Vanadium pentoxide (V(2)O(5)) induced mucin production by airway epithelium

Evaluate the Work-Related Exposure of Vanadium on Scalp Hair Samples of Outdoor and Administrative Workers of Oil Drilling Field: Related Health Risks

Petrochemical facilities, including oil well drilling, are discharging resources of extensive noxious waste into the environment. The workers in different sections might be exposed to vanadium (V) through different routes (groundwater and soil), which is linked with extensive physiological disorders, hypertension, respiratory disorders, anemia, skin, and gastrointestinal disorders. This study determined the contents of V in a biological sample (scalp hair) of workers of different categories (outdoor and office workers) in an oil drilling field in Sindh, Pakistan. The environmental samples, groundwater, bottled mineral water, and soil samples were also analyzed for V. For comparative purposes, the scalp hair of age-matched male subjects residing in domestic areas of Hyderabad city, Pakistan, was also analyzed. Generally, the concentrations of V in groundwater near the oil drilling field and drilled soil illustrated significant variations. The results show that the vanadium concentration in the scalp hair of non-exposed referents (controls) and office workers (exposed referents) was 62% and 45% lower than those observed for outdoor drilling and cleaning mud workers. It was observed that high exposure to V in outdoor workers might be linked with different physiological disorders such as anemia, eye problems, and bronchial disorders.

Effects of occupational exposure to dust, gas, vapor and fumes on chronic bronchitis and lung function

Background

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality worldwide, and therefore the identification of the modifiable risk factors [such as exposure to vapors, gases, dust and fumes (VGDF)] for accelerate disease progression has important significance.

Methods

We conducted COPD surveillance in six cities of southern China between 2014 and 2019. We recorded the diagnosis of chronic bronchitis, respiratory symptoms, occupational exposure to VGDF and other covariates by using a structured questionnaire. Logistic regression and multivariate linear regression model were adopted for analysis. We performed sensitivity analyses based on two methods of propensity score (PS) methods to evaluate the robustness of our results.

Results

A total of 7,418 participants were included. Cough [odds ratios (ORs): 1.60, 95% confidence interval (CI): 1.22 to 2.08] and phlegm (OR: 1.49, 95% CI: 1.19 to 1.85) correlated significantly with exposure to dust. There was an increased risk of cough (OR: 1.53, 95% CI: 1.11 to 2.07) for occupational exposure to gas/vapor/fume. Dual exposure to dust and gas/vapor/fume was associated with a significantly increased risk of chronic bronchitis (OR: 1.74, 95% CI: 1.20 to 2.52), cough (OR: 1.43, 95% CI: 1.15 to 1.79) and phlegm (OR: 1.49, 95% CI: 1.24 to 1.79). In 5,249 participants with complete data of spirometry, gas/vapor/fume was associated with a decreased ratio of forced expiratory volume in one second and forced vital capacity (FEV1/FVC) (β: -1.05, 95% CI: -1.85 to -0.26) and maximal mid-expiratory flow (MMEF) (β: -0.15, 95% CI: -0.23 to -0.07). Dual exposure to dust and gas/vapor/fume was significantly associated with decreased FEV1/FVC (β: -0.74, 95% CI: -1.28 to -0.20) and MMEF (β: -0.06, 95% CI: -0.12 to -0.01). Results of sensitivity analysis were not materially changed.

Conclusions

VGDF exposure is associated with chronic bronchitis, respiratory symptoms and decreased lung function, suggesting that VGDF contributes to the pathogenesis and progression of COPD.

Gene Expression in Bronchial Epithelial Cell Responses to Vanadium Exposure

Vanadium exposure has the adverse effect on lung function in human, whereas the detailed mechanisms of vanadium exposure-induced pulmonary toxicity are limited. Hence, the present study aimed to investigate the hub genes and signaling pathways related to sodium metavanadate (SMV)-induced pulmonary toxicity. The transcript expression profile GSE36684 downloaded from Gene Expression Omnibus contained eight human bronchial epithelial cell (HBEC) samples including five SMV-treated and three control HBEC samples. Totally 455 differentially expressed genes (DEGs) were screened, especially 201 and 254 genes were up- and down-regulated in the HBECs treated with SMV. Gene ontology analysis suggested that the DEGs were mainly involved in signal transduction, the response to drug, cell proliferation, adhesion, and migration. Pathway analysis demonstrated that the DEGs were primarily participated in NF-κB, Wnt, MAPK, and PI3K-Akt signaling pathways. Moreover, the hub genes, including ITGA5, ITGB3, ITGA2, LAMC2, MMP2, and ITGA4, might contribute to SMV-induced pulmonary toxicity. Our study improves the understanding of the molecular mechanisms by which SMV induced the pulmonary toxicity.

