Intracellular Iron Content Research Articles

TRIM46 accelerates H1N1 influenza virus-induced ferroptosis and inflammatory response by regulating SLC7A11 ubiquitination.

Influenza A (H1N1) virus is an acute respiratory infection responsible for enormous morbidity and mortality worldwide. The tripartite motif-containing protein 46 (TRIM46) has an antiviral function that inhibits various viral infections. This study is designed to explore the role and mechanism of TRIM46 in the progress of H1N1 infection. Herein, we infected A549 or 16HBE cells with the H1N1 virus at different times to assess TRIM46 and solute carrier family 7 member 11 (SLC7A11) expression. TRIM46 and Influenza A nucleoprotein mRNA levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). TRIM46, solute carrier family 7 member 11 (SLC7A11), and Nucleoprotein protein levels were detected using protein level were detected by western blot assay. Cell virulence was determined using Virulence assay (TCID50) assay. Cell viability was determined using Cell Counting Kit-8 (CCK-8) assay. Reactive oxygen species (ROS), intracellular iron content, Malondialdehyde (MDA), and Glutathione (GSH) levels were determined using special assay kits. The stability of SLC7A11 was assessed by Cycloheximide (CHX) assay. Interaction between TRIM46 and SLC7A11 was verified using Co-immunoprecipitation (CoIP) assay. The biological role of TRIM46 was assessed in H1N1 virus-challenged lung injury mice in vivo. TRIM46 level was significantly increased during H1N1 virus infection, and SLC7A11 expression was decreased. TRIM46 downregulation could suppress H1N1 virus replication and relieve H1N1 infection-induced ferroptosis and inflammation in A549 or 16HBE cells. Mechanistically, TRIM46 could promote SLC7A11 ubiquitination and decrease its stability. TRIM46 knockdown repressed H1N1 virus-induced lung injury in vivo. TRIM46 could contribute to influenza A H1N1 virus infection by promoting SLC7A11 ubiquitination in A549 cells, which indicates that targeting TRIM46 may improve the prognosis of patients.

An Integrated Approach to Elucidate the Interplay between Iron Uptake Dynamics and Magnetosome Formation at the Single-Cell Level in Magnetospirillum gryphiswaldense.

Iron is a crucial element integral to various fundamental biological molecular mechanisms, including magnetosome biogenesis in magnetotactic bacteria (MTB). Magnetosomes are formed through the internalization and biomineralization of iron into magnetite crystals. However, the interconnected mechanisms by which MTB uptake and regulate intracellular iron for magnetosome biomineralization remain poorly understood, particularly at the single-cell level. To gain insights we employed a holistic multiscale approach, i.e., from elemental iron species to bacterial populations, to elucidate the interplay between iron uptake dynamics and magnetosome formation in Magnetospirillum gryphiswaldense MSR-1 under near-native conditions. We combined a correlative microscopy approach integrating light and X-ray tomography with analytical techniques, such as flow cytometry and inductively coupled plasma spectroscopy, to evaluate the effects of iron and oxygen availability on cellular growth, magnetosome biogenesis, and intracellular iron pool in MSR-1. Our results revealed that increased iron availability under microaerobic conditions significantly promoted the formation of longer magnetosome chains and increased intracellular iron uptake, with a saturation point at 300 μM iron citrate. Beyond this threshold, additional iron did not further extend the magnetosome chain length or increase total intracellular iron levels. Moreover, our work reveals (i) a direct correlation between the labile Fe2+ pool size and magnetosome content, with higher intracellular iron concentrations correlating with increased magnetosome production, and (ii) the existence of an intracellular iron pool, distinct from magnetite, persisting during all stages of biomineralization. This study offers insights into iron dynamics in magnetosome biomineralization at a single-cell level, potentially enhancing the industrial biomanufacturing of magnetosomes.

Nanocarriers Targeting Circular RNA ADARB1 Boost Radiosensitivity of Nasopharyngeal Carcinoma through Synergically Promoting Ferroptosis.

