The detection of micro- and nanoplastics (MNPs) in the human brain is a critical frontier in neurotoxicology, yet analysis is severely hindered by the brain’s complex, lipid-rich matrix. Recent concerns regarding “false positive” signals from endogenous fats necessitate the development of rigorous, validatable pretreatment protocols. This study optimized pretreatment procedures for post-mortem human dorsal thalamus samples. We compared oxidative (H₂O₂), alkaline-oxidative (NaOH/H₂O₂), and acidic microwave-assisted (HNO₃) digestion. MNP presence and polymer integrity were cross-validated using a multi-analytical suite: Laser Direct Infrared (LDIR) imaging, Optical Photothermal Infrared (O-PTIR) spectroscopy, SEM-EDS, and MALDI-TOF MS. Lipid removal efficiency was quantitatively assessed via GC-MS. Standard oxidative or alkaline digestions were found insufficient, as they promote the formation of insoluble zinc and calcium lipid salts (soaps) that mimic polymer spectra. A critical methodological advancement was achieved by incorporating an ethanol-assisted solvent stage and a 5
Microplastics (MPs) are pervasive environmental contaminants that have been increasingly detected in human tissues. However, their molecular effects on the human placenta, a critical interface for maternal–fetal exchange and fetal development, remain poorly understood. This study aimed to characterize the placental microplastic burden and to investigate transcriptomic, proteomic, and metabolomic alterations associated with different levels of MPs exposure using an integrated multi-omics approach. MPs were systematically quantified in human placental tissues using pyrolysis–gas chromatography–mass spectrometry. Placental samples were stratified into high- and low-burden groups according to MPs exposure levels. Integrated transcriptomic, proteomic, and metabolomic analyses were then performed to identify exposure-associated molecular perturbations. The DIABLO framework was applied to integrate multi-omics datasets and identify discriminatory cross-omics features, followed by network analysis to explore key regulatory hubs and pathways. Placental tissues with higher MP burden exhibited multi-layer molecular perturbations involving immune dysregulation, antifolate resistance, oxidative stress, and altered lipid and purine metabolism. Integrative DIABLO analysis identified a set of cross-omics features that robustly distinguished the high- and low-burden groups, including MINPP1, PARG, NDUFS6, and cinnamoside. Network analysis further positioned NDUFS6 as a central hub connecting transcriptomic, proteomic, and metabolomic changes, suggesting that mitochondrial dysfunction may represent a key axis of placental response to MPs exposure. These findings provide a systems-level understanding of placental molecular alterations associated with MPs exposure and highlight potential pathways and regulatory factors that may contribute to the effects of environmental exposure on maternal–fetal health.
Respirable dust and fibres in occupational settings are major contributors to lung dysfunction, imposing a significant societal burden. Following the ban on asbestos in most countries, silica and coal mine dust have emerged as primary concerns due to their abundance and persistence in workplace dust. Exposure to dust containing these elements has been strongly linked to pulmonary fibrosis and lung cancer. Extensive research has explored the molecular mechanisms underlying respirable occupational dust-induced cytotoxicity and immune dysregulation. The toxic effects of respirable occupational dust and fibres are largely induced by oxidative stress, mitochondrial dysfunction, lysosomal damage, inflammasome activation and immune suppression. These exposures can trigger multiple cell death pathways, including ferroptosis, necrosis, and pyroptosis. While sharing common toxicological features, silica, coal dust, and asbestos exhibit distinct toxic effects on various pulmonary cell types involved in fibrosis and cancer progression. The immunological consequences of dust exposure are profound, as dust-induced activation of macrophages and neutrophils, together with natural killer (NK) cell dysfunction, sustains chronic inflammation and disrupts epithelial repair and fibroblast regulation, thereby promoting fibrosis and tumorigenesis. Although no curative treatments exist for pulmonary fibrosis, especially coal workers’ pneumoconiosis and silicosis, this review also discusses emerging therapeutic approaches, such as antifibrotic agents and immunotherapy, aimed at mitigating lung fibrosis and lung cancer. This review summarises recent findings on the toxicological mechanisms underlying respirable occupational dust- and fibre-induced lung diseases, with a focus on crystalline silica, and coal dust and asbestos, especially those bearing reduced iron minerals. By highlighting both cellular toxicity and immunological effects, as well as potential therapeutic strategies, this work provides insights into current trends, challenges, and future research directions in the study of respirable occupational dust- and fibre-induced lung diseases.
