Molecular imaging of tropoelastin in atherosclerotic ApoE–/– and control mice using the tetrameric Gd4-TESMA contrast
agent. (A) The 3D reconstructed angiogram (MRA) shows the vasculature.
Late gadolinium enhancement (LGE) images (B1–D1) and merged LGE and angiography images (B2–D2) compare the signal enhancement of atherosclerotic plaques
located in the brachiocephalic artery of the same animal imaged serially
after the administration of the elastin-binding Gd-ESMA (2 h), the
tropoelastin-binding Gd-TESMA (0.5 h), and the tropoelastin-binding
tetrameric Gd4-TESMA (1 h) agents. (E1, E2) LGE and merged images show a low uptake of the tetrameric
tropoelastin-binding agent attached to a scrambled peptide (Gd4-scTESMA). (F1, F2) LGE and merged LGE
and angiography images show signal enhancement of the brachiocephalic
artery of control mice after the injection of the elastin agent Gd-ESMA
but (G1, G2) no enhancement after the injection
of the tropoelastin agent Gd4-TESMA. Immunohistochemistry
using a tropoelastin antibody shows the absence of tropoelastin in
control tissues (H) and dense tropoelastin molecules (dark/purple
signal) in the disease artery (I).