The estrogen-related receptors and the adipocyte

The estrogen-related receptors (ERR alpha, beta, and gamma) are orphan members of the nuclear receptor superfamily. ERR alpha and gamma are highly expressed in tissues displaying elevated energy demands and are involved in several aspects of energetic metabolism, which they regulate mostly in association with members of the PGC-1 coactivator family. These activities have mostly been documented in the liver, heart, or skeletal muscle. ERR alpha and gamma are also highly expressed in adipocytes. Their precise roles in this cell type are less documented, although published data indicate that they contribute to cell differentiation as well as functionality. This review describes these activities.