Effects of Zearalenone Exposure on the TGF-β1/Smad3 Signaling Pathway and the Expression of Proliferation or Apoptosis Related Genes of Post-Weaning Gilts

Short-term consumption of the mycotoxin zearalenone by pubertal gilts causes persistent changes in the histoarchitecture of reproductive tissues

Consumption of zearalenone (ZEN) detrimentally affects tissues and systems throughout the body, and these deleterious effects are especially pronounced in swine. The objectives of this project were to determine the effects of short-term consumption of ZEN (at concentrations that could be found on-farm) on growth, carcass weight, liver weight, and reproductive tissues of pubertal gilts, and to determine if the effects are transient or persistent. Cross-bred gilts (107.25 ± 2.69 kg) were randomly assigned to one of three feed treatments: 1) solvent only for 21 d (CON; n = 10), 2) ZEN for 7 d followed by 14 d of solvent (ZEN-7; 6 mg/d; n = 10), and 3) ZEN for 21 d (ZEN-21; 6 mg/d; n = 10). Body weights were collected at the beginning and end of the experiment (189.1 ± 0.8 and 211.1 ± 0.8 d of age, respectively). Carcass weights and tissues were collected at harvest. There were no treatment-based differences in growth, carcass, liver, or reproductive tissue weights. Histological analyses revealed differences based on treatment and the interaction between treatment and luteal status. The thickness of the ampullary muscularis declined with ZEN exposure (P < 0.05), while the isthmic epithelial cell height (P < 0.01) and uterine endometrial thickness (P < 0.02) increased. Interestingly, the thickness of the isthmic muscularis, uterine myometrium, and epithelial cell height only differed in the presence of a corpus luteum. Uterine epithelial cell height in the luteal phase was lowest in ZEN-7 pigs (P < 0.01). The isthmic muscularis in the luteal phase was thinner in pigs from both ZEN treatments (P < 0.01). Conversely, the luteal-stage myometrium was thicker in pigs from both ZEN treatments (P < 0.01). The discovery of these tissue-based differences during the luteal phase is particularly concerning since this corresponds with the time when embryos would be affected by the functional competency of the oviduct and uterus. The results of this work demonstrate that short-term consumption of ZEN produces microscopic, but not macroscopic alterations in reproductive organs which are likely to have negative effects on their subsequent function and that these differences persist even after ZEN consumption ceases. Taken together, these results indicate that it is insufficient to rely solely on outwardly visible symptoms as indicators of zearalenone exposure, as detrimental effects on reproductive tissues were found in the absence of phenotypic and morphologic changes.

Betulinic acid alleviates zearalenone-induced uterine injury in mice

Zearalenone (ZEA) is a mycotoxin with estrogen-like biological activity, which widely present in feed and raw materials, with strong reproductive system toxicity and a major threat to animal reproduction. Betulinic acid (BA) is a natural plant compound with antioxidant, anti-inflammatory and other pharmacological activities. However, the mechanism of ZEA-induced uterine injury and the protective effect of BA have not been reported. Our results show that ZEA could cause uterine histopathological damage and cellular ultrastructural damage, affecting the secretion of sex hormones, such as estradiol (E2) and progesterone (P4), and increase the mRNA and protein expression of estrogen receptor α (ERα). ZEA could inhibit the activities of catalase (CAT) and superoxide dismutase (SOD), increase the production of malondialdehyde (MDA) and reactive oxygen species (ROS), and cause uterine oxidative stress. Furthermore, ZEA affected the homeostasis of uterine cell proliferation and death by regulating the expression of proliferating cell nuclear antigen (PCNA) and activating the mitochondrial apoptotic pathway. ZEA-induced uterine injury might be related to the activation of p38/ERK MAPK signaling pathway. However, the regulatory effect of ZEA on the uterus was reversed after BA treatment. In conclusion, the uterus is an important target organ attacked by ZEA, and BA showed a good therapeutic effect.

Quantitative Proteomic Analysis of Zearalenone Exposure on Uterine Development in Weaned Gilts

The aim of this study was to explore the effect of zearalenone (ZEA) exposure on uterine development in weaned gilts by quantitative proteome analysis with tandem mass spectrometry tags (TMT). A total of 16 healthy weaned gilts were randomly divided into control (basal diet) and ZEA3.0 treatments groups (basal diet supplemented with 3.0 mg/kg ZEA). Results showed that vulva size and uterine development index were increased (p < 0.05), whereas serum follicle stimulation hormone, luteinizing hormone and gonadotropin-releasing hormone were decreased in gilts fed the ZEA diet (p < 0.05). ZEA, α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) were detected in the uteri of gilts fed a 3.0 mg/kg ZEA diet (p < 0.05). The relative protein expression levels of creatine kinase M-type (CKM), atriopeptidase (MME) and myeloperoxidase (MPO) were up-regulated (p < 0.05), whereas aldehyde dehydrogenase 1 family member (ALDH1A2), secretogranin-1 (CHGB) and SURP and G-patch domain containing 1 (SUGP1) were down-regulated (p < 0.05) in the ZEA3.0 group by western blot, which indicated that the proteomics data were dependable. In addition, the functions of differentially expressed proteins (DEPs) mainly involved the cellular process, biological regulation and metabolic process in the biological process category. Some important signaling pathways were changed in the ZEA3.0 group, such as extracellular matrix (ECM)-receptor interaction, focal adhesion and the phosphoinositide 3-kinase−protein kinase B (PI3K-AKT) signaling pathway (p < 0.01). This study sheds new light on the molecular mechanism of ZEA in the uterine development of gilts.