Black phosphorus is the most stable allotrope of phosphorus and possesses a unique layered structure. Black phosphorus nanosheets and black phosphorus quantum dots are the two main forms of black phosphorus nanomaterials (BPNM). BPNM hold significant application potential across various fields, yet a comprehensive evaluation of their biosafety, particularly the impact on hepatic metabolism, remains insufficient. This study investigates the hepatotoxic effects and mechanisms induced by BPNM, with a focus on lipid metabolic disorders. Following a 28-day daily oral administration of black phosphorus quantum dots or black phosphorus nanosheets at doses of 0.1 and 1 mg/kg, mice exhibited reduced insulin sensitivity, increased inflammatory responses, decreased serum levels of triglycerides and very-low-density lipoprotein (VLDL), and exacerbated hepatic lipid accumulation. RNA-sequencing revealed that oxidative stress is a key contributor to BPNM-induced metabolic disruption, accompanied by severe mitochondrial dysfunction. Similarly, BPNM exposure also elevated intracellular reactive oxygen species (ROS), impaired mitochondrial respiratory function and ATP production, consequently disrupted VLDL assembly and secretion in AML12 hepatocyte line. Moreover, ROS scavenger and ATP supplementation restored mitochondrial function and triglycerides transport in vitro. Findings demonstrate that BPNM promote hepatic lipid accumulation possibly by triggering oxidative stress and impairing mitochondrial function, thereby interfering with lipid transport, and resulting in hepatic lipid accumulation. This study highlights the potential metabolic disruption risks of BPNM and provides critical insights for their biosafety assessment and sustainable application.
Microplastics (MPs) and nanoplastics (NPs) have recently been detected in several human biological matrices; however, evidence in children remains limited. This exploratory study aimed to investigate the presence and concentration of urinary MPs and NPs (MNPs) in primary school children residing in Cyprus. First-morning urine samples from 29 children were analyzed using scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM/EDX), applying strict contamination-control measures and focusing on particles < 10 μm. Pyrolysis–GC/MS was additionally used to characterize polymer composition, identifying polyethylene (PE) and polypropylene (PP) as the predominant polymers. MNPs < 10 μm were detected in all samples, with concentrations ranging from 393 to 8050 particles/ml (median: 1217 particles/ml; IQR: 800–2030). Particle diameters ranged from 0.88 μm to 3.44 μm (median: 1.69 μm; IQR: 1.25–2.25 μm; minimum: 0.77 μm; maximum: 4.88 μm). No statistically significant associations were observed between MNP concentrations and body mass index (BMI)-for-age categories or hand-to-mouth behavior. Although direct comparisons with previous studies are limited due to methodological variability among studies and the lack of standardized protocols for MNP quantification in human urine, these findings provide preliminary evidence of urinary MNPs in children. Further large-scale studies using harmonized analytical approaches are needed to better characterize exposure patterns in pediatric populations.
