Plasma and tissue transferrin and ferritin, and gene expression of ferritin, transferrin, and transferrin receptors I and II in channel catfish Ictalurus punctatus fed diets with different concentrations of inorganic or organic iron.

Ferritin, transferrin, and transferrin receptors I and II play a vital role in iron metabolism, health, and indication of iron deficiency anaemia in fish. To evaluate the use of high-iron diets to prevent or reverse channel catfish (Ictalurus punctatus) anaemia of unknown causes, we investigated the expression of these iron-regulatory genes and proteins in channel catfish fed plant-based diets. Catfish fingerlings were fed five diets supplemented with 0 (basal), 125, and 250 mg/kg of either inorganic iron or organic iron for 2 weeks. Ferritin, transferrin, and transferrin receptor I and II mRNA and protein expression levels in fish tissues (liver, intestine, trunk kidney, and head kidney) and plasma were determined. Transferrin (iron transporter) and TfR (I and II) genes were generally highly expressed in fish fed the basal diet compared to those fed the iron-supplemented diets. In contrast, ferritin (iron storage) genes were more expressed in the trunk kidney of fish fed the iron-supplemented diets than in those fed the basal diet. Our results demonstrate that supplementing channel catfish plant-based diets with iron from either organic or inorganic iron sources affected the expression of the iron-regulatory genes and increased body iron status in the fish.

Imbalance of Iron Availability and Demand in Patients With Acute and Chronic Heart Failure.

BACKGROUND: Iron deficiency (ID) is a frequent comorbidity in patients with acute (AHF) and chronic heart failure (CHF) associated with morbidity and death. We aimed to better characterize iron homeostasis in patients with heart failure applying different biomarkers and to evaluate the accuracy of current ID definition by the European Society of Cardiology/American College of Cardiology/American Heart Association to indicate tissue iron availability and demand. METHODS AND RESULTS: We performed a retrospective cohort study investigating 277 patients with AHF and 476 patients with CHF between February 2021 and May 2022. Patients with AHF had more advanced ID than patients with CHF, reflected by increased soluble transferrin receptor and soluble transferrin receptor-ferritin index, and lower ferritin, serum iron, transferrin saturation, hepcidin, and reticulocyte hemoglobin. Decreased iron availability or increased tissue iron demand, reflected by increased soluble transferrin receptor-ferritin index and decreased reticulocyte hemoglobin, was found in 84.1% (AHF) and 28.0% (CHF) with absolute ID and in 50.0% (AHF) and 10.5% (CHF) with combined ID according to the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition. Low hepcidin expression as an indicator of systemic ID was found in 91.1% (AHF) and 80.4% (CHF) of patients with absolute ID and in 32.3% (AHF) and 18.8% (CHF) of patients with combined ID. ID definitions with higher specificity reduce the need for iron supplementation by 25.5% in patients with AHF and by 65.6% in patients with CHF. CONCLUSIONS: Our results suggest that the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition might overestimate true ID, particularly in CHF. More stringent thresholds for ID could more accurately identify patients with heart failure with reduced tissue iron availability who benefit from intravenous iron supplementation.

Real-world experience of intravenous iron sucrose supplementation and dynamics of soluble transferrin receptor and hepcidin in a Spanish cohort of absolute iron deficient patients.

The study evaluated the safety and effectiveness of the generic intravenous (IV) iron treatment (Feriv®), in a Spanish cohort with absolute iron deficiency (ID) (serum ferritin <50 ng/ml, with or without anaemia) (n = 122; 91% women; median age of 44 years [IQR: 33.7-54]). Iron-related biomarkers were measured before treatment (baseline), 2 weeks after beginning the protocol (intermediate control, IC) and between 7 and 10 days after treatment completion (final time-point). Primary efficacy endpoints were ferritin levels ≥ 50 ng/ml, anaemia restoration or an increase in haemoglobin (Hb) of at least one point in patients without baseline anaemia. After treatment, iron-related biomarkers improved, including ferritin, Hb, sideremia, transferrin, transferrin saturation index, soluble transferrin receptor (sTfR), and hepcidin. Baseline ferritin concentration (13.5 ng/ml [IQR: 8-24.2]) increased at the IC and continued rising at the final time-point, reaching a median ferritin of 222 ng/ml and 97.3% of patients ≥ 50 ng/ml. At the final time-point, anaemia prevalence decreased from 26.2% to 5%, while the 34.1% without baseline anaemia showed an increase in Hb of at least one point. Headache was the only drug-adverse event recorded in 2.3% of patients. At a late time-point (27.5 median weeks after ending therapy [IQR: 22-40]), evaluated in a subgroup of 66 patients, 18% had ferritin levels < 50 ng/ml. Multivariate analysis showed that low baseline ferritin and high sTfR/hepcidin ratio tended to be independently associated with ID recurrence. Feriv® is a safe, effective first-line treatment for absolute ID, with improvement of serum ferritin and Hb. ID recurrence was associated with the baseline degree of iron stores depletion, indicated by serum ferritin, and sTfR/hepcidin ratio.

