Gene expression analysis of diet induced obesity model zebrafish
Ontology highlight
ABSTRACT: As microarray based gene expression profiling is well suited to study the complex diseases such as obesity, we revealed gene expression changes of fat tissues on obesity model zebrafish to elcidate the pathophysiological function of each fat tissue in metabolic syndrome. Zebrafish in over-feeding group were fed three times per day with Artemia (60 mg cysts/fish/day) through 8weeks. 1week over-feeding group were fed three times per day with Artemia (60 mg cysts/fish/day) through 1week. For caloric restriction, zebrafish were fed with Artemia (2.5 mg cysts/fish/day) for 2 weeks after over-fed with Artemia for 8 weeks.
Project description:Silver nanoparticles (NPs) are extensively used due to their antimicrobial activity and, therefore, their input into the ecosystem will increase. Silver can be bioaccumulated by low trophic level organisms and, then, incorporated into the food chain, reaching high level predators. The objectives of this study were to test the acute toxicity of N-vynil-2-pirrolidone/polyethylenimine (PVP-PEI) coated Ag NPs of 5 nm to brine shrimp (Artemia sp) larvae and to assess bioaccumulation and effects of silver transferred by the diet. For the later, brine shrimps were exposed to two different concentrations of Ag NPs, 100 ng/L as an environmentally relevant concentration and 100 µg/L as a likely effective concentration, in parallel with an unexposed control group and, then, used to feed zebrafish during 21 days in order to simulate two trophic levels of a simplified food web. For brine shrimp larvae, EC50 values ranged from 7.39 mg Ag/L (48 h post hatch larvae (hph) exposed for 48 h) to 19.63 mg Ag/L (24 hph larvae exposed for 24 h. Silver accumulation was measured in brine shrimps exposed to 0.1 and 1 mg/L of Ag NPs for 24 h. In zebrafish fed with brine shrimps exposed to Ag NPs, intestine showed higher metal accumulation than liver, although both organs presented the same pattern of dose and time-dependent metal accumulation as revealed by autometallography. Feeding of zebrafish for 3 days with brine shrimps exposed to 100 ng/L of Ag NPs was enough to impair fish health as reflected by the significant reduction of the lysosomal membrane stability and the presence of several histopathological conditions in the liver. Overall, results showed that Ag NPs were able to exert toxic effects on zebrafish through dietary exposure, even at an environmentally relevant concentration, which should act as concern of the need of studies in further detail about real impact of nanomaterials in the environment.
2017-03-21 | GSE90457 | GEO
Project description:Transcriptome of Artemia cysts
Project description:The effect of a year-long 10 reduction in water temperature on global gene expression in tail skeletal muscle from adult, male zebrafish was determined using a long oligonucleotide probe set (16,399 65mers from Compugen) spotted onto glass slides. Outbred male zebrafish were obtained from a commercial supplier (Liles Tropical Fish, FL) at 6 months of age. Fish were maintained at 28 until 10 months of age. (see Gerhard et al., Exp Gerontol 37,1055-68, 2002) For temperature reduction, water temperature was decreased by 2.5 per week for 4 weeks. Fish were maintained until 22 months of age. Fish were fed fish flakes (Wardely Corp. Secaucus, NJ) twice per day. Each feeding was a discrete event in which a small measured amount of granular food was sprinkled on the water surface. A second small aliquot was offered if the first has been eaten within a few minutes. The feeding stopped when food from the previous aliquot has not been eaten and feeding behavior has ceased. By providing a consecutive series of small aliquots until food is no longer accepted, every member of the tank has an opportunity to eat until satiety, yet the amount of uneaten food is minimized. At 22 months of age, fish were euthanized by decapitation. Total RNA was harvested from a pool of tail muscle samples from 5 fish. Two independent pools of 5 fish per pool were collected from fish maintained at 18 and 28. Flip-dye hybridizations were performed on each pool for a total of 4 hybridizations in this study. Experiments DAR011d0001 and DAR011d0002 are flip-dye hybridizations from Pool 1. Experiments DAR011d0003 and DAR011d004 are flip-dye hybridizations from Pool 2.
