Ferric Research Articles

The Heme Oxygenase/Biliverdin Reductase System and Its Genetic Variants in Physiology and Diseases

Heme oxygenase (HO) metabolizes heme into ferrous iron, carbon monoxide (CO), and biliverdin-IXα (BV), the latter being reduced into bilirubin-IXα (BR) by the biliverdin reductase-A (BVR). Heme oxygenase exists as two isoforms, HO-1, inducible and involved in the cell stress response, and HO-2, constitutive and committed to the physiologic turnover of heme and in the intracellular oxygen sensing. Many studies have identified genetic variants of the HO/BVR system and suggested their connection in free radical-induced diseases. The most common genetic variants include (GT)n dinucleotide length polymorphisms and single nucleotide polymorphisms. Gain-of-function mutations in the HO-1 and HO-2 genes foster the ventilator response to hypoxia and reduce the risk of coronary heart disease and age-related macular degeneration but increase the risk of neonatal jaundice, sickle cell disease, and Parkinson’s disease. Conversely, loss-of-function mutations in the HO-1 gene increase the risk of type 2 diabetes mellitus, chronic obstructive pulmonary disease, and some types of cancers. Regarding BVR, the reported loss-of-function mutations increase the risk of green jaundice. Unfortunately, the physiological role of the HO/BVR system does not allow for the hypothesis gene silencing/induction strategies, but knowledge of these mutations can certainly facilitate a medical approach that enables early diagnoses and tailored treatments.

Use of different protein and antioxidant sources in couscous production to improve chemical and functional properties.

In this study, it was aimed to improve couscous chemical and functional properties by replacing wheat flour used in traditional couscous production with pea and mung bean flours as different protein sources at the rate of 20% and with ginger and turmeric powders as antioxidant sources at the rate of 1%, 2%, and 3%. Sixteen different couscous formulations were produced. In those couscous samples, some chemical contents (moisture, ash, protein, fat, and phytic acid), bioactive contents (2,2-diphenyl-1-picrylhydrazyl radical, ferric reducing antioxidant power assay and ion reducing antioxidant capacity antioxidant activities and total phenolic content), color (L*, a*, and b*), firmness and cooking properties were determined. The use of pea and mung bean flour decreased the L* value of the samples, while turmeric increased the yellowness values. In addition, the weight increase and firmness values of couscous decreased with the use of leguminous flours and antioxidant sources. The use of peas and mung beans significantly increased the amount of ash, protein, and phytic acid values compared to the control. The antioxidant activity value of ion-reducing antioxidant activity capacity increased by 7 and 5 times, and the total phenolic contents increased approximately 2 times, respectively, in the samples with the substitution of 3% turmeric and pea and mung bean flour. Pea flour and mung bean flour provided a significant increase in the amounts of Ca, Mg, K, and Zn. The combination of pea flour with 3% turmeric powder resulted in couscous with superior nutritional and functional properties.

Iron-Doxorubicin Hyaluronan Nanogel as an Effective Targeted Chemotherapy with Modulated Cardiotoxicity.

The complex of doxorubicin (Dox) and intracellular iron in cardiomyocytes generates reactive oxygen species (ROS), contributing to commonly observed cardiotoxicity. To enhance the anticancer potency and minimize the cardiotoxicity, here Dox was formulated into a hyaluronan (HA) nanogel using ferric ion (Fe3+) coordination to control the intracellular distribution and release of Dox. Taking advantage of the paramagnetic properties of iron and the fluorescence of Dox, we conveniently monitored the targeted delivery of the HA@Dox nanogel in murine breast tumors through both T1-weighted magnetic resonance imaging and fluorescence imaging. Compared with free Dox, HA@Dox nanogel affords a CD44-targeted delivery, lysosomal distribution, pH-responsive release, and significant tumor inhibition. Mechanistically, the lysosome-enriched HA@Dox produces ROS, causing lysosomal membrane permeabilization, which further promotes the intracellular Dox distribution. This HA@Dox nanogel not only provides a facile cancer-targeted delivery but also successfully relieves Dox toxicity, representing a potent delivery system for Dox.

