Effects of purified zearalenone on selected immunological and histopathologic measurements of spleen in post-weanling gilts

The present study was aimed at investigating the adverse effects of dietary zearalenone (ZEA) on the lymphocyte proliferation rate (LPR), interleukin-2 (IL-2), mRNA expressions of pro-inflammatory cytokines, and histopathologic changes of spleen in post-weanling gilts. A total of 20 crossbred piglets (Yorkshire × Landrace × Duroc) with an initial BW of 10.36 ± 1.21 kg (21 d of age) were used in the study. Piglets were fed a basal diet with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. The results showed that LPR and IL-2 production of spleen decreased linearly (P < 0.05) as dietary ZEA increased. Splenic mRNA expressions of interleukin-1β (IL-1β) and interleukin-6 (IL-6) were linearly up-regulated (P < 0.05) as dietary ZEA increased. On the contrary, linear down-regulation (P < 0.05) of mRNA expression of interferon-γ (IFN-γ) was observed as dietary ZEA increased. Swelling splenocyte in 1.1 mg/kg ZEA treatments, atrophy of white pulp and swelling of red pulp in 2.0 and 3.2 mg/kg ZEA treatments were observed. The cytoplasmic edema in 1.1 mg/kg ZEA treatments, significant chromatin deformation in 2.0 mg/kg ZEA treatment and phagocytosis in 3.2 mg/kg ZEA treatment were observed. Results suggested that dietary ZEA at 1.1 to 3.2 mg/kg can induce splenic damages and negatively affect immune function of spleen in post-weanling gilts

Zearalenone Promotes Uterine Development of Weaned Gilts by Interfering with Serum Hormones and Up-Regulating Expression of Estrogen and Progesterone Receptors

In this study, we aimed to assess the effect of diet ZEA on serum hormones, the location and expression of estrogen receptor ER&alpha;/&beta; and progesterone receptor (PR) of the uterus in weaned piglets and to reveal the mechanism underneath. A total of 40 healthy weaned gilts were randomly allocated to basal diet supplemented with 0 (Control), 0.5 (ZEA0.5), 1.0 (ZEA1.0) and 1.5 (ZEA1.5) mg ZEA/kg and fed individually for 35 days. Meanwhile, the porcine endometrial epithelial cells (PECs) were incubated for 24 h with ZEA at 0 (Control), 5 (ZEA5), 20 (ZEA20) and 80 (ZEA80) &mu;mol/L, respectively. The results showed that nutrient apparent digestibility (CP and GE), nutrient apparent availability (ME/GE, BV and NPU), the uterine immunoreactive integrated optic density (IOD), relative mRNA and protein expression of ER-&alpha;, ER-&beta; and PR and the relative mRNA and protein expression of ER-&alpha; and ER-&beta; in PECs all increased linearly (p &lt; 0.05) with ZEA. Collectively, ZEA can interfere with the secretion of some reproductive hormones in the serum and promote the expression of estrogen/progesterone receptors in the uterus and PECs. All these indicate that ZEA may promote the development of the uterus in weaned gilts through estrogen receptor pathway

Effects of Dietary Zearalenone Exposure on the Growth Performance, Small Intestine Disaccharidase, and Antioxidant Activities of Weaned Gilts

Zearalenone (ZEA) is a secondary metabolite with estrogenic effects produced by Fusarium fungi and mainly occurs as a contaminant of grains such as corn and wheat. ZEA, to which weaned gilts are extremely sensitive, is the main Fusarium toxin detected in corn&ndash;soybean meal diets. Our aim was to examine the effects of ZEA on the growth performance, intestinal disaccharidase activity, and anti-stress capacity of weaned gilts. Twenty 42-day-old healthy Duroc &times; Landrace &times; Large White weaned gilts (12.84 &plusmn; 0.26 kg) were randomly divided into control and treatment (diet containing 1.04 mg/kg ZEA) groups. The experiment included a 7-day pre-trial period followed by a 35-day test period, all gilts were euthanized and small intestinal samples were collected and subjected to immunohistochemical and western blot analyses. The results revealed that inclusion of 1.04 mg/kg ZEA in the diet significantly reduced the activities of lactase, sucrase, and maltase in the duodenum, jejunum, and ileum of gilts. Similarly, the activities of superoxide dismutase and glutathione peroxidase in the duodenum, jejunum, and ileum, and activities of catalase in the jejunum and ileum were reduced (p &lt; 0.05). Conversely, the content of malondialdehyde in the duodenum, jejunum, and ileum, and the integrated optical density (IOD), IOD in single villi, and the mRNA and protein expression of heat shock protein 70 (Hsp70) were significantly increased (p &lt; 0.05). The results of immunohistochemical analyses revealed that the positive reaction of Hsp70 in the duodenum, jejunum, and ileum of weaned gilts was enhanced in the ZEA treatment, compared with the control. The findings of this study indicate the inclusion of ZEA (1.04 mg/kg) in the diet of gilts reduced the activity of disaccharidase enzymes and induced oxidative stress in the small intestine, thereby indicating that ZEA would have the effect of reducing nutrient absorption in these animals

