EGR1 is essential for deoxynivalenol-induced G2/M cell cycle arrest in HepG2 cells via the ATF3ΔZip2a/2b-EGR1-p21 pathway

Deoxynivalenol induces m6A-mediated upregulation of p21 and growth arrest of mouse hippocampal neuron cells in vitro

Hippocampal neurons maintain the ability of proliferation throughout life to support neurogenesis. Deoxynivalenol (DON) is a mycotoxin that exhibits brain toxicity, yet whether and how DON affects hippocampal neurogenesis remains unknown. Here, we use mouse hippocampal neuron cells (HT-22) as a model to illustrate the effects of DON on neuron proliferation and to explore underlying mechanisms. DON exposure significantly inhibits the proliferation of HT-22 cells, which is associated with an up-regulation of cell cycle inhibitor p21 at both mRNA and protein levels. Global and site-specific m6A methylation levels on the 3'UTR of p21 mRNA are significantly increased in response to DON treatment, whereas inhibition of m6A hypermethylation significantly alleviates DON-induced cell cycle arrest. Further mechanistic studies indicate that the m6A readers YTHDF1 and IGF2BP1 are responsible for m6A-mediated increase in p21 mRNA stability. Meanwhile, 3'UTR of E3 ubiquitin ligase TRIM21 mRNA is also m6A hypermethylated, and another m6A reader YTHDF2 binds to the m6A sites, leading to decreased TRIM21 mRNA stability. Consequently, TRIM21 suppression impairs ubiquitin-mediated p21 protein degradation. Taken together, m6A-mediated upregulation of p21, at both post-transcriptional and post-translational levels, contributes to DON-induced inhibition of hippocampal neuron proliferation. These results may provide new insights for epigenetic therapy of neurodegenerative diseases.

Discovery of WS-384, a first-in-class dual LSD1 and DCN1-UBC12 protein-protein interaction inhibitor for the treatment of non-small cell lung cancer

Abnormally high expression of lysine-specific demethylase 1 A (LSD1) and DCN1 plays a vital role in the occurrence, development, and poor prognosis of non-small cell lung cancer (NSCLC). Accumulating evidence has shown that the development of small-molecule inhibitors dually targeting LSD1 and the DCN1-UBC12 interaction probably have therapeutic promise for cancer therapy. This work reported that WS-384 dually targeted LSD1 and DCN1-UBC12 interactions and evaluated its antitumor effects in vitro and in vivo. Specifically, WS-384 inhibited A549 and H1975 cells viability and decreased colony formation and EdU incorporation. WS-384 could also trigger cell cycle arrest, DNA damage, and apoptosis. Moreover, WS-384 significantly decreased tumor weight and volume in A549 xenograft mice. Mechanistically, WS-384 increased the gene and protein level of p21 by suppressing the neddylation of cullin 1 and decreasing H3K4 demethylation at the CDKN1A promoter. The synergetic upregulation of p21 contributed to cell cycle arrest and the proapoptotic effect of WS-384 in NSCLC cells. Taken together, our proof of concept studies demonstrated the therapeutic potential of dual inhibition of LSD1 and the DCN1-UBC12 interaction for the treatment of NSCLC. WS-384 could be used as a lead compound to develop new dual LSD1/DCN1 inhibitors for the treatment of human diseases in which LSD1 and DCN1 are dysregulated.

The Dual Roles of Activating Transcription Factor 3 (ATF3) in Inflammation, Apoptosis, Ferroptosis, and Pathogen Infection Responses

Transcription factors are pivotal regulators in the cellular life process. Activating transcription factor 3 (ATF3), a member of the ATF/CREB (cAMP response element-binding protein) family, plays a crucial role as cells respond to various stresses and damage. As a transcription factor, ATF3 significantly influences signal transduction regulation, orchestrating a variety of signaling pathways, including apoptosis, ferroptosis, and cellular differentiation. In addition, ATF3 serves as an essential link between inflammation, oxidative stress, and immune responses. This review summarizes the recent advances in research on ATF3 activation and its role in regulating inflammatory responses, cell apoptosis, and ferroptosis while exploring the dual functions of ATF3 in these processes. Additionally, this article discusses the role of ATF3 in diseases related to pathogenic microbial infections. Our review may be helpful to better understand the role of ATF3 in cellular responses and disease progression, thus promoting advancements in clinical treatments for inflammation and oxidative stress-related diseases.

