Gene expression in broiler livers upon supplementation with selenized yeast
ABSTRACT: Selenium (Se) is an essential cofactor of the antioxidant enzyme glutathione peroxidase beside other functions. The evaluation of optimal selenium supplementation in chicken feed and the subsequent effects on animal health and performance requires comprehensive knowledge of the overall metabolic effects of selenium. Therefore the gene expression was measured in the control group with a standard diet and in the group with a Se supplemented diet (0.5mg Se/kg diet) to determine significantly altered gene expression. The selenium was supplemented in the form of selenized yeast (Se-yeast), which mainly consists of organic Se in the form of L-selenomethionine and L-selenocysteine. The control group received a diet, which contained 70μg of Se / kg diet and the Se-yeast group 620μg of Se / kg diet (analyzed). The one-day old broiler chicks were separated into two groups and received the control or the Se-supplemented diet ad libitum for 35 days. After slaughter the gene expression was determined in the liver of four control and five samples from the Se-yeast group. One sample from the control group did not correspond to the quality requirements and was excluded from the analysis.
Project description:Selenium (Se) is an essential cofactor of the antioxidant enzyme glutathione peroxidase beside other functions. The evaluation of optimal selenium supplementation in chicken feed and the subsequent effects on animal health and performance requires comprehensive knowledge of the overall metabolic effects of selenium. Therefore the gene expression was measured in the control group with a standard diet and in the group with a Se supplemented diet (0.5mg Se/kg diet) to determine significantly altered gene expression. The selenium was supplemented in the form of selenized yeast (Se-yeast), which mainly consists of organic Se in the form of L-selenomethionine and L-selenocysteine. The control group received a diet, which contained 70μg of Se / kg diet and the Se-yeast group 620μg of Se / kg diet (analyzed). Overall design: The one-day old broiler chicks were separated into two groups and received the control or the Se-supplemented diet ad libitum for 35 days. After slaughter the gene expression was determined in the liver of four control and five samples from the Se-yeast group. One sample from the control group did not correspond to the quality requirements and was excluded from the analysis.
Project description:Selenium (Se) is an essential nutrient for beef cattle health and commercial production. The molecular mechanisms responsible for physiological responses of the animal to dietary Se supplementation, however, have not been evaluated. Furthermore, the potential effect of two chemical forms (organic vs. inorganic) of Se on gene expression by Se-sufficient cattle has not been evaluated. Microarray analysis using the GeneChip Bovine Genome Array (Affymetrix, Inc., Santa Clara, CA) was conducted to determine if dietary Se supplementation in organic vs. inorganic form (OSe vs. ISe) differentially affects the liver gene expression profile in growing beef heifers. Sodium selenite (Prince Se Concentrate; Prince Agri Products, Inc., Quincy, IL) was used as the source of ISe form. Se-enriched yeast (Sel-Plex; Alltech, Inc., Nicholasville, KY) was used as the source of OSe form. Thirty Angus heifers (BW 393 ± 9 kg) were randomly assigned to 3 dietary treatments (n = 10): Control (Ctrl) group received no dietary Se supplementation; ISe treatment group daily received dietary supplementation of Se at 3 mg/animal from ISe source; OSe treatment group daily received dietary supplementation of Se at 3 mg/animal from OSe source. Six animals were randomly selected from each of 3 treatment groups for RNA extraction and microarray analysis.
Project description:Transcriptional profiling of porcine expanded blastocysts comparing control (EB obtained from 4 sows treated with basal diet) with either inorganic Se + B6 (EB obtained from 4 sows treated with basal diet plus inorganic Se and B6) or organic Se + B6 (EB obtained from 3 sows treated with basal diet plus organic Se and B6). Three-condition experiment, EB without and with maternal diet supplemented B6 plus either inorganic Se or organic Se. Four biological replicates for inorganic Se and three biological replicates and one technical replicate for organic Se. Pooled of four biological replicates for control group.
