Iron Homeostasis in Health and Disease

APOE and Alzheimer's disease: Pathologic clues from transgenic Drosophila melanogaster

Alzheimer's disease (AD) is one of the most common forms of neurodegenerative diseases. Apolipoprotein E4 (ApoE4) is the main genetic risk factor in the development of late-onset AD. However, the exact mechanism underlying ApoE4-mediated neurodegeneration remains unclear. We utilized Drosophila melanogaster to examine the neurotoxic effects of various human APOE isoforms when expressed specifically in glial and neural cells. We assessed impacts on mitochondrial dynamics, ER stress, lipid metabolism, and bio-metal ion concentrations in the central nervous system (CNS) of the transgenic flies. Dachshund antibody staining revealed a reduction in the number of Kenyon cells. Behavioral investigations including ethanol tolerance and learning and memory performance demonstrated neuronal dysfunction in APOE4-expressing larvae and adult flies. Transcription level of marf and drp-1 were found to be elevated in APOE4 flies, while atf4, atf6, and xbp-1 s showed down regulation. Enhanced concentrations of triglyceride and cholesterol in the CNS were observed in APOE4 transgenic flies, with especially pronounced effects upon glial-specific expression of the gene. Spectrophotometry of brain homogenate revealed enhanced Fe++ and Zn++ ion levels in conjunction with diminished Cu++ levels upon APOE4 expression. To explore therapeutic strategies, we subjected the flies to heat-shock treatment, aiming to activate heat-shock proteins (HSPs) and assess their potential to mitigate the neurotoxic effects of APOE isoforms. The results showed potential therapeutic benefits for APOE4-expressing flies, hinting at an ability to attenuate memory deterioration. Overall, our findings suggest that APOE4 can alter lipid metabolism, bio metal ion homeostasis, and disrupt the harmonious fission-fusion balance of neuronal and glial mitochondria, ultimately inducing ER stress. These alterations mirror the main clinical manifestations of AD in patients. Therefore, our work underscores the suitability of Drosophila as a fertile model for probing the pathological roles of APOE and furthering our understanding of diverse isoform-specific functions.

The Puzzle of Aspirin and Iron Deficiency: The Vital Missing Link of the Iron-Chelating Metabolites

Acetylsalicylic acid or aspirin is the most commonly used drug in the world and is taken daily by millions of people. There is increasing evidence that chronic administration of low-dose aspirin of about 75-100 mg/day can cause iron deficiency anaemia (IDA) in the absence of major gastric bleeding; this is found in a large number of about 20% otherwise healthy elderly (>65 years) individuals. The mechanisms of the cause of IDA in this category of individuals are still largely unknown. Evidence is presented suggesting that a likely cause of IDA in this category of aspirin users is the chelation activity and increased excretion of iron caused by aspirin chelating metabolites (ACMs). It is estimated that 90% of oral aspirin is metabolized into about 70% of the ACMs salicyluric acid, salicylic acid, 2,5-dihydroxybenzoic acid, and 2,3-dihydroxybenzoic acid. All ACMs have a high affinity for binding iron and ability to mobilize iron from different iron pools, causing an overall net increase in iron excretion and altering iron balance. Interestingly, 2,3-dihydroxybenzoic acid has been previously tested in iron-loaded thalassaemia patients, leading to substantial increases in iron excretion. The daily administration of low-dose aspirin for long-term periods is likely to enhance the overall iron excretion in small increments each time due to the combined iron mobilization effect of the ACM. In particular, IDA is likely to occur mainly in populations such as elderly vegetarian adults with meals low in iron content. Furthermore, IDA may be exacerbated by the combinations of ACM with other dietary components, which can prevent iron absorption and enhance iron excretion. Overall, aspirin is acting as a chelating pro-drug similar to dexrazoxane, and the ACM as combination chelation therapy. Iron balance, pharmacological, and other studies on the interaction of iron and aspirin, as well as ACM, are likely to shed more light on the mechanism of IDA. Similar mechanisms of iron chelation through ACM may also be implicated in patient improvements observed in cancer, neurodegenerative, and other disease categories when treated long-term with daily aspirin. In particular, the role of aspirin and ACM in iron metabolism and free radical pathology includes ferroptosis, and may identify other missing links in the therapeutic effects of aspirin in many more diseases. It is suggested that aspirin is the first non-chelating drug described to cause IDA through its ACM metabolites. The therapeutic, pharmacological, toxicological and other implications of aspirin are incomplete without taking into consideration the iron binding and other effects of the ACM.

HIF-2α/TFR1 mediated iron homeostasis disruption aggravates cartilage endplate degeneration through ferroptotic damage and mtDNA release: A new mechanism of intervertebral disc degeneration

Backgroud

Iron overload is a prevalent condition in the elderly, often associated with various degenerative diseases, including intervertebral disc degeneration (IDD). Nevertheless, the mechanisms responsible for iron ion accumulation in tissues and the mechanism that regulate iron homeostasis remain unclear. Transferrin receptor-1 (TFR1) serves as the primary cellular iron gate, playing a pivotal role in controlling intracellular iron levels, however its involvement in IDD pathogenesis and the underlying mechanism remains obscure.

Methods

Firstly, IDD mice model was established to determine the iron metabolism associated proteins changes during IDD progression. Then CEP chondrocytes were isolated and treated with TBHP or pro-inflammatory cytokines to mimic pathological environment, western blotting, immunofluorescence assay and tissue staining were employed to explore the underlying mechanisms. Lastly, TfR1 siRNA and Feristatin II were employed and the degeneration of IDD was examined using micro-CT and immunohistochemical analysis.

Results

We found that the IDD pathological environment, characterized by oxidative stress and pro-inflammatory cytokines, could enhance iron influx by upregulating TFR1 expression in a HIF-2α dependent manner. Excessive iron accumulation not only induces chondrocytes ferroptosis and exacerbates oxidative stress, but also triggers the innate immune response mediated by c-GAS/STING, by promoting mitochondrial damage and the release of mtDNA. The inhibition of STING through siRNA or the reduction of mtDNA replication using ethidium bromide alleviated the degeneration of CEP chondrocytes induced by iron overload.

Conclusion

Our study systemically explored the role of TFR1 mediated iron homeostasis in IDD and its underlying mechanisms, implying that targeting TFR1 to maintain balanced iron homeostasis could offer a promising therapeutic approach for IDD management.

The translational potential of this article

Our study demonstrated the close link between iron metabolism dysfunction and IDD, indicated that targeting TfR1 may be a novel therapeutic strategy for IDD.

Influence of supplementation with iron and probiotic bacteria Lactobacillus plantarum and Lactobacillus curvatus on selected parameters of inflammatory state in rats on a high-fat iron-deficient diet

BACKGROUND

A high-fat (HF) diet, diet iron deficiency and iron supplementation may affect inflammatory parameters. Probiotics influence both iron metabolism and inflammation. We compared the inflammatory state in rats on a HF iron-deficient diet receiving oral iron, Lactobacillus plantarum and Lactobacillus curvatus in different combinations.

METHODS

This was a two-stage experiment. In groups C (n = 8) and HF (n = 8), rats ate a control or HF diet, respectively, for 16 weeks. In the group HFDEF (n = 48), rats ate a HF iron-deficient diet for 8 weeks (first stage) and were subsequently divided into 6 groups (n = 8 each) receiving the following for a further 8 weeks (second stage): HFDEF - a HF iron-deficient diet; HFDEFFe - a HF iron-deficient diet with iron; HFDEFLp and HFDEFLc - a HF iron-deficient diet with L. plantarum or L. curvatus, respectively; and HFDEFFeLp and HFDEFFeLc - a HF iron-deficient diet with iron and L. plantarum or L. curvatus, respectively. Body composition analysis and blood sampling was performed. Markers of iron status and levels of total antioxidant status (TAS), C-reactive protein (CRP), tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were measured in the blood.

RESULTS

TAS was higher in the HFDEF group (756.57 ± 489.53 ng mL-1) versus the HFDEFLc group (187.04 ± 47.84 ng mL-1; P = 0.022). No more differences were found between groups, or in TAS, CRP, TNF-α and IL-6 concentrations. Also, no differences were found between groups for alanine and aspartate aminotransferases, glucose, total cholesterol, low- and high-density lipoproteins and triglycerides. TAS level was positively correlated with ferritin concentration, IL-6 with TAS and TNF-α with hepcidin level.

CONCLUSIONS

Supplementation with L. plantarum, L. curvatus and iron in combinations exerts no influence on inflammatory status, lipid profile, hepatic function and serum fasting glucose in rats on a HF iron-deficient diet. © 2024 Society of Chemical Industry.

