Transcription Factor FOXO3a Is a Negative Regulator of Cytotoxicity of Fusarium mycotoxin in GES-1 Cells

Protective Mechanisms of Various Active Substances on Cell DNA Damage and Apoptosis Induced by Deoxynivalenol

Deoxynivalenol (DON) is a secondary metabolite of fungi that is harmful to humans and animals. This study examined the protective effects of natural substances, including resveratrol, quercetin, vitamin E, vitamin C, and microbe-derived antioxidants (MA), on both human gastric mucosal cells (GES-1) and pig small intestinal epithelial cells (IPEC-1) when induced by DON. Cells were incubated with active substances for 3 h and then exposed to DON for 24 h. The oxidative stress index, cell cycle, and apoptosis were measured. As compared to cells treated only with DON, pretreatment with active substances improved the balance of the redox status in cells caused by DON. Specifically, quercetin, vitamin E, vitamin C, and MA showed the potential to alleviate the G2 phase cell cycle arrest effect that was induced by DON in both kinds of cells. It was observed that vitamin E and vitamin C can alleviate DON-induced apoptosis and the G2 phase cycle arrest effect mediated via the ATM-Chk 2-Cdc 25C and ATM-P53 signaling pathways in GES-1 cells. In IPEC-1 cells, vitamin C and MA can alleviate both DON-induced apoptosis and the G2 phase cycle arrest effect via the ATM-Chk 2-Cdc 25C signaling pathway. Different bioactive substances utilize different protective mechanisms against DON in interacting with different cells. The proper addition of vitamin E and vitamin C to food can neutralize the toxic effect of DON, while the addition of vitamin C and MA to animal feed can reduce the harm DON does to animals.

Deoxynivalenol: Emerging Toxic Mechanisms and Control Strategies, Current and Future Perspectives

Deoxynivalenol (DON) is the most frequently present mycotoxin contaminant in food and feed, causing a variety of toxic effects in humans and animals. Currently, a series of mechanisms involved in DON toxicity have been identified. In addition to the activation of oxidative stress and the MAPK signaling pathway, DON can activate hypoxia-inducible factor-1α, which further regulates reactive oxygen species production and cancer cell apoptosis. Noncoding RNA and signaling pathways including Wnt/β-catenin, FOXO, and TLR4/NF-κB also participate in DON toxicity. The intestinal microbiota and the brain-gut axis play a crucial role in DON-induced growth inhibition. In view of the synergistic toxic effect of DON and other mycotoxins, strategies to detect DON and control it biologically and the development of enzymes for the biodegradation of various mycotoxins and their introduction in the market are the current and future research hotspots.

Deoxynivalenol Induces Apoptosis via FOXO3a-Signaling Pathway in Small-Intestinal Cells in Pig

Deoxynivalenol (DON) is a mycotoxin that is found in feed ingredients derived from grains such as corn and wheat. Consumption of DON-contaminated feed has been shown to cause damage to the intestine, kidneys, and liver. However, the molecular mechanism by which DON exerts its effect in the small intestine is not completely understood. As a result, we profiled gene expression in intestinal epithelial cells treated with DON and examined the molecular function in vitro. We hypothesized that DON could induce apoptosis via the FOXO3a-signaling pathway in intestinal epithelial cells based on these findings. DON induced the apoptosis and the translocation of FOXO3a into the nucleus. Moreover, the inhibiting of FOXO3a alleviated the apoptosis and expression of apoptosis-related genes (TRAL, BCL-6, CASP8, and CASP3). ERK1/2 inhibitor treatment suppressed the translocation of FOXO3a into the nucleus. Our discovery suggests that DON induces apoptosis in intestinal epithelial cells through the FOXO3a-signaling pathway.

Deoxynivalenol induces apoptosis and autophagy in human prostate epithelial cells via PI3K/Akt signaling pathway

Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway is one of the most deregulated signaling pathway in prostate cancer. It controls basic processes in cells: cell proliferation and death. Any disturbances in the balance between cell death and survival might result in carcinogenesis. Deoxynivalenol (DON) is one of the most common mycotoxins, a toxic metabolites of fungi, present in our everyday diet and feed. Although previous studies reported DON to induce oxidative stress, modulate steroidogenesis, DNA damage and cell cycle modulation triggering together its toxicity, its effect on normal prostate epithelial cells is not known. The aim of the study was to evaluate the effect of DON on the apoptosis and autophagy in normal prostate epithelial cells via modulation of PI3K/Akt signaling pathway. The results showed that DON in a dose of 30 µM and 10 µM induces oxidative stress, DNA damage and cell cycle arrest in G2/M cell cycle phase. The higher concentration of DON induces apoptosis, whereas lower one autophagy in PNT1A cells, indicating that modulation of PI3K/Akt by DON results in the induction of autophagy triggering apoptosis in normal prostate epithelial cells.