Age, dose, and binding to TfR on blood cells influence brain delivery of a TfR-transported antibody.

BACKGROUND: Transferrin receptor 1 (TfR1) mediated brain delivery of antibodies could become important for increasing the efficacy of emerging immunotherapies in Alzheimer's disease (AD). However, age, dose, binding to TfR1 on blood cells, and pathology could influence the TfR1-mediated transcytosis of TfR1-binders across the blood-brain barrier (BBB). The aim of the study was, therefore, to investigate the impact of these factors on the brain delivery of a bispecific TfR1-transported Aß-antibody, mAb3D6-scFv8D3, in comparison with the conventional antibody mAb3D6. METHODS: Young (3-5 months) and aged (17-20 months) WT and tg-ArcSwe mice (AD model) were injected with 125I-labeled mAb3D6-scFv8D3 or mAb3D6. Three different doses were used in the study, 0.05 mg/kg (low dose), 1 mg/kg (high dose), and 10 mg/kg (therapeutic dose), with equimolar doses for mAb3D6. The dose-corrected antibody concentrations in whole blood, blood cells, plasma, spleen, and brain were evaluated at 2 h post-administration. Furthermore, isolated brains were studied by autoradiography, nuclear track emulsion, and capillary depletion to investigate the intrabrain distribution of the antibodies, while binding to blood cells was studied in vitro using blood isolated from young and aged mice. RESULTS: The aged WT and tg-ArcSwe mice showed significantly lower brain concentrations of TfR-binding [125I]mAb3D6-scFv8D3 and higher concentrations in the blood cell fraction compared to young mice. For [125I]mAb3D6, no significant differences in blood or brain delivery were observed between young and aged mice or between genotypes. A low dose of [125I]mAb3D6-scFv8D3 was associated with increased relative parenchymal delivery, as well as increased blood cell distribution. Brain concentrations and relative parenchymal distribution of [125I]mAb3D6-scFv8D6 did not differ between tg-ArcSwe and WT mice at this early time point but were considerably increased compared to those observed for [125I]mAb3D6. CONCLUSION: Age-dependent differences in blood and brain concentrations were observed for the bispecific antibody mAb3D6-scFv8D3 but not for the conventional Aß antibody mAb3D6, indicating an age-related effect on TfR1-mediated brain delivery. The lowest dose of [125I]mAb3D6-scFv8D3 was associated with higher relative BBB penetration but, at the same time, a higher distribution to blood cells. Overall, Aß-pathology did not influence the early brain distribution of the bispecific antibody. In summary, age and bispecific antibody dose were important factors determining brain delivery, while genotype was not.

Markers of Iron Metabolism and Outcomes in Patients with Heart Failure: A Systematic Review.

Iron deficiency (ID) in conjunction with heart failure (HF) poses a challenge for clinicians and is associated with worse HF outcomes. Treatment of ID with IV iron supplementation for patients with HF has demonstrated benefits in quality of life (QoL) and HF-related hospitalizations. The aim of this systematic review was to summarize the evidence linking iron metabolism biomarkers with outcomes in patients with HF to assist in the optimal use of these biomarkers for patient selection. A systematic review of observational studies in English from 2010 to 2022 was conducted using PubMed, with keywords of "Heart Failure" and respective iron metabolism biomarkers ("Ferritin", "Hepcidin", "TSAT", "Serum Iron", and "Soluble Transferrin Receptor"). Studies pertaining to HF patients, with available quantitative data on serum iron metabolism biomarkers, and report of specific outcomes (mortality, hospitalization rates, functional capacity, QoL, and cardiovascular events) were included, irrespective of left ventricular ejection fraction (LVEF) or other HF characteristics. Clinical trials of iron supplementation and anemia treatment were removed. This systematic review was conducive to formal assessment of risk of bias via Newcastle-Ottawa Scale. Results were synthesized based on their respective adverse outcomes and iron metabolism biomarker(s). Initial and updated searches identified 508 unique titles once duplicates were removed. The final analysis included 26 studies: 58% focused on reduced LVEF; age range was 53-79 years; males composed 41-100% of the reported population. Statistically significant associations of ID were observed with all-cause mortality, HF hospitalization rates, functional capacity, and QoL. Increased risk for cerebrovascular events and acute renal injury have also been reported, but these findings were not consistent. Varying definitions of ID were utilized among the studies; however, most studies employed the current European Society of Cardiology criteria: serum ferritin < 100 ng/mL or the combination of ferritin between 100-299 ng/mL and transferrin saturation (TSAT) < 20%. Despite several iron metabolism biomarkers demonstrating strong association with several outcomes, TSAT better predicted all-cause mortality, as well as long-term risk for HF hospitalizations. Low ferritin was associated with short-term risk for HF hospitalizations, worsening functional capacity, poor QoL, and development of acute renal injury in acute HF. Elevated soluble transferrin receptor (sTfR) levels were associated with worse functional capacity and QoL. Finally, low serum iron was significantly associated with increased risk for cardiovascular events. Considering the lack of consistency among the iron metabolism biomarkers for association with adverse outcomes, it is important to incorporate additional biomarker data, beyond ferritin and TSAT, when assessing for ID in HF patients. These inconsistent associations question how best to define ID to ensure proper treatment. Further research, potentially tailored to specific HF phenotypes, is required to optimize patient selection for iron supplementation therapy and appropriate targets for iron stores replenishment.

