Background: Exercise has a positive effect on overall health. This study was performed to get an overview of the effects of mixed exercise training on skeletal muscl
Identification of human exercise-induced myokines using secretome analysis.
Sex, Age, Race
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 SamplesThis SuperSeries is composed of the SubSeries listed below.
Peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) but not PPARalpha serves as a plasma free fatty acid sensor in liver.
Sex, Specimen part
View SamplesLipid overload and adipocyte dysfunction are key to the development of insulin resistance and can be induced by a high-fat diet. CD1d-restricted invariant natural killer T (iNKT) cells have been proposed as mediators between lipid overload and insulin resistance, but recent studies found decreased iNKT cell numbers and marginal effects of iNKT cell depletion on insulin resistance under high-fat diet conditions. Here, we focused on the role of iNKT cells under normal conditions. We showed that iNKT celldeficient mice on a low-fat diet, considered a normal diet for mice, displayed a distinctive insulin resistance phenotype without overt adipose tissue inflammation. Insulin resistance was characterized by adipocyte dysfunction, including adipocyte hypertrophy, increased leptin, and decreased adiponectin levels. The lack of liver abnormalities in CD1d-null mice together with the enrichment of CD1d-restricted iNKT cells in both mouse and human adipose tissue indicated a specific role for adipose tissueresident iNKT cells in the development of insulin resistance. Strikingly, iNKT cell function was directly modulated by adipocytes, which acted as lipid antigen-presenting cells in a CD1d-mediated fashion. Based on these findings, we propose that, especially under low-fat diet conditions, adipose tissueresident iNKT cells maintain healthy adipose tissue through direct interplay with adipocytes and prevent insulin resistance.
Natural killer T cells in adipose tissue prevent insulin resistance.
Specimen part
View SamplesActivation of macrophages by inflammatory stimuli leads to reprogramming of mitochondrial metabolism to support the production of pro-inflammatory cytokines. Hallmarks of this metabolic rewiring are downregulation of a-ketoglutarate formation via isocitrate dehydrogenase (IDH) and accumulation of glutamine-derived succinate, which enhances the inflammatory response via the activity of succinate dehydrogenase (SDH). Here, we identify the nuclear receptor Nur77 (Nr4a1) as a key regulator of the pro-inflammatory metabolic switch in macrophages. Nur77-deficient macrophages fail to downregulate IDH expression and accumulate higher levels of succinate and other downstream TCA cycle metabolites in response to an inflammatory stimulus. Consequently, these macrophages produce more nitric oxide and pro-inflammatory cytokines in an SDH-dependent manner. In vivo, bone marrow Nur77 deficiency exacerbates atherosclerosis development and leads to increased systemic succinate levels. In conclusion, Nur77 supports an anti-inflammatory metabolic state in macrophages that protects against chronic inflammatory diseases such as atherosclerosis. Overall design: Gene expression profiling by RNA-seq was performed in triplicate in RAW264.7 mouse macrophage stable cell lines with doxycycline-inducible overexpression of HA-tagged NUR77 or GFP as control.
Nuclear Receptor Nur77 Limits the Macrophage Inflammatory Response through Transcriptional Reprogramming of Mitochondrial Metabolism.
Cell line, Treatment, Subject
View SamplesAngiopoietin-like protein 4 (ANGPTL4, also referred to as Fiaf) has been proposed as circulating mediator between the gut microbiota and fat storage in adipose tissue. Very little is known about mechanisms of regulation of ANGPTL4 in the colon. Here we show that transcription and subsequent secretion of ANGPTL4 in human T84 and HT-29 colonocytes is highly induced by physiological concentrations of products of bacterial fermentation, the short chain fatty acids (SCFA). Induction of ANGPTL4 by SCFA cannot be mimicked by the histone deacetylase inhibitor Trichostatin A. SCFA induce ANGPTL4 by activating the nuclear receptor PPAR, as shown by use of PPAR antagonist, PPAR knock-down, and transactivation assay, which shows activation of PPAR but not PPAR and PPAR. At concentrations required for PPAR activation and ANGPTL4 induction in colonocytes, SCFA do not stimulate PPAR in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPAR modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modelling. Consistent with the notion that fermentation leads to PPAR activation in vivo, feeding mice a diet rich in inulin was associated with induction of PPAR target genes and pathways in the colon, as shown by microarray and subsequent gene set enrichment analysis. It can be concluded that 1) SCFA potently stimulate ANGPTL4 synthesis in human colonocytes; 2) SCFA transactivate and bind to PPAR by serving as selective PPAR modulators. Our data point to activation of PPAR as a novel mechanism of gene regulation by SCFA in the colon.
