Combined exposure to benzo(a)pyrene and dibutyl phthalate aggravates pro-inflammatory macrophage polarization in spleen via pyroptosis involving cathepsin B

Association of diurnal temperature range and childhood asthma: a population-based cross-sectional study in a Tropical City, China

BACKGROUND

Climate change has significantly impacted the diurnal temperature range (DTR), particularly in tropical regions of China, where DTR fluctuations are more frequent. While previous studies have primarily focused on the link between short-term DTR exposure and childhood asthma, there is limited information on the long-term effects from large-scale studies.

METHODS

In 2022, a cross-sectional survey involving 9,130 children aged 2-10 years was conducted using stratified cluster random sampling in tropical Sanya, Hainan Province, China. Data on demographics, and asthma symptoms were collected using the validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Temperature, precipitation and Normalized Difference Vegetation Index (NDVI) were obtained from remote sensing satellite. A generalized linear model (GLM) was employed to analyze the association between DTR exposure and asthma, and stratified analyses were conducted based on environmental and lifestyle factors.

RESULTS

The prevalence of childhood asthma was 7.57%, with the annual average DTR ranging from 5.15℃ to 7.26℃. After adjusting for potential confounders, each 1℃ increase in DTR was associated with a 65.9% higher risk of asthma (95% CI: 1.058, 2.602). Stratified analyses indicated that the impact of DTR on asthma risk was stronger among children living in areas with higher temperatures, higher precipitation, lower vegetation coverage (measured by NDVI), as well as those who were not breastfed, exposed to passive smoking, or whose mothers had pets during pregnancy.

CONCLUSIONS

In Sanya, increased annual DTR was significantly associated with a higher odds of childhood asthma, and this effect was influenced by environmental and lifestyle factors. Therefore, public health strategies could mitigate childhood asthma risk associated with DTR through urban greening, advocating for breastfeeding, reducing secondhand smoke, and avoiding pet ownership during pregnancy.

Identification of benzo(a)pyrene-related toxicological targets and their role in chronic obstructive pulmonary disease pathogenesis: a comprehensive bioinformatics and machine learning approach

BACKGROUND

Chronic obstructive pulmonary disease (COPD) pathogenesis is influenced by environmental factors, including Benzo(a)pyrene (BaP) exposure. This study aims to identify BaP-related toxicological targets and elucidate their roles in COPD development.

METHODS

A comprehensive bioinformatics approach was employed, including the retrieval of BaP-related targets from the Comparative Toxicogenomics Database (CTD) and Super-PRED database, identification of differentially expressed genes (DEGs) from the GSE76925 dataset, and protein-protein interaction (PPI) network analysis. Functional enrichment and immune infiltration analyses were conducted using GO, KEGG, and ssGSEA algorithms. Feature genes related to BaP exposure were identified using SVM-RFE, Lasso, and RF machine learning methods. A nomogram was constructed and validated for COPD risk prediction. Molecular docking was performed to evaluate the binding affinity of BaP with proteins encoded by the feature genes.

RESULTS

We identified 72 differentially expressed BaP-related toxicological targets in COPD. Functional enrichment analysis highlighted pathways related to oxidative stress and inflammation. Immune infiltration analysis revealed significant increases in B cells, DC, iDC, macrophages, T cells, T helper cells, Tcm, and TFH in COPD patients compared to controls. Correlation analysis showed strong links between oxidative stress, inflammation pathway scores, and the infiltration of immune cells, including aDC, macrophages, T cells, Th1 cells, and Th2 cells. Seven feature genes (ACE, APOE, CDK1, CTNNB1, GATA6, IRF1, SLC1A3) were identified across machine learning methods. A nomogram based on these genes showed high diagnostic accuracy and clinical utility. Molecular docking revealed the highest binding affinity of BaP with CDK1, suggestive of its pivotal role in BaP-induced COPD pathogenesis.

CONCLUSIONS

The study elucidates the molecular mechanisms of BaP-induced COPD, specifically highlighting the role of oxidative stress and inflammation pathways in promoting immune cell infiltration. The identified feature genes may serve as potential biomarkers and therapeutic targets. Additionally, the constructed nomogram demonstrates high accuracy in predicting COPD risk, providing a valuable tool for clinical application in BaP-exposed individuals.

