Impact of exudative diathesis induced by selenium deficiency on LncRNAs and their roles in the oxidative reduction process in broiler chick veins

Blood selenium level can alleviate the nephrotoxicity of lead and cadmium in the general population of the United States: a retrospective cross section analysis of population-based nationally representative data

The current understanding of the interplay between blood selenium, cadmium and lead levels, and chronic kidney disease (CKD) is limited. Our objective was to investigate whether elevated blood selenium levels can mitigate the nephrotoxic effects of lead and cadmium. The exposure variables examined in this study include blood selenium, cadmium, and lead levels measured by ICP-MS. The outcome of interest was CKD, defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m². In total, 10630 participants (mean (SD) age:48.9 ± 18.4; 48.3% male) were included in this analysis. The median (IQR) of blood selenium, cadmium, and lead levels was 191 (177-207) μg/L, 0.300 (0.180-0.540) μg/L, and 0.940 (0.570-1.510) μg/dL, respectively. We observed a significant positive association between cadmium and lead levels and CKD (OR; 1.86; 95%CI: 1.31- 2.64; OR:2.23; 95%CI:1.54-3.24). However, selenium had a negative association with CKD (OR:0.096; 95%CI:0.020-0.457). Based on a reference group with a selenium concentration of ≤ 191 μg/L and cadmium level of > 0.300 μg/L, a significant protective factor in the CKD was seen in subjects with high plasma selenium and lower cadmium concentrations (OR:0.685; 95%CI:0.515-0.912). Then selenium concentration of ≤ 191 μg/L and lead level of > 0.940 μg/dL were set as a reference group, and the OR for CKD decreased among the other group (OR:0.564; 95%CI;0.417- 0.762). The subgroup analysis indicated that there were no effect modifiers. Blood selenium has the potential to mitigate the nephrotoxic effects of lead and cadmium in the general population of the United States.

Transcriptome analysis reveals the potential roles of long non-coding RNAs in feed efficiency of chicken

Feed efficiency is an important economic trait and reduces the production costs per unit of animal product. Up to now, few studies have conducted transcriptome profiling of liver tissue in feed efficiency-divergent chickens (Ross vs native breeds). Also, molecular mechanisms contributing to differences in feed efficiency are not fully understood, especially in terms of long non-coding RNAs (lncRNAs). Hence, transcriptome profiles of liver tissue in commercial and native chicken breeds were analyzed. RNA-Seq data along with bioinformatics approaches were applied and a series of lncRNAs and target genes were identified. Furthermore, protein-protein interaction network construction, co-expression analysis, co-localization analysis of QTLs and functional enrichment analysis were used to functionally annotate the identified lncRNAs. In total, 2,290 lncRNAs were found (including 1,110 annotated, 593 known and 587 novel), of which 53 (including 39 known and 14 novel), were identified as differentially expressed genes between two breeds. The expression profile of lncRNAs was validated by RT-qPCR. The identified novel lncRNAs showed a number of characteristics similar to those of known lncRNAs. Target prediction analysis showed that these lncRNAs have the potential to act in cis or trans mode. Functional enrichment analysis of the predicted target genes revealed that they might affect the differences in feed efficiency of chicken by modulating genes associated with lipid metabolism, carbohydrate metabolism, growth, energy homeostasis and glucose metabolism. Some gene members of significant modules in the constructed co-expression networks were reported as important genes related to feed efficiency. Co-localization analysis of QTLs related to feed efficiency and the identified lncRNAs suggested several candidates to be involved in residual feed intake. The findings of this study provided valuable resources to further clarify the genetic basis of regulation of feed efficiency in chicken from the perspective of lncRNAs.

Selenium in Human Health and Gut Microflora: Bioavailability of Selenocompounds and Relationship With Diseases

This review covers current knowledge of selenium in the dietary intake, its bioavailability, metabolism, functions, biomarkers, supplementation and toxicity, as well as its relationship with diseases and gut microbiota specifically on the symbiotic relationship between gut microflora and selenium status. Selenium is essential for the maintenance of the immune system, conversion of thyroid hormones, protection against the harmful action of heavy metals and xenobiotics as well as for the reduction of the risk of chronic diseases. Selenium is able to balance the microbial flora avoiding health damage associated with dysbiosis. Experimental studies have shown that inorganic and organic selenocompounds are metabolized to selenomethionine and incorporated by bacteria from the gut microflora, therefore highlighting their role in improving the bioavailability of selenocompounds. Dietary selenium can affect the gut microbial colonization, which in turn influences the host's selenium status and expression of selenoproteoma. Selenium deficiency may result in a phenotype of gut microbiota that is more susceptible to cancer, thyroid dysfunctions, inflammatory bowel disease, and cardiovascular disorders. Although the host and gut microbiota benefit each other from their symbiotic relationship, they may become competitors if the supply of micronutrients is limited. Intestinal bacteria can remove selenium from the host resulting in two to three times lower levels of host's selenoproteins under selenium-limiting conditions. There are still gaps in whether these consequences are unfavorable to humans and animals or whether the daily intake of selenium is also adapted to meet the needs of the bacteria.

