Regulation of ferritin genes and protein

Expression of recombinant swine ferritin heavy chain with enhanced solubility in Escherichia coli and simplified purification of ferritin nanoparticles

Ferritin is a versatile biomolecule used in various medical applications such as drug delivery, vaccines, biological imaging, and diagnostics. The purity and concentration of the ferritin nanoparticles are crucial for achieving excellent outcomes. In this study, we expressed and purified the recombinant swine ferritin heavy chain (rsFTH) as a new candidate for recombinant ferritin nanoparticles. We generated two types of plasmids that can express rsFTH in mammalian and prokaryotic systems. The myc-tagged rsFTH expressed in the mammalian system was purified and ferritin nanoparticles were validated using dynamic light scattering (DLS) and transmission electron microscopy (TEM). A prokaryotic expression system was used to produce rsFTH on a large scale. Protein expression was optimized in Escherichia coli BL21 under varying temperatures and IPTG conditions, and solubility was enhanced by incubation at 25 °C for 18-22 h in auto-induction media, resulting in approximately >50 % protein content in the soluble fraction compared with the pellet. Protein purification was achieved using His-tag affinity chromatography and dialysis with Tris-HCl buffer, yielding adequately pure rsFTH without any apparent protein aggregates. SDS-PAGE and Western blot analysis confirmed the expected molecular weight of rsFTH, and Native-PAGE demonstrated polymerization into higher molecular weight forms. Particle size analysis of purified rsFTH revealed a mean diameter of 15.5 nm, with transmission electron microscopy (TEM) imaging confirming spherical ferritin particles with an iron core. These results suggest that rsFTH can be efficiently expressed and purified in both mammalian and bacterial systems, and has potential applications in nanotechnology and biotechnology.

Iron metabolism in rheumatic diseases

Iron is a crucial element for living organism in terms of oxygen transport, hematopoiesis, enzymatic activity, mitochondrial respiratory chain function and also immune system function. The human being has evolved a mechanism to regulate body iron. In some rheumatic diseases such as rheumatoid arthritis (RA), systemic lupus erythematous (SLE), systemic sclerosis (SSc), ankylosing spondylitis (AS), and gout, this balanced iron regulation is impaired. Altered iron homeostasis can contribute to disease progression through ROS production, fibrosis, inflammation, abnormal bone homeostasis, NETosis and cell senescence. In this review, we have focused on the iron metabolism in rheumatic disease and its role in disease progression.

Prevalence of iron deficiency in acute and chronic heart failure according to different clinical definitions

AIMS

Iron is essential to maintain cellular energy metabolism in the myocardium. Impaired cellular iron availability negatively affects myocardial physiology and can aggravate heart failure (HF). Iron deficiency (ID) is frequently found in patients with acute and chronic HF (AHF, CHF) and associated with clinical outcome. The aim of this analysis was to assess the true ID prevalence in HF patients on the basis of different ID definitions.

METHODS

We performed a retrospective analysis of 329 AHF and 613 CHF patients, recruited between 02/2021 and 05/2022 at the Innsbruck Medical University (47%/32% female, median age 81/64 years). ID was defined according to a general definition, gastroenterology and cardiology guidelines as ferritin <30 or <45 ng/mL or <100/ng/mL (absolute ID), ferritin 30-100 or 45-150 or 100-299 ng/mL plus TSAT <20% (combined ID), and ferritin >100 or >150 or ≥300 ng/mL plus TSAT <20% (functional ID).

RESULTS

ID prevalence was significantly higher in AHF compared with CHF patients: general definition (74.8% vs. 32.6%, P < 0.001), gastroenterology guidelines (75.7% vs. 34.7%, P < 0.001), cardiology guidelines (79.9% vs. 47.3%, P < 0.001). We found distinctive differences in prevalence of ID types between the three definitions. Absolute ID prevalence was highest when applying cardiology compared with gastroenterology guidelines and general definition (AHF: 44.7% vs. 20.4% vs. 7.0%; CHF: 34.1% vs. 13.4% vs. 7.2%), while frequency of combined ID was almost equally distributed. Functional ID prevalence was highest when applying general definition compared with gastroenterology and cardiology guidelines (AHF: 34.7% vs. 23.4% vs. 11.6%; CHF: 13.1% vs. 9.0% vs. 3.4%). Out of 494 patients classified as having absolute or combined ID according to the cardiology guidelines, only 252 patients received the same classification while 107 and 135 patients were classified having no and functional ID when applying the general definition.

CONCLUSIONS

We show that ID prevalence is higher in AHF versus CHF patients in a continuous cohort of HF patients managed at the same institution over the same period of time. There were distinctive differences in detection of ID and the type of ID when applying several recommended definitions thus affecting sensitivity and specificity for absolute and functional ID detection. This may result in exclusion of patients, which may benefit from iron supplementation and inclusion of those who may not respond or even anticipate site effects. Our study calls for the urgent need of prospective trials for redefinition of ID and identification of biomarkers associated with therapeutic response to optimize patient outcomes.

A clinical predictive score of high liver iron content in metabolic hyperferritinemia: a retrospective cohort pilot study

BACKGROUND

In metabolic hyperferritinemia, most patients do not require bloodletting as the liver iron content is mildly increased. We aimed to develop a clinical predictive score of high liver iron content in metabolic hyperferritinemia to guide the prescription of magnetic resonance imaging of the liver.

METHODS

We conducted a single-center retrospective cohort study including consecutive patients with metabolic hyperferritinemia who underwent a liver iron content evaluation at diagnosis. Excessive alcohol consumption was an exclusion criterion. A multivariate analysis followed by a 1000 bootstrap replicate analysis with an expectation-maximization algorithm was used to identify the predictive factors of high liver iron content. A ROC curve analysis was built to study the performance of the score based on the odds-ratio provided by the multivariate analysis.

RESULTS

217 patients (180 men, mean age 57 years old) were included. Fifty-five patients (25%) had high liver iron content (≥ 100 µmol/g). In univariate analysis, a family history of hyperferritinemia requiring phlebotomies was associated with high LIC, as well as an increase of transferrin saturation > 45% (p < 0.001). In multivariate regression, a family history of hyperferritinemia (OR 6.15, CI95 [2.11-17.92]), increased ferritin level ≥ 600 µg/L (OR 5.53, CI95 [1.43-21.42]) and increased transferrin saturation ≥ 45% (OR 2.63, CI95 [1.32-5.23]) were significantly associated with high liver iron content. A 15-point predictive score (area-under-the-curve 0.72, CI95 [0.64-0.79], p < 0.001) was built, providing an OR of 4.17 (CI95 [2.15-8.07], p < 0.001) for high liver iron content (sensitivity 60%, specificity 97%, negative predictive value 84%).

CONCLUSION

in this pilot study, ferritin ≥ 600 µg/L, transferrin saturation ≥ 45% and a family history of hyperferritinemia requiring bloodletting provided a simple clinical score to predict high liver iron content in metabolic adult hyperferritinemia. The bootstrap analysis confirmed the robustness of our model.

Lipid Peroxidation and Type I Interferon Coupling Fuels Pathogenic Macrophage Activation Causing Tuberculosis Susceptibility

A quarter of human population is infected with Mycobacterium tuberculosis, but less than 10% of those infected develop pulmonary TB. We developed a genetically defined sst1-susceptible mouse model that uniquely reproduces a defining feature of human TB: the development of necrotic lung granulomas and determined that the sst1-susceptible phenotype was driven by the aberrant macrophage activation. This study demonstrates that the aberrant response of the sst1-susceptible macrophages to prolonged stimulation with TNF is primarily driven by conflicting Myc and antioxidant response pathways leading to a coordinated failure 1) to properly sequester intracellular iron and 2) to activate ferroptosis inhibitor enzymes. Consequently, iron-mediated lipid peroxidation fueled Ifn-beta superinduction and sustained the Type I Interferon (IFN-I) pathway hyperactivity that locked the sst1-susceptible macrophages in a state of unresolving stress and compromised their resistance to Mtb. The accumulation of the aberrantly activated, stressed, macrophages within granuloma microenvironment led to the local failure of anti-tuberculosis immunity and tissue necrosis. The upregulation of Myc pathway in peripheral blood cells of human TB patients was significantly associated with poor outcomes of TB treatment. Thus, Myc dysregulation in activated macrophages results in an aberrant macrophage activation and represents a novel target for host-directed TB therapies.

A causal inference study exploring the impact of iron status on the risk of thyroid cancer based on two-sample mendelian randomization

BACKGROUND & AIMS

Thyroid cancer is prone to early lymph node metastasis.This study investigated the influence of iron status on thyroid cancer risk and its mediating role in the relationship between thyroid cancer incidence and thyroid cancer-related exposure factors.

METHOD

Utilizing iron status-related Single Nucleotide Polymorphisms as instrumental variables, the research analyzed summary data on iron status and thyroid cancer from Genome-Wide Association Studies following the Two-sample Mendelian randomization guidelines, primarily using the Inverse-variance weighted method, with Mendelian randomization-Egger method, weighted median method, simple mode, and weighted mode as supplementary analyses. The reliability and robustness of the results were assessed using the Leave-one-out analysis and Cochran's Q Test.