Transferrin receptor 2 deficiency promotes macrophage polarization and inflammatory arthritis.

OBJECTIVE: Rheumatoid arthritis is an inflammatory joint disease in which synovial iron deposition has been described. Transferrin receptor 2 (Tfr2) represents a critical regulator of systemic iron levels. Loss of Tfr2 function in humans and mice results in iron overload. As iron contributes to inflammatory processes, we investigated whether Tfr2-deletion affects the pathogenesis of inflammatory arthritis in an iron-dependent manner. METHODS: Using a global and conditional genetic disruption of Tfr2, we assessed the relevance of Tfr2 in K/BxN serum-transfer arthritis (STA) and macrophage polarization. RESULTS: Male Tfr2-/- mice subjected to STA developed pronounced joint swelling, and bone erosion as compared to Tfr2+/+ littermate-controls (P < 0.01). Furthermore, an increase of neutrophils and macrophages/monocytes was observed in the inflammatory infiltrate within the paws of Tfr2-/- mice. To elucidate whether Tfr2 in myeloid cells has a direct role in the pathogenesis of arthritis or whether the effects were mediated via the systemic iron overload, we induced STA in Tfr2fl/fl-LysMCre + mice, which showed normal iron-loading. Cre + female mice displayed increased disease development compared to Cre-controls. As macrophages regulate iron availability and innate immunity, we hypothesized that Tfr2-deficiency would polarize macrophages toward a pro-inflammatory state (M1) that contributes to arthritis progression. In response to IFN-γ stimulation, Tfr2-/- macrophages showed increased expression of M1-like cytokines, IFN-γ-target genes, nitric-oxide production, and prolonged STAT1 activation compared to Tfr2+/+ macrophages (P < 0.01), while pre-treatment with ruxolitinib abolished Tfr2-driven M1-like polarization. CONCLUSION: Taken together, these findings suggest a protective role of Tfr2 in macrophages on the progression of arthritis via suppression of M1-like polarization.

Potential Interactions When Prescribing SGLT2 Inhibitors and Intravenous Iron in Combination in Heart Failure.

In patients with heart failure, sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to decrease hepcidin and ferritin and increase transferrin receptor protein, changes that are typically indicative of worsening absolute iron deficiency, as would be seen with poor dietary intake or gastrointestinal bleeding, neither of which is provoked by SGLT2 inhibitors. Therefore, 2 alternative conceptual frameworks may explain the observed pattern of changes in iron homeostasis proteins. According to the "cytosolic iron depletion hypothesis," the effect of SGLT2 inhibitors to decrease hepcidin and ferritin and increase transferrin receptor is related to a decline in cytosolic Fe2+ that occurs after drug-induced erythropoietin-related increase in iron use. Erythropoietin-mimetics (eg, darbepoietin) elicit this type of iron-deficiency pattern of response, and it is typically accompanied by erythropoietin resistance that is alleviated by intravenous iron supplementation. In contrast, according to the "cytosolic iron repletion hypothesis," the effect of SGLT2 inhibitors to decrease hepcidin and ferritin and increase transferrin receptor represents a direct action of these drugs: 1) to reverse inflammation-related increases in hepcidin and ferritin, and, thus, alleviate functional blocks on iron utilization; and 2) to increase in sirtuin-1 signaling, which suppresses hepcidin, accelerates the degradation of ferritin, and up-regulates transferrin receptor protein. Through either or both mechanisms, direct suppression of hepcidin and ferritin would be expected to increase cytosolic Fe2+, thus allowing an unattenuated erythrocytic response to erythropoietin without the need for intravenous iron supplementation. The totality of clinical evidence supports the "cytosolic iron repletion hypothesis" because SGLT2 inhibitors elicit a full and sustained erythrocytosis in response to erythropoietin, even in overtly iron-deficient patients and in the absence of intravenous iron therapy. Therefore, the emergence of an iron-deficiency pattern of response during SGLT2 inhibition does not reflect worsening iron stores that are in need of replenishment, but instead, represents potential alleviation of a state of inflammation-related functional iron deficiency that is commonly seen in patients with chronic heart failure. Treatment with intravenous iron may be unnecessary and theoretically deleterious.

