Iron in infection and immunity

Ferritin's role in infectious diseases: Exploring pathogenic mechanisms and clinical implications

Ferritin, an iron storage protein, is crucial for maintaining iron metabolism balance throughout the body and serves as a key biomarker for evaluating the body's iron reserves. Reduced ferritin levels typically indicate iron deficiency, whereas elevated ferritin levels indicate an acute inflammatory response in infectious diseases. Recent research has established a significant link between elevated ferritin levels and disease severity and prognosis. The concept of hyperferritinemic syndrome has underscored ferritin's role as a pathogenic mediator. During infections, ferritin not only serves as a biomarker of inflammation but also exerts pro-inflammatory functions, which is a key factor in perpetuating the vicious pathogenic cycle. This review offers a comprehensive exploration of ferritin, covering its structural characteristics, regulatory mechanisms, and how diverse pathogens modulate ferritin. Understanding its pivotal role in infectious diseases is essential for identifying novel therapeutic prospects and enhancing disease management and prevention.

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.

Dual role of hepcidin in response to pathogens

Hepcidin is the primary regulator of vertebrate iron homeostasis. Its production is stimulated by systemic iron levels and inflammatory signals. Although the role of hepcidin in iron homeostasis is well characterized, its response to pathogenic agents is complex and diverse. In this review, we examine studies that investigate the role of hepcidin in response to infectious agents. Interleukin-6 (IL-6) is a key factor responsible for the induction of hepcidin expression. During infection, hepcidin-mediated depletion of extracellular iron serves as a protective mechanism against a variety of pathogens. However, accumulation of iron in macrophages through hepcidin-mediated pathways may increase susceptibility to intracellular pathogens such as Mycobacterium tuberculosis. Prolonged elevation of hepcidin production can lead to anemia due to reduced iron availability for erythropoiesis, a condition referred to as anemia of inflammation. In addition, we highlight the role of hepcidin upregulation in several infectious contexts, including HIV-associated anemia, iron deficiency anemia in Helicobacter pylori infection, and post-malarial anemia in pediatric patients. In addition, we show that certain infectious agents, such as hepatitis C virus (HCV), can suppress hepcidin production during both the acute and chronic phases of infection, while hepatitis B virus (HBV) exhibits similar suppression during the chronic phase.

Ferroptosis-mediated immune responses in osteoporosis

Osteoporosis is a common systemic metabolic disease, characterized by decreased bone mass and susceptibility to fragility fractures, often associated with aging, menopause, genetics, and immunity. Ferroptosis plays an underestimated yet crucial role in the further impact of immune function changes on osteoporosis. Cell ferroptosis can induce alterations in immune function, subsequently influencing bone metabolism. In this context, this review summarizes several mechanisms of ferroptosis and introduces the latest insights on how ferroptosis regulates immune responses, exploring the interactions between ferroptosis and other mechanisms such as oxidative stress, inflammation, etc. This review elucidates potential treatment strategies for osteoporosis, emphasizing the promising potential of ferroptosis as an emerging target in the treatment of osteoporosis. In conclusion, preparations related to ferroptosis exhibit substantial clinical promise for enhancing bone mass restoration. The translational potential of this article: This review elucidates a nuanced conversation between the immune system and osteoporosis, with ferroptosis serving as the connecting link. These findings underscore the potential of ferroptosis inhibition as a therapeutic strategy for osteoporosis.

Presetting CAR-T cells during ex vivo biomanufacturing

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of hematologic malignancies. However, it continues to encounter significant obstacles, including treatment relapse and limited efficacy in solid tumors. While effector T cells exhibit robust cytotoxicity, central memory T cells and stem cell-like T cells are essential for in vivo expansion, long-term survival, and persistence. Strategies such as genetic engineering to enhance CAR-T cell efficacy and durability are often accompanied by increased safety risks, which not only raise regulatory approval thresholds but also escalate CAR-T production costs. In contrast, optimizing ex vivo manufacturing conditions represents a more straightforward and practical approach, offering the potential for rapid application to commercially approved CAR-T products and enhancement of their clinical outcomes. This review examines several factors that have been shown to improve T cell memory phenotype and in vivo cytotoxic activity, including cytokines, electrolytes, signaling pathway inhibitors, metabolic modulators, and epigenetic agents. The insights provided will guide the optimization of CAR-T cell industrial production. Furthermore, considerations for selecting appropriate conditions are discussed, balancing effectiveness, cost-efficiency, safety, and regulatory compliance while addressing current challenges in the field.

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.

Macrophages hijack carbapenem-resistance hypervirulent Klebsiella pneumoniae by blocking SLC7A11/GSH-manipulated iron oxidative stress

Infection with carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) is life-threatening because of its pronounced virulence and antibiotic resistance. Recent studies revealed that iron and ROS enhance the ability of macrophages to eliminate intracellular pathogenic bacteria. However, whether and how iron-related oxygen stress responses in macrophages elicit a protective role against CR-hvKP infection remains largely unknown. In a mouse model of CR-hvKP pulmonary infection, the production of the Solute Carrier Family 7 member 11 (SLC7A11) was increased. Treatment with the ferroptosis agonist Erastin or Sorafenib decreased the SLC7A11 expression and the bacterial load in infected lung tissues, alleviating CR-hvKP-induced acute lung injury, increasing the content of TLR4, ROS and LPO. In vitro experiments showed that CR-hvKP infection resulted in a remarkable time-dependent changes in the expression of SLC7A11, GSH, ferrous iron, ROS and LPO in MH-S cells. Mechanically, blocking the expression of SLC7A11 in CR-hvKP-infected MH-S cells increased iron and ROS, improving the ability of macrophages to clear CR-hvKP in an LPO-dependent manner. Taken together, our study reveals that improving iron-related oxygen stress via blocking the SLC7A11/GSH pathway promoting the macrophages to phagocytose and eliminate CR-hvKP, which provides a new promising strategy against CR-hvKP infection.

Development and validation of a machine learning model for predicting intrapartum fever using pre-labor analgesia clinical indicators: a multicenter retrospective study

BACKGROUND

Labor anesthesia is commonly used for pain relief during labor, but it can increase the risk of intrapartum fever. Currently, there are no reliable tools to predict which parturients might develop fever before labor anesthesia. The prediction model we developed aims to predict the incidence of intrapartum fever before labor analgesia.

METHODS

This study retrospectively analyzed the clinical data of parturients who underwent labor analgesia at Chengdu Jinjiang District Maternal & Child Health Hospital and Sichuan Jinxin Xinan Women's & Children's Hospital from January 2021 to June 2023. After the data were processed, the parturients were randomly divided into training and validation cohorts at an 8:2 ratio. The least absolute shrinkage and selection operator method was used for feature selection. Six machine learning models were developed and subjected to comprehensive analysis to assess and validate their predictive capabilities, ultimately selecting the best-performing model.

RESULTS

The study included a total of 5,052 parturients, with 418 (8.27%) parturients experiencing intrapartum fever. The predictive factors were primiparity, estimated neonatal weight, degree of uterine dilatation, presence of anemia, number of vaginal examinations, and height. The multilayer perceptron model emerged as the best-performing predictive model, achieving an area under the curve of 0.707, a sensitivity of 0.753, and a specificity of 0.584.

CONCLUSIONS

The multilayer perceptron model, utilizing readily available pre-labor analgesia variables, demonstrates potential for predicting intrapartum fever. In comparison to existing tools, this model may enable earlier identification of high-risk parturients, supporting timely interventions and potentially enhancing maternal and neonatal health outcomes.

Nutritional Factors and Food and Nutrition Insecurity in Patients with Tuberculosis

Background/Objectives: Brazil has a high incidence of new tuberculosis cases influenced by socioeconomic factors. Inadequate housing, limited access to health services, and insufficient food increase vulnerability to the disease. This study aimed to identify sociodemographic, nutritional, and anthropometric factors associated with active pulmonary tuberculosis. Methods: This case-control study was conducted at the tuberculosis (TB) Referral Hospital in São Luís, Maranhão, Brazil, from 2022 to 2024. It included 65 patients with active pulmonary TB and 73 comparison individuals. Sociodemographic and nutritional data were collected using an adapted semi-quantitative questionnaire with 77 items, based on the validated ELSA-BRASIL questionnaire for adults, to assess the consumption of calcium, phosphorus, iron, zinc, vitamin B3, vitamin B6, vitamin C, vitamin E, and vitamin D. The Brazilian Food Insecurity Scale (EBIA) was used to analyze food and nutrition security or insecurity. Body Mass Index (BMI) was calculated based on weight and height measurements. Results: The TB patients were predominantly men (73.8%), of mixed ancestry (69.4%), with low education levels (73.4%), and had a mean age of 39 years. Furthermore, 26.2% of the patients were underweight, and 64% experienced some degree of food and nutrition insecurity. The variables education level, vitamin D, and BMI were associated with the outcome in the final model. Conclusions: The study identified a high prevalence of food insecurity and vitamin E deficiency in individuals with active tuberculosis, in addition to associating low educational levels, inadequate vitamin D intake, and overweight with a higher risk of TB. Although it has limitations, such as the cross-sectional design and sample size, the results highlight the importance of these determinants and point to the need for longitudinal research to confirm and expand the evidence.

