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The purpose of this research was to explore the effect of selenium on mercury-mediated apoptosis of follicular granulosa cells in laying hens. Moreover, the ATF6/CHOP pathway was investigated to explore the mechanism in this progress. Hg, Se, and 4-phenyl butyric acid were used alone or in combination to treat the cells. Our results showed that the nuclear in cells became condensate after Hg exposure, while Se addition significantly alleviated this change. Hg exposure significantly induced the apoptosis and the reduction of mitochondrial membrane potential in cells (P < 0.05), Nevertheless co-treatment of Se significantly inhibited these effects (P < 0.05). Additionally, Hg exposure dramatically elevated the gene expressions of Bax/Bcl-2 (P < 0.05), Caspase-3 (P < 0.05), Caspase-9 (P < 0.05), protein kinase RNA-like endoplasmic reticulum kinase (P < 0.05), activating transcription factor 6 (P < 0.05), C/EBP homologous protein (CHOP; P < 0.05), inositol-requiring enzyme 1α (P < 0.05), tumor necrosis factor-associated factor 2 (P < 0.05), activating transcription factor 6 (ATF6; P < 0.05) and apoptosis signal-regulating kinase 1 (P < 0.05) in cells, whereas Se addition reversed these changes. The exposure to Hg considerably boosted the expression of ATF6 and CHOP protein (P < 0.05), while Se addition significantly alleviated above-mentioned enhancements (P < 0.05). In summary, Hg exposure induced apoptosis, which was considerably reduced alleviated by Se addition, which was linked to the ATF6/CHOP pathway in follicular granulosa cells in laying hens.

In this study, we explored the effect of dietary lead nitrate on zootechnical performance, egg quality, accumulation of ovarian plumbum (Pb), follicular atresia rate, and ovarian oxidative stress in laying hens. Furthermore, the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling molecule was studied to reveal the molecular mechanism of the stress. A total of 512 Hy-Line Brown laying hens aged 40 wk were randomly allocated to 4 groups (with 8 pens per group and 16 hens per pen). The Pb concentrations used to treat the 4 groups were 3.20, 33.20, 63.20, and 93.20 mg/kg. The results revealed that dietary Pb exposure significantly linearly reduced the zootechnical performance (P < 0.01) but significantly linearly increased the feed conversion ratio (P < 0.01). The dietary Pb exposure significantly linearly reduced the Haugh units (P < 0.01), albumen height (P < 0.01), eggshell thickness (P < 0.01), and eggshell strength (P < 0.01). In addition, the dietary Pb exposure significantly enhanced the follicular atresia rate (P < 0.01). After dietary Pb exposure, superoxide dismutase (P < 0.01) and glutathione peroxidase (GSH-Px) (P < 0.01) activities and glutathione (P < 0.01) contents were significant decreased quadratically, and there were significant linear decreases in the activities of catalase (CAT) (P < 0.01) and glutathione reductase (GR) (P < 0.01), whereas malondialdehyde content was significantly linearly increased (P < 0.01). In addition, except for manganese superoxide dismutase, the gene expressions of copper-zinc superoxide dismutase (P < 0.01), CAT (P < 0.01), and GR (P < 0.01) were significant decreased linearly. In addition, there were significantly quadratic decreases in the mRNA expressions of GSH-Px (P < 0.01) and Nrf2 (P < 0.01). By way of contrast, the Kelch-like ECH-associated protein 1 (Keap1) gene expression was significantly linearly increased (P < 0.01). In conclusion, dietary Pb exposure could induce oxidative stress by impairing the Nrf2-Keap1 signal pathway in the ovaries of laying hens.

This study investigated that the effect of nano-selenium (nano-Se) addition preventing prehierarchical follicular atresia induced by mercury (Hg) exposure in laying hens. Furthermore, endoplasmic reticulum (ER) stress pathway was explored to reveal the protective mechanism of nano-Se in vitro. The results revealed that Hg could significantly reduce laying performance (P 0.05) and egg quality (P 0.05), whereas nano-Se addition partially reversed the reductions. Besides, Hg significantly induced the deposition of Hg in prehierarchical follicles (P 0.05) and prehierarchical follicular atresia (P 0.05), whereas nano-Se addition could alleviate these toxicities in vitro. In addition, Hg exposure could significantly reduce cell viability (P 0.05) and induce pyknotic nucleus in prehierarchical granulosa cells, while nano-Se addition reversed these effects. The levels of follicle-stimulating hormone (P 0.05), luteinizing hormone (P 0.05), progesterone (P 0.05), and estradiol (P 0.05) were significantly decreased after Hg exposure in vitro. However, nano-Se addition reversed the decreases of sex hormone levels. Furthermore, Hg exposure significantly increased the gene expressions of CHOP (P 0.05), PERK (P 0.05), ATF4 (P 0.05), ATF6 (P 0.05), ASK1 (P 0.05), IRE1α (P 0.05), TRAF2 (P 0.05), caspase-9 (P 0.05), caspase-3 (P 0.05), and Bax/Bcl-2 (P 0.05), whereas nano-Se addition reversed these increases of gene expressions in vitro. In summary, this study provides that Hg can induce prehierarchical follicular atresia, whereas nano-Se addition can ameliorate it, and elucidates an important role of ER stress in nano-Se alleviating prehierarchical follicular atresia induced by Hg in laying hens.

