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Hepatic TRAP80 selectively regulates lipogenic activity of liver X receptor
- Source :
- Journal of Clinical Investigation. January 1, 2015, p183, 11 p.
- Publication Year :
- 2015
-
Abstract
- Inflammation in response to excess low-density lipoproteins in the blood is an important driver of atherosclerosis development. Due to its ability to enhance ATP-binding cassette A1-dependent (ABCA1-dependent) reverse cholesterol transport (RCT), liver X receptor (LXR) is an attractive target for the treatment of atherosclerosis. However, LXR also upregulates the expression of sterol regulatory element-binding protein 1c (SREBP-1c), leading to increased hepatic triglyceride synthesis, an independent risk factor for atherosclerosis. Here, we developed a strategy to separate the favorable and unfavorable effects of LXR by exploiting the specificity of the coactivator thyroid hormone receptor-associated protein 80 (TRAP80). Using human hepatic cell lines, we determined that TRAP80 selectively promotes the transcription of SREBP-1c but not ABCA1. Adenovirus-mediated expression of shTRAP80 inhibited LXR-dependent SREBP-1c expression and RNA polymerase II recruitment to the LXR responsive element (LXRE) of SREBP-1c, but not to the LXRE of ABCA1. In murine models, liver-specific knockdown of TRAP80 ameliorated liver steatosis and hypertriglyceridemia induced by LXR activation and maintained RCT stimulation by the LXR ligand. Together, these data indicate that TRAP80 is a selective regulator of hepatic lipogenesis and is required for LXR-dependent SREBP-1c activation. Moreover, targeting the interaction between TRAP80 and LXR should facilitate the development of potential LXR agonists that effectively prevent atherosclerosis.<br />Introduction Liver X receptor (LXR) is a member of the nuclear receptor super-family and acts as a cholesterol sensor to regulate the expression of several key proteins involved in lipid [...]
Details
- Language :
- English
- ISSN :
- 00219738
- Database :
- Gale General OneFile
- Journal :
- Journal of Clinical Investigation
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.401506563
- Full Text :
- https://doi.org/10.1172/JCI73615