Terahertz Wave Desensitizes Ferroptosis by Inhibiting the Binding of Ferric Ions to the Transferrin

Ferroptosis is a classic type of programmed cell death characterized by iron dependence, which is closely associated with many diseases such as cancer, intestinal ischemic diseases, and nervous system diseases. Transferrin (Tf) is responsible for ferric-ion delivery owing to its natural Fe3+ binding ability and plays a crucial role in ferroptosis. However, Tf is not considered as a classic druggable target for ferroptosis-associated diseases since systemic perturbation of Tf would dramatically disrupt blood iron homeostasis. Here, we reported a nonpharmaceutical, noninvasive, and Tf-targeted electromagnetic intervention technique capable of desensitizing ferroptosis with directivity. First, we revealed that the THz radiation had the ability to significantly decrease binding affinity between the Fe3+ and Tf via molecular dynamics simulations, and the modulation was strongly wavelength-dependent. This result provides theoretical feasibility for the THz modulation-based ferroptosis intervention. Subsequent extracellular and cellular chromogenic activity assays indicated that the THz field at 8.7 μm (i.e., 34.5 THz) inhibited the most Fe3+ bound to the Tf, and the wavelength was in good agreement with the simulated one. Then, functional assays demonstrated that levels of intracellular Fe2+, lipid peroxidation, malondialdehyde (MDA) and cell death were all significantly reduced in cells treated with this 34.5 THz wave. Furthermore, the iron deposition, lipid peroxidation, and MDA in the ferroptosis disease model induced by ischemia-reperfusion injury could be nearly eliminated by the same radiation, validating THz wave-induced desensitization of ferroptosis in vivo. Together, this work provides a preclinical exemplar for electromagnetic irradiation-stimulated desensitization of ferroptosis and predicts an innovative, THz wave-based therapeutic method for ferroptosis-associated diseases in the future.

Molecular Insights into the Interaction of Cathepsin D and Iron in Chronic Wound Healing: Exploring Therapeutic Potential and Mechanisms

Background: Chronic wounds, such as diabetic ulcers, often fail to progress through healing due to persistent inflammation, infections, and extracellular matrix (ECM) imbalances. Cathepsin D, an aspartate protease active in acidic environments, plays a pivotal role in wound healing by mediating inflammatory responses, ECM remodeling, and macrophage phenotype transitions. Its dysregulation, however, can impair healing, highlighting the need for targeted modulation of its activity. The aim of this study was to investigate the molecular interaction between Fe2+ and cathepsin D's catalytic core and ionic zipper under physiological and acidic conditions to identify strategies to enhance tissue repair and accelerate the healing of chronic wounds. Methods: The molecular structure of active cathepsin D was obtained from the Protein Data Bank (PDB) and analyzed using UCSF Chimera. Molecular interactions between cathepsin D and ferrous ions (Fe2+) were studied, focusing on key residues (D33 and D231) and ionic zipper residues (E5, E180, and D187). Results: Our results showed that the active form of cathepsin D, a 96 kDa dimer, consisted of heterodimers with distinct amino acid chains, where residues D33 and D231 formed the active site, and E5, E180, and D187 constituted the ionic zipper. A functional pocket containing the conserved residues D33 and D231, essential for proteolytic activity, was identified. At physiological pH (~7.5), D33 exhibited the most potent interactions with Fe2+, with interaction energies of -7 × 1017 J at oxygen atoms of the carboxylate group (OD1) and α-carbon (CA) atoms, whereas D231 showed slightly lower energies of -6 × 1017 J at γ-carbon atom (CG) and CA atoms. At acidic pH (~4), E5 was the primary interacting residue, with the shortest distance to Fe2+ (2.69 Å), and showed stable interactions across several atoms, emphasizing its role in metal binding. Conclusions: pH conditions strongly influence the interaction of cathepsin D with Fe2. At physiological pH, residues D33 and D231 demonstrate robust and energetically efficient binding with Fe2+. At the same time, under acidic conditions, E5 emerges as the primary residue involved, potentially affecting the ionic zipper of cathepsin D. These insights provide a molecular foundation for targeting specific residues to modulate cathepsin D activity, presenting promising opportunities for therapeutic strategies aimed at improving chronic wound healing.

SaaS sRNA promotes the interfering effect of Salmonella on hepatic iron metabolism via modulating ferroportin 1

Iron limitation plays a fundamental role in host immunity against Salmonella infection. The mechanisms by which Salmonella antagonizes nutritional immunity, particularly those regulated by small non-coding RNAs (sRNAs), remain incompletely understood. In this study, we investigated the role of a previously identified sRNA, Salmonella adhesive-associated sRNA (SaaS), in host iron metabolism. Utilizing a combined BALB/c mouse model and HepG2 cell model, we demonstrated that SaaS enhances hepcidin synthesis via the bone morphogenetic protein (BMP)-SMAD pathway, leading to decreased ferroportin 1 level. This suppression of ferroportin 1 results in reduced serum iron and increased hepatic iron accumulation, ultimately causing iron-deficiency anemia. The accumulation of iron triggers hepatic oxidative stress, exacerbating liver damage. Concurrently, SaaS activates the signal transducer and activator of transcription 3 (STAT3) pathway in a triggering receptor expressed on myeloid cells-1 (TREM1)-interleukin (IL)-6-dependent manner, intensifying the inflammatory response. Collectively, these results provide evidence that sRNAs serve as crucial regulators of Salmonella pathogenesis and underscore the potential of targeting sRNAs for the prevention of salmonellosis.

Impact of p. Gingivalis-induced chronic apical periodontitis on systemic iron homeostasis via the hepatic IL-6/STAT3/Hepcidin signaling pathway

BACKGROUND AND AIMS

Chronic apical periodontitis (CAP), an inflammatory disease of the oral cavity caused by bacterial infections with Porphyromonas gingivalis (P. gingivalis) as a key pathogen, has been associated with systemic effects, potentially influencing distant organs including liver. The liver plays a key role in iron metabolism and immunity by hepcidin. This study aims to investigate the impact of P. gingivalis-induced CAP on liver and systemic iron metabolism, focusing on the role of the IL-6/STAT3 signaling pathway in hepatic hepcidin synthesis.

METHODS

A murine model of CAP was established by pulp chamber infection with P. gingivalis. Serum levels of IL-6, ferritin, and hepcidin were measured via ELISA. High-throughput sequencing was used to analyze hepatic gene expression, and immunohistochemistry with fluorescent staining was performed to validate protein expression in liver tissues.

RESULTS

CAP led to significant changes in serum iron, ferritin, and IL-6. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed enrichment in pathways like JAK/STAT signaling and acute-phase responses, and gene set enrichment analysis (GSEA) also indicated activation of IL-6/JAK/STAT3 signaling pathway. Iimmunofluorescence confirmed increased IL-6, p-STAT3, and hepcidin expression. These levels were alleviated by stattic treatment, mitigating CAP-induced inflammatory and iron-regulatory effects.

CONCLUSION

P. gingivalis-induced CAP triggered systemic inflammation and disrupts iron metabolism via the IL-6/STAT3 signaling pathway, potentially affecting liver function. Targeting this pathway may offer therapeutic strategies for managing iron dysregulation in chronic inflammatory diseases like CAP.

A NIR fluorescent probe based on carbamoyl oxime with high specificity for detecting ferrous ions in food and in vivo

Ferrous ions (Fe2+), the primary form of iron in cells, play a crucial role in various biological processes. The presence and absorption of Fe2+ in food has an important impact on human health. Proper dietary intake and iron supplementation are conducive to prevent and treat iron-related diseases. Therefore, it is of great value to develop tools that can specifically and sensitively detect Fe2+ in foods and organisms. Near-infrared (NIR) fluorescent probes have attracted much attention due to their advantages including deep tissue penetration and lower background fluorescence. Herein, a NIR fluorescent probe DICO-Fe(II) with a new recognition mechanism was constructed. DICO-Fe(II) achieves the highly specific recognition of Fe2+ through its carbamoyl oxime recognition site and exhibits high sensitivity with a limit of detection of 47 nM. DICO-Fe(II) can quantitatively detect Fe2+ with the naked eye through RGB values. It was also successfully applied to detect Fe2+ in food samples, cells, zebrafish, and mice tissues, confirming its potential as a modern analytical tool for the detection of Fe2+ in food and biological organisms.

