Effects of high dietary molybdenum in rabbits

The activated ATM/AMPK/mTOR axis promotes autophagy in response to oxidative stress-mediated DNA damage co-induced by molybdenum and cadmium in duck testes

Cadmium (Cd) and excess molybdenum (Mo) have multiple organ toxicity, and testis is one of their important target organs, but the reproductive toxicity of Mo and Cd combined treatment is still unclear. To explore the effects of Mo and Cd co-exposure on DNA damage and autophagy from the insight of ATM/AMPK/mTOR axis in duck testes, we randomly assigned 40 healthy 8-day-old ducks to control, Mo (100 mg/kg Mo), Cd (4 mg/kg Cd), and Mo + Cd groups for 16 weeks. Results found that Mo and/or Cd exposure caused trace elements imbalance, oxidative stress with a decrease in the activities of GSH-Px, CAT, T-SOD and GSH content, an increase in the concentrations of H₂O₂ and MDA and pathological damage. Additionally, Mo and/or Cd markedly raised DNA damage-related factors expression levels and 8-OHdG content, caused G1/S arrest followed by decreasing CDK2 and Cyclin E protein levels and increasing CDK1 and Cyclin B protein levels, and activated ATM/AMPK/mTOR axis by enhancing p-ATM/ATM, p-AMPK/AMPK and reducing p-mTOR/mTOR protein levels, eventually triggered autophagy by elevating LC3A, LC3B, Atg5, Beclin-1 mRNA levels and LC3II/LC3I, Beclin-1 protein levels and reducing P62, Dynein, mTOR mRNA levels and P62 protein level. Moreover, these changes were most apparent in the combined group. Altogether, the results reveal that autophagy caused by Mo and/or Cd may be associated with activating the DNA damage-mediated ATM/AMPK/mTOR axis in duck testes, and Mo and Cd co-exposure exacerbates these changes.

The effect of exposure to MoO3-NP and common bean fertilized by MoO3-NPs on biochemical, hematological, and histopathological parameters in rats

Nanotechnologies has been used to introduce several beneficial tools in the agricultural field. Herein, the effect of molybdenum oxide nanoparticles (MoO₃-NPs) was investigated by evaluating the hematological, biochemical, and histopathological parameters in rats orally exposed to MoO₃-NPs or fed common beans (CB) fertilized by MoO₃-NPs. In the first study, 18 rats were randomly divided into 3 groups: G1 (control group) was given water orally, while G2 and G3 were administered 10 and 40 ppm MoO₃-NPs by oral gavage tube, respectively. There was a significant increase in the levels of alanine aminotransferase (ALT), albumin, and total protein; however, there was a a significant decrease in body weight change (BWC), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatinine, creatine kinase–MB (CK-MB), thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and testosterone levels in G3 compared to G1. In the second study, 24 rats were divided into 4 groups: the control (C) group was fed a balanced diet, and three groups were fed on a balanced diet plus 10% CB that was fertilized with 0, 10, and 40 ppm MoO₃-NPs, resulting in nCB, CB10, and CB40 groups, respectively. This revealed a significant increase in BWC and total food intake (TFI) but a significant decrease in relative kidney weight in all the CB groups compared to the control group. In CB10 and CB40 groups ALT, LDH, TSH, FT3, and testosterone levels were significantly lower than the respective levels in the control group. We concluded that high doses of MoO₃-NPs caused more side effects than low doses in both experiments.

Biocompatibility and Degradation Behavior of Molybdenum in an In Vivo Rat Model

The biocompatibility and degradation behavior of pure molybdenum (Mo) as a bioresorbable metallic material (BMM) for implant applications were investigated. In vitro degradation of a commercially available Mo wire (ø250 µm) was examined after immersion in modified Kokubo's SBF for 28 days at 37 °C and pH 7.4. For assessment of in vivo degradation, the Mo wire was implanted into the abdominal aorta of female Wistar rats for 3, 6 and 12 months. Microstructure and corrosion behavior were analyzed by means of SEM/EDX analysis. After explantation, Mo levels in serum, urine, aortic vessel wall and organs were investigated via ICP-OES analysis. Furthermore, histological analyses of the liver, kidneys, spleen, brain and lungs were performed, as well as blood count and differentiation by FACS analysis. Levels of the C-reactive protein were measured in blood plasma of all the animals. In vitro and in vivo degradation behavior was very similar, with formation of uniform, non-passivating and dissolving product layers without occurrence of a localized corrosion attack. The in vitro degradation rate was 101.6 µg/(cm2·d) which corresponds to 33.6 µm/y after 28 days. The in vivo degradation rates of 12, 33 and 36 µg/(cm2·d) were observed after 3, 6 and 12 months for the samples properly implanted in the aortic vessel wall. This corresponds with a degradation rate of 13.5 µm/y for the 12-month cohort. However, the magnitude of degradation strongly depended on the implant site, with the wires incorporated into the vessel wall showing the most severe degradation. Degradation of the implanted Mo wire neither induced an increase in serum or urine Mo levels nor were elevated Mo levels found in the liver and kidneys compared with the respective controls. Only in the direct vicinity of the implant in the aortic vessel wall, a significant amount of Mo was found, which, however, was far below the amounts to be expected from degrading wires. No abnormalities were detected for all timepoints in histological and blood analyses compared to the control group. The C-reactive protein levels were similar between all the groups, indicating no inflammation processes. These findings suggest that dissolved Mo from a degrading implant is physiologically transported and excreted. Furthermore, radiographic and µCT analyses revealed excellent radiopacity of Mo in tissues. These findings and the unique combination with its extraordinary mechanical properties make Mo an interesting alternative for established BMMs.

