The association between multi-heavy metals exposure and lung function in a typical rural population of Northwest China

Per and poly-fluoroalkyl substances and respiratory health in an Inuit community

BACKGROUND

Concentrations of plasma per and poly-fluoroalkyl substances (PFAS) are elevated in the Inuit population of Nunavik and may be causing adverse health effects. Respiratory health outcomes have been associated with PFAS, but have not been explored in Inuit communities. The aim of the study was to examine the association between PFAS and respiratory health outcomes, and the moderating role of nutritional biomarkers.

METHODS

We included up to 1298 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Generalized regression models were used to estimate the associations between six individual PFAS congeners and four self-reported symptoms, four spirometry measures, and physician-diagnosed asthma. Outcomes associated with PFAS from single chemical models were further explored using Bayesian Kernel Machine Regression (BKMR). The modifying effect of n-3 PUFA in red blood cell quartiles and vitamin D deficiency were examined on the associations between PFAS and respiratory outcomes.

RESULTS

PFNA and PFOS were associated with asthma (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.12, 2.32; OR 1.45 95% CI 1.04, 2.03). PFOA, PFNA, PFDA and PFHxS were associated with a decrease in the ratio between the forced expiratory volume in the first second and forced vital capacity (FEV1/FVC). No associations were observed with self-reported respiratory symptoms. No associations were observed between a PFAS mixture and asthma. Some associations were modified by nutritional factors, namely, stronger associations between PFOA and PFHxS and asthma with lower n-3 PUFA levels and stronger associations between PFDA, PFUnDA and PFOS and FEV1/FVC with vitamin D deficiency.

CONCLUSION

These findings add to the growing literature on the impacts of PFAS on respiratory health, and the importance of their global regulation. Associations were modified by nutritional factors pointing to the nutritional value of traditional Inuit foods.

Independent and joint associations of multiple metals exposure with vital capacity index: a cross-sectional study in Chinese children and adolescents

OBJECTIVE

The current study aimed to explore the relationships between urinary metals and vital capacity index (VCI) in 380 children and adolescents in Northeast China using a variety of statistical methods.

METHODS

A cross-sectional survey was conducted among 380 children and adolescents in Liaoning Province, China. To assess the relationships between urinary metals and VCI, Elastic-net (ENET) regression, multivariate linear regression, weighted quantile sum (WQS), bayesian kernel machine regression (BKMR) and quantile-based g computation (qgcomp) were adopted.

RESULTS

The ENET model selected magnesium (Mg), vanadium (V), manganese (Mn), arsenic (As), tin (Sn) and lead (Pb) as crucial elements. In multiple linear regression, we observed urinary Pb, Mn was negatively correlated with VCI individually in both total study population and adolescents (all p values < 0.05) in the adjustment model. The WQS indices were negatively related with VCI in total study population (β=-3.19, 95%CI: -6.07, -0.30) and adolescents (β=-3.46, 95%CI: -6.58, -0.35). The highest weight in total study population was Pb (38.80%), in adolescents was Mn (35.10%). In the qgcomp, Pb (31.90%), Mn (27.20%) were the major negative contributors to the association in the total population (β=-3.51, 95%CI: -6.29, -0.74). As (42.50%), Mn (39.90%) were the main negative contributors (β=-3.95, 95% CI: -6.68, -1.22) among adolescents. The results of BKMR were basically consistent with WQS and qgcomp analyses.

CONCLUSIONS

Our results indicated that Pb and Mn were priority toxic materials on VCI. The cumulative effect of metals was negatively related to VCI, and this relationship was more pronounced in adolescents.

Co-exposure effects of urinary polycyclic aromatic hydrocarbons and metals on lung function: mediating role of systematic inflammation

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) and metals were associated with decreased lung function, but co-exposure effects and underlying mechanism remained unknown.

METHODS

Among 1,123 adults from National Health and Nutrition Examination Survey 2011-2012, 10 urinary PAHs, 11 urinary metals, and peripheral white blood cell (WBC) count were determined, and 5 lung function indices were measured. Least absolute shrinkage and selection operator, Bayesian kernel machine regression, and quantile-based g-computation were used to estimate co-exposure effects on lung function. Mediation analysis was used to explore mediating role of WBC.

RESULTS

These models demonstrated that PAHs and metals were significantly associated with lung function impairment. Bayesian kernel machine regression models showed that comparing to all chemicals fixed at median level, forced expiratory volume in 1 s (FEV1)/forced vital capacity, peak expiratory flow, and forced expiratory flow between 25 and 75% decreased by 1.31% (95% CI: 0.72%, 1.91%), 231.62 (43.45, 419.78) mL/s, and 131.64 (37.54, 225.74) mL/s respectively, when all chemicals were at 75th percentile. In the quantile-based g-computation, each quartile increase in mixture was associated with 104.35 (95% CI: 40.67, 168.02) mL, 1.16% (2.11%, 22.40%), 294.90 (78.37, 511.43) mL/s, 168.44 (41.66, 295.22) mL/s decrease in the FEV1, FEV1/forced vital capacity, peak expiratory flow, and forced expiratory flow between 25% and 75%, respectively. 2-Hydroxyphenanthrene, 3-Hydroxyfluorene, and cadmium were leading contributors to the above associations. WBC mediated 8.22%-23.90% of association between PAHs and lung function.

CONCLUSIONS

Co-exposure of PAHs and metals impairs lung function, and WBC could partially mediate this relationship. Our findings elucidate co-exposure effects of environmental mixtures on respiratory health and underlying mechanisms, suggesting that focusing on highly prioritized toxicants would effectively attenuate adverse effects.

