Fusarium mycotoxins: Effects on reproductive function in domestic animals—A review

Biotransformation of zearalenone to non-estrogenic compounds with two novel recombinant lactonases from Gliocladium

BACKGROUND

The mycotoxin zearalenone (ZEA) produced by toxigenic fungi is widely present in cereals and its downstream products. The danger of ZEA linked to various human health issues has attracted increasing attention. Thus, powerful ZEA-degrading or detoxifying strategies are urgently needed. Biology-based detoxification methods are specific, efficient, and environmentally friendly and do not lead to negative effects during cereal decontamination. Among these, ZEA detoxification using degrading enzymes was documented to be a promising strategy in broad research. Here, two efficient ZEA-degrading lactonases from the genus Gliocladium, ZHDR52 and ZHDP83, were identified for the first time. This work studied the degradation capacity and properties of ZEA using purified recombinant ZHDR52 and ZHDP83.

RESULTS

According to the ZEA degradation study, transformed Escherichia coli BL21(DE3) PLySs cells harboring the zhdr52 or zhdp83 gene could transform 20 µg/mL ZEA within 2 h and degrade > 90% of ZEA toxic derivatives, α/β-zearalanol and α/β-zearalenol, within 6 h. Biochemical analysis demonstrated that the optimal pH was 9.0 for ZHDR52 and ZHDP83, and the optimum temperature was 45 °C. The purified recombinant ZHDR52 and ZHDP83 retained > 90% activity over a wide range of pH values and temperatures (pH 7.0-10.0 and 35-50 °C). In addition, the specific activities of purified ZHDR52 and ZHDP83 against ZEA were 196.11 and 229.64 U/mg, respectively. The results of these two novel lactonases suggested that, compared with ZHD101, these two novel lactonases transformed ZEA into different products. The slight position variations in E126 and H242 in ZDHR52/ZEA and ZHDP83/ZEA obtained via structural modelling may explain the difference in degradation products. Moreover, the MCF-7 cell proliferation assay indicated that the products of ZEA degradation using ZHDR52 and ZHDP83 did not exhibit estrogenic activity.

CONCLUSIONS

ZHDR52 and ZHDP83 are alkali ZEA-degrading enzymes that can efficiently and irreversibly degrade ZEA into non-estrogenic products, indicating that they are potential candidates for commercial application. This study identified two excellent lactonases for industrial ZEA detoxification.

A novel case of cutaneous, nasal and systemic fusariosis in a goat

The clinical findings associated with nasal, cutaneous and systemic fusariosis in a 3-year-old billy Boer goat are summarised. The clinical features, treatment, postmortem findings and laboratory diagnostics are reported and discussed in the context of existing knowledge on mycoses of small ruminants. The goat presented primarily for respiratory signs (inspiratory dyspnoea) with unilateral left-sided mucopurulent nasal discharge, and multifocal variably ulcerative and necrotic cutaneous nodules. Histopathology of nasal and cutaneous biopsies revealed necrotising pyogranulomatous inflammation with intralesional septate hyphal elements that correlated with culture of Fusarium oxysporum. The patient continued to deteriorate clinically during treatment with oxytetracycline and meloxicam, with the addition of sodium iodide and potassium iodide, and was humanely euthanased. Postmortem examination revealed multifocal nodular lesions throughout the kidneys, abdominal lymph nodes and lungs. These lesions were consistent with those identified antemortem from which F. oxysporum was cultured. Although treatment was unsuccessful, to the author's knowledge, no instance of rhinofacial or systemic caprine infection with Fusarium spp. has been documented in the veterinary literature, making this the first recognised instance of this form of infection in small ruminant species.

Effects of a Multi-Component Mycotoxin-Detoxifying Agent on Oxidative Stress, Health and Performance of Sows

This in vivo study aimed to investigate the effects of a multi-component mycotoxin-detoxifying agent, containing clays (bentonite, sepiolite), phytogenic feed additives (curcumin, silymarin) and postbiotics (yeast cell wall, hydrolyzed yeast) on the antioxidant capacity, health and reproductive performance of pregnant and lactating sows challenged by mycotoxins. Eighty (80) primiparous sows (mean age 366 ± 3 days) per each of the two trial farms were divided into two groups in each farm: a) T1 (control group): 40 sows received the contaminated feed and b) T2 group (experimental group): 40 sows received the contaminated feed plus the mycotoxin-detoxifying agent, one month before farrowing until the end of the lactation period. Thiobarbituric acid reactive substances (TBARS), protein carbonyls (CARBS) and total antioxidant capacity (TAC) were evaluated as biomarkers of oxidative stress. Clinical and reproductive parameters were recorded. Our results indicate that the administration of a multi-component mycotoxin-detoxifying agent's administration in sow feed has beneficial effects on oxidative stress biomarkers and can improve sows' health and performance.

The Mycotoxin De-Epoxy-Deoxynivalenol (DOM-1) Increases Endoplasmic Reticulum Stress in Ovarian Theca Cells

Deoxynivalenol (DON) is a major mycotoxin present in animal feed and negatively affects growth and reproduction in farm species, including pigs and cattle. The mechanism of DON action involves the ribotoxic stress response (RSR), and it acts directly on ovarian granulosa cells to increase cell death. In ruminants, DON is metabolized to de-epoxy-DON (DOM-1), which cannot activate the RSR but has been shown to increase cell death in ovarian theca cells. In the present study, we determined if DOM-1 acts on bovine theca cells through endoplasmic stress using an established serum-free cell culture model and to assess whether also DON activates endoplasmic stress in granulosa cells. The results show that DOM-1 increased the cleavage of ATF6 protein, increased the phosphorylation of EIF2AK3, and increased the abundance of cleaved XBP1 mRNA. Activation of these pathways led to an increased abundance of mRNA of the ER stress target genes GRP78, GRP94, and CHOP. Although CHOP is widely associated with autophagy, inhibition of autophagy did not alter the response of theca cells to DOM-1. The addition of DON to granulosa cells partially increased ER stress pathways but failed to increase the abundance of mRNA of ER stress target genes. We conclude that the mechanism of action of DOM-1, at least in bovine theca cells, is through the activation of ER stress.

Extraction, characterization, and biological activities of exopolysaccharides from plant root soil fungus Fusarium merismoides A6

The exploration of polysaccharides from microorganisms is of great importance. In this study, a new type of exopolysaccharide excreted by Fusarium merismoides A6 (FM-EPS) was isolated, and the extraction conditions were optimized using a response surface methodology (RSM). The extraction temperature at 0 °C, a precipitation time of 7.83 h, and an ethanol precipitation concentration of 77.64% were predicted and proved to be the best extraction conditions with the maximum extraction yield of 0.74 g/mL. Then, two fractions of F. merismoides A6 exopolysaccharides (FM-EPS1 and FM-EPS2) were obtained through DEAE Sepharose fast flow column chromatography. As indicated by monosaccharide composition analysis, both fractions mainly consisted of mannose, glucose, galactose, and ribose, with an average molecular weight of 5.14 × 104 and 6.50 × 104 g/mol, respectively. FT-IR and NMR spectroscopy indicated the FM-EPSs had both α- and β-glycosidic bonds. Moreover, the determination of antioxidant and antiproliferative activities in vitro proved that FM-EPSs had good antioxidant activities and antiproliferation activities. FM-EPS1 showed stronger antioxidant activities than FM-EPS2. FM-EPS2 showed antiproliferation activities on HeLa and HepG2 cells, while FM-EPS1 had no obvious antiproliferative activity. Therefore, FM-EPSs could be explored as potential antioxidant and anticancer agent applied in food, feed, nutraceutical, pharmaceutical, cosmetics, and chemical industries.

Recent Progress in Electrochemical Nano-Biosensors for Detection of Pesticides and Mycotoxins in Foods

Pesticide and mycotoxin residues in food are concerning as they are harmful to human health. Traditional methods, such as high-performance liquid chromatography (HPLC) for such detection lack sensitivity and operation convenience. Efficient, accurate detection approaches are needed. With the recent development of nanotechnology, electrochemical biosensors based on nanomaterials have shown solid ability to detect trace pesticides and mycotoxins quickly and accurately. In this review, English articles about electrochemical biosensors in the past 11 years (2011-2022) were collected from PubMed database, and various nanomaterials are discussed, including noble metal nanomaterials, magnetic metal nanoparticles, metal-organic frameworks, carbon nanotubes, as well as graphene and its derivatives. Three main roles of such nanomaterials in the detection process are summarized, including biomolecule immobilization, signal generation, and signal amplification. The detection targets involve two types of pesticides (organophosphorus and carbamate) and six types of mycotoxins (aflatoxin, deoxynivalenol, zearalenone, fumonisin, ochratoxin A, and patulin). Although significant achievements have been made in the evolution of electrochemical nano-biosensors, many challenges remain to be overcome.