Roles of selenoprotein S in reactive oxygen species-dependent neutrophil extracellular trap formation induced by selenium-deficient arteritis

Selenium (Se) deficiency and poor plasma Se levels can cause cardiovascular diseases by decreasing selenoprotein levels. Neutrophil extracellular traps (NETs) may be the vicious cycle center of inflammation in vasculitis. Here, we show that Se deficiency induced arteritis mainly by reducing selenoprotein S (SelS), and promoted the progression of arteritis by regulating the recruitment of neutrophils and NET formation. Silencing SelS induced chicken arterial endothelial cells (PAECs) to secrete cytokines, and activated neutrophils to promote NET formation. Conversely, scavenging DNA-NETs promoted cytokine secretion in PAECs. The NET formation regulated by siSelS was dependent on a reactive oxygen species (ROS) burst. We also found that the PPAR pathway was a major mediator of NET formation induced by Se-deficient arteritis. Overall, our results reveal how Se deficiency regulates NET formation in the progression of arteritis and support silencing-SelS worsens arteritis.

Differential epigenetic profiles induced by sodium selenite in breast cancer cells

OBJECTIVES

Selenium (Se) was a potential anticancer micronutrient with proposed epigenetic effect. However, the Se-induced epigenome in breast cancer cells was yet to be studied.

METHODS

The profiles of DNA methylation, microRNA (miRNA), long non-coding RNA (lncRNA), and message RNA (mRNA) in breast cancer cells treated with sodium selenite were examined by microarrays. We verified the epigenetic modifications by integrating their predicted target genes and differentially expressed mRNAs. The epigenetically regulated genes were further validated in a breast cancer cohort by associating with tumor progression. We conducted a series of bioinformatics analyses to assess the biological function of these validated genes and identified the critical genes.

RESULTS

The Se-induced epigenome regulated the expression of 959 genes, and 349 of them were further validated in the breast cancer cohort. Biological function analyses suggested that these validated genes were enriched in several cancer-related pathways, such as PI3K/Akt and metabolic pathways. Based on the degrees of expression change, hazard ratio difference, and connectivity, NEDD4L and FMO5 were identified as the critical genes.

CONCLUSIONS

These results confirmed the epigenetic effects of sodium selenite and revealed the epigenetic profiles in breast cancer cells, which would help understand the mechanisms of Se against breast cancer.

LncRNA 0003250 accelerates heart autophagy and binds to miR-17-5p as a competitive endogenous RNA in chicken induced by selenium deficiency

Long noncoding RNAs (LncRNAs) have been demonstrated to be associated with a variety of myocardial diseases, but how LncRNAs regulate autophagy in selenium (Se)-deficient myocardial injury is infrequently reported. Here, we screened out a novel long noncoding RNA, microRNA, and ATG7 through transcriptomic results. We employed a Se-deficient chicken model in vivo, and primary cultured cardiomyocytes treated by correlation in vitro. The results showed that Se deficiency upregulated the expression of ATG7, and miR-17-5p inhibited cardiomyocyte autophagy by targeting ATG7. Furthermore, we found that LncRNA 0003250 regulated miR-17-5p, and thus affected the expression of ATG7 and autophagic cell death. Our present study proposed a novel model for the regulation of cardiomyocytes autophagy, which includes LncRNA 0003250, miR-17-5p and ATG7 in the chicken heart. Our conclusions may provide a feasible diagnostic tool for Se-deficient cardiomyocyte injury.

