Ena-DATASET-DUNDEE-05-08-2016-18:52:13:500-38 - samples
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PROVIDER: EGAD00001002277 | EGA |
REPOSITORIES: EGA
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Project description:Objective: To investigate the effects of metformin on intestinal carbohydrate metabolism in vivo.
Method: Male mice preconditioned with a high-fat, high-sucrose diet were treated orally with metformin or a control solution for two weeks. Fructose metabolism, glucose production from fructose, and production of other fructose-derived metabolites were assessed using stably labeled fructose as a tracer.
Results: Metformin treatment decreased intestinal glucose levels and reduced incorporation of fructose-derived metabolites into glucose. This was associated with decreased intestinal fructose metabolism as indicated by decreased enterocyte F1P levels and diminished labeling of fructose-derived metabolites. Metformin also reduced fructose delivery to the liver. Proteomic analysis revealed that metformin coordinately down-regulated proteins involved carbohydrate metabolism including those involved in fructolysis and glucose production within intestinal tissue.
Conclusion: Metformin reduces intestinal fructose metabolism, and this is associated with broad-based changes in intestinal enzyme and protein levels involved in sugar metabolism indicating that metformin's effects on sugar metabolism are pleiotropic.
2024-04-27 | PXD041833 | JPOST Repository
Project description:Metformin is among the most prescribed anti-diabetic drugs, but the primary molecular mechanism by which metformin lowers blood glucose levels is unknown. Previous studies have proposed numerous mechanisms by which acute metformin lowers blood glucose, including the inhibition of mitochondrial complex I of the electron transport chain (ETC). Here, we used transgenic mice that globally express the Saccharomyces cerevisiae protein NDI1 to determine whether the glucose lowering effect of acute oral administration of metformin requires inhibition of mitochondrial complex I of the ETC in vivo. NDI1 is a yeast NADH dehydrogenase enzyme that complements the loss of mammalian mitochondrial complex I electron transport function and is insensitive to pharmacologic mitochondrial complex I inhibitors including metformin. We demonstrate that NDI1 expression attenuates metformin’s ability to lower blood glucose levels under standard chow and high-fat diet conditions. Our results indicate that acute oral administration of metformin targets mitochondrial complex I to lower blood glucose.
2024-10-12 | GSE278099 | GEO
Project description:Background: Myofibroblasts (MYFs) are generally considered the principal culprits in excessive extracellular matrix deposition and scar formation in the pathogenesis of lung fibrosis. Lipofibroblasts (LIFs), on the other hand, are defined by their lipid-storing capacity and are predominantly found in the alveolar regions of the lung. They have been proposed to play a protective role in lung fibrosis. We previously reported that a LIF to MYF reversible differentiation switch occurred during fibrosis formation and resolution. In this study, we tested whether WI-38 cells, a human embryonic lung fibroblast cell line, could be used to study fibroblast differentiation towards the LIF or MYF phenotype and whether this could be relevant for idiopathic pulmonary fibrosis (IPF). Methods: using WI-38 cells, MYF differentiation was triggered using TGF-β1 treatment and LIF differentiation using Metformin treatment. We analyzed the LIF to MYF and MYF to LIF differentiation by pre-treating the WI-38 cells with TGF-β1 or Metformin first, followed by treatment with Metformin and TGF-β1, respectively. We used IF, qPCR and bulk RNA-Seq to analyze the phenotypic and transcriptomic changes in the cells. We correlated our in vitro transcriptome data from WI-38 cells (obtained via bulk RNA sequencing) with the transcriptomic signature of LIFs and MYFs derived from the IPF cell atlas as well as with our own single-cell transcriptomic data from IFP patients-derived lung fibroblasts (LF-IPF) cultured in vitro. We also carried out alveolosphere assays to evaluate the ability of the proposed LIF and MYF cells to support the growth of alveolar epithelial type 2 cells. Results: WI-38 and LF-IPF display similar phenotypical and gene expression responses to TGF-β1 and Metformin treatment. Bulk RNA-Seq analysis of WI-38 and LF-IPF treated with TGF-β1, or Metformin indicate similar transcriptomic changes. We also show the partial conservation of the LIF and MYF signature extracted from the Habermann et al. scRNA-seq dataset in WI-38 cells treated with Metformin or TGF-β1, respectively. Alveolosphere assays indicate that LIFs enhance organoid growth, while MYFs inhibit organoid growth. Finally, we provide evidence supporting the LIF to MYF reversible switch using WI-38 cells. Conclusions: WI-38 cells represent a versatile and reliable model to study the intricate dynamics of fibroblast differentiation towards the MYF or LIF phenotype associated with lung fibrosis formation and resolution, providing valuable insights to drive future research
