Pro-inflammatory effects of metals in persons and animals exposed to tobacco smoke

Characterization of MDCK cells and evaluation of their ability to respond to infectious and non-infectious stressors

The Madin-Darby Canine Kidney (MDCK) cell line is widely used as epithelial cell model in studies ranging from viral infection to environmental pollutants, and vaccines production. However, little is known about basal expression of genes involved in innate immunity, and the ability to respond to infectious and non-infectious stressors. Therefore, the aims of our study were to evaluate the basal level of expression of pivotal genes in the innate immune response and cell cycle regulation, as well as to evaluate the ability of this cell line to respond to infectious or non-infectious stressors. As surmised in our working hypothesis, we demonstrated the constitutive expression of genes involved in the innate immune response and cell defense alike, including TLRs, Interleukins, Myd88, p65/NF-kB and p53. Moreover, we described the ability of this cell line to respond to LPS and cadmium (Cd2+) in terms of gene expression and cytokine release. These data confirm the possibility of using this cell line as a model in studies of host/pathogen interaction and response to non-infectious stressors.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

Source Apportionment of Fine-Particle, Water-Soluble Organic Nitrogen and Its Association with the Inflammatory Potential of Lung Epithelial Cells

Identifying the key chemical compounds and source contributions in ambient particles associated with the burden of cardiopulmonary disease is important to develop cost-effective air pollution mitigating strategies that maximize the protection of public health. To help address this need, we examined 109 daily ambient fine particulate matter samples (PM_2.5) that were collected in Beijing in one year. The samples were analyzed for chemical composition including organic and elemental carbons, metals, ions, as well as organic molecular markers. In addition, the secretion of pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured by exposing lung epithelial cells (A549) to water extracts of PM_2.5 samples. Single pollutant and constituent-PM_2.5 joint linear models were used to estimate the associations. Higher PM_2.5 mass and measured chemical components were found in cold seasons than in warm seasons due to the greater contributions of secondary inorganic sources, biomass burning, and coal combustion. Water-soluble organic nitrogen (WSON) had the strongest associations with levels of pro-inflammatory cytokines compared to PM_2.5 mass and other chemical species in both the one and constituent-PM_2.5 joint linear models. Our study is the first to highlight that ambient WSON from diverse sources dominates the inflammatory potential of lung epithelial cells.

Cyanidin-3-O-glucoside protects against cadmium-induced dysfunction of sex hormone secretion via the regulation of hypothalamus-pituitary-gonadal axis in male pubertal mice

Cadmium (Cd) has been generally recognized as an endocrine-disrupting chemical for its toxic effects on the hypothalamus-pituitary-gonadal (HPG) axis accompanied by dysfunction in sex hormone secretion. Particularly, exposure to Cd during puberty versus post-puberty exhibits differing age-dependent effects that require further examination. This study sought to determine if cyanidin-3-O-glucoside (C3G), a typical anthocyanin with neuroprotective bioactivity, could protect against Cd-induced sex hormone-disorder in Pubertal male mice. C3G treatment reversed the disruption of hormone levels and increased Gnrh1 gene expression in the hypothalamus. In addition, the levels of gonadotropins, including luteinizing hormone (LH) and follicle stimulating hormone (FSH), were reversed by C3G. Interestingly, C3G improved the expression of LH and FSH receptor in the testis in mice exposed to Cd. Furthermore, C3G activated the signaling pathway related to the synthesis of testosterone processing. In conclusion, C3G protected against Cd-induced dysfunction of sex hormone secretion through the regulation of the HPG axis in male mice during puberty. The results of this study suggest that consumption of anthocyanins can be protective against metal-induced male reproductive dysfunction.

Decreases in Paraoxonase-1 Activities Promote a Pro-inflammatory Effect of Lipids Peroxidation Products in Non-smoking and Smoking Patients with Acute Pancreatitis