Review: Long non-coding RNA in livestock

Less than 2% of mammalian genomes code for proteins, but 'the majority of its bases can be found in primary transcripts' - a phenomenon termed the pervasive transcription, which was first reported in 2007. Even though most of the transcripts do not code for proteins, they play a variety of biological functions, with regulation of gene expression appearing as the most common one. Those transcripts are divided into two groups based on their length: small non-coding RNAs, which are maximally 200 bp long, and long non-coding RNAs (lncRNAs), which are longer than 200 nucleotides. The advances in next-generation sequencing methods provided a new possibility of investigating the full set of RNA molecules in the cell. In this review, we summarized the current state of knowledge on lncRNAs in three major livestock species - Sus scrofa, Bos taurus and Gallus gallus, based on the literature and the content of biological databases. In the NONCODE database, the largest number of identified lncRNA transcripts is available for pigs, but cattle have the largest number of lncRNA genes. Poultry is represented by less than a half of records. Genomic annotation of lncRNAs showed that the majority of them are assigned to introns (pig, poultry) or intergenic (cattle). The comparison with well-annotated human and mouse genomes indicates that such annotation is a result of lack of proper lncRNA annotation data. Since lncRNAs play an important role in genomic studies, their characterization in farm animals' genomes is critical in bridging the gap between genotype and phenotype.

Long noncoding RNAs in lipid metabolism: literature review and conservation analysis across species

BACKGROUND

Lipids are important for the cell and organism life since they are major components of membranes, energy reserves and are also signal molecules. The main organs for the energy synthesis and storage are the liver and adipose tissue, both in humans and in more distant species such as chicken. Long noncoding RNAs (lncRNAs) are known to be involved in many biological processes including lipid metabolism.

RESULTS

In this context, this paper provides the most exhaustive list of lncRNAs involved in lipid metabolism with 60 genes identified after an in-depth analysis of the bibliography, while all "review" type articles list a total of 27 genes. These 60 lncRNAs are mainly described in human or mice and only a few of them have a precise described mode-of-action. Because these genes are still named in a non-standard way making such a study tedious, we propose a standard name for this list according to the rules dictated by the HUGO consortium. Moreover, we identified about 10% of lncRNAs which are conserved between mammals and chicken and 2% between mammals and fishes. Finally, we demonstrated that two lncRNA were wrongly considered as lncRNAs in the literature since they are 3' extensions of the closest coding gene.

CONCLUSIONS

Such a lncRNAs catalogue can participate to the understanding of the lipid metabolism regulators; it can be useful to better understand the genetic regulation of some human diseases (obesity, hepatic steatosis) or traits of economic interest in livestock species (meat quality, carcass composition). We have no doubt that this first set will be rapidly enriched in coming years.

The effect of Mycoplasma gallisepticum infection on energy metabolism in chicken lungs: Through oxidative stress and inflammation

Mycoplasma gallisepticum (Mg) causes chronic respiratory disease (CRD) in chickens. However, the effect of Mg infection on energy metabolism in chicken lungs is still unknown. The present study was aimed to investigate the effect of Mg infection on energy metabolism in chicken lungs. Four-weeks-old white leghorn chickens were randomly divided into control group (L1) and Mg infection group (L2). Histopathology, transmission electron microscopy, qRT-PCR and Western blot were used to determine the hallmarks of ultrastructural analysis, inflammation and energy metabolism. Results revealed that Mg infection induced oxidative stress in the chicken lungs and serum cytokine activities were enhanced at the three time points. Chickens infected with Mg revealed abnormal morphology and cellular damage including increased inflammatory cells infiltrate, cellular debris and exudate, mitochondrial and DNA damage in the lungs. The mRNA and protein expression level of inflammation-related genes were significantly increased in L2 group, showing that Mg induced inflammation in chicken lungs. In addition, ATPase activities were reduced in L2 group compared to L1 group. Meanwhile, the expression of energy metabolism related genes were decreased at both mRNA and protein level at all assessed time points, which showed that Mg infection weakened energy metabolism in chicken lungs. In summary, the data suggested that Mg infection induced oxidative stress, inflammation and energy metabolism dysfunction in the chicken lungs, exploring new therapeutic targets and providing a reference for comparative veterinary medicine.

Antagonistic Effects Of Baicalin On Mycoplasma gallisepticum-Induced Inflammation And Apoptosis By Restoring Energy Metabolism In The Chicken Lungs

Background

Baicalin possesses potential anti-inflammatory, anti-tumor and anti-oxidant activities. In the present study, we attempted to investigate the preventive effects of baicalin against Mycoplasma gallisepticum (MG)-induced inflammation, apoptosis and energy metabolism dysfunction in chicken lungs.