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.

Zearalenone promotes follicle development through activating the SIRT1/PGC-1α signaling pathway in the ovaries of weaned gilts

This study aimed to investigate the effect of zearalenone (ZEA) exposure on follicular development in weaned gilts, and its mechanism based on the silent information regulator 1 (SIRT1)/peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) signaling pathway. A total of 32 healthy female weaned piglets (Landrace × Yorkshire × Duroc) with an average body weight of 12.39 ± 0.24 kg were randomly allotted to a basal diet supplemented with 0, 0.15, 1.5, or 3.0 mg/kg ZEA for a 32-d feeding test. Blood and ovarian samples were obtained at the end of the experiment to determine serum toxin concentrations, ovarian histology, and the expressions of proliferating cell nuclear antigen (PCNA) and SIRT1/PGC-1α signaling pathway-related genes. Results showed that the vulva area, serum concentrations of ZEA, α-zearalenol and β-zearalenol, the thickness of the growing follicular layer, and the diameter of the largest growing follicles, as well as the expressions of SIRT1, PGC-1α, estrogen-related receptor α (ERRα), ATP synthase subunit beta (ATP5B), and PCNA, increased linearly (P < 0.05) with increasing dietary ZEA, whereas the thickness of the primordial follicle layer decreased linearly (P < 0.05). Immunohistochemical analysis showed that the immunoreactive substances of SIRT1 and PGC-1α in the ovaries enhanced with the increasing dietary ZEA (P < 0.05). In addition, the thickness of the growing follicular layer and the diameter of the largest growing follicle were positively correlated with relative mRNA and protein expressions of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). However, the thickness of the primordial follicle layer was negatively correlated with the mRNA and protein expression of SIRT1, PGC-1α, ERRα, ATP5B, and PCNA (P < 0.05). Interestingly, the 1.5 mg/kg ZEA treatment had highly hyperplastic follicles, whereas 3.0 mg/kg ZEA resulted in a large number of follicular atresia, which indicated that low-dose ZEA exposure accelerated follicular proliferation, while high-dose ZEA promoted follicular atresia, although the critical value interval needs further confirmation. Results provide a theoretical basis for finding the therapeutic target of ZEA-induced reproductive disorders in weaned gilts.

Zearalenone Exposure Triggered Cecal Physical Barrier Injury through the TGF-β1/Smads Signaling Pathway in Weaned Piglets

This study aims to investigate the effects of exposure to different dosages of zearalenone (ZEA) on cecal physical barrier functions and its mechanisms based on the TGF-β1/Smads signaling pathway in weaned piglets. Thirty-two weaned piglets were allotted to four groups and fed a basal diet supplemented with ZEA at 0, 0.15, 1.5, and 3.0 mg/kg, respectively. The results showed that 1.5 and 3.0 mg/kg ZEA damaged cecum morphology and microvilli, and changed distribution and shape of M cells. Moreover, 1.5 and 3.0 mg/kg ZEA decreased numbers of goblet cells, the expressions of TFF3 and tight junction proteins, and inhibited the TGF-β1/Smads signaling pathway. Interestingly, the 0.15 mg/kg ZEA had no significant effect on cecal physical barrier functions but decreased the expressions of Smad3, p-Smad3 and Smad7. Our study suggests that high-dose ZEA exposure impairs cecal physical barrier functions through inhibiting the TGF-β1/Smads signaling pathway, but low-dose ZEA had no significant effect on cecum morphology and integrity through inhibiting the expression of smad7. These findings provide a scientific basis for helping people explore how to reduce the toxicity of ZEA in feeds.

Zearalenone promotes apoptosis of mouse Leydig cells by targeting phosphatase and tensin homolog and thus inhibiting the PI3K/AKT signal pathway

Zearalenone (ZEA) is a mycotoxin with estrogenic activity whose main effect is to impair the reproductive systems of animals. It leads to reproductive disorders in livestock and thus causes serious losses to agriculture and animal husbandry. This study aims to examine whether ZEA induces toxicity in Leydig cells through the PI3K/AKT signaling pathway and also to investigate the role played by the upstream phosphatase and tensin homolog (PTEN) gene. An adenovirus vector model was constructed to interfere with the PTEN gene to investigate whether ZEA promotes the apoptosis of TM3 cells through the PI3K/AKT pathway. Apoptosis was detected cytometrically and the protein expression levels of PTEN, AKT, p-AKT, Bax, and Bcl-2 were evaluated via western blot analysis. The results show that ZEA induces apoptosis of TM3 cells. PTEN expression is significantly increased (P < 0.01), Bax expression is increased (P < 0.05), AKT and p-AKT expression of anti-apoptotic protein is significantly decreased (P < 0.01), and Bcl-2 protein expression is decreased (P < 0.05) in the ZEA group compared with the control group. In the shRNA+ZEA group, the expression levels of PTEN and Bax proteins are significantly decreased (P < 0.01), AKT protein is significantly increased (P < 0.01), and p-AKT protein is increased (P < 0.05) compared with the ZEA group. This study thus demonstrates that ZEA promotes apoptosis of TM3 cells by targeting PTEN and thus inhibiting the PI3K/AKT signal pathway.

