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Liver gene transcription during energy balance perturbations in C57/BL/J6 mice.

ABSTRACT: A control group consisting of nine C57/BL/6J mice was maintained on a normal diet consisting of Purina Rodent Chow (Harlan Teklad, catalog #5008, 6.5% fat, 49% carbohydrate, 23% protein, 3.5 kcal/ g). The experimental group consisted of nine mice grown on a specialty high-fat diet (Harlan Teklad, catalog #TD88137, 42.16% fat, 42.81% carbohydrate, 15.02% protein, 4.53 kcal/ g). Mice were maintained for ten weeks on their respective diets in a controlled environment with standard light and feeding schedule. Two days before tissue harvest, the experimental group on the high-fat diet was divided into one group of five and one group of four mice. The first group continued on the high-fat diet for the final two days, while the second group fasted. Mouse weights were recorded two days prior, and the day of tissue harvest. At the end of the fasting period liver tissue samples were harvested from each mouse. RNA was purified from the liver tissue samples. Each tissue was homogenized in 1 mL of STAT-60 (Tel-Test, Inc., Friendswood, TX) and the homogenate was mixed with 200 uL of chloroform. The aqueous phase was removed, and mixed with 500 uL of isopropanol to precipitate the RNA. The resulting RNA pellet was washed with 500 uL of 70% ethanol and allowed to air dry. The pellet was dissolved in RNase free water (Ambion, TX), quantified by UV spectroscopy, and stored at -80C. Total RNA control samples (Universal Mouse Reference RNA, catalog # 740100, Stratagene) were labeled using Cy3 dCTP (Perkin-Elmer), and liver total RNA experimental samples were labeled using Cy5 dCTP (Perkin-Elmer) during reverse transcription. For reverse transcription 10 ug of total RNA was mixed with 2 uL of 10X Cy-labeled dCTP, 2 uL of 100 mM DTT (Invitrogen), 4 uL of 5X First Strand Buffer (Invitrogen), 2 uL of a dNTP mixture containing 5 mM dGTP, dATP, dTTP and 2 mM dCTP (Invitrogen), 2 uL of 0.5 mg/ mL oligo-dT18-20 (Invitrogen), and 2 uL of Superscript II reverse transcriptase (Invitrogen). The control RNA samples were additionally mixed with 2 uL of random hexamers. The reaction mixtures were incubated at 42 C for two hours. After the reverse transcription reactions, the RNA templates were degraded by addition of 2 uL of 1 N NaOH and incubation at 65 C for 10 minutes. The alkaline conditions were neutralized by addition of 2 uL of 1 N HCl. Liver cDNA samples were then mixed with a control cDNA sample, and the mixtures were cleaned using a QIAquick Nucleotide Removal kit (Qiagen) as described by the manufacturer's instructions. The cleaned samples were concentrated in a speed vacufuge (Eppendorf) for 20 minutes at 65 C, and were dissolved in 32 uL of prewarmed hybridization buffer (Clontech Laboratories), quantified, and hybridized to prepared oligonucleotide microarrays. Hybridization occurred overnight at 55 C using Corning hybridization chambers. The following day the arrays were washed in Glass Hybridization Wash Solution (Clontech Laboratories), then in 1X SSC, and finally in 0.1X SSC. The arrays were dried by centrifugation and scanned using a GenePix 4000B scanner (Axon Instruments). The resulting data was downloaded and formatted in Excel (Microsoft), and analyzed using Matlab (The MathWorks, Inc.). Microarrays were prepared using GAPS glass slides (Corning), and a Virtek arrayer (Bio-Rad). Arrays contained 16,847 features, printed from a synthesized oligonucleotide mouse library (Operon). The library was suspended in 3X SSC, centrifuged, and loaded into the arrayer. Arrays were printed at approximately 50% humidity. Once printed, the probes were crosslinked using a UV Stratalinker (Stratagene). The slides were then blocked for 15 minutes in a 250 mL mixture containing 15.7 g/ L succinic anhydride (Fluka AG), 239 mL 1-methyl-2-pyrrolidinone (EM Science), and 10.7 mL of 1 M boric acid (Fisher), pH 8.0. They were cleaned by rinsing twice in 250 mL of milli-Q water, followed by 250 mL of 95% ethanol (Pharmco Products). After blocking, they were dried using filtered air and stored in the dark at room temperature. In this experiment the gene expression data of the control mice is given by samples GSM6592, GSM6593, GSM6594, and GSM6595. The gene expression data of the high-fat mice is given by samples GSM6599, GSM6600, GSM6601, and GSM6602. The gene expression data of the fasted mice is given by samples GSM6596, GSM6597, and GSM6598. Keywords = mouse, liver, energy homeostasis, gene expression, microarrays Keywords: repeat sample