Recent advances in removal techniques of vanadium from water: A comprehensive review

In recent years, with the development of economy and industry, water contaminated with heavy metal has become a global environmental problem. Vanadium (V) is an emerging contaminant reported in wastewater along with the increasing mining, smelting and recovering of vanadium ores and application in many fields as a significant national strategy resource. The increasing attention has been paid to the separations of V from water due to its potential toxic to animals and human beings. In the present study, the most common V removal techniques including adsorption, microbiological treatment, chemical precipitation, solvent extraction, electrokinetic remediation, photocatalysis, coagulation and membrane filtration are presented with discussion of their advantages, limitations and the recent achievements. Several major influencing factors and mechanisms of various processes have been briefly analyzed. Some research perspectives are proposed for improving the capacities to remove V from water. The core objective of this review is to provide comprehensive information or database for the superior approach for V removal.

Engineered metal oxide nanomaterials inhibit corneal epithelial wound healing in vitro and in vivo

Ocular exposure to metal oxide engineered nanomaterials (ENMs) is common as exemplified by zinc oxide (ZnO), a major constituent of sunscreens and cosmetics. The ocular surface that includes the transparent cornea and its protective tear film are common sites of exposure for metal ENMs. Despite the frequency of exposure of the ocular surface, there is a knowledge gap regarding the effects of metal oxide ENMs on the cornea in health and disease. Therefore, we studied the effects of metal oxide ENMs on the cornea in the presence or absence of injury. Cell viability of immortalized human corneal epithelial (hTCEpi) cells was assessed following treatment with 11 metal oxide ENMs with a concentration ranging from 0.5 to 250 μg/mL for 24 hours. An epithelial wound healing assay with a monolayer of hTCEpi cells was then performed using 11 metal oxide ENMs at select concentrations based on data from the viability assays. Subsequently, based on the in vitro results, in vivo testing of precorneal tear film (PTF) quantity and stability as well as a corneal epithelial wound healing were tested in the presence or absence ZnO or vanadium pentoxide (V₂O₅) at a concentration of 50 μg/mL. We found that WO₃, ZnO, V₂O₅ and CuO ENMs significantly reduced hTCEpi cell viability in comparison to vehicle control or the other metal oxide ENMs tested. Furthermore, ZnO and V₂O₅ ENMs also significantly decreased hTCEpi cell migration. Although ZnO and V₂O₅ did not alter PTF parameters of rabbits in vivo, corneal epithelial wound healing was significantly delayed by topical ZnO while V₂O₅ did not alter wound healing. Finally, hyperspectral images confirmed penetration of ZnO and V₂O₅ through all corneal layers and into the iris stroma. Considering the marked epithelial toxicity and corneal penetration of ZnO, further investigations on the impact of this ENM on the eye are warranted.

Vanadium in Biological Action: Chemical, Pharmacological Aspects, and Metabolic Implications in Diabetes Mellitus

Vanadium compounds have been primarily investigated as potential therapeutic agents for the treatment of various major health issues, including cancer, atherosclerosis, and diabetes. The translation of vanadium-based compounds into clinical trials and ultimately into disease treatments remains hampered by the absence of a basic pharmacological and metabolic comprehension of such compounds. In this review, we examine the development of vanadium-containing compounds in biological systems regarding the role of the physiological environment, dosage, intracellular interactions, metabolic transformations, modulation of signaling pathways, toxicology, and transport and tissue distribution as well as therapeutic implications. From our point of view, the toxicological and pharmacological aspects in animal models and humans are not understood completely, and thus, we introduced them in a physiological environment and dosage context. Different transport proteins in blood plasma and mechanistic transport determinants are discussed. Furthermore, an overview of different vanadium species and the role of physiological factors (i.e., pH, redox conditions, concentration, and so on) are considered. Mechanistic specifications about different signaling pathways are discussed, particularly the phosphatases and kinases that are modulated dynamically by vanadium compounds because until now, the focus only has been on protein tyrosine phosphatase 1B as a vanadium target. Particular emphasis is laid on the therapeutic ability of vanadium-based compounds and their role for the treatment of diabetes mellitus, specifically on that of vanadate- and polioxovanadate-containing compounds. We aim at shedding light on the prevailing gaps between primary scientific data and information from animal models and human studies.

Occupational exposures and incidence of chronic bronchitis and related symptoms over two decades: the European Community Respiratory Health Survey

OBJECTIVES

Chronic bronchitis (CB) is an important chronic obstructive pulmonary disease (COPD)-related phenotype, with distinct clinical features and prognostic implications. Occupational exposures have been previously associated with increased risk of CB but few studies have examined this association prospectively using objective exposure assessment. We examined the effect of occupational exposures on CB incidence in the European Community Respiratory Health Survey.