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck, prevalent in regions such as Southern China and Southeast Asia. Radiotherapy serves as the primary clinical treatment for this carcinoma. However, resistance to radiotherapy is a fundamental cause of treatment failure and patient mortality, with the underlying mechanisms yet to be fully elucidated. We identified a recently characterized circular RNA, circADARB1, which is markedly upregulated in NPC tissues and closely associated with poor prognosis and radiotherapy resistance. Both in vitro and in vivo experiments demonstrated that circADARB1 inhibited ferroptosis, thereby inducing radiotherapy resistance in NPC cells. Building on these findings, we synthesized a biomimetic nanomaterial consisting of semiconducting polymer nanoparticles wrapped in cell membranes, designed to deliver both siRNA targeting circADARB1 and iron ions. The application of this nanomaterial not only efficiently suppressed the expression of circADARB1 and boosted intracellular iron concentrations, but also enhanced ferroptosis induced by radiotherapy, improving the radiosensitivity of NPC cells. Furthermore, our study revealed that circADARB1 upregulated the expression of heat shock protein HSP90B1, which repaired misfolded SLC7A11 and GPX4 proteins triggered by radiotherapy, thereby preserving their stability and biological functions. Mechanistically, SLC7A11 facilitated cysteine transportation into cells and glutathione synthesis, while GPX4 employed glutathione to mitigate intracellular lipid peroxidation induced by radiotherapy, shielding cells from oxidative damage and inhibiting ferroptosis, and ultimately leading to radiotherapy resistance in NPC cells. Our investigation elucidates molecular mechanisms with substantial clinical relevance, highlights the promising application prospects of nanotechnology in precision cancer therapy.

The hepcidin-ferroportin axis modulates liver endothelial cell BMP expression to influence iron homeostasis in mice

The liver hormone hepcidin regulates systemic iron homeostasis to provide enough iron for vital processes while limiting toxicity. Hepcidin acts by degrading its receptor ferroportin (encoded by Slc40a1) to decrease iron export to plasma. Iron controls hepcidin production in part by inducing liver endothelial cells (LECs) to produce bone morphogenetic proteins (BMPs), which activate hepcidin transcription in hepatocytes. Here, we used in vitro and in vivo models to investigate whether ferroportin contributes to LEC intracellular iron content to modulate BMP expression and thereby hepcidin. Quantitative proteomics of LECs from mice fed different iron diets demonstrated an inverse relationship between dietary iron and endothelial ferroportin expression. Slc40a1 knockdown primary mouse LECs and endothelial Slc40a1 knockout mice exhibited increased LEC iron and BMP ligand expression. Endothelial Slc40a1 knockout mice also exhibited altered systemic iron homeostasis with decreased serum and total liver iron but preserved erythropoiesis. Although endothelial Slc40a1 knockout mice had similar hepcidin expression as control mice, hepcidin levels were inappropriately high relative to iron levels. Moreover, when iron levels were equalized with iron treatment, hepcidin levels were higher in endothelial Slc40a1 knockout mice than controls. Finally, LEC ferroportin levels were inversely correlated with hepcidin levels in multiple mouse models, and treatment of hepcidin-deficient mice with mini-hepcidin decreased LEC ferroportin expression. Overall, these data show that LEC ferroportin modulates LEC iron and consequently BMP expression to influence hepcidin production. Furthermore, LEC ferroportin expression is regulated by hepcidin, demonstrating bidirectional communication between LECs and hepatocytes to orchestrate systemic iron homeostasis.

A low frequency magnetic field regulated the synthesis of carotenoids in Rhodotorula mucilaginosa by influencing iron metabolism

The purpose of this study is to investigate the effect of low frequency magnetic fields (LFMF) on carotenoid synthesis and iron metabolism in Rhodotorula mucilaginosa and to explore potential connections between the two processes. Various LFMF intensities were employed to assess carotenoid production, intracellular iron content, and the expression levels of genes related to carotenoid synthesis and iron metabolism in R. mucilaginosa. The results show that a LFMF could promote carotenoid synthesis, resulting in varying increases in intracellular iron content. Specifically, the expression of the iron metabolism-related gene transferrin receptor (TFR) was upregulated, while the expression of ferroportin 1 (FPN1) was downregulated. Meanwhile, the expressions of the carotenoid synthesis-related genes geranylgeranyl diphosphate synthases (GGPPS) and phytoene synthase (PSY) displayed varying degrees of upregulation at different time points. Further, the TFR and FPN1 gene knockout strains of R. mucilaginosa were subjected to treatment with a 3.5-mT LFMF, the results of which showed that an LFMF is capable of influencing the iron metabolism levels and subsequently regulating carotenoid synthesis in R. mucilaginosa.

