Iron overload induces colitis by modulating ferroptosis and interfering gut microbiota in mice

Iron Status and Risk of Periodontitis and Dental Caries: A Mendelian Randomization Study

BACKGROUND

Previous studies have indicated a potential relationship between iron status and oral health outcomes, specifically periodontitis and dental caries. This study employed Mendelian randomization (MR) to investigate the causal effects of iron status on these oral health conditions. The focus of this study was on key iron biomarkers, namely serum iron, ferritin, transferrin saturation (TSAT), and total iron-binding capacity (TIBC).

METHODS

This two-sample MR analysis employed genome-wide association study (GWAS) data. The instrumental variables (IVs) were selected based on their genome-wide significance and independence from confounders. The statistical analyses employed the inverse variance weighted (IVW) method, MR-Egger regression, weighted median, and weighted mode. Additionally, sensitivity analyses were conducted to verify the reliability of the causal association results.

RESULTS

The MR analysis indicated a suggestive negative causal relationship between TIBC and periodontitis, with an odds ratios of 0.875 and a 95% CI of 0.766-0.998, with a P-value of .047. No significant other associations were found. The results of sensitivity analyses demonstrated the robustness of these findings.

CONCLUSION

This MR study suggested a potential negative association between TIBC and periodontitis, highlighting the importance of considering iron status in the clinical management of chronic periodontitis. However, more standardized, multi-population studies are needed to confirm this causality.

Absence of gut microbiota alleviates iron overload-induced colitis by modulating ferroptosis in mice

INTRODUCTION

Iron overload disrupts gut microbiota and induces ferroptosis, contributing to colitis. However, whether gut microbiota directly drives iron overload-induced colitis and its underlying mechanism remain unclear.

OBJECTIVES

The study aimed to explore whether gut microbiota can directly regulate iron overload-induced colitis and its underling mechanism.

METHODS

Male C57BL/6N mice were fed with ferrous sulfate to establish an iron overload model. Antibiotics and dextran sulfate sodium salt (DSS) were used to create germ-free and colitis models, respectively.

RESULTS

Results showed that iron overload caused disruption of systemic iron homeostasis via activating pro-inflammation response, which caused induction of ferroptosis and eventually resulted in colitis in mice. Notably, iron overload inhibited System Xc- and activated the nuclear factor E2-related factor 2/heme oxygenase-1 pathway, driving ferroptosis and colitis progression. Similar results were observed in mouse colon epithelial cells, which were treated with high doses ferric ammonium citrate. Additionally, iron overload exacerbated DSS-induced colitis by activating the ferroptosis and increasing harmful bacteria (e.g., Mucispirillum) abundance. Interestingly, eliminating gut microbiota attenuated iron overload-induced colitis, without affecting systemic inflammation through inhibiting ferroptosis of mice. Depletion of the gut microbiota partially mitigated the exacerbating effect of iron overload on DSS-induced colitis through inhibiting ferroptosis of mice.

CONCLUSION

Iron overload activates ferroptosis in colonic cells, increases the relative abundance of harmful bacteria, and exacerbates DSS-induced colitis in mice. Iron overload exacerbates DSS-induced ferroptosis and colitis in a microbiota-dependent manner. Targeting gut microbiota may offer new strategies for managing iron overload-induced colitis.

Mulberry leaf benefits the intestinal epithelial barrier via direct anti-oxidation and indirect modulation of microbiota in pigs

BACKGROUND

Diarrhea and intestinal dysfunction commonly occur in young mammals, causing malnutrition and growth retardation in both human and livestock. As the traditional Chinese herb, mulberry leaf contains various bioactive compounds and showed several health benefits, such as regulating glucose and lipid metabolism, and modulating gut microbiota. Mulberry leaf exhibits the potential to modulate redox homeostasis and improve gut health, but the function and underlying mechanisms remains elucidative.

PURPOSE

To investigate the benefit of mulberry leaf on intestinal barrier in weanling pigs, illustrate the possible involvement of Keap1-Nrf2 mediated anti-oxidation and gut microbiota.