Aim: The study investigated the extent to which tobacco smoke exposure causes changes in lipids biochemistry through measurement blood concentrations of: paraoxonase-1 (PON-1) activities as lipid-bound enzyme into cell membrane, concentration of malonyldialdehyde (MDA), protein adducts of 4-hydroxynonenal (HNE-adducts), oxidized low density lipoproteins (oxLDL), total cholesterol (CH) and high-density lipoprotein cholesterol (HDL). Additionally, the activity of P isoform of glutathione S-transferase (GST-π) was measured. Methods: Investigations were performed in the blood of patients with acute pancreatitis (AP) on the 1st, 3rd and 7th day of hospitalization and in healthy volunteers. The activities of PON-1 forms, GST-π were determined spectrophotometrically. Concentrations of PON-1, MDA, HNE-adducts, oxLDL, HDL, CH were measured using commercial tests. Results: Near 2-fold higher concentrations of MDA, HNE-adducts, oxLDL, correlating with inflammatory markers in AP patients compared to healthy subjects were demonstrated, which were accompanied by gradually increasing CH/HDL ratio during hospitalization. During hospital treatment, decreased activities of all PON-1 subtypes were observed in AP patients compared to healthy subjects, more pronounced in tobacco smokers. A decreased PON-1 phosphotriesterase activity in non-AP control group smokers compared to non-smokers was noted. In non-smoking AP patients GST-π activity normalized during hospitalization in contrast to smokers. Conclusions: GST-π and PON-1 phosphotriesterase activities seem to be a sensitive marker of pro/antioxidative imbalance in smokers. Lipids peroxidation products generated during AP can intensify preexisting inflammation. Increasing stay in the hospital was associated with worsening of lipids peroxidation markers and the parameters of lipid profile, in both non-smoking and smoking AP patients, what can indicate that the oxidative-inflammatory process are not extinguished.

Smoking fewer than 20 cigarettes per day and remaining abstinent for more than 12 hours reduces carboxyhemoglobin levels in packed red blood cells for transfusion

Background

The prevalence of smokers among blood donors and the effect of smoking on the quality of donated blood have not been extensively explored. In the present study, we determined the prevalence of smoker donors in a large blood bank in Southern Brazil and evaluated the quality of packed red blood cells (RBCs) from these donors through recommended quality control tests and measurement of carboxyhemoglobin (COHb) levels. We then assessed the influence of smoking habits and abstinence before donation on these parameters.

Material and methods

An observational study was conducted to determine the prevalence of smoking donors, while a prospective cohort study compared conventional hematological and serological parameters and COHb levels at 0, 15, and 30 days after donation in RBCs donated by smokers (N = 31) and nonsmokers (N = 31) and their association with smoking habits and abstinence before donation.

Results

Of 14,428 blood donations received in 1 year, 5.9% were provided by smokers. Storage over time slightly altered some quality parameters, such as hematocrit, hemoglobin, hemolysis, and COHb levels, in RBC packs. COHb levels were higher in RBC packs from smokers (8%) than from non-smokers (2%), and increased as a function of the number of cigarettes smoked daily and time elapsed since the last cigarette smoked before donation. Lower levels were found in RBC packs from donors who smoked fewer than 20 cigarettes per day or remained abstinent for more than 12h before giving blood.

Conclusion

Although cigarette smoke had no significant effect on blood quality parameters such as hematocrit, hemoglobin, or hemolysis, it quadrupled COHb levels in packed RBCs. Abstinence from smoking for more than 12h or smoking fewer than 20 cigarettes daily helped decrease COHb levels.

Implications

Given the increasing prevalence of tobacco use worldwide, we suggest blood banks recommend 12h of tobacco abstinence before donation and analyze COHb levels in donated blood as an approach to reduce risk for high-risk recipients.

Protective Effect of Increased Zinc Supply against Oxidative Damage of Sublingual Gland in Chronic Exposure to Cadmium: Experimental Study on Rats

Cadmium is one of the main chemical pollutants found in the daily environment of developed countries. Cigarettes are a significant source of that metal, which makes it important in terms of oral cavity health. The aim of this study was to determine if increased supply of zinc in chronic exposure to cadmium might protect the sublingual gland structure against oxidative damage. The experiment took 12 months and was conducted on 72 adult male rats. They were randomized into 9 groups. Eight groups received cadmium in drinking water (as CdCl₂) at 5 or 50 mg Cd/dm³ and/or zinc (as ZnCl₂) at 30 or 60 mg Zn/dm³. The control group received regular water. In the sublingual gland of all animal groups, levels of oxidative parameters were measured. The oxidative stress index was calculated as a TOS/TAS ratio. Cadmium exposure at 5 mg and 50 mg Cd/dm³ induced oxidative stress in the sublingual glands of the rats. Cadmium reduced the TAS and GSH levels and increased LPO, H₂O₂, TOS, and OSI. In cadmium exposure conditions, increasing the supply of zinc by 79% or 151%, as compared to the standard dietary intake of this microelement, completely prevented the reduction of TAS and GSH levels and accumulation of LPO, H₂O₂, and TOS in the examined gland at both exposure levels to that metal. The outcome data confirm the protective effect of increased zinc intake on the sublingual gland tissue in chronic cadmium exposure.

