Serum Amyloid A and Lipoprotein Retention in Murine Models of Atherosclerosis

OBJECTIVE—Elevated serum amyloid A (SAA) levels are associated with increased cardiovascular risk in humans. Because SAA associates primarily with lipoproteins in plasma and has proteoglycan binding domains, we postulated that SAA might mediate lipoprotein retention on atherosclerotic extracellular matrix. METHODS AND RESULTS—Immunohistochemistry was performed for SAA, apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), and perlecan on proximal aortic lesions from chow-fed low-density lipoprotein receptor (LDLR) and apoE mice euthanized at 10, 50, and 70 weeks. SAA was detected on atherosclerotic lesion extracellular matrix at all time points in both strains. SAA area correlated highly with lesion areas (apoE, r=0.76; LDLR, r=0.86), apoA-I areas (apoE, r=0.88; LDLR, r=0.80), apoB areas (apoE, r=0.74; LDLR, r=0.89), and perlecan areas (apoE, r=0.83; LDLR, r=0.79) (all P