Nanoplastics induce molecular toxicity in earthworm: Integrated multi-omics, morphological, and intestinal microorganism analyses

Microplastic pollution inhibits the phagocytosis of E. coli by earthworm immune cells in soil

It has not been known how immune responses in soil invertebrates occur against microplastics (MPs). This study aims to investigate the effects of MPs on endocytosis, including phagocytosis and pinocytosis, of immune cells of soil invertebrates in the soil ecosystem in the process of bacterial infection. We employed polystyrene microplastics (∼ 1 μm PS MPs) to treat earthworm Eisenia andrei during the infection of Escherichia coli for in vitro (1, 5, 10, and 50 mg/L) and in vivo (1, 10, and 1000 mg/kg dry soil) assays. The results of in vitro migration assay revealed that MPs caused inhibitory effects on the phagocytosis, pinocytosis and oxidative stress in coelomocytes. Soil bioassay also confirmed that endocytosis of coelomocytes and mitochondrial damages in the intestinal epithelium were significantly altered in the polluted soil with MPs. Thus, MPs induced adverse effects to inhibit bacterial endocytosis, which may disturb the immune system of soil invertebrates. This study is the first report on the inhibition of phagocytosis in the soil invertebrates by MPs. These findings contribute to understanding the response of soil invertebrates, which play important roles in the soil food web with cellular level towards microplastic pollution in soil.

Impacts of microplastics on gut health: Current status and future directions

BACKGROUND AND OBJECTIVES

Microplastics are pervasive environmental pollutants, attracting significant concern due to their potential adverse effects on ecosystems and human health. This study hypothesizes that microplastics may significantly impact gastrointestinal (GI) health through various mechanisms. The objective of this systematic review is to explore the effects of microplastics on GI health, focusing on animal models such as mice, fish and earthworms.

METHODS

A systematic review approach was employed, analyzing studies that investigate the impact of microplastics on the gut microbiota, gut barrier integrity and GI inflammation. The review includes a synthesis of findings from multiple animal models.

RESULTS

The review reveals consistent evidence that microplastics can disrupt the gut microbiota, impair the gut barrier, and induce inflammatory responses in the GI tract. Statistical analysis shows a significant correlation between microplastic exposure and GI health deterioration across various animal models.

CONCLUSIONS

The findings underscore the harmful effects of microplastics on GI health, emphasizing the urgent need for policy interventions to reduce plastic pollution. Implementing measures to limit the production and usage of disposable plastics is crucial for mitigating the risks posed by microplastic contamination to promote environmental sustainability and safeguard human well-being.

6PPD-quinone exposure induces oxidative damage and physiological disruption in Eisenia fetida: An integrated analysis of phenotypes, multi-omics, and intestinal microbiota

The environmental prevalence of the tire wear-derived emerging pollutant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q) has increasingly raised public concern. However, knowledge of the adverse effects of 6PPD-Q on soil fauna is scarce. In this study, we elucidated its impact on soil fauna, specifically on the earthworm Eisenia fetida. Our investigation encompassed phenotypic, multi-omics, and microbiota analyses to assess earthworm responses to a gradient of 6PPD-Q contamination (10, 100, 1000, and 5000 μg/kg dw soil). Post-28-day exposure, 6PPD-Q was found to bioaccumulate in earthworms, triggering reactive oxygen species production and consequent oxidative damage to coelomic and intestinal tissues. Transcriptomic and metabolomic profiling revealed several physiological perturbations, including inflammation, immune dysfunction, metabolic imbalances, and genetic toxicity. Moreover, 6PPD-Q perturbed the intestinal microbiota, with high dosages significantly suppressing microbial functions linked to metabolism and information processing (P < 0.05). These alterations were accompanied by increased mortality and weight loss in the earthworms. Specifically, at an environmental concentration of 6PPD-Q (1000 μg/kg), we observed a substantial reduction in survival rate and physiological disruptions. This study provides important insights into the environmental hazards of 6PPD-Q to soil biota and reveals the underlying toxicological mechanisms, underscoring the need for further research to mitigate its ecological footprint.

Functional Modification of Ferroferric Oxide Nanoparticle Regulates the Uptake, Oxidative Stress, Tissue Damage, and Metabolic Profiles in Eisenia fetida

Ferroferric oxide nanoparticles (Fe3O4 NPs) are widely utilized as nanoenabled agrochemicals and soil remediation agents, with functional modification significantly enhancing their stability and biocompatibility. However, excessive use of Fe3O4 NPs may pose unassessed ecological risks in soils, particularly concerning the regulatory role of two most common surface modifiers as polyvinylpyrrolidone (PVP) and citric acid (CA) which influence the interactions of NPs with soil organisms and potential toxicity. This study evaluated the nanotoxic effects of bare Fe3O4 NPs (B-Fe3O4 NPs), CA-Fe3O4 NPs, and PVP-Fe3O4 NPs on Eisenia fetida in soil ecosystems. After 7 days of exposure, the B-, CA- and PVP-Fe3O4 NPs decreased the weight of the earthworms, caused oxidative stress and tissue damage. Functional Fe3O4 NPs showed increased accumulation in earthworms while alleviating oxidative stress and homeostatic imbalance by accelerating the activation of related enzymes. Moreover, hyperspectral and pathological observations indicated that CA and PVP modifications effectively alleviated tissue damage caused by Fe3O4 NPs via an improvement in NP biocompatibility, dispersion and stability evidenced by the levels of inositol metabolites, which has been upregulated more significantly by B-Fe3O4 NPs. Significant metabolic disturbances were observed, indicating that functional modifications forced earthworms to adjust amino acid metabolism and consume more energy to detoxify and repair damage. This work supplements the toxic assessment of Fe3O4 NPs and provides crucial insights for optimizing the safety of NPs through functionalization.

Long-term nanoplastics exposure contributes to impaired steroidogenesis by disrupting the hypothalamic-testis axis: Evidence from integrated transcriptome and metabolome analysis

Cumulative evidence suggested that nanoplastics (NPs) cause male toxicity, but the mechanisms of which are still misty. Steroidogenesis is a key biological event that responsible for maintaining reproductive health. However, whether dysregulated steroidogenesis is involved in NPs-induced impaired male reproductive function and the underlying mechanism remains unclear. In our study, Balb/c mice were continuously exposed to pristine-NPs or NH2-NPs for 12 weeks, spanning the puberty and adult stage. Upon the long-term NPs treatment, the hypothalamus and testis were subjected to transcriptome and metabolome analysis. And the results demonstrated that both primitive-NPs and NH2-NPs resulted in impaired spermatogenesis and steroidogenesis, as evidenced by a significant reduction in sperm quality, testosterone, FSH, and LH. The expression of genes involved in hypothalamic-pituitary-testis (HPT) axis, such as Kiss-1 and Cyp17a1 that encoded the key steroid hormone synthetase, was also diminished. Furthermore, the phosphatidylcholine and pantothenic acid that mainly enriched in glycerophospholipid metabolism were significantly reduced in the testis. Comprehensive analysis of the transcriptome and metabolome indicated that down-regulated Cyp17a1 was associated with decreased metabolites phosphatidylcholine and pantothenic acid. Overall, we speculate that the disturbed HPT axis induced by long-term NPs contributes to disordered glycerophospholipid metabolism and subsequently impaired steroidogenesis. Our findings deepen the understanding of the action of the mechanism responsible for NPs-induced male reproductive toxicology.

