Urotensin-II promotes vascular smooth muscle cell proliferation through store-operated calcium entry and EGFR transactivation.

Aims: Urotensin-II (UII) is a vasoactive peptide that promotes vascular smooth muscle cells (VSMCs) proliferation and is involved in the pathogenesis of atherosclerosis, restenosis, and vascular remodelling. This study aimed to determine the role of calcium (Ca(2+))-dependent signalling and alternative signalling pathways in UII-evoked VSMCs proliferation focusing on store-operated Ca(2+) entry (SOCE) and epithelium growth factor receptor (EGFR) transactivation.

Methods And Results: We used primary cultures of VSMCs isolated from Wistar rat aorta to investigate the effects of UII on intracellular Ca(2+) mobilization, and proliferation determined by the 5-bromo-2-deoxyuridine (BrdU) assay.

Urotensin-II signaling mechanism in rat coronary artery: role of STIM1 and Orai1-dependent store operated calcium influx in vasoconstriction.

Objective: Human urotensin-II (UII) is considered the most potentendogenous vasoconstrictor discovered to date, although the precise mechanism activated downstream of its receptor UTS2R in blood vessels remains elusive. The aim of this study was to determine the role of the store operated Ca(2+) entry (SOCE) signaling pathway in UII-induced coronary artery vasoconstriction.

Methods And Results: We used a combination of isometric tension measurement, Ca(2+) imaging, pharmacology, and molecular approaches to study UII-mediated rat coronary artery vasoconstriction and intracellular Ca(2+) mobilization in coronary smooth muscle cells.

Urocortin-2 induces vasorelaxation of coronary arteries isolated from patients with heart failure.

1. Urocortin-2 (Ucn2) is a vasoactive peptide belonging to the corticotrophin-releasing factor (CRF) family that has potent cardiovascular actions. It has been suggested that Ucn2 participates in the pathophysiology of heart failure.

Urocortin induces positive inotropic effect in rat heart.

Aims: The aim of this study is to evaluate the positive inotropic effect of urocortin (Ucn) and to characterize its signalling pathways.

Methods And Results: Contractility was measured in ex vivo Langendorff-perfused hearts isolated from Wistar rats. Isolated ventricular cardiomyocytes were used to analyse intracellular calcium ([Ca(2+)](i)) transients evoked by electrical stimulation and L-type Ca(2+) current by confocal microscopy and whole-cell patch-clamping, respectively.