Project description:Liver X receptor α (LXRα) is a key regulator of lipid homeostasis and effective inhibitors of inflammation. We used the second-generation transcriptome sequencing(RNA-seq) to determine the expression changes of each gene in LXRα-/- mices and wild type mices fed with a chow diet or a high fat diet (HFD).We investigated the downstream molecular mechanisms by which loss of LXRα regulates lipid synthesis and metabolism in HFD.
Project description:Dietary flavonoids are supposed to be protective against cardiovascular diseases (CVD). Elevated circulating lipid levels and hepatic lipid accumulation are known risk factors for CVD. We investigated the effects and underlying molecular mechanisms of the flavonoid quercetin on hepatic lipid metabolism in mice with diet induced body weight gain and hepatic lipid accumulation. Adult male mice received a high-fat diet without or with supplementation of 0.33% (w/w) quercetin for 12 weeks. Body weight gain was 29% lower in quercetin-fed mice (p<0.01), while the energy intake was not significantly different. Quercetin supplementation reduced hepatic lipid accumulation with 71% (p<0.05). 1H nuclear magnetic resonance serum lipid profiling revealed that the supplementation lowered serum lipids (p<0.0001). Global gene expression profiling of liver showed that key target genes of the transcription factor Constitutive androstane receptor (Car; official symbol Nr1i3) were regulated, in particular Cytochrome P450 2b (Cyp2b) genes. Quercetin can decrease high-fat diet induced body weight gain, hepatic lipid accumulation and serum lipid levels, which might be explained by the regulation of Cytochrome P450 genes under transcriptional control of CAR, an effect which is likely dependent on dietary background. Liver samples were obtained from 24 C57BL/6J male adult mice. All mice started with a three week adaptation phase, in which they were fed a normal-fat diet. During the intervention of 12 weeks, the mice received a high-fat diet without (HF) or with supplementation of 0.33% (w/w) quercetin (HF-Q). Based on visual inspection, three arrays lacked homogenous hybridization and were therefore excluded.
Project description:Dietary flavonoids are supposed to be protective against cardiovascular diseases (CVD). Elevated circulating lipid levels and hepatic lipid accumulation are known risk factors for CVD. We investigated the effects and underlying molecular mechanisms of the flavonoid quercetin on hepatic lipid metabolism in mice with diet induced body weight gain and hepatic lipid accumulation. Adult male mice received a high-fat diet without or with supplementation of 0.33% (w/w) quercetin for 12 weeks. Body weight gain was 29% lower in quercetin-fed mice (p<0.01), while the energy intake was not significantly different. Quercetin supplementation reduced hepatic lipid accumulation with 71% (p<0.05). 1H nuclear magnetic resonance serum lipid profiling revealed that the supplementation lowered serum lipids (p<0.0001). Global gene expression profiling of liver showed that key target genes of the transcription factor Constitutive androstane receptor (Car; official symbol Nr1i3) were regulated, in particular Cytochrome P450 2b (Cyp2b) genes. Quercetin can decrease high-fat diet induced body weight gain, hepatic lipid accumulation and serum lipid levels, which might be explained by the regulation of Cytochrome P450 genes under transcriptional control of CAR, an effect which is likely dependent on dietary background.
Project description:The ketogenic diet has been successful in promoting weight loss among patients that have struggled with weight gain. This is due to the cellular switch in metabolism that utilizes liver-derived ketone bodies for the primary energy source rather than glucose. Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the transport of exogenous long chain fatty acids (LCFA) and in the activation to CoA thioesters of very long chain fatty acids (VLCFA). We have completed a multi-omic study of FATP2-null (Fatp2-/-) mice maintained on a ketogenic diet (KD) or paired control diet (CD), with and without a 24-hour fast (KD-fasted and CD-fasted) to address the impact of deleting FATP2 under high-stress conditions. Control (wt/wt) and Fatp2-/- mice were maintained on their respective diets for 4-weeks. Afterwards, half the population was sacrificed while the remaining were fasted for 24-hours prior to sacrifice. We then performed paired-end RNA-sequencing on the whole liver tissue to investigate differential gene expression. The differentially expressed genes mapped to ontologies such as the metabolism of amino acids and derivatives, fatty acid metabolism, protein localization, and components of the immune system’s complement cascade, and were supported by the proteome and histological staining.
Project description:Liver X Receptors (LXRα and β) are ligand-activated transcription factors that play a key role in the control of lipid homeostasis, as well as modulation of immunity and inflammation. LXR activity can be regulated by posttranslational modifications, such as phosphorylation. This study aims to assess changes in the hepatic transcriptional profiles of mice that carry a whole-body phosphorylation deficient knock in mutant of LXRα (S196A) compared to wild-type (WT) upon being fed a HFHC diet.