Project description:Gut microbiota dysbiosis characterizes systemic metabolic alteration, yet its causality is debated. To address this issue, we transplanted antibiotic-free conventional wild-type mice with either dysbiotic (“obese”) or eubiotic (“lean”) gut microbiota and fed them either a NC or a 72%HFD. We report that, on NC, obese gut microbiota transplantation reduces hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-transplanted mice. Of note, this phenotype is blunted in conventional NOD2KO mice. By contrast, lean microbiota transplantation did not affect hepatic gluconeogenesis. In addition, obese microbiota transplantation changed both gut microbiota and microbiome of recipient mice. Interestingly, hepatic gluconeogenesis, PEPCK and G6Pase activity were reduced even once mice transplanted with the obese gut microbiota were fed a 72%HFD, together with reduced fed glycaemia and adiposity compared to non-transplanted mice. Notably, changes in gut microbiota and microbiome induced by the transplantation were still detectable on 72%HFD. Finally, we report that obese gut microbiota transplantation may impact on hepatic metabolism and even prevent HFD-increased hepatic gluconeogenesis. Our findings may provide a new vision of gut microbiota dysbiosis, useful for a better understanding of the aetiology of metabolic diseases. all livers are from NC-fed mice only.
Project description:Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide(TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT), and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic ER stress and inflammation in part by decreasing hepatic oxysterol levels and subsequent LXR activation. FMO3 is thus identified as a central integrator of hepatic cholesterol and triacylglycerol metabolism, inflammation, and ER stress. These studies suggest that the gut microbiota-driven TMA/FMO3/TMAO pathway is a key regulator of lipid metabolism and inflammation. To identify potential regulators of macrophage reverse cholesterol transport (RCT), liver was isolated from two independent mouse models where the non-biliary RCT pathway known as transintestinal cholesterol excretion (TICE) was either chronically (NPC1L1-liver-transgenic mice) or acutely (ACAT2 antisense oligonucleotide treatment) stimulated. Total RNA was isolated and gene expression levels were profiled on the Affymetrix GeneAtlas MG-430 PM Array Strip (Affymetrix; Santa Clara, CA, USA)
Project description:Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide(TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT), and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic ER stress and inflammation in part by decreasing hepatic oxysterol levels and subsequent LXR activation. FMO3 is thus identified as a central integrator of hepatic cholesterol and triacylglycerol metabolism, inflammation, and ER stress. These studies suggest that the gut microbiota-driven TMA/FMO3/TMAO pathway is a key regulator of lipid metabolism and inflammation.
Project description:Dietary lipids and gut microbiota may both influence adipose tissue physiology. By feeding conventional and germ-free mice high fat diets with different lipid compositon we aimed to investigate how dietary lipids and the gut microbiota interact to influence inflammation and metabolism in the liver
Project description:Dietary lipids and gut microbiota may both influence adipose tissue physiology. By feeding conventional and germ-free mice high fat diets with different lipid compositon we aimed to investigate how dietary lipids and the gut microbiota interact to influence inflammation and metabolism in epididymal adipiose tissue (EWAT)
Project description:Dietary lipids and gut microbiota may both influence adipose tissue physiology. By feeding conventional and germ-free mice high fat diets with different lipid compositon we aimed to investigate how dietary lipids and the gut microbiota interact to influence inflammation and metabolism in the liver Wild-type C57Bl/6 male mice 11 weeks of age were fed isocaloric diets (45% kcal fat) with either menhaden fish oil (Research Diets, D05122102) or lard (Research Diets, D10011202) for 11 weeks. Liver samples were harvested at the end of the experiment and analyzed by microarray.
Project description:Dietary lipids and gut microbiota may both influence adipose tissue physiology. By feeding conventional and germ-free mice high fat diets with different lipid compositon we aimed to investigate how dietary lipids and the gut microbiota interact to influence inflammation and metabolism in epididymal adipiose tissue (EWAT) Wild-type C57Bl/6 male mice 11 weeks of age were fed isocaloric diets (45% kcal fat) with either menhaden fish oil (Research Diets, D05122102) or lard (Research Diets, D10011202) for 11 weeks. Epididymal WAT samples were harvested at the end of the experiment and analyzed by microarray.
