Interactive effects of arsenic and a high-fat diet on hepatic gene expression
ABSTRACT: Chronic exposure to inorganic arsenic (iAs) or a high-fat diet (HFD) can produce liver injury. However, the interactive molecular biological effects and mechanism of iAs and HFD are as of yet unclear. We used microarrays to detail the interactive effects of arsenic and a high-fat diet on hepatic gene expression. The C57BL/6 Mice fed low-fat diet (LFD) or HFD were exposed to 3 mg/L iAs or deionized water for 10 weeks. Then, hepatic RNA were extraction and hybridization on Affymetrix microarrays. Differentially expressed genes in LFD+As, HFD, and HFD+As groups compared to LFD group were identified, and interactive molecular biological effects and mechanism of iAs and HFD were discussed.
Project description:Gene expression for genes differentially expressed between early vs. late tumor onset and high fat diet (HFD) vs. low fat diet (LFD) in P53 -/- mice. 4 HFD early tumor onset, 7 HFD late tumor onset, 4 HFD to LFD switch with early tumor onset, 6 HFD to LFD switch with late tumor onset, 4 LFD early tumor onset, 7 LFD late tumor onset, 5 LFD to HFD switch with early tumor onset, 4 LFD to HFD switch with late tumor onset
Project description:Diet-induced obesity is reported to induce a phenotypic switch in adipose tissue macrophages from an antiinflammatory M2 state to a proinflammatory M1 state. Telmisartan, an angiotensin II type 1 receptor antagonist and a peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist, reportedly has beneficial effects on insulin sensitivity. We studied the effects of telmisartan on the adipose tissue macrophage phenotype in high fat-fed mice. Telmisartan was administered for 5 weeks to high fat-fed C57BL/6 mice. Insulin sensitivity, macrophage infiltration, and the gene expressions of M1 and M2 markers in epididymal fat tissues were examined. Insulin- or a glucose-tolerance test showed that telmisartan treatment improved insulin resistance, decreasing the body weight gain, visceral fat weight and adipocyte size without affecting the amount of food intake. Telmisartan treatment reduced the number of CD11c-positive cells and crown-like structures. Telmisartan reduced the mRNA expressions of M1 macrophage markers, such as TNF-alpha and IL-6, and increased the expression of M2 markers, such as IL-10 and Mgl2. The reduction of M1 macrophage markers, as well as the increased gene expression of M2 markers especially IL-10, is a possible mechanism for the improvement of insulin sensitivity by telmisartan. Six-week-old male C57BL/6J mice were purchased from CLEA Japan. The mice were fed a chow that contained 10% of its calories from fat (control) or a high-fat diet (HFD) that contained 30% of its calories from fat for 24 weeks. The high fat-fed mice were randomized to 3 groups. Either telmisartan (~3 mg/kg/day) in drinking water (HFD+Tel), candesartan (~3 mg/kg/day) in drinking water (HFD+Can), or a HFD without any drugs (HFD) was administered for the next 5 weeks. Two mice were treated per group. Epididymal adipose tissues were rapidly removed from each mouse. Gene expression in epididymal fat tissue was analyzed using a GeneChip® system with the Mouse Genome 430 2.0 Array, which was spotted with 45,101 probe sets (Affymetrix, Santa Clara, CA, USA). Sample preparation for the array hybridization was performed according to the manufacturer’s instructions. In short, 5 μg of total RNA was used to synthesize double-stranded cDNA using the GeneChip® Expression 3′-Amplification Reagents One-Cycle cDNA Synthesis Kit (Affymetrix). Biotin-labeled cRNA was then synthesized from the cDNA using GeneChip® Expression 3′-Amplification Reagents for IVT Labeling (Affymetrix). After fragmentation, the biotinylated cRNA was hybridized to arrays at 45 °C for 16 h. The arrays were washed, stained with streptavidin-phycoerythrin, and scanned using a probe array scanner. The scanned chip was analyzed using the GeneChip Analysis Suite software (Affymetrix). Hybridization intensity data were converted into a presence/absence call for each gene, and changes in gene expression between experiments were detected by a comparison analysis. Data was shown as the fold change relative to the expression level of normal chow-fed mice.