Microbiological Reduction of Molybdenum to Molybdenum Blue as a Sustainable Remediation Tool for Molybdenum: A Comprehensive Review

Molybdenum (Mo) microbial bioreduction is a phenomenon that is beginning to be recognized globally as a tool for the remediation of molybdenum toxicity. Molybdenum toxicity continues to be demonstrated in many animal models of spermatogenesis and oogenesis, particularly those of ruminants. The phenomenon has been reported for more than 100 years without a clear understanding of the reduction mechanism, indicating a clear gap in the scientific knowledge. This knowledge is not just fundamentally important-it is specifically important in applications for bioremediation measures and the sustainable recovery of metal from industrial or mine effluent. To date, about 52 molybdenum-reducing bacteria have been isolated globally. An increasing number of reports have also been published regarding the assimilation of other xenobiotics. This phenomenon is likely to be observed in current and future events in which the remediation of xenobiotics requires microorganisms capable of degrading or transforming multi-xenobiotics. This review aimed to comprehensively catalogue all of the characterizations of molybdenum-reducing microorganisms to date and identify future opportunities and improvements.

Cadmium and molybdenum co-induce pyroptosis via ROS/PTEN/PI3K/AKT axis in duck renal tubular epithelial cells

Cadmium (Cd) and excess molybdenum (Mo) are harmful to animals, but the combined nephrotoxic mechanism of Cd and Mo in duck remains poorly elucidated. To assess joint effects of Cd and Mo on pyroptosis via ROS/PTEN/PI3K/AKT axis in duck renal tubular epithelial cells, cells were cultured with 3CdSO₄·8H₂O (4.0 μM), (NH₄)₆Mo₇O₂₄·4H₂O (500.0 μM), MCC950 (10.0 μM), BHA (100.0 μM) and combination of Cd and Mo or Cd, Mo and MCC950 or Cd, Mo and BHA for 12 h, and the joint cytotoxicity was explored. The results manifested that toxicity of non-equitoxic binary mixtures of Mo and Cd exhibited synergic interaction. Mo or/and Cd elevated ROS level, PTEN mRNA and protein levels, and decreased PI3K, AKT and p-AKT expression levels. Simultaneously, Mo or/and Cd upregulated ASC, NLRP3, NEK7, Caspase-1, GSDMA, GSDME, IL-18 and IL-1β mRNA levels and Caspase-1 p20, NLRP3, ASC, GSDMD protein levels, increased the percentage of pyroptotic cells, LDH, NO, IL-18 and IL-1β releases as well as relative conductivity. Moreover, NLRP3 inhibitor MCC950 and ROS scavenger BHA could ameliorate the above changed factors induced by Mo and Cd co-exposure. Collectively, our results reveal that combination of Mo and Cd synergistically cause oxidative stress and trigger pyroptosis via ROS/PTEN/PI3K/AKT axis in duck tubular epithelial cells.

Molybdenum Induces Mitochondrial Oxidative Damage in Kidney of Goats

The purpose of this study was to evaluate the effects of excessive molybdenum (Mo) on renal function and oxidative stress in goats. Twenty-seven healthy goats were randomly allotted in three groups and were fed deionized water to which sodium molybdate [(NH₄)₆Mo₇O₂₄·4H₂O] was added at different doses of 0, 15, and 45 mg Mo/(kg·BW) for 50 days, respectively. The results indicated that white blood cell (WBC) counts were significantly increased (P < 0.05), while red blood cell (RBC) counts, hemoglobin (HGB), and mean corpuscular hemoglobin concentration (MCH) were tended to decrease with the increasing of the experimental period in high-Mo group compared with the control group. Besides, blood urea nitrogen (BUN) and creatinine (CREA) contents in serum were increased (P < 0.05) in both groups supplemented with molybdenum. Meanwhile, contents of copper (Cu) from the both experimental groups were significantly decreased (P < 0.05), while contents of zinc (Zn) and iron (Fe) were increased (P < 0.05) in serum. The contents of Cu were significantly increased (P < 0.05), while the contents of zinc (Zn) and iron (Fe) did not obviously change (P > 0.05) in the kidney. In addition, the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) significantly decreased (P < 0.05) in the mitochondria, whereas malondialdehyde (MDA) and nitric oxide synthase (NOS) expression significantly increased (P < 0.05). Collectively, these results indicated that excess Mo exposure could induce secondary Cu deficiency and oxidative stress in the kidney, which finally undermine the renal function of goats.