Immunomodulatory Effects of Selected Non-Nutritive Bioactive Compounds and Their Role in Optimal Nutrition

The contemporary approach to nutrition increasingly considers the role of non-nutritive bioactive compounds in modulating the immune system and maintaining health. This article provides up-to-date insight into the immunomodulatory effects of selected bioactive compounds, including micro- and macronutrients, vitamins, as well as other health-promoting substances, such as omega-3 fatty acids, probiotics, prebiotics, postbiotics (including butyric acid and sodium butyrate), coenzyme Q10, lipoic acid, and plant-derived components such as phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins, carotenoids, and terpenoids. Micro- and macronutrients, such as zinc, selenium, magnesium, and iron, play a pivotal role in regulating the immune response and protecting against oxidative stress. Vitamins, especially vitamins C, D, E, and B, are vital for the optimal functioning of the immune system as they facilitate the production of cytokines, the differentiation of immunological cells, and the neutralization of free radicals, among other functions. Omega-3 fatty acids exhibit strong anti-inflammatory effects and enhance immune cell function. Probiotics, prebiotics, and postbiotics modulate the intestinal microbiota, thereby promoting the integrity of the intestinal barrier and communication between the microbiota and the immune system. Coenzyme Q10, renowned for its antioxidant attributes, participates in the protection of cells from oxidative stress and promotes energy processes essential for immune function. Sodium butyrate and lipoic acid exhibit anti-inflammatory effects and facilitate the regeneration of the intestinal epithelium, which is crucial for the maintenance of immune homeostasis. This article emphasizes the necessity of an integrative approach to optimal nutrition that considers not only nutritional but also non-nutritional bioactive compounds to provide adequate support for immune function. Without them, the immune system will never function properly, because it has been adapted to this in the course of evolution. The data presented in this article may serve as a foundation for further research into the potential applications of bioactive components in the prevention and treatment of diseases associated with immune dysfunction.

Short-term effects of air pollution on the infectious disease spectrum in Shanghai, China: a time-series analysis from 2013 to 2019

Background

Epidemiological evidence on the effects of air pollution on infectious diseases remains inconsistent, highlighting the need for further research and analysis. We aimed to investigate the relationship between exposure to fine particulate matter (PM2.5) and ozone (O3) and the risk of national notifiable infectious diseases in Shanghai, a megacity in China.

Methods

A double-pollutant model was used for each air pollutant, utilizing time-series analysis to separately apply single and distributed lag models (DLMs) to assess the exposure-lag-response relationship for 43 national notifiable infectious diseases (NNIDs) from 2013 to 2019. The model was adjusted for seasonality, long-term trends, mean temperature, relative humidity, and other air pollutants. Analysis was further conducted for seven NNID categories (vaccine-preventable; bacterial; gastrointestinal and enterovirus; sexually transmitted and bloodborne; vector-borne; zoonotic; and quarantinable diseases) as well as specific diseases.

Results

The study included 661,267 NNID cases and found that PM2.5 and O3 exposures were associated with increased NNID risks, although not within the same categories. A 10 μg/m3 increase in O3 was associated with a higher risk of total NNIDs (relative risk [RR] at lag 1 month: 1.29, 95% confidence interval [CI]: 1.02-1.65), vaccine-preventable diseases (RR at lag 1 month: 1.75, 95% CI: 1.02-3.01), and sexually transmitted and bloodborne diseases (RR at lag 2 month: 1.12, 95% CI: 1.00-1.26). However, the association with PM2.5 remained inconclusive.

Conclusion

These findings suggest a potential link between ambient air pollution exposure and the risk of infectious diseases, highlighting the urgent need for a comprehensive understanding of the relationship between air pollution and notifiable infectious diseases, as well as an in-depth evaluation of disparities across the disease spectrum.

Phase-dependent iron depletion differentially regulates the niche of intestinal stem cells in experimental colitis via ERK/STAT3 signaling pathway

Introduction

Ulcerative colitis (UC) is a global gastrointestinal disease, which is mainly caused by both dysfunctional epithelial barrier and inflammation response. Iron is a critical fundamental element for both the maintenance of homeostasis and the mediation of inflammation in many tissues. However, the role and mechanism of iron in the phase of enteritis and the subsequent repairing phase of intestinal stem cells has not been elucidated. In this study, we aimed to explore whether and how iron depletion would affect the occurrence and outcome of experimental colitis.

Methods

Iron depletion was realized by deferoxamine (DFO) at either the early stage or late stage of dextran sulfate sodium (DSS) induced experimental colitis in mice. The gross images of colons, general health, histology, barrier integrity, and qRT-PCR were performed. Meanwhile, cell culture and colonic organoids were used to examine the influence of iron depletion in vitro. Signaling pathway and inflammatory infiltration were investigated by immunostaining.

Results

Iron depletion within the early stage of DSS treatment significantly inhibited the onset of the inflammatory response, maintained the integrity of the colonic epithelium, and preserved the activity of intestinal stem cells (ISCs) both in vivo and in vitro. However, both continuous iron depletion by DFO and late DFO treatment aggravated colonic injury and postponed the recovery from colitis. Early DFO-induced iron depletion was able to maintain the p-STAT3 and p-ERK1/2 signaling pathways within the colonic epithelium at the early phase of colitis, but late DFO treatment inhibited the activity of these two pathways.

Discussion

Our study demonstrated that the manipulation of iron depletion by DFO might greatly affect the outcomes of experimental colitis in a phase-dependent manner, which suggests that the balance of iron metabolism might be an effective therapeutic target for the clinical treatment of IBD patients.

Preeclampsia and eclampsia: the role of hemolytic protozoan iron

Organisms as well as pathogens require several transition metals including iron, copper, zinc, manganese, nickel and cobalt, for genetic replication and other cellular functions. Of these, iron is vital and plays a key role in DNA replication, transcription, synthesis of cofactors and other essential enzymes. During infection, iron deprivation, particularly sequestration thereof, represents a unique response against pathogen attack. The host sequesters ferrous (Fe2+) and ferric (Fe3+) iron via lactoferrin binding at mucosal surfaces, transferrin in blood and tissue and ferritin in blood and cytoplasm. Despite this protective mechanism, pathogens can be resilient in obtaining iron. For example, hemolytic protozoan parasites can obtain iron from heme by rupturing red blood cells. Furthermore, earlier pathogens, driven from active to inactive infections by iron deprivation, could now acquire sufficient iron to enable reactivation resulting in chronic inflammation, oxidative stress to organs and/or circulatory hypertension potentially leading to death. This review discusses the impact of hemolytic protozoan parasite infection in reactivation of latent iron-deprived pathogen infections thus explaining two puzzling pregnancy disorders, pre-eclampsia (PE) and eclampsia. The unknown causations of both disorders have created centuries of confusion and killed millions of women worldwide. Furthermore, reduction-oxidation reactions with iron promote additional oxidative stress damage to vital organs, particularly the kidneys, a common symptom in PE and eclampsia.

Iron-related Genes and Proteins Involved in Iron Homeostasis in Animal Models of Allergic Asthma: A Systematic Review

The involvement of the immune oxidative stress response in the pathophysiology and pathogenesis of allergic asthma is well documented. However, reports on the role of iron homeostasis in allergic asthma is scarce. Therefore, this study aims to identify iron-related genes and proteins in mouse models of allergic asthma. Related articles were identified from SCOPUS and Web of Science databases. The article search was limited to publications in English, within a 10-year period (2014 - 2023, up to 16 August 2023) and original/research papers. All identified articles were screened for eligibility using the inclusion and exclusion criteria. All eligible articles were quality appraised prior to data extraction. Five studies were selected for data extraction. Based on the extracted data, three themes and seven subthemes related to iron homeostasis were identified. The type of samples and analytical methods used were also identified. In conclusion, our study elucidates that iron-related proteins are regulated in animal models of allergic asthma. However, the currently available data do not allow us to conclude whether the disease model resulted in iron accumulation or depletion. Therefore, further studies with other related markers should be conducted.