Methods

Experimental chickens were randomly divided into 1) control group, 2) MG infection group, 3) MG-infected group treated with baicalin at a dose of 450 mg/kg and 4) baicalin alone treated group (450 mg/kg). After 7 days of post-treatment, serum and lung tissues were collected for different experimental analyses. The hallmarks of inflammation, apoptosis and energy metabolism dysfunction were detected by histological and ultrastructural examination, qRT-PCR, Western blotting and terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) assay.

Results

The level of serum inflammatory markers were increased with MG infection. Histological and ultrastructural analysis showed excessive inflammatory cells infiltrates, alveolar wall thickening, hemorrhages, mitochondrial and nuclear damage, including mitochondrial swelling and condensation of DNA in the lungs of chickens infected with MG. TUNEL assay positive-stained nuclei were significantly increased in MG infection group. In addition, the mRNA and protein expression level of energy metabolism-related genes and ATPase activities were significantly reduced. Meanwhile, MG-induced morphological and ultrastructural changes were partially disappeared with baicalin-treatment, and the level of serum inflammatory markers were significantly reduced. It has been noted that baicalin significantly attenuated MG-induced inflammation and apoptosis in the chicken lungs through the suppression of nuclear factor-kappa B and reduced extensive positive-stained apoptotic nuclei. More importantly, ATPase activities and mRNA and protein expression level of energy metabolism-related genes were significantly improved with baicalin-treatment in the lungs of chickens infected with MG.

Conclusion

Conclusively, it has been suggested from these results that baicalin-treatment efficiently prevented MG-induced inflammation, apoptosis and energy metabolism dysfunction in the chicken lungs and provide basis for new therapeutic targets to control MG infection.

The association between plasma selenium and chronic kidney disease related to lead, cadmium and arsenic exposure in a Taiwanese population

This study aimed to determine the interaction of red blood cell cadmium and lead, total urinary arsenic, and plasma selenium in chronic kidney disease (CKD). We recruited 220 CKD patients as well as 438 gender- and age-matched controls, and we defined CKD as <60 mL/min/1.73 m² estimated glomerular filtration rate (eGFR) for three or more consecutive months. Plasma selenium and red blood cell cadmium and lead concentrations were measured by ICP-MS. Urinary arsenic species were determined via HPLC-HG-AAS and were summed to determine the total urinary arsenic concentration. Plasma selenium was positively correlated to eGFR, and subjects with high plasma selenium levels (>243.90 μg/L) had a significantly lower odds ratio (OR) and 95% confidence interval (CI) (0.23, 0.13-0.42) for CKD compared to those with low plasma selenium levels (≤ 196.70 μg/L). High plasma selenium and low red blood cell cadmium or lead concentrations interacted to decrease the OR and 95% CI for CKD (0.12, 0.06-0.26; 0.09, 0.04-0.19). High plasma selenium and low red blood cell lead levels also interacted to increase the eGFR (20.70, 15.56-26.01 mL/min/1.73 m²). This study is the first to suggest that selenium modifies the eGFR and OR in CKD induced by environmental toxicants.

MicroRNA-33-3p Regulates Vein Endothelial Cell Apoptosis in Selenium-Deficient Broilers by Targeting E4F1

Selenium (Se) is a type of nutrient element. The tissues of organisms can have pathological damage, including apoptosis, due to Se deficiency. Apoptosis is an important cell process and plays a key role in vascular disease and Se-deficient symptoms. In this study, the Se-deficient broiler model was duplicated, miR-33-3p in the vein was overexpressed in response to Se-deficiency, and miR-33-3p target gene E4F transcription factor 1 (E4F1) expression was also confirmed. We utilized ectopic miR-33-3p expression to validate its function for apoptosis. The results showed that miR-33-3p-targeted E4F1 are involved in the glucose-regulated protein 78- (GRP78-) induced endoplasmic reticulum stress (ERS) apoptosis pathway. We presumed that Se deficiency might trigger apoptosis via downregulating miR-33-3p. Interestingly, the miR-33-3p inhibitor and VER-155008 (GRP78 inhibitor) partly hindered the apoptosis caused by Se deficiency. Thus, the above information provides a new avenue toward understanding the mechanism of Se deficiency and reveals a novel apoptotic injury regulation model in vascular disease.

Varied doses and chemical forms of selenium supplementation differentially affect mouse intestinal physiology

Varied doses and chemical forms of selenium supplementation differentially affect mouse intestinal physiology and perturbed the fecal metabolic profiles of and jejunal protein expression in mice.