From ribosome to ribotoxins: understanding the toxicity of deoxynivalenol and Shiga toxin, two food borne toxins

Ribosomes that synthesize proteins are among the most central and evolutionarily conserved organelles. Given the key role of proteins in cellular functions, prokaryotic and eukaryotic pathogens have evolved potent toxins to inhibit ribosomal functions and weaken their host. Many of these ribotoxin-producing pathogens are associated with food. For example, food can be contaminated with bacterial pathogens that produce the ribotoxin Shiga toxin, but also with the fungal ribotoxin deoxynivalenol. Shiga toxin cleaves ribosomal RNA, while deoxynivalenol binds to and inhibits the peptidyl transferase center. Despite their distinct modes of action, both groups of ribotoxins hinder protein translation, but also trigger other comparable toxic effects, which depend or not on the activation of the ribotoxic stress response. Ribotoxic stress response-dependent effects include inflammation and apoptosis, whereas ribotoxic stress response-independent effects include endoplasmic reticulum stress, oxidative stress, and autophagy. For other effects, such as cell cycle arrest and cytoskeleton modulation, the involvement of the ribotoxic stress response is still controversial. Ribotoxins affect one organelle yet induce multiple toxic effects with multiple consequences for the cell. The ribosome can therefore be considered as the cellular "Achilles heel" targeted by food borne ribotoxins. Considering the high toxicity of ribotoxins, they pose a substantial health risk, as humans are highly susceptible to widespread exposure to these toxins through contaminated food sources.

Resveratrol protects against deoxynivalenol-induced ferroptosis in HepG2 cells

Deoxynivalenol (DON) is one of the most serious mycotoxins that contaminate food and feed, causing hepatocyte death. However, there is still a lack of understanding regarding the new cell death modalities that explain DON-induced hepatocyte toxicity. Ferroptosis is an iron-dependent type of cell death. The aim of this study was to explore the role of ferroptosis in DON-exposed HepG2 cytotoxicity and the antagonistic effect of resveratrol (Res) on its toxicity, and the underlying molecular mechanisms. HepG2 cells were treated with Res (8μM) or/and DON (0.4μM) for 12hours. We examined cell viability, cell proliferation, expression of ferroptosis-related genes, levels of lipid peroxidation and Fe(II). The results revealed that DON reduced the expression levels of GPX4, SLC7A11, GCLC, NQO1, and Nrf2 while promoting the expression of TFR1, GSH depletion, accumulation of MDA and total ROS. DON enhanced production of 4-HNE, lipid ROS and Fe(II) overload, resulting in ferroptosis. However, pretreatment with Res reversed these changes, attenuating DON-induced ferroptosis, improving cell viability and cell proliferation. Importantly, Res prevented Erastin and RSL3-induced ferroptosis, suggesting that Res exerted an anti-ferroptosis effect by activating SLC7A11-GSH-GPX4 signaling pathways. In summary, Res ameliorated DON-induced ferroptosis in HepG2 cells. This study provides a new perspective on the mechanism of DON-induced hepatotoxicity formation, and Res may be an effective drug to alleviate DON-induced hepatotoxicity.

Mycotoxins Have a Potential of Inducing Cell Senescence: A New Understanding of Mycotoxin Immunotoxicity

Mycotoxins result in immune dysfunction and cause immune diseases in animals and humans. However, the mechanisms of immunotoxicity involved in mycotoxins have not been fully explored, and emerging evidence suggests that these toxins may promote their immunotoxicity via cellular senescence. Mycotoxins induce cell senescence after DNA damage, and activate signaling via the NF-κB and JNK pathways to promote the secretion of senescence-associated secretory phenotype (SASP) cytokines including IL-6, IL-8, and TNF-α. DNA damage can also over-activate or cleave poly (ADP-ribose) polymerase-1 (PARP-1), increase the expression of cell cycle inhibitory proteins p21, and p53, and induce cell cycle arrest and then senescence. These senescent cells further down-regulate proliferation-related genes and overexpress inflammatory factors resulting in chronic inflammation and eventual immune exhaustion. Here we review the underlying mechanisms by which mycotoxins trigger cell senescence and the potential roles of SASP and PARP in these pathways. This work will help to further understand the mechanisms of immunotoxicity involved in mycotoxins.