In Situ 2D-XAS Imaging and Modeling Analysis of Cerium Migration in Proton Exchange Membrane Fuel Cells

Abstract In-situ two-dimensional X-ray absorption spectroscopy (XAS) imaging was employed to analyze cerium ion (Ce3+) migration in the through-plane direction in proton exchange membrane fuel cells (PEMFCs), offering fundamental insights supporting improvement of their power density and membrane durability. The transport of Ce3+ was visualized in both unreinforced thick Nafion membranes (Nafion 115, 127 µm) and reinforced thin (12 µm) perfluorosulfonic acid (PFSA) membranes under either an electrical potential gradient or a water activity gradient. The diffusion coefficients of Ce3+ were ascertained based on its behavior after removal of these gradients in both membrane types. Additionally, using a one-dimensional cation transport model, the mobility and electroosmotic drag coefficients of Ce3+ were derived from experimentally obtained data of the thick Nafion membrane. Our measurements also demonstrate that the migration of Ce3+ in the thick membranes was notably impeded by the presence of ferrous ion (Fe2+) impurities. Because Fe2+ is known to accelerate membrane degradation by promoting hydroxyl radical formation, this effect might further exacerbate membrane degradation. It therefore warrants careful consideration.

Pericardial Involvement in Hereditary Hemorrhagic Telangiectasia

Hereditary haemorrhagic telangiectasia is a rare disease characterized by cutaneo-mucous and visceral arteriovenous malformations. Cardiac involvement is uncommon and was presented primarily by hyper-output heart failure. Hemorrhagic pericardial effusion, although is extremely rare, can occur during HHT. We report the case of a 48-years-old woman which was hospitalized in 2015 in internal medicine department, Sfax, Tunisia in 2015 for anicteric cholestasis. She noticed a personnel and familial history of recurrent epistaxis. Biologic findings revealed anemia and moderate cholestasis. Viral investigations and immunologic tests were negative. Abdominal tomography showed multiple arterio-venous shunts of the liver. Liver involvement due to Rendu Osler Weber disease was retained. She was treated by ferrous iron, but she was lost to follow up. She was presented in February 2021, with severe anemia (5 g/dL). Physical examination revealed signs of global heart failure. Biological investigations found anemia, inflammatory biological syndrome, cytolysis and cholestasis. Heart ultrasound revealed an abundant pericardial effusion. Only 500cc of hemorrhagic fluid could be aspirated before the needle became blocked. Unfortunately, one week after, re-accumulation of pericardial fluid and worsening occurred. She underwent a partial surgical pericardial excision with pleuropericardial opening. Analysis of the fluid ruled out any infectious cause of this effusion. Histological examination confirmed the vascular dysplasia with signs of hemorrhage and inflammation. The patient was discharged 1 month after surgery with no other bleeding episodes. For her anemia, she received a transfusion of red blood cells. Then, the patient was treated by iron treatment.

Inhibition of GPR68 induces ferroptosis and radiosensitivity in diverse cancer cell types

Radioresistance is thought to be a major consequence of tumor milieu acidification resulting from the Warburg effect. Previously, using ogremorphin (OGM), a small molecule inhibitor of GPR68, an extracellular proton sensing receptor, we demonstrated that GPR68 is a key pro-survival pathway in glioblastoma cells. Here, we demonstrate that GPR68 inhibition also induces ferroptosis in lung cell carcinoma (A549) and pancreatic ductal adenocarcinoma (Panc02) cells. Moreover, OGM synergized with ionizing radiation to induce lipid peroxidation, a hallmark of ferroptosis, as well as reduce colony size in 2D and 3D cell culture. GPR68 inhibition is not acutely detrimental but increases intracellular free ferrous iron, which is known to trigger reactive oxygen species (ROS) generation. In summary, GPR68 inhibition induces lipid peroxidation in cancer cells and sensitizes them to ionizing radiation in part through the mobilization of intracellular free ferrous iron. Our results suggest that GPR68 is a key mediator of cancer cell radioresistance activated by acidic tumor microenvironment.

