Iron Status Research Articles

Association of whole blood essential metals with neurodevelopment among preschool children.

Essential metals may play roles in neurodevelopment. The aim was to evaluate the associations of magnesium (Mg), iron (Fe), copper (Cu), and zinc (Zn) levels with neurodevelopment among preschool children. The medical records of eligible children enrolled between January 2019 and July 2022 were retrospectively reviewed for required information. The quantitative measurement of metals was conducted using atomic absorption spectroscopy, while screening of neurodevelopment was performed using the Ages and Stages Questionnaire. Modified Poisson regression and Bayesian kernel machine regression (BKMR) analyses were used to evaluate the prevalence ratio (PR) of their independent and joint associations. 662 (14.8%) children were found to have possible neurodevelopmental delays. Modified Poisson regression showed that Mg, Cu, and Zn levels were independently and negatively associated with the risk of neurodevelopmental delay. The PRs (95% CIs) for per log2 increment of the above metals were 0.35 (0.19-0.62), 0.57 (0.42-0.77), and 0.63 (0.42-0.96). These negative associations were more pronounced in the gross motor and personal-social domains while considering the concrete five domains. BKMR showed a negative association of metal mixture with the risk of neurodevelopmental delay. Mg, Cu, and Zn were inversely associated with neurodevelopmental delay. Sufficient essential metal levels are important for neurodevelopment. Essential metals play a key role in neurodevelopment. The association of essential metal mixture with neurodevelopment is relatively scarce. Preschool children with possible neurodevelopmental delay are found to have lower Mg, Cu, and Zn levels than their counterparts. Single Mg, Cu, Zn levels, and elevated essential metal mixture are negatively associated with the risk of possible neurodevelopmental delay.

Changing dynamics in daily rhythms of oxidative stress indicators in SCN and extra-SCN brain regions with aging in male Wistar rats.

The suprachiasmatic nucleus (SCN) in the hypothalamus regulates circadian timing system (CTS) by co-ordinating peripheral tissue clocks and extra-SCN oscillators in the brain. Aging disrupts the CTS, impairing physiological functions and reducing antioxidant defences, which contribute to neurodegeneration. The brain is vulnerable to oxidative damage due to its high metabolic activity, oxygen consumption, and levels of iron and lipids. Antioxidant enzymes, such as catalase (CAT), glutathione S-transferase (GST), superoxide dismutase (SOD), and lipid peroxidation (LPO), help against oxidative damage. In this study, we examined the temporal patterns of these antioxidant stress indicators in the SCN and extra-SCN brain regions (frontal cortex, cerebellum, and hippocampus) at various time points in male Wistar rats 3, 12, and 24months. The rhythmicity of GST and LPO levels persisted across brain regions with aging, while CAT rhythmicity was lost in the SCN and hippocampus of older rats. SOD rhythmicity persisted in cortex, cerebellum, and hippocampus but was lost in the SCN. The daily rhythm parameters of CAT were affected most significantly, followed by SOD, GST, and LPO. Our findings demonstrate that aging leads to desynchronization of oxidative stress indicators potentially contributing to neurodegeneration and circadian dysfunction with varying effects across different brain tissues.

Bone phenotyping of murine hemochromatosis models with deficiencies of Hjv, Alk2, or Alk3: The influence of sex and the bone compartment.

Osteopenia is frequently observed in patients with iron overload, especially in those with HFE-dependent hereditary hemochromatosis (HH). Interestingly, not all mouse models of HH show bone loss, suggesting that iron overload alone may not suffice to induce bone loss. In this study, the bone phenotypes of Hjv-/- and hepatocyte-specific Alk2- and Alk3-deficient mice as additional mouse models of HH were investigated to further clarify, how high iron levels lead to bone loss and which signaling mechanisms are operational. Neither male nor female 12-week-old Hjv-/- mice had an altered trabecular or cortical bone mass or bone turnover, despite severe iron overload. Male 12-month-old Hjv-/- mice even presented with a higher femoral trabecular bone volume compared to wildtype mice. Similarly, female mice with hepatocyte-specific Alk2 or Alk3 deficiency did not show an altered bone phenotype at 3, 6, and 12 months of age. Male hepatocyte-specific Alk3-deficient mice also had a normal trabecular bone mass at all ages analyzed, despite showing increased bone resorption and decreased bone formation parameters. Interestingly, hepatocyte-specific Alk2-deficient mice showed reduced femoral trabecular bone at 6 months of age due to suppressed bone formation. Cortical thickness at the femur was reduced in both, 6-month-old male hepatocyte-specific Alk2- and Alk3-deficient mice. Raising hepatocyte-specific Alk2-deficient male mice on an iron-deficient diet rescued the bone phenotype. Taken together, despite iron overload, trabecular bone microarchitecture was not altered in mice deficient of Hjv or Alk3. Only male hepatocyte-specific Alk2-deficient mice showed site-specific lower trabecular and cortical bone mass at the femur, which was dependent on iron. Thus, bone loss does not correlate with the extent of iron overload in these mouse models, but may relate to the amount of iron-loaded macrophages, as precursors of osteoclasts, in the bone marrow.

