The effect of vanadium on platelet function

Association between plasma metal elements and platelet dysfunction in trauma-induced coagulopathy rat model

BACKGROUND

Disorders of metal elements and platelet dysfunction are common in patients with trauma-induced coagulopathy (TIC).

AIM

The aim of this study was to explore the potential role of plasma metal elements in platelet dysfunction in TIC.

METHODS

Thirty Sprague-Dawley rats were divided into control, hemorrhage shock (HS) and multiple injury (MI) groups. At timepoints of 0.5 and 3 h after trauma and being documented as _{HS 0.5 h}, HS_3 h, _{MI 0.5 h} or MI_3 h, blood samples were harvested for inductively coupled plasma mass spectrometer, conventional coagulation function and thromboelastograph.

RESULTS

The plasma zinc (Zn), vanadium (V) and cadmium (Ca) decreased initially in HS _0.5 h and recovered slightly in HS_3 h, whereas their plasma concentrations continued to decrease from beginning till MI_3 h (p < 0.05). In HS, plasma Ca, V and nickel were negatively correlated to the time taken to reach the initial formation (R), whereas R was positively correlated to plasms Zn, V, Ca and selenium in MI (p < 0.05). In MI, plasma Ca was positively correlated to maximum amplitude, and plasma V was positively correlated to platelet count (p < 0.05).

CONCLUSION

The plasma concentrations of Zn, V and Ca appeared to contribute to platelet dysfunction in _{HS 0.5 h}, HS_3 h, _{MI 0.5 h} and MI_3 h, which were trauma type sensitive.

Adaptive changes in redox response and decreased platelet aggregation in lead-exposed workers

Chronic lead exposure can generate pro-oxidative and pro-inflammatory conditions in the blood, related to high platelet activation and aggregation, altering cell functions. We studied ADP-stimulated aggregation and the oxidant/antioxidant system of platelets from chronically lead-exposed workers and non-exposed workers. Platelet aggregation was low in lead-exposed workers (62 vs. 97%), who had normal platelet counts and showed no clinical manifestations of hemostatic failure. ADP-activated platelets from lead-exposed workers failed to increase superoxide release (3.3 vs. 6.6 µmol/g protein), had low NADPH concentration (60 vs. 92 nmol/mg protein), high concentration of hydrogen peroxide (224 vs. 129 nmol/mg protein) and high plasma PGE₂ concentration (287 vs. 79 pg/mL). Altogether, those conditions, on the one hand, could account for the low platelet aggregation and, on the other, indicate an adaptive mechanism for the oxidative status of platelets and anti-aggregating molecules to prevent thrombotic problems in the pro-oxidant and pro-inflammatory environment of chronic lead exposure.

The Gilded Clot: Review of Metal-Modulated Platelet Activation, Coagulation, and Fibrinolysis

The processes of blood coagulation and fibrinolysis that in part maintain the physical integrity of the circulatory system and fluidity of its contents are complex as they are critical for life. While the roles played by cellular components and circulating proteins in coagulation and fibrinolysis are widely acknowledged, the impact of metals on these processes is at best underappreciated. In this narrative review we identify twenty-five metals that can modulate the activity of platelets, plasmatic coagulation, and fibrinolysis as determined by in vitro and in vivo investigations involving several species besides human beings. When possible, the molecular interactions of the various metals with key cells and proteins of the hemostatic system were identified and displayed in detail. It is our intention that this work serve not as an ending point, but rather as a fair evaluation of what mechanisms concerning metal interactions with the hemostatic system have been elucidated, and as a beacon to guide future investigation.

Toxic Effects of Inhaled Vanadium Attached to Particulate Matter: A Literature Review

Environmental pollution is a worldwide problem recognized by the World Health Organization as a major health risk factor that affects low-, middle- and high-income countries. Suspended particulate matter is among the most dangerous pollutants, since it contains toxicologically relevant agents, such as metals, including vanadium. Vanadium is a transition metal that is emitted into the atmosphere especially by the burning of fossil fuels to which dwellers are exposed. The objective of this literature review is to describe the toxic effects of vanadium and its compounds when they enter the body by inhalation, based especially on the results of a murine experimental model that elucidates the systemic effects that vanadium has on living organisms. To achieve this goal, we reviewed 85 articles on the relevance of vanadium as a component of particulate matter and its toxic effects. Throughout several years of research with the murine experimental model, we have shown that this element generates adverse effects in all the systems evaluated, because it causes immunotoxicity, hematotoxicity, neurotoxicity, nephrotoxicity and reprotoxicity, among other noxious effects. The results with this experimental model add evidence of the effects generated by environmental pollutants and increase the body of evidence that can lead us to make more intelligent environmental decisions for the welfare of all living beings.

