In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 106, No. 14 ( 2009-04-07), p. 5825-5830
Abstract:
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 (AT 1 Rs). Until now, the general consensus for AngII signaling to aldosterone production has been that it proceeds via activation of G q/11 -proteins, to which the AT 1 R normally couples. Here, we describe a novel signaling pathway underlying this AT 1 R-dependent aldosterone production mediated by β-arrestin-1 (βarr1), 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 βarr1-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 βarr, but not G protein coupling to the AT 1 R, recapitulates the effects of AngII on aldosterone production and secretion. In vivo, increased adrenal βarr1 activity, by means of adrenal-targeted adenoviral-mediated gene delivery of a βarr1 transgene, resulted in a marked elevation of circulating aldosterone levels in otherwise normal animals, suggesting that this adrenocortical βarr1-mediated signaling pathway is operative, and promotes aldosterone production and secretion in vivo, as well. Thus, inhibition of adrenal βarr1 activity on AT 1 Rs might be of therapeutic value in pathological conditions characterized and aggravated by hyperaldosteronism.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0811706106
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2009
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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