ROS-mediated M1 polarization-necroptosis crosstalk involved in Di-(2-ethylhexyl) phthalate-induced chicken liver injury

The widespread use of plasticizers poses a serious threat to the environment and poultry health. Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer that can cause liver damage with prolonged exposure. Oxidative stress is closely associated with DEHP toxicity. Macrophage polarization plays an important role in many physiological and pathological processes and regulates disease development. This study aims to elucidate the mechanism of chronic DEHP exposure leading to chicken liver injury through oxidative stress-induced M1 polarization-necroptosis. In this study, the DEHP exposure model of chicken liver and the single and co-culture model of LMH and HD11 cells were established. With increasing dose and time, DEHP decreased body weight, increased liver coefficient, raised activities of liver function indicators and caused pathological liver damage in chickens. Further studies revealed the increase of reactive oxygen species (ROS) level and malonaldehyde (MDA) content, and the decrease of total antioxidant capacity (T-AOC) level, total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities, which led to excessive oxidative stress in the liver. In addition, there was increased infiltration of liver macrophages (CD68), upregulation of M1 polarization indicators (CD86, iNOS, IL-1β, TNF-α) and downregulation of M2 polarization indicators (CD163, Arg-1, IL-10, TGF-β) and appearance of necroptosis (RIPK1, RIPK3, MLKL). The vitro experiments confirmed the addition of N-acetylcysteine (NAC) inhibited M1 polarization and necroptosis. Besides, M1 polarization of HD11 cells promoted necroptosis of LMH cells in the HD11-LMH co-culture system. In brief, ROS-mediated M1 polarization-necroptosis is involved in DEHP-induced liver injury. This study provides a reference for environmental toxicant exposure in livestock and poultry farming.

Arsenic and Benzo[a]pyrene Co-exposure Effects on MDA-MB-231 Cell Viability and Migration

Although humans are frequently exposed to multiple pollutants simultaneously, research on their harmful effects on health has typically focused on studying each pollutant individually. Inorganic arsenic (As) and benzo[a]pyrene (BaP) are well-known pollutants with carcinogenic potential, but their co-exposure effects on breast cancer cell progression remain incompletely understood. This study aimed to assess the combined impact of BaP and As on the viability and migration of MDA-MB-231 cells. The results indicated that even at low levels, both inorganic As (0.01 μM, 0.1 μM, and 1 μM) and BaP (1 μM, 2.5 μM), individually or in combination, enhanced the viability and migration of the cells. However, the cell cycle analysis revealed no significant differences between the control group and the cells exposed to BaP and As. Specifically, exposure to BaP alone or in combination with As (As 0.01 μM + BaP 1 μM) for 24 h led to a significant increase in vimentin gene expression. Interestingly, short-term exposure to As not only did not induce EMT but also modulated the effects of BaP on vimentin gene expression. However, there were no observable changes in the expression of E-cadherin mRNA. Consequently, additional research is required to evaluate the prolonged effects of co-exposure to As and BaP on the initiation of EMT and the progression of breast cancer.

Fine particulate matter‑induced cardiac developmental toxicity (Review)

Fine particulate matter (PM2.5) has become an important risk factor threatening human health. Epidemiological and toxicological investigations have revealed that PM2.5 not only leads to cardiovascular dysfunction, but it also gives rise to various adverse health effects on the human body, such as cardiovascular and cerebrovascular diseases, cancers, neurodevelopmental disorders, depression and autism. PM2.5 is able to penetrate both respiratory and placental barriers, thereby resulting in negative effects on fetal development. A large body of epidemiological evidences has suggested that gestational exposure to PM2.5 increases the incidence of congenital diseases in offspring, including congenital heart defects. In addition, animal model studies have revealed that gestational exposure to PM2.5 can disrupt normal heart development in offspring, although the potential molecular mechanisms have yet to be fully elucidated. The aim of the present review was to provide a brief overview of what is currently known regarding the molecular mechanisms underlying cardiac developmental toxicity in offspring induced by gestational exposure to PM2.5.