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Exploring progress in iron supplement formulation approaches for treating iron deficiency anemia through bibliometric and thematic analysis

Anemia is a severe health issue that affects around one-third of the global population. Therefore, the present study aims to conduct a bibliometric analysis to investigate the research trends regarding advancements on iron formulations in treating iron deficiency anemia via oral or parenteral route. This study adopts thematic and bibliometric methods on existing research on novel iron formulations. It also provides perspective into the existing understanding on treatment strategies for iron deficiency anemia. This study is conducted on 543 papers on various ferrous and ferric formulations used in the treatment of iron deficiency anemia. The study period is from 1977 to 2022, and the papers are identified from the Scopus database. The bibliometric analysis was carried out using the R tool's Bibliometrix package. The study discusses performance analysis, including annual publications, geographic analysis, relevant affiliations, journal analysis, and citation analysis. In addition, the conceptual structure, including the co-occurrence network, thematic map, thematic evolution, intellectual structure highlighting co-citation analysis, and social structure depicting the collaboration network and collaboration world map, are presented. The results showed increased research on formulation strategies for the treatment of iron deficiency anemia from 2010 onwards. The top 5 contributing countries are the USA, Italy, India, Germany, and the UK, and peer-reviewed journals from the area of nutrition. The most trending areas of study are iron deficiency anemia in pregnancy, chronic kidney diseases, inflammatory bowel diseases, and various intravenous formulations used in its treatment. The authors from Europe collaborate the most with authors from other countries. The study concludes that a safer and more effective iron formulation is needed to reduce the prevalence of anemia. The findings of the study are helpful in advancing research on innovative formulations for treating iron deficiency anemia. The insights from the study are helpful to policymakers in designing specific health policies and investing more in research and development of novel formulations for the treatment of iron deficiency anemia.

Targeting ferroptosis for leukemia therapy: exploring novel strategies from its mechanisms and role in leukemia based on nanotechnology

The latest findings in iron metabolism and the newly uncovered process of ferroptosis have paved the way for new potential strategies in anti-leukemia treatments. In the current project, we reviewed and summarized the current role of nanomedicine in the treatment and diagnosis of leukemia through a comparison made between traditional approaches applied in the treatment and diagnosis of leukemia via the existing investigations about the ferroptosis molecular mechanisms involved in various anti-tumor treatments. The application of nanotechnology and other novel technologies may provide a new direction in ferroptosis-driven leukemia therapies. The article explores the potential of targeting ferroptosis, a new form of regulated cell death, as a new therapeutic strategy for leukemia. It discusses the mechanisms of ferroptosis and its role in leukemia and how nanotechnology can enhance the delivery and efficacy of ferroptosis-inducing agents. The article not only highlights the promise of ferroptosis-targeted therapies and nanotechnology in revolutionizing leukemia treatment, but also calls for further research to overcome challenges and fully realize the clinical potential of this innovative approach. Finally, it discusses the challenges and opportunities in clinical applications of ferroptosis.

Dietary Iron Is Necessary to Support Proliferative Regeneration after Intestinal Injury

BACKGROUND

Tissue repair and regeneration in the gastrointestinal system are crucial for maintaining homeostasis, with the process relying on intricate cellular interactions and affected by micro- and macro-nutrients. Iron, essential for various biological functions, plays a dual role in tissue healing by potentially causing oxidative damage and participating in anti-inflammatory mechanisms, underscoring its complex relationship with inflammation and tissue repair.

OBJECTIVE

The study aimed to elucidate the role of low dietary iron in gastrointestinal tissue repair.

METHODS

We utilized quantitative iron measurements to assess iron levels in inflamed regions of patients with ulcerative colitis and Crohn's disease. In addition, 3 mouse models of gastrointestinal injury/repair (dextran sulfate sodium-induced colitis, radiation injury, and wound biopsy) were used to assess the effects of low dietary iron on tissue repair.

RESULTS

We found that levels of iron in inflamed regions of both patients with ulcerative colitis and Crohn's disease are elevated. Similarly, during gastrointestinal repair, iron levels were found to be heightened, specifically in intestinal epithelial cells across the 3 injury/repair models. Mice on a low-iron diet showed compromised tissue repair with reduced proliferation. In standard diet, epithelial cells and the stem cell compartment maintain adequate iron stores. However, during a period of iron deficiency, epithelial cells exhaust their iron reserves, whereas the stem cell compartments maintain their iron pools. During injury, when the stem compartment is disrupted, low iron levels impair proliferation and compromise repair mechanisms.

CONCLUSIONS

Low dietary iron impairs intestinal repair through compromising the ability of epithelial cells to aid in intestinal proliferation.

TfR1 mediated iron metabolism dysfunction as a potential therapeutic target for osteoarthritis

OBJECTIVE

Transferrin receptor-1 (TfR1) plays important roles in controlling cellular iron levels, but its role in OA pathology is unknown. Herein we aim to investigate the role of TfR1 in OA progression and its underlying mechanisms.

METHODS

TfR1 expression in cartilage during OA development were examined both in vivo and in vitro. Then IL-1β was used to induce chondrocytes degeneration in vitro and TfR1 siRNA was used for observing the effect of TfR1 in modulating iron homeostasis, mitochondrial function and degrading enzymes expression. Also the inhibitor of TfR1 was exploited to analyze the protective effect of TfR1 inhibition in vivo.

RESULTS

TfR1 is elevated in OA cartilage and contributes to OA inflammation condition. Excess iron not only results in oxidative stress damage and sensitizes chondrocytes to ferroptosis, but also triggers c-GAS/STING-mediated inflammation by promoting mitochondrial destruction and the release of mtDNA. Silencing TfR1 using TfR1 siRNA not only reduced iron content in chondrocytes and inhibited oxidative stress, but also facilitated the mitophagy process and suppressed mtDNA/cGAS/STING-mediated inflammation. Importantly, we also found that Ferstatin II, a novel and selective TfR1 inhibitor, could substantially suppress TfR1 activity both in vivo and in vitro and ameliorated cartilage degeneration.

CONCLUSION

Our work demonstrates that TfR1 mediated iron influx plays important roles in chondrocytes degeneration and OA pathogenesis, suggesting that maintaining iron homeostasis through the targeting of TfR1 may represent a novel therapeutic strategy for the treatment of OA.

Inhibition of SAT1 alleviates chondrocyte inflammation and ferroptosis by repressing ALOX15 expression and activating the Nrf2 pathway

Aims

Osteoarthritis (OA) is the most common chronic pathema of human joints. The pathogenesis is complex, involving physiological and mechanical factors. In previous studies, we found that ferroptosis is intimately related to OA, while the role of Sat1 in chondrocyte ferroptosis and OA, as well as the underlying mechanism, remains unclear.

Methods

In this study, interleukin-1β (IL-1β) was used to simulate inflammation and Erastin was used to simulate ferroptosis in vitro. We used small interfering RNA (siRNA) to knock down the spermidine/spermine N1-acetyltransferase 1 (Sat1) and arachidonate 15-lipoxygenase (Alox15), and examined damage-associated events including inflammation, ferroptosis, and oxidative stress of chondrocytes. In addition, a destabilization of the medial meniscus (DMM) mouse model of OA induced by surgery was established to investigate the role of Sat1 inhibition in OA progression.

Results

The results showed that inhibition of Sat1 expression can reduce inflammation, ferroptosis changes, reactive oxygen species (ROS) level, and lipid-ROS accumulation induced by IL-1β and Erastin. Knockdown of Sat1 promotes nuclear factor-E2-related factor 2 (Nrf2) signalling. Additionally, knockdown Alox15 can alleviate the inflammation-related protein expression induced by IL-1β and ferroptosis-related protein expression induced by Erastin. Furthermore, knockdown Nrf2 can reverse these protein expression alterations. Finally, intra-articular injection of diminazene aceturate (DA), an inhibitor of Sat1, enhanced type II collagen (collagen II) and increased Sat1 and Alox15 expression.

Conclusion

Our results demonstrate that inhibition of Sat1 could alleviate chondrocyte ferroptosis and inflammation by downregulating Alox15 activating the Nrf2 system, and delaying the progression of OA. These findings suggest that Sat1 provides a new approach for studying and treating OA.

Quantitative susceptibility mapping for iron monitoring of multiple subcortical nuclei in type 2 diabetes mellitus: a systematic review and meta-analysis

Introduction

Iron accumulation in the brain has been linked to diabetes, but its role in subcortical structures involved in motor and cognitive functions remains unclear. Quantitative susceptibility mapping (QSM) allows the non-invasive quantification of iron deposition in the brain. This systematic review and meta-analysis examined magnetic susceptibility measured by QSM in the subcortical nuclei of patients with type 2 diabetes mellitus (T2DM) compared with controls.

Methods

PubMed, Scopus, and Web of Science databases were systematically searched [following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines] for studies reporting QSM values in the deep gray matter (DGM) regions of patients with T2DM and controls. Pooled standardized mean differences (SMDs) for susceptibility were calculated using fixed-effects meta-analysis models, and heterogeneity was assessed using I2. Sensitivity analyses were conducted, and publication bias was evaluated using Begg's and Egger's tests.

