Expression and Localization of Estrogen Receptor-β in Murine and Human Bone

Open Access
Publisher Website
Google Scholar
Abstract
Estrogens have profound effects on bone metabolism. Cellular responses to estrogens are mediated by estrogen receptors (ERs) which belong to the nuclear receptor superfamily. Two estrogen receptors, ERα and ERβ, have been cloned. Previously expression of ERα has been shown in osteoblasts. Here we demonstrate that the transcript for ERβ can be detected in the human osteosarcoma cell lines (MG-63 and SaOS-2) and in cultured human osteoblast-like cells. We also show that ERβ protein is present in nuclear extracts from these cells. Furthermore, ERβ immunoreactivity is found in sections of murine and human bone. Murine and human osteoblast and osteocyte nuclei are immunoreactive for ERβ. Osteoclasts are also ERβ immunoreactive but the staining is mainly cytoplasmic. The present study demonstrates that ERβ is present in all the cellular compartments involved in bone formation and bone resorption, both in human and in murine bone tissue.