Polystyrene Nanoplastics Elicit Multiple Responses in Immune Cells of the Eisenia fetida (Savigny, 1826)

The improper disposal of plastic products/wastes can lead to the release of nanoplastics (NPs) into environmental media, especially soil. Nevertheless, their toxicity mechanisms in soil invertebrates remain unclear. This study investigated the impact of polystyrene NPs on Eisenia fetida (Savigny, 1826) immune cells, focusing on oxidative stress, immune responses, apoptosis, and necrosis. Results showed that 100 nm NPs were internalized into the cells, causing cytotoxicity. NPs were observed to inhibit cell viability by increasing reactive oxygen species, decreasing the levels of antioxidants (e.g., superoxide dismutase, catalase, and glutathione), and inducing lipid peroxidation and DNA oxidation. Additionally, assays on neutral red retention time, lysozyme activity, and Ca2⁺ levels demonstrated that NPs resulted in a loss of lysosomal membrane stability and a reduction in immune resistance. The depolarization of the mitochondrial membrane potential and the results of the apoptosis assays confirmed that the NPs induced the onset of early apoptosis. The difficulty of the NP in causing cell death by disrupting the plasma membrane was demonstrated by the results of the lactate dehydrogenase release assays in relation to cell necrosis. This research provides cellular-level insights into the ecological risks of NP exposure on soil fauna.

Negative effects of polyvinyl chloride microplastics and the plasticizer DnOP on earthworms: Co-exposure enhances oxidative stress and immune system damage in earthworms

Polyvinyl chloride microplastics (PVC-MPs) are the most used plastics in agriculture. Di-n-octyl phthalate (DnOP), a commonly used plasticizer in PVC-MPs, may be released from plastic and coexist with PVC-MPs. The effects of DnOP alone and coexisting with PVC-MPs are not known. We evaluated the effects of DnOP or/and PVC-MPs on earthworms, and used integrated biomarker response (IBR) to assess the combined toxicity. Molecular docking and transcriptomics were employed for further interpretation of possible toxicity mechanisms. The results showed that exposure to DnOP or/and PVC-MPs caused oxidative damage and interfered with reproduction, adversely affecting the growth and reproduction of earthworms. IBR results showed that toxicity of DnOP+PVC-MPs exposure was greater than that of DnOP and PVC-MPs exposure alone. DnOP has the ability to directly bind to proteins that are associated with antioxidant enzymes and alter their structure. The transcriptomics results indicated that DnOP and PVC-MPs exposure alone mainly affected growth and development-related pathways, while co-exposure affected apoptosis and immune system-related pathways more. To the best of our knowledge, this is the first comprehensive investigation of the combined toxicity of DnOP or/and PVC-MPs to earthworms from different perspectives, which gives scientifically sound evidence for the rational use of plasticizers DnOP and PVC-MPs.

Are Biobased Microfibers Less Harmful than Conventional Plastic Microfibers: Evidence from Earthworms

Biobased plastics are sometimes promoted as "environmentally friendly" compared to their conventional petrochemical-based counterparts, but their ecotoxicity is only partially understood. Biobased fibers are widely used in clothing and wet wipes and can accumulate in soils through the application of biosolid fertilizers. This study examined the lethal thresholds and sublethal toxicity of chemically characterized, additive-free, biobased (viscose and lyocell) compared to petrochemical-based (polyester) fibers on the key ecosystem engineer, Esenia fetida. Viscose and lyocell had LC20 values of 14.00 and 22.66 mg·L-1, respectively, and no observed effect concentrations (NOEC) of 0-2.8 mg·L-1 (72 h, OECD TG207 filter paper method), while for polyester these were LC20 15.6-31.3 mg·L-1 and NOEC 0-15.6 mg·L-1. Following 28 days of exposure to soils (OECD TG222) contaminated with environmentally relevant concentrations (100 mg kg-1), viscose significantly reduced the mass of progeny compared to polyester. Earthworms exposed to lyocell had a marginal growth reduction (-18%; compared to -11% to -13% in other treatments) linked to increased bioturbation activity. The biobased fibers examined here have greater acute toxicity at high concentrations and broadly similar sublethal effects on E. fetida compared to polyester. Our study highlights the importance of detailed testing before advocating specific materials as plastic alternatives/substitutes to conventional plastics.

Ecological risk assessment of castor oil based waterborne polyurethane: Mechanism of anionic/cationic state selective toxicity to Eisenia fetida

Cationic and anionic castor oil-based waterborne polyurethanes (C-WPU/A and C-WPU/C) have great potential for development in agriculture. However, it is still unclear whether these polyurethanes are harmful or toxic to soil fauna. Based on multilevel toxicity endpoints and transcriptomics, we investigated the effects of C-WPU/A and C-WPU/C on earthworms (Eisenia fetida). The acute toxicity results showed that C-WPU/A was highly toxic to the earthworms, whereas C-WPU/C was nearly nontoxic. C-WPU/A significantly affected the body weight, burrowing ability and cocoon production rate of earthworms compared to C-WPU/C. After exposure to C-WPU/A, the results showed accumulation of reactive oxygen species (ROS), abnormal peroxidase activity, and increased malondialdehyde levels. Additionally, more serious histopathological damage was observed in earthworms, such as epidermal damage, vacuolization, longitudinal muscle disorganization, and shedding of intestinal epidermal cells. At the cellular level, C-WPU/A induced more severe lysosomal damage, DNA damage and apoptosis than C-WPU/A. C-WPU/A made more differentially expressed genes and considerably more enriched pathways at the transcriptional level than C-WPU/C. These pathways are largely involved in cell membrane signaling, detoxification, and apoptosis. These results provide an important reference for elucidating the selective toxicity mechanisms of C-WPU/A and C-WPU/C in earthworms.

Plastic pollution in terrestrial ecosystems: Current knowledge on impacts of micro and nano fragments on invertebrates

The increasing accumulation of small plastic particles, in particular microplastics (>1 µm to 5 mm) and nanoplastics (< 1 µm), in the environment is a hot topic in our rapidly changing world. Recently, studies were initiated to better understand the behavior of micro- and nanoplastics (MNP) within complex matrices like soil, as well as their characterization, incorporation and potential toxicity to terrestrial biota. However, there remains significant knowledge gaps in our understanding of the wide-extent impacts of MNP on terrestrial invertebrates. We first summarized facts on global plastic pollution and the generation of MNP. Then, we focused on compiling the existing literature examining the consequences of MNP exposure in terrestrial invertebrates. The diversity of investigated biological endpoints (from molecular to individual levels) were compiled to get a better comprehension of the effects of MNP according to different factors such as the shape, the polymer type, the organism, the concentration and the exposure duration. The sublethal effects of MNP are acknowledged in the literature, yet no general conclusion was drawn as their impacts are highly dependent on their characteristic and experimental design. Finally, the synthesis highlighted some research gaps and remediation strategies, as well as a protocol to standardize ecotoxicological studies.

Polylactic acid micro/nanoplastic-induced hepatotoxicity: Investigating food and air sources via multi-omics

Micro/nanoplastics (MNPs) are detected in human liver, and pose significant risks to human health. Oral exposure to MNPs derived from non-biodegradable plastics can induce toxicity in mouse liver. Similarly, nasal exposure to non-biodegradable plastics can cause airway dysbiosis in mice. However, the hepatotoxicity induced by foodborne and airborne biodegradable MNPs remains poorly understood. Here we show the hepatotoxic effects of biodegradable polylactic acid (PLA) MNPs through multi-omics analysis of various biological samples from mice, including gut, fecal, nasal, lung, liver, and blood samples. Our results show that both foodborne and airborne PLA MNPs compromise liver function, disrupt serum antioxidant activity, and cause liver pathology. Specifically, foodborne MNPs lead to gut microbial dysbiosis, metabolic alterations in the gut and serum, and liver transcriptomic changes. Airborne MNPs affect nasal and lung microbiota, alter lung and serum metabolites, and disrupt liver transcriptomics. The gut Lachnospiraceae_NK4A136_group is a potential biomarker for foodborne PLA MNP exposure, while nasal unclassified_Muribaculaceae and lung Klebsiella are potential biomarkers for airborne PLA MNP exposure. The relevant results suggest that foodborne PLA MNPs could affect the "gut microbiota-gut-liver" axis and induce hepatoxicity, while airborne PLA MNPs could disrupt the "airway microbiota-lung-liver" axis and cause hepatoxicity. These findings have implications for diagnosing PLA MNPs-induced hepatotoxicity and managing biodegradable materials in the environment. Our current study could be a starting point for biodegradable MNPs-induced hepatotoxicity. More research is needed to verify and inhibit the pathways that are crucial to MNPs-induced hepatotoxicity.

