Effects of deoxynivalenol on mitochondrial dynamics and autophagy in pig spleen lymphocytes

Hesperidin Alleviates Hepatic Injury Caused by Deoxynivalenol Exposure through Activation of mTOR and AKT/GSK3β/TFEB Pathways

Deoxynivalenol (DON) is a common agricultural mycotoxin that is chemically stable and not easily removed from cereal foods. When organisms consume food made from contaminated crops, it can be hazardous to their health. Numerous studies in recent years have found that hesperidin (HDN) has hepatoprotective effects on a wide range of toxins. However, few scholars have explored the potential of HDN in attenuating DON-induced liver injury. In this study, we established a low-dose DON exposure model and intervened with three doses of HDN, acting on male C57 BL/6 mice and AML12 cells, which served as in vivo and in vitro models, respectively, to investigate the protective mechanism of HDN against DON exposure-induced liver injury. The results suggested that DON disrupted hepatic autophagic fluxes, thereby impairing liver structure and function, and HDN significantly attenuated these changes. Further studies revealed that HDN alleviated DON-induced excessive autophagy through the mTOR pathway and DON-induced lysosomal dysfunction through the AKT/GSK3β/TFEB pathway. Overall, our study suggested that HDN could ameliorate DON-induced autophagy flux disorders via the mTOR pathway and the AKT/GSK3β/TFEB pathway, thereby reducing liver injury.

Deoxynivalenol Induces Drp-1-Mediated Mitochondrial Dysfunction via Elevating Oxidative Stress

Mitochondrial dysfunction is often linked to neurotoxicity and neurological diseases and stems from oxidative stress, yet effective therapies are lacking. Deoxynivalenol (DON or vomitoxin) is one of the most common and hazardous type-B trichothecene mycotoxins, which contaminates crops used for food and animal feed. Despite the abundance of preliminary reports, comprehensive investigations are scarce to explore the relationship between these fungal metabolites and neurodegenerative disorders. The present study aimed to elucidate the precise role of DON in mitochondrial dynamics and cell death in neuronal cells. Excessive mitochondrial fission is associated with the pathology of several neurodegenerative diseases. Human SH-SY5Y cells were treated with different concentrations of DON (250-1000 ng/mL). Post 24 and 48 h DON treatment, the indexes were measured as follows: generation of reactive oxygen species (ROS), ATP levels, mitochondrial membrane potential, calcium levels, and cytotoxicity in SH-SY5Y cells. The results showed that cytotoxicity, intracellular calcium levels, and ROS in the DON-treated group increased, while the ATP levels and mitochondrial membrane potential decreased in a dose-dependent manner. With increasing DON concentrations, the expression levels of P-Drp-1, mitochondrial fission proteins Mff, and Fis-1 were elevated with reduced activities of MFN1, MFN2, and OPA1, further resulting in an increased expression of autophagic marker LC3 and beclin-1. The reciprocal relationship between mitochondrial damage and ROS generation is evident as ROS can instigate structural and functional deficiencies within the mitochondria. Consequently, the impaired mitochondria facilitate the release of ROS, thereby intensifying the cycle of damage and exacerbating the overall process. Using specific hydroxyl, superoxide inhibitors, and calcium chelators, our study confirmed that ROS and Ca2+-mediated signaling pathways played essential roles in DON-induced Drp1 phosphorylation. Therefore, ROS and mitochondrial fission inhibitors could provide critical research tools for drug development in mycotoxin-induced neurodegenerative diseases.

Effects of the commensal microbiota on spleen and mesenteric lymph node immune function: investigation in a germ-free piglet model

Commensal microbial-host interaction is crucial for host metabolism, growth, development, and immunity. However, research on microbial-host immunity in large animal models has been limited. This study was conducted to investigate the effects of the commensal microbiota on immune function in two model groups: germ-free (GF) and specific-pathogen-free (SPF) piglets. The weight and organ index of the spleen of the GF piglet were larger than those in the SPF piglet (P < 0.05). The histological structure of the red pulp area and mean area of germinal centers were larger in the SPF piglet than in the GF piglet (P < 0.05), whereas the areas of staining of B cells and T cells in the spleen and mesenteric lymph nodes (MLNs) were lower in the GF piglet (P < 0.05). We identified immune-related genes in the spleen and MLNs using RNA sequencing, and used real-time quantitative PCR to analyze the expression of core genes identified in gene set enrichment analysis. The expression levels of genes in the transforming growth factor-β/SMAD3 signaling pathway, Toll-like receptor 2/MyD88/nuclear factor-κB signaling pathway, and pro-inflammatory factor genes IL-6 and TNF-α in the spleen and MLNs were higher in the SPF piglet and in splenic lymphocytes compared with those in the GF and control group, respectively, under treatment with acetic acid, propionic acid, butyric acid, lipopolysaccharide (LPS), or concanavalin A (ConA). The abundances of plasma cells, CD8++ T cells, follicular helper T cells, and resting natural killer cells in the spleen and MLNs were significantly greater in the SPF piglet than in the GF piglet (P < 0.05). In conclusion, the commensal microbiota influenced the immune tissue structure, abundances of immune cells, and expression of immune-related pathways, indicating the importance of the commensal microbiota for spleen and MLNs development and function. In our study, GF piglet was used as the research model, eliminating the interference of microbiota in the experiment, and providing a suitable and efficient large animal research model for exploring the mechanism of "microbial-host" interactions.