In Vitro Effects of Enniatin A on Steroidogenesis and Proliferation of Bovine Granulosa Cells

The emerging Fusarium mycotoxins enniatins (ENNs) have been the focus of new research because of their well-documented existence in various cereal and grain products. Research findings indicate that reproductive disorders may be caused by exposure to Fusarium mycotoxins, but little work has evaluated ENNs on reproductive function. Therefore, to determine the effects of ENNA on the proliferation and steroidogenesis of granulosa cells (GC), experiments were conducted using bovine GC cultures. In vitro, ENNA (1−5 μM) inhibited (p < 0.05) hormone-induced GC progesterone and estradiol production. The inhibitory effect of ENNA on estradiol production was more pronounced in small- than large-follicle GC. In large-follicle GC, 0.3 μM ENNA had no effect (p > 0.10) whereas 1 and 3 μM ENNA inhibited GC proliferation. In small-follicle GC, ENNA (1−5 μM) dramatically decreased (p < 0.05) GC proliferation. Using cell number data, the IC50 of ENNA was estimated at 2 μM for both follicle sizes. We conclude that ENNA can directly inhibit ovarian function in cattle, decreasing the proliferation and steroid production of GC.

Effects of zearalenone on ovarian development of prepubertal gilts through growth hormone axis

This experiment aimed to establish the effects of zearalenone (ZEN) on ovarian development in prepubertal gilts through the growth hormone axis [growth hormone-releasing hormone (GHRH) / growth hormone (GH) / growth hormone receptor (GHR)]. In a 40-day experiment, 48 Landrace × Yorkshire crossbred prepubertal gilts were randomly allocated to four dietary treatments, including a basal diet supplemented with 0 (control), 400 (T1), 800 (T2), and 1,600 (T3) μg/kg ZEN. The ovary index of T2 (P = 0.058) and T3 (P = 0.065) increased compared to the control group. Besides, histopathological examination revealed that ZEN promoted the development of ovaries and follicles. The GHR content, relative expression levels of GHR, janus activated kinase 2 (JAK2) mRNA, and mean optical density of GHR in the ovaries of prepubertal gilts in the T2 experimental group increased significantly at P &lt; 0.05 compared to the control group. The T3 group had significantly higher GHR content, relative JAK2 expression levels, and signal transducer and activator of transcriptions 3 (STAT3) mRNA. In conclusion, ZEN enhances the biological effect of GH, promotes the development of the ovary (follicle), and exerts reproductive toxicity by increasing the expression level of GHR, JAK2, and STAT3 mRNA ovary and immune intensity of GHR protein.

Effects of grape phenolics, myricetin and piceatannol, on bovine granulosa and theca cell proliferation and steroid production in vitro

Myricetin (a flavonol) and piceatannol (a stilbenoid) are naturally occurring phenolic compounds in red wine with cardio-protective and anti-carcinogenic effects, but their potential reproductive effects have not been investigated. Thus, the present study was designed to determine if myricetin and piceatannol can directly affect ovarian function using bovine granulosa cells (GC) and theca cells (TC) as in vitro model systems to evaluate effects on cell proliferation and steroid production. In Experiment 1 and 2, myricetin and piceatannol at 30 μM blocked insulin-like growth factor 1 (IGF1)-induced progesterone production by GC without affecting GC numbers. In contrast, myricetin stimulated IGF1-induced estradiol production, whereas piceatannol at 30 μM inhibited IGF1-induced estradiol production by 90% in GC. In Experiment 3 and 4, TC androstenedione and progesterone production and TC proliferation was inhibited by myricetin and piceatannol at 30 μM. In Experiment 5, piceatannol (30 μM) reduced the Fusarium mycotoxin, beauvericin (6 μM)-induced inhibition on progesterone production and cell proliferation. Myricetin (30 μM) reduced the inhibitory effect of beauvericin on estradiol but not progesterone production or cell proliferation. In conclusion, the red wine phenols, myricetin and piceatannol, directly affected GC and TC steroidogenesis, and were able to reduce some of the inhibitory effects of beauvericin on GC function.

Effects of Chronic Exposure to Diets Containing Moldy Corn or Moldy Wheat Bran on Growth Performance, Ovarian Follicular Pool, and Oxidative Status of Gilts

Background: We investigated the effect of replacing normal corn (NC) or normal wheat bran (NW) with moldy corn (MC) or moldy wheat bran (MW) on growth, ovarian follicular reserves, and oxidative status. Methods: Sixty-three Landrace × Yorkshire gilts were assigned to seven diets formulated by using MC to replace 0% (control), 25% (25% MC), 50% (50% MC), 75% (75% MC), and 100% NC (100% MC), MW to replace 100% NW (100% MW), and MC and MW to replace 100% NC and 100% NW (100% MC + MW), from postnatal day 110 to day 19 of the second estrous cycle. Results: Feeding the gilts with MC or MW induced a lower average daily gain at days 29−56 of the experiment. Age at puberty remained unchanged, but MC inclusion resulted in a linear decrease in antral follicles with diameter >3.0 mm, and control gilts had a 12.7 more large antral follicles than gilts in the 100% MC + MW treatment. MC inclusion linearly decreased the numbers of primordial follicles, growing follicles, and corpora lutea, associated with a lower anti-Müllerian hormone level in serum and 17β-estradiol level in follicular fluid. MC inclusion decreased the serum concentrations of insulin-like growth factor 1 and its mRNA levels in the liver, combined with higher malondialdehyde concentration and lower total superoxide dismutase activities in serum and liver. Conclusion: Chronic exposure to MC-containing diets caused the loss of follicles, even if levels of deoxynivalenol, zearalenone, and aflatoxin B1 were below the levels allowed by China and Europe standards.

Providing Biological Plausibility for Exposure–Health Relationships for the Mycotoxins Deoxynivalenol (DON) and Fumonisin B1 (FB1) in Humans Using the AOP Framework

Humans are chronically exposed to the mycotoxins deoxynivalenol (DON) and fumonisin B1 (FB1), as indicated by their widespread presence in foods and occasional exposure in the workplace. This exposure is confirmed by human biomonitoring (HBM) studies on (metabolites of) these mycotoxins in human matrices. We evaluated the exposure–health relationship of the mycotoxins in humans by reviewing the available literature. Since human studies did not allow the identification of unequivocal chronic health effects upon exposure to DON and FB1, the adverse outcome pathway (AOP) framework was used to structure additional mechanistic evidence from in vitro and animal studies on the identified adverse effects. In addition to a preliminary AOP for DON resulting in the adverse outcome (AO) ‘reduced body weight gain’, we developed a more elaborated AOP for FB1, from the molecular initiating event (MIE) ‘inhibition of ceramide synthases’ leading to the AO ‘neural tube defects’. The mechanistic evidence from AOPs can be used to support the limited evidence from human studies, to focus FB1- and DON-related research in humans to identify related early biomarkers of effect. In order to establish additional human exposure–health relationships in the future, recommendations are given to maximize the information that can be obtained from HBM.

Low Dose of Deoxynivalenol Aggravates Intestinal Inflammation and Barrier Dysfunction Induced by Enterotoxigenic Escherichia coli Infection through Activating Macroautophagy/NLRP3 Inflammasomes

The toxicity of deoxynivalenol (DON) in healthy humans and animals has been extensively studied. However, whether the natural-low-dose DON is scatheless under unhealthy conditions, especially intestinal injury, is unknown. Infection of enterotoxigenic Escherichia coli (ETEC) is a classical intestinal injury model. In this study, we explored the effects of low-dose DON on intestinal injury induced by the ETEC infection and the underlying mechanism in piglets, mice, and IPEC-J2 monolayer cells. Results showed that significant growth slowdown, severe diarrhea, and intestinal damage, bacterial multiplication, and translocation were observed in the experimental group (low-dose DON, 0.75 mg/kg in feed for piglets, and 1 mg/kg body weight for mice, combined with the ETEC infection). Meanwhile, more aggressive intestinal inflammation and barrier dysfunction were observed in animals and IPEC-J2 monolayer cells. Higher expression levels of NLRP3 inflammasome and LC3B were observed in jejunum and IPEC-J2 in the experimental group. After treatment with NLRP3 or caspase1 inhibitors, excessive intestinal inflammation rather than barrier dysfunction in the experimental group was limited. CRISPR-Cas9-mediated knockout of LC3B alleviated intestinal inflammation and barrier dysfunction and also inhibited NLRP3 inflammasome. In conclusion, a low dose of DON aggravates intestinal inflammation and barrier dysfunction induced by the ETEC infection by activating macroautophagy and NLRP3 inflammasome.

