Interactions between polycyclic aromatic hydrocarbons and epoxide hydrolase 1 play roles in asthma

Elevated plasma solMER concentrations link ambient PM2.5 and PAHs to myocardial injury and reduced left ventricular systolic function in children

Exposure to fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) is known to be associated with the polarization of pro-inflammatory macrophages and the development of various cardiovascular diseases. The pro-inflammatory polarization of resident cardiac macrophages (cMacs) enhances the cleavage of membrane-bound myeloid-epithelial-reproductive receptor tyrosine kinase (MerTK) and promotes the formation of soluble MerTK (solMER). This process influences the involvement of cMacs in cardiac repair, thus leading to an imbalance in cardiac homeostasis, myocardial injury, and reduced cardiac function. However, the relative impacts of PM2.5 and PAHs on human cMacs have yet to be elucidated. In this study, we aimed to investigate the effects of PM2.5 and PAH exposure on solMER in terms of myocardial injury and left ventricular (LV) systolic function in healthy children. A total of 258 children (aged three to six years) were recruited from Guiyu (an area exposed to e-waste) and Haojiang (a reference area). Mean daily PM2.5 concentration data were collected to calculate the individual chronic daily intake (CDI) of PM2.5. We determined concentrations of solMER and creatine kinase MB (CKMB) in plasma, and hydroxylated PAHs (OH-PAHs) in urine. LV systolic function was evaluated by stroke volume (SV). Higher CDI values and OH-PAH concentrations were detected in the exposed group. Plasma solMER and CKMB were higher in the exposed group and were associated with a reduced SV. Elevated CDI and 1-hydroxynaphthalene (1-OHNa) were associated with a higher solMER. Furthermore, increased solMER concentrations were associated with a lower SV and higher CKMB. CDI and 1-OHNa were positively associated with CKMB and mediated by solMER. In conclusion, exposure to PM2.5 and PAHs may lead to the pro-inflammatory polarization of cMacs and increase the risk of myocardial injury and systolic function impairment in children. Furthermore, the pro-inflammatory polarization of cMacs may mediate cardiotoxicity caused by PM2.5 and PAHs.

Asthma, COPD, Respiratory, and Allergic Health Effects in an Adult Population Living near an Italian Refinery: A Cross-Sectional Study

BACKGROUND AND AIM

Asthma and chronic obstructive pulmonary disease (COPD) are leading causes of morbidity and mortality worldwide. Globally, 545 million people suffer from chronic respiratory diseases with a wide geographical variability. Risk factors for asthma are both genetic and related to several environmental factors (internal and external pollutants); these also have an important role in the occurrence of COPD. The aim of this study was to describe the prevalence of asthma, COPD, and asthma/COPD overlap (ACO) in an adult population living in two municipalities located in the Po Valley.

METHODS

A standardized questionnaire on respiratory symptoms and sociodemographic characteristics was self-administered to a random sample of the adult population aged 20-64 years, living near a refinery in Northern Italy during the period between 2016 and 2019. Logistic and multinomial regression were implemented to explore factors associated with asthma, COPD, and ACO.

RESULTS

In total, 1108 subjects filled out the questionnaire, the mean age was 48.02 ± 12.34 years (range 21-68), and 53% of the respondents/participants were female. Half of the responders were non-smokers, but the frequency of current and former smokers was significantly greater in men than in women (p < 0.001). The likelihood of being a probable case of asthma decreased with increasing age and increased for smokers. Tobacco smoke was associated with the presence of COPD and ACO.

CONCLUSION

Respiratory diseases such as asthma and COPD are common in the general population, with differences among countries worldwide. Our findings show, on the basis of the main confirmed risk factor, namely smoking, that it is useful to plan target programs and actions in order to reduce smoking, thus improving the quality of life in public health.

Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in agricultural and dumpsite soils in Sierra Leone

This study investigates the concentration and distribution of polycyclic aromatic hydrocarbons (PAHs) in soils, potential sources, risk assessment, and soil physicochemical properties influencing PAH distribution in developed and remote cities in Sierra Leone. Seventeen topsoil samples (0-20 cm) were collected and analyzed for 16 PAHs. The average concentrations of Σ₁₆PAH in soils in the surveyed areas were 1142 ng g^-1 dw, 265 ng g^-1 dw, 79.7 ng g^-1 dw, 54.3 ng g^-1 dw, 54.2 ng g^-1 dw, 52.3 ng g^-1 dw, and 36.6 ng g^-1 dw in Kingtom, Waterloo, Magburaka, Bonganema, Kabala, Sinikoro, and Makeni, respectively. Based on the European soil quality guidelines, Kingtom and Waterloo soils were categorized as heavily and weakly contaminated soil PAHs respectively. The main PAH compounds of this study were 2-ring, 4-ring, and 5-ring PAHs. High molecular weight PAHs (4-6 rings) made up 62.5% of the total PAHs, while low molecular weight PAHs (2-3 rings) was 37.5%. In general, HMWPAHs were predominant in Kingtom, followed by Waterloo. The appointment of PAH sources using different methods revealed mixed sources, but predominantly pyrogenic sources (petroleum, biomass, coal, and fossil fuel contributions). Soil pH has a significant impact on PAH distribution. The toxicity equivalent quantity (TEQ_BaP) levels in soils pose a potential health risk to residents in developed cities but pose a negligible health risk to residents in remote cities. This study is significant as its findings reveal the status of PAH soil contamination in Sierra Leone. The results have important implications for policymakers and stakeholders to identify high-risk zones and establish proper environmental monitoring programs, pollution control measures, and remediation strategies to prevent future risks.

Proteasome Inhibitors and Their Pharmacokinetics, Pharmacodynamics, and Metabolism

The proteasome is responsible for mediating intracellular protein degradation and regulating cellular function with impact on tumor and immune effector cell biology. The proteasome is found predominantly in two forms, the constitutive proteasome and the immunoproteasome. It has been validated as a therapeutic drug target through regulatory approval with 2 distinct chemical classes of small molecular inhibitors (boronic acid derivatives and peptide epoxyketones), including 3 compounds, bortezomib (VELCADE), carfilzomib (KYPROLIS), and ixazomib (NINLARO), for use in the treatment of the plasma cell neoplasm, multiple myeloma. Additionally, a selective inhibitor of immunoproteasome (KZR-616) is being developed for the treatment of autoimmune diseases. Here, we compare and contrast the pharmacokinetics (PK), pharmacodynamics (PD), and metabolism of these 2 classes of compounds in preclinical models and clinical studies. The distinct metabolism of peptide epoxyketones, which is primarily mediated by microsomal epoxide hydrolase, is highlighted and postulated as a favorable property for the development of this class of compound in chronic conditions.

PAH exposure is associated with enhanced risk for pediatric dyslipidemia through serum SOD reduction

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) is linked to abnormal lipid metabolism, but evidence regarding PAHs as risk factors for dyslipidemia is lacking.

OBJECTIVE

To investigate the respective role and interaction of PAH exposure and antioxidant consumption in the risk for pediatric dyslipidemia.

METHODS

We measured the concentrations of serum lipids, superoxide dismutase (SOD) and urinary hydroxylated PAHs (OH-PAHs) in 403 children, of which 203 were from an e-waste-exposed area (Guiyu) and 200 were from a reference area (Haojiang). Biological interactions were calculated by additive models.

RESULTS

Guiyu children had higher serum triglyceride concentration and dyslipidemia incidence, and lower serum concentration of high-density lipoprotein (HDL) than Haojiang children. Elevated OH-PAH concentration, and concomitant SOD reduction, were both associated with lower HDL concentration and higher hypo-HDL risk (∑₃OH-Phes: B for lgHDL = -0.048, P < 0.01; OR for hypo-HDL = 3.708, 95% CI: 1.200, 11.453; SOD: B_T3 for lgHDL = 0.061, P < 0.01; OR_T3 for hypo-HDL = 0.168, 95% CI: 0.030, 0.941; all were adjusted for confounders). Biological interaction between phenanthrol exposure and SOD reduction was linked to dyslipidemia risk (RERI = 2.783, AP = 0.498, S = 2.537). Children with both risk factors (higher ∑₃OH-Phes and lower SOD) had 5.594-times (95% CI: 1.119, 27.958) the dyslipidemia risk than children with neither risk factors (lower ∑₃OH-Phes and higher SOD).