METHODS

Chemical compositions of mulberry leaf powder (MLP) and mulberry leaf extract (MLE) were determined. The effects of MLP on growth performance, intestinal barrier integrity, anti-oxidative capacity, immune function and gut microbiota were evaluated in weaned pigs. The regulation of redox homeostasis by MLE and the involvement of Keap1-Nrf2 signaling were further determined in H2O2 induced oxidative stress (OS) model in IPEC-J2 cells via determining reactive oxygen species (ROS) production by flow cytometry and related protein abundance by western blot analysis.

RESULTS

In weanling pigs, MLP reduced diarrhea incidence, and increased villus height, intestinal integrity and expression of tight junctions in intestinal mucosa. The improvement of intestinal barrier by MLP was associated with the enhancement in anti-oxidative capacity and the changes in gut microbiota and related short chain fatty acids production. Our study further revealed the direct regulation of MLE on tight junction expressions and ROS production to alleviate H2O2 induced OS in IPEC-J2 cells via the activating Keap1-Nrf2 signaling pathway.

CONCLUSIONS

Mulberry leaf in diet improved epithelial barrier via the direct anti-oxidation through the activation of Keap1-Nrf2 signaling pathway and the indirect modulation of gut microbiota in weaned pigs.

Gut microbiota in health and disease: advances and future prospects

The gut microbiota plays a critical role in maintaining human health, influencing a wide range of physiological processes, including immune regulation, metabolism, and neurological function. Recent studies have shown that imbalances in gut microbiota composition can contribute to the onset and progression of various diseases, such as metabolic disorders (e.g., obesity and diabetes) and neurodegenerative conditions (e.g., Alzheimer's and Parkinson's). These conditions are often accompanied by chronic inflammation and dysregulated immune responses, which are closely linked to specific forms of cell death, including pyroptosis and ferroptosis. Pathogenic bacteria in the gut can trigger these cell death pathways through toxin release, while probiotics have been found to mitigate these effects by modulating immune responses. Despite these insights, the precise mechanisms through which the gut microbiota influences these diseases remain insufficiently understood. This review consolidates recent findings on the impact of gut microbiota in these immune-mediated and inflammation-associated conditions. It also identifies gaps in current research and explores the potential of advanced technologies, such as organ-on-chip models and the microbiome-gut-organ axis, for deepening our understanding. Emerging tools, including single-bacterium omics and spatial metabolomics, are discussed for their promise in elucidating the microbiota's role in disease development.

Enhanced CRC Growth in Iron-Rich Environment, Facts and Speculations

The contribution of nutritional factors to disease development has been demonstrated for several chronic conditions including obesity, type 2 diabetes, metabolic syndrome, and about 30 percent of cancers. Nutrients include macronutrients and micronutrients, which are required in large and trace quantities, respectively. Macronutrients, which include protein, carbohydrates, and lipids, are mainly involved in energy production and biomolecule synthesis; micronutrients include vitamins and minerals, which are mainly involved in immune functions, enzymatic reactions, blood clotting, and gene transcription. Among the numerous micronutrients potentially involved in disease development, the present review will focus on iron and its relation to tumor development. Recent advances in the understanding of iron-related proteins accumulating in the tumor microenvironment shed light on the pivotal role of iron availability in sustaining pathological tumor hallmarks, including cell cycle regulation, angiogenesis, and metastasis.

Inhibition of DDR1 promotes ferroptosis and overcomes gefitinib resistance in non-small cell lung cancer

