there is a strict regulation mechanism for iron homeostasis in the human body and brain, it is usually inevitably disturbed by genetic and environmental factors, or disordered with aging, which leads to iron metabolism diseases, including many neurodegenerative diseases such as Alzheimer's disease (AD). AD is one of the most common degenerative diseases of the central nervous system (CNS) threatening human health. However, the precise pathogenesis of AD is still unclear, which seriously restricts the design of interventions and treatment drugs based on the pathogenesis of AD. Many studies have observed abnormal iron accumulation in different regions of the AD brain, resulting in cognitive, memory, motor and other nerve damages. Understanding the metabolic balance mechanism of iron in the brain is crucial for the treatment of AD, which would provide new cures for the disease. This paper reviews the recent progress in the relationship between iron and AD from the aspects of iron absorption in intestinal cells, storage and regulation of iron in cells and organs, especially for the regulation of iron homeostasis in the human brain and prospects the future directions for AD treatments.

Evaluation of the Association of Transferrin Receptor Type 2 Gene Mutation (Y250X) with Iron Overload in Major β- Thalassemia

Thalassemia is an inherited blood disorder in which the body produces defective hemoglobin. One of the important processes to reduce the complication of major β-thalassemia is blood transfusion that leads to elevated ferritin levels in the blood. Many patients who have major β-thalassemia may have hemochromatosis conditions resulting from iron metabolism disorders. In patients who have β-thalassemia, the mutation Y250X in the TFR2 gene may play a role in the incidence of hemochromatosis. This study aimed to determine the relationship between ferritin levels and Y250X mutation in major β-thalassemia patients. In the present study, 12 blood samples were divided into nine major β-thalassemia patients and three healthy controls. The DNA was isolated from blood samples and the amplification of the target region was performed based on the specific primers. Sanger sequencing was used to find genetic single nucleotide polymorphisms associated with iron overload. Blood parameters, such as hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, and serum ferritin levels were analyzed and the recorded data showed the following results: 8.1±0.8 g/dL, 84.6±5.5 fL, 27±0.7 pg, respectively. The recorded data showed that the mean serum ferritin level in major β-thalassemia patients was 1921.7±848 ng/mL. The Y250X mutation was not found in major β-thalassemia patients and healthy controls.

HMOX1 upregulation promotes ferroptosis in diabetic atherosclerosis

OBJECTIVE

Atherosclerotic vascular disease remains the principal cause of death and disability among patients with type 2 diabetes. Unfortunately, the problem is not adequately resolved by therapeutic strategies with currently available drugs or approaches that solely focus on optimal glycemic control. To identify the key contributors and better understand the mechanism of diabetic atherosclerotic vascular disease, we aimed to elucidate the key genetic characteristics and pathological pathways in atherosclerotic vascular disease through nonbiased bioinformatics analysis and subsequent experimental demonstration and exploration in diabetic atherosclerotic vascular disease.

METHODS AND RESULTS

Sixty-eight upregulated and 23 downregulated genes were identified from the analysis of gene expression profiles (GSE30169 and GSE6584). A comprehensive bioinformatic assay further identified that ferroptosis, a new type of programmed cell death and HMOX1 (a gene that encodes heme oxygenase), were vital factors in atherosclerotic vascular disease. We further demonstrated that diabetes significantly increased ferroptosis and HMOX1 levels compared to normal controls. Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated diabetic atherosclerosis, suggesting the causative role of ferroptosis in diabetic atherosclerosis development. At the cellular level, Fer-1 ameliorated high glucose high lipid-induced lipid peroxidation and downregulated ROS production. More importantly, HMOX1 knockdown attenuated Fe2+ overload, reduced iron content and ROS, and alleviated lipid peroxidation, which led to a reduction in ferroptosis in diabetic human endothelial cells.

CONCLUSIONS

We demonstrated that HMOX1 upregulation is responsible for the increased ferroptosis in diabetic atherosclerosis development, suggesting that HMOX1 may serve as a potential therapeutic or drug development target for diabetic atherosclerosis.

