J Bone Metab.  2013 Nov;20(2):83-88. 10.11005/jbm.2013.20.2.83.

Bone Morphogenetic Protein-2 Desensitizes MC3T3-E1 Osteoblastic Cells to Estrogen Through Transcriptional Downregulation of Estrogen Receptor 1

• Ishibashi

• KMID: 2286298
• DOI: http://doi.org/10.11005/jbm.2013.20.2.83

Abstract

BACKGROUND
Estrogens exert preferable effects on bone metabolism through two estrogen receptors (ERs), ER1 and ER2, which activate the transcription of a set of genes as ligand-dependent transcription factors. Thus, growth factors and hormones which modulate ER expression in the bone, if any, may possibly modulate the effect of estrogens on bone metabolism. However, research as to which of these molecules regulate the expression of ERs in osteoblasts has not been well documented.
METHODS
A reporter assay system developed in this study was used to explore molecules that modulate ER1 expression in MC3T3-E1 osteoblastic cells. Gene expression was analyzed by reverse transcription-polymerase chain reaction.
RESULTS
A pilot study using the reporter system revealed that bone morphogenetic protein (BMP)-2 negatively regulated ER1, but not ER2, expression in MC3T3-E1 cells. Consistently, estradiol-induced reporter activity via an estrogen responsive element was strongly suppressed in MC3T3-E1 cells pretreated with BMP-2.
CONCLUSIONS
BMP-2 desensitizes osteoblastic cells to estrogen through downregulation of ER1 expression.

Keyword

Bone morphogenetic proteins; Osteoblasts; Receptors estrogen

MeSH Terms

Bone Morphogenetic Proteins
Down-Regulation*
Estrogen Receptor alpha*
Estrogens*
Gene Expression
Intercellular Signaling Peptides and Proteins
Metabolism
Osteoblasts*
Pilot Projects
Receptors, Estrogen
Transcription Factors
Bone Morphogenetic Proteins
Estrogen Receptor alpha
Estrogens
Intercellular Signaling Peptides and Proteins
Receptors, Estrogen
Transcription Factors