Ferric Ammonium Citrate Research Articles

Astrocyte-derived lactoferrin inhibits neuronal ferroptosis by reducing iron content and GPX4 degradation in APP/PS1 transgenic mice

Increased astrocytic lactoferrin (Lf) expression was observed in the brains of elderly individuals and Alzheimer's disease (AD) patients. Our previous study revealed that astrocytic Lf overexpression improved cognitive capacity by facilitating Lf secretion to neurons to inhibit β-amyloid protein (Aβ) production in APP/PS1 mice. Here, we further discovered that astrocytic Lf overexpression inhibited neuronal loss by decreasing iron accumulation and increasing glutathione peroxidase 4 (GPX4) expression in neurons within APP/PS1 mice. Furthermore, human Lf (hLf) treatment inhibited ammonium ferric citrate (FAC)-induced ferroptosis by chelating intracellular iron. Additionally, machine learning analysis uncovered a correlation between Lf and GPX4. hLf treatment boosted low-density lipoprotein receptor-related protein 1 (LRP1) internalization and facilitated its interaction with heat shock cognate 70 (HSC70), thereby inhibiting HSC70 binds to GPX4, and eventually attenuating GPX4 degradation and FAC-induced ferroptosis. Overall, astrocytic Lf overexpression inhibited neuronal ferroptosis through two pathways: reducing intracellular iron accumulation and promoting GPX4 expression via inhibiting chaperone-mediated autophagy (CMA)-mediated GPX4 degradation. Hence, upregulating astrocytic Lf expression is a promising strategy for combating AD.

Glioblastoma mesenchymal subtype enhances antioxidant defence to reduce susceptibility to ferroptosis

Glioblastoma (GBM) represents an aggressive brain tumor, characterized by intra- and inter-tumoral heterogeneity and therapy resistance, leading to unfavourable prognosis. An increasing number of studies pays attention on the regulation of ferroptosis, an iron-dependent cell death, as a strategy to reverse drug resistance in cancer. However, the debate on whether this strategy may have important implications for the treatment of GBM is still ongoing. In the present study, we used ferric ammonium citrate and erastin to evaluate ferroptosis induction effects on two human GBM cell lines, U-251 MG, with proneural characteristics, and T98-G, with a mesenchymal profile. The response to ferroptosis induction was markedly different between cell lines, indeed T98-G cells showed an enhanced antioxidant defence, with increased glutathione levels, as compared to U-251 MG cells. Moreover, using bioinformatic approaches and analysing publicly available datasets from patients’ biopsies, we found that GBM with a mesenchymal phenotype showed an up-regulation of several genes involved in antioxidant mechanisms as compared to proneural subtype. Thus, our results suggest that GBM subtypes differently respond to ferroptosis induction, emphasizing the significance of further molecular studies on GBM to better discriminate between various tumor subtypes and progressively move towards personalized therapy.

Nanoparticle-delivered quercetin exhibits enhanced efficacy in eliminating iron-overloaded senescent chondrocytes.

Aim: The therapeutic potential of senolytic drugs in osteoarthritis (OA) is poorly known. Quercetin, a senolytic agent exhibits promising potential to treat OA, having limited bioavailability. We investigated the effects of Quercetin-loaded nanoparticles (Q-NP) with enhanced bioavailability in human chondrocytes mimicking OA phenotype.Materials & methods: The C-20/A4 chondrocytes were exposed to ferric ammonium citrate to induce OA phenotype, followed by treatment with free Quercetin/Q-NP for 24 and 48-h. Q-NP were synthesized by nanoprecipitation method. Following treatment chondrocytes were assessed for drug cellular bioavailability, viability, cell cycle, apoptosis, oxidative stress and expression of key senescence markers.Results: Q-NP exhibited 120.1±1.2nm particle size, 81±2.4% encapsulation efficiency, increased cellular bioavailability and selective apoptosis of senescent chondrocytes compared with free Quercetin. Q-NP treatment also induced oxidative stress and reduced the expressions of senescence markers, including TRB3, p16, p62 and p21 suggesting their ability to eliminate senescent cells. Last, Q-NP arrested the cell cycle in the sub-G0 phase, potentially creating a beneficial environment for tissue repair.Conclusion: Q-NP propose a promising delivery system for treating OA by eliminating senescent chondrocytes through apoptosis. Furthermore, their enhanced cellular bioavailability and capacity to modify cell cycle and senescent pathways warrant further investigations.