Results

Six studies including 192 patients with T2DM and 245 controls were included. This study found a significant increase in iron deposition in the subcortical nuclei of patients with T2DM compared to the control group. The study found moderate increases in the putamen (SMD = 0.53, 95% CI 0.33 to 0.72, p = 0.00) and dentate nucleus (SMD = 0.56, 95% CI 0.27 to 0.85, p = 0.00) but weak associations between increased iron levels in the caudate nucleus (SMD = 0.32, 95% CI 0.13 to 0.52, p = 0.00) and red nucleus (SMD = 0.22, 95% CI 0.00 0.44, p = 0.05). No statistical significance was found for iron deposition alterations in the globus pallidus (SMD = 0.19; 95% CI -0.01 to 0.38; p = 0.06) and substantia nigra (SMD = 0.12, 95% CI -0.10, 0.34, p = 0.29). Sensitivity analysis showed that the findings remained unaffected by individual studies, and consistent increases were observed in multiple subcortical areas.

Discussion

QSM revealed an increase in iron in the DGM/subcortical nuclei in T2DM patients versus controls, particularly in the motor and cognitive nuclei, including the putamen, dentate nucleus, caudate nucleus, and red nucleus. Thus, QSM may serve as a potential biomarker for iron accumulation in T2DM patients. However, further research is needed to validate these findings.

Iron, Oxidative Stress, and Metabolic Dysfunction-Associated Steatotic Liver Disease

Excess free iron is a substrate for the formation of reactive oxygen species (ROS), thereby augmenting oxidative stress. Oxidative stress is a well-established cause of organ damage in the liver, the main site of iron storage. Ferroptosis, an iron-dependent mechanism of regulated cell death, has recently been gaining attention in the development of organ damage and the progression of liver disease. We therefore summarize the main mechanisms of iron metabolism, its close connection to oxidative stress and ferroptosis, and its particular relevance to disease mechanisms in metabolic-dysfunction-associated fatty liver disease and potential targets for therapy from a clinical perspective.

Nrf2 protects against cartilage endplate degeneration through inhibiting NCOA4‑mediated ferritinophagy

Iron overload and ferroptosis are associated with intervertebral disc degeneration (IDD); however, the mechanism underlying the regulation of iron homeostasis remains to be elucidated. Nuclear factor erythroid 2‑related factor 2 (Nrf2) has been reported to regulate cellular iron homeostasis; however, its impact on IDD pathology and the underlying mechanism of action requires further investigation. In the present study, immunohistochemistry analysis of Nrf2 expression in the cartilage endplate (CEP) was conducted and it was demonstrated that Nrf2 expression was increased in the CEP at the early stages of the development of IDD, whereas it was decreased at the late stages of the development of IDD. The results of western blot analysis indicated that the inadequate activation of Nrf2 may aggravate mitochondrial dysfunction and oxidative stress, thus promoting CEP chondrocyte degeneration and calcification. It was also revealed that Nrf2 was involved in TNF‑α‑induced CEP chondrocyte iron metabolism dysfunction and ferroptosis. Inhibition of Nrf2 expression using Nrf2 small interfering RNA could enhance the process of nuclear receptor coactivator 4 (NCOA4)‑mediated ferritinophagy and increase ferrous ion content, which may promote CEP chondrocyte ferroptotic cell death and extracellular matrix degradation. Furthermore, a decrease in cellular iron concentration may inhibit CEP chondrocyte ferroptosis, and CEP degeneration and calcification. The present study highlights the role of the Nrf2/NCOA4 axis in chondrocyte ferroptosis and IDD pathogenesis, thus suggesting that activation of Nrf2 may be a promising strategy for IDD treatment.

Multipurpose Iron-Chelating Ligands Inspired by Bioavailable Molecules

Because of their capacity to bind metals, metal chelators are primarily employed for therapeutic purposes, but they can also find applications as colorimetric reagents and cleaning solutions as well as in soil remediation, electroplating, waste treatment, and so on. For instance, iron-chelation therapy, which is used to treat iron-overload disorders, involves removing excess iron from the blood through the use of particular molecules, like deferoxamine, that have the ability to chelate the metal. The creation of bioinspired and biodegradable chelating agents is a crucial objective that draws inspiration from natural products. In this context, starting from bioavailable molecules such as maltol and pyrogallol, new molecules have been synthetized and characterized by potentiometry, infrared spectroscopy and cyclic voltammetry. Finally, the ability of these to bind iron has been investigated, and the stability constants of ferric complexes are measured using spectrophotometry. These compounds offer intriguing scaffolds for an innovative class of versatile, multipurpose chelating agents.

Synergistic Effect of Retinoic Acid and Lactoferrin in the Maintenance of Gut Homeostasis

Lactoferrin (LF) is a glycoprotein that binds to iron ions (Fe2+) and other metallic ions, such as Mg2+, Zn2+, and Cu2+, and has antibacterial and immunomodulatory properties. The antibacterial properties of LF are due to its ability to sequester iron. The immunomodulatory capability of LF promotes homeostasis in the enteric environment, acting directly on the beneficial microbiota. LF can modulate antigen-presenting cell (APC) biology, including migration and cell activation. Nonetheless, some gut microbiota strains produce toxic metabolites, and APCs are responsible for initiating the process that inhibits the inflammatory response against them. Thus, eliminating harmful strains lowers the risk of inducing chronic inflammation, and consequently, metabolic disease, which can progress to type 2 diabetes mellitus (T2DM). LF and retinoic acid (RA) exhibit immunomodulatory properties such as decreasing cytokine production, thus modifying the inflammatory response. Their activities have been observed both in vitro and in vivo. The combined, simultaneous effect of these molecules has not been studied; however, the synergistic effect of LF and RA may be employed for enhancing the secretion of humoral factors, such as IgA. We speculate that the combination of LF and RA could be a potential prophylactic alternative for the treatment of metabolic dysregulations such as T2DM. The present review focuses on the importance of a healthy diet for a balanced gut and describes how probiotics and prebiotics with immunomodulatory activity as well as inductors of differentiation and cell proliferation could be acquired directly from the diet or indirectly through the oral administration of formulations aimed to maintain gut health or restore a eubiotic state in an intestinal environment that has been dysregulated by external factors such as stress and a high-fat diet.

Comparative prebiotic potential of galacto- and fructo-oligosaccharides, native inulin, and acacia gum in Kenyan infant gut microbiota during iron supplementation

Iron fortification to prevent anemia in African infants increases colonic iron levels, favoring the growth of enteropathogens. The use of prebiotics may be an effective strategy to reduce these detrimental effects. Using the African infant PolyFermS gut model, we compared the effect of the prebiotics short-chain galacto- with long-chain fructo-oligosaccharides (scGOS/lcFOS) and native inulin, and the emerging prebiotic acacia gum, a branched-polysaccharide-protein complex consisting of arabinose and galactose, during iron supplementation on four Kenyan infant gut microbiota. Iron supplementation did not alter the microbiota but promoted Clostridioides difficile in one microbiota. The prebiotic effect of scGOS/lcFOS and inulin was confirmed during iron supplementation in all investigated Kenyan infant gut microbiota, leading to higher abundance of bifidobacteria, increased production of acetate, propionate, and butyrate, and a significant shift in microbiota composition compared to non-supplemented microbiota. The abundance of the pathogens Clostridium difficile and Clostridium perfringens was also inhibited upon addition of the prebiotic fibers. Acacia gum had no effect on any of the microbiota. In conclusion, scGOS/lcFOS and inulin, but not acacia gum, showed a donor-independent strong prebiotic potential in Kenyan infant gut microbiota. This study demonstrates the relevance of comparing fibers in vitro prior to clinical studies.

Transferrin receptor levels and its rare variant are associated with human obesity

AIM

Iron homeostasis is critical for functional respiratory chain complex of mitochondrial, thus potentially contributing to fat biology and energy homeostasis. Transferrin receptor (Tfrc) binds to transferrin for extracellular iron uptake and is recently reported to be involved in brown fat development and functionality. However, whether TFRC levels and variants are associated with human obesity is unknown.

METHODS

To investigate the association of TFRC levels and variants with human obesity, fat biopsies were obtained from surgery. Exon-sequencing and genetic assessments were conducted of a case-control study. For TFRC levels assessment in fat biopsy, 9 overweight and 12 lean subjects were involved. For genetic study, obese (n = 1271) and lean subjects (n = 1455) were involved. TFRC levels were compared in abdominal mesenteric fat of pheochromocytoma patients versus control subjects, and overweight versus lean subjects. For genetic study, whole-exome sequencing of obese and matched control subjects were conducted and analyzed. In addition, the possible disruption in protein stability of TFRC variant was assessed by structural and molecular analysis.

RESULTS

TFRC levels are increased in human browning adipose tissue and decreased in fat of overweight patients. Besides, TFRC levels are negatively correlated with body mass index and positively correlated with uncoupling protein 1 levels. Furthermore, a rare heterozygous missense variant p.I337V in TFRC shows a tendency to enrich in obese subjects. Structural and functional study reveals impaired protein stability of the TFRC variant compared to wild-type.

CONCLUSIONS

Reduced TFRC levels and its rare variant p.I337V with protein instability are associated with human obesity.