Treponema Pallidum protein Tp47 triggers macrophage inflammatory senescence via PKM2-mediated metabolic reprogramming

Syphilis is a sexually transmitted disease caused by Treponema pallidum. The mechanisms enabling T. pallidum to persist despite macrophage eradication efforts in syphilis remain unclear. Pathogens can exploit senescent cells to enhance host susceptibility, and cellular senescence can be induced by pyroptosis, which known as inflammatory senescence. While recent studies have linked metabolic reprogramming to inflammatory senescence, their role in syphilis remained to be clarified. This study investigated the mechanisms of Tp47 on metabolic reprogramming and inflammatory senescence in macrophages. The results demonstrated that Tp47 triggered NLRP3 inflammasome-mediated pyroptosis by activating the phosphorylation of EIF2AK2 (a protein kinase), increasing senescence-associated pro-inflammatory cytokines secretion and leading to inflammatory senescence in macrophages. Additionally, Tp47 competitively bound to pyruvate kinase M2 (PKM2) with STUB1(a ubiquitin ligase), thereby inhibiting PKM2 ubiquitination degradation. By promoting the Y105 phosphorylation of PKM2, Tp47 modulated the intracellular function of PKM2, and facilitated PKM2-mediated metabolic reprogramming, which produced lactate that subsequently led to EIF2AK2 phosphorylation. Furthermore, inhibitors targeting EIF2AK2, lactate, glycolysis, and PKM2 effectively suppressed the inflammatory senescence induced by Tp47. In conclusion, Tp47 could mediate immune metabolic reprogramming through interaction with PKM2 to trigger macrophage inflammatory senescence. These discoveries offer a novel perspective for targeted therapies against syphilis.

The attenuating effects of serine against cadmium induced immunotoxicity through regulating M1/M2 and Th1/Th2 balance in spleen of C57BL/6 mice

Cadmium (Cd) has adverse effects on organisms. Serine is an essential nutritional factor and its nutritional value is extremely high for body. To explore the effects of serine on spleen toxicity induced by Cd in mice, cadmium chloride (CdCl2, 50 mg/L) and serine (50 g/L) were individually administered or co-administrated in drinking water of mice for 18 weeks. Results demonstrated that Cd exposure induced splenic toxicity and serine against the toxicity damage caused by Cd in mice. Under Cd stress, trace element homeostasis was disturbed, the mice's body weight and spleen index were increased, and splenic morphology and ultrastructure were altered. Furthermore, Cd exposure led to the cell populations disorder, which in turn triggers cell death. Notably, Cd treatment induced oxidative stress and inflammation, increased M1/M2 (iNOS, CD68) and Th1/Th2 (T-bet, CD4) levels, decreased M1/M2 (Arg1) and Th1/Th2 (GATA3) levels, while disrupted the macrophages and lymphocytes homeostasis, which trigged apoptosis and pyroptosis in spleen. In contrast, serine supplementation changed the levels of Cd and other elements, weakened Cd-induced tissue damage and inflammation, enhanced antioxidant capacity, significantly restored cell homeostasis, and effectively inhibited Cd-induced apoptosis and pyroptosis in the spleen. Shortly, the results verified that serine had an ameliorating toxicity effect and restored the M1/M2 and Th1/Th2 balance, restrained apoptosis and pyroptosis induced by Cd.

A smartphone-assisted photoelectrochemical POCT method via Z-scheme CuCo2S4/Fe3O4 for simultaneously detecting co-contamination with microplastics in food and the environment

As emerging contaminants, microplastics threaten food and environmental safety. Dibutyl phthalate (DBP, released from microplastics) and benzo[a]pyrene (BaP, adsorbed on microplastics) coexisted in food and the environment, harming human health, requesting a sensitive and simultaneous testing method to monitor. To address current sensitivity, simultaneousness, and on-site portability challenges during dual targets in complex matrixes, CuCo2S4/Fe3O4 nanoflower was designed to develop a smartphone-assisted photoelectrochemical point-of-care test (PEC POCT). The carrier transfer mechanism in CuCo2S4/Fe3O4 was proven via density functional theory calculation. Under optimal conditions, the PEC POCT showed low detection limits of 0.126, and 0.132 pg/mL, wide linearity of 0.001-500, and 0.0005-50 ng/mL for DBP and BaP, respectively. The smartphone-assisted PEC POCT demonstrated satisfied recoveries (80.00%-119.63%) in real samples. Coherent results were recorded by comparing the PEC POCT to GC-MS (DBP) and HPLC (BaP). This novel method provides a practical platform for simultaneous POCT for food safety and environment monitoring.

