Similar Datasets
Project description:To investigate the impact of liver-specific deletion of Cpt1a on lipoprotein metabolism.
2025-07-30 | GSE277312 | GEO
Project description:Ablation of Hepatic CPT1a Lowers Plasma Cholesterol Levels
| PRJNA1161701 | ENA
Project description:Ablation of Hepatic CPT1a Lowers Plasma Cholesterol Levels.
| PRJNA1162113 | ENA
Project description:Hepatosteatosis, defined as excessive intrahepatic lipid accumulation, represents the first step in the development of NAFLD. However, the molecular events directly caused by hepatic lipid build-up, in terms of its impact on liver biology and other peripheral organs, remain unclear. Carnitine palmitoyltransferase 1A (CPT1A) is the rate limiting enzyme for long chain fatty acid beta-oxidation in the liver. Here we utilise hepatocyte-specific Cpt1a knockout (LKO) mice to investigate the physiological consequences of abolishing hepatic long chain fatty acid metabolism to NAFLD and systemic metabolic homeostasis. We show that LKO mice displayed more severe hepatosteatosis but were otherwise protected against diet-induced weight gain, insulin resistance, hepatic ER stress and damage in response to high fat diets. Furthermore, increased energy expenditure accompanied by enhanced adipose tissue browning was observed in LKO mice. Mechanistically, hepatic CPT1A deficiency actives the peroxisome proliferator activator alpha (PPARα)- fibroblast growth factor 21 (FGF21) axis and the elevation of FGF21 contributes to the improved liver pathology and adipose browning in HFD-treated LKO mice. Thus, our study demonstrates that liver with deficient CPT1A expression adopts a healthy steatotic status that protects against HFD-evoked liver damage and potentiates adipose browning in an FGF21-dependent manner. Inhibition of hepatic CPT1A may serve as a viable strategy for the treatment of obesity and NAFLD.
2022-09-10 | GSE183650 | GEO
Project description:Cholesterol is an essential lipid in vertebrates, but excess blood cholesterol promotes atherosclerosis. In the liver, cholesterol is metabolized to bile acids by cytochrome P450, family 7, subfamily a, polypeptide 1 (CYP7A1), the transcription of which is negatively regulated by the ERK pathway. Fibroblast growth factor 21 (FGF21), a hepatokine, induces ERK phosphorylation and suppresses Cyp7a1 transcription. Taurine, a sulfur-containing amino acid, reportedly promotes cholesterol metabolism and lowers blood and hepatic cholesterol levels. However, the influence of long-term feeding of taurine on cholesterol levels and metabolism remains unclear. Here, to evaluate the more chronic effects of taurine on cholesterol levels, we analyzed mice fed a taurine-rich diet for 14-16 weeks. Long-term feeding of taurine lowered plasma cholesterol and bile acids without significantly changing other metabolic parameters, but hardly affected these levels in the liver. Moreover, taurine upregulated Cyp7a1 levels, while downregulated phosphorylated ERK and Fgf21 levels in the liver. Likewise, taurine-treated Hepa1-6 cells, a mouse hepatocyte line, exhibited downregulated Fgf21 levels and upregulated promoter activity of Cyp7a1. These results indicate that taurine promotes cholesterol metabolism by suppressing the FGF21/ERK pathway followed by upregulating Cyp7a1 expression. Collectively, this study shows that long-term feeding of taurine lowers both plasma cholesterol and bile acids, reinforcing that taurine effectively prevents hypercholesterolemia.
| S-EPMC8836270 | biostudies-literature
Project description:To investigate the impact of liver-specific deletion of Cpt1a in hepatic lipid metabolism.
2025-02-26 | GSE225769 | GEO
Project description:Controlling intestinal lipid absorption is an important strategy for maintaining lipid homeostasis. Accumulation of lipids in the liver is a major risk factor for metabolic syndrome and nonalcoholic fatty liver disease. It is well-known that sphingomyelin (SM) can inhibit intestinal cholesterol absorption. It is, however, unclear if dietary SM also lowers liver lipid levels. In the present study (i) the effect of pure dietary egg SM on hepatic lipid metabolism and intestinal cholesterol absorption was measured with [(14)C]cholesterol and [(3)H]sitostanol in male C57BL/6 mice fed a high-fat (HF) diet with or without 0.6% wt/wt SM for 18 days; and (ii) hepatic lipid levels and gene expression were determined in mice given a HF diet with or without egg SM (0.3, 0.6 or 1.2% wt/wt) for 4 weeks. Mice supplemented with SM (0.6% wt/wt) had significantly increased fecal lipid and cholesterol output and reduced hepatic [(14)C]cholesterol levels after 18 days. Relative to HF-fed mice, SM-supplemented HF-fed mice had significantly lower intestinal cholesterol absorption (-30%). Liver weight was significantly lower in the 1.2% wt/wt SM-supplemented mice (-18%). Total liver lipid (mg/organ) was significantly reduced in the SM-supplemented mice (-33% and -40% in 0.6% wt/wt and 1.2% wt/wt SM, respectively), as were triglyceride and cholesterol levels. The reduction in liver triglycerides was due to inactivation of the LXR-SREBP-1c pathway. In conclusion, dietary egg SM has pronounced hepatic lipid-lowering properties in mice maintained on an obesogenic diet.
