The association of co-exposure to polycyclic aromatic hydrocarbons (PAHs) and phthalates (PAEs) with blood cell-based inflammatory biomarkers is largely unknown. We conducted a panel study of 144 children aged 4–12 years, with up to 3 repeated visits across 3 seasons. For each visit, we collected the first-morning urine for 4 consecutive days and fasting blood on the day of physical examination. We developed a gas chromatography/tandem mass spectrometry method to detect the metabolites of 10 PAHs (OH-PAHs) and 10 PAEs (mPAEs) in urine samples. We employed linear mixed-effects models to evaluate the individual associations of each OH-PAH and mPAE with blood cell-based inflammatory biomarkers over different lag times. Bayesian kernel machine regression (BKMR) and quantile g-computation were used to evaluate the overall associations of OH-PAHs and mPAEs mixtures with blood cell-based inflammatory biomarkers. After multiple adjustments, we found positive associations of summed hydroxylphenanthrene (∑OHPHE), summed OH-PAHs, and mono-n-butyl phthalate with inflammatory biomarkers such as neutrophil count, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the systemic immune-inflammation index (SII) at lag 0 (the day of physical examination). Each 1% increase in ∑OHPHE was related to a 0.18% (95% confidence interval: 0.10%, 0.25%) increase in SII, which was the strongest among the above associations. The results of BKMR and quantile g-computation suggested that co-exposure to PAHs and PAEs mixture was associated with an elevated white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and SII, to which ∑OHPHE and 1-hydroxypyrene (1-OHPYR) might be the major contributors. In addition, gender and age modified the associations of ∑OHPHE and 1-OHPYR with inflammatory biomarkers, where girls and younger children were more susceptible. In conclusion, co-exposure to PAHs and PAEs was associated with elevated inflammation in children, in which ∑OHPHE and 1-OHPYR might play important roles.

The influenza is a common viral infection that can be fatal, especially in high-risk groups such as children, pregnant women, elderly, and immune-deficient individuals. Vaccination is the most efficient approach to prevent the spreading of viral infection and promote individual and public health. In contrast, exposure to environmental pollutants such as cigarette smoke reduces the efficacy of vaccination. We investigated whether chronic exposure to hydroquinone (HQ), the most abundant compound of the tobacco particulate phase, could impair the adaptive immune responses elicited by influenza vaccination. For this, adult male C57BL/6 mice were daily exposed to either nebulized HQ or PBS for 1 h for a total of eight weeks. At weeks 6 and 8, the mice were primed and boosted with the trivalent influenza vaccine via IM respectively. Although the HQ exposure did not alter the body weight of the mice and the biochemical and hematological parameters, the pollutant increased the oxidative stress in splenocytes of immunized animals, modified the morphology of spleen follicles, and augmented the size of their lymph nodes. The lymphoid organs of HQ-exposed mice presented a similar number of vaccine-specific IgG-secreting cells, titers of vaccine-specific total IgG, and respective subclasses. Transcriptome studies with HQ, benzene, or cigarette smoke exposure were also analyzed. The genes up-regulated upon pollutant exposure were associated with neutrophil migration and were shown to be co-expressed with antibody-secreting cell genes. Therefore, these findings suggest that HQ exposure may trigger an immune-compensatory mechanism that enhances the humoral responses induced by influenza vaccination.

Di (2-ethylhexyl) phthalate (DEHP), a widely spreading environmental endocrine disruptor, has been confirmed to adversely affect the development of animals and humans. The formation of neutrophil extracellular traps (NETs) termed NETosis, is a recently identified antimicrobial mechanism for neutrophils. Though previous researches have investigated inescapable role of the immunotoxicity in DEHP-exposed model, relatively little is known about the effect of DEHP on NETs. In this study, carp peripheral blood neutrophils were treated with 40 and 200 μmol/L DEHP to investigate the underlying mechanisms of DEHP-induced NETs formation. Through the morphological observation of NETs and quantitative analysis of extracellular DNA, we found that DEHP exposure induced NETs formation. Moreover, our results proved that DEHP could increase reactive oxygen species (ROS) levels, decrease the expression of the anti-autophagy factor (mTOR) and the anti-apoptosis gene Bcl-2, and increase the expression of pro-autophagy genes (Dynein, Beclin-1 and LC3B) and the pro-apoptosis factors (BAX, Fas, FasL, Caspase3, Caspase8, and Caspase9), thus promoting autophagy and apoptosis. These results indicate that DEHP-induced ROS burst stimulates NETs formation mediated by autophagy and increases apoptosis in carp neutrophils.