Micro- and nano-sized polyethylene plastics (PE-MPs and PE-NPs) are emerging as potential risk factors for pulmonary disease and risk assessment. Currently, their is no direct evidence suggests this appreciable health risk extends to humans. Furthermore, the toxicological evaluation of PE-MPs and PE-NPs is insufficient to support their safe use. This study was aimed to characterize the toxicity of PE-MPs and PE-NPs after 13 weeks of intratracheal instillation in Sprague–Dawley (SD) rats and to assess the reversibility of any effects during a 4-week recovery period. Exposure levels for PE-MPs and PE-NPs were set at 0, 40, 80, and 120 μg per rat once a week. The results indicated that the treatment administration resulted in observable lung tissue alterations. Inflammatory cells were present in the perivascular and peribronchiolar regions in both sexes at ≥ 40 μg per rat in the PE-MPs and PE-NPs-treated groups, indicating a biological response that can turn into toxicity. Additionally, thickened alveolar ducts and alveolar epithelial hyperplasia were noted in males at 120 μg per rat PE-MPs, in males at ≥ 80 μg per rat PE-NPs, and in females at ≥ 40 μg per rat PE-MPs and PE-NPs-treated groups. Interestingly, when instilled repeatedly with both sizes of polyethylene particles, IL-1β and TNF-α secretion was significantly more enhanced in female rats compared to male rats. At the same time, the pulmonary level of IL-6 increased more clearly in male rats than in female rats. The pulmonary level of C-reactive protein, a marker for acute inflammation, was increased in all treated groups. These findings suggest that the lowest-observed-adverse-effect level (LOAEL) for PE-MPs and PE-NPs based on repeated exposures is below 40 μg per rat for both sexes. However, the toxicological data for PE-MPs and PE-NPs remain insufficient to confirm their safety, and further research is necessary to evaluate their potential risks to human health.
Biodegradable plastics are increasingly being used as a sustainable alternative, but their degradation in biological environments may produce transformation products with unexpected toxicological characteristics. These products generate a distribution pattern in the kidneys that differs from other organs, with the accumulation of low-molecular-weight polylactic acid microplastics (PLA MPs) being far higher than that of high-molecular-weight tissues. PLA is used as a representative bioplastic. We used polymeric and oligomeric MPs to simulate their original and partially degraded states. Mice were exposed to these MPs through repeated oral administration under controlled experimental exposure conditions for 28 consecutive days to study the accumulation and inflammatory damage caused by PLA oligomer and polymer MPs in the kidneys. In combination with in vitro transcriptomic analysis, we explored the potential mechanisms by which oligomers drive nephrotoxicity. Exposure to PLA oligomer MPs results in significantly higher accumulation in the kidneys compared to PLA polymer MPs, and triggers more severe inflammatory damage. The mechanism is that renal macrophages preferentially phagocytose PLA oligomer MPs and decode them through macrophage scavenger receptor 1 (MSR1), activating phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling and inducing chemokine ligand 2 (CCL2)-dependent macrophage recruitment, thereby establishing a self-amplifying inflammatory loop. Inhibiting MSR1 or PI3K/AKT effectively reduces oligomer-driven cytokine production, macrophage infiltration, and renal injury, narrowing the toxicity gap between oligomeric and polymeric PLA MPs in the kidneys. These findings reveal that biodegradation can heighten the inflammatory potential of MPs, and that distinct polymerization states of the same material elicit different immune interpretations. Our work provides mechanistic clarity on how degradability reshapes microplastic toxicity, underscoring the need to incorporate degradation-state profiling into the safety assessment of biodegradable MPs.
Millions of U.S. troops and supporting personnel have been deployed to military bases in the Middle East. Essentially all personnel on military bases were exposed to the combustion emissions generated by open pit waste burning. Chronic multisymptom illness (CMI) is a term advanced to characterize the complex health effects of inhalation exposures to military burn pits (BP). Because of the diversity of geography, environmental conditions, and deployment operations, it is very challenging to estimate the number of Veterans affected by CMI, but it has been reported to be in the range of 40–60
Abstract Background Exposure to wood smoke is associated with negative respiratory health outcomes such as airway infections and development of chronic obstructive pulmonary disease (COPD). Previous controlled exposure studies in humans with bronchoscopy sampling have shown wood smoke-induced bronchial cytotoxicity and impaired macrophage phagocytosis. The present study investigated whether an early and transient acute inflammatory response, as reflected in bronchial mucosal biopsies and lavage fluids, could be detected 6 h after wood smoke exposure. Methods On two separate occasions, fourteen healthy participants were exposed, in a double-blind, randomised crossover design, for 2 h to filtered air and diluted wood smoke generated from incomplete wood log combustion with a mean particulate matter concentration of 409 ± 43 µg/m3. Bronchoscopy with endobronchial mucosal biopsies, bronchial wash (BW) and bronchoalveolar lavage (BAL) was performed 6 h post-exposure. Biopsies were immunohistochemically stained, and lavage fluids analysed for soluble mediators. Results In bronchial mucosal biopsies, nuclear translocation of the transcription factors aryl hydrocarbon receptor (AhR) and phosphorylated c-jun (p-c-jun) was significantly reduced within the bronchial epithelium after wood smoke exposure compared to filtered air. There was no endothelial adhesion molecule-mediated recruitment of neutrophils or other inflammatory cells into the bronchial mucosa. Conclusions Exposure to wood smoke from incomplete wood log combustion suppressed nuclear translocation of transcription factors and the expected inflammatory response in endobronchial mucosal biopsies at 6 h post-exposure. This contrasts to the strong proinflammatory effects of other air pollutants such as ozone and diesel exhaust. Together with previous findings of increased cytotoxicity and impaired airway macrophage phagocytosis in humans, this response may be in line with compromised immune defence and increased susceptibility to airway infections, chronic bronchitis and COPD observed in populations exposed to high levels of indoor air pollution from wood smoke.
