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1.
Toxicol Appl Pharmacol ; 432: 115754, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34634286

ABSTRACT

Exposure to dust from active and abandoned mining operations may be a very significant health hazard, especially to sensitive populations. We have previously reported that inhalation of real-world mine tailing dusts during lung development can alter lung function and structure in adult male mice. These real-world dusts contain a mixture of metal(loid)s, including arsenic. To determine whether arsenic in inhaled dust plays a role in altering lung development, we exposed C57Bl/6 mice to a background dust (0 arsenic) or to the background dust containing either 3% or 10% by mass, calcium arsenate. Total level of exposure was kept at 100 µg/m3. Calcium arsenate was selected since arsenate is the predominant species found in mine tailings. We found that inhalation exposure during in utero and postnatal lung development led to significant increases in pulmonary baseline resistance, airway hyper-reactivity, and airway collagen and smooth muscle expression in male C57Bl/6 mice. Responses were dependent on the level of calcium arsenate in the simulated dust. These changes were not associated with increased expression of TGF-ß1, a marker of epithelial to mesenchymal transition. However, responses were correlated with decreases in the expression of club cell protein 16 (CC16). Dose-dependent decreases in CC16 expression and increases in collagen around airways was seen for animals exposed in utero only (GD), animals exposed postnatally only (PN) and animals continuously exposed throughout development (GDPN). These data suggest that arsenic inhalation during lung development can decrease CC16 expression leading to functional and structural alterations in the adult lung.


Subject(s)
Arsenates/toxicity , Calcium Compounds/toxicity , Lung/drug effects , Prenatal Exposure Delayed Effects , Age Factors , Airway Remodeling/drug effects , Airway Resistance/drug effects , Animals , Bronchoconstriction/drug effects , Collagen/metabolism , Down-Regulation , Dust , Female , Gestational Age , Inhalation Exposure , Lung/growth & development , Lung/metabolism , Lung/pathology , Male , Mice, Inbred C57BL , Pregnancy , Uteroglobin/metabolism
2.
J Appl Toxicol ; 41(9): 1357-1366, 2021 09.
Article in English | MEDLINE | ID: mdl-33340130

ABSTRACT

Lung cancer is the most common neoplasm and the primary cause-related mortality in developed and in most of nondeveloped countries. Epidemiological studies have demonstrated that even at low arsenic doses, the lungs are one of the main target organs and that chronic arsenic exposure has been associated with an increase in lung cancer development. Among the risk factors for cancer, arsenic methylation efficiency (As3MT) and the clearance of arsenic from cells by two members of the ATP-binding cassette (ABC) transporter family (multidrug resistance protein 1 [MRP1] and P-glycoprotein [P-gp]) play an important role in processing of arsenic and decreasing its intracellular levels. This study aimed to evaluate the association between chronic exposure to arsenic with polymorphism of three proteins involved in arsenic metabolism and efflux of the metalloid in subjects with lung cancer. Polymorphism in As3MT, MRP1, and P-gp modified the arsenic metabolism increasing significantly the AsV urinary levels. A significant association between MRP1 polymorphisms with an increase in the risk for cancer was found. The high inorganic arsenic urinary levels registered in the studied subjects suggest a reduction in the efficiency of As3MT, MRP1, and P-gp firstly because of gene polymorphisms and secondarily because of high internal inorganic arsenic levels. MRP1 polymorphism was associated with a twofold increase in the risk of lung cancer.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Arsenic/metabolism , Lung Neoplasms/chemically induced , Lung Neoplasms/genetics , Methyltransferases/genetics , Multidrug Resistance-Associated Proteins/genetics , Polymorphism, Genetic/genetics , Adult , Aged , Aged, 80 and over , Arsenic/analysis , Arsenic/urine , Cohort Studies , Cross-Sectional Studies , Drinking Water/analysis , Environmental Exposure , Female , Genotype , Humans , Lung Neoplasms/epidemiology , Male , Methylation , Mexico/epidemiology , Middle Aged , Risk Factors , Surveys and Questionnaires , Young Adult
3.
Toxicol Appl Pharmacol ; 394: 114959, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32201329