Iron Overload Induces Hepatic Ferroptosis and Insulin Resistance by Inhibiting the Jak2/stat3/slc7a11 Signaling Pathway.

Recent studies showed that patients with iron overload had increased risk of insulin resistance or diabetes. Ferroptosis is a new type of cell death mainly caused by iron-dependent oxidative damage. In the present study, we investigated potential mechanisms of iron overload induced hepatic ferroptosis and insulin resistance through in vivo and in vitro experiments. In vivo, the mice models of iron overload were established by intraperitoneal injection of iron dextran. The changes of body weight, serum ferritin and blood glucose were measured. Hematoxylin-eosin (HE) and Perl's stainings were used to observe the pathological changes and iron deposition in the liver of mice. In vitro, HepG2 cells were treated with ferric ammonium citrate (FAC, 9 mmol/L, 24 h) to establish the cell models of iron overload. The labile iron pool, cell viability, glucose consumption and glycogen contents were measured. The ultrastructure of mitochondria was observed by transmission electron microscope (TEM). The malondialdehyde (MDA) and glutathione (GSH) kits were used to detect lipid peroxidation in liver tissues of mice and HepG2 cells. RT-PCR and Western blot were used to detect the mRNA and protein expression levels of ferroptosis factors and JAK2/STAT3 signaling pathway. In this study, we used the iron chelator deferasirox in mice and HepG2 cells. Iron overload caused weight loss, elevated serum ferritin, fasting blood glucose, fasting insulin, HOMA-IR, impaired glucose tolerance, and decreased insulin sensitivity in mice. HE staining and Perls staining showed clumps of iron deposition in the liver of iron overload mice. Iron overload could reduce the glucose consumption, increase MDA contents of HepG2 cells, while reduce glycogen and GSH contents in liver tissues of mice and HepG2 cells. TEM showed deletion of mitochondrial ridge and rupture of outer membrane in HepG2 cells with iron overload. Iron chelator deferasirox could significantly improve the above indicators, which might be related to the activation of JAK2/STAT3/SLC7A11 signaling pathway and hepatic ferroptosis. Iron overload could induce hepatic ferroptosis and insulin resistance by inhibiting the JAK2/STAT3/SLC7A11 signaling pathway, and the iron chelator deferasirox might improve hepatic insulin resistance induced by iron overload.

LncRNA OIP5-AS1 regulates ferroptosis and mitochondrial dysfunction-mediated apoptosis in spinal cord injury by targeting the miR-128-3p/Nrf2 axis

BackgroundFerroptosis is an important way of neuronal cell death in acute phase and participates in the inflammatory cascade after spinal cord injury (SCI). It is reported that microRNA (miRNA) and long non-coding RNA (lncRNA) are key mediators in the regulation of ferroptosis. This study will explore the inhibitory effect of LncRNA OIP5-AS1 on ferroptosis and mitochondrial dysfunction-mediated apoptosis in SCI. MethodsThe ferric ammonium citrate (FAC)-induced cell model and the SCI rat model were established. The expression of LncRNA OIP5-AS1, miR-128-3p and Nrf2 were transfected to evaluated the effect on the viability and apoptosis of FAC-induced cell. The interaction between LncRNA OIP5-AS1 and miR-128-3p or miR-128-3p and Nrf2 were analyzed. In addition, expressions of markers related to ferroptosis and mitochondrial dysfunction were analyzed in vitro and in vivo. Histopathologic slide staining was used to analyze spinal cord injury in vivo. ResultsLncRNA OIP5-AS1 expression was abnormally down-regulated in FAC-induced SCI cell model and SCI rats. The LncRNA OIP5-AS1 deficiency induced decreased Nrf2 level by less sponging miR-128-3p, thus, aggravating spinal cord injury and inducing more apoptosis, ferroptosis and mitochondrial dysfunction in neural stem cells with SCI. However, overexpression of LncRNA OIP5-AS1 inhibited apoptosis, ferroptosis and mitochondrial dysfunction, thus effectively ameliorating spinal cord injury. ConclusionThis finding demonstrates that LncRNA OIP5-AS1 overexpression could enhance the recovery of spinal cord injury by regulating the miR-128-3p/Nrf2 axis.