Effects of Vanadium Inhalation and Sweetened Beverage Ingestion in Mice: Morphological and Biochemical Changes in the Liver

The aim of this report was to evaluate the morphological and biochemical changes in the liver by the inhalation of vanadium and consumption of sweetened beverages in a subchronic murine model. Forty CD-1 male mice were randomly divided into four groups: control, vanadium (V), sucrose 30% (S), and vanadium-sucrose (V + S). V was inhaled (1.4 mg/m³) for 1h, twice/week; 30% sucrose solution was given orally ad libitum. Blood samples were obtained for AST, ALT, and LDH determination. Liver samples were processed for histological and oxidative stress immunohistochemical evaluation with 4-hydroxynonenal at weeks 4 and 8 of exposure. Regarding liver function tests, a statistically significant increase (P < 0.05) was observed in groups V, S, and V + S at weeks 4 and 8 compared to the control group. A greater number of hepatocytes with meganuclei and binuclei were observed in V and V + S at week 8 compared to the other groups. Steatosis and regenerative changes were more extensive in the eighth week V + S group. 4-Hydroxynonenal immunoreactivity increased in the V + S group at both exposure times compared to the other groups; however, the increment was more evident in the V + S group at week 4 compared to the V + S group at week 8. An increase in De Ritis ratio (>1) was noticed in experimental groups at weeks 4 and 8. Findings demonstrate that in the liver, V, S, and V + S induced oxidative stress and regenerative changes that increased with the length of exposure. Results support possible potentiation of liver damage in areas with high air pollution and high-sweetened beverage consumption.

Hematological parameters and protein metabolism in the blood of pregnant rats under the effect of vanadium citrate

Dose-dependent changes in protein metabolism in the blood and hematological parameters of pregnant rats under the effect of vanadium citrate are presented in the article. The animals were divided into five groups: group I – non-pregnant females, II – pregnant females consuming pure water without additives, III, IV, V – females which during the mating and pregnancy period received the solution of vanadium citrate at concentrations of 0.03, 0.125 and 0.50 μg V/mL water. The research findings show that in pregnant animals of group II, the level of urea and alkaline phosphatase activity increased, meanwhile aspartate aminotransferase activity decreased, as compared to the non-pregnant females of group І. The levels of total protein and albumin decreased; however, the content of β-globulins increased in the pregnant animals of group II, as compared with that in group I. Also, in the rats of group II, there was a decrease in hemolysis time, total content of erythrocytes and hemoglobin, the content of old and mature erythrocytes, while the content of young erythrocytes increased, as compared to group I. The platelet content and thrombocrit in rats of group II increased in comparison with group I. The content of leukocytes and lymphocytes in pregnant animals of group II decreased, while the content of granulocytes increased, in contrast to non-pregnant rats. Under the effect of vanadium citrate at concentrations of 0.03–0.50 μg V/mL, there was a significant increase in the maximum number of prohemolized erythrocytes, the time of maximum hemolysis was delayed by 0.4–0.6 min, as compared with the pregnant rats of group II. This did not affect the time of total hemolysis in rats of groups III and V, as compared with the pregnant animals in group II. Under the effect of vanadium citrate, an increase in the content of young erythrocytes was observed, as compared with group II. The hemoglobin content decreased at the concentration of 0.125 μg V/mL, while at the concentration of 0.50 μg V/mL it increased, as compared to the pregnant animals of group II. Also, under the effect of vanadium citrate there was a decrease in the mean hemoglobin concentration in the erythrocyte. In pregnant animals fed with vanadium citrate solutions, the platelet content and thrombocrit, the relative width of platelet distribution by volume decreased, as compared with the pregnant rats of group II. The content of leukocytes, lymphocytes and granulocytes under the effect of vanadium citrate increased, as compared with the pregnant animals in group II. Under the effect of vanadium citrate at the concentration of 0.03 μg V/mL, the level of albumin, creatinine and aspartate aminotransferase activity increased in blood plasma in comparison with group II. Meanwhile, at the concentration of 0.125 μg V/mL, the relative content of γ-globulins and aspartate aminotransferase activity increased, alkaline phosphatase activity and urea level decreased in comparison with group II. However at the concentration of 0.50 μg V/mL, the relative α- and γ-globulins content and aspartate aminotransferase activity increased, at the same time, the relative β-globulins content and urea level decreased in comparison with group II. Therefore, vanadium citrate normalizes the indicators of protein metabolism during pregnancy, thus it can be considered as a potential dietary drug for the pregnant.