ORGANISM(S): Mus musculus

PROVIDER: GSE432 | GEO | 2003/05/16

SECONDARY ACCESSION(S): PRJNA85007

REPOSITORIES: GEO

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Project description:A mouse hepatoma cell line (Hepa1-6 cells, ATCC) was grown in T-25 tissue culture flasks (Corning) at 37ºC in 5% CO2 under two conditions. The first condition was the control, which contained DMEM medium (Gibco BRL) with 25 mM glucose, 4 mM glutamine, 1% penicillin-streptomycin (Sigma), and 10% CPSR-3 (Sigma). The second condition was identical to the first, however the glutamine concentration was altered periodically. Once the cells had grown to confluency, the experiment began at 9:30 PM by exchanging the medium in all flasks. The control flasks received the same medium, containing 4 mM glutamine, while the experimental flasks received identical medium with no glutamine. Twenty-four hours later, the medium was exchanged again, however this time all flasks received medium containing 4 mM glutamine. The first medium exchange was repeated at 48 hours into the experiment, while the second was repeated at 72 hours into the experiment. Hence the glutamine concentration of the experimental flasks oscillated between 0 mM and 4 mM glutamine over 96 hours, while the glutamine concentration of the control flasks remained constant at 4 mM glutamine. At regular intervals, the flasks were sampled. Total RNA was isolated, medium samples were retained, and isotopic measurements were performed from flasks fed different labelled compounds. All samples taken during the experiment were analyzed. The total RNA harvested was labeled and hybridized to DNA microarrays to measure the abundance of transcripts present. Total RNA control samples were labeled using Cy3 dCTP (Perkin-Elmer), and total RNA experimental samples were labeled using Cy5 dCTP (Perkin-Elmer) during reverse transcription. For reverse transcription 10 ug of total RNA was aliquoted into a 6 uL volume. If concentration of the RNA was necessary, this was conducted using a speed vacufuge (Eppendorf) at 60ºC for 10 minutes. The RNA sample was then mixed with 2 uL of 10X Cy-labeled dCTP, 2 uL of 100 mM DTT (Invitrogen), 4 uL of 5X First Strand Buffer (Invitrogen), 2 uL of a dNTP mixture containing 5 mM dGTP, dATP, dTTP and 2 mM dCTP (Invitrogen), 2 uL of 0.5 mg/ mL oligo-dT18-20 (Invitrogen), and 2 uL of Superscript II reverse transcriptase (Invitrogen). This reaction mixture was incubated at 42ºC for approximately two hours. Following the reverse transcription reaction, the RNA template was degraded by addition of 2 uL of 1 N NaOH and incubation at 65 ºC for 10 minutes. The alkaline conditions were then neutralized by addition of 2 uL of 1 N HCl. Samples from identical time points that were to be compared on DNA microarrays were then mixed. The combined sample was cleaned to remove extra primers and nucleotides using a QIAquick Nucleotide Removal kit as described by the manufacturer's instructions. Once cleaned, the sample was concentrated using a speed vacufuge (Eppendorf) for 20 minutes at 65ºC. Following concentration, the sample was resuspended in 32 uL of prewarmed hybridization buffer (Clontech Laboratories), 1 uL was removed for quantitation, and hybridized to prepared oligonucleotide microarrays. Hybridization occurred overnight at 55 ºC using Corning hybridization chambers. The following day the arrays were washed in Glass Hybridization Wash Solution (Clontech Laboratories), and then in 1X SSC, and finally 0.1X SSC. Each wash step was conducted for 20 minutes under high agitation. The arrays were dried by centrifugation and scanned using GenePix 4000B scanner (Axon Instruments). The resulting data was downloaded and formatted in Excel (Microsoft), and then analyzed using Matlab (The MathWorks, Inc.). The arrays used for hybridization were prepared using GAPS glass slides (Corning), and a Virtek arrayer (Bio-Rad). These arrays contained 17,280 features, printed from a synthesized oligonucleotide mouse library (Operon). Briefly, the library was resuspended in 3X SSC, centrifuged, and loaded into the arrayer. Arrays were printed using 32 pins (Telechem), at approximately 50% humidity. Once printed, the probes were crosslinked to the glass slides using a UV Stratalinker (Stratagene). The slides were then blocked for 15 minutes in a 250 mL mixture containing 15.7 g/ L succinic anhydride, 239 mL 1-methyl-2-pyrrolidinone, and 10.7 mL of 1 M boric acid, pH 8.0. They were cleaned by rinsing in 250 mL of milli-Q water (X2), followed by 250 mL of 95% ethanol. They were finally dried using filtered air and stored in the dark at room temperature. Keywords = mouse, liver, hepatoma, cell culture, glutamine, carbon metabolism Keywords: time-course