The activation of the metal-containing regulatory protein NiaR from Thermotoga maritima by its effector, nicotinic acid.

NiaR is a regulatory protein that represses the expression of proteins involved in the de novo biosynthesis and uptake of nicotinic acid (NA), with NA acting as a co-repressor. The previously published structure of NiaR from Thermotoga maritima (TmNiaR) identified it as a functional homodimer containing a transition metal ion in a suspected NA-binding pocket. Here, we present the crystal structure of NA bound to the iron-metalated form of TmNiaR. Supported by spectroscopic and solution studies, this structure shows that NA binds to a protein-bound ferrous ion via its ring nitrogen. In addition, the carboxylate group on NA interacts with Tyr108 from the dyad-related subunit, repositioning the likely DNA-binding domains of the dimer to promote high-affinity interactions with DNA operators. The specificity of TmNiaR for NA can be explained by the hydrogen bonding scheme within the NA-binding pocket.

Siderophore-Functionalized Nanodrug for Treating Antibiotic-Resistant Bacteria.

The development of nanodrugs targeting multidrug-resistant bacteria, while sparing the beneficial constituents of the microbiome, has emerged as a promising approach to combat disease and curb the rise of antimicrobial resistance. In this investigation, we devised a siderophore-functionalized nanodrug based on a gold nanoparticle construct (AuNP-NSC; Gold nanoparticle_N-heterocyclic_Siderophore_Cyanine7), offering an innovative treatment modality against drug-resistant bacterial pathogens. As a proof of concept, the efficacy of this nanodrug delivery and antimicrobial therapy was evaluated against the notoriously resistant bacterium P. aeruginosa. N-Heterocyclic carbenes (NHCs) exhibit a strong affinity for transition metals, forming highly stable complexes resistant to ligand displacement. The entry of siderophore-conjugated nanodrugs into bacteria is facilitated through specific receptors on the outer membrane. In our study, AuNP-NSC was specifically targeted and imported into resistant Gram-negative P. aeruginosa via binding with ferric iron. Treatment with the developed nanodrug significantly inhibited the proliferation of antibiotic-resistant P. aeruginosa, reducing bacterial counts by more than 95% and mitigating drug resistance. Furthermore, AuNP-NSC markedly diminished P. aeruginosa-induced skin lesions and forestalled systemic organ failure triggered by secondary sepsis in mouse models. These findings underscore the potential of nanodrugs as specialized therapeutic agents for the management of antibiotic-resistant bacterial infections.

Ginkgetin enhances breast cancer radiotherapy sensitization by suppressing NRF2-HO-1 axis activity.

Breast cancer (BC) is a critical threat to women's lives. Radiotherapy (RT) is a pivotal treatment modality for BC, but the failure of RT due to radioresistance is still not well facilitated. Ginkgetin (GK) has a potent anti-tumor activity intimately associated with ferroptosis. This study applied in vitro and in vivo experimental models to ascertain the GK mechanism of action on BC radioresistance. The outcomes reported that GK could inhibit BC cell growth and increase apoptosis. In addition, when BC cells generated radioresistance, GK promoted ferroptosis of radioresistant BC cells by mitigating NRF2 expression, suppressing HO-1 and NQO1 expression, increasing the intracellular content of reactive oxygen species (ROS) and ferrous ions, accelerating the glutathione (GSH) depletion, and decreasing GPX4 expression. Notably, GK can damage intracellular mitochondria and cause a substantial increase in ferrous ions in BC cells. Therefore, GK shows immense potential for enhancing breast cancer radiotherapy sensitivity, which may provide pivotal evidence for subsequent RT sensitization.

Ferritin Hinders Ferroptosis in Non-Tumorous Diseases: Regulatory Mechanisms and Potential Consequences.

