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The disorderly discharge of industrial wastewater containing heavy metals has caused serious water pollution and ecological environmental risks, ultimately threatening human life and health. Biological treatment methods have obvious advantages, but the existing microorganisms exhibit issues such as poor resistance, adaptability, colonization ability, and low activity. However, a wide variety of microorganisms in deep-sea hydrothermal vent areas are tolerant to heavy metals, possessing the potential for efficient treatment of heavy metal wastewater. Based on this, the study obtained a group of deep-sea microbial communities dominated by Burkholderia-Caballeronia-Paraburkholderia through shake flask experiments from the sediments of deep-sea hydrothermal vents, which can simultaneously achieve the synchronous removal of vanadium and cadmium heavy metals through bioreduction, biosorption, and biomineralization. Through SEM-EDS, XRD, XPS, and FT-IR analyses, it was found that V(V) was reduced to V(IV) through a reduction process and subsequently precipitated. Glucose oxidation accelerated this process. Cd(II) underwent biomineralization to form precipitates such as cadmium hydroxide and cadmium carbonate. Functional groups on the microbial cell surface, such as -CH2, C=O, N-H, -COOH, phosphate groups, amino groups, and M-O moieties, participated in the bioadsorption processes of V(V) and Cd(II) heavy metals. Under optimal conditions, namely a temperature of 40 °C, pH value of 7.5, inoculation amount of 10%, salinity of 4%, COD concentration of 600 mg/L, V 5+ concentration of 300 mg/L, and Cd 2+ concentration of 40 mg/L, the OD 600 can reach its highest at 72 h, with the removal efficiency of V 5+ , Cd 2+ , and COD in simulated vanadium smelting wastewater reaching 86.32%, 59.13%, and 61.63%, respectively. This study provides theoretical insights and practical evidence for understanding the dynamic changes in microbial community structure under heavy metal stress, as well as the resistance mechanisms of microbial treatment of industrial heavy metal wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The modulation of autophagy has been presented as a very useful strategy in anticancer treatments. In this sense, the vanadium complex (VC) bis(2,2'-bipyridine)chlorooxovanadium(IV), [VO(bpy) 2 Cl], is known for its ability to induce autophagy in triple-negative breast cancer cells (TNBC). An excellent resource to investigate the role of VC in the induction of autophagy is to make use of Molecular Dynamics (MD) simulations. However, until now, the scarcity of force field parameters for the VC prevented a reliable analysis. The autophagy signaling pathway starts with the PI3K protein and ends with ULK1. Therefore, in the first stage of this work, we developed a new AMBER force field for the VC (VCFF) from a quantum structure, obtained by DFT calculations. In the second stage, the VCFF was validated through structural analyses. From this, it was possible to investigate, through docking and MD (200 ns), the performance of the PI3K-VC and ULK1-VC systems (third stage). The analyses of this last stage involved RMSD, hydrogen bonds, RMSF and two pathways for the modulation of autophagy. In general, this work fills in the absence of force field parameters (FF) for VC by proposing an efficient and new FF, in addition to investigating, at the molecular level, how VC is able to induce autophagy in TNBC cells. This study encourages new parameterizations of metallic complexes and contributes to the understanding of the duality of autophagic processes.Communicated by Ramaswamy H. Sarma.

This study explores the reasons behind the variations in the enantioselectivity of the sulfoxidation of methyl phenyl sulfide by marine-derived vanadium-dependent haloperoxidases (VHPOs). Twelve new VHPOs of marine organisms were overexpressed, purified, and tested for their ability to oxidize sulfide. Most of these marine enzymes exhibited nonenantioselective behavior, underscoring the uniqueness of An VBPO from the brown seaweed Ascophyllum nodosum and Cp VBPO from the red seaweed Corallina pilulifera , which produce ( R )- and ( S )-sulfoxides, respectively. The enantioselective sulfoxidation pathway is likely due to direct oxygen transfer within the VHPO active site. This was demonstrated through molecular docking and molecular dynamics simulations, which revealed differences in the positioning of sulfide within An VBPO and Cp VBPO, thus explaining their distinct enantioselectivities. Nonenantioselective VHPOs probably follow a different oxidation pathway, initiating with sulfide oxidation to form a positively charged radical. Further insights were gained from studying the catalytic effect of VO 4 3- on H 2 O 2 -driven sulfoxidation. This research improves the understanding of VHPO-mediated sulfoxidation and aids in developing biocatalysts for sulfoxide synthesis.

The primary goal of this research is to investigate the mitigating effect of silicon (Si; 2 mM) on the growth of tomato seedlings under vanadium (V; 40 mg) stress. V stress caused higher V uptake in leaf, and enhanced concentration of leaf anthocyanin, H 2 O 2 , O 2 •- , and MDA, but a decreased in plant biomass, root architecture system, leaf pigments content, mineral elements, and Fv/Fm (PSII maximum efficiency). Si application increased the concentrations of crucial antioxidant molecules such as AsA and GSH, as well as the action of key antioxidant enzymes comprising APX, GR, DHAR, and MDHAR. Importantly, oxidative damage was remarkably alleviated by upregulation of these antioxidant enzymes genes. Moreover, Si application enhanced the accumulation of secondary metabolites as well as the expression their related-genes, and these secondary metabolites may restricted the excessive accumulation of H 2 O 2 . In addition, Si rescued tomato plants against the damaging effects of MG by boosting the Gly enzymes activity. The results confirmed that spraying Si to plants might diminish the V accessibility to plants, along with promotion of V stress resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Masson SAS.)

In enzymatic catalysis, the redox site and Lewis acid are the two main roles played by metal to assist amino acids. However, the reported enzyme mimics only focus on the redox-active metal as redox site, while the redox-inert metal as Lewis acid has, to the best of our knowledge, not been studied, presenting a bottleneck of enzyme mimics construction. Based on this, a series of highly efficient M x V 2 O 5 ·nH 2 O peroxidase mimics with vanadium as redox site and alkaline-earth metal ion (M 2+ ) as Lewis acid are reported. Experimental results and theoretical calculations indicate the peroxidase-mimicking activity of M x V 2 O 5 ·nH 2 O show a periodic change with the Lewis acidity (ion potential) of M 2+ , revealing the mechanism of redox-inert M 2+ regulating electron transfer of V-O through non-covalent polarization and thus promoting H 2 O 2 adsorbate dissociation. The biomimetic synergetic effect of redox site and Lewis acid is expected to provide an inspiration for design of enzyme mimics., (© 2024. The Author(s).)

With continuous mine exploitation, regional ecosystems have been damaged, resulting in a decline in the carbon sink capacity of mining areas. There is a global shortage of effective soil ecological restoration techniques for mining areas, especially for vanadium (V) and titanium (Ti) magnetite tailings, and the impact of phytoremediation techniques on the soil carbon cycle remains unclear. Therefore, this study aimed to explore the effects of long-term Pongamia pinnata remediation on soil organic carbon transformation of V-Ti magnetite tailing to reveal the bacterial community driving mechanism. In this study, it was found that four soil active organic carbon components (ROC, POC, DOC, and MBC) and three carbon transformation related enzymes (S-CL, S-SC, and S-PPO) in vanadium titanium magnetite tailings significantly (P < 0.05) increased with P. pinnata remediation. The abundance of carbon transformation functional genes such as carbon degradation, carbon fixation, and methane oxidation were also significantly (P < 0.05) enriched. The network nodes, links, and modularity of the microbial community, carbon components, and carbon transformation genes were enhanced, indicating stronger connections among the soil microbes, carbon components, and carbon transformation functional genes. Structural equation model (SEM) analysis revealed that the bacterial communities indirectly affected the soil organic carbon fraction and enzyme activity to regulate the soil total organic carbon after P. pinnata remediation. The soil active organic carbon fraction and free light fraction carbon also directly regulated the soil carbon and nitrogen ratio by directly affecting the soil total organic carbon content. These results provide a theoretical reference for the use of phytoremediation to drive soil carbon transformation for carbon sequestration enhancement through the remediation of degraded ecosystems in mining areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

