What is the Origin of Liver X Receptor Alpha?

LXRα was discovered in the early 1990s as part of a family of orphan nuclear receptors, so named because their endogenous ligands were initially unknown. Subsequent research identified its role as a lipid sensor, integrating dietary fat intake and cellular cholesterol status with gene expression. The receptor's nomenclature includes "Alpha" to distinguish it from the related LXR-beta receptor, which has a broader tissue distribution.

What is the Mechanism of Liver X Receptor Alpha?

When LXRα is activated by oxysterols, the LXRα/RXR heterodimer binds to LXR response elements (LXREs) in the promoter regions of target genes. This binding upregulates the expression of genes involved in cholesterol efflux, such as ABCA1, which moves cholesterol out of cells like macrophages. Simultaneously, LXRα activation influences the expression of lipogenic enzymes, linking the body's cholesterol clearance system directly to its overall fat synthesis and storage pathways.

Liver X Receptor Alpha ∞ Area

Liver X Receptor Alpha

Meaning

Liver X Receptor Alpha (LXRα) is a nuclear receptor protein that functions as a master regulator of cholesterol, fatty acid, and glucose metabolism in various tissues, most prominently the liver, adipose tissue, and macrophages. As a transcription factor, LXRα forms a heterodimer with the Retinoid X Receptor (RXR) and is activated by oxysterols, which are oxidized derivatives of cholesterol. Its activation is critical for promoting reverse cholesterol transport and regulating lipid homeostasis.