ToxSci Advance Access originally published online on November 8, 2006
Toxicological Sciences 2007 95(1):89-97; doi:10.1093/toxsci/kfl142
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Expression Profiling of Heat Stress Effects on Mice Fed Ergot Alkaloids
* Division of Animal Sciences, University of Missouri-Columbia, Columbia, MO 65211
Department of Statistics, University of Missouri-Columbia, Columbia, Missouri 65211
1 To whom correspondence should be addressed at S140A, Animal Science Research Center, Columbia, Missouri, 920 East Campus Drive. Fax: 573-882-6827. E-mail: antonioue{at}missouri.edu.
Received August 31, 2006; accepted October 20, 2006
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Fescue toxicosis affects wild and domestic animals consuming ergot alkaloids contained in tall fescue forage infected with the endophytic fungus, Neotyphodium coenophialum. When animals are consuming infected fescue (E+) forage during periods of elevated ambient temperatures (summer), a range of phenotypic disorders collectively called summer slump is observed. It is characterized by hyperthermia, with an accompanying decrease in feed intake, growth, milk yield, and reproductive fitness. Laboratory mice also exhibit symptoms of fescue toxicosis at thermoneutral (TN) temperature, as indicated by reduced growth rate and reproductive fitness. Our goal was to characterize the differences in gene expression in liver of mice exposed to summer-type heat stress (HS) and E+ when compared to mice fed E+ at TN temperature. Mice were fed E+ diet under HS (34 ± 1°C; n = 13; E+HS) or TN conditions (24 ± 1°C; n = 14; E+TN) for a period of 2 weeks between 47 and 60 days of age. Genes differentially expressed between E+HS versus E+TN were identified using DNA microarrays. Forty-one genes were differentially expressed between treatment groups. Expressions of eight genes were measured using quantitative real-time PCR. Genes coding for phase I detoxification enzymes were upregulated in E+HS mouse liver. This detoxification pathway is known to produce reactive oxidative species. We observed an upregulation of genes involved in the protection against reactive oxidative species. Key genes involved in de novo lipogenesis and lipid transport were also upregulated. Finally, genes involved in DNA damage control and unfolded protein responses were downregulated.
Key Words: microarray; environmental toxicology; gene expression/regulation.
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Intake of ergot alkaloids found in tall fescue grass infected with an endophyte, Neotyphodium coenophialum, produces a detrimental condition known as fescue toxicosis. The endophytic fungus produces ergot alkaloids, mostly ergopeptine alkaloids such as ergovaline (EV), which are responsible for fescue toxicosis. Signs of fescue toxicosis include decreased feed intake, weight gain, and milk production, peripheral vasoconstriction, and rough hair coat (Schmidt and Osborn, 1993
; Thompson and Stuedemann, 1993). Summer slump is a complex disease syndrome that occurs during heat stress (HS) periods, when animals are consuming infected fescue (E+) forage, and is characterized by hyperthermia, with an accompanying decrease in feed intake and growth. Hyperthermia and poor body weight gain from the toxicosis are most severe at the onset of high ambient temperature and increased relative humidity during the spring and summer (Hemken et al., 1981). Rectal temperature and respiration rate also increased in E+ fed heifers and steers under HS conditions but not at cooler temperatures (Hemken et al., 1981). Laboratory mice were used previously as a model for fescue toxicosis because these animals exhibit reduced growth, reproduction, and lactation when fed an E+ diet (Miller et al., 1994; Zavos et al., 1987). Consumption of an E+ diet by mice at TN resulted in changes in expression of genes involved in carbohydrate, cholesterol, and lipid metabolism (Bhusari et al., 2006). The objective of this experiment was to identify hepatic gene expression changes in mice fed an E+ diet under HS condition. In an attempt to understand the interaction between HS and E+ on hepatic gene expression in mouse liver, mice were exposed to TN temperatures or controlled HS while consuming E– or E+ diet. In mammals, the liver plays an important role in detoxification and metabolism of toxins and is a prime target of tissue injury in response to various physiological challenges like HS. Consequently, we use microarray-based expression profiling to study the transcriptional response of mouse liver genes to the ergopeptine alkaloids and HS by comparing E+HS to E+TN mice. |
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Animals.
Mice used in this study were of the outbred ICR strain (Harlan Sprague Dawley, Indianapolis, IN). Pups from 11 litters were weaned at 21 days of age. Thirteen male and 14 female mice were first fed an E– diet for 1 week, then switched to a E+ diet under HS (34 ± 1°C; n = 13; E+HS) or TN conditions (24 ± 1°C; n = 14; E+TN) from 47 to 60 days of age. Endophyte E+ seeds and rodent chow (Formulab Diet # 5008, PMI Feeds, St Louis, MO) were ground to pass through a 1-mm screen and mixed in equal part.
