Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Hepatic nonvesicular cholesterol transport is critical for systemic lipid homeostasis

ABSTRACT: In cell models, changes in the “accessible” pool of plasma membrane (PM) cholesterol are linked with the regulation of ER sterol synthesis and metabolism by the Aster family of nonvesicular transporters. However, the relevance of such nonvesicular transport mechanisms for lipid homeostasis in vivo has not been defined. Here we reveal two physiological contexts that generate accessible PM cholesterol and engage the Aster pathway in liver: fasting and reverse cholesterol transport (RCT). During fasting, adipose tissue–derived fatty acids activate hepatocyte sphingomyelinase to liberate sequestered PM cholesterol. Aster-dependent cholesterol transport during fasting facilitates cholesteryl ester (CE) formation, cholesterol movement into bile, and VLDL production. During RCT, HDL delivers excess cholesterol to the hepatocyte PM through SR-BI. Loss of hepatic Asters impairs cholesterol movement into feces, raises plasma cholesterol levels, and causes cholesterol accumulation in peripheral tissues. These results reveal fundamental mechanisms by which Aster cholesterol flux contributes to hepatic and systemic lipid homeostasis.

ORGANISM(S): Mus musculus

PROVIDER: GSE206278 | GEO | 2022/10/24

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

The TMAO Generating Enzyme Flavin Monooxygenase 3 is a Central Regulator of Cholesterol Balance

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)

2014-12-19 | E-GEOD-64326 | biostudies-arrayexpress

Cooperation between ASTER-dependent nonvesicular transport and NPC1L1 facilitates dietary cholesterol uptake

Project description:Intestinal cholesterol absorption is an important determinant of systemic cholesterol homeostasis. Niemann-Pick C1 Like 1 (NPC1L1), the target of the drug ezetimibe, is a critical player in dietary cholesterol uptake. But how cholesterol moves within the cell downstream of NPC1L1 is unknown. Here we show that the nonvesicular sterol transporters Aster-B and -C cooperate with NPC1L1 to deliver dietary cholesterol from the gut lumen to the enterocyte ER for chylomicron packaging. Aster proteins are recruited to the enterocyte plasma membrane (PM) in response to NPC1L1-dependent cholesterol accumulation. Mice lacking Asters in intestine have impaired cholesterol absorption, and reduced plasma cholesterol. NanoSIMS imaging and tracer studies reveal delayed lipid trafficking into chylomicrons in Aster-deficient enterocytes. Interestingly, in addition to potently blocking NPC1L1, ezetimibe is also a low-affinity inhibitor of Aster-B and -C but not -A, and the structure of the Aster-C-ezetimibe complex reveals the basis for this selectivity. Our findings support a model in which NPC1L1 enriches dietary cholesterol at the apical PM, and ASTERs subsequently traffic this cholesterol to the ER. The findings identify the enterocyte Aster pathway as potential target for treatment of hypercholesterolemia. Alessandra Ferrari, PhD

2023-12-21 | GSE206780 | GEO

The TMAO Generating Enzyme Flavin Monooxygenase 3 is a Central Regulator of Cholesterol Balance

2014-12-19 | GSE64326 | GEO

RNA-sequencing of liver tissue from wild type and Gramd1c knockout mice fed with high and low cholesterol diet

Project description:The Aster-C protein (encoded by the Gramd1c gene) is an endoplasmic reticulum (ER) resident protein that has been reported to transport cholesterol from the plasma membrane to the ER . Although there is a clear role for the closely-related Aster-B protein in cholesterol transport and downstream esterification in the adrenal gland, the specific role for Aster-C in tissue cholesterol homeostasis is not well understood. Here, we have examined whole body cholesterol balance in mice globally lacking Aster-C under low or high dietary cholesterol conditions.transport and metabolism under divergent dietary cholesterol conditions. These results strongly suggest that Aster-C alone is not sufficient to control whole body cholesterol balance, but can modestly impact circulating cortisol and bile acid levels when dietary cholesterol is limited.

2024-01-11 | GSE250230 | GEO

Fasting-sensitive SUMO-switch on Prox1 controls hepatic cholesterol metabolism

Project description:Accumulation of excess nutrients hampers proper liver function and is linked to non-alcoholic fatty liver disease (NAFLD) in obesity. However, the signals responsible for an impaired adaptation of hepatocytes to obesogenic dietary cues remain still largely unknown. Post-translational modification by the Small Ubiquitin-like Modifier (SUMO), allows for adynamic regulation of numerous processes including transcriptional reprograming. We demonstrate that specific SUMOylation of transcription factor Prox1 represents a nutrient-sensitive determinant of hepatic fasting metabolism. Prox1 was highly SUMOylated on lysine 556 in the liver of ad libitum and re-fed mice, while this modification was abolished upon fasting. In the context of diet-induced obesity, Prox1 SUMOylation became less sensitive to fasting cues. The hepatocyte-selective knock-in of a SUMOylation-deficient Prox1 mutant into mice fed a high-fat/high-fructose diet led to a reduction of systemic cholesterol levels, associated with the induction of liver bile acid detoxifying pathways during fasting. The generation of tools to maintain the nutrient-sensitive SUMO-switch on Prox1 may thus contribute to the development of “fasting-based” approaches for the preservation of metabolic health.