Project description:The gut microbiota-intestine-liver relationship is emerging as an important factor in multiple hepatic pathologies, but the hepatic sensors and effectors of microbial signals are not well defined. By comparing publicly available liver transcriptomics data from conventional vs. germ-free mice, we identified pregnane X receptor (PXR, NR1I2) transcriptional activity as strongly affected by the absence of gut microbes. Microbiota depletion in Pxr+/+ vs Pxr-/- C57Bl6/J mice revealed that most microbiota-sensitive genes were PXR-dependent in the liver in males, but not in females. Pathway enrichment analysis revealed that microbiota-PXR interaction controlled fatty-acid and xenobiotic metabolism. Antibiotic treatment reduced liver triglyceride content and hampered xenobiotic metabolism in livers from Pxr+/+ but not Pxr-/- male mice. These findings identify PXR as a hepatic effector of sexually dimorphic responses to microbiota-derived signals and reveal a potential new mechanism for unexpected drug-drug or food-drug interactions.
Project description:Mardinoglu2015 - Tissue-specific genome-scale
metabolic network - Brain medulla
This model is described in the article:
The gut microbiota modulates
host amino acid and glutathione metabolism in mice.
Mardinoglu A, Shoaie S, Bergentall
M, Ghaffari P, Zhang C, Larsson E, Bäckhed F, Nielsen
J.
Mol. Syst. Biol. 2015; 11(10):
834
Abstract:
The gut microbiota has been proposed as an environmental
factor that promotes the progression of metabolic diseases.
Here, we investigated how the gut microbiota modulates the
global metabolic differences in duodenum, jejunum, ileum,
colon, liver, and two white adipose tissue depots obtained from
conventionally raised (CONV-R) and germ-free (GF) mice using
gene expression data and tissue-specific genome-scale metabolic
models (GEMs). We created a generic mouse metabolic reaction
(MMR) GEM, reconstructed 28 tissue-specific GEMs based on
proteomics data, and manually curated GEMs for small intestine,
colon, liver, and adipose tissues. We used these functional
models to determine the global metabolic differences between
CONV-R and GF mice. Based on gene expression data, we found
that the gut microbiota affects the host amino acid (AA)
metabolism, which leads to modifications in glutathione
metabolism. To validate our predictions, we measured the level
of AAs and N-acetylated AAs in the hepatic portal vein of
CONV-R and GF mice. Finally, we simulated the metabolic
differences between the small intestine of the CONV-R and GF
mice accounting for the content of the diet and relative gene
expression differences. Our analyses revealed that the gut
microbiota influences host amino acid and glutathione
metabolism in mice.
This model is hosted on
BioModels Database
and identified by:
MODEL1509220000.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Mardinoglu2015 - Tissue-specific genome-scale
metabolic network - Embryonic tissue
This model is described in the article:
The gut microbiota modulates
host amino acid and glutathione metabolism in mice.
Mardinoglu A, Shoaie S, Bergentall
M, Ghaffari P, Zhang C, Larsson E, Bäckhed F, Nielsen
J.
Mol. Syst. Biol. 2015; 11(10):
834
Abstract:
The gut microbiota has been proposed as an environmental
factor that promotes the progression of metabolic diseases.
Here, we investigated how the gut microbiota modulates the
global metabolic differences in duodenum, jejunum, ileum,
colon, liver, and two white adipose tissue depots obtained from
conventionally raised (CONV-R) and germ-free (GF) mice using
gene expression data and tissue-specific genome-scale metabolic
models (GEMs). We created a generic mouse metabolic reaction
(MMR) GEM, reconstructed 28 tissue-specific GEMs based on
proteomics data, and manually curated GEMs for small intestine,
colon, liver, and adipose tissues. We used these functional
models to determine the global metabolic differences between
CONV-R and GF mice. Based on gene expression data, we found
that the gut microbiota affects the host amino acid (AA)
metabolism, which leads to modifications in glutathione
metabolism. To validate our predictions, we measured the level
of AAs and N-acetylated AAs in the hepatic portal vein of
CONV-R and GF mice. Finally, we simulated the metabolic
differences between the small intestine of the CONV-R and GF
mice accounting for the content of the diet and relative gene
expression differences. Our analyses revealed that the gut
microbiota influences host amino acid and glutathione
metabolism in mice.
This model is hosted on
BioModels Database
and identified by:
MODEL1509220001.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.