Search

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

Kathleen F Pirollo,1 Manish Moghe,1 Miaoyin Guan,1 Antonina S Rait,1 Aibing Wang,1 Sang-Soo Kim,1,2 Esther H Chang,1 Joe B Harford2 1Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA; 2SynerGene Therapeutics, Inc., Potomac, MD, 20854, USACorrespondence: Esther H Chang, Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road N.W., Research Building E420, Washington, DC, 20057, USA, Tel +1 202 687 8418, Email change@georgetown.eduIntroduction: Organophosphates are among the deadliest of known chemicals based on their ability to inactivate acetylcholinesterase in neuromuscular junctions and synapses of the central and peripheral nervous systems. The consequent accumulation of acetylcholine can produce severe acute toxicities and death. Oxime antidotes act by reactivating acetylcholinesterase with the only such reactivator approved for use in the United States being 2-pyridine aldoxime methyl chloride (a.k.a., pralidoxime or 2-PAM). However, this compound does not cross the blood–brain barrier readily and so is limited in its ability to reactivate acetylcholinesterase in the brain.Methods: We have developed a novel formulation of 2-PAM by encapsulating it within a nanocomplex designed to cross the blood–brain barrier via transferrin receptor-mediated transcytosis. This nanocomplex (termed scL-2PAM) has been subjected to head-to-head comparisons with unencapsulated 2-PAM in mice exposed to paraoxon, an organophosphate with anticholinesterase activity.Results and Discussion: In mice exposed to a sublethal dose of paraoxon, scL-2PAM reduced the extent and duration of cholinergic symptoms more effectively than did unencapsulated 2-PAM. The scL-2PAM formulation was also more effective than unencapsulated 2-PAM in rescuing mice from death after exposure to otherwise-lethal levels of paraoxon. Improved survival rates in paraoxon-exposed mice were accompanied by a higher degree of reactivation of brain acetylcholinesterase.Conclusion: Our data indicate that scL-2PAM is superior to the currently used form of 2-PAM in terms of both mitigating paraoxon toxicity in mice and reactivating acetylcholinesterase in their brains.Keywords: lipid nanoparticle, nanodelivery, organophosphate, paraoxon, blood–brain barrier, transcytosis

Receptor mediated transport of therapeutic antibodies through the blood-brain barrier (BBB) give promise for drug delivery to alleviate brain diseases. We developed a low-cost method to obtain nanoscale localization data of putative cargo receptors. We combine existing ex vivo isolation methods with expansion microscopy (ExM) to analyze receptor localizations in brain microcapillaries. Using this approach, we show how to analyze receptor localizations in endothelial cells of brain microcapillaries in relation to the abluminal marker collagen IV. By choosing the thinnest capillaries, microcapillaries for analysis, we ensure the validity of collagen IV as an abluminal marker. With this tool, we confirm transferrin receptors as well as sortilin to be both luminally and abluminally localized. Furthermore, we identify basigin to be an abluminal receptor. Our methodology can be adapted to analyze different types of isolated brain capillaries and we anticipate that this approach will be very useful for the research community to gain new insight into cargo receptor trafficking in the slim brain endothelial cells to elucidate novel paths for future drug design. [ABSTRACT FROM AUTHOR]

Aim. To assess the diagnostic value of the detection of soluble transferrin receptors (sTfR) and ferritin index (sTfR/log Fer) in patients with spondyloarthritis (SpA) and anemia for the revealing absolute iron deficiency (ID). Materials and methods. The study included 68 patients with SpA: median age 39 [34; 47] years, men: 38 (55.9%). Hemogram, C-reactive protein levels and ferrokinetics parameters were assessed, including sTfR testing by the method of quantitative enzyme-linked immunosorbent assay (Monobind Inc., USA). We also calculated sTfR/log Fer. Based on ferrokinetics parameters and C-reactive protein levels, chronic disease anemia (CDA), iron deficiency anemia (IDA), or their combination (CDA/IDA) were diagnosed. Results. CDA was diagnosed in 16 patients, CDA/IDA in 32 patients, and 20 patients had no anemia. An increase in sTfR concentration in patients with CDA/IDA (1.7 [1.4; 2.2] mg/L) compared with patients with CDA (1.5 [1.1; 1.7] mg/L, p0.05) was revealed. sTfR/log Fer in patients with CDA/IDA (0.93 [0.82; 1.24]) was higher than in patients with CDA (0.64 [0.48; 0.75], p0.0001). When evaluating the ROC curves, it was found that sTfR levels 1.39 mg/L and sTfR/log Fer levels 0.83 indicate the presence of absolute ID. The area under the ROC curve for sTfR was 0.72 (95% confidence interval 0.600.82, p0.001), for sTfR/log Fer 0.85 (95% confidence interval 0.740.92, p0.001). The sensitivity and specificity of sTfR/log Fer (75 and 83%, respectively) were higher compared with sTfR (53 and 81%, respectively). Conclusion. In patients with SpA having CDA/IDA, sTfR and sTfR/log Fer are statistically significantly increased. The results obtained indicate the possibility of diagnosing ID by using these parameters.

While developing vaccines targeting surface transferrin receptor proteins in Gram-negative pathogens of humans and food production animals, the common features derived from their evolutionary origins has provided us with insights on how improvements could be implemented in the various stages of research and vaccine development. These pathogens are adapted to live exclusively on the mucosal surfaces of the upper respiratory or genitourinary tract of their host and rely on their receptors to acquire iron from transferrin for survival, indicating that there likely are common mechanisms for delivering transferrin to the mucosal surfaces that should be explored. The modern-day receptors are derived from those present in bacteria that lived over 320 million years ago. The pathogens represent the most host adapted members of their bacterial lineages and may possess factors that enable them to have strong association with the mucosal epithelial cells, thus likely reside in a different niche than the commensal members of the bacterial lineage. The bacterial pathogens normally lead a commensal lifestyle which presents challenges for development of relevant infection models as most infection models either exclude the early stages of colonization or subsequent disease development, and the immune mechanisms at the mucosal surface that would prevent disease are not evident. Development of infection models emulating natural horizontal disease transmission are also lacking. Our aim is to share our insights from the study of pathogens of humans and food production animals with individuals involved in vaccine development, maintaining health or regulation of products in the human and animal health sectors.