Intracellular Iron Deficiency and Abnormal Metabolism, Not Ferroptosis, Contributes to Homocysteine-Induced Vascular Endothelial Cell Death.

Background/Objectives: Homocysteine (Hcy) and iron are factors co-related with the progression of cardiovascular diseases. The vascular endothelium is an important barrier for physiological homeostasis, and its impairment initiates cardiovascular injury. However, the mechanism underlying Hcy-caused vascular endothelial cell injury and the participation of iron are not fully elucidated. This study aims to investigate the Hcy-induced vascular endothelial injury and iron metabolism dysfunction as well as the underlying molecular mechanism. Methods: Human umbilical vein endothelial cells (HUVECs) were employed as the experimental model to examine the Hcy-induced endothelial injury and its underlying mechanism via various biochemical assays. Results: Hcy suppressed the cell viability and proliferation and caused cell death in a concentration-dependent manner. Hcy induced cell cycle arrest, apoptosis, and autophagy as well as impairment of intracellular energy metabolism. Hcy disrupted the intracellular antioxidant system and mitochondrial function by increasing intracellular ROS, MDA and mitochondrial content, and decreasing the SOD activity and mitochondrial membrane potential. Hcy significantly reduced the GSH-Px activity along with the accumulation of intracellular GSH in a concentration-dependent manner. Ferroptosis inhibitors, Ferrostatin-1 (Fer-1), and Deferoxamine (DFO) significantly decreased the Hcy-caused cytotoxicity accompanied by a reduction in dysregulated mitochondria content, but only DFO ameliorated the elevation of intracellular ROS, and neither Fer-1 nor DFO affected the Hcy-caused reduction in intracellular ATP. In addition, Hcy decreased the intracellular concentration of iron, and supplementing Hcy with various concentrations of Fe3+ increased the cell viability and decreased the LDH release in a concentration-dependent manner. Hcy dramatically decreased the mRNA expression level of transferrin receptor while increasing the mRNA expression levels of transferrin, ferritin light chain, ferritin heavy chain, ferroportin, and SLC7A11. Moreover, Hcy suppressed the protein expression of phospho-Akt, phospho-mTOR, Beclin-1, LC3A/B, Nrf2, HO-1, phospho-MEK1/2, phospho-ERK1/2, and Caspase-3 in concentration- and time-dependent manners. Conclusions: Hcy-induced vascular endothelial injury is likely to be associated with apoptosis and autophagy, but not ferroptosis. The key underlying mechanisms are involved in the disruption of the intracellular antioxidant system and iron metabolism via regulation of PI3K/Akt/mTOR, MAPKs, Nrf2/HO-1, and iron metabolism.

MiRNA Regulates Ferroptosis in Cardiovascular and Cerebrovascular Diseases.

Cardiovascular and cerebrovascular diseases (CCVDs) significantly contribute to global mortality and morbidity due to their complex pathogenesis involving multiple biological processes. Ferroptosis is an important physiological process in CCVDs, manifested by an abnormal increase in intracellular iron concentration. MiRNAs, a key class of noncoding RNA molecules, are crucial in regulating CCVDs through pathways like glutathione-glutathione peroxidase 4, glutamate/cystine transport, iron metabolism, lipid metabolism, and other oxidative stress pathways. This article summarizes the progress of miRNAs' regulation on CCVDs, aiming to provide insights for the diagnosis and treatment of CCVDs.