Cardamonin attenuates iron overload-induced osteoblast oxidative stress through the HIF-1α/ROS pathway

BackgroundOsteoporosis(OP) is a bone disease under research. Iron overload is a significant risk factor. Iron balance is crucial for bone metabolism and biochemical processes. When there is an excess of iron in the body, it tends to produce reactive oxygen species (ROS) which can cause oxidative damage to cells. The flavonoid compound, Cardamonin (CAR), possesses potent anti-inflammatory and anti-iron overload properties that can be beneficial in mitigating the risk of OP. PurposeThis study investigates the potential therapeutic interventions and underlying mechanisms of CAR for treating OP in individuals with iron overload. MethodsThe model of iron-overloaded mice was established by intraperitoneally injecting iron dextran(ID) into the mice. OP severity was evaluated with micro-CT and Hematoxylin-Eosin (HE) staining in vivo. In vitro, the iron-overloaded osteoblast model was induced by ferric ammonium citrate. Cell counting kit 8 assay to evaluate cell viability, Annexin V-FITC/PI assay to detect cell apoptosis. A range of cellular markers were detected, including the variation in mitochondrial membrane potential (MMP), levels of malondialdehyde (MDA), ROS, and lipid hydroperoxide (LPO). ResultsCAR can reverse bone loss in iron overload-induced OP mouse models in vivo.CAR attenuates the impairment of iron overload on the activity and apoptosis of MC3T3-E1 cells as well as the accumulation of ROS and LPO activation via HIF-1α/ROS pathways. ConclusionCAR downregulating HIF-1α pathways prevents inhibition of iron overload-induced osteoblasts dysfunctional by attenuating ROS accumulation, reducing oxidative stress, promotes bone formation, and alleviates OP.

Optimization of Culture Conditions for Microalgae Treatment Fly Ash Leachate System

In order to explore the feasibility of using algae to treat the fly ash leachate from a safe landfill site, leachate samples taken from a certain safe landfill site in Wenzhou City were treated with two different microalgae, Chlorella vulgaris and Scenedesmus obliquus, and the effectiveness of each treatment was evaluated in terms of its efficiency of pollutant removal. The effects of conditions such as pretreatment of leachate by sterilization, the initial concentration of leachate, and the addition of nutrients on pollutant removal efficiency and algae growth were studied. Sterilization of the leachate was found to have a relatively small impact on the growth of C. vulgaris and S. obliquus, as well as the removal of pollutants from the leachate. Therefore, sterilization treatment may not be necessary for engineering applications. Algal growth and the removal of pollutants were optimal when the leachate was used at a concentration of 10%, but when the leachate concentration was 30% or higher, the growth of both algae was weakened. The inclusion of 0.2 g/L K2HPO4·3H2O and 0.06 g/L ammonium ferric citrate in the system led to higher algal growth and pollutant removal. The chlorophyll a levels of C. vulgaris and S. obliquus were 555.53% and 265.15%, respectively, and the nitrogen removal rates were also the highest, reaching 59.51% and 56.69%, respectively. This study optimized the cultivation conditions of a microalgae treatment leachate system, providing technical support and a theoretical basis for the practical engineering of a harmless treatment of leachate.

Iron Overloading Potentiates the Antitumor Activity of 5-Fluorouracil by Promoting Apoptosis and Ferroptosis in Colorectal Cancer Cells.