Project description:Protein and mRNA levels for several selenoproteins, such as glutathione peroxidase-1 (Gpx1), are down-regulated dramatically by selenium (Se) deficiency. Selenoprotein levels in rats increase sigmoidally with increasing dietary Se and reach defined plateaus at the Se requirement, making them sensitive biomarkers for Se deficiency, but not high for Se status. Biomarkers for high Se status are needed as super-nutritional Se intakes are associated with beneficial and adverse health outcomes, but conventional biomarkers are not especially useful above the Se requirement. To characterize Se regulation of the transcriptome, we conducted 3 microarray experiments in weanling mice and rats fed Se-deficient diets supplemented with levels of Se up to 5 µg Se/g diet. Rats or mice were fed Se-deficient diets supplemented with sodium selenite up to 5 ug Se/g diet for 28 or 35 days. Affymetrix Rat 230 2.0 and Mouse 430 2.0 Genome Arrays were used to analyze gene expression in liver in all studies plus kidney in the mouse study.
Project description:Selenium is an essential micronutrient. Its recommended daily allowance is not attained by a significant proportion of the population in many countries and its intake has been suggested to affect colorectal carcinogenesis. Therefore, microarrays were used to determine how both selenoprotein and global gene expression patterns in the mouse colon were affected by marginal selenium deficiency comparable to variations in human dietary intakes. Two groups of 12 mice each were fed a selenium-deficient (0.086mg Se/kg) or a selenium-adequate (0.15mg Se/kg) diet. After 6wk, plasma selenium level, liver, and colon glutathione peroxidase (GPx) activity in the deficient group was 12, 34, and 50%, respectively, of that of the adequate group. Differential gene expression was analysed with mouse 44K whole genome microarrays. Pathway analysis by GenMAPP identified the protein biosynthesis pathway as most significantly affected, followed by inflammation, Delta-Notch and Wnt pathways. Selected gene expression changes were confirmed by quantitative real-time PCR. GPx1 and the selenoproteins W, H, and M, responded significantly to selenium intake making them candidates as biomarkers for selenium status. Thus, feeding a marginal selenium-deficient diet resulted in distinct changes in global gene expression in the mouse colon. Modulation of cancer-related pathways may contribute to the higher susceptibility to colon carcinogenesis in low selenium status. Overall design: Male C57BL/6J mice (3–4 wk of age) from Charles River (Sulzfeld, Germany) were randomly assigned to the selenium-deficient or selenium-adequate group (12 mice per group) with free access to food and water. The selenium-adequate diet (Se-adeq) was produced by mixing selenomethionine (Acros, Geel, Belgium) into the selenium-deficient diet (Se-def; No. C1045 with 50% carbohydrates, 17% protein, 5% fat, 4% fibre, and mixture of micronutrients; Altromin, Lage, Germany) containing 0.086mg Se/kg (Riese et al., Endocrinology 2006) to yield a selenium content of 0.15 mg/kg corresponding to the dietary reference intake for mice. Diets were fed as powder for 6wk until mice were killed in the non-fasted state. Animals were anesthetized with isofluran and blood was withdrawn from the retro-orbital plexus. Anesthetized animals were killed by cervical dislocation. Plasma and tissues freeze clamped in liquid nitrogen were stored at -80C.
Project description:Genome-wide expression analysis in C. Elegans grown in axenic media with low to toxic selenium concentrations We performed Affymetrix micorarray-based transcriptional profiling on wild-type C. Elegans Bristol N2 grown in low Se axenic media supplemented with five concentrations of selenium, from low to toxic, and harvested at the L4-larva stage. RNA was prepared for hybridization to Affy microarrays from synchronized cultures of wild-type C. elegans seeded in low Se axenic media, supplemented with graded 0, 0.05, 0.1, 0.2, and 0.4 mM Se added as sodium selenite, and harvested at the L4-larva stage (1 culture/sample per Se concentgration).