Project description:Gene expression for genes differentially expressed between early vs. late tumor onset and high fat diet (HFD) vs. low fat diet (LFD) in mice. Overall design: 2 class analysis of early vs late tumor onset samples; 5 LFD late tumor onset, 3 HFD early tumor onset, 6 HFD late tumor onset, 4 LFD-HFD late tumor onset, 3 HFD-LFD early tumor onset, 3 HFD-LFD late tumor onset
Project description:To profile the expression of circulating miRNAs in a mouse model of diet-induced obesity (DIO) with subsequent weight-reduction with low-fat diet (LFD), eighteen C57BL/6 male mice were grouped into three subgroups as: (1) Control: the mice fed with the standard AIN-76A (fat: 11.5 kcal%) diet for 12 wks; (2) DIO: the mice fed with 58 kcal% high-fat diet for 12 wks; (3) DIO+LFD: the mice fed with high-fat diet for 8 wks to induce obesity, then changed to 10.5 kcal% low-fat diet for subsequent 4 wks. C57BL/6 mice were purchased from BioLasco (Taipei, Taiwan). All housing conditions were maintained, and surgical procedures, including analgesia, were performed in an Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC)-accredited SPF facility according to national and institutional guidelines. In this experiment, eighteen C57BL/6 wild type male mice were randomly grouped into three subgroups (n=6 in each group): (1) Control: the control mice were fed ad libitum a standard AIN-76A (fat: 11.5 kcal%) diet for 12 wks; (2) DIO: the mice were fed ad libitum a 58 kcal% HFD (D12331; Research Diets Inc., New Brunswick, NJ) for 12 wks to induce obesity; (3) DIO+LFD: the mice fed ad libitum a 58 kcal% HFD (D12331) for 8 wks to induce obesity, then continued the feeding of 10.5 kcal% LFD (D 12329; Research Diets Inc.) for additional 4 wks. Weight measurements were performed on a weekly basis to for these three groups of mice. Evaluation of blood glucose levels was performed at the beginning and in the end of the experiment to confirm that the HFD-fed mice developed an obese and insulin resistant phenotype. After the end of experiment at 12w, all mice were killed. The abdominal WAT of each mice was removed and weighted. Paraffin-embedded abdominal WAT was sectioned at 5 μm and stained with hematoxylin and eosin to measure mean adipocyte area. A volume of 1 mL of whole blood was collected into a plain tube and allowed to clot for 1 hour. The sera samples were aliquoted after centrifugation at 3,000 × g for 10 minutes and stored at −80°C until further analysis.
Project description:Overnutrition during pregnancy inﬂuences the future health of the offspring, with outcomes differing depending on the child’s sex. The placenta is involved in the programming of obesity, type 2 diabetes and cardiovascular disease. Sex-specific adaptation of the placenta may be central to the differences in fetal growth and survival. The impact of diet and fetal sex on placental gene expression and epigenetic marks was investigated in mice fed a high-fat (HFD) or a control diet (CD), during the first 15 days of gestation Microarrays analysis revealed that expression was affected by maternal diet and was sexually dimorphic. We analyzed the placentae of 4 mice litters fed with an high-fat diet (HFD) and 4 with a control diet (CD). For each litter, the placenta transcriptome was analysed according to the foetus sex using the Affymetrix Human Exon 1.0 ST platform. Array data was processed by Affymetrix Exon Array Computational Tool. No technical replicates were performed.