ABSTRACT

Arsenic is a ubiquitous environmental toxicant, found in high concentrations worldwide. Although abundant research has dealt with arsenic-induced cancers, studies on mechanisms of non-malignant lung diseases have not been complete. In addition, decades of research have mostly concentrated on high-dose arsenic exposure, which has very limited use in modeling the biological effects of today's low-dose exposures. Indeed, accumulated evidence has shown that low-dose arsenic exposure (i.e. ≤100 ppb) may also alter lung homeostasis by causing host susceptibility to viral infection. However, the underlying mechanism of this alteration is unknown. In this study, we found that low-dose sodium arsenite (As (III)) repressed major airway mucins-MUC5AC and MUC5B at both mRNA and protein levels. We further demonstrated that this repression was not caused by cellular toxicity or mediated by the reduction of a common mucin-inducing pathway-EGFR. Other established mucin activators- dsRNA, IL1ß or IL17 were not able to override As (III)-induced mucin repression. Interestingly, the suppressing effect of As (III) appeared to be partially reversible, and supplementation of all trans retinoic acid (t-RA) doses dependently restored mucin gene expression. Further analyses indicated that As (III) treatment significantly reduced the protein level of retinoic acid receptors (RARα, γ and RXRα) as well as RARE promoter reporter activity. Therefore, our study fills in an important knowledge gap in the field of low-dose arsenic exposure. The interference of RA signaling, and mucin gene expression may be important pathogenic factors in low-dose arsenic induced lung toxicity.


Subject(s)
Arsenic/toxicity , Mucins/biosynthesis , Respiratory Mucosa/metabolism , Signal Transduction/drug effects , Tretinoin , Arsenites/toxicity , Cell Line , Cell Survival/drug effects , ErbB Receptors/antagonists & inhibitors , Gene Expression/drug effects , Gene Expression Regulation/drug effects , Humans , Mucin 5AC/antagonists & inhibitors , Mucin 5AC/genetics , Mucin-5B/antagonists & inhibitors , Mucin-5B/genetics , Respiratory Mucosa/drug effects , Sodium Compounds/toxicity
4.
Toxicol Appl Pharmacol ; 287(2): 161-167, 2015 Sep 01.
Article in English | MEDLINE | ID: mdl-26048584

ABSTRACT

Evidence suggests that exposure to arsenic in drinking water during early childhood or in utero has been associated with an increase in respiratory symptoms or diseases in the adulthood, however only a few studies have been carried out during those sensitive windows of exposure. Recently our group demonstrated that the exposure to arsenic during early childhood or in utero in children was associated with impairment in the lung function and suggested that this adverse effect could be due to a chronic inflammation response to the metalloid. Therefore, we designed this cross-sectional study in a cohort of children associating lung inflammatory biomarkers and lung function with urinary As levels. A total of 275 healthy children were partitioned into four study groups according with their arsenic urinary levels. Inflammation biomarkers were measured in sputum by ELISA and the lung function was evaluated by spirometry. Fifty eight percent of the studied children were found to have a restrictive spirometric pattern. In the two highest exposed groups, the soluble receptor for advanced glycation end products' (sRAGE) sputum level was significantly lower and matrix metalloproteinase-9 (MMP-9) concentration was higher. When the biomarkers were correlated to the urinary arsenic species, negative associations were found between dimethylarsinic (DMA), monomethylarsonic percentage (%MMA) and dimethylarsinic percentage (%DMA) with sRAGE and positive associations between %DMA with MMP-9 and with the MMP-9/tissue inhibitor of metalloproteinase (TIMP-1) ratio. In conclusion, chronic arsenic exposure of children negatively correlates with sRAGE, and positively correlated with MMP-9 and MMP-9/TIMP-1 levels, and increases the frequency of an abnormal spirometric pattern. Arsenic-induced alterations in inflammatory biomarkers may contribute to the development of restrictive lung diseases.


Subject(s)
Arsenic/adverse effects , Arsenic/urine , Drinking Water/analysis , Pneumonia/chemically induced , Water Pollutants/adverse effects , Water Pollutants/urine , Arsenicals/metabolism , Biomarkers , Cacodylic Acid/metabolism , Child , Cross-Sectional Studies , Environmental Exposure/analysis , Female , Humans , Inflammation/physiopathology , Male , Matrix Metalloproteinase 9/biosynthesis , Pneumonia/physiopathology , Receptor for Advanced Glycation End Products , Receptors, Immunologic/antagonists & inhibitors , Rural Population , Spirometry , Tissue Inhibitor of Metalloproteinase-1/metabolism
5.
J Appl Toxicol ; 35(4): 358-66, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25131850

ABSTRACT

The lung is a target organ for adverse health outcomes following exposure to As. Several studies have reported a high prevalence of respiratory symptoms and diseases in subjects highly exposed to As through drinking water; however, most studies to date has been performed in exposed adults, with little information on respiratory effects in children. The objective of the study was to evaluate the association between urinary levels of As and its metabolites with lung function in children exposed in utero and in early childhood to high As levels through drinking water. A total of 358 healthy children were included in our study. Individual exposure was assessed based on urinary concentration of inorganic As. Lung function was assessed by spirometry. Participants were exposed since pregnancy until early childhood to an average water As concentration of 152.13 µg l⁻¹. The mean urinary As level registered in the studied subjects was 141.2 µg l⁻¹ and only 16.7% had a urinary concentration below the national concern level. Forced vital capacity was significantly decreased in the studied population and it was negatively associated with the percentage of inorganic As. More than 57% of the subjects had a restrictive spirometric pattern. The urinary As level was higher in those children with restrictive lung patterns when compared with the levels registered in subjects with normal spirometric patterns. Exposure to As through drinking water during in utero and early life was associated with a decrease in forced vital capacity and with a restrictive spirometric pattern in the children evaluated.