Selenium-Related Transcriptional Regulation of Gene Expression

The selenium content of the body is known to control the expression levels of numerous genes, both so-called selenoproteins and non-selenoproteins. Selenium is a trace element essential to human health, and its deficiency is related to, for instance, cardiovascular and myodegenerative diseases, infertility and osteochondropathy called Kashin–Beck disease. It is incorporated as selenocysteine to the selenoproteins, which protect against reactive oxygen and nitrogen species. They also participate in the activation of the thyroid hormone, and play a role in immune system functioning. The synthesis and incorporation of selenocysteine occurs via a special mechanism, which differs from the one used for standard amino acids. The codon for selenocysteine is a regular in-frame stop codon, which can be passed by a specific complex machinery participating in translation elongation and termination. This includes a presence of selenocysteine insertion sequence (SECIS) in the 3′-untranslated part of the selenoprotein mRNAs. Nonsense-mediated decay is involved in the regulation of the selenoprotein mRNA levels, but other mechanisms are also possible. Recent transcriptional analyses of messenger RNAs, microRNAs and long non-coding RNAs combined with proteomic data of samples from Keshan and Kashin–Beck disease patients have identified new possible cellular pathways related to transcriptional regulation by selenium.

Regulation of lipid peroxidation and ferroptosis in diverse species

This review by Conrad et al. reviews the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea, and discusses the potential evolutionary roles of lipid peroxidation and ferroptosis.

Lipid peroxidation is the process by which oxygen combines with lipids to generate lipid hydroperoxides via intermediate formation of peroxyl radicals. Vitamin E and coenzyme Q₁₀ react with peroxyl radicals to yield peroxides, and then these oxidized lipid species can be detoxified by glutathione and glutathione peroxidase 4 (GPX4) and other components of the cellular antioxidant defense network. Ferroptosis is a form of regulated nonapoptotic cell death involving overwhelming iron-dependent lipid peroxidation. Here, we review the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea. We also discuss the potential evolutionary roles of lipid peroxidation and ferroptosis.

The Protective Effect of Selenium on the Chicken Pancreas against Cadmium Toxicity via Alleviating Oxidative Stress and Autophagy

Cadmium (Cd) is a highly toxic heavy metal that can affect human and animal health. Selenium (Se) is an essential microelement that can protect various organs against toxic heavy metals. Although many studies have investigated the adverse effect of Cd in rats and several other animals, little is known regarding the mechanisms of Cd-induced autophagy in the chicken pancreas and the antagonistic effect of Se on Cd. In the current study, we fed chickens Se, Cd, or Se and Cd supplements to establish the Se and Cd interaction model and to measure the concentrations of Se and Cd in the chicken pancreas. The ultrastructure changes of the chicken pancreas were also observed, and we detected oxidative stress indexes in each group. The expression levels of autophagy-related genes were also examined. We found that Cd exposure could increase the concentration of Cd, the activities of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); and the total antioxidant capacity (T-AOC) content in the chicken pancreas. The protein expression levels of dynein, Beclin1, LC3-1, LC3-2, and Atg5 were increased and that of TOR was decreased under Cd exposure conditions. However, the changes induced by Cd were significantly alleviated by Se. This study suggested that Cd could accumulate in the chicken pancreas and lead to oxidative stress and autophagy. Se was shown to antagonize Cd toxicity though reducing Cd accumulation, alleviating oxidative stress, and inhibiting autophagy. This study revealed a concrete mechanism for the Se antagonism of Cd and might provide a new clue for the detoxification of Cd poisoning.

MiR-128-1-5p regulates tight junction induced by selenium deficiency via targeting cell adhesion molecule 1 in broilers vein endothelial cells

Vein endothelial cells (VECs) constitute an important barrier for macromolecules and circulating cells from the blood to the tissues, stabilizing the colloid osmotic pressure of the blood, regulating the vascular tone, and rapidly changing the intercellular connection, and maintaining normal physiological function. Tight junction has been discovered as an important structural basis of intercellular connection and may play a key role in intercellular connection injuries or vascular diseases and selenium (Se) deficiency symptoms. Hence, we replicated the Se-deficient broilers model and detected the specific microRNA in response to Se-deficient vein by using quantitative real time-PCR (qRT-PCR) analysis. Also, we selected miR-128-1-5p based on differential expression in vein tissue and confirmed its target gene cell adhesion molecule 1 (CADM1) by the dual luciferase reporter assay and qRT-PCR in VECs. We made the ectopic miR-128-1-5p expression for the purpose of validating its function on tight junction. The result showed that miR-128-1-5p and CADM1 were involved in the ZO-1-mediated tight junction, increased paracellular permeability, and arrested cell cycle. We presumed that miR-128-1-5p and Se deficiency might trigger tight junction. Interestingly, miR-128-1-5p inhibitor and fasudil in part hinder the destruction of the intercellular structure caused by Se deficiency. The miR-128-1-5p/CADM1/tight junction axis provides a new avenue toward understanding the mechanism of Se deficiency, revealing a novel regulation model of tight junction injury in vascular diseases.