Project description:A mouse hepatoma cell line (Hepa1-6 cells, ATCC) was grown in T-25 tissue culture flasks (Corning) at 37ÂºC in 5% CO2 under two conditions. The first condition was the control, which contained DMEM medium (Gibco BRL) with 25 mM glucose, 4 mM glutamine, 1% penicillin-streptomycin (Sigma), and 10% CPSR-3 (Sigma). The second condition was identical to the first, however the glutamine concentration was altered periodically. Once the cells had grown to confluency, the experiment began at 9:30 PM by exchanging the medium in all flasks. The control flasks received the same medium, containing 4 mM glutamine, while the experimental flasks received identical medium with no glutamine. Twenty-four hours later, the medium was exchanged again, however this time all flasks received medium containing 4 mM glutamine. The first medium exchange was repeated at 48 hours into the experiment, while the second was repeated at 72 hours into the experiment. Hence the glutamine concentration of the experimental flasks oscillated between 0 mM and 4 mM glutamine over 96 hours, while the glutamine concentration of the control flasks remained constant at 4 mM glutamine. At regular intervals, the flasks were sampled. Total RNA was isolated, medium samples were retained, and isotopic measurements were performed from flasks fed different labelled compounds. All samples taken during the experiment were analyzed. The total RNA harvested was labeled and hybridized to DNA microarrays to measure the abundance of transcripts present. Total RNA control samples were labeled using Cy3 dCTP (Perkin-Elmer), and total RNA experimental samples were labeled using Cy5 dCTP (Perkin-Elmer) during reverse transcription. For reverse transcription 10 ug of total RNA was aliquoted into a 6 uL volume. If concentration of the RNA was necessary, this was conducted using a speed vacufuge (Eppendorf) at 60ÂºC for 10 minutes. The RNA sample was then mixed with 2 uL of 10X Cy-labeled dCTP, 2 uL of 100 mM DTT (Invitrogen), 4 uL of 5X First Strand Buffer (Invitrogen), 2 uL of a dNTP mixture containing 5 mM dGTP, dATP, dTTP and 2 mM dCTP (Invitrogen), 2 uL of 0.5 mg/ mL oligo-dT18-20 (Invitrogen), and 2 uL of Superscript II reverse transcriptase (Invitrogen). This reaction mixture was incubated at 42ÂºC for approximately two hours. Following the reverse transcription reaction, the RNA template was degraded by addition of 2 uL of 1 N NaOH and incubation at 65 ÂºC for 10 minutes. The alkaline conditions were then neutralized by addition of 2 uL of 1 N HCl. Samples from identical time points that were to be compared on DNA microarrays were then mixed. The combined sample was cleaned to remove extra primers and nucleotides using a QIAquick Nucleotide Removal kit as described by the manufacturer's instructions. Once cleaned, the sample was concentrated using a speed vacufuge (Eppendorf) for 20 minutes at 65ÂºC. Following concentration, the sample was resuspended in 32 uL of prewarmed hybridization buffer (Clontech Laboratories), 1 uL was removed for quantitation, and hybridized to prepared oligonucleotide microarrays. Hybridization occurred overnight at 55 ÂºC using Corning hybridization chambers. The following day the arrays were washed in Glass Hybridization Wash Solution (Clontech Laboratories), and then in 1X SSC, and finally 0.1X SSC. Each wash step was conducted for 20 minutes under high agitation. The arrays were dried by centrifugation and scanned using GenePix 4000B scanner (Axon Instruments). The resulting data was downloaded and formatted in Excel (Microsoft), and then analyzed using Matlab (The MathWorks, Inc.). The arrays used for hybridization were prepared using GAPS glass slides (Corning), and a Virtek arrayer (Bio-Rad). These arrays contained 17,280 features, printed from a synthesized oligonucleotide mouse library (Operon). Briefly, the library was resuspended in 3X SSC, centrifuged, and loaded into the arrayer. Arrays were printed using 32 pins (Telechem), at approximately 50% humidity. Once printed, the probes were crosslinked to the glass slides using a UV Stratalinker (Stratagene). The slides were then blocked for 15 minutes in a 250 mL mixture containing 15.7 g/ L succinic anhydride, 239 mL 1-methyl-2-pyrrolidinone, and 10.7 mL of 1 M boric acid, pH 8.0. They were cleaned by rinsing in 250 mL of milli-Q water (X2), followed by 250 mL of 95% ethanol. They were finally dried using filtered air and stored in the dark at room temperature. Keywords = mouse, liver, hepatoma, cell culture, glutamine, carbon metabolism