LCN2 aggravates diabetic cataracts by promoting ferroptosis in lens epithelial cells

Abstract Background Cataracts are the leading cause of reversible blindness worldwide. Diabetic cataract (DC), a prevalent complication of diabetes mellitus, is characterized by its high occurrence, rapid progression, and severe impact. The prevalence of diabetes varies greatly between the northern and southern regions, with higher rates observed among northern residents. DC-induced lens opacity is mainly attributed to oxidative stress. However, it remains unclear whether ferroptosis, a form of regulated cell death, occurs in crystalline epithelial cells during the pathogenesis, which may represent a novel mechanism contributing to DC. Methods Transmission electron microscopy, quantitative assays for iron levels and reactive oxygen species (ROS), real-time quantitative polymerase chain reaction (RT-qPCR), western blotting, immunofluorescence, and immunohistochemistry were used to detect ferroptosis. Gene editing techniques were utilized to study the regulatory relationships among lipocalin 2 (LCN2), glutathione peroxidase 4 (GPX4), and ferritin heavy chain (FTH). Local knockdown of the LCN2 gene in B-3 cells and the eyes of Sprague Dawley (SD) rats was performed to verify and further explore the role and regulatory mechanisms of LCN2 in DC-associated ferroptosis. Results An in vitro model using high glucose levels and an in vivo model with streptozotocin-induced diabetes in SD rats were successfully established. Ferroptosis was observed in both in vitro and in vivo experiments. LCN2 protein was normally expressed in human and rat lens epithelial cells, but its expression significantly increased during ferroptosis. The ferroptosis inhibitor, ferrostatin-1 (Fer-1) effectively inhibited ferroptosis and reduced LCN2 protein expression. Notably, local knockdown of LCN2 via gene editing protected lens epithelial cells from ferroptosis in vitro and slowed the progression of DC in SD rats in vivo. Conclusion Our findings underscore the significant role of ferroptosis in the pathogenesis of DC, suggesting that selectively targeting LCN2 activation and enhancing ferroptosis resistance may offer a novel therapeutic approach for treating DC.

The causal relationships between iron status and sarcopenia in Europeans: a bidirectional two-sample Mendelian randomization study.

Previous studies have indicated potential associations between metals, lifestyle factors, and sarcopenia. However, the specific causal relationships between iron status, lifestyle factors, and sarcopenia remain unclear. Therefore, we conducted a bidirectional two-sample Mendelian Randomization (MR) approach to investigate these relationships. The exposure variables included iron status, living alone, coffee intake, alcohol taken with meals, and moderate physical activity, while the outcome variable was sarcopenia, assessed by grip strength in both hands and usual walking pace. We employed the Weighted Median (WM), the Inverse Variance-Weighted (IVW), and other MR methods to explore these problems for analysis. Simultaneously, we conducted a bidirectional MR analysis to assess whether sarcopenia has a reverse causal relationship with internal iron status. In our present research, we found serum iron (P = 0.033), ferritin (P = 0.001), transferrin saturation (P = 0.029) and coffee intake (P = 0.002) revealed a negative trend for sarcopenia, living alone (P = 0.022) and alcohol taken with meal (P = 0.006) showed a opposite trend for sarcopenia. Whereas sarcopenia showed negative trend for ferritin (P = 0.041) and transferrin saturation (P = 0.043), showed the opposite trend for transferrin (P = 0.021). Our study suggested that higher serum iron levels might reduce the risk of sarcopenia. Moreover, living alone and alcohol consumption might increase the sarcopenia risk, while coffee intake and moderate physical activity could reduce the sarcopenia risk.