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which serves the critical pillar for the treatment of non-small cell lung cancer (NSCLC). However, the acquired resistance remains a challenge for its clinical application, for which, practical strategies to reverse gefitinib resistance in NSCLC are necessary. Ferroptosis, a programmed cell death driven by ferritin-dependent lipid peroxidation, involves in NSCLC progression and related chemoresistance. In our previous work, the self-synthesised EGFR inhibitor Yfq07 (N4, N6-disubstituted pyrimidine-4,6-diamine derivatives) displayed a considerable inhibitory effect on NSCLC both in vitro and in vivo. Herein, we observed that Yfq07 suppressed the proliferation of PC-9GR and HCC827GR cells, two gefitinib resistance NSCLC cell lines. Mechanically, Yfq07 inhibited the phosphorylation of the Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase (RTK) highly expressed in multiple cancers, accompanied by downregulated miR-3648 and upregulated SOCS2. Inhibition or knockdown of DDR1 suppressed the proliferation, migration, and invasion of gefitinib-resistant NSCLC cells, and on the other hand, also downregulated miR-3648 and promoted SOCS2 expression. More specifically, miR-3648 targeted the 3'UTR segment of SOCS2 mRNA and thus affecting the P-ERK signalling pathway to regulate the malignant behaviors of gefitinib-resistant NSCLC cells. Furthermore, Yfq07 also indirectly induced the ferroptosis of gefitinib-resistant NSCLC cells via SOCS2 triggered inhibition of xCT-GPX4 pathway. In conclusion, our study indicates that DDR1 inhibitor Yfq07 promotes ferroptosis and reverses gefitinib-resistance of NSCLC through DDR1-miR-3648-SOCS2 signalling pathway, which provides insights for targeted therapy of gefitinib-resistant NSCLC and drug developments targeting ferroptosis.

Ferroptosis-related oxaliplatin resistance in multiple cancers: Potential roles and therapeutic Implications

Oxaliplatin (OXA)-based therapy is effective in the treatment of multiple cancers. However, primary or acquired OXA resistance remains an emerging challenge for its clinical application. Ferroptosis is an iron-dependent mode of cell death that has been demonstrated to play an essential role in the chemoresistance of many drugs, including OXA. In particular, dysregulation of SLC7A11-GPX4, one of the major antioxidant systems of ferroptosis, was found in the OXA resistance of colorectal cancer (CRC) and hepatocellular carcinoma (HCC). In addition, Nrf2, the upstream regulator of GPX4 and many other antioxidant factors, is also involved in the OXA resistance of CRC and HCC. Inhibition of SLC7A11-GPX4 or Nrf2 by genetic deletion of pharmaceutical inhibition could significantly reverse OXA resistance. Long noncoding RNA (lncRNA) also participates in chemoresistance and ferroptosis of cancer cells. Specifically, LINC01134 promotes the recruitment of Nrf2 to the promoter of GPX4, thereby exerting transcriptional regulation of GPX4, which eventually increases the OXA sensitivity of HCC through upregulation of ferroptosis. On the other hand, a novel lncRNA DACT3-AS1 sensitizes gastric cancer cells to OXA through miR-181a-5p/sirtuin 1(SIRT1)-mediated ferroptosis. Therapies based on ferroptosis or a combination of OXA and ferroptosis enhancers could provide new therapeutic insights to overcome OXA resistance. In the present review, we present the current understanding of ferroptosis-related OXA resistance, highlight ferroptosis pathogenesis in OXA chemoresistance, and summarize available therapies that target OXA resistance by enhancing ferroptosis.

Micronutrient (iron, selenium, vitamin D) supplementation and the gut microbiome

PURPOSE OF REVIEW

Deficiencies in micronutrients persist as widespread global challenges, where supplementation remains a crucial therapeutic approach. This review aims to elucidate the intricate relationships between micronutrient supplementation - specifically iron, selenium (Se), and vitamin D (Vit D) - and gut microbiota composition, investigating their collective impact on host health and disease susceptibility.

RECENT FINDINGS

Maintaining balanced iron levels is essential for gut microbiota equilibrium and host health, as both iron deficiency and excess disrupt gut bacterial balance, affecting colon health. Se supplementation can restore and improve the gut microbial balance, influencing health outcomes not only in the gut but also in areas such as neuroprotection in the brain, testicular health, and metabolic syndrome. Clinical and experimental models demonstrate that Vit D modulates the gut microbiome, enhancing anti-inflammatory effects, supporting metabolic health, and potentially reducing the risk of gut-related behavioral changes and diseases.

SUMMARY

Findings of this review emphasize that balanced iron levels are essential for maintaining a healthy gut microbiota composition and underscore the beneficial effects of Se and Vit D in modulating the gut microbiome. The interactions between micronutrients and the gut microbiome are complex but may have a broad spectrum of health outcomes.