RESULTS

The findings indicate that the iron status has a vital causal relationship with the occurrence of thyroid cancer. The Inverse-variance weighted model results revealed Iron || id:ieu-a-1049: OR = 1.409, 95%CI = (1.043, 1.904), P < 0.05; Ferritin || id:ieu-a-1050: OR = 2.029, 95% CI = (1.081, 3.808), P < 0.05; Transferrin Saturation || id:ieu-a-1051: OR = 1.337, 95%CI = (1.058, 1.690), P < 0.05. The reliability and robustness of these results were further supported by the Leave-one-out analysis and Cochran's Q Test (P > 0.05).

CONCLUSION

The study establishes a certain causal link between iron status and thyroid cancer, indicating that transferrin saturation, serum ferritin and serum iron are associated with thyroid cancer incidence.

Redox imbalance drives magnetic property and function changes in mice

The magnetic properties of substances directly determine their response to an externally applied magnetic field, which are closely associated with magnetoreception, magnetic resonance imaging (MRI), and magnetic bioeffects. However, people's understanding of the magnetic properties of living organisms remains limited. In this study, we utilized NRF2 (nuclear factor erythroid 2-related factor 2) deficient mice to investigate the contribution of redox (oxidation-reduction) homeostasis, in which the key process is the transfer of electron, a direct target of magnetic field and origin of paramagnetism. Our results show that the NRF2-/- mice exhibit significantly altered systemic redox state, accompanied by increased magnetic susceptibility, particularly in the liver and spleen. Further analyses reveal that the levels of paramagnetic reactive oxygen species (ROS) in these tissues are markedly elevated compared to wild-type mice. Moreover, the concentrations of Fe2+ and Fe3+ are significantly elevated in NRF2-/- mice, which are directly correlated with the increased magnetic susceptibility. The disrupted redox balance in NRF2-/- mice not only exacerbates oxidative stress and iron deposition, but also induces impairment to the liver and spleen. The findings highlight the combined effects of ROS and iron metabolism in driving magnetic susceptibility changes, providing valuable theoretical insights for further research into magnetic bioeffects and organ-specific sensitivity to magnetic fields.

Hepcidin-regulated iron metabolism disorders in patients with stage III/IV periodontitis

Background

/purposeThe disorders of iron metabolism in periodontal diseases have been reported, however, there is still lack of comprehensive and thorough analyses about the association between periodontitis and iron metabolism disorders. This study aimed to examine the association between periodontitis and iron metabolism disorders, and to analyze the characteristic changes of iron metabolism in periodontitis patients.

Materials and methods

79 Stage III/IV periodontitis patients and 79 healthy controls were enrolled in this study. Periodontal clinical parameters, system inflammation markers, iron metabolism parameters and hematological parameters were collected and compared at baseline and 3 months after non-surgical periodontal therapy.

Results

Stage III/IV periodontitis patients exhibited higher levels of systemic inflammatory markers including white blood cell (WBC) counts and high-sensitivity C-reactive protein (hs- CRP). Serum hepcidin and ferritin were significantly increased in the periodontitis group, meanwhile serum iron and transferrin were significantly decreased. Periodontal therapy attenuated the higher levels of hepcidin and ferritin, and the lower levels of Fe and transferrin in periodontitis patients at 3 months after therapy. Probing depth (PD), bleeding index (BI) and clinical attachment loss (CAL) were positively correlated with hepcidin and ferritin, and negatively correlated with Fe and transferrin respectively. Hepcidin was significantly negatively correlated with Fe and positively correlated with ferritin in periodontitis patients.

Conclusion

Our findings suggest the association between periodontitis and iron metabolism disorders and indicate that periodontitis-activated host responses may increase the risk of iron metabolism disorders, while meaningfully provide new insights into the systemic effects of periodontitis.

Silicone Oil Affects Fibrosis of Human Trabecular Meshwork Cells by Upregulating Ferroptosis Through a ROS/NOX4/Smad3 Axis

Purpose

Silicone oil (SiO) is commonly employed as an intravitreal tamponade to manage complex retinal detachments associated with proliferative diabetic retinopathy, trauma, or severe myopia and to facilitate retinal reattachment. Nevertheless, SiO usage is linked to several complications, notably secondary glaucoma, which constitutes a significant proportion of adverse effects. This study investigated the impact of SiO on trabecular meshwork cells, given their pivotal role in regulating aqueous humor outflow.

Methods

Human trabecular meshwork cells (HTMCs) were co-cultured with SiO. The impact on proliferation, fibrosis-related markers, and ferroptosis levels on these cells was evaluated using 5-ethynyl-2'-deoxyuridine (EdU), western blot, and immunofluorescence assays. Further gene knockdown experiments with NOX4 and Smad3 were conducted to elucidate the underlying mechanisms of SiO-induced changes.

Results

SiO intervention inhibited HTMC proliferation, upregulated fibrosis-related markers, and elevated ferroptosis levels. Gene knockdown experiments revealed that SiO-induced ferroptosis and reactive oxygen species (ROS) increase were mediated through NOX4 upregulation and Smad3 activation.

Conclusions

These findings highlight the significance of ferroptosis and the ROS/NOX4/Smad3 axis in the mechanism of SiO-induced intraocular pressure elevation. The insights gained from this study identify potential therapeutic targets to mitigate postoperative complications associated with SiO tamponade in ophthalmic surgery.

Dopamine degrades ferritin by chaperone-mediated autophagy to elevate mitochondrial iron level in astroglial cells

Iron accumulation and mitochondrial dysfunction in astroglia are reported in Parkinson's disease (PD). Astroglia control iron availability in neurons in which dopamine (DA) synthesis is affected in PD. Despite their intimate relationship the role of DA in astroglial iron homeostasis is limited. Here we show that DA degrades iron storage protein ferritin in astroglial cells involving lysosomal proteolysis. Lysosomal ferritinophagy is mainly associated with macroautophagy; however, we revealed the involvement of chaperone-mediated autophagy (CMA) in DA-induced ferritin degradation. In CMA, cytosolic proteins containing a specific pentapeptide motif bind with HSC70 to be transported to lysosome mediated by LAMP2A. We identified the conserved pentapeptide motif in ferritin-H (Ft-H), mutations of which resulted loss of its interaction with HSC70. Pharmacological inhibitors of HSC70 or LAMP2/2A knockdown blocks DA-induced Ft-H degradation. DA also induces cytosolic cargo NCOA4 for ferritinophagy. We further reveal that DA promotes cathepsin B to lysis ferritin within the lysosome. Inhibitor of cathepsin B, knocking down of LAMP2, or HSC70 inhibitor attenuate DA-induced elevated mitochondrial iron level. Our results establish a direct role of DA on astroglial iron homeostasis and novel involvement of CMA in ferritin degradation in response to a biological stimulus. These results also may help in better understanding iron dyshomeostasis and mitochondrial dysfunction reported in PD.

Cancer-associated fibroblasts promote doxorubicin resistance in triple-negative breast cancer through enhancing ZFP64 histone lactylation to regulate ferroptosis

BACKGROUND

Cancer-associated fibroblasts (CAFs) have been identified to drive chemotherapy resistance in triple-negative breast cancer (TNBC). This study evaluated the functions of CAFs-mediated suppressive ferroptosis in doxorubicin (DOX) resistance in TNBC and its detailed molecular mechanisms.

METHODS

TNBC cell lines were co-cultured with CAFs isolated from DOX-sensitive (CAF/S) or DOX-resistant (CAF/R) breast cancer tissues. Cell viability and death were assessed by cell counting Kit-8 (CCK-8) and propidium iodide (PI) staining. Ferroptosis was evaluated by detection of Fe2+, malondialdehyde (MDA), glutathione (GSH), and lipid reactive oxygen species (ROS) levels. Histone lactylation was determined by lactate production, pan-Kla and H3K18la expression. Molecular mechanism was determined by chromatin immunoprecipitation (ChIP) and dual luciferase reporter system. Molecule and protein expression was detected by quantitative Real-Time PCR (RT-qPCR), Western blotting, immunofluorescence and immunohistochemical staining. TNBC cells were injected into the mammary fat pad of nude mice to investigate DOX sensitivity in vivo.

RESULTS

CAFs-derived lactate repressed ferroptosis to confer resistance of TNBC cells to DOX. Moreover, zinc finger protein 64 (ZFP64) expression was elevated in DOX-resistant TNBC and was associated with high histone lactylation level. CAFs facilitated histone lactylation to enhance ZFP64 expression, which triggered ferroptosis inhibition and DOX resistance. In addition, ZFP64 bound to the promoters of GTP cyclohydrolase-1 (GCH1) and ferritin heavy chain 1 (FTH1), thereby promoting their expression. Rescue experiments indicated that ZFP64 silencing-induced ferroptosis and high sensitivity of TNBC cells to DOX could be counteracted by GCH1 or FTH1 overexpression.

CONCLUSION

CAFs acted as a ferroptosis inhibitor to cause DOX resistance of TNBC via histone lactylation-mediated ZFP64 up-regulation and subsequent promotion of GCH1-induced lipid peroxidation inhibition and FTH1-induced intracellular Fe2+ consumption.

A retrospective study of the correlation between high serum ferritin levels and the risk of gestational diabetes mellitus in midpregnant women

Aims

Gestational diabetes mellitus (GDM) is any degree of glucose intolerance with onset or first detection during pregnancy, with an inconsistent association with serum ferritin (SF). We aimed to ascertain the relationship between SF and the risk of GDM in mid-pregnancy and provide evidence for implementing clinical individualized and reasonable iron supplementation regimens.