Subject(s)
Arsenic/toxicity , Environmental Exposure/adverse effects , Environmental Illness/chemically induced , Lung Diseases/chemically induced , Lung/drug effects , Prenatal Exposure Delayed Effects , Water Pollutants, Chemical/toxicity , Arsenic/analysis , Arsenic/urine , Child , Drinking Water/chemistry , Environmental Illness/epidemiology , Environmental Illness/physiopathology , Environmental Illness/urine , Environmental Monitoring , Female , Humans , Lung/embryology , Lung/physiopathology , Lung Diseases/epidemiology , Lung Diseases/physiopathology , Lung Diseases/urine , Male , Mexico/epidemiology , Pregnancy , Prevalence , Risk Factors , Rural Health , Severity of Illness Index , Vital Capacity/drug effects , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/urine , Water Pollution, Chemical/adverse effects
6.
J Appl Toxicol ; 40(3): 342-351, 2020 03.
Article in English | MEDLINE | ID: mdl-31631368

ABSTRACT

The identification of gene-environment interactions related to breast cancer reveals the biological and molecular mechanisms underlying the disease and allows the distinction of women at high risk from women at lower risk, which could decrease the morbimortality of this neoplasm. The current study evaluated the association between polymorphisms rs1820453 and rs11225161 of the Yes-associated protein (YAP) gene in women with breast cancer exposed to arsenic (As) through drinking water. In total, 182 women were assessed for the frequency of YAP rs1820453 and rs11225161 polymorphisms and As urinary levels. The results demonstrated a positive and significant association between breast cancer and smoking, type of drinking water, and levels of AsIII , AsV and inorganic As (iAs) but not the YAP gene polymorphisms evaluated. In conclusion, our data showed that the source of drinking water and AsV and iAs urinary levels increased the risk for breast cancer, but no interactions between YAP gene polymorphisms and As urinary levels were found.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Arsenicals/adverse effects , Breast Neoplasms/genetics , Drinking Water/adverse effects , Gene-Environment Interaction , Polymorphism, Single Nucleotide , Transcription Factors/genetics , Water Pollutants, Chemical/adverse effects , Adult , Arsenicals/urine , Breast Neoplasms/diagnosis , Breast Neoplasms/ethnology , Cross-Sectional Studies , Female , Genetic Predisposition to Disease , Humans , Mexico , Middle Aged , Phenotype , Risk Assessment , Risk Factors , Smoking/adverse effects , Water Pollutants, Chemical/urine , YAP-Signaling Proteins
7.
Toxicol Appl Pharmacol ; 265(3): 292-9, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-22975029

ABSTRACT

Exposure to arsenic is associated with an increased risk of lung disease. Novel strategies are needed to reduce the adverse health effects associated with arsenic exposure in the lung. Nrf2, a transcription factor that mediates an adaptive cellular defense response, is effective in detoxifying environmental insults and prevents a broad spectrum of diseases induced by environmental exposure to harmful substances. In this report, we tested whether Nrf2 activation protects mice from arsenic-induced toxicity. We used an in vivo arsenic inhalation model that is highly relevant to low environmental human exposure to arsenic-containing dusts. Two-week exposure to arsenic-containing dust resulted in pathological alterations, oxidative DNA damage, and mild apoptotic cell death in the lung; all of which were blocked by sulforaphane (SF) in an Nrf2-dependent manner. Mechanistically, SF-mediated activation of Nrf2 alleviated inflammatory responses by modulating cytokine production. This study provides strong evidence that dietary intervention targeting Nrf2 activation is a feasible approach to reduce adverse health effects associated with arsenic exposure.


Subject(s)
Arsenic/toxicity , Inhalation Exposure/adverse effects , Lung Injury/chemically induced , Lung Injury/prevention & control , NF-E2-Related Factor 2/immunology , Thiocyanates/pharmacology , Animals , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , Cytokines/genetics , Cytokines/immunology , DNA Damage , Immunohistochemistry , Isothiocyanates , Lung Injury/immunology , Mice , Mice, Knockout , NF-E2-Related Factor 2/genetics , RNA/chemistry , RNA/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sulfoxides
8.
Res Rep Health Eff Inst ; (159): 3-40, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21877416