Complementary transcriptomic and proteomic analyses elucidate the toxicological molecular mechanisms of deoxynivalenol-induced contractile dysfunction in enteric smooth muscle cells

Deoxynivalenol (DON) is one of the frequent Fusarium mycotoxins and poses a serious threat to public health worldwide. DON-induced weight loss is tightly connected with its ability to decrease feed intake by influencing gastrointestinal tract (GIT) motility. Our previous reports indicated that DON interfered with intestinal motility by injuring the contractility of enteric smooth muscle cells (SMC). Here, we further explored the potential mechanisms by employing a complementary method of transcriptomics and proteomics using the porcine enteric smooth muscle cell line (PISMC) as an experimental model. The transcriptomic and proteomic data uncover that the expression of numerous extracellular matrix (ECM) proteins and multiple integrin subunits were downregulated in PISMC under DON exposure, suppressing the ECM-integrin receptor interaction and its mediated signaling. Furthermore, DON treatment could depress actin polymerization, as reflected by the upregulated expression of Rho GTPase-activating proteins and cofilin in PISMC. Meanwhile, the expression levels of downstream contractile apparatus genes were significantly inhibited after challenge with DON. Taken together, the current results suggest that DON inhibits enteric SMC contractility by regulating the ECM-integrin-actin polymerization signaling pathway. Our findings provide novel insights into the potential mechanisms behind the DON toxicological effects in the GIT of humans and animals.

Novel insights into DEHP-induced zebrafish spleen damage: Cellular apoptosis, mitochondrial dysfunction, and innate immunity

DEHP (Di(2-ethylhexyl) phthalate) is the most abundant phthalate component detected in environmental samples as it is widely used in the manufacturing of children's toys, medical devices and furniture. Due to its wide prevalence and propensity to accumulate in the food chain, significant concerns have risen about the safety profile of DEHP. Here, we used a zebrafish model to investigate the toxicity mechanisms of DEHP. Our results indicated that exposure to DEHP altered the ROS content in zebrafish spleen and inhibited the activities of antioxidant enzymes SOD and CAT, detoxification enzyme GSH-Px and induced histopathological damage. In addition, elucidated the mechanism of DEHP significantly promoted apoptosis and caused damage in spleen cells through the bax/bcl-2 pathway. Further genetic testing demonstrated significant alterations in mitochondrial biogenesis, fission, and fusion-related genes and suggested potential mechanistic pathways, including GM10532/m6A/FIS1 axis, the STAT3/POA1 axis, and the NFR1/TFAM axis. Serological and genomic analysis indicated that DEHP exposure activated the C3 complement cascade immune pathway and interfered with innate immune function. IBRv2 analysis proposes that innate immunity may serve as a signal indicator of early toxic responses to DEHP pollutants. This study provided comprehensive cellular and genetic data for DEHP toxicity studies and emphasized the need for future management and remediation of DEHP contamination. It also provides data to specifically support the health risk assessments of DEHP, as well as contributing to broader health and environmental research.

Lycopene Maintains Mitochondrial Homeostasis to Counteract the Enterotoxicity of Deoxynivalenol

The intestinal tract is a target organ for Deoxynivalenol (DON) absorption and toxicity. Mitochondrial homeostasis imbalance is the gut toxicity mechanism of DON. Lycopene (LYC) has intestinal protective effects and can maintain mitochondrial homeostasis in response to various danger signals. The purpose of this study was to explore the protective effect of LYC on DON-induced IPEC-J2 cells damage. These results showed that DON exposure induced an increase in the levels of malondialdehyde and reactive oxygen species (ROS) in IPEC-J2 cells. DON impaired IPEC-J2 cell barrier function and caused mitochondrial dysfunction by inducing mitochondrial permeability transition pore (MPTP) opening, mitochondrial membrane potential (MMP) reducing, destroying mitochondrial fission factors, mitochondrial fusion factors, and mitophagy factors expression. However, adding LYC can reduce the toxic effects of DON-induced IPEC-J2 cells and decrease cellular oxidative stress, functional damage, mitochondrial dynamics imbalance, and mitophagy processes. In conclusion, LYC maintains mitochondrial homeostasis to counteract the IPEC-J2 cells' toxicity of DON.

