Thyroid Hormone Enhances the Ability of Serum to Accept Cellular Cholesterol via the ABCA1 Transporter

Atherosclerosis. 2011 Sep;218(1):77-82. doi: 10.1016/j.atherosclerosis.2011.04.028. Epub 2011 May 6.

Abstract

Objective: The goal of this study was to examine the effects of thyroid hormone status on the ability of serum to accept cellular cholesterol.

Methods and results: Sera from hypophysectomized rats treated ± T(3) was used to evaluate the role of thyroid hormone on serum efflux capacity. 2D-DIGE analysis of serum proteins showed that T(3) treated rats had increased ApoA-I, ApoA-IV and fetuin A levels with decreased Apo E levels. Microarray and real-time RT-PCR analysis of rat liver revealed large increases in ApoA-I, ApoA-IV, ABCG5, and ABCG8 in response to T(3). J774 macrophages, BHK cells, and Fu5AH rat hepatoma cells were used to measure cholesterol efflux mediated by ABCA1, ABCG1 transporters or SR-BI. Sera from T(3)-treated rats stimulated efflux via ABCA1 but not by ABCG1 or SR-BI. Gel filtration chromatography revealed that T(3) treatment caused a decrease in HDL particle size accompanied by higher levels of lipid-poor ApoA-I.

Conclusions: Thyroid hormone enhances the ability of serum to accept cellular cholesterol via the ABCA1 transporter. This effect is most likely attributable to increases in small HDL and lipid poor ApoA-I in response to T(3).

MeSH terms

  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters / metabolism*
  • Animals
  • Apolipoprotein A-I / chemistry
  • Atherosclerosis / metabolism
  • Biological Transport
  • Cell Line, Tumor
  • Cholesterol, HDL / metabolism
  • Cricetinae
  • Lipids / chemistry
  • Liver / metabolism
  • Macrophages
  • Male
  • Mice
  • Models, Biological
  • Oligonucleotide Array Sequence Analysis
  • Particle Size
  • Rats
  • Real-Time Polymerase Chain Reaction / methods
  • Thyroid Hormones / metabolism*

Substances

  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters
  • Apolipoprotein A-I
  • Cholesterol, HDL
  • Lipids
  • Thyroid Hormones