[Display omitted] • Vanadium oxoanions and polyoxoanions. • Vanadium metabolism, toxicology and detoxification. • Vanadium coordination compounds with biologically relevant ligands. • Pharmacological activity of vanadium compounds. • Structural and spectroscopic studies. Different aspects of the chemistry and biochemistry of vanadium are analyzed in this review. The preparation and characterization of oxovanadates and polyoxovanadates, including simple orthovanadates, vanadates with the apatite structure, materials belonging to the CrVO 4 structural type, as well as divanadates, metavanadates and decavanadates were initially discussed. The second part is devoted to vanadium compounds and systems related to vanadium biochemistry. The coordination chemistry involved in vanadium metabolism is discussed in great detail, followed by the investigation of vanadium complexes of nucleotides, carbohydrates, amino acids, and related systems. Complexes of oxo-diacetic acid and of 8-hydroxyquinoline and related ligands were also investigated. The biological activity of some of these complexes is also analyzed. Besides, systems involved in enzymatic reactions and in the activity of vanadium-dependent-haloperoxidases as well as in vanadium toxicology and detoxification are discussed. In these studies different physicochemical characterization methodologies were used, usually including vibrational (IR and Raman) and electronic absorption spectroscopy. Crystallographic studies were performed in some cases as well as the investigation of the thermal, electrochemical and magnetic behaviour. Resonance-Raman, ESR and photoelectron spectroscopy were also used in certain cases. [ABSTRACT FROM AUTHOR]

The sea squirt Ciona robusta (formerly Ciona intestinalis type A) has been the subject of many interdisciplinary studies. Known as a vanadium-rich ascidian, C. robusta is an ideal model for exploring microbes associated with the ascidian and the roles of these microbes in vanadium accumulation and reduction. In this study, we discovered two bacterial strains that accumulate large amounts of vanadium, CD2-88 and CD2-102, which belong to the genera Pseudoalteromonas and Vibrio, respectively. The growth medium composition impacted vanadium uptake. Furthermore, pH was also an important factor in the accumulation and localization of vanadium. Most of the vanadium(V) accumulated by these bacteria was converted to less toxic vanadium(IV). Our results provide insights into vanadium accumulation and reduction by bacteria isolated from the ascidian C. robusta to further study the relations between ascidians and microbes and their possible applications for bioremediation or biomineralization., (© 2024. The Author(s).)

Vanadium (V) pollution potentially threatens human health. Here, it is found that nsp1 and nsp2, Rhizobium symbiosis defective mutants of Medicago truncatula, are sensitive to V. Concentrations of phosphorus (P), iron (Fe), and sulfur (S) with V are negatively correlated in the shoots of wild-type R108, but not in mutant nsp1 and nsp2 shoots. Mutations in the P transporter PHT1, PHO1, and VPT families, Fe transporter IRT1, and S transporter SULTR1/3/4 family confer varying degrees of V tolerance on plants. Among these gene families, MtPT1, MtZIP6, MtZIP9, and MtSULTR1; 1 in R108 roots are significantly inhibited by V stress, while MtPHO1; 2, MtVPT2, and MtVPT3 are significantly induced. Overexpression of Arabidopsis thaliana VPT1 or M. truncatula MtVPT3 increases plant V tolerance. However, the response of these genes to V is weakened in nsp1 or nsp2 and influenced by soil microorganisms. Mutations in NSPs reduce rhizobacterial diversity under V stress and simplify the V-responsive operational taxonomic unit modules in co-occurrence networks. Furthermore, R108 recruits more beneficial rhizobacteria related to V, P, Fe, and S than does nsp1 or nsp2. Thus, NSPs can modulate the accumulation and tolerance of legumes to V through P, Fe, and S transporters, ion homeostasis, and rhizobacterial community responses., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

Vanadium-dependent haloperoxidases (VHPOs) are a unique family of enzymes that utilize vanadate, an aqueous halide ion, and hydrogen peroxide to produce an electrophilic halogen species that can be incorporated into electron rich organic substrates. This halogen species can react with terpene substrates and trigger halonium-induced cyclization in a manner reminiscent of class II terpene synthases. While not all VHPOs act in this capacity, several notable examples from algal and actinobacterial species have been characterized to catalyze regio- and enantioselective reactions on terpene and meroterpenoid substrates, resulting in complex halogenated cyclic terpenes through the action of single enzyme. In this article, we describe the expression, purification, and chemical assays of NapH4, a difficult to express characterized VHPO that catalyzes the chloronium-induced cyclization of its meroterpenoid substrate., (Copyright © 2024. Published by Elsevier Inc.)

In this article, the implications of binding competition of vanadates(V) with dodecyl sulfates for bovine serum albumin on cytotoxicity of vanadium(V) species against prostate cancer cells have been investigated. The pH- and SDS-dependent vanadate(V)-BSA interactions were observed. At pH 5, there is only one site capable of binding ten vanadates(V) ions (logK (ITC)1  = 4.96 ± 0.06; ΔH (ITC)1  = -1.04 ± 0.03 kcal mol -1 ), whereas at pH 7 two distinctive binding sites on protein were found, saturated with two and seven V(V) ions, respectively (logK (ITC)1  = 6.11 ± 0.06; ΔH (ITC)1  = 0.78 ± 0.12 kcal mol -1 ; logK (ITC)2  = 4.80 ± 0.02; ΔH (ITC)2  = - 4.95 ± 0.14 kcal mol -1 ). SDS influences the stoichiometry and the stability of the resulting V(V)-BSA complexes. Finally, the cytotoxicity of vanadates(V) against prostate cancer cells (PC3 line) was examined in the presence and absence of SDS in the culture medium. In the case of a 24-h incubation with 100 μM vanadate(V), a ca. 20 % reduction in viability of PC3 cells was observed in the presence of SDS. However, in other considered cases (various concentrations and time of incubation) SDS does not affect the dose-dependent action of vanadates(V) on the investigated prostate cancer cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Exposure to heavy metals, such as vanadium, poses an ongoing environmental and health threat, heightening the risk of neurodegenerative disorders. While several compounds have shown promise in mitigating vanadium toxicity, their efficacy is limited. Effective strategies involve targeting specific subunits of the NMDA receptor, a glutamate receptor linked to neurodegenerative conditions. The potential neuroprotective effects of ZA-II-05, an NMDA receptor antagonist, against vanadium-induced neurotoxicity were explored in this study. Organotypic rat hippocampal slices, and live mice, were used as models to comprehensively evaluate the compound's impact. Targeted in vivo fluorescence analyses of the hippocampal slices using propidium iodide as a marker for cell death was utilized. The in vivo study involved five dams, each with eight pups, which were randomly assigned to five experimental groups ( n = 8 pups). After administering treatments intraperitoneally over six months, various brain regions were assessed for neuropathologies using different immunohistochemical markers. High fluorescence intensity was observed in the hippocampal slices treated with vanadium, signifying cell death. Vanadium-exposed mice exhibited demyelination, microgliosis, and neuronal cell loss. Significantly, treatment with ZA-II-05 resulted in reduced cellular death in the rat hippocampal slices and preserved cellular integrity and morphological architecture in different anatomical regions, suggesting its potential in countering vanadium-induced neurotoxicity.

Increasing evidence suggests that organic vanadium compounds are bioavailable and safe therapeutic agents with insulin-mimetic and insulin-enhancing features. The objective of the current study was to examine the effect of vanadium-enriched yeast (VEY) supplementation on the gene expression level of insulin receptor substrates and clinical manifestations of obese type 2 diabetic mellitus (T2DM) patients. In this randomized, double-blind, placebo-controlled clinical trial, 44 obese T2DM patients were randomly allocated into either VEY (0.9 mg/day vanadium pentoxide) or placebo group for 12 weeks. The mRNA expression level of protein tyrosine phosphatase 1B (PTP1B), phosphatase and tensin homolog (PTEN), mitogen-activated protein kinase (MAPK), ribosomal protein S6 kinase (S6K), and nuclear factor kappa-light-chain-enhancer of activated B cells (NFƘB) genes in the peripheral blood mononuclear cells, serum levels of metabolic parameters, anthropometric indices, as well as the quality of life, and dietary intake were collected at pre- and post-intervention phases. Analysis of covariance was performed to obtain the corresponding effect size. Results showed that VEY administration significantly decreased anthropometric indices and glycemic parameters and increased insulin sensitivity after adjusting for potential covariates (p < 0.05), in comparison to the placebo group. Additionally, VEY supplementation was significantly effective on MAPK, PTP1B, and NFƘB gene expression level, compared to the placebo group. No significant changes were noticed for dietary intake, quality of life, and lipid profile in the VEY group, compared to the placebo group. Overall, VEY supplementation can be considered as a promising safe adjunct therapy for improving anthropometric indices and glycemic parameters in T2DM patients., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Vanadium is available as a dietary supplement and also is known to be toxic if inhaled, yet little information is available concerning the effects of vanadium on mammalian metabolism when concentrations found in food and water. Vanadium pentoxide (V +5 ) is representative of the most common dietary and environmental exposures, and prior research shows that low-dose V +5 exposure causes oxidative stress measured by glutathione oxidation and protein S-glutathionylation. We examined the metabolic impact of V +5 at relevant dietary and environmental doses (0.01, 0.1, and 1 ppm for 24 h) in human lung fibroblasts (HLFs) and male C57BL/6J mice (0.02, 0.2, and 2 ppm in drinking water for 7 mo). Untargeted metabolomics using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) showed that V +5 induced significant metabolic perturbations in both HLF cells and mouse lungs. We noted 30% of the significantly altered pathways in HLF cells, including pyrimidines and aminosugars, fatty acids, mitochondrial and redox pathways, showed similar dose-dependent patterns in mouse lung tissues. Alterations in lipid metabolism included leukotrienes and prostaglandins involved in inflammatory signaling, which have been associated with the pathogenesis of idiopathic pulmonary fibrosis (IPF) and other disease processes. Elevated hydroxyproline levels and excessive collagen deposition were also present in lungs from V +5 -treated mice. Taken together, these results show that oxidative stress from environmental V +5 , ingested at low levels, could alter metabolism to contribute to common human lung diseases. NEW & NOTEWORTHY We used relevant dietary and environmental doses of Vanadium pentoxide (V +5 ) to examine its metabolic impact in vitro and in vivo. Using liquid chromatography-high-resolution mass spectrometry (LC-HRMS), we found significant metabolic perturbations, with similar dose-dependent patterns observed in human lung fibroblasts and male mouse lungs. Alterations in lipid metabolism included inflammatory signaling, elevated hydroxyproline levels, and excessive collagen deposition were present in V +5 -treated lungs. Our findings suggest that low levels of V +5 could trigger pulmonary fibrotic signaling.