Genetic Support of A Causal Relationship Between Iron Status and Type 2 Diabetes: A Mendelian Randomization Study

CONTEXT

Iron overload is a known risk factor for type 2 diabetes (T2D); however, iron overload and iron deficiency have both been associated with metabolic disorders in observational studies.

OBJECTIVE

Using mendelian randomization (MR), we assessed how genetically predicted systemic iron status affected T2D risk.

METHODS

A 2-sample MR analysis was used to obtain a causal estimate. We selected genetic variants strongly associated (P < 5 × 10-8) with 4 biomarkers of systemic iron status from a study involving 48 972 individuals performed by the Genetics of Iron Status consortium and applied these biomarkers to the T2D case-control study (74 124 cases and 824 006 controls) performed by the Diabetes Genetics Replication and Meta-analysis consortium. The simple median, weighted median, MR-Egger, MR analysis using mixture-model, weighted allele scores, and MR based on a Bayesian model averaging approaches were used for the sensitivity analysis.

RESULTS

Genetically instrumented serum iron (odds ratio [OR]: 1.07; 95% CI, 1.02-1.12), ferritin (OR: 1.19; 95% CI, 1.08-1.32), and transferrin saturation (OR: 1.06; 95% CI, 1.02-1.09) were positively associated with T2D. In contrast, genetically instrumented transferrin, a marker of reduced iron status, was inversely associated with T2D (OR: 0.91; 95% CI, 0.87-0.96).

CONCLUSION

Genetic evidence supports a causal link between increased systemic iron status and increased T2D risk. Further studies involving various ethnic backgrounds based on individual-level data and studies regarding the underlying mechanism are warranted for reducing the risk of T2D.

BULL'S EYE MACULOPATHY POSSIBLY DUE TO IRON OVERLOAD IN A CHILD WITH THALASSEMIA MAJOR: A CASE OF POSSIBLE "FERRITIN RETINOPATHY"

PURPOSE

To report a case of bull's eye maculopathy probably caused by iron overload in a child with thalassemia major.

METHODS

Case report.

RESULTS

A 6-year-old girl with thalassemia major who was on chronic multiple blood transfusions since 2 years of age presented with blurred vision in both eyes for 2 months. Blood reports showed very high serum ferritin levels in the range 400 to 2,250 ng/mL (checked every 3 months) since 4 years of age. She was on oral iron chelator deferasirox for 2 years, which was stopped a month ago. Fundus examination of both eyes showed a characteristic bull's eye macula with a purplish hue in the outer ring probably due to iron deposition. The center of the bull's eye had a beaten bronze appearance.

CONCLUSION

Careful history-taking is important in children with bull's eye maculopathy because all such retinopathies need not be hereditary fundus dystrophies. Further progression can be arrested by identifying and removing the cause vision loss.

Dysregulation of iron metabolism in cardiovascular diseases: From iron deficiency to iron overload

Iron deficiency and iron overload are the most prevalent and opposite forms of dysregulated iron metabolism that affect approximately 30 percent of the world population, in particularly, elderly and patients with chronic diseases. Both iron deficiency and overload are frequently observed in a wide range of cardiovascular diseases, contributing to the onset and progression of these diseases. One of the devastating seqeulae for iron overload is the induction of ferroptosis, a newly defined form of regulated cell death which heavily impacts cardiac function through ferroptotic cell death in cardiomyocytes. In this review, we will aim to evaluate iron deficiency and iron overload in cardiovascular diseases. We will summarize current therapeutic strategies to tackle iron deficiency and iron overload, major pitfalls of current studies, and future perspectives.

A Systematic Review and Meta-Analysis of Stature Growth Complications in β-thalassemia Major Patients

Background

Blood transfusion is a traditional treatment for β-thalassemia (β-thal) that improves the patients' anemia and lifespan, but it may lead to iron overload in parenchymal tissue organs and endocrine glands that cause their dysfunctions as the iron regulatory system can't excrete excess iron from the bloodstream.

