Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease with high mortality and limited treatment options. How blood lipids regulate AAA development is unknown. Here lipidomics and genetic models demonstrate a central role for procoagulant enzymatically oxidized phospholipids (eoxPL) in regulating AAA. Specifically, through activating coagulation, eoxPL either promoted or inhibited AAA depending on tissue localization. Ang II administration to ApoE -/- mice increased intravascular coagulation during AAA development. Lipidomics revealed large numbers of eoxPL formed within mouse and human AAA lesions. Deletion of eoxPL-generating enzymes (Alox12 or Alox15) or administration of the factor Xa inhibitor rivaroxaban significantly reduced AAA. Alox-deficient mice displayed constitutively dysregulated hemostasis, including a consumptive coagulopathy, characterized by compensatory increase in prothrombotic aminophospholipids (aPL) in circulating cell membranes. Intravenously administered procoagulant PL caused clotting factor activation and depletion, induced a bleeding defect, and significantly reduced AAA development. These data suggest that Alox deletion reduces AAA through diverting coagulation away from the vessel wall due to eoxPL deficiency, instead activating clotting factor consumption and depletion in the circulation. In mouse whole blood, ∼44 eoxPL molecular species formed within minutes of clot initiation. These were significantly elevated with ApoE -/- deletion, and many were absent in Alox -/- mice, identifying specific eoxPL that modulate AAA. Correlation networks demonstrated eoxPL belonged to subfamilies defined by oxylipin composition. Thus, procoagulant PL regulate AAA development through complex interactions with clotting factors. Modulation of the delicate balance between bleeding and thrombosis within either the vessel wall or circulation was revealed that can either drive or prevent disease development.

Original publication

DOI

10.1073/pnas.1814409116

Type

Journal article

Journal

Proceedings of the National Academy of Sciences of the United States of America

Publication Date

03/04/2019

Addresses

Systems Immunity Research Institute, School of Medicine, Cardiff University, CF14 4XN Cardiff, United Kingdom.