Integrated lncRNA transcriptomics, proteomics, and metabolomics to identify early cellular response variation in deoxynivalenol-treated IPEC-J2 cells

Metabolomics and Lipidomics Reveal the Metabolic Disorders Induced by Single and Combined Exposure of Fusarium Mycotoxins in IEC-6 Cells

Deoxynivalenol (DON), fumonisin B1 (FB1), and zearalenone (ZEN) are typical fusarium mycotoxins that occur worldwide in foodstuffs, posing significant health hazards to humans and animals. Single and combined exposure of DON, FB1, and ZEN leads to intestinal toxicity but the toxicology mechanism research is still limited. In this study, we explored the cytotoxicity effects of DON, FB1, ZEN, and their combination in rat intestinal epithelial cell line 6 (IEC-6) cells. Cell viability results showed that the cytotoxicity potency ranking was DON > ZEN > FB1. Furthermore, both DON + FB1 and DON + ZEN presented synergism to antagonism effects based on a combination index (CI)-isobologram equation model. Integrated metabolomics and lipidomics was adopted to explore cell metabolism disorders induced by fusarium mycotoxin exposure. A total of 2011 metabolites and 670 lipids were identified. An overlap of 37 and 62 differential compounds was confirmed after single and combined mycotoxin exposure by multivariate analysis, respectively. Some of the differential compounds were endocellular antioxidants and were significantly downregulated in mycotoxin exposure groups, indicating metabolic disorders as well as antioxidant capacity damage in cells. Pathway enrichment analysis annotated ethanol metabolism production of ROS by CYP2E1 was mainly involved in the disturbance of DON, FB1, and ZEN. The results obtained in this study help to define the toxicity effects of DON, FB1, and ZEN singly and in co-existence, providing an important scientific basis for combined risk recognition of mycotoxin contamination.

Eucommia ulmoides flavonoids alleviate intestinal oxidative stress damage in weaned piglets by regulating the Nrf2/Keap1 signaling pathway

This study examined how Eucommia ulmoides flavonoids (EUF) protect against intestinal oxidative stress induced by deoxynivalenol (DON) in weaned piglets. Forty weaned piglets were randomly assigned to four dietary groups for a period of 14 days. The piglets were fed a control diet (Control) or the Control diet supplemented with 100 mg EUF/kg (EUF group), 4 mg DON/kg diet (DON group) or both (EUF+DON group) in a 2×2 factorial design. DON-challenged piglets on the EUF-supplemented diet showed significant improvements in growth performance. They also had notably lower serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) compared to those not receiving supplementation (P<0.05). In the EUF group, the relative weights of the liver, spleen, and kidneys were significantly lower than those in the control group (P<0.05). However, there were no significant differences in the relative heart weights among the four groups (P>0.05). Piglets challenged with DON and fed a diet supplemented with EUF showed significantly lower levels of interleukin-8 (IL-8) and interferon-γ (IFN-γ) mRNA and protein expression in serum and intestinal tissues compared to those in the DON group (P < 0.05). The EUF+DON group significantly increased the serum levels of glutathione peroxidase (GSH-Px), reactive oxygen species (ROS), and total antioxidative capability enzymes compared to the DON group (P<0.05). The EUF and DON group had significantly higher villus height, crypt depth, and villus height to crypt depth ratio in the small intestine compared to the supplemented DON-challenged piglets (P<0.05). Moreover, compared to the DON group, EUF can significantly enhance the expression of nuclear factor erythroid 2-related factor 2(Nfr2)/Kelch-like ECH-associating protein 1(Keap1) and antioxidant genes (i.e., HO-1, GCLC, GCLM), as well as their proteins in the DON-induced small intestines of piglets (P<0.05). In conclusion, EUF helps protect piglets from intestinal oxidative stress caused by DON by influencing the Nrf2/Keap1 signaling pathway, thereby supporting their intestinal health.

