Evaluation of nanoplastics toxicity in the soil nematode Caenorhabditis elegans by iTRAQ-based quantitative proteomics

Navigating nanotoxicity: Unraveling nanomaterial-induced effects via multi-omics integration

The growing use of nanomaterials in industry and medicine raises significant concerns about their safety, particularly regarding their interactions with biological systems. Traditional toxicological methods, with limited throughput and mechanistic understanding, are increasingly being complemented by omics technologies. Genomics, transcriptomics, proteomics, and metabolomics provide comprehensive insights into the molecular mechanisms of nanomaterial toxicity and enable the identification of potential biomarkers. In addition, single-cell and spatial omics approaches are emerging as powerful tools to assess toxicity at the cellular and tissue levels, revealing heterogeneous responses and spatial distribution of nanomaterials. Despite their advantages, omics technologies face challenges in nanotoxicology, including large, complex data sets, integration difficulties, and a lack of standardized protocols. To address these challenges, we propose the development of new bioinformatics tools, multi-omics integration platforms, and standardized analysis processes to enhance research efficiency and accuracy. These efforts can provide a practical roadmap for integrating the application of omics technologies, including single-cell and spatial approaches, in the study of nanomaterial toxicity studies.

Distinct responses of Caenorhabditis elegans to polyethylene microplastics and plant secondary metabolites

Soil worms are among the most abundant and functionally diverse soil animals. However, they have been largely overlooked in studies on microplastic (MP) toxicity. MPs and plant secondary metabolites (PSMs) are ubiquitous in soil due to plant litter decomposition and heavy MP contamination, inevitably interacting and exerting combined toxicity on soil organisms. However, little research has been conducted on their joint effects. This study investigates the individual and combined toxic effects of polyethylene (PE) MPs and three PSMs (glycyrrhizic acid, tannic acid, and matrine) on the model organism Caenorhabditis elegans. Physiological and biochemical responses were assessed using fluorescence microscopy, image analysis, and statistical methods. After 42 h of exposure to PE MPs and/or PSMs, worm growth and development were negatively impacted. Under experimental conditions, matrine and PE MPs synergistically inhibited worm growth, exacerbated neurological damage, and induced oxidative stress. In contrast, glycyrrhizic acid and tannic acid alleviated PE MP-induced growth inhibition, mitigated oxidative stress, and demonstrated antioxidant properties that counteracted oxidative damage. This study offers new insights into the combined effects of MPs and PSMs in soil ecosystems, contributing to ecological risk assessments and pollution management strategies.

Maternal exposure to phthalates and nanoplastics, isolated or combined: Impacts on placental structure, development, and antioxidant defense as a trigger for maternal-fetal adversities

The placenta is an essential maternal-fetal organ for the healthy development of the fetus, linking maternal and fetal circulations. Endocrine disrupting chemicals (EDCs), such as phthalates derived from plastic residues, may impair offspring development and increase the risk of metabolic disorders. Plastics also degrade into microplastics (MPs) and nanoplastics (NPs), which can cross the placenta, carrying EDCs and impacting fetal development. The objective of this study was to investigate whether gestational exposure to a phthalate mixture (PM) and NPs interferes with the maternal-fetal interface, altering female reproductive efficiency and placental morphophysiology. Pregnant SD rats were divided into 6 groups: CTR(control; vehicle), T1(20 μg/kg/day-PM), T2(200 mg/kg/day-PM), T3(1 mg/kg/day NPs-100nm), T4(20 μg/kg/dayPM+1 mg/kg/day-NPs-100nm), and T5(200 mg/kg/day-PM+1 mg/kg/day-NPs-100 nm). Treatment was administered orally from gestational day 5 (GD5) to GD20. At GD20, 5-8 rats from each group were anesthetized and underwent laparotomy, and blood, ovaries, uterus, and placentas were analyzed. There was an increase in pre-implantation loss in T3, T4 and T5 groups, a reduction in placental weight, and an increase in placental efficiency in male offspring in T3 group. An increase in the number of fetuses small for gestational age was observed in T3 and T5 vs. C. Furthermore, the treatment caused an increase in the expression of targets related to trophoblast cell differentiation in T5, and growth factors related to angiogenesis in the placenta in T3 and T4 groups. There was a decrease in TBARS, SOD, and GSTpi levels in T2, while CAT increased in T3, suggesting that these pollutants modulate placental gene expression and energy metabolism.