Project description:MicroPoly(A)Pure kits (Ambion) were used to prepare mRNA from P. salmonis-infected and control Atlantic salmon head kidney. Head kidney mRNA samples were prepared from pooled (n = 10) infected or control kidney. Approximately 200 ng of infected or control head kidney mRNA was used as template in aRNA synthesis reactions. Two infected head kidney samples were pooled to yield 8.9 ug of aRNA, and a single control head kidney sample contained 8.4 ug of aRNA. Infected and control head kidney aRNA samples were visualized on agarose gels to check quality and quantity (data not shown). Except for the amounts of aRNA and reverse transcription (RT) primer used, head kidney target labeling reactions and microarray hybridizations were identical. Head kidney target syntheses used 2 ug of aRNA and 2 ug of random primers (Roche). RT primers were mixed with aRNA samples, and nuclease-free H2O (Invitrogen) was added to make 10 ul total volume. Samples were incubated at 70 degrees C for 4 min, then placed on ice. RT reactions included 50 mM Tris HCl pH 8.3, 75 mM KCl, 3 mM MgCl2, 10 mM DTT, 0.5 mM each dATP, dCTP, and dGTP, 0.2 mM dTTP, 0.05 mM Cy3-dUTP or Cy5-dUTP (Amersham), 40U RNAguard ribonuclease inhibitor (Amersham), and 400U Superscript II Rnase H- reverse transcriptase (Invitrogen). RT reactions were incubated at 42 degrees C for 2.5 h, followed by addition of 0.025U RNase A (Sigma) and 1.5U RNase H (New England BioLabs) and incubation at 37 degrees C for 30 min. Labeled targets were cleaned using the Qiaquick PCR purification kit (Qiagen) and precipitated, with 300 mM sodium acetate, 1 ul of 20 ug/ul glycogen (Invitrogen), and 2.5 volumes of 100% ethanol, at -20 degrees C overnight. Each labeled target was recovered by centrifugation (14,000 rpm, 4 degrees C, 1 h), washed in 70% ethanol, air-dried, and resuspended in 60 ul of hybridization buffer: 50% deionized formamide, 5X SSC, 0.1% SDS, 5 ul of 5 ug/ul oligo dT (5’T18[Q-N]3’), 5 ul of 2 ug/ul BSA (Pierce), and 2 ul of 10 ug/ul sonicated human placental DNA (Sigma). Targets were incubated at 96 degrees C for 3 min, and then at 65 degrees C until applied to microarrays. Microarrays were prepared for hybridization by washing 2 X 5 min in 0.1% SDS, washing 5 X 1 min in MilliQ H2O, immersing 3 min in 95 degrees C MilliQ H2O, and drying by centrifugation (2000 rpm, 5 min, in 50 ml conical tube). Microarray hybridizations were run in the dark under HybriSlips hybridization covers (Grace Biolabs) in slide hybridization chambers (Corning) submerged in a 45 degrees C water bath for 16 h. Coverslips were floated off in 45 degrees C (1X SSC, 0.2% SDS), and arrays were washed 1 X 10 min in 45 degrees C (1X SSC, 0.2% SDS), 3 X 4 min in room temperature (0.1X SSC, 0.1% SDS), and 4 X 4 min in room temperature 0.1X SSC. Slides were dried by centrifugation as before. Fluorescent images of hybridized arrays were acquired immediately at 10 um resolution using ScanArray Express (PerkinElmer). The Cy3 and Cy5 cyanine fluors were excited at 543 nm and 633 nm respectively, and the same laser power (90%) and photomultiplier tube (PMT) settings were used for all slides in a study (PMT 75 Cy3, PMT 63 or 64 Cy5 for head kidney study). Fluorescent intensity data were extracted from TIF images using Imagene 5.5 software (Biodiscovery). Keywords: other