Abstract Growing production and use of plastics have led to significant environmental pollution including the formation and accumulation of plastic nanoparticles (PNPs). Due to their small size, PNPs easily enter the human food chain; however, humans are also exposed to plastics through other consumer pathways, such as the use of cosmetic products. Despite considerable efforts to investigate the potential adverse effects of plastics, their impact on human health is not yet fully understood. In particular, endocrine disruption has emerged as a potential mechanism underlying reported reproductive and hormonal effects of micro- and nanoplastics. We applied an OECD-aligned in vitro test guidelines (TGs) to a factorial panel of eight PNPs spanning four common polymers (polystyrene (PS), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET)) with size-resolved materials and polymer-matched mixtures. Thus, estrogen receptor a (ERα) transactivation (TG 455), androgen receptor (AR) transactivation (TG 458, antagonist mode), and H295R steroidogenesis (TG 456) assays were performed using HeLa-9903, AR-EcoScreen GR KO M1, and NCI-H295R cell models, respectively. Across 0.1–10 mg L⁻¹, no cytotoxicity was observed. PENPs (350 nm) and PPNPs (180 nm) acted as ER agonists, whereas PPNPs (50 and 180 nm) and PENPs (350 nm) antagonized AR; PSNPs and PETNPs showed no activity when tested individually. Notably, several mixtures elicited ER and AR responses even when constituent singles were inactive, indicating mixture-dependent potentiation. In contrast, the H295R assay did not meet the OECD decision rule for altered steroidogenesis: sporadic shifts in pathway intermediates did not propagate to estradiol or testosterone. Altogether, the data support a surface- and polymer-dependent, receptor-proximal mode of action for PNPs and highlight mixture effects as a critical, underappreciated driver. These results move endocrine hazard evaluation beyond polystyrene surrogates and provide decision-useful guidance on which polymers/sizes and mixture contexts merit priority in exposure monitoring and risk assessment.
BackgroundEnvironmental aging processes, such as oxidation, can substantially modify the physicochemical properties and toxicity of microplastics (MPs). Nevertheless, most studies have focused on pristine MPs, overlooking aged forms that more accurately represent environmental exposure conditions. Understanding the toxicological consequences of oxidative aging is essential for realistic ecological risk assessment.ResultsWe investigated the toxicological effects of pristine polyethylene (PE) and oxidized polyethylene (OPE) microplastics using a dual-species aquatic model comprising Daphnia magna and zebrafish (Danio rerio) embryos. Physicochemical characterization revealed that OPE particles exhibited increased surface roughness, a more negative surface charge, and a higher proportion of oxygen-containing functional groups on the particle surface compared with PE. Exposure to OPE induced pronounced lipid accumulation and significantly reduced heart rate in both models. Transcriptomic analysis indicated that OPE downregulated key genes related to lipid transport and metabolism, including mttp, apoea, and apobb. These findings were further validated by quantitative PCR and Oil Red O staining. Notably, zebrafish embryos exposed to OPE displayed developmental impairment even with intact chorions, implying enhanced bioavailability and barrier penetration of oxidized particles.ConclusionsOur findings demonstrate that oxidative aging amplifies the biological toxicity of polyethylene microplastics by disrupting lipid metabolism and developmental processes. This study underscores the importance of considering environmentally aged MPs in ecological risk evaluations, as pristine particles may underestimate their actual hazard potential in aquatic ecosystems.