Maternal exposure to polystyrene nanoplastics induces sex-specific kidney injury in offspring

Maternal exposure to polystyrene nanoplastics (PS-NPs) during pregnancy and lactation has been linked to adverse effects on offspring kidney development, with sex-specific outcomes. This study investigated the impact of maternal PS-NPs exposure on kidney weight, histology, transcriptomics, and functional pathways in offspring mice. Offspring exposed to PS-NPs exhibited significantly lower body weight (P < 0.05) and an increased kidney-to-body weight ratio (P < 0.05), particularly in males. Histological analysis revealed a reduction in glomerular number in PS-NP-treated groups. Transcriptome profiling identified 758 differentially expressed genes (DEGs) in male and 101 DEGs in female offspring, with males showing a more pronounced alteration in gene expression. KEGG pathway enrichment highlighted disruptions in immune response, cell cycle regulation, and metabolism, with males exhibiting more extensive pathway changes than females. Additionally, PS-NPs exposure increased renal fibrosis (P < 0.05), with molecular analyses confirming sex-specific gene expression patterns linked to fibrosis and apoptosis. Immunohistochemical analysis revealed enhanced macrophage infiltration and cleaved caspase-3 expression, indicating heightened immune and apoptotic responses in males. Further investigation identified small molecules BI-D1870 and Resatorvid as potential therapeutic agents, reducing fibrosis, inflammation, and apoptosis in male and female offspring, respectively. These findings demonstrate that maternal PS-NPs exposure induces sex-specific kidney injury in offspring, disrupting key biological processes and pathways. The study underscores the need for targeted therapeutic interventions to mitigate these effects and highlights potential compounds for future treatment.

Aged Biodegradable Nanoplastics Enhance Body Accumulation Associated with Worse Neuronal Damage in Caenorhabditis elegans

The environmental and health challenges posed by petroleum-based biodegradable plastics, such as polybutylene succinate (PBS) and polybutyleneadipate-co-terephthalate (PBAT), are a significant concern because they are increasingly present in the environment and contribute a substantial proportion of microplastics (MPs) or nanoplastics (NPs). In this study, ultraviolet (UV)-aged PBS-NPs and PBAT-NPs are found to have a higher propensity to accumulate within the body of Caenorhabditis elegans (C. elegans) by prolonging the defecation interval, which could induce severe neuronal damage compared to pristine NPs. The increased accumulation of biodegradable nanoplastics (BNPs) and subsequent impairments of neurobehavior are highly attributed to their reduced particle size and altered surface properties, including changed chemical bonds and functional groups after photoaging. Aged BNPs also cause more severe damage to GABAergic neurons and neurotransmitter receptors, resulting in disrupted neuronal homeostasis and behaviors. Overall, BNPs of both PBS and PBAT components show no significant differences in biological accumulation and mechanisms of neural damage, highlighting the commonalities and characteristics of the adverse effects of petroleum-based BNPs on the nervous system. Our study opens up the exploration of the health impacts of photoaging and the degradation state of BNPs that are increasingly present in the environment.

Metagenomics and metaproteomics reveal the effects of sludge types and inoculation modes on N,N-dimethylformamide degradation pathways and the microbial community involved

This study demonstrated the effects of the sludge type and inoculation method on the N,N-dimethylformamide degradation pathway and associated microbial communities. The sludge type is critical for DMF metabolism, with acclimatized aerobic sludge having a significant advantage in terms of DMF metabolism performance, whereas acclimatized anaerobic sludge has a reduced DMF metabolism capacity. Metagenomic revealed increased abundances of Methanosarcina, Pelomona and Xanthobacter in the adapted anaerobic sludge, suggesting that anaerobic sludge can utilize the methyl products produced by DMF metabolism for growth. Adapted aerobic sludge had high Mycobacterium abundance, significantly boosting DMF hydrolysis. In addition, a large number of dmfA2 genes were found in aerobic sludge, more so in acclimatized sludge, indicating stronger DMF metabolism. Conversely, acclimatized anaerobic sludge showed lower abundance of dmd-tmd and mauA/B, qhpA genes, implying long-term DMF toxicity reduced anaerobic microbial activity. Metaproteomic analysis showed that Methanosarcina and Methanomethylovorans enzymes in anaerobic sludge metabolized dimethylamine and methylamine to methane, aiding DMF degradation. In the aerobic sludge, aminohydrolase proteins, which hydrolyze DMF, were significantly upregulated. These findings provide insights into DMF wastewater treatment.