Molybdenum and Cadmium co-induced the levels of autophagy-related genes via adenosine 5'-monophosphate-activated protein kinase/mammalian target of rapamycin signaling pathway in Shaoxing Duck (Anas platyrhyncha) kidney

To investigate Molybdenum (Mo) and Cadmium (Cd) co-induced the levels of autophagy-related genes via AMPK/mTOR signaling pathway in Shaoxing Duck (Anas platyrhyncha) kidney, 60 healthy 11-day-old ducks were randomly divided into 6 groups, which were treated with Mo or/and Cd at different doses on the basal diet for 120 d. Kidney samples were collected on day 120 to determine the mRNA expression levels of adenosine 5′-monophosphate (AMP)-activated protein kinase α1 (AMPKα1), mammalian target of rapamycin (mTOR), Beclin-1, autophagy-related gene-5 (Atg5), microtubule-associated protein light chain A (LC3A), microtubule-associated protein light chain B (LC3B), sequestosome-1, and Dynein by real-time quantitative polymerase chain reaction. Meanwhile, ultrastructural changes of the kidney were observed. The results indicated that the mTOR and P62 mRNA expression levels were significantly downregulated, but the Atg5 and Beclin-1 mRNA levels were remarkably upregulated in all treated groups compared to control group, and their changes were greater in joint groups. Additionally, compared to control group, the Dynein mRNA expression level was apparently downregulated in co-treated groups, the LC3B, LC3A, and AMPKα1 expression levels were dramatically upregulated in single treated groups and they were not obviously different in co-treated groups. Ultrastructural changes showed that Mo and Cd could markedly increase the number of autophagosomes. Taken together, it suggested that dietary Mo and Cd might induce autophagy via AMPK/mTOR signaling pathway in duck kidney, and it showed a possible synergistic relationship between the 2 elements.

Molybdenum and cadmium co-induce oxidative stress and apoptosis through mitochondria-mediated pathway in duck renal tubular epithelial cells

High doses of molybdenum (Mo) and cadmium (Cd) cause adverse reactions on animals, but the joint toxic effects of Mo and Cd on duck renal tubular epithelial cells are not fully illustrated. To investigate the combined effects of Mo and Cd on oxidative stress and mitochondrial apoptosis in primary duck renal tubular epithelial cells, the cells were either treated with (NH₄)₆Mo₇O₂₄·4H₂O (480, 960 μM Mo), 3CdSO₄·8H₂O (2.5, 5.0 μM Cd) or combination of Mo and Cd for 12 h, and then the joint cytotoxicity was evaluated. The results demonstrated that Mo or/and Cd exposure could induce release of intracellular lactate dehydrogenase, reactive oxygen species generation, acidification, increase levels of malondialdehyde and [Ca²⁺]i, decrease levels of glutathione, glutathione peroxidase, catalase, superoxide dismutase, total antioxidant capacity, Na⁺/K⁺-ATPase, Ca²⁺-ATPase, and mitochondrial membrane potential; upregulate mRNA levels of Caspase-3, Bak-1, Bax, and cytochrome C, inhibit Bcl-2 mRNA level, and induce cell apoptosis in a dose-dependent manner. Furthermore, the changes of these indicators in co-treated groups were more remarkable. The results indicated that exposure to Mo or/and Cd could induce oxidative stress and apoptosis via the mitochondrial pathway in duck renal tubular epithelial cells and the two metals may have a synergistic effect.

Alteration of the Antioxidant Capacity and Gut Microbiota under High Levels of Molybdenum and Green Tea Polyphenols in Laying Hens

High dietary levels of molybdenum (MO) can negatively affect productive performances and health status of laying hens, while tea polyphenol (TP) can mitigate the negative impact of high MO exposure. However, our understanding of the changes induced by TP on MO challenged layers performances and oxidative status, and on the microbiota, remains limited. The aim of the present study was to better understand host (performances and redox balance) and microbiota responses in MO-challenged layers with dietary TP. In this study, 200 Lohmann laying hens (65-week-old) were randomly allocated in a 2 × 2 factorial design to receive a diet with or without MO (0 or 100 mg/kg), and supplemented with either 0 or 600 mg/kg TP. The results indicate that 100 mg/kg MO decreased egg production (p = 0.03), while dietary TP increased egg production in MO challenged layers (p < 0.01). Egg yolk color was decreased by high MO (p < 0.01), while dietary TP had no effect on yolk color (p > 0.05). Serum alanine transaminase (ALT), aspartate aminotransferase (AST), and malonaldehyde (MDA) concentration were increased by high MO, while total antioxidant capacity (T-AOC), xanthine oxidase (XOD) activity, glutathione s-transferase (GSH-ST), and glutathione concentration in serum were decreased (p < 0.05). Dietary TP was able to reverse the increasing effect of MO on ALT and AST (p < 0.05). High MO resulted in higher MO levels in serum, liver, kidney, and egg, but it decreased Cu and Se content in serum, liver, and egg (p < 0.05). The Fe concentration in liver, kidney, and eggs was significantly lower in MO supplementation groups (p < 0.05). High MO levels in the diet led to lower Firmicutes and higher Proteobacteria abundance, whereas dietary TP alone and/or in high MO treatment increased the Firmicutes abundance and the Firmicutes/Bacteroidetes ratio at phylum level. High MO increased the abundance of Proteobacteria (phylum), Deltaproteobacteria (class), Mytococcales (order), and Nanocystaceae (family), whereas dietary TP promoted the enrichment of Lactobacillus agilis (species). Dietary TP also enhanced the enrichment of Bacilli (class), Lactobacillates (order), Lactobacillus (family), and Lactobacillus gasseri (species). Microbiota analysis revealed differentially enriched microbial compositions in the cecum caused by MO and TP, which might be responsible for the protective effect of dietary TP during a MO challenge.

