Submitted on September 5, 2002
Accepted on June 23, 2003
Estrogen Decreases Biglycan mRNA Expression in Resistance Blood Vessels
Manoj C Rodrigo1, Douglas S Martin1, and Kathleen M Eyster1*
1 Basic Biomedical Sciences, University of South Dakota, Vermillion, SD, USA
* To whom correspondence should be addressed. E-mail: keyster{at}usd.edu.
This study was designed to identify new gene targets of estrogen in the mesenteric arteries and to determine whether the soy phytoestrogens could mimick estrogen effects. Ovariectomized rats were treated with estradiol, genistein or daidzein for four days. The mesenteric arteries were harvested, total RNA was extracted, mRNA was reverse transcribed in the presence of [33P]dCTP, and the labelled probes were hybridized with DNA microarrays. Analysis of the microarray data identified biglycan as a target of estrogenic regulation. Semi-quantitative RT-PCR was used to confirm and quantitate the decrease in biglycan gene expression in response to estrogen (-37%), genistein (-15%), and daidzein (-10%). Treatment with the pure estrogen receptor antagonist, ICI 182,780, reversed the inhibition of biglycan gene expression. The decrease in biglycan gene expression in response to estrogens was paralleled with a decrease in biglycan protein expression. Biglycan protein was localized to the media of the mesenteric arteries by immunohistochemistry. Collectively, these data suggest that biglycan is a vascular protein regulated at the genomic level by estrogens.
