Zinc- and Copper-Induced Interleukin-6 Release in Primary Cell Cultures From Rat Heart

Burn Pit Smoke Condensate-Mediated Toxicity in Human Airway Epithelial Cells

Burn pits are a method of open-air waste management that was common during military operations in Iraq, Afghanistan, and other regions in Southwest Asia. Veterans returning from deployment have reported respiratory symptoms, potentially from exposure to burn pit smoke, yet comprehensive assessment of such exposure on pulmonary health is lacking. We have previously shown that exposure to condensates from burn pit smoke emissions causes inflammation and cytotoxicity in mice. In this study, we explored the effects of burn pit smoke condensates on human airway epithelial cells (HAECs) to understand their impact on cellular targets in the human lung. HAECs were cultured at the air-liquid interface (ALI) and exposed to burn pit waste smoke condensates (plywood, cardboard, plastic, mixed, and mixed with diesel) generated under smoldering and flaming conditions. Cytotoxicity was evaluated by measuring transepithelial electrical resistance (TEER) and lactate dehydrogenase (LDH) release; toxicity scores (TSs) were quantified for each exposure. Pro-inflammatory cytokine release and modulation of gene expression were examined for cardboard and plastic condensate exposures. Burn pit smoke condensates generated under flaming conditions affected cell viability, with flaming mixed waste and plywood exhibiting the highest toxicity scores. Cardboard and plastic smoke condensates modulated cytokine secretion, with GM-CSF and IL-1β altered in more than one exposure group. Gene expression of detoxifying enzymes (ALDH1A3, ALDH3A1, CYP1A1, CYP1B1, NQO1, etc.), mucins (MUC5AC, MUC5B), and cytokines was affected by several smoke condensates. Particularly, expression of IL6 was elevated following exposure to all burn pit smoke condensates, and polycyclic aromatic hydrocarbon acenaphthene was positively associated with the IL-6 level in the basolateral media of HAECs. These observations demonstrate that exposure to smoke condensates of materials present in burn pits adversely affects HAECs and that aberrant cytokine secretion and altered gene expression profiles following burn pit material smoke exposure could contribute to the development of airway disease.

Copper homeostasis and cuproptosis in atherosclerosis: metabolism, mechanisms and potential therapeutic strategies

Copper is an essential micronutrient that plays a pivotal role in numerous physiological processes in virtually all cell types. Nevertheless, the dysregulation of copper homeostasis, whether towards excess or deficiency, can lead to pathological alterations, such as atherosclerosis. With the advent of the concept of copper-induced cell death, termed cuproptosis, researchers have increasingly focused on the potential role of copper dyshomeostasis in atherosclerosis. In this review, we provide a broad overview of cellular and systemic copper metabolism. We then summarize the evidence linking copper dyshomeostasis to atherosclerosis and elucidate the potential mechanisms underlying atherosclerosis development in terms of both copper excess and copper deficiency. Furthermore, we discuss the evidence for and mechanisms of cuproptosis, discuss its interactions with other modes of cell death, and highlight the role of cuproptosis-related mitochondrial dysfunction in atherosclerosis. Finally, we explore the therapeutic strategy of targeting this novel form of cell death, aiming to provide some insights for the management of atherosclerosis.

Evaluation of some trace elements and antioxidants in sera of patients with rheumatoid arthritis: a case-control study

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that destroys joints. The concentrations of elements (Zn, Cu, Mg, Mn, Fe, Ni, Cr, K, Na, Ca, Pb, and Cd), as well as antioxidant glutathione GSH and lipid peroxidation marker malondialdehyde MDA, will be determined in this study.

METHOD

The study involves 120 female RA patients and 60 healthy females in the control group, all of whom are between the ages of 20 and 60. Patients having diabetes, hypertension, hyperthyroidism, or psoriasis, in addition to RA, were excluded.

RESULTS

When RA patients were compared to healthy individuals, the levels of Cu, Ni, Na, Pb, and Cd were significantly higher (p < 0.01), whereas the levels of Zn, Mg, Mn, Cr, Ca, K, and Fe were significantly lower (p < 0.01). The Cu/Zn (2.21 and 1.16) and Na/k (38.67 and 34.87) ratios were also found to be significantly higher in RA patients compared to controls. Furthermore, the data indicated that GSH concentrations in RA patients were significantly lower (p < 0.01) than those in controls (655.90 and 1345.17 mol/l, respectively). MDA levels in RA patients were significantly higher (p < 0.01) than those in controls (2.739 and 1.673 mol/l, respectively).