Mycotoxin risk management for dairy cows by monitoring blood parameters, reproduction status and SCC in milk

ABSTRACT The objective of this study was to determine the effectiveness of mycotoxin management with feed additive by monitoring biochemical blood parameters, reproduction status and udder health in cows. During the first 1-12-months, the reproduction performance was assessed. The cows were fed only total mixed ration (TMR) with naturally contaminated mycotoxins (ZEN;DON;AFB1;OTA) and the cows were regarded as a control group (CG). In months 13-15, two groups were created: control (CG)(n=30) and experimental (EG)(n=60). The CG was fed with contaminated TMR and the EG was fed with the same TMR+40g/cow mycotoxins management feed additive (TMXL1000). During this period, blood indicators and udder health were studied. Beginning with months 16-24, all cows were fed with contaminated TMR+40 g/cow (TMXL1000) and regarded as the EG. The IgA concentrations in the CG decreased in the 15th month (p<0.05). The concentrations of cortisol decreased by two times (p<0.05) in the EG. Ovarian cyst treatment was more effective by 14.98% (p<0.05) in the EG than in the CG (p<0.05). The EG performed an effective (18.02%) (p<0.05) response to applied ovsynch protocol compared with the CG. According to the obtained results, it can be concluded that feed additive for mycotoxins management had a positive impact on dairy cow health.

Emerging mycotoxins and reproductive effects in animals: A short review

Emerging Fusarium mycotoxins beauvericin (BEA), enniatins (ENNs) and moniliformin (MON) are gaining increasing interest due to their wide presence especially in cereals and grain-based products. In vitro and in vivo studies indicate that Fusarium mycotoxins can be implicated in reproductive disorders in animals. Of these mycotoxins BEA may affect reproductive functions, impairing the development of oocytes in pigs and sheep. Studies show dramatic inhibitory effects of BEA and ENNA on bovine granulosa cell steroidogenesis. ENNs also inhibit boar sperm motility and cause detrimental effects on embryos in mice and pigs. Although little data are reported on reproductive effects of MON, in vitro studies show inhibitory effects of MON on Chinese hamster ovary cells. The present review aims to summarize the reproductive toxicological effects of emerging Fusarium mycotoxins BEA, ENNs and MON on embryo development, ovarian function, and testicular function of animals. In vitro and in vivo toxicological data are reported although additional studies are needed for proper risk assessment.

Deoxynivalenol and zearalenone: Different mycotoxins with different toxic effects in donkey (Equus asinus) endometrial epithelial cells

Deoxynivalenol (DON) and zearalenone (ZEA), which are commonly found in feed products, exhibit serious negative effects on the reproductive systems of domestic animals. However, the toxicity of mycotoxins on the uterine function of donkey (Equus asinus) remains unclear. This study investigated the biological effects of DON and ZEA exposure on donkey endometrial epithelial cells (EECs). It was administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro. The results showed that 10 μM DON exposure markedly changed the expression levels of pyroptosis-associated genes and that 30 μM ZEA exposure changed the expression levels of inflammation-associated genes in EECs. The mRNA expression of cancer-promoting genes was markedly upregulated in cells exposed to DON and 30 μM ZEA; in particular, 10 μM and 30 μM DON and ZEA markedly disturbed the expression of androgen and estrogen secretion-related genes. Furthermore, Q-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed EECs. Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of EECs from donkey in vitro.

Zearalenone interferes with the sperm-triggered inflammation in the bovine uterus in vitro: Negative impact on sperm motility and survival

Zearalenone (ZEN)-contaminated diets induce detrimental effects on the bovine reproduction. Recently, we reported that active sperm induce pro-inflammatory responses in bovine endometrial epithelial cells (BEECs) in vitro. This study aimed to investigate the impact of presence of ZEN on the sperm-uterine crosstalk in vitro. BEECs monolayers were stimulated by ZEN (10, 100, and 1000 ng/mL) for 0, 3, 6, 12, or 24 h and gene expressions were analyzed by real-time PCR. Moreover, BEECs were pre-exposed to ZEN (10, 100, and 1000 ng/mL) for 24 h then, co-incubated with sperm for 6 h. Conditioned media (CM) from a sperm-BEECs co-culture, after pre-exposure to ZEN, were harvested and exploited to challenge either polymorphonuclear cells (PMNs) or sperm. Both PMNs phagocytic activity toward sperm and sperm motility parameters were then assessed. Results showed that ZEN alone induced pro-inflammatory responses in BEECs through the induction of mRNA expressions of pro-inflammatory cytokines (TNFA and IL1B) and PGES1 at different time points. Pre-exposure of BEECs to ZEN, amplified the sperm-triggered upregulation of pro-inflammatory cytokines (TNFA and IL1B) and chemokine IL8 mRNA abundance in BEECs. Sperm-BEECs conditioned media, primed by ZEN, stimulated the PMNs phagocytosis for sperm whereas suppressed sperm motility parameters. Taken together, these findings indicate that the presence of ZEN augments the pro-inflammatory cascade triggered by sperm in BEECs, provokes PMNs phagocytosis for sperm, and reduces sperm motility parameters. Such immunological reactions may create a hostile environment for sperm competence and survival in the bovine uterus, thus impair fertility.

Grape Seed Proanthocyanidin Ameliorates FB1-Induced Meiotic Defects in Porcine Oocytes

Fumonisin B₁ (FB₁), as the most prevalent and toxic fumonisin, poses a health threat to humans and animals. The cytotoxicity of FB₁ is closely related to oxidative stress and apoptosis. The purpose of this study is to explore whether Grape seed proanthocyanidin (GSP), a natural antioxidant, could alleviate the meiotic maturation defects of oocytes caused by FB₁ exposure. Porcine cumulus oocyte complexes (COCs) were treated with 30 μM FB₁ alone or cotreated with 100, 200 and 300 μM GSP during in vitro maturation for 44 h. The results show that 200 μM GSP cotreatment observably ameliorated the toxic effects of FB₁ exposure, showing to be promoting first polar body extrusion and improving the subsequent cleavage rate and blastocyst development rate. Moreover, 200 μM GSP cotreatment restored cell cycle progression, reduced the proportion of aberrant spindles, improved actin distribution and protected mitochondrial function in FB₁-exposed oocytes. Furthermore, reactive oxygen species (ROS) generation was significantly decreased and the mRNA levels of CAT, SOD2 and GSH-PX were obviously increased in the 200 μM GSP cotreatment group. Notably, the incidence of early apoptosis and autophagy level were also significantly decreased after GSP cotreatment and the mRNA expression levels of BAX, CASPASE3, LC3 and ATG5 were markedly decreased, whereas BCL2 and mTOR were observably increased in the oocytes after GSP cotreatment. Together, these results indicate that GSP could exert significant preventive effects on FB₁-induced oocyte defects by ameliorating oxidative stress through repairing mitochondrial dysfunction.

Brazilian bentonite and a new modified bentonite material, BAC302, reduce zearalenone-induced cell death

Bentonite clays exhibit high adsorptive capacity for contaminants and is frequently used as a feed additive to reduce the bioavailability and thus the toxicity of several mycotoxins. Zearalenone (ZEN) is a secondary Fusarium toxic metabolite that can contaminate a wide range of food- and feedstuff. Since organophilic treatments is known to increase the adsorption capacity of bentonites, the aim of study was to evaluate and compare the ability of natural bentonite and bentonite treated with BAC302 to protect against ZEN-induced cytotoxicity in the epithelial colorectal adenocarcinoma (Caco-2) and human leukemia monocytic (THP-1) cell lines. The two materials were not toxic to the cell lines at lower concentrations. Furthermore, the results indicate that the two materials protect the Caco-2 and THP-1 cells against ZEN-induced cytotoxicity, probably by extracellular adsorption of ZEN. The tested natural bentonite shows potential for in vivo testing to evaluate if it is suitable for intoxication in ZEN contaminated animal feeds.