Toxic and essential metals: metabolic interactions with the gut microbiota and health implications

Human exposure to heavy metals, which encompasses both essential and toxic varieties, is widespread. The intestine functions as a critical organ for absorption and metabolism of heavy metals. Gut microbiota plays a crucial role in heavy metal absorption, metabolism, and related processes. Toxic heavy metals (THMs), such as arsenic (As), mercury (Hg), lead (Pb), and cadmium (Cd), can cause damage to multiple organs even at low levels of exposure, and it is crucial to emphasize their potential high toxicity. Nevertheless, certain essential trace elements, including iron (Fe), copper (Cu), and manganese (Mn), play vital roles in the biochemical and physiological functions of organisms at low concentrations but can exert toxic effects on the gut microbiota at higher levels. Some potentially essential micronutrients, such as chromium (Cr), silicon (Si), and nickel (Ni), which were considered to be intermediate in terms of their essentiality and toxicity, had different effects on the gut microbiota and their metabolites. Bidirectional relationships between heavy metals and gut microbiota have been found. Heavy metal exposure disrupts gut microbiota and influences its metabolism and physiological functions, potentially contributing to metabolic and other disorders. Furthermore, gut microbiota influences the absorption and metabolism of heavy metals by serving as a physical barrier against heavy metal absorption and modulating the pH, oxidative balance, and concentrations of detoxification enzymes or proteins involved in heavy metal metabolism. The interactions between heavy metals and gut microbiota might be positive or negative according to different valence states, concentrations, and forms of the same heavy metal. This paper reviews the metabolic interactions of 10 common heavy metals with the gut microbiota and their health implications. This collated information could provide novel insights into the disruption of the intestinal microbiota caused by heavy metals as a potential contributing factor to human diseases.

Ramulus Mori (Sangzhi) Alkaloids Alleviate Diabetic Nephropathy through Improving Gut Microbiota Disorder

Diabetic nephropathy (DN), one of the leading causes of end-stage kidney failure worldwide, is closely associated with high mortality in diabetic patients. However, therapeutic drugs for DN are still lacking. Ramulus Mori alkaloids (SZ-A), an effective component of alkaloids extracted from Ramulus Mori, have been found to improve glucose and lipid metabolism to mitigate diabetes and obesity; however, few studies have focused on their effects on DN progression. Thus, we investigated the protective role of SZ-A on DN through 16S rRNA sequencing, non-targeted metabolomics, and fecal microbiota transplantation (FMT) experiments. To address our hypothesis, we established the DN mouse model by combining a high-fat diet (HFD) with streptozotocin (STZ) injection. Herein, we demonstrated that SZ-A supplementation was recalcitrant to renal injury in DN mice, improving glomerular morphology, reversing the blood biochemistry parameters, and ameliorating podocyte injury. Importantly, the composition of the gut microbiota altered after SZ-A treatment, especially with the elevated abundance of Dubosiella and the increased level of serum pentadecanoic acid. FMT experiments further revealed that the gut microbiota exerted critical effects in mediating the beneficial roles of SZ-A. In vitro experiments proved that pentadecanoic acid administration improved podocyte apoptosis induced by AGEs. Taken together, SZ-A play a renoprotective role, possibly through regulating the gut microbiota and promoting pentadecanoic acid production. Our current study lends support to more extensive clinical applications of SZ-A.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

Ferroptosis: Biology and Role in Gastrointestinal Disease

Ferroptosis is a form of nonapoptotic cell death that involves iron-dependent phospholipid peroxidation induced by accumulation of reactive oxygen species, and results in plasma membrane damage and the release of damage-associated molecular patterns. Ferroptosis has been implicated in aging and immunity, as well as disease states including intestinal and liver conditions and cancer. To date, several ferroptosis-associated genes and pathways have been implicated in liver disease. Although ferroptotic cell death is associated with dysfunction of the intestinal epithelium, the underlying molecular basis is poorly understood. As the mechanisms regulating ferroptosis become further elucidated, there is clear potential to use ferroptosis to achieve therapeutic benefit.