Resistance to 5-fluorouracil (5-FU) remains a significant challenge in colorectal cancer (CRC) treatment. Ferric ammonium citrate (FAC) is commonly used as an iron supplement due to its food-fortification properties; however, its potential role as a chemosensitizer in cancer therapy has not been studied. In this study, we explored the ability of FAC to sensitize CRC cells and increase their susceptibility to 5-FU-mediated anticancer effects. We assessed cell viability, cell cycle progression, apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, ferroptosis, and iron metabolism-related protein expression using two CRC cell lines. Additionally, we conducted in silico analyses to compare iron markers in normal colon and CRC tumor tissues. Compared to controls, CRC cells pretreated with FAC and then treated with 5-FU exhibited significantly reduced growth and viability, along with increased ROS-mediated ferroptosis. Mechanistically, FAC-pretreated then 5-FU-treated CRC cells showed enhanced apoptosis, increased Bak/Bax expression, MMP depolarization, and decreased antiapoptotic protein levels (Bcl-2 and Bcl-xL). This combined treatment also led to G2/M cell cycle arrest, upregulation of p21 and p27, and downregulation of cyclin D1, c-Myc, survivin, and GPX4. Analysis of human colon tumor tissue revealed decreased expression of IRP-1, HMOX-1, and FTH1 but increased HAMP expression. In contrast, FAC-pretreated/5-FU-treated CRC cells exhibited a reverse pattern, suggesting that FAC-induced chemosensitization enhances 5-FU-mediated anticancer activity in CRC by disrupting iron homeostasis. These findings highlight the potential of iron overload as a chemosensitization strategy for improving CRC chemotherapy.

Abstract Mo013: Regulation of Ferroptosis by Wnt5a in the Heart: Implication in Cardio-Oncology

Ferroptosis is an iron and lipid peroxidation dependent form of cell death. It has been implicated in ischemia/reperfusion injury, heart failure, and doxorubicin (Dox)-induced cardiotoxicity (DIC). While Wingless-type family member (Wnt) pathways are crucial for heart development and remodeling, the role of Wnt5a in regulating ferroptosis in cardiac cells and its relevance to DIC remain unclear. In the present study, we investigate the role of Wnt5a signaling in cardiac ferroptosis and its implication in cardio-oncology. We observed an increase in Wnt5a secretion in H9C2 cardiac cells upon treatment with ferroptosis inducers such as ferric ammonium citrate (FAC 2 mM) and RSL3 (20 nM). Live/Dead viability analyses in cultured mouse cardiomyocytes (CMs) and cardiac fibroblasts (CFs) revealed that the Wnt5a antagonist BOX5 (100 µM) attenuated ferroptosis induced by FAC or RSL3 in both CMs and CFs. Similarly, FAC- and RSL3-induced ferroptotic death rates were reduced in CMs from Wnt5a conditional knockout (cKO) mice. Recombinant Wnt5a (rWnt5a) induced CM death in a dose-dependent manner (5, 7, 10 µg/ml) and was partially prevented by Fer-1 (10 µM), a selective ferroptosis inhibitor. Moreover, rWnt5a (10 µg/ml) also effectively induced CF ferroptosis which was inhibited by Fer-1. rWnt5a and its mimicking peptide Foxy5 also modulated the sensitivity to various ferroptosis inducers. Furthermore, FAC-, RSL3- and rWnt5a-induced ferroptosis were attenuated in CMs from frizzled 2 receptor cKO mice. We further delineated the role of Wnt5a upregulation in Dox-induced ferroptosis and the development of DIC. In a chronic DIC mouse model, Wnt5a upregulation in the heart correlated with left ventricular dysfunction which was abrogated in Wnt5a cKO mice. Live/Dead viability analyses showed that Dox induced ferroptosis which was partially prevented by Fer-1 in CMs. Inhibition of the Wnt5a pathway by BOX5 led to a decrease in the rate of Dox-induced ferroptosis, while the sensitivity to ferroptosis was enhanced by rWnt5a. Our study has shown for the first time that the production and secretion of Wnt5a in an autocrine and/or paracrine manner promotes ferroptosis in CMs and CFs. Wnt5a is likely to be a critical mediator of Dox-induced ferroptosis and cardiotoxicity.