Project description:We identified that the adiponectin gene expression in rainbow trout muscle decreased by restrected feeding. In order to identify the genes differently expressed by the same treatment, micrarray analysis was conducted Fish were fed ad libitum once a week (RF, restricted feed group) or fed ad libitum twice per day (control). After 1 month, the muscle was desected from 4 individuals from each group.
Project description:Recent evidence has suggested that fluoxetine, a serotonin-reuptake inhibitor and emerging environmental contaminant, can have non-targeted effects on metabolism in fish exposed to this waterborne pollutant. Using the highest, environmentally relevant, detectable level of fluoxetine (540 ng/L) we examined the impact of fluoxetine on the miRNA profile in the liver of zebrafish that were both fed and fasted for a period of 7 days. These results were further compared to the miRNA profile of zebrafish fasted and fed for 7 days, which were not exposed to fluoxetine. Results indicated that several miRNA that were involved with downregulating genes/pathways in response to fasting were also upregulated in fish exposed to fluoxetine, irrespective to fasting or feeding. These results suggest fluoxetine can have non-targeted effects on metabolic pathways mediated through miRNA expression. Furthermore, specific miRNA (dre-let-7d & dre-miR-140-5p) were found to target the catalytic subunit (AMPKa1 & AMPKa2, respectively) of AMP-Kinase, a master regulator of metabolism. Using predictive software and qPCR validation, combined with the expression profile of these two miRNA, we were able to establish a significant relationship between the expression of these specific miRNA to the downregulation of AMPKa subunit under the influence of 540 ng/L fluoxetine. Adult, female zebrafish were either fed or fasted for 7 days with and without the presense of 540 ng/L fluoxetine, and livers extracted and miRNA purified for miRNA microaary experiment.
Project description:An intrinsic property of the heart is an ability to rapidly and coordinately adjust flux through metabolic pathways in response to physiologic stimuli (termed metabolic flexibility). Cardiac metabolism also fluctuates across the 24-hr day, in association with diurnal sleep-wake and fasting-feeding cycles. Although loss of metabolic flexibility has been proposed to play a causal role in the pathogenesis of cardiac disease, it is currently unknown whether day-night variations in cardiac metabolism are altered during disease states. Here, we tested the hypothesis that diet-induced obesity disrupts cardiac “diurnal metabolic flexibility”, which is normalized by time-of-day-restricted feeding. Chronic high fat feeding (20-wk) induced obesity in mice, abolished diurnal rhythms in whole body metabolic flexibility, and increased markers of adverse cardiac remodeling (hypertrophy, fibrosis, and steatosis). RNAseq analysis revealed that 24-hr rhythms in the cardiac transcriptome were dramatically altered during obesity; only 22% of rhythmic transcripts in control hearts were unaffected by obesity. However, day-night differences in cardiac substrate oxidation were essentially identical in control and high fat fed mice. In contrast, day-night differences in both cardiac triglyceride synthesis and lipidome were abolished during obesity. Next, a subset of obese mice (induced by 18-wks ad libitum high fat feeding) were allowed access to the high fat diet only during the 12-hr dark (active) phase, for a 2-wk period. Dark phase restricted feeding partially restored whole body metabolic flexibility, as well as day-night differences in cardiac triglyceride synthesis and lipidome. Moreover, this intervention partially reversed adverse cardiac remodeling in obese mice. Collectively, these studies reveal diurnal metabolic inflexibility of the heart during obesity specifically for non-oxidative lipid metabolism (but not for substrate oxidation), and that restricting food intake to the active period partially reverses obesity-induced cardiac lipid metabolism abnormalities and adverse remodeling of the heart.