Alzheimer's disease-related brain insulin resistance and the prospective therapeutic impact of metformin

Besides COVID-19, two of the most critical outbreaks of our day are insulin resistance, type 2 diabetes mellitus (T2DM), and Alzheimer's disease (AD). Each disease's pathophysiology is well established. Furthermore, a substantial overlap between them has coexisted. Uncertainty remains on whether T2DM and AD are parallel illnesses with the same origin or separate illnesses linked through violent pathways. The current study was aimed at testing whether the insulin resistance in the brain results in AD symptoms or not. Insulin resistance was induced in the brains of rats using a single intracerebroventricular streptozotocin (STZ) dose. We then measured glucose, insulin receptor substrate 2 (IRS-2), amyloid β (Aβ) deposition, and tau phosphorylation in the brain to look for signs of insulin resistance and AD. The results of this study indicated that a single dose of STZ was able to induce insulin resistance in the brain and significantly decline IRS-2. This resistance was accompanied by obvious memory loss, Aβ deposition, and tau phosphorylation, further visible diminishing in neurotransmitters such as dopamine and acetylcholine. Furthermore, oxidative stress was increased due to the antioxidant system being compromised. Interestingly, the pancreas injury and peripheral insulin resistance coexisted with brain insulin resistance. Indeed, the antidiabetic metformin was able to enhance all these drastic effects. In conclusion, brain insulin resistance could lead to AD and vice versa. These are highly linked syndromes that could influence peripheral organs. Further studies are required to stabilize this putative pathobiology relationship between them.

TGF-β-regulated different iron metabolism processes in the development and cisplatin resistance of ovarian cancer

The impact of different iron metabolism processes (DIMP) on ovarian cancer remains unclear. In this study, we employed various gene chips and databases to investigate the role of DIMP in the initiation and development of ovarian cancer. cBioPortal was used to determine mutations in DIMP-associated genes in ovarian cancer. Kaplan-Meier plotter was used to examine the influence of DIMP on the prognosis of ovarian cancer. By analyzing 1669 serous ovarian cancer cases, we identified a range of mutations in iron metabolism genes, notably in those coding for the transferrin receptor (19%), melanotransferrin (19%), and ceruloplasmin (10%) in the iron import process, and glucose-6-phosphate isomerase (9%), hepcidin antimicrobial peptide (9%), metal regulatory transcription factor 1 (8%), and bone morphogenetic protein 6 (8%) in the iron regulation process. Compared to the unaltered group, the group with gene alterations exhibited a higher tumor mutation burden count (43 vs. 54) and more advanced histologic grade (78.19% vs. 87.90%). Compared to the normal ovarian counterparts, a reduction in expression was observed in 9 out of the 14 genes involved in iron utilization and 4 out of the 5 genes involved in iron export in ovarian cancer; in contrast, an increase in expression was observed in 2 out of the 3 genes involved in iron storage in ovarian cancer. Furthermore, in cisplatin-resistant cells compared to cisplatin-sensitive ones, the expression of all genes in iron storage and 13 out of 14 genes in iron import was decreased, while that of 8 out of the 10 genes in iron utilization was increased. In addition, survival curve analysis indicated that a higher expression in the majority of genes in the iron import process (12/21), or a reduced expression in most genes in the iron export process (4/5) correlated with poor progression-free survival. Additionally, TGF-β could regulate the expression of most iron metabolism-associated genes; particularly, expression of genes involved in the iron storage process (2/2) was inhibited after TGF-β1 or TGF-β2 treatment. In conclusion, DIMP plays multifaceted roles in the initiation, chemo-resistance, and prognosis of ovarian cancer. Therapeutically targeting DIMP may pave the way for more tailored treatment approaches for ovarian cancer.

Iron overload enhances TBI-induced cardiac dysfunction by promoting ferroptosis and cardiac inflammation

Previous studies have proved that cardiac dysfunction and myocardial damage can be found in TBI patients, but the underlying mechanisms of myocardial damage induced by TBI can't be illustrated. We want to investigate the function of ferroptosis in myocardial damage after TBI and determine if inhibiting iron overload might lessen myocardial injury after TBI due to the involvement of iron overload in the process of ferroptosis and inflammation. We detect the expression of ferroptosis-related proteins in cardiac tissue at different time points after TBI, indicating that TBI can cause ferroptosis in the heart in vivo. The echocardiography and myocardial enzymes results showed that ferroptosis can aggravate TBI-induced cardiac dysfunction. The result of DHE staining and 4-HNE expression showed that inhibition of ferroptosis can reduce ROS production and lipid peroxidation in myocardial tissue. In further experiments, DFO intervention was used to explore the effect of iron overload inhibition on myocardial ferroptosis after TBI, the production of ROS, expression of p38 MAPK and NF-κB was detected to explore the effect of iron overload on myocardial inflammation after TBI. The results above show that TBI can cause heart ferroptosis in vivo. Inhibition of iron overload can alleviate myocardial injury after TBI by reducing ferroptosis and inflammatory response induced by TBI.

Morphopathological Effect of Ferrihydrite Nanoparticles in an Experimental Model of Toxic Hemolytic Anemia

We studied the effect of biogenic ferrihydrite nanoparticles synthesized as a result of the culturing of Klebsiella oxytoca on Wistar rats with experimental toxic hemolytic anemia. The pathology was simulated by single intraperitoneal injection of phenylhydrazine hydrochloride. On day 4, the functional parameters of erythrocytes in rats corresponded to the state of toxic hemolytic anemia. It is shown that ferrihydrite nanoparticles suspension has chronic toxicity and causes morphological changes in organs (mainly in the spleen), which are characterized by accumulation of nanoparticles. Administration of phenylhydrazine induced systemic vascular damage and the formation of extramedullary hematopoietic foci, which indicated a compensatory activation in hematopoiesis in the liver and spleen. Injection of nanoparticles reduced discirculatory and necrotic changes in the kidneys.

The Role of Iron Overload in Diabetic Cognitive Impairment: A Review

It is well documented that diabetes mellitus (DM) is strongly associated with cognitive decline and structural damage to the brain. Cognitive deficits appear early in DM and continue to worsen as the disease progresses, possibly due to different underlying mechanisms. Normal iron metabolism is necessary to maintain normal physiological functions of the brain, but iron deposition is one of the causes of some neurodegenerative diseases. Increasing evidence shows that iron overload not only increases the risk of DM, but also contributes to the development of cognitive impairment. The current review highlights the role of iron overload in diabetic cognitive impairment (DCI), including the specific location and regulation mechanism of iron deposition in the diabetic brain, the factors that trigger iron deposition, and the consequences of iron deposition. Finally, we also discuss possible therapies to improve DCI and brain iron deposition.

Deferoxamine Prevents Neonatal Posthemorrhagic Hydrocephalus Through Choroid Plexus-Mediated Iron Clearance

Posthemorrhagic hydrocephalus occurs in up to 30% of infants with high-grade intraventricular hemorrhage and is associated with the worst neurocognitive outcomes in preterm infants. The mechanisms of posthemorrhagic hydrocephalus after intraventricular hemorrhage are unknown; however, CSF levels of iron metabolic pathway proteins including hemoglobin have been implicated in its pathogenesis. Here, we develop an animal model of intraventricular hemorrhage using intraventricular injection of hemoglobin at post-natal day 4 that results in acute and chronic hydrocephalus, pathologic choroid plexus iron accumulation, and subsequent choroid plexus injury at post-natal days 5, 7, and 15. This model also results in increased expression of aquaporin-1, Na+/K+/Cl- cotransporter 1, and Na+/K+/ATPase on the apical surface of the choroid plexus 24 h post-intraventricular hemorrhage. We use this model to evaluate a clinically relevant treatment strategy for the prevention of neurological sequelae after intraventricular hemorrhage using intraventricular administration of the iron chelator deferoxamine at the time of hemorrhage. Deferoxamine treatment prevented posthemorrhagic hydrocephalus for up to 11 days after intraventricular hemorrhage and prevented the development of sensorimotor gating deficits. In addition, deferoxamine treatment facilitated acute iron clearance through the choroid plexus and subsequently reduced choroid plexus iron levels at 24 h with reversal of hemoglobin-induced aquaporin-1 upregulation on the apical surface of the choroid plexus. Intraventricular administration of deferoxamine at the time of intraventricular hemorrhage may be a clinically relevant treatment strategy for preventing posthemorrhagic hydrocephalus and likely acts through promoting iron clearance through the choroid plexus to prevent hemoglobin-induced injury.

Iron Load Toxicity in Medicine: From Molecular and Cellular Aspects to Clinical Implications

Iron is essential for all organisms and cells. Diseases of iron imbalance affect billions of patients, including those with iron overload and other forms of iron toxicity. Excess iron load is an adverse prognostic factor for all diseases and can cause serious organ damage and fatalities following chronic red blood cell transfusions in patients of many conditions, including hemoglobinopathies, myelodyspasia, and hematopoietic stem cell transplantation. Similar toxicity of excess body iron load but at a slower rate of disease progression is found in idiopathic haemochromatosis patients. Excess iron deposition in different regions of the brain with suspected toxicity has been identified by MRI T2* and similar methods in many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Based on its role as the major biological catalyst of free radical reactions and the Fenton reaction, iron has also been implicated in all diseases associated with free radical pathology and tissue damage. Furthermore, the recent discovery of ferroptosis, which is a cell death program based on free radical generation by iron and cell membrane lipid oxidation, sparked thousands of investigations and the association of iron with cardiac, kidney, liver, and many other diseases, including cancer and infections. The toxicity implications of iron in a labile, non-protein bound form and its complexes with dietary molecules such as vitamin C and drugs such as doxorubicin and other xenobiotic molecules in relation to carcinogenesis and other forms of toxicity are also discussed. In each case and form of iron toxicity, the mechanistic insights, diagnostic criteria, and molecular interactions are essential for the design of new and effective therapeutic interventions and of future targeted therapeutic strategies. In particular, this approach has been successful for the treatment of most iron loading conditions and especially for the transition of thalassemia from a fatal to a chronic disease due to new therapeutic protocols resulting in the complete elimination of iron overload and of iron toxicity.