Transcriptome profiling uncovers differentially expressed genes linked to nutritional quality in vegetable soybean.

Vegetative soybean (maodou or edamame) serves as a nutrient-rich food source with significant potential for mitigating global nutritional deficiencies. This study undertook a thorough examination of the nutritional profiles and transcriptomic landscapes of six soybean cultivars, including three common cultivars (Heinong551, Heinong562, and Heinong63) and three fresh maodou cultivars (Heinong527, HeinongXS4, and HeinongXS5). Nutrient analysis of the seeds disclosed notable differences in the levels of protein, fat, soluble sugars, vitamin E, calcium, potassium, magnesium, manganese, iron, and zinc across the cultivars. Through comparative transcriptome profiling and RNA sequencing, distinct variations in differentially expressed genes (DEGs) were identified between fresh and traditional maodou cultivars. Functional enrichment analyses underscored the involvement of DEGs in critical biological processes, such as nutrient biosynthesis, seed development, and stress responses. Additionally, association studies demonstrated robust correlations between specific DEG expression patterns and seed nutrient compositions across the different cultivars. Sankey diagrams illustrated that DEGs are strongly linked with seed quality traits, revealing potential molecular determinants that govern variations in nutritional content. The identified DEGs and their relationships with nutritional profiles offer valuable insights for breeding programs focused on developing cultivars with improved nutritional quality, tailored to specific dietary needs or industrial applications.

Efficiency of Reverse Osmosis Usage in Drinking Water Depots to Reduce Iron (Fe3+), Copper (Cu2+) and Zinc (Zn2+) Ion Levels

Research on the efficiency of reverse-osmosis drinking water depot to decreased levels of iron (Fe3+), Copper (Cu2+) and Zinc (Zn2+) ions have been done. The raw, the treated, and waste water are filtered using reverse osmosis (RO) three times a week. HNO3 then was added to the sample until it reached 15 mL. The determination of the concentration of the three ions was performed using atomic absorption spectrophotometer (AAS). The results showed a decrease of Fe3+ concentration of 73.21%, for Cu2+ decrease by 80.25%, while Zn2+ decrease by 82.08%. For waste water obtained iron ion concentration of 0.1794 mg/L, for Cu2+ by 0.0239 mg/L, while Zn2+ by 0.0962 mg/L.

Association of Oral Manifestations with Iron Deficiency Anemia: A Case-Control Study

Insufficient iron levels cause oral signs of iron insufficiency. Iron is necessary for several biological activities, including oral tissue health. Low iron levels might alter oral tissues, causing particular symptoms. The aim of this study to detect the oral manifestations of iron deficiency anemia as well as to investigate the link between the severity of these manifestations and the degree of the iron deficiency. The study includes 100 patients with iron deficiency anemia at an Azadi Teaching Hospital, in Duhok City, North of Iraq, and 98 healthy persons. A full history was obtained, and complete blood count and serum ferritin were recorded. In terms of gender distribution, a clear dominance of females was observed, as they represented 94% of the total cases compared to only 6% for males. Regarding the severity of anemia, most patients had moderate to mild degrees, while severe anemia cases represented a smaller percentage (12%). The comparison between patients and healthy people showed highly significant statistical differences in all pathological changes of the oral mucosa. Complete absence of pathological changes was more common in healthy controls (85%) than in patients (34%). Some pathological changes were closely associated with iron deficiency anemia, such as atrophic glossitis and angular cheilitis. This study concludes by highlighting the strong correlation between iron deficiency anemia (IDA) and oral mucosal lesions, and the most common oral manifestations are present in patients with severe iron deficiency anemia.