Composition of control and treatment diets was as previously described, and seed EV (the major ergot alkaloid associated with fescue toxicosis; Spiers et al., 2005) levels were measured. Control (E–) seed contained 22 ppb of EV, whereas E+ contained a concentration of 4100 ppb on a dry matter basis as measured by HPLC (detection limit = 50 ppb and CV = 7%; Rottinghaus et al., 1993). Feed and water were provided ad libitum throughout the study. All mice were housed in individual cages with relative humidity maintained at 35–50% and a 12:12 light-dark cycle with lights on at 0700 h. Mice were weighed on days 1, 7, and 14 of the experiment. At the end of the experiment, mice were euthanized with carbon dioxide gas followed by cervical dislocation. Livers were weighed and frozen at – 80°C. The Animal Care and Use Committee, University of Missouri-Columbia, approved all procedures and protocols. Only mice fed the E+ diet under TN or HS conditions were used in the microarray and quantitative PCR experiments.
RNA extraction.
Extraction of RNA was done using the RNAqueous-Midi kit (Ambion Inc., Austin, TX) as described previously by Bhusari et al. (2006). The extracted RNA samples were kept in a – 80°C freezer until used.
Microarray preparation and hybridization.
Microarrays were prepared by printing 1353 oligos, 50 mers in length, representing rat genes expressed in liver, on Pan epoxy glass slides (MWG Biotech AG, Ebersberg, Germany). The microarray protocol, including cDNA synthesis, hybridization and washing, scanning, and data acquisition, was described by Bhusari et al. (2006). Extracted RNA from each of the six (three male and three female) randomly selected E+HS mice and six (three male and three female) E+TN mice treatment groups were individually hybridized to the array with reference RNA (Universal Mouse Reference RNA, Stratagene, La Jolla, CA) in a reference microarray design. In a reference design, each experimental sample is hybridized against a common reference RNA sample (Churchill, 2002). Two or three replicates (arrays) were done per animal, which are done in a dye swap design. The data generated from microarrays were stored in the BioArray Software Environment database (BASE; Saal et al., 2002).
Assessing technical variation due to microarray.
We carried out "self-self" hybridizations for three different samples. For each sample, equal amounts of RNA were labeled with Cy3 and Cy5 fluorescent-dyes and cohybridized on the same array. The mean ± 2 SD fold change was calculated for all the genes on the array (1 ± 1.38). To remove false positives but avoid being too conservative, we decided that genes showing more than ± 1.30 fold changes were considered for differential gene expression.
Statistical analyses of microarray data.
Microarray results were filtered in the BASE database to remove control spots, 3x Standard Saline Citrate, and blank spots. Then the background-corrected median intensities were normalized using external plant control genes using GenePix Pro 4.0.1.12
[EC]
software (Axon Instruments Inc., Union City, CA). The normalized intensities were then inputted into the software package MAANOVA (Wu et al., 2003) to model the data and run statistical analyses. Intensities were first log2 transformed and then a two-stage ANOVA model was applied (Wolfinger et al., 2001). The first stage was the normalization model to remove the effect of array and dye at the across gene level
 |
 |
and r are the residuals from the linear models.
A permutation Fs test (an F test designed specifically for microarray data) (Cui et al., 2005) was run to test the significance of sample effect for each probe. Probes with a permutation Fs test p value less than 0.05 were regarded as significantly differentially expressed across samples. The filtered list was then input into The Institute for Genomic Research multiexperiment viewer software (Saeed et al., 2003) to run hierarchical clustering. Gene ontology (GO) was obtained using DAVID (Dennis et al., 2003) and Entrez-Gene (http://www.ncbi.nih.gov/entrez/query.fcgi?db=gene) from the National Center for Biotechnology Information. The microarray data files on which this paper is based have been deposited with National Center for Biotechnology Information Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/) with series number GSE5642
[NCBI GEO]
.
Quantitative real-time PCR.