A brief review of the biology of megakaryocytes and platelets and their role in thrombosis associated with particulate air pollution

Air pollution is a worldwide public health issue and it is associated with millions of premature deaths due to cancer, thrombosis, and pulmonary and cardiovascular diseases. Thrombosis is the excessive clotting that blocks a blood vessel, and its etiology is multifactorial. In recent years, growing evidence has linked air pollution, especially particulate matter (PM) and metals, to the development of thrombosis. PM and metals induce lung and systemic inflammation and oxidative stress that are frequent mechanisms in thrombosis. Platelets are important effectors of physiological hemostasis and pathological thrombosis. They are responsible for the formation of the initial plug and are important in the cellular model of coagulation. Therefore, any changes in their morphology or function or an increase in activation could be extremely relevant in thrombosis. Megakaryocytes (MKs) in the bone marrow and in the lungs are the precursor cells of platelets, and the latter is the first organ injured by air pollution. There is substantial evidence of the effect that PM and metals have on platelets, but there is almost no research about the effect of PM and metals on MKs. It is very likely that the alterations produced by air pollution originate in these cells. In this article, we review the biology of MKs and platelets and their role in particulate air pollution-related thrombosis to emphasize the need for further research in this field.

Vanadium inhalation induces retinal Müller glial cell (MGC) alterations in a murine model

BACKGROUND

Vanadium (V) is a transition metal adhered to suspended particles. Previous studies demonstrated that V inhalation causes oxidative stress in the ependymal epithelium, the choroid plexus on brain lateral ventricles and in the retina. Inhaled-V reaches the eye´s retina through the systemic circulation; however, its effect on the retina has not been widely studied. The Müller glial cell provides support and structure to the retina, facilitates synapses and regulates the microenvironment and neuronal metabolism. Hence, it is of great interest to study the effect of V exposure on the expression and localization of specific biomarkers on this cell.

METHODS

Male CD-1 mice were exposed to V inhalation 1 h/twice/week for 4 and 8-Wk. Expression changes in the retina of Glial fibrillary acidic protein, highly expressed in Müller glial cell when retina is damaged, and Glutamine synthetase, important in preventing excitotoxicity in the retina, were analysed by immunohistochemistry.

RESULTS

Glial fibrillary acidic protein expression increased at 4-Wk of V inhalation compared to the control and decreased at 8-Wk of exposure. A time-dependent gradual reduction in glutamine synthetase expression was observed.

CONCLUSION

Changes in glial fibrillary acidic protein expression induced by V suggest retinal damage, whereas glutamine synthetase gradual reduction might indicate that photoreceptors, which produce most of the glutamine synthetase substrate in the retina, are degenerating, probably as a consequence of the oxidative stress induced by V.

Serum trace elements are associated with hemostasis, lipid spectrum and inflammatory markers in men suffering from acute ischemic stroke

The primary objective of the study is investigation of the association between trace elements status and hemostasis, lipid spectrum and inflammatory markers in acute ischemic stroke (AIS). A total of 30 men suffering from AIS and 30 healthy controls were involved in the current survey. Blood count, serum lipid spectrum, complement components C4 and C3a, vascular endothelial growth factor (VEGF), S100B protein, NR2 antibodies (NR2Ab), and total antioxidant status (TAS), as well as plasma fibrinogen, and D-dimer levels and activated partial thromboplastin time (APTT) were assessed. Serum trace elements were analyzed using inductively coupled plasma mass spectrometry. AIS patients were characterized by significantly increased fibrinogen, D-dimer, TG, C3a, C4, NR2Ab, and VEGF levels. The leukocyte count, erythrocyte sedimentation rate and serum atherogenic index were also increased in stroke patients. Oppositely, TAS and APTT values, bleeding and blood coagulation time were decreased. AIS patients were characterized by significantly decreased serum Fe and Co concentrations, whereas the level of Cu, I, Li, Mn, Se, Zn, As, Pb, Ni, and especially V and B in serum was significantly increased. Serum V and B tightly correlated with the procoagulant state and inflammatory markers. Multiple regression analysis revealed a significant inverse association between serum Se levels and stroke markers after adjustment for covariates. Therefore, it is hypothesized that elements like vanadium and boron may be closely involved in stroke pathogenesis by modulation of hemostasis and inflammation, whereas the observed increase in Se levels may be considered as a compensatory reaction.

