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Updated: May 30, 2026
06:47
ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography
Published on: August 25, 2023
ATP-binding cassette G5/G8 deficiency causes hypertriglyceridemia by affecting multiple metabolic pathways
Jesús Méndez-González1, Josep Julve, Noemí Rotllan
1IIB Sant Pau, Barcelona, Spain.
Biochimica Et Biophysica Acta
|August 23, 2011
Summary
ABCG5/G8 transporter deficiency in mice significantly elevates triglyceride (TG) levels. This occurs due to impaired TG breakdown and increased liver and intestinal TG secretion, contributing to insulin resistance.
Area of Science:
- Biochemistry
- Genetics
- Metabolic Diseases
Background:
- Mutations in ABCG5 or ABCG8 transporters cause sitosterolemia, a disease marked by plant sterol accumulation.
- Understanding the role of these transporters in lipid metabolism is crucial for metabolic disease research.
Purpose of the Study:
- To investigate the impact of ABCG5 and ABCG8 deficiency on triglyceride (TG) metabolism in mice.
- To elucidate the mechanisms behind altered TG levels in ABCG5/G8-deficient models.
Main Methods:
- Comparison of plasma and tissue TG levels in wild-type, heterozygous, and homozygous ABCG5/G8-deficient mice.
- Assessment of TG fractional catabolic rate and lipoprotein lipase activity.
- Measurement of liver and intestinal TG secretion.
- Analysis of gene expression related to lipid metabolism (LXR, FAS, ACAC, CD36).
- Evaluation of insulin resistance using the HOMA index.
Main Results:
- Fasted and postprandial plasma TG levels were significantly elevated in ABCG5/G8-deficient mice.
- Fractional catabolic rate and postheparin plasma lipoprotein lipase activity were reduced.
- Liver and intestinal TG secretion were markedly increased.
- Gene expression of LXR, FAS, ACAC, and CD36 was upregulated in the liver.
- Increased HOMA index indicated insulin resistance in deficient mice.
Conclusions:
- ABCG5/G8 deficiency in mice significantly raises TG levels under a standard chow diet.
- Impaired TG catabolism and increased hepatic and intestinal TG secretion are key mechanisms.
- These metabolic alterations contribute to a state of insulin resistance.
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