Genes for quantitative real-time PCR (qPCR) were chosen based on the gene lists obtained using MAANOVA and the p values of genes. Expression profiles of eight genes were measured with qPCR. From each mouse, 10 µg of total RNA were reverse transcribed using Stratascript RT (Stratagene) with oligo dT and random hexamer primers. Then, 6.25 ng of cDNA were added to a 25-µl PCR reaction to get a final concentration of 0.25 ng/µl of cDNA. Forward and reverse primer final concentrations were 100nM in the SYBR green assay. Forward and reverse primer sequences are shown in Table 1. The reactions were performed using the Brilliant SYBR Green QPCR Master Mix (Stratagene). Primers were designed using Primer Express (Applied Biosystems, Foster City, CA) with an annealing temperature of 60°C and amplification size of less than 150 bp. ß-Actin was chosen as the endogenous control gene in our qPCR experiments. The qPCR was done in an ABI prism 7500 sequence detection system (Applied Biosystems). Relative quantification of gene expression changes was recorded after normalizing for ß-actin expression, computed by using the 
method (user manual #2, ABI Prism 7700 SDS). In the analysis, the threshold cycle (CT) from E+TN mice was used as a calibrator sample. Statistical analyses of the data were performed by comparing E+HSCT with E+TNCT for each gene using a two-tailed t-test with unequal group variance.
|
3') Used in Real-Time PCR (gene accession numbers are listed in |
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Microarray Work
Six E+TN (out of 14) and six E+HS (out of 13) randomly chosen mice were used in a microarray experiment to detect gene expression changes. The analysis identified 41 genes (p
0.05) as differentially expressed between treatment groups (E+TN vs. E+HS). The E+HS resulted in upregulation of 33 genes, while eight genes were downregulated. Lists of differentially expressed genes (p 0.05) are shown in Table 2. Principal component analysis was used to classify mice based on the differentially expressed genes. The mice are divided in two groups. Five of the six E+TN mice clustered together while the last E+TN mouse is closer to the E+HS mice group (Fig. 1). Genes involved in reactive oxygen species (ROS) and antioxidant response (seven genes), lipid metabolism (14 genes), xenobiotic metabolism, and detoxification (11 genes) were identified as differentially expressed in response to E+HS (Table 2).
|
|
qPCR Results
Expressions of eight genes were verified using qPCR in liver samples from 13 E+HS and 14 E+TN mice. These mice include the six E+HS and the six E+TN mice used in the microarray experiment. The qPCR results of seven genes were in agreement with microarray results in terms of magnitude and direction of change (Fig. 2). Six of these seven genes (Lsr, Cyb3r5, Cyp3a25, ApoB, Acly, and Mt1) had concordance in terms of statistical significance using a two-way Student t-test (p < 0.05). For Fmo5, qPCR results showed opposite direction fold change compared to that with the microarray experiment (Fmo5, downregulation in E+HS mice with microarray = 40%, upregulation in E+HS mice with qPCR = 42%, p < 0.05). There are three possible explanations for this discrepancy. The microarray fold change for Fmo5 might be a false positive result, multiple splicing variants of Fmo5 could hybridize the array probe, or multiple genes with similar sequences might cross-hybridized to the oligonucleotide probe on the arrays (the PCR primers for Fmo5 do not hybridize anywhere else in the mouse genome).
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Overrepresented GO Biological Process Terms
The DAVID database (Dennis et al., 2003
) and associated statistical tools were used to identify GO biological terms overrepresented in the list of differentially expressed genes (Table 3). Three groups of biological processes stand out; amine catabolism/nitrogen compound catabolism/amino acid metabolism, electron transport, and lipid biosynthesis/cellular lipid metabolism. The fourth term category, carboxylic acid metabolism, contains genes that are already included in the lipid metabolism and amino acid metabolism groups.
|
Amine Catabolism/Nitrogen Compound Catabolism/Amino Acid Metabolism
The fumarylacetoacetate hydrolase (Fah), dehydratase/dimerization cofactor of hepatocyte nuclear factor 1 alpha 1 (Pcbd1), and the 4-hydroxyphenylpyruvic acid dioxygenase (Hpd) genes are upregulated. These genes are implicated in the catabolism of phenylalanine and tyrosine (Table 2). Formiminotransferase cyclodeaminase is also upregulated and involved in the metabolism of histidine. Arginase 1 (Arg1) is downregulated and participate in the degradation of arginine.
Lipid and Cholesterol Metabolism and Biosynthesis
Numerous genes involved in lipid and cholesterol metabolism are differentially expressed in mice exposed to E+HS. ATP-citrate lyase (Acly) was upregulated in E+HS mice by 228% (qPCR) compared to E+TN mice. This gene codes for a cytosolic enzyme that catalyzes the formation of acetyl-coenzyme A (CoA) and oxaloacetate from citrate and CoA. The acetyl-CoA formed is a key building block in de novo lipogenesis (Beigneux et al., 2004). The gene product of Acly is required for the export of lipid building blocks from mitochondria and for lipid biosynthesis in cytosol.
