A leukocyte-mimetic magnetic resonance imaging contrast agent homes rapidly to activated endothelium and tracks with atherosclerotic lesion macrophage content.
Arterioscler Thromb Vasc Biol
; 32(6): 1427-35, 2012 Jun.
Article
en En
| MEDLINE
| ID: mdl-22499989
ABSTRACT
OBJECTIVE:
Endothelial cell activation is an important mediator of monocyte recruitment to sites of vascular inflammation. We hypothesized that high-affinity dual-ligand microparticles of iron oxide (MPIO), targeted to P-selectin and vascular cell adhesion molecule-1 (PV-MPIO), would identify activated endothelial cells during atherosclerosis progression. METHODS ANDRESULTS:
In vivo magnetic resonance imaging in apolipoprotein E-deficient mice showed rapid binding of PV-MPIO to the aortic root, which was maximal 30 minutes post-MPIO injection and maintained at 60 minutes. Minimal binding was observed for control IgG-MPIO. Intensely low magnetic resonance signal areas, corresponding to PV-MPIO binding, were detected early (14 weeks), during foam cell formation. Contrast effects increased at 20 weeks during fibrofatty lesion development (P<0.05), but reduced by 30 weeks (P<0.01). Across all lesion severities, magnetic resonance imaging contrast effects correlated with lesion macrophage area quantified by immunohistochemistry (R=0.53; P<0.01). Near-infrared fluorescently labeled PV-MPIO were shown, by flow cytometry, to bind only activated endothelial cells and not to macrophages. Using en face immunofluorescence, we further demonstrate selective PV-MPIO accumulation at atherosclerosis-susceptible sites, with minimal binding to atherosclerosis-spared regions.CONCLUSIONS:
This high-affinity leukocyte-mimetic magnetic resonance imaging agent reveals endothelial activation. PV-MPIO demonstrate exceptionally rapid in vivo steady state accumulation, providing conspicuous magnetic resonance contrast effects that can be objectively quantified. In atherosclerosis progression, PV-MPIO tracked closely with the burden and distribution of plaque macrophages, not merely plaque size. On a biocompatible platform, this approach has potential for quantitative magnetic resonance imaging of inflammatory disease activity.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Aorta
/
Enfermedades de la Aorta
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Endotelio Vascular
/
Imagen por Resonancia Magnética
/
Medios de Contraste
/
Materiales Biomiméticos
/
Aterosclerosis
/
Leucocitos
/
Macrófagos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Arterioscler Thromb Vasc Biol
Asunto de la revista:
ANGIOLOGIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Reino Unido