The valence state of iron-based nanomaterials determines the ferroptosis potential in a zebrafish model

The transferrin a signaling pathway mediates uranium-induced hematopoietic dysfunction

OBJECTIVE

This study was designed to explore the toxic effects of Transferrin a(tfa)-mediated uranium exposure on the hematopoietic system.

METHODS

Zebrafish embryos were subjected to uranium nitrate solutions at concentrations of 50, 100, 250, and 500 μg/L for a defined period, followed by sample collection. The impact of uranium on hematopoietic system development in zebrafish was evaluated through hemoglobin staining, qRT-PCR, and in situ hybridization. RNA-Seq was utilized to detect differentially expressed genes (DEGs) in embryos exposed to 100 μg/L uranium, with subsequent bioinformatics analysis to confirm these DEGs. Furthermore, blood samples from patients with hematological disorders and impaired hematopoietic function were collected, and RNA-Seq was applied to identify DEGs.

RESULTS

Uranium exposure in zebrafish embryos led to reduced hemoglobin expression, with key transcription factors for primitive and definitive hematopoiesis being significantly downregulated at 100 μg/L uranium exposure. Overexpression of tfa resulted in a marked increase in hemoglobin content and upregulation of GATA1, a key factor in primitive hematopoiesis. Patients with hematopoietic dysfunction exhibited abnormalities in the tfa signaling pathway.

CONCLUSION

tfa plays a role in mediating the inhibitory effects of uranium on hematopoietic function.

Transcriptomics-based analysis of neurotoxic and reproductive effects in turbot (Scophthalmus maximus) after exposure to tris (2-chloroethyl) phosphate (TCEP)

BACKGROUND

Tris (2-chloroethyl) phosphate (TCEP), a widely used flame retardant, is widespread in the environment and potentially harmful to organisms. However, the specific mechanisms of TCEP-induced neurological and reproductive toxicity in fish are largely unknown. Turbot (Scophthalmus maximus) is cultivated on a large scale, and the emergence of pollutants with endocrine disrupting effects seriously affects its economic benefits. This study aimed to investigate the toxic effects of TCEP on turbot by integrating physio-biochemical and transcriptomic analyses.

RESULTS

TCEP exposure induced severe neuroendocrine disrupting effects in turbot. Firstly, the hormone levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), and 11-ketotestosterone (11-KT) were significantly decreased under prolonged TCEP stress, which may have a negative impact on normal reproductive function. We identified and summarized representative differentially expressed genes (DEGs) and their functions, such as endocrine system and oxidative stress. Pathway enrichment showed that the toxicological characteristics of TCEP on turbot were neuroendocrine regulation disorders, including oxidative phosphorylation, apoptosis, steroid biosynthesis, GnRH signaling pathway and so on. Weighted gene co-expression network analysis (WGCNA) also revealed key genes involved in these pathways. Among these genes, those encoding the components of the electron transport chain presented an initial increase in expression followed by a decrease, indicating that TCEP stress might affect mitochondrial function and lead to cell damage. This finding was also supported by the upregulation of apoptosis-related gene expression. Moreover, acute exposure to TCEP regulated MAPK-mediated transduction and regulation of GnRH signaling, thereby altering the expression of hypothalamic-pituitary-gonadal (HPG) axis-related genes.

CONCLUSIONS

These findings revealed the endocrine disrupting effects of TCEP on turbot and identified biomarkers related to reproductive toxicity, providing early warning for the monitoring of healthy aquaculture.

MoS2 Nanosheets at Low Doses Induced Cardiotoxicity in Developing Zebrafish via Ferroptosis: Influence of Lateral Size and Surface Modification

