TY - JOUR
T1 - Serum amyloid A and lipoprotein retention in murine models of atherosclerosis
AU - O'Brien, Kevin D.
AU - McDonald, Thomas O.
AU - Kunjathoor, Vidya
AU - Eng, Kimli
AU - Knopp, Eleanor A.
AU - Lewis, Katherine
AU - Lopez, Roland
AU - Kirk, Elizabeth A.
AU - Chait, Alan
AU - Wight, Thomas N.
AU - DeBeer, Frederick C.
AU - LeBoeuf, Renee C.
PY - 2005/4
Y1 - 2005/4
N2 - 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<0.0001). In vitro, SAA enrichment increased high-density lipoprotein (HDL) binding to heparan sulfate proteoglycans, and immunoprecipitation experiments using plasma from apoE-/- and LDLR-/- mice demonstrated that SAA was present on both apoA-I-containing and apoB-containing lipoproteins. Conclusions - In chow-fed apoE-/- and LDLR-/- mice, SAA is deposited in murine atherosclerosis at all stages of lesion development, and SAA immunoreactive area correlates highly with lesion area, apoA-I area, apoB area, and perlecan area. These findings are consistent with a possible role for SAA-mediated lipoprotein retention in atherosclerosis.
AB - 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<0.0001). In vitro, SAA enrichment increased high-density lipoprotein (HDL) binding to heparan sulfate proteoglycans, and immunoprecipitation experiments using plasma from apoE-/- and LDLR-/- mice demonstrated that SAA was present on both apoA-I-containing and apoB-containing lipoproteins. Conclusions - In chow-fed apoE-/- and LDLR-/- mice, SAA is deposited in murine atherosclerosis at all stages of lesion development, and SAA immunoreactive area correlates highly with lesion area, apoA-I area, apoB area, and perlecan area. These findings are consistent with a possible role for SAA-mediated lipoprotein retention in atherosclerosis.
KW - Atherosclerosis
KW - Lipoproteins
KW - Perlecan
KW - Proteoglycans
KW - Serum amyloid A
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UR - http://www.scopus.com/inward/citedby.url?scp=20144387658&partnerID=8YFLogxK
U2 - 10.1161/01.ATV.0000158383.65277.2b
DO - 10.1161/01.ATV.0000158383.65277.2b
M3 - Article
C2 - 15692094
AN - SCOPUS:20144387658
SN - 1079-5642
VL - 25
SP - 785
EP - 790
JO - Arteriosclerosis, Thrombosis, and Vascular Biology
JF - Arteriosclerosis, Thrombosis, and Vascular Biology
IS - 4
ER -