A herbal pair of Scutellaria barbata D. Don and Scleromitrion diffusum (Willd.) R.J. Wang induced ferroptosis in ovarian cancer A2780 cells via inducing heme catabolism and ferritinophagy

ObjectiveDespite the combination of Scutellaria barbata D. Don and Scleromitrion diffusum (Willd.) R.J. Wang (SB-SD) being a recognized Chinese medicinal herbal pair that is commonly used in the treatment of ovarian cancer, there is a poor understanding of their pharmacological mechanisms. This study examines the antitumor properties and potential mechanisms of SB-SD on human ovarian cancer A2780 cells through a multi-omics approach, establishing a pharmacological basis for clinical utilization. MethodsA range of mass ratios and reagents were used in the hot reflux extraction of SB-SD. The inhibitory effect of the SB-SD extracts on A2780 cell proliferation was assessed using the cell-counting kit 8 assay. A zebrafish tumor implantation model was used to evaluate the effects of SB-SD extracts on tumor growth and metastasis in vivo. Transcriptomics and proteomics were used to investigate alterations in biological pathways in A2780 cells after treatment with different concentrations of SB-SD extract. Cell cycle, cell apoptosis, intracellular free iron concentration, intracellular reactive oxygen species (ROS) concentration, malondialdehyde (MDA), and mitochondrial membrane potential were measured. Real-time quantitative reverse transcription polymerase chain reaction and Western blotting were utilized to investigate the effects of heme catabolism and ferritinophagy on ferroptosis induced by SB-SD extract in A2780 cells. ResultsThe 70% ethanol extract of SB-SD (a mass ratio of 4:1) inhibited A2780 cell proliferation significantly with a half maximal inhibitory concentration of 660 μg/mL in a concentration- and time-dependent manner. Moreover, it effectively suppressed tumor growth and metastasis in a zebrafish tumor implantation model. SB-SD extract induced the accumulation of free iron, ROS, MDA, and mitochondrial damage in A2780 cells. The mechanisms might involve the upregulated expression of ferritinophagy-related genes microtubule-associated protein 1 light chain 3, autophagy-related gene 5, and nuclear receptor coactivator 4. ConclusionsSB-SD extract effectively inhibited the development of ovarian cancer both in vitro and in vivo. Its mechanism of action involved inducing ferroptosis by facilitating heme catabolism and ferritinophagy. This herbal pair holds promise as a potential therapeutic option for ovarian cancer treatment and may be utilized in combination with routine treatment to improve the treatment outcomes of ovarian cancer patients.

Selenium alleviates dextran sulfate sodium-induced colitis and inhibits ferroptosis of intestinal epithelial cells via upregulating glutathione peroxidase 4.

Selenium, an essential micronutrient for humans, has been shown to be protective against ulcerative colitis (UC), but the exact mechanism remains unclear. The role of selenium, protecting against ferroptosis of intestinal epithelial cells (IECs) in colitis, was investigated in this current study. Serum selenium level and ferroptosis-related gene expression in the colonic mucosa were measured in UC patients and healthy controls. The effects of sodium selenite supplementation on experimental colitis were investigated in dextran sulfate sodium (DSS)-treated mice. The influence of sodium selenite on IEC ferroptosis was evaluated through assessing cell death rate, intracellular ferrous iron content, lipid reactive oxygen species level, and mitochondrial membrane damage of DSS-treated Caco-2 cells. Moreover, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4, ferroptosis-related genes, were detected in Caco-2 cells and mouse intestines. Serum selenium was decreased in UC patients in comparison with healthy individuals. Additionally, serum selenium level was negatively correlated with disease activity and was associated with clinical inflammation and nutrition indicators. The expression of GPX4 in the mucosa of UC was positively correlated with serum selenium level. The in vivo experiments showed that selenium treatment ameliorated DSS-induced colitis and inhibited ferroptosis in IECs. The in vitro results suggested that selenium supplementation inhibited DSS-induced ferroptosis in Caco-2 cells. GPX4 was upregulated after selenium supplementation both in vivo and in vitro. Serum selenium level was associated with IEC ferroptosis in UC patients. Selenium supplementation alleviates DSS-induced colitis and inhibits ferroptosis in IECs by upregulating the expression of GPX4.