Introduction. Chronic obstructive pulmonary disease (COPD) was associated with polycythemia as a result of respiratory failure and regarded as a compensatory response of erythropoiesis to chronic hypoxia for a long time. Recent epidemiological studies have shown that anemia is observed in 17.0-24.0 % of patients with COPD and only 6.0-10.0 % of such patients have polycythemia Aim. To find out the clinical and functional features of COPD course, depending on the red branch of blood and content of soluble transferrin receptors (sTFR). Materials and methods. The study enrolled 202 patients aged >40 years with COPD who have signed the consent to participate in the study. The exclusion criteria were: severe concomitant diseases (pulmonary tuberculosis, oncopathology, alcohol and/or drug addiction, AIDS, heart failure – class ІІВ stage III, and decompensated liver failure, kidney failure, or other failures); defined source of bleeding (complications of peptic ulcer, nonspecific ulcerative colitis, chronic hemorrhoids, etc.); diagnosed true anemias (megaloblastic, aplastic, hemolytic); use of angiotensin-converting enzyme inhibitors; pregnancy or lactation; chronic administration of systemic corticosteroids. All examined patients underwent the general clinical, laboratory and instrumental examination. The degree of obstruction and severity of the disease were determined in accordance with GOLD (2014) recommendations: the degree of obstruction was determined by computer spirography (FEVp detected 15 minutes after inhalation of 400.0 mcg of salbutamol), the severity of dyspnea was determined by the modified Medical Research Council (mMRC), and quality of life was determined by COPD Assessment Test (CAT). Patients with COPD were divided into 4 study groups depending on the hemogram parameters and sTFR: 1 group included 144 patients without anemia, 2 group – 33 with anemia of chronic disease (ACD), 3 group – 12 with erythrocytosis, and 4 group – 13 with iron deficiency anemia (IDA). Statistical analysis of the results was performed using SPSS-21 program. Results. As a result of the detailed analysis of the anamnesis, objective examination and laboratory results in patients from group 4, the cause of IDA was established, namely, 5 patients were diagnosed with chronic non-atrophic gastritis, 4 had chronic gastroduodenitis, 2 had peptic ulcer of stomach, 1 had peptic ulcer of duodenum, and in 1 – chronic gastroduodenitis and chronic pancreatitis with exocrine insufficiency. It has been found that ACD is present in patients with COPD II – IV stage of obstruction and is not observe among COPD patients with degree I obstruction. It is established that the frequency of ACD increases according to the degree of obstruction and the severity of the disease. Patients with COPD with ACD and IDA had significantly lower levels of FEVj compared to patients without anemia and erythrocytosis. It was revealed that patients with COPD with ACD and COPD with IDA had a higher rate according to CAT and, lower quality of life compared with patients without anemia and erythrocytosis accordingly. As a result of the correlation analysis, it was found that there is negative correlation between the degree of obstruction and the results of mMRC (r = – 0.591; p = 0.001) and CAT (r = – 0.608; p = 0.001). Consequently, dyspnea significantly increases and the quality of life decreases in the patients with COPD and ACD with the increase of the degree of obstruction. The frequency of exacerbations was higher in patients with COPD and ACD compared with other groups. Conclusions. Anemia is detected in 22.7 % of patients with COPD, specifically, IDA – in 6.4 % of patients, and ACD – in 16.3 %. The frequency of ACH increases with the degree of obstruction and the severity of COPD. Patients with COPD with anemia (ACD or IDA) have significantly lower levels of FEVP dyspnea and quality of life are significantly worsened with the increase of the obstruction degree in patients with COPD and ACD. The frequency of exacerbations was higher in patients with COPD and ACD.

ABSTRACT Background Methods Results Conclusion Existing studies have shown that transferrin receptor (TfR) is highly expressed on the surface of lung cancer cells, and nanoparticles (NPs) have been widely used as delivery vehicles. The aim of this study was to investigate the effect of the targeted delivery of Fe3O4 NPs modified with transferrin (Tf) compared with photothermal treatment for lung cancer.The morphology and properties of Fe3O4 NPs modified with Tf were tested by internal morphological characterization experiments including transmission electron microscopy, particle size meter infrared spectrometer and other experiments. The delivery of materials was investigated by cell proliferation and apoptosis experiments, and western blot experiment was used to detect yes‐associated protein 1(YAP1) protein expression changes after delivering miR‐15a‐5p. In addition, animal models were constructed to further explore the targeting properties of the material.The results demonstrated that the nanomaterial has good stability and targeting properties. Meanwhile, we also discovered that the miR‐15a‐5p carried by NPs can inhibit cell growth after its entry to the lung cancer cells. The effect became more evident when the nanomaterials were assisted with laser therapy, as verified by in vivo and in vitro experiments. In terms of the related mechanism, miR‐15a‐5p inhibited YAP1 expression, which affected cell proliferation and apoptosis.In this study, Fe3O4 NPs modified with Tf delivered miR‐15a‐5p in combination with photothermal therapy for lung cancer. In future research, the targeted delivery of Tf and the photothermal synergy of nanomaterials will provide a theoretical basis for cancer treatment. [ABSTRACT FROM AUTHOR]

