Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A three-organelle complex made by wrappER contacts with peroxisomes and mitochondria responds to liver lipid flux changes

ABSTRACT: Hepatic lipid homeostasis depends on intracellular pathways that respire fatty acid in peroxisomes and mitochondria, and on systemic pathways that secrete fatty acid into the bloodstream, either free or condensed in very-low-density lipoprotein (VLDL) triglycerides. These systemic and intracellular pathways are interdependent, but it is unclear whether and how they integrate into a single cellular circuit. Here, we report that mouse liver wrappER, a distinct endoplasmic reticulum (ER) compartment with apparent fatty acid- and VLDL secretion functions, connects peroxisomes and mitochondria. Correlative light electron microscopy, quantitative serial section electron tomography and three-dimensional organelle reconstruction analysis show that the number of peroxisome-wrappER-mitochondria complexes changes throughout fasting-to-feeding transitions and doubles when VLDL synthesis stops following acute genetic ablation of Mttp in the liver. Quantitative proteomic analysis of peroxisome-wrappER-mitochondria complex-enriched fractions indicates that the loss of Mttp upregulates global fatty acid ?-oxidation, thereby integrating the dynamics of this three-organelle association into hepatic fatty acid flux responses. Therefore, liver lipid homeostasis occurs through the convergence of systemic and intracellular fatty acid-elimination pathways in the peroxisome-wrappER-mitochondria complex.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Mus Musculus (ncbitaxon:10090)

SUBMITTER: Luca Pellegrini

PROVIDER: MSV000087291 | MassIVE | Fri Apr 23 06:52:00 BST 2021

SECONDARY ACCESSION(S): PXD025598

REPOSITORIES: MassIVE

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Effect of deletion of Carnitine Palmitoyltransferase2 in hepatocytes on liver gene expression upon a 24 hour fast

Project description:The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid Î²-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L-/-), an obligate step in mitochondrial long-chain fatty acid Î²-oxidation. Surprisingly, Cpt2L-/- mice survived the perinatal period and a 24hr fast with sufficient blood glucose. The loss of hepatic fatty acid oxidation resulted in a significant loss in circulating ketones that remained unaltered by fasting. Fasting induced serum dyslipidemia, hepatic steatosis and adaptations in hepatic and systemic oxidative gene expression in Cpt2L-/- mice to maintain systemic energy homeostasis. Alternatively, feeding a ketogenic diet resulted in severe hepatomegaly, liver damage and death within one week with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting. In this dataset, we include the expression data obtained from dissected mouse liver from mice fasted for 24 hours with and without the deletion of carnitine palmitoyltransferase 2 (i.e. hepatocytes unable to beta-oxidize long chain fatty acids in mitochondria). WildType and KnockOut mice were fasted for 24 hours. Three biologic replicates were compared per class, thus six mice.

2016-06-16 | E-GEOD-76079 | biostudies-arrayexpress

Alteration of Liver Peroxisomal and Mitochondrial Functionality in the NZO Mouse Model of Metabolic Syndrome.

Project description:Purpose: MetS consist of five risk factors: elevated blood pressure and fasting glucose, visceral obesity, dyslipidemia and hypercholesterinemia. The physiological impact of lipid metabolism indicated as visceral obesity and hepatic lipid accumulation is still under debate. One major cause of disturbed lipid metabolism might be dysfunction of cellular organelles controlling energy homeostasis, i.e. mitochondria and peroxisomes. Experimental design: The New Zealand Obese (NZO) mouse model exhibits a polygenic syndrome of obesity, insulin resistance, triglyceridemia and hypercholesterolemia that resembles human metabolic syndrome. We applied a combinatorial approach of lipidomics with liver transcriptomics, 2D-DIGETM and mass spectroscopy based organelle proteomics of highly purified mitochondria and peroxisomes in male mice, to investigate molecular mechanisms related to the impact of lipid metabolism in the pathophysiology of the metabolic syndrome. Conclusions and clinical relevance: Proteome analyses of liver organelles indicated differences in fatty acid metabolism, oxidative stress and response, mainly influenced by PG-C1α/PPARα mediated pathways. These results were in accordance with serum lipid profiles and elevated organelle functionality. These data emphasize that metabolic syndrome is accompanied with increased mitochondria and peroxisomal activity controlling directly cellular energy homeostasis to cope with dyslipidemia and hypercholesterinemia driven hepatic lipid overflow in developing a fatty liver.

2017-11-01 | GSE95489 | GEO

Peroxisomes and mitochondria are dysfunctional in obese diabetic (db/db) mice with fatty liver

Project description:Major causes of lipid accumulation in liver are increased import, synthesis or decreased catabolism of fatty acids. The latter is caused by dysfunction of cellular organelle controlling energy homeostasis, i.e. mitochondria. However, peroxisomes appear to be an important organelle in lipid metabolism of hepatocytes, but little is known about their role in the development of non-alcoholic fatty liver disease (NAFLD). To investigate the role of peroxisomes next to mitochondria in excessive hepatic lipid accumulation we used the leptin resistant db/db mice on C57BLKS background, a mouse model that develops hyperphagia induced diabetes with obesity and NAFLD. We used microarrays to determine differences in hepatic gene expression in a mouse model for NAFDL (BKS.Cg-Leprdb (db/db)) and their wildtype littermates C57BL/KSlepr+/+ (BKS) to determine the effect of persistent hepatic lipid accumulation.