Methods

A retrospective study was conducted to investigate 1,052 pregnant women at 24-28 weeks of gestation who were examined in the obstetrics department of The Fourth Hospital of Shijiazhuang from January 2019 to December 2021. Questionnaires were used to obtain the general information. The levels of serum ferritin (SF), serum calcium, glycated haemoglobin (HbA1c) and Oral-Glucose-Tolerance-Test (OGTT) were reviewed. The GDM was diagnosed by glucose tests. Multivariate logistic regression was used to determine the relationship between serum ferritin and GDM.

Results

Compared to the non-GDM group, the GDM group had significantly higher level of SF (13.95 (8.59-23.65) ng/mL vs. 12.11 (7.27-19.86) ng/mL, (p = 0.012)). While SF levels positively correlated with 1-hour plasma glucose levels (PG1H) (r = 0.061, p = 0.047), there was a negative correlation between SF and HbA1c levels (r =  - 0.078, p = 0.011). The risk of GDM with higher levels of SF was increased (1.010 (95% CI [1.001-1.020], p = 0.025)). In the univariate logistic regression model, the risk of GDM in pregnant women with high ferritin levels was 1.010 (95% CI [1.001-1.020], p = 0.025). After adjustment for age and pre-pregnancy body mass index (BMI), the risk of GDM was significantly increased by 44% and 42% respectively (adjusted odds ratio (AOR) = 1.440, 95% CI [1.025-2.023], p = 0.035), AOR = 1.420 (95% CI [1.011-1.995], p = 0.043). After multivariate adjustment for age and pre-pregnancy BMI, the results were moderately revised (AOR = 1.427, 95%CI [1.013-2.008], p = 0.042).

Conclusions

Elevated SF levels of mid-pregnancy was associated with risk of GDM, which may guide the implementation of pregnancy-specific supplementation to some extent with the support of further clinical trials.

Ferritin as an Effective Prognostic Factor and Potential Cancer Biomarker

Ferritin is found in all cells of the body, serving as a reservoir of iron and protecting against damage to the molecules that make up cellular structures. It has emerged as a biomarker not only for iron-related disorders but also for inflammatory diseases and conditions in which inflammation plays a key role, including cancer, neurodegeneration, and infection. Oxidative stress, which can cause cellular damage, is induced by reactive oxygen species generated during the Fenton reaction, activating signaling pathways associated with tumor growth and proliferation. This review primarily emphasizes basic studies on the identification and function of ferritin, its essential role in iron metabolism, its involvement in inflammatory diseases, and its potential as an important prognostic factor and biomarker for cancer detection.

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 3 days 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 8 weeks 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.

Macrophage activation syndrome in Sepsis: from pathogenesis to clinical management

BACKGROUND

Sepsis represents a significant global health and hygiene challenge. Excessive activation of macrophages in sepsis can result in certain patients displaying characteristics akin to those observed in Macrophage Activation Syndrome (MAS). MAS represents a grave immune system disorder characterized by persistent and severe inflammation within the body. In the context of sepsis, MAS presents atypically, leading some researchers to refer to it as Macrophage Activation-Like Syndrome (MALS). However, there are currently no effective treatment measures for this situation. The purpose of this article is to explore potential treatment methods for sepsis-associated MALS.

OBJECTIVE

The objective of this review is to synthesize the specific pathophysiological mechanisms and treatment strategies of MAS to investigate potential therapeutic approaches for sepsis-associated MALS.

METHOD

We searched major databases (including PubMed, Web of Science, and Google Scholar etc.) for literature encompassing macrophage activation syndrome and sepsis up to Mar 2024 and combined with studies found in the reference lists of the included studies.

CONCLUSION

We have synthesized the underlying pathophysiological mechanism of MALS in sepsis, and then summarized the diagnostic criteria and the effects of various treatment modalities utilized in patients with MAS or MALS. In both scenarios, heterogeneous treatment responses resulting from identical treatment approaches were observed. The determination of whether the patient is genuinely experiencing MALS significantly impacts the ultimate outcomes of therapeutic efficacy. In order to tackle this concern, additional clinical trials and research endeavors are imperative.

Bacterial Organelles in Iron Physiology

Bacteria were once thought to be simple organisms, lacking the membrane-bound organelles found in eukaryotic cells. However, recent advancements in microscopy have changed this view, revealing a diverse array of organelles within bacterial cells. These organelles, surrounded by lipid bilayers, protein-lipid monolayers, or proteinaceous shells, play crucial roles in facilitating biochemical reactions and protecting cells from harmful byproducts. Unlike eukaryotic organelles, which are universally present, bacterial organelles are species-specific and induced only under certain conditions. This review focuses on the bacterial organelles that contain iron, an essential micronutrient for all life forms but potentially toxic when present in excess. To date, three types of iron-related bacterial organelles have been identified: two membrane-bound organelles, magnetosomes and ferrosomes, and one protein-enclosed organelle, the encapsulated ferritin-like proteins. This article provides an updated overview of the genetics, biogenesis, and physiological functions of these organelles. Furthermore, we discuss how bacteria utilize these specialized structures to adapt, grow, and survive under various environmental conditions.

Human Umbilical Cord Mesenchymal Stem Cells Alleviate Diabetic Nephropathy by Inhibiting Ferroptosis via the JNK/KEAP1/NRF2 Signaling Pathway

Aims: Diabetic nephropathy (DN) is a major cause of end-stage renal disease, with no therapeutic interventions available to control its progression. Ferroptosis, an iron-dependent regulated cell death characterized by lipid peroxidation, plays a pivotal role in the pathogenesis of DN. Human umbilical cord mesenchymal stem cells (hUCMSCs) are an effective treatment modality for DN; however, the underlying mechanism of action remains unclear. The aim of the present study was to investigate whether hUCMSCs alleviate DN via inhibiting ferroptosis and its molecular mechanisms in type 2 diabetic mice and high-glucose and palmitate-stimulated human renal tubular epithelial cell (HK-11) models. Results: Our findings revealed that hUCMSCs improved the renal structure and function and tubular injuries. HUCMSC treatment can inhibit ferroptosis by decreasing iron content, reducing reactive oxygen species, malondialdehyde and 4-hydroxynonenal generation, decreasing the expression of positive ferroptosis mediator transferrin receptor 1 and long-chain acyl-CoA synthetase 4, and enhancing the expression of negative ferroptosis mediators (i.e., ferritin heavy chain, glutathione peroxidase 4, and system Xc-cystine/glutamate reverse transporter). Mechanistically, hUCMSC treatment inhibited c-Jun N-terminal kinase (JNK) and Kelch-like ECH-associated protein 1 (KEAP1) activation while increasing the expression of nuclear factor erythroid 2-related factor 2 (NRF2). Furthermore, pretreatment of HK-11 cells with NRF2 siRNA, the JNK inhibitor SP600125, or the JNK agonist anisomycin demonstrated the regulation of the JNK/KEAP1/NRF2 signaling pathway by hUCMSCs. Innovation and Conclusion: HUCMSCs inhibit ferroptosis in DN via the JNK/KEAP1/NRF2 signaling pathway, providing a new perspective and scientific evidence for treating DN. Antioxid. Redox Signal. 00, 000-000.

Zearalenone induces liver injury in mice through ferroptosis pathway

Throughout the world, some foods and feeds commonly consumed by humans and animals are inadvertently contaminated with mycotoxins. Zearalenone (ZEA) is a typical environmental/food contaminant that can cause varying degrees of damage to the body, such as reproductive toxicity, hepatotoxicity, immunotoxicity, etc. It poses a serious threat to the living environment and human and animal health. Increasing evidence shows that mycotoxin-induced organ damage may be closely related to ferroptosis. However, the mechanism of ZEA-induced liver injury is still not fully understood. Therefore, this study aimed to explore whether ZEA can trigger ferroptosis in the liver and cause liver injury. This study was conducted by establishing in vivo and in vitro ZEA exposure models. The results showed that ZEA exposure led to typical liver injury indicators. ZEA inhibited the Nrf2/keap1 antioxidant signaling pathway, aggravated the oxidative stress response, and inhibited the body's antioxidant function. Additionally, it was found that ZEA can aggravate lipid peroxidation by blocking the system Xc-/GSH/GPX4 axis, upregulating the protein expression of ACSL4, and affecting the import, storage, and export of iron ions, thereby inducing iron ion metabolism disorders. A combination of multiple factors induces ferroptosis in mouse liver and AML12 cells. Pretreatment with deferoxamine, an inhibitor of ferroptosis, can alleviate ferroptosis damage induced by ZEA, indicating the crucial role of ferroptosis in cell damage caused by ZEA. This study deeply explores the hepatic ferroptosis pathway induced by ZEA, provides a new theoretical basis for ZEA-induced hepatotoxicity, and offers new insights for exploring potential treatment strategies.

Ferroptosis in Osteoarthritis: Current Understanding

Osteoarthritis (OA) is a prevalent degenerative disease in elderly people that is characterized by cartilage loss and abrasion, leading to joint pain and dysfunction. The aetiology of OA is complicated and includes abnormal mechanical stress, a mild inflammatory environment, chondrocyte senescence and apoptosis, and changes in chondrocyte metabolism. Ferroptosis is a regulated cell death modality characterized by the excessive accumulation of lipid peroxidation and mitochondrial dysfunction. The role of ferroptosis in OA pathogenesis has aroused researchers' attention in the past two years, and there is mounting evidence indicating that ferroptosis is destructive. However, the impact of ferroptosis on OA and how the regulators of ferroptosis affect OA development are unclear. Here, we reviewed the current understanding of ferroptosis in OA pathogenesis and summarized several drugs and compounds targeting ferroptosis in OA treatment. The accumulation of intracellular iron, the trigger of Fenton reaction, the excessive production of ROS, the peroxidation of PUFA-PLs, and mitochondrial and membrane damage are involved in chondrocyte ferroptosis. System Xc - and GPX4 are the most important regulators that control ferroptosis. Several compounds, such as DFO and Fer-1, have been proven effective in preventing ferroptosis and slowing OA progression on animal models. Collectively, targeting ferroptosis shows great potential in treating OA.

