Journal
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
Volume 33, Issue 10, Pages 2389-2396Publisher
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/ATVBAHA.113.302175
Keywords
aortic aneurysm; catalase; hydrogen peroxide; inflammation; smooth muscle
Categories
Funding
- National Institutes of Health [HL70531, HL090584]
Ask authors/readers for more resources
Objective Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species promotes the development of AAA remains unclear. Here, we investigate the effect of hydrogen peroxide (H2O2)-degrading enzyme catalase on the formation of AAA. Approach and Results AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.910.1 versus 0.76 +/- 0.09 mm). Similarly, in a transgenic mouse model, catalase overexpression in the vascular smooth muscle cells preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85 +/- 0.14 versus 0.57 +/- 0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacological administration or genetic overexpression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and vascular smooth muscle cell apoptosis was evident in aortas of catalase-overexpressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic overexpression of catalase in vascular smooth muscle cells did not alter the total aortic H2O2 levels. Conclusions The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic vascular smooth muscle cell survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available