Role of epigenetics in mycotoxin toxicity: a review

Mycotoxins can induce cell cycle disorders, cell proliferation, oxidative stress, and apoptosis through pathways such as those associated with MAPK, JAK2/STAT3, and Bcl-w/caspase-3, and cause reproductive toxicity, immunotoxicity, and genotoxicity. Previous studies have explored the toxicity mechanism of mycotoxins from the levels of DNA, RNA, and proteins, and proved that mycotoxins have epigenetic toxicity. To explore the toxic effects and mechanisms of these changes in mycotoxins, this paper summarizes the changes in DNA methylation, non-coding RNA, RNA and histone modification induced by several common mycotoxins (zearalenone, aflatoxin B1, ochratoxin A, deoxynivalenol, T-2 toxin, etc.) based on epigenetic studies. In addition, the roles of mycotoxin-induced epigenetic toxicity in germ cell maturation, embryonic development, and carcinogenesis are highlighted. In summary, this review provides theoretical support for a better understanding of the regulatory mechanism of mycotoxin epigenotoxicity and the diagnosis and treatment of diseases.

Impact of Deoxynivalenol and Zearalenone as Single and Combined Treatment on DNA, Cell Cycle and Cell Proliferation in HepG2 Cells

The study aimed to investigate toxicity and the mechanism of toxicity of two Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZEA). DON and ZEA were applied to HepG2 cells as single compounds and in combination at low environmentally relevant concentrations. HepG2 cells were exposed to DON (0.5, 1, and 2 µM), ZEA (5, 10, and 20 µM) or their combinations (1 µM DON + 5 µM ZEA, 1 µM DON + 10 µM ZEA and 1 µM DON + 20 µM ZEA) for 24 h and cell viability, DNA damage, cell cycle and proliferation were assessed. Both mycotoxins reduced cell viability, however, combined treatment with DON and ZEA resulted in higher reduction of cell viability. DON (1 µM) induced primary DNA damage, while DON (1 µM) in combination with higher ZEA concentrations showed antagonistic effects compared to DON alone at 1 µM. DON arrested HepG2 cells in G2 phase and significantly inhibited cell proliferation, while ZEA had no significant effect on cell cycle. The combined treatment with DON and ZEA arrested cells in G2 phase to a higher extend compared to treatment with single mycotoxins. Potentiating effect observed after DON and ZEA co-exposure at environmentally relevant concentrations indicates that in risk assessment and setting governments' regulations, mixtures of mycotoxins should be considered.

Hainanolide inhibits the progression of colon cancer via inducing the cell cycle arrest, cell apoptosis and activation of the MAPK signaling pathway

Hainanolide (HN) is a norditerpenoid metabolite extract from Cephalotaxus fortunei Hook. f. C. fortunei Hook. f. is renowned for the active alkaloids, such as harringtonine (HT) and homoharringtonin (HTT), which have been clinically used to treat chronic myeloid leukemia. Nowadays, diterpenoids, another important metabolite, attracted the attention of chemists. Among them, Hainanolide (HN), a cephalotane-type diterpenoid, has been proven to possess potent antitumor activities. However, the underlying therapeutic mechanisms of HN in anti-tumor have not been investigated yet. Our present study demonstrated that HN inhibited HCT-116 and HCT-15 cell proliferation in a dose- and time-dependent manner. Further studies demonstrated that HN can induce G2/M phase arrest and alter the Cdc25C/Cdc2/CyclinB1 proteins. Western blot indicated that HN promoted apoptosis by up-regulating Bax and down-regulated Bcl-2. And the caspase-3 and caspase-9 activities of HCT-116 and HCT-15 cells were increased. Transcriptome analysis is used to reveal the possible mechanism. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggested the genes were mainly enriched in the MAPK signaling pathway. Certainly, HN activates MAPK signaling pathway. In vivo, HN prevented the AOM/DSS-induced tumorigenesis of colon cancer in C57BL/6 mice. Our study indicated that HN inhibits the progression of colon cancer cells by blocking the cell cycle, inducing apoptosis, and activating the MAPK pathway. This study provides a theoretical and experimental scientific basis for future investigations of the antitumor effects of HN against colon cancer.

