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Regulated expression of the prostacyclin receptor (IP) gene by androgens within the vasculature: Combined role for androgens and serum cholesterol
Author(s)
Date Issued
2016-10
Date Available
2017-10-01T01:00:25Z
Abstract
The prostanoid prostacyclin plays a key cardioprotective role within the vasculature. There is increasing evidence that androgens may also confer cardioprotection but through unknown mechanisms. This study investigated whether the androgen dihydrotestosterone (DHT) may regulate expression of the prostacyclin/I prostanoid receptor or, in short, the IP in platelet-progenitor megakaryoblastic and vascular endothelial cells. DHT significantly increased IP mRNA and protein expression, IP-induced cAMP generation and promoter (PrmIP)-directed gene expression in all cell types examined. The androgen-responsive region was localised to a cis-acting androgen response element (ARE), which lies in close proximity to a functional sterol response element (SRE) within the core promoter. In normal serum conditions, DHT increased IP expression through classic androgen receptor (AR) binding to the functional ARE within the PrmIP. However, under conditions of low-cholesterol, DHT led to further increases in IP expression through an indirect mechanism involving AR-dependent upregulation of SCAP expression and enhanced SREBP1 processing & binding to the SRE within the PrmIP. Chromatin immunoprecipitation assays confirmed DHT-induced AR binding to the ARE in vivo in cells cultured in normal serum while, in conditions of low cholesterol, DHT led to increased AR and SREBP1 binding to the functional ARE and SRE cis-acting elements, respectively, within the core PrmIP resulting in further increases in IP expression. Collectively, these data establish that the human IP gene is under the transcriptional regulation of DHT, where this regulation is further influenced by serum-cholesterol levels. This may explain, in part, some of the protective actions of androgens within the vasculature.
Sponsorship
European Commission - European Regional Development Fund
Health Research Board
Irish Cancer Society
Other Sponsorship
Programme for Research in Third Level Institutions (PRTLI; MolCellBiol)
Movember Foundation
Type of Material
Journal Article
Publisher
Elsevier
Journal
Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms
Volume
1859
Issue
10
Start Page
1333
End Page
1351
Copyright (Published Version)
2016 Elsevier
Language
English
Status of Item
Peer reviewed
This item is made available under a Creative Commons License
File(s)
Name
Eivers&Kinsella AR Regulation of PTGIR BBA MCR 2016 v1859p1333-51.pdf
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Complete Ms & Supplemental Data
Size
1.61 MB
Format
Owning collection
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