Deoxynivalenol and Zearalenone: Different Mycotoxins with Different Toxic Effects in the Sertoli Cells of Equus asinus

(1) Background: Deoxynivalenol (DON) and zearalenone (ZEA) are type B trichothecene mycotoxins that exert serious toxic effects on the reproduction of domestic animals. However, there is little information about the toxicity of mycotoxins on testis development in Equus asinus. This study investigated the biological effects of DON and ZEA exposure on Sertoli cells (SCs) of Equus asinus; (2) Methods: We administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro; (3) Results: The results showed that 10 μM DON exposure remarkably changed pyroptosis-associated genes and that 30 μM ZEA exposure changed inflammation-associated genes in SCs. The mRNA expression of cancer-promoting genes was remarkably upregulated in the cells exposed to DON or 30 μM ZEA; in particular, DON and ZEA remarkably disturbed the expression of androgen and oestrogen secretion-related genes. Furthermore, quantitative RT-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed SCs; (4) Conclusions: Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of SCs from Equus asinus in vitro.

Biomonitoring of Multiple Mycotoxins in Urine by GC-MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran

A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON; 3-acetyldeoxynivalenol, 3-ADON; 15-acetyldeoxynivalenol, 15-ADON; fusarenon-X, FUS-X; diacetoxyscirpenol, DAS; nivalenol, NIV; neosolaniol, NEO; zearalenone, ZON; zearalanone, ZAN; T-2 toxin, T-2; and HT-2 toxin, HT-2) in esophageal cancer patients was performed with the urinary biomarkers approach in Golestan, Iran. Urine multimycotoxin analysis was performed by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry (GC–MS/MS) analysis, and values were normalized with urinary creatinine (μg/g). Four mycotoxins, namely NEO (40%), HT-2 (17.6%), DON (10%), and HT-2 (5.8%), were detected in the analyzed urine samples. DON was only detected in the control group (5.09 μg/g creatinine), while T-2 (44.70 μg/g creatinine) was only present in the esophageal cancer group. NEO and HT-2 were quantified in both control and case groups, showing average of positive samples of 9.09 and 10.45 μg/g creatinine for NEO and 16.81 and 29.09 μg/g creatinine for HT-2, respectively. Mycotoxin co-occurrence was observed in three samples as binary (NEO/HT-2 and T-2/HT-2) and ternary (DON/NEO/HT-2) combinations, reaching total concentrations of 44.58, 79.13, and 30.04 µg/g creatinine, respectively. Further investigations are needed to explore a causal association between mycotoxin contamination and esophageal cancer. For this pilot study in Golestan, the low sample size was a very limiting factor.

Simultaneous determination of zearalenone and ochratoxin A based on microscale thermophoresis assay with a bifunctional aptamer

Nowadays, contamination of various mycotoxins in crops and their products exposes increasing risks to human health. Efficient determination methods are urgently needed. Herein, a bifunctional aptamer and a simple aptasensor based on microscale thermophoresis assay (MST) were constructed for the first time for simultaneous determination of two mycotoxins, i.e. zearalenone (ZEN) and ochratoxin A (OTA). The bifunctional aptamer was engineered by splicing a ZEN aptamer and an OTA aptamer with a linker according to the structure analysis of aptamers. The binding mechanism of the bifunctional aptamer to ZEN and OTA were revealed basing on the molecular docking studies. The MST assay proved that the bifunctional aptamer showed high affinity and specificity towards ZEN and OTA. Furthermore, a bifunctional aptamer-based MST-aptasensor was developed for simultaneous detection of ZEN and OTA in corn oil sample. The MST-aptasensor provided a limit of detection (LOD) of 0.12 nM, with satisfactory recoveries of 93.31-104.19% and excellent selectivity, indicating that the bifunctional aptamer and MST-aptasensor had great potential in practical applications.

Ovarian toxicity by fusariotoxins in pigs: Does it imply in oxidative stress?

Mycotoxins are natural contaminants of food and feed occurring worldwide. Deoxynivalenol (DON) and fumonisin B1 (FB₁) are the most frequent fusariotoxins and induce immune and intestinal toxicity in humans and animals. Recently, an association between mycotoxins exposure and impaired fertility has been suggested. However, the effects of these mycotoxins on the reproductive system are not well established. This study aimed to evaluate the effects of FB₁ and DON, in combination or alone, on the ovarian morphology and oxidative responses using porcine explants. Seventy-two explants were obtained from six pigs and submitted to the following treatments: control (MEM medium), DON (10 μM), FB₁ (100 μM FB₁), and DON + FB₁ (10 μM + 100 μM). Histological and immunohistochemical assays were performed to evaluate ovarian changes, cell proliferation, and apoptosis. Oxidative stress response was evaluated through lipid peroxidation and antioxidant capacity response assays. The exposure to mycotoxins induced significant histological changes in the ovaries, which were characterized by a decrease in viable follicles and increase in degenerated follicles. A significant decrease in granulosa cell proliferation was observed in explants exposed to all mycotoxins. In addition the multi-contaminated treatment was responsible for an increase in the cell apoptosis index of growing follicles. On the other hand, the FB₁ and multi-contaminated treatments induced a significant decrease in lipid peroxidation accompanied by an increase in antioxidant responses. Altogether, our results indicate a reproductive toxicity induced by fusariotoxins. Moreover, mycotoxins, alone or in combination, modulate oxidative stress response, interfering with the production of free radicals and affecting the reproductive capacity of pigs.

Toxic Effects of Fumonisins, Deoxynivalenol and Zearalenone Alone and in Combination in Ducks Fed the Maximum EUTolerated Level

Toxic effects among fumonisins B (FB), deoxynivalenol (DON) and zearalenone (ZEN) administered alone and combined were investigated in 84-day-old ducks during force-feeding. 75 male ducks, divided into five groups of 15 animals, received daily during the meal a capsule containing the desired among of toxin. Treated animals received dietary levels of toxins equivalent to 20 mg FB1+FB2/kg (FB), 5 mg DON/kg (DON), 0.5 mg ZEN/kg (ZEN) and 20, 5 and 0.5 mg/kg of FB, DON and ZEN (FBDONZEN), respectively. Control birds received capsules with no toxin. After 12 days, a decrease in body weight gain accompanied by an increase in the feed conversion ratio was observed in ducks exposed to FBDONZEN, whereas there was no effect on performances in ducks exposed to FB, DON and ZEN separately. No difference among groups was observed in relative organ weight, biochemistry, histopathology and several variables used to measure oxidative damage and testicular function. A sphinganine to sphingosine ratio of 0.32, 1.19 and 1.04, was measured in liver in controls and in ducks exposed to FB and FBDONZEN, respectively. Concentrations of FB1 in liver were 13.34 and 15.4 ng/g in ducks exposed to FB and FBDONZEN, respectively. Together ZEN and its metabolites were measured after enzymatic hydrolysis of the conjugated forms. Mean concentrations of α-zearalenol in liver were 0.82 and 0.54 ng/g in ducks exposed to ZEN and FBDONZEN, respectively. β-zearalenol was 2.3-fold less abundant than α-zearalenol, whereas ZEN was only found in trace amounts. In conclusion, this study suggests that decreased performance may occur in ducks exposed to a combination of FB, DON and ZEN, but does not reveal any other interaction between mycotoxins in any of the other variables measured.

FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum

In filamentous fungi, hyphal growth depends on the continuous delivery of vesicles to the growing tips. It is unclear how fast-growing hyphae coordinate simultaneous cell extension and expansion in the tip cells. We have functionally characterized 12 TBC (Tre-2/Bub2/Cdc16) domain-containing proteins in Fusarium graminearum. Among them, FgMsb3 is found to regulate hyphal tip expansion and to be required for pathogenicity. The regulatory mechanism of FgMsb3 has been further investigated by genetic, high-resolution microscopy and high-throughput co-immunoprecipitation strategies. The FgMsb3 protein localizes at the polarisome and the hyphal apical dome (HAD) where it acts as a GTPase-activating protein for FgRab8 which is required for apical secretion-mediated growth and pathogenicity. Deletion of FgMSB3 causes excessive polarized trafficking but blocks the fusion of FgSnc1-associated vesicles to the plasma membrane. Moreover, we establish that FgSpa2 interacts with FgMsb3, enabling FgMsb3 tethering to the polarisome. Loss of FgSpa2 or other polarisome components (FgBud6 and FgPea2) causes complete shifting of FgMsb3 to the HAD and this affects the polarized growth and pathogenicity of the fungus. In summary, we conclude that FgSpa2 regulates FgMsb3-FgRab8 cascade and this is crucial for creating a steady-state equilibrium that maintains continuous polarized growth and contributes to the pathogenicity of F. graminearum.

