Angiotensin Converting Enzyme (ACE) and ACE2 Bind Integrins and ACE2 Regulates Integrin Signalling

The angiotensin converting enzymes (ACEs) are the key catalytic components of the renin-angiotensin system, mediating precise regulation of blood pressure by counterbalancing the effects of each other. Inhibition of ACE has been shown to improve pathology in cardiovascular disease, whilst ACE2 is cardioprotective in the failing heart. However, the mechanisms by which ACE2 mediates its cardioprotective functions have yet to be fully elucidated. Here we demonstrate that both ACE and ACE2 bind integrin subunits, in an RGD-independent manner, and that they can act as cell adhesion substrates. We show that cellular expression of ACE2 enhanced cell adhesion. Furthermore, we present evidence that soluble ACE2 (sACE2) is capable of suppressing integrin signalling mediated by FAK. In addition, sACE2 increases the expression of Akt, thereby lowering the proportion of the signalling molecule phosphorylated Akt. These results suggest that ACE2 plays a role in cell-cell interactions, possibly acting to fine-tune integrin signalling. Hence the expression and cleavage of ACE2 at the plasma membrane may influence cell-extracellular matrix interactions and the signalling that mediates cell survival and proliferation. As such, ectodomain shedding of ACE2 may play a role in the process of pathological cardiac remodelling

A local angle compensation method based on kinematics constraints for non-invasive vascular axial strain computations on human carotid arteries.

International audienceNon invasive vascular elastography (NIVE) was developed to highlight atherosclerotic plaque constituents. However, NIVE motion estimates are affected by artifacts, such as an underestimation of deformations due to projected movement angles with respect to the ultrasound beam, movements of the operator or of the patient during image acquisition. The main objective of this work was to propose a local angle compensation method within small measurement windows for the axial strain based on kinematics constraints, and to introduce a filtering process on the strain time-varying curve to reduce as much as possible the impact of motion artifacts. With such preprocessing, we successfully quantified the strain behavior of near and far walls in longitudinal images of internal carotid arteries without (n=30) and with (n=21) significant atherosclerotic disease (greater than 50% stenosis). Maximum strain rates of 4.49% s(-1) for the healthy group and of 2.29% s(-1) for the atherosclerotic group were calculated on the far wall of internal carotid arteries; significant differences were found between these values (p=0.001). The minimum strain rates, also on the far wall of internal carotid arteries, of -3.68% s(-1) for the healthy group and of -1.89% s(-1) for the atherosclerotic group were significantly different as well (p=8×10(-4)). The mean systolic, diastolic and cumulated axial strains could also distinguish the two groups after normalization by the pressure gradient between acquired images. To conclude, the proposed techniques allowed to differentiate healthy and atherosclerotic carotid arteries and may help to diagnose vulnerable plaques

Élaboration des programmes d'études techniques : cadre général, cadre technique document de référence /

Rév. /Titre de l'écran-titre (visionné le 16 avril 2009)Version électronique d'un document imprimé publié en 2002"Le présent document est le résultat de la révision du Cadre général et du Cadre technique d'élaboration de la partie ministérielle des programmes d'études techniques produit par Jean-Paul Lemieux, Guy Mercure et Manon Paquette en 1995." - Verso de la p. de t

La formation professionnelle et technique

Titre de l'écran-titreSur la couv.: La formation professionnelle et techniqu

Élaboration des programmes d'études techniques : guide de validation du projet de formation : document de travail /

21 mars 1994Notes (part. bibliogr.) au bas des p

Secteur de formation 13 : communications et documentation

Titre de l'écran-titre (visionné le 29 avril 2008)"Secteur de formation 13 : communications et documentation"Bibliogr