This study evaluated the effect of epigallocatechin-3-gallate (EGCG) alleviating the reduction of antioxidant capacity induced by dietary vanadium (V) in the liver, kidney, and ovary of laying hens. Furthermore, Kelch-like ECH-associated protein 1(Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)-small Maf proteins (sMaf) pathway was explored to reveal the molecular mechanism. A total of 768 40-week-old Hyline-Brown laying hens were randomly allocated to 4 groups with 8 pens per group and 24 hens per pen. The experimental groups were as follows: control (basal diet); V15, control + 15 mg/kg V; EGCG150, control + 150 mg/kg EGCG; V15 + EGCG150, V15 + 150 mg/kg EGCG. Our results revealed that dietary EGCG supplementation completely alleviated the V-induced reductions of hen-day egg production, average egg weight, Haugh unit, albumen height, eggshell strength, and eggshell thickness. Dietary EGCG supplementation completely prevented the V-induced reductions of serum follicle-stimulating hormone and luteinizing hormone levels. Besides, dietary EGCG supplementation reversed the V-induced increments of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr), and uric acid (UA). In addition, dietary EGCG supplementation partially alleviated the V-induced reductions of the enzyme activities and gene expressions of superoxidative dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GSH-Px). Furthermore, dietary EGCG supplementation partially alleviated the V-induced reductions of Nrf2 and sMaf gene expressions, and the increments of Keap1 gene expression. In summary, EGCG partially alleviated V-induced reduction of antioxidant capacity through Keap1-Nrf2-sMaf pathway in the liver, kidney, and ovary of laying hens.

International audience; AbstractMandibular gland (MG) secretions of honey bee are synthesized through a three-step bifurcation pathway, and the initiate hydroxylation step is carried out by cytochrome P450 enzymes (P450). We have previously revealed that CYP6AS8 and CYP6AS11 are possibly participating in this process. In this study, we evaluated the function of CYP6AS8 in honey bee worker’s MG using RNA interference technology, and we investigated the expression pattern of CYP6AS8 in MGs from workers of different ages. We found that the expression of CYP6AS8 was detectable in MGs across the whole life cycle of Apis mellifera except for newly emerged workers and predominately expressed at day 15. RNAi knockdown revealed that the production of 10-HDA was synchronized with the expression level of CYP6AS8 in MG of honey bee workers; the downregulation of CYP6AS8 caused a significant reduction of 10-HDA content, demonstrating that CYP6AS8 is indispensable for 10-HDA biosynthesis. Our current results confirm that CYP6AS8 modulates 10-HDA biosynthesis in MGs of western honey bee worker and provided the first evidence to identify the certain P450 participate in the MG secretion biosynthesis of honey bee workers.

Overexpression of the HER2/neu (HER2) is linked to an adverse outcome in ovarian cancer. Short-interfering RNA (siRNA) is a HER2 inhibitor, which in combination with chemotherapy improves survival rate. The aim of this study was to evaluate the efficacy of adenovirus mediated HER2-siRNA in combination with cisplatin (Ad-HER2-siRNA+DDP) on treating HER2-positive ovarian cancer xenografts and explore the effectiveness ofMice with ovarian cancer xenografts were treated with different therapy regimens and imaged at 1, 4, 8, 12, 24, 48, 72, and 96 h postinjection withThe in vivo therapy experiments revealed that tumor weight and volume of Ad-HER2-siRNA+DDP group was the least of all. The IHC results further confirmed that HER2 protein level was significantly downregulated in this group. The results of SPECT imaging showed that the T/B ratios at each time point in Ad-HER2-siRNA +DDP group was the lowest (p0.05).The data demonstrate that the growth of xenografts of human ovarian cancer with high expression of HER2 could be inhibited effectively by Ad-HER2-siRNA+DDP.

The objective of this study was to determine the effects of mercury chloride (HgCl2) on laying performance, egg quality, hepatic and renal histopathology, and serum biochemical profiles in laying hens. A total of 768 Hy-line brown laying hens aged 40 weeks were randomly allocated to four groups (8 pens per group and 24 hens per pen). The concentrations of mercury (Hg) in four groups were 0.280, 3.325, 9.415, and 27.240 mg/kg. Results revealed that dietary Hg could significantly reduce laying performance (P