The Vital Role Played by Deferiprone in the Transition of Thalassaemia from a Fatal to a Chronic Disease and Challenges in Its Repurposing for Use in Non-Iron-Loaded Diseases

The iron chelating orphan drug deferiprone (L1), discovered over 40 years ago, has been used daily by patients across the world at high doses (75-100 mg/kg) for more than 30 years with no serious toxicity. The level of safety and the simple, inexpensive synthesis are some of the many unique properties of L1, which played a major role in the contribution of the drug in the transition of thalassaemia from a fatal to a chronic disease. Other unique and valuable clinical properties of L1 in relation to pharmacology and metabolism include: oral effectiveness, which improved compliance compared to the prototype therapy with subcutaneous deferoxamine; highly effective iron removal from all iron-loaded organs, particularly the heart, which is the major target organ of iron toxicity and the cause of mortality in thalassaemic patients; an ability to achieve negative iron balance, completely remove all excess iron, and maintain normal iron stores in thalassaemic patients; rapid absorption from the stomach and rapid clearance from the body, allowing a greater frequency of repeated administration and overall increased efficacy of iron excretion, which is dependent on the dose used and also the concentration achieved at the site of drug action; and its ability to cross the blood-brain barrier and treat malignant, neurological, and microbial diseases affecting the brain. Some differential pharmacological activity by L1 among patients has been generally shown in relation to the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the drug. Unique properties exhibited by L1 in comparison to other drugs include specific protein interactions and antioxidant effects, such as iron removal from transferrin and lactoferrin; inhibition of iron and copper catalytic production of free radicals, ferroptosis, and cuproptosis; and inhibition of iron-containing proteins associated with different pathological conditions. The unique properties of L1 have attracted the interest of many investigators for drug repurposing and use in many pathological conditions, including cancer, neurodegenerative conditions, microbial conditions, renal conditions, free radical pathology, metal intoxication in relation to Fe, Cu, Al, Zn, Ga, In, U, and Pu, and other diseases. Similarly, the properties of L1 increase the prospects of its wider use in optimizing therapeutic efforts in many other fields of medicine, including synergies with other drugs.

Biogenic Elements and Heavy Metals in Hermann's Tortoises-Testudo hermanni: Effect on Serum Biochemistry and Oxidative Status Parameters

BACKGROUND

Conservation of species diversity is the need of the hour for preserving life forms on Earth. Extinction of any part of the ecosystem has negative impacts on many processes and systems. The objective of this work was to analyze some biochemical and molecular indicators and their correlations to biogenic elements and heavy metals in Testudo hermanni (n = 16).

METHODS

Biochemical parameters were analyzed using the commercial kit DiaSys and biochemical analyzer Randox RX Monza. Sodium, potassium, and chlorides were measured using the EasyLite analyzer. Oxidative stress was evaluated using colorimetric and luminometric methods. Quantification of chemical elements in the blood was carried out using inductively coupled plasma mass spectrometry (ICPS).

RESULTS

Biochemical values of analyzed samples from Hermann's tortoises were almost the same as referential values described by multiple authors, with minor aberrations in the total protein parameter. Values of arsenic (As) and nickel (Ni) showed correlation with biochemical parameters and the parameters of oxidative stress. Cadmium (Cd) exhibited correlation with aspartate aminotransferase (AST).

CONCLUSIONS

This study reports correlations among four heavy metals, and their levels were again correlated with biochemical and molecular parameters in Hermann's tortoises.

The Emerging Roles of Ferroptosis in Neonatal Diseases

Ferroptosis is a novel type of programmed cell death involved in many diseases' pathological processes. Ferroptosis is characterized by lipid peroxidation, reactive oxygen species accumulation, and iron metabolism disorder. Newborns are susceptible to ferroptosis due to their special physiological state, which is prone to abnormal iron metabolism and the accumulation of reactive oxygen species. Recent studies have linked ferroptosis to a variety of diseases in the neonatal period (including hypoxic-ischemic encephalopathy, bronchopulmonary dysplasia, and necrotizing enterocolitis). Ferroptosis may become an effective target for the treatment of neonatal-related diseases. In this review, the ferroptosis molecular mechanism, metabolism characteristics of iron and reactive oxygen species in infants, the relationship between ferroptosis and common infant disorders, and the treatment of infant diseases targeted for ferroptosis are systematically summarized.

From Obesity-Induced Low-Grade Inflammation to Lipotoxicity and Mitochondrial Dysfunction: Altered Multi-Crosstalk between Adipose Tissue and Metabolically Active Organs

Obesity is a major risk factor for several metabolic diseases, including type 2 diabetes, hyperlipidemia, cardiovascular diseases, and brain disorders. Growing evidence suggests the importance of inter-organ metabolic communication for the progression of obesity and the subsequent onset of related disorders. This review provides a broad overview of the pathophysiological processes that from adipose tissue dysfunction leading to altered multi-tissue crosstalk relevant to regulating energy homeostasis and the etiology of obesity. First, a comprehensive description of the role of adipose tissue was reported. Then, attention was turned toward the unhealthy expansion of adipose tissue, low-grade inflammatory state, metabolic inflexibility, and mitochondrial dysfunction as root causes of systemic metabolic alterations. In addition, a short spot was devoted to iron deficiency in obese conditions and the role of the hepcidin-ferroportin relationship in the management of this issue. Finally, different classes of bioactive food components were described with a perspective to enhance their potential preventive and therapeutic use against obesity-related diseases.

Metal Complexes of Omadine (N-Hydroxypyridine-2-thione): Differences of Antioxidant and Pro-Oxidant Behavior in Light and Dark Conditions with Possible Toxicity Implications

Omadine or N-hydroxypyridine-2-thione and its metal complexes are widely used in medicine and show bactericidal, fungicidal, anticancer, and photochemical activity. The redox activity of omadine complexes with iron, copper, and zinc on lipid peroxidation under light and dark conditions has been investigated. The monitoring of the oxidation of linoleic acid micelles, resembling a model of lipid membrane, was carried out using nuclear magnetic resonance (¹H-NMR). It has been shown that the omadine-zinc complex can induce the oxidation of linoleic acid under light irradiation, whereas the complexes with iron and copper are photochemically stable. All the chelating complexes of omadine appear to be redox-inactive in the presence of hydrogen peroxide under dark conditions. These findings suggest that omadine can demonstrate antioxidant behavior in processes involving reactive oxygen species generation induced by transition metals (Fenton and photo-Fenton reactions). However, the omadine complex with zinc, which is widely used in shampoos and ointments, is photochemically active and may cause oxidative cell membrane damage when exposed to light, with possible implications to health.

Polydatin ameliorates inflammation and oxidative stress associated with MSU-induced gouty arthritis in mice by regulating PPAR-γ and ferritin activation

AIMS

Polygonum cuspidatum Sieb. et Zucc is one of the commonly used herbs for the treatment of gouty arthritis, and polydatin is one of its main effective components. This study evaluated the therapeutic potential of polydatin for the treatment of gout.

MAIN METHODS

The ankle joint of C57BL/6 mice were injected with MSU suspensions to simulate human gouty arthritis, and oral treatment with polydatin (25, 50, and 100 mg/kg body weight) was performed at 1 h after MSU crystal injection. The effect of polydatin on model mice was evaluated by measuring ankle swelling, gait, histopathological analysis, proinflammatory cytokine expression, as well as the contents of NO, MDA and GSH. The targets of polydatin were explored by Real-Time PCR and IHC.

KEY FINDINGS

Treatment with polydatin inhibited ankle swelling, improved abnormal gait, and reduced ankle lesions dose-dependently. Moreover, polydatin decreased pro-inflammatory cytokine expression, and promoted expression of anti-inflammatory cytokine. In addition, polydatin inhibited MSU-induced oxidative stress by decreasing oxidative product (NO, MDA) generation and promote the antioxidant (GSH). Further, we found that polydatin reduced inflammation by decreasing the expression of NLRP3 inflammasome component via activating PPAR-γ. Moreover, polydatin can protect against iron overload and attenuate oxidative stress by promoting the activation of ferritin.

SIGNIFICANCE

Our findings indicates that polydatin ameliorates MSU-induced inflammation and oxidative stress by regulating PPAR-γ and ferritin activation in gouty arthritis model mice, and this research result suggests that polydatin has therapeutic potential for the treatment of gout in humans through multiple targets.