METHODS

Population samples aged 20-44 were randomly selected in 1991-1993, and followed up twice over 20 years. Participants without chronic cough or phlegm at baseline were analysed. Coded job histories during follow-up were linked to the ALOHA Job Exposure Matrix, generating occupational exposure estimates to 12 categories of chemical agents. Their association with CB incidence over both follow-ups was examined with Poisson models using generalised estimating equations.

RESULTS

8794 participants fulfilled the inclusion criteria, contributing 13 185 observations. Only participants exposed to metals had a higher incidence of CB (relative risk (RR) 1.70, 95% CI 1.16 to 2.50) compared with non-exposed to metals. Mineral dust exposure increased the incidence of chronic phlegm (RR 1.72, 95% CI 1.43 to 2.06). Incidence of chronic phlegm was increased in men exposed to gases/fumes and to solvents and in women exposed to pesticides.

CONCLUSIONS

Occupational exposures are associated with chronic phlegm and CB, and the evidence is strongest for metals and mineral dust exposure. The observed differences between men and women warrant further investigation.

VAOS, a novel vanadyl complexes of alginate saccharides, inducing apoptosis via activation of AKT-dependent ROS production in NSCLC

Previous studies have confirmed that protein tyrosine phosphatase 1B (PTP1B) can promote tumour progression in non-small cell lung cancer (NSCLC). Vanadyl alginate oligosaccharides (VAOS) is a new coordination compounds that possesses a good PTP1B inhibitory activity. However, the potent anticancer efficacy of VAOS in human NSCLC requires further study. In this study, VAOS exhibited effective inhibitory effects in NSCLC both in cultured cells and in a xenograft mouse model. VAOS was further identified to induce NSCLC cell apoptosis through activating protein kinase B (AKT) to elevate intracellular reactive oxygen species (ROS) levels by increasing in oxygen consumption and impairing the ROS-scavenging system. Neither silencing of PTP1B by siRNA nor transient overexpression of PTP1B had an effect on the AKT phosphorylation triggered by VAOS, indicating that PTP1B inhibition was not involved in VAOS-induced apoptosis. Through phosphorus colorimetric assay, we demonstrated that VAOS notably inhibited phosphatase and tensin homologue deleted on chromosome 10 (PTEN) dephosphorylation activity, another member of the protein tyrosine phosphatases (PTPases)-upstream factor of AKT. Interestingly, PTEN knockdown sensitized cells to VAOS, whereas ectopic expression of PTEN markedly rescued VAOS-mediated lethality. In vivo, VAOS treatment markedly reduced PTEN activity and tumour cell burden with low systemic toxicity. Thus, our data not only provided a new therapeutic drug candidate for NSCLC, but presented new understanding into the pharmacological research of VAOS.

Functional and morphological olfactory bulb modifications in mice after vanadium inhalation

Neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, have olfaction impairment. These pathologies have also been linked to environmental pollutants. Vanadium is a pollutant, and its toxic mechanisms are related to the production of oxidative stress. In this study, we evaluated the effects of inhaled vanadium on olfaction, the olfactory bulb antioxidant, through histological and ultrastructural changes in granule cells. Mice in control group were made to inhale saline; the experimental group inhaled 0.02-M vanadium pentoxide (V2O5) for 1 hr twice a week for 4 weeks. Animals were sacrificed at 1, 2, 3, and 4 weeks after inhalation. Olfactory function was evaluated by the odorant test. The activity of glutathione peroxidase (GPx) and glutathione reductase (GR) was assayed in olfactory bulbs and processed for rapid Golgi method and ultrastructural analysis. Results show that olfactory function decreased at 4-week vanadium exposure; granule cells showed a decrease in dendritic spine density and increased lipofuscin, Golgi apparatus vacuolation, apoptosis, and necrosis. The activity of GPx and GR in the olfactory bulb was increased compared to that of the controls. Our results demonstrate that vanadium inhalation disturbs olfaction, histology, and the ultrastructure of the granule cells that might be associated with oxidative stress, a risk factor in neurodegenerative diseases.

Synergistic up-regulation of CXCL10 by virus and IFN γ in human airway epithelial cells

Airway epithelial cells are the first line of defense against viral infections and are instrumental in coordinating the inflammatory response. In this study, we demonstrate the synergistic stimulation of CXCL10 mRNA and protein, a key chemokine responsible for the early immune response to viral infection, following treatment of airway epithelial cells with IFN γ and influenza virus. The synergism also occurred when the cells were treated with IFN γ and a viral replication mimicker (dsRNA) both in vitro and in vivo. Despite the requirement of type I interferon (IFNAR) signaling in dsRNA-induced CXCL10, the synergism was independent of the IFNAR pathway since it wasn't affected by the addition of a neutralizing IFNAR antibody or the complete lack of IFNAR expression. Furthermore, the same synergistic effect was also observed when a CXCL10 promoter reporter was examined. Although the responsive promoter region contains both ISRE and NFκB sites, western blot analysis indicated that the combined treatment of IFN γ and dsRNA significantly augmented NFκB but not STAT1 activation as compared to the single treatment. Therefore, we conclude that IFN γ and dsRNA act in concert to potentiate CXCL10 expression in airway epithelial cells via an NFκB-dependent but IFNAR-STAT independent pathway and it is at least partly regulated at the transcriptional level.