| S-EPMC3567029 | biostudies-literature
Project description:The secretory pathway of eukaryotic cells packages cargo proteins into COPII-coated vesicles for transport from the endoplasmic reticulum (ER) to the Golgi. We now report that complete genetic deficiency for the COPII component SEC24A is compatible with normal survival and development in the mouse, despite the fundamental role of SEC24 in COPII vesicle formation and cargo recruitment. However, these animals exhibit markedly reduced plasma cholesterol, with mutations in Apoe and Ldlr epistatic to Sec24a, suggesting a receptor-mediated lipoprotein clearance mechanism. Consistent with these data, hepatic LDLR levels are up-regulated in SEC24A-deficient cells as a consequence of specific dependence of PCSK9, a negative regulator of LDLR, on SEC24A for efficient exit from the ER. Our findings also identify partial overlap in cargo selectivity between SEC24A and SEC24B, suggesting a previously unappreciated heterogeneity in the recruitment of secretory proteins to the COPII vesicles that extends to soluble as well as trans-membrane cargoes. DOI:http://dx.doi.org/10.7554/eLife.00444.001.
| S-EPMC3622177 | biostudies-literature
Project description:BackgroundFew trials have examined the effects of coconut oil consumption in comparison with polyunsaturated fatty acid-rich oils such as corn oil.ObjectiveThis trial assessed the effects of consuming foods made with corn oil compared with coconut oil on lipids, glucose homeostasis, and inflammation.MethodsThis was a preliminary randomized crossover study of men (n = 12) and women (n = 13) with a mean age of 45.2 y, mean body mass index (in kg/m2) of 27.7, fasting LDL cholesterol ≥115 mg/dL and <190 mg/dL, and triglycerides (TGs) ≤375 mg/dL. Subjects consumed muffins and rolls providing 4 tablespoons (∼54 g) per day of corn oil or coconut oil as part of their habitual diets for 4 wk, with a 3-wk washout between conditions. Fasting plasma lipids and high-sensitivity C-reactive protein (hs-CRP) and glucose metabolism were assessed via an intravenous glucose tolerance test at baseline and 15 and 29 d of treatment. Responses were compared between treatments by ANCOVA.ResultsMedian baseline concentrations of LDL cholesterol, non-HDL cholesterol, total cholesterol (total-C), HDL cholesterol, total-C:HDL cholesterol, and TGs were 123, 144, 188, 46.0, 4.21, and 92.5 mg/dL, respectively. Changes from baseline for corn oil and coconut oil conditions, respectively, were: LDL cholesterol (primary outcome; -2.7% compared with +4.6%), non-HDL cholesterol (-3.0% compared with +5.8%), total-C (-0.5% compared with +7.1%), HDL cholesterol (+5.4% compared with +6.5%), total-C:HDL cholesterol (-4.3% compared with -3.3%), and TGs (-2.1% compared with +6.0%). Non-HDL cholesterol responses were significantly different between corn and coconut oil conditions (P = 0.034); differences between conditions in total-C and LDL cholesterol approached significance (both P = 0.06). Responses for hs-CRP and carbohydrate homeostasis parameters did not differ significantly between diet conditions.ConclusionsWhen incorporated into the habitual diet, consumption of foods providing ∼54 g of corn oil/d produced a more favorable plasma lipid profile than did coconut oil in adults with elevated cholesterol. This trial was registered at clinicaltrials.gov as NCT03202654.
| S-EPMC6168703 | biostudies-literature
Project description:To determine the efficacy and underlying mechanism of Astragalus polysaccharides (APS) on plasma lipids in hypercholesterolemia hamsters. The effect of APS (0.25 g/kg/d) on plasma and liver lipids, fecal bile acids and neutral sterol, cholesterol absorption and synthesis, HMG-CoA reductase activity, and gene and protein expressions in the liver and small intestine was investigated in twenty-four hypercholesterolemia hamsters. Treatment periods lasted for three months. APS significantly lowered plasma total cholesterol by 45.8%, triglycerides by 30%, and low-density lipoprotein-cholesterol by 47.4%, comparable to simvastatin. Further examinations revealed that APS reduced total cholesterol and triglycerides in the liver, increased fecal bile acid and neutral sterol excretion, inhibited cholesterol absorption, and by contrast, increased hepatic cholesterol synthesis and HMG-CoA reductase activity. Plasma total cholesterol or low-density lipoprotein-cholesterol levels were significantly correlated with cholesterol absorption rates. APS up-regulated cholesterol-7α-hydroxylase and LDL-receptor gene expressions. These new findings identify APS as a potential natural cholesterol lowering agent, working through mechanisms distinct from statins.
| S-EPMC3217967 | biostudies-literature