Inhibition of CISD2 enhances sensitivity to doxorubicin in diffuse large B-cell lymphoma by regulating ferroptosis and ferritinophagy

BackgroundCDGSH iron-sulfur domain 2 (CISD2), an iron-sulfur protein with a [2Fe-2S] cluster, plays a pivotal role in the progression of various cancers, including Diffuse Large B-cell Lymphoma (DLBCL). However, the mechanisms by which CISD2 regulates the occurrence and development of DLBCL remain to be fully elucidated.MethodsThe potential role of CISD2 as a predictive marker in DLBCL patients treated with the R-CHOP regimen was investigated through bioinformatics analysis and clinical cohort studies. DLBCL cell lines (SUDHL-4 and HBL-1) were employed in this research. Adenoviral (AV) plasmids were used to either silence or overexpress CISD2 in these DLBCL cell lines. Additionally, the induction of ferroptosis in DLBCL cell lines was assessed. Various parameters, including cell proliferation, intracellular free iron levels, lipid peroxides, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP), were measured. Furthermore, the expression of proteins associated with ferroptosis and ferritinophagy was analyzed. Drug-resistant DLBCL cell lines were developed by gradually increasing doxorubicin (DOX) concentration over 6 months. The biological role of CISD2 in these drug-resistant DLBCL cell lines was subsequently assessed.ResultsElevated CISD2 levels were found to be associated with decreased sensitivity of DLBCL patients to the R-CHOP regimen, as indicated by bioinformatics and clinical cohort analysis. Silencing CISD2 significantly reduced cell proliferation, increased iron accumulation, depleted glutathione (GSH), and elevated malondialdehyde (MDA) levels, alongside the accumulation of ROS and increased MMP. Additionally, BECN1 and NCOA4 expressions were upregulated, while p62, FTH1, and GPX4 expressions were downregulated. Conversely, overexpression of CISD2 reversed these effects. Treatment of DLBCL cell lines with Erastin led to decreased CISD2 levels. Notably, in drug-resistant DLBCL cell lines, CISD2 knockdown promoted ferroptosis and ferritinophagy, restoring sensitivity to DOX and enhancing the efficacy of Erastin treatment.ConclusionOur findings suggest that CISD2 may play a role in the drug resistance observed in DLBCL patients. Inhibition of CISD2 could enhance ferroptosis and ferritinophagy, potentially improving the sensitivity of DLBCL cells to DOX treatment.

Effects of iron overload in human joint tissue explant cultures and animal models.

Osteoarthritis (OA) is a prevalent degenerative joint disease affecting over 530 million individuals worldwide. Recent studies suggest a potential link between iron overload, a condition characterised by the excessive accumulation of iron in the body, and the onset of OA. Iron is essential for various biological processes, and any disruption in its homeostasis can trigger significant health effects, including OA. This study aimed to elucidate the effects of excess iron on joint tissue and the underlying mechanisms associated with excess iron and OA development. Human articular cartilage (n = 6) and synovium (n = 4) were collected from patients who underwent total knee arthroplasty. Cartilage and synovium explants were incubated with a gradually increasing concentration of ferric ammonium citrate for 3days respectively. The effects of iron homeostasis in tissue explants were analysed using a Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). To further study the effects of iron excess on OA initiation and development, male 3-week-old Hfe-/- and 5-week-old Tfr2-/- mice, animal models of hereditary haemochromatosis were established. Littermate wild-type mice were fed a high-iron diet to induce dietary overload. All animals were sacrificed at 8weeks of age, and knee joints were harvested for histological analysis. The LA-ICP-MS analysis unveiled changes in the elemental composition related to iron metabolism, which included alterations in FTH1, FPN1, and HAMP within iron(III)-treated cartilage explants. While chondrocyte viability remained stable under different iron concentrations, ex vivo treatment with a high concentration of Fe3+ increased the catabolic gene expression of MMP13. Similar alterations were observed in the synovium, with added increases in GAG content and inflammation markers. In vivo studies further supported the role of iron overload in OA development as evidenced by spontaneous OA symptoms, proteoglycan loss, increased Mankin scores, synovial thickening, and enhanced immunohistochemical expression of MMP13, ADAMTS5, and P21 in Hfe-/-, Tfr2-/-, and diet-induced iron overload mouse models. Our findings elucidate the specific pathways through which excess iron accelerates OA progression and highlights potential targets for therapeutic intervention aimed at modulating iron levels to mitigate OA symptoms. KEY MESSAGES: Iron overload alters joint iron metabolism, increasing OA markers in cartilage and synovium. High iron levels in mice accelerate OA, highlighting genetic and dietary impacts. Excess iron prompts chondrocyte iron storage response, signalling potential OA pathways. Iron dysregulation linked to increased cartilage degradation and synovial inflammation. Our findings support targeted therapies for OA based on iron modulation strategies.