Genetic susceptibility to interstitial pulmonary fibrosis in mice induced by vanadium pentoxide (V2O5)

Interstitial lung diseases (ILDs) are characterized by injury, inflammation, and scarring of alveoli, leading to impaired function. The etiology of idiopathic forms of ILD is not understood, making them particularly difficult to study due to the lack of appropriate animal models. Consequently, few effective therapies have emerged. We developed an inbred mouse model of ILD using vanadium pentoxide (V2O5), the most common form of a transition metal found in cigarette smoke, fuel ash, mineral ores, and steel alloys. Pulmonary responses to V2O5, including dose-dependent increases in lung permeability, inflammation, collagen content, and dysfunction, were significantly greater in DBA/2J mice compared to C57BL/6J mice. Inflammatory and fibrotic responses persisted for 4 mo in DBA/2J mice, while limited responses in C57BL/6J mice resolved. We investigated the genetic basis for differential responses through genetic mapping of V2O5-induced lung collagen content in BXD recombinant inbred (RI) strains and identified significant linkage on chromosome 4 with candidate genes that associate with V2O5-induced collagen content across the RI strains. Results suggest that V2O5 may induce pulmonary fibrosis through mechanisms distinct from those in other models of pulmonary fibrosis. These findings should further advance our understanding of mechanisms involved in ILD and thereby aid in identification of new therapeutic targets.

Regulation of human corneal epithelial mucins by rebamipide

PURPOSE

Membrane-associated mucins (MAMs) play important roles in barrier function and tear stability, and their expression on the ocular surface is altered in dry eye disease. Rebamipide is a mucin secretagogue that promotes the production of mucin-like glycoproteins in human corneal epithelial (HCE) cells. However, the expression of MAMs on the corneal epithelia (MUC1, MUC4, MUC16), which is induced by rebamipide, is poorly understood. In this study, we investigated the effect of rebamipide on the regulation of MAM expression in HCE cells.

MATERIALS AND METHODS

MUC16, Ki67 and PCNA expression levels in HCE cells isolated at confluence and at 24 hours after confluence were examined by Western blotting to assess cell proliferation. HCE cells isolated at 24 hours after confluence were cultured in medium supplemented with 1-10 µM rebamipide or 0.3-30 nM of epidermal growth factor (EGF). Real-time PCR (RT-PCR) and Western blot analysis of MAMs were performed to evaluate the effect of rebamipide. Western blot analysis of cells treated with an EGF receptor inhibitor (AG1478) or MEK1/2 inhibitor (U0126) was performed to reveal the relationship between EGF receptor activation and rebamipide-induced MAM expression.

RESULTS

HCE cells isolated at 24 hours after confluence had lower cell proliferation activity and increased MUC16 expression compared with cells isolated at confluence. RT-PCR and Western blot analysis revealed that rebamipide increased MAM gene expression for 2 hours and protein expression for 24 hours in HCE cells. EGF inhibitor treatment led to reduced levels of all three MAMs that are normally induced by rebamipide, whereas EGF induced the expression of all three MAMs.

CONCLUSIONS

We suggested that rebamipide increased MUC1, MUC4 and MUC16 expression levels through signals involved in EGF receptor activation in the human corneal epithelia. These data suggest that rebamipide may improve subjective symptoms of dry eye disease by upregulating MAM expression.

Mucin deficiency causes functional and structural changes of the ocular surface

MUC5AC is the most abundant gel-forming mucin in the ocular system. However, the specific function is unknown. In the present study, a Muc5ac knockout (KO) mouse model was subject to various physiological measurements as compared to its wide-type (WT) control. Interestingly, when KO mice were compared to WT mice, the mean tear break up time (TBUT) values were significantly lower and corneal fluorescein staining scores were significantly higher. But the tear volume was not changed. Despite the lack of Muc5ac expression in the conjunctiva of KO mice, Muc5b expression was significantly increased in these mice. Corneal opacification, varying in location and severity, was found in a few KO mice but not in WT mice. The present results suggest a significant difference in the quality, but not the quantity, of tear fluid in the KO mice compared to WT mice. Dry eye disease is multifactorial and therefore further evaluation of the varying components of the tear film, lacrimal unit and corneal structure of these KO mice may help elucidate the role of mucins in dry eye disease. Because Muc5ac knockout mice have clinical features of dry eye, this mouse model will be extremely useful for further studies regarding the pathophysiology of the ocular surface in dry eye in humans.