The effect of propofol on the proliferation and apoptosis of hepatocellular carcinoma cells through TGF-Β1/Smad2 signaling pathway

Malignant tumors are a serious threat to human health. Surgical resection is the most effective treatment for liver cancer. However, liver cancer is mostly found at an advanced stage, is difficult to remove by surgery, and has a very high recurrence rate after surgery. The current liver cancer treatment drugs have serious side effects, and the treatment effect is not ideal, far from meeting the clinical needs. Based on this, this paper studies the effect of propofol on the proliferation and apoptosis of liver cancer cells through the TGF-B1/Smad2 signaling pathway, and explores the proliferation, adhesion and apoptosis of cancer cells in patients with propofol. This paper uses a comparative experiment. With medical imaging method, 80 rats with liver cancer in the same period were cultured. High-precision microscope and radiolocation method were used to observe and record the whole process of propofol regulating Smad2 signal pathway. The results show that propofol can effectively inhibit the proliferation of cancer cells in patients with liver cancer. Propofol can increase the activity and content of transforming growth factor-β1 by 12% and 20%, respectively, and then inhibit the proliferation rate of liver cancer cells by 10% through the Smad2 signaling pathway, and exponentially increase the apoptotic number of liver cancer cells. This shows that propofol has a significant inhibitory effect on the cycle of liver cancer cells. Under the action of propofol, the life cycle of liver cancer cells is shortened, which provides a certain theoretical basis for the treatment of liver cancer.

Downregulation of microRNA-96-5p protects TM3 cells against zearalenone toxicity via targeting ATG9A

Male infertility factor accounts for ~50% of all infertility cases, and traditional treatments for male infertility are limited. The association between the dysfunction of Leydig cells and hypospermatogenesis is essential for developing novel treatment methods for male infertility. It was previously stated that elevated expression of microRNA (miR)-96-5p was associated with the toxicological response of Leydig cells to treatment with zearalenone (ZEN). However, the exact role of miR-96-5p in Leydig cells remains to be illustrated. The mouse Leydig cell line TM3 was used in the present study to investigate the role of miR-96-5p. ZEN was used to induce cell injury in TM3 cells. Cell Counting Kit-8 assay and the Ki67 staining method were used to evaluate cell viability. Reverse transcription-quantitative PCR was used to determine the expression levels of miR-96-5p. In addition, a dual luciferase assay was used to investigate the target of miR-96-5p. Annexin V/propidium iodide staining was performed to detect cell apoptosis. Western blot analysis was used to detect the expression levels of certain proteins. Finally, monodansylcadaverine (MDC) and LC3 staining were applied for monitoring the level of autophagy. ZEN inhibited the proliferation of TM3 cells in a dose-dependent manner. In addition, the level of miR-96-5p were significantly increased in ZEN-treated TM3 cells. Meanwhile, inhibition of miR-96-5p could reverse ZEN-induced decrease in viability in TM3 cells. Moreover, ZEN notably inhibited autophagy in TM3 cells and this phenomenon was reversed by the application of the miR-96-5p inhibitor. Autophagy related 9A (ATG9A) was identified as the biological target of miR-96-5p. The results derived from MDC and LC3 staining demonstrated that downregulation of miR-96-5p expression levels protected TM3 cells against ZEN toxicity by regulating autophagy. Inhibition of miR-96-5p expression protected TM3 cells against ZEN via targeting ATG9A. Therefore, miR-96-5p may serve as a potential biomarker for male infertility.

Zearalenone Affect the Intestinal Villi Associated with the Distribution and the Expression of Ghrelin and Proliferating Cell Nuclear Antigen in Weaned Gilts

This study explored and investigated how zearalenone (ZEA) affects the morphology of small intestine and the distribution and expression of ghrelin and proliferating cell nuclear antigen (PCNA) in the small intestine of weaned gilts. A total of 20 weaned gilts (42-day-old, D × L × Y, weighing 12.84 ± 0.26 kg) were divided into the control and ZEA groups (ZEA at 1.04 mg/kg in diet) in a 35-d study. Histological observations of the small intestines revealed that villus injuries of the duodenum, jejunum and ileum, such as atrophy, retardation and branching dysfunction, were observed in the ZEA treatment. The villi branch of the ileum in the ZEA group was obviously decreased compared to that of the ileum, jejunum and duodenum, and the number of lymphoid nodules of the ileum was increased. Additionally, the effect of ZEA (1.04 mg/kg) was decreased by the immunoreactivity and distribution of ghrelin and PCNA in the duodenal and jejunal mucosal epithelial cells. Interestingly, ZEA increased the immunoreactivity of ghrelin in the ileal mucosal epithelial cells and decreased the immunoreactivity expression of PCNA in the gland epithelium of the small intestine. In conclusion, ZEA (1.04 mg/kg) had adverse effects on the development and the absorptive capacity of the villi of the intestines; yet, the small intestine could resist or ameliorate the adverse effects of ZEA by changing the autocrine of ghrelin in intestinal epithelial cells.