A radioactive and fluorescent dual modality cysteine cathepsin-B activity-based probe for the detection and treatment evaluation in rheumatoid arthritis

Activated macrophages are key effector cells and specific markers in patients with rheumatoid arthritis (RA). Cysteine cathepsin B (CTS-B) is highly expressed in macrophages and positively associated with RA activity and severity. This study aims to evaluate an activity-based multi-modality diagnostic agent, 68Ga-BMX2, which targets CTS-B to visualize the arthritis activity and evaluate the treatment efficacy. A CTS-B activity-based probe, BMX2, was labeled efficiently with 68Ga to produce 68Ga-BMX2 for fluorescent and positron emission tomography (PET) multi-modality imaging. The affinity and specificity of BMX2 binding with the CTS-B enzyme in macrophages were determined by radioactive experiment using RAW 264.7 cell lines, with CA074 and BMX5 as the inhibitors to test the specificity of the binding. Then, PET and fluorescence imaging were acquired on collagen-induced arthritis (CIA) mice. Additionally, the treatment monitoring capability of 68Ga-BMX2 PET/CT imaging was tested with methotrexate (MTX). RAW 264.7 macrophage cells showed significant uptake of 68Ga-BMX2. The binding of BMX2 with CTS-B in RAW 264.7 macrophage cells is time-dependent and could be blocked by CA074 and BMX5. In vivo optical and PET imaging showed high signals in the right hind arthritis in CIA mice from 68Ga-BMX2 and BMX2 accumulated for at least 120 h. Additionally, 68Ga-BMX2 signals were significantly reduced in the MTX-treated CIA mice compared to the control group. The 68Ga-BMX2, a radioactive and fluorescent dual-modality diagnostic agent targeting CTS-B, demonstrated a practical approach for CIA PET and fluorescence imaging. The 68Ga-BMX2 multimodality imaging could significantly monitor the treatment response in the CIA mice.

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.

Phthalate drives splenic inflammatory response via activating HSP60/TLR4/NLRP3 signaling axis-dependent pyroptosis

As the most produced phthalate, di-(2-ethylhexyl) phthalate (DEHP) is a widely environmental pollutant primarily used as a plasticizer, which cause the harmful effects on human health. However, the impact of DEHP on spleen and its underlying mechanisms are still unclear. Pyroptosis is a novel form of cell death induced by activating NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes and implicated in pathogenesis of numerous inflammatory diseases. The current study aimed to explore the impact of DEHP on immune inflammatory response in mouse spleen. In this study, the male ICR mice were treated with DEHP (200 mg/kg) for 28 days. Here, DEHP exposure caused abnormal pathohistological and ultrastructural changes, accompanied by inflammatory cells infiltration in mouse spleen. DEHP exposure arouse heat shock response that involves increase of heat shock proteins 60 (HSP60) expression. DEHP also elevated the expressions of toll-like receptor 4 (TLR4) and myeloid differentiation protein 88 (MyD88) proteins, as well as the activation of NF-κB pathway. Moreover, DEHP promoted NLRP3 inflammasome activation and triggered NLRP3 inflammasome-induced pyroptosis. Mechanistically, DEHP drives splenic inflammatory response via activating HSP60/TLR4/NLRP3 signaling axis-dependent pyroptosis. Our findings reveal that targeting HSP60-mediated TLR4/NLRP3 signaling axis may be a promising strategy for inflammatory diseases treatment.

HgCl2 exposure mediates pyroptosis of HD11 cells and promotes M1 polarization and the release of inflammatory factors through ROS/Nrf2/NLRP3

Mercury (Hg) is a serious metal environmental pollutant. HgCl2 exposure causes pyroptosis. When macrophages are severely stimulated, they often undergo M1 polarization and release inflammatory factors. However, the mechanisms by which mercuric chloride exposure induces macrophage apoptosis, M1 polarization, and inflammatory factors remain unclear. HD11 cells were exposed to different concentrations of Hg chloride (180, 210 and 240 nM HgCl2). The results showed that mercury chloride exposure up-regulated ROS, C-Nrf2 and its downstream factors (NQO1 and HO-1), and down-regulated N-Nrf2. In addition, the expressions of focal death-related indicators (Caspase-1, NLRP3, GSDMD, etc.), M1 polarization marker CD86 and inflammatory factors (TNF-α, IL-1β) increased, and the above changes were related to mercury. Oxidative stress inhibitor (NAC) can block ROS/ NrF2-mediated oxidative stress, inhibit mercury-induced pyroptosis and M1 polarization, and effectively reduce the release of inflammatory factors. The addition of Vx-765 to inhibit pyroptosis can effectively alleviate M1 polarization of HD11 cells and reduce the expression of inflammatory factors. HgCl2 mediates pyroptosis of HD11 cells by regulating ROS/Nrf2/NLRP3, promoting M1 polarization and the release of inflammatory factors.