Project description:Using standardized, semipurified diets is a crucial factor for reproducibility of experimental nutritional studies. For the purpose of comparability and integration of research, two European consortia, Mitofood and BIOCLAIMS, proposed an AIN-93-based standard reference diet, the standardized BIOCLAIMS low-fat diet (LFD) as well as a high-fat diet (HFD). In order to evaluate the BIOCLAIMS LFD and HFD, we performed short-term (5 days) and long-term (12 weeks) feeding experiments using male C57BL/6 mice. The HFD has the same composition as the LFD except the fat content is increased to 40% energy in exchange for carbohydrates. Both diets were accepted by the animals and proof of principle was given that the BIOCLAIMS HFD increases body weight and body fat and affects glucose homeostasis. Short-term feeding trials (5 days) were performed in order to identify metabolic and molecular parameters which can serve as acute predictors for metabolic disorders due to high-fat diet-induced obesity. We analyzed gene expression in gonadal white adipose tissue of short- and long-term fed animals with whole genome microarrays. The BIOCLAIMS HFD strongly influenced gene expression in white adipose tissue after short- and long-term intervention. A total number of 973 and 4678 transcripts were significantly different between both diets after 5 days feeding and 12 weeks feeding, respectively. A total number of 764 transcripts encoding 549 genes were significantly differentially regulated between LF and HF animals after 12 weeks feeding as well as after 5 days feeding. Of these 549 overlapping genes, a substantial number (434 genes) were expressed at a lower level and 115 genes were expressed at a higher level in the HF mice compared to the LF mice. Without exception, all genes were regulated equally. Pathway analysis revealed a prominent role for genes involved in lipid metabolism, carbohydrate metabolism and oxidative phosphorylation. This was confirmed by quantitative real-time reverse transcription PCR. The high predictive value of gene expression changes in our short-term study compared to long-term high fat feeding is a promising step to get well-defined, early biomarkers that could shorten animal trials considerably and allow a more rapid and efficient screening of different compounds. C57BL/6J wildtype male mice, aged 12 weeks, received a low-fat diet or a high-fat diet for 5 days or 12 weeks. After sacrification, white adipose tissue depots were dissected, and immediately snap frozen in liquid nitrogen. Total RNA was isolated, quantified and qualified, and subsequently used for global gene expression profiling using Agilent 4x44K microarrays.
Project description:The present study aimed to examine the effect of high-fat diet prior to pregnancy on the liver of mouse offspring. Female C57BL/6J mice were fed a normal chow (15.2% fat by energy) (CTR and CTR-PP groups) or a high-fat chow (31.2% fat by energy) (HFD and HFD-PP groups) for 3−4 weeks and then mated with male C57BL/6J mice fed normal chow. Some mothers continued on the same diet until pups reached 21 days of age (CTR and HFD), and others were fed the different chows from gestational day 0 (CTR-PP and HFD-PP) to determine the effects of a high-fat diet during the pre-pregnancy period in HFD-PP/CTR and HFD/CTR-PP comparisons. RNA sample was taken from liver of 3-week-old mouse prenatally received high-fat diet prior to pregnancy, during pregnancy and lactation, or through prior to and during pregnancy and lactation, while control RNA was taken from control counterpart prenatally received normal diet alone. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.
Project description:Recent discovery reveals HFD insult can cause insulin resistance very rapidly, but the underlying mechanism is still not well understood. We performed a short term experiment in a Diet Induced Insulin resistance mouse model. Objective: Insulin resistance (IR) is one of the earliest predictors of type 2 diabetes. However, diagnosis of IR is limited. High fat fed mouse models provide key insights into IR. We hypothesized that early features of IR are associated with persistent changes in gene expression (GE) and endeavoured to (a) develop novel methods for improving signal:noise in analysis of human GE using mouse models; (b) identify a GE motif that accurately diagnoses IR in humans; and (c) identify novel biology associated with IR in humans. Methods: We integrated human muscle GE data with longitudinal mouse GE data and developed an unbiased three-level cross-species analysis platform (single-gene, gene-set and networks) to generate a gene expression motif (GEM) indicative of IR. A logistic regression classification model validated GEM in 3 independent human datasets (n =115). Results: This GEM of 93 genes substantially improved diagnosis of IR compared to routine clinical measures across multiple independent datasets. Individuals misclassified by GEM possessed other metabolic features raising the possibility that they represent a separate metabolic subclass. The GEM was enriched in pathways previously implicated in insulin action and revealed novel associations between β-catenin and Jak1 and IR. Functional analyses using small molecule inhibitors showed an important role for these proteins in insulin action. Conclusions: This study shows that systems approaches for identifying molecular signatures provides a powerful way to stratify individuals into discrete metabolic groups. Moreover, we speculate that the β-catenin pathway may represent a novel biomarker for IR in humans that warrant future investigation. Comparison of gene expression in muscle tissue during High Fat Diet (HFD) time course (day 5 and day 42). Chow diet will serve as control for HFD. 4 samples per group serve as experimental replicates.
