Hepatic gene expression study
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ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE13936 | GEO | 2009/12/10
SECONDARY ACCESSION(S): PRJNA110271
REPOSITORIES: GEO
Similar Datasets
Project description:The aim of this study was to compare the effects of cocoa butter and safflower oil on hepatic transcript profiles, lipid metabolism and insulin sensitivity in healthy rats. Cocoa butter-based high-fat feeding for three days did not affect plasma total triglyceride (TG) levels or TG-rich VLDL particles or hepatic insulin sensitivity, but changes in hepatic gene expression were induced that might lead to increased lipid synthesis, lipotoxicity, inflammation and insulin resistance if maintained. Safflower oil increased hepatic β-oxidation, was beneficial in terms of circulating TG-rich VLDL particles, but led to reduced hepatic insulin sensitivity. The effects of safflower oil on hepatic gene expression were partly overlapping with those exerted by cocoa butter, but fewer transcripts from anabolic pathways were altered. Increased hepatic cholesterol levels and increased expression of hepatic CYP7A1 and ABCG5 mRNA, important gene products in bile acid production and cholesterol excretion, were specific effects elicited by safflower oil only. Common effects on gene expression included increased levels of p8, DIG-1 IGFBP-1 and FGF21, and reduced levels of SCD-1 and SCD-2. This indicates that a lipid-induced program for hepatic lipid disposal and cell survival was induced by three days of high-fat feeding, independent on the lipid source. Based on the results, we speculate that hepatic TG infiltration leads to reduced expression of SCD-1, which might mediate either neutral, beneficial or unfavourable effects on hepatic metabolism upon high-fat feeding, depending on which fatty acids were provided by the diet. Keywords: Hepatic gene expression Two-condition experiment. Biological replicates: 4 male rat livers from rats on a standard diet, 4 male rat livers from rats on a cocoa butter diet, 4 male rat livers from rats on a high-fat (safflower oil) diet. One replicate per array.
2010-05-18 | E-GEOD-13936 | biostudies-arrayexpress
Project description:Background and Aims: Inflammasome-mediated caspase-1 activity regulates the maturation and release of the pro-inflammatory cytokines interleukin (IL)-1M-CM-^_ and IL-18. Recently, we showed that caspase-1 deficiency strongly reduces high fat diet-induced adiposity although the mechanism is still unclear. We now aimed to elucidate the mechanism by which caspase-1 deficiency reduces modulates resistance to high fat diet-feeding fat accumulation in adipose tissue by focusing on the role of caspase-1 in the regulation of triglyceride (TG)-rich lipoprotein metabolism. Methods: Caspase-1 deficient and wild-type mice (both C57Bl/6 background) were used to determine postprandial TG kinetics, intestinal TG absorption, VLDL-TG production as well as TG clearance, all of which strongly contribute to the supply of TG for storage in adipose tissue. Micro-array and qPCR analysis were used to unravel intestinal and hepatic metabolic pathways involved. Results: Caspase-1 deficiency reduced the postprandial response to an oral lipid load, while tissue specific clearance of TG-rich lipoproteins was not changed. Indeed, an oral olive oil gavage containing [3H]TG revealed that caspase-1 deficiency significantly decreased intestinal chylomicron-TG production and reduced the uptake of [3H]TG-derived FA by liver, muscle, and adipose tissue. Similarly, caspase-1 deficiency reduced the hepatic VLDL-TG production without reducing VLDL-apoB production, despite an elevated hepatic TG content. Pathway analysis revealed that caspase-1 deficiency reduces intestinal and hepatic expression of genes involved in lipogenesis. Conclusions: Absence of caspase-1 reduces assembly and secretion of TG-rich lipoproteins, thereby reducing the availability of TG-derived FA for uptake by peripheral organs including adipose tissue. We anticipate that caspase-1 represents a novel link between innate immunity and lipid metabolism. Keywords: Expression profiling by array Wild-type (WT) and Casp1-null mice were maintained at lab chow. Animals, aged between 14 and 16 weeks (n=3 per genotype), were killed and liver and intestinal segments were removed. Livers were isolated from mice that were fasted over night, whereas intesines were removed from mice 2 hrs after they received an oral lipid load.Total RNA was isolated and subjected to gene expression profiling.