Project description:This study evaluated transcriptional effects of the lung carcinogen NNK ( 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) injection and selenocystine consumption on the murine lung. Female A/J mice at 5 weeks of age were obtained from The Jackson Laboratory. Animals were stabilized on an unsupplemented AIN-76 diet for one week prior to being given the selenium supplemented diet. The basal level of selenium in the diet is 0.35 ppm Se, the selenocytine supplemention was at 15 ppm. NNK was administered i.p. as a single 10 uM injection in 0.2 mL saline. With this protocol, 100% of animals reproducibly develop lung tumors after 3 months. Three days after NNK administration, animals were provided AIN-76A diets supplemented with selenocystine at 15 ppm selenium ad libitum for 10 days. Animals were sacrificed thirteen days after NNK administration. Lung tissue was harvested, immediately homogenized in Trizol and frozen. The organic extracted RNAs were run over Qiagen RNeasy columes before quantifying and qualifying them. All samples had RNA quality index's greater than 9. Four groups of A/J mice were utilized with 4 biological replicates per group. 1) Untreated - controls on the AIN-76 diet (0.35 ppm Se). 2) NNK treated - single injection of NNK, maintained on norma AIN-76 diet, sacraficed after 13 days. 3) SECY - selenocystine supplemented (15 ppm) for 10 days on a AIN-76 diet then sacraficed. 4) NNK plus SECY - single injection of NNK, after 3 days, selenocystine supplemented (15 ppm) diet for 10 days then sacraficed. RNAs from the the four untreated mice were combined to phenotypically anchor the dual color expression profile. mouse lung responses to NNK injection and/or selenocystine dietary supplementation
Project description:Little is known regarding the relationship between Selenium (Se) concentrations in the liver and liver gene expression. Because most cow-calf operations in Se-poor soils provide enough Se in mineral mixes to avoid deficiency, the aim of this study was to determine the effects of 4 Se form supplementation strategies (none or inorganic, organic, or 1:1 inorganic:organic mix) on liver gene expression profiles using a Se-adequate model. Microarray analysis was conducted using the custom WT Btau 4.0 Array (version 1; GeneChip, Affymetrix, Inc., Santa Clara, CA, USA) to determine if dietary Se supplementation form differentially affects the hepatic gene expression profiles of maturing beef heifers. Sodium selenite was used as the source of inorganic Se and Se-enriched yeast was the source of organic selenium. Thirty-six Angus heifers (BW 400 ± 9.0 kg) were ranked on the Se concentration of their biopsied (day -14) liver sample and randomly assigned to one of four dietary Se treatments: Control (Ctrl) group received no exogenous dietary Se supplementation; inorganic (ISe) treatment group received daily dietary Se supplementation at 3 mg/ animal of the ISe form; organic (OSe) treatment group received daily dietary Se supplementation of 3 mg/ animal of OSe form; and the mix (1:1 ISe:OSe) received daily dietary Se supplementation of 3 mg/ animal of 50:50 mix of ISe and OSe forms. RNA was extracted from biopsied liver samples taken 168 days after initiation of Se supplementation and microarray analyses were conducted.
Project description:We tested the hypothesis that the behavioral response to selenium (Se) follows a hormetic dose response pattern, manifested through the functions of selenoproteins within the brain. We measured anxiety-related behaviors in zebrafish (Danio rerio) at deficient, control and supplemented levels of dietary Se, and measured the transcriptional response of selenoprotein genes important for neuroprotection. We also used a microarray approach to assess the transcriptomic response of the midbrain to Se. The behavioral response to Se was characterized by hormesis, and the direction, magnitude, and shape of the hormetic responses were dependent on both sex and zebrafish population. Transcription of selenoproteins within the midbrain also responded to Se in a similar hormetic dose-dependent manner, with sex and population influencing the trajectory of the responses. The hormetic behavioral response to Se may therefore be manifested through selenoproteins in the brain, but the influence is not direct. We performed a microarray analysis comparing the midbrain-specific transcriptome between male zebrafish from two populations (Pargana: P and Transgenic Mosaic 1: T) fed either a control, Se deficient, or Se supplemented diet (17 total samples: 9 fish per population, 3 fish per diet: missing 1 P control sample).
Project description:The possible benefits of selenium (Se) supplementation are currently under investigation for prevention of certain cancers and treatment of neurological disorders. Little is known concerning the response of the brain to increased dietary Se under conditions of Se sufficiency, despite the majority of Se supplementation trials occurring in healthy subjects considered Se sufficient. We evaluated the transcriptional response of the zebrafish (Danio rerio) brain to supplementation with nutritionally relevant levels of dietary Se (sodium selenite) during conditions of assumed Se sufficiency. We used a microarray approach to analyze the global gene expression response of the brain to dietary Se supplementation for 14 days. The experiment used Affymetrix microarrays to compare whole brain RNA from 8 adult zebrafish (Danio rerio) fed a diet with control selenium levels (1.4ppmSe) and 8 fed a diet supplemented with sodium selenite (5.6ppmSe) for 14 days, and with an equal sex ratio within each diet.