Ferritin, as an iron storage protein, has the potential to inhibit ferroptosis by reducing excess intracellular free iron concentrations and lipid reactive oxygen species (ROS). An insufficient amount of ferritin is one of the conditions that can lead to ferroptosis through the Fenton reaction mediated by ferrous iron. Consequently, upregulation of ferritin at the transcriptional or posttranscriptional level may inhibit ferroptosis. In this review, we have discussed the essential role of ferritin in ferroptosis and the regulatory mechanism of ferroptosis in ferritin-deficient individuals. The description of the regulatory factors governing ferritin and its properties in regulating ferroptosis as underlying mechanisms for the pathologies of diseases will allow potential therapeutic approaches to be developed.

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 47nM. 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.

Hyaluronic acid regulated facile synthesis of size-tunable multifunctional nanomedicine for effective cancer therapy.

The complex and heterogeneous nature of cancer necessitates the development of innovative multifunctional nanomedicines (MN). Hyaluronic acid (HA) is a functional carbohydrate polysaccharide that is widely used in various biomedical fields. In this study, we employed HA as a stabilizer and regulator for the synthesis of a size-tunable nanomedicine comprising ferric ions, doxorubicin, and epigallocatechin gallate (EGCG), referred to as HDE-MN, for cancer therapy. A change in the HA ratio can yield HDE-MNs with sizes varying from ~20nm to over 100nm. Modified HA can respond to hyaluronidase (HAase) to provide controllable pH/HAase dual-responsive drug release for improved cancer therapy. Moreover, HA can mediate the targeted delivery of HDE-MNs both in vitro and in vivo to cancer cells. In addition, HDE-MNs reversed multidrug resistance owing to the incorporation of EGCG, inducing ferroptosis due to the involvement of ferric ions. More importantly, HDE-MNs have a photothermal conversion effect, enabling photothermal therapy, photothermally enhanced drug release, and ferroptosis, which collectively contribute to significantly improved cancer therapy. Therefore, the HDE-MNs with laser irradiation achieved full ablation of the in vivo tumors. Together with its good biocompatibility, HDE-MNs may be promising for effective cancer therapy.

The effect of persistent exposure to thiocyanate and the impact on inhibition of ferrous iron oxidation in an industrial strain of Acidiplasma cupricumulans

The effect of persistent exposure to thiocyanate and the impact on inhibition of ferrous iron oxidation in an industrial strain of Acidiplasma cupricumulans

Integrated network pharmacology, bioinformatics, and experiment analysis to decipher the molecular mechanism of Salidroside on Gastric cancer via targeting NCOA4-mediated ferritinophagy.

Gastric cancer (GC) is a highly aggressive and heterogeneous malignancy. The process of ferroptosis regulates tumor growth and represents a promising therapeutic target for GCs. Despite Salidroside (Sal) being able to regulate ferroptosis in a variety of diseases, there are still limited reports on its therapeutic effects and potential targets in treating GC. This study aimed to investigate the potential mechanism of Sal-induced ferroptosis in GC. Our analysis, integrating databases like PharmMapper, Swiss Target Prediction, TargetNet, GeneCards, TTD, OMIM, STRING, and DAVID. Human gastric cancer MGC803cells and tumor-bearing mice were used to evaluate the anti-tumor effect of Sal on GC in vitro and in vivo. CCK-8, LDH, and Calcein-AM/PI were used to assess cell viability and damage. FerroOrange, Lillie's Ferrous Iron Stain, MDA, ROS, BODIPY™ 581/591C11, GSH, and GPxs were used to detect intracellular Fe2+ concentration, lipid peroxidation level, and antioxidant defense system. qRT-PCR and Western blot were performed to explore relevant mechanism studies. Network pharmacology results showed that Sal shares 322 targets with GC, which have biological functions related to lipid metabolism, cell death, and lipid peroxidation. Experiments further confirmed that Sal inhibits MGC803cells by inducing ferroptosis, as evidenced by the induction of elevated Fe2+ and increased lipid peroxidation. Fer-1, an inhibitor of ferroptosis, reversed the anti-GC effect of Sal in MGC803cells and GC tumor-bearing mice. Further confirmation of the association between Sal and ferroptosis in GC. Subsequently, bioinformatics and machine learning algorithms identified nuclear receptor coactivator 4 (NCOA4) as a candidate signature gene associated with ferroptosis in GC, and molecular docking shows that NCOA4 binds Sal. We then performed in vivo and in vitro experiments to elucidate that Sal targeting NCOA4, a cargo receptor mediating ferritinophagy, mediates autophagic degradation of ferritin heavy chain 1 (FTH1, Fe2+ storage protein), which further increases Fe2+ and lipid peroxidation. In addition, Sal induces mitochondrial dysfunction and increases mitochondrial ROS levels, which activates autophagy and triggers autophagic degradation of FTH1. Taken together, we revealed that NCOA4 is a new target for Sal-anchored GC and that Sal may be a potential therapeutic drug for the treatment of GC.