2024-07-03 | GSE264038 | GEO
Project description:Obesity-induced insulin resistance of the liver is characterised by increased gluconeogenesis, which contributes to elevated blood glucose levels in individuals with type 2 diabetes. Research into how fatty acids induce insulin resistance has commonly focused on the induction of insulin resistance. We hypothesise that by shifting focus to the reversal of an insulin resistant phenotype, novel insights can be made into the mechanisms by which insulin resistance can be overcome. Using global gene and lipid expression profiling, we aimed to identify biological pathways altered in parallel with restoration of palmitate-induced deregulation of glucose production using metformin and sodium salicylate. FAO hepatoma cells were treated with palmitate (0.075mM, 48h) with or without metformin (0.25mM) and sodium salicylate (2mM) in the final 24h of palmitate treatment, and effects on glucose production were determined. Microarray followed by gene set enrichment analysis was performed to investigate pathway regulation. A lipidomic analysis (HPLC-MS/MS) and measurement of secreted bile acids and cholesterol were performed. Reversal of palmitate-induced impairment of glucose production by metformin and sodium salicylate was characterised by down-regulated expression of metabolic pathways regulating acetyl-CoA to cholesterol and bile acid biosynthesis. Total levels of intracellular and secreted cholesterol and bile acids were not different between impaired and restored glucose production. Total intracellular levels of diacylgycerol, triacylglycerol and cholesterol esters increased with palmitate (impaired glucose production), however, these were not further altered with metformin and sodium salicylate (restored glucose production). Six individual lipid species containing 18:0 and 18:1 side-chains were reduced by metformin and sodium salicylate. Widespread lipid metabolism changes induced by the reversal of palmitate-induced deregulation of glucose production with metformin and sodium salicylate were identified. While cholesterol and bile acid levels remained unchanged, the flux through these pathways may in part explain these findings. The identification of lipid species containing 18:0 and 18:1 side chains being regulated alongside changes to glucose production may indicate potential mediators of glucose production and insulin resistance. Three-condition experiment, Vehicle, Palmitate (PA) and Palmitate (PA) + Metformin (Met) + Sodium Sailcylate (NaS) with biological replicates: 8 Vehicle, 20 PA and 20 PA+Met+NaS , independently grown and harvested. One replicate per array.
2013-11-08 | E-GEOD-52204 | biostudies-arrayexpress
Project description:Metformin is the first-line antidiabetic drug with over 100 million users worldwide, yet its mechanism of action remains unclear1. Here the Metformin Genetics (MetGen) Consortium reports a three-stage genome wide association study (GWAS), consisting of 13,123 participants of different ancestries. The C-allele of rs8192675 in the intron of SLC2A2, which encodes the facilitated glucose transporter GLUT2, was associated with a 0.17% (p=6.6x10-14) greater metformin induced HbA1c reduction in 10,577 participants of European ancestry. rs8192675 is the top cis-eQTL for SLC2A2 in 1,226 human liver samples, suggesting a key role for hepatic GLUT2 in regulation of metformin action. In obese individuals C-allele homozygotes at rs8192675 had a 0.33% (3.6mmol/mol) greater absolute HbA1c reduction than T-allele homozygotes.This is about half the effect seen with the addition of a DPP-4 inhibitor, and equates to a dose difference of 550mg of metformin, suggesting rs8192675 as a potential biomarker for stratified medicine.
| EGAS00001001875 | EGA
Project description:Metformin is a well tolerated and often prescribed treatment for type 2 diabetes. However, the effect of metformin on gene expression in endothelial cells remains unknown. We used RNA-seq to profile gene expression in primary human aortic endothelial cells stimulated with metformin in normoglycaemic and hyperglycaemic conditions. We identified novel pathways in hyperglycaemic endothelial cells that may be involved in the development of endothelial dysfunction. Hyperglycaemic endothelial cells expressed interferon-response pathway genes such as MX1 and IFI27. Transcription factor analysis implicates the activation of STAT1 and IRF1. Co-treatment of hyperglycaemic cells with metformin prevented glucose-dependent changes in gene expression, including interferon response genes. Indeed, the effects of metformin in endothelial cells were dependent on glucose levels. In normoglycaemic cells, metformin subtly regulated changes in gene expression. In contrast, metformin was strongly associated with the reversal of gene expression changes induced by hyperglycaemia.
