UMMS Affiliation

Department of Cell Biology

Date

5-17-2010

Document Type

Article

Medical Subject Headings

Animals; Aromatase; Base Sequence; Bone Density; Bone and Bones; Cell Line; Core Binding Factor Alpha 1 Subunit; Embryo, Mammalian; Estrogens; Exons; Female; *Gene Expression Regulation, Enzymologic; Humans; Mice; Mice, Knockout; Molecular Sequence Data; Osteoblasts; Progesterone; Promoter Regions, Genetic

Disciplines

Cell Biology

Abstract

The essential osteoblast-related transcription factor Runx2 and the female steroid hormone estrogen are known to play pivotal roles in bone homeostasis; however, the functional interaction between Runx2- and estrogen-mediated signaling in skeletal tissues is minimally understood. Here we provide evidence that aromatase (CYP19), a rate-limiting enzyme responsible for estrogen biosynthesis in mammals, is transcriptionally regulated by Runx2. Consistent with the presence of multiple Runx2 binding sites, the binding of Runx2 to the aromatase promoter was demonstrated in vitro and confirmed in vivo by chromatin immunoprecipitation assays. The bone-specific aromatase promoter is activated by Runx2, and endogenous aromatase gene expression is upregulated by Runx2 overexpression, establishing the aromatase gene as a target of Runx2. The biological significance of the Runx2 transcriptional control of the aromatase gene is reflected by the enhanced estrogen biosynthesis in response to Runx2 in cultured cells. Reduced in vivo expression of skeletal aromatase gene and low bone mineral density are evident in Runx2 mutant mice. Collectively, these findings uncover a novel link between Runx2-mediated osteoblastogenic processes and the osteoblast-mediated biosynthesis of estrogen as an osteoprotective steroid hormone.

Rights and Permissions

Originally published: Molecular and Cellular Biology. 2010 May;30(10):2365-75. Epub 2010 Mar 15. Link to article on publisher's site

Related Resources

Link to Article in PubMed

PubMed ID

20231365

Included in

Cell Biology Commons

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