Generation of hydroxyl radicals and singlet oxygen by particulate matter and its inorganic components

Particulate matter (PM) can strongly affect redox biochemistry and therefore induce the response of the immune system and aggravate the course of autoimmune diseases. Nanoparticles containing transition metal compounds possessing semiconductor properties (TiO₂, ZnO) may act as photocatalysts and accelerate the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this study, the NIST standard reference material, SRM 1648a, has been analyzed in terms of this consideration. Organic compounds present in SRM 1648a were removed by cold oxygen plasma treatment. Samples of SRM 1648a with removed organic content (<2% of organic carbon, <1% of nitrogen) were obtained within 2 h of this treatment. The treatment did not affect the morphology of the powder. The reference material and PM2.5 collected in Kraków are composed of smaller particles and nanoparticles forming aggregates. The efficiency of (photo)generation of hydroxyl radicals and singlet oxygen was compared for original and organics-free samples. The analyzed samples showed the highest activity towards ROS generation when exposed to UV-vis-NIR light, moderate under UV irradiation, and the lowest in dark. Data collected in the present study suggest that the organic fraction is mostly responsible for singlet oxygen generation, as almost twice higher efficiency of ¹O₂ generation was observed for the original NIST sample compared to the material without the organic fraction. However, particulate matter collected in Kraków was found to have a five times higher activity in singlet oxygen generation (compared for original NIST and Kraków dust samples).

Chronic exposure to inorganic mercury induces biochemical and morphological changes in the salivary glands of rats

Mercury exposure is considered to be a public health problem due to the generation of toxic effects on human health as a result of environmental and occupational conditions. The inorganic form of mercury (HgCl₂) can cause several biological changes in cells and tissues through its cumulative toxic potential, but little has been experimentally proven about the effects of inorganic mercury on salivary glands, an important modulator organ of oral health. This study analyzes the effects of prolonged low dose exposure to HgCl₂ on the salivary glands of rats. Adult animals received a dose of 0.375 mg kg^-1 day^-1 over a period of 45 days. The parotid and submandibular glands were collected for analysis of the mercury levels and evaluation of oxidative stress, histological parameters and immunomodulation for metallothionein I and II (MT-I/II). In this investigation, biochemical and tissue changes in the salivary glands were verified due to the mercury levels, causing reduction in antioxidant capacity against peroxyl radicals, with consequent cellular lipid peroxidation and an increase in nitrite levels, volumetric changes and cytoskeletal damage in the submandibular glands, with less severe damage to the parotid glands. The results also have shown the occurrence of a cytoprotection mechanism due to increased MT-I/II expression, but not enough to avoid the morphology and oxidative damage. This evidence highlights, for the first time, that inorganic mercury is able to alter the morphology and oxidative biochemistry in salivary glands when exposed for a long time in low doses.

E-Cigarette Toxicity?

Tobacco smoking is the most preventable cause of morbidity and mortality. In just a few short years, electronic cigarettes (e-cigarettes) have become increasingly popular, especially for younger individuals. Many people believe that e-cigarettes are safe. The inhaled aerosols of e-cigarettes contain numerous potential toxicities, some of which could be dangerous for health with long-term use. The safety of prolonged aerosol exposure is not known. The use of e-cigarettes as a harm-reduction tool at stopping tobacco smoking is not uniformly successful. E-cigarettes may be safer than tobacco products, but repeated prolonged exposure to their aerosols has its own considerable potential risk. The long-term health consequences of their use remain to be established. Physicians should vigorously discourage the use of e-cigarettes and tobacco products, with special emphasis on abstinence for younger people and during pregnancy or lactation.

Oxidative Signaling Response to Cadmium Exposure

Changes in the intracellular thiol-disulfide balance are considered major determinants in the redox status/signaling of the cell. Cellular signaling is very sensitive to both exogenous and intracellular redox status and respond to many exogenous pro-oxidative or oxidative stresses. Redox status has dual effects on upstream signaling systems and downstream transcription factors. Redox signaling pathways use reactive oxygen species (ROS) to transfer signals from different sources to the nucleus to regulate such functions as growth, differentiation, proliferation, and apoptosis. Mitogen-activated protein kinases are activated by numerous cellular stresses and ligand-receptor bindings. An imbalance in the oxidant/antioxidant system, either resulting from excessive ROS/reactive nitrogen species production and/or antioxidant system impairment, leads to oxidative stress. Glutathione (GSH) is known to play a critical role in the cellular defense against unregulated oxidative stress in mammalian cells and involvement of large molecular antioxidants include classical antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Cadmium (Cd), a potent toxic heavy metal, is a widespread environmental contaminant. It is known to cause renal dysfunction, hepatic toxicity, genotoxicity, and apoptotic effects depending on the dose, route, and duration of exposure. This review examines the signaling pathways and mechanisms of activation of transcription factors by Cd-induced oxidative stress thus representing an important basis for understanding the mechanisms of Cd effect on the cells.