Lower Selenoprotein T Expression and Immune Response in the Immune Organs of Broilers with Exudative Diathesis Due to Selenium Deficiency

The objective of the present study was to investigate whether dietary selenium (Se) deficiency would affect the expression of selenoprotein T (SelT) and immune response in the immune organs of broilers. Changes in expression of inflammatory cytokines and oxidative stress response caused by Se deficiency can lead to organism damage, which in turn leads to immune response. Sixty (1-day-old) broilers were divided into the control group and Se-deficiency group. Animal models with exudative diathesis were duplicated in the broilers by feeding them Se-deficient diet for 20 days. After the Se-deficient group exhibited symptoms of exudative diathesis, all the broilers were euthanized, and their immune organs were taken for analysis. The tissues including spleen, bursa of Fabricius, and thymus were treated to determine the pathological changes (including microscopic and ultramicroscopic), the messenger RNA (mRNA) expression levels of SelT and its synthetase (SecS and SPS1), cytokine mRNA expression levels, and antioxidant status. The microscopic and ultramicroscopic analyses showed that immune tissues were obviously injured in the Se-deficient group. The mRNA expression of SelT was decreased compared with that in the control group. Meanwhile, the mRNA expression levels of SecS and SPS1 were downregulated. In the Se-deficient group, the mRNA expression levels of IL-1R and IL-1β were higher than those of three control organs. Additionally, the IL-2 and INF-γ mRNA expression levels were lower than those of the control group. The activity of CAT was decreased, and the contents of H₂O₂ and •OH were increased due to Se deficiency. Pearson method analysis showed that the expression of SelT had a positive correlation with IL-2, INF-γ, SecS, and SPS1 and a negative correlation with IL-1R and IL-1β. In summary, these data indicated that Se-deficient diet decreased the SelT expression and its regulation of oxidative stress, and it inhibited a pleiotropic mechanism of the immune response.

Long-term neurocognitive dysfunction in offspring via NGF/ ERK/CREB signaling pathway caused by ketamine exposure during the second trimester of pregnancy in rats

Early life exposure to ketamine caused neurohistopathologic changes and persistent cognitive dysfunction. For this study, a pregnant rat model was developed to investigate neurocognitive effects in the offspring, following ketamine exposure during the second trimester. Pregnant rats on gestational day 14 (equal to midtrimester pregnancy in humans), intravenously received 200 mg/kg ketamine for 3 h. Their behavior was tested (Morris water maze, odor recognition test, and fear conditioning) at postnatal days (P25-30). Furthermore, hippocampal morphology of the offspring (P30) was examined via Nissl staining and hippocampal dendritic spine density was determined via Golgi staining. The hippocampal protein levels of nerve growth factor (NGF), extracellular signal-regulated kinase (ERK), phosphorylated-ERK (p-ERK), cyclic adenosine monophosphate response element-binding (CREB), p-CREB, synaptophysin (SYP), synapsin (SYN), and postsynaptic density-95 (PSD95) were measured via western blot. Additionally, SCH772984 (an ERK inhibitor) was used to evaluate both role and underlying mechanism of the ERK pathway in PC12 cells. We found that ketamine caused long-term neurocognitive dysfunction, reduced the density of the dendritic spin, caused neuronal loss, and down-regulated the expression of NGF, ERK, p-ERK, mitogen, and stress-activated protein kinase (MSK), CREB, p-CREB, SYP, SYN, and PSD95 in the hippocampus. These results suggest that ketamine induced maternal anesthesia during period of the fetal brain development can cause long-term neurocognitive dysfunction in the offspring, which likely happens via inhibition of the NGF-ERK-CREB pathway in the hippocampus. Our results highlight the central role of ERK in neurocognition.