The initiation of this study relies on a targeted genome-mining approach to highlight the presence of a putative vanadium-dependent haloperoxidase-encoding gene in the deep-sea hydrothermal vent fungus Hortaea werneckii UBOCC-A-208029. To date, only three fungal vanadium-dependent haloperoxidases have been described, one from the terrestrial species Curvularia inaequalis, one from the fungal plant pathogen Botrytis cinerea, and one from a marine derived isolate identified as Alternaria didymospora. In this study, we describe a new vanadium chloroperoxidase from the black yeast H. werneckii, successfully cloned and overexpressed in a bacterial host, which possesses higher affinity for bromide (K m  = 26 µM) than chloride (K m  = 237 mM). The enzyme was biochemically characterized, and we have evaluated its potential for biocatalysis by determining its stability and tolerance in organic solvents. We also describe its potential three-dimensional structure by building a model using the AlphaFold 2 artificial intelligence tool. This model shows some conservation of the 3D structure of the active site compared to the vanadium chloroperoxidase from C. inaequalis but it also highlights some differences in the active site entrance and the volume of the active site pocket, underlining its originality., (© 2023. The Author(s).)

Immunoglobulin A nephropathy (IgAN) is the most common type of glomerulonephritis in adults worldwide. Environmental metal exposure has been reported to be involved in the pathogenic mechanisms of kidney diseases, yet no further epidemiological study has been conducted to assess the effects of metal mixture exposure on IgAN risk. In this study, we conducted a matched case‒control design with three controls for each patient to investigate the association between metal mixture exposure and IgAN risk. A total of 160 IgAN patients and 480 healthy controls were matched for age and sex. Plasma levels of arsenic, lead, chromium, manganese, cobalt, copper, zinc, and vanadium were measured using inductively coupled plasma mass spectrometry. We used a conditional logistic regression model to assess the association between individual metals and IgAN risk, and a weighted quantile sum (WQS) regression model to analyze the effects of metal mixtures on IgAN risk. Restricted cubic splines were used to evaluate overall associations between plasma metal concentrations and estimated glomerular filtration rate (eGFR) levels. We observed that except for Cu, all the metals analyzed were nonlinearly associated with decreased eGFR, and higher concentrations of arsenic and lead were associated with elevated IgAN risk in both single-metal [3.29 (1.94, 5.57), 6.10 (3.39, 11.0), respectively] and multiple-metal [3.04 (1.66, 5.57), 4.70 (2.47, 8.97), respectively] models. Elevated manganese [1.76 (1.09, 2.83)] levels were associated with increased IgAN risk in the single-metal model. Copper was inversely related to IgAN risk in both single-metal [0.392 (0.238, 0.645)] and multiple-metal [0.357 (0.200, 0.638)] models. The WQS indices in both positive [2.04 (1.68, 2.47)] and negative [0.717 (0.603, 0.852)] directions were associated with IgAN risk. Lead, arsenic, and vanadium contributed significant weights (0.594, 0.195, and 0.191, respectively) in the positive direction; copper, cobalt, and chromium carried significant weights (0.538, 0.253, and 0.209, respectively). In conclusion, metal exposure was related to IgAN risk. Lead, arsenic, and copper were all significantly weighted factors of IgAN development, which may require further investigation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Vanadium (V) induced hazardous effects posturing a serious concern on crop production as well as food security. However, the nitric oxide (NO)-mediated alleviation of V-induced oxidative stress in soybean seedlings is still unknown. Therefore, this research was designed to explore the effects of exogenous NO to mitigate the V-induced phytotoxicity in soybean plants. Our upshots disclosed that NO supplementation considerably improved the plant biomass, growth, and photosynthetic attributes by regulating the carbohydrates, and plants biochemical composition, which further improved the guard cells, and stomatal aperture of soybean leaves. Additionally, NO regulated the plant hormones, and phenolic profile which restricted the V contents absorption (65.6%), and translocation (57.9%) by maintaining the nutrient acquisition. Furthermore, it detoxified the excessive V contents, and upsurged the antioxidants defense mechanism to lower the MDA, and scavenge ROS production. The molecular analysis further verified the NO-based regulation of lipid, sugar production, and degradation as well as detoxification mechanism in the soybean seedlings. Exclusively, we elaborated very first time the behind mechanism of V-induced oxidative stress alleviation by exogenous NO, hence illustrating the NO supplementation role as a stress alleviating agent for soybean grown in V contaminated areas to elevate the crop development and production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Microbial techniques have been extensively used for the remediation of nitrate and V(V) co-contaminations, but the mechanisms of electron and substances transport and metabolism of co-contaminations under oligotrophic niche have been largely overlooked. This study quantified the electron transfer and consumption, substance transfer, and metabolic pathways in the nitrate and V(V) co-contamination system under oligotrophic condition to explore the underlying mechanisms by characterizing the products and elucidating conventional cognitive pathways. This study compared the composition of the precipitates under the conditions of sufficient and insufficient carbon sources using energy-dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, and discovered the re-oxidation process of the already reduced V(IV). Electronic evidence for the re-oxidation process of V(IV) was also provided by electron transfer and quantitative analysis. Besides, this study found that the electron contribution ratio of NO 3 - -N → NO 2 - -N and V(V) → V(IV) reduction was 40.2:1. In addition, based on the functional prediction of PICRUSt 2, it was found that the utilization of intracellular reserve carbon source and enzymes in the transport chain were enhanced in oligotrophic microbiology niche. These results provide new insights into the stability of co-contamination reduction in oligotrophic microbiology niche and demonstrate a new mobilization pathway for V(V) in oligotrophic systems., Competing Interests: Declaration of competing interest This article implies that the work described has not been published previously. It is not under consideration for publication elsewhere, that its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Excessive vanadium (V) contamination is an attracting growing concern, which can negatively affect the health of human and ecosystems. But how V causes nephrotoxicity and the role of mitochondria-associated endoplasmic reticulum membrane (MAM) in V-induced nephrotoxicity have remained elusive. To explore the detailed mechanism and screen of potential effective drugs for V-evoked nephrotoxicity, a total of 72 ducks were divided into two groups, control group and V group (30 mg/kg V). Results showed that excessive V damaged kidney function of ducks including causing histopathological abnormality, biochemical makers derangement and oxidative stress. Then MAM of duck kidneys was extracted to investigate differentially expressed proteins (DEPs) under V exposure using proteomics analysis. Around 4240 MAM-localized proteins were identified, of which 412 DEPs showed dramatic changes, including 335 upregulated and 77 downregulated DEPs. On the basis of gene ontology (GO), string and KEGG database analysis, excessive V led to nephrotoxicity primarily by affecting MAM-mediated metabolic pathways, especially elevating the endoplasmic Reticulum (ER) proteostasis related pathway. Further validation analysis of the detected genes and proteins of ER proteostasis related pathway under V poisoning revealed a consistent relationship with proteome analysis, indicating that V disrupted MAM-mediated ER proteostasis. Accordingly, our data proved the critical role for MAM in V-evoked nephrotoxicity, particularly with MAM-mediated ER proteostasis, providing promising insights into the toxicological exploration mechanisms of V., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Osseointegration of titanium-based implants possessing complex macroscale/microscale/mesoscale/nanoscale (multiscale) topographies support a direct and functional connection with native bone tissue by promoting recruitment, attachment and osteoblastic differentiation of bone marrow stromal cells (MSCs). Recent studies show that the MSCs on these surfaces produce factors, including bone morphogenetic protein 2 (BMP2) that can cause MSCs not on the surface to undergo osteoblast differentiation, suggesting they may produce an osteogenic environment in vivo . This study examined if soluble factors produced by MSCs in contact with titanium-aluminum-vanadium (Ti6Al4V) implants possessing a complex multiscale biomimetic topography are able to induce osteogenesis ectopically. Ti6Al4V disks were grit-blasted and acid-etched to create surfaces possessing macroscale and microscale roughness (MM), micro/meso/nanoscale topography (MN), and macro/micro/meso/nanoscale topography (MMN TM ). Polyether-ether-ketone (PEEK) disks were also fabricated by machining to medical-grade specifications. Surface properties were assessed by scanning electron microscopy, contact angle, optical profilometry, and x-ray photoelectron spectroscopy. MSCs were cultured in growth media (GM). Proteins and local factors in their conditioned media (CM) were measured on days 4, 8, 10 and 14: osteocalcin, osteopontin, osteoprotegerin, BMP2, BMP4, and cytokines interleukins 6, 4 and 10 (IL6, IL4, and IL10). CM was collected from D14 MSCs on MMN TM and tissue culture polystyrene (TCPS) and lyophilized. Gel capsules containing active demineralized bone matrix (DBM), heat-inactivated DBM (iDBM), and iDBM + MMN-GM were implanted bilaterally in the gastrocnemius of athymic nude mice ( N = 8 capsules/group). Controls included iDBM + GM; iDBM + TCPS-CM from D5 to D10 MSCs; iDBM + MMN-CM from D5 to D10; and iDBM + rhBMP2 (R&D Systems) at a concentration similar to D5-D10 production of MSCs on MMN TM surfaces. Legs were harvested at 35D. Bone formation was assessed by micro computed tomography and histomorphometry (hematoxylin and eosin staining) with the histology scored according to ASTM 2529-13. DNA was greatest on PEEK at all time points; DNA was lowest on MN at early time points, but increased with time. Cells on PEEK exhibited small changes in differentiation with reduced production of BMP2. Osteoblast differentiation was greatest on the MN and MMN TM , reflecting increased production of BMP2 and BMP4. Pro-regenerative cytokines IL4 and IL10 were increased on Ti-based surfaces; IL6 was reduced compared to PEEK. None of the media from TCPS cultures was osteoinductive. However, MMN-CM exhibited increased bone formation compared to iDBM and iDBM + rhBMP2. Furthermore, exogenous rhBMP2 alone, at the concentration found in MMN-CM collected from D5 to D10 cultures, failed to induce new bone, indicating that other factors in the CM play a critical role in that osteoinductive microenvironment. MSCs cultured on MMN TM Ti6Al4V surfaces differentiate and produce an increase in local factors, including BMP2, and the CM from these cultures can induce ectopic bone formation compared to control groups, indicating that the increased bone formation arises from the local response by MSCs to a biomimetic, multiscale surface topography., (Creative Commons Attribution license.)