Exosomes derived from hepatitis B virus-infected hepatocytes promote liver fibrosis via miR-222/TFRC axis.

Exosomal miRNAs activates hepatic stellate cell (HSC) and promote fibrosis. miR-222 was found to be increased in hepatitis B virus (HBV)-infected hepatocytes, and ferroptosis was reported to ameliorate liver fibrosis (LF). Although miR-222 and ferroptosis have been implicated in LF, the association between miR-222 and ferroptosis and how they coordinate to regulate LF are still not explicit. This study investigates the roles of miR-222 and transferrin receptor (TFRC) in LF. Lipid reactive oxygen species (ROS) level was analyzed by flow cytometry. FerroOrange staining was used to measure intracellular iron level. Luciferase reporter assay was adopted to confirm the binding of miR-222 and TFRC. Real-time quantitative PCR and immunoblots were applied to analyze gene and protein expression. The results showed that supplementation of exosomes derived from HBV-infected LO2 cells remarkably enhanced LX-2 cell activation, evidenced by elevated hydroxyprolin (Hyp) secretion and α-SMA and COL1A2 expression. miR-222 was significantly increased in HBV-Exo. Overexpressing miR-222 upregulated cell viability, secretion of Hpy, and expression of α-SMA and COL1A2, which were all blocked by overexpression of TFRC. Further study showed that TFRC was a target of miR-222, and miR-222 promoted LX-2 cell activation through suppressing TFRC-induced ferroptosis in LX-2 cells. Exosomal miR-222 derived from HBV-infected hepatocytes promoted LF through inhibiting TFRC and TFRC-induced ferroptosis. This study emphasizes the significance of miR-222/TFRC axis in LF and suggests new insights in clinical decision making while treating LF. Exosomes derived from HBV-infected LO2 cells promote LX-2 cell activation and liver fibrosis in mouse Exosomal miR-222 derived from HBV-infected LO2 cells promotes LX-2 cell activation TFRC is a target of miR-222 and inhibits LX-2 cell activation induced by miR-222 miR-222 promotes LX-2 cell activation through inhibiting TFRC-induced ferroptosis.

Effect of hemoglobin extracted from Tegillarca granosa on iron deficiency anemia in mice.

Iron deficiency anemia (IDA) is the most common nutritional deficiency in the world. This study was aimed to evaluate the therapeutic effects of hemoglobin from Tegillarca granosa (T. granosa) on IDA in mice. Mice were randomly divided into five groups: a normal control group, an anemia model group, a positive (FeSO4) control group, a low-dose and high-dose hemoglobin groups. After 4-week iron supplements administration, it was observed that hemoglobin at 2.0 mg iron/kg body weight had better restorative effective on IDA mice than that of FeSO4 with regard to routine blood parameters and serum biochemical indicators. Meanwhile, the IDA-caused alterations of organ coefficients and liver morphology were ameliorated in mice after hemoglobin supplementation in a dose-dependent manner. Further correlation analysis of indicators showed that serum ferritin (iron storage protein) and soluble transferrin receptor (cellular iron uptake membrane glycoprotein) were susceptible to iron deficiency, indicating possibledisorder of iron metabolism caused by IDA. And levels of serum ferritin and soluble transferrin receptor were restored after administration of hemoglobin. These findings confirmed the safety and effectiveness of T. granosa derived hemoglobin in alleviating IDA in mice, suggesting its great potential as an alternative for iron supplementation.

Iron Status and Homeostasis Across 2 Competitive Seasons in NCAA Division I Collegiate Cross-Country Runners Residing at Low Altitude.