Variability of drinking water for pigs and poutry the southern region of Brazil over a twelve – month period

The increase in global food demand has led to intensified production of pigs and poultry. In this context, water quality on farms needs to be monitored to ensure maximum production and animal welfare. This study aimed to evaluate the quality and variability of drinking water for animals over twelve months in properties in the Southern Region of Brazil. Physical, chemical, microbiological parameters, and the average rainfall index of nine water sources were observed. Variations in pH were noted among the evaluated water sources, as well as within the same source over monthly collections. A relationship between average rainfall and elevated iron levels was also demonstrated. Nitrate and nitrite levels exceeded Brazilian legislation at certain sampling points, posing risks to human and animal health. In 67.59% of samplings, total coliforms were present, and 59.26% showed the presence of Escherichia coli. The study highlighted the variability of water sources in the Southern Region of Brazil, reflecting the need for constant monitoring and treatment measures, such as water treatment stations, chlorination systems, and acidification in rural properties.

Hematological and iron status in aerobic vs. anaerobic female athletes: an observational study

IntroductionPhysical training induces iron status impairment in athletic females in the short term and over prolonged periods. Nevertheless, the existing literature lacks a comprehensive evaluation of the differential impacts of aerobic vs. anaerobic training on hematological indices and iron status among adolescent female athletes. The aim of this study was to assess the hematological factors and iron status in aerobic vs. anaerobic training in athletic females.MethodsThis observational, cross-sectional study recruited twenty-five adolescent athletic females; thirteen of them participated in an aerobic sport (long-distance running), while twelve of them participated in an anaerobic sport (broad jumping). Hematological factors were assessed by analyzing blood concentrations of hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC) count, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC), while the iron status assessment was conducted through evaluating levels of serum transferrin and serum ferritin.ResultsAthletic females who participated in the aerobic sport showed significantly lower Hb (MD −0.84; 95% CI −1.63: −0.04; p = 0.041), Hct (MD −5.49; 95% CI −7.86: −3.12; p = 0.0001), RBC count (MD −0.37; 95% CI −0.57: −0.17; p = 0.001), and MCV (MD −5.15; 95% CI −9.41: −0.89; p = 0.020), as well as significantly higher MCHC (MD 2.99; 95% CI 2.18: 3.79; p = 0.0001) and serum transferrin (MD 46.77; 95% CI 10.95: 82.59; p = 0.013) than athletic females who participated in the anaerobic sport. However, there was an insignificant difference in serum ferritin levels (MD −3.18; 95% CI −11.49: 5.13; p = 0.437) between both groups.ConclusionExcept for the ferritin level that exhibited an insignificant difference between aerobic and anaerobic training, aerobic training was associated with a worse impact on the hematological factors and iron status than anaerobic training in adolescent athletic females.

Associations between iron status and psychosocial wellbeing among pregnant women in Cape Coast, Ghana: a longitudinal study.

To determine the associations among iron status, depressive/anxiety symptoms, and quality of life (QoL) throughout pregnancy. This longitudinal study recruited participants in their 1st trimester (< 13 weeks; n=116) and followed in their 2nd (n=71) and 3rd (n=71) trimesters. Sociodemographic, food security, anxiety, depressive symptoms, and QoL questions were collected. Hemoglobin (Hb), ferritin (Ft), and transferrin saturation (TSAT) were determined. Women were categorized as iron improvers or non-improvers based on changes in iron status. Associations were assessed using difference-in-difference analyses. Cape Coast, Ghana between October 2017 to September 2018. Pregnant women, 18-38 years. Improvement in Ft levels from the 1st to 2nd trimester were associated with reduced depressive symptoms (-2.96 vs -0.58, p=0.028), and higher overall QoL (13.99 vs 1.92, p=0.006) particularly role physical (23.32 vs -2.55, p=0.025) and role emotional (27.50 vs 10.06, p=0.025) subscales. Improvement in Hb levels during the same period were linked to less anxiety, particularly fear factor (-2.62 vs -0.51, p=0.020); and worsened physical health aspect of QoL (-21.80 vs -3.75, p=0.005). Improvement in TSAT levels from 2nd to 3rd trimester were associated with increased total anxiety (1.56 vs -0.64, p=0.030) and panic factor (0.45 vs -0.26, p=0.004) and decreased total QoL (-1.08 vs 7.94, p=0.017), specifically role physical (-10.98 vs 11.93, p=0.018). Increases in iron status from first to second trimester were related to improvements in psychosocial wellbeing, implying potential benefit of iron supplementation on affect in early pregnancy. Larger studies are needed to confirm these findings.