Overexpression Bcl-2 alleviated ferroptosis induced by molybdenum and cadmium co-exposure through inhibiting mitochondrial ROS in duck kidneys.

Excessive molybdenum (Mo) and cadmium (Cd) are environmental pollutants with serious nephrotoxicity. B-cell lymphoma 2 (Bcl-2) plays a critical role in modulating mitochondrial ROS (Mito-ROS). Ferroptosis is a form of cell death dependent on lipid peroxidation. However, the impacts of Mo and Cd co-exposure on ferroptosis in duck kidneys and the function of Bcl-2 in the process are still unclear. Ducks and duck primary renal tubular epithelial cells exposed to different doses of Mo and/or Cd were used as the research target. Our work suggested that Mo and/or Cd significantly decreased Bcl-2 protein level and induced ferroptosis with the increase of ferrous ion, lipid peroxidation, TF protein level and the decrease of GPX4, FT protein levels. The Bcl-2 inhibitor HA14-1 exacerbated the changes of these indexes, but Bcl-2 overexpression had the opposite effect. Mito-ROS inhibitor ROS-IN-1 alleviated ferroptosis induced by Mo and Cd. Besides, Bcl-2 was involved in mitochondrial dysfunction induced by Mo and Cd, accompanied by disturbing Mito-ROS, ATP level, mitochondrial complex IV activity, Bcl-2 and COX-2 co-localization, lipid peroxidation, mitochondrial membrane potential (MMP) and mitochondrial structure. These findings substantiated that overexpression Bcl-2 alleviated ferroptosis co-induced by Mo and Cd through reducing Mito-ROS level in duck kidneys.

Lithium Enhances Ferroptosis Sensitivity in Melanoma Cells and Promotes CD8+ T Cell Infiltration and Differentiation

Lithium exposure reduces melanoma incidence and mortality, yet its therapeutic mechanisms are unclear. This study explores the effects of lithium on ferroptosis sensitivity and anti-tumor T cell response in melanoma. We found that lithium significantly enhanced RSL3-induced ferroptosis in vitro, evidenced by increased mitochondrial peroxide, lipid peroxidation, and mitochondrial abnormalities. Lithium also inhibited B16-F10 melanoma cell proliferation and migration in a dose-dependent manner. Cell cycle analysis showed lithium and RSL3 induced distinct perturbations, including G2/M and G0/G1 phase arrests. Mechanistically, lithium influenced intracellular ferrous ion levels by downregulating ferritin heavy chain (Fth1), crucial for iron homeostasis. The combination of lithium and RSL3 significantly suppressed tumor growth in mice, correlating with reduced Fth1 expression and increased iron deposition in the spleen and liver, highlighting a novel interaction between lithium and iron metabolism. Additionally, this combination enhanced CD8+ T cell infiltration and IFN-γ expression in the tumor microenvironment, especially among cytotoxic effector CD8+ T cells. These findings reveal the pro-ferroptotic and immune regulation roles of lithium, broaden our understanding of its biological roles, and propose new strategies for ferroptosis-targeted therapies in melanoma.

