期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2009
卷号：106
期号：14
页码：5825-5830
DOI：10.1073/pnas.0811706106
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Aldosterone produces a multitude of effects in vivo, including promotion of postmyocardial infarction adverse cardiac remodeling and heart failure progression. It is produced and secreted by the adrenocortical zona glomerulosa (AZG) cells after angiotensin II (AngII) activation of AngII type 1 receptors (AT1Rs). Until now, the general consensus for AngII signaling to aldosterone production has been that it proceeds via activation of Gq/11-proteins, to which the AT1R normally couples. Here, we describe a novel signaling pathway underlying this AT1R-dependent aldosterone production mediated by {beta}-arrestin-1 ({beta}arr1), a universal heptahelical receptor adapter/scaffolding protein. This pathway results in sustained ERK activation and subsequent up-regulation of steroidogenic acute regulatory protein, a steroid transport protein regulating aldosterone biosynthesis in AZG cells. Also, this {beta}arr1-mediated pathway appears capable of promoting aldosterone turnover independently of G protein activation, because treatment of AZG cells with SII, an AngII analog that induces {beta}arr, but not G protein coupling to the AT1R, recapitulates the effects of AngII on aldosterone production and secretion. In vivo, increased adrenal {beta}arr1 activity, by means of adrenal-targeted adenoviral-mediated gene delivery of a {beta}arr1 transgene, resulted in a marked elevation of circulating aldosterone levels in otherwise normal animals, suggesting that this adrenocortical {beta}arr1-mediated signaling pathway is operative, and promotes aldosterone production and secretion in vivo, as well. Thus, inhibition of adrenal {beta}arr1 activity on AT1Rs might be of therapeutic value in pathological conditions characterized and aggravated by hyperaldosteronism.
关键词：adrenocortical zona glomerulosa cell ; G protein-coupled receptor ; angiotensin II receptor type I ; adrenal steroid hormones ; biased agonism