Colorectal carcinoma-induced iron deficiency anemia: A literature review and a case scenario

Colorectal carcinoma (CRC) is among the leading cancers worldwide and a major cause of cancer-related mortality. Iron deficiency anemia (IDA), resulting from inadequate iron for hemoglobin production, has been increasingly linked to CRC, often leading to misdiagnosis. This study reviews the clinicopathological associations of IDA in the context of colorectal cancer, using the medical records of a septuagenarian diagnosed with both conditions as a case study. Employing the Problem-Intervention-Comparison-Outcome model, we searched for &amp;ldquo;colorectal carcinoma&amp;rdquo; and &amp;ldquo;iron deficiency anemia&amp;rdquo; as keywords. CRC ranks among the top five cancers of global health importance, with socioeconomic factors, sedentary lifestyles, and dietary choices significantly influencing both conditions. Notably, IDA is particularly associated with the right-sided CRC in individuals over 40. Upregulation of interleukin-6 in CRC cells stimulates hepcidin release, which mediates anemia of chronic disorders and IDA. The case revealed right-sided signet ring cell CRC, microcytic hypochromic anemia, bone marrow metastasis, and low serum iron and ferritin levels. This study highlights the need for increased suspicion of CRC in middle-aged and elderly patients presenting with recurrent IDA. Regular screening is essential for the early detection and improved treatment outcomes. While colonoscopy is the gold standard for prevention, its effectiveness in detecting early molecular links between neoplasia and chronic inflammation is limited. There is also no consensus on surveillance protocols, and many gastroenterologists do not adhere to recommended biopsy sampling practices. In conclusion, this study advocates for including complete blood count and iron studies as essential tests in guidelines for screening and diagnosis for CRC-related IDA to enhance diagnostic practices.

Anemia prevalence, its determinants, and profile of micronutrient status among rural school adolescent girls aged 14-19 years: A cross-sectional study in Nagpur district, Maharashtra, India".

The objective of our study was to determine the prevalence of anemia among 14-19 years school going girls, risk factors for it and profile of micronutrient status among rural girls from western state of India. Using a cross-sectional design, we obtained information on socio-demography, menstruation, dietary habits, knowledge and daily consumption of the government recommended iron and folic acid (IFA) tablets, and anthropometry. Blood was collected to assess haemoglobin, red blood cell indices, serum iron, folate and vitamin B12 levels. Nagpur district, Maharashtra, India. A total of 221 girls aged 14-19 years studying in 24 government institutes included. 57% girls were anaemic, 84% had deficiency of one or more micronutrients and 60% were malnourished based on Body Mass Index (BMI). The prevalence of iron, vitamin B12 and folate deficiency was 37.7%, 69.8% and 1.4% respectively. Among anaemic girls, iron and vitamin B12 deficiency was observed in 45.5% and 67.5% respectively, vs. among non-anaemic girls it was 27% and 73% respectively. Iron deficiency was a predictor of anaemia and its severity. Girls residing in non-nuclear family were more likely to have anaemia. The consumption of daily non-vegetarian food and green leafy vegetables was 3% and 3.6% respectively. Only 9% consumed IFA tablets in the past two weeks. Anemia is common in adolescent girls, particularly associated with iron and vitamin B12 deficiency. There is need to reconsider the approach to prevention of anaemia in adolescent girls, particularly before they become pregnant.

