Studies in mice have shown that PPAR is an important regulator of hepatic lipid metabolism and the acute phase response. However, little information is available on the role of PPAR in human liver. Here we set out to compare the function of PPAR in mouse and human hepatocytes via analysis of target gene regulation. Primary hepatocytes from 6 human and 6 mouse donors were treated with PPAR agonist Wy14643 and gene expression profiling was performed using Affymetrix GeneChips followed by a systems biology analysis. Baseline PPAR expression was similar in human and mouse hepatocytes. Depending on species and time of exposure, Wy14643 significantly induced the expression of 362-672 genes. Surprisingly minor overlap was observed between the Wy14643-regulated genes from mouse and human, although more substantial overlap was observed at the pathway level. Xenobiotics metabolism and apolipoprotein synthesis were specifically regulated by PPAR in human hepatocytes, whereas glycolysis-gluconeogenesis was regulated specifically in mouse hepatocytes. Most of the genes commonly regulated in mouse and human were involved in lipid metabolism and many represented known PPAR targets, including CPT1A, HMGCS2, FABP, ACSL, and ADFP. Several genes were identified that were specifically induced by PPAR in human (MBL2, ALAS1, CYP1A1, TSKU) or mouse (Fbp2, lgals4, Cd36, Ucp2, Pxmp4). Furthermore, several putative novel PPAR targets were identified that were commonly regulated in both species, including CREB3L3, KLF10, KLF11 and MAP3K8. Our results suggest that PPAR activation has a major impact on gene regulation in human hepatocytes. Importantly, the role of PPAR as master regulator of hepatic lipid metabolism is generally well-conserved between mouse and human. Overall, however, PPAR regulates a mostly divergent set of genes in mouse and human hepatocytes.
Comparative analysis of gene regulation by the transcription factor PPARalpha between mouse and human.
Sex, Age, Specimen part, Subject, Time
View SamplesStudies in mice have shown that PPAR is an important regulator of hepatic lipid metabolism and the acute phase response. However, little information is available on the role of PPAR in human liver. Here we set out to compare the function of PPAR in mouse and human hepatocytes via analysis of target gene regulation. Primary hepatocytes from 6 human and 6 mouse donors were treated with PPAR agonist Wy14643 and gene expression profiling was performed using Affymetrix GeneChips followed by a systems biology analysis. Baseline PPAR expression was similar in human and mouse hepatocytes. Depending on species and time of exposure, Wy14643 significantly induced the expression of 362-672 genes. Surprisingly minor overlap was observed between the Wy14643-regulated genes from mouse and human, although more substantial overlap was observed at the pathway level. Xenobiotics metabolism and apolipoprotein synthesis were specifically regulated by PPAR in human hepatocytes, whereas glycolysis-gluconeogenesis was regulated specifically in mouse hepatocytes. Most of the genes commonly regulated in mouse and human were involved in lipid metabolism and many represented known PPAR targets, including CPT1A, HMGCS2, FABP, ACSL, and ADFP. Several genes were identified that were specifically induced by PPAR in human (MBL2, ALAS1, CYP1A1, TSKU) or mouse (Fbp2, lgals4, Cd36, Ucp2, Pxmp4). Furthermore, several putative novel PPAR targets were identified that were commonly regulated in both species, including CREB3L3, KLF10, KLF11 and MAP3K8. Our results suggest that PPAR activation has a major impact on gene regulation in human hepatocytes. Importantly, the role of PPAR as master regulator of hepatic lipid metabolism is generally well-conserved between mouse and human. Overall, however, PPAR regulates a mostly divergent set of genes in mouse and human hepatocytes.
Comparative analysis of gene regulation by the transcription factor PPARalpha between mouse and human.