Project description:MicroPoly(A)Pure kits (Ambion) were used to prepare mRNA from P. salmonis-infected and control Atlantic salmon macrophages. Infected and control (24 h incubation) macrophage mRNA samples were subjected to two rounds of amplification using the MessageAmp aRNA kit (Ambion) and manufacturer's instructions. Approximately 400 ng of macrophage mRNA was used as template in the first round of amplification, yielding 8.1 ug of infected macrophage aRNA and 7.8 ug of control macrophage aRNA. Approximately 1 ug of first-round macrophage aRNA was used as template in the second round of amplification, yielding 81.2 ug of infected macrophage aRNA and 83.3 ug of control macrophage aRNA. Infected and control macrophage aRNA samples were visualized on agarose gels to check quality and quantity. Except for the amounts of aRNA and reverse transcription (RT) primer used, macrophage target labeling reactions and microarray hybridizations were identical. Macrophage target syntheses used 5 ug of second-round aRNA and 5 ug of random primers (Roche). RT primers were mixed with aRNA samples, and nuclease-free H2O (Invitrogen) was added to make 10 ul total volume. Samples were incubated at 70 degrees C 4 min, then placed on ice. RT reactions included 50 mM Tris HCl pH 8.3, 75 mM KCl, 3 mM MgCl2, 10 mM DTT, 0.5 mM each dATP, dCTP, and dGTP, 0.2 mM dTTP, 0.05 mM Cy3-dUTP or Cy5-dUTP (Amersham), 40U RNAguard ribonuclease inhibitor (Amersham), and 400U Superscript II Rnase H- reverse transcriptase (Invitrogen). RT reactions were incubated at 42 degrees C for 2.5 h, followed by addition of 0.025U RNase A (Sigma) and 1.5U RNase H (New England BioLabs) and incubation at 37 degrees C for 30 min. Labeled targets were cleaned using the Qiaquick PCR purification kit (Qiagen) and precipitated, with 300 mM sodium acetate, 1 ul of 20 ug/ul glycogen (Invitrogen), and 2.5 volumes of 100% ethanol, at -20 degrees C overnight. Each labeled target was recovered by centrifugation (14,000 rpm, 4 degrees C, 1 h), washed in 70% ethanol, air-dried, and resuspended in 60 ul of hybridization buffer: 50% deionized formamide, 5X SSC, 0.1% SDS, 5 ul of 5 ug/ul oligo dT (5'T18[Q-N]3'), 5 ul of 2 ug/ul BSA (Pierce), and 2 ul of 10 ug/ul sonicated human placental DNA (Sigma). Targets were incubated at 96 degrees C for 3 min, and then at 65 degrees C until applied to microarrays. Microarrays were prepared for hybridization by washing 2 X 5 min in 0.1% SDS, washing 5 X 1 min in MilliQ H2O, immersing 3 min in 95 degrees C MilliQ H2O, and drying by centrifugation (2000 rpm, 5 min, in 50 ml conical tube). Microarray hybridizations were run in the dark under HybriSlips hybridization covers (Grace Biolabs) in slide hybridization chambers (Corning) submerged in a 45 degrees C water bath for 16 h. Coverslips were floated off in 45 degrees C (1X SSC, 0.2% SDS), and arrays were washed 1 X 10 min in 45 degrees C (1X SSC, 0.2% SDS), 3 X 4 min in room temperature (0.1X SSC, 0.1% SDS), and 4 X 4 min in room temperature 0.1X SSC. Slides were dried by centrifugation as before. Fluorescent images of hybridized arrays were acquired immediately at 10 um resolution using ScanArray Express (PerkinElmer). The Cy3 and Cy5 cyanine fluors were excited at 543 nm and 633 nm respectively, and the same laser power (90%) and photomultiplier tube (PMT) settings were used for all slides in a study (PMT 72 Cy3, PMT 63 or 64 Cy5 for macrophage study). Fluorescent intensity data were extracted from TIF images using Imagene 5.5 software (Biodiscovery). Keywords: other