Molybdenum and Cadmium exposure influences the concentration of trace elements in the digestive organs of Shaoxing duck (Anas platyrhyncha)

To investigate the toxic effects of Molybdenum (Mo) and Cadmium (Cd) on trace elements in digestive organs of Shaoxing duck (Anas platyrhyncha), 120 Shaoxing ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. On the 60th and 120th days, the beak, esophagus, glandular stomach, muscular stomach, small intestine, large intestine and feces were collected to determine contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn) and selenium (Se), then correlation analysis was performed. The results showed that Cd content in digestive organs significantly increased in co-treated groups compared to single treated groups and Mo concentration increased in Mo-treated groups compared to control group, whereas Cu, Fe, Zn and Se concentrations in digestive organs decreased in co-treated groups. Furthermore, Cd and Mo were mainly accumulated in the small intestine and esophagus, respectively. There was a strongly positive correlation between Cd and Mo while they had negative correlation with Cu, Fe, Zn and Se, respectively. In feces, Mo and Fe contents in high dose of Mo group and high Mo combined with Cd group were significantly higher than those in control group, and Cu content in all treated groups significantly increased and Cd, Zn and Se concentrations had no difference. The results indicated that dietary Mo or/and Cd might disturb homeostasis of trace elements in digestive organs of Shaoxing duck. Moreover, the two elements presented a synergistic relationship.

Alterations of mitochondrial antioxidant indexes and apoptosis in duck livers caused by Molybdenum or/and cadmium

Cadmium (Cd) and high Molybdenum (Mo) can lead to adverse reactions on animals, but the co-induced toxicity of Mo and Cd to liver in ducks was not well understood. To investigate the co-induced toxic effects of Mo combined with Cd on mitochondrial oxidative stress and apoptosis in duck livers. 240 healthy 11-day-old ducks were randomly divided into 6 groups (control, LMo group, HMo group, Cd group, LMoCd group and HMoCd group). After being treated for 30, 60, 90 and 120 days, liver mitochondrial antioxidant indexes, ceruloplasmin (CP), metallothionein (MT), Bak-1 and Caspase-3 genes mRNA expression levels, and ultrastructural changes were evaluated. The results showed that total antioxidative capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD) and xanthine oxidase (XOD) activities in experimental groups were decreased, whereas malondialdehyde (MDA) content and nitric oxide synthase (NOS) activity were increased compared with control group, and these changes of co-treated groups were more obvious in the later period of the experiment. The mRNA expression levels of CP, Bak-1 and Caspase-3 were up-regulated in experimental groups compared with control group and showed significant difference between co-treated groups and single treated groups. The mRNA expression level of MT in Cd group was higher than that in co-treated groups. Additionally, ultrastructural changes showed karyopyknosis, mitochondrial swelling, vacuolation and disruption of mitochondrial cristae in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to mitochondrial oxidative stress and apoptosis in duck livers, and it showed a possible synergistic relationship between the two elements.

Alterations in antioxidant function and cell apoptosis in duck spleen exposed to molybdenum and/or cadmium

To investigate the effects of molybdenum (Mo) and/or cadmium (Cd) on antioxidant function and the apoptosis-related genes in duck spleens. Sixty healthy 11-day-old ducks were randomly divided into six groups of 10 ducks (control, low Mo group, high Mo, Cd, low Mo + Cd, and high Mo + Cd groups). All were fed a basal diet containing low or high dietary doses of Mo and/or Cd. Relative spleen weight, antioxidant indices, apoptosis-related gene mRNA expression levels, and ultrastructural changes were evaluated after 120 days. The results showed that the relative spleen weight decreased significantly in the high Mo + Cd treatment group which compared with control group. Malondialdehyde levels increased and xanthine oxidase and catalase activities decreased in the Mo and/or Cd groups compared with levels in the control group. Bak-1 and Caspase-3 expressions were upregulated in the high Mo + Cd group, while Bcl-2 was downregulated. In addition, mitochondrial crest fracture, swelling, vacuolation, deformed nuclei, and karyopyknosis in both Mo + Cd treated groups were more severe than in the other groups. The results suggest that Mo and/or Cd can induce oxidative stress and apoptosis of spleen via effects on the mitochondrial intrinsic pathway. Moreover, the results indicate the two elements have a possible synergistic relationship.