Evaluating the toxicity effects of thiamethoxam and its main metabolite clothianidin to earthworms (Eisenia fetida) from the perspective of endogenous metabolites

The widespread application of neonicotinoid insecticides (NNIs) has attracted widespread attention to their potential ecotoxicological effects. In this study, we systematically evaluated the toxic effects of thiamethoxam (TMX) and its metabolite clothianidin (CLO) on earthworms (Eisenia fetida). Specifically, the antioxidant system responses and endogenous metabolite metabolism responses in earthworms were analyzed in the temporal dimension after 7, 14, 21 and 28 days of exposure to TMX and CLO. The results found that TMX and CLO could inhibit the growth phenotype of earthworms and cause significant changes in antioxidant system related indicators. More importantly, we found that TMX and CLO could cause significant changes in the metabolic profiles of earthworms through NMR-based metabolomics. From the changes in endogenous metabolites, the toxicity effects of TMX on earthworms gradually increases with prolonged exposure time. Differently, the toxicity effects of CLO on earthworms is significantly higher than that of TMX in the early stages of exposure. Meanwhile, these impacts will not weaken with prolonged exposure time. Furthermore, the results of KEGG enrichment pathway analysis indicated that TMX and CLO could significantly interfere with energy homeostasis, redox homeostasis, osmotic regulation, amino acid metabolism and protein synthesis in earthworms. These findings further deepen our understanding of the ecotoxicological effects of NNIs on soil organism.

Development of a Simple Cost Effective Oxygenation System for In Vivo Solution State NMR in 10 mm NMR Tubes

In vivo NMR is evolving into an important tool to understand biological processes and environmental responses. Current approaches use flow systems to sustain the organisms with oxygenated water and food (e.g., algae) inside the NMR. However, such systems have the potential to leak and clog (potentially damaging costly hardware), require large volumes of media, and multiple expensive HPLC pumps. The proposed "oxygenation system", uses a simple "double slit" adapter and a single air/oxygen flow line into the NMR. The design is especially suited to larger diameter probes given that standard flow systems would require higher flow rates thus amplifying the potential and impact of leaks/clogs. Traditionally, in vivo NMR of small organisms (e.g., Daphnia) have required 2D NMR in combination with 13C enrichment to overcome susceptibility distortions and provide information rich metabolic profiles. Here Daphnia magna, Eisenia fetida and Artemia franciscana are used to demonstrate the potential of the oxygenation system. Survivability tests and 1H time-resolved monitoring were first performed on D. magna, while E. fetida contained enough biomass to permit 1H-13C HSQC, 13C-1H HETCOR and 31P NMR without isotopic enrichment. Finally, STOCSY of 1D 13C NMR was used to follow the growth of A. franciscana (without 13C enrichment) for 48 h after birth, which helps visualize trends across a series of 1D in vivo data. In summary, application of the oxygenation system toward larger diameter probes allows the collection of NMR data without enrichment, offering a promising solution to better understand processes in vivo.

Co-exposure of decabromodiphenyl ethane and cadmium increases toxicity to earthworms: Enrichment, oxidative stress, damage and molecular binding mechanisms

The increase of electronic waste worldwide has resulted in the exacerbation of combined decabromodiphenyl ethane (DBDPE) and cadmium (Cd) pollution in soil, posing a serious threat to the safety of soil organisms. However, whether combined exposure increases toxicity remains unclear. Therefore, this study primarily investigated the toxic effects of DBDPE and Cd on earthworms at the individual, tissue, and cellular levels under single and combined exposure. The results showed that the combined exposure significantly increased the enrichment of Cd in earthworms by 50.32-90.42 %. The toxicity to earthworms increased with co-exposure, primarily resulting in enhanced oxidative stress, inhibition of growth and reproduction, intensified intestinal and epidermal damage, and amplified coelomocyte apoptosis. PLS-PM analysis revealed a significant and direct relationship between the accumulation of target pollutants in earthworms and oxidative stress, damage, as well as growth and reproduction of earthworms. Furthermore, IBR analysis indicated that SOD and POD were sensitive biomarkers in earthworms. Molecular docking elucidated that DBDPE and Cd induced oxidative stress responses in earthworms through the alteration of the conformation of the two enzymes. This study enhances understanding of the mechanisms behind the toxicity of combined pollution and provides important insights for assessing e-waste contaminated soils.

Multi-omics integration identifies ferroptosis involved in black phosphorus quantum dots-induced renal injury

Black phosphorus quantum dots (BPQDs) have recently emerged as a highly promising contender in biomedical applications ranging from drug delivery systems to cancer therapy modalities. Nevertheless, the potential toxicity and its effects on human health need to be thoroughly investigated. In this study, we utilized multi-omics integrated approaches to explore the complex mechanisms of BPQDs-induced kidney injury. First, histological examination showed severe kidney injury in male mice after subacute exposure to 1 mg/kg BPQDs for 28 days. Subsequently, transcriptomic and metabolomic analyses of kidney tissues exposed to BPQDs identified differentially expressed genes and metabolites associated with ferroptosis, an emerging facet of regulated cell death. Our findings highlight the utility of the multi-omics integrated approach in predicting and elucidating potential toxicological outcomes of nanomaterials. Furthermore, our study provides a comprehensive understanding of the mechanisms driving BPQDs-induced kidney injury, underscoring the importance of recognizing ferroptosis as a potential toxic mechanism associated with BPQDs.

A metabolomics perspective on the effect of environmental micro and nanoplastics on living organisms: A review

The increasing trend regarding the use of plastics has arisen an exponential concern on the fate of their derived products to the environment. Among these derivatives, microplastics and nanoplastics (MNPs) have been featured for their associated environmental impact due to their low molecular size and high surface area, which has prompted their ubiquitous transference among all environmental interfaces. Due to the heterogenous chemical composition of MNPs, the study of these particles has focused a high number of studies, as a result of the myriad of associated physicochemical properties that contribute to the co-transference of a wide range of contaminants, thus becoming a major challenge for the scientific community. In this sense, both primary and secondary MNPs are well-known to be adscribed to industrial and urbanized areas, from which they are massively released to the environment through a multiscale level, involving the atmosphere, hydrosphere, and lithosphere. Consequently, much research has been conducted on the understanding of the interconnection between those interfaces, that motivate the spread of these contaminants to biological systems, being mostly represented by the biosphere, especially phytosphere and, finally, the anthroposphere. These findings have highlighted the potential hazardous risk for human health through different mechanisms from the environment, requiring a much deeper approach to define the real risk of MNPs exposure. As a result, there is a gap of knowledge regarding the environmental impact of MNPs from a high-throughput perspective. In this review, a metabolomics-based overview on the impact of MNPs to all environmental interfaces was proposed, considering this technology a highly valuable tool to decipher the real impact of MNPs on biological systems, thus opening a novel perspective on the study of these contaminants.