Highly active carbon dots based nanozyme for enhanced cholesterol detection and antibacterial activity

Recently, nanozyme have emerged as promising direction for chemical sensing, biomedicine, environmental monitoring. However, the novel nanozyme with better catalytic activity and specificity is urgently required realized great application performance. Herein, Fe doped carbon dots (Cit-Fe-CDs) with peroxidase (POD) like activity are synthesized by hydrothermal treatment of ferric ammonium citrate. Due to the strong coordination capacity between Fe(Ⅲ) and citric acid, the Cit-Fe-CDs exhibited excellent POD activity. Namely the catalytic constant (Kcat) and catalytic efficiency (Kcat /Km) are determined, which are much higher than previous work. Highly effective colorimetric detection of cholesterol in human serum have been realized by the POD activity of Cit-Fe-CDs. Under optimal conditions, the linear range is determined to be 10 and 100 μM with a detection limit (LOD) of 0.061 μM. The LOD is two orders of magnitude lower than most of the existing analysis method. Since substantial amounts of free radicals are involved in the catalytic cycle of POD activity, excellent antibacterial activity against Methicillin-Resistant Staphylococcus aureus (MRSA) should be realized by Cit-Fe-CDs. Notably, about 99.999 % inactivation rate towards MRSA can be realized by 125 μg/mL Cit-Fe-CDs, which showcases promising prospects in addressing bacterial resistance concerns. And we have confirmed that the antibacterials mechanism is related to the generation of hydroxyl radicals by the excellent POD activity of Cit-Fe-CDs.

Iron Reduces the Trafficking of Fatty Acids from Human Immortalised Brain Microvascular Endothelial Cells Through Modulation of Fatty Acid Transport Protein 1 (FATP1/SLC27A1)

PurposeAlzheimer’s disease (AD) is associated with brain accumulation of amyloid-beta (Aβ) and neurofibrillary tangle formation, in addition to reduced brain docosahexaenoic acid (DHA) and increased brain iron levels. DHA requires access across the blood–brain barrier (BBB) to enter the brain, and iron has been shown to affect the expression and function of a number of BBB transporters. Therefore, this study aimed to assess the effect of iron on the expression and function of fatty acid binding protein 5 (FABP5) and fatty acid transport protein 1 (FATP1), both which mediate brain endothelial cell trafficking of DHA.MethodsThe mRNA and protein levels of FABP5 and FATP1 in human cerebral microvascular endothelial (hCMEC/D3) cells was assessed by RT-qPCR and Western blot, respectively following ferric ammonium citrate (FAC) treatment (up to 750 µM, 72 h). The function of FABP5 and FATP1 was assessed via uptake and efflux of radiolabelled 3H-oleic acid and 14C-DHA.ResultsFAC (500 µM, 72 h) had no impact on the expression of FABP5 at the protein and mRNA level in hCMEC/D3 cells, which was associated with a lack of effect on the uptake of 14C-DHA. FAC led to a 19.7% reduction in FATP1 protein abundance in hCMEC/D3 cells with no impact on mRNA levels, and this was associated with up to a 32.6% reduction in efflux of 14C-DHA.ConclusionsThese studies demonstrate a role of iron in down-regulating FATP1 protein abundance and function at the BBB, which may have implications on fatty acid access to the brain.Graphical

Iron Regulates Cellular Proliferation by Enhancing the Expression of Glucose Transporter GLUT3 in the Liver.

Iron is often accumulated in the liver during pathological conditions such as cirrhosis and cancer. Elevated expression of glucose transporters GLUT1 and GLUT3 is associated with reduced overall survival in patients with hepatocellular carcinoma. However, it is not known whether iron can regulate glucose transporters and contribute to tumor proliferation. In the present study, we found that treatment of human liver cell line HepG2 with ferric ammonium citrate (FAC) resulted in a significant upregulation of GLUT3 mRNA and protein in a dose-dependent manner. Similarly, iron accumulation in mice fed with high dietary iron as well as in mice injected intraperitoneally with iron dextran enhanced the GLUT3 expression drastically in the liver. We demonstrated that iron-induced hepatic GLUT3 upregulation is mediated by the LKB1/AMPK/CREB1 pathway, and this activation was reversed when treated with iron chelator deferiprone. In addition, inhibition of GLUT3 using siRNA prevented iron-mediated increase in the expression of cell cycle markers and cellular hyperproliferation. Furthermore, exogenous sodium beta-hydroxybutyrate treatment prevented iron-mediated hepatic GLUT3 activation both in vitro and in vivo. Together, these results underscore the importance of iron, AMPK, CREB1 and GLUT3 pathways in cell proliferation and highlight the therapeutic potential of sodium beta-hydroxybutyrate in hepatocellular carcinoma with high GLUT3 expression.