2013-09-15 | E-GEOD-32515 | biostudies-arrayexpress
Project description:Background and Aims: Inflammasome-mediated caspase-1 activity regulates the maturation and release of the pro-inflammatory cytokines interleukin (IL)-1ß and IL-18. Recently, we showed that caspase-1 deficiency strongly reduces high fat diet-induced adiposity although the mechanism is still unclear. We now aimed to elucidate the mechanism by which caspase-1 deficiency reduces modulates resistance to high fat diet-feeding fat accumulation in adipose tissue by focusing on the role of caspase-1 in the regulation of triglyceride (TG)-rich lipoprotein metabolism. Methods: Caspase-1 deficient and wild-type mice (both C57Bl/6 background) were used to determine postprandial TG kinetics, intestinal TG absorption, VLDL-TG production as well as TG clearance, all of which strongly contribute to the supply of TG for storage in adipose tissue. Micro-array and qPCR analysis were used to unravel intestinal and hepatic metabolic pathways involved. Results: Caspase-1 deficiency reduced the postprandial response to an oral lipid load, while tissue specific clearance of TG-rich lipoproteins was not changed. Indeed, an oral olive oil gavage containing [3H]TG revealed that caspase-1 deficiency significantly decreased intestinal chylomicron-TG production and reduced the uptake of [3H]TG-derived FA by liver, muscle, and adipose tissue. Similarly, caspase-1 deficiency reduced the hepatic VLDL-TG production without reducing VLDL-apoB production, despite an elevated hepatic TG content. Pathway analysis revealed that caspase-1 deficiency reduces intestinal and hepatic expression of genes involved in lipogenesis. Conclusions: Absence of caspase-1 reduces assembly and secretion of TG-rich lipoproteins, thereby reducing the availability of TG-derived FA for uptake by peripheral organs including adipose tissue. We anticipate that caspase-1 represents a novel link between innate immunity and lipid metabolism. Keywords: Expression profiling by array
2013-09-15 | GSE32515 | GEO
Project description:The PPAR? activator fenofibrate efficiently decreases plasma triglycerides (TG), which is generally attributed to enhanced VLDL-TG clearance and decreased VLDL-TG production. However, since data on the effect of fenofibrate on VLDL production are controversial, we aimed to investigate in (more) detail the mechanism underlying the TG-lowering effect by studying VLDL-TG production and clearance using APOE*3-Leiden.CETP mice, a unique mouse model for human-like lipoprotein metabolism. Male mice were fed a Western-type diet for 4 weeks, followed by the same diet without or with fenofibrate (30 mg/kg bodyweight/day) for 4 weeks. Fenofibrate strongly lowered plasma cholesterol (-38%; P<0.001) and TG (-60%; P<0.001) caused by reduction of VLDL. Fenofibrate markedly accelerated VLDL-TG clearance, as judged from a reduced plasma half-life of intravenously injected glycerol tri[3H]oleate-labeled VLDL-like emulsion particles (-68%; P<0.01). This was associated with an increased post-heparin LPL activity (+110%; P<0.0001) and an increased uptake of VLDL-derived fatty acids by skeletal muscle, white adipose tissue and liver. Concomitantly, fenofibrate markedly increased the VLDL-TG production rate (+73%; P<0.0001) but not the VLDL-apoB production rate. Kinetic studies using [3H]palmitic acid showed that fenofibrate increased VLDL-TG production by equally increasing incorporation of re-esterified plasma FA and liver TG into VLDL, which was supported by hepatic gene expression profiling data. We conclude that fenofibrate decreases plasma TG by enhancing LPL-mediated VLDL-TG clearance, which results in a compensatory increase in VLDL-TG production by the liver. Male mice were fed a Western-type diet for 4 weeks, followed by the same diet without or with fenofibrate (30 mg/kg bodyweight/day) for 4 weeks. After 4 hours fasting, livers were isolated and individual gene arrays were performed.