Structure-toxicity relationships, toxicity mechanisms and health risk assessment of food-borne modified deoxynivalenol and zearalenone: A comprehensive review

Mycotoxin, as one of the most common pollutants in foodstuffs, poses great threat to food security and human health. Specifically, deoxynivalenol (DON) and zearalenone (ZEN)-two mycotoxin contaminants with considerable toxicity widely existing in food products-have aroused broad public concerns. Adding to this picture, modified forms of DON and ZEN, have emerged as another potential environmental and health threat, owing to their higher re-transformation rate into parent mycotoxins inducing accumulation of mycotoxin in humans and animals. Given this, a better understanding of the toxicity of modified mycotoxins is urgently needed. Moreover, the lack of toxicity data means a proper risk assessment of modified mycotoxins remains challenging. To better evaluate the toxicity of modified DON and ZEN, we have reviewed the relationship between their structures and toxicities. The toxicity mechanisms behind modified DON and ZEN have also been discussed; briefly, these involve acute, subacute, chronic, and combined toxicities. In addition, this review also addresses the global occurrence of modified DON and ZEN, and summarizes novel methods-including in silico analysis and implementation of relative potency factors-for risk assessment of modified DON and ZEN. Finally, the health risk assessment of modified DON and ZEN has also been discussed comprehensively.

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.

In Vitro Analysis of Deoxynivalenol Influence on Steroidogenesis in Prostate

Deoxynivalenol (DON) is a type-B trichothecene mycotoxin produced by Fusarium species, reported to be the most common mycotoxin present in food and feed products. DON is known to affect the production of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) in male rats, consequently affecting reproductive endpoints. Our previous study showed that DON induces oxidative stress in prostate cancer (PCa) cells, however the effect of DON on the intratumor steroidogenesis in PCa and normal prostate cells was not investigated. In this study human normal (PNT1A) and prostate cancer cell lines with different hormonal sensitivity (PC-3, DU-145, LNCaP) were exposed to DON treatment alone or in combination with dehydroepiandrosterone (DHEA) for 48 h. The results of the study demonstrated that exposure to DON alone or in combination with DHEA had a stimulatory effect on the release of estradiol and testosterone and also affected progesterone secretion. Moreover, significant changes were observed in the expression of genes related to steroidogenesis. Taken together, these results indicate that DON might affect the process of steroidogenesis in the prostate, demonstrating potential reproductive effects in humans.

T-2 Toxin Induces Oxidative Stress at Low Doses via Atf3ΔZip2a/2b-Mediated Ubiquitination and Degradation of Nrf2

T-2 toxin is mainly produced by Fusarium species, which is an extremely toxic mycotoxin to humans and animals. It is well known that T-2 toxin induces oxidative stress, but the molecular mechanism is still unknown. In this study, we found that T-2 toxin significantly promoted reactive oxygen species (ROS) accumulation in MCF-7 cells at low doses which maintains cell viability at least 80%. Further analysis showed that T-2 toxin downregulated the expression of the master regulator of antioxidant defense gene, nuclear factor erythroid 2-related factor (Nrf2), and its targeted antioxidant genes. Overexpression of Nrf2 or its target gene heme oxygenase 1 (HO1) significantly blocked the ROS accumulation in MCF-7 cells under T-2 toxin treatment. Moreover, we found that T-2 toxin downregulated the antioxidant genes via inducing the expression of ATF3ΔZip2a/2b. Importantly, overexpression of ATF3ΔZip2a/2b promoted the ubiquitination and degradation of Nrf2. Altogether, our results demonstrated that T-2 toxin-induced ROS accumulation via ATF3ΔZip2a/2b mediated ubiquitination and degradation of Nrf2, which provided a new insight into the mechanism of T-2 toxin-induced oxidative stress.

Deoxynivalenol Induces Inflammation in the Small Intestine of Weaned Rabbits by Activating Mitogen-Activated Protein Kinase Signaling

Deoxynivalenol (DON) can activate related signaling pathways and induce gastrointestinal disorders. Based on the results of previous studies, this study tried to explore the relationship between DON-induced intestinal inflammation of weaned rabbits and the ERK-p38 signaling pathway. Forty-five weaned rabbits were divided into three treatments: control, LD and HD group. All rabbits were treated with diet containing a same nutrient content, but animals in the LD and HD groups were additionally administered DON via drinking water at 0.5 and 1.5 mg/kg b.w./d, respectively. The protocol consisted of a total feeding period of 31 days, including a pre-feeding period of 7 days. Western blotting, qRT-PCR, and immunohistochemistry were applied for analysis the expression of protein and mRNA of extracellular signal-regulated kinase (ERK), p38, double-stranded RNA-activated protein kinase (PKR), and hematopoietic cell kinase (Hck) in the duodenum, jejunum, and ileum of rabbits, as well as the distribution of positive reactants. The results proved that DON intake could enhance the levels of inflammatory factors in serum and damage the intestinal structure barrier of rabbits. Meanwhile, DON addition can stimulate the protein and mRNA expression for ERK, p38, PKR, and Hck in the intestine of rabbits, especially in the duodenum, as well as expand the distribution of positive reactants, in a dose-dependent manner.