CONCLUSIONS

The data indicate that Cu/Zn and Na/k ratios can be of great value in the diagnosis and evaluation of RA patients. On this basis, we conclude that these elements can be relied upon to provide indications of RA risk and the measurement of oxidative stress can serve as a biomarker to monitor disease activity and severity in RA patients. Key Points • Trace elements may be of value and may have an expected significance in the early diagnosis, prognosis, and treatment evaluation of rheumatoid arthritis. • The distortion in the levels of trace elements may reflect their possible role in the pathogenesis of rheumatoid arthritis. • Oxidative stress can act as a biomarker to monitor disease activity and severity in patients with rheumatoid arthritis. • The trace elements can contribute to the manifestation of inflammatory diseases due to their role in the synthesis of some antioxidants or due to their effect on the immune system.

Comparative studies on regional variations in PM2.5 in the induction of myocardial hypertrophy in mice

Exposure to fine particulate matter (PM_2.5) has been indicated to be related to an increased risk of cardiovascular diseases (CVDs) in sensitive people. However, the underlying mechanisms of PM_2.5-induced CVDs are poorly understood. In the present study, PM_2.5 samples were collected during winter from four cities (Taiyuan, Beijing, Hangzhou, and Guangzhou) in China. Ten-month-old C57BL/6 female mice were exposed to PM_2.5 suspension at a dosage of 3 mg·kg^-1 (b. w.) every other day for 4 weeks by oropharyngeal aspiration. PM_2.5 from Taiyuan increased the blood pressure and the thicknesses of the left ventricular anterior and posterior walls, decreased the ratio of nucleus to cytoplasm in cardiomyocytes and reduced the systolic function of the heart in mice. Further investigation revealed that PM_2.5 from Taiyuan induced lung inflammatory cytokines with up-regulated expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The mRNA expression levels of myocardial hypertrophy markers atrial natriuretic peptide and the β isoform of myosin heavy chain (ANP and β-MHC), matrix metalloproteinase 2 (MMP2), MMP9, and inflammatory cytokines TNF-α and IL-6 in the myocardium were significantly increased after exposure to PM_2.5 of Taiyuan. Furthermore, PM_2.5 from Taiyuan activated the IL-6/JAK2/STAT3/β-MHC signaling pathway in the myocardium. The correlation between the PM_2.5 components and myocardial hypertrophy markers suggested that Zinc (Zn) and acenaphthene (AC) are related to the changes in ANP and β-MHC at the transcriptional level, respectively. The above results indicated that PM_2.5 exposure induced myocardial hypertrophy in older mice, which might be related to the critical contributions of Zn and AC in PM_2.5. The present study provides new insights into the mechanism of myocardial hypertrophy after PM_2.5 exposure.

Association between serum copper levels and prevalence of hyperuricemia: a cross-sectional study

Hyperuricemia has been recognized as a worldwide public health concern. This study was conducted to examine the association between serum copper (Cu) concentration and the prevalence of hyperuricemia in a middle-aged and elderly population. Serum Cu concentration was measured by Roche modular P800 using the PAESA method. Serum uric acid (UA) concentration was detected by a Beckman Coulter AU 5800. Presence of hyperuricemia was defined as serum UA ≥ 416 μmol/L for men and ≥360 μmol/L for women. The association between serum Cu concentration and the prevalence of hyperuricemia was evaluated by logistic regression. The prevalence of hyperuricemia was 17.6% (n = 6,212) in the present study. Relative to the lowest quintile, the age- and sex-adjusted odds ratios for hyperuricemia were 1.38 (95% CI: 1.12 to 1.70), 1.34 (95% CI: 1.07 to 1.66), and 1.53 (95% CI: 1.23 to 1.91) in the third, fourth, and fifth serum Cu concentration quintiles (P for trend < 0.001). Similar results were found both in men and women subgroups. None of the findings were materially altered after adjustment for additional potential confounders. In conclusion, in this population-based cross-sectional study, serum Cu concentration was positively associated with the prevalence of hyperuricemia.

Multiple plasma metals, genetic risk and serum C-reactive protein: A metal-metal and gene-metal interaction study

Background

C-reactive protein (CRP) is a well-recognized biomarker of inflammation, which can be used as a predictor of cardiovascular disease. Evidence have suggested exposure to multiple metals/metalloids may affect immune system and give rise to cardiovascular disease. However, it is lack of study to comprehensively evaluate the association of multiple metals and CRP, the interactions between metals, and the gene-metal interaction in relation to CRP levels.

Aims

To explore the associations of multiple plasma metals with serum CRP, and to test the interactions between metals, and gene-metal interactions on the levels of serum CRP.

Methods

We included 2882 participants from the Dongfeng-Tongji cohort, China, and measured 23 plasma metals and serum CRP concentrations. The genetic risk score (GRS) was calculated based on 7 established CRP-associated variants. For metals which were associated with the levels of CRP, we further tested the interactions between metals on CRP, and analyzed the gene-metal interactions on CRP.