Deoxynivalenol-Induced Spleen Toxicity in Mice: Inflammation, Endoplasmic Reticulum Stress, Macrophage Polarization, and the Dysregulation of LncRNA Expression

The spleen is a primary target of deoxynivalenol (DON) toxicity, but its underlying molecular mechanisms remain unclear. This study investigates the effects of DON on inflammation, splenic macrophage polarization, endoplasmic reticulum (ER) stress, and transcriptome changes (mRNA and lncRNAs) in mouse spleen. We found that DON exposure at doses of 2.5 or 5 mg/kg BW significantly induced inflammation and polarized splenic macrophages towards the M1 phenotype. Additionally, DON activated PERK-eIF2α-ATF4-mediated ER stress and upregulated apoptosis-related proteins (caspase-12, caspase-3). The ER stress inhibitor, 4-Phenylbutyric acid, significantly alleviated DON-induced ER stress, apoptosis, and the M1 polarization of splenic macrophages. Transcriptome analysis identified 1968 differentially expressed (DE) lncRNAs and 2664 DE mRNAs in mouse spleen following DON exposure. Functional enrichment analysis indicated that the upregulated genes were involved in pathways associated with immunity, including Th17 cell differentiation, TNF signaling, and IL-17 signaling, while downregulated mRNAs were linked to cell survival and growth pathways. Furthermore, 370 DE lncRNAs were predicted to target 255 DE target genes associated with immune processes, including the innate immune response, interferon-beta response, cytokine production regulation, leukocyte apoptosis, and NF-κB signaling genes. This study provides new insights into the mechanisms underlying DON toxicity and its effects on the immune system.

New insight into mycotoxins and bacterial toxins: Toxicity assessment, molecular mechanism and food safety (preface to the special issue of food and chemical toxicology on the outcomes of Myco & bacterial toxin)

The special issue "New Insight into Mycotoxins and Bacterial Toxins: Toxicity Assessment, Molecular Mechanism and Food Safety" in Food and Chemical Toxicology contains 19 articles on current hot topics in mycotoxins and bacterial toxins. Dietary exposure to mycotoxins and risk assessments are reported in this issue. Molecular mechanisms of multiple mycotoxins and emerging mechanisms of toxicity are especially concerned by researchers. Moreover, mycotoxin-detoxifying substances and antimicrobial agents are also fully investigated in the context. This special issue will help to further understand the mycotoxins and bacterial toxins, casting new light for the control of food safety.

Effects and mechanisms of N6-methyladenosine RNA methylation in environmental pollutant-induced carcinogenesis

Environmental pollution, including air pollution, plastic contamination, and heavy metal exposure, is a pressing global issue. This crisis contributes significantly to pollution-related diseases and is a critical risk factor for chronic health conditions, including cancer. Mounting evidence underscores the pivotal role of N6-methyladenosine (m6A) as a crucial regulatory mechanism in pathological processes and cancer progression. Governed by m6A writers, erasers, and readers, m6A orchestrates alterations in target gene expression, consequently playing a vital role in a spectrum of RNA processes, covering mRNA processing, translation, degradation, splicing, nuclear export, and folding. Thus, there is a growing need to pinpoint specific m6A-regulated targets in environmental pollutant-induced carcinogenesis, an emerging area of research in cancer prevention. This review consolidates the understanding of m6A modification in environmental pollutant-induced tumorigenesis, explicitly examining its implications in lung, skin, and bladder cancer. We also investigate the biological mechanisms that underlie carcinogenesis originating from pollution. Specific m6A methylation pathways, such as the HIF1A/METTL3/IGF2BP3/BIRC5 network, METTL3/YTHDF1-mediated m6A modification of IL 24, METTL3/YTHDF2 dynamically catalyzed m6A modification of AKT1, METTL3-mediated m6A-modified oxidative stress, METTL16-mediated m6A modification, site-specific ATG13 methylation-mediated autophagy, and the role of m6A in up-regulating ribosome biogenesis, all come into play in this intricate process. Furthermore, we discuss the direction regarding the interplay between pollutants and RNA metabolism, particularly in immune response, providing new information on RNA modifications for future exploration.