Pulmonary alveolar proteinosis (PAP) is a rare lung disease with primary (usually autoimmune) and secondary forms. Unlike the autoimmune type, which can be treated with cytokine therapy or whole-lung lavage, the secondary form associated with occupational particulate exposure, such as indium compounds, has no established therapy and remains challenging to treat. PAP was experimentally induced in rats through intratracheal exposure to indium oxide nanoparticles (In2O3 NPs). To assess potential therapeutic interventions, we administered four pharmacological agents: aspirin and naproxen, which are expected to attenuate inflammation, and pioglitazone and indomethacin, peroxisome proliferator-activated receptor (PPAR)-γ agonists anticipated to restore impaired surfactant homeostasis. The efficacy of their amelioration of In2O3 NP-induced PAP and the underlying mechanisms were evaluated by bronchoalveolar lavage fluid analysis, histopathology, and gene expression profiling. Treatment with pioglitazone and indomethacin markedly attenuated In2O3 NP–induced PAP by reducing foamy macrophage accumulation and restoring the expression of PPAR-γ and its downstream ATP-binding cassette (ABC) transporters, such as ABCG1 and ABCG4. In contrast, aspirin and naproxen only slightly decreased neutrophil infiltration. Among the tested agents, indomethacin showed relatively pronounced effects on several PAP-related endpoints, suggesting its potential to improve macrophage lipid handling and surfactant balance. Targeting PPAR-γ–dependent macrophage lipid regulation may serve to attenuate In2O3 NP-induced secondary PAP-like pathology by reducing foamy macrophage accumulation and improving surfactant clearance. The effects were more pronounced when treatment was administered before disease establishment, whereas established pathology was only partially reversed, supporting the PPAR-γ–ABC transporter pathway as a potential target for future intervention.
BackgroundAir pollution exposure is associated with increased risk of developing acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). While the possibility of air pollution priming the immune system to exacerbate ALI is postulated, it lacks experimental evidence. NOD-like Receptor X1 (NLRX1) is a mitochondria-localized protein that regulates a variety of cellular functions including inflammation and oxidant generation. Presently, the role of NLRX1 in the context of air pollution-mediated priming of ALI remains unclear. We hypothesized that a subacute ozone (O3) and ultrafine carbon black (CB) mixed inhalation exposure would prime for worse ALI responses and NLRX1 would exert a protective role. We exposed male C57BL/6J (Nlrx1+/+) and Nlrx1-/- mice to a mixture of 250 ppb O3 and 1 mg/m3 CB 3 hours per day for 5 days a week over 3 weeks by whole body inhalation. After 3 weeks of exposure, we induced ALI by administering 1.5 IU/Kg bleomycin (BLM) and euthanized mice 14 days post-BLM exposure. We assessed survival, lung function, inflammation, lung remodeling and proportions of immune cells.ResultsIn Nlrx1-/- mice air pollution exposure primed for worsened bleomycin-induced survival. The adverse phenotype in Nlrx1-/- mice was associated with increased inflammation, greater lung function decline and increased collagen deposition. Immune cell phenotyping indicated modulation of macrophages (alveolar and interstitial), neutrophils and CD103+ dendritic cells in Nlrx1-/- exposed and BLM challenged mice.ConclusionsWe identify NLRX1 as a novel mediator for air pollution-induced priming of worsened ALI.