Recently, chemical compounds containing lanthanides were used in various fields of biology and medicine. It has been described that such compounds can be applied in scanning electron microscopy (SEM) to increase the contrast and simplify the sample preparation process due to the process of replacing calcium with lanthanides in cell. However cell death by different mechanisms under influence of lanthanides seems possible. Here, we described that mummification process is a cell death physiologically realized in time: some time after lanthanide contrasting, the cell remains metabolically active and is able to biochemically transform neodymium-containing contrast, oxidize it and form large agglomerates. A distinctive feature of mummification induced by neodymium-containing contrast (NCC) is the formation of a high-rigid oxygen-containing “shield” on the surface of a neutrophil granulocyte.

Airborne particulate matter (PM) has become a serious health issue causing pulmonary diseases such as asthma. Due to the side effects and non-specificity of conventional drugs, there is a need to develop natural-product-based alternative treatments. Sargassum horneri is a brown alga shown to have anti-oxidant, anti-inflammatory, and anti-allergic effects. Thus, we sought to determine whether ethanol extract of Sargassum horneri (SHE) mitigates the effect of PM exposure on asthma development. To establish a mouse model of asthma, BALB/c mice were sensitized with ovalbumin (OVA, 10 μg) and challenged with PM (5 mg/m³) for 7 days consecutively. SHE (200, 400 mg/kg), Prednisone (5 mg/kg), or PBS was daily administrated orally before PM exposure. SHE mitigated PM exacerbated dendritic cell activation. More importantly, SHE restrained Th2 polarization by attenuating transcription factors GATA3 and STAT5, which further mitigated the expression of Th2 cytokines interleukin (IL)-4, IL-5, and IL-13 in the lung homogenates of PM-exacerbated asthmatic mice. SHE further attenuated PM-exacerbated eosinophil infiltration in the lung, trachea, and BALF. In addition, SHE markedly mitigated the activation of mast cells and the IgE level in serum. Concomitantly, SHE further restrained the Th17 cell response in PM-exposed allergic mice through attenuating expression of transcription factors RORγT, STAT3 and expression of relevant effector cytokines IL-17a. This resulted in mitigated neutrophil infiltration in the lung. Taken together, SHE significantly suppressed PM-exacerbated hypersecretion of mucus in asthmatic mice. These results suggest that SHE has therapeutic potential for treating PM-exacerbated allergic asthma through concomitantly inhibiting Th2/Th17 responses.

Cadmium (Cd) is a ubiquitous toxic heavy metal derived mainly from industrial processes. In industrialized societies, individuals are exposed to a plethora of sources of Cd pollution. Cd can trigger serious diseases such as rheumatoid arthritis (RA) and chronic obstructive pulmonary disease (COPD) by the over-activating immune system. As an effector mechanism in innate immunity, neutrophil extracellular traps (NETs) not only play an important role in defending against infection but also lead to tissue damage. However, the role of NETs in Cd-induced lung damage process has not been previously studied. In this study, we aimed to investigate the potential effects of Cd-induced NETs on lung injury in vivo and further to clarify the molecular mechanisms of Cd-induced NETs formation. In vivo, Cd treatment destroyed the structural integrity of lung tissue and significantly increased the levels of NETs in the bronchoalveolar lavage fluid (BALF). The known NETs inhibitor DNase I ameliorated pathologic changes and significantly decreased levels of NETs in BALF, which suggesting the curial role of NETs in Cd-induced lung injury. Further investigation showed that Cd could significantly trigger NETs formation, which is composed of DNA backbone decorated with histones (H3) and neutrophils elastase (NE). The inhibitors of NADPH oxidase, ERK1/2 and p38 MAPK-signaling pathways significantly reduced the formation of NETs, and western blotting analysis also showed that Cd significantly increased the phosphorylation of p38 and ERK1/2 signaling pathways. Above results confirmed that NADPH oxidase, ERK1/2 and p38 MAPK-signaling pathways were related to Cd-induced NETs formation. In conclusion, NETs was involved in Cd-induced lung injury, and the mechanisms of Cd-induced NETs formation was via activating NADPH oxidase, ERK1/2 and p38 MAPK-signaling pathways, which might provide a new perspective in Cd-induced lung injury.

Atrazine (ATR), a selective herbicide, is consistently used worldwide and has been confirmed to be harmful to the health of aquatic organisms. The release of neutrophil extracellular traps (NETs) is one of the newly discovered antimicrobial mechanisms. Although several immune functions have been analyzed under ATR exposure, the effect of ATR on NETs remains mainly unexplored. In the present study, we treated carp neutrophils using 5 μg/ml ATR and 5 μg/ml ATR combined with 100 nM rapamycin to elucidate the underlying mechanisms and to clarify the effect of ATR on phorbol myristate acetate (PMA)-induced NETs. The results of the morphological observation and quantitative analysis of extracellular DNA and myeloperoxidase (MPO) showed that NETs formation were significantly inhibited by ATR exposure. Moreover, we found that in the NETs process, ATR downregulated the expression of the anti-apoptosis gene B-cell lymphoma-2 (Bcl-2), increased the expression of the pro-apoptosis factors Bcl-2-Associated X (BAX), cysteinyl aspartate specific proteinases (Caspase3, 9), and anti-autophagy factor mammalian target of rapamycin (mTOR), decreased the expression of autophagy-related protein light chain 3B (LC3B) and glucose transport proteins (GLUT1, 4), disturbed the activities of phosphofructokinase (PFK), pyruvate kinase (PKM), and hexokinase (HK) and limited reactive oxygen species (ROS) levels, indicating that the reduced NETs release was a consequence of increased apoptosis and diminished ROS burst, autophagy and down-regulated glycolysis under ATR treatment. Meanwhile, rapamycin restored the inhibited autophagy and glycolysis and thus resisted the ATR-suppressed NETs. The present study perfects the mechanism theory of ATR immunotoxicity to fish and has a certain value for human health risk assessment.