Metal ion formulations for diabetic wound healing: Mechanisms and therapeutic potential

Metals are vital in human physiology, which not only act as enzyme catalysts in the processes of superoxide dismutase and glucose phosphorylation, but also affect the redox process, osmotic adjustment, metabolism and neural signals. However, metal imbalances can lead to diseases such as diabetes, which is marked by chronic hyperglycemia and affects wound healing. The hyperglycemic milieu of diabetes impairs wound healing, posing significant challenges to patient quality of life. Wound healing encompasses a complex cascade of hemostasis, inflammation, proliferation, and remodeling phases, which are susceptible to disruption in hyperglycemic conditions. In recent decades, metals have emerged as critical facilitators of wound repair by enhancing antimicrobial properties (e.g., iron and silver), providing angiogenic stimulation (copper), promoting antioxidant activity and growth factor synthesis (zinc), and supporting wound closure (calcium and magnesium). Consequently, research has pivoted towards the development of metal ion-based therapeutics, including innovative formulations such as nano-hydrogels, nano-microneedle dressings, and microneedle patches. Prepared by combining macromolecular materials such as chitosan, hyaluronic acid and sodium alginate with metals, aiming at improving the management of diabetic wounds. This review delineates the roles of key metals in human physiology and evaluates the application of metal ions in diabetic wound management strategies.

Importance of trace elements in the immunometabolic health of people living with HIV/AIDS: a literature review

Trace elements (TEs) are essential for human health and for maintaining immune responses against potentially aggressive pathogens, such as the human immunodeficiency virus (HIV). During the infectious process, the body needs greater amounts of TEs in order to coordinate an efficient immune response to combat the invading agent, a condition that reflects in lymphocyte proliferation and activation of the antioxidant defense system of neutrophils and macrophages. Thus, during the progression phase of a viral infection, immunomodulation of TEs such as iron, zinc, chromium, magnesium, selenium, copper, calcium, and manganese occurs, can lead to immunosuppression and increased oxidative stress. Furthermore, the adverse effects caused by the use of antiretroviral therapy (ART) trigger nutritional disorders and metabolic alterations that contribute to deficiencies in TEs, associated with compromised immune function. Therefore, this narrative literature review aims to contribute as a teaching tool on the TEs involved in the pathogenesis of HIV, by reviewing the role of TEs in the immunometabolic health of people living with HIV/AIDS.

Imbalanced and Unchecked: The Role of Metal Dyshomeostasis in Driving COPD Progression

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by persistent inflammation and oxidative stress, which ultimately leads to progressive restriction of airflow. Extensive research findings have cogently suggested that the dysregulation of essential transition metal ions, notably iron, copper, and zinc, stands as a critical nexus in the perpetuation of inflammatory processes and oxidative damage within the lungs of COPD patients. Unraveling the intricate interplay between metal homeostasis, oxidative stress, and inflammatory signaling is of paramount importance in unraveling the intricacies of COPD pathogenesis. This comprehensive review aims to examine the current literature on the sources, regulation, and mechanisms by which metal dyshomeostasis contributes to COPD progression. We specifically focus on iron, copper, and zinc, given their well-characterized roles in orchestrating cytokine production, immune cell function, antioxidant depletion, and matrix remodeling. Despite the limited number of clinical trials investigating metal modulation in COPD, the advent of emerging methodologies tailored to monitor metal fluxes and gauge responses to chelation and supplementation hold great promise in unlocking the potential of metal-based interventions. We conclude that targeted restoration of metal homeostasis represents a promising frontier for ameliorating pathological processes driving COPD progression.

Genetically Predicted Iron Status Is a Causal Risk of Rheumatoid Arthritis: A Mendelian Randomization Study

Background  Current knowledge on iron's role in rheumatoid arthritis (RA) development is very limited, with studies yielding inconsistent findings. We conducted a two-sample Mendelian randomization study to assess the associations of iron status with the risk of RA. Methods  This study leveraged genetic data from a large genome-wide association study (GWAS) of 257,953 individuals to identify single nucleotide polymorphisms (SNPs) associated with iron status. We then analyzed these data in conjunction with summary-level data on RA from the IEU open GWAS project, which included 5,427 RA cases and 479,171 controls. An inverse-variance weighted method with random effects was employed, along with sensitivity analyses, to assess the relationship between iron status and RA risk. Results  Genetic predisposition to high ferritin and serum iron status was causally associated with lower odds of RA. Ferritin had an odds ratio (OR) of 0.997 (95% confidence interval [CI]: 0.995-0.997; p  = 0.010), indicating that a one-unit increase in ferritin is associated with a 0.3% decrease in the odds of RA. Similarly, serum iron had an OR of 0.997 (95% CI: 0.995-0.999; p  = 0.014). However, MR analyses found no significant causal associations between total iron-binding capacity (OR = 1.0, 95% CI: 0.999-1.002; p  = 0.592) or transferrin saturation percentage (OR = 0.998, 95% CI: 0.996-1.000; p  = 0.080) and risk of developing RA. Conclusions  This study suggests that individuals with genes linked to higher iron levels may have a lower risk of developing RA. Our findings indicate that the total amount of iron in the body, rather than how it is distributed, might be more important for RA. This raises the intriguing possibility that iron supplementation could be a preventative strategy, but further research is necessary.

Screening and treatment practices for iron deficiency in anaemic pregnant women: A cross-sectional survey of healthcare workers in Nigeria

BACKGROUND

Iron deficiency anaemia in pregnancy is a significant contributor to maternal and perinatal morbidity and mortality globally. Despite international and national guidelines for its screening and treatment, knowledge and prescription practices of healthcare providers vary.

AIM

To determine maternal healthcare workers' screening and treatment practices for iron deficiency in anaemic pregnancy women in two states in Nigeria.

METHODOLOGY

This cross-sectional study sampled maternal healthcare workers from 84 randomly selected public health facilities in Lagos and Kano States. Data on methods of diagnosis and prescription practices for iron deficiency anaemia were collected using a self-administered questionnaire. Means and percentages were reported using probability weights, and a comparison of practices of anaemia treatment between doctors and nurses/midwives was done using Chi-square test or Fishers exact.

RESULTS

Of the 467 maternal healthcare workers surveyed (232 from Lagos, 235 from Kano), 40.0% were doctors, 54.0% nurses or midwives and 6.0% community health extension workers. In the sample, 27.6% always and 58.7% sometimes screened anaemic pregnant women for iron deficiency; among these, 84.7% screened using complete blood count. Oral iron for treatment of iron deficiency anaemia was prescribed by 96.9%. Intravenous iron for treatment was prescribed by 30.2%, but by only by 18.6% as first-line drug (as iron dextran by 69.3% and as iron sucrose by 31.5% of intravenous iron prescribers). Commonest reasons for low usage of intravenous iron were cost and need for venepuncture. Fifty-three percent of maternal healthcare workers' prescribed iron supplements for anaemia during concomitant infection, with the prescription practice similar among doctors versus nurse/midwives (p = 0.074).

CONCLUSION

We found suboptimal levels of screening for iron deficiency among anaemic pregnant women. Iron deficiency anaemia in pregnancy is almost exclusively treated with oral iron by maternal healthcare workers in the two Nigerian states, similarly between doctors and nurses/midwives. Further research into potential reasons for low screening for iron deficiency and low use of intravenous iron are needed.

Metals at the Host-Fungal Pathogen Battleground

Fungal infections continue to represent a major threat to public health, particularly with the emergence of multidrug-resistant fungal pathogens. As part of the innate immune response, the host modulates the availability of metals as armament against pathogenic microbes, including fungi. The transition metals Fe, Cu, Zn, and Mn are essential micronutrients for all life forms, but when present in excess, these same metals are potent toxins. The host exploits the double-edged sword of these metals, and will either withhold metal micronutrients from pathogenic fungi or attack them with toxic doses. In response to these attacks, fungal pathogens cleverly adapt by modulating metal transport, metal storage, and usage of metals as cofactors for enzymes. Here we review the current state of understanding on Fe, Cu, Zn, and Mn at the host-fungal pathogen battleground and provide perspectives for future research, including a hope for new antifungals based on metals.

Human and environmental risk assessment and plausible sources of toxic heavy metals at beach placers in southeast Sri Lanka

Beach placers are typically rich in heavy minerals, which are crucial for a wide range of industrial applications. This study investigates the human and environmental risks posed by toxic heavy metals (As, Pb, Zn, Cu, Cr, Fe, V and Mn) in beach placers of southeastern Sri Lanka using 42 X-ray fluorescence data. Risk indicators (EF, Igeo, CF and PLI) indicate the polluted nature of the placers. Correlation analysis (correlation matrix and HCA) identified pollution sources as heavy mineral-rich rocks, agricultural fertilizers, pesticides and municipal wastes. The environmental impact caused by toxic metals is less in placers. The highest non-carcinogenic risks (HI) resulted by Cr (1.69E+00), V (4.29E+00) and Fe (2.06E+00) to children. The total cancer risk of As and Cr in placers is unacceptable (children: 2.60E-04, 2.48E-03, and adults: 3.14E-05, 2.87E-04, respectively). Different strategies are introduced to mitigate the identified risks in source areas and the coastal environment.