Exploring the Neuroprotective Effects of Grape Seed Procyanidins on Amyloid-β-Induced Toxicity in Caenorhabditis elegans

Alzheimer's disease (AD), a major neurodegenerative disorder, is characterized by the progressive accumulation of amyloid-β (Aβ) plaques, leading to cognitive decline. Despite the existing treatments, their limited efficacy highlights the urgent need for novel therapeutic strategies. The present study investigates the neuroprotective effects of a grape seed polyphenol extract (GSPE) on transgenic Caenorhabditis elegans models specifically expressing human Aβ proteins. The obtained results show that GSPE not only significantly attenuates Aβ-induced paralysis but also extends the lifespan and improves sensory responses in these models, suggesting improved neural function and overall health. Additionally, GSPE treatment reduces proteasomal activity, which could lead to a reduction in the accumulation of misfolded proteins. It also modulates the expression of key genes involved in autophagy and proteostasis, thereby enhancing cellular mechanisms to manage protein aggregation and combat oxidative stress. On the whole, these findings support the potential of grape seed procyanidins (the main components in the extract) to be used as an effective dietary approach to mitigate Alzheimer's disease pathology through the modulation of critical neuroprotective pathways.

Short-term microplastic effects on marine meiofauna abundance, diversity and community composition

Background

Due to the copious disposal of plastics, marine ecosystems receive a large part of this waste. Microplastics (MPs) are solid particles smaller than 5 millimeters in size. Among the plastic polymers, polystyrene (PS) is one of the most commonly used and discarded. Due to its density being greater than that of water, it accumulates in marine sediments, potentially affecting benthic communities. This study investigated the ingestion of MP and their effect on the meiofauna community of a sandy beach. Meiofauna are an important trophic link between the basal and higher trophic levels of sedimentary food webs and may therefore be substantially involved in trophic transfer of MP and their associated compounds.

Methods

We incubated microcosms without addition of MP (controls) and treatments contaminated with PS MP (1-µm) in marine sediments at three nominal concentrations (103, 105, 107particles/mL), for nine days, and sampled for meiofauna with collections every three days. At each sampling time, meiofauna were collected, quantified and identified to higher-taxon level, and ingestion of MP was quantified under an epifluorescence microscope.

Results

Except for Tardigrada, all meiofauna taxa (Nematoda, turbellarians, Copepoda, Nauplii, Acari and Gastrotricha) ingested MP. Absorption was strongly dose dependent, being highest at 107 particles/mL, very low at 105 particles/mL and non-demonstrable at 103 particles/mL. Nematodes accumulated MP mainly in the intestine; MP abundance in the intestine increased with increasing incubation time. The total meiofauna density and species richness were significantly lower at the lowest MP concentration, while at the highest concentration these parameters were very similar to the control. In contrast, Shannon-Wiener diversity and evenness were greater in treatments with low MP concentration. However, these results should be interpreted with caution because of the low meiofauna abundances at the lower two MP concentrations.

Conclusion

At the highest MP concentration, abundance, taxonomic diversity and community structure of a beach meiofauna community were not significantly affected, suggesting that MP effects on meiofauna are at most subtle. However, lower MP concentrations did cause substantial declines in abundance and diversity, in line with previous studies at the population and community level. While we can only speculate on the underlying mechanism(s) of this counterintuitive response, results suggest that further research is needed to better understand MP effects on marine benthic communities.