Short-chain fatty acids stimulate angiopoietin-like 4 synthesis in human colon adenocarcinoma cells by activating peroxisome proliferator-activated receptor γ.
Sex, Age, Specimen part
View SamplesAngiopoietin-like protein 4 (ANGPTL4, also referred to as Fiaf) has been proposed as a circulating mediator between the gut microbiota and fat storage in adipose tissue. Very little is known about the mechanisms of regulation of ANGPTL4 in the colon. Here we show that transcription and subsequent secretion of ANGPTL4 in human T84 and HT-29 colonocytes is highly induced by physiological concentrations of products of bacterial fermentation, the short-chain fatty acids. Short-chain fatty acids induce ANGPTL4 by activating the nuclear receptor PPAR, as shown by microarray, transactivation assays, coactivator peptide recruitment assay, and use of PPAR antagonist. At concentrations required for PPAR activation and ANGPTL4 induction in colonocytes, SCFA do not stimulate PPAR in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPAR modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modelling. It can be concluded that 1) SCFA potently stimulate ANGPTL4 synthesis in human colonocytes, and 2) SCFA transactivate and bind to PPAR by serving as selective PPAR modulators. Our data point to activation of PPAR as a novel mechanism of gene regulation by SCFA in the colon.
Short-chain fatty acids stimulate angiopoietin-like 4 synthesis in human colon adenocarcinoma cells by activating peroxisome proliferator-activated receptor γ.
Specimen part, Cell line, Treatment
View SamplesWe analyzed total leukocyte gene expression using Affymetrix microarrays from healthy smokers, COPD patients and non-smoking control subjects before and after exposure to acute cigarette smoke (smoking two cigarettes in 30 minutes).
Systemic inflammatory response to smoking in chronic obstructive pulmonary disease: evidence of a gender effect.
Sex, Specimen part, Disease
View SamplesAlterations in the presence of sperm RNAs have been identified using microarrays in teratozoospermic (abnormal morphology) or other types of infertile patients. However, so far no studies had been reported on the sperm RNA content using microarrays in asthenozoospermic patients (low motility).
Differential RNAs in the sperm cells of asthenozoospermic patients.
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View SamplesMultiple signaling pathways, structural proteins and transcription factors are involved in regulation of endothelial barrier function. The Forkhead protein FOXF1 is a key transcriptional regulator of lung embryonic development, and we use a conditional knockout approach to examine the role of FOXF1 in adult lung homeostasis and lung injury and repair. Tamoxifen-regulated deletion of both Foxf1 alleles in endothelial cells of adult mice (Pdgfb-iCreER/Foxf1 caused lung inflammation and edema, leading to respiratory insuffency and uniform mortality. Deletion of a single foxf1 allele was sufficient to increase susceptibility of heterozygous mice to acute lung injury. FOXF1 abundance was decreased in pulmonary endothelial cells of human patients with acute lung injury. Gene expression analysis of pulmonary endothelial cells of FOXF1 deletion indicated reduced expression for genes critical for maintance and regulation of adherens junctions. FOXF1 knockdown in vitro and in vivo disrupted adherens junctions, increased lung endothelial permeability, and the abundance of mRNA and protein for sphingosine 1 phosphate receptor 1 (S1PR1), a key regulator of endothelial barrier function. Chromatin immunoprecipitation and luciferase reporter assay demonstrated that FOXF1 directly bound to and induced the tanscriptional activity of the S1pr1 promoter. Pharmacological administratiion of S1P to injured pdgfb-iCreER/Foxf1 mice restored endothelial barrier function, decreased lung edema and improved survival. Thus, FOXF1 promotes normal lung homeostasis and lung repair, at least in part, by enhancing endothelial barrier function through transcriptional activation of the S1P/S1PR1/ signaling pathway. Overall design: RNA was isolated and pooled from the lungs of multiple mice with either the Foxf1 floxed alleles alone or Pdgfb-iCreER Foxf1 floxed mice.
FOXF1 maintains endothelial barrier function and prevents edema after lung injury.
Specimen part, Subject
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