Ascidians use a class of cysteine-rich proteins generally referred to as vanabins to reduce vanadium ions, one of the many biological processes that involve the redox conversion between disulfide and dithiolate mediated by transition-metal ions. To further understand the nature of disulfide/dithiolate exchange facilitated by a vanadium center, we report herein a six-coordinate non-oxido V IV complex containing an unbound disulfide moiety, [V IV (PS3″)(PS1″ S-S )] ( 1 ) (PS3″ = [P(C 6 H 3 -3-Me 3 Si-2-S) 3 ] 3- , where PS1″ S-S is a disulfide form of PS3″). Complex 1 is obtained from a reaction of previously reported [V V (PS3″)(PS2″S H )] ( 2 ) (PS2″S H = [P(C 6 H 3 -3-Me 3 Si-2-SH)(C 6 H 3 -3-Me 3 Si-2-S) 2 ] with TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidin-1-yl)oxyl) via hydrogen atom transfer. Importantly, complex 1 can be reduced by two electrons to form an eight-coordinate V IV complex, [V IV (PS3″) 2 ] 2- ( 4 ). The reaction can be reversed through a two-electron oxidation process to regenerate complex 1 . The redox pathways both proceed through a common intermediate, [V(PS3″) 2 ] - ( 3 ), that has been previously reported as a resonance form of V V -dithiolate and a V IV -(thiolate)(thiyl-radical) species. This work demonstrates an unprecedented example of reversible disulfide/dithiolate interconversion mediated by a V IV center, as well as provides insights into understanding the function of V V reductases in vanabins.

The extensive application of nitrogen fertilizer in intensive irrigation areas poses a potential threat to groundwater. Given that the vadose zone acts as a buffer zone for the underground entry of surface pollutants, an in-depth understanding of its microbial community structure and function was crucial for controlling groundwater nitrogen pollution. In this study, soil samples from paddy vadose under groundwater irrigation with different depths (G1: 6.8 m, G2: 13.7 m, G3: 15.6 m, and G4: 17.8 m) were collected to unravel the differences in microbial community structure and function at different vadose depths (0-250 cm), as well as their relationship with soil properties. Results showed some differences among soil physicochemical factors under groundwater irrigation with different depths and that some electron acceptors were more abundant than others under deep groundwater irrigation (G2-G4). Remarkable differences in microbial communities under shallow- and deep-groundwater irrigation were found. The high abundances of anammox bacteria Candidatus&#95;Brocadia in G2 and G3 indicated that deep groundwater irrigation was beneficial to its enrichment. Iron-reducing bacteria Anaeromyxobacter and sulfate-reducing bacteria Desulfovibrio were widely distributed in vadose zone and possessed the potential for anammox coupled with Fe(III)/sulfate reduction. Norank&#95;f&#95;Gemmatimonadaceae had nitrate- and vanadium-reducing abilities and could participate in anammox in vadose zone. Dissimilatory nitrate reduction to ammonia (DNRA) bacteria Geobacter facilitated Fe(II)-driven DNRA and thus provided electron donors and acceptors to anammox bacteria. Soil nutrients and electron donors/acceptors played important roles in shaping microbial community structure at phylum and genus levels. Microorganisms in vadose zone under groundwater irrigation showed good material/energy metabolism levels. Deep groundwater irrigation was conducive to the occurrence of anammox coupled with multi-electron acceptors. Our findings highlight the importance of understanding the structure and function of microbial communities in paddy vadose under groundwater irrigation and reveal the potential role of indigenous microorganisms in in-situ nitrogen removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The increasing industrial use of vanadium (V), as well as its recent medical use in various pathologies has intensified its environmental release, making it an emerging pollutant. The sea urchin embryo has long been used to study the effects induced by metals, including V. In this study we used an integrated approach that correlates the biological effects on embryo development with proteolytic activities of gelatinases that could better reflect any metal-induced imbalances. V-exposure caused morphological/morphometric aberrations, mainly concerning the correct distribution of embryonic cells, the development of the skeleton, and the embryo volume. Moreover, V induced a concentration change in all the gelatinases expressed during embryo development and a reduction in their total proteolytic activity. The presence of three MMP-like gelatinases (MMP-2, -9, and -14) was also demonstrated and their levels depended on V-concentration. In particular, the MMP-14-like protein modified its expression level during embryo development in a time- and dose-dependent manner. This enzyme also showed a specific localization on filopodia, suggesting that primary mesenchyme cells (PMCs) could be responsible for its synthesis. In conclusion, these results indicate that an integrated study among morphology/morphometry, proteolytic activity, and MMP-14 expression constitutes an important response profile to V-action.