Metallothionein 2A gene polymorphism and trace elements in mother-newborn pairs in the Croatian population

The main source of exposure for all essential and toxic elements in the general population is diet. In smokers, the main route for cadmium (Cd) and lead (Pb) intake is the inhalation of tobacco smoke. Besides gender, age, nutrition, lifestyle, and physiological conditions such as pregnancy, specific genetic characteristics also influence individual element uptake. Metallothionein MT2 is a cysteine-rich low-weight protein found ubiquitously throughout the body. Specific gene polymorphism may influence MT2 expression and subsequent binding, transfer and organ accumulation of metals, though data on these influences are lacking, especially in human mother-newborn pairs. The objective of this study was to determine selected toxic (Cd, Pb, Hg) and essential (Fe, Zn, Cu, Se) elements in maternal blood, placenta, and cord blood (by ICP-MS), and MT2 levels in maternal serum (by ELISA) in relation to maternal MT2A -5A/G (rs28366003) polymorphism (by RFLP-PCR and electrophoresis). Study participants were healthy postpartum women in Croatia (n=268, mean age 29 years) with term vaginal childbirth in a maternity ward assigned into two study groups by self-reporting about their smoking habit (by questionnaire). Smokers vs. non-smokers had increased levels of Cd and Pb in all measured samples, Fe and Cu in cord blood, Zn in placenta, and MT2 in maternal serum. Among subjects with AG/GG genotype, placental Fe was significantly lower only among non-smokers, while MT2 levels in serum were lower, though not significantly, regardless of maternal smoking habit. There was no impact of MT2A -5A/G SNP on any element in maternal or cord blood. In conclusion, the results confirmed maternal smoking-related increases in Cd and Pb levels in the maternal-placental-foetal unit. They also provided additional data on concomitant metal concentrations in representative samples of maternal blood, placenta, and cord blood, as well as increased cord blood Fe and Cu, placental Zn, and maternal serum MT2 in smokers. New evidence is that MT2A -5A/G SNP was associated with decreased placental Fe levels in non-smokers. For a final conclusion on the influence of the MT2A -5A/G polymorphism on toxic and essential element levels in mother-newborn pairs, further research would require a larger number of participants divided across subgroups defined by the main source of particular toxic metal exposure (such as specific food intake, cigarette smoking, air pollution and/or occupational exposure).

Resistin as a Prooxidant Factor and Predictor of Endothelium Damage in Patients with Mild Acute Pancreatitis Exposed to Tobacco Smoke Xenobiotics

Objectives

The study was aimed to assess the influence of tobacco smoke exposure on the intensity of inflammation measured by IL-6, α₁-antitripsin (AAT) and α₁-acid glycoprotein (AGP) concentrations, and Cd level and oxidative stress intensity measured by advanced oxidation protein product (AOPP) concentration in the blood of healthy subjects and AP patients during hospitalization. Endothelin-1 (ET-1) and resistin concentrations, markers of endothelium injury, were determined.

Results

An increased IL-6 concentration in healthy smokers compared to nonsmokers and AP patients compared to controls was shown. An increased AAT and AGP concentrations during hospitalization of AP patients were noted, in both smokers (AAT, AGP) and nonsmokers (AAT). In comparison to control groups, in AP patients, a 2-fold increased resistin concentration correlating with ET-1 concentration and decreased albumin concentration accompanied by increased AOPP concentration were demonstrated. AOPP concentration was higher in smokers with AP compared to nonsmokers and gradually enhanced during their hospitalization.

Conclusions

Tobacco smoke exposure can have a proinflammatory effect in both healthy subjects and AP patients. Increased resistin concentration in AP patients negatively correlating with albumin concentration has prooxidative effect on this protein resulting in enhanced AOPP level. Increased resistin concentration can intensify AAT and AGP production during AP.

The effect of ozone on the expression of metallothionein in tissues of rats chronically exposed to cadmium

Our aims were to evaluate the expression of metallothionein (MT) in an experimental rat model which experienced chronic exposure to cadmium (Cd) and to measure its expression after ozone therapy (OT) or oxygen (Ox) in the same model, as compared to the control group, which was exposed to neither cadmium nor ozone. Forty male Wistar rats were divided into 5 groups: control, Cd, Cd and Ox, Cd and Oz, and Oz. During our research, Cd concentration (ASA) and MT concentration (ELISA) were determined in supernatants of the kidneys, liver and pancreas. SDS-PAGE analyses and immunohistochemical localization were used to evaluate the level of MT expression in the tissue. In rats intoxicated with Cd, the highest concentration of both Cd and MT was observed in the kidneys and liver, with a significantly lower concentration measured in the pancreas. Ozone therapy reduces the accumulation of cadmium in the liver and kidneys, resulting in a reduced expression of metallothionein in those tissues.