Objective

To evaluate the prevalence of iron-related complications (short stature, growth retardation, and growth hormone deficiency) in β-thalassemia major (βTM) patients.

Methods

We performed an electronic search in PubMed, Scopus, and Web of Sciences to evaluate the prevalence of growth hormone impairment in β-thalassemia major (βTM) patients worldwide. Qualities of eligible studies were assessed by the Joanna Briggs Institute checklist for the prevalence study. We used Comprehensive Meta-Analysis (Version 2) to calculate the event rate with 95% CIs, using a random-effects model for all analyses.

Findings

Seventy-four studies were included from five continents between 1978 and 2019; 70.27% (Asia), 16.21% (Europe), 6.75% (Africa), 2.70% (America), 1.35% (Oceania), and 2.70% (Multicenter). The overall mean age of the participants was about 14 years. The pooled prevalence of short stature (ST) was 48.9% (95% CI 35.3-62.6) and in male was higher than female (61.9%, 95% CI 53.4-69.7 vs. 50.9%, CI 41.8-59.9). The pooled prevalence of growth retardation (GR) was 41.1% and in male was higher than in female (51.6%, 95% CI 17.8-84 vs. 33.1%, CI 9.4-70.2). The pooled prevalence of growth hormone deficiency (GHD) was 26.6% (95% CI 16-40.8).

Conclusion

Our study revealed that near half of thalassemia patients suffer from growth impairments. However, regular evaluation of serum ferritin levels, close monitoring in a proper institute, suitable and acceptable treatment methods besides regular chelation therapy could significantly reduce the patients' complications.

Mitoferrin 2 deficiency prevents mitochondrial iron overload-induced endothelial injury and alleviates atherosclerosis

Endothelial dysfunction is an early step in the development of atherosclerotic cardiovascular disease. Iron overload can lead to excessive mitochondrial reactive oxygen species (mtROS) production, resulting in mitochondrial dysfunction and vascular endothelial cell (EC) damage. Mitoferrin 2 (Mfrn2) is an iron transporter in the inner mitochondrial membrane. This study aimed to assess whether Mfrn2 and mitochondrial iron overload were involved in atherosclerosis progression and to explore the potential mechanism. We observed significant upregulation of Mfrn2 in the arteries of high-fat diet (HFD)-fed Apolipoprotein E-/- (ApoE-/-) mice and in TNF-α-induced mouse aortic endothelial cells (MAECs). Mfrn2 gene silencing inhibited mitochondrial iron overload, stabilized mitochondrial membrane potential and improved mitochondrial function in TNF-α-induced MAECs. Vascular EC-specific knockdown of Mfrn2 in ApoE-/- mice markedly decreased atherosclerotic lesion formation and the levels of ICAM-1 in aortas and reduced monocyte infiltration into the vascular wall. Furthermore, TNF-α increased the binding of 14-3-3 epsilon (ε) and Mfrn2, preventing Mfrn2 degradation and leading to mitochondrial iron overload in ECs, while 14-3-3ε overexpression increased Mfrn2 stability by inhibiting its ubiquitination. Together, our results reveal that Mfrn2 deficiency attenuates endothelial dysfunction by decreasing iron levels within the mitochondria and mitochondrial dysfunction. These findings may provide new insights into preventive and therapeutic strategies against vascular endothelial dysfunction in atherosclerotic disease.

Iron Overload in Functional Hyperandrogenism: In a Randomized Trial, Bloodletting Does Not Improve Metabolic Outcomes

CONTEXT

Functional hyperandrogenism may be associated with a mild increase in body iron stores. Iron depletion exerts a beneficial effect on metabolic endpoints in other iron overload states.

OBJECTIVES

(i) To determine the effect of iron depletion on the insulin sensitivity and frequency of abnormal glucose tolerance in patients with functional hyperandrogenism submitted to standard therapy with combined oral contraceptives (COC). ii) To assess the overall safety of this intervention.

DESIGN

Randomized, parallel, open-label, clinical trial.