Epidemiological and transcriptome data identify association between iron overload and metabolic dysfunction-associated steatotic liver disease and hepatic fibrosis

The primary objective of this study was to examine the association between iron overload (IO), metabolic dysfunction-associated steatotic liver disease (MASLD), and hepatic fibrosis. We hypothesized that there is a significant association. Data from the NHANES (2017-2020) were analyzed to explore IO's impact on MASLD and hepatic fibrosis in U.S. adults. We assessed serum ferritin, controlled attenuation parameter (CAP), liver stiffness measurement (LSM), and various covariates. Gene expression data were sourced from the FerrDb V2 and GEO databases. Differential gene expression analysis, Protein-Protein Interaction (PPI) Network construction, and Gene Ontology (GO) and KEGG pathway enrichment analyses were performed. The study verified the link between MASLD, hepatic fibrosis, and iron overload hub genes. This study of 5927 participants, averaging 46.78 years of age, revealed significant correlations between serum ferritin and CAP, LSM, after adjusting for covariates. Threshold effect analysis indicated nonlinear associations between serum ferritin and CAP, LSM, with distinct patterns observed by age and gender. Moreover, the area under the ROC curve for serum ferritin with MASLD and hepatic fibrosis was 0.8272 and 0.8376, respectively, demonstrating its performance in assessing these conditions. Additionally, molecular analyses identified potential hub genes associated with iron overload and MASLD, and hepatic fibrosis, revealing the underlying mechanisms. Our study findings reveal an association between iron overload, MASLD, and hepatic fibrosis. Additionally, the hub genes may be implicated in iron overload and subsequently contribute to the progression of MASLD and hepatic fibrosis. These findings support precision nutrition strategies.

Inhibin subunit beta B (INHBB): an emerging role in tumor progression

The gene inhibin subunit beta B (INHBB) encodes the inhibin βB subunit, which is involved in forming protein members of the transforming growth factor-β (TGF-β) superfamily. The TGF-β superfamily is extensively involved in cell proliferation, differentiation, adhesion, movement, metabolism, communication, and death. Activins and inhibins, which belong to the TGF-β superfamily, were first discovered in ovarian follicular fluid. They were initially described as regulators of pituitary follicle-stimulating hormone (FSH) secretion both in vivo and in vitro. Later studies found that INHBB is expressed not only in reproductive organs such as the ovary, uterus, and testis but also in numerous other organs, including the brain, spinal cord, liver, kidneys, and adrenal glands. This wide distribution implies its involvement in the normal physiological functions of various organs; however, the mechanisms underlying these functions have not yet been fully elucidated. Recent studies suggest that INHBB plays a significant, yet complex role in tumorigenesis. It appears to have dual effects, promoting tumor progression in some contexts while inhibiting it in others, although these roles are not yet fully understood. In this paper, we review the different expression patterns, functions, and mechanisms of INHBB in normal and tumor tissues to illustrate the research prospects of INHBB in tumor progression.

Unraveling the full impact of SPD_0739: a key effector in S. pneumoniae iron homeostasis

Streptococcus pneumoniae is a common member of the nasopharynx commensal microflora and the leading etiological agent of bacterial pneumonia in young children and aging adults. SPD_0739, a highly expressed lipoprotein, is the predicted substrate-binding component of an ABC transporter linked to the uptake of nucleosides and heme by independent studies (named PnrA or Spbhp-37, respectively). Here, we demonstrate that SPD_0739 binds heme in vitro and contributes to the bacterial binding to hemoglobin. A ∆spd_0739 strain exhibited growth attenuation that was relieved by the inactivation of the piuBCDA transporter. Knocking out spd_0739 in the wild type, or the ΔpiuBCDA strain resulted in heme accumulation, higher sensitivity to heme toxicity, and a small growth reduction compared to medium supplemented with a nucleoside mixture. In addition, spd_0739 loss results in higher iron- and heme-related gene expression and lower H2O2 production. Altogether, the data are consistent with a role in nucleoside import and show that SPD_0739 does not import heme. Instead, it indirectly influences iron and heme metabolism, linking nucleosides and iron status in S. pneumoniae.

IMPORTANCE

S. pneumoniae obtains growth essential iron from hemoglobin and other host hemoproteins. Still, the bacterial mechanisms involved are only partially understood, and there are inconsistent reports regarding the function of several transporters implicated in iron uptake. In this study, we clarified the role of PnrA/Spbhp-37, a ligand-binding protein previously linked to nucleoside or heme by different studies. We present data supporting a role in nucleoside scavenging rather than heme import and reveal that PnrA/Spbhp-37 modulates iron and heme uptake, likely by influencing the nucleoside cellular pool. Hence, this work provides a new understanding of a process critical to the pathophysiology of a significant human pathogen. Moreover, PnrA/Spbhp-37 is an abundant and immunogenic surface protein that is highly conserved. Hence, this study also clarifies the function of a promising vaccine target.

The role of genetically predicted serum iron levels on neurodegenerative and cardiovascular traits

Iron is an essential mineral that supports numerous biological functions. Studies have reported associations between iron dysregulation and certain cardiovascular and neurodegenerative diseases, but the direction of influence is not clear. Our goal was to use computational approaches to better understand the role of genetically predicted iron levels on disease risk. We meta-analyzed genome-wide association study summary statistics for serum iron levels from two cohorts and two previous meta-analyses. We then obtained summary statistics from 11 neurodegenerative, cerebrovascular, cardiovascular or lipid traits to assess global and regional genetic correlation between iron levels and these traits. We used two-sample Mendelian randomization (MR) to estimate causal effects. Sex-stratified analyses were also carried out to identify effects potentially differing by sex. Overall, we identified three significant global correlations between iron levels and (i) coronary heart disease, (ii) triglycerides, and (iii) high-density lipoprotein (HDL) cholesterol levels. A total of 194 genomic regions had significant (after correction for multiple testing) local correlations between iron levels and the 11 tested traits. MR analysis revealed two potential causal relationships, between genetically predicted iron levels and (i) total cholesterol or (ii) non-HDL cholesterol. Sex-stratified analyses suggested a potential protective effect of iron levels on Parkinson's disease risk in females, but not in males. Our results will contribute to a better understanding of the genetic basis underlying iron in cardiovascular and neurological health in aging, and to the eventual identification of new preventive interventions or therapeutic avenues for diseases which affect women and men worldwide.

Decrease in Hemoglobin Levels during Acute Attacks in Patients with Idiopathic Recurrent Pericarditis: A Model of Anemia in Acute Disease

Background/Objectives: Anemia during acute inflammation is not well described in the literature. We aimed to study whether patients develop a transient hemoglobin decrease during an acute attack of recurrent pericarditis. Methods: We retrospectively analyzed patients with recurrent pericarditis. The primary endpoint was the difference in hemoglobin levels during an acute attack and in the following remission. As secondary endpoints, we correlated this variation with laboratory and clinical features; we also evaluated the available baseline hemoglobin values. Results: Sixty-two patients, including thirty females (48.4%), with a median age of 39 years, were observed during an acute attack and remission. The attack indexed was the first in 21 patients and the second or the third in 41, with pre-attack hemoglobin levels available for the latter group. Median hemoglobin levels (IQR) were 13.8 (12.8-15.1) g/dL at baseline, 12.0 (11.2-13.4) during attacks and 13.6 (13.1-14.0) during remission (p < 0.001). The median hemoglobin reduction between an acute attack and remission was 1.4 g/dL. Their mean corpuscular volume remained in the normal range. Hb reduction significantly correlated with C-reactive protein (CRP) elevation, neutrophilia and the neutrophil-to-lymphocyte ratio, but not serosal involvement. Only CRP elevation remained associated with the variation of Hb in a multivariate analysis (p = 0.007). Conclusions: This study is a proof of concept: hemoglobin levels may decline rapidly during acute inflammation in correlation with CRP elevation, with transient normocytic anemia, followed by a rapid rebound. In this regard, idiopathic pericarditis may represent a pathogenetic model of this type of anemia.

Ferritin and Iron Levels Inversely Associated With Lymphoma Risk: A Mendelian Randomization Study

Background

Current knowledge on iron's role in lymphoma development is very limited, with studies yielding inconsistent findings. To address this gap, we conducted a rigorous two-sample mendelian randomization study, aiming to elucidate the potential associations between iron storage and the risk of developing lymphoma.