The Effects of Zearalenone on the Localization and Expression of Reproductive Hormones in the Ovaries of Weaned Gilts

This study aims to investigate the effects of zearalenone (ZEA) on the localizations and expressions of follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), gonadotropin releasing hormone (GnRH) and gonadotropin releasing hormone receptor (GnRHR) in the ovaries of weaned gilts. Twenty 42-day-old weaned gilts were randomly allocated into two groups, and treated with a control diet and a ZEA-contaminated diet (ZEA 1.04 mg/kg), respectively. After 7-day adjustment, gilts were fed individually for 35 days and euthanized for blood and ovarian samples collection before morning feeding on the 36th day. Serum hormones of E₂, PRG, FSH, LH and GnRH were determined using radioimmunoassay kits. The ovaries were collected for relative mRNA and protein expression, and immunohistochemical analysis of FSHR, LHR, GnRH and GnRHR. The results revealed that ZEA exposure significantly increased the final vulva area (p < 0.05), significantly elevated the serum concentrations of estradiol, follicle stimulating hormone and GnRH (p < 0.05), and markedly up-regulated the mRNA and protein expressions of FSHR, LHR, GnRH and GnRHR (p < 0.05). Besides, the results of immunohistochemistry showed that the immunoreactive substances of ovarian FSHR, LHR, GnRH and GnRHR in the gilts fed the ZEA-contaminated diet were stronger than the gilts fed the control diet. Our findings indicated that dietary ZEA (1.04 mg/kg) could cause follicular proliferation by interfering with the localization and expression of FSHR, LHR, GnRH and GnRHR, and then affect the follicular development of weaned gilts.

Impact of Fusarium-Derived Mycoestrogens on Female Reproduction: A Systematic Review

Contamination of the world’s food supply and animal feed with mycotoxins is a growing concern as global temperatures rise and promote the growth of fungus. Zearalenone (ZEN), an estrogenic mycotoxin produced by Fusarium fungi, is a common contaminant of cereal grains and has also been detected at lower levels in meat, milk, and spices. ZEN’s synthetic derivative, zeranol, is used as a growth promoter in United States (US) and Canadian beef production. Experimental research suggests that ZEN and zeranol disrupt the endocrine and reproductive systems, leading to infertility, polycystic ovarian syndrome-like phenotypes, pregnancy loss, and low birth weight. With widespread human dietary exposure and growing experimental evidence of endocrine-disrupting properties, a comprehensive review of the impact of ZEN, zeranol, and their metabolites on the female reproductive system is warranted. The objective of this systematic review was to summarize the in vitro, in vivo, and epidemiological literature and evaluate the potential impact of ZEN, zeranol, and their metabolites (commonly referred to as mycoestrogens) on female reproductive outcomes. We conducted a systematic review (PROSPERO registration CRD42020166469) of the literature (2000–2020) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The data sources were primary literature published in English obtained from searching PubMed, Web of Science, and Scopus. The ToxR tool was applied to assess risk of bias. In vitro and in vivo studies (n = 104) were identified and, overall, evidence consistently supported adverse effects of mycoestrogens on physiological processes, organs, and tissues associated with female reproduction. In non-pregnant animals, mycoestrogens alter follicular profiles in the ovary, disrupt estrus cycling, and increase myometrium thickness. Furthermore, during pregnancy, mycoestrogen exposure contributes to placental hemorrhage, stillbirth, and impaired fetal growth. No epidemiological studies fitting the inclusion criteria were identified.

Exploiting genetic diversity in two European maize landraces for improving Gibberella ear rot resistance using genomic tools

KEY MESSAGE

High genetic variation in two European maize landraces can be harnessed to improve Gibberella ear rot resistance by integrated genomic tools. Fusarium graminearum (Fg) causes Gibberella ear rot (GER) in maize leading to yield reduction and contamination of grains with several mycotoxins. This study aimed to elucidate the molecular basis of GER resistance among 500 doubled haploid lines derived from two European maize landraces, "Kemater Landmais Gelb" (KE) and "Petkuser Ferdinand Rot" (PE). The two landraces were analyzed individually using genome-wide association studies and genomic selection (GS). The lines were genotyped with a 600-k maize array and phenotyped for GER severity, days to silking, plant height, and seed-set in four environments using artificial infection with a highly aggressive Fg isolate. High genotypic variances and broad-sense heritabilities were found for all traits. Genotype-environment interaction was important throughout. The phenotypic (r) and genotypic ([Formula: see text]) correlations between GER severity and three agronomic traits were low (r =  - 0.27 to 0.20; [Formula: see text]=  - 0.32 to 0.22). For GER severity, eight QTLs were detected in KE jointly explaining 34% of the genetic variance. In PE, no significant QTLs for GER severity were detected. No common QTLs were found between GER severity and the three agronomic traits. The mean prediction accuracies ([Formula: see text]) of weighted GS (wRR-BLUP) were higher than [Formula: see text] of marker-assisted selection (MAS) and unweighted GS (RR-BLUP) for GER severity. Using KE as the training set and PE as the validation set resulted in very low [Formula: see text] that could be improved by using fixed marker effects in the GS model.