Project description:Examination of molecular basis of malaria resistance. Spleens from malaria resistant AcB55 and AcB61strains compared with A/J mice. Animals were sacrificed and spleens were rapidly frozen in liquid nitrogen, and subsequently stored at 80oC. Tissues were mechanically homogenized with a polytron and total cellular RNA was extracted using a commercially available reagent (TMTRIzol; Invitrogen). The poly-(A)+ fraction of the RNA was isolated by chromatography with oligo d(T) cellulose beads. For cDNA labeling, either 25 mg of total RNA or 2.5 mg of poly-(A) RNA was converted into cDNA using reverse transcriptase (RT; Super Script II, Invitrogen) and alternatively Cy5 or Cy3-labeled dCTP (1mM, Perkin Elmer-Cetus/NEN, Boston) in a reaction mixture containing 1.5 mL oligo (dT) (100pmol/ mL), 3 mL dNTP-dCTP (6.67mM each), 1 mL dCTP (2mM), 4 mL DTT (100mM), 8 mL 5 X RT Buffer (Invitrogen, California). The reactions were carried out at 42¼C for 3 hrs, after which the RNA was degraded by the addition of 0.5 mL RNase A (1 mg/mL) and 1.5 mL RNaseH 5 units/mL). Labeled cDNA was separated from unincorporated nucleotides (Qiagen column) and further concentrated by evaporation under vacuum. The arrays were pre-hybridized for 1-2hrs with DIGEasy hybridization buffer (Roche) containing 10ug/ml denatured salmon sperm DNA, and 10ug/ml yeast tRNA. The Cy5 and Cy3 labelled cDNAs were combined and hybridized in the same medium and incubated with the arrays for 16-18hrs at 37Co. Finally, the arrays were washed 3 x 10 mins in 0.1 x SSC (20 X SSC is 3M sodium chloride, 0.3 M sodium citrate, pH 7.0), 0.1%SDS at 50Co, and 4 x 3min in 0.1 x SSC at room temperature, and dried by centrifugation. Fluorescent array images were collected for both Cy3 and Cy5 with a ScanArray fluorescent scanner and image intensity data were extracted and analyzed with QuantArray 3.0 analysis software. Quantification data was imported in GeneSpring (Silicon Genetics). The import format was modified to maintain information relevant to user-contributed flagging as well as QC parameter furnished by the array manufacturer. Dye swap and Intensity-based normalization (Lowess) were performed using the default settings. Keywords: other