In situ profiling reveals spatially metabolic injury in the initiation of polystyrene nanoplastic-derived intestinal epithelial injury in mice

Despite increasing concerns regarding the harmful effects of plastic-induced gut injury, mechanisms underlying the initiation of plastic-derived intestinal toxicity remain unelucidated. Here, mice were subjected to long-term exposure to polystyrene nanoplastics (PS-NPs) of varying sizes (80, 200, and 1000 nm) at doses relevant to human dietary exposure. PS-NPs exposure did not induce a significant inflammatory response, histopathological damage, or intestinal epithelial dysfunction in mice at a dosage of 0.5 mg/kg/day for 28 days. However, PS-NPs were detected in the mouse intestine, coupled with observed microstructural changes in enterocytes, including mild villous lodging, mitochondrial membrane rupture, and endoplasmic reticulum (ER) dysfunction, suggesting that intestinal-accumulating PS-NPs resulted in the onset of intestinal epithelial injury in mice. Mechanistically, intragastric PS-NPs induced gut microbiota dysbiosis and specific bacteria alterations, accompanied by abnormal metabolic fingerprinting in the plasma. Furthermore, integrated data from mass spectrometry imaging-based spatial metabolomics and metallomics revealed that PS-NPs exposure led to gut dysbiosis-associated host metabolic reprogramming and initiated intestinal injury. These findings provide novel insights into the critical gut microbial-host metabolic remodeling events vital to nanoplastic-derived-initiated intestinal injury.

Comparison of anti-allergic activities of different types of lotus seed resistant starch in OVA-induced mouse model

Currently, evidence from observational studies suggests dietary fiber intake may be associated with decreased risk of food allergy. As a type of dietary fiber, resistant starch was also widely reported to possess anti-allergic properties. However, there is a relative paucity of studies assessing the influence of resistant starch types on their anti-allergic activity and its possible underlying mechanisms. In the current study, the anti-allergic effects of RS3-type (retrograded starch), RS4-type (chemically modified starch, cross-bonded), and RS5-type (starch-palmitic acid complex) of lotus seed resistant starch were evaluated in the OVA (100 mg/kg)-induced food allergic mice model. The results showed that oral administration of RS3 or RS4 lotus seed resistant starch (0.3 g/100 g b.w.) for 25 days significantly improved adverse symptoms of food allergy such as weight loss, increases in allergy symptom score and diarrhea rate; with significant reduction of serum specific antibody IgE, TNF-α, IL-4 levels and improved Th1/Th2 balance being observed. The mechanism may involve the regulation of lotus seed resistant starch on intestinal flora and the metabolites short-chain fatty acids and bile acids. Taken together, the findings may enhance understanding towards ameliorative effects of resistant starch on food allergy, and offer valuable insights for the exploration of novel anti-allergic bioactive compounds.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Inhibition of circRNA NGFR promotes ferroptosis in gallbladder carcinoma cells

Background

Gallbladder carcinoma (GBC) is a formidably aggressive malignancy. Circular RNAs (circRNAs) play crucial regulatory roles in cancer. NGFR is a novel circRNA implicated in various types of cancers. The primary goal of this study was to elucidate the role of NGFR in GBC.

Methods

NGFR variants exhibiting discernible discrepancies were identified using RNA sequencing and validated using real-time PCR. Cell proliferation was assessed using 5-ethynyl-2'-deoxyuridine and Cell Counting Kit-8 assays. The ferroptotic phenotype was characterized by assessing the reactive oxygen species and Fe2+ levels. Western blotting was used to analyze ferroptosis-associated proteins. Superoxide dismutase, malondialdehyde, and glutathione levels were measured using commercially available reagent kits. The severity of mitochondrial damage was evaluated by assessing JC-1, MitoSOX, and ATP activities.

Results

NGFR was upregulated, and its suppression inhibited cell proliferation and increased Fe2+ levels in GBC cells. Furthermore, NGFR downregulation disrupted mitochondrial function.