Modulation of the local angiotensin II: Suppression of ferroptosis and radiosensitivity in nasopharyngeal carcinoma via the HIF-1α-HILPDA axis.

Radiotherapy presents a curative approach for nasopharyngeal carcinoma (NPC); however, the cellular radiosensitivity heterogeneity limits its efficacy. Thus, investigating the specific mechanisms of radioresistance in NPC is crucial for identifying and employing effective radiosensitizing agents to enhance treatment success. Radioresistant NPC cell lines HONE1-RR and SUNE1-RR were established. Quantitative reverse transcription-PCR (qRT-PCR), western blot, and enzyme-linked immuno sorbent assay (ELISA) were employed to detect the activation of the angiotensinogen (AGT) and local angiotensin II (Ang II). Transmission electron microscopy, ferrous ion detection, and lipid oxidation levels were utilized to detect radiation-induced ferroptosis in NPC. Bioinformatics analysis, along with qRT-PCR, western blotting, co-immunoprecipitation, and dual-luciferase assays were employed to explore downstream mechanisms. Colony formation assay, Cell Counting Kit-8 (CCK-8) assay, and a nude mouse xenograft model were utilized to assess NPC radiosensitivity. The expression of AGT, hypoxia-inducible factor-1 alpha (HIF-1α), hypoxia-inducible lipid droplet-associated protein (HILPDA), and glutathione peroxidase 4 (GPX4) in NPC tissues was detected through immunohistochemistry. Activation of local Ang II was revealed to play a critical role in driving radioresistance in NPC cells modulating ferroptosis. This local Ang II established a positive feedback loop with HIF-1α through two parallel pathways; Ang II stabilizes HIF-1α by activating the MAPK pathway, and AGT directly binds HIF-1α to prevent its degradation. This AGT-HIF-1α loop regulated NPC cell ferroptosis via transcriptional regulation of HILPDA expression. Moreover, the co-administration of Ang II receptor antagonist (ARB) and ferroptosis inducers markedly increased NPC radiosensitivity.Additionally, the expression of AGT, HIF-1α, and HILPDA was closely correlated with the intensity of ferroptosis, radiosensitivity, and prognosis in NPC. Our findings suggest that the AGT-HIF-1α-HILPDA pathway promotes radioresistance in NPC by enhancing lipid droplet accumulation, thereby suppressing ferroptosis. Targeting local Ang II alongside ferroptosis induction offers a promising strategy to improve radiosensitivity in NPC.

Changes in functional activities and volatile flavor compounds of fermented mung beans, cowpeas, and quinoa started with Bacillus amyloliquefaciens SY07.

In this work, the functional activities including α-glucosidase, α-amylase, angiotensin converting enzyme (ACE) inhibitory activity, and antioxidant activity of mixed grains (mung beans, cowpeas, and quinoa) fermented with Bacillus amyloliquefaciens SY07 were investigated. The volatile flavor of the mixed grains collected every 12h during 72h-fermentation were further detected as well. The inhibition on α-glucosidase and α-amylase reached up to 89.34% and 50.03% with the sample concentration of 5.17 and 9.38mg/mL, respectively. Moreover, the ACE inhibitory activity reached to 93.66% with the sample concentration of 0.59mg/mL. The antioxidant capacity of the mixed grains, evaluated by ABTS and DPPH radical scavenging capacities and ferric ion reducing power, was also significantly improved (p<0.05) during fermentation. The maximum of ABTS and DPPH radical scavenging capacities increased to 8.64 and 3.21mg TE/g DW, respectively, and the maximum ferric ion reducing power reached to 5.73mg TE/g DW. Twenty-one volatile flavor compounds with odor activity values (OAVs)≥1 were detected, and six key volatile flavor substances were identified by OPLS-DA analysis, namely, isovaleric acid, acetoin, phenylacetic acid, (Z)-2-nonenol, 1-hexanol, and 1-octen-3-ol, with overall strong creamy, sweet, baked-potato, and cocoa flavors upon fermentation. These findings revealed a favorable pathway for B. amyloliquefaciens SY07 to be used to improve the functional and flavor properties of fermented grains, which would also be of great value for further elucidating the mechanism of the formation of the volatile flavor differences and developing novel quality cereal-based products.