Polystyrene nanoparticles strengthen high glucose toxicity associated with alteration in insulin signaling pathway in C. elegans

Using Caenorhabditis elegans as animal model, we investigated the effect of exposure to polystyrene nanoparticles (PS-NPs) in the range of μg/L on high glucose toxicity induction. With lifespan and locomotion behavior as endpoints, we observed that PS-NP (10 and 100 μg/L) enhanced toxicity in 50 mM glucose treated animals. In insulin signaling pathway, expressions of genes encoding insulin receptor (daf-2), kinases (age-1 and akt-1/2), and insulin peptides (ins-9, ins-6, and daf-28) were increased, and expressions of daf-16 and its target of sod-3 were decreased in high glucose treated nematodes followed by PS-NP exposure. Toxicity enhancement in high glucose treated nematodes by PS-NP exposure was inhibited by RNAi of daf-2, age-1, akt-2, akt-1, and 3 insulin peptides genes, but increased by RNAi of daf-16 and sod-3. The resistance of animals with RNAi of daf-2 to toxicity in high glucose treated nematodes followed by PS-NP exposure could be suppressed by RNAi of daf-16. Moreover, in high glucose treated animals followed by PS-NP exposure, daf-2 expression was inhibited by RNAi of ins-6, ins-9, and daf-28. Our data demonstrated the risk of PS-NP exposure in enhancing the high glucose toxicity. More importantly, alteration in expression of genes in insulin signaling pathway was associated with the toxicity enhancement in high glucose treated nematodes followed by PS-NP exposure.

Mechanistic Insights into Cellular and Molecular Basis of Protein-Nanoplastic Interactions

Plastic waste is ubiquitously present across the world, and its nano/sub-micron analogues (plastic nanoparticles, PNPs), raise severe environmental concerns affecting organisms' health. Considering the direct and indirect toxic implications of PNPs, their biological impacts are actively being studied; lately, with special emphasis on cellular and molecular mechanistic intricacies. Combinatorial OMICS studies identified proteins as major regulators of PNP mediated cellular toxicity via activation of oxidative enzymes and generation of ROS. Alteration of protein function by PNPs results in DNA damage, organellar dysfunction, and autophagy, thus resulting in inflammation/cell death. The molecular mechanistic basis of these cellular toxic endeavors is fine-tuned at the level of structural alterations in proteins of physiological relevance. Detailed biophysical studies on such protein-PNP interactions evidenced prominent modifications in their structural architecture and conformational energy landscape. Another essential aspect of the protein-PNP interactions includes bioenzymatic plastic degradation perspective, as the interactive units of plastics are essentially nano-sized. Combining all these attributes of protein-PNP interactions, the current review comprehensively documented the contemporary understanding of the concerned interactions in the light of cellular, molecular, kinetic/thermodynamic details. Additionally, the applicatory, economical facet of these interactions, PNP biogeochemical cycle and enzymatic advances pertaining to plastic degradation has also been discussed.

Insights into the Neuroprotective Potential of Epicatechin: Effects against Aβ-Induced Toxicity in Caenorhabditis elegans

Medical therapies to avoid the progression of Alzheimer's disease (AD) are limited to date. Certain diets have been associated with a lower incidence of neurodegenerative diseases. In particular, the regular intake of foods rich in polyphenols, such as epicatechin (EC), could help prevent or mitigate AD progression. This work aims to explore the neuroprotective effects of EC using different transgenic strains of Caenorhabditis elegans, which express human Aβ1-42 peptides and contribute to elucidating the mechanisms involved in the effects of EC in AD. The performed assays indicate that this flavan-3-ol was able to reduce the signs of β-amyloid accumulation in C. elegans, improving motility and chemotaxis and increasing survival in transgenic strain peptide producers compared to nematodes not treated with EC. The neuroprotective effects exhibited by EC in C. elegans could be explained by the modulation of inflammation and stress-associated genes, as well as autophagy, microgliosis, and heat shock signaling pathways, involving the regulation of cpr-5, epg-8, ced-7, ZC239.12, and hsp-16 genes. Overall, the results obtained in this study support the protective effects of epicatechin against Aβ-induced toxicity.