Heme: The Lord of the Iron Ring

Heme is an iron-protoporphyrin complex with an essential physiologic function for all cells, especially for those in which heme is a key prosthetic group of proteins such as hemoglobin, myoglobin, and cytochromes of the mitochondria. However, it is also known that heme can participate in pro-oxidant and pro-inflammatory responses, leading to cytotoxicity in various tissues and organs such as the kidney, brain, heart, liver, and in immune cells. Indeed, heme, released as a result of tissue damage, can stimulate local and remote inflammatory reactions. These can initiate innate immune responses that, if left uncontrolled, can compound primary injuries and promote organ failure. In contrast, a cadre of heme receptors are arrayed on the plasma membrane that is designed either for heme import into the cell, or for the purpose of activating specific signaling pathways. Thus, free heme can serve either as a deleterious molecule, or one that can traffic and initiate highly specific cellular responses that are teleologically important for survival. Herein, we review heme metabolism and signaling pathways, including heme synthesis, degradation, and scavenging. We will focus on trauma and inflammatory diseases, including traumatic brain injury, trauma-related sepsis, cancer, and cardiovascular diseases where current work suggests that heme may be most important.

Pro-Inflammatory Priming of the Brain: The Underlying Cause of Parkinson's Disease

Parkinson's disease (PD) is a multifactorial neurodegenerative pathology characterized by the progressive loss of dopaminergic neurons in the substantia nigra of the brain. Aging is considered the main risk factor for the development of idiopathic PD. However, immunity and inflammation play a crucial role in the pathogenesis of this disorder. In mice, we showed that pro-inflammatory priming of the brain sensitizes to severe PD development, regardless of animal age. Age-related sub-acute inflammation, as well as the activation of the immune response upon exposure to harmful stimuli, enhances PD manifestations. The severity of PD is influenced by the engagement of host resistance mechanisms against infection based on the removal of iron (Fe) from the circulation. The sequestration of Fe by immune cells prevents pathogens from proliferating. However, it leads to the formation of a Fe-loaded circulating compartment. When entering the brain through a compromised blood-brain barrier, Fe-loaded immune cells contribute to enhancing neuroinflammation and brain Fe overload. Thus, pro-inflammatory priming of the brain exacerbates neuronal damage and represents a risk factor for the development of severe PD symptoms. Further investigations are now required to better understand whether therapeutic interventions inhibiting this phenomenon might protect against PD.

Probability of Concurrent Deficiency of Vitamin D and Iron in Hypothyroidism: A Cross-Sectional Study

BACKGROUND

Hypothyroidism is the most common pathophysiological condition that affects mostly females in both developed and developing countries. Data on hypothyroidism among adult females are essential to understand the underactive status of the thyroid gland among the female population and its correlated effects on a deficiency of vitamin D and iron, as effective prevention of osteoporotic changes and iron deficiency anemia is possible. Therefore, the present study was designed to investigate the probability of concurrent iron and vitamin D deficiency among the adult hypothyroid female population of Abu Dhabi, UAE.

MATERIALS AND METHODS

This cross-sectional study was carried out from September 2019 to July 2021 among 500 adult females aged 18 to 45 years old in Sheikh Shakhbout Medical City (SSMC) and Sheikh Khalifa Medical City (SKMC), Abu Dhabi, UAE. After obtaining written informed consent, subjects' demographic characteristics (sun exposure, dressing code, food consumption), anthropometry (height, weight, BMI), and biochemical parameters (thyroid profile, vitamin D profile, iron profile, and blood indices) were measured.

RESULTS

In this study, serum vitamin D and iron levels were significantly (p<0.01) decreased in the hypothyroid female group (study group). The serum vitamin D and iron levels showed a significant negative (p<0.01) correlation with thyroid-stimulating hormone (TSH). Out of 250 study group participants, 61 had a concurrent deficiency of serum vitamin D and iron, yielding a probability (P of low vitamin D and iron and hypothyroidism) of 0.244, which indicates that if 1000 hypothyroid patients are tested for serum vitamin D and iron levels, 24 patients are probable to have low vitamin D and iron.

CONCLUSION

The study concluded that vitamin D and iron bi-deficiency were observed in adult hypothyroid females in Abu Dhabi, UAE. So, the routine check-up of thyroid function and vitamin D and iron profiles should be done early. Therefore, early vitamin D and iron deficiencies can be detected, and supplements can be given to prevent further health complications like osteoporosis and iron deficiency anemia.

Gut Dysbiosis: A Target for Protective Interventions against Parkinson’s Disease

Sub-chronic inflammation, caused by age-related dysbiosis, primes the brain to neuroinflammation and neurodegenerative diseases. Evidence revealed that Parkinson’s disease (PD) might originate in the gut, demonstrating gastro-intestinal disturbances, as reported by PD patients long before developing motor symptoms. In this study, we conducted comparative analyses in relatively young and old mice maintained in conventional or gnotobiotic conditions. We aimed to confirm that the effects induced by age-related dysbiosis, rather than aging itself, sensitize to PD onset. This hypothesis was confirmed in germ-free (GF) mice, which proved resistant to the pharmacological induction of PD, regardless of their age. Contrary to conventional animals, old GF mice did not develop an inflammatory phenotype or an accumulation of iron in the brain, two catalysts sensitizing to disease onset. The resistance of GF mice to PD is reverted when colonized with stool collected from conventional old animals, but not if receiving bacterial content from young mice. Hence, changes in gut microbiota composition are a risk factor for PD development and can be targeted preventively by iron chelators, shown to protect the brain from pro-inflammatory intestinal priming that sensitizes to neuroinflammation and the development of severe PD.

Antioxidant and Lipid-Lowering Effects of Buriti Oil (Mauritia flexuosa L.) Administered to Iron-Overloaded Rats

The indiscriminate use of oral ferrous sulfate (FeSO4) doses induces significant oxidative damage to health. However, carotene-rich foods such as buriti oil can help the endogenous antioxidant defense and still maintain other body functions. This study aimed to assess the effects of buriti oil intake in iron-overloaded rats by FeSO4 administration. Buriti oil has β-carotene (787.05 mg/kg), α-tocopherol (689.02 mg/kg), and a predominance of monounsaturated fatty acids (91.30 g/100 g). Wistar rats (n = 32) were subdivided into two control groups that were fed a diet containing either soybean or buriti oil; and two groups which received a high daily oral dose of FeSO4 (60 mg/kg body weight) and fed a diet containing either soybean (SFe) or buriti oil (Bfe). The somatic and hematological parameters, serum lipids, superoxide dismutase (SOD), and glutathione peroxidase (GPx) were determined after 17 days of iron overload. Somatic parameters were similar among groups. BFe showed a decrease in low-density lipoprotein (38.43%) and hemoglobin (7.51%); an increase in monocytes (50.98%), SOD activity in serum (87.16%), and liver (645.50%) hepatic GPx (1017.82%); and maintained serum GPx compared to SFe. Buriti oil showed systemic and hepatic antioxidant protection in iron-overloaded rats, which may be related to its high carotenoid, tocopherol, and fatty acid profile.

Deferiprone and Iron-Maltol: Forty Years since Their Discovery and Insights into Their Drug Design, Development, Clinical Use and Future Prospects

The historical insights and background of the discovery, development and clinical use of deferiprone (L1) and the maltol-iron complex, which were discovered over 40 years ago, highlight the difficulties, complexities and efforts in general orphan drug development programs originating from academic centers. Deferiprone is widely used for the removal of excess iron in the treatment of iron overload diseases, but also in many other diseases associated with iron toxicity, as well as the modulation of iron metabolism pathways. The maltol-iron complex is a recently approved drug used for increasing iron intake in the treatment of iron deficiency anemia, a condition affecting one-third to one-quarter of the world's population. Detailed insights into different aspects of drug development associated with L1 and the maltol-iron complex are revealed, including theoretical concepts of invention; drug discovery; new chemical synthesis; in vitro, in vivo and clinical screening; toxicology; pharmacology; and the optimization of dose protocols. The prospects of the application of these two drugs in many other diseases are discussed under the light of competing drugs from other academic and commercial centers and also different regulatory authorities. The underlying scientific and other strategies, as well as the many limitations in the present global scene of pharmaceuticals, are also highlighted, with an emphasis on the priorities for orphan drug and emergency medicine development, including the roles of the academic scientific community, pharmaceutical companies and patient organizations.

A 13-week subchronic toxicity study of heme iron in SD rats

Heme iron (HI) has been widely used as a food additive and supplement to support iron fortification. However, no sufficient toxicological data to evaluate the safety of HI have been reported. In the current study, we performed a 13-week subchronic toxicity study of HI in male and female Crl:CD(SD) rats. Rats were orally administered HI in the diet at concentrations of 0%, 0.8%, 2%, and 5%. Observations of general condition, body weight (bw) and food consumption, urinalysis, hematology, serum biochemistry, and macroscopic and histopathological examination were performed. The results showed that HI had no adverse effects on any of the examined parameters. Therefore, we concluded that the no-observed-adverse-effect level (NOAEL) for HI was estimated to be 5% for both sexes (2,890 mg/kg bw/day for males and 3,840 mg/kg bw/day for females). Since the iron content of HI used in this study was in a range of 2.0-2.6%, iron content at NOAEL for HI was calculated to be 57.8-75.1 mg/kg bw/day for males and 76.8-99.8 mg/kg bw/day for females.