Organ-differential Roles of Akt/FoxOs Axis as a Key Metabolic Modulator during Aging

FoxOs and their post-translational modification by phosphorylation, acetylation, and methylation can affect epigenetic modifications and promote the expression of downstream target genes. Therefore, they ultimately affect cellular and biological functions during aging or occurrence of age-related diseases including cancer, diabetes, and kidney diseases. As known for its key role in aging, FoxOs play various biological roles in the aging process by regulating reactive oxygen species, lipid accumulation, and inflammation. FoxOs regulated by PI3K/Akt pathway modulate the expression of various target genes encoding MnSOD, catalases, PPARγ, and IL-1β during aging, which are associated with age-related diseases. This review highlights the age-dependent differential regulatory mechanism of Akt/FoxOs axis in metabolic and non-metabolic organs. We demonstrated that age-dependent suppression of Akt increases the activity of FoxOs (Akt/FoxOs axis upregulation) in metabolic organs such as liver and muscle. This Akt/FoxOs axis could be modulated and reversed by antiaging paradigm calorie restriction (CR). In contrast, hyperinsulinemia-mediated PI3K/Akt activation inhibited FoxOs activity (Akt/FoxOs axis downregulation) leading to decrease of antioxidant genes expression in non-metabolic organs such as kidneys and lungs during aging. These phenomena are reversed by CR. The results of studies on the process of aging and CR indicate that the Akt/FoxOs axis plays a critical role in regulating metabolic homeostasis, redox stress, and inflammation in various organs during aging process. The benefical actions of CR on the Akt/FoxOs axis in metabolic and non-metabolic organs provide further insights into the molecular mechanisms of organ-differential roles of Akt/FoxOs axis during aging.

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.

FoxO3 Modulates LPS-Activated Hepatic Inflammation in Turbot (Scophthalmus maximus L.)

In mammals, forkhead box O3 (foxo3) plays important roles in liver immune system. The foxo3 can regulate cell cycle, DNA repair, hypoxia, apoptosis and so on. However, as such an important transcription factor, few studies on foxo3 in fish have been reported. The present study characterized the foxo3 in turbot (Scophthalmus maximus L.). Lipopolysaccharide (LPS) incubated in vitro (hepatocytes) and injected in vivo (turbot liver) were used to construct inflammatory models. The foxo3 was interfered and overexpressed to investigate its functions in liver inflammation. The open reading frame (ORF) of foxo3 was 1998 bp (base pair), encoding 665 amino acids. Sequence analysis showed that foxo3 of turbot was highly homologous to other fishes. Tissue distribution analysis revealed that the highest expression of foxo3 was in muscle. Immunofluorescence result showed that foxo3 was expressed in cytoplasm and nucleus. Knockdown of foxo3 significantly increased mRNA levels of tumor necrosis factor-α (tnf-α), interleukin-1β (il-1β), interleukin-6 (il-6), myeloid-differentiation factor 88 (myd88), cd83, toll-like receptor 2 (tlr-2) and protein level of c-Jun N-terminal kinase (JNK) in sifoxo3 + LPS (siRNA of foxo3+ LPS) group compared with NC + LPS (negative control + LPS) group in turbot hepatocytes. Overexpressed foxo3 significantly decreased mRNA levels of tnf-α, il-6, nuclear transcription factor-kappa B (nf-κb), cd83, tlr-2 and the protein level of JNK in vitro. In vivo analysis, foxo3 knockdown significantly increased levels of GOT in serum after LPS injection compared with NC+LPS group. Overexpressed foxo3 significantly decreased levels of GPT and GOT in pcDNA3.1-foxo3+LPS group compared with pcDNA3.1+LPS group in vivo. Foxo3 knockdown significantly increased mRNA levels of tnf-α, il-1β, il-6, nf-κb, myd88 and protein level of JNK in vivo in sifoxo3+LPS group compared with NC+LPS group in turbot liver. Overexpressed foxo3 significantly decreased mRNA levels of il-1β, il-6, myd88, cd83, jnk and protein level of JNK in pcDNA3.1-foxo3+LPS group compared with pcDNA3.1+LPS group in turbot liver. The results indicated that foxo3 might modulate LPS-activated hepatic inflammation in turbot by decreasing the proinflammatory cytokines, the levels of GOT and GPT as well as activating JNK/caspase-3 and tlr-2/myd88/nf-κb pathways. Taken together, these findings indicated that FoxO3 may play important roles in liver immune responses to LPS in turbot and the research of FoxO3 in liver immunity enriches the studies on immune regulation, and provides theoretical basis and molecular targets for solving liver inflammation and liver injury in fish.