Nanopesticides have been progressively incorporated into contemporary agricultural systems owing to their distinctive physicochemical characteristics and superior pest management capabilities. Given their environmental persistence and propensity for bioaccumulation, nanopesticides are increasingly recognized as emerging cardiovascular toxicants, thus warranting systematic investigation of their exposure-associated cardiotoxic effects. In the present study, the impact of Cu(OH)2 nanopesticide on cardiac homeostasis was systematically investigated in a C57BL/6 mouse model following one-month exposure administered via oral gavage, with copper concentrations set at 0 (vehicle control), 1, and 5 mg/kg bw. Multiple molecular biology techniques were employed to elucidate the nanopesticide-induced cardiac impairment and the underlying mechanisms. It was demonstrated that prolonged exposure to this copper-based nanopesticide resulted in significant deterioration of ventricular systolic and diastolic function, induction of ventricular chamber remodeling, disturbance of hemodynamic stability, and dysregulation of cardiac substructural gene expression, collectively mirroring the characteristic phenotypic manifestations and underlying molecular hallmarks of clinical heart failure. The dysregulation of Cu(OH)2 nanopesticide in the Wnt/β-catenin signaling pathway through the targeting of mmu-miRNA-590-3p and mmu-miRNA-338-5p provided a proposed explanation for the underlying mechanism of the nanopesticide-induced imbalance of cardiac homeostasis. The present findings provide new insights into the cardiovascular hazards posed by Cu(OH)2 nanopesticide, advancing the development of a more rigorous risk assessment protocol for this emerging category of agricultural nanomaterial.
Biodegradable polylactic acid (PLA) plastic is considered to be an effective method to solve the global white pollution caused by petroleum-based plastics. Its wide application in disposable tableware and food packaging has led to the risk of human exposure to PLA microplastics (MPs), but its impact on bone health is unclear. Our study investigated the skeletal developmental toxicity of PLA-MPs at environmentally accessible concentrations in adolescent mice and its potential mechanism. Here we demonstrated that PLA-MPs treatment in adolescent mice showed significant skeletal developmental toxicity, manifested as shortened body length and slowed growth of femur and tibia. Further analysis found that PLA-MPs caused a diminution of epiphyseal plate thickness, a decrement in the count of bone trabeculae, damaged femoral microstructure, and inhibited femoral new bone formation. Notably, PLA-MPs enter osteoblasts and destroy their osteogenic differentiation, resulting in a dose-dependent damage that reduces the formation of calcium nodules. Transcriptome analysis further demonstrated that PLA-MPs exposure was associated with disrupted arachidonic acid metabolism, which may contribute to impaired osteoblast formation, especially Cyp2j5 gene and its downstream metabolite epoxyeicosatrienoic acids were significantly inhibited. Subsequent studies have indicated that Ophiopogonin D (Oph D) can activate Cyp2j5 signal to alleviate PLA-MPs-induced damaged osteoblast differentiation. Furthermore, alleviating impaired differentiation function of osteoblasts using Oph D can significantly improve the reduction of trabecular bone and bone microstructure damage caused by adolescent PLA-MPs exposure. This study not only identifies a potential mechanistic association between PLA-MPs exposure and poor bone development, but also emphasizes the need for targeted interventions to protect bone health in adolescent children and the broader impact on environmental and public health policies.
Automobile cabin air filter-deposited particulate matter represents an underappreciated exposure source, yet the differential toxicity between filter sides and underlying mechanisms remain unclear. Here, we systematically investigated particles extracted from the inside (cabin-facing) and outside (environment-facing) membranes of used automobile air filters. Morphological analysis revealed that inside particles exhibited smaller size and greater dispersion, consistent with ultrafine particle enrichment. In a murine exposure model, inside particles induced more severe pulmonary inflammation, histopathological injury, and elevated interleukin-1β levels compared to outside particles at equivalent doses. Single-cell RNA sequencing identified alveolar macrophages as the predominant responding cell type, with significant enrichment of the NOD-like receptor signaling pathway. Mechanistic investigations demonstrated that particle exposure activated the NLRP3 inflammasome and triggered Gasdermin D-mediated pyroptosis through a reactive oxygen species-independent pathway. Furthermore, we employed structure-based virtual screening of over two thousand natural compounds, from which we identified the cyclic dipeptide Cyclo-(Tyr-Phe) as a novel NLRP3 inhibitor. Molecular dynamics simulations and cellular thermal shift assays confirmed direct NLRP3 binding, while functional validation demonstrated that Cyclo-(Tyr-Phe) effectively attenuated particle-induced pyroptosis and inflammatory responses. These findings illuminate the heightened toxicity of ultrafine-enriched filter particles and provide a promising therapeutic candidate for mitigating particle-induced lung injury.