ABSTRACT

In this study, we examined the role of neprilysin (NEP), a key membrane-bound endopeptidase, in the inflammatory response induced by diesel exhaust emissions (DEE) in the airways through a number of approaches: in vitro, animal, and controlled human exposure. Our specific aims were (1) to examine the role of NEP in inflammatory injury induced by diesel exhaust particles (DEP) using Nep-intact (wild-type) and Nep-null mice; (2) to examine which components of DEP are associated with NEP downregulation in vitro; (3) to determine the molecular impact of DEP exposure and decreased NEP expression on airway epithelial cells' gene expression in vitro, using a combination of RNA interference (RNAi) and microarray approaches; and (4) to evaluate the effects on NEP activity of human exposure to DEE. We report four main results: First, we found that exposure of normal mice to DEP consisting of standard reference material (SRM) 2975 via intratracheal installation can downregulate NEP expression in a concentration-dependent manner. The changes were accompanied by increases in the number of macrophages and epithelial cells, as well as proinflammatory cytokines, examined in bronchoalveolar lavage (BAL) fluid and cells. Nep-null mice displayed increased and/or additional inflammatory responses when compared with wild-type mice, especially in response to exposure to the higher dose of DEP that we used. These in vivo findings suggest that loss of NEP in mice could cause increased susceptibility to injury or exacerbate inflammatory responses after DEP exposure via release of specific cytokines from the lungs. Second, we found evidence, using in vitro studies, that downregulation of NEP by DEP in cultured human epithelial BEAS-2B cells was mostly attributable to DEP-adsorbed organic compounds, whereas the carbonaceous core and transition metal components of DEP had little or no effect on NEP messenger RNA (mRNA) expression. This NEP downregulation was not a specific response to DEP or its contents because the change also occurred after exposure to urban dust (SRM 1649a), which differs in physical and chemical composition from DEP. Third, we also collected the transcriptome profiles of the concentration-effects of SRM 2975 in cultured BEAS-2B cells through a 2 X 3 factorial design. DEP exposure upregulated 151 genes and downregulated 59 genes. Cells with decreased NEP expression (accomplished by transfecting an NEP-specific small interfering RNA [siRNA]) substantially altered the expression of genes (upregulating 17 and downregulating 14) associated with DNA/protein binding, calcium channel activities, and the cascade of intracellular signaling by cytokines. Data generated from the combined RNAi and microarray approaches revealed that there is a complex molecular cascade mediated by NEP in different subcellular compartments, possibly influencing the inflammatory response. Fourth, in a controlled human exposure study, we observed significant increases in soluble NEP in sputum after acute exposure to DEE, with an average net increase of 31%. We speculate that the change in NEP activity in sputum, if confirmed in larger epidemiologic investigations at ambient exposure levels to DEE, may provide a useful endpoint and promote insight into the mechanism of DEE-induced airway alterations.


Subject(s)
Bronchitis/chemically induced , Bronchitis/enzymology , Neprilysin/metabolism , Vehicle Emissions/poisoning , Adult , Animals , Down-Regulation , Epithelial Cells/enzymology , Female , Gene Expression , Humans , Inflammation , Male , Mice , Mice, Knockout , Neprilysin/genetics , Particle Size , Sputum/enzymology , Young Adult
9.
Environ Sci Pollut Res Int ; 28(26): 34355-34366, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33650048

ABSTRACT

Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and an increase in the expression of matrix metalloproteinase-9 (MMP-9), both biomarkers of lung inflammation and negative respiratory outcomes. The objectives of this study were to determine if the levels of serum CC16 and MMP-9 and subsequent respiratory infections in children are associated with the ingestion of arsenic by drinking water. This cross-sectional study included 216 children from three Yaqui villages, Potam, Vicam, and Cocorit, with levels of arsenic in their ground water of 70.01 ± 21.85, 23.3 ± 9.99, and 11.8 ± 4.42 µg/L respectively. Total arsenic in water and urine samples was determined by inductively coupled plasma/optical emission spectrometry. Serum was analyzed for CC16 and MMP-9 using ELISA. The children had an average urinary arsenic of 79.39 µg/L and 46.8 % had levels above of the national concern value of 50 µg/L. Increased arsenic concentrations in drinking water and average daily arsenic intake by water were associated with decreased serum CC16 levels (ß = - 0.12, 95% CI - 0.20, - 0.04 and ß = - 0.10, 95% CI - 0.18, - 0.03), and increased serum MMP-9 levels (ß = 0.35, 95% CI 0.22, 0.48 and ß = 0.29, 95% CI 0.18, 0.40) at significant levels (P < 0.05). However, no association was found between levels of these serum biomarkers and urinary arsenic concentrations. In these children, reduced serum CC16 levels were significantly associated with increased risk of respiratory infections (OR = 0.34, 95% CI 0.13, 0.90). In conclusion, altered levels of serum CC16 and MMP-9 in the children may be due to the toxic effects of arsenic exposure through drinking water.