Dose-Effect of Zearalenone on the Localization and Expression of Growth Hormone, Growth Hormone Receptor, and Heat Shock Protein 70 in the Ovaries of Post-weaning Gilts

Zearalenone (ZEA) has an estrogen-like effect, which can injure the reproductive system of animals, causing infertility, and abortion in sows. However, the underlying mechanisms are still not clear. The objective of this study was to assess the effects of ZEA on the localization and expression of growth hormone (GH), growth hormone receptor (GHR), and heat shock protein 70 (Hsp70) in the ovaries of post-weaning gilts. Forty healthy post-weaning gilts were randomly provided one of four diets: normal basal diet supplemented with 0 (control), 0.5 (ZEA0.5), 1.0 (ZEA1.0), and 1.5 (ZEA1.5) mg ZEA/kg. Gilts were housed and fed individually for 35 days; the ovaries were collected after euthanasia for antioxidant index, relative mRNA and protein expression, and immunohistochemical analyses of GH, GHR, and Hsp70. The results revealed that the glutathione peroxidase and total superoxide dismutase levels decreased (p < 0.05), whereas the malondialdehyde level increased (p < 0.05) with increasing ZEA content. The localization pattern of GH, GHR, and Hsp70 in ZEA-treated gilts was the same as that in the control; however, the localization of yellow and brown immunoreactive substances of GH, GHR, and Hsp70 was stronger in the ZEA groups than in the control. The relative mRNA and protein expression of GHR and Hsp70 was the highest in the ZEA1.0 group (p < 0.05), whereas that of GH was the highest in the ZEA0.5 group (p < 0.05). The mRNA and protein expression of GH was lower in the ZEA1.5 group than in the control (p < 0.05). Hsp70 results showed adverse responses to increasing ZEA levels in gilt ovaries, suggesting that Hsp70 played an important role in alleviating ZEA-induced oxidative stress.

Zearalenone regulates key factors of the Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1-nuclear factor erythroid 2-related factor 2 signaling pathway in duodenum of post-weaning gilts

OBJECTIVE

This study explored the mechanism of the Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway under conditions of zearalenone (ZEA)-induced oxidative stress in the duodenum of post-weaning gilts.

METHODS

Forty post-weaning gilts were randomly allocated to four groups and fed diets supplemented with 0, 0.5, 1.0, or 1.5 mg/kg ZEA.

RESULTS

The results showed significant reductions in the activity of the antioxidant enzymes total superoxide dismutase and glutathione peroxidase and increases the malondialdehyde content with increasing concentrations of dietary ZEA. Immunohistochemical analysis supported these findings by showing a significantly increased expression of Nrf2 and glutathione peroxidase 1 (GPX1) with increasing concentrations of ZEA. The relative mRNA and protein expression of Nrf2, GPX1 increased linearly (p<0.05) and quadratically (p<0.05), which was consistent with the immunohistochemical results. The relative mRNA expression of Keap1 decreased linearly (p<0.05) and quadratically (p<0.05) in the duodenum as the ZEA concentration increased in the diet. The relative mRNA expression of modifier subunit of glutamate-cysteine ligase (GCLM) increased quadratically (p<0.05) in all ZEA treatment groups and the relative mRNA expression of quinone oxidoreductase 1 (NQO1) catalytic subunit of glutamate-cysteine ligase decreased linearly (p<0.05) and quadratically (p<0.05) in the ZEA1.0 group and ZEA1.5 group. The relative protein expression of Keap1 and GCLM decreased quadratically (p<0.05) in the duodenum as the ZEA concentration increased in the diet, respectively. The relative protein expression of NQO1 increased linearly (p<0.05) and quadratically (p<0.05) in all ZEA treatment groups in the duodenum.

CONCLUSION

These findings suggest that ZEA regulates the expression of key factors of the Keap1-Nrf2 signaling pathway in the duodenum, which enables resistance to ZEA-induced oxidative stress. Further studies are needed to examine the effects of ZEA induced oxidative stress on other tissues and organs in post-weaning gilts.

Effects of zearalenone-induced oxidative stress and Keap1-Nrf2 signaling pathway-related gene expression in the ileum and mesenteric lymph nodes of post-weaning gilts

Zearalenone (ZEA) contamination of feed affects animal husbandry and the human health. Currently, the molecular mechanism underlying small intestine-related diseases caused by ZEA-induced oxidative stress is not well understood. In this study, we aimed to identify the mechanisms involved in ZEA (0.5-1.5 mg/kg)-induced oxidative stress in the ileum and mesenteric lymph nodes (MLNs) and the role of the Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in post-weaning gilts. Forty post-weaning gilts (Landrace × Yorkshire × Duroc) with an average body weight of 14.01 ± 0.86 kg were randomly allocated to four groups and fed a corn-soybean meal basal diet supplemented with < 0.1, 0.5, 1.0, or 1.5 mg/kg ZEA. The results showed that the activity of total superoxide dismutase and glutathione peroxidase decreased (p < 0.05) linearly and quadratically and that the content of malondialdehyde increased (p < 0.05) quadratically in the ileum and MLNs with increasing ZEA in the diet. Immunohistochemical analysis showed that the expression of Nrf2 and glutathione peroxidase 1 (Gpx1) immunoreactive proteins in the ileum and MLNs were significantly enhanced with increasing ZEA. The relative mRNA and protein expression of Nrf2, Gpx1, quinone oxidoreductase 1 (Nqo1), hemeoxygenase 1 (Ho1), modifier subunit of glutamate-cysteine ligase (Gclm), and catalytic subunit of glutamate-cysteine ligase (Gclc) increased (p < 0.05) linearly and quadratically, and the relative mRNA and protein expression of Keap1 decreased (p < 0.05) linearly and quadratically in the ileum with increasing ZEA concentrations in the diet. Further, the relative mRNA and protein expression of Nrf2 and Gpx1 increased (p < 0.05) linearly and quadratically, and the relative mRNA and protein expression of Nqo1, Ho1, and Gclm decreased (p < 0.05) quadratically in the MLNs as ZEA concentrations increased in the diet. Our results provide valuable genetic information on ZEA-induced oxidative stress in the ileum and MLNs of post-weaning gilts and have elucidated the key regulatory genes involved in the Keap1-Nrf2 signaling pathway. Results indicated that the Keap1-Nrf2 signaling pathway might be a key target to further prevent and treat ZEA-induced injury to the ileum in post-weaning gilts.