WWOX-mediated p53/SAT1 and NRF2/FPN1 axis contribute to toosendanin-induced ferroptosis in hepatocellular carcinoma.

Although ferroptosis as an emerging way exhibits tremendous promising in the therapy of hepatocellular carcinoma (HCC), the novel therapeutic agents targeting ferroptosis are still scarce. In our previous study, we found that the natural products toosendanin (TSN) possessed significant anti-proliferative efficacy by regulating WW domain-containing oxidoreductase (WWOX) in HCC. However, there is very limited understanding about TSN-induced ferroptosis, and the role of WWOX in ferroptosis has not been studied. In present study, we investigated the effect and underlying molecular mechanisms of TSN in WWOX-mediated ferroptosis in HCC. We found that TSN induced ferroptosis in HCC cells and its effect was dependent on WWOX. RNA-seq and RT-qPCR assay identified that TSN significantly increased spermidine/spermine N1-acetyltransferase 1 (SAT1) expression while decreased solute carrier family 40 member 1 (SLC40A1) expression, which play vital roles in ferrous ion transport. Further dual-luciferase reporter assay and Co-IP assay revealed that TSN-induced WWOX activation controlled the transcriptional activity of p53 and NF-E2-related factor 2 (NRF2) by regulating their interaction. Meanwhile, IF assay and WB assay confirmed that TSN increased the nuclear distribution of p-WWOX and p-p53 dimers, but impeded the nuclear translocation of NRF2 by inducing its ubiquitination degradation, ultimately regulating the transcription of their downstream target genes. In addition, the results from cell viability assay and the tumor xenograft model verified that co-treatment of TSN, ML385 (NRF2 inhibitor), and MIRA-1 (p53 activator) could effectively inhibit HCC cells growth in the presence of Fer-1 (ferroptosis inhibitor) in vitro and in vivo. Overall, our study contributes to the necessary understanding of the molecular mechanisms of WWOX-mediated ferroptosis regulation, and identifies TSN as a potential therapeutic agent targeting ferroptosis for HCC.

PH Threshold Impacts Chalcopyrite Bioleaching Dynamics for the Extreme Thermoacidophile Sulfurisphaera ohwakuensis.

The extremely thermoacidophilic archaeon Sulfurisphaera ohwakuensis served as the basis for probing how initial pH (pHinitial) affects copper mobilization from chalcopyrite. Screening of small-scale cultures (75 mL) at 75°C revealed that ~pH 3.0 was a maximal threshold for bioleaching onset. Subsequently, chalcopyrite at 10 g/L in 750 mL culture media, containing small amounts of ferric ion, adjusted to pH 2.5 with sulfuric acid and incubated for 24 h at 75°C before inoculation, brought the pH to approximately 3.0 through abiotic chemical reactions. However, the resulting subtle differences in pHinitial (3.0 ± 0.15) in bioleaching cultures, while not affecting microbial growth, were critical to bioleaching onset and progress. Initial iron levels were less important than pHinitial in starting the bioleaching process. X-Ray Diffraction (XRD) surface analysis informed bioleaching trajectories over 21 days and reinforced the impact of pHinitial. The subtle differences in pHinitial markedly affected S. ohwakuensis onset and outcomes, as it presumably would for other bioleaching thermoacidophilic archaea. Furthermore, the findings here highlight the challenges faced in replicating bioleaching experiments across, and even within, laboratories as well as in achieving consistent results in bioleaching processes.