Liver of MAT1A WT and MAT1A KO mice treated with placebo or SAMe during 8 weeks
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE77084 | GEO | 2017/02/02
SECONDARY ACCESSION(S): PRJNA309410
REPOSITORIES: GEO
Similar Datasets
Project description:Methionine adenosyltransferase (MAT) enzymes generate SAMe (S-adenosylmethionine), the main biological methyl donor. There are two MAT encoding genes in mammals (Mat1a and Mat2a), which show different activities and cellular distribution. Mat1a encodes the enzyme mainly expressed in normal liver. Mat1a ablation in mice results in the spontaneous development of non-alcoholic steatohepatitis (NASH). We observed that SAMe depletion in Mat1a KO mice had three main effects on hepatic lipid metabolism: 1) impaired TG (triglyceride) export via VLDL; 2) impaired mitochondrial FA (fatty acid) oxidation (as evidenced by membrane depolarization, downregulation of Phb1 (prohibitin 1, a mitochondrial chaperone protein) and Mcj/Dnajc15 (endogenous mitochondrial repressor of respiratory chain), and accumulation of long-chain acylcarnitines); and 3) increased FA uptake. The convergence of these three factors induced TG accumulation in LD (lipid droplets). LD expansion confronts hepatocytes with a high demand of PC (phosphatidylcholine) molecules to cover the LD surface since other phospholipids, such as PE (phosphatidylethanolamine), cannot stabilize LD and prevent coalescence. In Mat1a KO this situation is aggravated, since SAMe-dependent PC synthesis via PE methylation is decreased, the PC/PE ratio reduced and mitochondrial FA oxidation impaired. To put a brake to this drain of PC molecules to LD, FA are rerouted in Mat1a KO mice liver to other catabolic (endoplasmic reticulum and peroxisome oxidation) and biosynthetic (ceramides synthesis) pathways, causing oxidative stress, inflammation and fibrosis. SAMe treatment for two months in 8-9 month old Mat1a KO mice ameliorated mitochondrial dysfunction (reduces membrane depolarization, improves Phb1 and Mcj expression, and increases SAMe transport to mitochondria) improving FA oxidation efficiency (FA and acylcarnitine levels decrease), which results in a drastic reduction in TG accumulation. SAMe treatment in Mat1a KO mice resulted in more PC available for proper membrane function, improving liver lipid homeostasis, histology (H&E, Sudan red, Sirius red) and liver injury (ALT, AST).
2017-02-02 | GSE77082 | GEO
Project description:Methionine adenosyltransferase (MAT) enzymes generate SAMe (S-adenosylmethionine), the main biological methyl donor. There are two MAT encoding genes in mammals (Mat1a and Mat2a), which show different activities and cellular distribution. Mat1a encodes the enzyme mainly expressed in normal liver. Mat1a ablation in mice results in the spontaneous development of non-alcoholic steatohepatitis (NASH). We observed that SAMe depletion in Mat1a KO mice had three main effects on hepatic lipid metabolism: 1) impaired TG (triglyceride) export via VLDL; 2) impaired mitochondrial FA (fatty acid) oxidation (as evidenced by membrane depolarization, downregulation of Phb1 (prohibitin 1, a mitochondrial chaperone protein) and Mcj/Dnajc15 (endogenous mitochondrial repressor of respiratory chain), and accumulation of long-chain acylcarnitines); and 3) increased FA uptake. The convergence of these three factors induced TG accumulation in LD (lipid droplets). LD expansion confronts hepatocytes with a high demand of PC (phosphatidylcholine) molecules to cover the LD surface since other phospholipids, such as PE (phosphatidylethanolamine), cannot stabilize LD and prevent coalescence. In Mat1a KO this situation is aggravated, since SAMe-dependent PC synthesis via PE methylation is decreased, the PC/PE ratio reduced and mitochondrial FA oxidation impaired. To put a brake to this drain of PC molecules to LD, FA are rerouted in Mat1a KO mice liver to other catabolic (endoplasmic reticulum and peroxisome oxidation) and biosynthetic (ceramides synthesis) pathways, causing oxidative stress, inflammation and fibrosis. SAMe treatment for two months in 8-9 month old Mat1a KO mice ameliorated mitochondrial dysfunction (reduces membrane depolarization, improves Phb1 and Mcj expression, and increases SAMe transport to mitochondria) improving FA oxidation efficiency (FA and acylcarnitine levels decrease), which results in a drastic reduction in TG accumulation. SAMe treatment in Mat1a KO mice resulted in more PC available for proper membrane function, improving liver lipid homeostasis, histology (H&E, Sudan red, Sirius red) and liver injury (ALT, AST).