Antagonistic effects of selenium on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens

Lead (Pb) may damage the immune function in human and animal. Selenium (Se) has antagonistic effects on Pb. In our study, brown layer chickens were randomly allocated to control group, Se group (1 mg/kg Se), Se+Pb group (1 mg/kg Se and 350 mg/kg Pb), and Pb group (350 mg/kg Pb). The chickens were sacrificed on the 90^th day; spleen tissues were subjected to observation of ultrastructure and detection of spleen-related indexes. The results revealed that in the Pb group, expression levels of the cytokines IL-1 and TNF-α significantly increased, and expression levels of IL-2 and INF-γ significantly decreased; activities of antioxidant enzyme GPX, SOD and CAT significantly decreased, and expression level of malondialdehyde (MDA) significantly increased; expression levels of mitochondrial fission-related genes (Mff and Drp1) significantly increased, and expression levels of mitochondrial fusion-related genes (Opa1, Mfn1 and Mfn2) significantly decreased; expression of autophagy-related genes (Beclin 1, Dynein, Atg 5, LC3-I and LC-II) was upregulated, while expression of mammalian target of rapamycin (mTOR) was downregulated. The results of transmission electron microscopy indicated that Pb induced mitochondrial fragmentation, and triggered autophagy in the spleen of chickens. The Se and Pb co-treatment remarkably alleviated these injuries induced by Pb in the spleen of chickens. In conclusion, Pb can induce the oxidative stress to influence the mitochondrial dynamics balance and lead to autophagy, which triggers the immune dysfunction in the spleen of chickens; the Se exhibits the antagonistic effects on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens.

The Antagonistic Effect of Selenium on Cadmium-Induced Damage and mRNA Levels of Selenoprotein Genes and Inflammatory Factors in Chicken Kidney Tissue

Selenium (Se) is a necessary trace mineral in the diet of humans and animals. Cadmium (Cd) is a toxic heavy metal that can damage animal organs, especially the kidneys. Antagonistic interactions between Se and Cd have been reported in previous studies. However, little is known about the effects of Se against Cd toxicity and on the mRNA levels of 25 selenoprotein genes and inflammatory factors in chicken kidneys. In the current study, we fed chickens with a Se-treated, Cd-treated, or Se/Cd treated diet for 90 days. We then analyzed the mRNA expression of inflammatory factors (including prostaglandin E synthase (PTGES), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2)) and 25 selenoprotein genes (Gpx1, Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Txnrd3, Dio1, Dio2, Dio3, SPS2, Sepp1, SelPb, Sep15, Selh, Seli, Selm, Selo, Sels, Sepx1, Selu, Selk, Selw, Seln, Selt). The results demonstrated that Cd exposure increased the Cd content in the chicken kidneys, renal tubular epithelial cells underwent denaturation and necrosis, and the tubules became narrow or disappeared. However, Se supplementation reduced the Cd content in chicken kidneys and induced normal development of renal tubular epithelial cells. In addition, we also observed that Se alleviated the Cd-induced increase in the mRNA levels of inflammatory factors and ameliorated the Cd-induced downtrend in the mRNA levels of 25 selenoprotein genes in chicken kidneys.

Selenium Supplementation Changes the Ion Profile in the Pancreas of Chickens Treated with Cadmium

Increasing evidence indicates that selenium (Se) could antagonize metal toxicity, including cadmium (Cd) toxicity. However, the effects of Se on Cd-induced changes in the ion profile in the pancreas of chickens have not been reported. In the present study, 128 Hy-Line brown laying chickens were divided into the control group, Se-treated group, Se/Cd-treated group, and Cd-treated group, and we detected the concentrations of 28 ions in the four groups by inductively coupled plasma mass spectrometry. In the Cd-treated group, the accumulation of Cd in the pancreas was 836.8 times higher that than in the control group (27,353.71 ppb/32.69 ppb). Meanwhile, the Ca, Ti, Fe, Mo, Li, Al, and Pb levels increased and the Cr, Mn, Ni, Cu, Zn, Se, Sr, and Sb levels decreased due to sub-chronic Cd poisoning. The Fe, Mo, Ba, and Pb levels decreased in the Se/Cd-treated group. Our findings suggest that Cd can accumulate in the chicken pancreas and affect the ion profiles, whereas Se can ameliorate the accumulation of Cd and change the ion profiles in the chicken pancreas.

