Nuclear receptors and AMPK: resetting metabolism.

Obesity, and in particular central adiposity, is a key feature of metabolic syndrome, which includes trends toward increased triglycerides, insulin resistance, high blood pressure, hypercholesterolemia, and heart disease. It has a prevalence of 25% or more and is a dominant component of the health care budgets in Western societies. In addition to genetic causes, high-fat diets and disrupted sleep patterns have major influences on the development of metabolic syndrome. Recent studies have demonstrated active roles for the nuclear receptor superfamily and the energy-sensing kinase adenosine monophosphate (AMP)-activated protein kinase (AMPK) in regulating metabolism and circadian rhythm. In this chapter, we review these findings and attempt to develop a better understanding of the interplay between metabolism and circadian rhythm and their coordinated regulation by nuclear receptors and AMPK. This supraregulatory network may be considered a target for novel therapeutic applications against metabolic syndrome.