Subject(s)
Arsenic , Drinking Water , Water Pollutants, Chemical , Adult , Arsenic/analysis , Biomarkers , Child , Cross-Sectional Studies , Drinking Water/analysis , Environmental Exposure/analysis , Humans , Inflammation , Mexico
10.
Toxicol Appl Pharmacol ; 235(1): 105-13, 2009 Feb 15.
Article in English | MEDLINE | ID: mdl-19095001

ABSTRACT

In addition to cancer endpoints, arsenic exposures can also lead to non-cancerous chronic lung disease. Exposures during sensitive developmental time points can contribute to the adult disease. Using a mouse model, in utero and early postnatal exposures to arsenic (100 ppb or less in drinking water) were found to alter airway reactivity to methacholine challenge in 28 day old pups. Removal of mice from arsenic exposure 28 days after birth did not reverse the alterations in sensitivity to methacholine. In addition, adult mice exposed to similar levels of arsenic in drinking water did not show alterations. Therefore, alterations in airway reactivity were irreversible and specific to exposures during lung development. These functional changes correlated with protein and gene expression changes as well as morphological structural changes around the airways. Arsenic increased the whole lung levels of smooth muscle actin in a dose dependent manner. The level of smooth muscle mass around airways was increased with arsenic exposure, especially around airways smaller than 100 microm in diameter. This increase in smooth muscle was associated with alterations in extracellular matrix (collagen, elastin) expression. This model system demonstrates that in utero and postnatal exposure to environmentally relevant levels of arsenic can irreversibly alter pulmonary structure and function in the adults.


Subject(s)
Arsenic/toxicity , Lung Diseases/chemically induced , Lung Diseases/pathology , Lung/growth & development , Lung/physiology , Aging , Animals , Animals, Newborn , Collagen/metabolism , Dose-Response Relationship, Drug , Elastin/metabolism , Female , Gene Expression Regulation, Developmental/drug effects , Lung/drug effects , Male , Mice , Mice, Inbred C57BL , Muscle, Smooth/drug effects , Muscle, Smooth/pathology , Muscle, Smooth/physiology , Pregnancy , Prenatal Exposure Delayed Effects
11.
Toxicology ; 254(1-2): 106-11, 2008 Dec 05.
Article in English | MEDLINE | ID: mdl-18930109

ABSTRACT

This study was designed to characterize and compare the pulmonary effects in distal lung from a low-level exposure to jet propellant-8 fuel (JP-8) and a new synthetic-8 fuel (S-8). It is hypothesized that both fuels have different airway epithelial deposition and responses. Consequently, male C57BL/6 mice were nose-only exposed to S-8 and JP-8 at average concentrations of 53mg/m(3) for 1h/day for 7 days. A pulmonary function test performed 24h after the final exposure indicated that there was a significant increase in expiratory lung resistance in the S-8 mice, whereas JP-8 mice had significant increases in both inspiratory and expiratory lung resistance compared to control values. Neither significant S-8 nor JP-8 respiratory permeability changes were observed compared to controls, suggesting no loss of epithelial barrier integrity. Morphological examination and morphometric analysis of airway tissue demonstrated that both fuels showed different patterns of targeted epithelial cells: bronchioles in S-8 and alveoli/terminal bronchioles in JP-8. Collectively, our data suggest that both fuels may have partially different deposition patterns, which may possibly contribute to specific different adverse effects in lung ventilatory function.


Subject(s)
Epithelium/drug effects , Hydrocarbons/pharmacology , Lung/drug effects , Animals , Male , Mice , Mice, Inbred C57BL , Respiratory Function Tests
12.
Toxicol Pathol ; 36(6): 805-17, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18812580

ABSTRACT

Chronic ingestion of arsenic is associated with increased incidence of respiratory and cardiovascular diseases. To investigate the role of arsenic in early events in vascular pathology, C57BL/6 mice ingested drinking water with or without 50 ppb sodium arsenite (AsIII) for four, five, or eight weeks. At five and eight weeks, RNA from the lungs of control and AsIII-exposed animals was processed for microarray. Sixty-five genes were significantly and differentially expressed. Differential expression of extracellular matrix (ECM) gene transcripts was particularly compelling, as 91% of genes in this category, including elastin and collagen, were significantly decreased. In additional experiments, real-time RT-PCR showed an AsIII-induced decrease in many of these ECM gene transcripts in the heart and NIH3T3 fibroblast cells. Histological stains for collagen and elastin show a distinct disruption in the ECM surrounding small arteries in the heart and lung of AsIII-exposed mice. Immunohistochemical detection of alpha-smooth muscle actin in blood vessel walls was decreased in the AsIII-exposed animals. These data reveal a functional link between AsIII exposure and disruption in the vascular ECM. These AsIII-induced early pathological events may predispose humans to respiratory and cardiovascular diseases linked to chronic low-dose AsIII exposure.