Transcriptome Analysis of Deoxynivalenol (DON)-Induced Hepatic and Intestinal Toxicity in Zebrafish: Insights into Gene Expression and Potential Detoxification Pathways

The effects of deoxynivalenol (DON, 50 µg/mL) on the zebrafish liver and intestine were studied. Differentially expressed genes (DEGs) from mRNA and lncRNA were analyzed by RNA seq. Gene Ontology (GO) and signaling pathways were studied where the top 30 DEGs of each type of RNA were involved. The results showed there were 2325 up-regulated and 934 down-regulated DEGs of lncRNA in the intestinal tract, and 95 up-regulated genes and 211 down-regulated genes in the liver, respectively. GO functional annotation analysis showed that lncRNA was enriched in the biological processes, involving the RNA splicing, CSF1-CSF1R complexes, and MAP kinase activity. DEGs of lncRNA located in the KEGG signal pathways include the C-type lectin receptor signaling and the NOD-like receptor signaling pathways. Metabolism involves the biosynthesis of indole alkaloids, cancer pathways for human disease, MAPK and Rap1signaling pathways for environmental information processing, necroptosis and focal adhesion for cell processes. The mRNA gene expression analysis showed there were 1939 up-regulated, 1172 down-regulated genes and 866 up-regulated, 1211 down-regulated genes in the intestine and liver of zebrafish, respectively. This study provides transcriptome analysis and toxicological investigation of DON in the zebrafish liver and intestine, offering insights into gene expression patterns and potential detoxification pathways.

Effects of DON on Mitochondrial Function, Endoplasmic Reticulum Stress, and Endoplasmic Reticulum Mitochondria Contact Sites in the Jejunum of Piglets

Recent research has emphasized the significance of investigating the interplay between organelles, with endoplasmic reticulum mitochondria contact sites (ERMCSs) being recognized as critical signaling hubs between organelles. The objective of the current study was to assess the impact of deoxynivalenol (DON) on jejunal mitochondria, ER, and ERMCSs. Twelve piglets (35 d, 10.22 ± 0.35 kg) were randomized into two groups: control group, basal diet; the DON group, basal diet + 1.5 mg/kg DON. The findings revealed that DON decreased growth performance, induced jejunal oxidative stress, and impaired jejunal barrier function. DON was also found to induce mitochondrial dysfunction, trigger endoplasmic reticulum stress (ERS) in the piglets' jejunum, and activate mitochondrial and ER apoptosis pathways by upregulating apoptosis-related proteins (Caspase-8, Caspase-12, Bax, and CHOP). To investigate the involvement of ERMCSs in DON-induced intestinal injury, we measured the protein levels of ERMCS proteins, such as mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), and glucose-regulated protein 75 (GRP75) and Pearson's correlation coefficient of ERMCS proteins and ERMCS ultrastructure. Our finding showed that DON upregulated the protein level of Mfn2 and GRP75 and increased the percentage of mitochondria with ERMCSs/total mitochondria, the length of ERMCSs compared to the perimeter of mitochondria, and the Pearson's correlation coefficient of voltage-dependent anion-selective channel protein 1 (VDAC1) and inositol 1,4,5-triphosphate receptors (IP3Rs) in piglets' jejunum. Furthermore, DON shortened the distance between mitochondria and ER at ERMCSs. These findings suggested that DON impaired mitochondrial function, triggered ERS, and increased ERMCSs, indicating that the increased ERMCSs could be related to mitochondrial dysfunction and ERS involved in the intestinal injury of piglets induced by DON.

Sodium Butyrate Ameliorates Deoxynivalenol-Induced Oxidative Stress and Inflammation in the Porcine Liver via NR4A2-Mediated Histone Acetylation

Mycotoxin-induced liver injury is often accompanied by oxidative stress (OS) and inflammation. This research aimed to explore the potential mechanism of sodium butyrate (NaBu) in modulating hepatic anti-oxidation and anti-inflammation pathways in deoxynivalenol (DON)-exposed piglets. The results show that DON induced liver injury, increased mononuclear cell infiltration, and decreased serum total protein and albumin concentrations. Transcriptomic analysis revealed that reactive oxygen species (ROS) and TNF-α pathways were highly activated upon DON exposure. This is associated with disturbed antioxidant enzymes and increased inflammatory cytokines secretion. Importantly, NaBu effectively reversed the alterations caused by DON. Mechanistically, the ChIP-seq result revealed that NaBu strongly depressed DON-increased enrichment of histone mark H3K27ac at the genes involved in ROS and TNF-α-mediated pathways. Notably, we demonstrated that nuclear receptor NR4A2 was activated by DON and remarkably recovered with the treatment of NaBu. In addition, the enhanced NR4A2 transcriptional binding enrichments at the promoter regions of OS and inflammatory genes were hindered by NaBu in DON-exposed livers. Consistently, elevated H3K9ac and H3K27ac occupancies were also observed at the NR4A2 binding regions. Taken together, our results indicated that a natural antimycotic additive, NaBu, could mitigate hepatic OS and inflammatory responses, possibly via NR4A2-mediated histone acetylation.