PM10 exposure induces bronchial hyperresponsiveness by upreguating acetylcholine muscarinic 3 receptor

Exposure to particulate matter (PM10) can induce respiratory diseases that are closely related to bronchial hyperresponsiveness. However, the involved mechanism remains to be fully elucidated. This study aimed to demonstrate the effects of PM10 on the acetylcholine muscarinic 3 receptor (CHRM3) expression and the role of the ERK1/2 pathway in rat bronchial smooth muscle. A whole-body PM10 exposure system was used to stimulate bronchial hyperresponsiveness in rats for 2 and 4 months, accompanied by MEK1/2 inhibitor U0126 injection. The whole-body plethysmography system and myography were used to detect the pulmonary and bronchoconstrictor function, respectively. The mRNA and protein levels were determined by Western blotting, qPCR, and immunofluorescence. Enzyme-linked immunosorbent assay was used to detect the inflammatory cytokines. Compared with the filtered air group, 4 months of PM10 exposure significantly increased CHRM3-mediated pulmonary function and bronchial constriction, elevated CHRM3 mRNA and protein expression levels on bronchial smooth muscle, then induced bronchial hyperreactivity. Additionally, 4 months of PM10 exposure caused an increase in ERK1/2 phosphorylation and increased the secretion of inflammatory factors in bronchoalveolar lavage fluid. Treatment with the MEK1/2 inhibitor, U0126 inhibited the PM10 exposure-induced phosphorylation of the ERK1/2 pathway, thereby reducing the PM10 exposure-induced upregulation of CHRM3 in bronchial smooth muscle and CHRM3-mediated bronchoconstriction. U0126 could rescue PM10 exposure-induced pathological changes in the bronchus. In conclusion, PM10 exposure can induce bronchial hyperresponsiveness in rats by upregulating CHRM3, and the ERK1/2 pathway may be involved in this process. These findings could reveal a potential therapeutic target for air pollution induced respiratory diseases.

Epithelial Na + Channels Function as Extracellular Sensors

The epithelial Na + channel (ENaC) resides on the apical surfaces of specific epithelia in vertebrates and plays a critical role in extracellular fluid homeostasis. Evidence that ENaC senses the external environment emerged well before the molecular identity of the channel was reported three decades ago. This article discusses progress toward elucidating the mechanisms through which specific external factors regulate ENaC function, highlighting insights gained from structural studies of ENaC and related family members. It also reviews our understanding of the role of ENaC regulation by the extracellular environment in physiology and disease. After familiarizing the reader with the channel's physiological roles and structure, we describe the central role protein allostery plays in ENaC's sensitivity to the external environment. We then discuss each of the extracellular factors that directly regulate the channel: proteases, cations and anions, shear stress, and other regulators specific to particular extracellular compartments. For each regulator, we discuss the initial observations that led to discovery, studies investigating molecular mechanism, and the physiological and pathophysiological implications of regulation. © 2024 American Physiological Society. Compr Physiol 14:5407-5447, 2024.

Associations of urinary zinc exposure with blood lipid profiles and dyslipidemia: Mediating effect of serum uric acid

The relationship between zinc (Zn) exposure and abnormal blood lipids including dyslipidemia is contentious. Serum uric acid (SUA) has been reported to be correlated to both Zn exposure and dyslipidemia. The underlying mechanisms of Zn exposure associated with blood lipids and the mediating effects of SUA remain unclear. Therefore, this study analyzed the data from Chinese 2110 adults (mean age: 59.0 years old) in rural areas across China to explore the associations of Zn exposure with blood lipid profiles and dyslipidemia, and to further estimate the mediating effects of SUA in these relationships. The study data showed that urinary Zn was associated with increased levels of blood lipid components triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C). Moreover, an increased risk of dyslipidemia was observed in the study participants who had higher urinary Zn levels. Compared with the first quartile, the fourth quartile of urinary Zn concentration corresponded to the increase of TG (β = 0.20, 95 % CI: 0.12, 0.28), LDL-C (β = 0.06, 95 % CI: 0.01, 0.10) and dyslipidemia risk (OR = 2.16, 95 % CI: 1.50, 3.10), respectively. Elevated urinary Zn was also associated with higher levels of SUA and hyperuricemia risk. The SUA levels were positively related to total cholesterol (TC), TG, LDL-C levels and dyslipidemia risk. Mediation analyses revealed that SUA mediated 31.75 %, 46.16 % and 19.25 % of the associations of urinary Zn with TG, LDL-C levels and dyslipidemia risk, respectively. The subgroup and sensitivity analyses confirmed the positive associations between urinary Zn and blood lipid profiles and the mediating effect of SUA. The national population-based study further enhanced our understanding of the associations between Zn exposure and blood lipid profiles and mediating effect of SUA among generally healthy, middle-aged, and elderly individuals.

A review on the potential risks and mechanisms of heavy metal exposure to Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease that affects patients as well as the health and economic stability of society as a whole. At the same time, heavy metal pollution is widely recognized as having a possible impact on the environment and human health. Therefore, these diseases have become important global public health issues. In recent years, researchers have shown great interest in the potential association between heavy metal exposure and the development of COPD, and there has been a substantial increase in the number of related studies. However, we still face the challenge of developing a comprehensive and integrated understanding of this complex association. Therefore, this review aimed to evaluate the existing epidemiological studies to clarify the association between heavy metal exposure and COPD. In addition, we will discuss the biological mechanisms between the two to better understand the multiple molecular pathways and possible mechanisms of action involved, and provide additional insights for the subsequent identification of potential strategies to prevent and control the effects of heavy metal exposure on the development of COPD in individuals and populations.