The Role of Estrogen Receptor in Bone Cells

Abstract

Estrogen is an essential regulator of the skeleton homeostasis during both childhood and adulthood. As a matter of fact, estrogens and selective estrogen receptor modulators are considered essential treatment tools by clinicians to prevent bone fractures in postmenopausal women. All these observations promote a great interest in discovering the mechanisms by which estrogens protect bone. Over the past years, research performed from several groups has established that the osteoprotective effects of estrogens are due to both direct actions on bone cells and indirect effects mediated through bone marrow cells. Experiments performed in humans and animals, in which estrogen receptor deletion was specifically carried out in different bone cells, have allowed unraveling some aspects of the estrogen actions on bone through these cells. This review highlights the current knowledge about the role of estrogens in the RANKL/OPG system, as well as their role in different bone cells and bone marrow cells.