Background: Iron deficiency is a common condition that is usually diagnosed using conventional laboratory tests of iron status, such as serum ferritin and transferrin saturation. However, both ferritin and transferrin proteins are markedly influenced by inflammation, behaving as acute-phase reactants and making it difficult to differentiate between iron-deficiency anemia (IDA) and anemia of chronic disease (ACD). Objectives: To evaluate the role of serum soluble transferrin receptors (STFR) to differentiate iron deficiency anaemia and anaemia of chronic disease. Material And Methods: A cross-sectional study was conducted in the Department of Medicine, Victoria hospital and Bowring and Lady Curzon hospital, Bangalore Medical College and Research institute, Bangalore. A total of 150 blood samples were evaluated, i.e., 50 samples from iron deficiency anaemia group and 50 samples from patients with anaemia of chronic disorders & 50 samples from healthy normal individual. Result: In present study, samples are age matched with mean age of control 45.66±10.23, ACD 50.68±18.03, IDA 48.14±18.47. Hb, MCV, MCHC & MCH were decreased in both the groups. However, the decrease in Hb & MCV was much more in IDA as compared to ACD. Microcytosis was seen in 92% cases of IDA while it was observed in only 11% cases of ACD. Serum soluble transferrin receptor levels is <3 µgm/ml in 90% of ACD group whereas >3 µgm/ml in 78% of IDA Group. STFR/log ferritin index was >1.5 in 80% of IDA. 90% of ACD and control subjects had STFR/log ferritin index <1.5. STFR levels were significantly higher in IDA (7.7± 5.8) as compared to the ACD cases (1.6 ±0.89) (p<0.001). STFR/Log ferritin index is significantly higher in patients with Iron deficiency anemia (9.34±10.25) as compared to ACD (0.76±0.52) (p<0.001). Conclusion: The STFR levels along with the STFR/Log ferritin index indices is very useful in differentiating pure IDA, ACD and ACD with coexisting iron deficiency, thus providing a non invasive alternative to bone marrow iron. [ABSTRACT FROM AUTHOR]

Soluble transferrin receptor (sTfR) is a marker of both erythropoiesis and iron status and is considered useful for detecting iron deficiency, especially in inflammatory conditions, but reference intervals covering the entire pediatric age spectrum are lacking. We studied 1,064 (48.5 % female) healthy children of the entire pediatric age spectrum to determine reference values and percentiles for sTfR and the ratio of sTfR to log-ferritin (sTfR-F index) using a standard immunoturbidimetric assay. Soluble TfR levels were highly age-specific, with a peak in infancy and a decline in adulthood, whereas the sTfR-F index was a rather constant parameter. There were positive linear relationships for sTfR with hemoglobin (Hb) (p=0.008) and transferrin (females p<0.001; males p=0.003). A negative association was observed between sTfR and ferritin in females (p<0.0001) and for transferrin saturation and mean corpuscular volume (MCV) in both sexes (both p<0.0001). We found a positive relationship between sTfR and body height, body mass index (BMI) and inflammatory markers (CrP p<0.0001; WBC p=0.0172), while sTfR-F index was not affected by inflammation. Soluble TfR values appear to reflect the activity of infant erythropoiesis and to be modulated by inflammation and iron deficiency even in a healthy cohort. [ABSTRACT FROM AUTHOR]

Transferrin receptors (TfRs) play an essential role in iron-withholding strategy, and are involved in immune response against bacterial infection. In this study, the transferrin receptor 1 (OnTfR1) and transferrin receptor 2 (OnTfR2) genes are identified and characterized in Nile tilapia (Oreochromis niloticus). The open reading frames of OnTfR1 and OnTfR2 are 2220 and 2343 bp of nucleotide sequence, encoding 739 and 780 amino acids, respectively. The deduced proteins of OnTfR1 and OnTfR2 are highly homologous to those of other species, containing three conserved TfR superfamily domains (PA TfR domain, M28 TfR domain and TfR dimer domain). Expression analyses of OnTfRs in the healthy tilapia reveal that the OnTfR1 and OnTfR2 transcripts are the most abundant in the liver. The in vivo studies show that the expressions of OnTfRs are significantly up-regulate in liver and spleen, following infections of Streptococcus agalactiae and Aeromonas hydrophila. In addition, the in vitro studies reveal that the up-regulations of OnTfR expressions are also significant in monocytes/macrophages and hepatocytes upon the stimulations of S. agalactiae and A. hydrophila. Moreover, the iron ion (Fe3+) could significantly increase the expressions of OnTfRs in monocytes/macrophages and hepatocytes. Taken together, the present study indicates that OnTfRs may be involved in host defense against bacterial infection and possess the function of combining or transporting iron ions in Nile tilapia. • The transcripts of OnTfRs were significantly up-regulated upon the challenge of pathogenic bacteria in vivo and in vitro. • The OnTfRs could quickly respond to iron stress and the expression was regulated by the concentration of iron ion. • The OnTfR1 mRNA was more sensitive to iron ion stimulation. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, presenting a persisting global health burden. Neutrophils have a double-edged role in tumor progression exhibiting both pro-tumor and anti-tumor functions. CD71, also known as transferrin receptor 1, performs a critical role in cellular iron uptake and is highly expressed on proliferating cells, and especially on activated immune cells. CD71 is known to be elevated in various types of solid cancers and is associated with poor prognosis, however, the expression of CD71 on neutrophils in PDAC and its potential clinical impact is still unknown. Therefore, we analyzed CD71 on circulating neutrophils in PDAC and clinical control patients and found a significant increased expression in PDAC patients. High expression of CD71 on neutrophils in PDAC patients was associated with reduced outcome compared to low expression. CD71 on neutrophils correlated positively with the levels of proinflammatory cytokines IL-6, IFN-γ, and growth factor ligands CD40-L, and BAFF in plasma of PDAC patients. Finally, we have demonstrated that high expression of CD71 on neutrophils was also associated with an increased expression of CD39 and CD25 on circulating T-cells. Based on our findings, we hypothesize that CD71 on neutrophils is associated with tumor progression in PDAC. Further studies are required to investigate the distinct functionality of CD71 expressing neutrophils and their potential clinical application. [ABSTRACT FROM AUTHOR]