Nano-TiO2 is immunotoxic to fish and reduces the bactericidal function of fish neutrophils. Here, fathead minnows (Pimephales promelas) were exposed to low and high environmentally relevant concentration of nano-TiO2 (2 ng g−1 and 10 μg g−1 body weight, respectively), and were challenged with common fish bacterial pathogens, Aeromonas hydrophila or Edwardsiella ictaluri. Pre-exposure to nano-TiO2 significantly increased fish mortality during bacterial challenge. Nano-TiO2 concentrated in the kidney and spleen. Phagocytosis assay demonstrated that nano-TiO2 has the ability to diminish neutrophil phagocytosis of A. hydrophila. Fish injected with TiO2 nanoparticles displayed significant histopathology when compared to control fish. The interplay between nanoparticle exposure, immune system, histopathology, and infectious disease pathogenesis in any animal model has not been described before. By modulating fish immune responses and interfering with resistance to bacterial pathogens, manufactured nano-TiO2 has the potential to affect fish survival in a disease outbreak.

Epidemiological studies have indicated that exposure to ambient air-borne fine particulate matter (PM2.5) is associated with many cardiopulmonary diseases; however, the underlying pathological mechanisms of PM2.5-induced lung injury remain unknown. In this study, we aimed to assess the impact of acute or prolonged exposure to water-insoluble fractions of PM2.5 (PM2.5 particulate) on lung injury and its molecular mechanisms. Balb/c mice were randomly exposed to PM2.5 once (acute exposure) or once every three days for a total of 6 times (prolonged exposure). Lung, BALF and blood samples were collected, and pulmonary pathophysiological alterations were analyzed. Nrf2 knockout mice were adapted to assess the involvement of Nrf2 in lung injury, and transcriptomic analysis was performed to delineate the mechanisms. Through transcriptomic analysis and validation of Nrf2 knockout mice, we found that acute exposure to PM2.5 insoluble particulates induced neutrophil infiltration-mediated airway inflammation, whereas prolonged exposure to PM2.5 insoluble particulate triggered lung fibrosis by decreasing the transcriptional activity of Nrf2, which resulted in the downregulated expression of antioxidant-related genes. In response to secondary LPS exposure, prolonged PM2.5 exposure induced more severe lung injury, indicating that prolonged PM2.5 exposure induced Nrf2 inhibition weakened its antioxidative defense capacity against oxidative stress injury, leading to the formation of pulmonary fibrosis and increasing its susceptibility to secondary bacterial infection.

Perfluorooctane sulfonate (PFOS) is one of the most widely used and distributed perfluorinated compounds proven to cause adverse health outcomes. Datasets of ecotoxico-genomics and proteomics have given greater insights for PFOS toxicological effect. However, the molecular mechanisms of hepatotoxicity of PFOS on post-translational modifications (PTMs) regulation, which is most relevant for regulating the activity of proteins, are not well elucidated. Protein glycosylation is one of the most ubiquitous PTMs associated with diverse cellular functions, which are critical towards the understanding of the multiple biological processes and toxic mechanisms exposed to PFOS. Here, we exploit the multilayered glycoproteomics to quantify the global protein expression levels, glycosylation sites, and glycoproteins in PFOS exposure and wild-type mouse livers. The identified 2439 proteins, 1292 glycosites, and 799 glycoproteins were displayed complex heterogeneity in PFOS exposure mouse livers. Quantification results reveal that 241 dysregulated proteins (fold change ≥ 2, p < 0.05) in PFOS exposure mouse livers were involved in the lipid and xenobiotic metabolism. While, 16 overexpressed glycoproteins were exclusively related to neutrophil degranulation, cellular responses to stress, protein processing in endoplasmic reticulum (ER). Moreover, the interactome and functional network analysis identified HP and HSP90AA1 as the potential glycoprotein biomarkers. These results provide unique insights into a deep understanding of the mechanisms of PFOS induced hepatotoxicity and liver disease. Our platform of multilayered glycoproteomics can be adapted to diverse ecotoxicological research.