Bols, Joris

Caenen, Annette

Fraga-Silva, Rodrigo

Modregger, Peter

Segers, Patrick

Stampanoni, Marco

Stergiopulos, Nikolaos

Tedgui, Alain

Trachet, Bram

Vardoulis, Orestis

English

Ghent University Academic Bibliography

Print this PagePresentation AbstractSession: 16-9-Arterial stiffness and disease - measurement, modelling and pathophysiologyPresentation: Synchrotron Imaging of Angiotensin II-induced Abdominal Aortic Aneurysm in MiceLocation: 312PresentationTime: Thursday, Jul 10, 2014, 11:00 AM -11:18 AMAuthor(s): B. Trachet1, R. A. Fraga-Silva1, O. Vardoulis1, J. Bols2, A. Caenen2, P. Modregger3, A. Astolfo3, M. Stampanoni3, A. Tedgui4, P. Segers2, N.Stergiopulos1;1EPFL, Lausanne, SWITZERLAND, 2Ghent University, Ghent, BELGIUM, 3PSI, Villigen, SWITZERLAND, 4INSERM, Paris, FRANCE.Abstract: Abdominal aortic aneurysm (AAA) is often studied in angiotensin II-infused mouse models since these present many features that are also present inhuman AAAs, such as thrombus formation, medial elastolysis and a higher propensity for male gender. However, murine AAAs sometimes have apolymorphic or eccentric rather than a symmetric shape, are located suprarenally instead of infrarenally, and show rapid luminal growth that is precededby a dissection of the medial layer. These findings have been documented in several labs but have never been fully understood, amongst others due to alack of sufficiently detailed small animal imaging modalities. In this work murine AAAs have been provoked by a combined infusion of angiotensin IIand anti-TGF-Beta antibodies in n=20 male normolipidemic C57BL6 mice (age 12 weeks) [1]. This mouse model leads to much more rupture-proneAAAs than the generally used angiotensin II infusion into hypercholesterolemic ApoE -/- mice. The animals were sacrificed at different stages ofaneurysm development: n=12 intact AAAs were sacrificed 2 to 15 days after aneurysm induction and n=6 AAAs were obtained post mortem fromanimals that had died from aortic rupture. All AAA samples were flushed with PBS and kept in parafolmadehyde to be scanned ex-vivo withsynchrotron-based X-ray tomographic microscopy (SRXTM) at the TOMCAT beamline of the Swiss Light Source of the Paul Scherrer Institute.Combining detailed soft tissue contrast provided by grating interferometry with anisotropic image resolution of 6.5 micron, the SRXTM images allowedus to describe aneurysm initiation, formation and rupture into unprecedented detail. We observed that angiotensin-provoked AAAs are not just precededby but the consequence of a small dissection in the medial layer near the coeliac artery. This dissection leads to an intramural hematoma that is causingthe rapid, and often eccentric expansion of the aortic lumen. The increased intramural blood volume subsequently causes the adventitial layer todelaminate and coagulated blood leads to intramural thrombus formation. In some cases the adventitial delamination leads to additional ruptures of themedial layer near the orifices of the intercostal arteries, which subsequently cause additional intramural hematomas that result in polymorphicaneurysms along the thoracic aorta. In conclusion, our data allow for the first time for a detailed, clear and unequivocal description of the morphology ofangiotensin II-induced AAA in mice.For technical inquiries, click here to contact OASIS Helpdesk or call 217-398-1792.Abstract Print View http://www.abstractsonline.com/Plan/AbstractPrintView.aspx?mID=3...1 van 1 22/01/2015 15:59

Synchrotron imaging of Angiotensin II-induced abdominal aortic aneurysm in mice

https://biblio.ugent.be/publication/5814870/file/5815018

Synchrotron imaging of Angiotensin II-induced abdominal aortic aneurysm in mice

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Ghent University Academic Bibliography