The fatty acid synthase (Fasn) gene was upregulated in E+HS mice by 48% compared to E+TN mice. The Fasn protein is a central enzyme in de novo lipogenesis in mammals and catalyzes all the reactions for the conversion of acetyl-coA and malonyl-CoA to palmitate. The products of Fasn, palmitate and stearate (C18), serve as substrates for chain elongation to produce very long-chain fatty acids. These fatty acids are important constituents of sphingolipids, ceramides, and glycolipids that are needed for cell division progression and brain structures and neurological functions (Chirala et al., 2003).
Thyroid hormone responsive SPOT14 homolog (S14) was upregulated in E+HS mice by 64%. The Spot 14 gene is mainly expressed in lipogenic tissues such as liver, adipose tissue, and mammary gland and is associated with de novo lipogenesis (Zhu et al., 2005). The Spot 14 protein functions as a transcription factor necessary for the induction of lipogenic enzyme gene expression (Kinlaw et al., 1995).
Expression of the acyl-coA synthetase 1 (Acsl1) gene was upregulated by 58% in E+HS mice (microarray). Acsl1 catalyzes the ATP-dependent acylation of fatty acids into long-chain acyl-coAs and is the first step in lipid metabolism following entry of fatty acid into the cell (Parkes et al., 2006). The Acsl1 gene product is linked to the storage pathway of lipid metabolism in liver and may act to channel fatty acids into triglyceride synthesis rather than into ß-oxidation and energy release (Parkes et al., 2006).
The lipolysis-stimulated receptor (Lsr) gene was upregulated in E+HS mice by 84% (qPCR) compared to E+TN mice. The Lsr gene product is a lipoprotein receptor primarily expressed in the liver and steroidogenic tissues (Mesli et al., 2004). The protein binds lipoproteins containing apoB and apoE (Mesli et al., 2004). Lsr is considered to be involved in a rate-limiting step for the clearance of dietary triglycerides and plays a role in determining their partitioning of lipids between the liver and peripheral tissues (Yen et al., 1999).
Expression of Apolipoprotein H (ApoH), primarily expressed in liver was upregulated in E+HS mice by 88%. About 40% of ApoH has been identified as a constituent of chylomicrons, Very Low-Density Lipoprotein (VLDL), and High-density lipoproteins (HDL). Apolipoprotein H is involved in lipoprotein metabolism (Polz and Kostner, 1979a,b).
Diazepam-binding inhibitor (Dbi), also called acyl-CoA–binding protein (Acbp), was upregulated in E+HS mice by 32%. Acyl-CoA–binding protein is an intracellular lipid-binding protein that selectively binds medium- and long-chain acyl-CoA esters (C14–C22) (Sandberg et al., 2005). It plays an important role in intracellular acyl-CoA transport to the mitochondria and cellular pool formation. Disruption of the Acbp gene in yeast indicates its involvement in the synthesis of very long-chain fatty acids, and it is required for proper protein sorting and vesicular trafficking (Gaigg et al., 2001). Dbi/Acbp is also involved in cholesterol translocation across mitochondrial membranes, a rate-limiting step in the biochemical synthesis of steroids (Swinnen et al., 1998).
Overall, there is upregulation of genes coding for rate-limiting enzymes involved in de novo lipogenesis in E+HS mice (Table 2). Genes involved in transport and partitioning of lipids such as lipolysis-stimulated receptor and acyl-CoA–binding protein (Table 2) were also differentially expressed, which would increase transport of lipids into the liver for downstream processes.
Detoxification Gene Expression Changes (GO term; electron transport)
Expression of cytochrome b5 reductase 3 (Cyb5r3) was upregulated in E+HS mice by 60% (Table 2, Fig. 2). The Cyb5r protein mediates electron transfer from NADH to fatty acid desaturases, P450 oxidases (Hildebrandt and Estabrook, 1971), and plays a direct role in xenobiotic metabolism (Kurian et al., 2004). This gene is also involved in modulating activities of the Cyp17 gene, which is essential to steroidogenesis (Akhtar et al., 2005).
The flavin-containing monooxygenase 5 (Fmo5) gene was upregulated in E+HS mice by 42% (qPCR, Fig. 2, Table 2). Flavin-containing monooxygenases are microsomal enzymes that catalyze the NADPH and oxygen-dependent oxidation of many important drugs and xenobiotics (Ziegler, 2002).