Strenuous training combined with erythropoietin induces red cell volume expansion-mediated hypervolemia and alters systemic and skeletal muscle iron homeostasis

Strenuous physical training increases total blood volume (BV) through expansion of plasma volume (PV) and red cell volume (RCV). In contrast, exogenous erythropoietin (EPO) treatment increases RCV but decreases PV, rendering BV stable or slightly decreased. This study aimed to determine the combined effects of strenuous training and EPO treatment on BV and markers of systemic and muscle iron homeostasis. In this longitudinal study, eight healthy nonanemic males were treated with EPO (50 IU/kg body mass, three times per week, sc) across 28 days of strenuous training (4 days/wk, exercise energy expenditures of 1,334 ± 24 kcal/day) while consuming a controlled, energy-balanced diet providing 39 ± 4 mg/day iron. Before (PRE) and after (POST) intervention, BV compartments were measured using carbon monoxide rebreathing, and markers of iron homeostasis were assessed in blood and skeletal muscle (vastus lateralis). Training + EPO increased (P < 0.01) RCV (13 ± 6%) and BV (5 ± 4%), whereas PV remained unchanged (P = 0.86). The expansion of RCV was accompanied by a large decrease in whole body iron stores, as indicated by decreased (P < 0.01) ferritin (-77 ± 10%) and hepcidin (-49 ± 23%) concentrations in plasma. Training + EPO decreased (P < 0.01) muscle protein abundance of ferritin (-25 ± 20%) and increased (P < 0.05) transferrin receptor (47 ± 56%). These novel findings illustrate that strenuous training combined with EPO results in both increased total oxygen-carrying capacity and hypervolemia in young healthy males. The decrease in plasma and muscle ferritin suggests that the marked upregulation of erythropoiesis alters systemic and tissue iron homeostasis, resulting in a decline in whole body and skeletal muscle iron stores.NEW & NOTEWORTHY Strenuous exercise training combined with erythropoietin (EPO) treatment increases blood volume, driven exclusively by red cell volume expansion. This hematological adaptation results in increased total oxygen-carrying capacity and hypervolemia. The marked upregulation of erythropoiesis with training + EPO reduces whole body iron stores and circulating hepcidin concentrations. The finding that the abundance of ferritin in muscle decreased after training + EPO suggests that muscle may release iron to support red blood cell production.

Ferritin Levels on Hospital Admission Predict Hypoxic-Ischemic Encephalopathy in Patients After Out-of-Hospital Cardiac Arrest: A Prospective Observational Single-Center Study

AIM

Out-of-hospital cardiac arrest (OHCA) is a major health concern in Western societies. Poor outcome after OHCA is determined by the extent of hypoxic-ischemic encephalopathy (HIE). Dysregulation of iron metabolism has prognostic relevance in patients with ischemic stroke and sepsis. The aim of this study was to determine whether serum iron parameters help to estimate outcomes after OHCA.

METHODS

In this prospective single-center study, 70 adult OHCA patients were analyzed. Serum ferritin, iron, transferrin (TRF), and TRF saturation (TRFS) were measured in blood samples drawn on day 0 (admission), day 2, day 4, and 6 months after the return of spontaneous circulation (ROSC). The association of 4 iron parameters with in-hospital mortality, neurological outcome (cerebral performance category [CPC]), and HIE was investigated by receiver operating characteristics and multivariate regression analyses.

RESULTS

OHCA subjects displayed significantly increased serum ferritin levels on day 0 and lowered iron, TRF, and TRFS on days 2 and 4 after ROSC, as compared to concentrations measured at a 6-month follow-up. Iron parameters were not associated with in-hospital mortality or neurological outcomes according to the CPC. Ferritin on admission was an independent predictor of features of HIE on cranial computed tomography and death due to HIE.

CONCLUSION

OHCA is associated with alterations in iron metabolism that persist for several days after ROSC. Ferritin on admission can help to predict HIE.

Critical role of non-coding RNA-mediated ferroptosis in urologic malignancies

Urologic malignancies, characterized by their high aggressiveness and metastatic potential, pose a significant public health challenge globally. Ferroptosis, a novel mode of cell death, typically arises from intracellular iron ion overload and the accumulation of lipid peroxides. This process has been shown to play a crucial regulatory role in various pathological conditions, particularly in cancer, including urologic cancers. However, the comprehensive regulatory mechanisms underlying ferroptosis remain poorly understood, which somewhat limits its broader application in cancer therapy. Non-coding RNAs (ncRNAs), which encompass microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are non-coding transcripts that play pivotal roles in various physiological processes, such as proliferation, differentiation, apoptosis, and cell cycle regulation, by modulating the expression of target genes. The biological functions and potential regulatory mechanisms of ncRNAs in the context of cancer-related ferroptosis have been partially elucidated. Research indicates that ncRNAs can influence the progression of urologic cancers by affecting cell proliferation, migration, and drug resistance through the regulation of ferroptosis. Consequently, this review aims to clarify the functions and mechanisms of the ncRNA-ferroptosis axis in urologic cancers and to evaluate the clinical significance of ferroptosis-related ncRNAs, thereby providing new insights into cancer biology and therapeutic strategies that may ultimately benefit a diverse range of cancer patients.

Iron homeostasis and insulin sensitivity: unraveling the complex interactions

Diabetes has arisen as a noteworthy global health issue, marked by escalating incidence and mortality rates. Insulin, crucial for preserving euglycemia, acts as a vital energy provider for various tissues. Iron metabolism notably plays a significant role in the development of insulin resistance, a key factor in the onset of various metabolic disorders. The intricate interaction between iron and insulin signaling encompasses complex regulatory mechanisms at the molecular level, thereby impacting cellular reactions to insulin. The intricate interplay between insulin and glucagon, essential for precise regulation of hepatic glucose production and systemic glucose levels, may be influenced by certain microelements for instance zinc, copper, iron, boron, calcium, cobalt, chromium, iodine, magnesium and selenium. While significant progress has been achieved in elucidating the pathophysiological connections between iron overload and glucose metabolism, our understanding of the involvement of the Fenton reaction and oxidative stress in insulin resistance influencing many chronical conditions remains limited. Furthermore, the exploration of the multifaceted roles of insulin in the human body continues to be a subject of active investigation by numerous scientific researchers. This review comprehensively outlines the potential adverse impact of iron overload on insulin function and glucose metabolism. Additionally, we provide a synthesis of findings derived from various research domains, encompassing population studies, animal models, and clinical investigations, to scrutinize the multifaceted relationship between iron and insulin sensitivity. Moreover, we delineate instances of correlations between serum iron levels and various medical conditions, including the diabetes also gestational diabetes and obesity.

The role of iron transporters and regulators in Alzheimer's disease and Parkinson's disease: Pathophysiological insights and therapeutic prospects

Brain iron homeostasis plays a vital role in maintaining brain development and controlling neuronal function under physiological conditions. Many studies have shown that the imbalance of brain iron homeostasis is closely related to the pathogenesis of neurodegenerative diseases (NDs), such as Alzheimer's disease (AD) and Parkinson's disease (PD). Recent advances have revealed the importance of iron transporters and regulatory molecules in the pathogenesis and treatment of NDs. This review summarizes the research progress on brain iron overload and the aberrant expression of several key iron transporters and regulators in AD and PD, emphasizes the pathological roles of these molecules in the pathogenesis of AD and PD, and highlights the therapeutic prospects of targeting these iron transporters and regulators to restore brain iron homeostasis in the treatment of AD and PD. A comprehensive understanding of the pathophysiological roles of iron, iron transporters and regulators, and their regulations in NDs may provide new therapeutic avenues for more targeted neurotherapeutic strategies for treating these diseases.

Understanding the Difficulties in Diagnosing Neonatal Sepsis: Assessing the Role of Sepsis Biomarkers

Background

Neonatal sepsis is a serious condition with high rates of morbidity and mortality, caused by the rapid growth of microorganisms that trigger a systemic reaction. Symptoms can range from mild to severe presentations. The causative microorganism is usually transmitted from mothers, especially from the urogenital tract, or can originate from the community or hospital.

Methods

Our retrospective study assessed 121 newborns, including both preterm and term infants, divided into three groups within the first 28 days of life: early-onset sepsis (35), late-onset sepsis (39), and a control group (47). Blood samples and cultures were obtained upon admission or at the onset of sepsis (at 24 and 72 hours). The study aimed to evaluate the limitations of commonly used biomarkers and new markers such as lactate dehydrogenase and ferritin in more accurately diagnosing neonatal sepsis.

Results

Our study revealed a significant difference between the initial and final measures of lactate dehydrogenase (LDH) and ferritin in the early-onset sepsis (EOS) and late-onset sepsis (LOS) groups.

Conclusion

Ferritin and LDH may serve as potential markers associated with systemic response and sepsis in cases of both early and late-onset sepsis. Monitoring these biomarkers can aid in the timely detection and management of sepsis, potentially improving patient outcomes.