2015-03-23 | GSE59930 | GEO

Effect of deletion of Carnitine Palmitoyltransferase2 in hepatocytes on liver gene expression upon a 24 hour fast

Project description:The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L-/-), an obligate step in mitochondrial long-chain fatty acid β-oxidation. Surprisingly, Cpt2L-/- mice survived the perinatal period and a 24hr fast with sufficient blood glucose. The loss of hepatic fatty acid oxidation resulted in a significant loss in circulating ketones that remained unaltered by fasting. Fasting induced serum dyslipidemia, hepatic steatosis and adaptations in hepatic and systemic oxidative gene expression in Cpt2L-/- mice to maintain systemic energy homeostasis. Alternatively, feeding a ketogenic diet resulted in severe hepatomegaly, liver damage and death within one week with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting. In this dataset, we include the expression data obtained from dissected mouse liver from mice fasted for 24 hours with and without the deletion of carnitine palmitoyltransferase 2 (i.e. hepatocytes unable to beta-oxidize long chain fatty acids in mitochondria).

2016-06-16 | GSE76079 | GEO

Malnutrition-associated hepatic steatosis and ATP depletion is caused by peroxisomal and mitochondrial dysfunction and rescued by fenofibrate

Project description:Severe malnutrition in young children is associated with signs of hepatic dysfunction such as steatosis and hypoalbuminemia, but its etiology is unknown. To investigate the underlying mechanisms of hepatic dysfunction we used a rat model of malnutrition by placing weanling rats on a low protein or control diet (5% or 20% of calories from protein, respectively) for four weeks. Low protein diet-fed rats developed hypoalbuminemia and severe hepatic steatosis, consistent with the human phenotype. Hepatic peroxisome content was decreased and metabolomic analysis indicated impaired peroxisomal function. Loss of peroxisomes was followed by accumulation of dysfunctional mitochondria and decreased hepatic ATP levels. Fenofibrate supplementation restored hepatic peroxisome abundance and increased mitochondrial fatty acid β-oxidation capacity, resulting in reduced steatosis and normalization of ATP and plasma albumin levels. These findings provide important insight into the metabolic disturbances associated with malnutrition and have potentially profound clinical consequences with respect to the management of malnourished children worldwide.

2016-06-18 | GSE63096 | GEO

Nuclear receptor NHR-49 promotes peroxisome proliferation to compensate for aldehyde dehydrogenase deficiency in C. elegans

Project description:The intracellular level of fatty aldehydes is tightly regulated to minimize the formation of toxic aldehyde adducts of cellular components. Accordingly, deficiency of a fatty aldehyde dehydrogenase FALDH causes the neurologic disorder Sjögren-Larsson syndrome (SLS) in humans. However, cellular responses to unresolved, elevated fatty aldehyde levels are poorly understood. Based on lipidomic and imaging analysis, we report that the loss of endoplasmic reticulum-, mitochondria- and peroxisomes-associated ALH-4, the C. elegans FALDH ortholog, increases fatty aldehyde levels and reduces fat storage. ALH-4 deficiency in the intestine, cell-nonautonomously induces NHR-49/NHR-79-dependent hypodermal peroxisome proliferation. This is accompanied by the upregulation of catalases and fatty acid catabolic enzymes, as indicated by RNA sequencing. Such a response is required to counteract ALH-4 deficiency since alh-4; nhr-49 double mutant animals are not viable. Our work reveals unexpected inter-tissue communication of fatty aldehyde levels, and suggests pharmacological modulation of peroxisome proliferation as a therapeutic strategy for SLS.

2021-06-07 | GSE162792 | GEO

Mitochondria-Rough-ER Contacts in The Liver Regulate Systemic Lipid Homeostasis

Project description:Contacts between organelles create microdomains that play major roles in regulating key intracellular activities and signaling pathways, but whether they also regulate systemic functions remains unknown. Here, we report the ultrastructural organization and dynamics of the inter-organellar contact established by rough-Endoplasmic Reticulum closely wrapped around the mitochondria (wrappER). To elucidate the in vivo function of this contact, mouse liver fractions enriched in wrappER-associated-mitochondria are analyzed by transcriptomics, proteomics and lipidomics. The biochemical signature of the wrappER points to a role in the biogenesis of very-low-density lipoproteins (VLDL). Altering wrappER-mitochondria contacts curtails VLDL secretion and increases hepatic fatty acids, lipid droplets and neutral lipid content. Conversely, acute liver-specific ablation of Mttp, the most upstream regulator of VLDL biogenesis, recapitulates this hepatic dyslipidemia phenotype and promotes remodelling of the wrappER-mitochondria contact. The discovery that liver wrappER-mitochondria contacts participate in VLDL biology suggests an involvement of inter-organelle contacts in systemic lipid homeostasis.