SETTING

Academic hospital.

PATIENTS

Adult women with polycystic ovary syndrome or idiopathic hyperandrogenism.

INTERVENTION

After a 3-month run-in period of treatment with 35 μg ethinylestradiol plus 2 mg cyproterone acetate, participants were randomized (1:1) to 3 scheduled bloodlettings or observation for another 9 months.

MAIN OUTCOME MEASURES

Changes in insulin sensitivity index and frequency of prediabetes/diabetes, and percentage of women in whom bloodletting resulted in plasma hemoglobin <120 g/L and/or hematocrit <0.36.

RESULTS

From 2015 to 2019, 33 women were included by intention-to-treat. During the follow-up, insulin sensitivity did not change in the whole group of women or between study arms [mean of the differences (MD): 0.0 (95%CI: -1.6 to 1.6)]. Women in the experimental arm showed a similar odds of having prediabetes/diabetes than women submitted to observation [odds ratio: 0.981 (95%CI: 0.712 to 1.351)]. After bloodletting, 4 (21.1%) and 2 women (10.5%) in the experimental arm had hemoglobin (Hb) levels <120 g/L and hematocrit (Hct) values <0.36, respectively, but none showed Hb <110 g/L or Hct <0.34.

CONCLUSIONS

Scheduled bloodletting does not improve insulin sensitivity in women with functional hyperandrogenism on COC.

Analytical evaluation of serum non-transferrin-bound iron and its relationships with oxidative stress and cardiac load in the general population

Excessive iron accumulation provokes toxic effects, especially in the cardiovascular system. Under iron overload, labile free non-transferrin-bound iron (NTBI) can induce cardiovascular damage with increased oxidative stress. However, the significance of NTBI in individuals without iron overload and overt cardiovascular disease has not been investigated. We aimed to examine the distribution of serum NTBI and its relationship with oxidative stress and cardiac load under physiological conditions in the general population.We enrolled individuals undergoing an annual health check-up and measured serum NTBI and derivatives of reactive oxygen metabolites (d-ROM), an oxidative stress marker. In addition, we evaluated serum levels of B-type natriuretic peptide (BNP) to examine cardiac load. We excluded patients with anemia, renal dysfunction, cancer, active inflammatory disease, or a history of cardiovascular disease.A total of 1244 individuals (57.8 ± 11.8 years) were enrolled, all of whom had detectable serum NTBI. d-ROM and BNP showed significant trends across NTBI quartiles. Multivariable regression analysis revealed that serum iron and low-density lipoprotein cholesterol were positively associated with NTBI but that age, d-ROM, and BNP showed an inverse association with this measure. In logistic regression analysis, NTBI was independently associated with a combination of higher levels of both d-ROM and BNP than the upper quartiles after adjustment for possible confounding factors.Serum NTBI concentration is detectable in the general population and shows significant inverse associations with oxidative stress and cardiac load. These findings indicate that serum NTBI in physiological conditions does not necessarily reflect increased oxidative stress, in contrast to the implications of higher levels in states of iron overload or pathological conditions.

Do Only Calcium and Vitamin D Matter? Micronutrients in the Diet of Inflammatory Bowel Diseases Patients and the Risk of Osteoporosis

Osteoporosis is one of the most common extraintestinal complications among patients suffering from inflammatory bowel diseases. The role of vitamin D and calcium in the prevention of a decreased bone mineral density is well known, although other nutrients, including micronutrients, are also of extreme importance. Despite the fact that zinc, copper, selenium, iron, cadmium, silicon and fluorine have not been frequently discussed with regard to the prevention of osteoporosis, it is possible that a deficiency or excess of the abovementioned elements may affect bone mineralization. Additionally, the risk of malnutrition, which is common in patients with ulcerative colitis or Crohn's disease, as well as the composition of gut microbiota, may be associated with micronutrients status.