Conclusion

Circular RNA NGFR can impede the advancement of GBC by modulating the ferroptotic phenotype, thereby potentially offering a novel avenue for the clinical diagnosis and treatment strategies of GBC.

Cr(VI) induces ferroptosis in DF-1 cells by simultaneously perturbing iron homeostasis of ferritinophagy and mitophagy

Hexavalent chromium [Cr(VI)] is an environmental pollutant known for its strong oxidizing and carcinogenic effects. However, its potential to induce ferroptosis in poultry remains poorly understood. This study aims to investigate the induction of ferroptosis by Cr(VI) in DF-1 cells and elucidate the underlying mechanisms. DF-1 cells exposed to Cr(VI) showed increased lipid reactive oxygen species and changes in ferroptosis marker genes (decreased expression of GPX4 and increased expression of COX2). Notably, the addition of the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) can reverse this effect. During the cell death process, Cr(VI) induced ferritinophagy, disrupting iron homeostasis and releasing labile iron ions. We predicted by docking that these iron ions would bind to mitochondrial membrane proteins through virtual docking. This binding was validated through colocalization analysis. In addition, Cr(VI) caused mitophagy, which releases additional ferrous ions. Therefore, Cr(VI) can induce the simultaneous release of ferrous ions through these pathways, thereby exacerbating lipid peroxidation and ultimately triggering ferroptosis in DF-1 cells. This study demonstrates that Cr(VI) can induce ferroptosis in DF-1 cells by disrupting intracellular iron homeostasis and providing valuable insights into the toxic effects of Cr(VI) in poultry and potentially other organisms.

Ferroptosis, Inflammation, and Microbiome Alterations in the Intestine in the Göttingen Minipig Model of Hematopoietic-Acute Radiation Syndrome

Hematopoietic acute radiation syndrome (H-ARS) involves injury to multiple organ systems following total body irradiation (TBI). Our laboratory demonstrated that captopril, an angiotensin-converting enzyme inhibitor, mitigates H-ARS in Göttingen minipigs, with improved survival and hematopoietic recovery, as well as the suppression of acute inflammation. However, the effects of captopril on the gastrointestinal (GI) system after TBI are not well known. We used a Göttingen minipig H-ARS model to investigate captopril's effects on the GI following TBI (60Co 1.79 or 1.80 Gy, 0.42-0.48 Gy/min), with endpoints at 6 or 35 days. The vehicle or captopril (0.96 mg/kg) was administered orally twice daily for 12 days, starting 4 h post-irradiation. Ilea were harvested for histological, protein, and RNA analyses. TBI increased congestion and mucosa erosion and hemorrhage, which were modulated by captopril. GPX-4 and SLC7A11 were downregulated post-irradiation, consistent with ferroptosis at 6 and 35 days post-irradiation in all groups. Interestingly, p21/waf1 increased at 6 days in vehicle-treated but not captopril-treated animals. An RT-qPCR analysis showed that radiation increased the gene expression of inflammatory cytokines IL1B, TNFA, CCL2, IL18, and CXCL8, and the inflammasome component NLRP3. Captopril suppressed radiation-induced IL1B and TNFA. Rectal microbiome analysis showed that 1 day of captopril treatment with radiation decreased overall diversity, with increased Proteobacteria phyla and Escherichia genera. By 6 days, captopril increased the relative abundance of Enterococcus, previously associated with improved H-ARS survival in mice. Our data suggest that captopril mitigates senescence, some inflammation, and microbiome alterations, but not ferroptosis markers in the intestine following TBI.

Nutritional Support: The Use of Antioxidants in Inflammatory Bowel Disease

The problem of treating inflammatory bowel disease continues to be a topic of great interest for researchers. Despite the complexity surrounding their treatment and strategies to prolong periods of remission, there is a promising exploration of various compounds that have potential in combating inflammation and alleviating symptoms. Selenium, calcium, magnesium, zinc, and iron are among these compounds, offering a glimpse of hope in the treatment of IBD. These essential minerals not only hold the promise of reducing inflammation in these diseases, but also show the potential to enhance immune function and possibly influence the balance of intestinal microflora. By potentially modulating the gut microbiota, they may help support overall immune health. Furthermore, these compounds could play a crucial role in mitigating inflammation and minimising complications in patients with IBD. Furthermore, the protective effect of these compounds against mucosal damage in IBD and the protective effect of calcium itself against osteoporosis in this group of patients are notable.