Multilevel investigation of the ecotoxicological effects of sewage sludge biochar on the earthworm Eisenia fetida

The ecological risks of sewage sludge biochar (SSB) after land use is still not truly reflected. Herein, the ecological risks of SSB prepared at different temperature were investigated using the earthworm E. fetida as a model organism from the perspectives of organismal, tissue, cellular, and molecular level. The findings revealed that the ecological risk associated with low-temperature SSB (SSB300) was more pronounced compared to medium- and high-temperature SSB (SSB500 and SSB700), and the ecological risk intensified with increasing SSB addition rates, as revealed by an increase in the integrated biomarker response v2 (IBRv2) value by 2.59-25.41 compared to those of SSB500 and SSB700. Among them, 10% SSB300 application caused significant oxidative stress and neurotoxicity in earthworms compared to CK (p < 0.001). The weight growth rate and cocoon production rate of earthworms were observed to decrease by 25.06% and 69.29%, respectively, while the mortality rate exhibited a significant increase of 33.34% following a 10% SSB300 application, as compared to the CK. Moreover, 10% SSB300 application also resulted in extensive stratum corneum injury and significant longitudinal muscle damage in earthworms, while also inducing severe collapse of intestinal epithelial cells and disruption of intestinal integrity. In addition, 10% SSB300 caused abnormal expression of earthworm detoxification and cocoon production genes (p < 0.001). These results may improve our understanding of the ecotoxicity of biochar, especially in the long term application, and contribute to providing the guidelines for applying biochar as a soil amendment.

Ecotoxicological impact of naproxen on Eisenia fetida: Unraveling soil contamination risks and the modulating role of microplastics

Soils represent crucial sinks for pharmaceuticals and microplastics, making them hotspots for pharmaceuticals and plastic pollution. Despite extensive research on the toxicity of pharmaceuticals and microplastics individually, there is limited understanding of their combined effects on soil biota. This study focused on the earthworm Eisenia fetida as test organism to evaluate the biotoxicity and bioaccumulation of the typical pharmaceutical naproxen and microplastics in earthworms. Results demonstrated that high concentrations of naproxen (100 mg kg-1) significantly increased the malondialdehyde (MDA) content, inducing lipid peroxidation. Even though the low exposure of naproxen exhibits no significant influence to Eisenia fetida, the lipid peroxidation caused by higher concentration than environmental relevant concentrations necessitate attention due to temporal and spatial concentration variability found in the soil environment. Meanwhile, microplastics caused oxidative damage to antioxidant enzymes by reducing the superoxide dismutase (SOD) activity and MDA content in earthworms. Metabolome analysis revealed increased lipid metabolism in naproxen-treated group and reduced lipid metabolism in the microplastic-treated group. The co-exposure of naproxen and microplastics exhibited a similar changing trend to the microplastics-treated group, emphasizing the significant influence of microplastics. The detection of numerous including lipids like 17-Hydroxyandrostane-3-glucuronide, lubiprostone, morroniside, and phosphorylcholine, serves to identify potential biomarkers for naproxen and microplastics exposure. Additionally, microplastics increased the concentration of naproxen in earthworms at sub-organ and subcellular level. This study contributes valuable insights into the biotoxicity and distribution of naproxen and microplastics in earthworms, enhancing our understanding of their combined ecological risk to soil biota.

Chlorella alleviates the intestinal damage of tilapia caused by microplastics

Polyethylene microplastics (MPs) of the different sizes may result in different response in fish. Studies showed microorganisms adhered to the surface of MPs have toxicological effect. Juveniles tilapia (Oreochromis niloticus, n = 600, 26.5 ± 0.6 g) were dispersed into six groups: the control group (A), 75 nm MP exposed group (B), 7.5 μm group (C) and 750 (D) μm group, 75 nm + 7.5 μm+750 μm group (E) and 75 nm + Chlorella vulgaris group (F), and exposed for 10 and 14 days. The intestinal histopathological change, enzymic activities, and the integrated "omics" workflows containing transcriptomics, proteomics, microbiota and metabolomes, have been performed in tilapia. Results showed that MPs were distributed on the surface of goblet cells, Chlorella group had severe villi fusion without something like intestinal damage, as in other MPs groups. The intestinal Total Cholesterol (TC, together with group E) and Tumor Necrosis Factor α (TNFα, except for group B) contents in group F were significantly increased, cytochrome p450 1a1 (EROD, group B and E) significantly increased, adenosine triphosphate (ATP), lipoprotein lipase (LPL) and caspase 3 (except group B) also significantly increased at 14 d. At 14 days, group E saw considerably higher regulation of the actin cytoskeleton, focal adhesion, insulin signaling pathway, and AGE-RAGE signaling pathway in diabetes complications. Whereas, chlorella enhanced the focal adhesion, cytokine-cytokine receptor interaction, and MAPK signaling pathways. PPAR signaling pathway has been extremely significantly enriched via the proteomics method. Candidatus latescibacteria, C. uhrbacteria, C. abyssubacteria, C. cryosericota significantly decreased caused by MPs of different particle sizes. Carboxylic acids and derivatives, indoles and derivatives, organooxygen compounds, fatty acyls and organooxygen compounds significantly increased with long-term duration, especially PPAR signaling pathway. MPs had a size-dependent long-term effect on histopathological change, gene and protein expression, and gut microbial metabolites, while chlorella alleviates the intestinal histopathological damage via the integrated "omics" workflows.

Expanding the insight of ecological risk on the novel chiral pesticide mefentrifluconazole: Mechanism of enantioselective toxicity to earthworms (Eisenia fetida)

Continued application of new chiral fungicide mefentrifluconazole (MFZ) increases its risk to soil ecosystem. However, the toxicity of MFZ enantiomers to soil fauna and whether stereoselectivity exists remains poorly elucidated. Based on multilevel toxicity endpoints and transcriptomics, we investigated the negative effects of racemic, R-(-)-, and S-(+)-MFZ on Eisenia fetida. After exposure to S-(+) configuration at 4 mg/kg for 28 day, its reactive oxygen species levels were elevated by 15.4% compared to R-(-) configuration, inducing enantiospecific oxidative stress and transcriptional aberrations. The S-(+) isomer induced more severe cell membrane damage and apoptosis than the R-(-) isomer, and notably, the selectivity of apoptosis is probably dominated by the mitochondrial pathway. Mechanistically, differential mitochondrial stress lies in: S-(+) isomer specifically up-regulated mitochondrial cellular component compared to R-(-) isomer and identified more serious mitochondrial fission. Furthermore, S-(+) conformation down-regulated biological processes associated with ATP synthesis and metabolism, with specific inhibition of mitochondrial respiratory electron transport chain complex I and IV activity resulting in more severe electron flow disturbances. These ultimately mediated enantioselective ontogenetic process disorders, which were supported at phenotypic (weight loss), genetic, and protein (reverse modulate TCTP and Sox2 expression) levels. Our findings offer an important reference for elucidating the enantioselective toxicological mechanism of MFZ in soil fauna.

Photoaged Tire Wear Particles Leading to the Oxidative Damage on Earthworms (Eisenia fetida) by Disrupting the Antioxidant Defense System: The Definitive Role of Environmental Free Radicals

Tire wear particles (TWPs) have caused increasing concerns due to their detrimental effects on the soil ecosystem. However, the role of weathering in altering the toxicity of TWP to soil organisms is poorly understood. In this study, the toxicity of original and photoaged TWP was compared using earthworms (Eisenia fetida) as soil model organisms. The obtained results indicated that photoaging of TWP resulted in an increase of environmentally persistent free radicals (EPFRs) from 3.69 × 1017 to 5.20 × 1017 spin/g. Meanwhile, photoaged TWP induced the changes of toxic endpoint in E. fetide, i.e., the increase of the weight loss and death ratio from 0.0425 to 0.0756 g/worm and 23.3 to 50% compared to original TWP under a 10% concentration, respectively. Analyses of transcriptomics, antioxidant enzyme activity, and histopathology demonstrated that the enhanced toxicity was mainly due to oxidative damage, which was induced by disruption in the antioxidant defense system. Free-radical quenching and correlation analysis further suggested that the excessive production of ex vivo reactive oxygen species, induced by EPFRs, led to the exhaustion of the antioxidant defense system. Overall, this work provides new insights into the potential hazard of the weathered TWP in a soil environment and has significant implications for the recycling and proper disposal of spent tire particles.