The widespread applications of molybdenum disulfide (MoS2) nanosheets inevitably result in their release into aquatic environments, necessitating an exploration of their potential toxic effects on aquatic organisms. This study analyzes the cardiac responses of zebrafish larvae exposed to MoS2, with a focus on the influence of size and surface modifications. At higher concentrations (1 and 5 mg/L), MoS2 nanosheets hampered larval growth without influencing cardiomyogenesis. At lower doses (0.5-100 μg/L), small-sized MoS2 (ssMoS2, 187.2 nm) significantly impaired cardiac development, as proved by morphology abnormality, decreased heartbeat, stroke volume, and cardiac output, whereas these undesirable changes were not observed in the cysteine-modified form. Large-sized nanosheets (1.638 μm) did not localize to the heart, barely showing a cardiac disorder. Transcriptomics, biochemical analysis, and computational simulation validated that ssMoS2 aggravated Fe2+ overload through excessive ferritinophagy and ferroportin-1 inhibition, accompanied by down-regulation of glutathione peroxidase 4 and activation of PUFAs esterification, leading to ferroptosis. Significant associations between ferroptosis signals and cardiac indices, along with the ferrostatin-1 inhibition test, confirmed the ferroptosis-mediated cardiotoxicity of ssMoS2. Our study provides a key understanding of molecular events underlying MoS2-induced cardiotoxicity and highlights the importance of size and surface characteristics, which are significant for risk assessment and the safe design of nanoproducts.

Environmental remediation and sustainable design of iron oxide nanoparticles for removal of petroleum-derived pollutants from water: A critical review

The global problem of major oil spills not only generates crude oil pollution, but produces many derivatives that pose ecological and human health challenges. While extensive research has focused on understanding the types of these contaminants, their transport modes, detection techniques, and ecotoxicological impacts, there are still significant research gaps in mechanisms for removal of petroleum-derived pollutants by iron oxide nanoparticles (IONPs). This work summarizes systematically the types and green synthesis of IONPs for the environmental remediation of various petroleum contaminants. We also provide comprehensive coverage of the excellent removal capacity and latest environmental remediation of IONPs-based materials (e.g., pristine, modified, or porous-supported IONPs materials) for the removal of petroleum-derived pollutants, potential interaction mechanisms (e.g., adsorption, photocatalytic oxidation, and synergistic biodegradation). A sustainable framework was highlighted in depth based on a careful assessment of the environmental impacts, associated hazards, and economic viability. Finally, the review provides an possible improvements of IONPs for petroleum-derived pollutants remediation and sustainable design on future prospect. In the current global environment of pollution reduction and carbon reduction, this information is very important for researchers to synthesize and screen suitable IONPs for the control and eradication of future petroleum-based pollutants with low environmental impact.

Quantum Dots-caused Retinal Degeneration in Zebrafish Regulated by Ferroptosis and Mitophagy in Retinal Pigment Epithelial Cells through Inhibiting Spliceosome

Quantum dots (QDs) are widely used, but their health impact on the visual system is little known. This study aims to elucidate the effects and mechanisms of typical metallic QDs on retinas using zebrafish. Comprehensive histology, imaging, and bulk RNA sequencing reveal that InP/ZnS QDs cause retinal degeneration. Furthermore, single-cell RNA-seq reveals a reduction in the number of retinal pigment epithelial cells (RPE) and short-wave cone UV photoreceptor cells (PR(UV)), accompanied by an increase in middle- and long-wave cone red, green, and blue photoreceptor cells [PR(RGB)]. Mechanistically, after endocytosis by RPE, InP/ZnS QDs inhibit the expression of splicing factor prpf8, resulting in gpx4b mRNA unsplicing, which finally decrease glutathione and induce ferroptosis and mitophagy. The decrease of RPE fails to engulf the damaged outer segments of PR, possibly promoting the differentiation of PR(UV) to PR(RGB). Knockout prpf8 or gpx4b with CRISPR/Cas9 system, the retinal damage is also observed. Whereas, overexpression of prpf8 or gpx4b, or supplement of glutathione can rescue the retinal degenerative damage caused by InP/ZnS QDs. In conclusion, this study illustrates the potential health risks of InP/ZnS QDs on eye development and provides valuable insights into the underlying mechanisms of InP/ZnS QDs-caused retinal degeneration.

