Project description:Male C57BL/6J mice were fed a high-fat diet (HFD, 60 kcal% fat, D12492, Research Diets, Inc) or normal standard chow diet with 10 kal% fat (ND, D09100304, Research Diets, Inc). Specifically, 6-week-old mice were fed a HFD for 12 weeks to induce insulin resistance (HFD-12w group); 14-week-old mice were fed a HFD for 4 weeks to induce obesity (HFD-4w group). Control mice were fed a ND continuously for 12 weeks starting at 6 weeks of age (ND group). All mice reached the experimental endpoint at 18 weeks of age. Insulin sensitivity was measured by glucose tolerance test and insulin tolerance test. Mice that developed insulin resistance in HFD-12w group and obese mice with normal insulin sensitivity in HFD-4w group were used for further experiments. Mice in ND group were used as controls. Upon reaching the experimental endpoint, livers from three insulin-resistant mice, three insulin-sensitive obese mice, and three control mice were removed for RNA sequencing.
Project description:Long-term high fat feeding leads to hepatic steatosis, dyslipidemia, and a pro-inflammatory state. In a previous study, we observed this dysregulated metabolic phenotype when C57BL/6 mice were fed a high fat diet (HFD) for sixteen weeks. Additionally, a five-fold increase in liver gene expression of serum amyloid A-1 (SAA-1), an acute phase response protein that associates with high density lipoprotein (HDL), was observed. Inflammation induced changes composition may alter HDL functions, including anti-oxidant, anti-inflammatory and reverse cholesterol transport properties. Diet-induced onset and progression of HDL dysfunction is poorly understood. To examine the relationship between high fat diet and HDL dysfunction, we performed a short-term diet study. Four-week high fat feeding caused an increase in total plasma cholesterol compared with mice fed normal control diet (ND). No change in plasma triglycerides or development of hepatic steatosis was observed. These mice did however show evidence for increase in acute phase reactants, with a 3.25-fold increase in SAA-1 expression in liver. Heavy water labelling was used to determine the turnover rates of proteins associated with HDL. High fat diet resulted in increased fractional catabolic rate (HFD vs ND) of several acute phase response proteins involved ininnate immunity , including – Complement C3 (7.06 ± 0.99 vs 5.20 ± 0.56 %/h, p < 0.005), complement factor B (6.17 ± 0.59 vs 5.09 ± 0.87 %/h, p < 0.05), complement Factor H (4.16 ± 0.41 vs 3.56 ± 0.36 %/h, p < 0.05), and Complement factor I (3.50 ± 0.26 vs 2.75 ± 0.14 %/h, p < 0.005). Our findings suggest that early immune response-induced inflammatory remodeling of HDL precedes the diet-induced steatosis and dyslipidemia. Early HDL dysfunction reflected on impaired reverse cholesterol transport likely results in increase in plasma cholesterol in the absence of other lipid abnormalities.
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.
Project description:Transcriptional profiling for screening olfactory receptor expressions in C57BL/6J mouse liver and adipose tissue under either ND and HFD
Project description:There is an increasing clinical evidence that obesity exerts deleterious effects on the skeleton. While obesity coexists with estrogen deficiency in postmenopausal women, their combined effects on the skeleton are poorly studied. Thus, we investigated the impact of high-fat diet (HFD) on bone and metabolism of ovariectomized (OVX) female mice (C57BL/6J). OVX or sham operated mice were fed either HFD (60%fat) or normal diet (ND) (10%fat) for 12 weeks. HFD-OVX group exhibited pronounced increase in body weight (~86% in HFD and ~122% in HFD-OVX, p<0.0005) and impaired glucose tolerance. Bone microCT-scanning revealed a pronounced decrease in trabecular bone volume/total volume (BV/TV) in HFD-OVX (15.6±0.48% in HFD and 37.5±0.235% in HFD-OVX, p<0.005) and expansion of bone marrow adipose tissue (BMAT) (+60.7±9.9% in HFD vs +79.5±5.86% in HFD-OVX, p<0.005). Mechanistically, HFD-OVX treatment led to upregulation of genes markers of senescence, bone resorption, adipogenesis and inflammation and downregulation of gene markers of bone formation and bone development. Similarly, HFD- OVX treatment resulted in significant changes in bone tissue levels of Purine/Pyrimidine and Glutamate metabolisms, known to play a regulatory role in bone metabolism. Obesity and estrogen deficiency exert combined deleterious effects on bone resulting in accelerated cellular senescence, expansion of BMAT and impaired bone formation leading to decreased bone mass. Our results suggest that obesity may increase bone fragility in post-menopausal women.
Project description:Mice are on a C57Bl/6J background strain, hearts were collected from Clock and WT mice at ZT07, following 24 weeks on either a HF or SC diet. The microarray approach allows the investigation of gene expression changes of all genes in Clock HFD vs. Clock SC vs. WT HFD vs. WT SC hearts.
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:To investigate the alterlation of liver gene expression by linoleic acid (LA) metabolite HYA (10-hydroxy-cis-12-octadecenoic acid) in a diet-induced NAFLD/NASH model, we evaluated liver of male C57BL/6J mice fed a nomal diet (ND), a high fat diet (HFD, Control(CT)), HFD supplemented with 1% HYA (HYA), or HFD supplemented with 1% LA (LA) for 26 weeks from 5-week-old. We then performed gene expression profiling analysis using data obtained from RNA-seq of these 4 groups.
Project description:Obesity is tightly associated with an increased risk of nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanisms of obesity-induced fatty liver remain largely unknown.In order to identify genes that are potentially involved in dysfunctional hepatic lipid homeostasis in obesity, we performed a clustering analysis of Affymetrix arrays,which revealed that a number of mRNAs were dys-regulated in the livers of mice fed a high-fat diet (HFD), compared with mice fed a normal chow diet (ND). To identify genes that are potentially involved in dysfunctional hepatic lipid homeostasis in obesity, male C57BL/6 mice aged 8 weeks were fed a normal diet (ND) or high-fat-diet (HFD) containing 60 Kcal% of fat for 12 weeks. Then mice were sacrificed and total RNAs were isoloated from hepatic tissues. Affymetrix array hybridisation and scanning were performed using Mouse Genome 430 2.0 chips.Total RNA samples obtained from six mice per group (ND and HFD) and pooled by each of the two were used for microarray analysis.
Project description:Increasing evidences indicate diet-induced metabolic disorder could be paternally inherited, but the exact sperm epigenetic carrier remains unclear. Here, in a paternal high-fat diet (HFD) mouse model, we revealed that a highly enriched subset of sperm small RNAs (30-34 nt) that derived from the 5â halves of tRNAs (tsRNAs), exhibit changes in both expression profiles and RNA modifications. Injection of sperm tsRNAs from HFD male but not synthetic tsRNAs lacking RNA modifications, into normal zygotes generated metabolic disorders in the F1 offspring. Injection of HFD sperm tsRNAs derails gene expression in both early embryos and islets of F1 offspring, enriched in metabolic pathways, but unrelated to DNA methylation at CpG-enriched region. Collectively, we uncover sperm tsRNAs as a type of âepigenetic carrierâ that mediate intergenerational inheritance of acquired traits. Mature sperm small-RNA profiles between High-fat-diet (HFD) and Normal-diet (ND) males; Transcriptional profiles of 8-cell embryos and balstocysts that developed from zygotes that injected with sperm RNAs from HFD vs ND males. Transcriptional profiles and RRBS profiles of islets of F1 offsrping that generated from zygotes that injected with sperm RNAs from HFD vs ND males.