Molecular mechanisms of nano-sized polystyrene plastics induced cytotoxicity and immunotoxicity in Eisenia fetida

Nanoplastics (NPs) are currently everywhere and environmental pollution by NPs is a pressing global problem. Nevertheless, until now, few studies have concentrated on the mechanisms and pathways of cytotoxic effects and immune dysfunction of NPs on soil organisms employing a multidimensional strategy. Hence, earthworm immune cells and immunity protein lysozyme (LZM) were selected as specific receptors to uncover the underlying mechanisms of cytotoxicity, genotoxicity, and immunotoxicity resulting from exposure to polystyrene nanoplastics (PS-NPs), and the binding mechanisms of PS-NPs-LZM interaction. Results on cells indicated that when earthworm immune cells were exposed to high-dose PS-NPs, it caused a notable rise in the release of reactive oxygen species (ROS), resulting in oxidative stress. PS-NPs exposure significantly decreased the cell viability of earthworm immune cells, inducing cytotoxicity through ROS-mediated oxidative stress pathway, and oxidative injury effects, including reduced antioxidant defenses, lipid peroxidation, DNA damage, and protein oxidation. Moreover, PS-NPs stress inhibited the intracellular LZM activity in immune cells, resulting in impaired immune function and immunotoxicity by activating the oxidative stress pathway mediated by ROS. The results from molecular studies revealed that PS-NPs binding destroyed the LZM structure and conformation, including secondary structure changes, protein skeleton unfolding/loosening, fluorescence sensitization, microenvironment changes, and particle size changes. Molecular docking suggested that PS-NPs combined with active center of LZM easier and inhibited the protein function more, and formed a hydrophobic interaction with TRP 62, a crucial amino acid residue closely associated with the function and conformation of LZM. This is also responsible for LZM conformational changes and functional inhibition /inactivation. These results of this research offer a fresh outlook on evaluating the detriment of NPs to the immune function of soil organisms using cellular and molecular strategies.

Co-exposure of butyl benzyl phthalate and TiO2 nanomaterials (anatase) in Metaphire guillelmi: Gut health implications by transcriptomics

During the COVID-19 pandemic, an abundance of plastic face masks has been consumed and disposed of in the environment. In addition, substantial amounts of plastic mulch film have been used in intensive agriculture with low recovery. Butyl benzyl phthalate (BBP) and TiO2 nanomaterials (nTiO2) are widely applied in plastic products, leading to the inevitable release of BBP and nTiO2 into the soil system. However, the impact of co-exposure of BBP and nTiO2 at low concentrations on earthworms remains understudied. In the present study, transcriptomics was applied to reveal the effects of individual BBP and nTiO2 exposures at a concentration of 1 mg kg-1, along with the combined exposure of BBP and nTiO2 (1 mg kg-1 BBP + 1 mg kg-1 nTiO2 (anatase)) on Metaphire guillelmi. The result showed that BBP and nTiO2 exposures have the potential to induce neurodegeneration through glutamate accumulation, tau protein, and oxidative stress in the endoplasmic reticulum and mitochondria, as well as metabolism dysfunction. The present study contributes to our understanding of the toxic mechanisms of emerging contaminants at environmentally relevant levels and prompts consideration of the management of BBP and nTiO2 within the soil ecosystems.

Microplastics in soils: Production, behavior process, impact on soil organisms, and related toxicity mechanisms

In recent years, microplastics (MPs) pollution has become a hot ecological issue of global concern and MP pollution in soil is becoming increasingly serious. Studies have shown that MPs have adverse effects on soil biology and ecological functions. Although MPs are evident in soils, identifying their source, abundance, and types is difficult because of the complexity and variability of soil components. In addition, the effects of MPs on soil physicochemical properties (PCP), including direct effects such as direct interaction with soil particles and indirect effects such as the impact on soil organisms, have not been reported in a differentiated manner. Furthermore, at present, the soil ecological effects of MPs are mostly based on biological toxicity reports of their exudate or size effects, whereas the impact of their surface-specific properties (such as environmentally persistent free radicals, surface functional groups, charge, and curvature) on soil ecological functions is not fully understood. Considering this, this paper reviews the latest research findings on the production and behavioral processes of MPs in soil, the effects on soil PCP, the impacts on different soil organisms, and the related toxic mechanisms. The above discussion will enhance further understanding of the behavioral characteristics and risks of MPs in soil ecosystems and provide some theoretical basis for further clarification of the molecular mechanisms of the effects of MPs on soil organisms.

A review on the fate of micro and nano plastics (MNPs) and their implication in regulating nutrient cycling in constructed wetland systems

This review discusses the micro-nano plastics (MNPs) and their interaction with physical, chemical and biological processes in a constructed wetland (CW) system that is typically used as a nature-based tertiary wastewater treatment for municipal as well as industrial applications. Individual components of the CW system such as substrate, microorganisms and plants were considered to assess how MNPs influence the CW processes. One of the main functions of a CW system is removal of nutrients like nitrogen (N) and phosphorus (P) and here we highlight the pathways through which the MNPs influence CW's efficacy of nutrient removal. The presence of morphologically (size and shape) and chemically different MNPs influence the growth rate of microorganisms important in N and P cycling, invertebrates, decomposers, and the plants which affect the overall efficiency of a CW treatment system. Certain plant species take up the MNPs, and some toxicity has been observed. This review focuses on two significant aspects: (1) the presence of MNPs in a significant concentration affects the efficiency of N and P removal, and (2) the removal of MNPs. Because MNPs reduce the enzyme activities in abundance and overproduction of ROS oxidizes the enzyme active sites, resulting in the depletion of proteins, ultimately inhibiting nitrogen and phosphorus removal within the substrate layer. The review found that the majority of the studies used sand-activated carbon (SAC), granular-activated carbon (GAC), rice straw, granular limestone, and calcium carbonate, as a substrate for CW treatment systems. Common plant species used in the CW include Phragmites, Arabidopsis thaliana, Lepidium sativum, Thalia dealbata, and Canna indica, which were also found to be dominant in the uptake of the MNPs in the CWs. The MNPs were found to affect earthworms such as Eisenia fetida, Caenorhabditis elegans, and, Enchytraeus crypticus, whereas Metaphire vulgaris were found unaffected. Though various mechanisms take place during the removal process, adsorption and uptake mechanism effectively emphasize the removal of MNPs and nitrogen and phosphorus in CW. The MNPs characteristics (type, size, and concentration) play a crucial role in the removal efficiency of nano-plastics (NPs) and micro-plastics (MPs). The enhanced removal efficiency of NPs compared to MPs can be attributed to their smaller size, resulting in a faster reaction rate. However, NPs dose variation showed fluctuating removal efficiency, whereas MPs dose increment reduces removal efficiency. MP and NPs dose variation also affected toxicity to plants and earthworms as observed from data. Understanding the fate and removal of microplastics in wetland systems will help determine the reuse potential of wastewater and restrict the release of microplastics. This study provides information on various aspects and highlights future gaps and needs for MNP fate study in CW systems.