Ferroptosis involvement in the neurotoxicity of flunitrazepam in zebrafish

In recent years, psychoactive drugs such as benzodiazepines (BZDs) have been frequently detected in water environments, however, there is still limited understanding regarding their potential impact on neurological health and underlying mechanisms. This study evaluated the neurotoxicity of the typical BZD drug flunitrazepam (FLZ, 0.2 and 5 μg/L) in zebrafish embryos and adults, and investigated the relationship between ferroptosis and FLZ-induced neurotoxicity. The results indicated that acute exposure to FLZ significantly inhibited zebrafish embryo hatching and promotes death, induced larval deformities, and led to abnormal neurobehavioral responses in larvae, likely due to ferroptosis induction. Results from a 30-day subacute exposure to FLZ showed that it decreased motor function and induced cognitive impairment in adult zebrafish. Immunofluorescence of brain tissues revealed a reduction in neurons in the telencephalon and an increase in microglia in the mesencephalon of the zebrafish exposed to FLZ. The ultrastructure of brain mitochondria showed serious damage. Besides, FLZ exposure increased iron levels, reduced GSH/GSSG and increased LPO in brain tissue, which is related to the abnormal expression of genes associated with ferroptosis. In the rescue experiments with co-exposure to deferoxamine (DFO), the motor-related parameters and biochemical indexes related to ferroptosis were restored, suggesting that FLZ can induce ferroptosis. The molecular docking results indicated that FLZ had a higher affinity with transferrin. This study elucidates the close relationship between ferroptosis and FLZ-induced neurotoxicity, which is significant for understanding the physiological damage caused by psychoactive substances and assessing environmental risks.

Toxicity and related molecular mechanisms of Sb(III) in the embryos and larvae of zebrafish (Danio rerio)

Antimony (Sb) pollution poses a severe threat to humans and ecosystems due to the extensive use of Sb in various fields. However, little is known about the toxic effects of Sb and its aquatic ecotoxicological mechanism. This study aimed to reveal the toxicity and related molecular mechanisms of trivalent Sb (Sb(III)) in zebrafish embryos/larvae. Sb(III) accumulated in larvae, which correlated with the exposure concentration. Although no significant lethal or teratogenic effects were observed, normal growth and development were affected. Exposure to 10 or 20 mg/L Sb(III) increased the levels of reactive oxygen species in the larvae while enhancing catalase activity and increasing cell apoptosis. Transcriptomic analysis revealed that Sb(III) promoted glutathione metabolism and the ferroptosis pathway. In addition, symptoms associated with ferroptosis, including mitochondrial damage, biochemical levels of related molecules and increased tissue iron content, were detected. Quantitative polymerase chain reaction (qPCR) analyses further confirmed that Sb(III) significantly altered the transcription levels of genes related to the ferroptosis pathway by disrupting iron homeostasis. Furthermore, ferrostatin-1 (Fer-1) mitigated the toxic effects induced by Sb(III) in zebrafish. Our research fills the gap in the literature on the toxicity and mechanism of Sb(III) in aquatic organisms, which is highly important for understanding the ecological risks associated with Sb.

Silver nanoparticles induce liver inflammation through ferroptosis in zebrafish

As the most widely employed artificial nanomaterials, silver nanoparticles (AgNPs) have been implicated in oxidative stress-induced liver injury. Despite these observations, the precise mechanisms underpinning AgNPs-induced hepatotoxicity have yet to be fully elucidated. This study embarked on an intersectional analysis of the GEO dataset (GSE139560), which encompassed murine liver tissues subjected to AgNPs, alongside datasets related to ferroptosis. Through this approach, three pivotal ferroptosis-associated genes (Arrdc3, Txnip, and Egfr) were identified. Further integration with disease model analysis from GSE111407 and GSE183158 unveiled a significant association between AgNPs exposure and alterations in glucose metabolism and insulin signaling pathways, intricately linked with the identified key ferroptosis genes. This correlation fostered the hypothesis that ferroptosis significantly contributed to the hepatotoxicity triggered by AgNPs. Subsequent Gene Set Enrichment Analysis (GSEA) pointed to the activation of ferroptosis-associated pathways, specifically MAPK and PPAR, under AgNPs exposure. Examination of the miRNA-mRNA interaction network revealed co-regulated upstream miRNAs targeting these pivotal genes, establishing a nexus to ferroptosis and heightened liver susceptibility. Experimental validation employing an adult zebrafish model exposed to AgNPs from 90 to 120 dpf demonstrated elevated levels of Fe2+ and MDA in the zebrafish livers, along with conspicuous mitochondrial morphological alterations, thereby reinforcing the notion that AgNPs precipitate liver dysfunction predominantly through the induction of ferroptosis. These insights collectively underscore the role of ferroptosis in mediating the adverse effects of AgNPs on liver glucose metabolism and insulin sensitivity, culminating in liver dysfunction. Overall, these results enhance the understanding of nanomaterial-induced hepatotoxicity and inform strategies to mitigate such health risks.