In silico analysis prediction of HepTH1-5 as a potential therapeutic agent by targeting tumour suppressor protein networks

Many studies reported that the activation of tumour suppressor protein, p53 induced the human hepcidin expression. However, its expression decreased when p53 was silenced in human hepatoma cells. Contrary to Tilapia hepcidin TH1-5, HepTH1-5 was previously reported to trigger the p53 activation through the molecular docking approach. The INhibitor of Growth (ING) family members are also shown to directly interact with p53 and promote cell cycle arrest, senescence, apoptosis and participate in DNA replication and DNA damage responses to suppress the tumour initiation and progression. However, the interrelation between INGs and HepTH1-5 remains unknown. Therefore, this study aims to identify the mechanism and their protein interactions using in silico approaches. The finding revealed that HepTH1-5 and its ligands had interacted mostly on hotspot residues of ING proteins which involved in histone modifications via acetylation, phosphorylation, and methylation. This proves that HepTH1-5 might implicate in an apoptosis signalling pathway and preserve the protein structure and function of INGs by reducing the perturbation of histone binding upon oxidative stress response. This study would provide theoretical guidance for the design and experimental studies to decipher the role of HepTH1-5 as a potential therapeutic agent for cancer therapy. Communicated by Ramaswamy H. Sarma.

Effect of Supplementation with Black Chokeberry (Aronia melanocarpa) Extract on Inflammatory Status and Selected Markers of Iron Metabolism in Young Football Players: A Randomized Double-Blind Trial

The use of herbal medicinal products and supplements in amateur and professional sports has increased in the last decades. This is because most of these products and supplements contain bioactive compounds with a variety of biological properties that exert a physiological effect on the human body. The aim of this study was to analyze the effect of dietary supplementation with lyophilized black chokeberry extract on the levels of pro-inflammatory cytokines, hepcidin, and selected markers of iron metabolism in a group of young football players. This double-blind study included 22 male football players (mean = 19.96 ± 0.56), divided into two groups: supplemented and placebo. Before and after a 90-day period of training combined with supplementation (6 g of lyophilized black chokeberry extract), participants performed maximal multistage 20-m shuttle run tests at the beginning and at the end of the supplementation period, with blood sampled for analysis at different times before and after exercise. The levels of IL-6, IL-10, ferritin, myoglobin, hepcidin, 8-OHdG, albumin, and TAC were analyzed. The analysis of variance revealed a significant effect of 90-day supplementation with the lyophilized extract on changes in the IL-6 and IL-10 levels, and TAC induced by maximal aerobic effort. In conclusion, supplementation with lyophilized black chokeberry extract improves the performance and antioxidant status of serum in humans and induces protective changes in inflammatory markers.

HIF2α activation and mitochondrial deficit due to iron chelation cause retinal atrophy

Iron accumulation causes cell death and disrupts tissue functions, which necessitates chelation therapy to reduce iron overload. However, clinical utilization of deferoxamine (DFO), an iron chelator, has been documented to give rise to systemic adverse effects, including ocular toxicity. This study provided the pathogenic and molecular basis for DFO-related retinopathy and identified retinal pigment epithelium (RPE) as the target tissue in DFO-related retinopathy. Our modeling demonstrated the susceptibility of RPE to DFO compared with the neuroretina. Intriguingly, we established upregulation of hypoxia inducible factor (HIF) 2α and mitochondrial deficit as the most prominent pathogenesis underlying the RPE atrophy. Moreover, suppressing hyperactivity of HIF2α and preserving mitochondrial dysfunction by α-ketoglutarate (AKG) protects the RPE against lesions both in vitro and in vivo. This supported our observation that AKG supplementation alleviates visual impairment in a patient undergoing DFO-chelation therapy. Overall, our study established a significant role of iron deficiency in initiating DFO-related RPE atrophy. Inhibiting HIF2α and rescuing mitochondrial function by AKG protect RPE cells and can potentially ameliorate patients' visual function.

Investigation of imbalances in essential/toxic metal levels in the blood of laryngeal cancer patients in comparison with controls

Laryngeal carcinoma is one of the common types of head and neck cancer, with men being more likely than women to develop it. Diet, age, gender, smoking habits, and environmental factors play important roles in its development. The goal of this study was to ascertain if there were imbalances in essential and toxic trace metals owing to the initiation and progression of laryngeal cancer. Atomic absorption spectrometry was employed to quantify selected macroelements, and essential/toxic trace metals in blood of the cancerous patients and matching controls. Significantly higher concentrations of Pb, Cu, Fe, and Sr while substantially lower levels of Na, K, Ca, and Mg were observed in the cancer patients compared with the controls. Considerably disparate mutual relationships among the macroelements, and essential/toxic trace metals in the patients and controls were manifested by their correlation coefficients. Similarly, multivariate apportionment of the metal levels showed appreciably diverse associations and grouping in the patients and controls. The laryngeal cancer patients exhibited significant disparities in the metal levels among various sub-types (supraglottic, subglottic, transglottic, and glottic cancer) and stages (I, II, III, and IV) of the disease. Most of the metals revealed distinct differences based on the gender, habitat, age, eating preferences, and smoking habits in both donor groups. Overall, the study demonstrated significant imbalances among the macroelements, and essential/toxic trace metal levels in the blood of laryngeal cancer patients compared to the controls.

Mitochondrial Toxicant-Induced Neuronal Apoptosis in Parkinson's Disease: What We Know so Far

Parkinson's disease (PD) is one of the most common progressive neurodegenerative diseases caused by the loss of dopamine-producing neuronal cells in the region of substantia nigra pars compacta of the brain. During biological aging, neuronal cells slowly undergo degeneration, but the rate of cell death increases tremendously under some pathological conditions, leading to irreversible neurodegenerative diseases. By the time symptoms of PD usually appear, more than 50 to 60% of neuronal cells have already been destroyed. PD symptoms often start with tremors, followed by slow movement, stiffness, and postural imbalance. The etiology of PD is still unknown; however, besides genetics, several factors contribute to neurodegenerative disease, including exposure to pesticides, environmental chemicals, solvents, and heavy metals. Postmortem brain tissues of patients with PD show mitochondrial abnormalities, including dysfunction of the electron transport chain. Most chemicals present in our environment have been shown to target the mitochondria; remarkably, patients with PD show a mild deficiency in NADH dehydrogenase activity, signifying a possible link between PD and mitochondrial dysfunction. Inhibition of electron transport complexes generates free radicals that further attack the macromolecules leading to neuropathological conditions. Apart from that, oxidative stress also causes neuroinflammation-mediated neurodegeneration due to the activation of microglial cells. However, the mechanism that causes mitochondrial dysfunction, especially the electron transport chain, in the pathogenesis of PD remains unclear. This review discusses the recent updates and explains the possible mechanisms of mitochondrial toxicant-induced neuroinflammation and neurodegeneration in PD.

Dysmetabolic Iron Overload Syndrome: Going beyond the Traditional Risk Factors Associated with Metabolic Syndrome

Dysmetabolic iron overload syndrome (DIOS) corresponds to the increase in iron stores associated with components of metabolic syndrome (MtS) and in the absence of an identifiable cause of iron excess. The objective of this work was to review the main aspects of DIOS. PUBMED and EMBASE were consulted, and PRISMA guidelines were followed. DIOS is usually asymptomatic and can be diagnosed by investigating MtS and steatosis. About 50% of the patients present altered hepatic biochemical tests (increased levels of γ-glutamyl transpeptidase itself or associated with increased levels of alanine aminotransferase). The liver may present parenchymal and mesenchymal iron overload, but the excess of iron is commonly mild. Steatosis or steatohepatitis is observed in half of the patients. Fibrosis is observed in about 15% of patients. Hyperferritinemia may damage the myocardium, liver, and several other tissues, increasing morbidity and mortality. Furthermore, DIOS is closely related to oxidative stress, which is closely associated with several pathological conditions such as inflammatory diseases, hypertension, diabetes, heart failure, and cancer. DIOS is becoming a relevant finding in the general population and can be associated with high morbidity/mortality. For these reasons, investigation of this condition could be an additional requirement for the early prevention of cardiovascular diseases.