Evaluation of the Individual and Combined Toxicity of Fumonisin Mycotoxins in Human Gastric Epithelial Cells

Fumonisin contaminates food and feed extensively throughout the world, causing chronic and acute toxicity in human and animals. Currently, studies on the toxicology of fumonisins mainly focus on fumonisin B1 (FB1). Considering that FB1, fumonisin B2 (FB2) and fumonisin B3 (FB3) could coexist in food and feed, a study regarding a single toxin, FB1, may not completely reflect the toxicity of fumonisin. The gastrointestinal tract is usually exposed to these dietary toxins. In our study, the human gastric epithelial cell line (GES-1) was used as in vitro model to evaluate the toxicity of fumonisin. Firstly, we found that they could cause a decrease in cell viability, and increase in membrane leakage, cell death and the induction of expression of markers for endoplasmic reticulum (ER) stress. Their toxicity potency rank is FB1 > FB2 >> FB3. The results also showed that the synergistic effect appeared in the combinations of FB1 + FB2 and FB1 + FB3. Nevertheless, the combinations of FB2 + FB3 and FB1 + FB2 + FB3 showed a synergistic effect at low concentration and an antagonistic effect at high concentration. We also found that myriocin (ISP-1) could alleviate the cytotoxicity induced by fumonisin in GES-1 cells. Finally, this study may help to determine or optimize the legal limits and risk assessment method of mycotoxins in food and feed and provide a potential method to block the fumonisin toxicity.

The Degradation of Deoxynivalenol by Using Electrochemical Oxidation with Graphite Electrodes and the Toxicity Assessment of Degradation Products

Deoxynivalenol (DON) is a common mycotoxin, which is known to be extremely harmful to human and livestock health. In this study, DON was degraded by electrochemical oxidation (ECO) using a graphite electrode and NaCl as the supporting electrolyte. The graphite electrode is advantageous due to its electrocatalytic activity, reusability, and security. The degradation process can be expressed by first-order kinetics. Approximately 86.4% of DON can be degraded within 30 min at a potential of 0.5 V. The degradation rate reached 93.2% within 30 min, when 0.5 V potential was used for electrocatalyzing a 10 mg/L DON solution. The degradation rate of DON in contaminated wet distiller's grain with solubles (WDGS) was 86.37% in 60 min. Moreover, results from the cell counting kit-8 (CCK-8) and 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining assay indicated that ECO reduced the DON-induced cytotoxicity and apoptotic bodies in a gastric epithelial cell line (GES-1) compared to the DON-treated group. These findings provide new insights into the application of ECO techniques for degrading mycotoxins, preventing food contamination, and assessing DON-related hazards.

Deoxynivalenol Modulates the Viability, ROS Production and Apoptosis in Prostate Cancer Cells

Deoxynivalenol (DON), known as vomitoxin, a type B trichothecene, is produced by Fusarium. DON frequently contaminates cereal grains such as wheat, maize, oats, barley, rye, and rice. At the molecular level, it induces ribosomal stress, inflammation and apoptosis in eukaryotic cells. Our findings indicate that DON modulates the viability of prostate cancer (PCa) cells and that the response to a single high dose of DON is dependent on the androgen-sensitivity of cells. DON appears to increase reactive oxygen species (ROS) production in cells, induces DNA damage, and triggers apoptosis. The effects of DON application in PCa cells are influenced by the mitogen-activated protein kinase (MAPK) and NFΚB- HIF-1α signaling pathways. Our results indicate that p53 is a crucial factor in DON-associated apoptosis in PCa cells. Taken together, our findings show that a single exposure to high concentrations of DON (2-5 µM) modulates the progression of PCa.