Vanadium (V) is a transitional metal that poses health risks to exposed humans. Microorganisms play an important role in remediating V contamination by reducing more toxic and mobile vanadate (V(V)) to less toxic and mobile V(IV). In this study, DNA-stable isotope probing (SIP) coupled with metagenomic-binning was used to identify microorganisms responsible for V(V) reduction and determine potential metabolic mechanisms in cultures inoculated with a V-contaminated river sediment. Anaeromyxobacter and Geobacter spp. were identified as putative V(V)-reducing bacteria, while Methanosarcina spp. were identified as putative V(V)-reducing archaea. The bacteria may use the two nitrate reductases NarG and NapA for respiratory V(V) reduction, as has been demonstrated previously for other species. It is proposed that Methanosarcina spp. may reduce V(V) via anaerobic methane oxidation pathways (AOM-V) rather than via respiratory V(V) reduction performed by their bacterial counterparts, as indicated by the presence of genes associated with anaerobic methane oxidation coupled with metal reduction in the metagenome assembled genome (MAG) of Methanosarcina. Briefly, methane may be oxidized through the "reverse methanogenesis" pathway to produce electrons, which may be further captured by V(V) to promote V(V) reduction. More specially, V(V) reduction by members of Methanosarcina may be driven by electron transport (CoMS-SCoB heterodisulfide reductase (HdrDE), F 420 H 2 dehydrogenases (Fpo), and multi-heme c-type cytochrome (MHC)). The identification of putative V(V)-reducing bacteria and archaea and the prediction of their different pathways for V(V) reduction expand current knowledge regarding the potential fate of V(V) in contaminated sites., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl 2 causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.

Iron (Fe), molybdenum (Mo), and vanadium (V) are the main components of the three known biological nitrogenases, which constrain nitrogen fixation and affect ecosystem productivity. Atmospheric deposition is an important pathway of these trace metals into ecosystems. Here, we explored the deposition flux, spatiotemporal pattern, and influencing factors of atmospheric wet Fe, Mo, and V deposition based on China Wet Deposition Observation Network (ChinaWD) data from 2016 to 2020. Our results showed that atmospheric wet Fe, Mo, and V deposition was 7.77 ± 7.24, 0.16 ± 0.11, and 0.13 ± 0.12 mg m -2 a -1 in Chinese terrestrial ecosystems, respectively, and revealed obvious spatial patterns but no significant annual trends. Wet Fe deposition was significantly correlated with the soil Fe content. Mo and V deposition was more affected by anthropogenic activities than Fe deposition. Wet Mo deposition was significantly affected by Mo ore reserves and waste incineration. V deposition was significantly correlated with domestic biomass burning. This study quantified wet Fe, Mo, and V deposition in China for the first time, and the implications of atmospheric trace metal deposition on biological nitrogen fixation were discussed.

As a prevalent progressive neurodegenerative disorder, Parkinson's disease (PD) is characterized by the neuropathological hallmark of the loss of nigrostriatal dopaminergic (DAergic) innervation and the appearance of Lewy bodies with aggregated α-synuclein. Although several familial forms of PD have been reported to be associated with several gene variants, most cases in nature are sporadic, triggered by a complex interplay of genetic and environmental risk factors. Numerous epidemiological studies during the past two decades have shown positive associations between PD and several environmental factors, including exposure to neurotoxic pesticides/herbicides and heavy metals as well as traumatic brain injury. Other environmental factors that have been implicated as potential risk factors for PD include industrial chemicals, wood pulp mills, farming, well-water consumption, and rural residence. In this review, we summarize the environmental toxicology of PD with the focus on the elaboration of chemical toxicity and the underlying pathogenic mechanisms associated with exposure to several neurotoxic chemicals, specifically 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, paraquat (PQ), dichloro-diphenyl-trichloroethane (DDT), dieldrin, manganese (Mn), and vanadium (V). Our overview of the current findings from cellular, animal, and human studies of PD provides information for possible intervention strategies aimed at halting the initiation and exacerbation of environmentally linked PD.

Although beneficial metalloid silicon (Si) has been proven to reduce the toxicity of several heavy metals, there is a lack of understanding regarding Si potential function in mitigating phytotoxicity induced by vanadium (V). In this study, effect of Si (1.5 mM) on growth, biomass production, V uptake, reactive oxygen species (ROS), methylglyoxal (MG) formation, selected antioxidants enzymes activities, glyoxalase enzymes under V stress (35 mg L -1 ) was investigated in hydroponic experiment. The results showed that V stress reduced rice growth, caused V accumulation in rice. Addition of Si to the nutritional medium increased plant growth, biomass yield, root length, root diameter, chlorophyll parameters, photosynthetic assimilation, ion leakage, antioxidant enzymes activities under V stress. Notably, Si sustained V-homeostasis and alleviated V caused oxidative stress by boosting ascorbate (AsA) levels and the activity of antioxidant enzymes in V stressed rice plants. Furthermore, Si protected rice seedlings against the harmful effects of methylglyoxal by increasing the activity of glyoxalase enzymes. Additionally, Si increased the expression of numerous genes involved in the detoxification of reactive oxygen species (e.g., OsCuZnSOD1, OsCaTB, OsGPX1, OsAPX1, OsGR2, and OsGSTU37) and methylglyoxal (e.g., OsGLYI-1 and OsGLYII-2). The findings supported that Si can be applied to plants to minimize the V availability to plant, and also induced V stress tolerance., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Alzheimer's disease (AD) is a complex and progressive neurodegenerative disease with impaired synapse, imbalanced mineral metabolism, protein mis-folding and aggregation. Bis(ethylmaltolato)oxidovanadium(IV) (BEOV), an organic bioactive vanadium compound with low toxicity and high bioavailability, has been studied as therapeutic agent against tuberculosis and diabetes. However, its neuroprotective effects have rarely been reported. Therefore, in this study, the potential application of BEOV in intervening AD cognitive dysfunction and neuropathology was evaluated. Both low- and high-dose of BEOV (0.2 mmol/L and 1.0 mmol/L) supplementation for 2 months improved the spatial learning and memory deficits of the triple-transgenic AD (3 × Tg AD) mice and mitigated the loss of synaptic proteins and synaptic dysfunction. By inhibiting the expression of amyloid-β precursor protein and β-secretase, and the phosphorylation of tau protein at Ser262, Ser396, Ser404, and Ser202/Thr205 residues, BEOV reduced the amyloid-β deposition and neurofibrillary tangle formation in AD mouse brains and primarily cultured neurons. Further analysis of the brain ionome revealed that BEOV supplementation could significantly affect the concentrations of a variety of metals, most of which, including several AD risk metals, showed reduced levels, particularly with a high-dose intake. Additionally, the elemental correlation network identified both conserved and specific elemental correlations, implying a highly complex and dynamic crosstalk between vanadium and other elements during long-term BEOV supplementation. Overall, our results suggest that BEOV is effective in AD intervention via both ameliorating the disease related pathology and regulating metal homeostasis., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Vanadium toxicology is a topic of considerable importance as this metal is widely used in industrial and biomedical fields. However, it represents a potential emerging environmental pollutant because wastewater treatment plants do not adequately remove metal compounds that are subsequently released into the environment. Vanadium applications are limited due to its toxicity, so it is urgent to define this aspect. This metal is associated with sea urchin embryo toxicity as it perturbs embryogenesis and skeletogenesis, triggering several stress responses. Here we investigated its bioaccumulation and the correlation with cellular and molecular developmental pathways. We used cytotoxic concentrations of 1 mM and 500 μM to perform quantitative analyses, showing that vanadium accumulation interferes with calcium uptake during sea urchin development and provokes a disruption in the biomineralization process. At the end of the whole treatment, the accumulation of vanadium was about 14 and 8 μg for embryos treated respectively with 1 mM and 500 μM, showing a dose-dependent response. Then, we monitored the cell signaling perturbation, analyzing key molecular markers of cell survival/cell death mechanisms and the DNA fragmentation associated with apoptosis. This paper clarifies vanadium's trend to accumulate directly into embryonic cells, interfering with calcium uptake. In addition, our results indicate that vanadium can modulate the ERK pathway and activate a cell-selective apoptosis. These results endorse the sea urchin embryo as an adequate experimental model to study metal-related cellular/molecular responses.