CONCLUSION

High PAH exposure combined with SOD reduction is recommended for predicting elevated risk for pediatric dyslipidemia. Risk assessment of PAH-related dyslipidemia should take antioxidant concentration into consideration.

Antioxidant alterations link polycyclic aromatic hydrocarbons to blood pressure in children

Exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with changes in blood pressure. However, the association is controversial in different studies, and antioxidants' roles involved in it remain unclear. To investigate the associations among PAH exposure, blood pressure, and antioxidant concentrations, we recruited 403 children (2-7 years old), of which 203 were from Guiyu, an e-waste-recycling area (exposed group), and 200 were from Haojiang, a nearby non-e-waste area (reference group). Levels of blood pressure, plasma vitamin E, serum superoxide dismutase (SOD), serum glutathione peroxidase (GPx), and eight urinary hydroxylated PAHs (OH-PAHs) were measured. Compared with Haojiang children, Guiyu children had higher urinary OH-PAH concentrations but lower systolic pressure, pulse pressure, serum SOD concentration, and serum GPx concentration (all P < 0.05). PAH exposure was associated with lower systolic pressure, pulse pressure, SOD (adjusted β = -0.091, -0.104 and -0.154, respectively, all P < 0.05, in all children), GPx (adjusted β_{∑7LMW-OH-PAHs-T3} = -0.332, only in Haojiang children) and vitamin E (adjusted OR_{∑7LMW-OH-PAHs} = 0.838, 95% CI: 0.706, 0.995, only in Guiyu children). Serum SOD and GPx were associated with higher blood pressure (β_SOD-T2 for diastolic pressure = 0.215 in all children, β_SOD-T3 for systolic pressure = 0.193 in all children, β_SOD-T3 for pulse pressure = 0.281 in high-∑₈OH-PAHs children, β_GPx-T2 = 0.283 and β_GPx-T3 = 0.289 for diastolic pressure in Haojiang children, all P < 0.05). Interactions between PAHs and vitamin E were associated with lower systolic pressure and pulse pressure; simple effects of vitamin E to raise systolic pressure and pulse pressure were only significant in low-∑₈OH-PAHs children. Our results indicate that PAH exposure, especially at high levels, and further antioxidant-decrease are potential risk factors for blood-pressure decrease in children; vascular function of PAH-exposed children may be impaired, manifesting as disordered blood pressure.

Distribution, source apportionment, and health risk assessment of polycyclic aromatic hydrocarbons in urban soils from Shenyang, China

A total of 74 urban topsoil samples were collected from the central area of Shenyang, China. The concentration, distribution, source, and health risk of 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed. The 16 USEPA priority PAHs were detected in all soil samples. The total concentrations of PAHs ranged from 283 to 21,821 ng/g dry weight (dw), with a mean value of 2370 ng/g and median value of 1427 ng/g. The benzo[a]pyrene toxicity equivalent (BaP_eq) concentrations ranged from 6.03 to 2403 ng/g dw, with a mean value of 308 ng/g and median value of 185 ng/g. High molecular weight PAHs were the predominant components. The spatial distribution revealed that soil PAH concentrations within the Two Ring Road were high, but low in the south of Hun River. Compared with other urban soils, the pollution of PAHs in urban soils of Shenyang was at a moderate level, but increased rapidly compared with previous years, especially fluoranthene. Diagnostic ratios of PAHs and positive matrix factorization model all suggested that PAHs in urban soils of Shenyang were dominantly from pyrogenic origins. The health risk assessment indicated that children had the highest total carcinogenic risk, followed by adolescents and adults. The differences between gender groups for the same age group were insignificant. Ingestion was the dominant exposure pathway, followed by dermal contact and inhalation. The total lifetime carcinogenic risks at all sampling sites were lower than the highest acceptable risk (10^-4), and those of Eastern, Central, and Western Shenyang were higher than those of Northern and Southern Shenyang.