Objective: Nowadays, the prevalence of cognitive impairment in women has gradually increased, especially in postmenopausal women. There were few studies on the mechanistic effects of iron exposure on neurotoxicity in postmenopausal women. The aim of this study is to investigate the effect of iron accumulation on cognitive ability in ovariectomized mice and its possible mechanism and to provide a scientific basis for the prevention of cognitive dysfunction in postmenopausal women. Methods: Female C57BL/6N ovariectomized model mice were induced with ferric citrate (FAC). The mice were randomly divided into 5 groups: control, sham, ovariectomized (Ovx), Ovx + 50 mg/kg FAC (Ovx + l), and Ovx + 100 mg/kg FAC (Ovx + h). The impact of motor and cognitive function was verified by a series of behavioral tests. The levels of serum iron parameters, malondialdehyde, and superoxide dismutase were measured. The ultrastructure of mice hippocampal microglia was imaged by transmission electron microscopy. The differential expression of hippocampal proteins was analyzed by Tandem Mass Tag labeling. Results: Movement and cognitive function in Ovx + l/Ovx + h mice were significantly decreased compared to control and Sham mice. Then, iron exposure caused histopathological changes in the hippocampus of mice. In addition, proteomic analysis revealed that 29/27/41 proteins were differentially expressed in the hippocampus when compared by Ovx vs. Sham, Ovx + l vs. Ovx, as well as Ovx + h vs. Ovx + l groups, respectively. Moreover, transferrin receptor protein (TFR1) and divalent metal transporter 1 (DMT1) protein expression were significantly increased in the iron accumulation mice model with ovariectomy. Conclusion: Iron exposure could cause histopathological damage in the hippocampus of ovariectomised mice and, by altering hippocampal proteomics, particularly the expression of hippocampal iron metabolism‐related proteins, could further influence cognitive impairment in ovariectomized mice. [ABSTRACT FROM AUTHOR]

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to be renoprotective in ischemia-reperfusion (I/R) injury, with several proposed mechanisms, though additional mechanisms likely exist. This study investigated the impact of luseogliflozin on kidney fibrosis at 48 h and 1 week post I/R injury in C57BL/6 mice. Luseogliflozin attenuated kidney dysfunction and the acute tubular necrosis score on day 2 post I/R injury, and subsequent fibrosis at 1 week, as determined by Sirius red staining. Metabolomics enrichment analysis of I/R-injured kidneys revealed suppression of the glycolytic system and activation of mitochondrial function under treatment with luseogliflozin. Western blotting showed increased nutrient deprivation signaling with elevated phosphorylated AMP-activated protein kinase and Sirtuin-3 in luseogliflozin-treated kidneys. Luseogliflozin-treated kidneys displayed increased protein levels of carnitine palmitoyl transferase 1α and decreased triglyceride deposition, as determined by oil red O staining, suggesting activated fatty acid oxidation. Luseogliflozin prevented the I/R injury-induced reduction in nuclear factor erythroid 2-related factor 2 activity. Western blotting revealed increased glutathione peroxidase 4 and decreased transferrin receptor protein 1 expression. Immunostaining showed reduced 4-hydroxynonenal and malondialdehyde levels, especially in renal tubules, indicating suppressed ferroptosis. Luseogliflozin may protect the kidney from I/R injury by inhibiting ferroptosis through oxidative stress reduction. [ABSTRACT FROM AUTHOR]

Macroautophagy, simply referred to below as autophagy, is an intracellular degradation system that is highly conserved in eukaryotes. Since the processes involved in autophagy are accompanied by membrane dynamics, RAB small GTPases, key regulators of membrane trafficking, are generally thought to regulate the membrane dynamics of autophagy. Although more than half of the mammalian RABs have been reported to be involved in canonical and selective autophagy, no consensus has been reached in regard to the role of RABs in mammalian autophagy. Here, we comprehensively analyzed a rab-knockout (KO) library of MDCK cells to reevaluate the requirement for each RAB isoform in basal and starvation-induced autophagy. The results revealed clear alteration of the MAP1LC3/LC3-II level in only four rab-KO cells (rab1-KO, rab2-KO, rab7a-KO, and rab14-KO cells) and identified RAB14 as a new regulator of autophagy, specifically at the autophagosome maturation step. The autophagy-defective phenotype of two of these rab-KO cells, rab2-KO and rab14-KO cells, was very mild, but double KO of rab2 and rab14 caused a severer autophagy-defective phenotype (greater LC3 accumulation than in single-KO cells, indicating an overlapping role of RAB2 and RAB14 during autophagosome maturation. We also found that RAB14 is phylogenetically similar to RAB2 and that it possesses the same properties as RAB2, i.e. autophagosome localization and interaction with the HOPS subunits VPS39 and VPS41. Our findings suggest that RAB2 and RAB14 overlappingly regulate the autophagosome maturation step through recruitment of the HOPS complex to the autophagosome.Abbreviation: AID2: auxin-inducible degron 2; ATG: autophagy related; BafA1: bafilomycin A1; CKO: conditional knockout; EBSS: Earle’s balanced salt solution; EEA1: early endosome antigen 1; HOPS: homotypic fusion and protein sorting; HRP: horseradish peroxidase; IP: immunoprecipitation; KD: knockdown; KO: knockout; LAMP2: lysosomal-associated membrane protein 2; MDCK: Madin-Darby canine kidney; mAb: monoclonal antibody; MEF: mouse embryonic fibroblast; MTORC1: mechanistic target of rapamycin kinase complex 1; 5-Ph-IAA: 5-phenyl-indole-3-acetic acid; pAb: polyclonal antibody; siRNA: small interfering RNA; SNARE: soluble NSF-attachment protein receptor; TF: transferrin; WT: wild-type. [ABSTRACT FROM AUTHOR]

Ferroptosis has been implicated in several neurological disorders and may be therapeutically targeted. However, the susceptibility to ferroptosis varies in different cells, and inconsistent results have been reported even using the same cell line. Understanding the effects of key variables of in vitro studies on ferroptosis susceptibility is of critical importance to facilitate drug discoveries targeting ferroptosis. Here, we showed that increased cell seeding density leads to enhanced resistance to ferroptosis by reducing intracellular iron levels. We further identified iron‐responsive protein 1 (IRP1) as the key protein affected by cell density, which affects the expression of ferroportin or transferrin receptor and results in altered iron levels. Such observations were consistent across different cell lines, indicating that cell density should be tightly controlled in studies of ferroptosis. Since cell densities vary in different brain regions, these results may also shed light on selective regional vulnerability observed in neurological disorders. [ABSTRACT FROM AUTHOR]