Subject(s)
Arsenites/toxicity , Blood Vessels/drug effects , Extracellular Matrix Proteins/genetics , Gene Expression/drug effects , Myocardium/pathology , Sodium Compounds/toxicity , Animals , Arsenic/toxicity , Arsenites/administration & dosage , Blood Vessels/metabolism , Blood Vessels/pathology , Collagen/genetics , Coronary Vessels/drug effects , Coronary Vessels/pathology , Elastin/genetics , Heat-Shock Proteins/genetics , Image Processing, Computer-Assisted , Immunohistochemistry , Lung/blood supply , Lung/drug effects , Lung/pathology , Mice , Mice, Inbred C57BL , NIH 3T3 Cells , Oligonucleotide Array Sequence Analysis , Reverse Transcriptase Polymerase Chain Reaction , Sodium Compounds/administration & dosage
13.
Geohealth ; 2(4): 118-138, 2018 Apr.
Article in English | MEDLINE | ID: mdl-30338309

ABSTRACT

Environmental contamination from legacy mine-waste deposits is a persistent problem due to the long history of hard-rock mining. Sulfide ore deposits can contain elevated levels of toxic metal(loid)s that, when mobilized by weathering upon O2 and H2O infusion, can result in groundwater contamination. Dry-climate and lack of vegetative cover result in near-surface pedogenic processes that produce fine-particulate secondary minerals that can be translocated as geo-dusts leading to ingestion or inhalation exposure in nearby communities. In this study, in vitro bioassays were combined with synchrotron-based x-ray spectroscopy and diffraction to determine the potential risk for toxic element release from dust (PM10) samples into biofluid simulants. PM10 were isolated from across the oxidative reaction front in the top meter of tailings subjected to 50 years of weathering under semi-arid climate, and introduced to synthetic gastric- and alveolar-fluids. Aqueous concentrations were measured as a function of reaction time to determine release kinetics. X-ray diffraction and absorption spectroscopy analyses were performed to assess associated changes in mineralogy and elemental speciation. In vitro bioaccessibility of arsenic and lead was highest in less-weathered tailings samples (80-110 cm) and lowest in samples from the sub-oxic transition zone (40-52 cm). Conversely, zinc release to biofluids was greatest in the highly-weathered near-surface tailings. Results indicate that bioaccessibility of As and Pb was controlled by (i) the solubility of Fe2+-bearing solids, (ii) the prevalence of soluble SO4 2-, and (iii) the presence of poorly-crystalline Fe(III) oxide sorbents, whereas Zn bioaccessibility was controlled by the pH-dependent solubility of the stable solid phase.

14.
Environ Health Perspect ; 115(4): 586-91, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17450228

ABSTRACT

OBJECTIVE: Environmental exposure to arsenic results in multiple adverse effects in the lung. Our objective was to identify potential pulmonary protein biomarkers in the lung-lining fluid of mice chronically exposed to low-dose As and to validate these protein changes in human populations exposed to As. METHODS: Mice were administered 10 or 50 ppb As (sodium arsenite) in their drinking water for 4 weeks. Proteins in the lung-lining fluid were identified using two-dimensional gel electrophoresis (n = 3) or multidimensional protein identification technology (MUDPIT) (n = 2) coupled with mass spectrometry. Lung-induced sputum samples were collected from 57 individuals (tap water As ranged from ~ 5 to 20 ppb). Protein levels in sputum were determined by ELISA, and As species were analyzed in first morning void urine. RESULTS: Proteins in mouse lung-lining fluid whose expression was consistently altered by As included glutathione-S-transferase (GST)-omega-1, contraspin, apolipoprotein A-I and A-IV, enolase-1, peroxiredoxin-6, and receptor for advanced glycation end products (RAGE). Validation of the putative biomarkers was carried out by evaluating As-induced alterations in RAGE in humans. Regression analysis demonstrated a significant negative correlation (p = 0.016) between sputum levels of RAGE and total urinary inorganic As, similar to results seen in our animal model. CONCLUSION: Combinations of proteomic analyses of animal models followed by specific analysis of human samples provide an unbiased determination of important, previously unidentified putative biomarkers that may be related to human disease.


Subject(s)
Arsenic/toxicity , Biomarkers/metabolism , Environmental Pollutants/toxicity , Gene Expression Profiling , Proteins/metabolism , Animals , Disease Models, Animal , Female , Humans , Mass Spectrometry , Mice , Proteomics/methods , Reference Values , Sputum/chemistry , Water Supply
15.
Clin Toxicol (Phila) ; 45(5): 490-8, 2007.
Article in English | MEDLINE | ID: mdl-17503254

ABSTRACT

Although at high levels arsenic exposure is associated with increased cancer incidence, information on the health effects of lower exposure levels is limited. The objective of this study was to determine whether arsenic at concentrations below 40 microg/L in drinking water is associated with increased urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage and repair. Urine samples were collected from 73 nonsmoking adults residing in two communities in Arizona (mean tap water arsenic (microg/L) 4.0 +/- 2.3 and 20.3 +/- 3.7), and 51 subjects in four communities in Sonora, Mexico (mean tap water arsenic (microg/L) ranging from 4.8 +/- 0.1 to 33.3 +/- 0.6). Although urinary arsenic concentration increased with higher exposure in tap water, urinary 8-OHdG concentration did not differ by community within Arizona or Sonora, and was not associated with urinary arsenic concentration. At the exposure levels evaluated in this study, drinking water arsenic was not associated with increased DNA oxidation as measured by urinary 8-OHdG.