Expression of epoxide hydrolase 2, cytoplasmic (Ephx2) was upregulated in E+HS mice by 40%. Epoxides are a class of compounds that can arise from the cytochrome P450–mediated oxidation of alkenes, aromatic hydrocarbons, and heterocycles. Epoxide hydrolases hydrolyze toxic epoxides into their corresponding diols which are typically less reactive, more water soluble, and more easily excreted from the body (DuTeaux et al., 2004). In a recent study, an E+ diet fed to rats resulted in an increased expression of the epoxide hydrolase 1 gene (Settivari et al., 2006).
Cytochrome P450, family 2, subfamily a, polypeptide 12 (Cyp2a12) and cytochrome P450, family 2, subfamily d, polypeptide 26 (Cyp2d26) genes were upregulated in E+HS mice by 42 and 49%, respectively (Table 2). Cytochrome P450, family 3, subfamily a, polypeptide 25 (Cyp3a25) was downregulated in E+HS mice by 60 (Table 2).
Metabolism of xenobiotic compounds involves biotransformation in two phases: functionalization, which uses oxygen to form a reactive site (phase I detoxification), and conjugation, which results in addition of a water-soluble group to the reactive site (phase II biotransformation) resulting in formation of more water-soluble compounds. The phase I detoxification is performed by monooxygenase enzymes including cytochrome P450s such as the ones differentially expressed in E + HS mice. In a study by Settivari et al. (2006), rats on an E+ diet for 5 days had higher expression of cytochrome P450s genes involved in phase I detoxification, while a downregulation of genes involved in antioxidant pathways was observed. To date, there is little information about the hepatic metabolism and detoxification of ergot alkaloids in livestock. Cytochrome P450, CYP3A has been cited as the main P450 subfamily responsible for the metabolism of ergot alkaloids in other species, with N-dealkylation, mono- and dihydroxylation as the main oxidative processes carried out by these enzymes (Ball et al., 1992; Moubarak and Rosenkrans, 2000). Male mice on an E+ diet had 1.5 times more concentration of total microsomal Cyp 450 than female mice, and this could be a source of potential variation in animal response to fescue toxins (Duringer et al., 2005). Upregulation of Cyp 450 enzymes in E+HS mice (Table 2) would help in effective metabolism and detoxification of fescue toxins. It is interesting to note that mice fed an E+ diet under TN conditions (Bhusari et al., 2006) did not display changes in Cyp 450 gene expression when compared to mice fed E– under TN conditions.
Antioxidant Gene Expression Changes
While enzymatic activity of cytochrome P450s is required for metabolism of xenobiotics, these reactions can lead to production of ROS and oxidative stress. During the course of the P450 catalytic cycle, P450s use H+ from NADPH to reduce O2 leading to the production of H2O2 and superoxide anion radicals (Gonzalez, 2005). Expression of antioxidant gene metallothienin-1 (Mt-1; qPCR; Table 2) was increased by 160% in E+HS mice. This gene is involved in a wide range of activities from heavy metal detoxification to ROS scavenging (Sato and Kondoh, 2002). In many in vitro experiments, Mt-1 has been shown to be a potent scavenger of hydroxyl radicals, protecting DNA from oxidative damage.
Expression of the carbonic anhydrase III gene (Car3; Table 2) was upregulated in E+HS mice by 117%. The mammalian carbonic anhydrase reversibly hydrate carbon dioxide, thus generating both bicarbonate and hydrogen ions for maintenance of pH homeostasis. Two reactive sulfhydryl groups of Car3 can conjugate to glutathione through a disulfide link, a process termed S-glutathionylation. Car3 is rapidly glutathionylated in vivo and in vitro when cells are exposed to oxidative stresses, and it is one of the most carbonylated proteins in rodent liver (Kim et al., 2004). Overexpression of Car3 reduced steady-state levels of intracellular ROS, increased proliferation rate, and protected cells against H2O2-induced apoptosis (Raisanen et al., 1999).
Expression of copper chaperone for superoxide dismutase (Ccs) was upregulated in E+HS mice by 51% (Table 2). The Ccs protein interacts with superoxide dismutase 1 (Sod1) and is responsible for copper incorporation into Sod1, which plays an important role in antioxidant metabolism (Wong et al., 2000). In mice with targeted disruption of the Ccs gene, SOD1 enzyme activity is reduced, and these mice had increased sensitivity to paraquat-induced oxidative stress (Wong et al., 2000).