Fumonisin B1 exposure adversely affects porcine oocyte maturation in vitro by inducing mitochondrial dysfunction and oxidative stress

Fumonisin B₁ (FB₁), as the most toxic fumonisin, is a common Fusarium mycotoxin contaminant of feed stuff and food, posing a potential health hazard to animals and humans. FB₁ has been reported to cause hepatotoxicity, neurotoxicity, nephrotoxicity, immunotoxicity and embryotoxicity; however, little information is available on whether FB₁ has toxic effects on mammalian oocytes. Herein, we adopted porcine oocytes as models to explore the effects and potential mechanisms of FB₁ on mammalian oocytes during in vitro maturation. Porcine cumulus oocyte complexes (COCs) were exposed to 0, 20, 30 and 40 μM FB₁ for 44 h during in vitro maturation, and the results reported that first polar body (PB1) extrusion was significantly inhibited when the FB₁ concentration reached 30 (P < 0.01) or 40 μM (P < 0.001). Further cell cycle analysis revealed that meiotic progression was disrupted, with a larger proportion of the 30 μM FB₁-treated oocytes being arrested at the germinal vesicle breakdown (GVBD) stage (P < 0.01). After being treated with 30 μM FB₁ for 28 h, the percentage of oocytes with aberrant spindle assembly was observably increased (P < 0.01), and the distribution of actin filaments on the plasma membrane was significantly reduced (P < 0.05). Furthermore, an observably higher rate of abnormal mitochondrial distribution (P < 0.05) and significantly decreased mitochondrial membrane potential (MMP) (P < 0.05) were observed in FB₁-exposed oocytes. In addition, ROS generation in FB₁-treated oocytes was rapidly increased (P < 0.05), while the transcriptional levels of antioxidant-related genes (CAT, SOD2 and GSH-Px) were sharply decreased compared with those in the control group. Additionally, the incidence of early apoptosis in FB₁-treated oocytes was also significantly increased (P < 0.05), suggesting that FB₁ exposure induced oxidative stress and further triggered apoptosis in porcine oocytes. Thus, these results suggested that FB₁ adversely affected oocyte maturation by disturbing cell cycle progression, destroying cytoskeletal dynamics and damaging mitochondrial function, which eventually induced oxidative stress and apoptosis in porcine oocytes.

Multivariate method for prediction of fumonisins B1 and B2 and zearalenone in Brazilian maize using Near Infrared Spectroscopy (NIR)

Fumonisins (FBs) and zearalenone (ZEN) are mycotoxins which occur naturally in grains and cereals, especially maize, causing negative effects on animals and humans. Along with the need for constant monitoring, there is a growing demand for rapid, non-destructive methods. Among these, Near Infrared Spectroscopy (NIR) has made great headway for being an easy-to-use technology. NIR was applied in the present research to quantify the contamination level of total FBs, i.e., fumonisin B1+fumonisin B2 (FB1+FB2), and ZEN in Brazilian maize. From a total of six hundred and seventy-six samples, 236 were analyzed for FBs and 440 for ZEN. Three regression models were defined: one with 18 principal components (PCs) for FB1, one with 10 PCs for FB2, and one with 7 PCs for ZEN. Partial least square regression algorithm with full cross-validation was applied as internal validation. External validation was performed with 200 unknown samples (100 for FBs and 100 for ZEN). Correlation coefficient (R), determination coefficient (R2), root mean square error of prediction (RMSEP), standard error of prediction (SEP) and residual prediction deviation (RPD) for FBs and ZEN were, respectively: 0.809 and 0.991; 0.899 and 0.984; 659 and 69.4; 682 and 69.8; and 3.33 and 2.71. No significant difference was observed between predicted values using NIR and reference values obtained by Liquid Chromatography Coupled to Tandem Mass Spectrometry (LC-MS/MS), thus indicating the suitability of NIR to rapidly analyze a large numbers of maize samples for FBs and ZEN contamination. The external validation confirmed a fair potential of the model in predicting FB1+FB2 and ZEN concentration. This is the first study providing scientific knowledge on the determination of FBs and ZEN in Brazilian maize samples using NIR, which is confirmed as a reliable alternative methodology for the analysis of such toxins.

Transfer of Mycotoxins from Lactation Feed to Colostrum of Sows

Studies regarding the transfer of mycotoxins from sow feed to colostrum are scarce. A sample of in-house produced lactation feed and one of colostrum were collected from two or three sows per farm (total 49) from 19 farms. The feed contents of aflatoxins (AFs), fumonisins (FUs), deoxynivalenol (DON) and zearalenone (ZEA) were assessed using ELISA and confirmed by liquid chromatography-mass spectrometry (LC-MS), The values were very low (10, 12, 17 and 2 positive samples for AFs, FUs, DON and ZEA, respectively), except for two samples (one AF, one DON). Based on feed values, colostrum samples from 13 farms were tested for at least one mycotoxin (Total 35). Aflatoxins were not found in any sample. A signal for FUs was observed in 5 of 11 colostra, despite low feed values; DON was frequently present in the colostrum (10/14). On the farm where the feed exceeded the DON suggested limits, a higher colostrum content was seen, 10.9 µg/kg, approximately 1/69 of the value showing toxicity in young pigs. The absence of reference values for neonate pigs, and the risk of higher and longer ingestion of DON by sows suggested considering routine checks of sow feed; more research on DON transfer and toxicity in piglets is needed.

Effect of Gamma-Radiation on Zearalenone-Degradation, Cytotoxicity and Estrogenicity

Zearalenone (ZEA) is produced in cereals by different species of Fusarium, being a non-steroidal estrogenic mycotoxin. Despite having a low acute toxicity, ZEA strongly interferes with estrogen receptors. Gamma-radiation has been investigated to eliminate mycotoxins from food and feed, showing promising results. The present study aims to investigate the gamma-radiation effect on ZEA at different moisture conditions and to evaluate the cytotoxicity and estrogenicity of the irradiated ZEA. Different concentrations of dehydrated ZEA and aqueous solutions of ZEA were exposed to gamma-radiation doses ranging from 0.4 to 8.6 kGy and the mycotoxin concentration determined after exposure by high performance liquid chromatography (HPLC) with fluorescence detection. Following this, the cytotoxicity of irradiated samples was assessed in HepG2 cells, by measuring alterations of metabolic activity, plasma membrane integrity and lysosomal function, and their estrogenicity by measuring luciferase activity in HeLa 9903 cells. Gamma-radiation was found to be effective in reducing ZEA, with significant increases in degradation with increased moisture content. Furthermore, a reduction of cytotoxicity with irradiation was observed. ZEA estrogenicity was also increasingly reduced with increasing radiation doses, but mainly in aqueous solutions. These results suggest reduction of ZEA levels and of its toxicity in food and feed commodities may be achieved by irradiation.

Nontoxic-dose deoxynivalenol aggravates lipopolysaccharides-induced inflammation and tight junction disorder in IPEC-J2 cells through activation of NF-κB and LC3B

Lipopolysaccharide (LPS) is the key factor in various intestinal inflammation which could disrupt the epithelial barrier function. Deoxynivalenol (DON), a well-known mycotoxin, can induce intestinal injury. However, the combined enterotoxicity of LPS and DON has rarely been studied. In this study, IPEC-J2 cell monolayers were exposed to LPS and nontoxic-dose DON for 12 and 24 h to investigate the effects of DON on LPS-induced inflammatory response and tight junction variation, and specific inhibitor and CRISPR-Cas9 were used to explore the underlying mechanisms. Our results showed that nontoxic-dose DON aggravated LPS-induced cellular inflammatory response, reflecting on more significant changes of inflammatory cytokines mRNA expression, higher protein expression of NOD-like receptor protein 3 (NLRP3) and procaspase-1. Moreover, nontoxic-dose DON aggravated LPS-induced mRNA and protein expression decreased, and distribution confused of tight junction proteins. We found that DON further enhanced LPS-induced phosphorylation and nucleus translocation of p65, and expression of LC3B-Ⅱ. NF-κB inhibitor and CRISPR-Cas9-mediated knockout of LC3B attenuated the effects of combination which indicated nontoxic-dose DON aggravated LPS-induced intestinal inflammation and tight junction disorder through activating NF-κB signaling pathway and autophagy-related protein LC3B. It further warns that ingesting low doses of mycotoxins may exacerbate the effects of intestinal pathogens on the body.

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Nontoxic-dose DON aggravates LPS-induced cellular inflammatory response in IPEC-J2 cell monolayers.

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Nontoxic-dose DON aggravates LPS-induced decrease and distribution disorder of tight junction in IPEC-J2 cell monolayers.