Background: Anemia is common complication in children with chronic kidney disease (CKD) mainly anemia of chronic disease (ACD), but iron deficiency anemia (IDA) is also common. Soluble transferrin receptor (sTfR) is important marker for IDA. This study aims to evaluate the utility of soluble transferrin Receptor-Ferritin Indices as markers of IDA and for differentiation ACD from IDA in childern with chronic kidney disease. Methods: cross-sectional study was conducted at Department of Pediatric Nephrology at Zagazig University Hospital including 45 anemic children (19 ACD, 13 IDA and 13 mixed). The duration of the study ranges from 6 to 12 months, Soluble serum transferrin receptor and Soluble serum transferrin receptor index were measured. Results: There was significant difference regard sTfR and sTfR index IDA group were significantly higher than other two groups then mixed and finally ACD were significantly lower. Conclusion: sTfR value was useful tool for assessment of iron status in patients with CKD, however, they are at best complementary to the existing indices of serum ferritin and TSAT. [ABSTRACT FROM AUTHOR]

Background: COVID-19 has significant effects on organ function, particularly on lung function and iron metabolism. Studies have shown increased levels of ferritin, an iron storage protein, in COVID-19 patients, indicating potential changes in iron utilization. Research has focused primarily on adults, with limited studies on paediatric patients and a lack of comparisons with MIS-C patients. This study aimed to assess iron status in paediatric COVID-19 patients using traditional and new biomarkers, soluble transferrin receptors (sTfR) and Reticulocyte hemoglobin equivalent (RET-He), to improve diagnosis and prognosis. Additionally, we sought to compare iron status between acute COVID-19 patients and MIS-C patients and evaluate the relationships among iron dysmetabolism, disease severity, and prognosis in paediatric patients. The study also involved monitoring iron status during and after infection to understand its impact on patient severity and prognosis. Methods: A cohort study involving 49 patients aged 1 month to 18 years was conducted at the isolation department of Mansoura University Children's Hospital. The study included 36 patients with acute COVID-19 and 13 with multisystem inflammatory syndrome of childhood (MIS-C). Diagnosis was based on PCR from a deep nasopharyngeal swab or a positive antibody test. Follow-up of survivors was conducted 3 months after recovery. Blood samples were obtained during infection and at follow-up for CBC, Ret-He, iron kinetics, and sTfR analyses. Results: Significant iron deficiency anaemia was observed in all patients during infection, with improvement after 3 months of recovery in survivors. The improvement was more obvious in MIS-C patients, with Hb and iron kinetics not significantly affected by disease severity. The STfR was significantly lower in nonsurvivors than in survivors. The ROC curve showed that a baseline sTfR ≤ 18 nmol/L was a statistically significant difference between nonsurvivors and survivors (area under the curve (AUC) = 0.810, p <.001), with 66.7% sensitivity and 82.5% specificity. Regression analysis revealed that patients with baseline sTfRs ≤ 18 nmol/L were 5.9 times more susceptible to death. Conclusion: This study revealed that COVID-19 in children caused iron deficiency anaemia, which improved within 3 months after recovery. Haemoglobin and sTfRs were identified as reliable indicators of IDA in these patients, unlike iron kinetics and RET-He. [ABSTRACT FROM AUTHOR]

Aim: We compared soluble transferrin receptors (sTfR), serum ferritin, mean cell volume (MCV) of red cells and the sTfR-ferritin index with the intensive method bone marrow trephine (BMT) iron stores in the diagnosis of iron deficiency anaemia (IDA) in Human Immunodeficiency Virus (HIV)-positive hospitalised participants., Methods: In this cross-sectional study, we recruited hospitalised HIV-positive and coronavirus of 2019 (COVID-19)-negative adults with anaemia who required a bone marrow examination as part of their diagnostic workup. We measured the full blood count, ferritin, sTfR and assessed iron using the intensive method in Haemotoxylin and Eosin (H&E)-stained BMT core biopsies of consenting participants., Results: Of the 60 enrolled participants, 57 were evaluable. Thirteen (22.80%) had IDA on H&E BMT iron stores assessment, and 44 (77.19%) had anaemia of chronic diseases (ACD). The sTfR and the sTfR-ferritin index had sensitivities of 61.54% and 53.85%, respectively, for IDA diagnosis. The sensitivity and specificity of ferritin was 7.69% and 92.31%, respectively. The sTfR and sTfR-ferritin index's diagnostic specificity was relatively low at 46.15% and 38.46%, respectively., Conclusion: In this pilot study in HIV-positive participants, the prevalence of iron deficiency using the BMT assessment was low. Both the sTfR and the sTfR-ferritin index had a better quantitative correlation to bone marrow iron stores when compared with the MCV and ferritin and, may be more accurate surrogate markers of IDA., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Muhammad Kashif Riaz,1 Xue Zhang,1 Ka Hong Wong,1 Huoji Chen,2 Qiang Liu,2 Xiaoyu Chen,1 Ge Zhang,1 Aiping Lu,1,3 Zhijun Yang1,31School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, People’s Republic of China; 2School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, People’s Republic of China; 3Changshu Research Institute, Hong Kong Baptist University, Changshu Economic and Technological Development (CETD) Zone, Changshu, Jiangsu Province, People’s Republic of ChinaPurpose: Lung cancer has a high incidence rate worldwide with a 5-year survival rate of 18%, and is the leading cause of cancer-related deaths. The aim of this study is to augment therapeutic efficacy of quercetin (QR) for lung cancer therapy by targeting transferrin receptors, which are overexpressed and confined to tumor cells.Methods: In this study, T7 surface-functionalized liposomes loaded with QR (T7-QR-lip) having different T7 peptide densities (0.5%, 1% and 2%) were prepared by the film hydration method. T7 surface-functionalized liposomes were characterized and evaluated in terms of in vitro cytotoxicity and cellular uptake, 3D tumor spheroid penetration and inhibition capabilities, in vivo biodistribution and therapeutic efficacy in mice with orthotopic lung-tumor implantation by fluorescent and bioluminescent imaging via pulmonary administration.Results: In vitro, 2% T7-QR-lip exhibited significantly augmented cytotoxicity (∼3-fold), higher apoptosis induction and S-phase cell-cycle arrest. A prominent peak right-shift and enhanced mean fluorescence intensity was observed in A549 cells treated with T7 Coumarin-6 liposomes (T7-Cou6-lip), confirming the target specificity of T7 targeted liposomes; while, after treatment with T7-QR-lip and non-targeted QR-lip, no significant difference was observed in cellular uptake and in vitro cytotoxicity studies in MRC-5 (normal lung fibroblast) cells. T7-Cou6-lip showed higher fluorescence intensity in A549 cells and a significantly deeper penetration depth of 120 μm in the core of the tumor spheroids and T7-QR-lip produced significantly higher tumor-spheroid growth inhibition. The in vivo biodistribution study via pulmonary delivery of T7 1,1’-dioctadecyltetramethyl-indotricarbocyanine iodide liposomes demonstrated liposome accumulation in the lungs and sustained-release behavior up to 96 h. Further, T7-QR-lip significantly enhanced the anticancer activity of QR and lifespan of mice (p