Combination of glycyrrhizic acid and compound probiotics alleviates deoxynivalenol-induced damage to weaned piglets

Deoxynivalenol (DON) can affect health and growth performance of pigs, resulting in significant economic losses in swine production. The aim of this study was to investigate the effect of glycyrrhizic acid combined with compound probiotics, i.e. Enterococcus faecalis plus Saccharomyces cerevisiae (GAP) on improving growth performance, intestinal health and its fecal microbiota composition change of piglets challenged with DON. A total of 160 42-day-old weaned piglets (Landrace × Large White) were used and the experimental period was 28 d. The results showed that supplementing GAP in the diet significantly improved the growth performance of piglets challenged with DON and alleviate DON-induced intestinal damage by reducing ALT, AST and LDH concentrations in serum, increasing the morphological parameters of jejunum, and decreasing DON residues in serum, liver and feces. Moreover, GAP could significantly decrease the expressions of inflammation and apoptosis genes and proteins (IL-8, IL-10, TNF-α, COX-2, Bax, Bcl-2 and Caspase 3), and increase the expressions of tight-junction proteins and nutrient transport factor genes and proteins (ZO-1, Occludin, Claudin-1, ASCT2 and PePT1). In addition, it was also found that GAP supplementation could significantly increase the diversity of gut microbiota, maintain microbial flora balance and promote piglet growth by significantly increasing the abundance of beneficial bacterium such as Lactobacillus and reducing the abundance of harmful bacterium such as Clostridium_sensu_stricto_1. In conclusion, GAP addition to piglet diets contaminated with DON could significantly promote the health and growth performance of piglets though alleviating DON-induced hazards. This study provided a theoretical basis for the application of GAP to alleviate DON toxicity for animals.

Ferroptosis is involved in deoxynivalenol-induced intestinal damage in pigs

BACKGROUND

Deoxynivalenol (DON) is a widespread issue for feed and food safety, leading to animal and human health risks. The objective of this study was to determine whether ferroptosis is involved in DON-induced intestinal injury in piglets. Three groups of 21-day-old male weanling piglets (n = 7/group) were fed a control diet, or diet adding 1.0 or 3.0 mg DON/kg. At week 4, serum and small intestines were collected to assay for biochemistry, histology, redox status and ferroptosis-related genes expression. In addition, the involvement of ferroptosis and the role of FTL gene in DON-induced cell death were further verified in the IPEC-J2 cells.

RESULTS

Compared to the control, dietary supplementation of DON at 1.0 and 3.0 mg/kg induced different degrees of damage in the duodenum, jejunum and ileum, and increased (P < 0.05) serum lipopolysaccharide concentration by 46.2%-51.4%. Dietary DON supplementation at 1.0 and (or) 3.0 mg/kg increased (P < 0.05) concentrations of malondialdehyde (17.4%-86.5%) and protein carbonyl by 33.1%-92.3% in the duodenum, jejunum and ileum. In addition, dietary supplemented with DON upregulated (P < 0.05) ferroptotic gene (DMT1) and anti-ferroptotic genes (FTL and FTH1), while downregulated (P < 0.05) anti-ferroptotic genes (FPN, FSP1 and CISD1) in the duodenum of the porcine. Furthermore, the in vitro study has demonstrated that deferiprone, a potent ferroptotic inhibitor, mitigated (P < 0.05) DON-induced cytotoxicity in porcine small intestinal IPEC-J2 cells. Additionally, deferiprone prevented or alleviated (P < 0.05) the dysregulation of ferroptosis-related genes (ACSL4 and FTL) by DON in IPEC-J2 cells. Moreover, specific siRNA knockdown FTL gene expression compromised the DON-induced cell death in IPEC-J2 cells.

CONCLUSIONS

In conclusion, this study revealed that ferroptosis is involved in DON-induced intestinal damage in porcine, and sheds a new light on the toxicity of DON to piglets.

Deoxynivalenol triggers porcine intestinal tight junction disorder: Insights from mitochondrial dynamics and mitophagy

Deoxynivalenol (DON) is universally detected trichothecene in most cereal commodities, which is considered as a major hazardous material for human and animal health. Intestine is the most vulnerable organ with higher concentration of DON than other organs, owing to the first defense barrier function to exogenous substances. However, the underling mechanisms about DON-induced intestinal toxicity remain poorly understood. Here, DON poisoning models of IPEC-J2 cells was established to explore adverse effect and the potential mechanism of DON-induced enterotoxicity. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Intestinal epithelial barrier injury was caused by DON with increasing LDH release, decreasing cell viability as well decreasing tight junction protein expressions (Occludin, N-Cad, ZO-1, Claudin-1 and Claudin-3). Moreover, DON caused mitochondrial dysfunction by opening mitochondrial permeability transition pore and eliminating mitochondrial membrane potential. DON exposure upregulated protein and mRNA expression of mitochondrial fission factors (Drp1, Fis1, MIEF1 and MFF) and mitophagy factors (PINK1, Parkin and LC3), downregulated mitochondrial fusion factors (Mfn1, Mfn2, except OPA1), resulting in mitochondrial dynamics imbalance and mitophagy. Overall, these findings suggested that DON induced tight junction dysfunction in IPEC-J2 cells was related to mitochondrial dynamics-mediated mitophagy.