Glutaredoxin 1 (Glrx1) was downregulated in E+HS mice by 45%. Glutaredoxin proteins are low-molecular weight proteins (9–12 kDa) with GSH-disulfide oxidoreductase activity. Glutaredoxins coupled to glutathione reductase are key players in antioxidant cellular processes based on the transfer of reducing equivalents from NADPH to disulfides via GSH (Porras et al., 2002). Cellular Glrx1 activity can be affected both directly (inactivation/inhibition) and indirectly by depletion of the second substrate, GSH, which occurs during oxidative stress and leads to accumulation of protein mixed disulfides (protein-SSG) that could trigger apoptosis (Chrestensen et al., 2000).
The significant upregulation of antioxidant gene expression (Table 2) could be aimed at counteracting the ROS and the resulting oxidative stress produced in the E+HS mice.
|
CONCLUSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Genes coding for phase I detoxification enzymes are upregulated in E+HS mouse liver. We observed an upregulation of genes involved in the protection against reactive oxidant species, most probably to cope with the increase production of ROS from the phase I detoxification pathways. However, the most interesting result is that key genes involved in de novo lipogenesis and lipid transport are upregulated. This is likely to have major consequence on hormone synthesis (steroids), circulating lipid concentrations, and cellular lipid composition.
When mice fed an E+ diet at TN condition were compared to mice fed a E– diet, genes involved in the phase I detoxification pathways or in the de novo lipid synthesis were not differentially expressed (Bhusari et al., 2006). Thus, it seems that the combined effect of HS and E+ diet is to upregulate these pathways. This might explain why this dual challenge (chromic HS plus ergot alkaloids) is more likely to decrease the overall health of the animals than exposure to ergot alkaloids alone (Hemken et al., 1981).
|
ACKNOWLEDGMENTS |
|---|
We would like to thank Henry Mesa and Kristi Cammack for assistance with mice work and tissue harvesting. Work presented in this report was supported, in part, by the Missouri Agriculture Experiment Station and Animal Health project number MO-ASAH0607. In addition, this material is based upon work that was partially supported by the U.S. Department of Agriculture, under agreement No. 6227-31230-004-I5S. Any opinions, findings, conclusion, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONCLUSIONREFERENCES |
|---|
Akhtar MK, Kelly SL, Kaderbhai MA. (2005) Cytochrome b5 modulation of 17{alpha} hydroxylase and 17–20 lyase (CYP17) activities in steroidogenesis. J. Endocrinol. 187:267–274.
Ball S, Maurer G, Zollinger M, Ladona M, Vickers A. (1992) Characterization of the cytochrome P-450 gene family responsible for the N-dealkylation of the ergot alkaloid CQA 206–291 in humans. Drug Metab. Dispos. 20:56–63.[Abstract]
Beigneux AP, Kosinski C, Gavino B, Horton JD, Skarnes WC, Young SG. (2004) ATP-citrate lyase deficiency in the mouse. J. Biol. Chem. 279:9557–9564.
Bhusari S, Hearne LB, Spiers DA, Lamberson WR, Antoniou E. (2006) Effect of fescue toxicosis on hepatic gene expression in mice. J. Anim. Sci. 84:1600–1612.
Chirala SS, Chang H, Matzuk M, Abu-Elheiga L, Mao J, Mahon K, Finegold M, Wakil SJ. (2003) Fatty acid synthesis is essential in embryonic development: Fatty acid synthase null mutants and most of the heterozygotes die in utero. Proc. Natl. Acad. Sci. U.S.A. 100:6358–6363.
Chrestensen CA, Starke DW, Mieyal JJ. (2000) Acute cadmium exposure inactivates thioltransferase (Glutaredoxin), inhibits intracellular reduction of protein-glutathionyl-mixed disulfides, and initiates apoptosis. J. Biol. Chem. 275:26556–26565.
Churchill GA. (2002) Fundamentals of experimental design for cDNA microarrays. Nat. Genet. 32:490–495.
Cui X, Hwang JTG, Qiu J, Blades NJ, Churchill GA. (2005) Improved statistical tests for differential gene expression by shrinking variance components estimates. Biostatistics 6:59–75.[Abstract]
Dennis G, Sherman B, Hosack D, Yang J, Gao W, Lane HC, Lempicki R. (2003) DAVID: Database for Annotation, Visualization, and Integrated Discovery. Genome Biol. 4:P3.[CrossRef][Medline]
Duringer JM, Lewis R, Kuehn L, Fleischmann T, Craig AM. (2005) Growth and hepatic in vitro metabolism of ergotamine in mice divergently selected for response to endophyte toxicity. Xenobiotica 35:531–548.[CrossRef][Web of Science][Medline]
DuTeaux SB, Newman JW, Morisseau C, Fairbairn EA, Jelks K, Hammock BD, Miller MG. (2004) Epoxide hydrolases in the rat epididymis: Possible roles in xenobiotic and endogenous fatty acid metabolism. Toxicol. Sci. 78:187–195.