Introduction. In recent years, determination of soluble transferrin receptor levels has been emerging as a test that can reliably indicate iron deficiency in various states, and that is non-invasive and easy to use. The aim of this study was: to determine reference values of soluble transferrin receptor concentrations in serums in our population, to examine the reliability of this method in the diagnosis of anemia due to iron deficiency and associated iron deficiency in anemia accompanying malignant hemopathies, and to identify possible limitations of the test in certain conditions.

Ferroptosis and cuproptosis are emerging modes of programmed cell death and have been increasingly used to eliminate tumor cells. However, converting ferroptosis/cuproptosis into effective treatments is challenging because of the inherent antioxidant and plasma membrane repair systems and inefficient copper ion delivery. Herein, an engineered doping method is developed to encapsulate ZnO2 with Cu2+‐doped ZIF‐8 and modify the surface by transferrin (Tf). In the resulting ZnO2@Cu/ZIF‐8‐Tf nanosystem, Tf specifically binds to transferrin receptors for targeting and aggregation. In the tumor microenvironment, Cu2+/Fe3+ is released from the nanosystem and reacted with glutathione (GSH) to produce Cu+/Fe2+. Excessive accumulation of Cu+ interfered with the tricarboxylic acid cycle and induced coproptosis. Furthermore, the additional Fe2+ caused iron overload and enhanced ferroptosis. ZnO2 supplied hydrogen peroxide to mediate the overproduction of reactive oxygen species (ROS). Moreover, the depletion of GSH deactivated glutathione peroxidase 4 (GPX4) and inhibited the system Xc−‐GSH‐GPX4 pathway, and the amplified ROS triggered lipid peroxidation and reprogrammed lipid metabolism, causing malfunctioning of both antioxidant and membrane repair systems. In summary, the ferroptosis/cuproptosis pathways are activated at multiple levels in the ZnO2@Cu/ZIF‐8‐Tf nanosystem, which ensures its outstanding antitumor effect. [ABSTRACT FROM AUTHOR]

While developing vaccines targeting surface transferrin receptor proteins in Gram-negative pathogens of humans and food production animals, the common features derived from their evolutionary origins has provided us with insights on how improvements could be implemented in the various stages of research and vaccine development. These pathogens are adapted to live exclusively on the mucosal surfaces of the upper respiratory or genitourinary tract of their host and rely on their receptors to acquire iron from transferrin for survival, indicating that there likely are common mechanisms for delivering transferrin to the mucosal surfaces that should be explored. The modern-day receptors are derived from those present in bacteria that lived over 320 million years ago. The pathogens represent the most host adapted members of their bacterial lineages and may possess factors that enable them to have strong association with the mucosal epithelial cells, thus likely reside in a different niche than the commensal members of the bacterial lineage. The bacterial pathogens normally lead a commensal lifestyle which presents challenges for development of relevant infection models as most infection models either exclude the early stages of colonization or subsequent disease development, and the immune mechanisms at the mucosal surface that would prevent disease are not evident. Development of infection models emulating natural horizontal disease transmission are also lacking. Our aim is to share our insights from the study of pathogens of humans and food production animals with individuals involved in vaccine development, maintaining health or regulation of products in the human and animal health sectors. [ABSTRACT FROM AUTHOR]

The bloodstream form of Trypanosoma brucei expresses large poly-N-acetyllactosamine (pNAL) chains on complex N-glycans of a subset of glycoproteins. It has been hypothesised that pNAL may be required for receptor-mediated endocytosis. African trypanosomes contain a unique family of glycosyltransferases, the GT67 family. Two of these, TbGT10 and TbGT8, have been shown to be involved in pNAL biosynthesis in bloodstream form Trypanosoma brucei, raising the possibility that deleting both enzymes simultaneously might abolish pNAL biosynthesis and provide clues to pNAL function and/or essentiality. In this paper, we describe the creation of a TbGT10 null mutant containing a single TbGT8 allele that can be excised upon the addition of rapamycin and, from that, a TbGT10 and TbGT8 double null mutant. These mutants were analysed by lectin blotting, glycopeptide methylation linkage analysis and flow cytometry. The data show that the mutants are defective, but not abrogated, in pNAL synthesis, suggesting that other GT67 family members can compensate to some degree for loss of TbGT10 and TbGT8. Despite there being residual pNAL synthesis in these mutants, certain glycoproteins appear to be particularly affected. These include the lysosomal CBP1B serine carboxypeptidase, cell surface ESAG2 and the ESAG6 subunit of the essential parasite transferrin receptor (TfR). The pNAL deficient TfR in the mutants continued to function normally with respect to protein stability, transferrin binding, receptor mediated endocytosis of transferrin and subcellular localisation. Further the pNAL deficient mutants were as viable as wild type parasites in vitro and in in vivo mouse infection experiments. Although we were able to reproduce the inhibition of transferrin uptake with high concentrations of pNAL structural analogues (N-acetylchito-oligosaccharides), this effect disappeared at lower concentrations that still inhibited tomato lectin uptake, i.e., at concentrations able to outcompete lectin-pNAL binding. Based on these findings, we recommend revision of the pNAL-dependent receptor mediated endocytosis hypothesis. Author summary: Blood-stage trypanosome parasites have a specialised invagination on the cell surface named the flagellar pocket (FP), where invariant essential nutrient receptors are located. The pocket houses diverse proteins, including a transferrin receptor (TfR), which facilitates uptake of host transferrin-bound iron for survival. Several FP proteins, including TfR, are linked to complex sugar molecules (carbohydrates), the functions of which are not well understood. Complex carbohydrates are made by enzymes called glycosyltransferases (GTs) and previously we partially inhibited complex carbohydrate synthesis by deletion of either TbGT8 or TbGT10. However, mutant parasites lacking either one of these enzymes survived, suggesting functional redundancy. Here, we created a parasite mutant that lacks both TbGT8 and TbG10 to understand the combined effect of losing both enzymes. The mutant parasites showed a decreased ability to uptake tomato lectin, a protein that specifically binds to these sugar conjugates in the FP, indicating a reduction in carbohydrate complexity. Despite reduced complexity in the sugar structures attached to TfR, its critical function in transferrin/iron uptake remained effective. Furthermore, the mutants remained viable in culture and in animal models, challenging previous assumptions about the necessity and function of these carbohydrate conjugates. Our findings imply a greater flexibility and redundancy in the carbohydrate complex roles than previously appreciated. [ABSTRACT FROM AUTHOR]