Analysis of the roles of the Notch1 signalling pathway in modulating deoxynivalenol cytotoxicity

Deoxynivalenol (DON) is a trichothecenes produced by fungi that is widespread and poses a threat to human and animal health. The Notch1 signalling pathway is tightly involved in cell fate determination. The aim of this study was to investigate the role of the Notch1 signalling pathway in DON exposure. Herein, we found that the Notch1 signalling pathway was significantly activated after DON exposure, while Notch1 expression was negatively regulated by DON-induced ROS. Then, the Notch1 signalling pathway was blocked by the γ-secretase inhibitor DAPT in DON exposure. Flow cytometry analysis and antioxidant parameter measurements revealed that DAPT treatment significantly aggravated the oxidative stress induced by DON. The detection of apoptosis showed that DAPT treatment increased the cell apoptotic rate. Further analysis revealed that inhibiting the Notch1 signalling pathway reduced autophagy upon DON exposure. RT-qPCR and Western blot analysis showed that inhibiting the Notch1 signalling pathway aggravated cellular inflammation and activated the MAPK pathway, indicating that the MAPK pathway may be the downstream signalling pathway. Taken together, our research revealed that the Notch1 signalling pathway is essential for protection against DON. Inhibition of Notch1 signalling increases oxidative stress, causes cell apoptosis, reduces autophagy and aggravates cell inflammation after DON exposure. This study investigated the role of the Notch1 signalling pathway in DON exposure and provided a basis for exploring the mechanism of DON.

Ochratoxin A induces cytotoxicity through ROS-mediated endoplasmic reticulum stress pathway in human gastric epithelium cells

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium species that greatly threatens human health. We previously showed that OTA induced cycle arrest, apoptosis and autophagy in human gastric epithelium cells (GES-1). However, the mechanism underlying these effects is still unclear. Here, we showed that OTA exposure increased the expression of endoplasmic reticulum (ER) stress indicators (GRP78, PERK, ATF6, eIF2α, and CHOP), suggesting the activation of the unfolded protein response pathway. 4-phenylbutyric acid (4-PBA), an ER stress-specific inhibitor, attenuated OTA-induced loss of cell viability and apoptosis in GES-1 cells. It also attenuated the G2 phase arrest and autophagy induced by OTA, as evidenced by upregulated G2 phase-related proteins (Cdc2, Cdc25C, and cyclinB1) and downregulated autophagy markers (LC3B and Beclin-1). Moreover, OTA was found to increase ROS generation, and the inhibition of ROS formation by N-acetylcysteine (NAC), an ROS inhibitor, attenuated OTA-induced ER stress and subsequent apoptosis, cell cycle arrest, and autophagy. Collectively, these results suggest that the ROS-mediated ER stress pathway contributes to the OTA toxin-induced cytotoxicity in GES-1 cells. This study offers new insights into the molecular mechanisms underlying OTA toxicity in gastric cells.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.

PINK1/Parkin-mediated mitophagy is activated to protect against AFB1-induced immunosuppression in mice spleen

Aflatoxin B₁ (AFB₁) can cause mitochondrial malfunction and immunosuppression in spleen. Mitochondrial damage can lead to oxidative stress and aggravate immune cell dysfunction. Phosphatase and tensin homolog (PTEN)-induced putative kinase1 (PINK1)/ E3 ubiquitin ligase PARK2 (Parkin)-mediated mitophagy can scavenge damaged mitochondria and alleviate oxidative stress to maintain cellular homeostasis. However, the role of PINK1/Parkin-mediated mitophagy in AFB₁-induced immunosuppression in spleen is unclear. In this study, sixty male mice were sensibilized orally with AFB₁ at different concentrations [0, 0.5, 0.75, and 1 mg/kg body weight (BW)] for 28 days, and AFB₁ caused splenic structure injury and immunosuppression, also led to upregulation of PINK1/Parkin-mediated mitophagy in a dose-dependent manner. Subsequently, thirty male WT C57BL/6 N mice and thirty male Parkin knockout (Parkin^-/-) C57BL/6 N mice were sensibilized orally with AFB₁ at 0 or 1 mg/kg BW for 28 days, and Parkin^-/- inhibited mitophagy and further aggravated AFB₁-induced splenic structure injury, immunosuppression, mitochondrial damage and oxidative stress. Collectively, these results indicate that AFB₁ exposure activates PINK1/Parkin-mediated mitophagy, which protects against immunosuppression in spleen.