The influence of persistent organic pollutants in the traditional Inuit diet on markers of inflammation

Concentrations of persistent organic pollutants (POPs) are high in Inuit living predominately on the traditional marine diet. Adverse effects of POPs include disruption of the immune system and cardiovascular diseases that are frequent in Greenland Inuit. We aimed to assess the association between exposure to POPs from the marine diet and inflammation, taking into account other factors such as vitamin D. We invited Inuit and non-Inuit living in settlements or the town in rural East Greenland or in the capital city Nuuk. Participants completed a food frequency questionnaire and donated a blood sample for measurement of the two markers of inflammation YKL-40 and hsCRP, 25-hydroxy-vitamin D, eleven organochlorine pesticides (OCPs), fourteen polychlorinated biphenyls (PCBs), one polybrominated biphenyl, and nine polybrominated diphenyl ethers (PBDEs) adjusted to the serum lipid content. Participants were 50 through 69 years old, living in settlements, town or city (n = 151/173/211; 95% participation rate). ΣOCP, ΣPCB and ΣPBDE serum levels were higher in Inuit than in non-Inuit (p<0.001/ p<0.001/ p<0.001), in older individuals (p<0.001/p<0.001/p = 0.002) and in participants with the highest intake of Greenlandic food items (p<0.001/p<0.001/p<0.001). Both YKL-40 and hsCRP serum levels were higher in Inuit compared to non-Inuit (p<0.001/p = 0.001), and increased with age (p<0.001/p = 0.001) and with the intake of Greenlandic food items (p<0.001/p = 0.002). Multivariate analysis conformed to a marked influence on both YKL-40 and hsCRP by ΣOCP (p<0.001/p<0.001) and ΣPCBs (p<0.001/p = 0.001) after adjusting for age, BMI, vitamin D, alcohol and smoking. POP levels were associated with the intake of the traditional Inuit diet and with markers of inflammation. This supports a pro-inflammatory role of POPs to promote chronic diseases common to populations in Greenland. These data inform guidelines on 'the Arctic dilemma' and encourage follow-up on the ageing Arctic populations.

The influence of occupational chronic lead exposure on the levels of selected pro-inflammatory cytokines and angiogenic factors

The aim of the study was to determine the effect of occupational exposure to lead on the blood levels of pro-inflammatory cytokines and selected factors that influence angiogenesis. The study population was divided into two groups. The first group consisted of 56 male workers chronically exposed to lead. The second group (control) was comprised of 24 male administrative workers. The serum levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were significantly higher in the group of workers chronically exposed to lead compared to control values by 38%, 68%, and 57%, respectively. Similarly, the values of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and fibroblast growth factor-basic (FGF-basic) were higher by 19% and 63%, respectively. In the group of workers chronically exposed to lead, there were positive correlations between the levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and angiogenic factors (VEGF, FGF-basic, sVEGFR-1, and soluble angiopoietin receptor). In the control group, there were no correlations between the levels of the abovementioned parameters. Results of the present study indicate that chronic occupational lead exposure promotes inflammatory processes via induction of pro-inflammatory cytokines, modulates angiogenesis, and elicits interdependencies between the immune response and angiogenic factors.

Arsenic Induction of Metallothionein and Metallothionein Induction Against Arsenic Cytotoxicity

Human exposure to arsenic (As) can lead to oxidative stress that can become evident in organs such as the skin, liver, kidneys and lungs. Several intracellular antioxidant defense mechanisms including glutathione (GSH) and metallothionein (MT) have been shown to minimize As cytotoxicity. The current review summarizes the involvement of MT as an intracellular defense mechanism against As cytotoxicity, mostly in blood. Zinc (Zn) and selenium (Se) supplements are also proposed as a possible remediation of As cytotoxicity. In vivo and in vitro studies on As toxicity were reviewed to summarize cytotoxic mechanisms of As. Intracellular antioxidant defense mechanisms of MT are linked in relation to As cytotoxicity. Arsenic uses a different route, compared to major metal MT inducers such as Zn, to enter/exit blood cells. A number of in vivo and in vitro studies showed that upregulated MT biosynthesis in blood components are related to toxic levels of As. Despite the cysteine residues in MT that aid to bind As, MT is not the preferred binding protein for As. Nonetheless, intracellular oxidative stress due to As toxicity can be minimized, if not eliminated, by MT. Thus MT induction by essential metals such as Zn and Se supplementation could be beneficial to fight against As toxicity.

Association between heavy metal exposure and poor working memory and possible mediation effect of antioxidant defenses during aging

BACKGROUND

Inverse associations have been observed between memory performance and blood concentrations of cadmium (Cd) and lead (Pb). Low antioxidant cell activity has also been linked to decline in memory due to aging. However, it has not yet been established whether the heavy metal-memory relationship is mediated by differences in antioxidant activity.