Effects of ferritin iron loading, subunit composition, and the NCOA4-iron sulfur cluster on ferritin-NCOA4 interactions: An isothermal titration calorimetry study

Ferritin is a 24-mer protein nanocage that stores iron and regulates intracellular iron homeostasis. The nuclear receptor coactivator-4 (NCOA4) binds specifically to ferritin H subunits and facilitates the autophagic trafficking of ferritin to the lysosome for degradation and iron release. Using isothermal titration calorimetry (ITC), we studied the thermodynamics of the interactions between ferritin and the soluble fragment of NCOA4 (residues 383-522), focusing on the effects of the recently identified FeS cluster bound to NCOA4, ferritin subunit composition, and ferritin-iron loading. Our findings show that in the presence of the FeS cluster, the binding is driven by a more favorable enthalpy change and a decrease in entropy change, indicating a key role for the FeS cluster in the structural organization and stability of the complex. The ferritin iron core further enhances this association, increasing binding enthalpy and stabilizing the NCOA4-ferritin complex. The ferritin subunit composition primarily affects binding stoichiometry of the reaction based on the number of H subunits in the ferritin H/L oligomer. Our results demonstrate that both the FeS cluster and the ferritin iron core significantly affect the binding thermodynamics of the NCOA4-ferritin interactions, suggesting regulatory roles for the FeS cluster and ferritin iron content in ferritinophagy.

Lactoferrin efficacy in treating hyperferritinemia in patients suffering from pathologies unrelated to hereditary hemochromatosis

Ferritin (Ftn), a globular protein, sequesters 4500 atoms of iron per molecule. Elevated serum Ftn levels (hyperferritinemia) is an indicator of iron homeostasis disorders. We present the results of an observational study involving 17 patients with hyperferritinemia unrelated to hereditary hemochromatosis (HH). All participants received treatment with 200 mg of bovine lactoferrin (bLf) once (n = 14) or twice (n = 3) a day before meals. The patients, treated with 200 mg/day of bLf, exhibited a significant increase in red blood cells (+10%, p < 0.001), hemoglobin (+4%, p < 0.001), and hematocrit (+15%, p = 0.004), accompanied by a significant reduction in serum Ftn levels (-52%, p < 0.001), C-reactive protein (CRP) (-85.0%, p < 0.001), and D-dimers (-19%, p < 0.001). Among the three patients treated with 400 mg/day of bLf, two had effects similar to those of patients bLf-treated with 200 mg/day and one experienced a strong reduction of Ftn, CRP, and erythrocyte sedimentation rate (from -97% to -75%). The decrease in serum Ftn levels due to bLf treatment was largely independent of gender (p = 0.78), age (p = 0.66), baseline symptoms (p = 0.20), and concomitant acute (p = 0.34) and chronic (p = 0.53) infections. Although this observational pilot study yields positive effects in patients with hyperferritinemia unrelated to HH treated with bLf, a larger sample size is needed for conclusive results.

Unveiling the Network regulatory mechanism of ncRNAs on the Ferroptosis Pathway: Implications for Preeclampsia

Non-coding RNAs (ncRNAs) are transcripts originating from the genome that do not serve as templates for protein synthesis. They function as epigenetic and translational regulators in various pathophysiological mechanisms, including cell proliferation and apoptosis. The ferroptosis signaling pathway, a novel mode of cell death, participates in numerous pathophysiological processes. Its signaling transmission is both complex and precise, featuring interconnected and interdependent pathways. Recent studies suggest that ncRNAs can finely regulate key genes in the ferroptosis pathway, thus modulating cellular functions, reducing oxidative stress, and maintaining maternal-fetal interface homeostasis. Future strategies targeting the ncRNA/ferroptosis axis may provide new perspectives and potential intervention points for treating preeclampsia. This article clarifies how the ncRNA/ferroptosis axis impacts preeclampsia, revealing how ncRNAs interact with ferroptosis, and pinpointing new molecular targets for the treatment of preeclampsia, thereby providing theoretical support for clinical strategies.

Self-Assembled Ferritin Nanoparticles for Delivery of Antigens and Development of Vaccines: From Structure and Property to Applications

Ferritin, an iron storage protein, is ubiquitously distributed across diverse life forms, fulfilling crucial roles encompassing iron retention, conversion, orchestration of cellular iron metabolism, and safeguarding cells against oxidative harm. Noteworthy attributes of ferritin include its innate amenability to facile modification, scalable mass production, as well as exceptional stability and safety. In addition, ferritin boasts unique physicochemical properties, including pH responsiveness, resilience to elevated temperatures, and resistance to a myriad of denaturing agents. Therefore, ferritin serves as the substrate for creating nanomaterials typified by uniform particle dimensions and exceptional biocompatibility. Comprising 24 subunits, each ferritin nanocage demonstrates self-assembly capabilities, culminating in the formation of nanostructures akin to intricate cages. Recent years have witnessed the ascendance of ferritin-based self-assembled nanoparticles, owing to their distinctive physicochemical traits, which confer substantial advantages and wide-ranging applications within the biomedical domain. Ferritin is highly appealing as a carrier for delivering drug molecules and antigen proteins due to its distinctive structural and biochemical properties. This review aims to highlight recent advances in the use of self-assembled ferritin as a novel carrier for antigen delivery and vaccine development, discussing the molecular mechanisms underlying its action, and presenting it as a promising and effective strategy for the future of vaccine development.

Unveiling the stochastic nature of human heteropolymer ferritin self-assembly mechanism

Despite ferritin's critical role in regulating cellular and systemic iron levels, our understanding of the structure and assembly mechanism of isoferritins, discovered over eight decades ago, remains limited. Unveiling how the composition and molecular architecture of hetero-oligomeric ferritins confer distinct functionality to isoferritins is essential to understanding how the structural intricacies of H and L subunits influence their interactions with cellular machinery. In this study, ferritin heteropolymers with specific H to L subunit ratios were synthesized using a uniquely engineered plasmid design, followed by high-resolution cryo-electron microscopy analysis and deep learning-based amino acid modeling. Our structural examination revealed unique architectural features during the self-assembly mechanism of heteropolymer ferritins and demonstrated a significant preference for H-L heterodimer formation over H-H or L-L homodimers. Unexpectedly, while dimers seem essential building blocks in the protein self-assembly process, the overall mechanism of ferritin self-assembly is observed to proceed randomly through diverse pathways. The physiological significance of these findings is discussed including how ferritin microheterogeneity could represent a tissue-specific adaptation process that imparts distinctive tissue-specific functions to isoferritins.

Alcohol- and Low-Iron Induced Changes in Antioxidant and Energy Metabolism Associated with Protein Lys Acetylation

Understanding the role of iron in ethanol-derived hepatic stress could help elucidate the efficacy of dietary or clinical interventions designed to minimize liver damage from chronic alcohol consumption. We hypothesized that normal levels of iron are involved in ethanol-derived liver damage and reduced dietary iron intake would lower the damage caused by ethanol. We used a pair-fed mouse model utilizing basal Lieber-DeCarli liquid diets for 22 weeks to test this hypothesis. In our mouse model, chronic ethanol exposure led to mild hepatic stress possibly characteristic of early-stage alcoholic liver disease, seen as increases in liver-to-body weight ratios. Dietary iron restriction caused a slight decrease in non-heme iron and ferritin (FeRL) expression while it increased transferrin receptor 1 (TfR1) expression without changing ferroportin 1 (FPN1) expression. It also elevated protein lysine acetylation to a more significant level than in ethanol-fed mice under normal dietary iron conditions. Interestingly, iron restriction led to an additional reduction in nicotinamide adenine dinucleotide (NAD+) and NADH levels. Consistent with this observation, the major mitochondrial NAD+-dependent deacetylase, NAD-dependent deacetylase sirtuin-3 (SIRT3), expression was significantly reduced causing increased protein lysine acetylation in ethanol-fed mice at normal and low-iron conditions. In addition, the detection of superoxide dismutase 1 and 2 levels (SOD1 and SOD2) and oxidative phosphorylation (OXPHOS) complex activities allowed us to evaluate the changes in antioxidant and energy metabolism regulated by ethanol consumption at normal and low-iron conditions. We observed that the ethanol-fed mice had mild liver damage associated with reduced energy and antioxidant metabolism. On the other hand, iron restriction may exacerbate certain activities of ethanol further, such as increased protein lysine acetylation and reduced antioxidant metabolism. This metabolic change may prove a barrier to the effectiveness of dietary reduction of iron intake as a preventative measure in chronic alcohol consumption.

Ferritin Heavy-like subunit is involved in the innate immune defense of the red swamp crayfish Procambarus clarkii

Iron-binding proteins, known as ferritins, play pivotal roles in immunological response, detoxification, and iron storage. Despite their significance to organisms, little is known about how they affect the immunological system of the red swamp crayfish (Procambarus clarkii). In our previous research, one ferritin subunit was completely discovered as an H-like subunit (PcFeH) from P. clarkii. The full-length cDNA of PcFerH is 1779 bp, including a 5'-UTR (untranslated region, UTR) of 89 bp, 3'-UTR (untranslated region, UTR) of 1180 bp and an ORF (open reading frame, ORF) of 510 bp encoding a polypeptide of 169 amino acids that contains a signal peptide and a Ferritin domain. The deduced PcFerH protein sequence has highly identity with other crayfish. PcFerH protein's estimated tertiary structure is quite comparable to animal structure. The PcFerH is close to Cherax quadricarinatus, according to phylogenetic analysis. All the organs examined showed widespread expression of PcFerH mRNA, with the ovary exhibiting the highest levels of expression. Additionally, in crayfish muscles, intestines, and gills, the mRNA transcript of PcFerH was noticeably up-regulated, after LPS and Poly I:C challenge. The expression of downstream genes in the immunological signaling system was suppressed when the PcFerH gene was knocked down. All of these findings suggested that PcFerH played a vital role in regulating the expression of downstream effectors in the immunological signaling pathway of crayfish.