Abstract Background Air pollution particles exacerbate allergic asthma and can enhance inflammatory responses to allergen exposure, but the cellular mechanisms involved remain incompletely defined. We examined how diesel exhaust particles (DEP) enhance house-dust-mite (HDM) inflammatory responses within the lung and characterised potential mechanisms that may contribute to enhanced type 2 (T2) inflammatory responses. Results In mice subjected to repeated intranasal exposures, DEP alone had modest effects, whereas DEP + HDM markedly increased type-2 inflammatory indicators (Serum IgE; Airway Il13, Il4 & Tslp) and eosinophilia alongside expansion of Th2 cells. Bulk transcriptomics showed far stronger differential expression in luminal airway cells than tissue, with a DEP + HDM-specific signature enriched for mast cells, alternatively activated macrophages (AAM), and B-cells in the lumen. Combined single-cell proteomic and transcriptomic profiling identified an expanded Cd11c⁺, SiglecF⁻, Apoe⁺, Gpnmb⁺ monocyte-derived macrophage subset (RM.Gp2), which showed increased type 2 chemokines Ccl8 and Ccl24 with DEP + HDM compared to HDM alone. Trajectory analysis placed RM.Gp2 downstream of Ccr2⁺ monocyte derived population, and protein/mRNA data supported a Ccl2–Ccr2-dependent influx that enlarges the RM.Gp2 pool. High-content imaging confirmed increased RM.Mo and RM.Gp2 numbers and higher total luminal Ccl8/Ccl24. F4/80⁺ luminal airway macrophages isolated from DEP pre-treated mice, demonstrated enhanced upregulation of Ccl8 and Ccl24 mRNA in response to ex vivo Il-4/Il-13 treatment, compared to macrophages isolated from control mice. Examination of an additional particle type (CeO2 Nanoparticles) in the same exposure model, revealed a shared luminal transcriptomic response and AAM/chemokine programme as with DEP. Conclusions Our data suggests that pollutant particles such as DEP may contribute to enhanced HDM induced type 2 inflammation by expanding Ccr2-dependent monocyte-derived macrophages into the airway lumen and licensing a Th2-cytokine-responsive chemokine programme (Ccl8- Ccr8 to recruit Th2 cells; Ccl24-Ccr3 to recruit eosinophils). These findings identify luminal recruited macrophages as important targets in allergic inflammation within the lung, providing insight into potential mechanisms from which exposure and disease mitigation strategies may be developed.
Toxicity studies of microplastics increasingly emphasize the importance of particle retention, transformation, and physicochemical properties within biological systems, as these factors critically influence hazard identification and dose–response interpretation. However, quantitative and qualitative analyses of microplastics in biological matrices remain technically challenging, and many existing digestion-based methods can alter particle properties, thereby confounding toxicological outcomes. Herein, we propose a novel methodology to provide quick, easy, non-destructive, cost-efficient, and reliable outcomes by offering a particle collection method for microplastics as-present in organs using proteinase K (PK) digestion and a simple quantification method based on ultraviolet-visible (UV-Vis) spectrophotometry. The test microplastic samples comprised three spherical polystyrene (0.1, 1, and 100 μm), two fragmented polystyrene (1 and 100 μm), one spherical polyethylene (10 μm), one fragmented polyethylene (100 μm), and two fragmented polypropylene (1 and 100 μm). Particles as-present in organs were successfully collected by conducting PK tissue digestion at 5 µg PK per mg dried tissue. The collected particles were then quantified using a standard curve, with absorbance measured at 750 nm. Spiking experiments with microplastics in mouse lung and mussel tissues showed > 90
