Format

Send to

Choose Destination
Curr Opin Endocrinol Diabetes Obes. 2010 Oct;17(5):408-13. doi: 10.1097/MED.0b013e32833d6d46.

New insights into regulation of lipid metabolism by thyroid hormone.

Author information

1
Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4264, USA.

Abstract

PURPOSE OF REVIEW:

Thyroid hormone (3,3',5-triiodo-L-thyronine) plays an important role in thermogenesis and maintenance of lipid homeostasis. The present article reviews the evidence that 3,3',5-triiodo-L-thyronine regulates lipid metabolism via thyroid hormone receptors, focusing particularly on in-vivo findings using genetically engineered mice.

RECENT FINDINGS:

That lipid metabolism is regulated via thyroid hormone receptor isoforms in a tissue-dependent manner was recently uncovered by using knockin mutant mice harboring an identical mutation in the Thra gene (Thra1(PV) mouse) or the Thrb gene (Thrb(PV) mouse). The mutation in the Thra gene dramatically decreases the mass of both white adipose tissue and liver. In contrast, the mutation in the Thrb gene markedly increases the mass of liver with an excess depot of lipids, but no significant abnormality is observed in white adipose tissue. Molecular studies show that the expression of lipogenic genes is decreased in white adipose tissue of Thra1(PV) mice, but not in Thrb(PV) mice. Markedly increased lipogenic enzyme expression, and decreased fatty acid beta-oxidation activity contribute to the adipogenic steatosis and lipid accumulation in the liver of Thrb(PV) mice. In contrast, reduced expression of genes critical for lipogenesis mediates decreased liver mass with lipid scarcity in Thra1(PV) mice.

SUMMARY:

Studies using Thra1(PV) and Thrb(PV) mice indicate that apo-thyroid hormone receptor-beta and apo-thyroid hormone receptor-alpha-1 mediate distinct deleterious effects on lipid metabolism. Thus, both thyroid hormone receptor isoforms contribute to the pathogenesis of lipid abnormalities in hypothyroidism, but in a target tissue-dependent manner. These studies suggest that thyroid hormone receptor isoform-specific ligands could be designed as therapeutic targets for lipid abnormalities.

Comment in

PMID:
20644471
PMCID:
PMC3457777
DOI:
10.1097/MED.0b013e32833d6d46
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wolters Kluwer Icon for PubMed Central
Loading ...
Support Center