Exogenous Iron Induces Mitochondrial Lipid Peroxidation, Lipofuscin Accumulation, and Ferroptosis in H9c2 Cardiomyocytes.

Lipid peroxidation plays an important role in various pathologies and aging, at least partially mediated by ferroptosis. The role of mitochondrial lipid peroxidation during ferroptosis remains poorly understood. We show that supplementation of exogenous iron in the form of ferric ammonium citrate at submillimolar doses induces production of reactive oxygen species (ROS) and lipid peroxidation in mitochondria that precede ferroptosis in H9c2 cardiomyocytes. The mitochondria-targeted antioxidant SkQ1 and the redox mediator methylene blue, which inhibits the production of ROS in complex I of the mitochondrial electron transport chain, prevent both mitochondrial lipid peroxidation and ferroptosis. SkQ1 and methylene blue also prevented accumulation of lipofuscin observed after 24 h incubation of cardiomyocytes with ferric ammonium citrate. Using isolated cardiac mitochondria as an in vitro ferroptosis model, it was shown that rotenone (complex I inhibitor) in the presence of ferrous iron stimulates lipid peroxidation and lipofuscin accumulation. Our data indicate that ROS generated in complex I stimulate mitochondrial lipid peroxidation, lipofuscin accumulation, and ferroptosis induced by exogenous iron.

Synthesis of green nanosorbent from bovine serum albumin and curcumin for magnetic solid phase extraction of pesticides from food samples

For the first time, a magnetic carbon nanocomposite was synthesized using one-step hydrothermal procedure, employing bovine serum albumin, curcumin, and ferric ammonium citrate. Additionally, the application of this novel composite as an adsorbent for magnetic dispersive solid phase extraction of fungicides and pesticides from water and food samples is a unique aspect of this study. Under optimum conditions (salt concentration: 5.0% w/v, pH: 7.0, desorption solvent: ethanol, sorbent amount: 20 mg, extraction time: 20 min, desorption time: 3 min, stirring rate: 500 rpm, sample volume: 30 mL, extraction temperature: room temperature, and desorption solvent volume: 150 μL) linearity (2.5 to 1400 ng mL−1), coefficients of determination (R2 ≥ 0.997), limits of detection (0.75 to 1.5 ng mL−1), and limits of quantification (2.5 to 5.0 ng mL−1) were achieved. The method validation results showed extraction recovery ranging from 71.2% to 93.4%, and preconcentration factors ranging from 142.5 to 186.1.

N‐Acetyl cysteine‐loaded liposomes to reduce iron overload‐induced toxicity in human kidney cells

AbstractBACKGROUNDIron overload in the body generates free radicals through the Fenton reaction, leading to adverse effects on various organs. Several antioxidants have been recommended to treat iron‐related diseases effectively. N‐Acetyl cysteine (NAC), a potent antioxidant, was investigated in this study for its potential to mitigate iron overload‐induced cell death. A liposomal formulation was developed to encapsulate NAC, employing the reverse phase evaporation method, to enhance its delivery and effectiveness. The liposomal NAC was characterized by evaluating its size, zeta potential, morphology and release profiles.RESULTSThe protective effect of liposomal NAC against iron overload‐induced toxicity was assessed in human kidney 2 (HK‐2) cells. Cell viability assays (Cell Counting Kit 8) and reactive oxygen species assays (DCFDA assay) confirmed the effectiveness of liposomal NAC in inhibiting ferroptosis induced by slow iron uptake (1 mmol L−1 ferric ammonium citrate). Additionally, liposomal NAC protected cells from toxicity resulting from rapid iron uptake (50 μmol L−1 ferric ammonium citrate, 20 μmol L−1 8‐hydroxyquinoline). The liposomal formulation demonstrated an enhanced protective effect compared to free NAC.CONCLUSIONThese findings suggest that liposomal NAC more effectively protects human kidney cells from toxicity caused by different iron uptake models than free NAC, highlighting its potential as a superior treatment option for iron overload‐induced cellular damage. © 2024 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Multifunctional N, Fe-doped carbon dots with peroxidase-like activity for the determination of H2O2 and ascorbic acid and cell protection against oxidation.