Ambient fine particulate matter aggravates atherosclerosis in apolipoprotein E knockout mice by iron overload via the hepcidin-ferroportin axis

AIMS

Exposure to fine particulate matter (PM2.5) is correlated to atherosclerosis, but the mechanism remains largely undefined. Iron overload is a significant contributor to atherosclerosis, and iron homeostasis is highly regulated by the hepcidin-ferroportin (FPN) axis. Here we aimed to investigate the association between iron overload and PM2.5-induced atherosclerotic mice.

MAIN METHODS

Apolipoprotein E knockout (ApoE-/-) mice were randomly assigned to filtered air (FA group) or PM2.5 (PM2.5 group) for 3-month inhalation. Daily PM2.5 mass concentrations, serum levels of ferritin, iron, pro-atherosclerotic cytokines and lipid profiles, atherosclerotic lesion areas, hepcidin, FPN and iron depositions in atherosclerotic lesions, hepcidin, FPN mRNA and protein expressions in the aorta were detected, respectively.

KEY FINDINGS

The daily average concentration of atmospheric PM2.5 was 68.2 ± 21.8 μg/m3. Serum levels of ferritin, iron, VEGF, MCP-1, IL-6, TNF-α, TC and LDL-C, atherosclerotic lesion areas, hepcidin and iron depositions in atherosclerotic lesions, hepcidin mRNA and protein expressions in the PM2.5 group were observably higher than those in the FA group. Nevertheless, FPN deposition in atherosclerotic lesions, FPN mRNA and protein expressions in the aorta of the PM2.5 group were markedly lower than those of the FA group.

SIGNIFICANCE

PM2.5 inhalation could exacerbate the formation and development of atherosclerosis in ApoE-/- mice, the potential mechanisms may be partly associated with iron overload via the hepcidin-FPN axis, as well as iron-triggered systemic inflammation and hyperlipidemia.

Oral Health Profiles and Related Quality of Life in Thalassemia Children in Relation to Iron Overload: A Cross-Sectional Study

The aim was to assess the oral health of children with β-thalassemia major (BTM) and their oral health-related quality of life (OHRQoL) in relation to the serum ferritin level (SFL). Thirty-nine children with BTM underwent an interview, salivary sampling and an oral clinical examination. The Early Childhood Oral Health Impact Scale (ECOHIS) was used to assess their OHRQoL. The mean age of the participants was 9 ± 3 years, with 62% females. The body mass index and salivary secretion rate were within normal ranges. The mean plaque index, gingival bleeding index and number of decayed, missing and filled tooth surfaces were 70 ± 29, 38 ± 25 and 3.2 ± 4, respectively, with no significant differences between individuals with SFL below or above 2000 ng/mL (p > 0.05). No significant differences were observed between the two groups in any of the ECOHIS questions (p > 0.05). The mean ECOHIS score was 4.2 ± 4. Individuals with SFL ≥2000 ng/mL had a significantly higher mean score in the family domain "Parent Distress" than those with lower SFL (p ≤ 0.05). Within the study limits, children with β-thalassemia major generally had high dental caries experience and gingival inflammation, yet an acceptable OHRQoL. Those with high SFL had less favorable scores in the domain "Parent Distress".

Management of Iron Overload in Beta-Thalassemia Patients: Clinical Practice Update Based on Case Series

Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.

A Potential Role for Excess Tissue Iron in Development of Cardiovascular Delayed Effects of Acute Radiation Exposure