Esketamine Exposure Impairs Cardiac Development and Function in Zebrafish Larvae

Esketamine is a widely used intravenous general anesthetic. However, its safety, particularly its effects on the heart, is not fully understood. In this study, we investigated the effects of esketamine exposure on zebrafish embryonic heart development. Zebrafish embryos were exposed to esketamine at concentrations of 1, 10, and 100 mg/L from 48 h post-fertilization (hpf) to 72 hpf. We found that after exposure, zebrafish embryos had an increased hatching rate, decreased heart rate, stroke volume, and cardiac output. When we exposed transgenic zebrafish of the Tg(cmlc2:EGFP) strain to esketamine, we observed ventricular dilation and thickening of atrial walls in developing embryos. Additionally, we further discovered the abnormal expression of genes associated with cardiac development, including nkx2.5, gata4, tbx5, and myh6, calcium signaling pathways, namely ryr2a, ryr2b, atp2a2a, atp2a2b, slc8a3, slc8a4a, and cacna1aa, as well as an increase in acetylcholine concentration. In conclusion, our findings suggest that esketamine may impair zebrafish larvae's cardiac development and function by affecting acetylcholine concentration, resulting in weakened cardiac neural regulation and subsequent effects on cardiac function. The insights garnered from this research advocate for a comprehensive safety assessment of esketamine in clinical applications.

Ferroptosis Induced by Pollutants: An Emerging Mechanism in Environmental Toxicology

Environmental pollutants have been recognized for their ability to induce various adverse outcomes in both the environment and human health, including inflammation, apoptosis, necrosis, pyroptosis, and autophagy. Understanding these biological mechanisms has played a crucial role in risk assessment and management efforts. However, the recent identification of ferroptosis as a form of programmed cell death has emerged as a critical mechanism underlying pollutant-induced toxicity. Numerous studies have demonstrated that fine particulates, heavy metals, and organic substances can trigger ferroptosis, which is closely intertwined with lipid, iron, and amino acid metabolism. Given the growing evidence linking ferroptosis to severe diseases such as heart failure, chronic obstructive pulmonary disease, liver injury, Parkinson's disease, Alzheimer's disease, and cancer, it is imperative to investigate the role of pollutant-induced ferroptosis. In this review, we comprehensively analyze various pollutant-induced ferroptosis pathways and intricate signaling molecules and elucidate their integration into the driving and braking axes. Furthermore, we discuss the potential hazards associated with pollutant-induced ferroptosis in various organs and four representative animal models. Finally, we provide an outlook on future research directions and strategies aimed at preventing pollutant-induced ferroptosis. By enhancing our understanding of this novel form of cell death and developing effective preventive measures, we can mitigate the adverse effects of environmental pollutants and safeguard human and environmental health.

High-Dose Exposure to Polymer-Coated Iron Oxide Nanoparticles Elicits Autophagy-Dependent Ferroptosis in Susceptible Cancer Cells

Ferroptosis, a form of iron-dependent, lipid peroxidation-driven cell death, has been extensively investigated in recent years, and several studies have suggested that the ferroptosis-inducing properties of iron-containing nanomaterials could be harnessed for cancer treatment. Here we evaluated the potential cytotoxicity of iron oxide nanoparticles, with and without cobalt functionalization (Fe₂O₃ and Fe₂O₃@Co-PEG), using an established, ferroptosis-sensitive fibrosarcoma cell line (HT1080) and a normal fibroblast cell line (BJ). In addition, we evaluated poly (ethylene glycol) (PEG)-poly(lactic-co-glycolic acid) (PLGA)-coated iron oxide nanoparticles (Fe₃O₄-PEG-PLGA). Our results showed that all the nanoparticles tested were essentially non-cytotoxic at concentrations up to 100 μg/mL. However, when the cells were exposed to higher concentrations (200-400 μg/mL), cell death with features of ferroptosis was observed, and this was more pronounced for the Co-functionalized nanoparticles. Furthermore, evidence was provided that the cell death triggered by the nanoparticles was autophagy-dependent. Taken together, the exposure to high concentrations of polymer-coated iron oxide nanoparticles triggers ferroptosis in susceptible human cancer cells.