Co-exposure to UV-aged microplastics and cadmium induces intestinal toxicity and metabolic responses in earthworms

Aged microplastics (MPs) alter the interaction with heavy metals due to changes in surface properties. However, the combined toxicological effects of aged MPs on heavy metals in soil remain poorly understood. In this study, earthworms were employed as model animals to investigate the effects of aged MPs on the biotoxicity of cadmium (Cd) by simulating the exposure patterns of original and UV-aged MPs (polylactic acid (PLA) and polyethylene (PE)) with Cd. The results showed that UV-aging decreased the zeta potential and increased the specific surface area of the MPs, which enhanced the bioaccumulation of Cd and caused more severe oxidative stress to earthworms. Meanwhile, the earthworm intestines exhibited increased tissue damage, including chloragogenous tissue congestion lesions, and typhlosole damage. Furthermore, the combined exposure to UV-aged MPs and Cd enhanced the complexity of the microbial network in the earthworm gut and interfered with endocrine disruption, membrane structure, and energy metabolic pathways in earthworms. The results emphasized the need to consider the degradation of MPs in the environment. Hence, we recommend that future toxicological studies use aged MPs that are more representative of the actual environmental conditions, with the results being important for the risk assessment and management of MPs.

Foodborne and airborne polyethersulfone nanoplastics respectively induce liver and lung injury in mice: Comparison with microplastics

Micro/nanoplastics (MNP) are ubiquitous in the environment and multiple living organisms. The toxicity of some common types of MNP, e.g., polyethersulfone (PES) MNP, remains poorly understood. Multi-omics approaches were used in this study to determine the effects of foodborne and airborne PES MNP on liver and lung, respectively. Foodborne MNP were capable of inducing gut microbial dysbiosis, gut and serum metabolic disruption, and liver transcriptomic dysregulation, and affecting serum antioxidant activity and liver function, resulting in liver injury. As for the airborne MNP, they were found to induce nasal and lung microbial dysbiosis, serum and lung metabolic disruption, and liver transcriptome disturbance, and cause disrupted serum antioxidant activity and lung injury. Foodborne and airborne PES NP were found to respectively induce greater liver and lung toxicity than MP, which could be associated with the differences between NP and MP exposures. The relevant results suggest that foodborne PES MNP could disrupt the "gut microbiota-gut-liver" axis and induce hepatic injury, while airborne PES MNP could affect the "airborne microbiota-lung" axis and cause lung injury. The findings could benefit the diagnoses of liver and lung injury respectively induced by foodborne and airborne PES MNP, as well as the proper use of PES in human living environment.

Exposure to polystyrene nanoplastics reduces bacterial and fungal biomass in microfabricated soil models

Nanoplastics have been proven to induce toxicity in diverse organisms, yet their effect on soil microbes like bacteria and fungi remains largely unexplored. In this paper, we used micro-engineered soil models to investigate the effect of polystyrene (PS) nanospheres on Pseudomonas putida and Coprinopsis cinerea. Specifically, we explored the effects of increasing concentrations of 60 nm carboxylated bovine serum albumin (BSA) coated nanospheres (0, 0.5, 2, and 10 mg/L) on these bacterial and fungal model organisms respectively, over time. We found that both microorganisms could disperse through the PS solution, but long-distance dispersal was reduced by high concentrations. Microbial biomass decreased in all treatments, in which bacteria showed a linear dose response with the strongest effect at 10 mg/L concentration, and fungi showed a non-linear response with the strongest effect at 2 mg/L concentration. At the highest nanoplastics concentration, the first colonizing fungal hyphae adsorbed most of the PS nanospheres present in their vicinity, in a process that we termed the 'vacuum cleaner effect'. As a result, the toxicity effect of the original treatment on subsequently growing fungal hyphae was reduced to a growth level indistinguishable from the control. We did not find evidence that nanoplastics are able to penetrate bacterial nor fungal cell walls. Overall, our findings provide evidence that nanoplastics can cause a direct negative effect on soil microbes and highlight the need for further studies that can explain how the microbial stress response might affect soil functions.

Micro- and nanoplastics in soil: Linking sources to damage on soil ecosystem services in life cycle assessment

Soil ecosystems are crucial for providing vital ecosystem services (ES), and are increasingly pressured by the intensification and expansion of human activities, leading to potentially harmful consequences for their related ES provision. Micro- and nanoplastics (MNPs), associated with releases from various human activities, have become prevalent in various soil ecosystems and pose a global threat. Life Cycle Assessment (LCA), a tool for evaluating environmental performance of product and technology life cycles, has yet to adequately include MNPs-related damage to soil ES, owing to factors like uncertainties in MNPs environmental fate and ecotoxicological effects, and characterizing related damage on soil species loss, functional diversity, and ES. This study aims to address this gap by providing as a first step an overview of the current understanding of MNPs in soil ecosystems and proposing a conceptual approach to link MNPs impacts to soil ES damage. We find that MNPs pervade soil ecosystems worldwide, introduced through various pathways, including wastewater discharge, urban runoff, atmospheric deposition, and degradation of larger plastic debris. MNPs can inflict a range of ecotoxicity effects on soil species, including physical harm, chemical toxicity, and pollutants bioaccumulation. Methods to translate these impacts into damage on ES are under development and typically focus on discrete, yet not fully integrated aspects along the impact-to-damage pathway. We propose a conceptual framework for linking different MNPs effects on soil organisms to damage on soil species loss, functional diversity loss and loss of ES, and elaborate on each link. Proposed underlying approaches include the Threshold Indicator Taxa Analysis (TITAN) for translating ecotoxicological effects associated with MNPs into quantitative measures of soil species diversity damage; trait-based approaches for linking soil species loss to functional diversity loss; and ecological networks and Bayesian Belief Networks for linking functional diversity loss to soil ES damage. With the proposed conceptual framework, our study constitutes a starting point for including the characterization of MNPs-related damage on soil ES in LCA.

Tissue-specific accumulation of DEHP and involvement of endogenous arachidonic acid in DEHP-induced spleen information and injury

The plasticizer Diethylhexyl phthalate (DEHP), one of the most common contaminants, is widely detected in environmental and biological samples. However, the accumulation of DEHP in tissue and the molecular mechanisms underlying its physiological damage in the spleen of aquatic organisms have not yet been reported. In this study, gas chromatography-mass spectrometry (GC-MS), histology and multi-omics analysis were used to investigate DEHP exposure-induced alterations in transcriptomic profiles and metabolic network of zebrafish model. After exposure to DEHP, higher concentrations of DEHP were found in the intestine, liver and spleen. Anatomical and histological analyses showed that the zebrafish spleen index was significantly increased and inflammatory damage was observed. Increased splenic neutrophil counts indicate inflammation and tissue damage. Transcriptomic filtering showed that 3579 genes were significantly altered. Metabolomic analysis detected 543 differential metabolites. Multi-omics annotation results indicated that arachidonic acid and 12-Hydroperoxyicosatetraenoic acid (HPETE) are involved in the key inflammatory pathway "Inflammatory mediator regulation of TRP channels". This study demonstrated the accumulation characteristics of DEHP in aquatic zebrafish and the mechanisms of inflammation and tissue damage in the spleen which involve endogenous arachidonic acid. This will provide theoretical basis and data support for health risk assessments and tissue damage of DEHP.