Selenomethionine protects the liver from dietary deoxynivalenol exposure via Nrf2/PPARγ-GPX4-ferroptosis pathway in mice

Deoxynivalenol (DON) is a significant Fusarium toxin that has gained global attention due to its high frequency of contamination in food and feed. It was reported to have hepatotoxicity, immunotoxicity, and reproduction toxicity in organs. On the other hand, Selenomethionine (SeMet) was proven to have anti-oxidation, tissue repairing, immunity improvement, and antifungal mycotoxin infection functions. However, the molecular mechanism by which SeMet alleviates DON damage is not yet clear. C57BL/6 mice were randomly divided into three groups, Se-A and Se-A+DON were fed with a diet containing 0.2 mg/kg Se whereas Se-S+DON were fed with a diet of 1.0 mg/kg Se. After feeding for four weeks, the mice were gavaged for 21 days with DON (2.0 mg/kg BW) or ultrapure water once per day. In the present study, we showed that SeMet significantly decreased the lipid peroxidation product malondialdehyde, and increased activities of antioxidant enzymes superoxide dismutase and total antioxidant capacity after DON exposure. In addition, our investigation revealed that SeMet regulated pathways related to lipid synthesis and metabolisms, and effectively mitigated DON-induced liver damage. Moreover, we have discovered that SeMet downregulation of N-acylethanolamine and HexCer accumulation induced hepatic lipotoxicity. Further study showed that SeMet supplementation increased protein levels of glutathione peroxidase 4 (GPX4), peroxisome proliferator-activated receptor γ (PPARγ), nuclear erythroid 2-related factor 2 (Nrf2), and upregulated target proteins, indicating suppression of oxidative stress in the liver. Meanwhile, we found that SeMet significantly reduced the DON-induced protein abundances of Bcl2, Beclin1, LC3B and proteins related to ferroptosis (Lpcat3, and Slc3a2), and downregulation of Slc7a11. In conclusion, SeMet protected the liver from damage by enhancing the Nrf2/PPARγ-GPX4-ferroptosis pathway, inhibiting lipid accumulation and hepatic lipotoxicity. The findings of this study indicated that SeMet has a positive impact on liver health by improving antioxidant capacity and relieving lipotoxicity in toxin pollution.

Simulating ozone degradation of deoxynivalenol and its bio-safety assessment by mouse model

Deoxynivalenol (DON), a trichothecene mycotoxin, is one of the most prevalent mycotoxins globally, primarily produced by Fusarium species. DON exposure could cause a range of symptoms, including nausea, vomiting, gastroenteritis, growth retardation, immunosuppression, and intestinal flora disorders in both humans and animals. Recently, ozone degradation technology has been applied for DON control. However, the safety of the contaminated grain after degradation was often ignored. Therefore, the implementation technology for assessing the safety of DON-contaminated grain degradation is of great significance for food safety. In this study, based on previous degradation result of DON, we further studied and assessed the toxicity of corn contaminated with ozone-degrading DON by animal experiments in mice. We simulated feed made from corn contaminated with DON produced by inoculated Fusarium graminearum, which was treated with an ozone aqueous solution. DON treated by ozone could effectively increase the expression of total protein in mice and improve the immune system efficacy. Meanwhile, compared with DON directly-exposed mice, the corn with degrading DON could effectively maintain the level of liver and kidney immune function, and improved growth performance, enterohepatic circulation, and energy metabolism. Our study indicated that the toxicity of fed corn contaminated with degrading-DON decreased significantly after ozone degradation, resulting in a much lower toxicity compared to the DON group, or nontoxicity to some extent. Therefore, we hope that this mouse model could be used as a promising approach for assessing the risk of fungal toxins on metabolism, immunity, and intestinal health.