Subject(s)
Arsenic/urine , Deoxyguanosine/analogs & derivatives , Water Pollutants, Chemical/urine , 8-Hydroxy-2'-Deoxyguanosine , Adult , Aged , Arizona , Arsenic/analysis , Arsenicals/urine , Biomarkers/urine , Cacodylic Acid/urine , DNA/metabolism , Deoxyguanosine/urine , Environmental Monitoring , Female , Humans , Male , Mexico , Middle Aged , Nails/chemistry , Oxidation-Reduction , Water Pollutants, Chemical/analysis , Water Supply/analysis
16.
Environ Toxicol Pharmacol ; 52: 183-187, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28433805

ABSTRACT

Exposure to inorganic arsenic (iAs) in drinking water is a global public health concern and is associated with a range of health outcomes, including immune dysfunction. Children are a particularly sensitive population to the effects of inorganic arsenic, yet the biological mechanisms underlying adverse health outcomes are understudied. Here we used a proteomic approach to examine the effects of iAs exposure on circulating serum protein levels in a cross-sectional children's cohort in Mexico. To identify iAs-associated proteins, levels of total urinary arsenic (U-tAs) and its metabolites were determined and serum proteins assessed for differences in expression. The results indicate an enrichment of Tumor Necrosis Factor-(TNF)-regulated immune and inflammatory response proteins that displayed decreased expression levels in relation to increasing U-tAs. Notably, when analyzed in the context of the proportions of urinary arsenic metabolites in children, the most robust response was observed in relation to the monomethylated arsenicals. This study is among the first serum proteomics assessment in children exposed to iAs.


Subject(s)
Arsenic/toxicity , Blood Proteins/analysis , Environmental Exposure/adverse effects , Arsenic/urine , Arsenicals/urine , Child , Female , Humans , Male , Mexico , Proteomics , Signal Transduction
17.
J Toxicol Sci ; 31(3): 219-28, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16960432

ABSTRACT

C57BL/6 mice were nose-only exposed to JP-8 jet fuel at average concentrations of 45, 267, and 406 mg JP-8/m(3) for 1 hr/d for 7 days to further test the hypothesis that exposure to JP-8 concentrations below the current permissible exposure level (PEL) of 350 mg/m(3) will induce lung injury, and to validate a new "in-line, real-time" total hydrocarbon analysis system capable of measuring both JP-8 vapor and aerosol concentrations. Pulmonary function and respiratory permeability tests were performed 24 to 30 hr after the final exposures. No significant effects were observed at 45 or 267 mg/m(3). The only significant effect observed at 406 mg/m(3) was a decrease in inspiratory dynamic lung compliance. Morphological examination and morphometric analysis of distal lung tissue demonstrated that alveolar type II epithelial cells showed limited cellular damage with the notable exception of a significant increase in the volume density of lamellar bodies (vacuoles), which is indicative of increased surfactant production, at 45 and 406 mg/m(3). The terminal bronchial epithelium showed initial signs of cellular damage, but the morphometric analysis did not quantify these changes as significant. The morphometric analysis techniques appear to provide an increased sensitivity for detecting the deleterious effects of JP-8 as compared to the physiological evidence offered by pulmonary function or respiratory permeability tests. These observations suggest that the current 350 mg/m(3) PEL for both JP-8 jet fuel and for other more volatile petroleum distillates should be reevaluated and a lower, more accurate PEL should be established with regard human occupational exposure limits.


Subject(s)
Hydrocarbons/toxicity , Animals , Hydrocarbons/administration & dosage , Inhalation Exposure , Lung/drug effects , Lung/pathology , Lung/physiology , Male , Maximum Allowable Concentration , Mice , Mice, Inbred C57BL , Respiration/drug effects
18.
Curr Pharmacol Rep ; 2(2): 91-101, 2016 04.
Article in English | MEDLINE | ID: mdl-27313980

