The in vivo effects of increased delivery of fatty acids (FA) to the liver are poorly defined. Therefore, we compared the effects of infusing either 6 mM oleic acid (OA) bound to albumin, 0.5-20% Intralipid, or saline for 3 or 6 h into male C57BL/6J mice. Infusions were followed by studies of triglyceride (TG) and apoB secretion. Although plasma FA levels increased similarly after either 20% Intralipid or 6 mM OA, TG secretion increased only after infusion of 4-20% Intralipid; TG secretion was unchanged by 6 mM OA. By contrast, 6-h infusions of either 6 mM OA or 4-20% Intralipid increased apoB secretion. 6 mM OA and 20% Intralipid each increased secretion of apoB from primary hepatocytes ex vivo. Importantly, 0.5-2% Intralipid, which delivered more FA to the liver than 6 mM OA, did not stimulate apoB secretion. Hepatic apoB mRNA levels were unaffected by either 6 mM OA or 20% Intralipid, but microsomal triglyceride transfer protein mRNA was significantly lower after 6-h infusions with 6 mM OA versus either saline or 20% Intralipid. Lower microsomal triglyceride transfer protein mRNA levels were associated with reduced hepatic TG mass after 6-h infusions of 6 mM OA. We conclude that 1) increased FA delivery to the liver in vivo increases secretion of apoB-lipoproteins via post-transcriptional mechanisms, 2) OA-induced apoB-lipoprotein secretion occurred at least in part via mechanisms other than by providing substrate for TG synthesis, and 3) the route of delivery of FA is important for its effects on apoB secretion.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1074/jbc.M400220200 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Restoration of Genetic Code in Macular Mouse Fibroblasts via APOBEC1-Mediated RNA Editing.
Biomolecules
January 2025
Bioscience, Biotechnology and Biomedical Engineering Research Area, Japan Advanced Institute of Science and Technology, Nomi 923-1211, Japan.
RNA editing is a significant mechanism underlying genetic variation and protein molecule alteration; C-to-U RNA editing, specifically, is important in the regulation of mammalian genetic diversity. The ability to define and limit accesses of enzymatic machinery to avoid the modification of unintended targets is key to the success of RNA editing. Identification of the core component of the apoB RNA editing holoenzyme, APOBEC, and investigation into new candidate genes encoding other elements of the complex could reveal further details regarding APOBEC-mediated mRNA editing.
View Article and Find Full Text PDFCharacterisation of pregnancy-induced alterations in apolipoproteins and their associations with maternal metabolic risk factors and offspring birth outcomes: a preconception and longitudinal cohort study.
EBioMedicine
January 2025
Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore; Department of Biochemistry and Precision Medicine Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. Electronic address:
Background: Apolipoproteins as an integral part of lipoproteins are crucial for the transport and metabolism of lipids. However, there is a lack of longitudinal studies to quantify the concentrations of maternal apolipoproteins from preconception to postpartum and their associations with maternal metabolic health and offspring birth outcomes.
Methods: Quantification of apolipoproteins was performed on maternal plasma samples (N = 243 trios) collected at preconception, 26-28 weeks' pregnancy, and three months postpartum in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO) cohort study.
Validation of the role of apolipoproteins in coronary artery disease patients with impaired kidney function for prognosis: a prospective cohort study in China.
Nutr J
January 2025
Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Objective: This study aims to evaluate the relationship between apolipoproteins (ApoA1, ApoB, and the ApoB/A1 ratio) and the incidence of major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) and impaired kidney function, assessing their potential role in secondary prevention.
Method: A prospective cohort of 1,640 patients with impaired kidney function who underwent percutaneous coronary intervention in China was analyzed. Patients were categorized based on the measurements of ApoA1, ApoB, and ApoB/A1 ratio.
Causal relationships between uremic metabolites or toxins and heart failure: Univariate and multivariate Mendelian randomization.
Medicine (Baltimore)
November 2024
Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Beijing, China.
Studies have shown that uremia, renal failure and heart failure (HF) are closely related. However, whether this association reflects a causal effect is still unclear. The aim of this study was to evaluate the causal effect of uremic metabolites or toxins on HF.
View Article and Find Full Text PDFBackground: Familial hyperlipidemia (familial hypercholesterolemia, FH) is an autosomal genetic disorder. It includes type heterozygous familial hyperlipidemia (heterozygous familial hypercholesterolemia). HeFH is mainly caused by mutations in the LDLR, APOB, and PCSK9 genes and is characterized by elevated plasma low-density lipoprotein cholesterol levels.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!