PURPOSE: Inflammatory cytokines including interleukin-6 can upregulate hepcidin and decrease iron absorption. Endurance exercise is associated with transient increases in cytokines, which may alter the risk of iron deficiency (ID). This study examined whether chronic elevations in basal levels of cytokines and hepcidin were associated with ID in highly trained runners. METHODS: Fifty-four collegiate runners (26 males and 28 females) living at ∼1625 m were recruited from an NCAA Division I cross-country team for this prospective cohort study. Over 2 seasons, fasted, preexercise blood draws were performed in the morning 4 times per season and were analyzed for hemoglobin concentration, ferritin, soluble transferrin receptor (sTfR), hepcidin, and 10 cytokines. Stages of ID were defined using ferritin, sTfR, and hemoglobin concentration. During the study, a registered dietician provided all runners with iron supplements using athletic department-created guidelines. RESULTS: Fifty-seven percent of females and 35% of males exhibited stage 2 ID (ferritin <20 ng/mL or sTfR >29.5 nmol/L) at least once. Cytokines, ferritin, and sTfR exhibited changes through the 2 years, but changes in cytokines were not associated with alterations in hepcidin, ferritin, or sTfR. In males and females, lower ferritin was associated with lower hepcidin (both P < .0001). One female exhibited higher hepcidin and lower iron stores compared with other individuals, suggesting a different etiology of ID. CONCLUSION: ID is common in highly trained collegiate runners. In general, the high prevalence of ID in this population is not associated with alterations in basal hepcidin or cytokine levels.

Prediction of Iron Deficiency Anemia in Third Trimester of Pregnancy Based on Data in the First Trimester: A Prospective Cohort Study in a High-Income Country.

Background: Systematic iron supplementation may be harmful in pregnant women with non-depleted iron. Our objectives were to estimate the prevalence of anemia at the third trimester of pregnancy (T3) and to identify the parameters at the first trimester (T1), which best predict anemia at T3. Methods: This prospective cohort study in France included pregnant women at T1 without non-iron deficiency anemia. Clinical and social characteristics, health-related quality of life, blood count, and a frozen blood sample were collected at T1 and/or T3. Secondly, a matched nested case−control study was built for women with anemia at T3 but not at T1. Multivariate analyses and ROC curves were used to identify the best predictive parameter(s) of anemia at T3. Results: The prevalence of anemia at T3 in the cohort (629 women) was 21.9% (95% CI 18.7−25.2%). In the matched nested case−control study (256 women), hemoglobin (Hb), serum ferritin (SF) and the SF/soluble transferrin receptor ratio at T1 were predictive of anemia at T3 (p < 0.001); however, clinical and social characteristics, as serum hepcidin were not. In multivariate analyses, Hb at T1 was the best predictive biomarker of anemia at T3 with a cut-off value of 120 g/L (specificity 87.5%). Conclusions: The prevalence of anemia at the end of pregnancy remained high in a High-Income Country. Clinical, social, and biochemical parameters did not seem useful to predict anemia at T3 and could not guide iron supplementation. We suggest systematically performing a simple blood count in the first trimester of pregnancy and offering oral iron supplementation for women with Hb < 120 g/L.

Deferasirox and vitamin D3 co-therapy mitigates iron-induced renal injury by enhanced modulation of cellular anti-inflammatory, anti-oxidative stress, and iron regulatory pathways in rat.

BACKGROUND: Chronic iron overload could induce nephropathy via oxidative stress and inflammation, and chelating therapy has limited efficacy in removing excess intracellular iron. Although vitamin D (VD) has shown potent antioxidant and anti-inflammatory effects, as well contribute to iron homeostasis, none of the previous studies measured its potential remedial effects against chronic iron toxicity. AIMS: To measure the alleviating effects of deferasirox (DFX) and/or vitamin D (VD) single and combined therapies against nephrotoxicity induced by chronic iron overload. METHODS: Forty male rats were divided into negative (NC) and positive (PC) controls, DFX, VD, and DFX/VD groups. The designated groups received iron for six weeks followed by DFX and/or VD for another six weeks. Then, the expression pattern of renal genes and proteins including hepcidin, ferroportin (FPN), megalin, transferrin receptor 1 (TfR1), ferritin heavy and light chains, VD receptor (VDR), VD synthesizing (Cyp27b1) and catabolizing (Cyp24a1) enzymes were measured alongside serum markers of renal function and iron biochemical parameters. Additionally, several markers of oxidative stress (MDA/H2O2/GSH/SOD1/CAT/GPx4) and inflammation (IL-1ß/IL-6/TNF-α/IL-10) together with renal cell apoptosis and expression of caspase-3 (Casp-3) were measured. RESULTS: The PC rats showed pathological iron and renal biochemical markers, hypovitaminosis D, increased renal tissue iron contents with increased Cyp24a1/Megalin/ferritin-chains/hepcidin, and decreased Cyp27b1/VDR/TfR1/FPN expression than the NC group. The PC renal tissues also showed abnormal histology, increased inflammatory (IL-1ß/IL-6/TNF-α), oxidative stress (MDA/H2O2), and apoptosis markers with decreased IL-10/GSH/SOD1/CAT/GPx4. Although DFX monotherapy reduced serum iron levels, it was comparable to the PC group in renal iron concentrations, VD and iron-homeostatic molecules, alongside markers of oxidative stress, inflammation, and apoptosis. On the other hand, VD monotherapy markedly modulated renal iron and VD-related molecules, reduced renal tissue iron concentrations, and preserved renal tissue relative to the PC and DFX groups. However, serum iron levels were equal in the VD and PC groups. In contrast, the best significant improvements in serum and renal iron levels, expression of renal iron-homeostatic molecules, oxidative stress, inflammation, and apoptosis were seen in the co-therapy group. CONCLUSIONS: iron-induced nephrotoxicity was associated with dysregulations in renal VD-system together with renal oxidative stress, inflammation, and apoptosis. While DFX reduced systemic iron, VD monotherapy showed better attenuation of renal iron concentrations and tissue damage. Nonetheless, the co-therapy approach exhibited the maximal remedial effects, possibly by enhanced modulation of renal iron-homeostatic molecules alongside reducing systemic iron levels. AVAILABILITY OF DATA AND MATERIALS: All data generated or analysed during this study are included in this published article [and its Supplementary information files].