Genome-wide transcriptional profiling and functional analysis reveal miR-330-MAPK15 axis involving in cellular responses to deoxynivalenol exposure

Deoxynivalenol (DON) is one of the mycotoxins that is toxic to agricultural environment, which poses high risks to human and farm animal health. Noncoding RNAs have been shown to be crucial regulators of toxicological processes and as promising biomarkers for toxicity monitoring and prevention of mycotoxin contamination. Herein, we characterized genome-wide transcriptional profiling of porcine intestinal epithelial cells upon DON exposure and illustrated a subset of miRNAs and lncRNAs involved in the cellular processes by targeting genes associated with stress responses. A total of 110 differential expression miRNAs and 143 differential expression lncRNAs were identified between the DON exposure and control cell samples. Interactive network analysis showed that miR-330 was one hub noncoding RNA, expression of which was significantly increased upon DON exposure. Functional enrichment analysis indicated that the genes involved in the networks were mainly enriched in the terms of plasma membrane bounded cell projection assembly, mRNA processing, and regulation of mitochondrion organization. Further functional analysis revealed that high expression of miR-330 inhibits the reactive oxygen species production, cell apoptosis, and autophagic flux in cells upon DON exposure. Luciferase assay further indicated that miR-330 could directly target MAPK15. Knockdown of MAPK15 resulted in decreased reactive oxygen species level and cell apoptosis induced by DON, indicating the existence of miR-330-MAPK15 regulatory axis in regulating DON toxicity. Our work shed novel insights into the mode of action of DON at cellular level and indicated the potential of miR-330 as a biomarker for toxicity monitoring of DON contamination, which contributes to the development of effective biomonitoring and prevention strategies to reduce the toxicological effects of DON.

Lactobacillus rhamnosus GG ameliorates deoxynivalenol-induced kidney oxidative damage and mitochondrial injury in weaned piglets

Deoxynivalenol (DON) is a common mycotoxin that pollutes food crops and adversely affects the health of animals, even humans. Lactobacillus rhamnosus GG (LGG) can alleviate intestinal injury, and anti-inflammatory and antioxidant effects. However, the potential of LGG in alleviating kidney injury induced by DON in piglets remains to be studied. The objective of this study was to investigate the adverse effect of DON on kidney injury and the protective ability of LGG. A total of twenty-seven weaned piglets were divided into three groups: CON group, DON group (3.11 mg kg^-1 feed) and LGG + DON group (LGG powder 1 g kg^-1 + DON 3.15 mg kg^-1 feed). DON increased the MDA content, and decreased antioxidant enzyme activity (GSH-Px) and total antioxidant capacity (P < 0.05). Meanwhile, DON activated the Nrf2 antioxidant pathway. However, LGG supplementation alleviated the damage of DON to the kidney antioxidant system of piglets. Notably, DON significantly reduced the Sirt3 expression (P < 0.05), which was alleviated by LGG addition. The expression of mitochondrial biogenesis related factors such as VDAC1 and Cyt C was up-regulated by DON (P < 0.05), and LGG could improve mitochondrial ultrastructural abnormalities and mitochondrial dysfunction. In addition, LGG mitigated DON-induced mitochondrial fusion inhibition, and prevented DON-mediated mitochondrial autophagy. In conclusion, LGG play a protective role in DON-induced kidney toxicity, and dietary intervention may be a strategy to reduce mycotoxins.

Maternal organic selenium supplementation alleviates LPS induced inflammation, autophagy and ER stress in the thymus and spleen of offspring piglets by improving the expression of selenoproteins

The thymus and spleen are the main reservoir for T lymphocytes, which can regulate the innate immune response and provide protection against pathogens and tissue damage. Oxidative stress, excessive inflammation, abnormal autophagy and endoplasmic reticulum (ER) stress can all lead to dysfunction of the thymus and spleen. This study was conducted to investigate the effect of maternal 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, an organic Se source) supplementation during pregnancy on the selenoprotein expression, inflammation, ER stress and autophagy of their young offspring's thymus and spleen. Thirty sows were randomly assigned to receive one of the following two diets during gestation: control diet (control, basal diet, n = 15) or HMSeBA supplemented diet (HMSeBA, basal diet +0.3 mg Se kg^-1 as HMSeBA, n = 15). Tissues of thymus and spleen were collected from the offspring at birth and weaning after the lipopolysaccharide challenge. Results showed that maternal HMSeBA supplementation significantly up-regulated the gene expression of selenoproteins in the thymus and spleen of newborn piglets compared with the basal diet (p < 0.05), as well as the protein abundance of GPX1 and GPX4 (p < 0.05). In addition, maternal HMSeBA supplementation effectively decreased the expression of inflammation and autophagy related proteins in the thymus and spleen of newborn piglets as compared with the control group (p < 0.05). In weaning piglets, maternal HMSeBA significantly increased the antioxidative capacity of thymus and spleen (p < 0.05), and reversed LPS induced MDA content as compared with the control group (p < 0.05). Furthermore, maternal HMSeBA supplementation during gestation reversed the activation of the MAPK/NF-κB pathway, ER stress and autophagy induced by the LPS challenge in the thymus and spleen of weaning piglets (p < 0.05). In conclusion, maternal HMSeBA supplementation during gestation could decrease the level of inflammation, autophagy and ER stress in the thymus and spleen of young offspring by improving the antioxidative capacity and selenoprotein expression in these tissues. Therefore, maternal HMSeBA supplementation during gestation might be beneficial for the immune function of their offspring by alleviating inflammation, autophagy and ER stress levels in the thymus and spleen. This study showed more evidence for the function of Se on mater-offspring integrated nutrition.