Analysis of Ferritin, Hepcidin, Zinc, C-Reactive Protein and IL-6 Levels in COVID-19 in Patients Living at Different Altitudes in Peru

BACKGROUND

Despite great scientific efforts, understanding the role of COVID-19 clinical biomarkers remains a challenge.

METHODS

A cross-sectional descriptive study in two Peruvian cities at different altitudes for comparison: Lima and Huaraz. In each place, three groups were formed, made up of 25 patients with COVID-19 in the ICU, 25 hospitalized patients with COVID-19 who did not require the ICU, and 25 healthy subjects as a control group. Five biomarkers were measured: IL-6, hepcidin, ferritin, C-reactive protein, and zinc using ELISA assays.

RESULTS

Ferritin, C-reactive protein, and IL-6 levels were significantly higher in the ICU and non-ICU groups at both study sites. In the case of hepcidin, the levels were significantly higher in the ICU group at both study sites compared to the non-ICU group. Among the groups within each study site, the highest altitude area presented statistically significant differences between its groups in all the markers evaluated. In the lower altitude area, differences were only observed between the groups for the zinc biomarker.

CONCLUSION

COVID-19 patients residing at high altitudes tend to have higher levels of zinc and IL-6 in all groups studied compared to their lower altitude counterparts.

Circ_BBS9 as an early diagnostic biomarker for lung adenocarcinoma: direct interaction with IFIT3 in the modulation of tumor immune microenvironment

Background

Introduction: Circular RNAs (circRNAs) have been identified as significant contributors to the development and advancement of cancer. The objective of this study was to examine the expression and clinical implications of circRNA circ_BBS9 in lung adenocarcinoma (LUAD), as well as its potential modes of action.

Methods

The expression of Circ_BBS9 was examined in tissues and cell lines of LUAD through the utilization of microarray profiling, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis. In this study, we assessed the impact of circ_BBS9 on the proliferation of LUAD cells, as well as its influence on ferroptosis and tumor formation. To analyze these effects, we employed CCK-8 assays and ferroptosis assays. The identification of proteins that interact with Circ_BBS9 was achieved through the utilization of RNA pull-down and mass spectrometry techniques. A putative regulatory network comprising circ_BBS9, miR-7150, and IFIT3 was established using bioinformatics study. The investigation also encompassed the examination of the correlation between the expression of IFIT3 and the invasion of immune cells.

Results

Circ_BBS9 was significantly downregulated in LUAD tissues and cell lines. Low circ_BBS9 expression correlated with poor prognosis. Functional experiments showed that circ_BBS9 overexpression inhibited LUAD cell proliferation and promoted ferroptosis in vitro and suppressed tumor growth in vivo. Mechanistically, circ_BBS9 was found to directly interact with IFIT3 and regulate its expression by acting as a sponge for miR-7150. Additionally, IFIT3 expression correlated positively with immune infiltration in LUAD.

Conclusion

Circ_BBS9 has been identified as a tumor suppressor in lung adenocarcinoma (LUAD) and holds promise as a diagnostic biomarker. The potential mechanism of action involves the modulation of ferroptosis and the immunological microenvironment through direct interaction with IFIT3 and competitive binding to miR-7150. The aforementioned findings offer new perspectives on the pathophysiology of LUAD and highlight circ_BBS9 as a potentially valuable target for therapeutic interventions.

Role of the PARP1/NF-κB Pathway in DNA Damage and Apoptosis of TK6 Cells Induced by Hydroquinone

Hydroquinone(HQ) is a widely used industrial raw material and is a topical lightening product found in over-the-counter products. However, inappropriate exposure to HQ can pose certain health hazards. This study aims to explore the mechanisms of DNA damage and cell apoptosis caused by HQ, with a focus on whether HQ activates the nuclear factor-κB (NF-κB) pathway to participate in this process and to investigate the correlation between the NF-κB pathway activation and poly(ADP-ribose) polymerase 1(PARP1). Through various experimental techniques, such as DNA damage detection, cell apoptosis assessment, cell survival rate analysis, immunofluorescence, and nuclear-cytoplasmic separation, the cytotoxic effects of HQ were verified, and the activation of the NF-κB pathway was observed. Simultaneously, the relationship between the NF-κB pathway and PARP1 was verified by shRNA interference experiments. The results showed that HQ could significantly activate the NF-κB pathway, leading to a decreased cell survival rate, increased DNA damage, and cell apoptosis. Inhibiting the NF-κB pathway could significantly reduce HQ-induced DNA damage and cell apoptosis and restore cell proliferation and survival rate. shRNA interference experiments further indicated that the activation of the NF-κB pathway was regulated by PARP1. This study confirmed the important role of the NF-κB pathway in HQ-induced DNA damage and cell apoptosis and revealed that the activation of the NF-κB pathway was mediated by PARP1. This research provides important clues for a deeper understanding of the toxic mechanism of HQ.

Extracellular vesicles-derived ferritin from lipid-induced hepatocytes regulates activation of hepatic stellate cells

Introduction

and objectives: Extracellular vesicles (EVs) have emerged as key players in intercellular communication within the context of non-alcoholic fatty liver disease (NAFLD). This study aims to explore the intricate crosstalk between hepatocytes and hepatic stellate cells (HSCs) mediated by EVs in NAFLD.

Materials and methods

EVs ferritin was detected in hepatocytes stimulated with free fatty acids (FFA) as well as in NAFLD mice. Deferoxamine (DFO) was employed to reduce ferritin levels, while GW4869 was utilized to inhibit EVs. The impact of EVs ferritin on the HSCs activation was evaluated both in vitro and in vivo. Additionally, serum EVs ferritin levels were compared between NAFLD patients and controls.

Results

FFA treatment induces the formation and secretion of EVs and facilitates the release of ferritin from hepatocytes via EVs. Subsequently, EVs ferritin is hijacked by HSCs, prompting accelerated HSCs activation. Silencing ferritin with DFO and inhibiting EVs formation and secretion with GW4869 can reverse the effects of FFA treatment and disrupt the communication between hepatocytes and HSCs. Accumulation of ferritin leads to excessive reactive oxygen species (ROS) production, promoting HSCs fibrogenesis. Conversely, depleting EVs ferritin cargo restores liver function, concurrently mitigating NAFLD-associated fibrosis. Notably, NAFLD patients exhibit significantly elevated levels of serum EVs ferritin.

Conclusions

This study unveils a previously underestimated role of ferritin in HSCs upon its release from hepatocytes, emphasizing DFO as a promising compound to impede NAFLD advancement.

Ribonuclease inhibitor 1 emerges as a potential biomarker and modulates inflammation and iron homeostasis in sepsis

Sepsis, marked by organ dysfunction, necessitates reliable biomarkers. Ribonuclease inhibitor 1 (RNH1), a ribonuclease (RNase) inhibitor, emerged as a potential biomarker for acute kidney injury and mortality in thoracoabdominal aortic aneurysm patients. Our study investigates RNH1 dynamics in sepsis, its links to mortality and organ dysfunction, and the interplay with RNase 1 and RNase 5. Furthermore, we explore RNH1 as a therapeutic target in sepsis-related processes like inflammation, non-canonical inflammasome activation, and iron homeostasis. We showed that RNH1 levels are significantly higher in deceased patients compared to sepsis survivors and correlate with creatine kinase, aspartate and alanine transaminase, bilirubin, serum creatinine and RNase 5, but not RNase 1. RNH1 mitigated LPS-induced TNFα and RNase 5 secretion, and relative mRNA expression of ferroptosis-associated genes HMOX1, FTH1 and HAMP in PBMCs. Monocytes were identified as the predominant type of LPS-positive PBMCs. Exogenous RNH1 attenuated LPS-induced CASP5 expression, while increasing IL-1β secretion in PBMCs and THP-1 macrophages. As RNH1 has contradictory effects on inflammation and non-canonical inflammasome activation, its use as a therapeutic agent is limited. However, RNH1 levels may play a central role in iron homeostasis during sepsis, supporting our clinical observations. Hence, RNH1 shows promise as biomarkers for renal and hepatic dysfunction and hepatocyte injury, and may be useful in predicting the outcome of septic patients.

Integration of metalloproteome and immunoproteome reveals a tight link of iron-related proteins with COVID-19 pathogenesis and immunity

Increasing clinical data show that the imbalance of host metallome is closely associated with different kinds of disease, however, the intrinsic mechanisms of action of metals in immunity and pathogenesis of disease remain largely undefined. There is lack of multiplexed profiling system to integrate the metalloproteome-immunoproteome information at systemic level for exploring the roles of metals in immunity and disease pathogenesis. In this study, we build up a metal-coding assisted multiplexed proteome assay platform for serum metalloproteomic and immunoproteomic profiling. By taking COVID-19 as a showcase, we unbiasedly uncovered the most evident modulation of iron-related proteins, i.e., Ft and Tf, in serum of severe COVID-19 patients, and the value of Ft/Tf could work as a robust biomarker for COVID-19 severity stratification, which overtakes the well-established clinical risk factors (cytokines). We further uncovered a tight association of transferrin with inflammation mediator IL-10 in COVID-19 patients, which was proved to be mainly governed by the monocyte/macrophage of liver, shedding light on new pathophysiological and immune regulatory mechanisms of COVID-19 disease. We finally validated the beneficial effects of iron chelators as anti-viral agents in SARS-CoV-2-infected K18-hACE2 mice through modulation of iron dyshomeostasis and alleviating inflammation response. Our findings highlight the critical role of liver-mediated iron dysregulation in COVID-19 disease severity, providing solid evidence on the involvement of iron-related proteins in COVID-19 pathophysiology and immunity.

