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

Integrative investigation of hematotoxic effects induced by low doses of lead, cadmium, mercury and arsenic mixture: In vivo and in silico approach

The effect of the lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) mixture (MIX) on hematotoxicity development was investigated trough combined approach. In vivo subacute study (28 days) was performed on rats (5 per group): a control group and five groups orally exposed to increasing metal(loid) mixture doses, MIX 1- MIX 5 (mg/kg bw./day) (Pb: 0.003, 0.01, 0.1, 0.3, 1; Cd: 0.01, 0.03, 0.3, 0.9, 3; Hg: 0.0002, 0.0006, 0.006, 0.018, 0.06; As: 0.002, 0.006, 0.06, 0.18, 0.6). Blood was taken for analysis of hematological parameters and serum iron (Fe) analysis. MIX treatment increased thrombocyte/platelet count and MCHC and decreased Hb, HCT, MCV and MCH values compared to control, indicating the development of anemia and thrombocytosis. BMDIs with the narrowest width were identified for MCH [pg] (6.030E-03 - 1.287E-01 mg Pb/kg bw./day; 2.010E-02 - 4.290E-01 mg Cd/kg bw./day; 4.020E-04 - 8.580E-03 mg Hg/kg bw./day; 4.020E-03 - 8.580E-02 mg As/kg bw./day). In silico analysis showed target genes connected with MIX and the development of: anemia - ACHE, GSR, PARP1, TNF; thrombocytosis - JAK2, CALR, MPL, THPO; hematological diseases - FAS and ALAD. The main extracted pathways for anemia were related to apoptosis and oxidative stress; for thrombocytosis were signaling pathways of Jak-STAT and TPO. Changes in miRNAs and transcription factors enabled the mode of action (MoA) development based on the obtained results, contributing to mechanistic understanding and hematological risk related to MIX exposure.

Cytotoxicity of vanadium dioxide nanoparticles to human embryonic kidney cell line: Compared with vanadium(IV/V) ions

Vanadium dioxide (VO2) is a class of thermochromic material with potential applications in various fields. Massive production and wide application of VO2 raise the concern of its potential toxicity to human, which has not been fully understood. Herein, a commercial VO2 nanomaterial (S-VO2) was studied for its potential toxicity to human embryonic kidney cell line HEK293, and two most common vanadium ions, V(IV) and V(V), were used for comparison to reveal the related mechanism. Our results indicate that S-VO2 induces dose-dependent cellular viability loss mainly through the dissolved V ions of S-VO2 outside the cell rather than S-VO2 particles inside the cell. The dissolved V ions of S-VO2 overproduce reactive oxygen species to trigger apoptosis and proliferation inhibition via several signaling pathways of cell physiology, such as MAPK and PI3K-Akt, among others. All bioassays indicate that the differences in toxicity between S-VO2, V(IV), and V(V) in HEK293 cells are very small, supporting that the toxicity is mainly due to the dissolved V ions, in the form of V(V) and/or V(IV), but the V(V)'s behavior is more similar to S-VO2 according to the gene expression analysis. This study reveals the toxicity mechanism of nanosized VO2 at the molecular level and the role of dissolution of VO2, providing valuable information for safe applications of vanadium oxides.

Vanadium inhalation effects on the corneal ciliary neurotrophic factor (CNTF): study in a murine model

PURPOSE

Air pollution is a public health problem caused by predatory human activities and the indiscriminate burning of fossil fuels that liberate particulate matter (PM) into the atmosphere. Vanadium (V) adheres to them and reaches the bloodstream and different organs such as the eye when inhaled. Another way to reach the eye is by direct contact, and the cornea is the first layer exposed. Ciliary neurotrophic factor (CNTF) is secreted by the corneal nerves and some of its functions include self-renewal maintenance and wound healing by the activation of STAT3. Previous reports from our group indicate the activation of STAT3 after the inhalation of V, adhered to PM.

OBJECTIVE

To analyse the effect of V inhalation in the expression of CNTF. Method: CD-1 male mice were exposed for 4 and 8 weeks to V inhalation. The eyes were removed, and the corneas were processed for immunohistochemistry for CNTF and analysed by densitometry. The same slides were used to evaluate histological modifications and to measure the corneas' anterior epithelial and endothelial thickness.

RESULTS

A decrease in CNTF expression in the anterior epithelium in the 8th week, as well as an increase in the endothelial and corneal thickness and disarray of all the layers of the anterior epithelium.

CONCLUSION

V inhalation disturbs the architecture of the cornea and modifies the presence of CNTF which might modify the renewal of the corneas after exposure to PM air pollution.

Vanadium(IV) oxide affects embryonic development in mice

Vanadium(V) and vanadium(IV) are the predominant redox forms present in the environment, and epidemiological studies have reported that prenatal vanadium exposure is associated with restricted fetal growth and adverse birth outcomes. However, data about the toxic effects of vanadium(IV) oxide (V₂ O₄ ) on the development of mammals are still limited. Therefore, in this work, 4.7, 9.4, or 18.7 mg/kg body weight/injection/day V₂ O₄ was administered through an intraperitoneal (ip) injection to pregnant mice from gestational days 6 to 16. The results showed that V₂ O₄ produced maternal and embryo-fetal toxicity and external abnormalities in the offspring, such as malrotated and malpositioned hind limbs, hematomas and head injuries. Moreover, the skeletons of the fetuses presented reduced ossification of the cranial bones, including the frontal and parietal bones, corresponding to head injuries observed in the external assessment of the fetuses. These results demonstrate that administration of V₂ O₄ to pregnant females in the organogenesis period adversely affects embryonic development.