CSIG-20. LIPOCALIN-2 DRIVES CELL-INTRINSIC FUNCTIONS IN GLIOBLASTOMA

Abstract Glioblastoma (GBM) continues to persist despite aggressive therapies, many of which are cytotoxic, and therapeutic failure is driven, in part, by the tumor cell’s ability to evade multiple forms of cell death, including ferroptosis. Lipocalin-2 (LCN2) functions to sequester iron and is considered an inflammatory marker through its function of limiting iron for bacterial usage; it has also been described to have pro and anti-tumorigenic effects depending on environmental iron status. In previously published studies in brain metastases, LCN2 promotes tumor cell proliferation by sequestering iron for cancer cells growth and survival, but the mechanisms of how LCN2 contributes to GBM progression is unknown. LCN2 expression in patient data revealed that high LCN2 expression is associated with reduced survival in GBM patients. A survey of mouse glioma models demonstrated a range of LCN2 secretion across models with KR158 and CPA being high and medium LCN2 secretors. LCN2 short hairpin knockdown of KR158 and CPA and decreased tumor cell viability and proliferation. Furthermore, when both KR158 and CPA control versus LCN2 knockdown cells were orthotopically implanted into mice, survival was increased. To understand if LCN2 impacted cell death dynamics, we investigated various cell death mechanisms and found that LCN2 knockdown increases tumor susceptibility to ferroptotic death by sensitizing cells to lipid peroxidation as well as reducing key anti-ferroptotic proteins GPX4 and xCT. To elucidate downstream mechanisms, we performed a phosphorylation array and discovered that phosphorylation of AXL, which has recently been linked to ferroptosis, is decreased with LCN2 knockdown. Moreover, AXL phosphorylation was localized to the nucleus, indicating that LCN2 knockdown attenuates AXL processing and downstream signaling. Overall, these findings indicate that LCN2 in GBM promotes tumor cell growth through AXL signaling and evasion of ferroptotic death, ultimately revealing a novel signaling network that can be leveraged for future therapeutic development.

TMET-09. SEX-BIASED ROLE OF TUMOR-ASSOCIATED MACROPHAGES IN GLIOBLASTOMA IRON METABOLISM

Abstract Glioblastoma (GBM) is an aggressive brain cancer that is extremely difficult to treat. GBM is sexually dimorphic in nature, where females are less susceptible to developing GBM, respond to therapy better, and get a survival advantage. Sex-biased differences in tumor iron metabolism play a significant part in making this disease sexually dimorphic. Macrophages constitute a significant population in the GBM tumor microenvironment and are key players in tumor iron homeostasis. Here, we examine macrophage iron homeostasis as a potential driver of sex biases in glioblastoma using bone marrow-derived macrophages (BMDM) isolated from C57BL/6 mice. Immunoblot analysis revealed higher ferritin L-chain (FTL) expression in male BMDM than in females (Fold change: 3.18, P = 0.02). Flow cytometric analysis revealed that male BMDMs had a significantly higher labile iron pool (LIP) (Fold change: 1.62, P = 0.0081). We used a stable isotope of iron (Fe57) to determine macrophage iron uptake by ICP-MS, and observed that male BMDMs have a higher iron uptake (fold change: 1.623, P = 0.0018) than females. These results indicate that macrophage iron metabolism is sexually dimorphic in nature. Next, we used a transwell co-culture system to study how macrophages regulate the iron status of GL261 cells. We found that GL261 cells had significantly lower H-Ferritin (FTH1) expression when co-cultured with male BMDMs (Fold change: 0.789, P = 0.0045). However, this decrease in ferritin didn’t result in a decrease in cellular LIP. We discovered that there was an increase in secreted ferritin in the GL261 culture media. Further experiments with Fe57-loaded GBM cells showed that this increase in secreted ferritin correlated with increased iron release from the GL261 cells. These results indicate that tumor-associated macrophages may regulate tumor iron homeostasis by inducing ferritin-bound iron release from GBM cells in a sex-biased manner.

PINK1-deficiency facilitates mitochondrial iron accumulation and colon tumorigenesis