Transferrin receptor 2 (Tfr2) genetic deletion makes transfusion-independent a murine model of transfusion-dependent ß-thalassemia.

ß-thalassemia is a genetic disorder caused by mutations in the ß-globin gene, and characterized by anemia, ineffective erythropoiesis and iron overload. Patients affected by the most severe transfusion-dependent form of the disease (TDT) require lifelong blood transfusions and iron chelation therapy, a symptomatic treatment associated with several complications. Other therapeutic opportunities are available, but none is fully effective and/or applicable to all patients, calling for the identification of novel strategies. Transferrin receptor 2 (TFR2) balances red blood cells production according to iron availability, being an activator of the iron-regulatory hormone hepcidin in the liver and a modulator of erythropoietin signaling in erythroid cells. Selective Tfr2 deletion in the BM improves anemia and iron-overload in non-TDT mice, both as a monotherapy and, even more strikingly, in combination with iron-restricting approaches. However, whether Tfr2 targeting might represent a therapeutic option for TDT has never been investigated so far. Here, we prove that BM Tfr2 deletion improves anemia, erythrocytes morphology and ineffective erythropoiesis in the Hbbth1/th2 murine model of TDT. This effect is associated with a decrease in the expression of α-globin, which partially corrects the unbalance with ß-globin chains and limits the precipitation of misfolded hemoglobin, and with a decrease in the activation of unfolded protein response. Remarkably, BM Tfr2 deletion is also sufficient to avoid long-term blood transfusions required for survival of Hbbth1/th2 animals, preventing mortality due to chronic anemia and reducing transfusion-associated complications, such as progressive iron-loading. Altogether, TFR2 targeting might represent a promising therapeutic option also for TDT.

Grab regulates transferrin receptor recycling and iron uptake in developing erythroblasts.

Developing erythroblasts acquire massive amounts of iron through the transferrin (Tf) cycle, which involves endocytosis, sorting, and recycling of the Tf-Tf receptor (Tfrc) complex. Previous studies on the hemoglobin-deficit (hbd) mouse have shown that the exocyst complex is indispensable for the Tfrc recycling; however, the precise mechanism underlying the efficient exocytosis and recycling of Tfrc in erythroblasts remains unclear. Here, we identify the guanine nucleotide exchange factor Grab as a critical regulator of the Tf cycle and iron metabolism during erythropoiesis. Grab is highly expressed in differentiating erythroblasts. Loss of Grab diminishes the Tfrc recycling and iron uptake, leading to hemoglobinization defects in mouse primary erythroblasts, mammalian erythroleukemia cells, and zebrafish embryos. These defects can be alleviated by supplementing iron together with hinokitiol, a small-molecule natural compound that can mediate iron transport independent of the Tf cycle. Mechanistically, Grab regulates the exocytosis of Tfrc-associated vesicles by activating the GTPase Rab8, which subsequently promotes the recruitment of the exocyst complex and vesicle exocytosis. Our results reveal a critical role for Grab in regulating the Tf cycle and provide new insights into iron homeostasis and erythropoiesis.

Detection of Ferritin Expression in Soft Tissue Sarcomas With MRI: Potential Implications for Iron Metabolic Therapy.