Changes in Trace Element Contents and Morphology in Bones of Duck Exposed to Molybdenum or/and Cadmium

Cadmium (Cd) and high molybdenum (Mo) can lead to adverse reactions on animals, but the coinduced toxicity of Mo and Cd to bone in ducks was not well understood. The objective of this study was to investigate the changes in trace elements' contents and morphology in bones of duck exposed to Mo or/and Cd. One hundred twenty healthy 11-day-old male ducks were randomly divided into six groups and treated with commercial diet containing Cd or/and Mo. On the 60th and 120th days, the blood, excretion, and metatarsals were collected to determine alkaline phosphatase (ALP) activity and the contents of Mo, Cd, calcium (Ca), phosphorus (P), copper (Cu), iron (Fe), zine (Zn), and selenium (Se). In addition, metatarsals were subjected to histopathological analysis with the optical microscope and radiography. The results indicated that Mo and Cd contents significantly increased while Ca, P, Cu, and Se contents remarkably decreased in metatarsals in coexposure groups (P < 0.01). Contents of Fe and Zn in metatarsals had no significant difference among groups (P > 0.05). Ca content in serum had no significant difference among experimental groups (P > 0.05), but P content was significantly decreased in HMo and HMo + Cd groups (P < 0.05). Contents of Ca and P in excretion and ALP activity were significantly increased in coinduced groups (P < 0.05). Furthermore, osteoporotic lesions, less and thinner trabecular bone were observed in combination groups. The findings suggested that dietary of Cd or/and Mo could lead to bone damages in ducks via disturbing the balance of Ca and P in body and homeostasis of Cu, Fe, Zn, and Se in bones; moreover, the two elements showed a possible synergistic relationship.

Effects of Different Levels of Molybdenum on Rumen Microbiota and Trace Elements Changes in Tissues from Goats

Molybdenum (Mo) is an essential trace element for animals and human beings. However, the negative effects on rumen function and distribution of trace elements in tissues induced by excessive Mo have not been well understood. Therefore, the purpose of present study was to investigate the impact of Mo on rumen microbiota, distribution of trace elements in various organs, and hematological parameters of goats. A total of 36 goats were randomly distributed into three groups with equal number and low-Mo and high-Mo groups were orally administered ammonium molybdate at 15 and 45 mg · Mo · kg^-1 · BW respectively, while the control group received corresponding quantitative deionized water. The results showed that the total number of ciliate and protozoa protein concentration decreased significantly (P < 0.01) on days 25 and 50. Concentrations of ammonia nitrogen and bacterial protein were significantly higher (P < 0.05) in low-Mo group, while they were lower (P < 0.05) in high-Mo group than the control group on days 25 and 50. In addition, Mo accumulated in serum and all detected tissues. Copper (Cu) and zinc (Zn) contents significantly decreased (P < 0.05) in hair and serum on days 25 and 50, while Cu contents increased (P < 0.05) and the change of Zn contents were not obvious (P > 0.05) in other tissues on days 25 and 50. Besides, there was no obvious variation in iron (Fe) contents during whole experiment period (P > 0.05). Furthermore, excessive Mo content had no significant effect on red blood cell (RBC) counts and hemoglobin (HGB) concentration (P > 0.05) on days 25 and 50, while white blood cell (WBC) counts increased significantly (P < 0.05) on day 50. These results indicated that excessive Mo content could impact the balance of ruminal microorganisms and interfere with the absorption and distribution of Mo and Cu mainly.

The co-induced effects of molybdenum and cadmium on the mRNA expression of inflammatory cytokines and trace element contents in duck kidneys

The aims of this study were determining the co-induced effects of dietary Cadmium (Cd) and high intake of Molybdenum (Mo) on renal toxicity in ducks. 240 healthy 11-day-old ducks were randomly divided into 6 groups, which were treated with Mo or/and Cd at different doses added to the basal diet for 120 days. Ducks of control group were fed with basal diet, LMo and HMo groups were fed with 15mg/kg Mo and 100mg/kg Mo respectively; ducks of Cd group were provided with 4mg/kg Cd which was added into basal diet. Two combination groups were treated with 15mg/kg Mo+4mg/kg Cd and 100mg/kg Mo+4mg/kg Cd respectively. On days 30, 60, 90 and 120, the mRNA expression levels of inflammatory cytokines and contents of trace elements were detected. In addition, transmission electron microscopic examination was used for ultrastructural studies. The results indicated that the mRNA expression levels of tumor necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and cyclooxygenase-2 (COX-2) showed an upward tendency in treatment groups in comparison with control group, and in the later period of the experiment it showed a significant rise in joint groups compared with the Mo and Cd group (P<0.01); the contents of copper (Cu) and iron (Fe) decreased in joint groups in the later period (P<0.05) while the contents of Mo and Cd significantly increased (P<0.01); zinc (Zn) and selenium (Se) concentration had a slight downtrend in treated groups, but showed no significant difference (P>0.05). The ultrastructural analysis showed that kidney tissues were severely injured in joint groups on day 120. These results suggested that the combination of Mo and Cd could aggravate damages to the kidney. In addition, dietary of Mo or/and Cd caused the decrease of Cu, Fe, Zn, and Se contents, inflammatory response and pathological lesions whose mechanism is somehow linked with Mo and Cd deposition in kidney.