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.

Functional connexion of bacterioferritin in antibiotic production and morphological differentiation in Streptomyces coelicolor

BackgroundSeveral two-component systems of Streptomyces coelicolor, a model organism used for studying antibiotic production in Streptomyces, affect the expression of the bfr (SCO2113) gene that encodes a bacterioferritin, a protein involved in iron storage. In this work, we have studied the effect of the deletion mutant ∆bfr in S. coelicolor.ResultsThe ∆bfr mutant exhibits a delay in morphological differentiation and produces a lesser amount of the two pigmented antibiotics (actinorhodin and undecylprodigiosin) compared to the wild type on complex media. The effect of iron in minimal medium was tested in the wild type and ∆bfr mutant. Consequently, we also observed different levels of production of the two pigmented antibiotics between the two strains, depending on the iron concentration and the medium (solid or liquid) used. Contrary to expectations, no differences in intracellular iron concentration were detected between the wild type and ∆bfr mutant. However, a higher level of reactive oxygen species in the ∆bfr mutant and a higher tolerance to oxidative stress were observed. Proteomic analysis showed no variation in iron response proteins, but there was a lower abundance of proteins related to actinorhodin and ribosomal proteins, as well as others related to secondary metabolite production and differentiation. Additionally, a higher abundance of proteins related to various types of stress, such as respiration and hypoxia among others, was also revealed. Data are available via ProteomeXchange with identifier PXD050869.ConclusionThis bacterioferritin in S. coelicolor (Bfr) is a new element in the complex regulation of secondary metabolism in S. coelicolor and, additionally, iron acts as a signal to modulate the biosynthesis of active molecules. Our model proposes an interaction between Bfr and iron-containing regulatory proteins. Thus, identifying these interactions would provide new information for improving antibiotic production in Streptomyces.

Iron Dyshomeostasis in Neurodegeneration with Brain Iron Accumulation (NBIA): Is It the Cause or the Effect?

Iron is an essential metal ion implicated in several cellular processes. However, the reactive nature of iron renders this metal ion potentially dangerous for cells, and its levels need to be tightly controlled. Alterations in the intracellular concentration of iron are associated with different neuropathological conditions, including neurodegeneration with brain iron accumulation (NBIA). As the name suggests, NBIA encompasses a class of rare and still poorly investigated neurodegenerative disorders characterized by an abnormal accumulation of iron in the brain. NBIA is mostly a genetic pathology, and to date, 10 genes have been linked to familial forms of NBIA. In the present review, after the description of the principal mechanisms implicated in iron homeostasis, we summarize the research data concerning the pathological mechanisms underlying the genetic forms of NBIA and discuss the potential involvement of iron in such processes. The picture that emerges is that, while iron overload can contribute to the pathogenesis of NBIA, it does not seem to be the causal factor in most forms of the pathology. The onset of these pathologies is rather caused by a combination of processes involving the interplay between lipid metabolism, mitochondrial functions, and autophagic activity, eventually leading to iron dyshomeostasis.

The intracellular accumulation of iron coincides with enhanced biohydrogen production by Thermoanaerobacterium thermosaccharolyticum

The aim of this study was to investigate the effects of different doses (10–200 mg/L) of magnetite (FeO·Fe2O3), Fe0, Ni0, and FeCl3 on the efficiency of dark fermentative H2 production from cheese whey using Thermoanaerobacterium thermosaccharolyticum SP-H2. Energy conversion efficiency and hydrogen yield increased significantly by 22.7 % and 34.8 %, respectively, when 10 mg/L of magnetite was added, and hydrogenase activity increased by 23.6 % when 100 mg/L of Fe0 was added compared to the control (p < 0.001). Using scanning electron microscopy and energy dispersive X-ray spectroscopy, it was found that during the early exponential phase of hydrogen evolution, T. thermosaccharolyticum cells accumulated up to 11.2 times more Fe (up to 2.8 wt%) in the presence of optimal concentrations of Fe additives compared to the control. Intracellular iron accumulation and hydrogen yield were positively correlated with acetate concentration (p < 0.001), suggesting an efficient acetate pathway for dark fermentation. During the stationary growth phase, with almost no H2 production, the intracellular iron content decreased by up to 67.9 %. The phenomenon of changes in the amount of metal in cells, depending on the phase of hydrogen production, was demonstrated for the first time. The findings suggest that intracellular metals can be used in cell metabolism to produce H2, and the mechanisms behind this process need further investigation. Overall, this study provides valuable insights into the optimal forms and doses of metals for enhancing biohydrogen production, as well as possible research directions for the potential use of metals by microorganisms during additive-assisted dark fermentation of carbohydrate-rich wastes.