The study of a novel high selectivity pyrenyl-based fluorescence probe with aggregation-induced emission characteristics for Fe3+ detection designed by a structure modulation strategy

The past decades have witnessed the feat of fluorescent probes for Fe³⁺ detection, where eliminating the interference by other metal ions plays a pivotal role in its detection by probes in complex environments. Herein, by taking advantage of the substituent effects, the electron-withdrawing group (EWG) -CF₃ and electron-donating group (EDG) -CH₃ were introduced to 2-(1-pyrenyl)pyridine (pypyr) to prepare two turn-off fluorescence probes, 5-trifluoromethyl-2-(1-pyrenyl)pyridine (pypyr-CF3) and 5-methyl-2-(1-pyrenyl)pyridine (pypyr-CH3). Intriguingly, both probes displayed novel aggregation-induced emission (AIE) characteristics in MeCN/H₂O mixtures and the size and morphology of the aggregated particles were studied via DLS and TEM. By the modulation strategy, pypyr-CF3 can detect Fe³⁺ in the presence of 29 different metal ions without interference. Comparatively, pypyr-CH3 experienced serious interference from other metal ions such as Hg²⁺ and Zr⁴⁺. Besides, pypyr-CF3 not only demonstrated a higher photoluminescence quantum yield (PLQY) of 65.25% and wider pH adaptability but is also capable of Fe³⁺ detection over a wide pH range of 2-11 with a short response time (5 seconds). A plausible quenching mechanism based on the inner filter effect has also been demonstrated. More importantly, the versatile applications of pypyr-CF3, such as the quantitative analysis of Fe³⁺ in actual water samples, anti-forgery ink, fingerprint identification, etc., further corroborate its superb capabilities. This study aims to lend concrete support to the design and selectivity modulation of probes.

Dietary Trace Element Intake and Risk of Breast Cancer: A Mini Review

Trace elements are essentially required for various physiological and metabolic functions, and any disturbance in the trace elements homeostasis may result in the development of chronic diseases including breast cancer. Breast cancer is the most prevalent cancer type reported in women equally affecting both the high-income and low-income countries. This review therefore aimed to evaluate the impact of dietary trace element intake in relation to the incidence of breast cancer. We focused on five trace elements, thus emphasizing dietary selenium, zinc, iron, copper, and cadmium intake and risk of breast cancer. A systematic approach was applied to perform this review through entering a search term in PubMed and Scopus databases. A total of 24 articles were included after meeting the inclusion and exclusion criteria. Most of the studies regarding dietary iron intake showed a detrimental effect of increased dietary heme iron on breast cancer incidence risk. In addition, there is a limited evidence of high dietary intake of selenium and zinc to reduce the risk of breast cancer. Also, a few studies showed a relationship between high cadmium consumption and risk of breast cancer. More studies related to cadmium and copper exposure are needed to confirm this relationship. As a result, the findings of this review suggested that high dietary heme iron is a potential risk factor for breast cancer.

TP53 Mutant Acute Myeloid Leukemia: The Immune and Metabolic Perspective

TP53 mutated/deleted acute myeloid leukemia (AML) stands out as one of the poorest prognosis forms of acute leukemia with a median overall survival not reaching one year in most cases, even in selected cases when allogenic stem-cell transplantation is performed. This aggressive behavior relies on intrinsic chemoresistance of blast cells and on high rates of relapse. New insights into the biology of the disease have shown strong linkage between TP53 mutant AML, altered metabolic features and immunoregulation uncovering new scenarios and leading to possibilities beyond current treatment approaches. Furthermore, new targeted therapies acting on misfolded/dysfunctional p53 protein are under current investigation with the aim to improve outcomes. In this review, we sought to offer an insight into TP53 mutant AML current biology and treatment approaches, with a special focus on leukemia-associated immune and metabolic changes.

Microglial Hemoxygenase-1 Deletion Reduces Inflammation in the Retina of Old Mice with Tauopathy

Tauopathies such as Alzheimer's disease are characterized by the accumulation of neurotoxic aggregates of tau protein. With aging and, especially, in Alzheimer's patients, the inducible enzyme heme oxygenase 1 (HO-1) progressively increases in microglia, causing iron accumulation, neuroinflammation, and neurodegeneration. The retina is an organ that can be readily accessed and can reflect changes that occur in the brain. In this context, we evaluated how the lack of microglial HO-1, using mice that do not express HO-1 in microglia (HMO-KO), impacts retinal macro and microgliosis of aged subjects (18 months old mice) subjected to tauopathy by intrahippocampal delivery of AAV-hTauP301L (TAU). Our results show that although tauopathy, measured as anti-TAUY9 and anti-AT8 positive immunostaining, was not observed in the retina of WT-TAU or HMO-KO+TAU mice, a morphometric study of retinal microglia and macroglia showed significant retinal changes in the TAU group compared to the WT group, such as: (i) increased number of activated microglia, (ii) retraction of microglial processes, (iii) increased number of CD68+ microglia, and (iv) increased retinal area occupied by GFAP (AROA) and C3 (AROC3). This retinal inflammatory profile was reduced in HMO-KO+TAU mice. Conclusion: Reduction of microglial HO-1 could be beneficial to prevent tauopathy-induced neuroinflammation.

Non-heme iron overload impairs monocyte to macrophage differentiation via mitochondrial oxidative stress

Iron is a key element for systemic oxygen delivery and cellular energy metabolism. Thus regulation of systemic and local iron metabolism is key for maintaining energy homeostasis. Significant changes in iron levels due to malnutrition or hemorrhage, have been associated with several diseases such as hemochromatosis, liver cirrhosis and COPD. Macrophages are key cells in regulating iron levels in tissues as they sequester excess iron. How iron overload affects macrophage differentiation and function remains a subject of debate. Here we used an in vitro model of monocyte-to-macrophage differentiation to study the effect of iron overload on macrophage function. We found that providing excess iron as soluble ferric ammonium citrate (FAC) rather than as heme-iron complexes derived from stressed red blood cells (sRBC) interferes with macrophage differentiation and phagocytosis. Impaired macrophage differentiation coincided with increased expression of oxidative stress-related genes. Addition of FAC also led to increased levels of cellular and mitochondrial reactive oxygen species (ROS) and interfered with mitochondrial function and ATP generation. The effects of iron overload were reproduced by the mitochondrial ROS-inducer rotenone while treatment with the ROS-scavenger N-Acetylcysteine partially reversed FAC-induced effects. Finally, we found that iron-induced oxidative stress interfered with upregulation of M-CSFR and MAFB, two crucial determinants of macrophage differentiation and function. In summary, our findings suggest that high levels of non-heme iron interfere with macrophage differentiation by inducing mitochondrial oxidative stress. These findings might be important to consider in the context of diseases like chronic obstructive pulmonary disease (COPD) where both iron overload and defective macrophage function have been suggested to play a role in disease pathogenesis.

Bridging oxidase catalysis and oxygen reduction electrocatalysis by model single-atom catalysts

Nanocatalysts with enzyme-like catalytic activities, such as oxidase mimics, are extensively used in biomedicine and environmental treatment. Searching for enzyme-like nanomaterials, clarifying the origins of catalytic activity and developing activity assessment methodologies are therefore of great significance. Here, we report that oxidase catalysis and oxygen reduction reaction (ORR) electrocatalysis can be well bridged based on their identical activity origins, which makes facile electrocatalytic ORR activity measurements intrinsically applicable to oxidase-like activity evaluations. Inspired by natural heme-copper oxidases, Cu/Fe-doped single-atom catalysts (SACs) were first synthesized and used as model catalysts. Chromogenic reactions, electrochemical voltammetric measurements and density functional theory calculations further verified the linear relationship between the oxidase-like and ORR catalytic activities of the catalysts; thus, an effective descriptor ([Formula: see text]) is proposed for rapid enzymatic catalyst evaluation. Evidence suggests that the enhanced tumour therapeutic efficacy of SACs is a result of their oxidase-like/ORR activities, which proves that numerous ORR electrocatalysts are promising candidates for oxidase mimics and tumour therapy. The synergistic catalytic effect of the biomimetic heterobinuclear Cu-Fe centres has also been thoroughly probed.

Iron overload promotes intervertebral disc degeneration via inducing oxidative stress and ferroptosis in endplate chondrocytes

Iron overload is a common phenomenon in the elderly population. Many clinical studies have indicated an association between iron overload and the incidence and pathological progression of intervertebral disc degeneration (IVDD). However, the role and underlying mechanism by which iron participates in the progression of IVDD has not yet been reported. In the present study, we aimed to elucidate the connection between iron overload and IVDD, and explore the underlying mechanisms of disease. Firstly, a clinical epidemiology study was conducted and revealed that iron overload is an independent risk factor for human IVDD. To elucidate the role of iron overload in IVDD, an iron overload mouse model was established, and we observed that iron overload promoted IVDD and cartilage endplate degeneration in a dose dependent manner. Endplate chondrocytes were further isolated and treated with FAC to mimic iron overload in vitro. Excess iron significantly promoted mineralization of endplate chondrocytes in addition to their degeneration via oxidative stress. Moreover, a high dose of excess iron promoted chondrocytes ferroptosis. An iron chelator (DFO), an antioxidant (NAC) and a ferroptosis inhibitor (Fer-1) demonstrated effective inhibition of endplate chondrocyte degeneration induced by iron overload, and our in vivo studies further demonstrated that DFO, NAC and Fer-1 could rescue high dose iron-induced IVDD and cartilage endplate calcification. In conclusion, our results indicate that iron overload is strongly associated with the onset and development of IVDD via oxidative stress and ferroptosis. Inhibiting oxidative stress or ferroptosis could therefore be promising therapeutic strategies for IVDD induced by iron overload.