Investigation the mechanism of iron overload-induced colonic inflammation following ferric citrate exposure

Iron overload occurs due to excessive iron intake compared to the body's demand, leading to iron deposition and impairment of multiple organ functions. Our previous study demonstrated that chronic oral administration of ferric citrate (FC) caused colonic inflammatory injury. However, the precise mechanism underlying this inflammatory response remains unclear. The current study aims to investigate the mechanism by which iron overload induced by FC exposure leads to colonic inflammation. To accomplish this, mice were orally exposed to three different concentrations of FC (71 mg/kg/bw (L), 143 mg/kg/bw (M) and 286 mg/kg/bw (H)) for continuous 16 weeks, with the control group receiving ultrapure water (C). Exposure to FC caused disturbances in the excretory system, altered colonic flora alpha diversity, and enriched pathogenic bacteria, such as Mucispirillum, Helicobacter, Desulfovibrio, and Shigella. These changes led to structural disorders of the colonic flora and an inflammatory response phenotype characterized by inflammatory cells infiltration, atrophy of intestinal glands, and irregular thickening of the intestinal wall. Mechanistic studies revealed that FC-exposure activated the NF-κB signaling pathway by up-regulating TLR4, MyD88, and NF-κB mRNA levels and protein expression. This activation resulted in increased production of pro-inflammatory cytokines, further contributing to the colonic inflammation. Additionally, in vitro experiments in SW480 cells confirmed the activation of NF-κB signaling pathway by FC exposure, consistent with the in vivo findings. The significance of this study lies in its elucidation of the mechanism by which iron overload caused by FC exposure leads to colonic inflammation. By identifying the role of pathogenic bacteria and the NF-κB signaling pathway, this study could potentially offer a crucial theoretical foundation for the research on iron overload, as well as provide valuable insights for clinical iron supplementation.

Examining the effect of iron (ferric) on physiological processes: Invertebrate models

Iron is a common and essential element for maintaining life in bacteria, plants and animals and is found in soil, fresh waters and marine waters; however, over exposure is toxic to organisms. Iron is used in electron transport complexes within mitochondria as well as a co-factor in many essential proteins. It is also established that iron accumulation in the central nervous system in mammals is associated with various neurological disorders. Ample studies have investigated the long-term effects of iron overload in the nervous system. However, its acute effects in nervous tissue and additional organ systems warrant further studies. This study investigates the effects of iron overload on development, behavior, survival, cardiac function, and glutamatergic synaptic transmission in the Drosophila melanogaster. Additionally, physiological responses in crayfish were examined following Fe3+ exposure. Fe3+ reduced neuronal excitability in proprioceptive neurons in a crayfish model. Thus, Fe3+ may block stretch activated channels (SACs) as well as voltage-gated Na+ channels. Exposure also rapidly reduces synaptic transmission but does not block ionotropic glutamatergic receptors, suggesting a blockage of pre-synaptic voltage-gated Ca2+ channels in both crustacean and Drosophila models. The effects are partly reversible with acute exposure, indicating the cells are not rapidly damaged. This study is relevant in demonstrating the effects of Fe3+ on various physiological functions in different organisms in order to further understand the acute and long-term consequences of overload.