Sex, Age, Specimen part, Subject, Time
View SamplesStudies in mice have shown that PPAR is an important regulator of hepatic lipid metabolism and the acute phase response. However, little information is available on the role of PPAR in human liver. Here we set out to compare the function of PPAR in mouse and human hepatocytes via analysis of target gene regulation. Primary hepatocytes from 6 human and 6 mouse donors were treated with PPAR agonist Wy14643 and gene expression profiling was performed using Affymetrix GeneChips followed by a systems biology analysis. Baseline PPAR expression was similar in human and mouse hepatocytes. Depending on species and time of exposure, Wy14643 significantly induced the expression of 362-672 genes. Surprisingly minor overlap was observed between the Wy14643-regulated genes from mouse and human, although more substantial overlap was observed at the pathway level. Xenobiotics metabolism and apolipoprotein synthesis were specifically regulated by PPAR in human hepatocytes, whereas glycolysis-gluconeogenesis was regulated specifically in mouse hepatocytes. Most of the genes commonly regulated in mouse and human were involved in lipid metabolism and many represented known PPAR targets, including CPT1A, HMGCS2, FABP, ACSL, and ADFP. Several genes were identified that were specifically induced by PPAR in human (MBL2, ALAS1, CYP1A1, TSKU) or mouse (Fbp2, lgals4, Cd36, Ucp2, Pxmp4). Furthermore, several putative novel PPAR targets were identified that were commonly regulated in both species, including CREB3L3, KLF10, KLF11 and MAP3K8. Our results suggest that PPAR activation has a major impact on gene regulation in human hepatocytes. Importantly, the role of PPAR as master regulator of hepatic lipid metabolism is generally well-conserved between mouse and human. Overall, however, PPAR regulates a mostly divergent set of genes in mouse and human hepatocytes.
Comparative analysis of gene regulation by the transcription factor PPARalpha between mouse and human.
Sex, Age, Specimen part, Time
View SamplesArgonaute (Ago) proteins, which act in post-transcriptional gene regulation directed by small RNAs, are vital for normal stem cell biology. Here we report the genomic characterization of stable Ago-deficient mouse embryonic stem cells (mESC) and determine the direct, primary and system level response to loss of Ago-mediated regulation. We find mESCs lacking all four Ago proteins are viable, do not repress microRNA (miRNA)-targeted cellular RNAs, and show distinctive gene network signatures. Profiling of RNA expression and epigenetic activity in an Ago mutant genetic series indicates that early responses to Ago loss are driven by transcriptional regulatory networks, in particular the Tgf-ß/Smad transcriptional network. This finding is confirmed using a time course analysis of Ago depletion and Ago rescue experiments. Detailed analysis places Tgf-ß/Smad activation upstream of cell cycle regulator activation, such as Cdkn1a, and repression of the c-Myc transcriptional network. The Tgf-ß/Smad pathway is directly controlled by multiple low-affinity miRNA interactions with Tgf-ß/Activin receptor mRNAs and receptor-mediated activation is required for Tgf-ß/Smad target induction with Ago loss. Our characterization reveals the interplay of post-transcriptional regulatory pathways with transcriptional networks in maintaining cell state and likely coordinating cell state transitions. Overall design: mRNA seq from stable genetic Dicer and Dgcr8 mutant mouse embryonic stem cells.
Temporal Control of the TGF-β Signaling Network by Mouse ESC MicroRNA Targets of Different Affinities.
Specimen part, Cell line, Subject
View SamplesThe effect of CLA on gene expression in Caco-2 cells
Conjugated linoleic acid alters global gene expression in human intestinal-like Caco-2 cells in an isomer-specific manner.
No sample metadata fields
View SamplesObesity and associated increased prevalence of non-alcoholic fatty liver (NAFLD) disease is suggested to be positively modulated by a high protein (HP) diet in humans and rodents. The aim was to detect mechanisms by which a HP diet prevents hepatic lipid accumulation by means of transcriptomics. To study the acute and long term effect of a high protein ingestion on hepatic lipid accumulation under both low and high fat (HF) conditions, mice were fed combinations of high (35%) or low (10%) fat and high (50%) or normal (15%) protein diets for 1 or 12 weeks. Body composition, liver fat, VLDL production rate and gene expression were investigated. Differences in metabolic processes and functions in the liver were identified using gene set enrichment analysis on microarray data. Mice fed the HP diets developed less adiposity and decreased hepatic lipid accumulation due a combination of induced processes mainly involved in protein catabolism such as transamination, TCA cycle and oxidative phosphorylation. Feeding a HP diet can successfully prevent the development of NAFLD by using ingested energy for oxidation instead of storage.
Dietary protein affects gene expression and prevents lipid accumulation in the liver in mice.
Sex, Age, Specimen part, Time
View SamplesIn this randomised placebo-controlled trial, irritable bowel syndrome (IBS) patients were treated with faecal material from a healthy donor (n=8, allogenic FMT) or with their own faecal microbiota (n=8, autologous FMT). The faecal transplant was administered by whole colonoscopy into the caecum (30 g of stool in 150 ml sterile saline). Two weeks before the FMT (baseline) as well as two and eight weeks after the FMT, the participants underwent a sigmoidoscopy, and biopsies were collected at a standardised location (20-25 cm from the anal verge at the crossing with the arteria iliaca communis) from an uncleansed sigmoid. In patients treated with allogenic FMT, predominantly immune response-related genes sets were induced, with the strongest response two weeks after FMT. In patients treated with autologous FMT, predominantly metabolism-related gene sets were affected.