2021-03-15 | GSE134777 | GEO

Fatty Liver Due to Increased de novo Lipogenesis: Alterations in the Hepatic Peroxisomal Proteome

Project description:In non-alcoholic fatty liver disease (NAFLD) caused by ectopic lipid accumulation, lipotoxicity is a crucial molecular risk factor. Mechanisms to eliminate lipid overflow can prevent the liver from functional complications. This may involve increased secretion of lipids or metabolic adaptation to ß-oxidation in lipid-degrading organelles such as mitochondria and peroxisomes. In addition to dietary factors, increased plasma fatty acid levels may be due to increased triglyceride synthesis, lipolysis, as well as de novo lipid synthesis (DNL) in the liver. In the present study, we investigated the impact of fatty liver caused by elevated DNL, in a transgenic mouse model with liver-specific overexpression of human sterol regulatory element-binding protein-1c (alb-SREBP-1c), on hepatic gene expression, on plasma lipids and especially on the proteome of peroxisomes by omics analyses, and we interpreted the results with knowledge-based analyses. In summary, the increased hepatic DNL is accompanied by marginal gene expression changes but massive changes in peroxisomal proteome. Furthermore, plasma phosphatidylcholine (PC) as well as lysoPC species were altered. Based on these observations, it can be speculated that the plasticity of organelles and their functionality may be directly affected by lipid overflow.

2019-10-15 | GSE132298 | GEO

Mitochondria-rough-ER Contacts in The Liver Regulate Systemic Lipid Homeostasis

Project description:Contacts between organelles create microdomains that play major roles in regulating key intracellular activities and signaling pathways, but whether they also directly regulate systemic cellular activities, remains unknown. Here, we report the ultrastructural organization and dynamics of a new type of inter-organelle contact which is formed by rough-Endoplasmic Reticulum that is closely wrapped around the mitochondrion (wrappER). To elucidate the in vivo function of this inter-organelle association, mouse liver fractions enriched in wrappER-associated-mitochondria were analyzed in parallel by transcriptomics, proteomics, and lipidomics. The biochemical signature of the wrappER points to an unexpected role in the biogenesis of very-low-density lipoproteins (VLDLs). Altering wrappER-mitochondria contacts curtails liver VLDL secretion and increases hepatic fatty acids, lipid droplets and neutral lipid content. Conversely, acute liver-specific ablation of Mttp, the most upstream regulator of VLDL biogenesis, mirrors this hepatic dyslipidemia phenotype and promotes remodelling of the wrappER-mitochondria contact. The participation of liver wrappER-mitochondria contacts in VLDL biology reveals a role of inter-organelle contacts in systemic lipid homeostasis.

2021-03-15 | PXD021826 | Pride

A temporal proteogenomic atlas of HCV-host interactions unravels cell circuits driving viral and metabolic liver disease.

Project description:Background and aims: Hepatitis C virus (HCV) infection is a major cause of liver disease including steatosis, fibrosis and liver cancer. Viral cure cannot fully eliminate the risk of disease progression and hepatocellular carcinoma (HCC) in advanced liver disease. The mechanisms for establishment of infection, liver disease progression and hepatocarcinogenesis are only partially understood. To address these questions, we probed the functional proteogenomic architecture of HCV infection within a hepatocyte-model. Methods: Time-resolved HCV infection of hepatocyte-like cells was analyzed by RNA sequencing, proteomics, metabolomics, and leveraged by integrative genomic analyses. Using differential expression, gene set enrichment analyses, and protein-protein interaction mapping we identified pathways relevant for liver disease pathogenesis that we validated in livers of 216 cirrhotic patients with HCV. Results: We uncovered marked changes in the protein expression of gene sets involved in innate immunity, metabolism and hepatocarcinogenesis. In infected cells, HCV enhances glucose metabolism and creates a Warburg-like shift of the lactate flux. HCV infection impaired the formation of peroxisomes -organelles required for long-chain fatty acid oxidation- causing intracellular fatty acid accumulation, which is a hallmark of non-alcoholic fatty liver disease (NAFLD). Ex vivo studies confirmed perturbed peroxisomes and revealed an association of hepatic catalase expression with clinical outcomes and phenotypes in HCV-associated cirrhosis, NAFLD and HCC cohorts. Conclusion: Our integrative analyses uncover how HCV perturbs the hepatocyte cell circuits to drive chronic liver disease and hepatocarcinogenesis. This proteogenomic atlas of HCV infection provides a model for the discovery of novel drivers for viral- and non-viral induced liver disease.

2019-04-17 | GSE126831 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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