ABSTRACT: This study looks at the effect of dietary manipulation on the development of hepatic steatosis and changes in hepatic gene expression in a feline model. We used microarray analysis to examine changes in hepatic gene transcription in response to Trans fat, High Fructose Corn Syrup (HFCS) and/or Monosodium Glutamate (MSG) in the domestic cat. The use of human Affymetrix arrays for the study of feline gene expression has previously been validated by Dowling and Bienzle, 2005, Journal of General Virology. 86(Pt 8), 2239-48 (PMID 16033971). Our study animals were bred from female Felis catus previously placed on one of 4 different dietary regimens for a period of 3 weeks prior to mating. The four dietary regimens used in this study were: [1] Standard Chow Control feline diet (Test Diet Purina catalog #5003); [2] MSG diet consisting of Control diet with 1.125% added Monosodium Glutamate (Diet A: Test Diet Purina catalog #5C1J); [3] Trans-fat/HFCS diet, containing 8.6% Trans fat and 24% HFCS (Diet B: Test Diet Purina catalog #5B4K); and [4] Trans-fat/HFCS and MSG diet, containing 8.6% Trans fat, 24% HFCS and 1.125% MSG (Diet C: Test Diet Purina catalog #5C1H). Following mating, the 4 groups of dams were maintained on their respective diets throughout the gestation and nursing period. Male offspring used in the following experiments were weaned onto the same diets and maintained on their respective dietary regimens until they reached 9 months of age. Hepatic tissues (4-5 per diet group) were used for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Gender dimorphism exists in the physiological response to diet and other environmental factors. Trans-hydrogenated fatty acid (TFA) intake is associated with an increase in coronary heart disease (CHD), and gender differences in the incidence of CHD are well documented. Neonatal administration of Monosodium Glutamate (MSG) causes stunted heart growth and hypoplasticity; and gender dimorphism at the growth hormone axis has been demonstrated in MSG-treated rodents. The identification of gender dimorphism in cardiac nutrigenomics may provide the basis for gender-specific medicine in the future. We used microarray analysis to examine changes in cardiac gene transcription in response to TFA and/or MSG feeding in male and female C57Bl/6J mice. Our study animals were bred from female C57Bl/6J mice fed a standard chow diet until 6 weeks of age whereupon they were placed on one of 4 different dietary regimens for a period of 3 weeks prior to mating. The four dietary regimens used in this study were: [1] Standard Chow (Control diet) with ad lib drinking water. [2] Standard Chow, with ad lib drinking water containing 0.64 g/L Monosodium Glutamate (MSG diet). [3] Trans fat diet of 20% (w/w) Partially Hydrogenated Vegetable Shortening containing 8.68% w/w Trans fatty acids(TFA diet). [4] Trans fat Diet #5C4M together with ad lib drinking water containing 0.64 g/L Monosodium Glutamate (TFA+MSG diet). Following mating, the 4 groups of dams were maintained on their respective diets throughout the gestation and nursing period. Male and female offspring used in the following experiments were weighed, weaned onto the same diets and maintained on their respective dietary regimens until they reached 32 weeks of age.Cardiac tissues (8 per diet group) were used at 32 weeks for RNA extraction and hybridization on Affymetrix microarrays.
Project description:C57BL/6J mice were from The Jackson Laboratory (Maine, USA) and were housed/caged and fed a standard chow diet until 6 weeks of age whereupon they were placed in one of 4 different dietary regimens for a period of 3 weeks prior to mating. Mice were housed under pathogen-free conditions of 21± 1°C, 40 to 60% humidity, and a 12 h-12 h light/dark cycle. The 4 diet regimens used in this study were: [1] ad lib Standard Chow (Control diet) with ad lib drinking water. [2] Ad lib Standard Chow, with ad lib drinking water containing 0.64 mg/ml (97 mg/Kg body weight) monosodium glutamate (MSG diet). [3] Ad lib Test Diet Purina 5001 with 20% 55-HFCS (5B4K, Purina, USA), and ad lib drinking water (HFCS diet). [4] Ad lib Purina 5001 with 20% 55-HFCS, and ad lib drinking water containing 0.64 mg/ml (97 mg/K body weight) monosodium glutamate (HFCS+MSG diet). See Table 1 for diet composition. Following mating, the 4 groups of dams were maintained on their respective diets throughout the gestation and nursing period. Male offspring used in these experiments were weighed, then weaned onto the same diets and maintained in this regimen until they reached either 16 or 32 weeks of age. Total RNA was prepared from the liver and visceral white adipose tissue (WAT) taken from 16-week-old mice in the 4 different diet groups using Qiagen RNeasy Kit (Qiagen USA) according to the manufacturers instructions and stored at -80 o C.<br>
Project description:Therapeutic effect of all-trans retinoic acid on diet-induced insulin resistance was found. To explore molecules involved in this pharmacological effect, the hepatic transcriptome was analyzed. RNA samples were prepared from the liver biopsies of control, HFHFr-N, HFHFr-NA, HFHFr-F, and HFHFr-FA groups (five mice in each group). The samples were pooled and analyzed using Whole Mouse Genome Microarray 4x44K (G4122F).