Effect of Illicium verum or Eucommia ulmoides leaf extracts on the anti-stress ability, and mRNA and protein expression of Nrf2 and TNF-α in Duroc × Landrace × Yorkshire and Chinese native Licha-black nursery piglets

Plant extracts are considered to be an effective alternative to antibiotics in response to weaning stress in piglets. This study evaluated the effect of Illicium verum extracts (IVE) or Eucommia ulmoides leaf extracts (ELE) on growth performance, serum and liver antioxidant ability of nursery piglets, as well as the difference of IVE and ELE on Duroc × Landrace × Yorkshire (DLY) and Chinese native Licha-black (LCB) piglets. A total of 96 nursery piglets (48 DLY and 48 LCB piglets) with an average body weight of 11.22 ± 0.32 kg were randomly divided into four treatments in a 2 × 4 factorial design. Each treatment had four replicates with 3 DLY and 3 LCB piglets per replicate respectively. Treatments included: basal diet, basal diet + 500 mg/kg IVE, basal diet + 250 mg/kg ELE and basal diet + 50 mg/kg chlortetracycline (CHL). All piglets were housed individually for the 42 days trial period after 7 days adaptation. Results showed that there were significant interactions (p < .05) between piglets species and dietary treatments in average daily gain (ADG) and feed efficiency, serum and hepatic glutathione peroxidase (GSH-Px) and malondialdehyde (MDA), hepatic integral optical density (IOD) of α-tumour necrosis factor (TNF-α), hepatic relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2)/TNF-α and protein expression of TNF-α. Regardless of piglets species, supplementation with IVE and ELE increased (p < .05) ADG and feed efficiency, T-SOD and GSH-Px in serum and liver, hepatic IOD of Nrf2, hepatic mRNA and protein expression of Nrf2/TNF-α. However, CHL treatment resulted in lower (p < .05) serum GSH-Px and hepatic mRNA and protein expression of Nrf2/TNF-α, and higher hepatic MDA and IOD of TNF-α. Compared to LCB, DLY piglets had higher (p < .05) ADG and feed efficiency, serum and hepatic MDA, and protein expression of TNF-α, but lower (p < .05) ADFI, liver index, serum and hepatic GSH-Px, hepatic IOD of TNF-α, mRNA expressions of Nrf2/TNF-α were observed. In conclusion, Illicium verum (500 mg/kg) and Eucommia ulmoides leaf (250 mg/kg) extracts can increase the growth performance and antioxidant ability of DLY and LCB piglets, while chlortetracycline produces undesirable side-effects on the antioxidant ability of DLY and LCB piglets. Illicium verum and Eucommia ulmoides leaf extracts produced different antioxidant effects in DLY and LCB piglets with the Chinese native Licha-black pig responding better than Duroc × Landrace × Yorkshire.

Genomics-assisted breeding for ear rot resistances and reduced mycotoxin contamination in maize: methods, advances and prospects

Genetic mapping, genomic profiling and bioinformatic approaches were used to identify putative resistance genes for ear rots and low mycotoxin contamination in maize. Genomic selection seems to have good perspectives. Maize is globally an indispensable crop for humans and livestock. About 30% of yield is lost by fungal diseases with Gibberella, Fusarium and Aspergillus ear rots (ERs) having a high economic impact in most maize-growing regions of the world. They reduce not only yield, but also contaminate grains with mycotoxins like deoxynivalenol, zearalenone, fumonisins and aflatoxins, respectively. These mycotoxins pose serious health problems to humans and animals. A number of studies have been conducted to dissect the genetic architecture of resistance to these three major ear rots over the past decade. The review concentrates on studies carried out to locate quantitative trait loci (QTL) and candidate genes (CG) on the maize genome as well as the application of genomic selection in maize for resistance against Fusarium graminearum, Fusarium verticillioides and Aspergillus flavus. QTL studies by linkage or genome-wide association mapping, omic technologies (genomics, proteomics, transcriptomics and metabolomics) and bioinformatics are the methods used in the current studies to propose resistance genes against ear rot pathogens. Though a number of QTL and CG are reported, only a few specific genes were found to directly confer ER resistance in maize. A combination of two or more gene identification methods would provide a more powerful and reliable tool. Genomic selection seems to be promising for ER resistance breeding, but there are only a limited number of studies in this area. A strategy that can accurately validate and predict genotypes with major effect QTL and CG for selection will be worthwhile for practical breeding against ERs and mycotoxin contamination in maize.