Project description:Female Sprague-Dawley rats were randomly separated into two groups: i) trained (Ex group) and ii) sedentary (Cont group). Animals from the Ex group were adapted to treadmill exercise for two consecutive weeks, involving a gradual increase in the running time till 60 min/day at 20 m/min, 0% grade, 5 days/week. This exercise program remained constant until the end of the 54 weeks. Mitochondria isolation from 10 animals (5 Ex group and 5 Cont group) was performed using the conventional methods of differential centrifugation. Mitochondrial protein extracts were reduced with dithiothreitol, alkylated with iodoacetamide and digested with trypsin using the FASP procedure (18). Briefly, each sample was solubilized in 4 % SDS, 0.1 M DTT, 0.1 M HEPES and incubated for 30 min at 60 C. Then, samples were mixed with 0.2 mL of a solution of 8 M Urea, 0.1 M HEPES, pH 8.5 (UH solution), loaded into the filtration devices (3k Microcon, Millipore), centrifuged at 14,000 g for 20 min, and washed twice with UH solution. After centrifugation, the concentrates were alkylated with 50 mM iodoacetamide in UH solution (dark, 25 C, 20 min), and washed twice with UH solution. The concentrate was diluted with 0.1 mL of 50 mM ammonium bicarbonate (ABC) and digested overnight (37 C) with the addition of 2 ug of trypsin diluted in 30 uL of 50 mM ABC. The resulting tryptic peptides were collected by centrifugation and the filter were washed twice with 50 uL of 50 mM ABC. Eluted peptides were acidified with 10 uL of formic acid and cleaned up on a homemade Empore C18 column (3M, St. Paul, MN, USA) (ref) for subsequent phospho-enrichment and/or analysis by LC-MS/MS. The dried protein digest was dissolved with 10 uL (3 % ACN, 0.1 % TFA), diluted 1:5 with loading buffer (1 M glycolic acid, 5 % TFA, 80 % ACN) and phosphopeptides were enriched on TiO2-beads as previously described (19). Briefly 5 mg of "Titansphere TiO2 5 um" were suspended in 100 uL of 100 % ACN, immobilized in a pipette-column and washed using 5 uL of loading buffer. Each sample was loaded in each pipette-column and then washed with 30 uL of washing buffer (1 % TFA, 80 % ACN). Phosphopeptides were eluted from the beads with 25 uL of 25 % ACN (v/v) containing 25 % NH4OH (m/v), acidified with 10 uL of 10 % TFA and vacuum- concentrated to approximately 4 uL. Samples were finally diluted to 10 uL with H2O + 0.1% formic acid prior to injection. The peptides mixtures were analyzed by online nanoflow liquid chromatography tandem mass spectrometry (nanoLC-MS/MS) on an EASY-nLC system (Proxeon Biosystems, Odense, Denmark) connected to the LTQ Orbitrap Velos instrument (Thermo Fisher Scientific, Bremen, Germany) through a nanoelectrospray ion source. Six microliters of the peptide mixture were auto-sampled directly onto the analytical HPLC column (120 mm x75 um I.D., 3 um particle size (Nikkyo Technos Co., Ltd.) with a 120-min gradient from 5 % to 50 % ACN in 0.1 % FA. The effluent from the HPLC column was directly electrosprayed into the mass spectrometer. The LTQ Orbitrap Velos instrument was operated in data-dependent acquisition mode to automatically switch between full scan MS and MS/MS acquisition. The MS survey scan was performed in the FT cell recording a window between 350 and 2000 m/z. The resolution was set to 60 000, and the automatic gain control was set to 1,000,000 ions with a maximal acquisition time of 400 ms. The 20 most intense peptide ions with charge states great than or equal to 2 were sequentially isolated to a target value of 5,000 and fragmented in the high-pressure linear ion trap by low-energy CID with normalized collision energy of 35% Q value of 0.25, and an activation time of 10 ms. Raw files were processed using Proteome Discoverer version 1.3 (Thermo Fisher Scientific, Bremen). Peak lists were searched using Mascot software version 2.3 (Matrix Science, UK) against a SwissProt database containing entries corresponding to Rattus norvegicus (version of July 2012), a list of common contaminants, and all the corresponding decoy entries. Trypsin was chosen as enzyme and a maximum of two miscleavages were allowed. Carbamidomethylation (C) was set as a fixed modification, whereas oxidation (M) and phosphorylation (STY) were used as variable modifications. Searches were performed using a peptide tolerance of 7 ppm, a product ion tolerance of 0.5 Da. Resulting data files were filtered for FDR less than 1 % at peptide level.

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Liver gene transcription during energy balance perturbations in C57/BL/J6 mice.

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