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Nontoxic-dose DON aggravates LPS-induced inflammatory response and tight junction disorder by activating NF-κB and LC3B.

Individual and Combined In Vitro Effects of Deoxynivalenol and Zearalenone on Boar Semen

Mycotoxins deoxynivalenol (DON) and zearalenone (ZEN) can negatively affect pig health. However, little is known about their effects on boar semen. We assessed the individual and combined effects of DON and ZEN on boar semen in vitro. In a pretrial, we determined the minimum dose (MiD) of each mycotoxin that induces a significant alteration of sperm progressive motility, as investigated using computer-assisted semen analysis (CASA). In the main trial, the individual and combined effects of each mycotoxin’s MiD on sperm motility and kinetics (CASA analysis), morphology (SpermBlue staining), viability (calcein-propidium iodide staining), membrane functional status (hypoosmotic swelling test), and chromatin integrity (acridine orange staining) were analyzed. Pretrial results suggested a MiD of 50.6 μM and 62.8 μM for DON and ZEN, respectively. In the main trial, DON and ZEN administered at MiD significantly affected CASA parameters (e.g., increase of immotile spermatozoa, reduction of progressive motile spermatozoa), decreased sperm viability, and affected sperm morphology (head abnormalities) and membrane functional status. DON and ZEN showed less than additive effects on most parameters tested and a synergistic effect on viability and on two CASA parameters. In conclusion, DON and ZEN showed individual and combined toxic effects on boar semen in vitro.

Developmental and hormonal regulation of ubiquitin-like with plant homeodomain and really interesting new gene finger domains 1 gene expression in ovarian granulosa and theca cells of cattle

Ubiquitin-like with plant homeodomain and really interesting new gene finger domains 1 (UHRF1) is a multi-domain nuclear protein that plays an important role in epigenetics and tumorigenesis, but its role in normal ovarian follicle development remains unknown. Thus, the present study evaluated if UHRF1 mRNA abundance in bovine follicular cells is developmentally and hormonally regulated, and if changes in UHRF1 are associated with changes in DNA methylation in follicular cells. Abundance of UHRF1 mRNA was greater in granulosa cells (GC) and theca cells (TC) from small (<6 mm) than large (≥8 mm) follicles and was greater in small-follicle GC than TC. In GC and TC, fibroblast growth factor 9 (FGF9) treatment increased (P < 0.05) UHRF1 expression by 2-fold. Also, luteinizing hormone (LH) and insulin-like growth factor 1 (IGF1) increased (P < 0.05) UHRF1 expression in TC by 2-fold, and forskolin (an adenylate cyclase inducer) alone or combined with IGF1 increased (P < 0.05) UHRF1 expression by 3-fold. An E2F transcription factor inhibitor (E2Fi) decreased (P < 0.05) UHRF1 expression by 44% in TC and by 99% in GC. Estradiol, progesterone, and dibutyryl-cAMP decreased (P < 0.05) UHRF1 mRNA abundance in GC. Treatment of GC with follicle-stimulating hormone (FSH) alone had no effect but when combined with IGF1 enhanced the UHRF1 mRNA abundance by 2.7-fold. Beauvericin (a mycotoxin) completely inhibited the FSH plus IGF1-induced UHRF1 expression in small-follicle GC. Treatments that increased UHRF1 mRNA (i.e., FGF9) in GC tended to decrease (by 63%; P < 0.10) global DNA methylation, and those that decreased UHRF1 mRNA (i.e., E2Fi) in GC tended to increase (by 2.4-fold; P < 0.10) global DNA methylation. Collectively, these results suggest that UHRF1 expression in both GC and TC is developmentally and hormonally regulated, and that UHRF1 may play a role in follicular growth and development as well as be involved in ovarian epigenetic processes.

The in vitro effects of aflatoxin B1 on physiological functions of swine alveolar macrophages

The toxic effects of aflatoxin B₁ (AFB₁ ) on the physiological functions of swine alveolar macrophages (SAM) were investigated. Freshly isolated SAM were incubated with various AFB₁ concentrations (1.6 × 10^-1  - 1.6 × 10⁵  nmol/L) and time periods, and their phagocytic ability, synthesis of DNA, RNA and protein, and cell activation by lipopolysaccharide (LPS), were analysed. Results demonstrated that a significant (p < .05) reduction (60%) in Staphylococcus aureus uptaken by SAM appeared 3 hr after AFB₁ (>16 nmol/L) treatment. The synthesis of DNA, RNA and protein were markedly reduced, among which DNA and protein synthesis were affected more noticeably. The activation of SAM by LPS was significantly (p < .05) suppressed when the concentration of AFB₁ reached 1.6 × 10³  nmol/L. In general, most of the analysed effects were more prominent as AFB₁ concentration or incubation period increased. Taken together, AFB ₁ could elicit significant adverse effects on the physiological functions of SAM. Exposure of pigs to aflatoxin-contaminated feed may increase their susceptibility to various secondary infections.

Toxicity of Fumonisins, Deoxynivalenol, and Zearalenone Alone and in Combination in Turkeys Fed with the Maximum European Union-Tolerated Level

Surveys of mycotoxins worldwide have shown that deoxynivalenol (DON), fumonisins (FB), and zearalenone (ZON) are the most abundant Fusarium mycotoxins (FUS) in European poultry feed, in both the level and the frequency of contamination. Previous studies reported that a combination of FUS at concentrations that individually are not toxic may negatively affect animals. However, although toxic thresholds and regulatory guidelines exist for FUS, none account for the risk of multiple contamination, which is the most frequent. The aim of this study was to compare DON, FB, and ZON toxicity, alone and in combination, in male turkey poults. Ground cultured toxigenic Fusarium strains were incorporated in corn-soybean-based feed in five experimental diets: control diet, containing no mycotoxins, DON diet (5 mg DON/kg), FB diet (20 mg FB1 + FB2/ kg), ZON diet (0.5 mg ZON/kg), and DONFBZON diet (5, 20, and 0.5 mg/kg of DON, FB1 + FB2, and ZON, respectively). Seventy male Grade Maker turkeys were reared in individual cages on mycotoxin-free diets from 0 to 55 days of age. On the 55th day, the turkeys were weighed and divided into five groups each comprising 14 birds. Each group was fed one of the five experimental diets for a period of 14 days. On the 70th day of age, feed was withheld for 8 hr, at which time a blood sample was collected, and then all the turkeys were killed, autopsied, and different tissues sampled. The weight of the different organs, analyses of performance, biochemistry, histopathology, oxidative damage, and testis toxicity revealed no significant effects attributable to FUS. Measurement of sphingolipids in the liver revealed an increase in the sphinganine to sphingosine ratio in turkeys fed diets containing FB, but had no apparent consequences in terms of toxicity. Finally, only slight differences were found in some variables and the results of this study showed no interactions between DON, FB, and ZON. Taken together, results thus suggest that the maximum tolerated levels established for individual contamination by DON, FB, and ZON can also be considered safe in turkeys fed with combinations of these FUS for a period of 14 days.

Relationship between body conditions and environmental contaminants in bovine ovarian cells

The effect of body condition and environmental contaminants on reproductive processes is known; however, it is not known whether basic ovarian cell functions and their response to these contaminants depend on body condition. This study aimed to understand the interrelationships between body conditions and environmental contaminants on ovarian cells. For this purpose, we compared ovarian granulosa cells isolated from cows with an emaciation tendency (body condition score, BCS2 on a scale from 1 to 5) and cows with average body condition (BCS3); proliferation, apoptosis, secretory activity and the response to environmental contaminants were all assessed in the cells. In the 1st series of experiments, ovarian granulosa cells isolated from BCS2 and BCS3 cows were cultured with and without benzene, xylene, and toluene (0.1%). The accumulation of nuclear and cytoplasmic markers of apoptosis (p53 and bax, respectively), a proliferation marker (PCNA), progesterone (P4), and insulin-like growth factor I (IGF-I) was evaluated by Western blot and radioimmunoassay (RIA) experiments. In the 2nd series of experiments, the groups of granulosa cells were cultured with and without mycotoxine deoxynivalenol (DON, 0, 10, 100, or 1000 ng/ml). The secretion of P4 and testosterone (T) was measured by RIA. In comparison to cells from BCS2 animals, ovarian cells isolated from BCS3 cows accumulated higher levels of bax and PCNA but not p53, and they secreted higher amounts of IGF-I but not P4 or T. In cells from BCS2 animals, benzene and xylene promoted p53 accumulation, and toluene reduced the accumulation. In the BCS2 group, all treatments promoted bax and PCNA expression. However, in cells from BCS3 animals, all environmental pollutants inhibited p53, toluene inhibited PCNA but not bax, and xylene did not affect the expression of proliferation or apoptosis markers. In the BCS2 group, P4 was inhibited by xylene, and IGF-I was stimulated by xylene but not by benzene or toluene. Low-dose exposure to DON (10 ng/ml) promoted P4 release from cells from both BCS2 and BCS3 animals, but high-dose exposure to DON (1000 ng/ml) reduced P4 secretion from the cells from BCS2 animals but not from the cells from BCS3 animals. The release of T was inhibited by high-dose exposure to DON (1000 ng/ml), irrespective of the BCS. An emaciation tendency reduces proliferation, apoptosis, and IGF-I release, and it induces or reverses the action of environmental contaminants on ovarian functions. Taken together, these observations demonstrate the effect of body condition and the direct influence of environmental contaminants on basic bovine ovarian functions. Furthermore, they demonstrate for the first time that the response of ovarian cells to environmental contaminants can be regulated by cow body condition.