Background: Cancer cells often have altered iron metabolism relative to non-malignant cells with increased transferrin receptor and ferritin expression. Targeting iron regulatory proteins as part of a cancer therapy regimen is currently being investigated in various malignancies. Anti-cancer therapies that exploit the differences in iron metabolism between malignant and non-malignant cells (e.g. pharmacological ascorbate and iron chelation therapy) have shown promise in various cancers, including glioblastoma, lung, and pancreas cancers. Non-invasive techniques that probe tissue iron metabolism may provide valuable information for the personalization of iron-based cancer therapies. T2* mapping is a clinically available MRI technique that assesses tissue iron content in the heart and liver. We aimed to investigate the capacity of T2* mapping to detect iron stores in soft tissue sarcomas (STS). Methods: In this study, we evaluated T2* relaxation times ex vivo in five STS samples from subjects enrolled on a phase Ib/IIa clinical trial combining pharmacological ascorbate with neoadjuvant radiation therapy. Iron protein expression levels (ferritin, transferrin receptor, iron response protein 2) were evaluated by Western blot analysis. Bioinformatic data relating clinical outcomes in STS patients and iron protein expression levels were evaluated using the KMplotter database. Results: There was a high level of inter-subject variability in the expression of iron protein and T2* relaxation times. We identified that T2* relaxation time is capable of accurately detecting ferritin-heavy chain expression (r = -0.96) in these samples. Bioinformatic data acquired from the KMplot database revealed that transferrin receptor and iron-responsive protein 2 may be negative prognostic markers while ferritin expression may be a positive prognostic marker in the management of STS. Conclusion: These data suggest that targeting iron regulatory proteins may provide a therapeutic approach to enhance STS management. Additionally, T2* mapping has the potential to be used a clinically accessible, non-invasive marker of STS iron regulatory protein expression and influence cancer therapy decisions that warrants further investigation. Level of Evidence: IV.

Associations of a metal mixture with iron status in U.S. adolescents: Evidence from the National Health and Nutrition Examination Survey.

Iron is needed for normal development in adolescence. Exposure to individual environmental metals (e.g., lead) has been associated with altered iron status in adolescence, but little is known about the cumulative associations of multiple metals with Fe status. We used data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) to examine associations between a metal mixture (lead, manganese, cadmium, selenium) and iron status in 588 U.S. adolescents (12-17 years). We estimated cumulative and interactive associations of the metal mixture with five iron status metrics using Bayesian Kernel Machine Regression (BKMR). Higher concentrations of manganese and cadmium were associated with lower log-transformed ferritin concentrations. Interactions were observed between manganese, cadmium, and lead for ferritin and the transferrin receptor, where iron status tended to be worse at higher concentrations of all metals. These results may reflect competition between environmental metals and iron for cellular uptake. Mixed metal exposures may alter normal iron function, which has implications for adolescent development.

The effect of oral iron supplementation on the gut microbiota, gut inflammation, and iron status in iron-depleted South African school-age children with virally suppressed HIV and without HIV.

PURPOSE: Both HIV and oral iron interventions may alter gut microbiota composition and increase gut inflammation. We determined the effect of oral iron supplementation on gut microbiota composition, gut inflammation, and iron status in iron-depleted South Africa school-aged children living with HIV (HIV+) but virally suppressed on antiretroviral therapy and children without HIV (HIV-ve). METHODS: In this before-after intervention study with case-control comparisons, we provided 55 mg elemental iron from ferrous sulphate, once daily for 3 months, to 33 virally suppressed (< 50 HIV RNA copies/mL) HIV+ and 31 HIV-ve children. At baseline and endpoint, we assessed microbial composition of faecal samples (16S rRNA sequencing), and markers of gut inflammation (faecal calprotectin), anaemia (haemoglobin) and iron status (plasma ferritin, soluble transferrin receptor). This study was nested within a larger trial registered at clinicaltrials.gov as NCT03572010. RESULTS: HIV+ (11.3y SD ± 1.8, 46% male) and HIV-ve (11.1y SD ± 1.7, 52% male) groups did not significantly differ in age or sex ratio. Following iron supplementation, improvements were observed in haemoglobin (HIV+ : 118 to 124 g/L, P = 0.003; HIV-ve: 120 to 124 g/L, P = 0.003), plasma ferritin (HIV+ : 15 to 34 µg/L, P < 0.001; HIV-ve: 18 to 37 µg/L, P < 0.001), and soluble transferrin receptor (HIV+ : 7.1 to 5.9 mg/L, P < 0.001; HIV-ve: 6.6 to 5.7 mg/L, P < 0.001), with no significant change in the relative abundance of any genera, alpha diversity of the gut microbiota (HIV+ : P = 0.37; HIV-ve: P = 0.77), or faecal calprotectin (HIV+ : P = 0.42; HIV-ve: P = 0.80). CONCLUSION: Our findings suggest that oral iron supplementation can significantly improve haemoglobin and iron status without increasing pathogenic gut microbial taxa or gut inflammation in iron-depleted virally suppressed HIV+ and HIV-ve school-age children.