Vanillic acid restores homeostasis of intestinal epithelium in colitis through inhibiting CA9/STIM1-mediated ferroptosis

The damage of integrated epithelial epithelium is a key pathogenic factor and closely associated with the recurrence of ulcerative colitis (UC). Here, we reported that vanillic acid (VA) exerted potent therapeutic effects on DSS-induced colitis by restoring intestinal epithelium homeostasis via the inhibition of ferroptosis. By the CETSA assay and DARTS assay, we identified carbonic anhydrase IX (CAIX, CA9) as the direct target of VA. The binding of VA to CA9 causes insulin-induced gene-2 (INSIG2) to interact with stromal interaction molecule 1 (STIM1), rather than SREBP cleavage-activating protein (SCAP), leading to the translocation of SCAP-SREBP1 from the endoplasmic reticulum (ER) to the Golgi apparatus for cleavage into mature SREBP1. The activation of SREBP1 induced by VA then significantly facilitated the transcription of stearoyl-CoA desaturase 1 (SCD1) to exert an inhibitory effect on ferroptosis. By inhibiting the excessive death of intestinal epithelial cells caused by ferroptosis, VA effectively preserved the integrity of intestinal barrier and prevented the progression of unresolved inflammation. In conclusion, our study demonstrated that VA could alleviate colitis by restoring intestinal epithelium homeostasis through CA9/STIM1-mediated inhibition of ferroptosis, providing a promising therapeutic candidate for UC.

Excessive dietary iron exposure increases the susceptibility of largemouth bass (Micropterus salmoides) to Aeromonas hydrophila by interfering with immune response, oxidative stress, and intestinal homeostasis

Iron is an essential cofactor in the fundamental metabolic pathways of organisms. Moderate iron intake can enhance animal growth performance, while iron overload increases the risk of pathogen infection. Although the impact of iron on the pathogen-host relationship has been confirmed in higher vertebrates, research in fish is extremely limited. The effects and mechanisms of different levels of iron exposure on the infection of Aeromonas hydrophila in largemouth bass (Micropterus salmoides) remain unclear. In this study, experimental diets were prepared by adding 0, 800, 1600, and 3200 mg/kg of FeSO4∙7H2O to the basal feed, and the impact of a 56-day feeding period on the mortality rate of largemouth bass infected with A. hydrophila was analyzed. Additionally, the relationships between mortality rate and tissue iron content, immune regulation, oxidative stress, iron homeostasis, gut microbiota, and tissue morphology were investigated. The results showed that the survival rate of largemouth bass infected with A. hydrophila decreased with increasing iron exposure levels. Excessive dietary iron intake significantly increased iron deposition in the tissues of largemouth bass, reduced the expression and activity of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, increased the content of lipid peroxidation product malondialdehyde, and thereby induced oxidative stress. Excessive iron supplementation could influence the immune response of largemouth bass by upregulating the expression of pro-inflammatory cytokines in the intestine and liver, while downregulating the expression of anti-inflammatory cytokines. Additionally, excessive iron intake could also affect iron metabolism by inducing the expression of hepcidin, disrupt intestinal homeostasis by interfering with the composition and function of the gut microbiota, and induce damage in the intestinal and hepatic tissues. These research findings provide a partial theoretical basis for deciphering the molecular mechanisms underlying the influence of excessive iron exposure on the susceptibility of largemouth bass to pathogenic bacteria.

Spotlight on iron overload and ferroptosis: Research progress in female infertility

Iron is an essential trace element for organisms. However, iron overload, which is common in haematological disorders (e.g. haemochromatosis, myelodysplastic syndromes, aplastic anaemia, and thalassaemia, blood transfusion-dependent or not), can promote reactive oxygen species generation and induce ferroptosis, a novel form of programmed cell death characterised by excess iron and lipid peroxidation, thus causing cell and tissue damage. Infertility is a global health concern. Recent evidence has indicated the emerging role of iron overload and ferroptosis in female infertility by inducing hypogonadism, causing ovary dysfunction, impairing preimplantation embryos, attenuating endometrial receptivity, and crosstalk between subfertility-related disorders, such as polycystic ovary syndrome and endometriosis. In addition, gut microbiota and their metabolites are involved in iron metabolism, ferroptosis, and female infertility. In this review, we systematically elaborate on the current research progress in female infertility with a novel focus on iron overload and ferroptosis and summarise promising therapies targeting iron overload and ferroptosis to recover fertility in women. In summary, our study provides new insights into female infertility and offers literature references for the clinical management of female infertility associated with iron overload and ferroptosis, which may be beneficial for females with haematopoietic disorders suffering from both iron overload and infertility.