Change in energy-consuming strategy, nucleolar metabolism and physical defense in Macrobrachium rosenbergii after acute and chronic polystyrene nanoparticles exposure

The COVID-19 pandemic has further intensified plastic pollution due to the escalated use of single-use gloves and masks, consequently leading to the widespread presence of microplastics (MPs) and nanoplastics (NPs) in major rivers and lakes worldwide. Macrobrachium rosenbergii has become an important experimental subject due to its ecological role and environmental sensitivity. In this study, we sought to comprehend the ramifications of NPs on the widely-distributed freshwater prawn, M rosenbergii, by conducting a detailed analysis of its responses to NPs after both 96 h and 30 days of exposure. The transcriptome analysis revealed 918 differentially expressed unigenes (DEGs) after 30 days of NPs exposure (356 upregulated, 562 downregulated) and 2376 DEGs after 96 h of NPs exposure (1541 upregulated, 835 downregulated). The results of DEGs expression indicated that acute NPs exposure enhanced carbohydrate transport and metabolism, fostering chitin and extracellular matrix processes. In contrast, chronic NPs exposure induced nucleolar stress in M. rosenbergii, impeding ribosome development and mRNA maturation while showing no significant changes in glucose metabolism. Our findings underscore the M. rosenbergii distinct coping mechanisms during acute and chronic NPs exposure, elucidating its vital adaptive strategies. These results contribute to our understanding of the ecological implications of NPs pollution and its impact on aquatic animals.

Nanoplastics induces oxidative stress and triggers lysosome-associated immune-defensive cell death in the earthworm Eisenia fetida

Nanoplastics (NPs) are increasingly perceived as an emerging threat to terrestrial environments, but the adverse impacts of NPs on soil fauna and the mechanisms behind these negative outcomes remain elusive. Here, a risk assessment of NPs was conducted on model organism (earthworm) from tissue to cell. Using palladium-doped polystyrene NPs, we quantitatively measured nanoplastic accumulation in earthworm and investigated its toxic effects by combining physiological assessment with RNA-Seq transcriptomic analyses. After a 42-day exposure, earthworm accumulated up to 15.9 and 143.3 mg kg-1 of NPs for the low (0.3 mg kg-1) and high (3 mg kg-1) dose groups, respectively. NPs retention led to the decrease of antioxidant enzyme activity and the accumulation of reactive oxygen species (O2- and H2O2), which reduced growth rate by 21.3 %-50.8 % and caused pathological abnormalities. These adverse effects were enhanced by the positively charged NPs. Furthermore, we observed that irrespective of surface charge, after 2 h of exposure, NPs were gradually internalized by earthworm coelomocytes (∼0.12 μg per cell) and mainly amassed at lysosomes. Those agglomerations stimulated lysosomal membranes to lose stability and even rupture, resulting in impeded autophagy process and cellular clearance, and eventually coelomocyte death. In comparison with negatively charged nanoplastics, the positively charged NPs exerted 83 % higher cytotoxicity. Our findings provide a better understanding of how NPs posed harmful effects on soil fauna and have important implications for evaluating the ecological risk of NPs.

Caenorhabditis elegans as a Prediction Platform for Nanotechnology-Based Strategies: Insights on Analytical Challenges

Nanotechnology-based strategies have played a pivotal role in innovative products in different technological fields, including medicine, agriculture, and engineering. The redesign of the nanometric scale has improved drug targeting and delivery, diagnosis, water treatment, and analytical methods. Although efficiency brings benefits, toxicity in organisms and the environment is a concern, particularly in light of global climate change and plastic disposal in the environment. Therefore, to measure such effects, alternative models enable the assessment of impacts on both functional properties and toxicity. Caenorhabditis elegans is a nematode model that poses valuable advantages such as transparency, sensibility in responding to exogenous compounds, fast response to perturbations besides the possibility to replicate human disease through transgenics. Herein, we discuss the applications of C. elegans to nanomaterial safety and efficacy evaluations from one health perspective. We also highlight the directions for developing appropriate techniques to safely adopt magnetic and organic nanoparticles, and carbon nanosystems. A description was given of the specifics of targeting and treatment, especially for health purposes. Finally, we discuss C. elegans potential for studying the impacts caused by nanopesticides and nanoplastics as emerging contaminants, pointing out gaps in environmental studies related to toxicity, analytical methods, and future directions.