Multifunctional N, Fe-doped carbon dots (N, Fe-CDs) were synthesized by the one-step hydrothermal method using ferric ammonium citrate and dicyandiamide as raw materials. The N, Fe-CDs exhibited peroxidase-like (POD) activity by catalyzing the oxidization of 3,3',5,5'-tetramethylbenzidine (TMB) to the green oxidation state ox-TMB in the presence of hydrogen peroxide (H2O2). Subsequently, based on the POD activity of N, Fe-CDs, an efficient and sensitive colorimetric method for the detection of H2O2 and ascorbic acid (AA) was established with a limit of detection of 0.40 µM and 2.05 µM. The proposed detection method has been successfully applied to detect AA in fruit juice, vitamin C tablets, and human serum samples and has exhibited excellent application prospects in biotechnology and food fields. Furthermore, N, Fe-CDs also showed a protective effect on the cell damage caused by H2O2 and could be used as an antioxidant agent.

A novel circPIK3C2A/miR‐31‐5p/TFRC axis drives ferroptosis and accelerates myocardial injury

Iron overload is common in cardiovascular disease, it is also the factor that drives ferroptosis. Noncoding RNAs play an important role in heart disease; however, their regulatory role in iron overload-mediated ferroptosis remains much unknown. In our study, the iron overload model in mice was constructed through a high-iron diet, and ammonium iron citrate treatment was used to mimic iron overload in vitro. We found iron overload induced ferroptosis incardiomyocytes, which was dependent on the high expression of transferrin receptor (TFRC). MiR-31-5p was downregulated during iron overload; it inhibitedcardiomyocyte ferroptosis by targeting TFRC. CircPIK3C2A, a highly expressed circRNA in the heart, was upregulated when iron was overloaded. CircPIK3C2A enhanced the expression of TFRC by sponging miR-31-5p and promoted ferroptosis during iron overload. Our results reveal a novel mechanistic insight into noncoding RNA-based ferroptosis and identify the circPIK3C2A/miR-31-5p/TFRC axis as a promising therapeutic target for myocardial damage.

Quercetin Inhibits Neuronal Pyroptosis and Ferroptosis by Modulating Microglial M1/M2 Polarization in Atherosclerosis.

Atherosclerosis (AS) with iron and lipid overload and systemic inflammation is a risk factor for Alzheimer's disease. M1 macrophage/microglia participate in neuronal pyroptosis and recently have been reported to be the ferroptosis-resistant phenotype. Quercetin plays a prominent role in preventing and treating neuroinflammation, but the protective mechanism against neurodegeneration caused by iron deposition is poorly understood. ApoE-/- mice were fed a high-fat diet with or without quercetin treatment. The Morris water maze and novel object recognition tests were conducted to assess spatial learning and memory, and nonspatial recognition memory, respectively. Prussian blue and immunofluorescence staining were performed to assess the iron levels in the whole brain and in microglia, microglia polarization, and the degree of microglia/neuron ferroptosis. In vitro, we further explored the molecular biological alterations associated with microglial polarization, neuronal pyroptosis, and ferroptosis via Western blot, flow cytometry, CCK8, LDH, propidium iodide, and coculture system. We found that quercetin improved brain lesions and spatial learning and memory in AS mice. Iron deposition in the whole brain or microglia was reversed by the quercetin treatment. In the AS group, the colocalization of iNOS with Iba1 was increased, which was reversed by quercetin. However, the colocalization of iNOS with PTGS2/TfR was not increased in the AS group, suggesting a character resisting ferroptosis. Quercetin induced the expression of Arg-1 and decreased the colocalizations of Arg-1 with PTGS2/TfR. In vitro, ox-LDL combined with ferric ammonium citrate treatment (OF) significantly shifted the microglial M1/M2 phenotype balance and increased the levels of free iron, ROS, and lipid peroxides, which was reversed by quercetin. M1 phenotype induced by OF caused neuronal pyroptosis and was promoted to ferroptosis by L-NIL treatment, which contributed to neuronal ferroptosis as well. However, quercetin induced the M1 to M2 phenotype and inhibited M2 macrophages/microglia and neuron pyroptosis or ferroptosis. In summary, quercetin alleviated neuroinflammation by inducing the M1 to M2 phenotype to inhibit neuronal pyroptosis and protected neurons from ferroptosis, which may provide a new idea for neuroinflammation prevention and treatment.