Discovery of new receptors regulating luteinizing hormone and follicle-stimulating hormone secretion by bovine gonadotrophs to explore a new paradigm for mechanisms regulating reproduction

Previous studies in the 1960s and 1970s have reported that both gonadotropin-releasing hormone (GnRH) and estradiol-activated nuclear estrogen receptors regulate gonadotropin secretion in women. However, I had previously reported that gonadotroph function is regulated by complex crosstalk between several membrane receptors. RNA-seq had previously revealed 259 different receptor genes expressed in the anterior pituitary of heifers. However, the biological roles of most of these receptors remain unknown. I identified four new receptors of interest: G protein-coupled receptor 30 (GPR30), anti-Mullerian hormone (AMH) receptor type 2 (AMHR2), and G protein-coupled receptors 61 and 153 (GPR61 and GPR153). GPR30 rapidly (within a few minutes) mediates picomolar, but not nanomolar, levels of estradiol to suppress GnRH-induced luteinizing hormone (LH) secretion from bovine gonadotrophs, without decreasing mRNA expressions of the LHα, LHβ, or follicle-stimulating hormone (FSH) β subunits. GPR30 is activated by other endogenous estrogens, estrone and estriol. Moreover, GPR30 activation by zearalenone, a nonsteroidal mycoestrogen, suppresses LH secretion. AMHR2, activated by AMH, stimulates LH and FSH secretion, thus regulating gonadotrophs, where other TGF-β family members, including inhibin and activin, potentially affect FSH secretion. I also show that GPR61, activated by its ligand (recently discovered) significantly alters LH and FSH secretion. GPR61, GPR153, and AMHR2 co-localize with the GnRH receptor in unevenly dispersed areas of the bovine gonadotroph cell surface, probably lipid rafts. The findings summarized in this review reveal a new paradigm regarding the mechanisms regulating reproduction via novel receptors expressed on bovine gonadotrophs.

Maternal Exposure to T-2 Toxin Affects Puberty Genes and Delays Estrus Cycle in Mice Offspring

Among foodborne toxicities, the T-2 toxin is the most toxic member of trichothecenes mycotoxins, which has been shown to impair the development and reproductive efficiency of animals. Pups are particularly more quickly prone to programming the effects of the maternal diet during the gestational and lactation periods. Few studies have reported the maternal toxic effect on the next generation. Dams were served the T-2 toxin at a dose of 0.005 and 0.05 mg/kg body weight/day and control group 0 mg/kg from gestation day 14 to lactation day 21. Female mice offspring were selected at the weaning age. Our observations indicate that age during the vaginal opening and di-estrus stage increased and the length of the estrus cycle, first di-estrus, and regular estrus cycling were delayed with prolonged di-estrus in the 0.05 mg/kg group compared to the 0.005 mg/kg and control group. Transcription level analysis showed that mice at a dose of 0.05 mg/kg exhibited a decrease in hypothalamic mRNA expression of Gnrh and Gnrhr, Lhb, and Fshb in the pituitary gland, with a significant decrease of Fshr and Lhr in the ovaries. Present findings report that postnatal exposure to the T-2 toxin delayed puberty age in female mice and induced oxidative stress, ovarian damage, and reduced vaginal epithelium wall majorly in the 0.05 mg/kg group, and showed fewer effects in the 0.005 mg/kg group.

Maternal Exposure to T-2 Toxin Induces Changes in Antioxidant System and Testosterone Synthesis in the Testes of Mice Offspring

Simple Summary

This study investigated the effects of maternal T-2 toxin exposure on the development of testis in the mice offspring. The detrimental effects were assessed by testicular weight, antioxidant capacity, and testosterone synthesis and secretion. Studies have shown that the toxin carried by the mother has bad effects on the testicular development of offspring at puberty, affecting the antioxidant system and testosterone synthesis in the testis, but the maternal exposure of T-2 toxin had no significant impact on the testes of offspring after sexual maturity, suggesting the recovery of reproductive function.

Abstract

T-2 toxin, the most toxic member of trichothecene mycotoxin, is widely distributed in cereals, and has been extensively studied, but few studies focus on the toxicity of maternal exposure to offspring. This study focused on the effects of maternal exposure to T-2 toxin (during gestation and lactation) on the testicular development of mice offspring. Dams were orally administered with T-2 toxin at 0, 0.005, or 0.05 mg/kg body weight from the late stage of gestation to the end of lactation. Testicular samples of the mice offspring were collected on the postnatal day 21, 28, and 56. The results showed significant decreases in body weight and testicular weight on the postnatal day 28. Moreover, significant inhibition of antioxidant system and testosterone synthesis was detected on the postnatal day 28. Furthermore, there were significant decreases in the gene expression levels of StAR and 3β-HSD, which are involved in testosterone synthesis. In general, present results demonstrated that maternal exposure to T-2 toxin during gestation and lactation led to bad effects on the capacity of antioxidant system and inhibited testosterone synthesis in testes during pre-puberty with no significant effects on post-puberty.

Betulinic Acid Attenuates T-2-Toxin-Induced Testis Oxidative Damage Through Regulation of the JAK2/STAT3 Signaling Pathway in Mice

T-2 toxin is one of the most toxic type A trichothecene mycotoxins in nature, and it exhibits reproductive toxicity. Betulinic acid (BA) is a natural pentacyclic triterpene compound found in species of Betula, and it has been reported to have antioxidant activity. The aim of the present study was to investigate the protective effect of BA on T-2-toxin-induced testicular injury in mice and explore its molecular mechanism. Sixty adult male mice were randomly divided into groups. The mice were pretreated orally with BA (0.25, 0.5, and 1.0 mg/kg) daily for 14 days, and the T-2 toxin (4 mg/kg body weight) was administered via intraperitoneal injection to induce oxidative stress after the last administration of BA. BA pretreatment significantly increased the secreted levels of testosterone and sperm motility. Moreover, BA pretreatment significantly increased the total antioxidant capacity (T-AOC), the activity of SOD and CAT, and the content of GSH, and it reduced the content of MDA. Furthermore, BA relieved testicular injury and reduced the number of apoptotic cells, and it significantly decreased the protein expression of Janus kinase 2 (JAK2), signal transducers and activators of transcription 3 (STAT3), caspsae-3, and Bcl-2-associated X protein (Bax). BA also increased the expression of B-cell lymphoma-2 (Bcl-2). We suggest that BA reduced the oxidative damage induced by T-2 toxin, and that these protective effects may be partially mediated by the JAK2/STAT3 signaling pathway.

Putative metabolic pathway for the bioproduction of bikaverin and intermediates thereof in the wild Fusarium oxysporum LCP531 strain

Fungal naphthoquinones, like red bikaverin, are of interest due to their growing applications in designing pharmaceutical products. Though considerable work has been done on the elucidation of bikaverin biosynthesis pathway in Fusarium fujikuroi, very few reports are available regarding its bioproduction in F. oxysporum. We are hereby proposing a putative metabolic pathway for bikaverin bioproduction in a wild F. oxysporum strain by cross-linking the pigment profiles we obtained under two different fermentation conditions with literature. Naphthoquinone pigments were extracted with a pressurized liquid extraction method, and characterized by HPLC–DAD and UHPLC-HRMS. The results led to the conclusions that the F. oxysporum LCP531 strain was able to produce bikaverin and its various intermediates, e.g., pre-bikaverin, oxo-pre-bikaverin, dinor-bikaverin, me-oxo-pre-bikaverin, and nor-bikaverin, in submerged cultures in various proportions. To our knowledge, this is the first report of the isolation of these five bikaverin intermediates from F. oxysporum cultures, providing us with steady clues for confirming a bikaverin metabolic pathway as well as some of its regulatory patterns in the F. oxysporum LCP531 strain, based on the previously reported model in F. fujikuroi. Interestingly, norbikaverin accumulated along with bikaverin in mycelial cells when the strain grew on simple carbon and nitrogen sources and additional cofactors. Along bikaverin production, we were able to describe the excretion of the toxin beauvericin as main extrolite exclusively in liquid medium containing complex nitrogen and carbon sources, as well as the isolation of ergosterol derivate in mycelial extracts, which have potential for pharmaceutical uses. Therefore, culture conditions were also concluded to trigger some specific biosynthetic route favoring various metabolites of interest. Such observation is of great significance for selective production of pigments and/or prevention of occurrence of others (aka mycotoxins).

