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- Buehler, Alexandra, et al.
(författare)
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cNGR: A novel homing sequence for CD13/APN targeted molecular imaging of murine cardiac angiogenesis in vivo
- 2006
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - : American Heart Association. - 1079-5642 .- 1524-4636. ; 26:12, s. 2681-2687
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:Previously, the peptide sequence cNGR has been shown to home specifically to CD13/APN (aminopeptidase N) on tumor endothelium. Here, we investigated the feasibility of selective imaging of cardiac angiogenesis using the cNGR-CD13/APN system.METHODS AND RESULTS:CD13/APN induction and cNGR homing were studied in the murine myocardial infarction (MI) model. By real-time polymerase chain reaction (PCR) at 7 days after MI, CD13/APN expression was 10- to 20-fold higher in the angiogenic infarct border zone and the MI area than in non-MI areas. In vivo fluorescence microscopy confirmed specific homing of fluorophore-tagged cNGR to the border zone and MI territory at 4 and 7 days after MI with a local advantage of 2.3, but not at 1 or 14 days after MI. Tissue residence half-life was 9.1+/-0.3 hours, whereas the half-life in plasma was 15.4+/-3.4 minutes. Pulse chase experiments confirmed reversible binding of cNGR in the infarct area. Fluorescent labeled cNGR conjugates or antibodies were injected in vivo, and their distribution was studied ex vivo by 2-photon laser scanning microscopy (TPLSM). cNGR co-localized exclusively with CD13/APN and the endothelial marker CD31 on vessels.CONCLUSIONS:In cardiac angiogenesis endothelial CD13/APN is upregulated. It can be targeted specifically with cNGR conjugates. In the heart cNGR binds its endothelial target only in angiogenic areas.
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