Toxicity of leachate from smoked cigarette butts to terrestrial animals: A case study on the earthworm Eisenia fetida

Cigarette butts, as easily overlooked littered wastes, have been evaluated for toxicity in various researches. In this study, we investigated the toxic effects of smoked cigarette butt leachate (SCBL) on the earthworm Eisenia fetida. The results showed the following: 1) E. fetida avoided SCBL in artificial soil, and the avoidance rate was positively correlated with the concentration of SCBL but negatively correlated with the exposure time; 2) the LD50 of SCBL on earthworms at 36 and 48 h of exposure were 3.71 × 10-4 and 2.67 × 10-4 butts/cm2, respectively. Moreover, both the body surface and intestinal tissues of E. fetida were damaged after exposure to SCBL; 3) the survival rates of E. fetida exposed to artificial soil with an SCBL of 3.6 butts/kg for 7 and 14 days were 80.00 ± 7.07 % and 68.00 ± 4.47 %, respectively; and 4) the mean biomass of the surviving E. fetida in all treated groups decreased with increasing SCBL concentration and exposure time. We concluded that SCBL exerted significant negative effects on soil animals, and suggested that SCBs should be collected, detoxified, and reused before entering the natural environment.

Systematic assessment of the ecotoxicological effects and mechanisms of biochar-derived dissolved organic matter (DOM) on the earthworm Eisenia fetida

Biochar-derived dissolved organic matter (DOM) contains toxic substances that are first released into the soil after biochar application. However, the ecological risks of biochar-derived DOM on soil invertebrate earthworms are unclear. Therefore, this study investigated the ecological risks and toxic mechanisms of sewage sludge biochar (SSB)-derived DOM on the earthworm Eisenia fetida (E. fetida) via microcosm experiments. DOM exposure induced earthworm death, growth inhibition, and cocoon decline. Moreover, DOM, especially the 10% DOM300 (derived from SSB prepared at 300 °C) treatments, disrupted the antioxidant defense response and lysosomal stability in earthworms. Integrated biomarker response v2 (IBRv2) analysis was performed to assess the comprehensive toxicity of DOM in E. fetida, and the results revealed that DOM300 might exert more hazardous effects on earthworms than DOM500 (prepared at 500 °C) and DOM700 (prepared at 700 °C), as revealed by increases in the IBRv2 value of 3.48-18.21. Transcriptome analysis revealed that 10% DOM300 exposure significantly disrupted carbohydrate and protein digestion and absorption and induced endocrine disorder. Interestingly, 10% DOM300 exposure also significantly downregulated the expression of genes involved in signaling pathways, e.g., the P13K-AKT, cGMP-PKG, and ErbB signaling pathways, which are related to cell growth, survival, and metabolism, suggesting that DOM300 might induce neurotoxicity in E. fetida. Altogether, these results may contribute to a better understanding of the toxicity and defense mechanisms of biochar-derived DOM on earthworms, especially during long-term applications, and thus provide guidelines for using biochar as a soil amendment.

Genetic evidence behind the Cd resistance of wild Metaphire californica: The global RNA regulation rather than specific mutation of well-known gene

Heavy metal contamination presents a profound threat to terrestrial biodiversity, yet the genetic adaptation and evolution of field organisms under persistent stress are poorly understood. In this study, the Cd-resistant earthworms Metaphire californica collected from the control (Meihua, MHC) and elevated-pollution (Lupu, LPC) pairwise sites were used to elucidate the underlying genetic mechanism. A 48-h acute test showed that LPC worms exhibited 2.34 times higher LC50 (50% lethal concentration values) compared to MHC ones. The Cd bioaccumulation, metallothionein (MT) protein contents, and MT gene expression of LPC M.californica were all significantly higher than those of MHC worms. The well-known MT gene of M.californica was successfully cloned and identified, however, the encoding nucleotide and amino acids displayed non-observable mutations and the phylogenetic tree also revealed that different populations clustered together. Additionally, the results of transcriptomics sequencing demonstrated 173 differentially expressed genes between LPC and MHC worms, primarily involved in stress-response and detoxification pathways, including signal transduction, material metabolism, and protein exports. The above results confirmed that the crucial MT gene did not undergo genetic mutations but rather exhibited global mRNA regulation responsible for the Cd resistance of M.californica. The current study partially disclosed the stress adaptation and evolution of organisms under long-term in situ contamination, which provides insights into maintaining biodiversity under adverse environment.

Adaptive response of triploid Fujian oyster (Crassostrea angulata) to nanoplastic stress: Insights from physiological, metabolomic, and microbial community analyses

Triploid Fujian oyster (Crassostrea angulata) is crucial to aquaculture and coastal ecosystems because of its accelerated growth and heightened resilience against environmental stressors. In light of the increasing prevalence of nanoplastic pollution in the ocean, understanding its potential impact on this organism, particularly its adaptive responses, is of paramount importance. Despite this, the effects of nanoplastic pollution on the physiology of C. angulata remain largely unexplored. In this study, we explored the responses of triploid Fujian oysters to nanoplastic stress during a 14-day exposure period, employing an integrative methodology that included physiological, metabolomic, and 16S rRNA sequencing analyses. Our results demonstrate that the oysters exhibit a strong adaptive response to nanoplastic exposure, characterized by alterations in enzyme activity, metabolic pathways, and microbial community composition, indicative of an adaptive recovery state as opposed to a disordered state. Oysters subjected to elevated nanoplastic levels exhibited adaptive responses primarily by boosting the activity of the antioxidant enzyme catalase and elevating the levels of antioxidants such as adenosine, 3-(4-hydroxyphenyl)pyruvate, D-sorbitol, d-mannose, and unsaturated fatty acids, as well as the functional amino acids l-proline and l-lysine. Nanoplastic treatment also resulted in increased activity of succinate dehydrogenase, a key component of energy metabolism, and increased contents of intermediate metabolites or products of energy metabolism, such as adenosine monophosphate, adenosine, guanosine, creatine, and thiamine. Nanoplastic treatment led to an increase in the abundance of certain advantageous genera of gut bacteria, specifically Phaeobacter and Nautella. The observed adaptive response of triploid Fujian oysters to nanoplastic stress provides valuable insights into the mechanisms underpinning resilience in marine bivalves.

Integrated microbiome and multi-omics analysis reveal the molecular mechanisms of Eisenia fetida in response to biochar-derived dissolved and particulate matters

At present, most ecotoxicological studies are still confined to focusing on the harmful effects of biochar itself on soil fauna. However, the potential ecotoxicity of different components separated from biochar to terrestrial invertebrates remains poorly understood. In this study, the dissolved matter (DM) and particulate matter (PM) were separated from biochar (BC) and then introduced into the soil-earthworm system to investigate the response mechanism of earthworms at the molecular level. The results showed that BC and DM exposure caused an increase in the abundance of Proteobacteria in the cast bacterial community, suggesting the dysbiosis of intestinal microbiota. It was also observed that the cast bacterial communities were more sensitive to DM exposure than PM exposure. Transcriptomic analysis showed that BC and DM exposure induced significant enrichment of functional pathways related to infectious and neuropathic diseases. Metabolomic profiling manifested that DM exposure caused metabolic dysfunction, antioxidant and detoxification abilities recession. Furthermore, significant differences in the responses of earthworms at transcriptomic and metabolic levels confirmed that DM exhibited greater ecotoxicity than PM. This study highlighted the significant contributions of dissolved matter to the ecotoxicity of biochar from the perspective of transcriptomic and metabolomic profiles.

Transcriptomic analysis of oxidative stress mechanisms induced by acute nanoplastic exposure in Sepia esculenta larvae

Nanoplastics (NPs), as a new type of pollutant with a size small than 1 μm, are ubiquitous and harmful to organisms. There has been an increasing amount of research concerning the effects of NPs on organisms over recent years, especially on aquatic animals. However, there is a limited study on the impact of NPs on mollusk cephalopods. In this research, Sepia esculenta, belonging to Cephalopoda, Coleoidea, Sepioidea, was selected to explore the effects caused by NPs exposure. The S. esculenta larvae were exposed to polystyrene NPs (PS-NPs) with diameter 50 nm (100 mg/L) for 4 h. The detection of oxidative stress biomarkers displayed an obvious increase in SOD (superoxide dismutase) activity and MDA (malondialdehyde) level. Then, RNA-Seq was performed to explore the oxidative stress response at mRNA level. The transcriptome analysis demonstrated that the expression of 2,570 genes was affected by PS-NPs. Besides, the signaling pathways of ribosome, ribosome biogenesis in eukaryotes, proteasome, and MAPK were enriched. This study not only provides novel references for understanding the mechanisms of oxidative stress response induced by NPs, but also reminds us to follow with interest the influence of acute exposure to NPs.

