Premium
New insights on endothelial CaMKII in angiotensin II‐induced hypertension (851.6)
Author(s) -
Charbel Chimene,
Toussaint Fanny,
Blanchette Alexandre,
Gillis MarcAntoine,
Comtois Philippe,
Ledoux Jonathan
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.851.6
Subject(s) - angiotensin ii , stimulation , nitric oxide , medicine , endocrinology , reactive oxygen species , chemistry , receptor , endothelial dysfunction , microbiology and biotechnology , biology
Angiotensin II‐induced arterial hypertension (AngII‐AH) is associated with an endothelial dysfunction characterized by a Ca2+ dyshomeostasis. Alteration of the delicate balance between reactive oxygen species (ROS) and nitric oxide (NO) then arise. Recent evidences suggest that hypertension stimulates Ca2+ pulsars and CaMKII but the contribution of AngII and the concomitant ROS remains elusive. The aim of this study was to establish a relationship between endothelial Ca2+ pulsars, ROS and CaMKII in AngII‐AH. Acute exposure to high (> 10‐8 M) concentrations of AngII stimulated Ca2+ pulsars and ROS production in high‐speed confocal microscopy. However, lower AngII level (10‐9 M) only increased Ca2+ pulsars frequency, suggesting a role for ROS in the Ca2+ pulsars stimulation. All AngII concentrations induced endothelial CaMKII recruitment within myoendothelial projections. AngII also stimulated NO production, an effect blunted by CaMKII inhibition (KN‐93). Candesartan, an AT1 blocker, partially reduced Ca2+ pulsars stimulation, suggesting roles for both AT receptors. Moreover, an increased in Ca2+ pulsars frequency and ROS production, associated with CaMKII clustering, is also observed in AngII‐AH mice. Our findings shed a new light on hypertension and Ca2+ dyshomeostasis along with their relationships with CaMKII, a key regulator of endothelial function. Grant Funding Source : Supported by CIHR, FRQS, CFI, HSFC and SQHA.