CAVIN2 is frequently silenced by CpG methylation and sensitizes lung cancer cells to paclitaxel and 5-FU

Aim: To explore the biological functions and clinical significance of CAVIN2 in lung cancer. Materials & methods: Methylation-specific PCR was used to measure promoter methylation of CAVIN2. The function of CAVIN2 was tested by Cell Counting Kit-8, colony formation, Transwell, flow cytometric analysis, acridine orange/ethidium bromide, chemosensitivity assay and xenograft assay. Results: CAVIN2 is significantly downregulated by promoter methylation in lung cancer. CAVIN2 overexpression inhibits lung cancer cell migration and invasion. Furthermore, ectopic expression of CAVIN2 inhibits cell proliferation in vivo and in vitro by inducing G2/M cell cycle arrest, which sensitizes the chemosensitivity of lung cancer cells to paclitaxel and 5-fluorouracil, but not cisplatin. Conclusion: CAVIN2 is a tumor suppressor in non-small-cell lung cancer and can sensitize lung cancer cells to paclitaxel and 5-fluorouracil.

Deoxynivalenol Exposure Suppresses Adipogenesis by Inhibiting the Expression of Peroxisome Proliferator-Activated Receptor Gamma 2 (PPARγ2) in 3T3-L1 Cells

Deoxynivalenol (DON)-a type B trichothecene mycotoxin, mainly produced by the secondary metabolism of Fusarium-has toxic effects on animals and humans. Although DON's toxicity in many organs including the adrenal glands, thymus, stomach, spleen, and colon has been addressed, its effects on adipocytes have not been investigated. In this study, 3T3-L1 cells were chosen as the cell model and treated with less toxic doses of DON (100 ng/mL) for 7 days. An inhibition of adipogenesis and decrease in triglycerides (TGs) were observed. DON exposure significantly downregulated the expression of PPARγ2 and C/EBPα, along with that of other adipogenic marker genes in 3T3-L1 cells and BALB/c mice. The anti-adipogenesis effect of DON and the downregulation of the expression of adipogenic marker genes were effectively reversed by PPARγ2 overexpression. The repression of PPARγ2's expression is the pivotal event during DON exposure regarding adipogenesis. DON exposure specifically decreased the di-/trimethylation levels of Histone 3 at lysine 4 in 3T3-L1 cells, therefore weakening the enrichment of H3K4me2 and H3K4me3 at the Pparγ2 promoter and suppressing its expression. Conclusively, DON exposure inhibited PPARγ2 expression via decreasing H3K4 methylation, downregulated the expression of PPARγ2-regulated adipogenic marker genes, and consequently suppressed the intermediate and late stages of adipogenesis. Our results broaden the current understanding of DON's toxic effects and provide a reference for addressing the toxicological mechanism of DON's interference with lipid homeostasis.

Low doses of deoxynivalenol inhibit the cell migration mediated by H3K27me3-targeted downregulation of TEM8 expression

Deoxynivalenol (DON) is a mycotoxin produced by multipleFusariumspecies that often contaminates cereals and threatens human and animal health. A wide range of cytotoxic effects, such as the induction of DNA damage, an increase in mitochondrial permeability and the inhibition of macromolecule synthesis, have been reported. However, the effects of DON on cell migration-a fundamental process in living cells critical for normal development, immune responses, and disease processes-and the mechanism underlying these effects are still unclear. Here, we showed that DONsignificantly inhibited the migration of MRC-5, CCD-18Co, HCT116 and WM793 cells at 50 ng/ml, 50 ng/ml, 400 ng/ml and 250 ng/ml, respectively, which maintained cell viability at 90%. Further analysis showed that DON inhibited the expression of tumour endothelial marker 8 (TEM8), a key gene in cell migration. Furthermore, we showed that DON inhibited the expression of TEM8 through increasing the level of H3K27me3 in the TEM8 promoter. Finally, overexpression of TEM8 or treating by H3K27me3-specific inhibitor GSK126 attenuated the inhibitory effect of DON on cell migration. In summary, low doses of DON at approximately dietary exposure significantly inhibited cell migration by downregulating the expression of TEM8 in a manner mediated by H3K27me3, which may generate increasing concerns for the risk of DON exposure.