METHODS

We examined Cd and Pb levels, as well as oxidative stress parameters, in blood samples from 125 older adults (age range 50-82years). The Counting Span Test (CST) was used to evaluate working memory capacity (WMC). The Monte Carlo Method for Assessing Mediation (MCMAM) was used to analyze the mediation role of antioxidant activity in the heavy metals-memory association.

RESULTS

High blood Cd (BCd) concentration alone, and in combination with elevated blood Pb (BPb) concentration, was associated with poor WMC (p≤0.001) and low enzymatic antioxidant defenses (p≥0.006). The variance in WMC accounted for by BCd or by BCd combine with BPb was 20.6% and 18.6%, respectively. The MCMAM revealed that the influence of BCd and BPb concentrations on WMC was mediated by low antioxidant capacity (confidence interval - CI: 0.072 to -0.064 for BCd; CI: -0.062 to -0.045 for BPb).

CONCLUSION

These findings showed Pb and Cd blood concentration in older adults, even at levels below the current recommended threshold, was negatively associated with WMC and that this relationship may be partly mediated by low antioxidant defenses. Knowledge on the environmental factors that negatively influence brain and cognition during aging can help inform public policy strategies to prevent and control the adverse effects of environmental contaminant exposure during aging.

Fluorinated near-infrared fluorescent probes for specific detection of Hg2+ in an aqueous medium and mitochondria of living cells

A near-infrared fluorescent probe (IR-DFT) could be used for specifically and sensitively detecting Hg²⁺ in mitochondria of living cells.

Short-term association between particular matter air pollution and pediatric clinical visits for wheezing in a subarea of Shanghai

To assess the association between the concentration of ambient particulate matter (PM) and the pediatric clinical visits for wheezing among children under 3 years old, data of daily air pollutants (PM2.5, PM10, NO2, SO2, CO), meteorological reports, along with the number of daily clinical visits of the children with wheezing at the Pediatric Department of Shanghai Renji Hospital (South Campus) were collected from January through December 2014. Correlation between the levels of air pollutants and the number of clinical patients for wheezing were analyzed by a time series analysis with a generalized addictive model (GAM). During the study period, the daily average concentrations of PM2.5, PM10, NO2, SO2, and CO were 51.84 ± 32.51, 72.69 ± 41.15, 43.25 ± 18.07, 17.45 ± 10.42, and 0.82 ± 0.26 μg/m(3), respectively, which were abnormally higher compared to the standard defined by the Chinese Ministry of Environment Protection. The average number of daily clinical patients with wheezing was 23 ± 14 persons/day. The number of clinical visit by children with wheezing was significantly correlated with concentration of PM2.5 or PM10 when the effect of SO2 and NO2 was adjusted (P < 0.05). It was also found that exposure-response relationship was a linear non-threshold mode when it was analyzed by the GAM, and the percent of the clinical visits of children with wheezing increased from 0 to nearly 20 % with every interquartile increase of PM2.5. The visiting number of children at a pediatric outpatient clinic increased due to the increase of PM2.5 in Pujiang, Shanghai, China.

Air pollution-related metals induce differential cytokine responses in bronchial epithelial cells

Different transition metals have been shown to induce inflammatory responses in lung. We have compared eight different metal ions with regard to cytokine responses, cytotoxicity and signalling mechanisms in a human lung epithelial cell model (BEAS-2B). Among the metal ions tested, there were large differences with respect to pro-inflammatory potential. Exposure to Cd(2+), Zn(2+) and As(3+) induced CXCL8 and IL-6 release at concentrations below 100μM, and Mn(2+) and Ni(2+) at concentrations above 200μM. In contrast, VO4(3-), Cu(2+) and Fe(2+) did not induce any significant increase of these cytokines. An expression array of 20 inflammatory relevant genes also showed a marked up-regulation of CXCL10, IL-10, IL-13 and CSF2 by one or more of the metal ions. The most potent metals, Cd(2+), Zn(2+) and As(3+) induced highest levels of oxidative activity, and ROS appeared to be central in their CXCL8 and IL-6 responses. Activation of the MAPK p38 seemed to be a critical mediator. However, the NF-κB pathway appeared predominately to be involved only in Zn(2+)- and As(3+)-induced CXCL8 and IL-6 responses. Thus, the most potent metals Cd(2+), Zn(2+) and As(3+) seemed to induce a similar pattern for the cytokine responses, and with some exceptions, via similar signalling mechanisms.

