Implications of albumin in cell culture media on the biological action of vanadates(V).

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.

Low-dose vanadium pentoxide perturbed lung metabolism associated with inflammation and fibrosis signaling in male animal and in vitro models.

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.

Nitric oxide mitigates vanadium toxicity in soybean (Glycine max L.) by modulating reactive oxygen species (ROS) and antioxidant system.

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.

Bone marrow stromal cells generate an osteoinductive microenvironment when cultured on titanium-aluminum-vanadium substrates with biomimetic multiscale surface roughness.

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 environmentin 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 (MMNTM). 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 MMNTMand 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 MMNTMsurfaces. 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 MMNTM, 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 MMNTMTi6Al4V 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.

Reversible Conversion of Disulfide/Dithiolate Occurring at a Vanadium(IV) Center: A Biomimetic System for Redox Exchange in Vanabin.

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 VIV complex containing an unbound disulfide moiety, [VIV(PS3″)(PS1″S-S)] (1) (PS3″ = [P(C6H3-3-Me3Si-2-S)3]3-, where PS1″S-S is a disulfide form of PS3″). Complex 1 is obtained from a reaction of previously reported [VV(PS3″)(PS2″SH)] (2) (PS2″SH = [P(C6H3-3-Me3Si-2-SH)(C6H3-3-Me3Si-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 VIV complex, [VIV(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 VV-dithiolate and a VIV-(thiolate)(thiyl-radical) species. This work demonstrates an unprecedented example of reversible disulfide/dithiolate interconversion mediated by a VIV center, as well as provides insights into understanding the function of VV reductases in vanabins.

Aluminum, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Mercury, Molybdenum, Nickel, Platinum, Thallium, Titanium, Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury.

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. NiCl2 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.

Atmospheric Wet Iron, Molybdenum, and Vanadium Deposition in Chinese Terrestrial Ecosystems.

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.

Silicon-mediated metabolic upregulation of ascorbate glutathione (AsA-GSH) and glyoxalase reduces the toxic effects of vanadium in rice.

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.

Protein binding and cytotoxic activities of monomeric and dimeric oxido-vanadium(V) salan complexes: Exploring the solution behavior of monoalkoxido-bound oxido-vanadium(V) complex.

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 (H2L1), N, N'-dimethyl-N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diamino-ethane (H2L2) and N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diaminocyclohexane (H2L3) have been synthesized by following Mannich condensation reaction. Reaction of these ligands with their corresponding vanadium metal precursors gave one oxidomethoxidovanadium(V) [VVOL1(OCH3)] (1) and two monooxido-bridged divanadium (V, V) complexes [VVOL2-3]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 [VVOL1(OCH3)] (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 [VVOL1]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.

Growth responses, accumulation, translocation and distribution of vanadium in tobacco and its potential in phytoremediation.

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 O2-· and H2O2 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.

The Pathopharmacological Interplay between Vanadium and Iron in Parkinson's Disease Models.

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)B9Drosophila 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.

Vanadium-protein complex inhibits human adipocyte differentiation through the activation of ß-catenin and LKB1/AMPK signaling pathway.

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 ß-catenin (t-ß-catenin), nuclear ß-catenin (n-ß-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/ß-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.

Vanadium(V/IV)-Transferrin Binding Disrupts the Transferrin Cycle and Reduces Vanadium Uptake and Antiproliferative Activity in Human Lung Cancer Cells.

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.

czcD gene from Bacillus megaterium and Microbacterium liquefaciens as a potential nickel-vanadium soil pollution biomarker.

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.

Anti-inflammatory effects of vanadium-binding protein from Halocynthia roretzi in LPS-stimulated RAW264.7 macrophages through NF-κB and MAPK pathways.

Vanadium-binding protein (VBP) was separated from the blood of the fresh sea urchin Halocynthia roretzi through (NH4)2SO4 precipitation, Diethylaminoethyl Sepharose fast-flow ion-exchange chromatography, and Sephacryl S-200 high-resolution size-exclusion chromatography. The protein size and purification yield of VBP were 27 kDa and 5.5%, respectively. VBP exerted anti-inflammatory effects in lipopolysaccharide-stimulated RAW264.7 macrophages by downregulating iNOS expression and inhibiting nitric oxide production. VBP also suppressed the expression of pro-inflammatory mediators such as COX-2, IL-1ß, IL-6, and TNF-α. The anti-inflammatory activity of VBP was further demonstrated in the NF-κB and MAPK inflammation pathways, in which VBP inhibited phosphorylation of signaling proteins such as p65, JNK, ERK1/2, and p38. Therefore, VBP from H. roretzi has anti-inflammatory effects and could potentially be used to treat inflammation.

Does metal porosity affect metal ion release in blood and urine following total hip arthroplasty? A short term study.

INTRODUCTION: The surface area of exposed metal in a trabecular-titanium acetabular component is wider compared to traditional-titanium implants. The purpose of this study is to establish if this increase in surface area can lead to a significant increase in systemic metal levels. METHODS: 19 patients with conventional acetabular component and 19 with trabecular-titanium cup were compared. Aluminum, Vanadium and Titanium in blood and urine were assessed before surgery and at intervals for 2 years. The samples were analysed using an inductively coupled plasma mass spectrometry. RESULTS: Patients with trabecular-titanium did not have significantly higher metal ion levels compared to patients with conventional cups up to 2 years. A trend over time was statistically significant in both blood and urine for aluminum and titanium concentrations. CONCLUSIONS: The three-dimensionality and the wide surface of the trabecular-titanium acetabular component did not affect metal ion release compared to traditional implants after 2 years.