Murine hematopoietic-acute radiation syndrome (H-ARS) survivors of total body radiation (TBI) have a significant loss of heart vessel endothelial cells, along with increased tissue iron, as early as 4 mo post-TBI. The goal of the current study was to determine the possible role for excess tissue iron in the loss of coronary artery endothelial cells. Experiments used the H-ARS mouse model with gamma radiation exposure of 853 cGy (LD50/30) and time points from 1 to 12 wk post-TBI. Serum iron was elevated at 1 wk post-TBI, peaked at 2 wk post-TBI, and returned to non-irradiated control values by 4 wk post-TBI. A similar trend was seen for transferrin saturation, and both results correlated inversely with red blood cell number. Perls' Prussian Blue staining, used to detect iron deposition in heart tissue sections, showed myocardial iron was present as early as 2 wk following irradiation. Pretreatment of mice with the iron chelator deferiprone decreased tissue iron but not serum iron at 2 wk. Coronary artery endothelial cell density was significantly decreased as early as 2 wk vs. non-irradiated controls (P<0.05), and the reduced density persisted to 12 wk after irradiation. Deferiprone treatment of irradiated mice prevented the decrease in endothelial cell density at 2 and 4 wk post-TBI compared to irradiated, non-treated mice (P<0.03). Taken together, the results suggest excess tissue iron contributes to endothelial cell loss early following TBI and may be a significant event impacting the development of delayed effects of acute radiation exposure.

Selenium or ozone: Effects on liver injury caused by experimental iron overload

AIMS

Iron is an important metal ion as a biocatalyst on the other hand iron overload causes various diseases. Iron overload can result in fibrosis and hepatocellular carcinoma with various pathophysiological mechanisms, including oxidative damage in the liver. Therefore; in this study the effects of ozone and selenium -whose antioxidant properties are known- were evaluated in liver injury induced by iron overload.

MATERIALS AND METHODS

Iron overload model was provided by intraperitoneal administration of 88 mg/kg iron dextrate for 4 weeks. After iron dextran administration, ozone and selenium administrations were made for 3 weeks. From the obtained blood and tissue samples total oxidant status (TOS) and total antioxidant status (TAS) were determined and histopathological examination was performed in liver tissue samples.

KEY FINDINGS

In rats with iron overload, the lowest mean serum TOS was observed in the selenium administration group. The highest tissue TOS means and the lowest tissue TAS means were determined in the group in which ozone and selenium were administrated together. When histopathological data were evaluated, the presence of increased apoptosis in the ozone group compared to the iron group (p = 0.019) and selenium group (p = 0.019) was noted. Similarly, increased periportal inflammation (p = 0.001) and fibrosis (p = 0.005) were observed in the ozone group compared to the selenium group.

SIGNIFICANCE

In iron-induced liver damage, ozone was thought to be effective by decreasing ROS, but contrary to expectations, it was observed that it may negatively affect the picture by showing synergistic effect. However, the effects of selenium on both serum and tissue levels are promising.

Hepatic transferrin plays a role in systemic iron homeostasis and liver ferroptosis

Although the serum-abundant metal-binding protein transferrin (encoded by the Trf gene) is synthesized primarily in the liver, its function in the liver is largely unknown. Here, we generated hepatocyte-specific Trf knockout mice (Trf-LKO), which are viable and fertile but have impaired erythropoiesis and altered iron metabolism. Moreover, feeding Trf-LKO mice a high-iron diet increased their susceptibility to developing ferroptosis-induced liver fibrosis. Importantly, we found that treating Trf-LKO mice with the ferroptosis inhibitor ferrostatin-1 potently rescued liver fibrosis induced by either high dietary iron or carbon tetrachloride (CCl4) injections. In addition, deleting hepatic Slc39a14 expression in Trf-LKO mice significantly reduced hepatic iron accumulation, thereby reducing ferroptosis-mediated liver fibrosis induced by either a high-iron diet or CCl4 injections. Finally, we found that patients with liver cirrhosis have significantly lower levels of serum transferrin and hepatic transferrin, as well as higher levels of hepatic iron and lipid peroxidation, compared with healthy control subjects. Taken together, these data indicate that hepatic transferrin plays a protective role in maintaining liver function, providing a possible therapeutic target for preventing ferroptosis-induced liver fibrosis.