ABSTRACT Mitophagy, the process by which cells eliminate damaged mitochondria, is mediated by PINK1 (PTEN induced kinase 1). Our recent research indicates that PINK1 functions as a tumor suppressor in colorectal cancer by regulating cellular metabolism. Interestingly, PINK1 ablation activated the NLRP3 (NLR family pyrin domain containing 3) inflammasome, releasing IL1B (interleukin 1 beta). However, inhibiting the NLRP3-IL1B signaling pathway with an IL1R (interleukin 1 receptor) antagonist or NLRP3 inhibitor did not hinder colon tumor growth after PINK1 loss. To identify druggable targets in PINK1-deficient tumors, ribonucleic acid sequencing analysis was performed on colon tumors from pink1 knockout and wild-type mice. Gene Set Enrichment Analysis highlighted the enrichment of iron ion transmembrane transporter activity. Subsequent qualitative polymerase chain reaction and western blot analysis revealed an increase in mitochondrial iron transporters, including mitochondrial calcium uniporter, in PINK1-deficient colon tumor cells and tissues. Live-cell iron staining demonstrated elevated cellular and mitochondrial iron levels in PINK1-deficient cells. Clinically used drugs deferiprone and minocycline reduced mitochondrial iron and superoxide levels, resulting in decreased colon tumor cell growth in vitro and in vivo. Manipulating the mitochondrial iron uptake protein MCU (mitochondrial calcium uniporter) also affected cell and xenograft tumor growth. This study suggests that therapies aimed at reducing mitochondrial iron levels may effectively inhibit colon tumor growth, particularly in patients with low PINK1 expression.

Alterations of Hepcidin and Iron Markers Associated with Obesity and Obesity-related Diabetes in Gambian Women

Aims Obesity, type 2 diabetes (T2D), and chronic inflammation are associated with disturbances in iron metabolism. Hepcidin is hypothesized to play a role in these alterations owing to its strong association with inflammation via the JAK-STAT3 pathway. The current study investigated the differences between inflammatory markers and iron indices and their association with hepcidin in lean women, women with obesity, and women with obesity and T2D (obesity-T2D) in The Gambia. Materials and methods In a cross-sectional study design, fasted blood samples were collected from three groups of women: lean women (n=42, body mass index (BMI)=20.9 kg/m2), women with obesity (n=48, BMI=33.1 kg/m2) and women with obesity-T2D (n=30, BMI=34.5 kg/m2). Markers of inflammation (IL-6 and CRP) and iron metabolism [hepcidin, iron, ferritin, soluble transferrin receptor (sTfR), transferrin, transferrin saturation, and unsaturated iron-binding capacity (UIBC)] were compared using linear regression models. Simple regression analyses were performed to assess the association between hepcidin levels and respective markers. Results Women with obesity and obesity-T2D showed elevated levels of inflammatory markers. There was no evidence that markers of iron metabolism differed between lean women and obese women, but women with obesity-T2D had higher transferrin saturation, higher serum iron concentration, and lower UIBC. Serum hepcidin concentrations were similar in all the groups. Hepcidin was not associated with markers of inflammation but was strongly associated with all other iron indices (all P&lt;0.002). Conclusion Contrary to our original hypothesis, hepcidin was not associated with markers of inflammation in the three groups of Gambian women, despite the presence of chronic inflammation in women with obesity and obesity-T2D.

Alterations in Zinc, Copper, and Iron Levels in the Retina and Brain of Alzheimer's Disease Patients and the APP/PS1 Mouse Model.

Transition metals like copper, iron, and zinc are vital for normal central nervous system function and are also linked to neurodegeneration, particularly in the onset and progression of Alzheimer's disease (AD). Their alterations in AD, identified prior to amyloid plaque aggregation, offer a unique target for staging pre-amyloid AD. However, analysing their levels in the brain is extremely challenging, necessitating the development of alternative approaches. Here, we utilised laser ablation-inductively coupled plasma-mass spectrometry and solution nebulisation-inductively coupled plasma-mass spectrometry to quantitatively measure Cu, Fe, and Zn concentrations in the retina and hippocampus samples obtained from human donors (i.e., AD and healthy controls), and in the APP/PS1 mouse model of AD, and Wild Type controls, aged 9 and 18 months. Our findings revealed significantly elevated Cu, Fe, and Zn levels in the retina (*p < 0.05, **p < 0.01, ***p < 0.001) and hippocampus (*p < 0.05, *p < 0.05, *p < 0.05) of human AD samples compared to healthy controls. Conversely, APP/PS1 mouse models exhibited notably lower metal levels in the same regions compared to WT mice, Cu, Fe, and Zn levels in the retina (**p < 0.01, *p < 0.05, *p < 0.05) and hippocampus (**p < 0.01, **p < 0.01, *p < 0.05). The contrasting metal profiles in human and mouse samples, yet similar patterns within each species' retina and brain, suggest the retina mirrors cerebral metal dyshomeostasis in AD. Our findings lay the groundwork for staging pre-AD pathophysiology through assessment of transition metal levels in the retina.