Comparative study of stress response, growth and development of uteri in post-weaning gilts challenged with zearalenone and estradiol benzoate

The objective of this study was to evaluate the effects of zearalenone (ZEA) and estradiol benzoate (EB) on stress injury and uterine development in post-weaning gilts. Thirty healthy post-weaning female gilts (Duroc × Landrace × Large White) aged 28-32 days were randomly allocated to three treatments as follows: (a) basal diet (Control), (b) basal diet plus 1.0 mg/kg purified ZEA (ZEA) and (c) basal diet plus 0.75 ml (1.5 mg) EB per pig at 3-days intervals by intramuscular injection (EB). The serum estradiol (E₂ ), the final and the increased vulvar area, uterine index, thickness of the myometrium and endometrium, and protein expression of heat shock protein 70 (HSP70) in ZEA group were higher than those in the control group (p < .05), but lower than those in the EB group (p < .05). The serum luteinizing hormone in ZEA group was lower than that of the control group (p < .05), but higher than that in the EB group (p < .05). Higher serum follicle-stimulating hormone and progesterone were observed in the ZEA and control groups than those in the EB group (p < .05). The serum glutathione peroxidase activity in the ZEA group was lower than that in the control and EB groups (p < .001), and the malondialdehyde in the ZEA group was higher than that in the control and EB groups (p < .001). Moreover, the relative mRNA and protein expression of growth hormone receptor (GHR) and relative mRNA expression of HSP70 in the ZEA and EB groups were higher than those in the control group (p < .05). In conclusion, both ZEA (1.0 mg/kg) and EB (1.5 mg at 3 days intervals by intramuscular injection) stimulated vulvar swelling and uterine hypertrophy by disordering serum hormones and up-regulating GHR expression, and induced stress by different mechanisms in this study. Furthermore, the observed up-regulating HSP70 expression challenged by ZEA or EB may be part of the mechanism to resist stress injury.

MicroRNAs in porcine uterus and serum are affected by zearalenone and represent a new target for mycotoxin biomarker discovery

The mycotoxin zearalenone (ZEN) poses a risk to animal health because of its estrogenic effects. Diagnosis of ZEN-induced disorders remains challenging due to the lack of appropriate biomarkers. In this regard, circulating microRNAs (small non-coding RNAs) have remarkable potential, as they can serve as indicators for pathological processes in tissue. Thus, we combined untargeted and targeted transcriptomics approaches to investigate the effects of ZEN on the microRNA expression in porcine uterus, jejunum and serum, respectively. To this end, twenty-four piglets received uncontaminated feed (Control) or feed containing 0.17 mg/kg ZEN (ZEN low), 1.46 mg/kg ZEN (ZEN medium) and 4.58 mg/kg ZEN (ZEN high). After 28 days, the microRNA expression in the jejunum remained unaffected, while significant changes in the uterine microRNA profile were observed. Importantly, 14 microRNAs were commonly and dose-dependently affected in both the ZEN medium and ZEN high group, including microRNAs from the miR-503 cluster (i.e. ssc-miR-424-5p, ssc-miR-450a, ssc-miR-450b-5p, ssc-miR-450c-5p, ssc-miR-503 and ssc-miR-542-3p). Predicted target genes for those microRNAs are associated with regulation of gene expression and signal transduction (e.g. cell cycle). Although the effects in serum were less pronounced, receiver operating characteristic analysis revealed that several microRNA ratios were able to discriminate properly between non-exposed and ZEN-exposed pigs (e.g. ssc-miR-135a-5p/ssc-miR-432-5p, ssc-miR-542-3p/ssc-miR-493-3p). This work sheds new light on the molecular mechanisms of ZEN, and fosters biomarker discovery.

Zearalenone induced oxidative stress in the jejunum in postweaning gilts through modulation of the Keap1-Nrf2 signaling pathway and relevant genes1

Researches have shown that dietary zearalenone (ZEA) caused oxidative stress in the liver and reproductive organs of postweaning gilts. However, information on the effects of ZEA on oxidative stress of the small intestine in the piglets is limited. The objective of this study was to determine the effects of ZEA exposure on oxidative stress, the Kelch-like erythroid cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and on immunohistochemistry of the jejunum in postweaning gilts. A 35-d feeding experiment using 40 postweaning gilts (Landrace × Yorkshire × Duroc) with an average BW of 14.01 ± 0.86 kg in 4 groups fed corn-soybean meal-based diets containing 0, 0.5, 1.0, and 1.5 mg ZEA/kg was conducted. The jejunum was obtained at the end of the experiment and used for analyses. The results showed that the activities of total superoxide dismutase and glutathione peroxidase and the relative expressions of Keap1 mRNA and protein in the jejunum linearly and quadratically decreased (P < 0.05) with increasing concentrations of ZEA in the diets. The malondialdehyde content, the integrated optical density of Nrf2 and glutathione peroxidase 1 (GPX1), and the relative expressions of Nrf2, GPX1, quinone oxidoreductase 1 (NQO1), and modifier subunit of glutamate-cysteine ligase (GCLM) mRNA and proteins linearly and quadratically increased (P < 0.05) with increasing levels of ZEA. Immunohistochemical analysis showed that Nrf2 and GPX1 immunoreactivity was enhanced by the ZEA treatments, and block localization of yellow and brown immunoreactive substances in the jejunum was observed with increasing levels of ZEA. The results suggest that ingested ZEA induced oxidative stress in the jejunum in postweaning gilts through upregulation of the Keap1-Nrf2 signaling pathway and downstream target genes NQO1, HO1, and GCLM, indicating the important role of the Keap1-Nrf2 signaling pathway in oxidative stress induced by ZEA in the jejunum of the postweaning piglets.