[Aceruloplasminemia, a rare condition not to be overlooked]

Aceruloplasminemia is a rare iron-overload disease that should be better known by physicians. It is an autosomal recessive disorder due to mutations in ceruloplasmin gene causing systemic iron overload, including cerebral and liver parenchyma. The impairment of ferroxidase ceruloplasmin activity leads to intracellular iron retention leading aceruloplasminemia symptoms. Neurologic manifestations include cognitive impairment, ataxia, extrapyramidal syndrome, abnormal movements, and psychiatric-like syndromes. Physicians should search for aceruloplasminemia in several situations with high ferritin levels: microcytic anaemia, diabetes mellitus, neurological and psychiatric disorders. Diagnosis approach is based on the study of transferrin saturation and hepatic iron content evaluated by magnetic resonance imaging of the liver. Ceruloplasmin dosage is required in case of low transferrin saturation and high hepatic iron content and genetic testing is mandatory in case of serum ceruloplasmin defect. Neurological manifestations occur in the sixties decade and leads to disability. Iron chelators are widely used. Despite their efficacy on systemic and cerebral iron overload, iron chelators tolerance is poor. Early initiation of iron chelation therapy might prevent or slowdown neurodegeneration, highlighting the need for an early diagnosis but their clinical efficacy remains uncertain.

Iron Overload Associated Endocrine Dysfunction Leading to Lower Bone Mineral Density in Thalassemia Major

CONTEXT

Patients with thalassemia major (TM) have a lower bone mineral density (BMD) and higher risk of fracture than the general population. The possible mechanisms include anemia, iron overload, malnutrition, and hormonal deficiency, but these have not been thoroughly investigated.

OBJECTIVE

To identify major mineral and hormonal factors related to BMD in adult TM patients to provide human evidence for the proposed mechanisms.

DESIGN

Retrospective study.

SETTING

Referral center.

PATIENTS

Twenty-nine patients with β-TM, aged 23 to 44 years who were followed-up during 2017 to 2018 were enrolled.

OUTCOME MEASUREMENTS

Endocrine profiles, including thyroid, parathyroid, and pituitary function, glucose, vitamin D, calcium, phosphate, and fibroblast growth factor 23 (FGF23) were obtained. The relationships among the above parameters, body height, fractures, and BMD were analyzed.

RESULTS

Abnormal BMD was observed in 42.9% of women and 23.1% of men. The mean final heights of women and men were 3.7 cm and 7.3 cm lower than the mean expected values, respectively. Fracture history was recorded in 26.7% of women and 35.7% of men. BMD was negatively correlated with parathyroid hormone, FGF23, thyrotropin, and glycated hemoglobin (HbA1c) levels, and positively correlated with testosterone, IGF-1, and corticotropin levels (all P < .05). Moreover, hypothyroidism was associated with lower BMD in both the lumbar spine (P = .024) and the femoral neck (P = .004). Patients with hypothyroidism had a higher percentage of abnormal BMD (P = .016).

CONCLUSION

Hypothyroidism, higher HbA1c, and lower adrenocorticotropin were predictors of abnormal BMD in patients with β-TM. Whether the correction of these factors improves BMD warrants further research.

Increased incidence of infection in patients with myelofibrosis and transfusion-associated iron overload in the clinical setting

Transfusion-associated iron overload may lead to increased risk of infection, but its role in myelofibrosis (MF) has been scarcely explored. We evaluated 106 consecutive patients with primary or secondary MF. Up to 38% of patients were transfusion-dependent (TD) with a median of 14 RBC units received. Median observation time was 36 months (range 3-203). Forty-five percent of patients experienced one or more infectious episodes for a total of 69 infectious events, 13 (19%) of which were severe. The 60-month cumulative incidence of infection was 64.1 ± 6.5%. TD patients showed a higher incidence of infection (HR = 2.13, p = 0.019). Transfusion burden was markedly greater in TD patients with infectious complication (median 24 RBC units vs 15 RBC units; p = 0.012). The 60-month overall survival was 40 ± 5.9%. Lower International Prognostic Scoring System (IPSS) risk (p < 0.0001) and ruxolitinib (p = 0.027) were significantly correlated with higher survival. This real-world study showed increased infections in patients with higher transfusion burden. It may therefore be interesting to further investigate the role of iron chelation in improving infection-free survival in MF patients.