Vanadium toxicity is a globally recognized threat to the reproductive health of man and animal. However the mechanism of vanadium-induced damage to the testicular and adrenocortical tissues is not fully characterized. It was hypothesized that prostaglandins may partially mediate the inflammatory response to vanadate damage. In this study prostaglandin (PG) mediated effects of vanadate on testicular and adrenocortical functions was substantiated by using indomethacin to block prostaglandin synthesis. Significant inhibition of spermatogenesis, decreased serum level of testosterone and gonadotropins in the vanadium-exposed group of rats indicated the damaging effects of vanadium-induced reactive oxygen species. This was also reflected in the appreciable increase in testicular lipid peroxidation (LPO) level and decline in the activities of steroidogenic and antioxidant enzymes. Histopathological studies revealed regressive and degenerative changes in testis. However, inhibition of cyclooxygenase activity by indomethacin increased steroid hormone production, gonadotropin level, elevated the specific activities of enzymes and decreased LPO level in rat testis exposed to vanadium. Vanadium also caused prostaglandin mediated adrenocortical hyperactivity, as inhibition of PG synthesis abolished these adrenal responses to vanadium. The studies showed that vanadium toxicity is directly linked to stimulation of prostaglandin synthesis. Therefore, indomethacin can be a good prospect to alleviate vanadium induced male infertility.

Three ONNO donor tetradentate diamino bis(phenolato) "salan" ligands, N, N'-dimethyl-N, N'-bis-(5-chloro-2-hydroxy-3-methyl-benzyl)-1,2-diaminoethane (H 2 L 1 ), N, N'-dimethyl-N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diamino-ethane (H 2 L 2 ) and N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diaminocyclohexane (H 2 L 3 ) have been synthesized by following Mannich condensation reaction. Reaction of these ligands with their corresponding vanadium metal precursors gave one oxidomethoxidovanadium(V) [V V OL 1 (OCH 3 )] (1) and two monooxido-bridged divanadium (V, V) complexes [V V OL 2-3 ] 2 (μ-O) (2-3). The complexes were characterized by IR, UV-vis, NMR and ESI mass spectrometry. Also, the structure of all the complexes (1-3) was confirmed by the Single-Crystal X-ray diffraction analysis, which revealed a distorted octahedral geometry around the metal centres. The solution behavior of the [V V OL 1 (OCH 3 )] (1) reveals the formation of two different types of V(V) species in solution, the structurally characterized compound 1 and its corresponding monooxido-bridged divanadium (V, V) complex [V V OL 1 ] 2 (μ-O), which was further studied by IR, and NMR spectroscopy. The electrochemical behavior of all the complexes was evaluated through cyclic voltammetry. Interaction of the salan-V(V) complexes with human serum albumin (HSA) and bovine serum albumin (BSA) were analysed through fluorescence quenching, UV-vis absorption titration, synchronous fluorescence, circular dichroism studies, and förster resonance energy transfer (FRET). Finally, the in vitro cytotoxicity of the complexes was investigated against MCF-7 and HT-29 and NIH-3T3 cell lines. Cytotoxicity value of complexes in both MCF-7 and HT-29 follows the same trend that is 3 > 1 > 2 which is in line with protein binding affinity of the complexes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

To anchor in seashore habitats, mussels fabricate adhesive byssus fibers that are mechanically reinforced by protein-metal coordination mediated by 3,4-dihydroxyphenylalanine (DOPA). The mechanism by which metal ions are integrated during byssus formation remains unknown. In this study, we investigated the byssus formation process in the blue mussel, Mytilus edulis , combining traditional and advanced methods to identify how and when metals are incorporated. Mussels store iron and vanadium ions in intracellular metal storage particles (MSPs) complexed with previously unknown catechol-based biomolecules. During adhesive formation, stockpiled secretory vesicles containing concentrated fluid proteins are mixed with MSPs within a microfluidic-like network of interconnected channels where they coalesce, forming protein-metal bonds within the nascent byssus. These findings advance our understanding of metal use in biological materials with implications for next-generation metallopolymers and adhesives.

An improved methodology was developed for V redox speciation in estuarine waters using a hyphenated technique consisting of ion chromatograph (IC) with an anion exchange column and a high-resolution inductively coupled plasma mass spectrometer (HR ICP-MS). This approach enables the direct determination of V(V), whereas reduced species (mainly V(IV)) are calculated by subtracting V(V) concentrations from the measured total V concentration. Based on the "on-column" V(V) chelation mechanism by EDTA, with the eluent composed of 40 mmol L -1 ammonium bicarbonate, 40 mmol L -1 ammonium sulphate, 8 mmol L -1 ethylenediaminetetraacetic acid and 3% acetonitrile, the method was successfully used for analyses of V redox speciation in samples taken in the vertical salinity gradient of the highly stratified Krka River estuary. Due to the matrix effects causing different sensitivities, a standard addition method was used for V(V) quantification purposes. The limit of detection (LOD) was also found to be matrix related: 101.68 ng L -1 in the seawater and 30.56 µg L -1 in the freshwater. Performed stability tests showed that V redox speciation is preserved at least 7 days in un-treated samples, possibly due to the stabilization of V-reduced species with natural organic matter (NOM). The dominant V form in the analysed samples was V(V) with the reduced V(IV) accounting for up to 26% of the total dissolved pool. The concentration of V(IV) was found to correlate negatively with the oxygen concentration. Significant removal of dissolved V was detected in oxygen depleted zones possibly related to the particle scavenging.

The metal tolerance mechanism of plants is of great importance to explore the plant-based clean-up of environmental substrata contaminated by heavy metals. Indoor experiment of tobacco (Nicotiana tabacum L.) seedlings growing hydroponically in nutrient solution containing 0, 0.1, 0.5, 2.0, and 4.0 mg L -1  V was conducted. The results indicated that plant overall growth performance was significantly affected at ≥ 2.0 mg L -1  V. Oxidative stress degree as indicated by foliar O 2 - · and H 2 O 2 content intensified markedly at ≥ 0.5 mg L -1  V treatments. In response, the plant activated its enzyme and non-enzyme protecting mechanism to cope with oxidative stress inflicted by vanadium. The activities of antioxidant enzymes, including SOD, POD, CAT, APX, and the concentration of non-enzyme antioxidants, e.g., AsA and GSH were all conspicuously (p < 0.5 or p < 0.1) enhanced at ≥ 0.5 mg L -1  V treatments. Vanadium accumulated in leaves, stems, and roots increased with increasing vanadium level. The majority of the absorbed vanadium retained in plant root, and minor portions were transferred to aerial parts. Vanadium concentration in plant tissues ordered as root ˃ stem ˃ leaf. Translocation factors (TF) in vanadium-treated tobaccos (TF « 1) were significantly lower than that of control (TF ˃ 1). In conclusion, although vanadium at ≥ 2.0 mg L -1 inhibited plant growth, tobacco exhibited a relatively good vanadium tolerance through self-adaptive regulation and has the potential as a phytostabilizer in decontaminating the environment contaminated by vanadium., (Copyright © 2020 Elsevier Inc. All rights reserved.)

For the first time, vanadium of biological origin, extracted from centrifugal fraction of vanadium-storing blood cells of the Ascidia sydneiensis samea species, was characterized as regards its isotopic composition and content of natural radioactive elements potassium (K), thorium (Th) and uranium (U). The natural abundance of vanadium isotopes has been confirmed with high accuracy, thus excluding a possible selectivity within bio-chemical reactions of vanadium concentration in blood cells from seawater. A large potassium concentration (up to 5500 × 10 -6  g g -1 ) was found in the blood cell samples. The concentration of thorium was determined to be about 30 × 10 -9  g g -1 , while the uranium concentration was about 150 × 10 -9  g g -1 . Hence, a highly efficient two-stage purification approach with a total vanadium recovery of better than 70% was developed and applied. The final concentrations of K < 100 × 10 -6  g g -1 and of U/Th < 0.5 × 10 -9  g g -1 in the purified vanadium-containing samples were achieved. Vanadium extracted from centrifugal fraction of vanadium-storing blood cells after two-stage purification approach could be utilized in various applications, where a high chemical purity compound is required. However, to be used as a source of radiopure vanadium in ultra-low-background experiment aimed to search for 50 V beta decay, it should be further purified by Electron Beam Melting against residual potassium., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The role of vanadium binding to transferrin (Tf) in the biological activities of vanadium-based drugs is a matter of considerable debate. In order to determine whether V(V) and/or V(IV) binding to Tf (in apo, monoferric(III), and diferric(III) forms) enhances or inhibits biological activities, cellular V uptake and in vitro antiproliferative activity were examined in the presence and absence of different forms of Tf and other biomolecules under normoxic conditions. These data were combined with studies on V-Tf binding in cell culture medium and its role in Tf interactions with transferrin receptor 1 (TfR1), using the biolayer interferometry (BLI) model of the Tf cycle that was developed in our group. The results showed that both V(V) and V(IV) oxidation states efficiently bind to vacant Fe(III) binding sites of Tf even in the presence of a 20-fold molar excess of albumin, although V does not displace Tf-bound Fe(III) under these conditions. Binding of V(V) or V(IV) to Tf in cell culture medium drastically reduced its cellular uptake and antiproliferative activity in the A549 (human lung cancer) cell line that expresses TfR1. BLI and gel electrophoresis studies showed that V(V/IV) binding to partially Fe(III) saturated Tf did not enhance the affinity of Tf binding to TfR1 at pH 7.4 but did disrupt Tf conformational changes under endosome-mimicking conditions (pH 5.6, 0.10 mM citrate). Hence, it is postulated that the absence of a significant cellular uptake of Tf-bound V(V/IV) is likely to be due to the return of undissociated V(V/IV)-Tf adducts to the cell surface after the endosomal step. Collectively, these data show that the biotransformation of V-based drugs leads to V(V/IV)-Tf binding in the blood serum and inhibits, rather than enhances, the biological activity of such drugs under aerobic conditions. These results indicate that the design of V-based drugs that are stable enough to survive in the blood, enter cells intact, and release the active components intracellularly is likely to be required for their clinical success.

