Work

Phosphate Regulates Osteopontin Gene Transcription

Year: 2009

Type: article

Abstract: Extracellular inorganic phosphate (ePi) is a key regulator of cementoblast behavior, both in vivo and in vitro, and results in a marked increase in osteopontin expression in vitro. To examine the molecular mechanisms involved in ePi induction of osteopontin gene expression, we transfected a series of osteopontin promoter-luciferase constructs into OCCM-30 cementoblasts. Our results demonstrate that ePi can directly induce osteopontin gene transcription. The region responsive to ePi signaling was localized to a 53-bp region of the promoter between -1454 and -1401 that contains a glucocorticoid response element (GRE). Mutation of the GRE abolished the ePi response, suggesting that glucocorticoid receptor (GR) signaling is required for ePi-mediated transcription. In addition, treatment of cells with the GR antagonist RU-486 (Mifepristone) prevented promoter activation by ePi. The results presented support a model demonstrating that inorganic phosphate regulates OPN gene transcription in cementoblasts through a pathway that requires a functional GR.

Source: Journal of Dental Research

DOI: 10.1177/0022034508328072

Authors: S. Fatherazi, D. Matsa-Dunn, B.L. Foster, R.B. Rutherford, M.J. Somerman, R.B. Presland

Institution: University of Washington

Language: English

Topic: Bone and Dental Protein Studies

Subfield: Rheumatology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, National Institute of Dental and Craniofacial Research