In Vitro Effect of Epigallocatechin Gallate on Heme Synthesis Pathway and Protoporphyrin IX Production.

Photodynamic therapy (PDT) treats nonmelanoma skin cancer. PDT kills cells through reactive oxygen species (ROS), generated by interaction among cellular O2, photosensitizer and specific light. Protoporphyrin IX (PpIX) is a photosensitizer produced from methyl aminolevulinate (MAL) by heme group synthesis (HGS) pathway. In PDT-resistant cells, PDT efficacy has been improved by addition of epigallocatechin gallate (EGCG). Therefore, the aim of this work is to evaluate the effect of EGCG properties over MAL-TFD and PpIX production on A-431 cell line. EGCG's role over cell proliferation (flow cytometry and wound healing assay) and clonogenic capability (clonogenic assay) was evaluated in A-431 cell line, while the effect of EGCG over MAL-PDT was determined by cell viability assay (MTT), PpIX and ROS detection (flow cytometry), intracellular iron quantification and gene expression of HGS enzymes (RT-qPCR). Low concentrations of EGCG (<50 µM) did not have an antiproliferative effect over A-431 cells; however, EGCG inhibited clonogenic cell capability. Furthermore, EGCG (<50 µM) improved MAL-PDT cytotoxicity, increasing PpIX and ROS levels, exerting a positive influence on PpIX synthesis, decreasing intracellular iron concentration and modifying HGS enzyme gene expression such as PGB (upregulated) and FECH (downregulated). EGCG inhibits clonogenic capability and modulates PpIX synthesis, enhancing PDT efficacy in resistant cells.

Deubiquitinating Enzyme USP19 Regulates Ferroptosis and Mitochondrial Damage in SH-SY5Y Cells by Targeting the NOX4 Protein.

Ferroptosis is extremely relevant to the progression of neurodegenerative pathologies such as Alzheimer's disease (AD). Ubiquitin-specific proteases (USP) can affect the NADPH oxidase family. Our study aimed to elucidate the potential role and molecular basis of a certain USP19 in reducing ferroptosis and mitochondrial injury in AD cells by targeting NOX4 stability. The deubiquitinase USP family gene USP19, which affects the stability of NOX4 protein, was first screened. The cell model of AD was constructed after interfering with SH-SY5Y cells by Aβ1-40, and then SH-SY5Y cells were infected with lentiviral vectors to knock down USP19 and overexpress NOX4, respectively. Finally, the groups were tested for cell viability, changes in cellular mitochondrial membrane potential, lipid reactive oxygen species, intracellular iron metabolism, and NOX4, Mf1, Mf2, and Drp1 protein expression. 5 μmol/L Aβ1-40 intervened in SH-SY5Y cells for 24 h to construct a cell model of AD. Knockdown of USP19 decreased the expression of NOX4 protein, promoted the expression of mitochondrial fusion proteins Mnf1 and Mnf2, and inhibited the expression of the splitting protein Drp1. Furthermore, USP19 knockdown decreased mitochondrial membrane potential, SOD, MDA, intracellular iron content and increased GSH/GSSG ratio in SH-SY5Y cells. Our study revealed that NOX4 protein interacts with USP19 and knockdown of USP19 enhanced ubiquitination to maintain NOX4 protein stability. USP19 attenuates mitochondrial damage in SH-SY5Y cells by targeting NOX4 protein with Aβ1-40.