Results

The median level for CRP in the total population was 1.17 mg/L. After multivariable adjustment, plasma copper was positively associated with serum CRP (FDR < 0.001), whereas selenium was negatively associated with serum CRP (FDR = 0.01). Moreover, selenium and zinc attenuated the positive association between high plasma copper and CRP (P for interaction < 0.001). Participants with a higher GRS had a higher CRP level, with the increase in ln-transformed CRP per increment of 5 risk alleles were 0.64 for weighted GRS, and 0.54 for unweighted GRS (both P < 0.001). Furthermore, the genetic association with CRP was modified by copper concentration (P for interaction < 0.001).

Conclusions

Our results suggest that serum CRP is positively associated with plasma concentration of copper, and inversely associated with selenium. Plasma zinc, selenium and CRP genetic predisposition would modify the associations between plasma copper and serum CRP.

•

We found that serum CRP was positively associated with plasma copper, and inversely associated with selenium.

•

The positive association of plasma copper with serum CRP appeared to be attenuated with high plasma zinc and selenium.

•

This is the first study that explored the potential gene-metal interactions in relation to CRP levels.

•

These novel findings may provide new insights to personalized prevention and interventions for inflammation.

Cardiac assessment in Wilson's disease patients based on electrocardiography and echocardiography examination

INTRODUCTION

Wilson's disease (WD) is a rare genetic disorder that leads to impairments in copper metabolism. Patients principally exhibit liver and neuropsychiatric symptoms, but because copper also accumulates in all body organs, other (typically milder) clinical symptoms can occur. To date, cardiac involvement has not been thoroughly investigated in patients with WD. This study aimed to evaluate heart structure and function in patients with WD with commonly available diagnostic methods.

MATERIAL AND METHODS

We compared 125 WD patients with an age- and sex-matched control group. Patients with WD were grouped according to their dominant symptoms - neurologic or hepatic. All subjects underwent clinical, electrocardiographic (ECG), and echocardiographic examinations.

RESULTS

All subjects had sinus rhythm on electrocardiography. The only ECG parameter that differed between patients with WD and the control group was the QRS prolongation (92.0 vs. 86.4 ms; p < 0.05). On echocardiography patients with WD exhibited more hypertrophy in the left ventricle than controls (posterior wall in diastole: 1.0 vs. 0.93; p < 0.01) and the left ventricle hypertrophy was more pronounced in the neurologic than in the hepatic subgroup (1.05 vs. 0.96 cm; p < 0.01). Left ventricular systolic function was similar in the WD and the control group (ejection fraction: 67.5% vs. 67.7%). On tissue Doppler echocardiography patients with WD demonstrated slowing of myocardial relaxation, which was more evident in the neurologic group.

CONCLUSIONS

Heart involvement in WD was manifested mainly by mild left ventricular hypertrophy and subclinical changes in diastolic function, particularly in the patients with the neurologic form of disease.

Effect of dietary copper level on the gut microbiota and its correlation with serum inflammatory cytokines in Sprague-Dawley rats

In China's swine industry, copper is generally supplemented above the National Research Council (NRC) requirement (2012) because of its antimicrobial properties and the potential for growth promotion. Yet few are concerned about whether this excess supplementation is necessary. In this study, the 16S rRNA pyrosequencing was designed and used to investigate the effect of dietary copper level on the diversity of the fecal microbial community and the correlation of copper level with the serum level of inflammatory cytokines in Sprague-Dawley rat models. The results showed that the diet containing a high level of Cu (120 and 240 mg/kg) changed the microbial richness and diversity of rat feces associated with the increased copper content in the rat ileac and colonic digesta. Furthermore, a Pearson's correlation analysis indicated that an accumulation of unabsorbed copper in the chyme was correlated with the microbial composition of the rat feces, which was linked with TNF-α in serum. The results suggest that dietary copper level may have a direct impact on circulating inflammatory cytokines in the serum, perhaps inducing an inflammatory response by altering the microbial composition of rat feces. Serum TNF-α could be the chief responder to excessive copper exposure.

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.

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.

Elevated circulating levels of copper and nickel are found in elderly subjects with left ventricular hypertrophy

Identified risk factors for left ventricular hypertrophy (LVH) are hypertension, diabetes and obesity. However, since these risk factors only explain a part of the variation in left ventricular mass, we investigated if trace and heavy metals might also play a role in LVH. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular mass index (LVMI) and relative wall thickness (RWT) were determined by echocardiography together with eleven different trace and heavy metals in 993 subjects aged 70 years. Only copper levels were significantly related to LVMI following adjustment for sex, blood pressure, antihypertensive treatment, diabetes and body mass index (BMI) (p<0.0001). However, both copper (Cu) and nickel (Ni) were related to RWT following adjustment (p<0.0001). When divided into four geometric groups, both Cu and Ni were elevated in subjects with concentric remodelling and concentric LVH, but not in those with eccentric hypertrophy, when compared to subjects with a normal left ventricle. No relationships were found for zinc, aluminium, manganese, molybdenum, mercury, lead, cadmium, cobalt or chromium. Elevated levels of copper and nickel are found in elderly subjects with LVH, especially of the concentric type, following adjustment for known risk factors for LVH.