A1 Refereed original research article in a scientific journal
Amyloid-Targeting PET Tracer [18F]Flutemetamol Accumulates in Atherosclerotic Plaques
Authors: Sanna Hellberg, Johanna M.U. Silvola, Heidi Liljenbäck, Max Kiugel, Olli Eskola, Harri Hakovirta, Sohvi Hörkkö, Veronique Morisson-Iveson, Ella Hirani , Pekka Saukko, Seppo Ylä-Herttuala, Juhani Knuuti, Antti Saraste, Anne Roivainen
Publisher: MDPI AG
Publication year: 2019
Journal: Molecules
Journal name in source: Molecules
Article number: 1072
Volume: 24
Issue: 6
Number of pages: 14
ISSN: 1420-3049
DOI: https://doi.org/10.3390/molecules24061072
Web address : https://www.mdpi.com/1420-3049/24/6/1072
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/39972718
Atherosclerosis is characterized by the accumulation of oxidized lipids in the artery wall, which triggers an inflammatory response. Oxidized low-density lipoprotein (ox-LDL) presents amyloid-like structural properties, and different amyloid species have recently been recognized in atherosclerotic plaques. Therefore, we studied the uptake of the amyloid imaging agent [ 18 F]Flutemetamol in atherosclerotic plaques. The binding of [ 18 F]Flutemetamol to human carotid artery plaque was studied in vitro. In vivo uptake of the tracer was studied in hypercholesterolemic IGF-II/LDLR − / − ApoB 100/100 mice and C57BL/6N controls. Tracer biodistribution was studied in vivo with PET/CT, and ex vivo by gamma counter and digital ex vivo autoradiography. The presence of amyloid, ox-LDL, and macrophages in the plaques was examined by immunohistochemistry. [ 18 F]Flutemetamol showed specific accumulation in human carotid plaque, especially in areas positive for amyloid beta. The aortas of IGF-II/LDLR − / − ApoB 100/100 mice showed large thioflavin-S-positive atherosclerotic plaques containing ox-LDL and macrophages. Autoradiography revealed 1.7-fold higher uptake in the plaques than in a lesion-free vessel wall, but no difference in aortic tissue uptake between mouse strains were observed in the in vivo PET/CT. In conclusion, [ 18 F]Flutemetamol binds to amyloid-positive areas in human atherosclerotic plaques. Further studies are warranted to clarify the uptake mechanisms, and the potential of the tracer for in vivo imaging of atherosclerosis in patients.
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