Gaigg B, Neergaard TBF, Schneiter R, Hansen JK, Fargeman NJ, Jensen NA, Andersen JR, Friis J, Sandhoff R, Schroder HD, et al. (2001) Depletion of acyl-coenzyme A-binding protein affects sphingolipid synthesis and causes vesicle accumulation and membrane defects in Saccharomyces cerevisiae. Mol. Biol. Cell 12:1147–1160.
Gonzalez FJ. (2005) Role of cytochromes P450 in chemical toxicity and oxidative stress: Studies with CYP2E1. Mutat. Res 569:101–110.[Web of Science][Medline]
Hemken RW, Boling JA, Bull LS, Hatton RH, Buckner RC, Bush LP. (1981) Interaction of environmental temperature and anti-quality factors on the severity of summer fescue toxicosis. J. Anim. Sci. 52:710–714.
Hildebrandt A and Estabrook RW. (1971) Evidence for the participation of cytochrome b 5 in hepatic microsomal mixed-function oxidation reactions. Arch. Biochem. Biophys. 143:66–79.[CrossRef][Web of Science][Medline]
Kim G, Lee T-H, Wetzel P, Geers C, Robinson MA, Myers TG, Owens JW, Wehr NB, Eckhaus MW, Gros G, et al. (2004) Carbonic anhydrase III is not required in the mouse for normal growth, development, and life span. Mol. Cell. Biol. 24:9942–9947.
Kinlaw WB, Church JL, Harmon J, Mariash CN. (1995) Direct evidence for a role of the "spot 14" protein in the regulation of lipid synthesis. J. Biol. Chem. 270:16615–16618.
Kurian JR, Bajad SU, Miller JL, Chin NA, Trepanier LA. (2004) NADH cytochrome b5 reductase and cytochrome b5 catalyze the microsomal reduction of xenobiotic hydroxylamines and amidoximes in humans. J. Pharmacol. Exp. Ther. 311:1171–1178.
Mesli S, Javorschi S, Berard AM, Landry M, Priddle H, Kivlichan D, Smith AJH, Yen FT, Bihain BE, Darmon M. (2004) Distribution of the lipolysis stimulated receptor in adult and embryonic murine tissues and lethality of LSR–/– embryos at 12.5 to 14.5 days of gestation. Eur. J. Biochem. 271:3103–3114.[Web of Science][Medline]
Miller BF, Armstrong KL, Wilson LA, Hohenboken WD, Saacke RG. (1994) Variation among inbred and linecross mice in response to fescue toxicosis. J. Anim. Sci. 72:2896–2904.[Abstract]
Moubarak AS and Rosenkrans CF Jr. (2000) Hepatic metabolism of ergot alkaloids in beef cattle by cytochrome p450. Biochem. Biophys. Res. Commun. 274:746–749.[CrossRef][Web of Science][Medline]
Parkes HA, Preston E, Wilks D, Ballesteros M, Carpenter L, Wood L, Kraegen EW, Furler S, Cooney GJ. (2006) Over-expression of Acyl-CoA Synthetase-1 increases lipid deposition in hepatic (HepG2) cells and rodent liver in vivo. Am. J. Physiol. Endocrinol. Metab 291:737–744.
Polz E and Kostner GM. (1979a) Binding of [beta]2-glycoprotein-I to Intralipid: Determination of the dissociation constant. Biochem. Biophys. Res. Commun. 90:1305–1312.[Web of Science][Medline]
Polz E and Kostner GM. (1979b) The binding of [beta]2-glycoprotein-I to human serum lipoproteins: Distribution among density fractions. FEBS Lett. 102:183–186.[CrossRef][Web of Science][Medline]
Porras P, Pedrajas JR, Martinez-Galisteo E, Alicia Padilla C, Johansson C, Holmgren A, Antonio Barcena J. (2002) Glutaredoxins catalyze the reduction of glutathione by dihydrolipoamide with high efficiency. Biochem. Biophys. Res. Commun. 295:1046–1051.[CrossRef][Web of Science][Medline]
Raisanen S, Lehenkari P, Tasanen M, Rahikila P, Harkonen PL, Vaananen HK. (1999) Carbonic anhydrase III protects cells from hydrogen peroxide-induced apoptosis. FASEB J. 13:513–522.
Rottinghaus GE, Schultz LM, Ross PF, Hill NS. (1993) An HPLC method for the detection of ergot in ground and pelleted feeds. J. Vet. Diagn. Invest. 5:242–247.