Trace metal imaging in diagnostic of hepatic metal disease

The liver is the most central organ and the largest gland of the body that influences and controls a variety of metabolic and catabolic processes. It produces inconceivable many essential proteins, is responsible for the recovery of various food components, degrades toxins, mediates the bile production, and is involved in the excretion of unwanted metabolites. Several of these anabolic or catabolic functions of the liver depend on trace elements. These are either integral part of enzymes, cofactors, or act as chemical catalysts. Therefore, a lack of trace elements can lead to organ failure or systemic illness. Conversely, excessive hepatic trace element deposition resulting from genetic disorders, intoxication, extensive dietary supply, or long-term parenteral nutrition may cause hepatic inflammation, fibrosis, cirrhosis, and even hepatocellular carcinoma. Although specific serum parameters currently allow rough assessment of metal deficit and excess, the precise quantification of hepatic metal content in liver is presently only possible by different titration or staining techniques of biopsy specimens. Recently, novel innovative metal imaging techniques were developed that are on the way to replace these traditional methods. In the present review, we summarize the function of different trace elements in liver health and disease and discuss the present knowledge on how quantitative biometal imaging techniques such as synchrotron X-ray fluorescence microscopy, secondary ion mass spectrometry, and laser ablation inductively coupled plasma mass spectrometry enrich diagnostics in the detection and quantification of hepatic metal disorders. We will further discuss sample preparation, sensitivity, spatial resolution, specificity, quantification strategies, and potential future applications of metal bioimaging in experimental research and clinical daily routine. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 35:666-686, 2016.

Oxidative Stress and Cell Apoptosis in Caprine Liver Induced by Molybdenum and Cadmium in Combination

To investigate the effects of co-exposure to molybdenum (Mo) and cadmium (Cd) on oxidative stress and cell apoptosis in caprine livers, 36 Boer goats were randomly divided into four groups with nine goats in each group. Three groups were randomly assigned with one of three oral treatments of CdCl2 (0.5 mg Cd kg(-1)·BW) and [(NH4)6Mo7O24·4H2O] (15 mg Mo kg(-1)·BW, 30 mg Mo kg(-1)·BW, 45 mg Mo kg(-1)·BW), while the control group received deionized water. Liver tissues on days 0, 25, and 50 were subjected to determine antioxidant activity indexes and the messenger RNA (mRNA) expression levels of ceruloplasmin (CP), cysteinyl aspartate-specific proteinase-3 (caspase-3), second mitochondria-derived activator of caspases (Smac), and cytochrome-C (Cyt-C) genes. The results showed that significant reductions were observed in total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) activities (P < 0.05), while activities or contents of malondialdehyde (MDA), nitric oxide (NO), and nitric oxide synthase (NOS) were increased (P < 0.05). The mRNA expression levels of CP, caspase-3, Smac, and Cyt-C genes were upregulated (P < 0.05). In addition, histopathological lesions showed different degrees of vacuolar degeneration and edematous and mitochondrial swelling. The results suggest that co-exposure to Mo and Cd could induce oxidative stress and cell apoptosis possibly associated with mitochondrial intrinsic pathway in goat liver and show possible synergistic effects between the two elements.

Alterations in trace element levels and mRNA expression of Hsps and inflammatory cytokines in livers of duck exposed to molybdenum or/and cadmium

To evaluate the effects of dietary Molybdenum (Mo) or/and Cadmium (Cd) on trace elements and the mRNA expression levels of heat shock proteins (Hsps) and inflammatory cytokines in duck livers. 240 healthy 11-day-old ducks were randomly divided into six groups with 40 ducks in each group, which were treated with Mo or/and Cd at different doses on the basal diet for 120 days. On days 30, 60, 90 and 120, 10 birds in each group were randomly selected and euthanized and then the livers were collected to determine the contents of Mo, Cd, copper (Cu), iron (Fe), zine (Zn), Selenium (Se) and the mRNA expression levels of Hsps, inflammatory cytokines. In addition, liver tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results showed that the mRNA expression of Hsp60, Hsp70, Hsp90, tumor necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and cyclooxygenase-2 (COX-2) were significantly (P<0.01) upregulated in combination groups; Contents of Cu, Fe, Zn, and Se decreased in combined groups (P<0.05) in the later period of the test while contents of Mo and Cd significantly increased (P<0.01); Furthermore severe hepatocyte diffuse fatty, hepatic cords swelling, hepatic sinusoid disappeared, and inflammatory cells infiltrated around the hepatic central vein were observed in Mo combined with Cd groups. The results indicated that dietary Mo or/and Cd might lead to stress, inflammatory response, tissue damage and disturb homeostasis of trace elements in duck livers. Moreover the two elements showed a possible synergistic relationship. And the high mRNA expression of HSPs and inflammatory cytokines may play a role in the resistance of liver toxicity induced by Mo and Cd.

Effects of Molybdenum or/and Cadmium on mRNA Expression Levels of Inflammatory Cytokines and HSPs in Duck Spleens

Cadmium (Cd) and high dietary intake of molybdenum (Mo) can cause multiple-organ injury in animals, but the co-induced toxicity of Mo and Cd to spleen in ducks is not well understood. The aim of this study was to investigate the co-induced effects of Mo and Cd on the mRNA expression levels of inflammatory cytokines and heat shock proteins (HSPs) in duck spleens. Two hundred forty healthy 11-day-old ducks were randomly divided into six groups and treated with a commercial diet containing Mo or/and Cd. After being treated with Mo or/and Cd for 30, 60, 90, and 120 days, the mRNA expression levels of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), HSP60, HSP70, and HSP90 were examined in duck spleens. Histopathology was examined in duck spleens at 120 days. The results indicated that the mRNA expression levels of HSPs were significantly upregulated in the co-induced groups (P < 0.01), while these decreased in the high dietary intake of Mo combined with Cd group at 120 days. Exposure to Mo or/and Cd upregulated the mRNA expression levels of NF-κB, COX-2, and TNF-α in the combination groups (P < 0.01). Furthermore, severe congestion, bleeding, splenic corpuscle structure fuzzy, wall thickness of sheath artery thickening, and oxyhematin were observed in the spleens of combination groups. Meanwhile, the organizational structure damage of the combined groups was more severe than that of the other groups. These results suggested that exposure to Mo or/and Cd might lead to tissue damage, and high expression of HSPs and inflammatory cytokines may play a role in the resistance of spleen toxicity induced by Mo or/and Cd. Interaction of Mo and Cd may have a synergistic effect on spleen toxicity.

