Development of receptor for advanced glycation end products-directed imaging of atherosclerotic plaque in a murine model of spontaneous atherosclerosis.
BACKGROUND
The receptor for advanced glycation end products (RAGE) is implicated in the development and progression of atherosclerosis. We tested the hypothesis that (99m)Tc-labeled anti-RAGE F(ab')(2) can be used as a noninvasive tool to image atherosclerotic lesions in apolipoprotein E-deficient (apoE(-/-)) mice.


RESULTS
A sequence in the V-type Ig extracellular domain of RAGE was used to develop a peptide injected into rabbits; serum was retrieved, IgG prepared and affinity-purified, and pepsin-digested into F(ab')(2). Thirteen 6-week apoE(-/-) mice were fed a Western diet. At 20 weeks, 6 were injected with 15.2+/-1.9 MBq (350 to 411 microCi) (99m)Tc-labeled anti-RAGE F(ab')(2), 6 were injected with (99m)Tc-labeled control nonspecific IgG F(ab')(2), and 1 was injected with dual-labeled (99m)Tc and rhodamine anti-RAGE F(ab')(2). Four 20-week C57BL/6 mice were injected with (99m)Tc-labeled anti-RAGE F(ab')(2). All mice were imaged on a high resolution mini-gamma camera 4 hours after injection and euthanized. The aortic tree was dissected and photographed, and the proximal aorta was sectioned for staining after gamma scintillation counting. All 6 apoE(-/-) mice injected with (99m)Tc-labeled anti-RAGE F(ab')(2) fragments showed focal tracer uptake in the proximal aorta (mean %ID/g, 1.98%). Disease and antibody controls showed no focal tracer uptake in the thorax (%ID/g, <1.0%). Histological sections of the proximal aorta showed American Heart Association class III lesions with lipid laden macrophages, smooth muscle cells, and positive staining for RAGE. On immunofluorescence, RAGE colocalized with macrophages.


CONCLUSIONS
These data show the feasibility of noninvasively imaging RAGE in atherosclerotic lesions in a murine model and confirm levels of RAGE expression sufficient to allow detection on in vivo imaging.
Tekabe
Yared
Y
Division of Cardiology, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA. yt2166@columbia.edu
Li
Qing
Q
Rosario
Rosa
R
Sedlar
Marija
M
Majewski
Stan
S
Hudson
Barry I
BI
Einstein
Andrew J
AJ
Schmidt
Ann Marie
AM
Johnson
Lynne L
LL
D000818:Animals; D000911:Antibodies, Monoclonal; D050197:Atherosclerosis / Q000175:diagnosis* / Q000378:metabolism*; D015902:Gamma Cameras; D017127:Glycation End Products, Advanced; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000032:analysis* / Q000276:immunology; D013667:Technetium
D000911:Antibodies, Monoclonal; D017127:Glycation End Products, Advanced; D007140:Immunoglobulin Fab Fragments; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D013667:Technetium