Functional consequence of Iron dyshomeostasis and ferroptosis in systemic lupus erythematosus and lupus nephritis

Systemic lupus erythematosus (SLE) and its renal manifestation Lupus nephritis (LN) are characterized by a dysregulated immune system, autoantibodies, and injury to the renal parenchyma. Iron accumulation and ferroptosis in the immune effectors and renal tubules are recently identified pathological features in SLE and LN. Ferroptosis is an iron dependent non-apoptotic form of regulated cell death and ferroptosis inhibitors have improved disease outcomes in murine models of SLE, identifying it as a novel druggable target. In this review, we discuss novel mechanisms by which iron accumulation and ferroptosis perpetuate immune cell mediated pathology in SLE/LN. We highlight intra-renal dysregulation of iron metabolism and ferroptosis as an underlying pathogenic mechanism of renal tubular injury. The basic concepts of iron biology and ferroptosis are also discussed to expose the links between iron, cell metabolism and ferroptosis, that identify intracellular pro-ferroptotic enzymes and their protein conjugates as potential targets to improve SLE/LN outcomes.

Decoding the influence of semen collection processes on goat sperm quality from a perspective of seminal plasma proteomics

This study aims to assess the impact of semen collection methods on goat semen quality and seminal plasma (SP) proteomes. Semen was collected by artificial vagina (AV) or electro-ejaculator (EE) and semen parameters were evaluated. Tandem mass tag coupled with liquid chromatography-tandem mass spectrometry was used to screen SP differentially abundant proteins (DAPs) between EE and AV. PRM was used to confirm the reliability of the data. In contrast to EE, a lower volume, higher progressive motility and concentration were observed in AV. No differences were found in total motility, membrane integrity, acrosome integrity, and ROS production between EE and AV. In total, 1692 proteins were identified in SP, including 210 DAPs. Among them, 120 and 90 proteins were down-regulated and up-regulated in AV compared to EE, respectively. The GO annotation showed that DAPs are mainly localized in the membrane, involved in deference responses to bacterium, RNA processing, and related to oxidoreductase activity. KEGG demonstrated tight associations of DAPs with specific amino acids, carbon metabolism, citrate cycle, and propanoate metabolism. In conclusion, this study provides valuable insights into the effects of semen collection on goat semen quality and explores the potential action mechanism based on the modification of SP proteomes. SIGNIFICANCE OF THE STUDY: The quality of fresh semen directly influences the results of artificial insemination and semen cryopreservation in livestock. This study represents the first attempt to evaluate the impact of semen collection methods including electroejaculation and artificial vagina on sperm quality and seminal plasma proteomes in goat. The results of this study demonstrated that semen collection methods directly impacted the quality of goat semen. Then, the proteomic strategy was used to explore the potential action mechanism of semen collection methods on sperm. Some differentially abundant proteins that potentially influence semen quality were identified. Furthermore, this study suggests the possibility of utilizing specific proteins as predictive markers for goat semen quality.

Effect of parenteral L-carnitine in hospitalized patients with moderate to severe COVID-19: A randomized double-blind clinical trial

Introduction

Pro-inflammatory responses have an important role in developing coronavirus disease 2019 (COVID-19). L-carnitine (LC) has been known to possess anti-inflammatory, anticoagulant, and antiviral effects. So, we aimed to evaluate the efficacy of LC in hospitalized patients with moderate-to-severe COVID-19.

Methods

This double-blind, placebo-controlled, randomized clinical trial was conducted on hospitalized patients with moderate to severe COVID-19. The patients were randomized (1:1) to receive LC (n = 50) at a dose of 20 mg/kg or matching placebo (n = 51) from normal saline once daily for 14 days or until hospitalization and standard care. The primary outcome was hospital mortality and disease severity according to the World Health Organization's clinical progression scale. We also assessed the free carnitine level at baseline and the end of the study. C-reactive protein (CRP), ferritin, D-dimer, lactate dehydrogenase (LDH), and improvement of respiratory conditions were chosen as secondary outcomes.

Results

From 104 patients who met the inclusion criteria, 101 individuals' data were analyzed. The LC group showed a significant reduction in LDH levels (P = 0.003), although CRP, ferritin, and D-dimer levels did not significantly differ from the placebo group. Also, no significant difference was observed in disease severity, oxygenation status, hospital mortality, or hospital stay between the two groups. Additionally, there was no increase in serum-free carnitine levels in the LC group (P > 0.05 for all).

Conclusion

The results of the current study did not support the superiority of LC over placebo in improving oxygenation, decreasing mortality, and hospital stay, as well as CRP, ferritin, and D-dimer in moderate to severe COVID-19 patients.

Trial Registration

IRCT20170609034406N10; https://en.irct.ir/trial/60306.

Anemia in patients receiving anticancer treatments: focus on novel therapeutic approaches

Anemia is common in cancer patients and impacts on quality of life and prognosis. It is typically multifactorial, often involving different pathophysiological mechanisms, making treatment a difficult task. In patients undergoing active anticancer treatments like chemotherapy, decreased red blood cell (RBC) production due to myelosuppression generally predominates, but absolute or functional iron deficiency frequently coexists. Current treatments for chemotherapy-related anemia include blood transfusions, erythropoiesis-stimulating agents, and iron supplementation. Each option has limitations, and there is an urgent need for novel approaches. After decades of relative immobilism, several promising anti-anemic drugs are now entering the clinical scenario. Emerging novel classes of anti-anemic drugs recently introduced or in development for other types of anemia include activin receptor ligand traps, hypoxia-inducible factor-prolyl hydroxylase inhibitors, and hepcidin antagonists. Here, we discuss their possible role in the treatment of anemia observed in patients receiving anticancer therapies.

Iron-carbohydrate complexes treating iron anaemia: Understanding the nano-structure and interactions with proteins through orthogonal characterisation

Intravenous (IV) iron-carbohydrate complexes are widely used nanoparticles (NPs) to treat iron deficiency anaemia, often associated with medical conditions such as chronic kidney disease, heart failure and various inflammatory conditions. Even though a plethora of physicochemical characterisation data and clinical studies are available for these products, evidence-based correlation between physicochemical properties of iron-carbohydrate complexes and clinical outcome has not fully been elucidated yet. Studies on other metal oxide NPs suggest that early interactions between NPs and blood upon IV injection are key to understanding how differences in physicochemical characteristics of iron-carbohydrate complexes cause variance in clinical outcomes. We therefore investigated the core-ligand structure of two clinically relevant iron-carbohydrate complexes, iron sucrose (IS) and ferric carboxymaltose (FCM), and their interactions with two structurally different human plasma proteins, human serum albumin (HSA) and fibrinogen, using a combination of cryo-scanning transmission electron microscopy (cryo-STEM), x-ray diffraction (XRD), small-angle x-ray scattering (SAXS) and small-angle neutron scattering (SANS). Using this orthogonal approach, we defined the nano-structure, individual building blocks and surface morphology for IS and FCM. Importantly, we revealed significant differences in the surface morphology of the iron-carbohydrate complexes. FCM shows a localised carbohydrate shell around its core, in contrast to IS, which is characterised by a diffuse and dynamic layer of carbohydrate ligand surrounding its core. We hypothesised that such differences in carbohydrate morphology determine the interaction between iron-carbohydrate complexes and proteins and therefore investigated the NPs in the presence of HSA and fibrinogen. Intriguingly, IS showed significant interaction with HSA and fibrinogen, forming NP-protein clusters, while FCM only showed significant interaction with fibrinogen. We postulate that these differences could influence bio-response of the two formulations and their clinical outcome. In conclusion, our study provides orthogonal characterisation of two clinically relevant iron-carbohydrate complexes and first hints at their interaction behaviour with proteins in the human bloodstream, setting a prerequisite towards complete understanding of the correlation between physicochemical properties and clinical outcome.

Erythrocyte sedimentation rate in heartworm naturally infected dogs "with or without" Leishmania infantum seropositivity: an observational prospective study

Canine heartworm disease by Dirofilaria immitis and canine leishmaniosis by Leishmania infantum (CanL) are both vector-borne diseases with frequently overlapping endemicity and able to trigger the acute phase response, being characterized by variations in acute phase proteins (APP). Recently, erythrocyte sedimentation rate (ESR), an indicator of inflammation, has gained attention in veterinary medicine, proving useful in several conditions that include CanL active forms in dogs. This study aims to evaluate ESR in heartworm-infected dogs, compare levels with heartworm-infected and L. infantum seropositive dogs as well as clinically healthy dogs, and assess correlations with other laboratory parameters. From October 2022 to January 2023, a prospective observational study was conducted enrolling heartworm-infected (Dirofilaria group) and heartworm-infected L. infantum seropositive (Dirofilaria/Leishmania group) animals subgrouped according to the CanL clinical form (Dirofilaria/Leishmania active and non-active groups). A group of clinically healthy dogs (control group) was also included. For each dog enrolled physical examination and laboratory tests (complete blood count, biochemical panel including APP, serum protein electrophoresis) were performed. Dirofilaria and Dirofilaria/Leishmania groups presented a significantly higher ESR level compared to healthy dogs. Dirofilaria/Leishmania active group had the highest ESR level among the groups considered. Dirofilaria/Leishmania non-active group had an ESR similar to the Dirofilaria group, but significantly higher and lower compared to the control and the Dirofilaria/Leishmania active group, respectively. A significant positive correlation between ESR and C-Reactive Protein has been found in all groups except for the Dirofilaria/Leishmania non-active group. In Dirofilaria/Leishmania active group a strong positive correlation between ESR and gamma globulins percentage as well as a strong negative correlation between ESR and albumin, albumin/globulins ratio were found. Overall, the ESR was confirmed to be an inflammation marker as well as a helpful disease index, being notably increased in heartworm-infected dogs affected by an active form of CanL.