Linalool and Geraniol Defend Neurons from Oxidative Stress, Inflammation, and Iron Accumulation in In Vitro Parkinson's Models.

Parkinson's disease is one of the most prevalent neurological disorders affecting millions of people worldwide. There is a growing demand for novel and natural substances as complementary therapies. Essential oils and their various compounds are highly investigated natural plant-based products as potential treatment options for common human diseases, such as microbial infections, chronic diseases, and neurodegenerative disorders. The present study focuses on the beneficial effects of linalool and geraniol, the major compounds of lavender (Lavandula angustifolia L.) and geranium (Pelargonium graveolens L'Hér. in Aiton) essential oils, on oxidative stress, inflammation, and iron metabolism of the rotenone and 6-hydroxydopamine-induced in vitro Parkinson's models. The experiments were carried out on all-trans retinoic acid differentiated SH-SY5Y cells. The effects of linalool and geraniol were compared to rasagiline, an MAO-B inhibitor. The results revealed that both essential oil compounds reduce the level of reactive oxygen species and alter the antioxidant capacity of the cells. They lower the secretion of IL-6, IL-8, and IL-1β pro-inflammatory cytokines. Moreover, linalool and geraniol change the expression of iron-related genes, such as the iron importer transferrin receptor 1, heme-oxygenase-1, and ferroportin iron exporter, and influence the intracellular iron contents. In addition, it has been unveiled that iron availability is concatenated with the actions of the essential oil compounds. Based on the results, linalool and geraniol are vigorous candidates as an alternative therapy for Parkinson's disease.

ZnO NPs induce miR-342-5p mediated ferroptosis of spermatocytes through the NF-κB pathway in mice

BackgroundZinc oxide nanoparticle (ZnO NP) is one of the metal nanomaterials with extensive use in many fields such as feed additive and textile, which is an emerging threat to human health due to widely distributed in the environment. Thus, there is an urgent need to understand the toxic effects associated with ZnO NPs. Although previous studies have found accumulation of ZnO NPs in testis, the molecular mechanism of ZnO NPs dominated a decline in male fertility have not been elucidated.ResultsWe reported that ZnO NPs exposure caused testicular dysfunction and identified spermatocytes as the primary damaged site induced by ZnO NPs. ZnO NPs led to the dysfunction of spermatocytes, including impaired cell proliferation and mitochondrial damage. In addition, we found that ZnO NPs induced ferroptosis of spermatocytes through the increase of intracellular chelatable iron content and lipid peroxidation level. Moreover, the transcriptome analysis of testis indicated that ZnO NPs weakened the expression of miR-342-5p, which can target Erc1 to block the NF-κB pathway. Eventually, ferroptosis of spermatocytes was ameliorated by suppressing the expression of Erc1.ConclusionsThe present study reveals a novel mechanism in that miR-342-5p targeted Erc1 to activate NF-κB signaling pathway is required for ZnO NPs-induced ferroptosis, and provide potential targets for further research on the prevention and treatment of male reproductive disorders related to ZnO NPs.Graphical

Biological characteristics of manganese transporter MntP in Klebsiella pneumoniae.

Klebsiella pneumoniae is an important opportunistic pathogen that causes a variety of infections. It is critical for bacteria to maintain metal homeostasis during infection. By using an isogenic mntP deletion mutant of K. pneumoniae strain NTUH-K2044, we found that MntP was a manganese efflux pump. Manganese increased the tolerance to oxidative stress, and oxidative stress could increase the intracellular manganese concentration. In oxidative stress, the mntP deletion mutant exhibited significantly higher sensitivity to manganese. Furthermore, iron could increase the tolerance of the mntP deletion mutant to manganese. Inductively coupled plasma mass spectrometry analysis revealed that the mntP deletion mutant had higher intracellular manganese and iron concentrations than wild-type and complementary strains. These findings suggested that iron could increase manganese tolerance in K. pneumoniae. This work elucidated the role of MntP in manganese detoxification and Mn/Fe homeostasis in K. pneumoniae.IMPORTANCEMetal homeostasis plays an important role during the process of bacterial infection. Herein, we revealed that MntP was involved in intracellular manganese homeostasis. Manganese promoted resistance to oxidative stress in Klebsiella pneumoniae. Furthermore, we demonstrated that the mntP deletion mutant exhibited significantly lower survival under manganese and H2O2 conditions. Oxidative stress increased the intracellular manganese content of the mntP deletion mutant. MntP played a critical role in maintaining intracellular manganese and iron concentrations. MntP contributed to manganese detoxification and Mn/Fe homeostasis in K. pneumoniae.