2010-05-27 | E-GEOD-21211 | biostudies-arrayexpress
Project description:The PPARα activator fenofibrate efficiently decreases plasma triglycerides (TG), which is generally attributed to enhanced VLDL-TG clearance and decreased VLDL-TG production. However, since data on the effect of fenofibrate on VLDL production are controversial, we aimed to investigate in (more) detail the mechanism underlying the TG-lowering effect by studying VLDL-TG production and clearance using APOE*3-Leiden.CETP mice, a unique mouse model for human-like lipoprotein metabolism. Male mice were fed a Western-type diet for 4 weeks, followed by the same diet without or with fenofibrate (30 mg/kg bodyweight/day) for 4 weeks. Fenofibrate strongly lowered plasma cholesterol (-38%; P<0.001) and TG (-60%; P<0.001) caused by reduction of VLDL. Fenofibrate markedly accelerated VLDL-TG clearance, as judged from a reduced plasma half-life of intravenously injected glycerol tri[3H]oleate-labeled VLDL-like emulsion particles (-68%; P<0.01). This was associated with an increased post-heparin LPL activity (+110%; P<0.0001) and an increased uptake of VLDL-derived fatty acids by skeletal muscle, white adipose tissue and liver. Concomitantly, fenofibrate markedly increased the VLDL-TG production rate (+73%; P<0.0001) but not the VLDL-apoB production rate. Kinetic studies using [3H]palmitic acid showed that fenofibrate increased VLDL-TG production by equally increasing incorporation of re-esterified plasma FA and liver TG into VLDL, which was supported by hepatic gene expression profiling data. We conclude that fenofibrate decreases plasma TG by enhancing LPL-mediated VLDL-TG clearance, which results in a compensatory increase in VLDL-TG production by the liver.
2010-05-27 | GSE21211 | GEO
Project description:Background: Non-alcoholic fatty liver disease (NAFLD) affects nearly 25% of the global population. Cardiovascular disease (CVD) is the most common cause of death among patients with NAFLD, in line with highly prevalent dyslipidemia in this population. Increased plasma triglyceride (TG)-rich lipoprotein (TRL) concentrations, an important risk factor for CVD, are closely linked with hepatic TG content. Therefore, it is of great interest to identify regulatory mechanisms of hepatic TRL production and remnant uptake in the setting of hepatic steatosis. Approach and results: To identify liver-regulated pathways linking intra-hepatic and plasma TG metabolism, we performed transcriptomic analysis of liver biopsies from two independent cohorts of obese patients. Hepatic APOF (encoding apolipoprotein F) expression showed the 4th strongest negatively correlation with hepatic steatosis and the strongest negative correlation with plasma TG levels. The effects of adenoviral-mediated human ApoF (hApoF) overexpression on plasma and hepatic TG were assessed in C57BL6/J mice. Surprisingly, hApoF overexpression increased both hepatic VLDL-TG secretion and hepatic lipoprotein remnant clearance, associated a ~25% reduction in plasma TG levels. Conversely, reducing endogenous ApoF expression reduced VLDL secretion in vivo, and reduced hepatocyte VLDL uptake by ~15% in vitro. Transcriptomic analysis of APOF-overexpressing mouse livers revealed a gene signature related to enhanced ApoB-lipoprotein clearance, including increased expression of Ldlr and Lrp1, among others. Conclusion: These data reveal a previously undescribed role for ApoF in the control of plasma and hepatic lipoprotein metabolism by favoring VLDL-TG secretion and hepatic lipoprotein remnant particle clearance.
2022-06-29 | GSE203290 | GEO
Project description:Alcohol’s impairment of both hepatic lipid metabolism and insulin resistance (IR) are key drivers of alcoholic steatosis, the initial stage of alcoholic liver disease (ALD). Pharmacologic reduction of lipotoxic ceramide prevents alcoholic steatosis and glucose intolerance in mice, but potential off-target effects limit its strategic utility. Here, we employed a hepatic-specific acid-ceramidase (ASAH) overexpression model to reduce hepatic ceramides in a Lieber-DeCarli model of experimental alcoholic steatosis. We examined effects of alcohol on hepatic lipid metabolism, body composition, energy homeostasis and insulin sensitivity as measured by hyperinsulinemic-euglycemic clamp. Our results demonstrate that hepatic ceramide reduction ameliorates the effects of alcohol on hepatic lipid droplet accumulation by promoting VLDL secretion and lipophagy, the latter of which involves ceramide cross-talk between the lysosomal and lipid droplet compartments. We additionally demonstrate that hepatic ceramide reduction prevents alcohol’s inhibition of hepatic insulin signaling. These effects on the liver are associated with a reduction in oxidative stress markers and are relevant to humans, as we observe peri-lipid droplet ASAH expression in human ALD. Together, our results suggest a potential role for hepatic ceramide inhibition in preventing ALD.