Allogenic Faecal Microbiota Transfer Induces Immune-Related Gene Sets in the Colon Mucosa of Patients with Irritable Bowel Syndrome.
Age, Specimen part, Subject
View SamplesRecent studies have identified intracellular metabolism as a fundamental determinant of macrophage function. In obesity, proinflammatory macrophages accumulate in adipose tissue and trigger chronic low-grade inflammation, that promotes the development of systemic insulin resistance, yet changes in their intracellular energy metabolism are currently unknown. We therefore set out to study metabolic signatures of adipose tissue macrophages (ATMs) in lean and obese conditions. F4/80-positive ATMs were isolated from obese vs lean mice. High-fat feeding of wild-type mice and myeloid-specific Hif1-/- mice was used to examine the role of hypoxia-inducible factor-1 (HIF-1) in ATMs part of obese adipose tissue. In vitro, bone marrow-derived macrophages were co-cultured with adipose tissue explants to examine adipose tissue-induced changes in macrophage phenotypes. Transcriptome analysis, real-time flux measurements, ELISA and several other approaches were used to determine the metabolic signatures and inflammatory status of macrophages. In addition, various metabolic routes were inhibited to determine their relevance for cytokine production. Transcriptome analysis and extracellular flux measurements of mouse ATMs revealed unique metabolic rewiring in obesity characterised by both increased glycolysis and oxidative phosphorylation. Similar metabolic activation of CD14+ cells in obese individuals was associated with diabetes outcome. These changes were not observed in peritoneal macrophages from obese vs lean mice and did not resemble metabolic rewiring in M1-primed macrophages. Instead, metabolic activation of macrophages was dose-dependently induced by a set of adipose tissue-derived factors that could not be reduced to leptin or lactate. Using metabolic inhibitors, we identified various metabolic routes, including fatty acid oxidation, glycolysis and glutaminolysis, that contributed to cytokine release by ATMs in lean adipose tissue. Glycolysis appeared to be the main contributor to the proinflammatory trait of macrophages in obese adipose tissue. HIF-1, a key regulator of glycolysis, nonetheless appeared to play no critical role in proinflammatory activation of ATMs during early stages of obesity. Our results reveal unique metabolic activation of ATMs in obesity that promotes inflammatory cytokine release. Further understanding of metabolic programming in ATMs will most likely lead to novel therapeutic targets to curtail inflammatory responses in obesity.
Unique metabolic activation of adipose tissue macrophages in obesity promotes inflammatory responses.
Sex, Specimen part
View SamplesDietary fatty acids have myriads of effects on human health and disease. Many of these effects are likely achieved by altering expression of genes. Several transcription factors have been shown to be responsive to fatty acids, including SREBP-1c, NF-kB, RXRs, LXRs, FXR, HNF4, and PPARs. However, the relative importance of these transcription factors in regulation of gene expression by dietary fatty acids remains unclear. Here, we take advantage of a unique experimental design using synthetic triglycerides composed of one single fatty acid in combination with gene expression profiling to examine the acute effects of individual dietary fatty acids on hepatic gene expression in mice. The dietary interventions were performed in parallel in wild-type and PPAR-/- mice, enabling the determination of the specific contribution of PPAR. Depending on chain length and degree of saturation, dietary fatty acids caused a statistically significant change in expression of over 400 genes. Surprisingly, the far majority of genes regulated by dietary fatty acids in wild-type mice were unaltered in mice lacking PPAR, indicating PPAR-dependent regulation. We conclude that the effects of dietary fatty acids on hepatic gene expression are almost entirely mediated by PPAR, indicating that PPAR dominates fatty acid-dependent gene regulation in liver.
Effect of synthetic dietary triglycerides: a novel research paradigm for nutrigenomics.
Sex, Specimen part
View SamplesBackground: The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called intestinal barrier proteins. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPAR), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPAR on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPAR-null mice. Treatment with the synthetic PPAR agonist WY14643 served as reference.
PPARalpha-mediated effects of dietary lipids on intestinal barrier gene expression.
No sample metadata fields
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