Deoxynivalenol globally affects the selection of 3' splice sites in human cells by suppressing the splicing factors, U2AF1 and SF1

Deoxynivalenol (DON) is one of the most abundant mycotoxins and has adverse effects on several biological processes, posing risks of protein synthesis-disrupting effects and ribotoxic response. Therefore, chronic exposure to DON would fundamentally reshape the global expression pattern. Whether DON causes toxic effects on mRNA splicing, a fundamental biological process, remains unclear. In this study, we found that administration of the relative low dosage of DON dramatically changed the alternative splicing of pre-mRNA in HepG2 cells. The overall number of transcripts with aberrant selection of 3' splice sites was significantly increased in DON-exposed HepG2 cells. This effect was further confirmed in two other human cell lines, HEK293 and Caco-2, suggesting that this DON-induced alteration in splicing patterns was universal in human cells. Among these DON-induced changes in alternative splicing, the expression levels of two related splicing factors, SF1 and U2AF1, which are essential for 3' splice site recognitions, were strongly suppressed. Overexpression of either of the two splicing factors strongly alleviated the DON-induced aberrant selection of 3' splice sites. Moreover, SF1 was required for human cell proliferation in DON exposure, and the restoration of SF1 expression partially reinstated the proliferation potential for DON-treated cells. In conclusion, our study suggests that DON, even at a low dosage, has great potential to change gene expression globally by affecting not only protein synthesis but also mRNA processing in human cells.

Comparison of the toxic mechanism of T-2 toxin and deoxynivalenol on human chondrocytes by microarray and bioinformatics analysis

T-2 toxin and deoxynivalenol (DON) are two representative mycotoxins that are commonly found in cereals and agricultural products. As T-2 toxin and DON are considered the cause of Kashin-Beck disease, a special osteoarticular disease, chondrocytes would be a vital target site for these toxins. To fully understand the toxicity effects of T-2 toxin and DON on chondrocytes, the present study investigated and compared the gene expression profiles and underlying mechanisms of T-2 toxin and DON on cultured human chondrocytes by microarray and bioinformatics analysis. Normal human chondrocytes were treated with T-2 toxin at 0.01 μg/ml and DON at 1.0 μg/ml for 72 h and analyzed by microarray using Affymetrix Human Gene Chip. Comprehensive analysis, including gene ontology, pathways and gene-gene networks was performed to identify the crucial gene functions, related signal pathways and key genes. A total of 175 and 237 differentially expressed genes were identified in human chondrocytes for T-2 toxin and DON treatment, respectively. Of these, 47 had the same expression tendencies in the two groups. The protein-protein interaction network analysis showed that the 10 hub genes were different between the two groups. Our results provide a comprehensive understanding of the toxic mechanism of T-2 toxin and DON on human chondrocytes and suggest that although T-2 toxin and DON showed some similar toxic mechanisms in human chondrocytes, they also had different toxic characteristics.

Aflatoxin B1 induces S phase arrest by upregulating the expression of p21 via MYC, PLK1 and PLD1

Aflatoxin B1 (AFB1), a member of the aflatoxin family, is a common contaminant in foods and feeds, and AFB1 exposure is associated with various clinical conditions. Thus far, research on the toxicity of AFB1 has mainly focused on its induction of liver cancer, but little research has been reported on renal toxicity, especially with regards to the underlying molecular mechanisms. In this study, we found that AFB1 treatment significantly induced kidney damage and reduced kidney weight. The human kidney cell line HEK293T was used to further study the molecular mechanism of the toxicity of AFB1 to kidney cells. We found that AFB1 significantly and dose-dependently induced S phase arrest and upregulated p21 mRNA and protein expression. Upstream of p21, three negative regulators, PLK1, MYC, and PLD1, were significantly downregulated under AFB1 treatment. Consistently, p21 was upregulated, and PLK1, MYC and PLD1 were downregulated in mouse kidney after AFB1 treatment. Interestingly, AFB1 also decreased the physical interaction between PLK1 and MYC and weakened the stability of the MYC protein. Importantly, overexpression of PLK1, MYC and PLD1 significantly blocked the upregulation of p21 and attenuated the S phase arrest caused by AFB1. In summary, AFB1 markedly induces kidney damage and strongly induces S phase arrest by upregulating the expression of p21 via PLK1, PLD1 and MYC, which represents a noval mechanism of the renal toxicity of AFB1.

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.