Supplementing daidzein in diets improves the reproductive performance, endocrine hormones and antioxidant capacity of multiparous sows

Certain hormones play important roles in modulating mammalian reproductive behaviour. Daidzein is a well-known isoflavonic phytoestrogen that possesses oestrogenic activity. This study was conducted to probe the effects of daidzein supplementation in gestation diets on the reproductive performance in sows. A total of 120 multiparous sows (Landrace × Yorkshire) were randomly assigned to 2 groups (n = 60) and fed either a base diet (control) or one containing 200 mg/kg daidzein during gestation. We discovered that daidzein supplementation significantly increased the total number of piglets born per litter and number of piglets born alive per litter (P < 0.05), decreased the farrowing time (P < 0.05) and increased the serum oestrogen and progesterone concentrations (P < 0.05) at 35 d of gestation. Moreover, serum immunoglobulin G (IgG) concentration and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were higher in the daidzein-treated group than in the control group at 35 d of gestation (P < 0.05). Daidzein increased the serum SOD activity and total anti-oxidative capacity (T-AOC) at 85 d of gestation (P < 0.05). Interestingly, daidzein elevated the expression levels of the sodium-coupled neutral amino acid transporter 1 (SLC38A1) and insulin-like growth factor 1 (IGF-1) genes in the placenta (P < 0.05). These results suggest that daidzein ingestion could improve sow reproductive performance by changing serum hormones, elevating anti-oxidative capacity and up-regulating critical functional genes in the placenta.

Deoxynivalenol: Mechanisms of action and its effects on various terrestrial and aquatic species

Deoxynivalenol, a type B trichothecene mycotoxin produced by Fusarium species of fungi, is a ubiquitious contaminant of cereal grains worldwide. Chronic, low dose consumption of feeds contaminated with DON is associated with a wide range of symptoms in terrestrial and aquatic species including decreased feed intake and feed refusal, reduced weight gain, and altered nutritional efficiency. Acute, high dose exposure to DON may be associated with more severe symptoms such as vomiting, diarrhea, intestinal inflammation and gastrointestinal hemorrhage. The toxicity of DON is partly related to its ability to disrupt eukaryotic protein synthesis via binding to the peptidyl transferase site of the ribosome. Moreover, DON exerts its effects at the cellular level by activating mitogen activated protein kinases (MAPK) through a process known as the ribotoxic stress response (RSR). The outcome of DON-associated MAPK activation is dose and duration dependent; acute low dose exposure results in immunostimulation characterized by the upregulation of cytokines, chemokines and other proinflammatory-related proteins, whereas longer term exposure to higher doses generally results in apoptosis, cell cycle arrest, and immunosuppression. The order of decreasing sensitivity to DON is considered to be: swine > rats > mice > poultry ≈ ruminants. However, studies conducted within the past 10 years have demonstrated that some species of fish, such as rainbow trout, are highly sensitive to DON. The aims of this review are to explore the effects of DON on terrestrial and aquatic species as well as its mechanisms of action, metabolism, and interaction with other Fusarium mycotoxins. Notably, a considerable emphasis is placed on reviewing the effects of DON on different species of fish.

The toxicity mechanisms of DON to humans and animals and potential biological treatment strategies

Deoxynivalenol, also known as vomitotoxin, is produced by Fusarium, belonging to the group B of the trichothecene family. DON is widely polluted, mainly polluting cereal crops such as wheat, barley, oats, corn and related cereal products, which are closely related to lives of people and animals. At present, there have been articles summarizing DON induced toxicity, biological detoxification and the protective effect of natural products, but there is no systematic summary of this information. In addition to ribosome and endoplasmic reticulum, recent investigations support that mitochondrion is also organelles that DON can damage. DON can't directly act on mitochondria, but can indirectly cause mitochondrial damage and changes through other means. DON can indirectly inhibit mitochondrial biogenesis and mitochondrial electron transport chain activity, ATP production, and mitochondrial transcription and translation. This review will provide the latest progress on mitochondria as the research object, and systematically summarizes all the toxic mechanisms of DON. Here, we discuss DON induced mitochondrial-mediated apoptosis and various mitochondrial toxicity. For the toxicity of DON, many methods have been derived to prevent or reduce the toxicity. Biological detoxification and the antioxidant effect of natural products are potentially effective treatments for DON toxicity.

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth, antioxidant status, and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.

