Genes and Metabolic Disorders
Liver X receptors and metabolic disorders
Tontonoz studies how genes are regulated in response to lipid metabolism. He has researched ways to slow the process of metabolism or speed it up.
He and his colleagues have identified enzymes called liver X receptors (LXRs) that are master regulators of cholesterol, fat and inflammatory gene expression. LXRs regulate fatty acid and cholesterol metabolism in many tissues, including liver, fat and brain. Gain or loss of LXR activity influences the development or progression of several metabolic disorders, including atherosclerosis, fatty liver disease, and Alzheimer’s.
The promise of LXRs in treating disease
The LXRs are ligand-activated transcription factors that are normally turned on by cholesterol derivatives. This has opened the door to the possibility of developing LXR activators or inhibitors for clinical use.
When stimulated, LXRs "turn on" several hundred genes that hold instructions to create proteins for carrying out bodily processes in cells, from transporting and excreting cholesterol to synthesizing fat in the liver. Evidence also shows that LXRs suppress inflammatory processes in several contexts.
In mice, compounds that turn on the receptors have been shown to lower cholesterol levels in blood and liver tissues, effectively treating:
- Diabetes
- Atherosclerosis
- Alzheimer’s disease
- Inflammation
“At its essence, obesity is a disorder of energy balance, and type 2 diabetes is a disorder of lipid, or fat, metabolism.”