Project description:Zebrafish (Danio rerio) were obtained from the Zebrafish Research Facility maintained in the Center for Environmental Biotechnology at the University of Tennessee. Fish husbandry, spawning, and experimental procedures were conducted with approval from the University of Tennessee Institutional Animal Care and Use Committee (Protocol #1690-1007). Water for holding fish and conducting experiments (hereafter referred to as fish water) consisted of MilliQ water (Millipore, Bedford, MA) with ions added: 19 mg/L NaHCO3, 1 mg/L sea salt (Instant Ocean Synthetic Sea Salt, Mentor, OH), 10 mg/L CaSO4, 10 mg/L MgSO4, 2 mg/L KCl. Embryos were obtained by spawning adult fish with no history of contaminant exposure. Fertilization of embryos took place at the same time (± 15 min.), such that larvae used in experiments were of similar age at the time of exposure. All activities (maintenance of adult fish, spawning, and experiments) were conducted in an environmental chamber with a temperature of 27± 1 ºC and 14:10h light:dark photoperiod.
Project description:Clinical cohort data suggest that high consumption of red meat containing N-glycolylneuraminic acid (Neu5Gc) may increase colorectal prevalence, therefore, we investigated the effect of high Neu5Gc intake on colon cancer using the APCMin/+ mouse model . Ten APCMin/+ male mice were divided into two groups and fed normal (control group: 0.0507 mg per mouse per day) and high concentrations (treatment group: 1.014 mg per mouse per day) of Neu5Gc to mimic Normal and excessive consumption of red meat in humans, respectively. After two weeks of feeding, colorectal and liver were collected for histopathological diagnosis and transcriptome analysis.
Project description:A collection of 1145 clones from an EST project on female tick salivary gland genes was hybridized on glass slides to RNA extracted from several feeding stages of adult female tick salivary glands, including unfed and replete, and from adult male ticks, either unfed or fed in the presence or absence of female ticks. In the female ticks, the early fed (<50 mg) and partially fed (30-200 mg) groups were very similar. The fast feeding (350-500 mg) and replete ticks were similar to each other, but different from the partially fed. The unfed ticks were more similar to the fast feeding – replete groups than the early fed-partially fed groups. In the males, there were differences between the males fed in the presence or absence of females, but overall, these groups were very similar. The unfed ticks were significantly different from the fed ticks. Males showed clear differences with females in expression, as well. The unfed females had high levels of genes involved in protein synthesis, while genes possibly involved in survival on the host, such as anticoagulants, seemed to be most expressed in the early and partially fed states. By contrast, in the males, the protein synthesis genes were expressed more in all three groups, while the putative secreted genes for survival were expressed less. Keywords: time course, effect of feeding, sex, effect of presence of females
Project description:Background: Poultry eggs are a low cost, high protein nutrient package that can be consumed as part of a quality diet. However, consumption of poultry egg products has been historically contentious, which highlights the importance of investigating impacts of long-term egg consumption on metabolic health. Objective: Our study utilized the zebrafish Danio rerio, a newly-defined model of human metabolic health, to understand the metabolic consequence of consuming egg products in lieu of other well-described protein sources. Methods: Reference diets were formulated to contain multi-source protein with casein and fish protein hydrolysate (CON; control protein sources), the protein sources of which have been vetted in numerous reference diets. These proteins were then replaced in part with either whole egg (WE; protein and lipid source), egg white (EW; protein source), wheat gluten (WG; cereal protein source), or a high lipid content diet containing a multi-source protein with casein and fish protein hydrolysate (HFCON; isonitrogenous and isolipidic with the WE diet) in a 34-week trial. Daily feeding was initiated at early juvenile life stage and terminated at late reproductive adult stage. Results: The amino acid composition of control vs egg product diets did not vary substantially, although methionine and lysine were apparently limiting in fish fed WG. At termination, fish fed EW as the protein source had similar weight gain and body composition to those fed the CON diet. Blood glucose, both fasting and postprandial, did not differ among any dietary treatment. Assessment of the liver transcriptome using RNAseq revealed no differential gene expression between zebrafish fed CON or WE diets. Zebrafish fed WG had lower weight gain in males. Conclusions: Long-term consumption of egg products promoted metabolic health equal to that of historically-relevant proteins. These data support the value of egg products for maintaining long-term metabolic health in animal diets.