ABSTRACT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the clinical manifestations of severe lung damage and respiratory failure. Characterized by severe inflammation and compromised lung function, ALI/ARDS result in very high mortality of affected individuals. Currently, there are no effective treatments for ALI/ARDS, and ironically, therapies intended to aid patients (specifically mechanical ventilation, MV) may aggravate the symptoms. Key events contributing to the development of ALI/ARDS are: increased oxidative and proteotoxic stresses, unresolved inflammation, and compromised alveolar-capillary barrier function. Since the airways and lung tissues are constantly exposed to gaseous oxygen and airborne toxicants, the bronchial and alveolar epithelial cells are under higher oxidative stress than other tissues. Cellular protection against oxidative stress and xenobiotics is mainly conferred by Nrf2, a transcription factor that promotes the expression of genes that regulate oxidative stress, xenobiotic metabolism and excretion, inflammation, apoptosis, autophagy, and cellular bioenergetics. Numerous studies have demonstrated the importance of Nrf2 activation in the protection against ALI/ARDS, as pharmacological activation of Nrf2 prevents the occurrence or mitigates the severity of ALI/ARDS. Another promising new therapeutic strategy in the prevention and treatment of ALI/ARDS is the activation of autophagy, a bulk protein and organelle degradation pathway. In this review, we will discuss the strategy of concerted activation of Nrf2 and autophagy as a preventive and therapeutic intervention to ameliorate ALI/ARDS.

19.
Phytochemistry ; 66(13): 1614-35, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15996695

ABSTRACT

Using techniques previously employed to identify ginger constituents in fresh organically grown Hawaiian white and yellow ginger varieties, partially purified fractions derived from the silica gel column chromatography and HPLC of a methylene chloride extract of commercially processed dry ginger, Zingiber officinale Roscoe, Zingiberaceae, which demonstrated remarkable anti-inflammatory activity, were investigated by gas chromatography-mass spectrometry. In all, 115 compounds were identified, 88 with retention times (R(t)) >21 min and 27 with <21 min. Of those 88 compounds, 45 were previously reported by us from fresh ginger, 12 are cited elsewhere in the literature and the rest (31) are new: methyl [8]-paradol, methyl [6]-isogingerol, methyl [4]-shogaol, [6]-isoshogaol, two 6-hydroxy-[n]-shogaols (n=8 and 10), 6-dehydro-[6]-gingerol, three 5-methoxy-[n]-gingerols (n=4, 8 and 10), 3-acetoxy-[4]-gingerdiol, 5-acetoxy-[6]-gingerdiol (stereoisomer), diacetoxy-[8]-gingerdiol, methyl diacetoxy-[8]-gingerdiol, 6-(4'-hydroxy-3'-methoxyphenyl)-2-nonyl-2-hydroxytetrahydropyran, 3-acetoxydihydro-[6]-paradol methyl ether, 1-(4'-hydroxy-3'-methoxyphenyl)-2-nonadecen-1-one and its methyl ether derivative, 1,7-bis-(4'-hydroxy-3'-methoxyphenyl)-5-methoxyheptan-3-one, 1,7-bis-(4'-hydroxy-3'-methoxyphenyl)-3-hydroxy-5-acetoxyheptane, acetoxy-3-dihydrodemethoxy-[6]-shogaol, 5-acetoxy-3-deoxy-[6]-gingerol, 1-hydroxy-[6]-paradol, (2E)-geranial acetals of [4]- and [6]-gingerdiols, (2Z)-neral acetal of [6]-gingerdiol, acetaldehyde acetal of [6]-gingerdiol, 1-(4-hydroxy-3-methoxyphenyl)-2,4-dehydro-6-decanone and the cyclic methyl orthoesters of [6]- and [10]-gingerdiols. Of the 27 R(t)<21 min compounds, we had found 5 from fresh ginger, 20 others were found elsewhere in the literature, and two are new: 5-(4'-hydroxy-3'-methoxyphenyl)-pent-2-en-1-al and 5-(4'-hydroxy-3'-methoxyphenyl)-3-hydroxy-1-pentanal. Most of the short R(t) compounds are probably formed by thermal degradation during GC (which mimics cooking) and/or commercial drying. The concentrations of gingerols, the major constituents of fresh ginger, were reduced slightly in dry ginger, while the concentrations of shogaols, the major gingerol dehydration products, increased.


Subject(s)
Dinoprostone/metabolism , Lipopolysaccharides/pharmacology , Zingiber officinale/chemistry , Zingiber officinale/metabolism , Chromatography, Gas , Chromatography, High Pressure Liquid , Food Handling , Zingiber officinale/drug effects , Methylene Chloride , Plant Extracts/chemistry , Plant Extracts/metabolism
20.
Curr Environ Health Rep ; 2(3): 329-37, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26231509

ABSTRACT

This report is the outcome of the meeting "Environmental and Human Health Consequences of Arsenic" held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13-15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food, and more than 200 million people ingest arsenic via drinking water at concentrations greater than international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 µg/L in public water supplies and the WHO has recommended an upper limit of 10 µg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies.


Subject(s)
Arsenic/toxicity , Drinking Water/standards , Environmental Exposure/adverse effects , Water Supply/legislation & jurisprudence , Arsenic/adverse effects , Community-Institutional Relations , Food Contamination/analysis , Government Regulation , Humans , Maximum Allowable Concentration , Public Health , Risk Assessment , United States , Water Pollutants, Chemical/adverse effects , Water Supply/standards
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