An Overview of Vanadium and Cell Signaling in Potential Cancer Treatments

Vanadium is an ultratrace element present in higher plants, animals, algae, and bacteria. In recent years, vanadium complexes have been studied to be considered as a representative of a new class of nonplatinum metal anticancer drugs. Nevertheless, the study of cell signaling pathways related to vanadium compounds has scarcely been reported on and reviewed thus far; this information is highly critical for identifying novel targets that play a key role in the anticancer activity of these compounds. Here, we perform a review of the activity of vanadium compounds over cell signaling pathways on cancer cells and of the underlying mechanisms, thereby providing insight into the role of these proteins as potential new molecular targets of vanadium complexes.

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.

Multiple metal exposure and platelet counts during pregnancy: A repeated measure study

BACKGROUND

Evidence from animal and in vitro studies suggest that some metals interfere with normal platelet counts (PLT). However, limited human studies have investigated the association of metals and PLT, a marker of hematologic and hemostatic, particularly in susceptible populations such as pregnant women.

OBJECTIVES

Our purpose was to investigate the associations of repeated measures of 13 urinary metals with PLT during pregnancy.

METHODS

The present study involved 3911 pregnant women participating in a prospective cohort study in Wuhan, China, from 2013 to 2016. We measured 13 metals in urine and PLT in blood samples collected in the first, second, and third trimester (median = 13, 24, and 35 weeks of gestation, respectively). Mixed linear models and general linear models were applied to analyze the associations between multiple metals and PLT during pregnancy. The odds ratio (OR) for gestational thrombocytopenia was examined using generalized estimating equations.

RESULTS

After adjusting for other metals and covariates, the repeated measure analyses showed that decreased levels of PLT were associated with a 10-fold increase in urinary concentration of cadmium (Cd) [percent difference (%Δ) = -5.02, 95%CI = -9.53, -0.29], manganese (Mn) [percent difference (%Δ) = -4.63, 95%CI = -7.50, -1.67], and arsenic (As) [percent difference (%Δ) = -4.56, 95%CI = -8.11, -0.86]. Cross-sectional analyses by trimesters revealed that Cd was inversely associated with PLT through the three trimesters. In addition, Cd was associated with an increased OR of 1.80 (95%CI: 1.26, 2.56), 1.65 (95%CI: 1.05, 2.59), 1.54 (95%CI: 1.02, 2.33) for gestational thrombocytopenia in the first, second, and third trimester, respectively.

CONCLUSIONS

Our study suggested an association of Cd, Mn, and As with decreased PLT during pregnancy. Particularly, Cd may increase the risk of gestational thrombocytopenia.

Changes in Ovarian and Uterine Morphology and Estrous Cycle in CD-1 Mice After Vanadium Inhalation

Vanadium is a metal present in particulate matter and its reprotoxic effects have been demonstrated in males and pregnant females in animal models. However, the effects of this metal on the reproductive organs of nonpregnant females have not been sufficiently studied. In a vanadium inhalation model in nonpregnant female mice, we found anestrous and estrous cycle irregularity, as well as low serum concentrations of 17β-estradiol and progesterone. A decrease in the diameter of secondary and preovulatory follicles, as well as a thickening of the myometrium and endometrial stroma, was observed in the vanadium-treated mice. There was no difference against the control group with respect to the presence of the estrogen receptor α in the uterus of the animals during the estrous stage. Our results indicate that when vanadium is administered by inhalation, effects are observed on the female reproductive organs and the production of female sex hormones.

Icaritin Provokes Serum Thrombopoietin and Downregulates Thrombopoietin/MPL of the Bone Marrow in a Mouse Model of Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a common acquired autoimmune disease, and thrombopoietin (TPO) is an important cytokine that regulates the production of megakaryocytes and platelets. We have identified a biologically active component, icaritin, from a Chinese herba epimedii extract. Icaritin promotes platelet production and regulates T cell polarization, but its mechanism is not clear. In this study, the BALB/c mouse model of ITP was established by injection of an antiplatelet antibody every other day for seven total times. The antiplatelet sera were derived from guinea pigs immunized with the platelets of BALB/c mice. Mice with ITP were treated with icaritin at low, moderate, or high doses of 4.73, 9.45, and 18.90 mg/kg, respectively, for fourteen consecutive days. The present study shows that icaritin can significantly increase peripheral blood platelet counts and thrombocytocrit, increase the TPO level in serum, attenuate splenomegaly, and reduce the abnormal proliferation of megakaryocytes in the spleen and bone marrow. Icaritin can also downregulate the expression of bone marrow TPO, myeloproliferative leukemia virus oncogene (MPL), and p-Stat3. Our results suggest that icaritin can significantly improve the health of mice with ITP via possible downregulation of p-Stat3 expression in the JAK2/Stat3 phosphorylation signaling pathway and regulation of bone marrow TPO/MPL metabolism.