Vanadium toxicity in the thymic development

The purpose of this study was to define the toxic effects of vanadium on thymic development in broilers fed on diets supplemented with 0, 5, 15, 30, 45 and 60 mg/kg of vanadium for 42 days. We examined the changes of relative weigh, cell cycle phase, apoptotic cells, and protein expression of Bcl-2, Bax, and caspase-3 in the thymus by the methods of flow cytometry, TUNEL (terminal-deoxynucleotidyl transferase mediated nick end labeling) and immunohistochemistry. The results showed that dietary high vanadium (30 mg/kg, 45 mg/kg and 60 mg/kg) caused the toxic effects on thymic development, which was characterized by decreasing relative weigh, increasing G0/G1 phase (a prolonged nondividing state), reducing S phase (DNA replication) and proliferating index (PI), and increasing percentages of apoptotic thymocytes. Concurrently, the protein expression levels of Bax and caspase-3 were increased, and protein expression levels of Bcl-2 were decreased. The thymic development suppression caused by dietary high vanadium further leads to inhibitive effects on T lymphocyte maturity and activity, and cellular immune function. The above-mentioned results provide new evidences for further understanding the vanadium immunotoxicity. In contrast, dietary 5 mg/kg vanadium promoted the thymic development by increasing relative weigh, decreasing G0/G1 phase, increasing S phase and PI, and reducing percentages of apoptotic thymocytes when compared to the control group and high vanadium groups.

Accumulation and speciation of vanadium in Lycium seedling

Lycium seedling was subjected to varying doses of V for 40-45 days to examine the effects on uptake, accumulation, and speciation of V in Lycium seedling by differential centrifugation and enzymolysis. V concentrations in Lycium seedling organs were in sequence as follows: root>leaf>stem. V uptake into stem and leaf were primarily combined with acid-soluble polar compounds, polysaccharide, and immobile materials on the cell walls. There were different speciations of V in root with different V stress levels. Enzymolysis results suggest that about 60% of the V in Lycium seedling root was combined with pectin and cellulose. It is the antidotal effect of pectin and cellulose in the cell wall that reduced the V damage to Lycium seedling.

Activation of Janus kinase/signal transducers and activators of transcription pathway involved in megakaryocyte proliferation induced by vanadium resembles some aspects of essential thrombocythemia

Vanadium (V) is an air pollutant released into the atmosphere by burning fossil fuels. Also, it has been recently evaluated for their carcinogenic potential to establish permissible limits of exposure at workplaces. We previously reported an increase in the number and size of platelets and their precursor cells and megakaryocytes in bone marrow and spleen. The aim of this study was to identify the involvement of Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway and thrombopoietin (TPO) receptor, and myeloproliferative leukemia virus oncogene (Mpl), in megakaryocyte proliferation induced by this compound. Mice were exposed twice a week to vanadium pentoxide inhalation (0.02 M) and were killed at 4th, 6th, and 8th week of exposure. Phosphorylated JAK2 (JAK2 ph), STAT3 (STAT3 ph), STAT5, and Mpl were identified in mice spleen megakaryocytes by cytofluorometry and immunohistochemistry. An increase in JAK2 ph and STAT3 ph, but a decrease in Mpl at 8-week exposure was identified in our findings. Taking together, we propose that the morphological findings, JAK/STAT activation, and decreased Mpl receptor induced by V leads to a condition comparable to essential thrombocythemia, so the effect on megakaryocytes caused by different mechanisms is similar. We also suggest that the decrease in Mpl is a negative feedback mechanism after the JAK/STAT activation. Since megakaryocytes are platelet precursors, their alteration affects platelet morphology and function, which might have implications in hemostasis as demonstrated previously, so it is important to continue evaluating the effects of toxics and pollutants on megakaryocytes and platelets.