Project description:We tried to identify miRs that are differentially expresssed during atherogenesis. Aortic miRs expression profile in female apoe-/- mice after 3 and 10 months of a high fat diet were compared with female apoe-/- mice on normal diet. 4 Female apoe-/- mice (6-8 weeks) were fed on high fat diet for 3 months. 3 female apoe-/- mice (6-8 weeks) were fed on high fat diet for 10 months. 4 female apoe-/- mice (6-8 weeks) on normal diet served as controls. Total RNA was isolated from whole aortic tissue. RNA samples with RIN>8 were used for array. The aortic miRs expression profile after 3 months of a high fat diet was compared with the control group. Biological replicates: 4 per group. One replicate per array.
Project description:We designed and constructed a genome-wide microarray with 22,987 70-mer oligonucleotides covering the presently known and predicted genes in the silkworm genome, and surveyed the gene expression in multiple silkworm tissues on day 3 of the fifth instar. Clusters of tissue-prevalent and tissue-specific genes and genes that are differentially expressed in different tissues were identified, and they reflect well major tissue-specific functions on the molecular level. The data presented in this study provide a new resource for annotating the silkworm genome. In the present study, we surveyed gene expression in the A/MSG, the PSG, testis, ovary, fat body, midgut, integument, hemocyte, malpighian tubule, and head from silkworm individuals on day 3 of the fifth instar. In order to establish gene expression differences between sexes, we prepared male and female samples of the same tissue. In addition, we also selectively performed the biological replicates at least twice for five tissues including testis, ovary, A/MSG, PSG and malpighian tubule, to evaluate biological reproducibility. In all, we prepared 30 two-channel hybridizations across the selected tissues for study. We extracted the single channel intensity instead of the ratio value from each two-channel hybridization for further analysis, a strategy that has been reported as being more flexible and valid previously.
Project description:Younger age and obesity increase the incidence and rates of metastasis of triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer. The tissue microenvironment, specifically the extracellular matrix (ECM), is known to promote tumor invasion and metastasis. We sought to characterize the effect of both age and obesity on the ECM of mammary fat pads. We used a diet-induced obesity (DIO) model where 10-week-old female mice were fed a high-fat diet (HFD) for 16 weeks or a control chow diet (CD) where time points were every 4 weeks to monitor age and obesity HFD progression. We isolated the mammary fat pads to characterize the ECM at each time point. Utilizing proteomics, we found that the early stages of obesity were sufficient to induce distinct differences in the ECM composition of mammary fat pads that promote TNBC cell invasion. ECM proteins previously implicated in driving TNBC invasion Collagen IV and Collagen VI, were enriched with weight gain. Together these data implicate ECM changes in the primary tumor microenvironment as mechanisms by which age and obesity contribute to breast cancer progression.
Project description:Systemic acute inflammatory signals can cause profound anorexia by disrupting the physiological appetite regulation in the hypothalamic milieu. Conversely, obesity related chronic inflammation of the hypothalamus can disturb anorexigenic signals and promote abnormal body weight control. The aim of the present study was to compare the global hypothalamic endophenotype in C57/Bl6 mice exposed to a high-fat diet or with acute illness mediated by LPS. Ten-week old male C57/Bl6 mice (n=18) were randomly divided into four groups; the control 1 group (n =3) was fed a normal diet whereas the high-fat diet (HFD) group (n =6) was fed a high-fat diet for eight weeks. The control 2 group (n=3) received an intraperitoneal injection of saline whereas the LPS group (n=6) received an intraperitoneal injection of LPS. Mice were sacrificed 18-hr post-injection. Both control 2 and LPS groups were fed a normal diet for eight weeks before the injection. The hypothalamic regions were removed and analysed using a 2D LC-MS methodology. The proteomic analysis profiled 9,235 proteins (q<0.05) across all biological states, of which 522 proteins were found modulated in the HFD group and another 579 in the LPS group. The proteomic profiles demonstrated that the systemic acute inflammation linked with anorexia induced a negative feedback loop of appetite control in the hypothalamus, suggesting an effort to re-establish homeostasis. By contrast, the chronic inflammation associated with obesity initiated a “perpetual cycle” of positive feedback enhancement of appetite regulation further exacerbating positive energy balance.