2019-02-01 | GSE77522 | GEO
Project description:Obesity-induced insulin resistance of the liver is characterised by increased gluconeogenesis, which contributes to elevated blood glucose levels in individuals with type 2 diabetes. Research into how fatty acids induce insulin resistance has commonly focused on the induction of insulin resistance. We hypothesise that by shifting focus to the reversal of an insulin resistant phenotype, novel insights can be made into the mechanisms by which insulin resistance can be overcome. Using global gene and lipid expression profiling, we aimed to identify biological pathways altered in parallel with restoration of palmitate-induced deregulation of glucose production using metformin and sodium salicylate. FAO hepatoma cells were treated with palmitate (0.075mM, 48h) with or without metformin (0.25mM) and sodium salicylate (2mM) in the final 24h of palmitate treatment, and effects on glucose production were determined. Microarray followed by gene set enrichment analysis was performed to investigate pathway regulation. A lipidomic analysis (HPLC-MS/MS) and measurement of secreted bile acids and cholesterol were performed. Reversal of palmitate-induced impairment of glucose production by metformin and sodium salicylate was characterised by down-regulated expression of metabolic pathways regulating acetyl-CoA to cholesterol and bile acid biosynthesis. Total levels of intracellular and secreted cholesterol and bile acids were not different between impaired and restored glucose production. Total intracellular levels of diacylgycerol, triacylglycerol and cholesterol esters increased with palmitate (impaired glucose production), however, these were not further altered with metformin and sodium salicylate (restored glucose production). Six individual lipid species containing 18:0 and 18:1 side-chains were reduced by metformin and sodium salicylate. Widespread lipid metabolism changes induced by the reversal of palmitate-induced deregulation of glucose production with metformin and sodium salicylate were identified. While cholesterol and bile acid levels remained unchanged, the flux through these pathways may in part explain these findings. The identification of lipid species containing 18:0 and 18:1 side chains being regulated alongside changes to glucose production may indicate potential mediators of glucose production and insulin resistance.
2013-11-08 | GSE52204 | GEO
Project description:Metformin is the front-line treatment for type 2 diabetes worldwide. It acts via effects on glucose and lipid metabolism in metabolic tissues, leading to enhanced insulin sensitivity. Despite significant effort, the molecular basis for metformin response remains poorly understood, with a limited number of specific biochemical pathways studied to date. To broaden our understanding of hepatic metformin response, we combine phospho-protein enrichment in tissue from genetically engineered mice with a quantitative proteomics platform to enable the discovery and quantification of basophilic kinase substrates in-vivo. We define proteins that binding to 14-3-3 are acutely regulated by metformin treatment and/or loss of the serine/threonine kinase, LKB1. Inducible binding of 250 proteins following metformin treatment is observed, 44% LKB1-dependent. Beyond AMPK, metformin activates Protein Kinase D and MAPKAPK2 in an LKB1-independent manner, revealing additional kinases that may mediate aspects of metformin response. Deeper analysis uncovered substrates of AMPK in endocytosis and calcium homeostasis.
2019-10-07 | MSV000084429 | MassIVE
Project description:Metformin is a kind of widely used antidiabetic agent, which regulates glucose homeostasis through inhibiting liver glucose production and increasing glucose uptake in muscle. Recent studies suggest that metformin exhibits anticancer properties in a variety of cancers. Although several antitumor mechanisms have been proposed for metformin action, its mode of action in human liver cancer remains not elucidated. In our study we investigated the underlying molecular mechanisms of metformin’s antitumor effect on Huh-7 cells of hepatocellular carcinoma (HCC) in vitro. RNA sequencing (RNA-seq) was performed to explore the effect of metformin on the transcriptome of Huh-7 cells. The results revealed that 4518 genes (with log2 fold change>1 or < -1, p-adjusted value<0.05) were differentially expressed in Huh-7 cells with treatment of 25mM metformin compared to 0mM metformin including 1812 up-regulated and 2706 down-regulated genes. Gene ontology and KEGG pathway analyses identified 54 classical pathways which were significantly enriched, and 16 pathways are closely associated with cancer, such as cell cycle, DNA replication, ECM-receptor interaction and so on. We selected 11 differentially expressed genes, which are closely associated with HCC to validate their differential expressions through quantitative real-time reverse transcription PCR (qRT-PCR). The result exhibited that the genes of FASN, MCM6, MCM5, MARCKS, FADS2, CXCL1, BMP4, SKP2, KNG1, PCNA were down-regulated and DUSP1 is significantly up-regulated in Huh-7 cells with treatment of 25mM metformin. These differentially expressed genes and pathways might play a crucial part in the antitumor effect of metformin, and might be potential targets of metformin treating HCC. Further investigations are required to evaluate the metformin mechanisms of anti-cancer action in vivo.
2021-12-05 | GSE190076 | GEO
Project description: Not available
| S-IHECRE00000009.1 | biostudies-other