Abstract Background Early neurodevelopment is a critical period during which environmental exposures can have lasting effects on brain function and behavior. One key indicator of early neurodevelopmental integrity in rodents is the production of neonatal ultrasonic vocalizations (USVs), which are essential for maternal-offspring communication. Given the widespread use of titanium dioxide nanoparticles (TiO2NPs) in food and consumer products, there is growing concern that perinatal exposure to these particles may interfere with normal neurodevelopment. However, the effects of TiO2NPs exposure on USV production remain poorly investigated. Results In the present study, pregnant mice were orally exposed to TiO2NPs (200 µg/g) from conception to weaning, and their offspring underwent a maternal separation test to assess USVs between postnatal day P2 and P13. TiO2NP-exposed pups exhibited a significant reduction in the number of USVs at P6-7, accompanied by a delayed peak vocalization period. This reduction was primarily attributable to shorter vocalization series rather than fewer isolated calls. Additionally, acoustic analysis revealed that pups emitted two types of USVs, simple and complex, both of which were significantly reduced in number at P6-7 in the exposed group. Fast Fourier transform (FFT)-based analysis showed that complex USVs had a lower mean frequency, while both call types exhibited increased variability in mean frequency. Furthermore, TiO2NP-exposed pups displayed alterations in USV syntax, including a lower proportion of simple USVs and disrupted developmental maturation of call structure. Electrophysiological recordings revealed that the intermediate reticular oscillator (iRO), a key brainstem center involved in vocalization control, exhibited reduced excitability and an increased activity variability in exposed pups, suggesting that nanoparticle exposure compromises vocal motor regulation at the neural level. Lastly, playback experiments demonstrated that USVs from TiO2NP-exposed pups failed to elicit appropriate maternal attraction, indicating impaired communicative effectiveness. Conclusions Perinatal exposure to TiO2NPs disrupts the normal development of USVs, impairing both vocalization patterns and neural excitability of the iRO. These changes may contribute to altered maternal-offspring interactions and highlight the potential neurodevelopmental risks of early-life TiO2NPs exposure. Given the widespread presence of TiO2NPs in consumer products, further research is necessary to assess their long-term consequences on neural circuits underlying communication and social behavior.
The rising prevalence of metabolic diseases represents a global health challenge, with metabolically unhealthy normal-weight (MUHNW) individuals remaining largely overlooked. In addition to direct fine particulate matter (PM2.5) inhalation, there is growing recognition that maternal PM2.5 exposure may be a contributing environmental factor for metabolic disorders. However, the mechanisms by which maternal PM2.5 exposure induced metabolic disorders in the offspring remain unknown. Eight-week-old pregnant C57BL/6N mice were exposed to either filtered air (FA) or ambient PM2.5 throughout gestation, from gestational day 0 to 18, using a whole-body inhalation exposure system. Eight-week-old male C57BL/6N mice were treated once daily for three consecutive days with an antibiotic cocktail containing 1 g/L ampicillin, 0.5 g/L neomycin, 0.5 g/L vancomycin, and 1 g/L metronidazole to generate pseudo-germ-free mice. Subsequently, fecal microbiota from maternal PM2.5-exposed three-week-old male mouse offspring (donor) were transplanted to pseudo-germ-free mice (recipient) via oral gavage twice weekly for five weeks. After fecal microbiota transplantation (FMT), fecal samples from donor and recipient mice were collected for full-length 16S rRNA sequencing. Liver tissue from donor mice was analyzed by 5R 16S rRNA sequencing. Maternal PM2.5 exposure induced non-obese insulin resistance in adult male mouse offspring, with the liver identified as a susceptible organ characterized by suppressed AKT phosphorylation. Subsequently, systemic and hepatic insulin resistance were recapitulated in pseudo-germ-free mice, which received gut microbiota from maternal PM2.5-exposed mouse offspring via FMT. Mechanistically, the increased abundance of Helicobacter hepaticus contributed to DNA damage-mediated colonic barrier injury. This impaired colonic barrier facilitated gut-to-liver translocation of bacteria and lipopolysaccharide (LPS), which triggered hepatic inflammation via activation of TLR4 signaling pathway, ultimately leading to insulin resistance. These findings indicated a causal role for gut microbiota dysbiosis in maternal PM2.5 exposure-induced non-obese insulin resistance in the offspring, providing potential insights into the developmental origins of MUHNW from the perspective of maternal exposure to air pollution.