A SARS-CoV-2 Nanobody Displayed on the Surface of Human Ferritin with High Neutralization Activity

Purpose

COVID-19 is rampant throughout the world, which has caused great damage to human lives and seriously hindered the development of the global economy. Aiming at the treatment of SARS-CoV-2, in this study, we proposed a novel fenobody strategy based on ferritin (Fe) self-assembly technology.

Methods

The neutralizing nanobody H11-D4 of SARS-CoV-2 fused to the C-terminus of end-modified human ferritin was expressed in E. coli and silkworm baculovirus expression systems. A large number of nanoparticles were successfully self-assembled in silkworms, while relatively few nanoparticles can be observed in the treated products from E. coli by electron microscopy. Subsequently, the fenobody's expression level and neutralizing activity were then evaluated.

Results

The results showed that the IC50 of H11-D4 and fenobody Fe-H11-D4 expressed in E. coli were 171.1 nmol L-1 and 20.87 nmol L-1, respectively. However, the IC50 of Fe-HD11-D4 expressed in silkworms was 1.46 nmol L-1 showing better neutralization activity.

Conclusion

Therefore, fenobodies can be well self-assembled in silkworm baculovirus expression system, and ferritin self-assembly technology can effectively improve nanobody neutralization activity.

Phospholipase D regulates ferroptosis signal transduction in mouse spleen hypoxia response

High-altitude hypoxia exposure can lead to phospholipase D-mediated lipid metabolism disorder in spleen tissues and induce ferroptosis. Nonetheless, the key genes underlying hypoxia-induced splenic phospholipase D and the ferroptosis pathway remain unclear. This study aimed to establish a hypoxia animal model. Combined transcriptomic and proteomic analyses showed that 95 predicted target genes (proteins) were significantly differentially expressed under hypoxic conditions. Key genes in phospholipase D and ferroptosis pathways under hypoxic exposure were identified by combining Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis techniques. Gene set enrichment analysis (GSEA) showed that the differential gene sets of the phospholipase D and ferroptosis signaling pathways were upregulated in the high-altitude hypoxia group. The genes in the phospholipase D signalling pathway were verified, and the expression levels of KIT and DGKG were upregulated in spleen tissues under hypoxic exposure. Subsequently, the mRNA and protein expression levels of genes from the exogenous pathway such as TFRC, SLC40A1, SLC7A11, TRP53, and FTH1 and those from the endogenous pathway such as GPX4, HMOX1, and ALOX15 differentials in the ferroptosis signalling pathway were verified, and the results indicated significant differential expression. In summary, exposure to high-altitude hypoxia mediated phospholipid metabolism disturbance through the phospholipase D signalling pathway and further induced ferroptosis, leading to splenic injury.

Mitochondrial ferritin alleviates ferroptosis in a kainic acid-induced mouse epilepsy model by regulating iron homeostasis: Involvement of nuclear factor erythroid 2-related factor 2

BACKGROUND

Epilepsy is a widespread and chronic disease of the central nervous system caused by a variety of factors. Mitochondrial ferritin (FtMt) refers to ferritin located within the mitochondria that may protect neurons against oxidative stress by binding excess free iron ions in the cytoplasm. However, the potential role of FtMt in epilepsy remains unclear. We aimed to investigate whether FtMt and its related mechanisms can regulate epilepsy by modulating ferroptosis.

METHODS

Three weeks after injection of adeno-associated virus (AAV) in the skull of adult male C57BL/6 mice, kainic acid (KA) was injected into the hippocampus to induce seizures. Primary hippocampal neurons were transfected with siRNA using a glutamate-mediated epilepsy model. After specific treatments, Western blot analysis, immunofluorescence, EEG recording, transmission electron microscopy, iron staining, silver staining, and Nissl staining were performed.

RESULTS

At different time points after KA injection, the expression of FtMt protein in the hippocampus of mice showed varying degrees of increase. Knockdown of the FtMt gene by AAV resulted in an increase in intracellular free iron levels and a decrease in the function of iron transport-related proteins, promoting neuronal ferroptosis and exacerbating epileptic brain activity in the hippocampus of seizure mice. Additionally, increasing the expression level of FtMt protein was achieved by AAV-mediated upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) gene in the hippocampus of seizure mice.

CONCLUSIONS

In epilepsy, Nrf2 modulates ferroptosis by involving the expression of FtMt and may be a potential therapeutic mechanism of neuronal injury after epilepsy. Targeting this relevant process for treatment may be a therapeutic strategy to prevent epilepsy.

Ferritin: Significance in viral infections

As an indispensable trace element, iron is essential for many biological processes. Increasing evidence has shown that virus infection can perturb iron metabolism and play a role in the occurrence and development of viral infection-related diseases. Ferritin plays a crucial role in maintaining the body's iron homoeostasis. It is an important protein to stabilise the iron balance in cells. Ferritin is a 24-mer hollow iron storage protein composed of two subunits: ferritin heavy chain and ferritin light chain. It was reported that ferritin is not only an intra-cellular iron storage protein, but also a pathogenic mediator that enhances the inflammatory process and stimulates the further inflammatory pathway, which is a key member of the vicious pathogenic cycle to perpetuate. Ferritin exerts immuno-suppressive and pro-inflammatory functions during viral infection. In this review, we describe in detail the basic information of ferritin in the first section, including its structural features, the regulation of ferritin. In the second part, we focus on the role of ferritin in viral infection-related diseases and the molecular mechanisms by which viral infection regulates ferritin. The last section briefly outlines the potential of ferritin in antiviral therapy. Given the importance of iron and viral infection, understanding the role of ferritin during viral infection helps us understand the relationship between iron metabolic dysfunction and viral infection, which provides a new direction for the development of antiviral therapeutic drugs.

Lipopolysaccharide inhibits translation of iron chaperone PCBP1 to regulate inflammatory cytokine response in macrophage

Macrophages play a key role in maintaining systemic iron homeostasis and immunity. During pro-inflammatory stage macrophages retain iron due to the decrease of the unique iron exporter ferroportin. Increased cellular iron is sequestered in to storage protein ferritin by iron chaperone poly(rC)-binding protein 1 (PCBP1). However, the fate of PCBP1 and its interaction with ferritin in pro-inflammatory macrophages has not been studied so far. Here we report that PCBP1 protein level is down-regulated in lipopolysaccharide (LPS) treated macrophages. LPS did not alter PCBP1 mRNA and protein stability suggesting inhibition of translation as a mechanism of PCBP1 down-regulation that was confirmed by 35S-methionine incorporation assay. PCBP1 interacts with ferritin-H (Ft-H) subunit to load iron into ferritin. We detected a decreased interaction between PCBP1 and Ft-H after LPS-stimulation. As a result iron loading in to ferritin was affected with simultaneous increase in labile iron pool (LIP). Pre-treatment of cells with iron chelator dampened LPS-induced expression of TNF-α, IL-1β and IL-6 mRNA. Silencing of PCBP1 increased the magnitude of expression of these cytokines compared to control siRNA transfected LPS-treated macrophages. In contrast, overexpression of PCBP1 resulted a decrease in expression of these cytokines compared to vector transfected macrophages. Our results reveal a novel regulation of PCBP1 and its role in expression of cytokines in LPS-induced pro-inflammatory macrophages.

High Ferritin and Low Total Iron-Binding Capacity in Plasma Predict All-Cause Mortality During the First 3 Years of Hemodialysis in Patients with End-Stage Chronic Kidney Disease

Aim

To determine all-cause mortality rate and the predictive value of plasma ferritin and total iron-binding capacity (TIBC) concentrations for mortality during the first 3 years of hemodialysis in patients with end-stage chronic renal disease (ESRD).

Methods

We conducted a study on 174 ESRD patients (estimated Glomerular Filtration Rate < 15 mL/min/1.73m2). The plasma TIBC level was quantified by the ELISA method in all patients at the time before hemodialysis. Based on TIBC concentration, patients were divided equally into 2 groups. Each group had 87 patients. Patients were initiated on hemodialysis, and patients who died from any cause during the first 3 years of hemodialysis were recorded.

Results

The all-cause mortality rate of ESRD patients in the first 3 years of maintenance hemodialysis was 22.9%. Plasma high hs-CRP, high ferritin, and low TIBC concentrations were independent factors associated with all-cause mortality in the patients. Plasma ferritin (cut-off value = 454.2 ng/L) and TIBC (cut-off value = 39.84 µmol/L) were predictors of all-cause mortality, AUC is: 0.772; 0.723, p < 0.001.

Conclusion

Plasma ferritin and TIBC were good predictors of all-cause mortality in ESRD patients during the first 3 years of hemodialysis.