Iron supplementation ameliorates aloin-induced iron deficiency anemia in rats.

Aloin, an anthraquinone glycoside, is one of other C-glycosides found in the leaf exudate of Aloe plant. Aloin possesses several biologic activities, including antitumor activity in vitro and in vivo. However, aloin treatment has shown iron deficiency anemia and erythropoiesis in vivo. The present study was undertaken to verify if iron supplementation could alleviate these perturbations, compared to doxorubicin, an anthracycline analog. Oral iron supplementation (20.56 mg elemental Fe/kg bw) to aloin-treated rats normalized red blood corpuscles count, hemoglobin concentration, and serum levels of total iron binding capacity and saturated transferrin, as well as hepatic iron content, hepcidin level, and mRNA expression of ferritin heavy chain (Ferr-H) and transferrin receptor-1 (TfR-1) genes. Although, serum hyperferremia, and leukocytosis were maintained, yet the spleen iron overload was substantially modulated. However, combined aloin and iron treatment increased iron storage levels in the heart and bone marrow, compared to aloin treatment per se. On other hand, oral iron supplementation to rats treated with doxorubicin (15 mg/kg bw) lessened the increase in the spleen iron content concomitantly with hepatic hepcidin level, rebound hepatic iron content to normal level, and by contrast augmented serum levels of iron and transferrin saturation. Also, activated Ferr-H mRNA expression and repressed TfR-1 mRNA expression were recorded, compared to doxorubicin treatment per se. Histopathological examination of the major body iron stores in rats supplemented with iron along with aloin or doxorubicin showed an increase in extramedullary hematopoiesis. In conclusion, iron supplementation restores the disturbances in iron homeostasis and erythropoiesis induced by aloin treatment.

Hepcidin and Iron Deficiency in Women One Year after Sleeve Gastrectomy: A Prospective Cohort Study.

Iron deficiency with or without anemia, needing continuous iron supplementation, is very common in obese patients, particularly those requiring bariatric surgery. The aim of this study was to address the impact of weight loss on the rescue of iron balance in patients who underwent sleeve gastrectomy (SG), a procedure that preserves the duodenum, the main site of iron absorption. The cohort included 88 obese women; sampling of blood and duodenal biopsies of 35 patients were performed before and one year after SG. An analysis of the 35 patients consisted in evaluating iron homeostasis including hepcidin, markers of erythroid iron deficiency (soluble transferrin receptor (sTfR) and erythrocyte protoporphyrin (PPIX)), expression of duodenal iron transporters (DMT1 and ferroportin) and inflammatory markers. After surgery, sTfR and PPIX were decreased. Serum hepcidin levels were increased despite the significant reduction in inflammation. DMT1 abundance was negatively correlated with higher level of serum hepcidin. Ferroportin abundance was not modified. This study shed a new light in effective iron recovery pathways after SG involving suppression of inflammation, improvement of iron absorption, iron supply and efficiency of erythropoiesis, and finally beneficial control of iron homeostasis by hepcidin. Thus, recommendations for iron supplementation of patients after SG should take into account these new parameters of iron status assessment.

Fusaricide is a Novel Iron Chelator that Induces Apoptosis through Activating Caspase-3.

Nonsmall cell lung cancer (NSCLC) has been a fatal and refractory disease worldwide. Novel therapeutic developments based on fundamental investigations of anticancer mechanisms underlie substantial foundations to win the fight against cancer diseases. In this study, we isolated a natural product fusaricide (FCD) from an endophytic fungus of Lycium barbarum, identified as Epicoccum sp. For the first time, we discovered that FCD potently inhibited proliferation in a variety of human NSCLC cell lines, with relatively less toxicity to normal cells. Our study exhibited that FCD induced apoptosis, caused DNA damage and cell cycle arrest in G0/G1 phase, and activated caspase-3 as well as other apoptosis-related factors in human NSCLC NCI-H460 cells. FCD was proven to be an iron chelator that actively decreased levels of cellular labile iron pool in NCI-H460 cells in our study. FeCl3 supplement reversed FCD-induced apoptosis. The upregulation of transferrin receptor 1 (TfR1) and downregulation of ferritin heavy chain (FTH) expression were observed after FCD treatment. In summary, our study highlighted the potential anticancer effects of FCD against human NSCLCs and demonstrated that the FCD-mediated apoptosis depended on binding to intracellular iron.