Amino Acid Chelated Iron Versus Ferric Ammonium Citrate on Iron Status in Egyptian Children with Iron Deficiency Anemia: A Randomized Controlled Study

AbstractFew studies have compared the relative effectiveness of different iron compounds on iron status in school-age children with iron deficiency anemia. The objective of this study was to compare the effect of iron amino acid chelated (AACI) preparation versus ferric ammonium citrate (FAC) in treatment of iron deficiency anemia. Patients and methods: A randomized, clinical study was conducted on one hundred and sixty children aged 5–13 years old proved to have iron deficiency according to guide lines of WHO, 2001. All included children were subjected to the following laboratory investigations: CBC, reticulocytic count, CRP, serum iron, total iron binding capacity (TIBC), serum ferritin (SF), and serum hepcidin. Patients were assigned to two treatment regimens on randomized base 1:1 either to supplement with (AACI) or (FAC) once daily at bedtime. The subjects were followed up for eight weeks. Results: At the end of the study, group 1 who received AACI had increase in: Hb from 9.9 ± 1.1to 11.5 ± 0.3 gm/l(p = 0.01), MCV(fl) from 63.57.7 ± to 69 ± 6.3 (p = 0.05), serum iron from 49.5 ± 5.8 to 87 ± 12.7ug/dl(p = 0.001), serum ferritin from26.2 ± 10.5to 116.4 ± 19.7ng/ml(p = 0.001) while in group 2 who received FAC, there was increase in: HB from10.1 ± 1.7 to 11.2 ± 0.8, (p = 0.1), MCV from 64.5 ± 8.02 to 73.2 ± 8.9 (p = 0.01), serum iron from 48.2 ± 3.5to74 .3 ± 15 ug/dl (p = 0.01) and serum ferritin from 28.1 ± 9.3 to 84.3 ± 15.2 ng/ml (p = 0.006). Conclusion: Our study showed much improvement in iron status indices in AACI preparation with no significant statistically difference between it and FAC.

Differentiation of intestinal stem cells toward goblet cells under systemic iron overload stress are associated with inhibition of Notch signaling pathway and ferroptosis

Iron overload can lead to oxidative stress and intestinal damage and happens frequently during blood transfusions and iron supplementation. However, how iron overload influences intestinal mucosa remains unknown. Here, the aim of current study was to investigate the effects of iron overload on the proliferation and differentiation of intestinal stem cells (ISCs). An iron overload mouse model was established by intraperitoneal injection of 120 mg/kg body weight iron dextran once a fortnight for a duration of 12 weeks, and an iron overload enteroid model was produced by treatment with 3 mM or 10 mM of ferric ammonium citrate for 24 h. We found that iron overload caused damage to intestinal morphology with a 64 % reduction in villus height/crypt depth ratio, and microvilli injury in the duodenum. Iron overload mediated epithelial function by inhibiting the expression of nutrient transporters and enhancing the expression of secretory factors in the duodenum. Meanwhile, iron overload inhibited the proliferation of ISCs and regulated their differentiation into secretory mature cells, such as goblet cells, through inhibiting Notch signaling pathway both in mice and enteroid. Furthermore, iron overload caused oxidative stress and ferroptosis in intestinal epithelial cells. In addition, ferroptosis could also inhibit Notch signaling pathway, and affected the proliferation and differentiation of ISCs. These findings reveal the regulatory role of iron overload on the proliferation and differentiation of ISCs, providing a new insight into the internal mechanism of iron overload affecting intestinal health, and offering important theoretical basis for the scientific application of iron nutrition regulation.