This study investigated the mechanism by which fucoxanthin acts as a novel ferroptosis inducer to inhibit tongue cancer. The MTT assay was used to detect the inhibitory effects of fucoxanthin on SCC−25 human tongue squamous carcinoma cells. The levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), and total iron were measured. Reverse transcription–quantitative polymerase chain reaction (RT−qPCR) and Western blotting were used to assess glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2−related factor 2 (Nrf2), Keap1, solute carrier family 7 member 11 (SLC7A11), transferrin receptor protein 1 (TFR1), p53, and heme oxygenase 1 (HO−1) expression. Molecular docking was performed to validate interactions. Compared with the control group, the activity of fucoxanthin−treated SCC−25 cells significantly decreased in a dose− and time−dependent manner. The levels of MMP, GSH, and SOD significantly decreased in fucoxanthin−treated SCC−25 cells; the levels of ROS, MDA, and total iron significantly increased. mRNA and protein expression levels of Keap1, GPX4, Nrf2, and HO−1 in fucoxanthin−treated cells were significantly decreased, whereas levels of TFR1 and p53 were significantly increased, in a concentration−dependent manner. Molecular docking analysis revealed that binding free energies of fucoxanthin with p53, SLC7A11, GPX4, Nrf2, Keap1, HO−1, and TFR1 were below −5 kcal/mol, primarily based on active site hydrogen bonding. Our findings suggest that fucoxanthin can induce ferroptosis in SCC−25 cells, highlighting its potential as a treatment for tongue cancer. [ABSTRACT FROM AUTHOR]

Developing vehicles that efficiently deliver genes throughout the human central nervous system (CNS) will broaden the range of treatable genetic diseases. We engineered an adeno-associated virus (AAV) capsid, BI-hTFR1, that binds human transferrin receptor (TfR1), a protein expressed on the blood-brain barrier. BI-hTFR1 was actively transported across human brain endothelial cells and, relative to AAV9, provided 40 to 50 times greater reporter expression in the CNS of human TFRC knock in mice. The enhanced tropism was CNS-specific and absent in wild-type mice. When used to deliver GBA1, mutations of which cause Gaucher disease and are linked to Parkinson's disease, BI-hTFR1 substantially increased brain and cerebrospinal fluid glucocerebrosidase activity compared with AAV9. These findings establish BI-hTFR1 as a potential vector for human CNS gene therapy. [ABSTRACT FROM AUTHOR]

Neurons regulate the microtubule-based transport of certain vesicles selectively into axons or dendrites to ensure proper polarization of function. The mechanism of this polarized vesicle transport is still not fully elucidated, though it is known to involve kinesins, which drive anterograde transport on microtubules. Here, we explore how the kinesin-3 family member KIF13A is regulated such that vesicles containing transferrin receptor (TfR) travel only to dendrites. In experiments involving live-cell imaging, knockout of KIF13A, BioID assay, we found that the kinase MARK2 phosphorylates KIF13A at a 14-3-3 binding motif, strengthening interaction of KIF13A with 14-3-3 such that it dissociates from TfR-containing vesicles, which therefore cannot enter axons. Overexpression of KIF13A or knockout of MARK2 leads to axonal transport of TfR-containing vesicles. These results suggest a unique kinesin-based mechanism for polarized transport of vesicles to dendrites. [ABSTRACT FROM AUTHOR]

Gonadotoxic agents could impair spermatogenesis and may lead to male infertility. The present study aimed to evaluate the effect of IL-1β on the development of spermatogenesis from cells isolated from seminiferous tubules (STs) of normal and busulfan-treated immature mice in vitro. Cells were cultured in a 3D in vitro culture system for 5 weeks. We examined the development of cells from the different stages of spermatogenesis by immunofluorescence staining or qPCR analyses. Factors of Sertoli and Leydig cells were examined by qPCR analysis. We showed that busulfan (BU) treatment significantly reduced the expression of testicular IL-1β in the treated mice compared to the control group (CT). Cultures of cells from normal and busulfan-treated immature mice induced the development of pre-meiotic (Vasa), meiotic (Boule), and post-meiotic (acrosin) cells. However, the percentage of developed Boule and acrosin cells was significantly lower in cultures of busulfan-treated mice compared to normal mice. Adding IL-1β to both cultures significantly increased the percentages of Vasa, Boule, and acrosin cells compared to their controls. However, the percentage of Boule and acrosin cells was significantly lower from cultures of busulfan-treated mice that were treated with IL-1β compared to cultures treated with IL-1β from normal mice. Furthermore, addition of IL-1β to cultures from normal mice significantly increased only the expression of androgen receptor and transferrin but no other factors of Sertoli cells compared to their CT. However, the addition of IL-1β to cultures from busulfan-treated mice significantly increased only the expression of androgen-binding protein and the FSH receptor compared to their CT. Adding IL-1β to cultures of normal mice did not affect the expression of 3βHSD compared to the CT, but it significantly reduced its expression in cultures from busulfan-treated mice compared to the CT. Our findings demonstrate the development of different stages of spermatogenesis in vitro from busulfan-treated mice and that IL-1β could potentiate this development in vitro. [ABSTRACT FROM AUTHOR]