The effect of occupational exposure on pro/antioxidant balance in the blood of non-smoking and smoking smelters with diabetes

Arsenic, lead and cadmium, potent environmental toxicants have been reported to induce diabetes mellitus, but their potential biological mechanism(s) have not been much investigated. The present study was designed to correlate parameters of pro/antioxidant balance with occupational exposure on heavy metals and smoking in smelters with diabetes compared on control group. The results showed a significant increase in the concentration of arsenic, cadmium and lead in the blood and urine of smelters, while smoking caused a further increase in the concentration of these metals. Increasing γ-glutamyltransferase activity and lead concentration due to occupational exposure in copper foundry, tobacco smoke and co-existing diabetes were observed. Also these factors have synergistic effects on metallothionein and glutathione concentrations as well as glutathione dependent enzymes activities. Our data suggests that sub-chronic arsenic, lead and cadmium exposure induces diabetic condition which may be mediated due to increased oxidative stress in blood.

A multivariate assessment of innate immune-related gene expressions due to exposure to low concentration individual and mixtures of four kinds of heavy metals on zebrafish (Danio rerio) embryos

Concerns over the potential health effects of mixtures of low concentration heavy metals on living organisms keep growing by the day. However, the toxicity of low concentration metal mixtures on the immune system of fish species has rarely been investigated. In this study, the zebrafish model was employed to investigate the effect on innate immune and antioxidant-related gene expressions, on exposure to environmentally relevant concentrations of individual and mixtures of Pb (0.01 mg/L), Hg (0.001 mg/L), As (0.01 mg/L) and Cd (0.005 mg/L). Messenger-RNA (mRNA) levels of IL1β, TNF-α, IFNγ, Mx, Lyz, C3B and CXCL-Clc which are closely associated with the innate immune system were affected after exposing zebrafish embryos to metals for 120 h post fertilization (hpf). Individual and mixtures of metals exhibited different potentials to modulate innate-immune gene transcription. IL1β genes were significantly up regulated on exposure to Pb + As (2.01-fold) and inhibited on exposure to Pb + Hg + Cd (0.13-fold). TNF-α was significantly inhibited on exposure to As (0.40-fold) and Pb + As (0.32-fold) compared to control. Metal mixtures generally up regulated IFNγ compared to individual metals. Additionally, antioxidant genes were affected, as CAT and GPx gene expressions generally increased, whiles Mn-SOD and Zn/Cu-SOD reduced. Multivariate analysis showed that exposure to individual metals greatly influenced modulation of innate immune genes; whiles metal mixtures influenced antioxidant gene expressions. This suggests that beside oxidative stress, there may be other pathways influencing gene expressions of innate immune and antioxidant-related genes. Low concentration heavy metals also affect expression of development-related (wnt8a and vegf) genes. Altogether, the results of this study clearly demonstrate that low concentration individual and mixtures of metals in aquatic systems will greatly influence the immune system. It is indicative that mechanisms associated with toxicity of metal mixtures is complex, however, further studies to elucidate them are ongoing in our research laboratory.

The impact of environmental and biological factors on paraoxonase 1 and γ-glutamyltranspeptydase activities in the blood of smelters

Disorders of paraoxonase and γ-glutamyltranspeptydase activities can induce development of the atherosclerotic process. The aim of the study was to examine the effect of occupational exposure to heavy metals, tobacco smoke and alcohol consumption on the activities of paraoxonase and γ-glutamyltranspeptydase as well as glutathione concentration. We have observed reduced paraoxonase activity and higher γ-glutamyltranspeptydase activity in serum of smelters when compared to control groups. In the blood of smoking smelters was demonstrated a negative correlation between paraoxonase activity and BMI value as well as between paraoxonase activity and tobacco smoke and consumption of 40% alcohol. Also, negative correlation was found for the activity of paraoxonase and glutathione concentration as well as γ-glutamyltranspeptydase activity. Higher γ-glutamyltranspeptydase activity and lower paraoxonase activity in the serum of smelters exposed to heavy metals and tobacco smoke can cause disorders in functioning of the body.

Activation of Proinflammatory Responses in Cells of the Airway Mucosa by Particulate Matter: Oxidant- and Non-Oxidant-Mediated Triggering Mechanisms

Inflammation is considered to play a central role in a diverse range of disease outcomes associated with exposure to various types of inhalable particulates. The initial mechanisms through which particles trigger cellular responses leading to activation of inflammatory responses are crucial to clarify in order to understand what physico-chemical characteristics govern the inflammogenic activity of particulate matter and why some particles are more harmful than others. Recent research suggests that molecular triggering mechanisms involved in activation of proinflammatory genes and onset of inflammatory reactions by particles or soluble particle components can be categorized into direct formation of reactive oxygen species (ROS) with subsequent oxidative stress, interaction with the lipid layer of cellular membranes, activation of cell surface receptors, and direct interactions with intracellular molecular targets. The present review focuses on the immediate effects and responses in cells exposed to particles and central down-stream signaling mechanisms involved in regulation of proinflammatory genes, with special emphasis on the role of oxidant and non-oxidant triggering mechanisms. Importantly, ROS act as a central second-messenger in a variety of signaling pathways. Even non-oxidant mediated triggering mechanisms are therefore also likely to activate downstream redox-regulated events.