2020-07-08 | GSE139015 | GEO
Project description:Recombinant human leptin (metreleptin) reduces hepatic lipid content in patients with lipodystrophy and overweight patients with non-alcoholic fatty liver disease and relative hypoleptinemia independent of its anorexic action. In rodents, leptin signaling in the brain increases very-low-density lipoprotein triglyceride (VLDL-TG) secretion and reduces hepatic lipid content via the vagus nerve. In this randomized, placebo-controlled crossover trial (EudraCT Nr. 2017-003014-22), we tested whether a comparable mechanism regulates hepatic lipid metabolism in humans. A single metreleptin injection stimulated hepatic VLDL-TG secretion (primary outcome) and reduced hepatic lipid content in fasted, lean men (n = 13, age range 20-38 years) but failed to do so in metabolically healthy liver transplant recipients (n = 9, age range 26-62 years) who represent a model for hepatic denervation. In an independent cohort of lean men (n = 10, age range 23-31 years), vagal stimulation by modified sham feeding replicated the effects of metreleptin on VLDL-TG secretion. Therefore, we propose that leptin has anti-steatotic properties that are independent of food intake by stimulating hepatic VLDL-TG export via a brain-vagus-liver axis.
2023-06-07 | MTBLS4231 | MetaboLights
Project description:We studied the effect of dietary fat type, varying in polyunsaturated/saturated fatty acid ratio's (P/S) on development of metabolic syndrome. C57Bl/6J mice were fed purified high-fat diets (45E% fat) containing palm oil (HF-PO; P/S 0.4), olive oil (HF-OO; P/S 1.1) or safflower oil (HF-SO; P/S 7.8) for 8 weeks. A low-fat palm oil diet (LF-PO; 10E% fat) was used as a reference. Additionally, we analyzed diet-induced changes in gut microbiota composition and mucosal gene expression. The HF-PO diet induced a higher body weight gain and liver triglyceride content compared to the HF-OO, HF-SO or LF-PO diet. In the intestine, the HF-PO diet reduced microbial diversity and increased the Firmicutes/Bacteroidetes ratio. Although this fits a typical obesity profile, our data clearly indicate that an overflow of the HF-PO diet to the distal intestine, rather than obesity itself, is the main trigger for these gut microbiota changes. A HF-PO diet-induced elevation of lipid metabolism-related genes in the distal small intestine confirmed the overflow of palm oil to the distal intestine. Some of these lipid metabolism-related genes were previously already associated with the metabolic syndrome. In conclusion, our data indicate that saturated fat (HF-PO) has a more stimulatory effect on weight gain and hepatic lipid accumulation than unsaturated fat (HF-OO and HF-SO). The overflow of fat to the distal intestine on the HF-PO diet induced changes in gut microbiota composition and mucosal gene expression. We speculate that both are directly or indirectly contributive to the saturated fat-induced development of obesity and hepatic steatosis. Keywords: Diet intervention study Nine-week-old C57Bl/6J mice were fed a low-fat diet (LF-PO) and three different types of high-fat diet, based on palm oil (HF-PO; P/S1.0), olive oil (HF-OO; P/S4.6) and safflower oil (HF-SO; P/S10.1) for 8 weeks. Body weight was recorded weekly and after 7 weeks of diet intervention an oral glucose tolerance test was performed. After 2 weeks of diet intervention, 6 mice per high-fat diet group were anaesthetized with a mixture of isofluorane (1.5%), nitrous oxide (70%) and oxygen (30%) and the small intestines were excised. Adhering fat and pancreatic tissue were carefully removed. The small intestines were divided in three equal parts along the proximal to distal axis (SI 1, SI 2 and SI 3) and microarray analysis was performed on mucosal scrapings.
2012-06-17 | E-GEOD-18586 | biostudies-arrayexpress
Project description:Contacts between organelles create microdomains that play major roles in regulating key intracellular activities and signaling pathways, but whether they also regulate systemic functions remains unknown. Here, we report the ultrastructural organization and dynamics of the inter-organellar contact established by rough-Endoplasmic Reticulum closely wrapped around the mitochondria (wrappER). To elucidate the in vivo function of this contact, mouse liver fractions enriched in wrappER-associated-mitochondria are analyzed by transcriptomics, proteomics and lipidomics. The biochemical signature of the wrappER points to a role in the biogenesis of very-low-density lipoproteins (VLDL). Altering wrappER-mitochondria contacts curtails VLDL secretion and increases hepatic fatty acids, lipid droplets and neutral lipid content. Conversely, acute liver-specific ablation of Mttp, the most upstream regulator of VLDL biogenesis, recapitulates this hepatic dyslipidemia phenotype and promotes remodelling of the wrappER-mitochondria contact. The discovery that liver wrappER-mitochondria contacts participate in VLDL biology suggests an involvement of inter-organelle contacts in systemic lipid homeostasis.
2021-03-15 | GSE134777 | GEO