Estrogen receptors alpha and beta in bone

Estrogens are important for bone metabolism via a variety of mechanisms in osteoblasts, osteocytes, osteoclasts, immune cells and other cells to maintain bone mineral density. Estrogens bind to estrogen receptor alpha (ER alpha) and ER beta, and the roles of each of these receptors are beginning to be elucidated through whole body and tissue specific knockouts of the receptors. In vitro and in vivo experiments have shown that ER alpha and ER beta antagonize each other in bone and in other tissues. This review will highlight the role of these receptors in bone, with particular emphasis on their antagonism. (C) 2016 Elsevier Inc. All rights reserved.