Emerging Frontiers in Nanotechnology for Precision Agriculture: Advancements, Hurdles and Prospects

This review article provides an extensive overview of the emerging frontiers of nanotechnology in precision agriculture, highlighting recent advancements, hurdles, and prospects. The benefits of nanotechnology in this field include the development of advanced nanomaterials for enhanced seed germination and micronutrient supply, along with the alleviation of biotic and abiotic stress. Further, nanotechnology-based fertilizers and pesticides can be delivered in lower dosages, which reduces environmental impacts and human health hazards. Another significant advantage lies in introducing cutting-edge nanodiagnostic systems and nanobiosensors that monitor soil quality parameters, plant diseases, and stress, all of which are critical for precision agriculture. Additionally, this technology has demonstrated potential in reducing agro-waste, synthesizing high-value products, and using methods and devices for tagging, monitoring, and tracking agroproducts. Alongside these developments, cloud computing and smartphone-based biosensors have emerged as crucial data collection and analysis tools. Finally, this review delves into the economic, legal, social, and risk implications of nanotechnology in agriculture, which must be thoroughly examined for the technology’s widespread adoption.

Transcriptomics reveals key regulatory pathways and genes associated with skin diseases induced by face paint usage

The use of face paint cosmetics can cause skin diseases in opera performers due to the presence of heavy metals and other toxic ingredients in the cosmetics. However, the underlying molecular mechanism for these diseases remains unknown. Here we examined the transcriptome gene profile of human skin keratinocytes exposed to artificial sweat extracts of face paints, and identified the key regulatory pathways and genes, using RNA sequencing technique. Bioinformatics analyses suggested that the face paint exposure induced the differentially expression of 1531 genes and enriched inflammation-relevant TNF and IL-17 signaling pathways after just 4 h of exposure. Inflammation-relevant genes CREB3L3, FOS, FOSB, JUN, TNF, and NFKBIA were identified as the potential regulatory genes, and SOCS3 capable to prevent inflammation-induced carcinogenesis as the hub-bottleneck gene. Long-term exposure (24 h) could exacerbate inflammation, accompanied by interference in cellular metabolism pathways, and the potential regulatory genes (ATP1A1, ATP1B1, ATP1B2, FXYD2, IL6, and TNF) and hub-bottleneck genes (JUNB and TNFAIP3) were all related to inflammation induction and other adverse responses. We proposed that the exposure to face paint might cause the inflammatory factors TNF and IL-17, which are encoded by the genes TNF and IL17, to bind to receptors and activate TNF and IL-17 signaling pathways, leading to the expression of cell proliferation factors (CREB and AP-1) and proinflammatory mediators including transcription factors (FOS, JUN, and JUNB), inflammatory factors (TNF-α and IL6), and intracellular signaling factors (TNFAIP3). This finally resulted in cell inflammation, apoptosis, and other skin diseases. TNF was identified as the key regulator and connector in all the enriched signaling pathways. Our study provides the first insights into the cytotoxicity mechanism of face paints to skin cells and highlights the need for stricter regulations in face paint safety.

Acute effects of polystyrene nanoplastics on the immune response in Sepia esculenta larvae

With extensive use of plastic products, microplastics (MPs, < 5 mm) and nanoplastics (NPs, < 1 μm) have become major pollutants in ecosystem, especially in marine environment. In recent years, researches on the impact of NPs on organisms have gradually increased. However, studies on the influence of NPs on cephalopods are still limited. Golden cuttlefish (Sepia esculenta), an important economic cephalopod, is a shallow marine benthic organism. In this study, the effect of acute exposure (4 h) to 50-nm polystyrene nanoplastics (PS-NPs, 100 μg/L) on the immune response of S. esculenta larvae was analyzed via transcriptome data. A total of 1260 DEGs were obtained in the gene expression analysis. The analyses of GO, KEGG signaling pathway enrichment, and protein-protein interaction (PPI) network were then performed to explore the potential molecular mechanisms of the immune response. Finally, 16 key immune-related DEGs were obtained according to the number of KEGG signaling pathways involved and the PPI number. This study not only confirmed that NPs had an impact on cephalopod immune response, but also provided novel insights for further unmasking the toxicological mechanisms of NPs.

Understanding the aggregation, consumption, distribution and accumulation of nanoparticles of polyvinyl chloride and polymethyl methacrylate in Ruditapes philippinarum

Plastic products have become an integral part of our life. A widespread usage, high stability, uncontrolled disposal and slow degradation of plastics in the environment led to the generation and accumulation of nanoparticles of polymers (NPs) in the marine environment. However, little is known about the aggregation, consumption and distribution of NPs from common polymers such as polyvinyl chloride (NP-PVC) and polymethyl methacrylate (NP-PMMA) inside marine animal physiologies. In the current study, two types of polymers (PVC and PMMA) × four exposure concentrations (1, 5, 15 and 25 mg/L) × four times (4, 8, 12 and 24 h) exposure studies were conducted to understand the consumption and distribution of luminescent NP-PVC (98.6 ± 17.6 nm) and NP-PMMA (111.9 ± 37.1 nm) in R. philippinarum. Under laboratory conditions, NP-PVC showed a higher aggregation rate than NP-PMMA in seawater within a period of 24 h. Aggregations of NPs increased with an increase in initial NP concentrations, leading to significant settling of nanoparticles within 24 h exposure. Such aggregation and settling of particles enhanced the consumption of NPs by benthic filter-feeding R. philippinarum at all exposure concentrations during 4 h exposure. More interestingly, NP-PVC and NP-PMMA were observed in large amounts in both liver and gills (22.6 % - 29.1 %) of the clams. Furthermore, NP-PVC was detected in most organs of R. philippinarum as compared to NP-PMMA. This study demonstrates that different polymers distribute and accumulate differently in the same biological model under laboratory exposure conditions based on their chemical nature.

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.

The effect and a mechanistic evaluation of polystyrene nanoplastics on a mouse model of type 2 diabetes

Nanoplastics have become ubiquitous in the global environment and have attracted increasing attention. However, whether there is an influence between exposure to nanoplastics and diabetes is unclear. To determine the effects of exposure to Polystyrene nanoplastics (PS-NPs) and evaluate the underlying mechanisms, mice were orally exposed to PS-NPs at dosages of 1, 10, 30 mg/kg/day for 8 weeks, alone or combined with a high fat diet and streptozocin (STZ) injection. Our data showed that exposure to 30 mg/kg/day PS-NPs alone induced a significant increase in blood glucose, glucose intolerance and insulin resistance. Combined with a high fat diet and STZ injection, PS-NPs exposure markedly aggravated oxidative stress, glucose intolerance, insulin tolerance and insulin resistance, and induced lesions in the liver and pancreas. PS-NPs exposure could decrease the phosphorylation of AKT and GSK3β, and treatment with SC79, a selective AKT activator, could increase the level of AKT and GSK3β phosphorylation, effectively alleviating the increase in ROS levels in the liver or pancreas, and slightly attenuating the increase in fasting blood glucose levels and insulin resistance induced by PS-NPs exposure. This showed that exposure to PS-NPs aggravated type 2 diabetes and the underlying mechanism partly involved in the inhibition of AKT/GSK3β phosphorylation.