Related Experiment Videos
Pathogenesis of carbohydrate-induced hypertriglyceridemia using HepG2 cells as a model system
K Cianflone1, S Dahan, J C Monge
1Royal Victoria Hospital, McGill Unit for the Prevention of Cardiovascular Disease, McGill University, Montreal, Canada.
Arteriosclerosis and Thrombosis : a Journal of Vascular Biology
|March 1, 1992
Summary
Glucose increases liver triacylglycerol synthesis and secretion, while fatty acids boost both triacylglycerol and cholesteryl ester synthesis and secretion. Fatty acid loads also increase apolipoprotein B secretion, impacting lipid particle release.
Area of Science:
- Hepatology and Lipid Metabolism
- Cellular Biology
- Biochemistry
Background:
- Hepatic lipid synthesis and apolipoprotein B (apo B) secretion are critical for lipoprotein metabolism.
- Understanding how different nutrient substrates influence these processes is vital for metabolic disease research.
Purpose of the Study:
- To compare the distinct effects of glucose and fatty acids on hepatic lipid synthesis and apo B secretion.
- To investigate the impact of substrate availability on the composition and quantity of secreted lipoproteins.
Main Methods:
- Utilized HepG2 cells incubated with varying concentrations of glucose or oleic acid.
- Measured intracellular and secreted triacylglycerol and cholesteryl ester synthesis using radioisotopic tracers and mass determination.
- Quantified apo B concentration in the medium via enzyme-linked immunosorbent assay.
Main Results:
- Glucose significantly increased intracellular and secreted triacylglycerol synthesis but did not affect apo B secretion or cholesteryl ester metabolism.
- Oleic acid markedly enhanced the synthesis and secretion of both triacylglycerol and cholesteryl ester.
- Fatty acid loading was associated with a significant increase in apo B secretion, indicating the release of more lipoprotein particles.
Conclusions:
- Hepatic response to glucose involves increased triacylglycerol-rich apo B particle secretion.
- Fatty acid stimulation leads to the secretion of a greater number of apo B particles with normal lipid composition.
- Differential nutrient regulation of hepatic lipid metabolism and lipoprotein assembly has implications for understanding dyslipidemia.