The Co-Induced Effects of Molybdenum and Cadmium on the Trace Elements and the mRNA Expression Levels of CP and MT in Duck Testicles

To investigate the chronic toxicity of molybdenum (Mo) and cadmium (Cd) on the trace elements and the mRNA expression levels of ceruloplasmin (CP) and metallothionein (MT) in duck testicles, 120 healthy 11-day-old male ducks were randomly divided into six groups with 20 ducks in each group. Ducks were treated with the diet containing different dosages of Mo or Cd. The source of Mo and Cd was hexaammonium molybdate ([(NH4)6Mo7O24·4H2O]) and cadmium sulfate (3CdSO4·8H2O), respectively, in this study. After being treated for 60 and 120 days, ten male birds in each group were randomly selected and euthanized and then testicles were aseptically collected for determining the mRNA expression levels of MT and CP, antioxidant indexes, and contents of trace elements in the testicle. In addition, testicle tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results showed that co-exposure to Mo and Cd resulted in an increase in malondialdehyde (MDA) level while decrease in xanthine oxidase (XOD) and catalase (CAT) activities. The mRNA expression level of MT gene was upregulated while CP was decreased in combination groups. Contents of Mo, copper (Cu), iron (Fe), and zinc (Zn) decreased in combined groups while Cd increased in Cd and combined groups at 120 days. Furthermore, severe congestion, low sperm count, and malformation were observed in low dietary of Mo combined with Cd group and high dietary of Mo combined with Cd group. Our results suggested that Mo and Cd might aggravate testicular degeneration synergistically through altering the mRNA expression levels of MT and CP, increasing lipid peroxidation through inhibiting related enzyme activities and disturbing homeostasis of trace elements in testicles. Interaction of Mo and Cd may have a synergistic effect on the testicular toxicity.

The Co-induced Effects of Molybdenum and Cadmium on Antioxidants and Heat Shock Proteins in Duck Kidneys

Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is harmful to health. To investigate the toxicity of Mo combined with Cd in duck kidneys, 240 ducks were randomly divided into six groups and treated with a commercial diet containing Mo, Cd or Mo combined with Cd. Kidneys were collected on days 30, 60, 90 and 120 for determining the expression of heat shock proteins (HSPs), including HSP60, HSP70 and HSP90 in the kidney through quantitative RT-PCR. We also determined the antioxidant activity indexes in the kidney mitochondria. Moreover, kidney tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results indicated that the expression of HSPs was highly significantly (P < 0.01) upregulated in the kidneys of the combination groups and the Cd group. Exposure to Cd and a high dose of Mo decreased the total antioxidative capacity and the activity of xanthine oxidase, while malondialdehyde levels and the activity of nitric oxide synthase increased compared with those of the control groups in the kidney mitochondria. This was particularly evident at 90 and 120 days. Histopathological lesions included congestion and bleeding in the renal interstitium, swelling of the distal convoluted tubule epithelial cells, granular degeneration and blister degeneration in the renal tubular epithelial cells. These results suggest that a combination of Mo and Cd leads to greater tissue damage and has a synergistic effect on kidney damage. Oxidative damage of kidney mitochondria may be a potential nephrotoxicity mechanism of molybdenum and cadmium, and the high expression of HSPs may play a role in the resistance of kidney toxicity induced by Mo and Cd.

In vitro changes in secretion activity of rat ovarian fragments induced by molybdenum

The aim of this in vitro study was to examine the secretion activity (progesterone, 17beta-estradiol and insulin-like growth factor-I) of rat ovarian fragments after molybdenum (Mo) addition. Rat ovarian fragments were incubated with ammonium molybdate (NH(4))(6)Mo(7)O(24).4H(2)O at the doses 90, 170, 330 and 500 microg.ml(-1) for 24 h and compared with control group without Mo addition. Release of progesterone (P(4)), estradiol (17beta-estradiol) and insulin-like growth factor I (IGF-I) by ovarian fragments was assessed by radioimmunoassay (RIA). Data show that P(4) release by ovarian fragments was not affected by (NH(4))(6).Mo(7)O(24).4H(2)O addition at all the doses used (90-500 microg.ml(-1)). However, addition of ammonium molybdate was found to cause a significant (P<0.05) dose-dependent decrease (at the doses 90, 170 and 500 microg.ml(-1)) in release of 17beta-estradiol by ovarian fragments in comparison to control. Also, addition of ammonium molybdate significantly (P<0.05) inhibited IGF-I release at all the doses (90-500 microg.ml(-1)) used in the study. Results suggest ammonium molybdate induced inhibition in the release of growth factor IGF-I and its dose-dependent effect on secretion of steroid hormone 17beta-estradiol but not progesterone. These data contribute to new insights regarding the mechanism of action of Mo on rat ovarian functions.