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 &lt; 0.05), significantly elevated the serum concentrations of estradiol, follicle stimulating hormone and GnRH (p &lt; 0.05), and markedly up-regulated the mRNA and protein expressions of FSHR, LHR, GnRH and GnRHR (p &lt; 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

Effects of purified zearalenone on selected immunological measurements of blood in post-weaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies have indicated that acute ZEA exposure induced various damages in different species; however, its transparent hematotoxicity in female piglets at dietary levels of 1.1 to 3.2 mg/kg has not been shown. The present study was conducted to investigate the effects of dietary ZEA (1.1–3.2 mg/kg) on hematology, T lymphocyte subset, immunoglobulin, antibody titer, lymphocyte proliferation rate (LPR), and interleukin-2 (IL-2) in peripheral blood of post-weaning gilts. A total of 20 female piglets (Landrace × Yorkshire × Duroc), weaned at 42 d with an average body weight of 10.36 ± 1.21 kg were used in the study. Female piglets were kept in a temperature controlled room, divided into four treatments, and fed a diet based on corn-soybean meal-fishmeal-whey, with an addition of 0, 1.1, 2.0, or 3.2 mg/kg purified ZEA for 18 d ad libitum. Feed intake and refusal were measured daily and individual pigs were weighed weekly. Blood and serum samples were collected for selected immunological measurements. Female piglets fed different levels of dietary ZEA grew similarly with no difference in feed intake. Hematological values including leukocytes, platelets, lymphocytes, hematocrit, and mean corpuscular hemoglobin (MCH) decreased linearly (P < 0.05) as dietary ZEA increased. Female piglets fed diets containing 2.0 mg/kg ZEA or greater showed significantly decreased CD4+CD8+, CD4+, and CD4+/CD8+ in comparison to the control (P < 0.05), whereas CD8+ was significantly increased (P = 0.026) in the gilts which were fed the diet containing 3.2 mg/kg ZEA. Serum immunoglobulin G (IgG) and the antibody titer on d 18 were reduced linearly as dietary ZEA levels increased (P < 0.001). Linear decrease in LPR was observed (P < 0.05). Female piglets fed diets containing 2.0 mg/kg ZEA or more showed significantly decreased IL-2 in comparison to the control (P < 0.05). The results suggested that dietary ZEA at the levels of 1.1 to 3.2 mg/kg can induce different degrees of hematotoxicity and negatively affect immune function in female piglets

Quantitative Proteomic Analysis of Zearalenone-Induced Intestinal Damage in Weaned Piglets

Zearalenone (ZEN), also known as the F-2 toxin, is a common contaminant in cereal crops and livestock products. This experiment aimed to reveal the changes in the proteomics of ZEN-induced intestinal damage in weaned piglets by tandem mass spectrometry tags. Sixteen weaned piglets either received a basal diet or a basal diet supplemented with 3.0 mg/kg ZEN in a 32 d study. The results showed that the serum levels of ZEN, &alpha;-zearalenol, and &beta;-zearalenol were increased in weaned piglets exposed to ZEN (p &lt; 0.05). Zearalenone exposure reduced apparent nutrient digestibility, increased intestinal permeability, and caused intestinal damage in weaned piglets. Meanwhile, a total of 174 differential proteins (DEPs) were identified between control and ZEN groups, with 60 up-regulated DEPs and 114 down-regulated DEPs (FC &gt; 1.20 or &lt;0.83, p &lt; 0.05). Gene ontology analysis revealed that DEPs were mainly involved in substance transport and metabolism, gene expression, inflammatory, and oxidative stress. The Kyoto Encyclopedia of Genes and Genomes analysis revealed that DEPs were significantly enriched in 25 signaling pathways (p &lt; 0.05), most of which were related to inflammation and amino acid metabolism. Our study provides valuable clues to elucidate the possible mechanism of ZEN-induced intestinal injury