The Micacocidin Production-Related RSc1806 Deletion Alters the Quorum Sensing-Dependent Gene Regulation of Ralstonia pseudosolanacearum Strain OE1-1.

The soil-borne phytopathogenic gram-negative bacterium Ralstonia solanacearum species complex (RSSC) produces staphyloferrin B and micacocidin as siderophores that scavenge for trivalent iron (Fe3+) in the environment, depending on the intracellular divalent iron (Fe2+) concentration. The staphyloferrin B-deficient mutant reportedly retains its virulence, but the relationship between micacocidin and virulence remains unconfirmed. To elucidate the effect of micacocidin on RSSC virulence, we generated the micacocidin productivity-deficient mutant (ΔRSc1806) that lacks RSc1806, which encodes a putative polyketide synthase/non-ribosomal peptide synthetase, using the RSSC phylotype I Ralstonia pseudosolanacearum strain OE1-1. When incubated in the condition without Fe2+, ΔRSc1806 showed significantly lower Fe3+-scavenging activity, compared with OE1-1. Until 8 days after inoculation on tomato plants, ΔRSc1806 was not virulent, similar to the mutant (ΔphcA) missing phcA, which encodes the LysR-type transcriptional regulator PhcA that regulates the expression of the genes responsible for quorum sensing (QS)-dependent phenotypes including virulence. The transcriptome analysis revealed that RSc1806 deletion significantly altered the expression of more than 80% of the PhcA-regulated genes in the mutant grown in medium with or without Fe2+. Among the PhcA-regulated genes, the transcript levels of the genes whose expression was affected by the deletion of RSc1806 were strongly and positively correlated between the ΔRSc1806 and the phcA-deletion mutant. Furthermore, the deletion of RSc1806 significantly modified QS-dependent phenotypes, similar to the effects of the deletion of phcA. Collectively, our findings suggest that the deletion of micacocidin production-related RSc1806 alters the regulation of PhcA-regulated genes responsible for QS-dependent phenotypes including virulence as well as Fe3+-scavenging activity. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Diversity and dynamic response of anaerobic ammonia oxidation granular sludge

Red anaerobic ammonia oxidation (Anammox) granular sludge (AnGS) has been reported in successfully operating Anammox systems, and its color is associated with sludge activity. However, in long-term operating systems, AnGS exhibits different sensory colors, physical structures, community structures, and denitrification performance, but the relationship between them has not yet been elucidated. The AnGS of the Anammox system, which has been in operation for more than a decade, can be divided into two main categories: red and white. The specific Anammox activity (SAA) in conventional red AnGS increased continuously as the particle size increased from <0.51 mm to 6.02 ± 0.84 mm. The SAA of white AnGS were slightly lower than those of red AnGS with similarly-size granules but significantly higher than AnGS with smaller red granules. Compared with red AnGS, the extracellular polymeric substances of white AnGS were significantly reduced, mainly due to the higher intracellular iron content, resulting in lower heme c concentration. Thus, heme c may prove not to be an evaluative tool for measuring Anammox activity. Red and white AnGS, whether through self-aggregation or adsorption by hydroxyl apatite and other carriers, will face the fate of internal voids during particle size growth. White AnGS exhibited a more complex microbial community than red AnGS. Candidatus Brocadia was abundant in red AnGS and the abundance increased with increasing granule size. Candidatus Kuenenia and Candidatus Jettenia made significant contributions to denitrification in white AnGS. This study provides a new perspective on particle selection for anammox engineering applications.