Methods

This study leveraged extensive genetic data derived from a comprehensive genome-wide association study (GWAS) comprising 257,953 individuals. The primary objective was to pinpoint single-nucleotide polymorphisms (SNPs) that are significantly associated with iron storage. Subsequently, this genetic information was analyzed in conjunction with summary-level data pertaining to lymphoma cases and controls, sourced from the IEU open GWAS project, which included a sample size of 3,546 lymphoma cases and 487,257 controls. To evaluate the relationship between iron storage and lymphoma risk, an inverse variance-weighted method with random effects was employed, complemented by rigorous sensitivity analyses.

Results

Genetic predisposition to high ferritin and serum iron status was causally associated with lower odds of lymphoma. Ferritin exhibited an odds ratio (OR) of 0.777 (95% confidence interval (CI): 0.628 - 0.961, P = 0.020), indicating 22.3% reduced odds of lymphoma associated with a one standard deviation increase in ferritin levels. Similarly, serum iron demonstrated an OR of 0.776 (95% CI: 0.609 - 0.989, P = 0.040), corresponding to 22.4% decreased odds of lymphoma for a one standard deviation increase in serum iron.

Conclusions

This study suggests that individuals with genes linked to higher iron storage levels have a lower risk of developing lymphoma, but further research is necessary before making any clinical recommendations.

Iron Level in Pregnant Rats is Associated with Caries Susceptibility in Offsprings

Iron deficiency anemia (IDA) is a prevalent issue in pregnant women and children. However, the causal relationship between IDA in pregnancy and caries susceptivity in offspring remains unclear. This study aimed to explore the role of iron level during pregnancy on caries susceptivity of offsprings. Here, low-iron (LI) and high-iron (HI) models were established in maternal rats, and iron-related characteristics were examined in maternal rats and their offsprings. After induction of caries in rat offsprings, the carious lesions were evaluated by the Keyes scores, and microstructural damages in molars were observed by scanning electron microscopy. The results showed that LI in maternal rats induced IDA in rat offsprings, and HI only increased serum ferritin in offsprings. LI and HI in maternal rats had no effect on the morphological structure of salivary glands in rat offsprings. After inducing caries, rat offsprings in the LI group exhibited significant increase in enamel lesions at the smooth surface, and on enamel, slight dentinal, and moderate dentinal lesions at the sulcal surface. Only enamel lesions at the sulcal surface were significantly weakened in the HI group. Additionally, visible enamel damages were observed in the LI group. To sum up, iron deficiency during pregnancy enhances caries susceptibility in rat offsprings.

Formulation of complementary flours from pretreated pumpkin pulp, soybeans and spinach leaves: Nutritional, functional and sensory characterization

One of the major causes of the high prevalence of young children suffering from malnutrition in developed countries is inadequate complementary feeding practices, and especially the low quality of homemade complementary foods. The present study aimed to use available local plant foods to formulate a complementary flour Which can be able to meet energy and nutrients requirements of children aged from 6 to 23 months. To achieve this goal, pumpkin was fermented, soybean soaked and roasted, and spinach steamed. The pre-treated ingredients were ground to obtain individual flours, which were blended in various proportions to obtain four complementary flours (PSS1, PSS2, PSS3, PSS4). The proximate and micronutrient composition, and the energy value of the blends were determined, and based on the results, two of them, that is; (PSS1 [Pumpkin 70 %/Soybean 25 %/Spinach 5 %], and PSS2 [Pumpkin 65 %/Soybean 25 %/Spinach 10 %]) were selected to pursue the Study. The functional properties (water absorption capacity, water solubility index, bulk density) and pasting properties of these two flours were then evaluated. Gruels were prepared from the flours and their energy densities, physical as well as sensory properties were evaluated. Moisture, ash, protein, fat, and sugar contents of PSS1 and PSS2 met the FAO/WHO standards. Fiber content in both flours was higher than the recommendation. Vitamin A and iron were sufficient in PSS2, while PSS1 had low iron content. Calcium, phosphorus, and magnesium content of PSS1 and PSS2 were significantly higher than the standards. PSS1 and PSS2 had good water absorption capacity and solubility index, with low viscosity values (213 and 173 cP respectively), interesting functional properties for complementary flours. The gruels prepared with PSS1 and PSS2 flours had good fluidity and energy densities. They were fairly appreciated based on their organoleptic characteristics, with scores of 5.96 and 5.75 for overall acceptability. PSS2 could be recommended as infant flour rich in iron, vitamin A, and protein, with good nutritional values and functional properties.

Whole genome sequence analysis reveals high genomic diversity and potential host-driven adaptations among multidrug-resistant Escherichia coli from pre-weaned dairy calves

Food-producing animals such as dairy cattle are potential reservoirs of antimicrobial resistance (AMR), with multidrug-resistant (MDR) organisms such as Escherichia coli observed in higher frequency in young calves compared to older cattle. In this study, we characterized the genomes of enteric MDR E. coli from pre-weaned dairy calves with and without diarrhea and evaluated the influence of host-level factors on genomic composition. Whole genome sequence comparative analysis of E. coli (n = 43) revealed substantial genomic diversity that primarily clustered by sequence type and was minimally driven by calf diarrheal disease status (healthy, diarrheic, or recovered), antimicrobial exposure, and dietary zinc supplementation. Diverse AMR genes (ARGs)-including extended-spectrum beta-lactamase genes and quinolone resistance determinants-were identified (n = 40), with unique sets of ARGs co-occurring in gene clusters with large AMR plasmids IncA/C2 and IncFIB(AP001918). Zinc supplementation was not significantly associated with the selection of individual ARGs in E. coli, however analysis of ARG and metal resistance gene pairs identified positive associations between certain aminoglycoside, beta-lactam, sulfonamide, and trimethoprim ARGs with acid, tellurium and mercury resistance genes. Although E. coli in this study lacked the typical virulence factors of diarrheagenic strains, virulence genes overlapping with those in major pathotypes were identified. Among the 103 virulence genes detected, the highest abundance and diversity of genes corresponded to iron acquisition (siderophores and heme uptake). Our findings indicate that the host-level factors evaluated in this study were not key drivers of genomic variability, but that certain accessory genes in enteric MDR E. coli may be enriched. Collectively, this work provides insight into the genomic diversity and host-microbe interface of MDR E. coli from pre-weaned dairy calves.

Metabolic regulation of the host-fungus interaction: from biological principles to therapeutic opportunities

Fungal infections present a significant global public health concern, impacting over 1 billion individuals worldwide and resulting in more than 3 million deaths annually. Despite considerable progress in recent years, the management of fungal infections remains challenging. The limited development of novel diagnostic and therapeutic approaches is largely attributed to our incomplete understanding of the pathogenetic mechanisms involved in these diseases. Recent research has highlighted the pivotal role of cellular metabolism in regulating the interaction between fungi and their hosts. In response to fungal infection, immune cells undergo complex metabolic adjustments to meet the energy demands necessary for an effective immune response. A comprehensive understanding of the metabolic circuits governing antifungal immunity, combined with the integration of individual host traits, holds the potential to inform novel medical interventions for fungal infections. This review explores recent insights into the immunometabolic regulation of host-fungal interactions and the infection outcome and discusses how the metabolic repurposing of immune cell function could be exploited in innovative and personalized therapeutic approaches.

The Metabolic Potential of the Human Lung Microbiome

The human lung microbiome remains largely underexplored, despite its potential implications in the pharmacokinetics of inhaled drugs and its involvement in lung diseases. Interactions within these bacterial communities and with the host are complex processes which often involve microbial small molecules. In this study, we employed a computational approach to describe the metabolic potential of the human lung microbiome. By utilizing antiSMASH and BiG-SCAPE software, we identified 1831 biosynthetic gene clusters for the production of specialized metabolites in a carefully compiled genome database of lung-associated bacteria and fungi. It was shown that RiPPs represent the largest class of natural products within the bacteriome, while NRPs constitute the largest class of natural products in the lung mycobiome. All predicted BGCs were further categorized into 767 gene cluster families, and a subsequent network analysis highlighted that these families are widely distributed and contain many uncharacterized members. Moreover, in-depth annotation allowed the assignment of certain gene clusters to putative lung-specific functions within the microbiome, such as osmoadaptation or surfactant synthesis. This study establishes the lung microbiome as a prolific source for secondary metabolites and lays the groundwork for detailed investigation of this unique environment.