Dual effects of molybdenum on mouse oocyte quality and ovarian oxidative stress

A sub-acute toxicity test was performed to investigate the effects of molybdenum (Mo) on ovarian function. ICR adult female mice were exposed to Mo by free access to distilled water containing the Mo at 5, 10, 20, and 40 mg/L for 14 days. Compared to the control group, M II oocyte morphology, ovary index, and ovulation improved within the 5 mg/L Mo group, but were negatively affected by Mo at 40 mg/L. Morphologically abnormal ovarian mitochondria were observed at ≥ 20 mg/L. These alterations accompanied the changes in superoxide dismutase (SOD), glutathione peroxidise (GPx), and malondialdehyde (MDA) levels in ovaries. In conclusion, Mo affects oocyte quality possibly through regulating ovarian oxidative stress in a dose-dependent manner. It appears that Mo may improve ovarian function at a suitable concentration, which might be a candidate for the treatment of female infertility.

Effect of dietary high molybdenum on peripheral blood T-cell subsets and serum IL-2 contents in broilers

The objectives of this study were to investigate the effects of dietary high molybdenum (Mo) on immune function by determining changes of the subsets of peripheral blood T-cells and serum interleukin (IL)-2 contents. 300 1-day-old avian broilers were divided into four groups and fed on a corn-soybean basal diet as control diet or the same diet amended to contain 500; 1,000; and 1,500 mg/kg of Mo supplied as sodium molybdate dihydrate. In comparison with those of the control group, the percentages of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) were decreased in 1,000 and 1,500 mg/kg of Mo intake groups from 14 days of age to 42 days of age. Also, the serum IL-2 contents were decreased in 1,000 and 1,500 mg/kg of Mo intake groups from 14 days of age to 42 days of age. Histopathologically, hypocellularity appeared in the thymus in 1,000 and 1,500 mg/kg of Mo intake groups. It was concluded that dietary high-Mo (1,000 mg/kg and 1,500 mg/kg) reduced the percentages of peripheral blood T-cell subsets and serum IL-2 contents and caused thymic lesions. The cellular immune function was finally injured in broilers.

Increased apoptotic lymphocyte population in the spleen of young chickens fed on diets high in molybdenum

The experiment was conducted with the objective of examining the effects of high molybdenum (Mo) on the apoptosis of splenic lymphocytes in broilers by the methods of experimental pathology and flow cytometry (FCM). Three hundred 1-day-old avian broilers were divided into four groups of 75 each and were fed on control diet (Mo 13 mg/kg) and high Mo diets (Mo 500 mg/kg, high Mo group I; Mo 1,000 mg/kg, high Mo group II; and Mo 1,500 mg/kg, high Mo group III) for 42 days. The results showed that the relative weight of spleen was decreased, and lymphocytes were histopathologically decreased in high Mo groups II and III. Ultrastructurally, the apoptotic cells showed typical condensed nuclei with dark-round, petal-like, and horseshoe-like shapes. The mitochondria were swelled, and the endoplasmic reticulum and the Golgi apparatus were dilated in high Mo groups II and III. The statistical analyses by FCM indicated that the percentage of cellular apoptosis was higher in high Mo groups II and III than in control group. Also, the TUNEL staining was consistent with the results of FCM. It was concluded that dietary molybdenum in 1,000 and 1,500 mg/kg caused splenic lesions and lymphocyte apoptosis, which could inhibit the development of spleen and could impair immune function in broilers.

In vitro assessment of molybdenum-induced secretory activity, proliferation and apoptosis of porcine ovarian granulosa cells

Molybdenum (Mo) is an essential trace element and it plays an important role in cell functions. The mechanism of the action of molybdenum in connection with growth factor IGF-I, proliferation-related peptide cyclin B1 and apoptosis-related peptide caspase-3 has not been examined previously in porcine ovarian granulosa cells. The general objective of this in vitro study was to examine the secretory activity of porcine ovarian granulosa cells after experimental Mo administration and to outline the potential intracellular mediators of its effects. Ovarian granulosa cells were incubated with ammonium molybdate for 18 hours: 1.0 mg/mL; 0.5 mg/mL; 0.33 mg/mL; 0.17 mg/mL and 0.09 mg/mL, while the control group received no Mo. The secretion of IGF-I was assessed by RIA and expression of cyclin B1 and caspase-3 by immunocytochemistry. IGF-I release was decreased by Mo addition at the doses 1.0 mg/mL and 0.5 mg/mL. The expression of cyclin B1 was stimulated by Mo addition at all doses ranging from 1.0-0.09 mg/mL. Caspase-3 expression was also stimulated after experimental Mo addition at the doses 1.0 and 0.5 mg/mL. These data contribute to new insights regarding the mechanism of action of Mo on porcine ovarian functions, secretory activity, proliferation and apoptosis of granulosa cells through hormonal and intracellular substances such as are cyclin B1 and caspase-3.