The effect of metallothionein 2A core promoter region single-nucleotide polymorphism on accumulation of toxic metals in sinonasal inverted papilloma tissues

Metallothioneins (MTs) are intracellular thiol-rich heavy metal-binding proteins which join trace metal ions protecting cells against heavy metal toxicity and regulate metal distribution and donation to various enzymes and transcription factors. The goal of this study was to identify the -5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene, and to investigate its effect on allele-specific gene expression and Cd, Zn, Cu and Ni content in sinonasal inverted papilloma tissue (IP), with non-cancerous sinonasal mucosa (NCM) as a control. The MT2A promoter region -5 A/G SNP was identified by restriction fragment length polymorphism using 117 IP and 132 NCM. MT2A gene analysis was performed by quantitative real-time PCR. Metal levels were analyzed by flame atomic absorption spectrometry. The frequency of A allele carriage was 99.2% and 100% in IP and NCM, respectively. The G allele carriage was detected in 23.9% of IP and in 12.1% of the NCM samples. As a result, a significant association of -5 A/G SNP in MT2A gene with mRNA expression in both groups was determined. A significant association was identified between the -5 A/G SNP in the MT2A gene with mRNA expression in both groups. A highly significant association was detected between the rs28366003 genotype and Cd and Zn content in IP. Furthermore, significant differences were identified between A/A and A/G genotype with regard to the type of metal contaminant. The Spearman rank correlation results showed the MT2A gene expression and both Cd and Cu levels were negatively correlated. The results obtained in this study suggest that the -5 A/G SNP in the MT2A gene may have an effect on allele-specific gene expression and toxic metal accumulation in sinonasal inverted papilloma.

Mitochondrial carnitine/acylcarnitine transporter, a novel target of mercury toxicity

The effect of Hg(2+) and CH3Hg(+) on the mitochondrial carnitine/acylcarnitine transporter (CACT) has been studied on the recombinant protein and on the CACT extracted from HeLa cells or Zebrafish and reconstituted in proteoliposomes. Transport was abolished upon treatment of the recombinant CACT in proteoliposomes by Hg(2+) or CH3Hg(+). Inhibition was reversed by the SH reducing agent 1,4-dithioerythritol, GSH, and N-acetylcysteine. IC50 for Hg(2+) and CH3Hg(+) of 90 nM and 137 nM, respectively, were measured by dose-response analyses. Inhibition was abolished in the C-less CACT mutant. Strong reduction of inhibition by both reagents was observed in the C136A and some reduction in the C155A mutants. Inhibition similar to that of the WT was observed in the C23V/C58V/C89S/C155V/C283S mutant, containing only C136. Optimal inhibition by Hg(2+)was found in the four replacement mutants C23V/C58V/C89S/C283S containing both C136 and C155 indicating cross-reaction of Hg(2+) with the two Cys residues. Inhibition kinetic analysis showed mixed inhibition by Hg(2+) or competitive inhibition by CH3Hg(+). HeLa cells or Zebrafish were treated with the more potent inhibitor. Ten micromolar HgCl2 caused clear impairment of viability of HeLa cells. The transport assay in proteoliposomes with CACT extracted from treated cells showed that the transporter was inactivated and that DTE rescued the activity. Nearly identical results were observed with Zebrafish upon extraction of the CACT from the liver of the treated animals that, indeed, showed accumulation of the mercurial compound.

The antioxidant profiles, lysosomal and membrane enzymes activity in patients with acute pancreatitis

Oxidative stress and inflammatory mediators, such as IL-6, play an important role in the pathophysiology of acute pancreatitis. The study was aimed to assess the degree of the pro/antioxidative imbalance and estimate which antioxidant plays a role in the maintenance of pro/antioxidative balance during acute pancreatitis. The study was investigated in the blood of 32 patients with acute pancreatitis and 37 healthy subjects. IL-6 concentration as early marker of inflammation was determinated. The intensity of oxidative stress was assessed by TBARS concentration. To investigate antioxidative status, the GPx and Cu/Zn SOD activities and the levels of GSH, MT, SH groups, and TRAP were measured. The concentrations of Cu and Zn as ions participating in the maintenance of antioxidant enzymes stability and playing a role in the course of disease were determinated. The activities of GGT, AAP, NAG, and β-GD as markers of tissue damage were also measured. An increase in IL-6 concentration, which correlated with Ranson criteria, and an increase in GPx activity, levels of MT, TBARS, or GGT, and NAG activities in patients group compared to healthy subjects were demonstrated. A decrease in GSH level in patients group compared to control group was noted. The studies suggest that GPx/GSH and MT play the role of the first line of defence against oxidative stress and pro/antioxidant imbalance in the course of acute pancreatitis.