Harnessing the Power of a Novel Triple Chelate Complex in Fermented Probiotic Dairy Products: A Promising Solution for Combating Iron Deficiency Anemia

This study discovered and examined novel triple chelate complexes involving iron, ascorbic acid, and essential amino acids (AsA-Fe-AmA triple chelate complexes) for the first time. The mechanism of complex formation was studied using FTIR spectroscopy and quantum chemical modeling. The produced complexes were shown to be suitable for fortifying food items with a pH of 3-7 that have not been exposed to heat treatment at temperatures over 75 °C for more than 15 min. Thus, it can be said that the concentration for milk fortification should be 0.005 mol/L or less. In vivo experiments in rats models revealed that the synthesized complexes increased serum iron levels after a single application to reference values within 24 h of oral administration. The iron level increased by 14.0 mmol/L at 2 mL dose of the complex. This fact makes it possible to consider the use of developed complexes and developed fermented dairy products for the prevention of iron deficiency and iron deficiency anemia. Research on the effect of discovered compounds on the physicochemical and organoleptic qualities of milk was conducted. Furthermore, iron ascorbate threoninate, iron ascorbate methioninate, iron ascorbate lysinate, and iron ascorbate tryptophanate all had a beneficial effect on Lacticaseibacillus rhamnosus at concentrations as low as 0.0005 mol/L, which is significant for milk fermentation. A study of fermented milk products revealed that the most effective AsA-Fe-AmA triple chelate complex is iron ascorbate lysinate, which might be further investigated as a viable molecule for dietary fortification in iron deficiency anemia. It was found that fortified fermented milk products had a titratable acidity of 67 ± 1°T, pH of 4.38 ± 0.05, and a viscosity of 2018 ± 142 Pa·s.

Advances in understanding immune homeostasis in latent tuberculosis infection

Nearly one-fourth of the global population is infected by Mycobacterium tuberculosis (Mtb), and approximately 90%-95% remain asymptomatic as latent tuberculosis infection (LTBI), an estimated 5%-10% of those with latent infections will eventually progress to active tuberculosis (ATB). Although it is widely accepted that LTBI transitioning to ATB results from a disruption of host immune balance and a weakening of protective immune responses, the exact underlying immunological mechanisms that promote this conversion are not well characterized. Thus, it is difficult to accurately predict tuberculosis (TB) progression in advance, leaving the LTBI population as a significant threat to TB prevention and control. This article systematically explores three aspects related to the immunoregulatory mechanisms and translational research about LTBI: (1) the distinct immunocytological characteristics of LTBI and ATB, (2) LTBI diagnostic markers discovery related to host anti-TB immunity and metabolic pathways, and (3) vaccine development focus on LTBI. This article is categorized under: Infectious Diseases > Molecular and Cellular Physiology Infectious Diseases > Genetics/Genomics/Epigenetics Immune System Diseases > Genetics/Genomics/Epigenetics.

The Hydroxypyridinone Iron Chelator DIBI Reduces Bacterial Load and Inflammation in Experimental Lung Infection

Iron plays a critical role in lung infections due to its function in the inflammatory immune response but also as an important factor for bacterial growth. Iron chelation represents a potential therapeutic approach to inhibit bacterial growth and pathologically increased pro-inflammatory mediator production. The present study was designed to investigate the impact of the iron chelator DIBI in murine lung infection induced by intratracheal Pseudomonas aeruginosa (strain PA14) administration. DIBI is a polymer with a polyvinylpyrrolidone backbone containing nine 3-hydroxy-1-(methacrylamidoethyl)-2-methyl-4(1H) pyridinone (MAHMP) residues per molecule and was given by intraperitoneal injection either as a single dose (80 mg/kg) immediately after PA14 administration or a double dose (second dose 4 h after PA14 administration). The results showed that lung NF-κBp65 levels, as well as levels of various inflammatory cytokines (TNFα, IL-1β, IL-6) both in lung tissue and bronchoalveolar lavage fluid (BALF), were significantly increased 24 h after PA14 administration. Single-dose DIBI did not affect the bacterial load or inflammatory response in the lungs or BALF. However, two doses of DIBI significantly decreased bacterial load, attenuated NF-κBp65 upregulation, reduced inflammatory cytokines production, and relieved lung tissue damage. Our findings support the conclusion that the iron chelator, DIBI, can reduce lung injury induced by P. aeruginosa, via its anti-bacterial and anti-inflammatory effects.

Mild Systemic Inflammation Increases Erythrocyte Fragility

There is growing evidence that inflammation impairs erythrocyte structure and function. We assessed the impact of mild systemic inflammation on erythrocyte fragility in three different settings. In order to investigate causation, erythrocyte osmotic fragility was measured in mice challenged with a live attenuated bacterial strain to induce low-grade systemic inflammation; a significant increase in erythrocyte osmotic fragility was observed. To gather evidence that systemic inflammation is associated with erythrocyte fragility in humans, two observational studies were conducted. First, using a retrospective study design, the relationship between reticulocyte-based surrogate markers of haemolysis and high-sensitivity C-reactive protein was investigated in 9292 healthy participants of the UK Biobank project. Secondly, we prospectively assessed the relationship between systemic inflammation (measured by the urinary neopterin/creatinine ratio) and erythrocyte osmotic fragility in a mixed population (n = 54) of healthy volunteers and individuals with long-term medical conditions. Both human studies were in keeping with a relationship between inflammation and erythrocyte fragility. Taken together, we conclude that mild systemic inflammation increases erythrocyte fragility and may contribute to haemolysis. Further research is needed to assess the molecular underpinnings of this pathway and the clinical implications in inflammatory conditions.

Crucial Roles of RSAD2/viperin in Immunomodulation, Mitochondrial Metabolism and Autoimmune Diseases

Autoimmune diseases are typically characterized by aberrant activation of immune system that leads to excessive inflammatory reactions and tissue damage. Nevertheless, precise targeted and efficient therapies are limited. Thus, studies into novel therapeutic targets for the management of autoimmune diseases are urgently needed. Radical S-adenosyl methionine domain-containing 2 (RSAD2) is an interferon-stimulated gene (ISG) renowned for the antiviral properties of the protein it encodes, named viperin. An increasing number of studies have underscored the new roles of RSAD2/viperin in immunomodulation and mitochondrial metabolism. Previous studies have shown that there is a complex interplay between RSAD2/vipeirn and mitochondria and that binding of the iron-sulfur (Fe-S) cluster is necessary for the involvement of viperin in mitochondrial metabolism. Viperin influences the proliferation and development of immune cells as well as inflammation via different signaling pathways. However, the function of RSAD2/viperin varies in different studies and a comprehensive overview of this emerging theme is lacking. This review will describe the characteristics of RSAD2/viperin, decipher its function in immunometabolic processes, and clarify the crosstalk between RSAD2/viperin and mitochondria. Furthermore, we emphasize the crucial roles of RSAD2 in autoimmune diseases and its potential application value.

MALDI-mass spectrometry imaging as a new technique for detecting non-heme iron in peripheral tissues via caudal vein injection of deferoxamine

As one of the most common iron-chelating agents, deferoxamine (DFO) rapidly chelates iron in the body. Moreover, it does not compete for the iron characteristic of hemoglobin in the blood cells, which is common in the clinical treatment of iron poisoning. Iron is a trace element necessary to maintain organism normal life activities. Iron deficiency can lead to anemia, whereas iron overload can cause elevated levels of cellular oxidative stress and cell damage. As a consequence, detection of the iron content in tissues and blood is of great significance. The traditional techniques for detecting the iron content include inductively coupled plasma-mass spectrometry and atomic absorption spectrometry, which cannot be used for imaging purposes. Laser ablation-ICP-MS and synchrotron radiation micro-X-ray fluorescence can map the concentration and distribution of iron in tissues. However, these methods can only be used to measure the total iron levels in blood or tissues. In recent years, due to the deepening understanding of iron metabolism, diseases related to iron overload have attracted increasing attention. Therefore, we took advantage of the properties of DFO in terms of chelating iron and investigated different sampling times following DFO injection in the tail vein of mice. We used mass spectrometry imaging (MSI) technology to detect the DFO and ferrioxamine content in the blood and different tissues to indirectly characterize the non-heme iron content.

Low-density lipoprotein cholesterol, erythrocyte, and platelet in heart failure with preserved ejection fraction

AIMS

Low-density lipoprotein cholesterol (LDL-C), anaemia and low platelets have been associated with worse clinical outcomes in heart failure patients. We investigated the relationship between the combination of these three components and clinical outcome in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

We examined the data of 1021 patients with HFpEF hospitalized with acute decompensated heart failure (HF) from the PURSUIT-HFpEF registry, a prospective, multicenter observational study. The enrolled patients were classified into four groups by an LEP (LDL-C, Erythrocyte, and Platelet) score of 0 to 3 points, with 1 point each for LDL-C, erythrocyte and platelet values less than the cut-off values as calculated by receiver operating characteristic curve analysis. The endpoint, a composite of all-cause death and HF readmission, was evaluated among the four groups. Median follow-up duration was 579 [300, 978] days. Risk of the composite endpoint significantly differed among the four groups (P < 0.001). Kaplan-Meier analysis showed that the groups with an LEP score of 2 had higher risk of the composite endpoint than those with an LEP score of 0 or 1 (P < 0.001, and P = 0.013, respectively), while those with an LEP score of 3 had higher risk than those with an LEP score of 0, 1 or 2 (P < 0.001, P < 0.001 and P = 0.020, respectively). Cox proportional hazards analysis showed that an LEP score of 3 was significantly associated with the composite endpoint (P = 0.030). Kaplan-Meier analysis showed that risk of the composite of all-cause death and HF readmission was significantly higher in low LDL values (less than the cut-off values as calculated by receiver operating characteristic curve analysis) patients with statin use than in those without statin use (log rank P = 0.002).