Bacillus velezensis A2 fermentation exerts a protective effect on renal injury induced by Zearalenone in mice

Zearalenone (ZEN) is an estrogen-like mycotoxin occurring in food and feeds, and it can cause oxidative damage and apoptosis in the testis, liver, and kidney. A current concern for researchers is how to reduce the harm it causes to humans and animals. In this study, our aim was to isolate and identify a novel and efficient ZEN-detoxifying strain of bacteria, and we aimed to assess the protective effect of the isolated strain on kidney damage caused by ZEN in mice. Our results indicated that a strain of Bacillus velezensis (B. velezensis), named A2, could completely degrade ZEN (7.45 μg/mL) after three days of incubation at 37 °C in the Luria-Bertani (LB) medium. This fermentation broth of the B. velezensis A2 strain was given to mice. The histopathological analysis indicated that the fermentation broth from the B. velezensis A2 strain reduced the degree of renal injury that is induced by ZEN. Furthermore, it greatly reduced the increase in serum levels of creatinine (CRE), uric acid (UA), and urea nitrogen (BUN) caused by ZEN. In addition, B. velezensis A2 strain also significantly inhibited the increase of malonaldehyde (MDA) content, and reversed the decreases of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities caused by ZEN. Studies have shown that ZEN is involved in the regulation of mRNA and protein levels of genes involved in the ER stress-induced apoptotic pathway, such as heavy chain binding protein (BIP), C-/-EBP homologous protein (CHOP), cysteine Aspartate-specific protease-12 (Caspase-12), c-Jun N-terminal kinase (JNK), and BCL2-related X protein (Bcl-2 and Bax). However, when mice were administered the fermentation broth of the B. velezensis A2 strain, it significantly reversed the expressions of these genes in their kidney tissue. In conclusion, our results indicate that the newly identified strain of B. velezensis A2, has a protective effect from renal injury induced by ZEN in mice. This strain has a potential application in the detoxification of ZEN in feed and protects animals from ZEN poisoning.

The Ethyl Acetate Extract of Gynura formosana Kitam. Leaves Inhibited Cervical Cancer Cell Proliferation via Induction of Autophagy

Gynura formosana Kitam. belongs to the Compositae family and has been traditionally used for the prevention of cancer, diabetes, and inflammation in China. Previous studies had indicated that the ethyl acetate extract of Gynura formosana Kitam. leaves (EAEG) exhibited antioxidant and anti-inflammatory activity. In this report, we demonstrated that EAEG possessed potent anticancer activity through autophagy-mediated inhibition of cell proliferation. EAEG induced a strong cytostatic effect towards HeLa cells and, to a lesser extent, HepG2 and MCF-7 cells. This cytostatic effect of EAEG was not a consequence of increased apoptosis, as neither DNA fragmentation nor change in protein expression level for a number of apoptosis-related genes including Bid, Bax, Bcl-2, and caspase-3 was observed after EAEG treatment, and the apoptosis inhibitor Z-VAD-FMK did not inhibit the EAEG-elicited cytostatic effect. On the other hand, EAEG induced autophagy in a dose-dependent fashion, as shown by increased GFP puncta formation, enhanced conversion of the microtubule-associated protein light chain LC3-I to LC3-II, and downregulation of the p62 protein. Treating the HeLa cells with EAEG together with Chloroquine (CQ) further accelerated LC3 conversion and p62 clearance, indicating that EAEG induced complete autophagy flux. Importantly, the autophagy inhibitor 3-methyladenine (3MA) significantly abrogated the cytostatic effect of EAEG, strongly suggesting that EAEG inhibited HeLa cell proliferation through the induction of autophagy rather than apoptosis. Our results provided a novel and interesting mechanistic insight into the anticancer action of EAEG, supporting the traditional use of this plant for the treatment of the cancer.

Assessment of Mycotoxin Exposure in Breastfeeding Mothers with Celiac Disease

OBJECTIVE

To assess the risk of mycotoxin exposure (aflatoxin M1, ochratoxin A, and zearalenone) in celiac disease (CD) breastfeeding mothers and healthy control mothers, as well as in their offspring, by quantifying these contaminants in breast milk.

STUDY DESIGN

Thirty-five breastfeeding women with CD on a gluten-free diet and 30 healthy breastfeeding controls were recruited. Milk sampling was performed three times per day for three consecutive days. Mycotoxin content was investigated by an analytical method using immunoaffinity column clean-up and high-performance liquid chromatography (HPLC) with fluorometric detection.

RESULTS

Aflatoxin M1 (AFM1) was detected in 37% of CD group samples (mean ± SD = 0.012 ± 0.011 ng/mL; range = 0.003-0.340 ng/mL). The control group showed lower mean AFM1 concentration levels in 24% of the analyzed samples (0.009 ± 0.007 ng/mL; range = 0.003-0.067 ng/mL, ANOVA on ranks, p-value < 0.01). Ochratoxin A and zearalenone did not differ in both groups.

CONCLUSION

Breast milk AFM1 contamination for both groups is lower than the European safety threshold. However, the estimated exposures of infants from CD mothers and control mothers was much higher (≃15 times and ≃11 times, respectively) than the threshold set by the joint FAO/WHO Expert Committee on Food Additives (JECFA). Since incongruities exist between JECFA and the European Union standard, a novel regulatory review of the available data on this topic is desirable. Protecting babies from a neglected risk of high AFM1 exposure requires prompt regulatory and food-control policies.