2017-02-02 | GSE77079 | GEO
Project description:Liver of MAT1A WT and MAT1A KO mice treated with placebo or SAMe during 8 weeks
| PRJNA309410 | ENA
Project description:The periodontal ligament (PDL), which connects the teeth to the alveolar bone, is essential for periodontal tissue homeostasis. Although the significance of the PDL is recognized, molecular mechanisms underlying PDL function are not well-known. We report that Mohawk homeobox (Mkx), a tendon-specific transcription factor, regulates PDL homeostasis by preventing its degeneration. Mkx is expressed in the mouse PDL at the age of 10 weeks and 12 months. In Mkx-/- mice, age-dependent expansion of the PDL at the maxillary 1st molar (M1) furcation area was observed. Transmission electron microscopy (TEM) revealed that Mkx-/- mice presented collagen fibril degeneration in PDL with age, while the collagen fibril diameter gradually increased in Mkx+/+ mice. PDL cells lost their shape in Mkx-/- mice, suggesting changes in PDL properties. Microarray and quantitative polymerase chain reaction (qPCR) analyses of Mkx-/- PDL revealed an increase in osteogenic gene expression and no change in PDL- and inflammatory-related gene expression. Additionally, COL1A1 and COL1A2 were upregulated in Mkx-overexpressing human PDL fibroblasts, whereas osteogenic genes were downregulated. Our results indicate that Mkx prevents PDL degeneration by regulating osteogenesis. Mohawk transcription factor is essential for homeostasis of the periodontal ligament by regulating osteogenic changes with age.
2017-01-17 | GSE92331 | GEO
Project description:Signaling through the Wnt/b-catenin pathway is a crucial determinant of hepatic zonal gene expression, liver development, regeneration, and tumorigenesis. The gene encoding b-catenin is called Ctnnb1. We have previously shown, that liver tumour promotion mediated by the model tumour promoter phenobarbital (PB) is completely lost in mice, where Ctnnb1 has been conditionally knocked out in hepatocytes (CTNNB1KO mice; Rignall et al., Carcinogenesis 32, 52-57, 2010). In the present study, the effect of a 12 weeks PB exposure on the liver miRNA expression pattern was investigated, in order to potentially get information on the nature of the loss of promotional activity in the CTNNB1KO mice.
2018-05-11 | GSE68779 | GEO
Project description:Signaling through the Wnt/b-catenin pathway is a crucial determinant of hepatic zonal gene expression, liver development, regeneration, and tumorigenesis. The gene encoding b-catenin is called Ctnnb1. We have previously shown that liver tumour promotion mediated by the model tumour promoter phenobarbital (PB) is completely lost in mice, where Ctnnb1 has been conditionally knocked out in hepatocytes (CTNNB1KO mice; Rignall et al., Carcinogenesis 32, 52-57, 2010). In the present study, the effect of a 12 weeks PB exposure on the liver miRNA expression pattern was investigated, in order to potentially get information on the nature of the loss of promotional activity in the CTNNB1KO mice.
2018-05-11 | GSE68786 | GEO
Project description:iTRAQ proteomics was performed for Liver samples from WT and Atg7 liver specific KO mice
2023-07-20 | PXD043936 |
Project description: Not available
| S-EPMC7349584 | biostudies-literature
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| S-EPMC9460185 | biostudies-literature
Project description:Lysosome-enriched fractions from the liver of Cln8 KO mice and WT mice. Included are four datasets: 1. Lysosome-enriched fraction from the liver of Cln8 KO mice, replicate 1 (CLN8_KO_1). 2. Lysosome-enriched fraction from the liver of Cln8 KO mice, replicate 2 (CLN8_KO_2). 3. Lysosome-enriched fraction from the liver of WT mice, replicate 1 (WT_1). 4. Lysosome-enriched fraction from the liver of WT mice, replicate 2 (WT_2).
| MSV000082938 | MassIVE