Liver X receptors as insulin-mediating factors in fatty acid and cholesterol biosynthesis.

The nuclear receptor liver X receptor (LXR) alpha, an important regulator of cholesterol and bile acid metabolism, was analyzed after insulin stimulation in liver in vitro and in vivo. A time- and dose-dependent increase in LXRalpha steady-state mRNA level was seen after insulin stimulation of primary rat hepatocytes in culture. A maximal induction of 10-fold was obtained when hepatocytes were exposed to 400 nm insulin for 24 h.