CONCLUSIONS

LEP score, which comprehensively reflects extra-cardiac co-morbidities, is significantly associated with clinical outcomes in HFpEF patients.

The cytosolic form of dual localized BolA family protein Bol3 is important for adaptation to iron starvation in Aspergillus fumigatus

Aspergillus fumigatus is the predominant mould pathogen for humans. Adaption to host-imposed iron limitation has previously been demonstrated to be essential for its virulence. [2Fe-2S] clusters are crucial as cofactors of several metabolic pathways and mediate cytosolic/nuclear iron sensing in fungi including A. fumigatus. [2Fe-2S] cluster trafficking has been shown to involve BolA family proteins in both mitochondria and the cytosol/nucleus. Interestingly, both A. fumigatus homologues, termed Bol1 and Bol3, possess mitochondrial targeting sequences, suggesting the lack of cytosolic/nuclear versions. Here, we show by the combination of mutational, proteomic and fluorescence microscopic analyses that expression of the Bol3 encoding gene leads to dual localization of gene products to mitochondria and the cytosol/nucleus via alternative translation initiation downstream of the mitochondrial targeting sequence, which appears to be highly conserved in various Aspergillus species. Lack of either mitochondrial Bol1 or Bol3 was phenotypically inconspicuous while lack of cytosolic/nuclear Bol3 impaired growth during iron limitation but not iron sensing which indicates a particular importance of [2Fe-2S] cluster trafficking during iron limitation. Remarkably, cytosolic/nuclear Bol3 differs from the mitochondrial version only by N-terminal acetylation, a finding that was only possible by mutational hypothesis testing.

LLL 44-1 Micronutrients in clinical nutrition: Trace elements

BACKGROUND

Trace elements are an essential component of metabolism and medical nutrition therapy, with key roles in metabolic pathways, antioxidation, and immunity, which the present course aims at summarizing.

RESULTS

Medical nutrition therapy includes the provision of all essential trace elements. The clinical essential issues are summarized for Copper, Iron, Selenium, Zinc, Iodine, Chromium, Molybdenum, and Manganese: the optimal analytical techniques are presented. The delivery of all these elements occurs nearly automatically when the patient is fed with enteral nutrition, but always requires separate prescription in case of parenteral nutrition. Isolated deficiencies may occur, and some patients have increased requirements, therefore a regular monitoring is required. The clinicians should always consider the impact of inflammation on blood levels, mostly lowering them even in absence of deficiency.

CONCLUSION

This text summarises the most relevant clinical manifestations of trace element depletion and deficiency, the difficulties in assessing status, and makes practical recommendations for provision for enteral and parenteral nutrition.

Systematic identification and functional characterization of the CFEM proteins in fishscale bamboo rhombic-spot pathogen Neostagonosporella sichuanensis

Fungal effectors play a crucial role in the interaction between pathogenic fungi and their hosts. These interactions directly influence the invasion and spread of pathogens, and the development of diseases. Common in fungal extracellular membrane (CFEM) effectors are closely associated with the pathogenicity, cell wall stability, and pathogenic processes of pathogenic fungi. The aim of this study was to investigate the role of CFEM proteins in Neostagonosporella sichuanensis in pathogen-host interactions. We retrieved 19 proteins containing CFEM structural domains from the genome of N. sichuanensis. By systematic analysis, five NsCFEM proteins had signal peptides but lacked transmembrane structural domains, and thus were considered as potential effectors. Among them, NsCFEM1 and NsCFEM2 were successfully cloned and their functions were further investigated. The validation results show that NsCFEM1 was localized in the cell membrane and nucleus, whereas NsCFEM2 was exclusively observed in the cell membrane. Both were identified as secreted proteins. Additionally, NsCFEM1 inhibited Bax-induced programmed cell death in Nicotiana benthamiana, whereas NsCFEM2 did not induce or inhibit this response. NsCFEM1 was implicated as a virulence factor that contributes to fungal growth, development, stress response, and pathogenicity. NsCFEM2 was implicated in maintenance of cell wall stability. This study lays a foundation for elucidating the role of CFEM proteins in the pathogen of fishscale bamboo rhombic-spot caused by N. sichuanensis. In particular, the functional studies of NsCFEM1 and NsCFEM2 revealed their potential roles in the interaction between N. sichuanensis and the host Phyllostachys heteroclada.

Anemia in Dogs with Acute Kidney Injury

Anemia is a well-known complication in CKD dogs, but its frequency in AKI dogs has been poorly investigated. The aim of the present study was to retrospectively evaluate frequency, degree of severity, and regeneration rate of anemia in relation to IRIS grade, etiology, therapy, and outcome. Medical records of dogs (2017-2023) with historical, laboratory, and ultrasound findings consistent with AKI were retrospectively reviewed. According to etiology, AKI was classified as ischemic/inflammatory (IS), infectious (INF), nephrotoxic (NEP), obstructive (OBS), and unknown (UK). AKI dogs were also classified according to therapeutical management (medical vs. hemodialysis), survival to discharge (survivors vs. non-survivors). Anemia was defined as HCT < 37% and classified as mild (HCT 30-37%), moderate (HCT 20-29%), severe (13-19%), or very severe (<13%). Anemia was classified as microcytic (MCV < 61 fL), normocytic (61 and 73 fL), and macrocytic (>73 fL). Anemia was considered hypochromic (MCHC< 32 g/dL), normochromic (32 and 38 g/dL), and hyperchromic (>38 g/dL). Regeneration rate was considered absent (RET ≤ 60,000/μL), mild 61,000-150,000/μL), and moderate (>150,000/μL). A total of 120 AKI dogs were included in the study, and anemia was found in 86/120 dogs (72%). The severity of anemia was mild in 32/86 dogs (37%), moderate in 40/86 dogs (47%), severe in 11/86 dogs (13%), and very severe in 3/86 (3%). Anemia was normochromic in 71/86 dogs (83%), hyperchromic in 12/86 dogs (14%), and hypochromic in 3/86 dogs (3%). Normocytic anemia was present in 56/86 dogs (65%), microcytic anemia in 27/86 dogs (31%), and macrocytic anemia in 3/86 dogs (4%). Non-regenerative anemia was found in 76/86 dogs (88%). The frequency of anemia increased significantly (p < 0.0001) with the progression of IRIS grade, although no significant difference in the severity of anemia was found among the IRIS grades. The frequency of non-regenerative forms of anemia was significantly higher than regenerative forms (p < 0.0001) in all IRIS grades. In our population of AKI dogs, anemia was a very frequent finding, in agreement with current findings in human nephrology.

Association of the systemic immune-inflammation index with anemia: a population-based study

Background

Inflammation has been reported to be related to anemia. As a novel inflammatory marker, Systemic immune-inflammation index (SII) has not been studied with Anemia. The aim of this study was to investigate the possible relationship between SII and anemia.

Methods

This retrospective cross-sectional survey was conducted using data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) population. In total, 19851 American adults aged ≥18 years were included. SII was calculated as the platelet count×neutrophil count/lymphocyte count. Anemia was defined as hemoglobin (Hgb) levels of < 13 g/dL in males and < 12 g/dL in females. Logistic regression analyses, subgroup analyses and sensitivity analyses were performed to investigate the relationship between SII and anemia.

Results

Our study included a total of 19851 patients, of which 1501 (7.6%) had anemia. After adjusting for all covariates, the multivariate logistic regression analysis showed that a higher SII (In-transform) level was associated with increased likelihood of anemia (OR=1.51, 95% CI: 1.36-1.68, P<0.001). The association between SII and anemia exhibited a nonlinear manner. The positive correlation between SII and anemia was related to the severity of anemia. Subgroup analysis showed that there was no significant dependence on age, family income, body mass index, hypertension, kidney disease and cancer except gender on this positive association. Furthermore, sensitivity analyses confirmed the robustness of our results.

Conclusion

Our study demonstrated that SII was positively associated with anemia especially among female participants. And this positive correlation was related to the severity of anemia. Further large-scale prospective studies are still needed to analyze the role of SII in anemia.