Project description:Atherosclerosis is causally related to disturbed flow through low and oscillatory shear stress. In order to study the miR expression profile in atherosclerotic plaques induced by disturbed flow, partial ligation of the carotid artery was performed. This procedure results acutely in severly reduced blood flow and in stenotic lesion formation within 6 weeks in apoe-/- mice on a high fat diet. We compared the miR expression profile in partially ligated left carotid arteries with the untreated right carotid artery to identify miRs which are involved in plaque formation through flow disturbances. The left carotid arteries of 6 female apoe-/- mice (6-8 weeks) were partially ligated (i.e. the external and internal carotid artery as well as the occipital artery were occluded; blood flow out of the common carotid artery occurs mainly through the superior thyroid artery). Following partial ligation the animals were fed a high fat diet for 6 weeks. Total RNA was isolated from partially ligated left carotid arteries and untreated right carotid arteries (control). MiRs expression profile of the partially ligated carotid arteries were compared with the control group. Biological replicates: 6 per group. One replicate per array.
Project description:Glioblastoma (GBM) remains among the deadliest of human malignancies, and the emergence of the cancer stem cell (CSC) phenotype represents a major challenge to durable treatment response. Because the environmental and lifestyle factors that impact CSC populations are not clear, we sought to understand the consequences of diet on CSC enrichment. We evaluated disease progression in mice fed an obesity-inducing high-fat diet (HFD) versus a low-fat, control diet. HFD resulted in hyper-aggressive disease accompanied by CSC enrichment and shortened survival. HFD drove intracerebral accumulation of saturated fats, which inhibited the production of the cysteine metabolite and gasotransmitter, hydrogen sulfide (H2S). H2S functions principally through protein S-sulfhydration and regulates multiple programs including bioenergetics and metabolism. Inhibition of H2S increased proliferation and chemotherapy resistance, whereas treatment with H2S donors led to death of cultured GBM cells and stasis of GBM tumors in vivo. GBM specimens present an overall reduction in protein S-sulfhydration, primarily associated with proteins regulating cellular metabolism. These findings provide new evidence that diet modifiable H2S signaling serves to suppress GBM by restricting metabolic fitness, while its loss triggers CSC enrichment and disease acceleration. Interventions augmenting H2S bioavailability concurrent with GBM standard of care may improve outcomes for GBM patients.
Project description:Cardiovascular (CV) disease is a leading cause of morbidity and mortality in Western societies. Even after accounting for traditional CV risk factors (e.g. obesity, smoking and hypertension), the inflammation-driven thickening and stiffening of central arteries is a strong predictor of adverse outcomes. Arterial wall changes are universally associated with advancing age and show unparalleled worsening in metabolic syndrome. In mice, resveratrol ameliorates a high-fat diet induced arterial wall inflammation and slows age-associated physiologic deteriorations within the arterial wall. Here we tested resveratrol in adult male rhesus monkeys, an experimental model relevant to humans. A diet rich in fat and sucrose (HFS) led to an increase in body weight as well as thickening and stiffening of the aortic wall, marked by diffuse inflammation, fibrosis and fat infiltration. Dietary resveratrol supplementation prevented diet-induced structural and functional alterations within the aortic wall, and abrogated the deleterious vascular endothelial and smooth muscle responses. Integrative genomic and proteomic analyses of aortic tissues revealed molecular signatures consistent with improved vascular functions. Thus, resveratrol conferred protection against the initiation of diet-induced inflammatory events that progress to pathological thickening and stiffening of large arteries. Dietary resveratrol may therefore hold promise as a novel therapy to ameliorate metabolic stress-induced CV disease. After baseline assessment, four male rhesus monkeys remained on the healthy standard diet (SD), 10 male rhesus monkeys were begun on a high fat/high sucrose (HFS) diet and 10 male rhesus monkeys were begun on a high fat/high sucrose (HFS) diet plus Resveratrol, 80mg/day. After one year of dietary intervention, the amount of resveratrol was increased to 240mg/day for one additional year. Tissues were then harvested for the array experiments.