Hepatic ABC transporters and triglyceride metabolism

John S. Parks, Soonkyu Chung, Gregory S. Shelness

Research output: Contribution to journalReview article

18 Scopus citations

Abstract

PURPOSE OF REVIEW: Elevated plasma triglyceride and reduced HDL concentrations are prominent features of metabolic syndrome and type 2 diabetes. Individuals with Tangier disease also have elevated plasma triglyceride concentrations and very low HDL, resulting from mutations in ATP-binding cassette transporter A1 (ABCA1), an integral membrane protein that facilitates nascent HDL particle assembly. Past studies attributed the inverse relationship between plasma HDL and triglyceride to intravascular lipid exchange and catabolic events. However, recent studies also suggest that hepatic signaling and lipid mobilization and secretion may explain how HDL affects plasma triglyceride concentrations. RECENT FINDINGS: Hepatocyte-specific ABCA1 knockout mice have markedly reduced plasma HDL and a two-fold increase in triglyceride due to failure to assemble nascent HDL particles by hepatocytes, causing increased catabolism of HDL apolipoprotein A-I and increased hepatic production of triglyceride-enriched VLDL. In-vitro studies suggest that nascent HDL particles may induce signaling to decrease triglyceride secretion. Inhibition of microRNA 33 expression in nonhuman primates augments hepatic ABCA1, genes involved in fatty acid oxidation, and decreases expression of lipogenic genes, causing increased plasma HDL and decreased triglyceride levels. SUMMARY: New evidence suggests potential mechanisms by which hepatic ABCA1-mediated nascent HDL formation regulates VLDL-triglyceride production and contributes to the inverse relationship between plasma HDL and triglyceride.

Original languageEnglish (US)
Pages (from-to)196-200
Number of pages5
JournalCurrent Opinion in Lipidology
Volume23
Issue number3
DOIs
StatePublished - Jun 1 2012

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Keywords

  • ATP-binding cassette transporter A1
  • Tangier disease
  • high-density lipoprotein formation
  • mRNA
  • very low-density lipoprotein production

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Molecular Biology
  • Genetics
  • Nutrition and Dietetics
  • Cardiology and Cardiovascular Medicine
  • Cell Biology

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