Project description:Global deficiency of catalytic subunit Ppp3cb, and tissue-specific ablation of regulatory subunit Ppp3r1 from skeletal muscle but not adipose tissue or liver led to protection from high-fat diet induced obesity and comorbid sequelæ. Ser637 hyperphosphorylation of dynamin-related protein 1 (Drp1) in skeletal muscle of calcineurin-deficient mice was associated with mitochondrial elongation into power-cable shaped filaments, increased mitochondrial respiration, but attenuated exercise performance. Mice used for microarray analyses were all male, and chronically exposed to HFD for at least 8 weeks.
Project description:SNPs affecting disease risk often reside in non-coding genomic regions. Here we show that SNPs are highly enriched at mouse strain-selective adipose tissue binding sites for PPARγ, a nuclear receptor for antidiabetic drugs. Many such SNPs alter binding motifs for PPARγ or cooperating factors, and functionally regulate nearby genes whose expression is strain-selective and imbalanced in heterozygous F1 mice. Moreover, genetically-determined binding of PPARγ accounts for mouse strain-specific transcriptional effects of TZD drugs, providing proof-of- concept for personalized medicine related to nuclear receptor genomic occupancy. In human fat, motif-altering SNPs cause differential PPARγ binding, provide a molecular mechanism for some expression quantitative trait loci, and are risk factors for dysmetabolic traits in genome- wide association studies. One PPARγ motif-altering SNP is associated with HDL levels and other metabolic syndrome parameters. Thus, natural genetic variation in PPARγ genomic occupancy determines individual disease risk and drug response. Comparison of 5 RNA-seq experiments between 2 strains of mice differing in diet and fat depot. One of the experiments was evaluation of the response to a drug Rosiglitazone. Our RNA-seq data comprises primarily of 4 main experiments: The first experiment consists of samples taken from 2 strains of mice and their F1 progeny The samples are all taken from the same depot and when the mice were fed the same chow diet The second experiment has 2 parts, the first one involves samples taken from the 2 strains from the same eWAT depot when they were kept on a Low Fat Diet (LFD) This first part serves as a control for the second one in which the mice were treated with a drug, rosiglitazone in conjunction with a LFD The third experiment consists of samples taken from mice being fed on LFD. The samples are taken from the eWAT depot for both the strains. The fourth experiment consists of samples taken from mice being fed on LFD. The samples are taken from the iWAT depot for both the strains. We also have a solitary sample from a GRO-seq experiment which was done on eWAT in a B6 strain of mice being fed a LFD eWAT: epididymal White Adipose Tissue iWAT: inguinal White Adipose Tissue LFD-12w: mice were fed a control low fat diet (Research Diet D12450B) chow: mice were fed standard rodent chow Diet LFD w/rosiglitazone: Drug rosiglitazone (Cayman Chemicals) was incorporated into low fat diet D12450B by Research Diets at 36mg/kg of diet. Mice received control low fat diet for 10 weeks (age 6-16 weeks), and the rosiglitazone-containing diet versus control diet for the final 2 weeks (until sacrifice at 18 weeks) LFD control for rosi: mice were fed a control low fat diet (Research Diet D12450B)