The role of Glutathione, Cysteine and D-Penicillamine in exchanging Palladium and Vanadium metals from albumin metal complex.

Thiol groups are extensively present across biological systems being found in range of small molecules (e.g. Glutathione, Homo-cysteine) and proteins (e.g. albumin, haemo-globin). Albumin is considered to be a major thiol containing protein present in circulating Plasma. Albumin contains a single thiolate group located at cysteine-34(cys-34) at its active site. Albumin also binds a wide variety of metals and metals complexes at various sites around the protein. Usually heavy metals are preferentially attached with the thiol group of albumin. The binding of heavy metals at cys-34 provides a mechanism by which the residence time of potentially toxic species in the body can be increased. In this research we have assessed the oxidative modification of and metal binding capacity of cys-34 with heavy metals Palladium and Vanadium to investigate the ease with which it is possible to effect disulfide-thiol exchange at this sites/or remove a metal bound at this position. Both the metals were treated with albumin and then the albumin metals (Pd and V) complexes were treated with small thoil molecules like Glutathione, Cysteine and D-Penicillamine. Our finding showed that the albumin thiol group retained the metals with itself by forming some strong bonding with the Thiols group, it is concluded from this finding that if by chance both the metals enter the living system; strongly disturb the chemistry and physiological function of this bio-molecule.

Expression Changes in Metal-Resistance Genes in Microbacterium liquefaciens Under Nickel and Vanadium Exposure.

Microbacterium liquefaciens MNSH2-PHGII-2 is a nickel-vanadium-resistant bacterium isolated from mine tailings located in Guanajuato, Mexico. In PHGII liquid media, M. liquefaciens has the ability to remove 29.5 ppm of Ni and 168.3 ppm of V. The present study reports, for the first time in M. liquefaciens, the presence of the genes nccA (Ni-Co-Cd resistance), hant (high-affinity nickel transporter), smtA, a metal-binding protein gene, and VAN2 (V resistance), which showed an increased expression under exposure to 200 ppm of Ni and 200 ppm of V during the logarithmic growth phase of the microorganism in PHGII liquid media. Data about the expression profile of genes conferring metal resistance to M. liquefaciens can improve the knowledge of those mechanisms involved in the processes of Ni-V resistance and probably in Ni-V removal processes. Based on our data, we can suggest that M. liquefaciens has the potential to be used in the biological treatment of toxic wastes with high Ni and V content.

Controlled Release of Vanadium from a Composite Scaffold Stimulates Mesenchymal Stem Cell Osteochondrogenesis.

Large bone defects often require the use of autograft, allograft, or synthetic bone graft augmentation; however, these treatments can result in delayed osseous integration. A tissue engineering strategy would be the use of a scaffold that could promote the normal fracture healing process of endochondral ossification, where an intermediate cartilage phase is later transformed to bone. This study investigated vanadyl acetylacetonate (VAC), an insulin mimetic, combined with a fibrous composite scaffold, consisting of polycaprolactone with nanoparticles of hydroxyapatite and beta-tricalcium phosphate, as a potential bone tissue engineering scaffold. The differentiation of human mesenchymal stem cells (MSCs) was evaluated on 0.05 and 0.025 wt% VAC containing composite scaffolds (VAC composites) in vitro using three different induction media: osteogenic (OS), chondrogenic (CCM), and chondrogenic/osteogenic (C/O) media, which mimics endochondral ossification. The controlled release of VAC was achieved over 28 days for the VAC composites, where approximately 30% of the VAC was released over this period. MSCs cultured on the VAC composites in C/O media had increased alkaline phosphatase activity, osteocalcin production, and collagen synthesis over the composite scaffold without VAC. In addition, gene expressions for chondrogenesis (Sox9) and hypertrophic markers (VEGF, MMP-13, and collagen X) were the highest on VAC composites. Almost a 1000-fold increase in VEGF gene expression and VEGF formation, as indicated by immunostaining, was achieved for cells cultured on VAC composites in C/O media, suggesting VAC will promote angiogenesis in vivo. These results demonstrate the potential of VAC composite scaffolds in supporting endochondral ossification as a bone tissue engineering strategy.

Influence of Environmental Factors and Relationships between Vanadium, Chromium, and Calcium in Human Bone.

The aim of this study was to investigate the impact of environmental factors on the concentrations of vanadium (V), chromium (Cr), and calcium (Ca) and to examine the synergistic or antagonistic relationships between these metals, in cartilage (C), cortical bone (CB), and spongy bone (SB) samples obtained following hip joint surgery on patients with osteoarthritis in NW Poland. We found significantly higher concentrations of V and Cr in spongy bone in patients who consumed game meat and also those with prosthetic implants. Chromium levels were significantly lower in patients with kidney diseases. The greatest positive correlations were found between spongy bone V and (i) the amount of consumed beer and (ii) seafood diet. Correlation analysis also showed a significant correlation between Cr levels and seafood diet. To a certain extent these results indicate that the concentrations of V, Cr, and Ca in the human hip joint tissues are connected with occupational exposure, kidney diseases, diet containing game meat, sea food, beer, and the presence of implants. Furthermore, we noted new types of interactions in specific parts of the femoral head. Vanadium may contribute to the lower bone Ca levels, especially in the external parts (cartilage and cortical bone).