Obesity is a common disease over the world and is tightly associated with diabetes mellitus, cardiovascular and cancer disease. Although our previous study showed that the synthetic vanadium-protein (V-P) complex had a better effect on antioxidant and antidiabetic, the relative molecular mechanisms are still entirely unknown. Hence, we investigated the effect of the synthetic V-P complex on adipocyte differentiation (adipogenesis) using human preadipocytes to clarify its molecular mechanisms of action. The primary human preadipocytes were cultured with and without V-P complex during adipocyte differentiation. The cell proliferation, lipid accumulation, and the protein expression of transcription factors and related enzymes were determined for the differentiated human preadipocytes. In this study, the 20 μg/mL of V-P complex reduced the lipid and triglyceride (TG) content by 74.47 and 57.39% (p < 0.05), respectively, and down-regulated the protein expressions of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), sterol regulatory element-binding protein 1 (SREBP-1) and fatty acid synthase (FAS). Additionally, the V-P complex significantly up-regulated the protein levels of total β-catenin (t-β-catenin), nuclear β-catenin (n-β-catenin), phosphorylated adenosine monophosphate-activated protein kinase alpha (p-AMPKα) and liver kinase B1 (p-LKB1). These showed that the inhibitory effect of V-P complex on human adipogenesis was mediated by activating Wnt/β-catenin and LKB1/AMPK-dependent signaling pathway. Therefore, the synthetic V-P complex could be considered as a candidate for prevention and treatment of obesity., Competing Interests: There are no patents, products in development or marketed products associated with this research to declare. The connection to Haizhibao company does not alter our adherence to PLOS ONE policies on sharing data and materials.

Parkinson's disease (PD) pathology is characterised by distinct types of cellular defects, notably associated with oxidative damage and mitochondria dysfunction, leading to the selective loss of dopaminergic neurons in the brain's substantia nigra pars compacta (SNpc). Exposure to some environmental toxicants and heavy metals has been associated with PD pathogenesis. Raised iron levels have also been consistently observed in the nigrostriatal pathway of PD cases. This study explored, for the first time, the effects of an exogenous environmental heavy metal (vanadium) and its interaction with iron, focusing on the subtoxic effects of these metals on PD-like oxidative stress phenotypes in Catecholaminergic a-differentiated (CAD) cells and PTEN-induced kinase 1 (PINK-1) B9 Drosophila melanogaster models of PD. We found that undifferentiated CAD cells were more susceptible to vanadium exposure than differentiated cells, and this susceptibility was modulated by iron. In PINK-1 flies, the exposure to chronic low doses of vanadium exacerbated the existing motor deficits, reduced survival, and increased the production of reactive oxygen species (ROS). Both Aloysia citrodora Paláu, a natural iron chelator, and Deferoxamine Mesylate (DFO), a synthetic iron chelator, significantly protected against the PD-like phenotypes in both models. These results favour the case for iron-chelation therapy as a viable option for the symptomatic treatment of PD.

For a long time the biological role of vanadium was not known, while now the possibility of using its derivatives as potential therapeutic agents has given rise to investigations on their probable side effects. Vanadium compounds may inhibit different biochemical processes and lead to a variety of toxic effects and serious diseases. But, on the other hand, vanadium is an essential element for life. In recent years, increasing evidence has been acquired on the possible roles of vanadium in the higher forms of life. Despite several biochemical and physiological functions that have been suggested for vanadium and notwithstanding the amount of the knowledge so far accumulated, it still does not have a clearly defined role in the higher forms of life. What functions could vanadium or its very stable oxidovanadium(IV) derivatives have had in the prebiotic world and in the origins of life? In this review, we have briefly tried to highlight the most useful aspects that can be taken into consideration to give an answer to this still unresolved question and to show the high versatility of the oxidovanadium(IV) group to act as promoter of several oxidation reactions when coordinated with a variety of ligands, including diketones like acylpyrazolones.

The nitrogenase cofactors are structurally and functionally unique in biological chemistry. Despite a substantial amount of spectroscopic characterization of protein-bound and isolated nitrogenase cofactors, electrochemical characterization of these cofactors and their related species is far from complete. Herein we present voltammetric studies of three isolated nitrogenase cofactor species: the iron-molybdenum cofactor (M-cluster), iron-vanadium cofactor (V-cluster), and a homologue to the iron-iron cofactor (L-cluster). We observe two reductive events in the redox profiles of all three cofactors. Of the three, the V-cluster is the most reducing. The reduction potentials of the isolated cofactors are significantly more negative than previously measured values within the molybdenum-iron and vanadium-iron proteins. The outcome of this study provides insight into the importance of the heterometal identity, the overall ligation of the cluster, and the impact of the protein scaffolds on the overall electronic structures of the cofactors., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Microbial treatment for vanadium contamination of soils is a favorable and environment-friendly method. However, information of the resistant mechanism of the strains in soils to vanadium, especially to tetravalent vanadium [vanadium(IV)], is still limited. Herein, potential of the vanadium(IV) biosorption and biotransformation of the strains (4K1, 4K2, 4K3 and 4K4) which were capable of tolerating vanadium(IV) was determined. For biosorption, the bioadsorption and the bioabsorption of vanadium(IV) occur on the bacterial cell wall and within the cell, respectively, were taken into consideration. Comparison of the vanadium(IV) adsorbed on the bacterial cell walls and remained in the cells after sorption indicated the major bacterial vanadium(IV) sorption role of the bioadsorption which was at least one order of magnitude higher than the bioabsorption amount. Isotherm study using various isotherm models revealed a monolayer and a multilayer vanadium(IV) biosorption by 4K2 and the others (4K1, 4K3 and 4K4), respectively. Higher biosorption was observed in acidic conditions than in alkaline conditions, and the maximum biosorption was 2.41, 9.35, 7.76 and 8.44 mg g -1 observed at pH 6 for 4K1, at pH 3 for 4K2, and at pH 4 for 4K3 and 4K4, respectively. At the present experimental range of the initial vanadium(IV) concentration, optimal biosorption capacity of the bacteria was observed at the vanadium(IV) level of 100-250 mg L -1 . Different biotransformation level of vanadium(IV) in soils by the stains was observed during a 28-d pot incubation of the soils mixed with the strains, which can be attributed to the discrepancy of both soil properties and bacterial species. Present study can help to fill up the gaps of the insufficient knowledge of the vanadium(IV) resistant mechanism of the strains in soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Vanadium is a multivalent redox-sensitive metal that is widely distributed in the environment. Low levels of vanadium elevate plant height, root length, and biomass production due to enhanced chlorophyll biosynthesis, seed germination, essential element uptake, and nitrogen assimilation and utilization. However, high vanadium concentrations disrupt energy metabolism and matter cycling; inhibit key enzymes mediating energy production, protein synthesis, ion transportation, and other important physiological processes; and lead to growth retardation, root and shoot abnormalities, and even death of plants. The threshold level of toxicity is highly plant species-specific, and in most cases, the half maximal effective concentration (EC 50 ) of vanadium for plants grown under hydroponic conditions and in soil varies from 1 to 50 mg/L, and from 18 to 510 mg/kg, respectively. Plants such as Chinese green mustard, chickpea, and bunny cactus could accumulate high concentrations of vanadium in their tissues, and thus are suitable for decontaminating and reclaiming of vanadium-polluted soils on a large scale. Soil pH, organic matter, and the contents of iron and aluminum (hydr)oxides, phosphorus, calcium, and other coexisting elements affect the bioavailability, toxicity, and plant uptake of vanadium. Mediation of these conditions or properties in vanadium-contaminated soils could improve plant tolerance, accumulation, or exclusion, thereby enhancing phytoremediation efficiency. Phytoremediation with the assistance of soil amendments and microorganisms is a promising method for decontamination of vanadium polluted soils., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2019. Published by Elsevier B.V.)