Well‐defined nanostructures are crucial for precisely understanding nano‐bio interactions. However, nanoparticles (NPs) fabricated through conventional synthesis approaches often lack poor controllability and reproducibility. Herein, a synthetic biology‐based strategy is introduced to fabricate uniformly reproducible protein‐based NPs, achieving precise control over heterogeneous components of the NPs. Specifically, a ferritin assembly toolbox system is developed that enables intracellular assembly of ferritin subunits/variants in Escherichia coli. Using this strategy, a proof‐of‐concept study is provided to explore the interplay between ligand density of NPs and their tumor targets/penetration. Various ferritin hybrid nanocages (FHn) containing human ferritin heavy chains (FH) and light chains are accurately assembled, leveraging their intrinsic binding with tumor cells and prolonged circulation time in blood, respectively. Further studies reveal that tumor cell uptake is FH density‐dependent through active binding with transferrin receptor 1, whereas in vivo tumor accumulation and tissue penetration are found to be correlated to heterogeneous assembly of FHn and vascular permeability of tumors. Densities of 3.7 FH/100 nm2 on the nanoparticle surface exhibit the highest degree of tumor accumulation and penetration, particularly in tumors with high permeability compared to those with low permeability. This study underscores the significance of nanoparticle heterogeneity in determining particle fate in biological systems. [ABSTRACT FROM AUTHOR]

Sepsis poses a significant challenge in clinical management. Effective strategies targeting iron restriction, toxin neutralization, and inflammation regulation are crucial in combating sepsis. However, a comprehensive approach simultaneously targeting these multiple processes has not been established. Here, an engineered apoptotic extracellular vesicles (apoEVs) derived from macrophages is developed and their potential as multifunctional agents for sepsis treatment is investigated. The extensive macrophage apoptosis in a Staphylococcus aureus‐induced sepsis model is discovered, unexpectedly revealing a protective role for the host. Mechanistically, the protective effects are mediated by apoptotic macrophage‐released apoEVs, which bound iron‐containing proteins and neutralized α‐toxin through interaction with membrane receptors (transferrin receptor and A disintegrin and metalloprotease 10). To further enhance therapeutic efficiency, apoEVs are engineered by incorporating mesoporous silica nanoparticles preloaded with anti‐inflammatory agents (microRNA‐146a). These engineered apoEVs can capture iron and neutralize α‐toxin with their natural membrane while also regulating inflammation by releasing microRNA‐146a in phagocytes. Moreover, to exploit the microcosmic movement and rotation capabilities, erythrocytes are utilized to drive the engineered apoEVs. The erythrocytes‐driven engineered apoEVs demonstrate a high capacity for toxin and iron capture, ultimately providing protection against sepsis associated with high iron‐loaded conditions. The findings establish a multifunctional agent that combines natural and engineered antibacterial strategies. [ABSTRACT FROM AUTHOR]

Background: Transferrin receptor 1 (TfR1), glucose transporter 1 (GLUT1), and CD98hc are candidates for targeted therapy at the blood–brain barrier (BBB). Our objective was to challenge the expression of TfR1, GLUT1, and CD98hc in brain capillaries using the histone deacetylase inhibitor (HDACi) valproic acid (VPA). Methods: Primary mouse brain capillary endothelial cells (BCECs) and brain capillaries isolated from mice injected intraperitoneally with VPA were examined using RT-qPCR and ELISA. Targeting to the BBB was performed by injecting monoclonal anti-TfR1 (Ri7217)-conjugated gold nanoparticles measured using ICP-MS. Results: In BCECs co-cultured with glial cells, Tfrc mRNA expression was significantly higher after 6 h VPA, returning to baseline after 24 h. In vivo Glut1 mRNA expression was significantly higher in males, but not females, receiving VPA, whereas Cd98hc mRNA expression was unaffected by VPA. TfR1 increased significantly in vivo after VPA, whereas GLUT1 and CD98hc were unchanged. The uptake of anti-TfR1-conjugated nanoparticles was unaltered by VPA despite upregulated TfR expression. Conclusions: VPA upregulates TfR1 in brain endothelium in vivo and in vitro. VPA does not increase GLUT1 and CD98hc proteins. The increase in TfR1 does not result in higher anti-TfR1 antibody targetability, suggesting targeting sufficiently occurs with available transferrin receptors without further contribution from accessory VPA-induced TfR1. [ABSTRACT FROM AUTHOR]

Physiological or pathophysiological changes lead to posttranslational changes in the sialic acid content of human serum transferrin (hTf), an essential mediator of iron transport in the human body, resulting in a significantly increased concentration of desialylated hTf. The intrinsic fluorescence quenching upon binding of iron to hTf was successfully modeled using the binding polynomial for two iron-binding sites, allowing measurements in a high-throughput format. Removal of sialic acid residues resulted in a 3-fold increase in iron binding affinity for both sites of hTf at pH 7.4. The pH-dependence of iron binding showed significant differences in equilibrium constants, resulting in a 10-fold increase in binding affinity for desialylated hTf at pH 5.9. The changes in hTf sialylation apparently result in tuning of the stability of the conformational state, which in turn contributes to the stability of the diferric hTf. The observed differences in the conditional thermodynamic equilibrium constants suggest that the desialylated protein has a higher preference for diferric hTf over monoferric hTf species down to pH 6.5, which may also influence the interaction with transferrin receptors that preferentially bind to diferric hTf. The results suggest a link between changes in hTf glycan structure and alterations in iron binding equilibrium associated with tissue acidosis. [ABSTRACT FROM AUTHOR]