Project description:Regulation of nutrient status during fasting and refeeding plays an important role in maintaining metabolic homeostasis in the liver. Thus, we investigated the impact of the physiological fed–fasted–refed cycle on hepatic gene expression in nutrient-sensitive mice. We performed transcriptomic analysis of liver samples in fed, fasted and refed groups of mice. Through mRNA-sequencing (RNA-Seq) and miRNA-Seq, we compared fasted and fed states (fasted versus fed cohort) as well as refed and fasted states (refed versus fasted cohort) to detect dynamic alterations of hepatic mRNA– miRNA expression during the fed–fasted–refed cycle
Project description:Regulation of nutrient status during fasting and refeeding plays an important role in maintaining metabolic homeostasis in the liver. Thus, we investigated the impact of the physiological fed–fasted–refed cycle on hepatic gene expression in nutrient-sensitive mice. We performed transcriptomic analysis of liver samples in fed, fasted and refed groups of mice. Through mRNA-sequencing (RNA-Seq) and miRNA-Seq, we compared fasted and fed states (fasted versus fed cohort) as well as refed and fasted states (refed versus fasted cohort) to detect dynamic alterations of hepatic mRNA– miRNA expression during the fed–fasted–refed cycle
Project description:Spatial heterogeneity and plasticity of the mammalian liver is critical for systemic metabolic homeostasis in response to fluctuating nutritional status. Here, we generated a high-resolution transcriptomic landscape of the livers from mice that were either fed chow (fed), fasted for 18 h (fasted), or fasted for 18 h and then refed for 6 h (refed) using spatial transcriptomics (ST) and quantified changes in gene expression. This work provides a critical foundation for future mechanistic studies of liver metabolic heterogeneity and plasticity, and will help to understand the zonated pathology during liver disease progression.
Project description:GATA4 is a transcription factor known for its crucial role in the development of many tissues, including liver; however, its role in adult liver metabolism is unknown. Here, using high-throughput sequencing technologies, including assay for transposase-accessible chromatin with sequencing (ATAC-Seq), we identified GATA4 as a transcriptional regulator of metabolism in liver. GATA4 expression is elevated in response to refeeding, and its occupancy is increased at enhancers of genes linked to fatty acid and lipoprotein metabolism. Knocking out GATA4 in adult liver (Gata4LKO) decreased transcriptional activity at GATA4 binding sites especially during feeding. Gata4LKO mice have reduced plasma HDL cholesterol and increased liver triglyceride levels. The expression of a panel of genes involved in cholesterol export and triglyceride hydrolysis was downregulated and the expression of those involved in lipid uptake were upregulated in Gata4LKO liver, We further demonstrate that GATA4 collaborates with LXR liver. GATA4 shares a number of binding sites and direct transcriptional targets with LXRs, and loss of GATA4 impairs the hepatic transcriptional response to LXR agonist. Collectively, these results show that hepatic GATA4 contributes to the transcriptional control of hepatic and systemic lipid homeostasis.
Project description:Transcript data from liver receptor homolog-1 (LRH-1) WT and LRH-1 K289R livers from mice fasted for 24h followed by 6h refed. We used microarrays to detail the global program of gene expression underlying hepatic function under refed conditions.
Project description:If the function of the nuclear receptor PPARa is well-known during a prolongated fasting, its hepatic biological function during feeding and refeeding conditions still needs to be investigated. Moreover, in vivo data collected so far on PPARa function during fasting were obtained using the total Ppara KO transgenic mouse model. To identify genes whose expression is under the strict dependence of hepatic PPARa activity, we generated a new mouse strain of PPARa-specific deletion in hepatocyte (albumin-Cre+/- Pparaflox/flox or LKO) and we compared them to total Ppara KO (KO), wild-type (WT) and liver WT (albumin-Cre-/- Pparaflox/flox or LWT) mice under three nutritional challenges. We used microarrays to detail the global programme of gene expression in liver of Ppara LKO, LWT, Ppara KO and WT male mice fed ad libitum, fasted for 24 hours and refed. There are 52 liver samples, each from an individual mouse. The samples are from Ppara liver KO (LKO), Ppara KO (KO), wild-type (WT) and liver WT (LWT) male mice of 8 week-old from the same genetic background (C57Bl/6J) fed ad libitum, fasted for 24 hours, fasted for 24 hours and then refed 24 hours more with glucose added in water (200g/l). In fed condition (Fed), n= 3 mice for LKO, LWT genotypes, n= 5 for KO and n= 4 fot WT; in fasting condition (Fas), n=5 for LKO, LWT and WT genotypes and n= 3 for KO; in refeeding condition (Ref), n= 5 for LKO, KO and WT genotypes and n= 4 for LWT. All mice were sacrified at ZT14.
Project description:We report the application of RNA-sequencing technology for high-throughput profiling of RNA abundance in Drosophila melanogaster brains. By obtaining RNA-sequencing reads, we generated quantitative transcriptome-wide measures in three nutritional states: sated, fasted, refed.