This study investigated the tolerance of plants to vanadium (Ⅴ). The hydroponic method was employed to evaluate the absorption, transport, content, and subcellular distribution of vanadium in the polysaccharide fraction of corn seedlings cell wall under different concentrations of vanadium stress. Results showed that: (a) vanadium was mainly concentrated in the roots of the corn seedlings, and only trace amounts were transported to the leaves; (b) in terms of its subcellular distribution, vanadium was mainly enriched in cell wall regions followed by soluble fraction; (c) the content of vanadium in polysaccharide fraction was highest in alkali-soluble pectin, followed by chelated pectin (P < 0.05)., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Biological nitrogen fixation is catalyzed by the molybdenum (Mo), vanadium (V) and iron (Fe)-only nitrogenase metalloenzymes. Studies with purified enzymes have found that the 'alternative' V- and Fe-nitrogenases generally reduce N 2 more slowly and produce more byproduct H 2 than the Mo-nitrogenase, leading to an assumption that their usage results in slower growth. Here we show that, in the metabolically versatile photoheterotroph Rhodopseudomonas palustris, the type of carbon substrate influences the relative rates of diazotrophic growth based on different nitrogenase isoforms. The V-nitrogenase supports growth as fast as the Mo-nitrogenase on acetate but not on the more oxidized substrate succinate. Our data suggest that this is due to insufficient electron flux to the V-nitrogenase isoform on succinate compared with acetate. Despite slightly faster growth based on the V-nitrogenase on acetate, the wild-type strain uses exclusively the Mo-nitrogenase on both carbon substrates. Notably, the differences in H 2 :N 2 stoichiometry by alternative nitrogenases (~1.5 for V-nitrogenase, ~4-7 for Fe-nitrogenase) and Mo-nitrogenase (~1) measured here are lower than prior in vitro estimates. These results indicate that the metabolic costs of V-based nitrogen fixation could be less significant for growth than previously assumed, helping explain why alternative nitrogenase genes persist in diverse diazotroph lineages and are broadly distributed in the environment., (© 2020 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)

Two samples of living blood cells and of cleared blood plasma from the Phlebobranch tunicate Ascidia ceratodes from Bodega Bay, California, and one of fresh Henze solution from A. ceratodes of Monterey Bay, California, have been examined using sulfur K-edge x-ray absorption spectroscopy (XAS). Biological sulfur included sulfate esters, sulfate and bisulfate ions, benzothiazole, thianthrene, epi-sulfide, thiol and disulfide. Glutathione dominated reduced sulfur, from which an average intracellular Voltage of -0.21 V was calculated. Sulfate-bisulfate ratios yielded blood cell pH values of 2.0 and 2.8. Total blood cell [sulfur] was 373±9 mM or 296±73 mM from BaSO 4 gravimetry. Two plasma samples (pH 6.9 or 7.0; [S] = 33±6 mM or 26±4 mM) were dominated by sulfate and disulfide. Fresh Henze solution evidenced a sulfur inventory similar to blood cells, with calculated pH = 2.7. A V(III)-sulfonate fraction varied systematically with intracellular pH across six independent blood cell samples, implying a vanadium mobilization pathway. Bodega Bay and Monterey Bay A. ceratodes appear to maintain alternative suites of low-valent sulfur. The significance of the vanabins to vanadium metabolism is critically examined in terms of known protein - V(IV) biochemistry. Finally, a detailed hypothesis for the reduction of [VO 4 ] 3 - to V(III) in ascidians is introduced. A vanadium oxido-reductase is proposed to span the signet ring membrane and to release V(III) into the inner acidic vacuole. The V(V) to V(III) reduction is predicted require an inner-sphere mechanism, a thiol reductant, 7-coordinate V(III), a biologically accessible Voltage, and proton-facilitated release of V(III)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Assessing the vanadium (V) fractionation and speciation to predict its bioavailability using a combined approach of geochemical extractions and micro-spectroscopic techniques is still not well studied. Therefore, we aimed to determine the bioavailability of V in rural soils using single extractants, sequential extraction procedure, and the X-ray absorption near edge structure (XANES) spectroscopy. We collected and characterized ninety four samples originated from horizons of seventeen soil profiles in Taiwan. We determined the total content of V and its geochemical fractions using the BCR sequential extraction procedure to predict its potential mobility. We also assessed the bioavailability of V in the soils using four availability indices i.e., CaCl 2 , HCl, ethylenediaminetetraacetic acid (EDTA), and NaHCO 3 and related them to its uptake by Chinese cabbage (Brassica chinensis L.). Additionally, we determined the V speciation by vanadium K-edge XANES spectra. Moreover, we studied the elemental compositions of the soils using Electron Probe Micro Analysis (EPMA). Vanadium was mainly distributed in the residual fraction (81-98% of total V). Among the potential mobile fractions, V was mainly associated with Fe oxides, as identified by the BCR sequential extraction and EMPA. The XANES analysis indicated that V mainly existed in the soils as V(IV) and V(V). The EDTA and NaHCO 3 extracted more V than CaCl 2 and HCl, and both, particularly NaHCO 3 were positively and significantly correlated with the total soil content and plant shoot concentrations of V; therefore NaHCO 3 might be recommended as a bioavailability index for soil V. We hypothesize that the NaHCO 3 may extract vanadate from soil surfaces and also vanadate transformed from vanadyl at alkaline pH during the extraction. The NaHCO 3 -extracted V can be predicted by a function of soil total V, CEC, and pH. Our results should be verified using different soils and plants in the future., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Metals are among the most prevalent pollutants released into the environment. For these reasons, the use of biomarkers for environmental monitoring of individuals and populations exposed to metal pollution has gained considerable attention, offering fast and sensitive detection of chemical stress in organisms. There are different metal resistance genes in bacteria that can be used as biomarkers, including cation diffusion facilitators carrying metal ions; the prototype is the cobalt-zinc-cadmium transporter (czcD). The present study reports the expression changes in the czcD gene in Bacillus megaterium and Microbacterium liquefaciens under nickel and vanadium exposure by real-time polymerase chain reaction. The nickel-vanadium-resistant strains of B. megaterium and M. liquefaciens used in this study were isolated from mine tailings in Guanajuato, Mexico. The czcD gene showed high expression under exposure to 200 ppm of Ni and 200 ppm of V during the logarithmic growth phase of M. liquefaciens in PHGII liquid media. In contrast, no changes were observed in B. megaterium during logarithmic and stationary growth, perhaps due to the gene having differential expression during the growth phases. The expression profiles obtained for czcD show the possibility of using this gene from M. liquefaciens as a biomarker of nickel and vanadium pollution in microorganisms., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Biological nitrogen fixation (BNF) by microorganisms associated with cryptogamic covers, such as cyanolichens and bryophytes, is a primary source of fixed nitrogen in pristine, high-latitude ecosystems. On land, low molybdenum (Mo) availability has been shown to limit BNF by the most common form of nitrogenase (Nase), which requires Mo in its active site. Vanadium (V) and iron-only Nases have been suggested as viable alternatives to countering Mo limitation of BNF; however, field data supporting this long-standing hypothesis have been lacking. Here, we elucidate the contribution of vanadium nitrogenase (V-Nase) to BNF by cyanolichens across a 600-km latitudinal transect in eastern boreal forests of North America. Widespread V-Nase activity was detected (∼15-50% of total BNF rates), with most of the activity found in the northern part of the transect. We observed a 3-fold increase of V-Nase contribution during the 20-wk growing season. By including the contribution of V-Nase to BNF, estimates of new N input by cyanolichens increase by up to 30%. We find that variability in V-based BNF is strongly related to Mo availability, and we identify a Mo threshold of ∼250 ng·g lichen -1 for the onset of V-based BNF. Our results provide compelling ecosystem-scale evidence for the use of the V-Nase as a surrogate enzyme that contributes to BNF when Mo is limiting. Given widespread findings of terrestrial Mo limitation, including the carbon-rich circumboreal belt where global change is most rapid, additional consideration of V-based BNF is required in experimental and modeling studies of terrestrial biogeochemistry., Competing Interests: The authors declare no competing interest., (Copyright © 2019 the Author(s). Published by PNAS.)