2023-10-24 | PXD041329 | Pride

Effects of Paramylon Extracted from Euglena gracilis EOD-1 on lipid metabolism in the Ileum and Liver in Diet-Induced Obese Mice Analyzed by DNA Microarray.

Project description:We have previously shown that paramylon (PM) supplementation to a high fat diet reduces the postprandial glucose rise, serum total and LDL-cholesterol, and abdominal fat accumulation in mice; however, the mechanism has not been determined. We evaluated the potential mechanism in male C57BL/6J mice fed a high-fat diet supplemented with 5% PM powder, extracted from Eu-glena gracilis, for 12 weeks. Abdominal fat weight, and serum lipids were measured; ileal and hepatic mRNA expression were assessed using DNA microarray and real-time PCR. The poten-tial mechanism of PM on modulating lipid metabolism was explored by gene ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Dietary supplementation with PM resulted in decreased abdominal fat accumulation and serum LDL-cholesterol concentrations via suppression of the digestion and absorption pathway in the ileum and activation of the hepatic PPAR signaling pathway. Improvement in glucose tolerance may be the result of lipid metabolism modification because the glucose metabolism pathway was not detected by GO classification and KEGG pathway analysis. PM intake also directly enhanced immunoglobulin production.

2021-08-04 | GSE181289 | GEO

Hepatocyte-Specific Transcriptional Profiling of the Hepatic Fasting Response

Project description:Hepatocyte-Specific Transcriptional Profiling of the Hepatic Fasting Response

| PRJNA753936 | ENA

Hepatocyte-Specific Genomic Profiling of the Hepatic Fasting Response

Project description:Hepatocyte-Specific Genomic Profiling of the Hepatic Fasting Response

| PRJNA753926 | ENA

Complementary gene regulation by NRF1 and NRF2 safeguard hepatic cholesterol detoxification

Project description:Metabolic-associated steatohepatitis is a progressive fatty liver disease caused, in part, by hepatocyte stress linked to cholesterol overload. Counteracting this stress may be beneficial but there is insufficient understanding of underlying stress defenses to develop a therapeutic strategy. Here, we aimed to elucidate how stress-adaptive transcription factors, nuclear factor erythroid 2 related factor-1 (NRF1) and -2 (NRF2), counteract hepatic cholesterol overload and determine whether they function cooperatively. C57bl/6 mice were fed high fat, fructose, and cholesterol diet (HFFC). Expression profiling and phenotypic analyses were done on liver of mice with adult-onset and hepatocyte-specific deficiency of NRF1, NRF2, or both, and results compared to control. Chromatin immunoprecipitation (ChIP) sequencing was done and combined with expression profiles to identify genes that NRF1 and NRF2 interact with and regulate in vivo. Three weeks HFFC diet feeding to mice with NRF1 and NRF2 deficiency caused severe steatohepatitis and increased hepatic cholesterol storage. These outcomes did not occur in single gene-deficient mice or control. Expression profiling at a time preceding hepatic cholesterol overload and ChIP sequencing profiling revealed complementary gene regulation by NRF1 and NRF2 to promote cholesterol excretion and mitigate hazardous metabolic biproducts generated from converting cholesterol to bile acid. Consequently, combined gene deficiency, and not single-gene deficiency, increased liver oxidized protein level, decreased cholesterol in bile, and increased unconjugated bile acid in liver and bile. We discover, for the first time, that NRF1 and NRF2 work together to protect liver against damaging effects of excess cholesterol. Targeting these combined actions may prove an effective therapeutic strategy

2023-03-22 | PXD032069 | Pride

Gene expression profiling using cDNA microarray of HMGB1fl/fl and HMGB1ΔHep liver samples from mice subjected to a 12 week-HFD regimen or a Fasting/Refeeding challenge

Project description:To unveil any gene expression difference induced by hepatocyte specific-Hmgb1 gene deletion in mice after a metabolic stress either induced by a 12-week high fat diet consumption or a fasting (6hours)-refeeding (8hours) challenge. Challenges known to generate a robust activation of hepatic lipogenesis and liver steatosis.

2022-03-31 | E-MTAB-11541 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data