Abstract 366: Biglycan Deficiency Does Not Affect Angiotensin Ii-induced Atherosclerosis but Promotes Aortic Aneurysms Formation
Background Proteoglycans play a critical role in the development of atherosclerosis due to their ability to bind and retain atherogenic lipoproteins. Of all the vascular proteoglycans, biglycan has been shown to be the one most closely associated with apolipoprotein B. Our previous studies showed that angII increases vascular biglycan content and predisposes to diet-induced atherosclerosis in Ldlr null mice. The purpose of this study was to determine whether biglycan deficiency protected against angII induced atherosclerosis in vivo.
Methods and Results Bgn KO or WT mice, crossed to Ldlr null (C57B/6 background), were infused with angII (1000 ng/kg/min) or saline for 28 days followed by 6-week western diet feeding. Bgn KO mice showed no difference in atherosclerotic lesion area at either aortic sinus or en face surface. Unexpectedly, Bgn KO mice exhibited a striking mortality (77% for males and 48% for females) due to aortic rupture upon angII infusion. Thus, a lower dose of angII was then infused to mice to study atherosclerosis. There was no difference in lesion area between Bgn KO or WT mice under angII (500 ng/kg/min) infusion followed by 6-week western diet feeding or under one-year normal chow feeding without angII infusion. However, angII (500 ng/kg/min) still induced greater aortic rupture in Bgn KO mice (30% for males and 13% for females) than in WT mice (0% for both gender). Besides rupture, 7 Bgn KO mice out of 35 also developed aneurysm at mid-thoracic aorta whereas only 1 Bgn WT mouse out of 25 developed abdominal aneurysm after angII (500 ng/kg/min) infusion. Therefore, our study demonstrated that biglycan deficiency did not affect atherosclerotic lesion development, but induced a striking aneurysm phenotype upon angII infusion.
- © 2013 by American Heart Association, Inc.