New Determination Methods, Toxic Mechanisms, and Control Strategies (Preface to the special issue of Food and Chemical Toxicology on the Outcomes of Mycotoxins in Food)

The special issue "Mycotoxins in Food: New Determination Methods, Toxic Mechanisms, and Control Strategies" in Food and Chemical Toxicology contains 28 articles on current hot topics in mycotoxins, including deoxynivalenol, T-2 toxin, and fumonisins. Intestinal toxicity, immune toxicity, and oxidative stress are especially concerned by researchers in this special issue; moreover, mycotoxin detoxification and exposure and assessments in humans are reported in this context. All the new results in this special issue will help to further understand the toxic mechanisms of mycotoxins and cast new light for the control of mycotoxin contamination.

Exploring the dermotoxicity of the mycotoxin deoxynivalenol: combined morphologic and proteomic profiling of human epidermal cells reveals alteration of lipid biosynthesis machinery and membrane structural integrity relevant for skin barrier function

Deoxynivalenol (vomitoxin, DON) is a secondary metabolite produced by Fusarium spp. fungi and it is one of the most prevalent mycotoxins worldwide. Crop infestation results not only in food and feed contamination, but also in direct dermal exposure, especially during harvest and food processing. To investigate the potential dermotoxicity of DON, epidermoid squamous cell carcinoma cells A431 were compared to primary human neonatal keratinocytes (HEKn) cells via proteome/phosphoproteome profiling. In A431 cells, 10 µM DON significantly down-regulated ribosomal proteins, as well as mitochondrial respiratory chain elements (OXPHOS regulation) and transport proteins (TOMM22; TOMM40; TOMM70A). Mitochondrial impairment was reflected in altered metabolic competence, apparently combined with interference of the lipid biosynthesis machinery. Functional effects on the cell membrane were confirmed by live cell imaging and membrane fluidity assays (0.1–10 µM DON). Moreover, a common denominator for both A431 and HEKn cells was a significant downregulation of the squalene synthase (FDFT1). In sum, proteome alterations could be traced back to the transcription factor Klf4, a crucial regulator of skin barrier function. Overall, these results describe decisive molecular events sustaining the capability of DON to impair skin barrier function. Proteome data generated in the study are fully accessible via ProteomeXchange with the accession numbers PXD011474 and PXD013613.

Hypoxia, oxidative stress, and immune evasion: a trinity of the trichothecenes T-2 toxin and deoxynivalenol (DON)

T-2 toxin and deoxynivalenol (DON) are type A and B trichothecenes, respectively. They widely occur as pollutants in food and crops and cause a series of toxicities, including immunotoxicity, hepatotoxicity, and neurotoxicity. Oxidative stress is the primary mechanistic basis of these toxic effects. Increasing amounts of evidence have shown that mitochondria are significant targets of apoptosis caused by T-2 toxin- and DON-induced oxidative stress via regulation of Bax/B-cell lymphoma-2 and caspase-3/caspase-9 signaling. DNA methylation and autophagy are involved in oxidative stress related to apoptosis, and hypoxia and immune evasion are related to oxidative stress in this context. Hypoxia induces oxidative stress by stimulating mitochondrial reactive oxygen species production and regulates the expression of cytokines, such as interleukin-1β and tumor necrosis factor-α. Programmed cell death-ligand 1 is upregulated by these cytokines and by hypoxia-inducible factor-1, which allows it to bind to programmed cell death-1 to enable escape of immune cell surveillance and achievement of immune evasion. This review concentrates on novel findings regarding the oxidative stress mechanisms of the trichothecenes T-2 toxin and DON. Importantly, we discuss the new evidence regarding the connection of hypoxia and immune evasion with oxidative stress in this context. Finally, the trinity of hypoxia, oxidative stress and immune evasion is highlighted. This work will be conducive to an improved understanding of the oxidative stress caused by trichothecene mycotoxins.

Protective effects of Bacillus subtilis ASAG 216 on growth performance, antioxidant capacity, gut microbiota and tissues residues of weaned piglets fed deoxynivalenol contaminated diets

Deoxynivalenol (DON) poses a serious health threat to animals and humans consuming DON-contaminated food and feed. Biological means of detoxification of DON are considered as one of the effective strategies. The aim of the work was to study ameliorative effects of Bacillus subtilis ASAG 216 on DON-induced toxicosis in piglets. A decrease in average daily gain and average daily feed intake was observed in piglets fed DON-contaminated feed. In addition, DON exposure increased the serum concentrations of aspartate aminotransferase, immunoglobulin A, diamine oxidase, endotoxin, and peptide YY. Moreover, DON exposure caused oxidative stress in the serum, liver and jejunum, induced intestinal inflammation, impaired the intestinal barrier, and disturbed the gut microbiota homeostasis. Supplementation of B. subtilis ASAG 216 effectively attenuated the aforementioned effects of DON on piglets. Moreover, DON and de-epoxy-DON (DOM-1) in the serum, liver and kidney were significantly decreased when B. subtilis ASAG 216 was added to DON-contaminated diet. Our results imply that B. subtilis ASAG 216 can protect against DON-induced toxicosis in piglets, and thus this strain has a potential to be used as an animal feed ingredient to counteract harmful effects of DON in animals.