Saal L, Troein C, Vallon-Christersson J, Gruvberger S, Borg A, Peterson C. (2002) BioArray Software Environment (BASE): A platform for comprehensive management and analysis of microarray data. Genome Biol. 3: software0003.1–software0003.6.
Saeed AI, Sharov V, White J, Li J, Liang W, Bhagabati N, Braisted J, Klapa M, Currier T, Thiagarajan M, et al. (2003) TM4: A free, open-source system for microarray data management and analysis. Biotechniques 34:374–378.[Web of Science][Medline]
Sandberg MB, Bloksgaard M, Duran-Sandoval D, Duval C, Staels B, Mandrup S. (2005) The gene encoding Acyl-CoA-binding protein is subject to metabolic regulation by both sterol regulatory element-binding protein and peroxisome proliferator-activated receptor {alpha} in hepatocytes. J. Biol. Chem. 280:5258–5266.
Sato M and Kondoh M. (2002) Recent studies on metallothionein: Protection against toxicity of heavy metals and oxygen free radicals. Tohoku J. Exp. Med. 196:9–22.[CrossRef][Web of Science][Medline]
Schmidt SP and Osborn TG. (1993) Effects of endophyte-infected tall fescue on animal performance. Agric. Ecosyst. Environ 44:233–262.
Settivari RS, Bhusari S, Evans T, Eichen PA, Hearne LB, Antoniou E, Spiers DE. (2006) Genomic analysis of the impact of fescue toxicosis on hepatic function. J. Anim. Sci. 84:1279–1294.
Spiers DE, Eichen PA, Rottinghaus GE. (2005) A model of fescue toxicosis: Responses of rats to intake of endophyte-infected tall fescue. J. Anim. Sci. 83:1423–1434.
Swinnen JV, Alen P, Heyns W, Verhoeven G. (1998) Identification of Diazepam-binding inhibitor/Acyl-CoA-binding protein as a sterol regulatory element-binding protein-responsive gene. J. Biol. Chem. 273:19938–19944.
Thompson FN and Stuedemann JA. (1993) Pathophysiology of fescue toxicosis. Agric. Ecosyst. Environ. 44:263–281.[CrossRef]
Wolfinger RD, Gibson G, Wolfinger ED, Bennett L, Hamadeh H, Bushel P, Afshari C, Paules RS. (2001) Assessing gene significance from cDNA microarray expression data via mixed models. J. Comput. Biol. 8:625–637.[CrossRef][Web of Science][Medline]
Wong PC, Waggoner D, Subramaniam JR, Tessarollo L, Bartnikas TB, Culotta VC, Price DL, Rothstein J, Gitlin JD. (2000) Copper chaperone for superoxide dismutase is essential to activate mammalian Cu/Zn superoxide dismutase. Proc. Natl. Acad. Sci. U.S.A. 97:2886–2891.
Wu H, Kerr K, Churchill G. (2003) MAANOVA: A Software Package for the Analysis of Spotted cDNA Microarray Experiments. In the Analysis of Gene Expression Data: An Overview of Methods and Software(Springer, New York) pp. 313–431.
Yen FT, Masson M, Clossais-Besnard N, Andre P, Grosset J-M, Bougueleret L, Dumas J-B, Guerassimenko O, Bihain BE. (1999) Molecular cloning of a lipolysis-stimulated remnant receptor expressed in the liver. J. Biol. Chem. 274:13390–13398.
Zavos PM, Varney DR, Jackson JA, Siegel MR, Bush LP, Hemken RW. (1987) Effect of feeding fungal endophyte (Acremonium Coenophialum)- infected tall fescue seed on reproductive performance in CD-1 mice through continuous breeding. Theriogenology 27:549–559.[CrossRef][Web of Science][Medline]
Zhu Q, Anderson GW, Mucha GT, Parks EJ, Metkowski JK, Mariash CN. (2005) The spot 14 protein is required for de novo lipid synthesis in the lactating mammary gland. Endocrinology 146:3343–3350.
Ziegler DM. (2002) An overview of the mechanism, substrate specificities, and structure of FMOs. Drug Metab. Rev. 34:503–511.[CrossRef][Web of Science][Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R. S. Settivari, T. J. Evans, L. P. Yarru, P. A. Eichen, P. Sutovsky, G. E. Rottinghaus, E. Antoniou, and D. E. Spiers Effects of short-term heat stress on endophytic ergot alkaloid-induced alterations in rat hepatic gene expression J Anim Sci, October 1, 2009; 87(10): 3142 - 3155. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||