Selenium against lead-induced apoptosis in chicken nervous tissues via mitochondrial pathway

To investigate alleviative effect of selenium (Se) on lead (Pb)-induced apoptosis in chicken nervous tissues, 7-day-old chickens were randomly divided into four groups. The control group was fed a standard diet and drinking water. In the Pb and Se/Pb groups, (CH₃OO)₂Pb was dissolved in drinking water. In the Se and Se/Pb groups, Na₂SeO₃ was put into the standard diet. Embryonic neurocytes were divided into the control, Se (containing Na₂SeO₃), Pb (containing (CH₃COO)₂Pb), and Se/Pb (containing Na₂SeO₃ and (CH₃COO)₂Pb) groups. The following contents were performed: Morphologic observation for 90 days in brain tissues and for 12, 24, 36, and 48 hours in embryonic neurocytes; and antioxidant indexes, messenger RNA (mRNA) expression of twenty-five selenoproteins, and mRNA and protein expression of five apoptosis-related genes for 30, 60, and 90 days in brain tissues and for 12, 24, 36, and 48 hours in embryonic neurocytes. The results indicated that Se alleviated Pb-caused morphological changes; the decrease of superoxide dismutase, glutathione peroxidase (GPx), GPx1, GPx2, GPx3, GPx4, thioredoxin reductases (Txnrd)1, Txnrd2, Txnrd3, iodothyronine deiodinases (Dio)1, Dio2, Dio3, selenoprotein (Sel)T, SelK, SelS, SelH, SelM, SelU, SelI, SelO, Selpb, selenoprotein (Sep)n1, Sepp1, Sepx1, Sepw1, 15-kDa selenoprotein, and selenophosphate synthetases 2, and B-cell lymphoma-2 (Bcl-2); the increase of malondialdehyde, p53, Bcl-2 associated X protein, cytochrome c, and Caspase-3. Pb had time-dependent effects on GPx4, SelM, and malondialdehyde in the brain tissues; and on SelU in the embryonic neurocytes. Our data demonstrated that Se alleviated Pb-induced apoptosis in the chicken nervous tissues via mitochondrial pathway.

Selenium accelerates chicken dendritic cells differentiation and affects selenoproteins expression

Selenium (Se) promotes immune cell differentiation and improves immune response. Antigen-presenting cells such as dendritic cells (DCs) play an important role in immune system, however, the impact of Se on DCs is still unclear. In this study, we successfully induced and cultured chicken DCs from peripheral blood mononuclear cells by incubating mononuclear cells with 50 ng/mL recombinant chicken granulocyte-macrophage colony stimulating factor and 10 ng/mL recombinant chicken interleukin-4 for total 9 days. In + Se group, we added 10^-7 mol/L sodium selenite from the first day of cell culture. The results showed that Se supplementation expedited and increased the expression of cell surface markers including CD11c, CD40, CD86, and MHC II. Principal component analysis showed that the expression of selenoproteins SelW, SelK, Dio3, GPX1, GPX2, SelN, SelS, SelH in chicken DCs was highly correlated, and SelW had highest correlation with the cell surface markers MHC II and CD11c. In conclusion, Se accelerates the differentiation and maturation of chicken DCs. Se regulates the differentiation and maturation of chicken DCs by selenoproteins. Selenoproteins has closely correlated to surface markers of chicken DCs.

Antagonistic effects of selenium on cadmium-induced apoptosis by restoring the mitochondrial dynamic equilibrium and energy metabolism in chicken spleens

The aim of this study was to investigate the mechanism of cadmium-induced apoptosis in chicken spleens and the antagonistic effects of selenium. We duplicated the selenium-cadmium interaction model and examined the expression of apoptosis-, immune-, mitochondrial dynamics- and energy metabolism-related genes. The results demonstrated that after treatment with cadmium, the frequency of apoptosis was significantly increased, and the morphological characteristics of apoptosis were observed. The expression of pro-apoptotic genes was increased, and that of anti-apoptotic genes was decreased. The mRNA levels of tumor necrosis factor-α and interlenkin-1β were observably increased, but the interlenkin-2 and interferon-γ levels were markedly decreased. Furthermore, the mRNA and protein levels of dynamin-related protein 1 and mitochondrial fission factor were significantly enhanced, whereas mitofusin 1, mitofusin 2, and optic atrophy 1 were markedly decreased. The expression of hexokinase 1, hexokinase 2, aconitase 2, lactate dehydrogenase A, lactate dehydrogenase B, succinatedehydrogenase B, pyruvate kinase and phosphofructokinase were also reduced. Selenium supplements remarkably attenuated cadmium-induced effects (p < 0.05). Based on the above results, conclude that the cadmium treatment promoted a mitochondrial dynamic imbalance and reduced energy metabolism, leading to apoptosis and immune dysfunction in chicken spleens, and selenium had an antagonistic effect on Cd-induced apoptosis.