T-2 toxin impairs male fertility by disrupting hypothalamic-pituitary-testis axis and declining testicular function in mice

T-2 toxin could impair male reproductive function. But, the toxicity mechanism is still unclear. In this study, male Kunming mice were orally administrated with T-2 toxin at the doses of 0, 0.5, 1 or 2 mg/kg body weight for 28 days. The fertility, body weight, reproductive organs volume, daily sperm production (DSP), and sperm malformation rate were detected. The expressions of testosterone (T) biosynthetic enzymes, luteinizing hormone (LH)-receptor, follicle stimulating hormone (FSH)-receptor and androgen binding protein (ABP) in testis were detected. The serum hormone level of gonadotropin-releasing hormone (GnRH), FSH, LH, T and progesterone (P), and the mRNA expression of GnRH, GnRH-receptor, LH and FSH were measured. These results demonstrated that T-2 toxin decreased body weight, reproductive organs volume and DSP, increased sperm malformation rate. T-2 toxin impaired fertility by decreasing the mating index, fertility index, numbers of implantation sites and viable fetuses, and increasing the number of animal with resorptions. Meantime, T-2 suppressed testicular function by inhibiting T biosynthesis and decreasing FSHR, LHR and ABP expression. Furthermore, the serum reproductive hormone contents and key factors expression of hypothalamic-pituitary-testis (HPT) axis were decreased by T-2 toxin. In summary, T-2 toxin impaired the male fertility by disrupting HPT axis and impairing testicular function.

Lack of Toxic Interaction Between Fusariotoxins in Broiler Chickens Fed throughout Their Life at the Highest Level Tolerated in the European Union

Fusarium mycotoxins (FUS) occur frequently in poultry diets, and regulatory limits are laid down in several countries. However, the limits were established for exposure to a single mycotoxin, whereas multiple contamination is more realistic, and different studies have demonstrated that it is not possible to predict interactions between mycotoxins. The purpose of this study was thus to compare the toxic effect of deoxynivalenol (DON), fumonisins (FB) and zearalenone (ZON), alone and in combination on broiler chickens, at the maximum tolerated level established by the EU for poultry feed. Experimental corn-soybean diets incorporated ground cultured toxigenic Fusarium strains. One feed was formulated for chickens 0 to 10 days old and another for chickens 11 to 35 days old. The control diets were mycotoxin free, the DON diets contained 5 mg DON/kg, the FB diet contained 20 mg FB1 + FB2/kg, and the ZON diet contained 0.5 mg ZON/kg. The DONFBZON diet contained 5, 20, and 0.5 mg/kg of DON, FB1 + FB2, and ZON, respectively. Diets were distributed ad libitum to 70 broilers (male Ross PM3) separated into five groups of 14 chickens each reared in individual cages from one to 35 days of age. On day 35, after a starvation period of 8 h, a blood sample was collected, and all the animals were killed and autopsied. No difference between groups that could be attributed to FUS was observed in performances, the relative weight of organs, biochemistry, histopathology, intestinal morphometry, variables of oxidative damage, and markers of testicle toxicity. A significant increase in sphinganine and in the sphinganine to sphingosine ratio was observed in broilers fed FB. Taken together, these results suggest that the regulatory guidelines established for single contamination of broiler chickens fed with DON, FB, and ZON can also be used in the case of multiple contamination with these toxins.

Spermatogenesis disorder caused by T-2 toxin is associated with germ cell apoptosis mediated by oxidative stress

T-2 toxin is an unavoidable contaminant in human food, animal feeds, and agricultural products. T-2 toxin has been found to impair male reproductive function. But, few data is available that reveals the reproductive toxicity mechanism. In the study, male Kunming mice were orally administrated with T-2 toxin at the doses of 0, 0.5, 1 or 2 mg/kg body weight for 28 days. The body and reproductive organs weight, the concentration, malformation rate and ultrastructure of sperm in cauda epididymis were detected. Oxidative stress biomarkers and apoptosis were also measured in testes. Histological change of testes was performed by H&E and TUNEL staining. T-2 toxin down-regulated body and reproductive organs (testis, epididymis and seminal vesicle) weight, sperm concentration, increased sperm malformation rate and damaged the ultrastructure of sperm and structure of testes. T-2 toxin treatment increased the reactive oxygen species (ROS) and malondialdehyde content, while, decreased the total anti-oxidation capacity (T-AOC) and the superoxide dismutase activity in testes. T-2 toxin exposure increased the TUNEL-positive germ cells, the activities and mRNA expressions of caspase-3, caspase-8 and caspase-9, the mRNA expression of Bax, and inhibited the Bcl-2 mRNA expression. Furthermore, the expressions of caspase-3, caspase-8 caspase-9 and Bax were positively correlated with ROS level, but negatively correlated with T-AOC in testis. In summary, T-2 toxin caused spermatogenesis disorder associated with the germ cell apoptosis medicated by oxidative stress, impairing the male reproductive function.

T-2 toxin downregulates LHCGR expression, steroidogenesis, and cAMP level in human cumulus granulosa cells

Our goals were to investigate whether environmentally relevant doses of T-2 toxin can affect human ovarian granulosa cells' function and to reveal the potential mechanism of T-2 toxin's action. Results showed that T-2 toxin strongly attenuated luteinizing hormone/choriogonadotropin receptor (LHCGR) mRNA expression in follicle-stimulating hormone (FSH)-stimulated human cumulus granulosa cells. Addition of human chorionic gonadotropin was not able to elicit maximal response of ovulatory genes amphiregulin, epiregulin, and progesterone receptor. T-2 toxin reduced mRNA levels of CYP19A1 and steroidogenic acute regulatory protein (STAR) and lowered FSH-stimulated estradiol and progesterone production. Mechanistic experiments demonstrated that T-2 toxin decreased FSH-stimulated cyclic adenosine monophosphate (cAMP) production. Addition of total PDE inhibitor 3-isobutyl-1-methylxanthine prevented T-2 toxin's action on LHCGR, STAR, and CYP19A1 mRNA expression in FSH-stimulated human cumulus granulosa cells. Furthermore, T-2 toxin partially decreased 8-bromoadenosine 3'5'-cyclic monophosphate (8-Br-cAMP)-stimulated LHCGR and STAR, but did not affect 8-Br-cAMP-stimulated CYP19A1 mRNA expression in human cumulus granulosa cells. Overall, our data indicate that environmentally relevant dose of T-2 toxin decreases steroidogenesis and ovulatory potency in human cumulus granulosa cells probably through activation of PDE, thus posing a significant risk for female fertility.

The Effects of Deoxynivalenol (DON) on the Gut Microbiota, Morphology and Immune System of Chicken – A Review

Feed contamination is a major cause of diseases outbreak in the poultry industry. There is a direct relationship between feeding, the intestinal microbiota and how the immune system responds to disease infestation. Cereals which form the bulk of poultry feed are mostly contaminated by mycotoxins of Fusarium origin. Adequate knowledge of mycotoxins and their effects on animals is necessary. Deoxynivalenol (DON) is a major contaminant of poultry feed. DON has the ability to bind with a large number of eukaryotic ribosomal subunits because of the presence of an epoxide group and these disrupt the activity of peptidyl transferase and the elongation or shortening of peptide chains. Deoxynivalenol has varying effect ranging from acute, overt diseases with high morbidity and death to chronic disease, decreased resistance to pathogens and reduced animal productivity. Deoxynivalenol also impairs the intestinal morphology, nutrient absorption, barrier function, and the innate immune response in chickens. This review highlights the impacts of deoxynivalenol on the immune system, intestinal microbiota composition and the morphology of chicken.